PCIM, A Bridge Connecting China and World Power Electronics Industry ——Interview with Mr·Udo Weller,president of Mesago PCIM and Dr·Lorenz, General Chair of PCIM China [Honorary advisor of power Electronics]

~~PCIM, A Bridge Connecting China and World Power Electronics Industry ——Interview with Mr·Udo Weller,president of Mesago PCIM and Dr·Lorenz, General Chair of PCIM China [Honorary advisor of power Electronics]@Mr.Udo Weller$president of Mesago PCIM @Dr.Lorenz$General Chair of PCIM China [Honorary advisor of power Electronics]…     

PCIM, A Bridge Connecting China and World Power Electronics Industry-Interview with Mr. Udo Weller, president of Mesago PCEM and Dr. Lorenz, General Chair of PCIM China

PCIM China, international conference and exhibition for power electronics, was held in Shanghai on March 21, 2006. PCIM is one of the most authoritative organizations and has won good reputation overseas for a long time. To allow more Chinese readers to     

BRIEFING ON CHINA＇S SATELLITE COMMUNICATIONS PROGRESS AND FUTURE

In China.there has been tremendous progress in the area of satellite communications and its applications over the past 40years.A space segment with extensive satellite resources for fixed satellite services has been set up,and it offers high-quality services to customers in China and Asia Pacific.A satellite communications network of certain scale has been established,and it meets various business requirements and plays a complementary and extended role to the terrestrial communications network.It is also used as an effective emergency backup.At present,a large-scale satellite broadcasting and television transmission network is in service,and it has significantly contributed to broadcasting and television coverage in China.     

China＇s National Research Project on Future Internet： Objectives,Ideas, and Progresses

The Internet today was designed in 1970s and is suffering various serious issues such as security, mobility and scalability. In order to deal with these issues, a national research project, supported by the prestigious National Basic Research Program （also called the ＂973 program＂） of China, was launched in May 2007. This project adopts a clean-slate approach and aims to design a novel future Internet that not only inherits the merit of the Internet today but also overcomes the drawbacks of the current Internet. In this paper, we make an overview of this project with a focus on its objectives, basic ideas, and progresses. Although this is a basic research project, its success will bring significant benefits to China as well as all other countries in the world.     

Block coding scheme for reducing PAPR in OFDM systems with large number of subcarriers

The major drawback in Orthogonal Frequency Division Multiplexing (OFDM) system is due to the high Peak-to-Average Power Ratio (PAPR), so the performance of the system is significantly degraded by the nonlinearity of a High Power Amplifier (HPA) in the transmitter. In order to mitigate distortion, a block coding scheme for reducing PAPR in OFDM systems with large number of subcarriers based on complementary sequences and predistortion is proposed, which is capable of both error correction and PAPR reduction. Computer simulation results show that the proposed scheme significantly improves Bit Error Rate(BER) performance as compared to an uncoded system when an HPA is employed or a coded system without predistortion.     

Live-Grid Operation and Maintenance of the 35 kV/121 MVA Superconducting Cable System

A 33.5 m, 35 kV/121 MVA, three-phase, warm dielectric HTS power cable system was successfully installed and activated in China Southern Power Grid at the Puji substation in Kunming on April 19th of 2004, supplying electricity to four industrial customers （including two metallurgical refineries） and a residential population of about 100000. In this paper, we give an update on the operation and maintenance status of the system and comments on reliability issues. We conclude that the superconducting cable system is currently quite robust and feasible for particular utility applications, and it will be improved by advancement in cryogenic equipment and system technology.     

A Perspective of 3G Construction in China

1. The problems on hybrid network combining TD-SCDMA 1）Hybrid network is imperative in China At present, there are several major wireless networks in China, namely, GSM network of China Mobile, GSM network and CDMA network of China Unicom, PHS network of China Telecom and China Netcom, and therefore the seamless transition from the existent wireless network to 3G network is an inevitable factor must be taken into account. In view of the difference of release sequence and release target of 3G license, the hybrid network combining TD-SCDMA, WCDMA and CDMA2000 technology will be probably adopted in future 3G construction in China.     

Photoluminescence Spectra of Post-heat-treated Porous Silicon

Porous silicon prepared by pulse electro-etching is heat-treated in O2 atmosphere with an enhancement of its PL peak and an improvement of its PL stability. The PL peak of a sample porous silicon treated in O2 atmosphere at 1000℃ presents itself a three-peak structure and, compared with an un- heat-treated sample, there exists blue shift of ～ 40nm.     

Strengthen the Supervision over Pharmaceuticals via Modern Automatic Identification

Fake pharmaceuticals inflicts severely upon people(?)~-s health through its circulation in markets.To strengthen the supervision of the pharmaceutical market,China is improving and is perfecting its national coding system in the field of pharmaceuticals. Bar-code tag and IC tag are available to the coding system.This paper summarizes the significance of IC tag to the supervision of pharmaceuticals and gives us a strategically general prospect of pharmaceutical supervision.     

A New Weighted Least Squares Support Vector Machines and Its Sequential Minimal Optimization Algorithm

Least squares support vector machines （LSSVM） is widely used in pattern recognition and artificial intelligence domain in recent years for its efficiency in classification and regression. The solution of LSSVM is an optimization problem of a Sum squared error （SSE） cost function with only equality constraints and can be solved in a simple linear system. However, its generalization performance is sensitive to noise points and outliers that are often existent in training dataset. In order to endow robustness to LSSVM, a new method for computing weight vector of error is proposed and the substituting of weighted error vector for original error vector in LSSVM gives birth to a new weighted LSSVM. The method gets weight factor by computing distance between sample and its corresponding class center. Sequential minimal optimization （SMO） algorithm is also extended to the new method for its efficient application. Comparison experiments show superiority of the new method in terms of generalization performance, robust property and sparse approximation. Especially, the new method is much faster than the other method for large number of samples.     

Design and experiment of electronic speckle shearing phase-shifting pattern interferometer

An electronic speckle shearing phase-shifting pattern interferometer （ESSPPI） based on Michelson interferometer was based in this paper. A rotatable mirror driven by a step motor in one of its reflective arm is used to generate an adjustable shearing and the mirror driven by piezoelectric transducer （PZT） in the other reflective arm was used to realize phaseshifting. In the experiments, the deformation of an aluminum plate with the same extern-force on different positions and different forces on the same position is measured. Meanwhile, the phase distribution and phase-unwrap image of the aluminum plate with the extern-force on its center position is obtained by the four-step phase-shifting method.     

Highly precise and fast computation of the continuous signal PAR in OFDM and DMT systems

Two procedures are developed here to compute the Peak-to-Average envelope power Ratio (PAR) of the continuous signal with N subcarriers in the Orthogonal Frequency Division Multiplexing (OFDM) and Discrete MultiTone (DMT) systems. The first one is an accurate computation method for small N, in which the peak of the Instantaneous Envelope Power Function (IEPF) is obtained by solving the roots of a polynomial, a linear sum of a set of Chebyshev polynomials of the first kind and the second kind. The second procedure, called Stepwise Refinement Algorithm (SRA), is a highly precise and fast computation method for arbitrary N by using Inverse Fast Fourier Transform (IFFT), the Chirp Z-Transform (CZT) and a newly introduced relationship between the IEPF peak and its most adjacent oversampled sample.     

Address for the Beginning Issue of “RFID Technologies and Applicationsn”

Recently RFID technology got a widely attentions. As a result of this, RFID Technology and Application is published as the first professional RFID publication mainly issuing in the China and Hong Kong, Macao and Taiwan. This article summarizes the RFID characteristic, suitable applied field and its development situation and its developing reason in Asia-Pacific area. The article also presents the Magazine's target and goal, column and the future perspective.     

Power control with coder-estimator sequences

Power control is an important issue in mobile communication systems and has been studied extensively in the literature. This paper has taken on a new perspective and modeled the problem as a state estimation problem with finite communication constraints. The problem is solved by using the 1-bit mean coder-estimator sequence. The performance of the coder-estimator sequence is compared with that of the simple feedback power control technique by evaluating their respective fade margins as in commonly done in radio system engineering.     

Power allocation in cooperative MIMO systems under individual power constraints

Power allocation(PA)plays an important role in capacity improvement for cooperative multiple-input multiple-output(Co-MIMO)systems.Many contributions consider a total power constraint(TPC)on the sum of transmit power from all nodes in addressing PA problem.However,in practical implementations,each transmit node is equipped with its own power amplifier and is limited by individual power constraint(IPC).Hence these PA methods under TPC are not realizable in practical systems.Meanwhile,the PA problem under IPC is essential,but it has not been studied.This paper extends the traditional non-cooperative water-filling PA algorithm to IPC-based Co-MIMO systems.Moreover,the PA matrix is derived based on the compound channel matrix from all the cooperative nodes to the user.Therefore,the cooperative gain of the IPC-based Co-MIMO systems is fully exploited,and further the maximal instantaneous capacity is achieved.Numerical simulations validate that,under the same IPC conditions,the proposed PA scheme considerably outperforms the non-cooperative water-filling PA and uniform PA design in terms of ergodic capacity.     

Call-for-Papers

The Journal of China Universities of Posts and Telecommunications ismainly sponsored by six universities in China. They are Beijing University of Posts and Telecommunications, Nanjing University of Posts and Telecommunications, Jilin University, Chongqing University of Posts and Telecommunications, Xi' an Institute of Posts and Telecommunications, and Shijiazhuang Post and Telecommunication Technical College. The Journal is published in English quarterly and distributed globally. I…     

A fuzzy-logic control algorithm for active Queue Management in IP networks

Active Queue Management （AQM） is an active research area in the Internet community. Random Early Detection （RED） is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the predominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theoretical analysis and Network Simulator （NS） simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router＇s ability in network congestion control in IP network.     

科技简讯

SCHOTT Opens Technical Application Center in Suzhou to Support Customers in China and Around Asia New Facility to Provide Technical Application Support and to Serve as Research and Development Hub for Asia SCHOTT AG, the international technology company headquartered in Germany, is offering customers throughout Asia improved technical application support with its new Application Center Asia (ACA) located at the company's production site in Suzhou, China.     

ZTE to Install the World's Largest Optical Transmission Network

The world' s largest optical transmission network is to be completed in China following an agreement between ZTE Corporation, the fastest growing global provider of telecommunications equipment and network solutions, and China Mobile, the nation's largest mobile operator for the second construction phase. The network, due for completion by March 2006, will include 521 network nodes covering 18 provinces in Western and Southern China. The network is based on ZTE's ZXWM M900 DWDM (Dense…     

NETWORK TELECOM

commenced publication in 1999, is the network ＆ telecommu nications industry＇s leading publication in China, specializing in the field of fiber optic communications, access network, mobile communications, CATV network： cabling system and data communications; and has established its reputation by a combination of authoritative editorial content, targeting a quahty circulation covering the entire China region.