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Articles 31171 - 31200 of 37017

Full-Text Articles in Engineering

Performance Analysis Of Low-Power, Short-Range Wireless Transceivers, Usha Neupane Jan 2004

Performance Analysis Of Low-Power, Short-Range Wireless Transceivers, Usha Neupane

Electronic Theses and Dissertations

To address the various emerging standards like BluetoothTM, Home RF, Wi-fiTM (IEEE 802.11), ZigBeeTM etc., in the field of wireless communications, different transceivers have been designed to operate at various frequencies such as 450 MHz, 902-920 MHz, 2.4 GHz, all part of designated ISM band. Though, the wireless systems have become more reliable, compact and easy to develop than before, a detailed performance analysis and characterization of the devices should be done. This report details the performance analysis and characterization of a popular binary FSK transceiver TRF6901 from Texas Instruments. The performance analysis of the device is done with respect …

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Effects Of Deposition Temperature And Post Deposition Annealing On The Electrical Properties Of Barium Strontium Titanate Thin Film For Embedded Capacitor Applications, Ranganathan, Ravip Peelamedu Jan 2004

Effects Of Deposition Temperature And Post Deposition Annealing On The Electrical Properties Of Barium Strontium Titanate Thin Film For Embedded Capacitor Applications, Ranganathan, Ravip Peelamedu

Electronic Theses and Dissertations

A higher degree of system level integration can be achieved by integrating the passive components into semiconductor devices, which seem to be an enabling technology for portable communication and modern electronic devices. Greater functionality, higher performance and increase in reliability can be achieved by miniaturizing and reducing the number of components in integrated circuits. The functional potential of small electronic devices can be enormously increased by implementing the embedded capacitors, resistors and inductors. This would free up surface real estate allowing either a smaller footprint or more silicon devices to be placed on the same sized substrate. This thesis focuses …

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Autonomous Robotic Automation Systemwith Vision Feedback, Jeffery Rosino Jan 2004

Autonomous Robotic Automation Systemwith Vision Feedback, Jeffery Rosino

Electronic Theses and Dissertations

In this thesis, a full design, development and application of an autonomous robotic automation system using vision feedback is performed. To realize this system, a cylindrical manipulator configuration is implemented, using a personal computer (PC) based PID controller from National Instruments. Full autonomous control will be achieved via a programmable human machine interface (HMI) developed on a PC using Borland C++ Builder. The vision feedback position control is accomplished using an ordinary "off-the-shelf" web camera. The manuscript is organized as follows; After Chapter 1, an introduction to automation history and its role in the manufacturing industry, Chapter 2 discusses and …

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Ubiquitous Map-Image Access Through Wireless Overlay Networks, Jianfei Cai, Haijie Huang, Zefeng Ni, Chang Wen Chen Jan 2004

Ubiquitous Map-Image Access Through Wireless Overlay Networks, Jianfei Cai, Haijie Huang, Zefeng Ni, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

With the availability of various wireless link-layer technologies, such as Bluetooth, WLAN and GPRS, in one wireless device, ubiquitous communications can be realized through managing vertical handoff in the environment of wireless overlay networks. In this paper, we propose a vertical handoff management system based on mobile IPv6, which can automatically manage the multiple network interfaces on the mobile device, and make decisions on network interface selection according to the current situation. Moreover, we apply our proposed vertical handoff management with JPEG-2000 codec to the wireless application of map image access. The developed system is able to provide seamless communications, …

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Speckle Denoising Using Wavelet Transforms And Higher-Order Statistics, Samuel Peter Kozaitis, Anurat Ingun Jan 2004

Speckle Denoising Using Wavelet Transforms And Higher-Order Statistics, Samuel Peter Kozaitis, Anurat Ingun

Electrical Engineering and Computer Science Faculty Publications

We reduced speckle noise in SAR imagery by retaining only those wavelet coefficients with significant third-order correlation coefficients. These coefficients were generated from the cross-correlation functions of the image and wavelet basis functions. Using this approach, we compared the results between directly applying our denoising method, and first preprocessing by taking the logarithm of an image. In our approach, we examined wavelet coefficients in an environment where the contribution from the second-order moment of the noise had been reduced.

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Antenna-Coupled Tunnel Diodes For Dual-Band Millimeter-Wave/Infrared F, Mohamed Abdel Rahman Jan 2004

Antenna-Coupled Tunnel Diodes For Dual-Band Millimeter-Wave/Infrared F, Mohamed Abdel Rahman

Electronic Theses and Dissertations

The infrared and millimeter-wave portions of the spectrum both have their advantages for development of imaging systems. Because of the difference in wavelengths, infrared imagers offer inherently high resolution, while millimeter-wave systems have better penetration through atmospheric aerosols such as fog and smoke. Shared-aperture imaging systems employing a common focal-plane array that responds to both wavebands are desirable from the viewpoint of overall size and weight. We have developed antenna-coupled sensors that respond simultaneously at 30 THz and at 94 GHz, utilizing electron-beam lithography. Slot-antenna designs were found to be particularly suitable for coupling radiation into metal-oxide-metal (MOM) tunnel diodes …

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Finite Element Analysis Of Left-Handed Waveguides, Balasubramaniam, Vellakkinar Jan 2004

Finite Element Analysis Of Left-Handed Waveguides, Balasubramaniam, Vellakkinar

Electronic Theses and Dissertations

In this work, waveguides with simultaneous negative dielectric permittivity and magnetic permeability, otherwise known as left-handed waveguides, are investigated. An approach of formulating and solving an eigenvalue problem with finite element method resulting in the dispersion relation of the waveguides is adopted in the analysis. Detailed methodology of one-dimensional scalar and two-dimensional vector finite element formulation for the analysis of grounded slab and arbitrary shaped waveguides is presented. Based on the analysis, for waveguides with conventional media, excellent agreement of results is observed between the finite element approach and the traditional approach. The method is then applied to analyze left-handed …

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Excimer Emission From Cathode Boundary Layer Discharges, Mohamed Moselhy, Karl H. Schoenbach Jan 2004

Excimer Emission From Cathode Boundary Layer Discharges, Mohamed Moselhy, Karl H. Schoenbach

Bioelectrics Publications

The excimer emission from direct current glow discharges between a planar cathode and a ring-shaped anode of 0.75 and 1.5 mm diameter, respectively, separated by a gap of 250 μm, was studied in xenon and argon in a pressure range from 75 to 760 Torr. The thickness of the “cathode boundary layer” plasma, in the 100 μm range, and a discharge sustaining voltage of approximately 200 V, indicates that the discharge is restricted to the cathode fall and the negative glow. The radiant excimer emittance at 172 nm increases with pressure and reaches a value of 4 W/cm2 for …

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Microscopic Analysis For Water Stressed By High Electric Fields In The Prebreakdown Regime, R. P. Joshi, J. Qian, K. H. Schoenbach, E. Schamiloglu Jan 2004

Microscopic Analysis For Water Stressed By High Electric Fields In The Prebreakdown Regime, R. P. Joshi, J. Qian, K. H. Schoenbach, E. Schamiloglu

Bioelectrics Publications

Analysis of the electrical double layer at the electrode-water interface for voltages close to the breakdown point has been carried out based on a static, Monte Carlo approach. It is shown that strong dipole realignment, ion-ion correlation, and finite-size effects can greatly modify the electric fields and local permittivity (hence, leading to optical structure) at the electrode interface. Dramatic enhancements of Schottky injection, providing a source for electronic controlled breakdown, are possible. It is also shown that large pressures associated with the Maxwell stress tensor would be created at the electrode boundaries. Our results depend on the ionic density, and …

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Synthesis Of Reversible Circuits From A Subset Of Muthukrishnan-Stroud Quantum Realizable Multi-Valued Gates, Marek Perkowski, Nicholas Denler, Bruce Yen, Pawel Kerntopf Jan 2004

Synthesis Of Reversible Circuits From A Subset Of Muthukrishnan-Stroud Quantum Realizable Multi-Valued Gates, Marek Perkowski, Nicholas Denler, Bruce Yen, Pawel Kerntopf

Electrical and Computer Engineering Faculty Publications and Presentations

We present a new type of quantum realizable reversible cascade. Next we present a new algorithm to synthesize arbitrary single-output ternary functions using these reversible cascades. The cascades use “Generalized Multi-Valued Gates” introduced here, which extend the concept of Generalized Ternary Gates introduced previously. While there were 216 GTGs, a total of 12 ternary gates of the new type are sufficient to realize arbitrary ternary functions. (The count can be further reduced to 5 gates, three 2-qubit and two 1-qubit). Such gates are realizable in quantum ion trap devices. For some functions, the algorithm requires fewer gates than results previously …

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A Transformation Based Algorithm For Ternary Reversible Logic Synthesis Using Universally Controlled Ternary Gates, Marek Perkowski, Eric Curtis Jan 2004

A Transformation Based Algorithm For Ternary Reversible Logic Synthesis Using Universally Controlled Ternary Gates, Marek Perkowski, Eric Curtis

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper a synthesis algorithm for reversible ternary logic cascades is presented. The algorithm can find a solution for any reversible ternary function with n inputs and n outputs utilizing ternary inverter gates and the new (quantum realizable) UCTG gates which are a powerful generalization of ternary Toffoli gates and Generalized Ternary Gates [4]. The algorithm is an extension of the algorithm presented by Dueck, Maslov, and Miller in [3]. A unique feature of this algorithm is that it utilizes no extra wires to generate the outputs. A basic compaction algorithm is defined to improve the results of the …

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Dynamic Spill Monitoring: A Coordinated Approach, Peter Jones, James K. Archibald, Randal Beard, Matthew Blake Jan 2004

Dynamic Spill Monitoring: A Coordinated Approach, Peter Jones, James K. Archibald, Randal Beard, Matthew Blake

Faculty Publications

Sponsorship: INEEL. This paper presents a coordinated control strategy for autonomous monitoring of a dynamically changing hazardous spill. The control strategy is a two level hierarchy that uses use coordination variables to communicate between the levels. The upper level is a resource allocator. The lower level consists of several "commanders" each with a possibly different objective. A physical description of the problem is given, as well as the methods of spill modeling and simulation. Tactics for locating, gravitating to and circling the spill are presented. Finally, both simulation and hardware results are given.

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Wideband Channel Model For Aeronautical Telemetry, Christian Bettweiser, Adam Davis, Michael D. Rice Jan 2004

Wideband Channel Model For Aeronautical Telemetry, Christian Bettweiser, Adam Davis, Michael D. Rice

Faculty Publications

A multipath channel model for wideband aeronautical telemetry links is presented. Channel sounding data were collected at Edwards AFB, CA, at both L-band and lower S-band. Frequency domain analysis techniques were used to evaluate candidate channel models. The channel model is composed of three propagation paths: a line-of-sight direct path and two specular reflections. The first specular reflection is characterized by a relative amplitude of 70% to 96% of the line-of-sight amplitude and a delay of 10—80 ns. This path is the result of “ground bounces” off the dry lake bed at Edwards and is a typical terrain feature at …

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The Frequency Distribution Of Quantization Error In Digitizers For Coherent Sampling, Sol Neeman Ph.D. Jan 2004

The Frequency Distribution Of Quantization Error In Digitizers For Coherent Sampling, Sol Neeman Ph.D.

Engineering Studies Faculty Publications and Creative Works

In this paper the frequency distribution of quantization error in coherent sampling of digitizers will be investigated. As the distribution of the quantization error affects the values of THD and SNR, it is relevant for a correct interpretation of THD and SNR of sine waves in coherent sampling. The distribution of the quantization error will be analyzed as a function of N, total number of samples and M, number of cycles in the sample set and it will be proved that for certain cases, the quantization error falls on odd harmonics only of the frequency of the sampled sine wave.

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A Fast And Simple Algorithm For Computing M-Shortest Paths In State Graph, M. Sherwood, Laxmi P. Gewali, Henry Selvaraj, Venkatesan Muthukumar Jan 2004

A Fast And Simple Algorithm For Computing M-Shortest Paths In State Graph, M. Sherwood, Laxmi P. Gewali, Henry Selvaraj, Venkatesan Muthukumar

Electrical & Computer Engineering Faculty Research

We consider the problem of computing m shortest paths between a source node s and a target node t in a stage graph. Polynomial time algorithms known to solve this problem use complicated data structures. This paper proposes a very simple algorithm for computing all m shortest paths in a stage graph efficiently. The proposed algorithm does not use any complicated data structure and can be implemented in a straightforward way by using only array data structure. This problem appears as a sub-problem for planning risk reduced multiple k-legged trajectories for aerial vehicles.

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Quantization With Knowledge Base Applied To Geometrical Nesting Problem, Grzegorz Chmaj, Leszek Koszalka Jan 2004

Quantization With Knowledge Base Applied To Geometrical Nesting Problem, Grzegorz Chmaj, Leszek Koszalka

Electrical & Computer Engineering Faculty Research

Nesting algorithms deal with placing two-dimensional shapes on the given canvas. In this paper a binary way of solving the nesting problem is proposed. Geometric shapes are quantized into binary form, which is used to operate on them. After finishing nesting they are converted back into original geometrical form. Investigations showed, that there is a big influence of quantization accuracy for the nesting effect. However, greater accuracy results with longer time of computation. The proposed knowledge base system is able to strongly reduce the computational time.

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Determination Of The Phase Of A Transfer Function: Theory Versus Practice, Pauline Sourdille, Aidan O'Dwyer Jan 2004

Determination Of The Phase Of A Transfer Function: Theory Versus Practice, Pauline Sourdille, Aidan O'Dwyer

Conference papers

In control systems, a way to evaluate the stability of a system is to determine the magnitude and phase of the open loop system transfer function in the frequency domain. But due to the nature of the phase expression, practice and theory are not aligned. Some problems arise when the phase is determined, caused by the properties of the arctan function. This paper analyses these phase problems for a third order lag system and a third order lag with time delay system. It also presents modifications to obtain the analytically correct phase values from the computed values.

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A Wireless Traffic Probe For Radio Resource Management And Qos Provisioning In Ieee 802.11 Wlans, Mark Davis Jan 2004

A Wireless Traffic Probe For Radio Resource Management And Qos Provisioning In Ieee 802.11 Wlans, Mark Davis

Conference papers

The emergence of real-time services such as voice over IP (VoIP) and video streaming imposes stringent requirements on the performance of a network if quality of service (QoS) targets are to be achieved. In the case of wireless networks, some form of radio resource management (RRM) is typically required to allocate the available resources among the contending stations in accordance with their needs and respective priorities. A critical aspect of any RRM scheme is the ability to monitor resource usage and to determine the resource requirements on a per-station basis. In this paper we describe a wireless traffic probe for …

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Power Coupling Between Two Step-Index Multimode Fibers Of Different Numerical Apertures With An Angular Misalignment, Cheng Gao, Gerald Farrell Jan 2004

Power Coupling Between Two Step-Index Multimode Fibers Of Different Numerical Apertures With An Angular Misalignment, Cheng Gao, Gerald Farrell

Articles

Coupling efficiency between two step- index multimode fibers of different numerical aper- tures with an angular misalignment is calculated. The theory is presented using radiometry and geometrical optics. The limit case of the calculation is consistent with a previously published result. The results may be useful for applications such as power launching between two types of fibers with different numerical apertures for example silica fiber and plastic optical fiber(POF) and with an angular misalignment.

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Neural Analysis Of Top Shielded Multilayered Coplanar Waveguides, Mustafa Türkmen, Celal Yildiz, Şeref Sağiroğlu Jan 2004

Neural Analysis Of Top Shielded Multilayered Coplanar Waveguides, Mustafa Türkmen, Celal Yildiz, Şeref Sağiroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Artificial neural networks (ANNs) have been promising tools for many applications. In recent years, a computer-aided design approach based on (ANNs) has been introduced to microwave modelling, simulation and optimization. In this work, the characteristic parameters of top shielded multilayered coplanar waveguides (CPWs) have been determined with the use of ANN models. These neural models were trained with Levenberg-Marquardt, resilient propagation, Bayesian regulation, quasi-Newton, and backpropagation learning algorithms. Better performance and learning speed with a simpler structure were achieved from these models. The results have shown that the estimated characteristic parameters are in very good agreement with the computed results …

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Mining Classification Rules By Using Genetic Algorithms With Non-Random Initial Population And Uniform Operator, Korkut Koray Gündoğan, Bi̇lal Alataş, Ali̇ Karci Jan 2004

Mining Classification Rules By Using Genetic Algorithms With Non-Random Initial Population And Uniform Operator, Korkut Koray Gündoğan, Bi̇lal Alataş, Ali̇ Karci

Turkish Journal of Electrical Engineering and Computer Sciences

Classification is a supervised learning method that induces a classification model from a database and is one of the most commonly applied data mining task. The frequently employed techniques are decision tree or neural network-based classification algorithms. This work presents an efficient genetic algorithm (GA) for classification rule mining technique that discovers comprehensible IF-THEN rules using a generalized uniform population method and a uniform operator inspired from the uniform population method. Initial population is generated by methodically eliminating the randomness by generalized uniform population method. In the subsequence generations, genetic diversity is ensured and premature convergence is prevented by the …

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A Simple And Global Optimization Algorithm For Engineering Problems: Differential Evolution Algorithm, Dervi̇ş Karaboğa, Selçuk Ökdem Jan 2004

A Simple And Global Optimization Algorithm For Engineering Problems: Differential Evolution Algorithm, Dervi̇ş Karaboğa, Selçuk Ökdem

Turkish Journal of Electrical Engineering and Computer Sciences

Differential Evolution (DE) algorithm is a new heuristic approach mainly having three advantages; finding the true global minimum regardless of the initial parameter values, fast convergence, and using few control parameters. DE algorithm is a population based algorithm like genetic algorithms using similar operators; crossover, mutation and selection. In this work, we have compared the performance of DE algorithm to that of some other well known versions of genetic algorithms: PGA, Grefensstette, Eshelman. In simulation studies, De Jong's test functions have been used. From the simulation results, it was observed that the convergence speed of DE is significantly better than …

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The 7 C'S For Creating Living Software: A Research Perspective For Quality-Oriented Software Engineering, Mehmet Akşi̇t Jan 2004

The 7 C'S For Creating Living Software: A Research Perspective For Quality-Oriented Software Engineering, Mehmet Akşi̇t

Turkish Journal of Electrical Engineering and Computer Sciences

This article proposes the 7 C's for realizing quality-oriented software engineering practices. All the desired qualities of this approach are expressed in short by the term living software. The 7 C's are: Concern-oriented processes, Canonical models, Composable models, Certifiable models, Constructible models, Closure property of models and Controllable models. Each C is explained by the help of a set of definitions, a short overview of the background work and the problems that software engineers may experience in realizing the corresponding C. Further, throughout the article, a software development example is presented for illustrating the realization of the 7 C's. Finally, …

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A Platform For Software Engineering Course Projects, Bi̇rol Aygün Jan 2004

A Platform For Software Engineering Course Projects, Bi̇rol Aygün

Turkish Journal of Electrical Engineering and Computer Sciences

The importance of projects in software engineering courses is well known. Both synthetic and real-life projects have various advantages and disadvantages. Our aim was to create a framework where students can develop projects which reflect some of the complexities of real-life, involving many concurrent, interacting, asynchronous processes, each in a different stage of development, with wide temporal differences among them - some occurring within millisconds of each other and others executing sporadically over much longer periods. In this project, which was carried out in different arrangements in several software engineering courses in three universities, the students developed both the sub- …

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A Pattern Based Approach To Web Design Formalization, Ahmet Sikici, Yasemi̇n Topaloğlu Jan 2004

A Pattern Based Approach To Web Design Formalization, Ahmet Sikici, Yasemi̇n Topaloğlu

Turkish Journal of Electrical Engineering and Computer Sciences

World Wide Web is a global information network that affects many fields of our lives. The distributed, interlinked, visual and heterogeneous structure of the web makes it an irregular development environment. In this paper we propose a pattern based approach for increasing the effectiveness of development for the Web environment. This approach is based on the representation of the core meaning of each design as a set of patterns and requires the formulation of abstract solutions in a mathematical precision. This way not only reusable design experience will be codified unambiguously, but a smooth transition between the design and implementation …

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An Agile Information Systems Development Method In Use, Mehmet Nafi̇z Aydin, Frank Harmsen, Kees Van Slooten, Robert Stegwee Jan 2004

An Agile Information Systems Development Method In Use, Mehmet Nafi̇z Aydin, Frank Harmsen, Kees Van Slooten, Robert Stegwee

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, agile information systems development methods, agile methods in short, have got considerable attention from practitioners. One of the reasons seems that agile methods, to some degree, can be adaptable to different project situations. However, little empirical research has been conducted on this subject. The major goal of this research is to identify which aspects of agile methods are perceived as most critical and difficult to realize and how such aspects are adapted in practice. To reach this goal we studied the working practices concerning the adaptation of an agile method in the IT department of one of the leading …

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A Robustness Analysis Of Game-Theoretic Cdma Power Control, Xingzhe Fan, Murat Arcak, John T. Wen Jan 2004

A Robustness Analysis Of Game-Theoretic Cdma Power Control, Xingzhe Fan, Murat Arcak, John T. Wen

Turkish Journal of Electrical Engineering and Computer Sciences

This paper studies robustness of a gradient-type CDMA uplink power control algorithm with respect to disturbances and time-delays. This problem is of practical importance because unmodeled secondary interference effects from neighboring cells play the role of disturbances, and propagation delays are ubiquitous in wireless data networks. We first show L_p-stability, for p \in [1,\infity], with respect to additive disturbances. We pursue L_{\infity}-stability within the input-to-state stability (ISS) framework of Sontag [7], which makes explicit the vanishing effect of the initial conditions. Next, using the ISS property and a loop transformation, we prove that global asymptotic stability is preserved for sufficiently …

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Global Stability Analysis Of An End-To-End Congestion Control Scheme For General Topology Networks With Delay, Tansu Alpcan, Tamer Başar Jan 2004

Global Stability Analysis Of An End-To-End Congestion Control Scheme For General Topology Networks With Delay, Tansu Alpcan, Tamer Başar

Turkish Journal of Electrical Engineering and Computer Sciences

We analyze the stability properties of an end-to-end congestion control scheme under fixed heterogeneous delays, and for general network topologies. The scheme analyzed is based on the congestion control game of [1], with the starting point being the unique Nash equilibrium of that game. We prove global stability of this solution (and hence of the congestion control algorithm) under a mild symmetricity condition. We further demonstrate the stability of the algorithm numerically for various delays, user numbers, and topologies

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Flow Controller Design And Performance Analysis For Self-Similar Network Traffic, Peng Yan Jan 2004

Flow Controller Design And Performance Analysis For Self-Similar Network Traffic, Peng Yan

Turkish Journal of Electrical Engineering and Computer Sciences

Recent studies of high-resolution traffic measurement discovered the self-similarity in both LAN and WAN traffic. In this paper, we introduce a two-degree of freedom rate based flow controller, which includes a robust H^{\infity} control block and an LMMSE based capacity predictor. The former part can guarantee the robust stability against time-varying time delay uncertainties and the latter improves the transient response by predicting the self-similar cross-traffic. Implementation issues are discussed and performance analysis is provided to validate our design. We also investigate the prediction and control in larger time scale which is more applicable for the real network environment

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Optimum And Suboptimum Blind Channel And Symbol Estimation For Siso Channels, T. Engi̇n Tuncer Jan 2004

Optimum And Suboptimum Blind Channel And Symbol Estimation For Siso Channels, T. Engi̇n Tuncer

Turkish Journal of Electrical Engineering and Computer Sciences

We present three methods for blind channel and symbol identification from a single or multi-block observation. These methods are deterministic approaches suitable for the identification of quickly changing wireless channels. The first method uses the finite alphabet property and it has good performance even for noisy observations. It requires only a single data frame, which is a unique feature of the method. This method can also be used to identify the channel order. For multi-block observations, we present the maximal ratio combining cross relation (MRCCR) method. It is an optimum approach in terms of instantaneous SNR and is based on …

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