Computer Engineering Commons^™

3d Outside Cell Interference Factor For An Air-Ground Cdma ‘Cellular’ System, David W. Matolak

Faculty Publications

We compute the outside-cell interference factor of a code-division multiple-access (CDMA) system for a three-dimensional (3-D) air-to-ground (AG) "cellular-like" network consisting of a set of uniformly distributed ground base stations and airborne mobile users. The CDMA capacity is roughly inversely proportional to the outside-cell interference factor. It is shown that for the nearly free-space propagation environment of these systems, the outside-cell interference factor can be larger than that for terrestrial propagation models (as expected) and depends approximately logarithmically upon both the cell height and cell radius.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 4, April 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

A Generic Object-Oriented Server Model, Brian Douglas Jones

Electrical & Computer Engineering Theses & Dissertations

The purpose of this paper is to introduce a generic, object-oriented model for the simulation of networks of queues. Generic simulation modeling provides robust ways of laying out processes in stochastic, event driven simulations. The approach taken is to define a methodology that will be implementation independent, termed the Generic Server Simulation Model (GSSM); thus, leaving the implementers to choose the best (most suited for their use) means of implementation. GSSM uses many object-oriented concepts to provide its basic structure and has in its design the ability to take advantage of these object-oriented concepts, including reuse of (existing) code. GSSM …

A Digital Pressure Sensor Data Acquisition System In A Wind Tunnel Model, John J. Novakoski

Electrical & Computer Engineering Theses & Dissertations

Pressure measurements on wind tunnel models provide an important aid to overall aerodynamic analysis and design of aircraft and vehicles. Most pressure measurements in wind tunnels are made using analog pressure sensors with interfacing electronics that connect to an external data acquisition unit. Some of desirable features of an improved pressure measurement system are that it be: 1) model embeddable, 2) inherently digital in nature, 3) intelligent, and 4) controllable by a remote computer.

An intelligent, model-embedded, eight-channel digital pressure sensor system has been developed and tested in a wind tunnel. The implemented system consists of Micro-Electro-Mechanical System (MEMS) digital …

Process Flow Optimization Studies Through Discrete Event Simulation, Milind Chokshi

Electrical & Computer Engineering Theses & Dissertations

Computer-aided simulation has begun to emerge as a powerful tool for numerical analysis of the behavior and anticipated performance of industrial systems and their optimization. Applications include materials handling, storage and controls systems, prediction of manufacturing efficiencies, and production optimization. Simulations are used to test baseline models and subsequently analyze new production concepts, operating strategies, and planned procedures prior to costly implementation.

The study of process flows in a manufacturing environment is difficult due to its inherent stochastic nature. Breakdown of the sub-systems and failures of machines is a random process and needs to be solved based on concepts of …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 3, March 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

A Distributed Agent Architecture For A Computer Virus Immune System, Paul K. Harmer

Theses and Dissertations

Information superiority is identified as an Air Force core competency and is recognized as a key enabler for the success of future missions. Information protection and information assurance are vital components required for achieving superiority in the Infosphere, but these goals are threatened by the exponential birth rate of new computer viruses. The increased global interconnectivity that is empowering advanced information systems is also increasing the spread of malicious code and current anti-virus solutions are quickly becoming overwhelmed by the burden of capturing and classifying new viral stains. To overcome this problem, a distributed computer virus immune system (CVIS) based …

Crop Updates 2000 Cereals - Part 3, Roslyn J. Jettner, Blakely Paynter, Glenn Macdonald, Pierre Fievez, Ian Foster, David Tennant, Wal Anderson, James Ridsdill-Smith, Celia Pavri, Ross Chapman, Senthold Asseng, Steve Carr, Brad Nutt, Lindrea Latham, Roger Jones, Anyou Liu, Clinton K. Revell, David Ferris, Roy Latta, Lisa-Jane Blacklow, Chris Matthews, Ted Woodburn, Paul Yeoh, Ian Rose, Anita Lyons, Simon Cook, Matthew L. Adams, Robert J. Corner

Crop Updates

This session covers eighteen papers from different authors:

BARLEY AND OAT AGRONOMY

1. Unicorn barley must meet malting specifications to be a viable option, Roslyn Jettnerand Blakely Paynter, Agriculture Western Australia

2. Optimum oat seed rates, Glenn McDonald, Agriculture Western Australia

3. Production and Quality of export Oaten Hay (1998 and 1989), Pierre Fievez, Pierre Fievez and Associates

FROST

4. Climatology of Frost in Southern Western Australia, Ian Foster, Agriculture Western Australia

5. Flowering calculator, David Tennant, Agriculture Western Australia

6. Some options for managing the risk of frost damage, Wal Anderson, Agriculture Western Australia

PASTURE

7. …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 2, February 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Characterization Of Poly-Si Thin Films Deposited By Magnetron Sputtering Onto Ni Prelayers, Elena A. Guliants, Wayne A. Anderson

Electrical and Computer Engineering Faculty Publications

A method of producing a polycrystalline silicon thin film on a foreign substrate without subsequent annealing has been developed. Thermally evaporated 5–100 nm thick Nifilms served as prelayers for magnetron sputtered Si thin films. A continuous film was obtained as a result of metal induced growth of polysilicon during low temperature (below 600 °C) deposition. The film uniformity is promising for large area device applications. The influence of the Ni prelayer thickness on the grain size of thus obtained films was investigated. Atomic force microscopy and cross-sectional scanning electron microscopy studies revealed features in the 150–600 nm size range while …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 1, January 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Notes On Coalgebras, Cofibrations And Concurrency, Alexander Kurz, Dirk Pattinson

Engineering Faculty Articles and Research

We consider categories of coalgebras as (co)-fibred over a base category of parameters and analyse categorical constructions in the total category of deterministic and non-deterministic coalgebras.

Nonlinear Self-Organization In Photorefractive Materials, Partha P. Banerjee, Nickolai Kukhtarev, John O. Dimmock

Electrical and Computer Engineering Faculty Publications

This chapter discusses self-organization and its effects in optics. One of the most exciting and potentially useful areas of current research in optics involves the understanding and exploitation of self-organization in nonlinear optical systems. This self-organization may sometimes lead to the evolution of complex spatial patterns that can be regarded as the nonlinear eigenmodes of the system. Generation of these patterns is characteristically marked by the presence of intensity thresholds. In a nonlinear system with complicated temporal dynamics, it turns out that one cannot retain purity in spatial dimensionality. It is therefore equally important to investigate the dynamics of the …

Lime: A Middleware For Physical And Logical Mobility, Gian Pietro Picco, Amy L. Murphy, Gruia-Catalin Roman

All Computer Science and Engineering Research

LIME is a middleware supporting the development of applications that exhibit physical mobility of hosts, logical mobility of agents, or both. LIME adopts a coordination perspective inspired by work on the Linda model. The context for computation, represented in Linda by a globally accessible, persistent tuple space, is represented in LIME by transient sharing of the tuple spaces carried by each individual mobile unit. Linda tuple spaces are also extended with a notion of location and with the ability to react to a given state. The hypothesis underlying our work is that the resulting model provides a minimalist set of …

A Rate-Based End-To-End Multicast Congestion Control Protocol, Sherlia Shi, Marcel Waldvogel

All Computer Science and Engineering Research

Current reliable multicast protocols do not have scalable congestion control mechanisms and this deficiency leads to concerns that multicast deployment may endanger stability of the network. In this paper, we present a sender-based approach for multicast congestion control targeted towards reliable bulk data transfer. We assume that there are a few bottleneck links in a large scale multicast group at any time period and these bottlenecks persist long enough to be identified and adapted to. Our work focus on dynamically identifying the worst congested path in the multicast tree and obtaining TCP-friendly throughput on this selected path. We device novel …

On Maintaining Group Membership Data In Ad Hoc Networks, Gruia-Catalin Roman, Qingfeng Huang, Ali Hazemi

All Computer Science and Engineering Research

The design of ad hoc mobile applications often requires the availability of a consistent view of the application state among the participating hosts. Essential to constructing a consistent view is the ability to know what hosts are within proximity of each other, i.e., form a group in support of the particular application. In this paper we propose an algorithm that allows hosts within communication range to maintain a consistent view of the group membership despite movement and frequent disconnections. The novel features of this algorithm are its reliance on location information and a conservative notion of logical connectivity that creates …

Data Archiving With The Srb*, Jinghua Zhou

All Computer Science and Engineering Research

We use the SRB (Storage Request Broker) middleware to design and implement a storage archival system which will be used to archive Neuroscience data. As part of the design process, we developed and used an experimenter's workbench to measure SRB performance. These experiments improved our understanding of both the functionality and the performance of the SRB. This technical report describes the scripts in the experimenter's workbench, the archiving scripts, and performance measurements.

The Design And Performance Of Meta-Programming Mechanisms For Object Request Broker Middleware, Nanbor Wang, Kirthika Parameswaran, Douglass Schmidt

All Computer Science and Engineering Research

Distributed object computing (DOC) middleware shields developers from many tedious and error-prone aspects of programming distribued applications. Without proper support from the middleware, however, it can be hard to evolve distributed applications after they are deployed. Therefore, DOC middleware should support meta-programming mechanisms, such as smart proxies and interceptors, that improve the adaptability of distributed applications by allowing their behavior to be modified without drastically changing existing software. This paper presents three contributions to the study of metaprogramming mechanisms for DOC middleware. First, it illustrates, compares, and contrasts several meta-programming mechanisms from an application developer's perspective. Second, it outlines the …

Synthesizer, A Pattern Language For Designing Digital Modular Synthesis Software, Thomas V. Judkins, Christopher D. Gill

All Computer Science and Engineering Research

Synthesizer is a pattern language for designing digital synthesizers using modular synthesis in software to generate sound. Software developed according to this pattern language emulates the abilities of an analog synthesizer. Modular synthesis is one of the oldest sound synthesis techniques. It was used in the earliest analog synthesizers, like the Moog [1] and ARP [2]. These machines introduced the oscillator-filter-amplifier paradigm, where sound generated by an oscillator is passed through a series of filters and amplifers before being sent to a speaker. These first machines had physical modules through which electrical signals were passed. These modules can be emulated …

Programming Active Networks Using Active Pipes, Ralph Keller, Jeyashankher Ramamirtham, Tilman Wolf, Bernhard Plattner

All Computer Science and Engineering Research

Active networks allow customized processing of data traffic within the network which can be used by applications to improve the quality of their sessions. To simplify development of active applications in a heterogeneous environment, we propose active network pipes as a programming abstraction to specify transmission and processing requirements. We describe a routing algorithm that maps application session requirements onto network resources and determines an optimal route through the network transiting all required processing sites. Additionally, we propose a network software architecture to implement the functionality required to support active pipes.

Design Tradeoffs For Embedded Network Processors, Tilman Wolf, Mark Franklin, Edward W. Spitznagel

All Computer Science and Engineering Research

Demands for flexible processing has moved general-purpose processing into the data path of networks. With the development of System-On-a-Chip technology, it is possible to put several processors with memory and I/O components on a single ASIC. We present a model of such a system with a simple performance metric and show how the number of processors and cache sizes can be optimized for a given workload. Based on a telecommunications benchmark we show the results of such an optimization and discuss how specialied hardware and appropriate scheduling can further improve system performance.

Profile-Based Routing: A New Framework For Mpls Traffic Engineering, Subhash Suri, Marcel Waldvogel, Priyank Ramesh Warkhede

All Computer Science and Engineering Research

We present a new algorithm and framework for dynamic routing of bandwidth guaranteed flows. The problem is motivated by the need to dynamically set up bandwidth guaranteed paths in carrier and ISP networks. Traditional routing algorithms such as minimum hop routing or widest path routing do not take advantage of any knowledge about the traffic distribution or ingress-egress pairs, and therefore can often lead to severe network underutilization. Our work is inspired by the recently proposed "minimum interference routing" algorithm (MIRA) of Kodialam and Lakshman, but it improves on their approach in several ways. Our main idea is to use …

Almi: An Application Level Multicast Infrastructure, Dimitrios Pendarakis, Sherlia Shi, Dinesh Verma, Marcel Waldvogel

All Computer Science and Engineering Research

The IP multicast model allows scalable and efficient multi-party communication, particularly for groups of large size. However, deployment of IP multicast requires substantial infrastructure modifications and is hampered by a host of unresolved open problems such as reliability, flow and congestion control, security and access control. Motivated by these problems, we have designed and implemented ALMI, an application level group communication middleware, which does not rely on network infrastructure support and thus, allows accelerated deployment and simplified configuration at the cost of a relatively small increase in traffic load. ALMI is tailored toward support of multicast groups of relatively small …

Parallel Fpga Programming Over Backplane Chassis, John Lockwood, Tom Mclaughlin, Tom Chaney, Yuhua Chen, Fred Rosenberger, Alex Chandra, Jon Turner

All Computer Science and Engineering Research

For systems with a large number of FPGAs, where a design is instantiated across multiple FPGAs in a chassis, an efficient mechanism of programming the FPGA devices is needed. The mechanism described herein allows multiple FPGAs to be programmed across a backplane. Only a single configuration PROM is required to store the configuration for the multiple instances of the design. When the system boots, all FPGAs are programmed in parallel. This design is applicable to any system which contains a multiple board system which has instances of identical FPGA implementations distributed across the boards. Signal integrity of signals is considered.

Codeweave: Exploring Fine-Grained Mobility Of Code, Cecilia Mascolo, Gian Pietro Picco, Gruia-Catalin Roman

All Computer Science and Engineering Research

This paper explores the range of constructs and issues facing the designer of mobile code systems which allow for the unit of mobility to be finer-grained than that of execution. Mobile UNITY, a notation and proof logic for mobile computing, provides for this research a clean abstract setting, i.e., unconstrained by compilation and performance considerations traditionally associated with programming language design. Within the context of Mobile UNITY, we take the extreme view that every line of code and every variable declaration is potentially mobile, i.e., it may be duplicated and/or moved from one program contxt to another on the same …

Configuring Sessions In Programmable Networks, Sumi Choi, Jonathan Turner, Tilman Wolf

All Computer Science and Engineering Research

The provision of advanced computational services within networks is rapidly becoming both feasible and economical. We present a general approach to the problem of configuring application sessions that require intermediate processing by showing how the session configuration problem can be transformed to a conventional shortest path problem. We show, through a series of examples, that the method can be applied to a wide variety of different situations.

B. A Java Dialectic, Douglas Lyon, Frances Grodzinsky

School of Computer Science & Engineering Faculty Publications

Many books often gush over Java. People want to know, before they learn a language, what the drawbacks are for a language. They want to know what the strenghs are. After all, a computer language is just a tool. We shape our tools, and there after, our tools shape us! This chapter contains a dialog between three Java instructors. The participants are, Professors Good, Bad and Ugly. Professor Good is a strong proponent of Java. Professor Bad is a strong opponent of Java. Professor Ugly has been leaning toward the asthetic analysis of the language, particularly with an eye toward …

Security In Distributed Systems - A Framework For Different Application Types, Ingo Stengel

Theses

Security is a factor which decides upon the applicability of distributed applications. Therefore this thesis deals with security in distributed systems. The complexity of the existing distributed technologies makes it necessary to reduce the number of distributed technologies considered in this thesis, i.e. concentrating on: Java, Mobile Agents and CORBA, where only Java-based mobile agents will be considered.

After a short review of basic security principles including firewalls, existing security problems in the above mentioned distributed technologies are analysed. Additional generic problems in distributed systems are outlined.

Solutions are referring to two different areas: those regarding security problems with firewalls …

Rekabentuk Cip Pemamtapatan Data, Ismail Shah Rizal

Student Works (2000-2009)

Dokumen ini telah disiapkan untuk membuat cadangan projek Timiah Tahun Akhir yang bertajuk Rekabentuk Perkakasan Cip Pemampatan Data. Babagian pertama adalah berkenaan pengenalan yang memberi gambaran tentang tujuan, objektif dan kepenringan projek juga keperluan perkakasan dan perisian dalarn proses pembanguoan. Bahagian kedua pula, tumpuan diberikan kepada pemampatan data iaitu jenis teknik, algoritma Huffman dan contoh penggunaan Huffman. Dalarn bahagian ketiga, pengenalan terhadap perisian yang akan digunakan iaitu perisian VHDL. Bahagian keempat dokumen menyentuh tentang pendekatan pembangunan modul rekabentuk dan rekabentuk akhir perkakasan yang akan dibangunkan. Juga turut dimasukkan ialab gambarajah status bertujuan untuk memudahkan pemahaman. Dalam bahagian lima pula, implementasi …

Sistem Waktu Solat Dan Tahun Hijrah (Laman Nurani) / Sharifah Haslinda Sayed Boniamin, Sayed Boniamin Sharifah Haslinda

Student Works (2000-2009)

Sistem Waktu Solat dan Tahun Hijrah ini adalah sistem yang akan memaparkan paparan kalender terkini, pertukaran kalender dari kalender Hijrah ke kalender Gregorian dan sebaliknya, serta paparan bagi waktu solat semasa meng1kut nama bandar atau daerah yang dipilih oleh pengguna.Selain daripada itu, pengguna juga dapat mengetahui perkara atau peristiwa yang penting di dalam Islam mengenai cara sambutan, kenapa diraikan, bila dan bagaimana. Sistem ini dibina berasaskan laman web, ini kerana pengguna akan lebih mudah mendapatkan sistem ini daripada internet berbanding dengan aplikasi perisian. Skop bagi sistem ini adalah merangkumi paparan waktu solat, pertukaran kalender dan juga peristiwa-peristiwa penting dalam Islam. …