ieee project

A Tabu Search Algorithm For Cluster Building In Wireless Sensor Networks -Mobile Computing – DOT NET 2009

The main challenge in wireless sensor network deployment pertains to optimizing energy consumption when collecting data from sensor nodes. This paper proposes a new centralized clustering method for a data collection mechanism in wireless sensor networks, which is based on network energy maps and Quality-of-Service (QoS) requirements. The clustering problem is modeled as a hypergraph partitioning and its resolution is based on a tabu search heuristic. Our approach defines moves using largest size cliques in a feasibility cluster graph. Compared to other methods (CPLEX-based method, distributed method, simulated annealing-based method), the results show that our tabu search-based approach returns high-quality solutions in terms of cluster cost and execution time. As a result, this approach is suitable for handling network extensibility in a satisfactory manner.

Route Stability In Manets Under The Random Direction Mobility Model – Mobile Computing -DOTNET 2009

A fundamental issue arising in mobile ad hoc networks (MANETs) is the selection of the optimal path between any two nodes. A method that has been advocated to improve routing efficiency is to select the most stable path so as to reduce the latency and the overhead due to route reconstruction. In this work, we study both the availability and the duration probability of a routing path that is subject to link failures caused by node mobility. In particular, we focus on the case where the network nodes move according to the Random Direction model, and we derive both exact and approximate (but simple) expressions of these probabilities. Through our results, we study the problem of selecting an optimal route in terms of path availability. Finally, we propose an approach to improve the efficiency of reactive routing protocols.

Greedy Routing With Anti-Void Traversal For Wireless Sensor Networks – Mobile Computing – DOTNET 2009

The unreachability problem (i.e., the so-called void problem) that exists in the greedy routing algorithms has been studied for the wireless sensor networks. Some of the current research work cannot fully resolve the void problem, while there exist other schemes that can guarantee the delivery of packets with the excessive consumption of control overheads. In this paper, a greedy antivoid routing (GAR) protocol is proposed to solve the void problem with increased routing efficiency by exploiting the boundary finding technique for the unit disk graph (UDG). The proposed rolling-ball UDG boundary traversal (RUT) is employed to completely guarantee the delivery of packets from the source to the destination node under the UDG network. The boundary map (BM) and the indirect map searching (IMS) scheme are proposed as efficient algorithms for the realization of the RUT technique. Moreover, the hop count reduction (HCR) scheme is utilized as a short-cutting technique to reduce the routing hops by listening to the neighbor’s traffic, while the intersection navigation (IN) mechanism is proposed to obtain the best rolling direction for boundary traversal with the adoption of shortest path criterion. In order to maintain the network requirement of the proposed RUT scheme under the non-UDG networks, the partial UDG construction (PUC) mechanism is proposed to transform the non-UDG into UDG setting for a portion of nodes that facilitate boundary traversal. These three schemes are incorporated within the GAR protocol to further enhance the routing performance with reduced communication overhead. The proofs of correctness for the GAR scheme are also given in this paper. Comparing with the existing localized routing algorithms, the simulation results show that the proposed GAR-based protocols can provide better routing efficiency.

Cell Breathing Techniques For Load Balancing In Wireless Lans -Mobile Computing DOT NET 2009

Maximizing network throughput while providing fairness is one of the key challenges in wireless LANs (WLANs). This goal is typically achieved when the load of access points (APs) is balanced. Recent studies on operational WLANs, however, have shown that AP load is often substantially uneven. To alleviate such imbalance of load, several load balancing schemes have been proposed. These schemes commonly require proprietary software or hardware at the user side for controlling the user-AP association. In this paper we present a new load balancing technique by controlling the size of WLAN cells (i.e., AP’s coverage range), which is conceptually similar to cell breathing in cellular networks. The proposed scheme does not require any modification to the users neither the 802.11 standard. It only requires the ability of dynamically changing the transmission power of the AP beacon messages. We develop a set of polynomial time algorithms that find the optimal beacon power settings which minimize the load of the most congested AP. We also consider the problem of network-wide min-max load balancing. Simulation results show that the performance of the proposed method is comparable with or superior to the best existing association-based methods.

Resequencing Analysis Of Stop-And-Wait Arq For Parallel Multichannel Communications – Networking-  DOT NET 2009

In this paper, we consider a multichannel data communication system in which the stop-and-wait automatic-repeat request protocol for parallel channels with an in-sequence delivery guarantee (MSW-ARQ-inS) is used for error control. We evaluate the resequencing delay and the resequencing buffer occupancy, respectively. Under the assumption that all channels have the same transmission rate but possibly different time-invariant error rates, we derive the probability generating function of the resequencing buffer occupancy and the probability mass function of the resequencing delay. Then, by assuming the Gilbert–Elliott model for each channel, we extend our analysis to time-varying channels. Through examples, we compute the probability mass functions of the resequencing  buffer occupancy and the resequencing delay for time-invariant channels. From numerical and simulation results, we analyze trends in the mean resequencing buffer occupancy and the mean resequencing delay as functions of system parameters. We expect that the modeling technique and analytical approach used in this paper can be applied to the performance evaluation of other ARQ protocols (e.g., the selective-repeat ARQ) over multiple time-varying channels. Index Terms—In-sequence delivery, modeling and performance, multichannel data communications, resequencing buffer occupancy, resequencing delay, SW-ARQ.

Resource Allocation In Ofdma Wireless Communications Systems Supporting Multimedia Services -Networking
-Dotnet -2009

We design a resource allocation algorithm for down-link of orthogonal frequency division multiple access (OFDMA) systems supporting real-time (RT) and best-effort (BE) services simultaneously over a time-varying wireless channel. The proposed algorithm aims at maximizing system throughput while satisfying quality of service (QoS) requirements of the RT and BE services. We take two kinds of QoS requirements into account. One is the required average transmission rate for both RT and BE services. The other is the tolerable average absolute deviation of transmission rate (AADTR) just for the RT services, which is used to control the fluctuation in transmission rates and to limit the RT packet delay to a moderate level. We formulate the optimization problem representing the resource allocation under consideration and solve it by using the dual optimization technique and the projection stochastic subgradient method. Simulation results show that the proposed algorithm well meets the QoS requirements with the high throughput and outperforms the modified largest weighted delay first (M-LWDF) algorithm that supports similar QoS requirements.

Enhancing Privacy And Authorization Control Scalability In The Grid Through Ontologies – Information Technology In Biomedicine – Java -2009

The use of data Grids for sharing relevant data has proven to be successful in many research disciplines. However, the use of these environments when personal data are involved (such as in health) is reduced due to its lack of trust. There are many approaches that provide encrypted storages and key shares to prevent the access from unauthorized users. However, these approaches are additional layers that should be managed along with the authorization policies. We present in this paper a privacy-enhancing technique that uses encryption and relates to the structure of the data and their organizations, providing a natural way to propagate authorization and also a framework that fits with many use cases. The paper describes the architecture and processes, and also shows results obtained in a medical imaging platform.

Combinatorial Approach For Preventing Sql Injection Attacks – Advance Computing Conference – J2ee – 2009

A combinatorial approach for protecting Web applications against SQL injection is discussed in this paper, which is a novel idea of incorporating the uniqueness of Signature based method and auditing method. The major issue of web application security is the SQL Injection, which can give the attackers unrestricted access to the database that underlie Web applications and has become increasingly frequent and serious. From signature based method standpoint of view, it presents a detection mode for SQL injection using pair wise sequence alignment of amino acid code formulated from web application form parameter sent via web server. On the other hand from the Auditing based method standpoint of view, it analyzes the transaction to find out the malicious access. In signature based method It uses an approach called Hirschberg algorithm, it is a divide and conquer approach to reduce the time and space complexity. This system was able to stop all of the successful attacks and did not generate any false positives.

Dynamic Search Algorithm In Unstructured Peer-To-Peer Networks – Parallel And Distributed Systems –Java -2009

Designing efficient search algorithms is a key challenge in unstructured peer-to-peer networks. Flooding and random walk (RW) are two typical search algorithms. Flooding searches aggressively and covers the most nodes. However, it generates a large amount of query messages and, thus, does not scale. On the contrary, RW searches conservatively. It only generates a fixed amount of query messages at each hop but would take longer search time. We propose the dynamic search (DS) algorithm, which is a generalization of flooding and RW. DS takes advantage of various contexts under which each previous search algorithm performs well. It resembles flooding for short-term search and RW for long-term search. Moreover, DS could be further combined with knowledge-based search mechanisms to improve the search performance. We analyze the performance of DS based on some performance metrics including the success rate, search time, query hits, query messages, query efficiency, and search efficiency. Numerical results show that DS provides a good tradeoff between search performance and cost. On average, DS performs about 25 times better than flooding and 58 times better than RW in power-law graphs, and about 186 times better than flooding and 120 times better than RW in bimodal topologies.

Analysis Of Shortest Path Routing For Large Multi-Hop Wireless Networks – Networking – Dot Net -2009

In this paper, we analyze the impact of straight line routing in large homogeneous multi-hop wireless networks. We estimate the nodal load, which is defined as the number of packets served at a node, induced by straight line routing. For a given total offered load on the network, our analysis shows that the nodal load at each node is a function of the node’s Voronoi cell, the node’s location in the network, and the traffic pattern specified by the source and destination randomness and straight line routing. In the asymptotic regime, we show that each node’s probability that the node serves a packet arriving to the network approaches the products of half the length of the Voronoi cell perimeter and the load density function that a packet goes through the node’s location. The density function depends on the traffic pattern generated by straight line routing, and determines where the hot spot is created in the network. Hence, contrary to conventional wisdom, straight line routing can balance the load over the network, depending on the traffic patterns.

Secure And Policy-Compliant Source Routing – Networking- Dotnet -2009

In today’s Internet, inter-domain route control remains elusive; nevertheless, such control could improve the performance, reliability, and utility of the network for end users and ISPs alike. While researchers have proposed a number of source routing techniques to combat this limitation, there has thus far been no way for independent ASes to ensure that such traffic does not circumvent local traffic policies, nor to accurately determine the correct party to charge for forwarding the traffic. We present Platypus, an authenticated source routing system built around the concept of network capabilities, which allow for accountable, fine-grained path selection by cryptographically attesting to policy compliance at each hop along a source route. Capabilities can be composed to construct routes through multiple ASes and can be delegated to third parties. Platypus caters to the needs of both end users and ISPs: users gain the ability to pool their resources and select routes other than the default, while ISPs maintain control over where, when, and whose packets traverse their networks. We describe the design and implementation of an extensive Platypus policy framework that can be used to address several issues in wide-area routing at both the edge and the core, and evaluate its performance and security. Our results show that incremental deployment of Platypus can achieve immediate gains.

Flexible Deterministic Packet Marking: An IP Traceback System to find the Real Source Of Attacks ¬- Parallel And Distributed Systems –JAVA -2009

Internet Protocol (IP) traceback is the enabling technology to control Internet crime. In this paper, we present a novel and practical IP traceback system called Flexible Deterministic Packet Marking (FDPM) which provides a defense system with the ability to find out the real sources of attacking packets that traverse through the network. While a number of other traceback schemes exist, FDPM provides innovative features to trace the source of IP packets and can obtain better tracing capability than others. In particular, FDPM adopts a flexible mark length strategy to make it compatible to different network environments; it also adaptively changes its marking rate according to the load of the participating router by a flexible flow-based marking scheme. Evaluations on both simulation and real system implementation demonstrate that FDPM requires a moderately small number of packets to complete the traceback process; add little additional load to routers and can trace a large number of sources in one traceback process with low false positive rates. The built-in overload prevention mechanism makes this system capable of achieving a satisfactory traceback result even when the router is heavily loaded. The motivation of this traceback system is from DDoS defense. It has been used to not only trace DDoS attacking packets but also enhance filtering attacking traffic. It has a wide array of applications for other security systems.

Node Isolation Model And Age-Based Neighbor Selection In Unstructured P2p Networks – Networking –JAVA -2009

Previous analytical studies of unstructured P2P resilience have assumed exponential user lifetimes and only con-sidered age-independent neighbor replacement. In this paper, we overcome these limitations by introducing a general node-isolation model for heavy-tailed user lifetimes and arbitrary neighbor-se-lection algorithms. Using this model, we analyze two age-biased neighbor-selection strategies and show that they significantly improve the residual lifetimes of chosen users, which dramatically reduces the probability of user isolation and graph partitioning compared with uniform selection of neighbors. In fact, the second strategy based on random walks on age-proportional graphs demonstrates that, for lifetimes with infinite variance, the system monotonically increases its resilience as its age and size grow. Specifically, we show that the probability of isolation converges to zero as these two metrics tend to infinity. We finish the paper with simulations in finite-size graphs that demonstrate the effect of this result in practice.
Distributed Algorithms For Constructing Approximate Minimum Spanning Trees In Wireless Sensor Networks – Parallel And Distributed Systems – Java -2009

While there are distributed algorithms for the minimum spanning tree (MST) problem, these algorithms require relatively large number of messages and time, and are fairly involved, making them impractical for resource-constrained networks such as wireless sensor networks. In such networks, a sensor has very limited power, and any algorithm needs to be simple, local, and energy efficient. Motivated by these considerations, we design and analyze a class of simple and local distributed algorithms called Nearest Neighbor Tree (NNT) algorithms for energy-efficient construction of an approximate MST in wireless networks. Assuming that the nodes are uniformly distributed, we show provable bounds on both the quality of the spanning tree produced and the energy needed to construct them. We show that while NNT produces a close approximation to the MST, it consumes asymptotically less energy than the classical message-optimal distributed MST algorithm due to Gallagery, Humblet, and Spira. Further, the NNTs can be maintained dynamically with polylogarithmic rearrangements under node insertions/deletions. We also perform extensive simulations, which show that the bounds are much better in practice. Our results, to the best of our knowledge, demonstrate the first tradeoff between the quality of approximation and the energy required for building spanning trees on wireless networks, and motivate similar considerations for other important problems.

Mobility Management Approaches For Mobile IP Networks: Performance Comparison And Use Recommendations – Networking – Java- 2009

In wireless networks, efficient management of mobility is a crucial issue to support mobile users. The Mobile Internet Protocol (MIP) has been proposed to support global mobility in IP networks. Several mobility management strategies have been proposed which aim reducing the signaling traffic related to the Mobile Terminals (MTs) registration with the Home Agents (HAs) whenever their Care-of-Addresses (CoAs) change. They use different Foreign Agents (FAs) and Gateway FAs (GFAs) hierarchies to concentrate the registration processes. For high-mobility MTs, the Hierarchical MIP (HMIP) and Dynamic HMIP (DHMIP) strategies localize the registration in FAs and GFAs, yielding to high-mobility signaling. The Multicast HMIP strategy limits the registration processes in the GFAs. For high-mobility MTs, it provides lowest mobility signaling delay compared to the HMIP and DHMIP approaches. However, it is resource consuming strategy unless for frequent MT mobility. Hence, we propose an analytic model to evaluate the mean signaling delay and the mean bandwidth per call according to the type of MT mobility. In our analysis, the MHMIP outperforms the DHMIP and MIP strategies in almost all the studied cases. The main contribution of this paper is the analytic model that allows the mobility management approaches performance evaluation.

Single-Link Failure Detection In All-Optical Networks Using Monitoring Cycles And Paths – Networking – Dot Net – 2009

In this paper, we consider the problem of fault localization in all-optical networks. We introduce the concept of monitoring cycles (MCs) and monitoring paths (MPs) for unique identification of single-link failures. MCs and MPs are required to pass through one or more monitoring locations. They are constructed such that any single-link failure results in the failure of a unique combination of MCs and MPs that pass through the monitoring location(s). For a network with only one monitoring location, we prove that three-edge connectivity is a necessary and sufficient condition for constructing MCs that uniquely identify any single-link failure in the network. For this case, we formulate the problem of constructing MCs as an integer linear program (ILP). We also develop heuristic approaches for constructing MCs in the presence of one or more monitoring locations. For an arbitrary network (not necessarily three-edge connected), we describe a fault localization technique that uses both MPs and MCs and that employs multiple monitoring locations. We also provide a linear-time algorithm to compute the minimum number of required monitoring locations. Through extensive simulations, we demonstrate the effectiveness of the proposed monitoring technique.

A Faithful Distributed Mechanism For Sharing The Cost Of Multicast Transmissions- Parallel And Distributed Systems -J2EE -2009

The problem of sharing the cost of multicast transmissions was studied in the past, and two mechanisms, Marginal Cost (MC) and Shapley Value (SH), were proposed to solve it. Although both of them are strategy proof mechanisms, the distributed protocols implementing them are susceptible to manipulation by autonomous nodes. We propose a distributed Shapley Value mechanism in which the participating nodes do not have incentives to deviate from the mechanism specifications. We show that the proposed mechanism is a faithful implementation of the Shapley Value mechanism. We experimentally investigate the performance of the existing and the proposed cost-sharing mechanisms by implementing and deploying them on PlanetLab. We compare the execution time of MC and SH mechanisms for the Tamper-Proof and Autonomous Node models. We also study the convergence and scalability of the mechanisms by varying the number of nodes and the number of users per node. We show that the MC mechanisms generate a smaller revenue compared to the SH mechanisms, and thus, they are not attractive to the content provider. We also show that increasing the number of users per node is beneficial for the systems implementing the SH mechanisms from both computational and economic perspectives.

Atomicity Analysis Of Service Composition Across Organizations -Software Engineering -J2ee -2009

Atomicity is a highly desirable property for achieving application consistency in service compositions. To achieve atomicity, a service composition should satisfy the atomicity sphere, a structural criterion for the backend processes of involved services. Existing analysis techniques for the atomicity sphere generally assume complete knowledge of all involved backend processes. Such an assumption is invalid when some service providers do not release all details of their backend processes to service consumers outside the organizations. To address this problem, we propose a process algebraic framework to publish atomicity-equivalent public views from the backend processes. These public views extract relevant task properties and reveal only partial process details that service providers need to expose. Our framework enables the analysis of the atomicity sphere for service compositions using these public views instead of their backend processes. This allows service consumers to choose suitable services such that their composition satisfies the atomicity sphere without disclosing the details of their backend processes. Based on the theoretical result, we present algorithms to construct atomicity-equivalent public views and to analyze the atomicity sphere for a service composition. Two case studies from the supply chain and insurance domains are given to evaluate our proposal and demonstrate the applicability of our approach.

Dynamic Routing With Security Considerations -Parallel And Distributed Systems – Java -2009

Security has become one of the major issues for data communication over wired and wireless networks. Different from the past work on the designs of cryptography algorithms and system infrastructures, we will propose a dynamic routing algorithm that could randomize delivery paths for data transmission. The algorithm is easy to implement and compatible with popular routing protocols, such as the Routing Information Protocol in wired networks and Destination-Sequenced Distance Vector protocol in wireless networks, without introducing extra control messages. An analytic study on the proposed algorithm is presented, and a series of simulation experiments are conducted to verify the analytic results and to show the capability of the proposed algorithm

CAR: Context-Aware Adaptive Routing For Delay-Tolerant Mobile Networks – Mobile Computing – Java -2009

Most of the existing research work in mobile ad hoc networking is based on the assumption that a path exists between the sender and the receiver. On the other hand, applications of decentralised mobile systems are often characterised by network partitions. As a consequence delay tolerant networking research has received considerable attention in the recent years as a means to obviate to the gap between ad hoc network research and real applications. In this paper we present the design, implementation and evaluation of the context-aware adaptive routing (CAR) protocol for delay tolerant unicast communication in intermittently connected mobile ad hoc networks. The protocol is based on the idea of exploiting nodes as carriers of messages among network partitions to achieve delivery. The choice of the best carrier is made using Kalman filter based prediction techniques and utility theory. We discuss the implementation of CAR over an opportunistic networking framework, outlining possible applications of the general principles at the basis of the proposed approach. The large scale performance of the CAR protocol are evaluated using simulations based on a social network founded mobility model, a purely random one and real traces from Dartmouth College.

Collusive Piracy Prevention in P2P Content Delivery Networks – Computers – J2ee – 2009

Collusive piracy is the main source of intellectual property violations within the boundary of a P2P network. Paid clients (colluders) may illegally share copyrighted content files with unpaid clients (pirates). Such online piracy has hindered the use of open P2P networks for commercial content delivery. We propose a proactive content poisoning scheme to stop colluders and pirates from alleged copyright infringements in P2P file sharing. The basic idea is to detect pirates timely with identity-based signatures and time stamped tokens. The scheme stops collusive piracy without hurting legitimate P2P clients by targeting poisoning on detected violators, exclusively. We developed a new peer authorization protocol (PAP) to distinguish pirates from legitimate clients. Detected pirates will receive poisoned chunks in their repeated attempts. Pirates are thus severely penalized with no chance to download successfully in tolerable time. Based on simulation results, we find 99.9 percent prevention rate in Gnutella, KaZaA, and Freenet. We achieved 85-98 percent prevention rate on eMule, eDonkey, Morpheus, etc. The scheme is shown less effective in protecting some poison-resilient networks like BitTorrent and Azureus. Our work opens up the low-cost P2P technology for copyrighted content delivery. The advantage lies mainly in minimum delivery cost, higher content availability, and copyright compliance in exploring P2P network resources.

Spread Spectrum Watermarking Security -Information Forensics and Security -Dot Net – 2009

This paper presents both theoretical and practical analyses of the security offered by watermarking and data hiding methods based on spread spectrum. In this context, security is understood as the difficulty of estimating the secret parameters of the embedding function based on the observation of watermarked signals. On the theoretical side, the security is quantified from an information-theoretic point of view by means of the equivocation about the secret parameters. The main results reveal fundamental limits and bounds on security and provide insight into other properties, such as the impact of the embedding parameters, and the tradeoff between robustness and security. On the practical side, workable estimators of the secret parameters are proposed and theoretically analyzed for a variety of scenarios, providing a comparison with previous approaches, and showing that the security of many schemes used in practice can be fairly low.

Local Construction Of Near-Optimal Power Spanners For Wireless Ad-Hoc Networks – Mobile Computing – Dot Net – 2009

We present a local distributed algorithm that, given a wireless ad hoc network modeled as a unit disk graph U in the plane, constructs a planar power spanner of U whose degree is bounded by k and whose stretch factor is bounded by 1 + (2sin pi/k)p, where k ges 10 is an integer parameter and p isin [2, 5] is the power exponent constant. For the same degree bound k, the stretch factor of our algorithm significantly improves the previous best bounds by Song et al. We show that this bound is near-optimal by proving that the slightly smaller stretch factor of 1 + (2sin pi/k+1)p is unattainable for the same degree bound k. In contrast to previous algorithms for the problem, the presented algorithm is local. As a consequence, the algorithm is highly scalable and robust. Finally, while the algorithm is efficient and easy to implement in practice, it relies on deep insights on the geometry of unit disk graphs and novel techniques that are of independent interest.

Multiple Routing Configurations For Fast Ip Network Recovery –Networking – Java – 2009

As the Internet takes an increasingly central role in our communications infrastructure, the slow convergence of routing protocols after a network failure becomes a growing problem. To assure fast recovery from link and node failures in IP networks, we present a new recovery scheme called Multiple Routing Configurations (MRC). Our proposed scheme guarantees recovery in all single failure scenarios, using a single mechanism to handle both link and node failures, and without knowing the root cause of the failure. MRC is strictly connectionless, and assumes only destination based hop-by-hop forwarding. MRC is based on keeping additional routing information in the routers, and allows packet forwarding to continue on an alternative output link immediately after the detection of a failure. It can be implemented with only minor changes to existing solutions. In this paper we present MRC, and analyze its performance with respect to scalability, backup path lengths, and load distribution after a failure. We also show how an estimate of the traffic demands in the network can be used to improve the distribution of the recovered traffic, and thus reduce the chances of congestion when MRC is used.

Compaction Of Schedules And A Two-Stage Approach For Duplication-Based Dag Scheduling – Parallel And Distributed Systems -Dot Net- 2009

Many DAG scheduling algorithms generate schedules that require prohibitively large number of processors. To address this problem, we propose a generic algorithm, SC, to minimize the processor requirement of any given valid schedule. SC preserves the schedule length of the original schedule and reduces processor count by merging processor schedules and removing redundant duplicate tasks. To the best of our knowledge, this is the first algorithm to address this highly unexplored aspect of DAG scheduling. On the average, SC reduced the processor requirement 91%, 82% and 72% for schedules generated by PLW, TCSD and CPFD algorithms, respectively. SC algorithm has a low complexity (O(|N |3) ) compared to most duplication based algorithms. Moreover, it decouples processor economization from schedule length minimization problem. To take advantage of these features of SC, we also propose a scheduling algorithm SDS, having the same time complexity as SC. Our experiments demonstrate that, schedules generated by SDS are only 3% longer than CPFD (O(|N |4) ), one of the best algorithms in that respect. SDS and SC together form a two-stage scheduling algorithm that produces schedules with high quality and low processor requirement, and has lower complexity than the comparable algorithms that produce similar high quality results.

The Effectiveness Of Checksums For Embedded Networks – Dependable And Secure Computing – Dot Net – 2009

Embedded control networks commonly use checksums to detect data transmission errors. However, design decisions about which checksum to use are difficult because of a lack of information about the relative effectiveness of available options. We study the error detection effectiveness of the following commonly used checksum computations for embedded networks: exclusive or (XOR), two’s complement addition, one’s complement addition, Fletcher checksum, Adler checksum, and cyclic redundancy codes (CRC). A study of error detection capabilities for random independent bit errors and burst errors reveals that XOR, two’s complement addition, and Adler checksums are suboptimal for typical application use. Instead, one’s complement addition should be used for applications willing to sacrifice error detection effectiveness to reduce compute cost, Fletcher checksum for applications looking for a balance of error detection and compute cost, and CRCs for applications willing to pay a higher compute cost for further improved error detection

Detecting Malicious Packet Losses – Parallel And Distributed Systems – Java – 2009
In this paper, we consider the problem of detecting whether a compromised router is maliciously manipulating its stream of packets. In particular, we are concerned with a simple yet effective attack in which a router selectively drops packets destined for some victim. Unfortunately, it is quite challenging to attribute a missing packet to a malicious action because normal network congestion can produce the same effect. Modern networks routinely drop packets when the load temporarily exceeds their buffering capacities. Previous detection protocols have tried to address this problem with a user-defined threshold: too many dropped packets imply malicious intent. However, this heuristic is fundamentally unsound; setting this threshold is, at best, an art and will certainly create unnecessary false positives or mask highly focused attacks. We have designed, developed, and implemented a compromised router detection protocol that dynamically infers, based on measured traffic rates and buffer sizes, the number of congestive packet losses that will occur. Once the ambiguity from congestion is removed, subsequent packet losses can be attributed to malicious actions. We have tested our protocol in Emulab and have studied its effectiveness in differentiating attacks from legitimate network behavior.

Virus Spread In Networks – Networking -Dot Net -2009

We study how the spread of computer viruses, worms, and other self-replicating malware is affected by the logical topology of the network over which they propagate. We consider a model in which each host can be in one of 3 possible states – susceptible, infected or removed (cured and no longer susceptible to infection). We characterize how the size of the population that eventually becomes infected depends on the network topology. Specially, we show that if the ratio of cure to infection rates is larger than the spectral radius of the graph, and the initial infected population is small, then the final infected population is also small in a sense that can be made precise. Conversely, if this ratio is smaller than the spectral radius, then we show in some graph models of practical interest (including power law random graphs) that the final infected population is large. These results yield insights into what the critical parameters are in determining virus spread in networks.

Biased Random Walks In Uniform Wireless Networks – Mobile Computing – Dot Net -2009

A recurrent problem when designing distributed applications is to search for a node with known property. File searching in peer-to-peer (P2P) applications, resource discovery in service-oriented architectures (SOAs), and path discovery in routing can all be cast as a search problem. Random walk-based search algorithms are often suggested for tackling the search problem, especially in very dynamic systems-like mobile wireless networks. The cost and the effectiveness of a random walk-based search algorithm are measured by the excepted number of transmissions required before hitting the target. Hence, to have a low hitting time is a critical goal. This paper studies the effect of biasing random walk toward the target on the hitting time. For a walk running over a network with uniform node distribution, a simple upper bound that connects the hitting time to the bias level is obtained. The key result is that even a modest bias level is able to reduce the hitting time significantly. This paper also proposes a search protocol for mobile wireless networks, whose results are interpreted in the light of the theoretical study. The proposed solution is for unstructured wireless mobile networks.

Information Content-Based Sensor Selection And Transmission Power Adjustment For Collaborative Target Tracking – Mobile Computing – Dot Net – 2009

For target tracking applications, wireless sensor nodes provide accurate information since they can be deployed and operated near the phenomenon. These sensing devices have the opportunity of collaboration among themselves to improve the target localization and tracking accuracies. An energy-efficient collaborative target tracking paradigm is developed for wireless sensor networks (WSNs). A mutual-information-based sensor selection (MISS) algorithm is adopted for participation in the fusion process. MISS allows the sensor nodes with the highest mutual information about the target state to transmit data so that the energy consumption is reduced while the desired target position estimation accuracy is met. In addition, a novel approach to energy savings in WSNs is devised in the information-controlled transmission power (ICTP) adjustment, where nodes with more information use higher transmission powers than those that are less informative to share their target state information with the neighboring nodes. Simulations demonstrate the performance gains offered by MISS and ICTP in terms of power consumption and target localization accuracy.

Presto: Feedback driven Data Management In Sensor Networks – Networking – Dot Net – 2009

This paper presents PRESTO, a novel two-tier sensor data management architecture comprising proxies and sensors that cooperate with one another for acquiring data and processing queries. PRESTO proxies construct time-series models of observed trends in the sensor data and transmit the parameters of the model to sensors. Sensors check sensed data with model-predicted values and transmit only deviations from the predictions back to the proxy. Such a model-driven push approach is energy efficient, while ensuring that anomalous data trends are never missed. In addition to supporting queries on current data, PRESTO also supports queries on historical data using interpolation and local archival at sensors. PRESTO can adapt model and system parameters to data and query dynamics to further extract energy savings. We have implemented PRESTO on a sensor test bed comprising Intel Stargates and Telos Motes. Our experiments show that in a temperature monitoring application, PRESTO yields one to two orders of magnitude reduction in energy requirements over on-demand, proactive or model-driven pull approaches. PRESTO also results in an order of magnitude reduction in query latency in a 1% duty-cycled five hop sensor network over a system that forwards all queries to remote sensor nodes.

Explicit Load Balancing Technique For Ngeo Satellite IP Networks With On-Board Processing Capabilities –Networking -Dot Net -2009

Non-geostationary (NGEO) satellite communication systems offer an array of advantages over their terrestrial and geostationary counterparts. They are seen as an integral part of next generation ubiquitous communication systems. Given the non-uniform distribution of users in satellite footprints, due to several geographical and/or climatic constraints, some Inter-Satellite Links (ISLs) are expected to be heavily loaded with data packets while others remain underutilized. Such scenario obviously leads to congestion of the heavily loaded links. It ultimately results in buffer overflows, higher queuing delays, and significant packet drops. To guarantee a better distribution of traffic among satellites, this paper proposes an explicit exchange of information on congestion status among neighboring satellites. Indeed, a satellite notifies its congestion status to its neighboring satellites. When it is about to get congested, it requests its neighboring satellites to decrease their data forwarding rates by sending them a self status notification signaling message. In response, the neighboring satellites search for less congested paths that do not include the satellite in question and communicate a portion of data, primarily destined to the satellite, via the retrieved paths. This operation avoids both congestion and packet drops at the satellite. It also ensures a better distribution of traffic over the entire satellite constellation. The proposed scheme is dubbed “Explicit Load Balancing” (ELB) scheme. While the multi-path routing concept of ELB has many advantages, it may lead to persistent packet reordering. In case of connection- oriented protocols, this phenomenon results in unnecessary shrinkage of the data transmission rate. A solution to this issue is also incorporated in the design of ELB. The interactions of ELB with mechanisms that provide different QoS by differentiating traffic (e.g., Differentiated Services) are also discussed. The good performance of ELB, in terms of better traffic distribution, higher throughput, and lower packet drops, is verified via a set of simulations using the Network Simulator (NS).

Delay Analysis For Maximal Scheduling With Flow Control In Wireless Networks With Bursty Traffic – Networking – Dot Net -2009

We consider the delay properties of one-hop networks with general interference constraints and multiple traffic streams with time-correlated arrivals. We first treat the case when arrivals are modulated by independent finite state Markov chains. We show that the well known maximal scheduling algorithm achieves average delay that grows at most logarithmically in the largest number of interferers at any link. Further, in the important special case when each Markov process has at most two states (such as bursty ON/OFF sources), we prove that average delay is independent of the number of nodes and links in the network, and hence is order-optimal. We provide tight delay bounds in terms of the individual auto-correlation parameters of the traffic sources. These are perhaps the first order-optimal delay results for controlled queueing networks that explicitly account for such statistical information. Our analysis treats cases both with and without flow control.

Optimized Resource Allocation For Software Release Planning -Software Engineering- Dot Net- 2009

Release planning for incremental software development assigns features to releases such that technical, resource, risk, and budget constraints are met. A feature can be offered as part of a release only if all of its necessary tasks are done before the given release date. We assume a given pool of human resources with different degrees of productivity to perform different types of tasks. In the context of release planning, the question studied in this paper is how to allocate these resources to the tasks of implementing the features such that the value gained from the released features is maximized. Planning of software releases and allocation of resources cannot be handled in isolation. To address the inherent difficulty of this process, we propose a two-phase optimization approach called OPTIMIZERASORP that combines the strength of two existing solution methods. Phase 1 applies integer linear programming to a relaxed version of the full problem. Phase 2 uses genetic programming in a reduced search space to generate operational resource allocation plans. The method is evaluated for a series of 600 randomly generated problems with varying problem parameters. The results are compared with a heuristic that locally allocates resources based on a greedy search

Automatic Extraction Of Heap Reference Properties In Object-Oriented Programs – Software Engineering – Dot Net -2009

We present a new technique for helping developers understand heap referencing properties of object-oriented programs and how the actions of the program affect these properties. Our dynamic analysis uses the aliasing properties of objects to synthesize a set of roles; each role represents an abstract object state intended to be of interest to the developer. We allow the developer to customize the analysis to explore the object states and behavior of the program at multiple different and potentially complementary levels of abstraction. The analysis uses roles as the basis for three abstractions: role transition diagrams, which present the observed transitions between roles and the methods responsible for the transitions; role relationship diagrams, which present the observed referencing relationships between objects playing different roles; and enhanced method interfaces, which present the observed roles of method parameters. Together, these abstractions provide useful information about important object and data structure properties and how the actions of the program affect these properties. We have implemented the role analysis and have used this implementation to explore the behavior of several Java programs. Our experience indicates that, when combined with a powerful graphical user interface, roles are a useful abstraction for helping developers explore and understand the behavior of object-oriented programs.

Energy Maps For Mobile Wireless Networks:Coherence Time Versus Spreading Period – Mobile Computing – Dot Net -2009

We show that even though mobile networks are highly unpredictable when viewed at the individual node scale, the end-toend quality-of-service (QoS) metrics can be stationary when the mobile network is viewed in the aggregate. We define the coherence time as the maximum duration for which the end-to-end QoS metric remains roughly constant, and the spreading period as the minimum duration required to spread QoS information to all the nodes. We show that if the coherence time is greater than the spreading period, the end-to-end QoS metric can be tracked. We focus on the energy consumption as the end-to-end QoS metric, and describe a novel method by which an energy map can be constructed and refined in the joint memory of the mobile nodes. Finally, we show how energy maps can be utilized by an application that aims to minimize a node’s total energy consumption over its near-future trajectory.

Randomcast: An Energy Efficient Communication Scheme For Mobile Ad Hoc Networks -Mobile Computing -Dot Net – 2009

In mobile ad hoc networks (MANETs), every node overhears every data transmission occurring in its vicinity and thus, consumes energy unnecessarily. In 802.11 Power Saving Mechanism (PSM), a packet must be advertised before it is actually transmitted. When a node receives an advertised packet that is not destined to itself, it switches to a lowpower sleep state during the data transmission period, and thus, avoids overhearing and conserves energy. However, since some MANET routing protocols such as Dynamic Source Routing (DSR) collect route information via overhearing, they would suffer if they are used in combination with 802.11 PSM. Allowing no overhearing may critically deteriorate the performance of the underlying routing protocol, while unconditional overhearing may offset the advantage of using PSM. This paper proposes a new communication mechanism, called RandomCast, via which a sender can specify the desired level of overhearing, making a prudent balance between energy and routing performance. In addition, it reduces redundant rebroadcasts for a broadcast packet and thus saves more energy. Extensive simulation using ns-2 shows that RandomCast is highly energy-efficient compared to conventional 802.11 as well as 802.11 PSM-based schemes, in terms of total energy consumption, energy goodput and energy balance.

Efficient Resource Allocation For Wireless Multicast  -Mobile Computing – Java – 2008

In this paper, we propose a bandwidth-efficient multicast mechanism for heterogeneous wireless networks. We reduce the bandwidth cost of an Internet Protocol (IP) multicast tree by adaptively selecting the cell and the wireless technology for each mobile host to join the multicast group. Our mechanism enables more mobile hosts to cluster together and leads to the use of fewer cells to save the scarce wireless bandwidth. Besides, the paths in the multicast tree connecting to the selected cells share more common links to save the wireline bandwidth. Our mechanism supports the dynamic group membership and offers mobility of group members. Moreover, our mechanism requires no modification to the current IP multicast routing protocols. We formulate the selection of the cell and the wireless technology for each mobile host in the heterogeneous wireless networks as an optimization problem. We use Integer Linear Programming to model the problem and show that the problem is NP-hard. To solve the problem, we propose a distributed algorithm based on Lagrangean relaxation and a network protocol based on the algorithm. The simulation results show that our mechanism can effectively save the wireless and wireline bandwidth as compared to the traditional IP multicast.

Mining File Downloading Time In Stochastic Peer To Peer Networks – Networking – Dot Net – 2008

On-demand routing protocols use route caches to make routing decisions. Due to mobility, cached routes easily become stale. To address the cache staleness issue, prior work in DSR used heuristics with ad hoc parameters to predict the lifetime of a link or a route. However, heuristics cannot accurately estimate timeouts because topology changes are unpredictable. In this paper, we propose proactively disseminating the broken link information to the nodes that have that link in their caches. We define a new cache structure called a cache table and present a distributed cache update algorithm. Each node maintains in its cache table the information necessary for cache updates. When a link failure is detected, the algorithm notifies all reachable nodes that have cached the link in a distributed manner. The algorithm does not use any ad hoc parameters, thus making route caches fully adaptive to topology changes. We show that the algorithm outperforms DSR with path caches and with Link-Max Life, an adaptive timeout mechanism for link caches. We conclude that proactive cache updating is key to the adaptation of on-demand routing protocols to mobility.

Enhancing Search Performance In Unstructured P2P Networks Based On Users’ Common Interest – Networking – Java -2008

Peer-to-peer (P2P) networks establish loosely coupled application-level overlays on top of the Internet to facilitate efficient sharing of resources. They can be roughly classified as either structured or unstructured networks. Without stringent constraints over the network topology, unstructured P2P networks can be constructed very efficiently and are therefore considered suitable to the Internet environment. However, the random search strategies adopted by these networks usually perform poorly with a large network size. In this paper, we seek to enhance the search performance in unstructured P2P networks through exploiting users’ common interest patterns captured within a probability-theoretic framework termed the user interest model (UIM). A search protocol and a routing table updating protocol are further proposed in order to expedite the search process through self organizing the P2P network into a small world. Both theoretical and experimental analyses are conducted and demonstrated the effectiveness and efficiency of our approach

Quiver: Consistent Object Sharing For Edge Services – Parallel And Distributed Systems – Java – 2008

We present Quiver, a system that coordinates service proxies placed at the “edge” of the Internet to serve distributed clients accessing a service involving mutable objects. Quiver enables these proxies to perform consistent accesses to shared objects by migrating the objects to proxies performing operations on those objects. These migrations dramatically improve performance when operations involving an object exhibit geographic locality, since migrating this object into the vicinity of proxies hosting these operations will benefit all such operations. This system reduces the workload in the server. It performs the all operations in the proxies itself.  In this system the operations performed in  First-In-First-Out process. This system handles two process serializability and strict serializabilty for durability in the consistent object sharing . Other workloads benefit from Quiver, dispersing the computation load across the proxies and saving the costs of sending operation parameters over the wide area when these are large. Quiver also supports optimizations for single-object reads that do not involve migrating the object. We detail the protocols for implementing object operations and for accommodating the addition, involuntary disconnection, and voluntary departure of proxies. Finally, we discuss the use of Quiver to build an e-commerce application and a distributed network traffic modeling service.

BRA: A Bidirectional Routing Abstraction For Asymmetric Mobile Ad Hoc Networks –Networking – Java – 2008

Wireless links are often asymmetric due to heterogeneity in the transmission power of devices, non-uniform environmental noise, and other signal propagation phenomenons. Unfortunately, routing protocols for mobile ad hoc networks typically work well only in bidirectional networks. This paper first presents a simulation study quantifying the impact of asymmetric links on network connectivity and routing performance. It then presents a framework called BRA that provides a bidirectional abstraction of the asymmetric network to routing protocols. BRA works by maintaining multi-hop reverse routes for unidirectional links and provides three new abilities: improved connectivity by taking advantage of the unidirectional links, reverse route forwarding of control packets to enable off-the-shelf routing protocols, and detection packet loss on unidirectional links. Extensive simulations of AODV layered on BRA show that packet delivery increases substantially (two-fold in some instances) in asymmetric networks compared to regular AODV, which only routes on bidirectional links.

An Efficient Clustering Scheme To Exploit Hierarchical Data In Network Traffic Analysis – Knowledge And Data Engineering – Java – 2008

There is significant interest in the data mining and network management communities about the need to improve existing techniques for clustering multivariate network traffic flow records so that we can quickly infer underlying traffic patterns. In this paper, we investigate the use of clustering techniques to identify interesting traffic patterns from network traffic data in an efficient manner. We develop a framework to deal with mixed type attributes including numerical, categorical, and hierarchical attributes for a one-pass hierarchical clustering algorithm. We demonstrate the improved accuracy and efficiency of our approach in comparison to previous work on clustering network traffic.

Rate & Delay Guarantees Provided By Close Packet Switches With Load Balancing – Networking – Java – 2008

In this paper, we consider an overarching problem that encompasses both performance metrics. In particular, we study the network capacity problem under a given network lifetime requirement. Specifically, for a wireless sensor network where each node is provisioned with an initial energy, if all nodes are required to live up to a certain lifetime criterion, Since the objective of maximizing the sum of rates of all the nodes in the network can lead to a severe bias in rate allocation among the nodes, we advocate the use of lexicographical max-min (LMM) rate allocation. To calculate the LMM rate allocation vector, we develop a polynomial-time algorithm by exploiting the parametric analysis (PA) technique from linear program (LP), which we call serial LP with Parametric Analysis (SLP-PA). We show that the SLP-PA can be also employed to address the LMM node lifetime problem much more efficiently than a state-of-the-art algorithm proposed in the literature. More important, we show that there exists an elegant duality relationship between the LMM rate allocation problem and the LMM node lifetime problem. Therefore, it is sufficient to solve only one of the two problems. Important insights can be obtained by inferring duality results for the other problem.

Geometric Approach To Improving Active Packet Loss Measurement –Networking –Java – 2008

Measurement and estimation of packet loss characteristics are challenging due to the relatively rare occurrence and typically short duration of packet loss episodes. While active probe tools are commonly used to measure packet loss on end-to-end paths, there has been little analysis of the accuracy of these tools or their impact on the network. The objective of our study is to understand how to measure packet loss episodes accurately with end-to-end probes. We begin by testing the capability of standard Poisson- modulated end-to-end measurements of loss in a controlled laboratory environment using IP routers and commodity end hosts. Our tests show that loss characteristics reported from such Poisson-modulated probe tools can be quite inaccurate over a range of traffic conditions. Motivated by these observations, we introduce a new algorithm for packet loss measurement that is designed to overcome the deficiencies in standard Poisson-based tools. Specifically, our method entails probe experiments that follow a geometric distribution to 1) enable an explicit trade-off between accuracy and impact on the network, and 2) enable more accurate measurements than standard Poisson probing at the same rate. We evaluate the capabilities of our methodology experimentally by developing and implementing a prototype tool, called BADABING. The experiments demonstrate the trade-offs between impact on the network and measurement accuracy. We show that BADABING reports loss characteristics far more accurately than traditional loss measurement tools.

A Precise Termination Condition Of The Probalastic Packet Marking Algorithm  – Dependable And Secure Computing – Java – 2008

The probabilistic packet marking (PPM) algorithm is a promising way to discover the Internet map or an attack graph that the attack packets traversed during a distributed denial-of-service attack. However, the PPM algorithm is not perfect, as its termination condition is not well defined in the literature. More importantly, without a proper termination condition, the attack graph constructed by the PPM algorithm would be wrong. In this work, we provide a precise termination condition for the PPM algorithm and name the new algorithm the Rectified PPM (RPPM) algorithm. The most significant merit of the RPPM algorithm is that when the algorithm terminates, the algorithm guarantees that the constructed attack graph is correct, with a specified level of confidence. We carry out simulations on the RPPM algorithm and show that the RPPM algorithm can guarantee the correctness of the constructed attack graph under 1) different probabilities that a router marks the attack packets and 2) different structures of the network graph. The RPPM algorithm provides an autonomous way for the original PPM algorithm to determine its termination, and it is a promising means of enhancing the reliability of the PPM algorithm.

Intrusion Detection In Homogeneous & Heterogeneous Wireless Sensor Networks – Mobile Computing – Java -2008

Intrusion detection in Wireless Sensor Network (WSN) is of practical interest in many applications such as detecting an intruder in a battlefield. The intrusion detection is defined as a mechanism for a WSN to detect the existence of inappropriate, incorrect, or anomalous moving attackers. In this paper, we consider this issue according to heterogeneous WSN models. Furthermore, we consider two sensing detection models: single-sensing detection and multiple-sensing detection… Our simulation results show the advantage of multiple sensor heterogeneous WSNs.

A Distributed And Scalable Routing Table Manager For The Next Generation Of Ip Routers – Dot Net – 2008

In recent years, the exponential growth of Internet users with increased bandwidth requirements has led to the emergence of the next generation of IP routers. Distributed architecture is one of the promising trends providing petabit routers with a large switching capacity and high-speed interfaces. Distributed routers are designed with an optical switch fabric interconnecting line and control cards. Computing and memory resources are available on both control and line cards to perform routing and forwarding tasks. This new hardware architecture is not efficiently utilized by the traditional software models where a single control card is responsible for all routing and management operations. The routing table manager plays an extremely critical role by managing routing information and in particular, a forwarding information table. This article presents a distributed architecture set up around a distributed and scalable routing table manager. This architecture also comes provides improvements in robustness and resiliency. The proposed architecture

Performance Of A Speculative Transmission Scheme For Scheduling Latency Reduction – Networking – Java – 2008

This work was motivated by the need to achieve low latency in an input centrally-scheduled cell switch for high-performance computing applications; specifically, the aim is to reduce the latency incurred between issuance of a request and arrival of the corresponding grant. We introduce a speculative transmission scheme to significantly reduce the average latency by allowing cells to proceed without waiting for a grant. It operates in conjunction with any centralized matching algorithm to achieve a high maximum utilization. An analytical model is presented to investigate the efficiency of the speculative transmission scheme employed in a non-blocking N*NR input-queued crossbar switch with receivers R per output. The results demonstrate that the can be almost entirely eliminated for loads up to 50%. Our simulations confirm the analytical results.

Efficient 2-D Gray Scale Morphological Transformations With Arbitraly Flat Structuring Elements – Image Processing -Dot Net – 2008

An efficient algorithm is presented for the computation of grayscale morphological operations with arbitrary 2-D flat structuring elements (S.E.). The required computing time is independent of the image content and of the number of gray levels used. It always outperforms the only existing comparable method, which was proposed in the work by Van Droogen broeck and Talbot, by a factor between 3.5 and 35.1, depending on the image type and shape of S.E. So far, filtering using multiple S.E.s is always done by performing the operator for each size and shape of the S.E. separately. With our method, filtering with multiple S.E.s can be performed by was proposed in the work by Van Droogen broeck and Talbot, by a factor between 3.5 and 35.1, depending on the image type and shape of S.E. So far, filtering using multiple S.E.s is always done by performing the operator for each size and shape of the S.E. separately. With our method, filtering with multiple S.E.s can be performed by a single operator for a slightly reduced computational cost per size or shape, which makes this method more suitable for use in granulometries, dilation-erosion scale spaces, and template matching using the hit-or-miss transform. The discussion focuses on erosions and dilations, from which other transformations can be derived. a single operator for a slightly reduced computational cost per size or shape, which makes this method more suitable for use in granulometries, dilation-erosion scale spaces, and template matching using the hit-or-miss transform. The discussion focuses on erosions and dilations, from which other transformations can be derived.

Rate Allocation and Network Lifetime Problem For Wireless Sensor Network – Networking -Dot Net – 2008

In this paper, we consider an overarching problem that encompasses both performance metrics. In particular, we study the network capacity problem under a given network lifetime requirement. Specifically, for a wireless sensor network where each node is provisioned with an initial energy, if all nodes are required to live up to a certain lifetime criterion, Since the objective of maximizing the sum of rates of all the nodes in the network can lead to a severe bias in rate allocation among the nodes, we advocate the use of lexicographical max-min (LMM) rate allocation. To calculate the LMM rate allocation vector, we develop a polynomial-time algorithm by exploiting the parametric analysis (PA) technique from linear program (LP), which we call serial LP with Parametric Analysis (SLP-PA). We show that the SLP-PA can be also employed to address the LMM node lifetime problem much more efficiently than a state-of-the-art algorithm proposed in the literature. More important, we show that there exists an elegant duality relationship between the LMM rate allocation problem and the LMM node lifetime problem. Therefore, it is sufficient to solve only one of the two problems. Important insights can be obtained by inferring duality results for the other problem.

Vision Based Processing For Real Time 3-D Data Acquisition Based Code Structured Light – Image Processing – Dot Net – 2008

The structured light vision system is a successfully used for the measurement of 3D surface in vision. There is some limitation in the above scheme, that is tens of picture are captured to recover a 3D sense. This paper presents an idea for real-time Acquisition of 3-D surface data by a specially coded vision system. To achieve 3-D measurement for a dynamic scene, the data acquisition must be performed with only a single image. A principle of uniquely color-encoded pattern projection is proposed to design a color matrix for improving the reconstruction efficiency. The matrix is produced by a special code sequence and a number of state transitions. A color projector is controlled by a computer to generate the desired color patterns in the scene. The unique indexing of the light codes is crucial here for color projection since it is essential that each light grid be uniquely identified by incorporating local neighborhoods so that 3-D reconstruction can be performed with only local analysis of a single image. A scheme is presented to describe such a vision processing method for fast 3-D data acquisition. Practical experimental performance is provided to analyze the efficiency of the proposed methods

Using The Conceptual Cohesion Of Classes For Fault Prediction In Object Oriented Systems – Software Engineering – Java – 2008

High cohesion is desirable property in software systems to achieve reusability and maintainability. In this project we are measures for cohesion in Object-Oriented (OO) software reflect particular interpretations of cohesion and capture different aspects of it. In existing approaches the cohesion is calculate from the structural information for example method attributes and references. In conceptual cohesion of classes, i.e. in our project we are calculating the unstructured information from the source code such as comments and identifiers. Unstructured information is embedded in the source code. To retrieve the unstructured information from the source code Latent Semantic Indexing is used. A large case study on three open source software systems is presented which compares the new measure with an extensive set of existing metrics and uses them to construct models that predict software faults. In our project we are achieving the high cohesion and we are predicting the fault in Object –Oriented Systems

Location Based Spatial Query Processing In Wireless Broadcast Environments – Mobile Computing – Java – 2008

Location-based spatial queries (LBSQ s) refer to spatial queries whose answers rely on the location of the inquirer. Efficient processing of LBSQ s is of critical importance with the ever-increasing deployment and use of mobile technologies. We show that LBSQ s has certain unique characteristics that the traditional spatial query processing in centralized databases does not address. For example, a significant challenge is presented by wireless broadcasting environments, which have excellent scalability but often exhibit high-latency database access. In this paper, we present a novel query processing technique that, though maintaining high scalability and accuracy, manages to reduce the latency considerably in answering LBSQ s. Our approach is based on peer-to-peer sharing, which enables us to process queries without delay at a mobile host by using query results cached in its neighboring mobile peers. We demonstrate the feasibility of our approach through a probabilistic analysis, and we illustrate the appeal of our technique through extensive simulation results.

Bandwidth Estimation For 802.11 Based Adhoc Network – Mobile Computing – Java – 2008

Since 2005, 802.11-based networks have been able to provide a certain level of quality of service (QoS) by the means of service differentiation, due to the 802.11e amendment. However, no mechanism or method has been standardized to accurately evaluate the amount of resources remaining on a given channel. Such an evaluation would, however, be a good asset for bandwidth-constrained applications. In multihop ad hoc networks, such evaluation becomes even more difficult. Consequently, despite the various contributions around this research topic, the estimation of the available bandwidth still represents one of the main issues in this field. In this paper, we propose an improved mechanism to estimate the available bandwidth in 802.11-based ad hoc networks. Through simulations, we compare the accuracy of the estimation we propose to the estimation performed by other state-of-the-art QoS protocols, BRuIT, AAC, and QoS-AODV.

Modeling  and Automated Containment Of Worms – Dependable And Secure Computing – Java – 2008

Self-propagating codes, called worms, such as Code Red, Nimda, and Slammer, have drawn significant attention due to their enormously adverse impact on the Internet. Thus, there is great interest in the research community in modeling the spread of worms and in providing adequate defense mechanisms against them. In this paper, we present a (stochastic) branching process model for characterizing the propagation of Internet worms. The model is developed for uniform scanning worms and then extended to preference scanning worms. This model leads to the development of an automatic worm containment strategy that prevents the spread of a worm beyond its early stage. Specifically, for uniform scanning worms, we are able to determine whether the worm spread will eventually stop. We then extend our results to contain uniform scanning worms. Our automatic worm containment schemes effectively contain both uniform scanning worms and local preference scanning worms, and it is validated through simulations and real trace data to be non intrusive.

Trust Worthy Computing Under Resource Constraints With The Down Policy – Dependable And Secure Computing -Dot Net – 2008

In this project we present a simple way to resolve a complicated network security. This is done by the following two ways. They are as follows, first is the decrypt only when necessary (DOWN) policy, which can substantially improve the ability of low-cost to protect the secrets. The DOWN policy relies on the ability to operate with fractional parts of secrets. We discuss the feasibility of extending the DOWN policy to various asymmetric and symmetric cryptographic primitives. The second is cryptographic authentication strategies which employ only symmetric cryptographic primitives, based on novel ID-based key pre-distribution schemes that demand very low complexity of operations to be performed by the secure coprocessors (ScP) and can take good advantage of the DOWN policy.

Benefit-Based Data Caching In Ad Hoc Networks – Mobile Computing – Java – 2008

Data caching can significantly improve the efficiency of information access in a wireless ad hoc network by reducing the access latency and bandwidth usage. However, designing efficient distributed caching algorithms is non-trivial when network nodes have limited memory. In this article, we consider the cache placement problem of minimizing total data access cost in ad hoc networks with multiple data items and nodes with limited memory capacity. The above optimization problem is known to be NP-hard. Defining benefit as the reduction in total access cost, we present a polynomial-time centralized approximation algorithm that provably delivers a solution whose benefit is at least one-fourth (one-half for uniform-size data items) of the optimal benefit. The approximation algorithm is amenable to localized distributed implementation, which is shown via simulations to perform close to the approximation algorithm. Our distributed algorithm naturally extends to networks with mobile nodes. We simulate our distributed algorithm using a network simulator (ns2), and demonstrate that it significantly outperforms another existing caching technique (by Yin and Cao [30]) in all important performance metrics. The performance differential is particularly large in more challenging scenarios, such as higher access frequency and smaller memory.

Statistical Techniques For Detecting Traffic Anomalies Through Packet Header Data – Networking – Dot Net – 2008

The frequent attacks on network infrastructure, using various forms of denial of service (DoS) attacks and worms, have led to an increased need for developing techniques for analyzing and monitoring network traffic. If efficient analysis tools were available, it could become possible to detect the attacks, anomalies and take action to suppress them before they have had much time to propagate across the network. In this paper, we study the possibilities of traffic-analysis based mechanisms for attack and anomaly detection. The motivation for this work came from a need to reduce the likelihood that an attacker may hijack the campus machines to stage an attack on a third party. A campus may want to prevent or limit misuse of its machines in staging attacks, and possibly limit the liability from such attacks. In particular, we study the utility of observing packet header data of outgoing traffic, such as destination addresses, port numbers and the number of flows, in order to detect attacks/anomalies originating from the campus at the edge of a campus. Detecting anomalies/attacks close to the source allows us to limit the potential damage close to the attacking machines. Traffic monitoring close to the source may enable the network operator quicker identification of potential anomalies and allow better control of administrative domain’s resources. Attack propagation could be slowed through early detection. Our approach passively monitors network traffic at regular intervals and analyzes it to find any abnormalities in the aggregated traffic. By observing the traffic and correlating it to previous states of traffic, it may be possible to see whether the current traffic is behaving in a similar (i.e., correlated) manner. The network traffic could look different because of flash crowds, changing access patterns, infrastructure problems such as router failures, and DoS attacks. In the case of bandwidth attacks, the usage of network may be increased and abnormalities may show up in traffic volume. Flash crowds could be observed through sudden increase in traffic volume to a single destination. Sudden increase of traffic on a certain port could signify the onset of an anomaly such as worm propagation. Our approach relies on analyzing packet header data in order to provide indications of Possible abnormalities in the traffic.

HBA Distributed Metadata Management For Large Scale Cluster Based Storage System – Parallel And Distributed Systems – Dot Net – 2008

An efficient and distributed scheme for file mapping or file lookup is critical in decentralizing metadata management within a group of metadata servers, here the technique used called HIERARCHICAL BLOOM FILTER ARRAYS (HBA) to map filenames to the metadata servers holding their metadata. The Bloom filter arrays with different levels of accuracies are used on each metadata server. The first one with low accuracy and used to capture the destination metadata server information of frequently accessed files. The other array is used to maintain the destination metadata information of all files. Simulation results show our HBA design to be highly effective and efficient in improving the performance and scalability of file systems in clusters with 1,000 to 10,000 nodes (or super clusters) and with the amount of data in the petabyte scale or higher. HBA is reducing metadata operation by using the single metadata architecture instead of 16 metadata server.

Temporal Portioning Of Communication Resources In An Integrated Architecture – Dependable And Secure Computing – Dot Net – 2008

Integrated architectures in the automotive and avionic domain promise improved resource utilization and enable a better coordination of application subsystems compared to federated systems. An integrated architecture shares the system’s communication resources by using a single physical network for exchanging messages of multiple application subsystems. Similarly, the computational resources (for example, memory and CPU time) of each node computer are available to multiple software components. In order to support a seamless system integration without unintended side effects in such an integrated architecture, it is important to ensure that the software components do not interfere through the use of these shared resources. For this reason, the DECOS integrated architecture encapsulates application subsystems and their constituting software components. At the level of the communication system, virtual networks on top of an underlying time-triggered physical network exhibit predefined temporal properties (that is, bandwidth, latency, and latency jitter). Due to encapsulation, the temporal properties of messages sent by a software component are independent from the behavior of other software components, in particular from those within other application subsystems

The Effect Of Pairs In Program Design Tasks – Software Engineering – Dot Net – 2008

In this project efficiency of pairs in program design tasks is identified by using pair programming concept. Pair programming involves two developers simultaneously collaborating with each other on the same programming task to design and code a solution. Algorithm design and its implementation are normally merged and it provides feedback to enhance the design. Previous controlled pair programming experiments did not explore the efficacy of pairs against individuals in program design-related tasks. Variations in programmer skills in a particular language or an integrated development environment and the understanding of programming instructions can cover the skill of subjects in program design-related tasks. Programming aptitude tests (PATs) have been shown to correlate with programming performance. PATs do not require understanding of programming instructions and do not require a skill in any specific computer language. By conducting two controlled experiments, with full-time professional programmers being the subjects who worked on increasingly complex programming aptitude tasks related to problem solving and algorithmic design. In both experiments, pairs significantly outperformed individuals, providing evidence of the value of pairs in program design-related tasks.

Constructing Inter-Domain Packet Filters To Control Ip Spoofing Based On Bgp Updates – Dependable and Secure Computing – Java – 2008

The Distributed Denial-of-Service (DDoS) attack is a serious threat to the legitimate use of the Internet. Prevention mechanisms are thwarted by the ability of attackers to forge or spoof the source addresses in IP packets. By employing IP spoofing, attackers can evade detection and put a substantial burden on the destination network for policing attack packets. In this paper, we propose an inter-domain packet filter (IDPF) architecture that can mitigate the level of IP spoofing on the Internet. A key feature of our scheme is that it does not require global routing information. IDPFs are constructed from the information implicit in Border Gateway Protocol (BGP) route updates and are deployed in network border routers. We establish the conditions under which the IDPF framework correctly works in that it does not discard packets with valid source addresses. Based on extensive simulation studies, we show that, even with partial deployment on the Internet, IDPFs can proactively limit the spoofing capability of attackers. In addition, they can help localize the origin of an attack packet to a small number of candidate networks.

Orthogonal Data Embedding For Binary Images In Morphological Transform Domain- A High-Capacity Approach – Multimedia – Dot Net – 2008

This paper proposes a data-hiding technique for binary images in morphological transform domain for authentication purpose. To achieve blind watermark extraction, it is difficult to use the detail coefficients directly as a location map to determine the data-hiding locations. Hence, we view flipping an edge pixel in binary images as shifting the edge location one pixel horizontally and vertically. Based on this observation, we propose an interlaced morphological binary wavelet transform to track the shifted edges, which thus facilitates blind watermark extraction and incorporation of cryptographic signature. Unlike existing block-based approach, in which the block size is constrained by 3times3 pixels or larger, we process an image in 2times2 pixel blocks. This allows flexibility in tracking the edges and also achieves low computational complexity. The two processing cases that flipping the candidates of one does not affect the flippability conditions of another are employed for orthogonal embedding, which renders more suitable candidates can be identified such that a larger capacity can be achieved. A novel effective Backward-Forward Minimization method is proposed, which considers both backwardly those neighboring processed embeddable candidates and forwardly those unprocessed flippable candidates that may be affected by flipping the current pixel. In this way, the total visual distortion can be minimized. Experimental results demonstrate the validity of our arguments.

Protection Of Database Security Via Collaborative Inference Detection – Knowledge And Data Engineering – J2ee – 2008

Malicious users can exploit the correlation among data to infer sensitive information from a series of seemingly innocuous data accesses. Thus, we develop an inference violation detection system to protect sensitive data content. Based on data dependency, database schema and semantic knowledge. we constructed a semantic inference model (SIM) that represents the possible inference channels from any attribute to the pre-assigned sensitive attributes. The SIM is then instantiated to a semantic inference graph (SIG) for query-time inference violation detection. For a single user case, when a user poses a query, the detection system will examine his/her past query log and calculate the probability of inferring sensitive information. The query request will be denied if the inference probability exceeds the pre specified threshold. For multi-user cases, the users may share their query answers to increase the inference probability. Therefore, we develop a model to evaluate collaborative inference based on the query sequences of collaborators and their task-sensitive collaboration levels. Experimental studies reveal that information authoritativeness, communication fidelity and honesty in collaboration are three key factors that affect the level of achievable collaboration. An example is given to illustrate the use of the proposed technique to prevent multiple collaborative users from deriving sensitive information via inference.

Estimation Of Defects Based On Efect Decay Model: Ed3m – Software Engineering – Dot Net – 2008

An accurate prediction of the number of defects in a software product during system testing contributes not only to the management of the system testing process but also to the estimation of the product’s required maintenance. Here, a new approach, called Estimation of Defects based on Defect Decay Model (ED3M) is presented that computes an estimate the defects in an ongoing testing process. ED3M is based on estimation theory. Unlike many existing approaches, the technique presented here does not depend on historical data from previous projects or any assumptions about the requirements and/or testers’ productivity. It is a completely automated approach that relies only on the data collected during an ongoing testing process. This is a key advantage of the ED3M approach as it makes it widely applicable in different testing environments. Here, the ED3M approach has been evaluated using five data sets from large industrial projects and two data sets from the literature. In addition, a performance analysis has been conducted using simulated data sets to explore its behavior using different models for the input data. The results are very promising; they indicate the ED3M approach provides accurate estimates with as fast or better convergence time in comparison to well-known alternative techniques, while only using defect data as the input.

Active Learning Methods For Interactive Image Retrieval – Image Processing- Dot Net – 2008

Active learning methods have been considered with increased interest in the statistical learning community. Initially developed within a classification framework, a lot of extensions are now being proposed to handle multimedia applications. This paper provides algorithms within a statistical framework to extend active learning for online content-based image retrieval (CBIR). The classification framework is presented with experiments to compare several powerful classification techniques in this information retrieval context. Focusing on interactive methods, active learning strategy is then described. The limitations of this approach for CBIR are emphasized before presenting our new active selection process RETIN. First, as any active method is sensitive to the boundary estimation between classes, the RETIN strategy carries out a boundary correction to make the retrieval process more robust. Second, the criterion of generalization error to optimize the active learning selection is modified to better represent the CBIR objective of database ranking. Third, a batch processing of images is proposed. Our strategy leads to a fast and efficient active learning scheme to retrieve sets of online images (query concept). Experiments on large databases show that the RETIN method performs well in comparison to several other active strategies.

Localized Sensor Area Coverage With Low Communication Overhead – Mobile Computing – Dot Net – 2008

We propose several localized sensor area coverage protocols for heterogeneous sensors, each with arbitrary sensing and transmission radii.  Each sensor has a time out period and listens to messages sent by respective nodes before the time out expires. Sensor nodes whose sensing area is not fully covered (or fully covered but with a disconnected set of active sensors) when the deadline expires decide to remain active for the considered round and transmit an activity message announcing it.  In our approach, sensor decides to sleep only if neighbor sensor is active or not covered. Covered nodes decide to sleep, with or without transmitting a withdrawal message to inform neighbors about the status. After hearing from more neighbors, inactive sensors may observe that they became covered and may decide to alter their original decision and transmit a retreat message.

Hardware Enhanced Association Rule Mining With Hashing And Pipelining – Knowledge And Data Engineering – Dot Net – 2008

Data mining techniques have been widely used in various applications. One of the most important data mining applications is association rule mining. Apriori-based association rule mining in hardware, one has to load candidate item sets and a database into the hardware.  Since the capacity of the hardware architecture is fixed, if the number of candidate item sets or the number of items in the database is larger than the hardware capacity, the items are loaded into the hardware separately.  The time complexity of those steps that need to load candidate item sets or database items into the hardware is in proportion to the number of candidate item sets multiplied by the number of items in the database. Too many candidate item sets and a large database would create a performance bottleneck.  In this paper, we propose a HAsh-based and PiPelIned (abbreviated as HAPPI) architecture for hardware enhanced association rule mining. Therefore, we can effectively reduce the frequency of loading the database into the hardware.  HAPPI solves the bottleneck problem in a priori-based hardware schemes.

Efficient Resource Allocation For Wireless Multicast – Mobile Computing – Dot Net – 2008

In this paper, we propose a bandwidth-efficient multicast mechanism for heterogeneous wireless networks. We reduce the bandwidth cost of a IP multicast tree by adaptively selecting the cell and the wireless technology for each mobile host to join the multicast group. Our mechanism enables more mobile hosts to cluster together and lead to the use of fewer cells to save the scarce wireless bandwidth. Besides, the paths in the multicast tree connecting to the selected cells share more common links to save the wireline bandwidth. Our mechanism supports the dynamic group membership and offers mobility of group members. Moreover, our mechanism requires no modification on the current IP multicast routing protocols. We formulate the selection of the cell and the wireless technology for each mobile host in the heterogeneous wireless networks as an optimization problem. We use Integer Linear Programming to model the problem and show that the problem is NP-hard. To solve the problem, we propose an distributed algorithm based on Lagrangean relaxation and a network protocol based on the algorithm. The simulation results show that our mechanism can effectively save the wireless and wireline bandwidth as compared to the traditional IP multicast.

Efficient Routing In Intermittently Connected Mobile Networks: The Multiple Copy Case – Networking – Dot Net – 2008

Intermittently connected mobile networks are wireless networks where most of the time there does not exist a complete path from the source to the destination. There are many real networks that follow this model, for example, wildlife tracking sensor networks, military networks, vehicular ad hoc networks, etc. In this context, conventional routing schemes fail, because they try to establish complete end-to-end paths, before any data is sent. To deal with such networks researchers have suggested to use flooding-based routing schemes. While flooding-based schemes have a high probability of delivery, they waste a lot of energy and suffer from severe contention which can significantly degrade their performance. Furthermore, proposed efforts to reduce the overhead of flooding-based schemes have often been plagued by large delays. With this in mind, we introduce a new family of routing schemes that “spray” a few message copies into the network, and then route each copy independently towards the destination. We show that, if carefully designed, spray routing

A Novel Framework For Semantic Annotation And Personalized Retrieval Of Sports Video – Multimedia – Dot Net – 2008

Sports video annotation is important for sports video semantic analysis such as event detection and personalization. We propose a novel approach for sports video semantic annotation and personalized retrieval. Different from the state of the art sports video analysis methods which heavily rely on audio/visual features, the proposed approach incorporates web-casting text into sports video analysis.  Compared with previous approaches, the contributions of our approach include the following. 1) The event detection accuracy is significantly improved due to the incorporation of web-casting text analysis. 2) The proposed approach is able to detect exact event boundary and extract event semantics that are very difficult or impossible to be handled by previous approaches. 3) The proposed method is able to create personalized summary from both general and specific point of view related to particular game, event, player or team according to user’s preference. We present the framework of our approach and details of text analysis, video analysis, text/video alignment, and personalized retrieval. The experimental results on event boundary detection in sports video are encouraging and comparable to the manually selected events. The evaluation on personalized retrieval is effective in helping meet users’ expectations.

Two Techniques For Fast Computation Of Constrained Shortest Path – Networking – Java – 2008

Computing constrained shortest paths is fundamental to some important network functions such as QoS routing, MPLS path selection, ATM circuit routing, and traffic engineering. The problem is to find the cheapest path that satisfies certain constraints. In particular, finding the cheapest delay-constrained path is critical for real-time data flows such as voice/video calls. Because it is NP-complete, much research has been designing heuristic algorithms that solve the -approximation of the problem with an adjustable accuracy. A common approach is to discretize (i.e., scale and round) the link delay or link cost, which transforms the original problem to a simpler one solvable in polynomial time. The efficiency of the algorithms directly relates to the magnitude of the errors introduced during discretization. In this paper, we propose two techniques that reduce the discretization errors, which allow faster algorithms to be designed. Reducing the overhead of computing constrained shortest paths is practically important for the successful design of a high-throughput QoS router, which is limited at both processing power and memory space. Our simulations show that the new algorithms reduce the execution time by an order of magnitude on power-law topologies with 1000 nodes.

Watermarking Relational Databases Using Optimization-Based Techniques- Knowledge And Data Engineering – Dot Net – 2008

Proving ownerships rights on outsourced relational database is a crucial issue in today’s internet based application environments and in many content distribution applications. In this paper, we present a mechanism for proof of ownership based on the secure embedding of a robust imperceptible watermark in relational data. We formulate the watermarking of relational databases as a constrained optimization problem and discus efficient techniques to solve the optimization problem and to handle the onstraints. Our watermarking technique is resilient to watermark synchronization errors because it uses a partioning approach that does not require marker tuple. Our approach overcomes a major weakness in previously proposed watermarking techniques. Watermark decoding is based on a threshold-based technique characterized by an optimal threshold that minimizes the probability of decoding errors. We implemented a proof of concept implementation of our watermarking technique and showed by experimental results that our technique is resilient to tuple deletion, alteration and insertion attacks

Probabilistic Packet Marking For Large-Scale Ip Trace Back – Networking – Dot Net – 2008

An approach to IP traces back based on the probabilistic packet marking paradigm. Our approach, which we call randomize-and-link, uses large checksum cords to “link” message fragments in a way that is highly scalable, for the checksums serve both as associative addresses and data integrity verifiers. The main advantage of these checksum cords is that they spread the addresses of possible router messages across a spectrum that is too large for the attacker to easily create messages that collide with legitimate messages.

Dual-Link Failure Resiliency Through Backup Link Mutual Exclusion – Networking – Java – 2008

Networks employ link protection to achieve fast recovery from link failures. While the first link failure can be protected using link protection, there are several alternatives for protecting against the second failure. This paper formally classifies the approaches to dual-link failure resiliency. One of the strategies to recover from dual-link failures is to employ link protection for the two failed links independently, which requires that two links may not use each other in their backup paths if they may fail simultaneously. Such a requirement is referred to as backup link mutual exclusion (BLME) constraint and the problem of identifying a backup path for every link that satisfies the above requirement is referred to as the BLME problem. This paper develops the necessary theory to establish the sufficient conditions for existence of a solution to the BLME problem. Solution methodologies for the BLME problem is developed using two approaches by: 1) formulating the backup path selection as an integer linear program; 2) developing a polynomial time heuristic based on minimum cost path routing. The ILP formulation and heuristic are applied to six networks and their performance is compared with approaches that assume precise knowledge of dual-link failure. It is observed that a solution exists for all of the six networks considered. The heuristic approach is shown to obtain feasible solutions that are resilient to most dual-link failures, although the backup path lengths may be significantly higher than optimal. In addition, the paper illustrates the significance of the knowledge of failure location by illustrating that network with higher connectivity may require lesser capacity than one with a lower connectivity to recover from dual-link failures.

Truth Discovery With Multiple Conflicting Information Providers On The Web – Knowledge And Data Engineering – J2ee – 2008

The World Wide Web has become the most important information source for most of us. Unfortunately, there is no guarantee for the correctness of information on the Web. Moreover, different websites often provide conflicting information on a subject, such as different specifications for the same product. In this paper, we propose a new problem, called Veracity, i.e., conformity to truth, which studies how to find true facts from a large amount of conflicting information on many subjects that is provided by various websites. We design a general framework for the Veracity problem and invent an algorithm, called TRUTHFINDER, which utilizes the relationships between websites and their information, i.e., a website is trustworthy if it provides many pieces of true information, and a piece of information is likely to be true if it is provided by many trustworthy websites. An iterative method is used to infer the trustworthiness of websites and the correctness of information from each other. Our experiments show that TRUTHFINDER successfully finds true facts among conflicting information and identifies trustworthy websites better than the popular search engines.

ieee projects 2014-2013,ieee project 2014,ieee project 2013,ieee projects 2013,NS2 Projects

Java Projects,.NET Projects,Matab Projects,application projects,Innovative Projects.

ieee projects 2013,ieee projects,2013 IEEE java projects,2013 ieee Project Titles, 2013 IEEE cse Project Titles,ns2 projects, 2013 IEEE NS2 Project Titles, 2012 IEEE dotnet Project Titles,ieee projects for cse 2013,ieee projects for cse free download,ieee projects for cse 2011,ieee projects with source code,ieee papers,main project topics for computer science,project topics computer science,ieee projects download,ieee projects for cse,ieee projects list,ieee projects on networking,ieee projects titles

College Name

Leave a Reply

Your email address will not be published. Required fields are marked *