Engineering Commons^™

Algorithme D’Elaboration D’Un Reseau Electrique A Gestion Optimale D’Ecoulement Des Puissances, Tarek Mesbah

Boukhemis Chetate

Un des baromètres (indicateurs du niveau d’évolution ) de développement d’un pays, est sa consommation en énergie électrique ; dont tout industrie et mode de vie des résidents en dépend. Partant sur ce point capital nous avons organisé la thèse afin de gérer le parc énergétique national d’une manière rationnelle. Cette étude peut servir dans la compréhension et l’analyse approfondie de l’état de la stabilité de notre réseau électrique, qui a montré sa fragilité après l’incident vécu le 03/02/2003, qui a prouvé l’urgence de prendre en charge toutes les insuffisances enregistrées pour éviter que cet incident se reproduise. La thèse …

A Novel Method Of Detecting Missing Parallel/Multiple Bond-Wires In Microwave Transistors That Is Amenable To Integration With Automated Test Handlers, Chin-Leong Lim

Chin-Leong Lim

A method of detecting a missing parallel-connected bond-wires in packaged microwave transistors is described. Instead of the conventional way of testing the transistor in the amplifier configuration, the new method tests the device as an oscillator. Using the oscillation frequency as the screening criterion reduces test complexity and allows easy integration with existing automated test handlers

Trends In Uspto Office Actions, Ron D. Katznelson

Ron D. Katznelson

No abstract provided.

0.5w High Linearity Power Amplifier For Broadband Wireless (3.3 ~ 3.9 Ghz), Chin-Leong Lim

Chin-Leong Lim

This paper presents a 0.5 Watt amplifier that operates over the 3.3 ~ 3.9 GHz range. The target applications are pre-driver in base-stations and power amplifier in subscriber units. The design marries good Third Order Output Intercept Point (OIP3) and exceptional Power Added Efficiency (PAE) at IdB gain compression point (PldB). The performances are: -G = 11.8 dB, IRL & ORL < -8 dB, PldB = 28.5 dBm and OIP3 = 42.6 dBm. The superior performance is achieved through the use of Avago Technologies' proprietary 0.25um GaAs Enhancement mode pHEMT process. The device requires simple matching components to achieve wide bandwidth because of the built-in input pre-match. From the reliability standpoint, pHEMT devices are eminently suited to PA use -the drain to source resistance (RDSon) will inherently rise to counteract the thermal runaway that blights bipolar and HBT PAs. The internal bias circuit is temperature compensated and can be adjusted for either class A or class AB operation. The device is housed inside a standard 16 pin LPCC 3X3 package.

Direct Torque Control Of Five-Phase Permanent Magnet Synchronous Machine, Mukhtar Ahmad

Mukhtar Ahmad

Permanent magnet synchronous machines are becoming attractive in many industrial applications due to their high torque to inertia ratio, higher efficiency , and power density . Interest in Multi-phase motor drives has considerably increased during last few years. The main applications of multi-phase machines are in electric traction, electric vehicles, and hybrid vehicles. Multi-phase motor drives have many advantages including higher reliability and power density, and lower torque pulsations at higher frequencies

Influence Of Overvoltages In Induction Motors Fed By Pwm Voltage Inverters On Power Efficiency, Boukhemis Chetate, Mohammed Tahar Belassel, Rachid Beguenane, Stéphane Simard

Boukhemis Chetate

No abstract provided.

Electric Power: Cyber And Electromagnetic Security Issues, George H. Baker

George H Baker

Electric power is essential to the functioning of U.S. society. The electric power system increasingly operates at or near its reliability limits. The geographic scale of the tightly coupled networks involved makes the system susceptible to large-scale outages. More frequent natural and accidental failures portend possible catastrophes from intentional disruption. Deregulation has been a major factor to the lack of investment in system upgrades. Techniques to prevent attacks and reduce vulnerabilities are available and affordable.

Evaluating Software Engineering Processes In Commercial And Community Open Source Projects, Tony Wasserman, Eugenio Capra

Tony Wasserman

We describe a current study for obtaining information about management of commercial and community open source projects. We have interviewed and surveyed leaders of more than 75 open source projects. Questions focused on the styles of leadership and communication, with a technical focus on testing and quality assurance processes. This paper describes the methods used to identify and contact subjects, as well as the questions posed and some results.

Designing Resource-Bounded Reasoners Using Bayesian Networks: System Health Monitoring And Diagnosis, Ole J. Mengshoel

Ole J Mengshoel

In this work we are concerned with the conceptual design of large-scale diagnostic and health management systems that use Bayesian networks. While they are potentially powerful, improperly designed Bayesian networks can result in too high memory requirements or too long inference times, to they point where they may not be acceptable for real-time diagnosis and health management in resource-bounded systems such as NASA’s aerospace vehicles. We investigate the clique tree clustering approach to Bayesian network inference, where increasing the size and connectivity of a Bayesian network typically also increases clique tree size. This paper combines techniques for analytically characterizing clique …

Continuous Improvement In Engineering Education Through Effective Value For Money Audits, Razimah Abdullah, Rozeha A Rashid, Mazlina Esa, Sadruddin Mohd Saidfudin

Razimah Abdullah

Elaboration D’Un Système Intelligent De Diagnostic Et De Surveillance En Temps Réel Des Moteurs À Induction, Djalal Eddine Khodja

Boukhemis Chetate

No abstract provided.

Development Of Measuring And Computer Interface System For An Industrial Electrostatic Precipitator, Omar H. Abdalla, Soliman M. Sharaf, Hazem F. Feshara

Omar H. Abdalla

The paper describes the design and practical implementation of a measuring and digital computer interface system for an electrostatic precipitator (ESP) filter used in a large cement factory. The objective is to develop a digital computer control system to replace an old analog controller for the ESP filter mounted on a cement production rotary kiln inside the National Cement Company. The main concern is to develop a modern technology for a real ESP controller designed and implemented locally in Egypt. The first phase of this research project is described in this paper. The computer interface system is developed to facilitate …

Emp: A National-Scale Threat To The U.S. Infrastructure, George H. Baker

George H Baker

Since the nuclear weapon atmospheric test days of the 1950s, it has been known that a single nuclear weapon detonated at altitudes from about 30-500 kilometers generates a strong electromagnetic pulse (EMP) that can disrupt electronic systems on the ground at large distances. During the Cold War, the effects of high altitude nuclear detonations were considered by many to be ephemeral, second order effects in comparison to direct blast/thermal/radiation effects from near-surface bursts in the context of mutually-assured-destruction (or MAD) scenarios. However, as infrastructure objectives have gained prominence in military operations, the likelihood of high altitude nuclear scenarios have gained …

Derivation And Application Of A Conserved Orbital Energy For The Inverted Pendulum Bipedal Walking Model, Jerry E. Pratt, Sergey V. Drakunov

Sergey V. Drakunov

New Technique Of One And Simultaneous Two Open-Switches Fault Automation Detection And Location In Two Level Three Voltage Inverter, Tarak Benslimane, Boukhemis Chetate

Boukhemis Chetate

No abstract provided.

Tackle Wideband Rf Switching With Pin Diodes, Chin-Leong Lim

Chin-Leong Lim

PIN diodes make cheaper, faster and more reliable RF switches than the mechanical competition. The two methods of constructing PIN diodes, bulk and epitaxial, result in significantly different bias current, linearity and lower frequency limit. This paper compares the wideband series switching performances of a bulk PIN diode (w = 22.5 um, Tau = 300 ns) and an epitaxial diode (w = 6.5 um, Tau = 180 ns) in similar low-cost, miniature SOD-323 packages. Through simulation and experiment, we detected significant differences in insertion loss, isolation, and third-order intercept (IP3) performances between the two diode types. In conclusion, the design …

Coordinated Control Of Uavs And Reusable Launch Vehicles, Raúl Ordóñez

Raúl Ordóñez

PI, funded by AFRL/DAGSI, $536,739, year: 2004-2007.

Managing The Business Of Software Porduct Line: An Empirical Investigation Of Key Business Factors, Faheem Ahmed, Luiz Capretz

Luiz Fernando Capretz

Business has been highlighted as one of the critical dimensions of software product line engineering. This paper's main contribution is to increase the understanding of the influence of key business factors by showing empirically that they play an imperative role in managing successful software product line.

Optimisation Des Régimes De Fonctionnement D'Un Moteur Asynchrone À Cage Entrainant Une Charge Variable, Malika Louanchi

Boukhemis Chetate

L’objectif de ce travail est l’optimisation du régime de fonctionnement des moteurs asynchrones lorsqu’ils sont sou chargés en minimisant le courant statorique absorbé en régime établit. La minimisation du courant statorique est obtenue en faisant varier la tension d’alimentation. Nous avons initialement procédé à la description et à la modélisation du moteur asynchrone, et à partir d’un schéma équivalent du moteur nous avons établit la relation liant le courant statorique minimal à la tension qui lui correspond. Pour la variation de la tension d’alimentation nous avons opté pour un gradateur triphasé à thyristors et pour un onduleur de tension à …

Using Flossmole Data In Determining Business Readiness Ratings, Tony Wasserman, Ashutosh Das

Tony Wasserman

This paper is a preliminary report on using FLOSSmole data retrieved from open source repositories (forges) to calculate Business Readiness Rating scores.

Methods And Tools For Developing Interactive Information Systems: An Historical Perspective, Tony Wasserman

Tony Wasserman

This paper describes the evolution of hardware and software technology over the past three decades, focusing on approaches for building interactive information systems and web applications. Successive generations of technology have used advances in hardware and software technology, along with increasingly sophisticated development methods and tools, to reduce development times and to produce a better user experience. After describing the key technology characteristics of each generation, this paper also describes the evolution of a specific methodology, User Software Engineering, from its origins in the 1970’s to its applicability to the development of modern applications.

On-Chip Implementation Of High Speed And High Resolution Pipeline Radix 2 Fft Algorithm, Rozita Teymourzadeh, Masuri Othman

Dr. Rozita Teymourzadeh, CEng.

Vlsi Implementation Of High Speed And High Resolution Fft Algorithm Based On Radix 2 For Dsp Application, Nooshin Mahdavi, Rozita Teymourzadeh, Masuri Othman

Dr. Rozita Teymourzadeh, CEng.

A Busy-Tone Based Mac Scheme For Wireless Ad Hoc Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu

Hong-Ning Dai

Applying directional antennas in wireless ad hoc networks offers numerous benefits, such as extended communication range, increased spatial reuse, improved capacity and suppressed interference. However, directional antennas can cause new location-dependent carrier sensing problems, such as new hidden terminal and deafness problems, which can cause severe penalties to the performance. Recently, a few schemes have been proposed to tackle these problems. However, these methods can provide limited solutions on the hidden terminal and deafness problems. We propose a new MAC protocol, termed the busy-tone based directional medium access control (BT-DMAC) protocol. When the transmission is in progress, the sender and …

A Novel Quasi-Resonant Snubber-Assisted Zcs-Pwm Dc-Dc Converter With High Frequency Link, Khairy F. A. Sayed Dr

Khairy F. A. Sayed Dr

In this paper, a novel type of auxiliary switched capacitor assisted edge resonant soft switching PWM resonant DC-DC Converter with two simple auxiliary commutation lossless inductor snubbers. The operation principle of this converter is described using the switching mode equivalent circuits. This newly developed multi resonant DC-DC Converter can regulate its dc output AC power under a principle of constant frequency edge-resonant soft switching commutation by asymmetrical PWM duty cycle control scheme. The high frequency power regulation and actual power characteristics of the proposed soft switching PWM resonant DC-DC Converter are evaluated and discussed. The operating performances of the newly …