A Socio-Economic Analysis of WiMAX

A Socio-Economic Analysis of WiMAX

Abstract:- The paper reports on an analysis of the WiMAX market for the purpose of positioning future contributions of WiMAX standards as part of the WiMAGIC project. The report examines nine key themes that are influencing current and future WiMAX deployments: WiMAX devices, confusion concerning WiMAX capabilities, spectrum allocation, WiMAX as 4G, WiMAX as an emerging country technology, political and regulatory factors, the economic crises, competition (WiMAX vs. LTE), and who are the WiMAX users. We conclude with a final section reviewing the potential market for any future development of WiMAX identifying a number of areas for future research. Subscribe to Complete IEEE Topics and Abstract by Email For more IEEE Topics .

Author:- European Commission’s Seventh Framework.
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Adaptive modulation systems for predicted wireless channels

Adaptive modulation systems for predicted wireless channels
Abstract:- When adaptive modulation is used to counter short-term fading in mobile radio channels, signaling delays create problems with outdated channel state information. The use of channel power prediction will improve the performance of the link adaptation. It is then of interest to take the quality of these predictions into account explicitly when designing an adaptive modulation scheme. We study the optimum design of an adaptive modulation scheme based on uncoded M-quadrature amplitude modulation, assisted by channel prediction for the flat Rayleigh fading channel. The data rate, and in some variants the transmit power, are adapted to maximize the spectral efficiency, subject to average power and bit-error rate constraints. The key issues studied here are how a known prediction error variance will affect the optimized transmission properties, such as the signal-to-noise ratio (SNR) boundaries that determine when to apply different modulation rates, and to what extent it affects the spectral efficiency. This investigation is performed by analytical optimization of the link adaptation, using the statistical properties of a particular, but efficient, channel power predictor. Optimum solutions for the rate and transmit power are derived, based on the predicted SNR and the prediction error variance.
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Author:-Falahati, S. Svensson, A. Ekman, T. Sternad, M.
Dept. of Signals & Syst., Uppsala Univ., Sweden
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Code Shift Keying Impulse Modulation for UWB Communications

Code Shift Keying Impulse Modulation for UWB Communications
Abstract:- In this paper, the system performance of M-ary code shift keying (MCSK) impulse modulation is studied in detail and compared to M-ary pulse position modulation (MPPM) under single- and multi-user scenarios. For that, bounds on the semi- analytic symbol-error rate (SER) expressions are derived and simulation studies are conducted. When practical implementations of MCSK and MPPM are considered, it is shown that MCSK can provide about 2 dB performance gain over MPPM as it reduces the effects of multipath delays on the decision variables by randomizing locations of the transmit pulse.
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Author:-Erkucuk, S.; Dong In Kim; Kyung Sup Kwak
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RFID Technology In Healthcare

RFID Technology in Healthcare

Abstract:- The RFID technology is a growing phenomenon among separate automated identification technologies. As a technology, it is used from the early 1940's, but just in the last decade, the IT (Information Technology) community and the healthcare sector have been taking more action on studying and developing the technology to correspond their requirements and needs. In this paper, we represent a short overview of the RFID technology in healthcare. We will focus on the technology itself, how it is used in different parts of healthcare and what kind of results have been found.Subscribe to Complete IEEE Topics and Abstract by Email For more IEEE Topics.

Author:-Lahtela, A.;
Dept. of Comput. Sci., Univ. of Kuopio, Kuopio, Finland
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Full Control Of A Quadrotor

Full Control Of A Quadrotor
Abstract:- The research on autonomous miniature flying robots has intensified considerably thanks to the recent growth of civil and military interest in unmanned aerial vehicles (UAV). This paper summarizes the final results of the modeling and control parts of OS4 project, which focused on design and control of a quadrotor.It introduces a simulation model which takes into account the variation of the aerodynamical coefficients due to vehicle motion. The control parameters found with this model are successfully used on the helicopter without re-tuning. The last part of this paper describes the control approach (integral backstepping) and the scheme we propose for full control of quadrotors (attitude, altitude and position). Finally, the results of autonomous take-off, hover, landing and collision avoidance are presented. Subscribe to Complete IEEE Topics and Abstract by Email For more IEEE Topics .
Author:-Bouabdallah, S. Siegwart, R.
ETH Zurich, Zurich
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Adaptive Inverse Multiplexing For Wide-Area Wireless Networks

Adaptive Inverse Multiplexing For Wide-Area Wireless Networks

Abstract:-The limited bandwidth of current wide-area wireless access networks (WWANs) is often insufficient for demanding applications, such as streaming audio or video, data mining applications, or high-resolution imaging. Inverse multiplexing is a standard application-transparent method used to provide higher end-to-end bandwidth by splitting traffic across multiple physical links, creating a single logical channel. While commonly used in ISDN and analog dialup installations, current implementations are designed for private links with stable channel characteristics. Unfortunately, most WWAN technologies use shared channels with highly variable link characteristics, including bandwidth, latency, and loss rates. This paper presents an adaptive inverse multiplexing scheme for WWAN environments, termed link quality balancing, which uses relative performance metrics to adjust traffic scheduling across bundled links. By exchanging loss rate information, we compute relative short-term available bandwidths for each link. We discuss the challenges of adaptation in a WWAN network, CDPD in particular, and present performance measurements of our current implementation of wide-area multi-link PPP (WAMP) for CDPD modems under both constant bit rate (CBR) and TCP loads.
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Author:-Snoeren, A.C.

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Design And Analysis Of A Portable High-Speed Clock Generator

Design and analysis of a portable high-speed clock generator

Abstract:-A new portable clock generator with full pull-in range and fast acquisition is presented in this paper, where it can be developed at hardware description language (HDL) to reduce design cycle as well as improve system-level integration simulation. In the proposed design, frequency tracking is performed by the “Prune-and-Search” algorithm, and the digital-controlled ring oscillator is constructed by CMOS standard cells. In order to reduce propagation delay of the loop divider, a novel structure is developed to provide a constant delay at any divider setting. In addition, input jitter can be isolated to avoid coupling by digital processing. Hence, the generated clock output becomes more clean and robust. Based on the proposed methodology, a test chip has been designed and verified on 0.6-μm CMOS process with frequency range of (360 ~ 800) MHz at 3.3 V and peak-to-peak jitter of less than 60 ps at 800 MHz/3.3 V. Subscribe to Complete IEEE Topics and Abstract by Email For more IEEE Topics .

Author:-Terng-Yin Hsu; Chung-Cheng Wang; Chen-Yi Lee


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Dynamic Search Algorithm in Unstructured Peer-to-Peer Networks

Dynamic Search Algorithm in Unstructured Peer-to-Peer Networks

Abstract:-
Designing efficient search algorithms is a key challenge in unstructured peer-to-peer networks. Flooding and random walk (RW) are two typical search algorithms. Flooding searches aggressively and covers the most nodes. However, it generates a large amount of query messages and, thus, does not scale. On the contrary, RW searches conservatively. It only generates a fixed amount of query messages at each hop but would take longer search time. We propose the dynamic search (DS) algorithm, which is a generalization of flooding and RW. DS takes advantage of various contexts under which each previous search algorithm performs well. It resembles flooding for short-term search and RW for long-term search. Moreover, DS could be further combined with knowledge-based search mechanisms to improve the search performance. We analyze the performance of DS based on some performance metrics including the success rate, search time, query hits, query messages, query efficiency, and search efficiency. Numerical results show that DS provides a good tradeoff between search performance and cost. On average, DS performs about 25 times better than flooding and 58 times better than RW in power-law graphs, and about 186 times better than flooding and 120 times better than RW in bimodal topologies. Subscribe to Complete IEEE Topics and Abstract by Email For more IEEE Topics .

Author:-Tsungnan Lin Pochiang Lin Hsinping Wang Chiahung Chen
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Design of Traffic Lights Controlling System Based on PLC and Configuration Technology

Design of Traffic Lights Controlling System Based on PLC and Configuration Technology

Abstract:-
A kind of traffic lights controlling system by using PLC was designed, and the automatic control of the traffic lights was performed by software. In the system, the original relay wiring was replaced by the program, and the hardware and software resources of PLC were used reasonably. The normally running and emergency transport were introduced in detail, and that the emergencies from the east-west and from the south-north can interlock. The traffic lights signal system was displayed with two seven-segment digital tubes in countdown order; meanwhile the wiring of hardware and PLC ladder diagram was discussed in details. The remote monitoring system of traffic lights at the crossroads was designed with configuration software MCGS, which monitored traffic lights in real-time and improved the reliability greatly. At the same time, we can change the states of the traffic lights by the configuration picture. Subscribe to Complete IEEE Topics and Abstract by Email For more IEEE Topics .

Author:- Liu Yang; Chen XianFeng;


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Feature Selection for MLP Neural Network: The Use of Random Permutation of Probabilistic Outputs

Feature Selection for MLP Neural Network: The Use of Random Permutation of Probabilistic Outputs

Abstract

This paper presents a new wrapper-based feature selection method for multilayer perceptron (MLP) neural networks. It uses a feature ranking criterion to measure the importance of a feature by computing the aggregate difference, over the feature space, of the probabilistic outputs of the MLP with and without the feature. Thus, a score of importance with respect to every feature can be provided using this criterion. Based on the numerical experiments on several artificial and real-world data sets, the proposed method performs, in general, better than several selected feature selection methods for MLP, particularly when the data set is sparse or has many redundant features. In addition, as a wrapper-based approach, the computational cost for the proposed method is modest. Subscribe to Complete IEEE Topics and Abstract by Email For more IEEE Topics .
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Improvement Of The Orthogonal Code Convolution Capabilities Using FPGA Implementation

Improvement of the orthogonal code convolution capabilities using FPGA implementation

Abstarct:

When data is stored, compressed, or communicated through a media such as cable or air, sources of noise and other parameters such as EMI, crosstalk, and distance can considerably affect the reliability of these data. Error detection and correction techniques are therefore required. Orthogonal Code is one of the codes that can detect errors and correct corrupted data. An n-bit orthogonal code has n/2 is and n/2 0s. In a previous work these properties have been exploited to detect and correct errors. In this paper we present a new methodology to enhance error detection capabilities of the orthogonal code. The technique was implemented experimentally using field programmable gate arrays (FPGA). The results show that the proposed technique improves the detection capabilities of the orthogonal code by approximately 50%, resulting in 99.9% error detection, and corrects as predicted up to (n/4-1) bits of error in the received impaired code with bandwidth efficiency.
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Regenerative Braking By Electric Hybrid Vehicles Using Super Capacitor And Power Splitting Generator

Regenerative Braking By Electric Hybrid Vehicles Using Super Capacitor And
Power Splitting Generator

Abstract:
Experimental electric hybrid car drive of the small power was implemented in the laboratory of Josef Bozek Research Center of Engine and Automotive Technology at the Technical University in Prague. The output is 7.5 kW, 0 - 6000 min-' . The super capacitor as a peak energy storage has lOOF, 56V and 400 A. It is able to accept the kinetic energy during breaking the vehicle of the mass 1500kg from the velocity 60km/hour and regenerate it during next speeding up. The laboratory measurements during regeneration are published in the paper.
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Author:Zdenek Cerovsky Pavel Mindl
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A Modeling Methodology for Real-Timemultimedia Operating Systems

A Modeling Methodology for Real-Timemultimedia Operating Systems

Real-time scheduling theory attempts to guarantee that a
real-time task set will always meet its deadlines. Historically,
there has existed a wide gap between real-time scheduling
theory and the reality of applying the theory to task sets
implemented via real-time operating systems (RTOSs). This
paper provides aftamwork to account for implementation
costs in real-time scheduling theory. In addition, an
engineering methodology that allows users and developers
to accurately model and evaluate RTOSs is presented. We
use this methodology to model three dinerent commercial
real-time operating systems that are being used in
multimedia applications. We show how to use the RTOS
scheduling models to evaluate the performance and design
of RTOSs. Subscribe to Complete IEEE Topics and Abstract by Email For more IEEE Topics .

Author :- Kevin A. Kettler, Daniel I. Katcher, anid Jay K. Strosnider'
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Intrusion Avoidance for SCADA Security in Industrial Plants

Intrusion Avoidance for SCADA Security in Industrial Plants

Abstract:
In this paper we present an overview of security threats to the cyber infrastructure of industrial and power plants and the current state of affairs of industrial and SCADA cyber security. Control systems security is of prime importance especially for energy sector. North American Electric Reliability Council (NERC) has issued mandatory rules which must be complied by 2010 by all registered power operators
in order to ensure control systems security for power plants. Cyber security assessment was conducted on ICS (Industrial control systems) of different companies for a period of four years and several vulnerabilities were identified.
Main problems included use of weak encryption, standard protocols and information disclosure using unencrypted communication among ICS hosts on the network.
Exploiting these vulnerabilities, a hacker could alter the communication between ICS and controlled equipment, resulting in malfunction. Overcoming these vulnerabilities is essential in order to protect the vital power sector in any country of the world. We present important guidelines and standards in cyber security and propose a simple intrusion detection scheme for SCADA networks.
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Coupling Thermodynamics And Mechanical Design In A Cross-Curricular Project

Coupling Thermodynamics And Mechanical Design In A Cross-Curricular Project

Abstract:
This paper describes a design-based effort to build an effective cross-curricular link between Thermodynamics and Mechanical Design -- two traditionally distinct subjects. The result was a design challenge in which the authors asked their junior engineering undergraduate students to design and build an air compressor as a project conducted simultaneously in their Thermodynamics and Mchanical Design Courses. This paper describes the design challenge, the results of this cross-curricular experiment, and future enhancements to the project.

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PLC Based Test Platform for Wind Turbine Gearbox

PLC Based Test Platform for Wind Turbine Gearbox

Abstarct:
Wind turbine gearbox is one of the most important and most expensive components of wind turbine. Once installed, it is difficult to repair. Therefore, it needs effective experiments during its design and production to meet the strict quality requirements. The test platform adopts Closure Design, which enables it to experiment two gearbox products at the same time.And thanks to the closed-loop design, the experiments are energy conservation. It's able to learn the running condition and operating parameters in real time. It can also intelligently control each system of the entire test platform, which including lubrication system, loading system, frequency converter, motor and other equipments. Besides, alarming when a problem occurs in the test platform is one function of the test platform.

Author: Zou Xinyu
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Fundamental Aspects of Near-Field Coupling Small Antennas for Wireless Power Transfer

Fundamental Aspects of Near-Field Coupling Small Antennas for Wireless Power Transfer

Abstract:
A physical limitation on the power transfer efficiency between two electrically small antennas in the near-field range is presented. By using a Z-parameter which describes the interaction between two antennas for spherical modes in connection with antenna parameters, the maximum power transfer efficiency and the optimum load impedance are shown as functions of the distance between two antennas, the radiation efficiency and the input impedance of the isolated antenna. The theory is verified by a simulation with a small helical antenna, which generates and modes, simultaneously.

Author:Jaechun Lee; Sangwook Nam;
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Dead-Time Elimination for Voltage Source Inverters

Dead-Time Elimination for Voltage Source Inverters

Abstract: A novel dead-time elimination method is presented in this paper for voltage source inverters. This method is based on decomposing of a generic phase-leg into two basic switching cells, which are configured with a controllable switch in series with
an uncontrollable diode. Therefore, dead-time is not needed. In comparison to using expensive current sensors, this method precisely determines the load current direction by detecting which anti-parallel diode conducts in a phase-leg. A low-cost diode-conduction detector is developed to measure the operating state of the anti-parallel diode. In comparison with complicated compensators, this method features simple logic and flexible implementation. This method significantly reduces the output distortion and regains the output RMS value. The principle of the proposed deadtime elimination method is described in detail. Simulation and experimental
results are given to demonstrate the validity and features of this new method.
Index Terms—Dead-time, gate drive, harmonic, phase-leg,
pulsewidth modulation (PWM) control.

Author: Lihua Chen and Fang Zheng Peng,
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