Computer Sciences Commons^™

A New Cryptographic Scheme For Securing Dynamic Conferences In Data Networks, Sarang Deshpande, Ajay Todimala, Ravi K Balachandran, Byrav Ramamurthy, Xukai Zou, N. V. Vinodchandran

School of Computing: Conference and Workshop Papers

Dynamic conferencing refers to a scenario wherein any subset of users in a universe of users form a conference for sharing confidential information among themselves. The key distribution (KD) problem in dynamic conferencing is to compute a shared secret key for such a dynamically formed conference. In literature, the KD schemes for dynamic conferencing either are computationally unscalable or require communication among users, which is undesirable. The extended symmetric polynomial based dynamic conferencing scheme (ESPDCS) is one such KD scheme which has a high computational complexity that is universe size dependent. In this paper we present an enhancement to the …

Router And Firewall Redundancy With Openbsd And Carp, Garhan Attebury, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

As more reliance is placed on computing and networking systems, the need for redundancy increases. The Common Address Redundancy Protocol (CARP) protocol and OpenBSD’s pfsync utility provide a means by which to implement redundant routers and firewalls. This paper details how CARP and pfsync work together to provide this redundancy and explores the performance one can expect from the open source solutions. Two experiments were run: one showing the relationship between firewall state creation and state synchronization traffic and the other showing how TCP sessions are transparently maintained in the event of a router failure. Discussion of these simulations along …

Autonomous Clustering-Based Heterogeneous Waveband Switching In Wdm Networks, Mengke Li, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Employing waveband switching (WBS) in WDM networks can reduce the network operational cost and the call blocking probability. However, upgrading the existing optical switching architecture requires time and money. It is expected that a heterogeneous waveband switching (HeteroWBS) architecture would be desirable, where some nodes can support WBS functions and some cannot. We study the performance of HeteroWBS networks in terms of call blocking probability and cost savings under dynamic traffic requests. We propose an autonomous clustering-based HeteroWBS (AS-HeteroWBS) architecture to clusters the network into multiple autonomous systems (ASs). An AS may contain some specific nodes that provide WBS functions …

Integrated Intermediate Waveband And Wavelength Switching For Optical Wdm Mesh Networks, Mengke Li, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

As wavelength-division multiplexing (WDM) evolves towards practical applications in optical transport networks, waveband switching (WBS) has been introduced to cut down the operational costs and to reduce the complexities and sizes of network components, e.g., optical cross-connects (OXCs). This paper considers the routing, wavelength assignment and waveband assignment (RWWBA) problem in a WDM network supporting mixed waveband and wavelength switching. First, the techniques supporting waveband switching are studied, where a node architecture enabling mixed waveband and wavelength switching is proposed. Second, to solve the RWWBA problem with reduced switching costs and improved network throughput, the cost savings and call blocking …

Dynamic Lightpath Scheduling In Next-Generation Wdm Optical Networks, Lu Shen, Ajay Todimala, Byrav Ramamurthy, Xi Yang

School of Computing: Conference and Workshop Papers

Lightpath scheduling is an important capability in next-generation wavelength-division multiplexing (WDM) optical networks to reserve resources in advance for a specified time period while provisioning end-to-end lightpaths. In this study, we propose an approach to support dynamic lightpath scheduling in such networks. To minimize blocking probability in a network that accommodates dynamic scheduled lightpath demands (DSLDs), resource allocation should be optimized in a dynamic manner. However, for the network users who desire deterministic services, resources must be reserved in advance and guaranteed for future use. These two objectives may be mutually incompatible. Therefore, we propose a two-phase dynamic lightpath scheduling …

A Survey Of Security Issues In Wireless Sensor Networks, Yong Wang, Garhan Attebury, Byrav Ramamurthy

School of Computing: Faculty Publications

Wireless Sensor Networks (WSNs) are used in many applications in military, ecological, and health-related areas. These applications often include the monitoring of sensitive information such as enemy movement on the battlefield or the location of personnel in a building. Security is therefore important in WSNs. However, WSNs suffer from many constraints, including low computation capability, small memory, limited energy resources, susceptibility to physical capture, and the use of insecure wireless communication channels. These constraints make security in WSNs a challenge. In this article we present a survey of security issues in WSNs. First we outline the constraints, security requirements, and …

The Performance Of Elliptic Curve Based Group Diffie-Hellman Protocols For Secure Group Communication Over Ad Hoc Networks, Yong Wang, Byrav Ramamurthy, Xukai Zou

School of Computing: Conference and Workshop Papers

The security of the two party Diffie-Hellman key exchange protocol is currently based on the discrete logarithm problem (DLP). However, it can also be built upon the elliptic curve discrete logarithm problem (ECDLP). Most proposed secure group communication schemes employ the DLP-based Diffie-Hellman protocol. This paper proposes the ECDLP-based Diffie-Hellman protocols for secure group communication and evaluates their performance on wireless ad hoc networks. The proposed schemes are compared at the same security level with DLP-based group protocols under different channel conditions. Our experiments and analysis show that the Tree-based Group Elliptic Curve Diffie-Hellman (TGECDH) protocol is the best in …

Spatial Correlation-Based Collaborative Medium Access Control In Wireless Sensor Networks, Mehmet C. Vuran, Ian F. Akyildiz

School of Computing: Faculty Publications

Wireless Sensor Networks (WSN) are mainly characterized by dense deployment of sensor nodes which collectively transmit information about sensed events to the sink. Due to the spatial correlation between sensor nodes subject to observed events, it may not be necessary for every sensor node to transmit its data. This paper shows how the spatial correlation can be exploited on the Medium Access Control (MAC) layer. To the best of our knowledge, this is the first effort which exploits spatial correlation in WSN on the MAC layer. A theoretical framework is developed for transmission regulation of sensor nodes under a distortion …

Eraid: Conserving Energy In High Performance Raid Systems With Conventional Disks, Dong Li, Jun Wang

School of Computing: Technical Reports

Recently energy consumption becomes an ever critical concern for both low-end and high-end storage server and data centers. A majority of existing energy conservation solutions resort to multi-speed disks. However, current server systems are still built with conventional disks.
In this paper, we propose an energy saving policy, eRAID, for conventional disk based RAID-1 systems. eRAID saves energy by spinning down partial or entire mirror disk group with predictable performance degradation. The heart work of eRAID is to develop an accurate dynamic performance control (including disk power management) scheme. To guarantee service quality, the dynamic performance control works for two …

Helping End-User Programmers “Engineer” Dependable Software, Gregg Rothermel

School of Computing: Conference and Workshop Papers

Not long ago, most software was written by professional programmers, who could be presumed to have an interest in software engineering methodologies and in tools and techniques for improving software dependability. Today, however, a great deal of software is written not by professionals but by end-users, who create applications such as multimedia simulations, dynamic web pages, and spreadsheets. Applications such as these are often used to guide important decisions or aid in important tasks, and it is important that they be sufficiently dependable, but evidence shows that they frequently are not. For example, studies have shown that a large percentage …

Spatio-Temporal Characteristics Of Point And Field Sources In Wireless Sensor Networks, Mehmet C. Vuran, Ӧzgür B. Akan

School of Computing: Conference and Workshop Papers

Wireless Sensor Networks (WSN) are comprised of densely deployed sensor nodes collaboratively observing and communicating extracted information about a physical phenomenon. Dense deployment of sensor nodes makes the sensor observations highly correlated in the space domain. In addition, consecutive samples obtained by a sensor node are also temporally correlated for the applications involving the observation of the variation of a physical phenomenon. Based on the physical characteristics and dispersion pattern over the area, the phenomenon to be observed can be modeled as point source or field source. Clearly, understanding the spatio-temporal correlation characteristics of the point and field sources brings …

A Cross-Layer Protocol For Wireless Sensor Networks, Ian F. Akyildiz, Mehmet C. Vuran, Ӧzgür B. Akan

School of Computing: Conference and Workshop Papers

Severe energy constraints of battery-powered sensor nodes necessitate energy-efficient communication protocols in order to fulfill application objectives of wireless sensor networks (WSN). However, the vast majority of the existing solutions are based on classical layered protocols approach. It is much more resource-efficient to have a unified scheme which melts common protocol layer functionalities into a cross-layer module for resource-constrained sensor nodes. To the best of our knowledge, to date, there is no unified cross-layer communication protocol for efficient and reliable event communication which considers transport, routing, medium access functionalities with physical layer (wireless channel) effects for WSNs.
In this paper, …

Cross-Layer Analysis Of Error Control In Wireless Sensor Networks, Mehmet C. Vuran, Ian F. Akyildiz

School of Computing: Conference and Workshop Papers

Severe energy constraints and hence the low power communication requirements amplify the significance of the energy efficient and preferably cross-layer error control mechanisms in Wireless Sensor Networks (WSN). In this paper, a crosslayer methodology for the analysis of error control schemes in WSNs is presented such that the effects of multi-hop routing and the broadcast nature of the wireless channel are investigated. More specifically, the cross-layer effects of routing, medium access and physical layers are considered. This analysis enables a comprehensive comparison of forward error correction (FEC) and automatic repeat request (ARQ) in WSNs.
FEC schemes improve the error resiliency …

A Constraint-Based Approach To Solving Minesweeper, Ken Bayer, Josh Snyder, Berthe Y. Choueiry

School of Computing: Conference and Workshop Papers

·Motivate the students for the study of Constraint Processing (CP). Minesweeper is perfect to this end because it allows us to illustrate the use of CP algorithms in a familiar context and show how they operate.

·Understand and demystify humans’ fascination with puzzles.

·Discourage graduate students from losing too much time playing the game by making a program that plays the game for them.

Evaluating The Effectiveness Of Slicing For Model Reduction Of Concurrent Object-Oriented Programs, Matthew B. Dwyer, John Hatcliff, Matthew Hoosier, Venkatesh Ranganath, Robby, Todd Wallentine

School of Computing: Book Chapters

Model checking techniques have proven effective for checking a number of non-trivial concurrent object-oriented software systems. However, due to the high computational and memory costs, a variety of model reduction techniques are needed to overcome current limitations on applicability and scalability. Conventional wisdom holds that static program slicing can be an effective model reduction technique, yet anecdotal evidence is mixed, and there has been no work that has systematically studied the costs/benefits of slicing for model reduction in the context of model checking source code for realistic systems. In this paper, we present an overview of the sophisticated Indus program …

A Maximum-Likelihood Approach To Symbolic Indirect Correlation, Ashutosh Joshi, George Nagy, Daniel Lopresti, Sharad C. Seth

School of Computing: Conference and Workshop Papers

Symbolic Indirect Correlation (SIC) is a nonparametric method that offers significant advantages for recognition of ordered unsegmented signals. A previously introduced formulation of SIC based on subgraph-isomorphism requires very large reference sets in the presence of noise. In this paper, we seek to address this issue by formulating SIC classification as a maximum likelihood problem. We present experimental evidence that demonstrates that this new approach is more robust for the problem of online handwriting recognition using noisy input.

On Reoptimizing Multi-Class Classifiers, Kun Deng, Chris Bourke, Stephen Scott, Robert E. Schapire, N. V. Vinodchandran

School of Computing: Technical Reports

Significant changes in the instance distribution or associated cost function of a learning problem require one to reoptimize a previously learned classifier to work under new conditions. We study the problem of reoptimizing a multi-class classifier based on its ROC hypersurface and a matrix describing the costs of each type of prediction error. For a binary classifier, it is straightforward to find an optimal operating point based on its ROC curve and the relative cost of true positive to false positive error. However, the corresponding multi-class problem (finding an optimal operating point based on a ROC hypersurface and cost matrix) …

Advances In Data Modeling Research, G. Allen, A. Bajaj, V. Khatri, S. Ram, Keng Siau

Research Collection School Of Computing and Information Systems

In this paper, we summarize the discussions of the panel on "Advances in Data Modeling Research," held at the Americas Conference on Information Systems (AMCIS) in 2005. We focus on four primary areas where data modeling research offers rich opportunities: spatio-temporal semantics, genome research, ontological analysis and empirical evaluation of existing models. We highlight past work in each area and also discuss open questions, with a view to promoting future research in the overall data modeling area.

Systems Analysis & Design: An Essential Part Of Is Education, Albert L. Harris, Michael Lang, Briony J. Oates, Keng Siau

Research Collection School Of Computing and Information Systems

Systems analysis and design has been as critical building block in Information Systems (IS) education since the inception of the IS major. Whether it is taught using the traditional or "structured approach or the object-oriented approach, it exposes students to the different methods, tools, and techniques used in developing new systems, develops students analytical and problem-solving skills, teaches fact-finding and data gathering techniques, and provides teamwork skills. All of these are valuable skills for systems analysts. This paper introduces the reader of this special issue on systems analysis and design education to the issue, discusses the two approaches to teaching …

Use Of A Weighted Matching Algorithm To Sequence Clusters In Spatial Join Processing, Husen Husen

Theses : Honours

One of the most expensive operations in a spatial database is spatial join processing. This study focuses on how to improve the performance of such processing. The main objective is to reduce the Input/Output (I/O) cost of the spatial join process by using a technique called cluster-scheduling. Generally, the spatial join is processed in two steps, namely filtering and refinement. The cluster-scheduling technique is performed after the filtering step and before the refinement step and is part of the housekeeping phase. The key point of this technique is to realise order wherein two consecutive clusters in the sequence have maximal …

A Real-Time Virtual Classroom System With Two-Way Communication For Distance Learning At King Mongkut’S University Of Technology Thonburi, Thailand, Surachai Suksakulchai, Chalathip Chunkul

EDU-COM International Conference

Because of high demands for higher education in the provinces of Thailand, the school of Industrial Education and Technology at KMUTT has started off-campus courses since 2002. However, the major problem of operation is distance. To cope with the problem, a real-time virtual classroom system with two-way communication has been developed. The system has to overcome the bandwidth problem, which is the major struggle of web-based learning in Thailand, and to maintain the two-way communication between instructors and students. To cope with those problems, video streaming and live chat systems are used. The technique is the trade-off between two-way and …

Testcase Tool, John Louis Van Hemert

Honors Program Theses

The title of my project is "TestCASE Tool." TestCASE Tool is the name, or label, I assigned to the software application that I created for this project. The application is a Tool for storing and reporting data in software testing projects. A Test Case consists of a planned action within a system, the expected result of that action and an assessment of whether the expected result occurred. The acronym, CASE, stands for Computer Aided Software Engineering, which is the software tool genre to which my application belongs.

Experimental Analysis And Evaluation Of Tidy Tree Drawing Algorithms, Pankaj Mahajan

Electronic Theses and Dissertations

Tree Drawings have been used extensively in software engineering and many other business and computer applications. The basic structure of a tree allows for the organization and representation of complex information. Many commercial tools allow their users to draw or construct trees to represent a problem and/or its solution. Our focus is on dynamic trees - trees subject to frequent changes and redisplay in highly user-friendly interactive computer applications. Tree presentations in such interactive tools have to be precise and maintainable, which means, the tree presentations should maintain a particular structure so that user's mental perception of the tree is …

Development Of Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Yitung Chen, Sean Hsieh

Separations Campaign (TRP)

The overall goal of this project is the creation of a framework that combines all the strengths of AMUSE’s complicated calculations, well-established commercial system process packages, and TRPSEMPro’s flexible parameter optimization modules. Development of the process simulation code can be done using the solvent extraction process at Argonne National Laboratory in collaboration with the UNLV Nevada Center for Advanced Computational Methods.

The major objectives are the following:

• Develop a framework for simulating the Spent Fuel Treatment Facility (SFTF) process using AMUSE code, commercial process package, such as ASPEN-PLUS, and system engineering model.
• Develop a middleware package that can communicate between …

Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng

Electrical & Computer Engineering Faculty Research

Combined input and output queuing (CIOQ) switches are being considered as high-performance switch architectures due to their ability to achieve 100% throughput and perfectly emulate output queuing (OQ) switch performance with a small speedup factor S. To realize a speedup factor S, a conventional CIOQ switch requires the switching fabric and memories to operate S times faster than the line rate. In this paper, we propose to use a CIOQ switch with space-division multiplexing expansion and grouped input/output ports (SDMG CIOQ switch for short) to realize speedup while only requiring the switching fabric and memories to operate at the line …

Handling The Subclassing Anomaly With Object Teams, Jeff Furlong, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Articles and Research

Existing Java software or libraries can evolve via subclassing. Unfortunately, subclassing may not properly support code adaptation when there are dependencies between classes. More precisely, subclassing in collections of related classes may require reimplementation of otherwise valid classes. This problem is defined as the subclassing anomaly, which is an issue when software evolution or code reuse is a goal of the programmer who is using existing classes. Object Teams offers an implicit fix to this problem and is largely compatible with the existing JVM’s. In this paper, we evaluate how well Object Teams succeeds in providing a solution for a …

Computational Sciences: At The Intersection Of Science And Engineering - Case Study For Academic And Research Programs, Menas Kafatos, P. A. Becker, Z. Boybeyi

Mathematics, Physics, and Computer Science Faculty Articles and Research

No abstract provided.

Coalgebras And Their Logics, Alexander Kurz

Engineering Faculty Articles and Research

"Transition systems pervade much of computer science. This article outlines the beginnings of a general theory of specification languages for transition systems. More specifically, transition systems are generalised to coalgebras. Specification languages together with their proof systems, in the following called (logical or modal) calculi, are presented by the associated classes of algebras (e.g., classical propositional logic by Boolean algebras). Stone duality will be used to relate the logics and their coalgebraic semantics."

Numerical Techniques For Fresnel Diffraction In Computational Holography, Richard Patrick Muffoletto

LSU Doctoral Dissertations

Optical holography can produce very realistic virtual images due to its capability to properly convey the depth cues that we use to interpret three-dimensional objects. Computational holography is the use of digital representations plus computational methods to carry out the holographic operations of construction and reconstruction. The large computational requirements of holographic simulations prohibit present-day existence of real-time holographic displays comparable in size to traditional two-dimensional displays. Fourier-based approaches to calculate the Fresnel diffraction of light provide one of the most efficient algorithms for holographic computations because this permits the use of the fast Fourier transform (FFT). The limitations on …

Adaptive Scalable Protocols For Heterogeneous Wireless Networks, Vamsi Krishna Paruchuri

LSU Doctoral Dissertations

The focus of this dissertation is to propose analytical models to study the impact of collisions and interference in heterogeneous wireless networks and propose simple scalable and lightweight protocols that use these models to adapt to network conditions thus increasing efficiency, decreasing energy consumption and prolonging network lifetime. The contributions of this dissertation are multifold and are summarized as follows: - Analytical models to study the impact of collisions and interference on both broadcast and unicast messages. These analytical models are incorporated into the proposed protocols to adapt to the prevailing network conditions to improve their performance. - Optimized Flooding …