Physical Sciences and Mathematics Commons^™

Aggregation, Foraging, And Formation Control Of Swarms With Non-Holonomic Agents Using Potential Functions And Sliding Mode Techniques, Veysel Gazi̇, Bariş Fi̇dan, Y. Si̇nan Hanay, İlter Köksal

Turkish Journal of Electrical Engineering and Computer Sciences

In this article we consider the aggregation, foraging, and formation control of swarms whose agents are moving in 2-dimensions with non-holonomic unicycle agent dynamics. We approach these problems using artificial potentials and sliding mode control. The main contribution is extension of the recent results (mainly for aggregation) in the literature based on a similar approach for simple integrator agent dynamics models to a significantly more realistic and more difficult setting with non-holonomic unicycle agent dynamics models. In particular, we design continuous-time control schemes via a constructive analysis based on artificial potential functions and sliding mode control techniques. The effectiveness of …

A Vrp-Based Route Planning For A Mobile Robot Group, Osman Parlaktuna, Aydin Si̇pahi̇oğlu, Ahmet Yazici

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a vehicle routing problem-based approach is presented to construct non-intersecting routes for the members of a mobile robot team. It is assumed that each robot starts from a central location such as the charging point, completes its route and returns to the starting location. The proposed method consists of three algorithms: a sweep algorithm determines the position of each node in clockwise (or counter clockwise) manner with respect to the starting location; savings algorithm calculates the saving obtained by adding a node to the route of a robot; Dijkstra's shortest path algorithm is used to calculate the …

Aggregation In Swarm Robotic Systems: Evolution And Probabilistic Control, Onur Soysal, Erki̇n Bahçeci̇, Erol Şahi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this study we investigate two approachees for aggregation behavior in swarm robotics systems: Evolutionary methods and probabilistic control. In first part, aggregation behavior is chosen as a case, where performance and scalability of aggregation behaviors of perceptron controllers that are evolved for a simulated swarm robotic system are systematically studied with different parameter settings. Using a cluster of computers to run simulations in parallel, four experiments are conducted varying some of the parameters. Rules of thumb are derived, which can be of guidance to the use of evolutionary methods to generate other swarm robotic behaviors as well. In the …

A Communication Module And Tdma Scheduling For A Swarm Of Small Submarines, Ram Somaraju, Felix Schill

Turkish Journal of Electrical Engineering and Computer Sciences

Swarming algorithms usually require fast and reliable local information distribution among neighbouring nodes. Additionally, many applications also require global information distribution in the shortest possible time. We show that communication links with a range which is small compared to the size of the swarm offer many advantages. We propose a system using low frequency radio communication as a viable alternative to acoustic communication. A time division multiple access algorithm is presented together with results from simulations. The presented system can be effectively used in large scale swarms of small submersibles.

Design And Implementation Of An Ad-Hoc Routing Protocol For Mobile Robots, Carlos Agüero, Jose M. Canas, Miguel Ortu˜No, Vicente Matellan

Turkish Journal of Electrical Engineering and Computer Sciences

Mobile robots need to be able to communicate among themselves, as well as with hosts participating in the task that they are all involved in. Wired networks are obviously not suitable for mobile robots. Current wireless networks based on a fixed infrastructure (GSM, WiFi, etc.) to route packets may not be suitable because this infrastructure does not cover every place and the requirements of its resources. The best choice for mobile robots are Ad-Hoc networks, which are wireless and do not need a fixed infrastructure. This article describes PERA, a complete communications library including link, net, and transport layers for …

Optimal Layout Of Multicast Groups Using Network Embedded Multicast Security In Ad Hoc Sensor Networks, Richard R. Brooks, Brijesh Pillai, Michele C. Weigle, Matthew Pirretti

Computer Science Faculty Publications

This paper considers the security of sensor network applications. Our approach creates multicast regions that use symmetric key cryptography for communications. Each multicast region contains a single keyserver that is used to perform key management and maintain the integrity of a multicast region. Communications between two multicast regions is performed by nodes that belong to both regions. To ease the network management burden, it is desirable for the networks to self-organize into regions and dynamically select their keyservers. This paper shows how to determine the number of keyservers (k) to use and the size in the number of hops (h) …

Clarifications Of Rule 2 In Teaching Geometric Dimensioning And Tolerancing, Cheng Lin, Alok Verma

Engineering Technology Faculty Publications

Geometric dimensioning and tolerancing is a symbolic language used on engineering drawings and computer generated three-dimensional solid models for explicitly describing nominal geometry and its allowable variation. Application cases using the concept of Rule 2 in the Geometric Dimensioning and Tolerancing (GD&T) are presented. The rule affects all fourteen geometric characteristics. Depending on the nature and location where each feature control frame is specified, interpretation on the applicability of Rule 2 is quite inconsistent. This paper focuses on identifying the characteristics of a feature control frame to remove this inconsistency. A table is created to clarify the confusions for students …

Optimal Discrete Rate Adaptation For Distributed Real-Time Systems With End-To-End Tasks, Yingming Chen, Chenyang Lu, Xenofon Koutsoukos

All Computer Science and Engineering Research

Many distributed real-time systems face the challenge of dynamically maximizing system utility in response to fluctuations in system workload. We present the MultiParametric Rate Adaptation (MPRA) algorithm for discrete rate adaptation in distributed real-time systems with end-to-end tasks. The key novelty and advantage of MPRA is that it can efficiently produce optimal solutions in response to workload changes such as dynamic task arrivals. Through oline preprocessing MPRA transforms a NP-hard utility optimization problem to a set of simple linear functions in different regions expressed in term of CPU utilization changes caused by workload variations. At run time MPRA produces optimal …

Fair Efficiency, Or Low Average Delay Without Starvation, Christoph Jechlitschek, Sergey Gorinsky

All Computer Science and Engineering Research

Elastic applications are primarily interested in minimal delay achievable for their messages under current network load. In this paper, we investigate how to transmit such messages over a bottleneck link efficiently and fairly. While SRPT (Shortest Remaining Processing Time) is an optimally efficient algorithm that minimizes average delay of messages, large messages might starve under SRPT in heavy load conditions. PS (Processor Sharing) and ViFi (Virtual Finish Time First) are fair but yield higher average delays than under SRPT. We explore the class of fair algorithms further and prove that no online algorithm in this class is optimally efficient. Then, …

Emergent Task Allocation For Mobile Robots Through Intentions And Directives, Nuzhet Atay, Burchan Bayazit

All Computer Science and Engineering Research

Multi-robot systems require efficient and accurate planning in order to perform mission-critical tasks. However, algorithms that find the optimal solution are usually computationally expensive and may require a large number of messages between the robots as the robots need to be aware of the global spatiotemporal information. In this paper, we introduce an emergent task allocation approach for mobile robots. Each robot uses only the information obtained from its immediate neighbors in its decision. Our technique is general enough to be applicable to any task allocation scheme as long as a utilization criteria is given. We demonstrate that our approach …

Network Access In A Diversified Internet, M. Wilson, F. Kuhns, J. Turner

All Computer Science and Engineering Research

There is a growing interest in virtualized network infrastructures as a means to enable experimental evaluation of new network architectures on a realistic scale. The National Science Foundation's GENI initiative seeks to develop a national experimental facility that would include virtualized network platforms that can support many concurrent experimental networks. Some researchers seek to make virtualization a central architectural component of a future Internet, so that new network architectures can be introduced at any time, without the barriers to entry that currently make this difficult. This paper focuses on how to extend the concept of virtualized networking through LAN-based access …

A Duality Theory With Zero Duality Gap For Nonlinear Programming, Yixin Chen

All Computer Science and Engineering Research

Duality is an important notion for constrained optimization which provides a theoretical foundation for a number of constraint decomposition schemes such as separable programming and for deriving lower bounds in space decomposition algorithms such as branch and bound. However, the conventional duality theory has the fundamental limit that it leads to duality gaps for nonconvex optimization problems, especially discrete and mixed-integer problems where the feasible sets are nonconvex. In this paper, we propose a novel extended duality theory for nonlinear optimization that overcomes some limitations of previous dual methods. Based on a new dual function, the extended duality theory leads …

Expression Profiling Of Human Donor Lungs To Understand Primary Graft Dysfunction After Lung Transplantation, Monika Ray, Sekhar Dharmarajan, Johannes Freudenberg, Weixiong Zhang, Alexander G. Patterson

All Computer Science and Engineering Research

Lung transplantation is the treatment of choice for end-stage pulmonary diseases. A limited donor supply has resulted in 4000 patients on the waiting list. Currently, 10-20% of donor organs offered for transplantation are deemed suitable under the selection criteria, of which 15-25% fails due to primary graft dysfunction (PGD). This has resulted in increased efforts to search for alternative donor lungs selection criteria. In this study, we attempt to further our understanding of PGD by observing the changes in gene expression across donor lungs that developed PGD versus those that did not. Our second goal is to use a machine …

Price Of Asynchrony: Queuing Under Ideally Smooth Congestion Control, Maxim Podlesny, Sergey Gorinsky

All Computer Science and Engineering Research

The ability of TCP (Transmission Control Protocol) or alternative congestion control algorithms to operate successfully in networks with small link buffers has recently become a subject of intensive research. In this paper, we investigate fundamental limitations on minimum buffer requirements for any congestion control. We present an idealized protocol where all flows always transmit at their fair rates. The ideally smooth congestion control causes link queuing only due to asynchrony of flow arrivals, which is intrinsic to computer networks. Our analysis and simulations for different distributions of flow interarrival times agree that the buffer size needed for a fixed loss …

Curing Regular Expressions Matching Algorithms From Insomnia, Amnesia, And Acalulia, Sailesh Kumar, Balakrishnan Chandrasekaran, Jonathan Turner, George Varghese

All Computer Science and Engineering Research

The importance of network security has grown tremendously and a collection of devices have been introduced, which can improve the security of a network. Network intrusion detection systems (NIDS) are among the most widely deployed such system; popular NIDS use a collection of signatures of known security threats and viruses, which are used to scan each packet's payload. Today, signatures are often specified as regular expressions; thus the core of the NIDS comprises of a regular expressions parser, such parsers are traditionally implemented as finite automata. Deterministic Finite Automata (DFA) are fast, therefore they are often desirable at high network …

Splice: A Standardized Peripheral Logic And Interface Creation Engine, Master's Thesis, May 2007, Justin Thiel

All Computer Science and Engineering Research

Recent advancements in FPGA technology have allowed manufacturers to place general-purpose processors alongside user-configurable logic gates on a single chip. At first glance, these integrated devices would seem to be the ideal deployment platform for hardware-software co-designed systems, but some issues, such as incompatibility across vendors and confusion over which bus interfaces to support, have impeded adoption of these platforms. This thesis describes the design and operation of Splice, a software-based code generation tool intended to address these types of issues by providing a bus-independent structure that allows end-users to easily integrate their customized peripheral logic into embedded systems. To …

Hexa: Compact Data Structures For Faster Packet Processing, Sailesh Kumar, Jonathan Turner, Patrick Crowley, Michael Mitzenmacher

All Computer Science and Engineering Research

Directed graphs with edge labels are used in packet processing algorithms for a variety of network applications. In this paper we present a novel representation for such graph that significantly reduces the memory required for such graphs. This approach called History-based Encoding, eXecution and Addressing (HEXA) challenges the conventional assumption that graph data structures must store pointers of log2n bits to identify successor nodes. HEXA takes advantage of implict information to reduce the information that must be stored explicitly. We demonstrate that the binary tries used for IP route lookup can be implemented using just two bytes per stored prefix …

Architecture For Document Clustering In Reconfigurable Hardware, Master's Thesis, December 2006, Adam G. Covington

All Computer Science and Engineering Research

High-performance document clustering systems enable similar documents to automatically self-organize into groups. In the past, the large amount of computational time needed to cluster documents prevented practical use of such systems with a large number of documents. A full hardware implementation of K-means clustering has been designed and implemented in reconfigurable hardware that rapidly clusters a half million documents. Documents and concepts are represented as vectors with 4000 dimensions. The circuit was implemented in Field Programmable Gate Array (FPGA) logic and uses four parallel cosine distance metrics to cluster document vectors together. An exploration of the effect of the integer …

Single Cell Expression Profiling Reveals Major Disruption Of Dna Repair Capacity In Incipient Alzheimer's Disease, Monika Ray, Weixiong Zhang

All Computer Science and Engineering Research

Understanding the pathogenesis in the early stages of late-onset Alzheimer's disease (LOAD) can help in gaining important mechanistic insights into this devastating neurodegenerative disorder. Alzheimer's disease (AD) is characterised by extensive cell death with disease progression. In this paper laser capture microdissection (LCM) based gene expression profiling, which is able to profile gene expression in a single cell type, is employed to analyse the gene expression regulation of incipient AD. Our analysis shows that LCM based gene expression profiling of neurons has a critical advantage over the conventional gene expression profiling method which uses samples of mixed cell types and …

Implementing Legba: Fine-Grained Memory Protection, Sheffield, Sowell, Wilson

All Computer Science and Engineering Research

Fine-grained hardware protection could provide a powerful and effective means for isolating untrusted code. However, previous techniques for providing fine-grained protection in hardware have lead to poor performance. Legba has been proposed as a new caching architecture, designed to reduce the granularity of protection, without slowing down the processor. Unfortunately, the designers of Legba have not attempted an implementation. Instead, all of their analysis is based purely on simulations. We present an implementation of the Legba design on a MIPS Core Processor, along with an analysis of our observations and results.

Leveraging Est Evidence To Automatically Predict Alternatively Spliced Genes, Master's Thesis, December 2006, Robert Zimmermann

All Computer Science and Engineering Research

Current methods for high-throughput automatic annotation of newly sequenced genomes are largely limited to tools which predict only one transcript per gene locus. Evidence suggests that 20-50% of genes in higher eukariotic organisms are alternatively spliced. This leaves the remainder of the transcripts to be annotated by hand, an expensive time-consuming process. Genomes are being sequenced at a much higher rate than they can be annotated. We present three methods for using the alignments of inexpensive Expressed Sequence Tags in combination with HMM-based gene prediction with N-SCAN EST to recreate the vast majority of hand annotations in the D.melanogaster genome. …

Byzantine Fault-Tolerant Web Services For N-Tier And Service Oriented Architectures, Sajeeva L. Pallemulle, Kenneth J. Goldman

All Computer Science and Engineering Research

Web Services that provide mission-critical functionality must be replicated to guarantee correct execution and high availability in spite of arbitrary (Byzantine) faults. Existing approaches for Byzantine fault-tolerant execution of Web Services are inadequate to guarantee correct execution due to several major limitations. Some approaches do not support interoperability between replicated Web Services. Other approaches do not provide fault isolation guarantees that are strong enough to prevent cascading failures across organizational and application boundaries. Moreover, existing approaches place impractical limitations on application development by not supporting long-running active threads of computation, fully asynchronous communication, and access to host specific information. We …

Gigabit Concept Mining: A Sensitivity Analysis, Masters Thesis, December 2006, Andrew Levine

All Computer Science and Engineering Research

Massive amounts of data are passed over public networks. There is a need for network administrators to analyze this traffic, but it was not previously possible to analyze live network data at high speed. It has been shown that streaming computation and deep packet analysis are possible at very high rates through the use of hardware acceleration. This work provides analysis for a larger project that involves digesting large amounts of network traffic. In this system, we process the traffic using hardware that has constraints. The workings of the system are first discussed. Tradeoffs in the design of hardware and …

Introduction: Special Issue For The Selected Papers In The Fourth International Conference On Intelligent Multimedia Computing And Networking (Immcn) 2005, Chong-Wah Ngo, Hong-Va Leong

Research Collection School Of Computing and Information Systems

This special issue introduces seven papers selected from the IMMCN’ 2005, covering a wide range of emerging topics in multimedia field. These papers receive high scores and good comments from the reviewers in their respective areas of intelligent and nextgeneration networking, technology and application, multimedia coding, content analysis and retrieval. The seven papers are extended to 20 pages and then gone through another review process before the final publication. In this issue, we have two papers for video streaming, two papers for multimedia applications, one paper for video coding, and two papers for image and video retrieval.

Computing Branches Out: On Revitalizing Computing Education., Ljubomir Perkovic, Amber Settle

Amber Settle

No abstract provided.

High-Resolution Mapping In Manus Basin, C. Roman, V. Ferrini

Christopher N. Roman

Near-bottom seafloor mapping with precisely navigated deep submergence vehicles has become increasingly common in a range of oceanographic settings. Recent mapping efforts at deep-water hydrothermal vent sites have resulted in high-resolution (sub-meter) bathymetry datasets that can be used to identify morphological features associated with volcanic, tectonic, and hydrothermal processes. The resolution of these maps, and our ability to accurately quantify the complex morphologic details of hydrothermal structures has been limited by a number of variables including navigational accuracy, sonar settings (e.g. acoustic wavelength, sonar orientation, ping rate), survey parameters (e.g. altitude, speed), data density, and data processing techniques (e.g. gridding …

A Fuzzy Logic Controller For Autonomous Wheeled Vehicles, Mohamed Trabia, Linda Z. Shi, Neil Eugene Hodge

Mechanical Engineering Faculty Research

Autonomous vehicles have potential applications in many fields, such as replacing humans in hazardous environments, conducting military missions, and performing routine tasks for industry. Driving ground vehicles is an area where human performance has proven to be reliable. Drivers typically respond quickly to sudden changes in their environment. While other control techniques may be used to control a vehicle, fuzzy logic has certain advantages in this area; one of them is its ability to incorporate human knowledge and experience, via language, into relationships among the given quantities. Fuzzy logic controllers for autonomous vehicles have been successfully applied to address various …

Gridfields: Model-Driven Data Transformation In The Physical Sciences, Bill Howe

Dissertations and Theses

Scientists' ability to generate and store simulation results is outpacing their ability to analyze them via ad hoc programs. We observe that these programs exhibit an algebraic structure that can be used to facilitate reasoning and improve performance. In this dissertation, we present a formal data model that exposes this algebraic structure, then implement the model, evaluate it, and use it to express, optimize, and reason about data transformations in a variety of scientific domains.

Simulation results are defined over a logical grid structure that allows a continuous domain to be represented discretely in the computer. Existing approaches for manipulating …

Robust Control Techniques Enabling Duty Cycle Experiments Utilizing A 6-Dof Crewstation Motion Base, A Full Scale Combat Hybrid Electric Power System, And Long Distance Internet Communications, Marc Compere, Jarrett Goodell, Miguel Simon, Wilford Smith, Mark Brudnak

Publications

The RemoteLink effort supports the U.S. Army's objective for developing and fielding next generation hybrid-electric combat vehicles. It is a distributed soldierin- the-Ioop and hardware-in-the-Ioop environment with a 6-DOF motion base for operator realism, a full-scale combat hybrid electric power system, and an operational context provided by OneSAF. The driver/gunner crewstations rest on one of two 6-DOF motion bases at the U.S. Army TARDEC Simulation Laboratory (TSL). The hybrid power system is located 2,450 miles away at the TARDEC Power and Energy System Integration Laboratory (P&E SIL). The primary technical challenge in the RemoteLink is to operate both laboratories together …

Modeling Local Interest Points For Semantic Detection And Video Search At Trecvid 2006, Yu-Gang Jiang, Xiaoyong Wei, Chong-Wah Ngo, Hung-Khoon Tan, Wanlei Zhao, Xiao Wu

Research Collection School Of Computing and Information Systems

Local interest points (LIPs) and their features have been shown to obtain surprisingly good results in object detection and recognition. Its effectiveness and scalability, however, have not been seriously addressed in large-scale multimedia database, for instance TRECVID benchmark. The goal of our works is to investigate the role and performance of LIPs, when coupling with multi-modality features, for high-level feature extraction and automatic video search.