OS and Networks Commons^™

Resource Sharing Via Planed Relay For Hwn, Chong Shen, Susan Rea, Dirk Pesch

NIMBUS Articles

We present an improved version of adaptive distributed cross-layer routing algorithm (ADCR) for hybrid wireless network with dedicated relay stations () in this paper. A mobile terminal (MT) may borrow radio resources that are available thousands mile away via secure multihop RNs, where RNs are placed at pre-engineered locations in the network. In rural places such as mountain areas, an MT may also communicate with the core network, when intermediate MTs act as relay node with mobility. To address cross-layer network layers routing issues, the cascaded ADCR establishes routing paths across MTs, RNs, and cellular base stations (BSs) and provides …

Integrating Temporal Difference Methods And Self‐Organizing Neural Networks For Reinforcement Learning With Delayed Evaluative Feedback, Ah-Hwee Tan, Ning Lu, Dan Xiao

Research Collection School Of Computing and Information Systems

This paper presents a neural architecture for learning category nodes encoding mappings across multimodal patterns involving sensory inputs, actions, and rewards. By integrating adaptive resonance theory (ART) and temporal difference (TD) methods, the proposed neural model, called TD fusion architecture for learning, cognition, and navigation (TD-FALCON), enables an autonomous agent to adapt and function in a dynamic environment with immediate as well as delayed evaluative feedback (reinforcement) signals. TD-FALCON learns the value functions of the state-action space estimated through on-policy and off-policy TD learning methods, specifically state-action-reward-state-action (SARSA) and Q-learning. The learned value functions are then used to determine the …

Management Framework For Hybrid Wireless Networks, Chong Shen

Theses

The objective of the Hybrid Wireless Network with dedicated Relay Nodes (HWN*) architecture is to interface the Base Station (BS) Oriented Mobile Network (BSON) and the 802.fix based Mobile Ad hoc Wireless Network (MANET) so that one system can be utilised as an alternative radio access network for data transmissions, while the incorporation of Relay Nodes (RN) is to extend the communication coverage, optimise medium resource sharing, increase spatial reuse opportunity, stabilise MANET link and create more micro-cells. The HWN* keeps the existing cellular infrastructure and a Mobile Terminal (MT) can borrow radio resources from other cells via secure multi-hop …

A Distributed Ai Approach For Large-Scale Wlan Design, Alan Mcgibney

Theses

The recent dramatic trend towards always-on-connectivity has driven the need for mobile ubiquitous computing environments with the advent of the Wireless Local Area Network (WLAN) seeing a shift from traditional wired networks to wireless networking. A WLAN typically contains a number of access points that allow wireless enabled clients access information and network resources such as the internet without the need for wires, offering flexibility and mobility to the users. Initial wireless networks were convenience based allowing users access to the primary wired network, and involved little planning prior to roll-out. The proliferation of low cost wireless devices combined wdth …

Efficient Corona Training Protocols For Sensor Networks, Alan A. Bertossi, Stephan Olariu, Cristina M. Pinotti

Computer Science Faculty Publications

Phenomenal advances in nano-technology and packaging have made it possible to develop miniaturized low-power devices that integrate sensing, special-purpose computing, and wireless communications capabilities. It is expected that these small devices, referred to as sensors, will be mass-produced and deployed, making their production cost negligible. Due to their small form factor and modest non-renewable energy budget, individual sensors are not expected to be GPS-enabled. Moreover, in most applications, exact geographic location is not necessary, and all that the individual sensors need is a coarse-grain location awareness. The task of acquiring such a coarse-grain location awareness is referred to as training. …

What Is Rcu, Fundamentally?, Paul E. Mckenney, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Read-copy update (RCU) is a synchronization mechanism that was added to the Linux kernel in October of 2002. RCU achieves scalability improvements by allowing reads to occur concurrently with updates. In contrast with conventional locking primitives that ensure mutual exclusion among concurrent threads regardless of whether they be readers or updaters, or with reader-writer locks that allow concurrent reads but not in the presence of updates, RCU supports concurrency between a single updater and multiple readers. RCU ensures that reads are coherent by maintaining multiple versions of objects and ensuring that they are not freed up until all pre-existing read-side …

Integrating Game Technology And Discrete Event Simulation To Analyze Mass Casualty Scenarios, Jason Loveland

Computational Modeling & Simulation Engineering Theses & Dissertations

In the last 10 years, video games have become complex simulation environments with high resolution 3D graphics enabled by powerhouse rendering engines, multi-player client server networks, user friendly displays and graphical user interface , while remaining relatively inexpensive. There is a critical need for systems engineering analysis and rapid trade studies due to changes in operations caused by current events such as terrorist attacks, asymmetric threats, natural disasters, etc. Modem games provide a unique way to visualize and interact with these complex environments, scenarios, missions, and operations. A discrete event simulator (DES) provides an environment to model system architecture behavior, …

Stochastic Estimation And Control Of Queues Within A Computer Network, Nathan C. Stuckey

Theses and Dissertations

An extended Kalman filter is used to estimate size and packet arrival rate of network queues. These estimates are used by a LQG steady state linear perturbation PI controller to regulate queue size within a computer network. This paper presents the derivation of the transient queue behavior for a system with Poisson traffic and exponential service times. This result is then validated for ideal traffic using a network simulated in OPNET. A more complex OPNET model is then used to test the adequacy of the transient queue size model when non-Poisson traffic is combined. The extended Kalman filter theory is …

Fault Modeling In Wireless Sensor Networks, Ahmed A. Elmiligui

Electrical & Computer Engineering Theses & Dissertations

A large amount of research has been done in the area of wireless sensor networks (WSN), but not much work has been done in modeling the fault tolerance and reliability of these networks. In this thesis, the fault tolerance of a WSN to node failures is studied and an analytical reliability model of the network is derived. A valid reliability model of a network could reveal an estimate of the network's performance before it is deployed.

A wireless sensor network was modeled as a k-out-of-n system and a generic fault tolerant framework for the network in terms of node losses …

Fault Arrangements And Their Effect On The Performance Of Wireless Sensor Networks, Dwayne Sayone Blai

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks face many reliability challenges. The networks are deployed in open, hostile environments, making them easily susceptible to network failure. As a result, there are countless faults that can occur in sensor networks, from component failure to outside attacks. Outside attacks take place when an adversary gains control over a node or set of nodes in the network. Outside attackers can destroy a network in numerous ways such as random attacks, clustering attacks, search-based attacks, etc. The method and strategy used in each of these attacks directly affects the network's reliability. Understanding how these adversaries are positioned is …

The Reliability Of The Computer Communication Networks Including Mobile Nodes, Sahin Yasar

Electrical & Computer Engineering Theses & Dissertations

The wireless computer networks have an uncertainty in their structures aside from their big advantages for the users. The environmental conditions, changing locations of the mobile hosts and the changing components in the system can easily affect their reliability. In order to know a system capability performing its functions, keep the reliability at a certain level and/or detect the deficiency of the system, it is necessary to analyze the reliability of a computer communication network including the wired and wireless parts. But the above reasons also make the analysis and a unique solution difficult so a set of algorithms is …

Poster Session A: A Multi-Priority Application Framework For Mobile Ad Hoc Networks, M. Ibrahim Channa, Ahsan Chaudhry, Kashif Sharif, Irum Memon

International Conference on Information and Communication Technologies

The fast spread of small wireless computers has enabled the design and deployment of wireless Ad Hoc networks. Typical applications proposed for such networks include both Real Time and Non-Real Time applications. We propose an architecture that provides a complete framework for Real Time applications and Best Effort traffic. The proposed architecture comprises of an Ad Hoc Routing Protocol for route setup and route repair, a Bandwidth Allocation and Reservation Scheme for Real Time traffic, and a MAC layer protocol that provides traffic differentiation. The Admission Control module is used to admit or reject a new Real Time flow request …

Secured Network Model For Management Information System Based On Ip Security (Ipsec) Encryption Using Multilayered Approach Of Network Security, Dr. Amir Hassan Pathan, Muniza Irshad

International Conference on Information and Communication Technologies

Secured flow of information through the network and play important role in the management information systems. In this paper I describe Secured Network Model For Corporate & Business Organization In Based On Network Level IP Security (IPSec) Encryption & Its Physical Layout Using Multilayered Approach. I have four important considerations for adoption of secured network model as secured network model for management information system.

G-Value Decoding Of Greedy Codes, Khalil Ahmad

International Conference on Information and Communication Technologies

Error-correcting codes are widely used to increase the reliability of transmission of information over various forms of communication channels. Codes with a given minimum distance d can be constructed by a greedy algorithm [2]. In this paper, I proposed a new algorithm for the allocation of g-values to the binary vectors. Hamming (7, 4, 3) code can be generated by the application of greedy algorithm on the binary vectors of length 7 arranged in B-ordering. This code is used to demonstrate a new decoding technique for linear codes in addition to the schemes already known for decoding such as Syndrome …

The Value Of Mobile Applications: A Utility Company Study, Fiona Fui-Hoon Nah, Keng Siau, Hong Sheng

Research Collection School Of Computing and Information Systems

The value proposition of mobile applications i.e. the net value of the benefits and costs associated with the adoption and adaptation of mobile applications is discussed. A means-ends network that depicts the fundamental relationships among the objectives such as efficiency, effectiveness, customer satisfaction, security, cost, and employee acceptance, was developed. The network is useful to researchers as it highlights the issues, concerns, and values of mobile applications. The network help the managers and practitioners to achieve their companies' objectives of implementing mobile and wireless applications.

Bottleneck Analysis Of Cports, Sreekalyana Chakravarthy Kajuluri

Electrical & Computer Engineering Theses & Dissertations

CPortS is a transportation logistics simulation that models the flow of military cargo through a seaport and the interaction of the cargo with the port resources and infrastructure. It provides information about the seaport's capabilities, how the cargo has been handled, how many days the cargo took to clear a particular port area, and the overall throughput of the seaport. The model is highly data intensive since it models the huge traffic in a real seaport.

Bottlenecks reduce system performance. Systems that are traffic intensive or simulations of systems, which are data intensive, encounter bottlenecks, which reduce their performance. In …

Modified Art 2a Growing Network Capable Of Generating A Fixed Number Of Nodes, Ji He, Ah-Hwee Tan, Chew-Lim Tan

Research Collection School Of Computing and Information Systems

This paper introduces the Adaptive Resonance Theory under Constraint (ART-C 2A) learning paradigm based on ART 2A, which is capable of generating a user-defined number of recognition nodes through online estimation of an appropriate vigilance threshold. Empirical experiments compare the cluster validity and the learning efficiency of ART-C 2A with those of ART 2A, as well as three closely related clustering methods, namely online K-Means, batch K-Means, and SOM, in a quantitative manner. Besides retaining the online cluster creation capability of ART 2A, ART-C 2A gives the alternative clustering solution, which allows a direct control on the number of output …

Qos Routing Optimization Strategy Using Genetic Algorithm In Optical Fiber Communication Networks, Zhaoxia Wang, Zengqiang Chen, Zhuzhi Yuan

Research Collection School Of Computing and Information Systems

This paper describes the routing problems in optical fiber networks, defines five constraints, induces and simplifies the evaluation function and fitness function, and proposes a routing approach based on the genetic algorithm, which includes an operator [OMO] to solve the QoS routing problem in optical fiber communication networks. The simulation results show that the proposed routing method by using this optimal maintain operator genetic algorithm (OMOGA) is superior to the common genetic algorithms (CGA). It not only is robust and efficient but also converges quickly and can be carried out simply, that makes it better than other complicated GA.

Using Dynamic Optimization For Control Of Real Rate Cpu Resource Management Applications, Varin Vahia, Ashvin Goel, David Steere, Jonathan Walpole, Molly H. Shor

Computer Science Faculty Publications and Presentations

In this paper we design a proportional-period optimal controller for allocating CPU to real rate multimedia applications on a general-purpose computer system. We model this computer system problem in to state space form. We design a controller based on dynamic optimization LQR tracking techniques to minimize short term and long term time deviation from the current time stamp and also CPU usage. Preliminary results on an experimental set up are encouraging.

Adaptive Live Video Streaming By Priority Drop, Jie Huang, Charles Krasic, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we explore the use of Priority-progress streaming (PPS) for video surveillance applications. PPS is an adaptive streaming technique for the delivery of continuous media over variable bit-rate channels. It is based on the simple idea of reordering media components within a time window into priority order before transmission. The main concern when using PPS for live video streaming is the time delay introduced by reordering. In this paper we describe how PPS can be extended to support live streaming and show that the delay inherent in the approach can be tuned to satisfy a wide range of …

Automatic Speaker Identification Using Reusable And Retrainable Binary-Pair Partitioned Neural Networks, Ashutosh Mishra

Electrical & Computer Engineering Theses & Dissertations

This thesis presents an extension of the work previously done on speaker identification using Binary Pair Partitioned (BPP) neural networks. In the previous work, a separate network was used for each pair of speakers in the speaker population. Although the basic BPP approach did perform well and had a simple underlying algorithm, it had the obvious disadvantage of requiring an extremely large number of networks for speaker identification with large speaker populations. It also requires training of networks proportional to the square of the number of speakers under consideration, leading to a very large number of networks to be trained …

Under The Plastic: A Quantitative Look At Dvd Video Encoding And Its Impact On Video Modeling, Wu-Chi Feng, Jin Choi, Wu-Chang Feng, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper, we examine the DVD encoding process and the implications this process has video modeling and network traffic analysis. We have assembled a system that allows us to extract the video data from the DVDs as they were encoded for distribution. Analyzing the resulting video trace data, we describe how DVD encodings have evolved over time. In addition, our findings show that the underlying video content is fundamentally different than those produced by basic consumer video capture boards. We demonstrate how this affects current video modeling proposals and their affect on network traffic characterization. This research is based …

On The Area Of Hypercube Layouts, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

This paper precisely analyzes the wire density and required area in standard styles for the hypercube. It shows that the most natural, regular layout of a hypercube of N^2 nodes in the plane, in a NxN grid arrangement, uses floor(2N/3)+1 horizontal wiring tracks for each row of nodes. (In the process, we see that the number of tracks per row can be reduced by 1 with a less regular design, as can also be seen from an independent argument of Bezrukov et al.) This paper also gives a simple formula for the wire density at any cut position and a …

Provisioning On-Line Games: A Traffic Analysis Of A Busy Counter-Strike Server, Wu-Chang Feng, Francis Chang, Wu-Chi Feng, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This paper describes the results of a 500 million packet trace of a popular on-line, multi-player, game server. The results show that the traffic behavior of this heavily loaded game server is highly predictable and can be attributed to the fact that current game designs target the saturation of the narrowest, last-mile link. Specifically, in order to maximize the interactivity of the game itself and to provide relatively uniform experiences between players playing over different network speeds, on-line games typically fix their usage requirements in such a way as to saturate the network link of their lowest speed players. While …

Supporting Low-Latency Tcp-Based Media Streams, Ashvin Goel, Charles Krasic, Kang Li, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The dominance of the TCP protocol on the Internet and its success in maintaining Internet stability has led to several TCP-based stored media-streaming approaches. The success of these approaches raises the question whether TCP can be used for low-latency streaming. Low latency streaming allows responsive control operations for media streaming and can make interactive applications feasible. We examined adapting the TCP send buffer size based on TCP's congestion window to reduce application perceived network latency. Our results show that this simple idea significantly improves the number of packets that can be delivered within 200 ms and 500 ms thresholds.

A Genetic Algorithm Solution To The Shortest Path Problem In Ospf And Mpls, Wee Jing Tee Wee Jing

Student Works (2000-2009)

This project studies and explores the potential of using genetic algorithm to solve the shortest path problem in Open Shortest Path First (OSPF) and Multiprotocol Label Switching (MPLS). The most critical task for developing a genetic algorithm to the shortest path problem is to how to encode a path in a network. In this project, two genetic algorithm solutions arc developed for the above two problem domains, i.e. Previous-node-based Encoding to solve the shortest path problem in OSPF and Priority-based Encoding to solve the shortest path problem in MPLS. For each of the shortest path problem domains, the proposed solution …

Issues In Implementing Ipv6 In The X-Kernel Simulator, Raja Singam Thillainathan

Student Works (2000-2009)

The new Internet Protocol Version 6(IPv6) or Internet Protocol Next Generation (TPNG) is bound to replace the existing Internet Protocol Version 4(TPv4). This new protocol is to address and resolve the limitations of the existing Internet Protocols. At the moment the new protocol is still in its infancy stage, and it is being implemented by both the research society and the private sector. The x-kernel being a research project done by University of Arizona is freely available on the Internet. This x-kemel is a networking software almost similar to the Berkeley version (BSD) and it is bundled together with a …

An Exploratory Study Of Internet Data Centres In Malaysia, Huai Peng Loh, Siew Hwa Tan

Student Works (2000-2009)

The explosion of Internet in Malaysia has spurred the growth of Internet Data Centres - a combination of Internet Service Providers, Information Technology Vendor Community and Telecommunication Service Providers providing co­location and managed services. These Internet Data Centres are targeting any organisations which have an internet strategy and which plan to outsource their IT infrastructures. This report aims to shed a light on the Malaysian Internet Data Centres, which are mainly concentrated in the Klang Valley. Readers will be able to gain insight into the target markets, infrastructure owned and services offered by the Internet Data Centres concerned. The report …

Design And Analysis Of Radio Frequency Deployment Algorithms For Gsm, Mónica Pérez-Carbonell

Theses

Due to the growth of the subscriber base and the introduction of new services, mobile communications networks’ demand for wireless resources is increasing. This has resulted in an increasing need to change the frequency allocation of a network in order to adapt the cellular network to new frequency demands.

Currently, a planning tool generates a new frequency plan, which is. then deployed to cell sites. The deployment should ideally be carried out with minimum disruption to network operation, which makes this deployment process a critical undertaking as any errors during or after the deployment can leave the network with poor …

Reifying Communication At The Application Level, Andrew P. Black, Jie Huang, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Middleware, from the earliest RPC systems to recent Object-Oriented Remote Message Sending (RMS) systems such as Java RMI and CORBA, claims transparency as one of its main attributes. Coulouris et al. define transparency as “the concealment from the … application programmer of the separation of components in a distributed system.” They go on to identify eight different kinds of transparency.

We considered titling this paper “Transparency Considered Harmful”, but that title is misleading because it implies that all kinds of transparency are bad. This is not our view. Rather, we believe that the choice of which transparencies should be offered …