
text
article
2010
per

Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
1
1
http://sjce.journals.sharif.edu/article_20461_2b23a832cf863b5f0984345ecdd23b3b.pdf

text
article
2010
per

Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
2
2
http://sjce.journals.sharif.edu/article_20460_6b2986a408b7e23ec4ecacd0a5899563.pdf
COMPARATIVE ANALYSIS OF ADSL EQUALIZATION TECHNIQUES
M. Re
Pakravan
Faculty of Electrical Engineering Sharif University of Technology
author
text
article
2010
per
This paper provides an overview of equalization techniques for Discrete MultiTone (DMT) modulation systems, which are used in ADSL modems. ADSL modems are used to provide broadband connectivity to home users using the existing telephone wirelines. Noting the distortions caused by the wireline channel by the wireline channel transfer function, ADSL receivers should use equalizers to compensate the channel effects. Several different techniques have been proposed for the design and implementation of an equalization block in DMT receivers. In this article, we provide an overview of some of the key techniques, report the results of their implementation on a sample standard loop and compare their respective performances. The analyzed and compared equalization methods are: Maximum Shortened SNR, the Divide and Conquer minimization technique, Maximum Geometric SNR and the Eigen approach. Simulation results demonstrate that the eigen approach provides the best performance: This technique
can also be implemented with lower complexity compared to MGSNR technique.
Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
3
10
http://sjce.journals.sharif.edu/article_1_2a15d051a83a42aa364fcb86e104409a.pdf
DESIGNING PIECEWISE H1 CONTROLLERS FOR PIECEWISE AFFINE SYSTEMS
B.
Molaei
Faculty of Electrical Engineering Sharif University of Technology
author
M.
Mobed
Faculty of Electrical Engineering Sharif University of Technology
author
text
article
2010
per
The problem of designing a piecewise linear dynamical controller of the piecewise H1 type for a piecewise afine system has been considered. This problem corresponds to a family of H1 controller design problems. It has been shown that this set of problems can be cast as a set of convex optimization problems subject to Linear Matrix Inequality constraints that are solvable efficiently using existing software. The closed loop, consisting of the proposed controller and the piecewise affine plant, is capable of command following; subject to limitations on the energy of the control signal. Conditions may be imposed that insure the continuity of the control input to the plant. Piecewise quadratic Lyapunov functions are used to analyze closed loop stability. Performance is verified through simulation.
Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
11
19
http://sjce.journals.sharif.edu/article_2_e6a8bee9c28c376a878f662a2b9455f2.pdf
ESTIMATION OF NON SINUSOIDAL VOLTAGE EFFECTS ON THE POWER CONSUMPTION OF AN AGGREGATED LOAD ON THE BASIS OF IMPROVED LOAD MODEL
R.
Bagheri
Dept. of Electrical Engineering Amir Kabir University of Technology
author
j.
shokralahi moghani
Dept. of Electrical Engineering Amir Kabir University of Technology
author
G.
Gharehpetian
Dept. of Electrical Engineering Amir Kabir University of Technology
author
text
article
2010
per
The harmonic content of supply voltages increases the power consumption of the loads and imposes economical losses on customers. However, the level of economic effects and also the role of power quality instruments for decreasing power losses are unknown. In this paper, an improved model for aggregated loads is proposed. Based on this model, the effects of voltage harmonics on load power consumption and its economical aspects are investigated. The model parameters are identified by practical means, such as capacitor bank switching or load switching methods. The proposed model is verified by comparison of the simulated and measured results. Keywords: voltage havmonics, modeling, parameter identification, power consumption.
Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
21
29
http://sjce.journals.sharif.edu/article_3_855de097b9b1b9286d2677c08f0d3d3e.pdf
SOURCE CODED MODULATION FOR DISCRETE SOURCES WITH MEMORY
A.
Payandeh
Dept. of Electrical Engineering Malek Ashtar University of Technology
author
M.
Ahmadian
Dept. of Electrical Engineering K. N. Toosi University of Technology
author
M.R.
Aref
Faculty of Electrical EngineeringSharif University of Technology
author
text
article
2010
per
For a source with memory, the outputs of the source are not independent and, therefore, previous outputs reveal some information about future ones. These redundancies are hidden in output sequences, and cannot be used for improving the error performance of communication systems. In this paper, we present a new joint sourcechannel coding scheme for sources with memory, called source coded modulation. Source coded modulation is a scheme in which source characteristics are used to provide error protection, via an appropriate signal assignment, to each symbol of the source. In this scheme, we use the source transition matrix to plot a trellis diagram and, then, we propose an algorithm for mapping a given signal constellation on branches of this diagram, based on source statistical characteristics. Finally, we investigate a method to determine the maximum achievable error protection by using the source redundancy. Simulation results show that the proposed scheme can obtain a robust and errorresistant performance over AWGN channels, proportional to the source redundancy.
Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
31
36
http://sjce.journals.sharif.edu/article_4_b378991e21a3587d82bc22f59f648a5d.pdf
INVESTIGATION OF FAULT LOCATION EFFECT ON THE INTERAREA OSCILLATIONS IN STRESSED POWER SYSTEMS USING MODAL SERIES METHOD
A.
Hesami Naghshbandy
Dept. of Electical Engineerin University o Kurdistan
author
A.
Kazemi
Dept. of Electrical Engineering Iran University of Science & Technology
author
H. M.
Shanechi
Dept. of Electrical Engineering Illinois Institute of Technology
author
text
article
2010
per
Heavily loaded, stressed power systems exhibit complex dynamic behavior, such as auto and hetero parametric resonances and interarea oscillations, when subjected to a disturbance. These behaviors cannot be analyzed by conventional linearization based methods. Nonlinear tools, such as normal form and modal series methods, can be utilized for studying and understanding them. In this paper, using a modal series technique, the effect of fault location and duration on the dynamic performance of the stressed power systems is investigated. Three indices are defined and used to explain the effect of different fault scenarios on the transient behaviors of the system. Also, a qualitative analysis of plant mode and interarea mode type behaviors are presented and typical differences are highlighted. The numerical simulations on the IEEE 50generator test system demonstrate the validity of the investigation carried out by the modal series analysis.
Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
37
46
http://sjce.journals.sharif.edu/article_5_4d8220f8c3ec0bf643d188afa79850ac.pdf
A NOVEL CONTROL STRATEGY FOR POWER SYSTEM STABILITY IMPROVEMENT USING FUZZY LOGIC CONTROLLED STATCOM WITH DIFFERENT INPUT SIGNALS
A.R
Ghafouri
Islamic Azad University, Sari
author
M.R.
Zolghadri
Faculty of Electrical Engineering Sharif University of Technology
author
M.
Ehsan
Faculty of Electrical Engineering Sharif University of Technology
author
text
article
2010
per
Power systems are changing rapidly because of deregulation, fast demand rising and wide area expansion. Controllability and stability of power systems can be improved by proper use of FACTS devices. STATCOM is one of the parallel FACTS devices that can be used for power system transient, steady state and dynamic stability. In this research, proper control and application of STATCOM is studied for improving power system transient stability. Fuzzy logic is used to overcome the existing uncertainties and complexities of the system. The controller is designed, based on different input signals, and the results are studied by simulation results.
Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
47
56
http://sjce.journals.sharif.edu/article_6_c39475e351ef8d5de3651d8036aea78c.pdf
LINEAR DISTINGUISHING ATTACK ON A SIMPLIFIED VERSION OF WG 128
A.
Shadman
Faculty of Electrical Engineering Sharif University of Technology
author
J.
Mohajeri
Electronics Research Center Sharif University of Technology
author
M.
Salmasizadeh
Electronics Research Center Sharif University of Technology
author
text
article
2010
per
WG is a new synchronous hardware oriented stream cipher, corresponding to Profile 2 of the ECRYPT call for stream cipher primitives. Its key length is variable between 80 and 128 bits. The WG cipher has been designed to produce key stream with guaranteed randomness properties. In this paper we present a linear approximation based distinguishing attack against a simplified version (without Trace Function) of WG 128. Our attack requires 232 output words of key stream generator to distinguish the output of simplified version of WG 128 from a truly random bit sequence.
Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
57
61
http://sjce.journals.sharif.edu/article_7_ad8efa0f9eaef731ab1e999c6f304a4a.pdf
Compare the performance spectral estimation algorithms and the angle of arrival algorithm with high accuracy and low computational volume Strjdyd
Khosrow
Sadeghi

author
text
article
2010
per
This article first spectral estimation algorithms, including angle of arrival Prtvv Shkldhndhy methods based methods Zyrfza is presented. Efficient algorithms In different conditions) such as sensitivity to SNR, the number of elements, the number of input data And Hmbsthbvdn signal sources (reviewed. Also, the computational volume Different algorithms were studied. Followed by a method for improving accuracy Sources close Bhhm separation has been suggested that some of the computational volume Also has. Conducted simulations of the proposed method shows advantages.
Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
63
69
http://sjce.journals.sharif.edu/article_8_2c1f136b3d3ff306afe6e098290c4b4b.pdf

text
article
2010
per

Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
72
75
http://sjce.journals.sharif.edu/article_20457_eea77dd0528fbc9790fd2b6fa4ee8cb3.pdf

text
article
2010
per

Sharif Journal of Civil Engineering
Sharif University of Technology
26764768
دوره 25
v.
52  ویژه مهندسی برق
no.
2010
75
75
http://sjce.journals.sharif.edu/article_20456_22b22c144c55bdb5d91602f976f2af3f.pdf