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2007

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Articles 2761 - 2790 of 3831

Full-Text Articles in Engineering

Configuring Low Cost Metanetworks On A Shared Substrate, Jing Lu, Jonathan Turner Jan 2007

Configuring Low Cost Metanetworks On A Shared Substrate, Jing Lu, Jonathan Turner

All Computer Science and Engineering Research

In a diversified internet, meta-networks (“metanets?for short) share a common substrate and offer value-added services to millions of users around the globe. Therefore, configuring low-cost metanets with links having enough bandwidth to accommodate all anticipated user traffic is critical to the success of the metanets. In this paper, we propose a novel pruning algorithm that configures metanets on any given substrate in a cost-efficient way. In contrast to other testbed configuration systems, we solve the metanet configuration problem from a higher level specification and produces a network that is dimensioned to handle the specified traffic. To the best of our …


Combined Controllers That Follow Imperfect Input Motions For Humanoid Robots, Gazihan Alankus, Burchan O. Bayazit Jan 2007

Combined Controllers That Follow Imperfect Input Motions For Humanoid Robots, Gazihan Alankus, Burchan O. Bayazit

All Computer Science and Engineering Research

Humanoid robots have the potential to become a part of everyday life as their hardware and software challenges are being solved. In this paper we present a system that gets as input a motion trajectory in the form of motion capture data, and produces a controller that controls a humanoid robot in real-time to achieve a motion trajectory that is similar to the input motion data. The controller expects the input motion data not to be dynamically feasible for the robot and employs a combined controller with corrective components to keep the robot balanced while following the motion. Since the …


Link Layer Support For Unified Radio Power Management In Wireless Sensor Networks, Master's Thesis, May 2007, Kevin Klues Jan 2007

Link Layer Support For Unified Radio Power Management In Wireless Sensor Networks, Master's Thesis, May 2007, Kevin Klues

All Computer Science and Engineering Research

Radio power management is of paramount concern in wireless sensor networks that must achieve long lifetimes on scarce amounts of energy. While a multitude of power management protocols have been proposed in the past, the lack of system support for flexibly integrating them with a diverse set of applications and network platforms has made them difficult to use. Instead of proposing yet another power management protocol, this thesis focuses on providing link layer support towards realizing a Unified Power Management Architecture (UPMA) for flexible radio power management in wireless sensor networks. In contrast to the monolithic approaches adopted by existing …


Mobile Wireless Sensor Network Connectivity Repair With K-Redundanc, Nuzhet Atay, Burchan Bayazit Jan 2007

Mobile Wireless Sensor Network Connectivity Repair With K-Redundanc, Nuzhet Atay, Burchan Bayazit

All Computer Science and Engineering Research

Connectivity is an important requirement for wireless sensor networks especially in real-time monitoring and data transfer applications. However, node movements and failures change the topology of the initial deployed network, which can result in partitioning of the communication graph. In this paper, we present a method for maintaining and repairing the communication network of a dynamic mobile wireless sensor network. We assume that we cannot control the motion of wireless sensor nodes, but there are robots whose motion can be controlled by the wireless sensor nodes to maintain and repair the connectivity of the network. At the heart of our …


Curing Regular Expressions Matching Algorithms From Insomnia, Amnesia, And Acalulia, Sailesh Kumar, Balakrishnan Chandrasekaran, Jonathan Turner, George Varghese Jan 2007

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 …


Optimal Discrete Rate Adaptation For Distributed Real-Time Systems, Yingming Chen, Chenyang Lu, Xenofon Kutsoukos Jan 2007

Optimal Discrete Rate Adaptation For Distributed Real-Time Systems, Yingming Chen, Chenyang Lu, Xenofon Kutsoukos

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 variations such as dynamic task arrivals. Through offline preprocessing MPRA transforms an NP-hard utility optimization problem to the evaluation of a piecewise linear function of the CPU utilization. At run time MPRA produces optimal solutions by evaluating the function based on the CPU …


Context-Aware Publish Subscribe In Mobile Ad Hoc Networks, Davide Frey, Gruia-Catalin Roman Jan 2007

Context-Aware Publish Subscribe In Mobile Ad Hoc Networks, Davide Frey, Gruia-Catalin Roman

All Computer Science and Engineering Research

The publish-subscribe communication paradigm is enjoying increasing popularity thanks to its ability to simplify the development of complex distributed applications. However, existing solutions in the publish-subscribe domain address only part of the challenges associated with the development of applications in dynamic scenarios such as mobile ad hoc networks. Mobile applications must be able to assist users in a variety of situations, responding not only to their inputs but also to the characteristics of the environment in which they operate. In this paper, we address these challenges by extending the publish-subscribe paradigm with the ability to manage and exploit context information …


Roadmap Analysis Of Protein-Protein Interactions. Master's Thesis, August 2007, Brian C. Haynes Jan 2007

Roadmap Analysis Of Protein-Protein Interactions. Master's Thesis, August 2007, Brian C. Haynes

All Computer Science and Engineering Research

The ability to effectively model the interaction between proteins is an important and open problem. In molecular biology it is well accepted that from sequence arises form and from form arises function but relating structure to function remains a challenge. The function of a given protein is defined by its interactions. Likewise a malfunction or a change in protein-protein interactions is a hallmark of many diseases. Many researchers are studying the mechanisms of protein-protein interactions and one of the overarching goals of the community is to predict whether two proteins will bind, and if so what the final conformation will …


Packet Buffer Management For A High-Speed Network Interface Card, Shalini Batra, Yul Chu, Yan Bai Jan 2007

Packet Buffer Management For A High-Speed Network Interface Card, Shalini Batra, Yul Chu, Yan Bai

Electrical and Computer Engineering Faculty Publications

Packet buffers in a smart network interface card are managed in a way to reduce any packet losses from high-speed burst incoming data. Currently, two types of packet buffer management techniques are used. They are static buffer management and dynamic buffer management techniques. Dynamic buffer management techniques are more efficient than the static ones because they change the threshold value according to network traffic conditions. However, current dynamic techniques cannot adjust threshold instantaneously. Thus, packet losses with dynamic techniques are still high. We, therefore, propose a history-based buffer management scheme to address the issue. Our experiment results show that the …


Ceg 477/677-01: Computer Graphics Ii, John A. Reisner Jan 2007

Ceg 477/677-01: Computer Graphics Ii, John A. Reisner

Computer Science & Engineering Syllabi

No abstract provided.


Ceg 210-01: Pc Networking I, Karen Meyer Jan 2007

Ceg 210-01: Pc Networking I, Karen Meyer

Computer Science & Engineering Syllabi

Introduction to PC networking hardware, concepts, and technologies. Focus is on LAN administration, hardware and software configuration.


Ceg 434/634-01: Concurrent Software Design, Natsuhiko Futamura Jan 2007

Ceg 434/634-01: Concurrent Software Design, Natsuhiko Futamura

Computer Science & Engineering Syllabi

No abstract provided.


Ceg 260-01: Digital Computer Hardware, Sridhar Ramachandran Jan 2007

Ceg 260-01: Digital Computer Hardware, Sridhar Ramachandran

Computer Science & Engineering Syllabi

Digital Computer Hardware. Topics include switching algebra and switching functions, logic design of combinational and sequential circuits using TTL, combinational logic design with MSI and LSI, busing, storage elements, and instrumentation. 3 hours lecture, 2 hours lab. Prerequisite: CS 241.


A Hybrid Simulation Model For Studying Acute Inflammatory Response, Wayne W. Wakeland, Louis Macovsky, Gary An Jan 2007

A Hybrid Simulation Model For Studying Acute Inflammatory Response, Wayne W. Wakeland, Louis Macovsky, Gary An

Complex Systems Faculty Publications and Presentations

The modeling of complex biological systems presents a significant challenge. Central to this challenge is striking a balance between the degree of abstraction required to facilitate analysis and understanding, and the degree of comprehensiveness required for fidelity of the model to its reference-system. It is likely necessary to utilize multiple modeling methods in order to achieve this balance. Our research created a hybrid simulation model by melding an agent-based model of acute local infection with a system dynamics model that reflects key systemic properties. The agent based model was originally developed to simulate global inflammation in response to injury or …


Measuring The Accuracy Of Predictions From Patient-Specific Models Of Intracranial Pressure Dynamics, Wayne W. Wakeland Jan 2007

Measuring The Accuracy Of Predictions From Patient-Specific Models Of Intracranial Pressure Dynamics, Wayne W. Wakeland

Complex Systems Faculty Publications and Presentations

Objective: Determine the prediction capability of a computer model of Intracranial pressure (ICP) dynamics.


Method And Apparatus For Improved Cooling Of Restistance Welding Cap, M. J. Karagoulis, R. Stevenson, Hai-Lung Tsai, P.-C. Wang Jan 2007

Method And Apparatus For Improved Cooling Of Restistance Welding Cap, M. J. Karagoulis, R. Stevenson, Hai-Lung Tsai, P.-C. Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

According to the invention a hollow cylindrical shank of electrically conducting metal is connected to a resistance welder. A coolant supply tube passes through the shank and has an interior coolant supply passage. The coolant supply tube has an outer diameter less than the inner diameter of the hollow cylindrical shank. A weld cap seats on the shank and has a cap tip and a cap skirt that depends from the cap tip and is attached to the shank. An underside of the cap tip faces the shank and the supply tube. A coolant receiving bore formed into the underside …


Method Of Metallurgically Bonding Articles And Article Therefor, L. G. Hector Jr, Hai-Lung Tsai, P.-C. Wang Jan 2007

Method Of Metallurgically Bonding Articles And Article Therefor, L. G. Hector Jr, Hai-Lung Tsai, P.-C. Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An article suitable for arc-welded metallurgical bonding having a first part having a lower surface, and a second part having an upper surface is disclosed. The lower surface of the first part is disposed at the upper surface of the second part to provide for a faying surface thereat. The faying surface has a plurality of channels with a depth equal to or greater than about 1 micron and equal to or less than about 1000 microns. The article is suitable for arc-welded metallurgical bonding at the faying surface. The plurality of channels has a repetitive pattern of channels arranged …


Method And System For Far-Field Microscopy To Exceeding Diffraction-Limit Resolution, C. Ya, Hai-Lung Tsai Jan 2007

Method And System For Far-Field Microscopy To Exceeding Diffraction-Limit Resolution, C. Ya, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The bio-sample (e.g., a live cell) is labeled with a proper number of nanoparticles. Each nanoparticle is pre-co-doped with a controlled ratio of fluorophore donors and acceptors. Two laser pulses are applied to the bio-sample. The first laser pulse has a center wavelength near the peak of absorption spectrum of acceptors. The intensity of first laser pulse is adjusted such that FRET saturation occurs near the center of the focal spot. The focal spot of the first laser pulse is a diffraction-limited Airy disk that has the highest laser intensity in the center of the focal spot. The second laser …


Flow Field And Heat Transfer Analyses Of Mechanical Seals, Zhaogao Luan Jan 2007

Flow Field And Heat Transfer Analyses Of Mechanical Seals, Zhaogao Luan

LSU Doctoral Dissertations

Mechanical seals are widely used in rotating equipment such as pumps, turbines and agitators to prevent leakage. One crucial factor for keeping seals reliable is the thermal behavior of the seal rings. The existing literature on thermal effects in seals primarily concentrates on the conduction of heat into the rings. Yet, a more complete analysis requires understanding of the flow field around the rings. In this dissertation, both the laminar and turbulent flows within the seal chamber are studied and their effects on the heat transfer in the seal rings are evaluated. Based on extensive sets of numerical simulations, heat …


Fracture Toughness Of Ceramic Moulds For Investment Casting With Ice Patterns, Qingbin Liu, Ming-Chuan Leu, Von Richards Jan 2007

Fracture Toughness Of Ceramic Moulds For Investment Casting With Ice Patterns, Qingbin Liu, Ming-Chuan Leu, Von Richards

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ice patterns can be used to make ceramic investment moulds for metal castings. Owing to the characteristics of ice, the ceramic mould must be made at subzero temperatures and consequently, requires a different formulation than shells built at room temperature. Success of this process depends greatly on the fracture toughness of mould materials. The present paper describes the experimental results of fracture toughness of mould materials processed from different compositions. The Taguchi method was used to reduce the trial runs. The parameters considered included the ratio of fibre containing fused silica and aluminosilicate powders, the volume of binder and the …


Product Family Design Knowledge Representation, Aggregation, Reuse, And Analysis, Jyotirmaya Nanda, Henri Thevenot, Timothy W. Simpson, Robert B. Stone, Matt R. Bohm, Steven B. Shooter Jan 2007

Product Family Design Knowledge Representation, Aggregation, Reuse, And Analysis, Jyotirmaya Nanda, Henri Thevenot, Timothy W. Simpson, Robert B. Stone, Matt R. Bohm, Steven B. Shooter

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A flexible information model for systematic development and deployment of product families during all phases of the product realization process is crucial for product-oriented organizations. In current practice, information captured while designing products in a family is often incomplete, unstructured, and is mostly proprietary in nature, making it difficult to index, search, refine, reuse, distribute, browse, aggregate, and analyze knowledge across heterogeneous organizational information systems. To this end, we propose a flexible knowledge management framework to capture, reorganize, and convert both linguistic and parametric product family design information into a unified network, which is called a networked bill of material …


Optimal Neuro-Controller Synthesis For Impulse-Driven System, Xiaohua Wang, S. N. Balakrishnan Jan 2007

Optimal Neuro-Controller Synthesis For Impulse-Driven System, Xiaohua Wang, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents a new controller design technique for systems driven with impulse inputs. Necessary conditions for optimal impulse control are derived. A neural network structure to solve the resulting equations is presented. The solution concepts are illustrated with a few example problems that exhibit increasing levels of difficulty. Two linear problems-one scalar and one vector-and a benchmark nonlinear problem-Van Der Pol oscillator-are used as case studies. Numerical results show the efficacy of the new solution process for impulse driven systems. Since the theoretical development and the design technique are free from restrictive assumptions, this technique is applicable to many …


Analysis Of A Small-Signal Model Of A Pwm Dc-Dc Buck-Boost Converter In Ccm, Julie Joann Lee Jan 2007

Analysis Of A Small-Signal Model Of A Pwm Dc-Dc Buck-Boost Converter In Ccm, Julie Joann Lee

Browse all Theses and Dissertations

The objective of this research is to analyze and simulate the pulse-width-modulated (PWM) dc-dc buck-boost converter and design a controller to gain stability for the buck-boost converter. The PWM dc-dc buck-boost converter reduces and/or increases dc voltage from one level to a another level in devices that need to, at different times or states, increase or decrease the output voltage.

In this thesis, equations for transfer funtions for a PWM dc-dc open-loop buck-boost converter operating in continuous-conduction-mode (CCM) are derived. For the pre-chosen design, the open-loop characterics and the step responses are studied. The converter is simulated in PSpice to …


Thermal Conductivity Improvement In Carbon Nanoparticle Doped Pao Oil: An Experimental Study, Shadab Shaikh, Khalid Lafdi, Rengasamy Ponnappan Jan 2007

Thermal Conductivity Improvement In Carbon Nanoparticle Doped Pao Oil: An Experimental Study, Shadab Shaikh, Khalid Lafdi, Rengasamy Ponnappan

Chemical and Materials Engineering Faculty Publications

The present work involves a study on the thermal conductivity of nanoparticle-oil suspensions for three types of nanoparticles, namely, carbon nanotubes(CNTs), exfoliated graphite (EXG), and heat treated nanofibers (HTT) with PAO oil as the base fluid. To accomplish the above task, an experimental analysis is performed using a modern light flash technique (LFA 447) for measuring the thermal conductivity of the three types of nanofluids, for different loading of nanoparticles.

The experimental results show a similar trend as observed in literature for nanofluids with a maximum enhancement of approximately 161% obtained for the CNT-PAO oil suspension. The overall percent enhancements …


Experimental Study On The Influence Of Foam Porosity And Pore Size On The Melting Of Phase Change Materials, Khalid Lafdi, Osama Mesalam Mesalhy, Shadab Shaikh Jan 2007

Experimental Study On The Influence Of Foam Porosity And Pore Size On The Melting Of Phase Change Materials, Khalid Lafdi, Osama Mesalam Mesalhy, Shadab Shaikh

Chemical and Materials Engineering Faculty Publications

Experimental study was carried out to study the phase change heat transfer within a composite of phase change material (PCM) infiltrated high thermal conductivity foam. An experimental setup was built to measure the temperature profiles and capture the melting evolution of the PCM inside aluminum foams. Aluminum foams were used as the porous material, and low melting temperature paraffin wax was used as the PCM. It was observed from the results that the system parameters of the wax/foam composite had a significant influence on its heat transfer behavior.

By using higher porosity aluminum foam, the steady-state temperature was reached faster …


Effect Of Carbon Nanofiber Heat Treatment On Physical Properties Of Polymeric Nanocomposites—Part I, Khalid Lafdi, William Fox, Matthew Matzek, Emel Yildiz Jan 2007

Effect Of Carbon Nanofiber Heat Treatment On Physical Properties Of Polymeric Nanocomposites—Part I, Khalid Lafdi, William Fox, Matthew Matzek, Emel Yildiz

Chemical and Materials Engineering Faculty Publications

The definition of a nanocomposite material has broadened significantly to encompass a large variety of systems made of dissimilar components and mixed at the nanometer scale. The properties of nanocomposite materials also depend on the morphology, crystallinity, and interfacial characteristics of the individual constituents. In the current work, vapor-grown carbon nanofibers were subjected to varying heat-treatment temperatures.

The strength of adhesion between the nanofiber and an epoxy (thermoset) matrix was characterized by the flexural strength and modulus. Heat treatment to 1800C∘ demonstrated maximum improvement in mechanical properties over that of the neat resin, while heat-treatment to higher temperatures demonstrated a …


Test 1894: John Deere 7730 Autoquad Plus, Nebraska Tractor Test Lab Jan 2007

Test 1894: John Deere 7730 Autoquad Plus, Nebraska Tractor Test Lab

Nebraska Tractor Tests

From John Deere: 7730 Series Large-Frame Tractor. At the heart of each machine is a new 6.8 L PowerTech Plus™ engine. Available Intelligent Power Management gives you up to 30 engine hp more in mobile rear PTO and transport applications – automatically.


Test 1892: John Deere 5403 Diesel 9-Speed, Nebraska Tractor Test Lab Jan 2007

Test 1892: John Deere 5403 Diesel 9-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA

The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data.

EXPLANATION OF THE TEST PROCEDURES

Purpose

The purpose of …


Test 1899: Case-Ih Magnum 245 And Mx 245 Diesel 19-Speed, Nebraska Tractor Test Lab Jan 2007

Test 1899: Case-Ih Magnum 245 And Mx 245 Diesel 19-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA

The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data.

EXPLANATION OF THE TEST PROCEDURES

Purpose

The purpose of …


Test 1893: John Deere 7630 Autoquad-Plus 20-Speed, Nebraska Tractor Test Lab Jan 2007

Test 1893: John Deere 7630 Autoquad-Plus 20-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA

The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data.

EXPLANATION OF THE TEST PROCEDURES

Purpose

The purpose of …