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Articles 10501 - 10530 of 12810

Full-Text Articles in Physical Sciences and Mathematics

Electronic Differential With Direct Torque Fuzzy Control For Vehicle Propulsion System, Kada Hartani, Mohamed Bourahla, Yahia Miloud, Mohamed Sekour Jan 2009

Electronic Differential With Direct Torque Fuzzy Control For Vehicle Propulsion System, Kada Hartani, Mohamed Bourahla, Yahia Miloud, Mohamed Sekour

Turkish Journal of Electrical Engineering and Computer Sciences

We model an electronic differential that will offer the best vehicle stability on a curved road. The proposed traction system consists of two permanent magnet synchronous (PMS) machines that ensure the drive of two back-driving wheels. The contribution of each wheel to the advance of the vehicle is represented by an element conveying the accumulation of mechanical coupling. The proposed control structure is based on the direct torque fuzzy control for each wheel-motor. Different simulations have been carried out: vehicle driven ons straight road, vehicle driven on straight road with slope, and vehicle driven over a road curved left and …


Conductive Emi Noise Measurement For Switched Reluctance Drive, Hao Chen, Xiaohui Qiu, Yang Zhao Jan 2009

Conductive Emi Noise Measurement For Switched Reluctance Drive, Hao Chen, Xiaohui Qiu, Yang Zhao

Turkish Journal of Electrical Engineering and Computer Sciences

The component parts of the tested four-phase Switched Reluctance drive are described with the four-phase 8/6 structure double salient reluctance motor, the four-phase asymmetric bridge power converter and the 89C52 MCU digital controller. The conductive electromagnetic interference noise measurement equipment is described with the function of separated common-mode noise and differential-mode noise. The tested results of common-mode noise and differential-mode noise of the tested Switched Reluctance drive are presented and the tested results of frequency spectrum are given.


Multicast Encryption Infrastructure For Security In Sensor Networks, Richard R. Brooks, Brijesh Pillai, Matthew Pirretti, Michele C. Weigle Jan 2009

Multicast Encryption Infrastructure For Security In Sensor Networks, Richard R. Brooks, Brijesh Pillai, Matthew Pirretti, Michele C. Weigle

Computer Science Faculty Publications

Designing secure sensor networks is difficult. We propose an approach that uses multicast communications and requires fewer encryptions than pairwise communications. The network is partitioned into multicast regions; each region is managed by a sensor node chosen to act as a keyserver. The keyservers solicit nodes in their neighborhood to join the local multicast tree. The keyserver generates a binary tree of keys to maintain communication within the multicast region using a shared key. Our approach supports a distributed key agreement protocol that identifies the compromised keys and supports membership changes with minimum system overhead. We evaluate the overhead of …


Modelling Situation Awareness For Context‐Aware Decision Support, Yu-Hong Feng, Teck-Hou Teng, Ah-Hwee Tan Jan 2009

Modelling Situation Awareness For Context‐Aware Decision Support, Yu-Hong Feng, Teck-Hou Teng, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Situation awareness modelling is popularly used in the command and control domain for situation assessment and decision support. However, situation models in real-world applications are typically complex and not easy to use. This paper presents a Context-aware Decision Support (CaDS) system, which consists of a situation model for shared situation awareness modelling and a group of entity agents, one for each individual user, for focused and customized decision support. By incorporating a rule-based inference engine, the entity agents provide functions including event classification, action recommendation, and proactive decision making. The implementation and the performance of the proposed system are demonstrated …


A Covert Encryption Method For Applications In Electronic Data Interchange, Jonathan Blackledge, Dmitry Dubovitskiy Jan 2009

A Covert Encryption Method For Applications In Electronic Data Interchange, Jonathan Blackledge, Dmitry Dubovitskiy

Articles

A principal weakness of all encryption systems is that the output data can be ‘seen’ to be encrypted. In other words, encrypted data provides a ‘flag’ on the potential value of the information that has been encrypted. In this paper, we provide a new approach to ‘hiding’ encrypted data in a digital image.

In conventional (symmetric) encryption, the plaintext is usually represented as a binary stream and encrypted using an XOR type operation with a binary cipher. The algorithm used is ideally designed to: (i) generate a maximum entropy cipher so that there is no bias with regard to any …


Analyzing The Impact Of A Virtual Machine On A Host Machine, Greg Dorn, Chris Marberry, Scott Conrad, Philip Craiger Jan 2009

Analyzing The Impact Of A Virtual Machine On A Host Machine, Greg Dorn, Chris Marberry, Scott Conrad, Philip Craiger

Publications

As virtualization becomes more prevalent in the enterprise and in personal computing, there is a great need to understand the technology as well as its ramifications for recovering digital evidence. This paper focuses on trace evidence related to the installation and execution of virtual machines (VMs) on a host machine. It provides useful information regarding the types and locations of files installed by VM applications, the processes created by running VMs and the structure and identity of VMs, ancillary files and associated artifacts.


A Novel Ep Approach For Multi-Area Economic Dispatch With Multiple Fuel Options, P. S. Manoharan, P. S. Kannan, V. Ramanathan Jan 2009

A Novel Ep Approach For Multi-Area Economic Dispatch With Multiple Fuel Options, P. S. Manoharan, P. S. Kannan, V. Ramanathan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a novel approach to multi-area economic dispatch problems with multiple fuel options using a hybrid evolutionary programming method. The objective is to minimize the operation cost of the entire system while satisfying the tie line constraints. In this paper, EP-LMO (Evolutionary Programming with Levenberg-Marquardt Optimization) technique is proposed to solve multi-area economic dispatch problems with multiple fuel options. The EP-LMO is developed in such a way that a simple evolutionary programming (EP) is applied as a base level search to find the direction of the optimal global region. And Levenberg-Marquardt Optimization (LMO) method is used as a …


Accurate Prediction Of Crosstalk For Rc Interconnects, Selahatti̇n Sayil, Merlyn Rudrapati Jan 2009

Accurate Prediction Of Crosstalk For Rc Interconnects, Selahatti̇n Sayil, Merlyn Rudrapati

Turkish Journal of Electrical Engineering and Computer Sciences

This work proposes an accurate crosstalk noise estimation method in the presence of multiple RC lines for use in design automation tools. The method correctly models the loading effects of non switching aggressors and aggressor tree branches using resistive shielding effect and realistic exponential input waveform. Noise peak and width expressions derived show very good results in comparison to HSPICE results. Results show that average error for noise peak is 4.1% and for the width is 6.8% while allowing for very fast analysis.


Softcomputing Identification Techniques Of Asynchronous Machine Parameters: Evolutionary Strategy And Chemotaxis Algorithm, Nouri Benaïdja Jan 2009

Softcomputing Identification Techniques Of Asynchronous Machine Parameters: Evolutionary Strategy And Chemotaxis Algorithm, Nouri Benaïdja

Turkish Journal of Electrical Engineering and Computer Sciences

Softcomputing techniques are receiving attention as optimisation techniques for many industrial applications. Although these techniques eliminate the need for derivatives computation, they require much work to adjust their parameters at the stage of research and development. Issues such as speed, stability, and parameters convergence remain much to be investigated. This paper discusses the application of the method of reference model to determine parameters of asynchronous machines using two optimisation techniques. Softcomputing techniques used in this paper are evolutionary strategy and the chemotaxis algorithm. Identification results using the two techniques are presented and compared with respect to the conventional simplex technique …


Analytical Regularization Method For Electromagnetic Wave Diffraction By Axially Symmetrical Thin Annular Strips, Fati̇h Di̇kmen, Yury Alexanderovich Tuchkin Jan 2009

Analytical Regularization Method For Electromagnetic Wave Diffraction By Axially Symmetrical Thin Annular Strips, Fati̇h Di̇kmen, Yury Alexanderovich Tuchkin

Turkish Journal of Electrical Engineering and Computer Sciences

A new mathematically rigorous and numerically efficient method based on the combination of Orthogonal Polynomials Method, and Analytical Regularization Method, for electromagnetic wave diffraction by a model structure for various antennae such as Fresnel zone plates is proposed. It can be used as validation tool for the other (more general or less accurate) numerical methods and physical approaches. The initial boundary value problem is equivalently reduced to the infinite system of the linear algebraic equations of the second kind, i.e. to an equation of the type (I+H) x=b in the space l_2 with compact operator H. This equation can be …


Pca Based Protection Algorithm For Transformer Internal Faults, Erdal Kiliç, Okan Özgönenel, Ömer Usta, Dave Thomas Jan 2009

Pca Based Protection Algorithm For Transformer Internal Faults, Erdal Kiliç, Okan Özgönenel, Ömer Usta, Dave Thomas

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a new protection scheme is introduced to detect and identify transformer winding faults. The new approach is based on artificial neural networks (ANNs) using radial basis functions (RBFs) and the principal component analysis (PCA). The nonlinear system's input and output data is manipulated without considering any model of the system. This approach is used to detect and identify internal short circuit faults of a three phase custom built transformer. The suggested technique is also able to distinguish between the fault and magnetizing inrush current. The test studies carried out shows that the proposed method leads to satisfactory …


Cdm Based Controller Design For Nonlinear Heat Exchanger Process, Erkan İmal Jan 2009

Cdm Based Controller Design For Nonlinear Heat Exchanger Process, Erkan İmal

Turkish Journal of Electrical Engineering and Computer Sciences

Most processes are nonlinear, and their control is a difficult yet important problem. The heat exchanger is an example onesuch nonlinear process. In the present paper, the effect of process nonlinearity on the performance of set point tracking and disturbance rejection in two controller methods is investigated. Initially, afirst order plus dead time (FOPDT) model of the process is obtainedvia a software known as Loop-Pro Trainer. Then, the PI-controller tuning values are computed using the internal model control (IMC) correlations based on truncated (first-order) Taylor series approximation. Next, another controller is designed using the coefficient diagram method (CDM). Finally, the …


Polymorphic Worm Detection Using Strong Token-Pair Signatures, Burak Bayoğlu, İbrahi̇m Soğukpinar Jan 2009

Polymorphic Worm Detection Using Strong Token-Pair Signatures, Burak Bayoğlu, İbrahi̇m Soğukpinar

Turkish Journal of Electrical Engineering and Computer Sciences

Malicious software has become a big threat to information systems, which are widely used to store, transfer and process information for many critical assets. Worms are one of the most harmful network-enabled malicious software that can threaten networks and applications. Two main characteristics of worms distinguish them from the well-known virus programs and as a result are much more dangerous than the virus programs. First, they do not need to attach themselves to an existing program. Second, worms do not require end-user interaction to realize the intended attack. Therefore, a large number of victims can be infected in a short …


Construction And Applications Of The Dirichlet-To-Neumann Operator In Transmission Line Modeling, Thomas Demeester, Daniel De Zutter Jan 2009

Construction And Applications Of The Dirichlet-To-Neumann Operator In Transmission Line Modeling, Thomas Demeester, Daniel De Zutter

Turkish Journal of Electrical Engineering and Computer Sciences

The Dirichlet-to-Neumann (DtN) operator is a useful tool in the characterization of interconnect structures. In combination with the Method of Moments, it can be used for the calculation of the per-unit length transmission line parameters of multi-conductor interconnections, or to directly determine the internal impedance of conductors. This paper presents a new and fast calculation method for the DtN boundary operator in the important case of rectangular structures, based on the superposition of parallel-plate waveguide modes. Especially for its non-differential form, some numerical issues need to be addressed. It is further explained how the DtN operator can be determined for …


Weak Penetration And Radiation Through Apertures In Conducting Bodies Of Revolution, Korkut Yeği̇n Jan 2009

Weak Penetration And Radiation Through Apertures In Conducting Bodies Of Revolution, Korkut Yeği̇n

Turkish Journal of Electrical Engineering and Computer Sciences

The simplest way to solve for penetration through small apertures in conducting surfaces is to treat the body as a scatterer and determine the interior field as the sum of the incident field and the scattered field contributed by the current induced on the surface of the body. However, it is well known that, if the aperture is very small or if the penetrated field is very weak this method yields very inaccurate results, which, in turn, prohibits proper design of electronic systems, especially for electromagnetic compatibility and interference. Previously, alternative integral equations formulations were proposed to remedy this problem …


Experimantal Characterization And Equivalent Circuit Extraction Of Nanowires For Signal Integrity Applications, Giulio Antonini, Marco Di Clerico, Antonio Orlandi, Vittorio Ricchiuti, Maurizio Passacantando, Sandro Santucci Jan 2009

Experimantal Characterization And Equivalent Circuit Extraction Of Nanowires For Signal Integrity Applications, Giulio Antonini, Marco Di Clerico, Antonio Orlandi, Vittorio Ricchiuti, Maurizio Passacantando, Sandro Santucci

Turkish Journal of Electrical Engineering and Computer Sciences

This paper illustrates the design steps of a printed circuit board used as test vehicles for the measurement of the electrical properties of carbon nanotube's deposit. The board has been built and used for the measurements. The measured data are post-processed in order to extract the required properties of the only nanotubes. An equivalent circuit is extracted for further use in EDA simulators and the IEEE P1597 Standard is used to compare the results.


Emc Education At The University Of Technology Zurich, Gökhan Apaydin, Ni̇yazi̇ Ari Jan 2009

Emc Education At The University Of Technology Zurich, Gökhan Apaydin, Ni̇yazi̇ Ari

Turkish Journal of Electrical Engineering and Computer Sciences

This paper illustrates educational issues in electromagnetic compatibility (EMC) engineering in Switzerland and presents the contents of courses and practical materials for EMC education at the University of Technology Zurich. After giving the fundamentals of theoretical part, practical applications have been given to make students and engineers aware of EMC issues and its problems.


Electromagnetic Compatibility Engineering Education: Problems, Challenges And Perspectives, Levent Sevgi̇ Jan 2009

Electromagnetic Compatibility Engineering Education: Problems, Challenges And Perspectives, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Education and training problems and challenges in EMC Engineering are discussed. The necessity of physics-based modeling (theory) and hands-on training (practice) are emphasized. An introductory level EMC lecture and a short course outline are given for modern EMC education.


Two Dimensional Ebg Structures For Multiband Noise Mitigation, Antonio Orlandi, Antonio Ciccomancini Jan 2009

Two Dimensional Ebg Structures For Multiband Noise Mitigation, Antonio Orlandi, Antonio Ciccomancini

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a two dimensional (2D) electromagnetic Bandgap (EBG) structure is proposed for multi band noise mitigation in PWR/GND plane pairs. Excellent noise suppression (-60 dB) is achieved in multiple bands within the range 0--8 GHz with a low start frequency. Because of the 2D EBG, no additional metal layer is required. Signal Integrity analysis is also studied by modelling a microstrip to stripline transition (both single ended and differential) and by evaluating insertion loss, TDR as well as eye diagram.


Development Of A Magnetic Field Model And Insertion~Into A Commercial Electromagnetic Simulator, Priscila Fernandez Lopez, Christian Arcambal, Yolanda Vives Gilabert, Abhishek Ramanujan, David Baudry, Anne Louis, Belahcene Mazari Jan 2009

Development Of A Magnetic Field Model And Insertion~Into A Commercial Electromagnetic Simulator, Priscila Fernandez Lopez, Christian Arcambal, Yolanda Vives Gilabert, Abhishek Ramanujan, David Baudry, Anne Louis, Belahcene Mazari

Turkish Journal of Electrical Engineering and Computer Sciences

To take into account~certain ElectroMagnetic Compatibility (EMC) aspects~and especially to evaluate the magnetic fields radiated by electronic components, different radiated emission models have been created. Within IRSEEM, a magnetic field model based on equivalent sources (electric dipoles) placed on a plane has been developed. Thus, this paper presents the modelling procedure that requires~magnetic near-field measurements and matrix inversion methods. Concerning the measurements of the field radiated by the component under test,~a near-field test bench with a loop antenna is used to~quantify the tangential components of the magnetic field in amplitude and phase. Then, these data are used as input to …


Electromagnetic Radiation From Multilayer Printed Circuit Boards: A 3d Fdtd-Based Virtual Emission Predictor, Gonca Çakir, Mustafa Çakir, Levent Sevgi̇ Jan 2009

Electromagnetic Radiation From Multilayer Printed Circuit Boards: A 3d Fdtd-Based Virtual Emission Predictor, Gonca Çakir, Mustafa Çakir, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

A novel FDTD-based virtual electromagnetic compatibility tool for the prediction of electromagnetic emissions from a multilayer printed circuit board is introduced. Tests are performed with characteristic structures and sample simulation results are presented.


Vlsi-Cell Placement Technique For Architecture Of Field Programmable Gate Array (Fpga) Design, Avnesh Verma, Sunil Dhingra, M. K. Soni Jan 2009

Vlsi-Cell Placement Technique For Architecture Of Field Programmable Gate Array (Fpga) Design, Avnesh Verma, Sunil Dhingra, M. K. Soni

Turkish Journal of Electrical Engineering and Computer Sciences

The Field Programmable Gate Array (FPGA) is an on field programmable device which can be designed for different applications. Various types of software are available for its synthesis. The cell placement depends upon the designing and programming languages used for FPGA. In this paper cell placement technique of FPGA architecture is analyzed for the application of Space Vector Pulse Width Modulation (SVPWM) technique used in speed control of an induction motor. The modulation pulses are produced due to the various components activated and their interconnection in Configurable Logic Blocks (CLBs). Few of its components are so analyzed to find out …


New Esd Standard And Influence On Test Equipment Requirements, Nicholas Wright Jan 2009

New Esd Standard And Influence On Test Equipment Requirements, Nicholas Wright

Turkish Journal of Electrical Engineering and Computer Sciences

The IEC61000-4 series of standards form a basic framework for the immunity and emissions testing of electrical and electronic equipment. They are the basis for EN standards used to test CE compliance of electrical and electronic products sold within the European Union. After a period of relative stability, changes are being introduced, designed to improve reliable application of the basic standards and ensure that the same results are obtained no matter where the tests are performed. Many changes relate to the calibration procedures for the test equipment. The surge standard, IEC61000-4-5, was revised at Edition 2 to amend impulse performance …


Performance-Engineered Network Overlays For High Quality Interaction In Virtual Worlds, Mart Haitjema, Ritun Patney, Jon Turner, Charlie Wiseman, John Dehart Jan 2009

Performance-Engineered Network Overlays For High Quality Interaction In Virtual Worlds, Mart Haitjema, Ritun Patney, Jon Turner, Charlie Wiseman, John Dehart

All Computer Science and Engineering Research

Overlay hosting systems such as PlanetLab, and cloud computing environments such as Amazon’s EC2, provide shared infrastructures within which new applications can be developed and deployed on a global scale. This paper ex-plores how systems of this sort can be used to enable ad-vanced network services and sophisticated applications that use those services to enhance performance and provide a high quality user experience. Specifically, we investigate how advanced overlay hosting environments can be used to provide network services that enable scalable virtual world applications and other large-scale distributed applications requiring consistent, real-time performance. We propose a novel network architecture called …


Partial Order Based Reduction In Planning: A Unifying Theory And New Algorithms, You Xi, Yixin Chen Jan 2009

Partial Order Based Reduction In Planning: A Unifying Theory And New Algorithms, You Xi, Yixin Chen

All Computer Science and Engineering Research

Partial order based reduction (POR) has recently attracted research in planning. POR algorithms reduce search space by recognizing interchangable orders between actions and expanding only a subset of all possible orders during the search. POR has been extensively studied in model checking and proved to be an enabling technique for reducing the search space and costs. Recently, two POR algorithms, including the expansion core (EC) and stratified planning (SP) algorithms, have been proposed. Being orthogonal to the development of accurate heuristic functions, these reduction methods show great potential to improve the planning efficiency from a new perspective. However, it is …


Throughput-Optimal Systolic Arrays From Recurrence Equations, Arpith C. Jacob, Jeremy D. Buhler, Roger D. Chamberlain Jan 2009

Throughput-Optimal Systolic Arrays From Recurrence Equations, Arpith C. Jacob, Jeremy D. Buhler, Roger D. Chamberlain

All Computer Science and Engineering Research

Many compute-bound software kernels have seen order-of-magnitude speedups on special-purpose accelerators built on specialized architectures such as field-programmable gate arrays (FPGAs). These architectures are particularly good at implementing dynamic programming algorithms that can be expressed as systems of recurrence equations, which in turn can be realized as systolic array designs. To efficiently find good realizations of an algorithm for a given hardware platform, we pursue software tools that can search the space of possible parallel array designs to optimize various design criteria. Most existing design tools in this area produce a design that is latency-space optimal. However, we instead wish …


A Simple Algorithm For Triconnectivity Of A Multigraph, Abusayeed Saifullah, Alper Ungor Jan 2009

A Simple Algorithm For Triconnectivity Of A Multigraph, Abusayeed Saifullah, Alper Ungor

All Computer Science and Engineering Research

Vertex-connectivity and edge-connectivity represent the extent to which a graph is connected. Study of these key properties of graphs plays an important role in varieties of computer science applications. Recent years have witnessed a number of linear time 3-edge-connectivity algorithms - with increasing simplicity. In contrast, the state-of-the-art algorithm for 3-vertex-connectivity due to Hopcroft and Tarjan lacks the simplicity in the sense of ease of implementation as well as the number of passes over the graph although its time and space complexity is theoretically linear. In this paper, we propose a linear time reduction from 3-vertex-connectivity to 3-edge- connectivity of …


Architectures For The Future Networks And The Next Generation Internet: A Survey, Subharthi Paul, Jianli Pan, Raj Jain Jan 2009

Architectures For The Future Networks And The Next Generation Internet: A Survey, Subharthi Paul, Jianli Pan, Raj Jain

All Computer Science and Engineering Research

Networking research funding agencies in the USA, Europe, Japan, and other countries are encouraging research on revolutionary networking architectures that may or may not be bound by the restrictions of the current TCP/IP based Internet. We present a comprehensive survey of such research projects and activities. The topics covered include various testbeds for experimentations for new architectures, new security mechanisms, content delivery mechanisms, management and control frameworks, service architectures, and routing mechanisms. Delay/Disruption tolerant networks, which allow communications even when complete end-to-end path is not available, are also discussed.


Scalable Scheduling Policy Design For Open Soft Real-Time Systems, Robert Glaubius, Terry Tidewell, Braden Sidoti, David Pilla, Justin Meden, Christopher Gill, William D. Smart Jan 2009

Scalable Scheduling Policy Design For Open Soft Real-Time Systems, Robert Glaubius, Terry Tidewell, Braden Sidoti, David Pilla, Justin Meden, Christopher Gill, William D. Smart

All Computer Science and Engineering Research

Open soft real-time systems, such as mobile robots, must respond adaptively to varying operating conditions, while balancing the need to perform multiple mission specific tasks against the requirement that those tasks complete in a timely manner. Setting and enforcing a utilization target for shared resources is a key mechanism for achieving this behavior. However, because of the uncertainty and non-preemptability of some tasks, key assumptions of classical scheduling approaches do not hold. In previous work we presented foundational methods for generating task scheduling policies to enforce proportional resource utilization for open soft real-time systems with these properties. However, these methods …


Robust Sensor Networks In Homes Via Reactive Channel Hopping, Mo Sha, Greg Hackmann, Chenyang Lu Jan 2009

Robust Sensor Networks In Homes Via Reactive Channel Hopping, Mo Sha, Greg Hackmann, Chenyang Lu

All Computer Science and Engineering Research

Home area networks (HANs) consisting of wireless sensors have emerged as the enabling technology for important applications such as smart energy and assisted living. A key challenge faced in deploying robust wireless sensor networks (WSNs) for home automation applications is the need to provide long-term, reliable operation in the face of the varied sources of interference found in typical residential settings. To better understand the channel dynamics in these environments, we performed an in-depth empirical study of the performance of HANs in ten real-life apartments. Our empirical study leads to several key insights into designing robust HANs for residential environments. …