量子力学系统与双线性系统可控性关系的对比研究

在界定了双线性系统、矩阵系统和右不变系统后,归纳出已有的3种不同系统的可控性定理,重点放在对右不变系统的可控性定理的总结以及与双线性系统可控性之间的关系上,特别强调了它们的可控性定理主要是根据李群、李代数的特性来判断的,以类似方法详细分析各种不同情况下的量子系统的可控性定理,通过对比,指出现有的有关量子系统可控性定理与双线性系统可控性定理之间的对应关系,由此揭示每一种量子系统可控性定理的适用情况以及各种不同量子系统可控性概念之间的相互关系.     

光学无源战地预警系统的应用与发展

介绍了国外无源战地预警系统的应用现状与发展趋势。无源战地预警系统主要有红外战地预警系统、紫外战地预警系统和以可见光为接收对象的光电战地预警系统。总结了各类预警系统的关键技术与性能特点,分析了预警系统的发展方向,重点展望了融合多类型无源探测技术的多谱段战地预警系统。     

Emerging optical code-division multiple access communicationsystems

All-optical systems, which perform signal processing functions optically so that the signal conversion from optical to electrical is done only when desired, are considered. Three such schemes are discussed, namely, fiber-optic code-division multiple-access (CDMA) systems, neuromorphic CDMA systems, and ultrashort-light-pulse CDMA systems. Fiber-optic CDMA systems in which incoherent optical signal processing techniques are used to establish optical CDMA systems are first examined. In particular, a novel class of sequences for incoherent fiber-optic CDMA systems, called optical orthogonal codes, are discussed. The codes are then applied to neuromorphic optical systems, and various applications of the networks are examined. Recent experiments that demonstrate the ability to encode and decode extremely fast, femtosecond optical pulses and that suggest the possibility of ultrahigh-speed CDMA systems based on ultrashort light pulses are described     

Signal Processing with Charge-Coupled Devices

The purpose of this paper is to discuss applications of charge-coupled devices in signal processing systems. Both analog and digital CCD concepts are considered. Recent developments in high-speed (~100 MHz) CCD's are discussed, and the uses of high-speed CCD and surface-acoustic wave (SAW) devices together are considered. Examples of the applications of CCD's in electro-optical systems, secure voice communication systems, sonar systems and radar systems are given. Finally, projections for future uses of CCD's in signal processing systems are presented.     

光纤电视系统

随着我国经济的发展,光纤(有线)电视系统也将在全国有一个大发展。本文将目前光纤电视技术的发展情况用深入浅出的文字作一综合叙述,其中包括光纤电视和目前无线电广播电视在质量上的比较、光纤电视系统及其布线结构。对光纤电视系统的两项重要技术:调制及多路复用,作了进一步探讨,提出了有关光纤电视系统将来在技术方面的可能发展。最后作者对我国发展光纤电视系统提出了一些看法。     

激光武器系统及相关技术分析

高能激光武器与其它常规武器相比,在速度和精确性方面具有无可比拟的优势.本文简要介绍了几种典型的高功率激光器.分析了激光武器系统的基本组成和关键技术,并对激光武器的国内外发展现状进行了综述.     

Signal processing with charge-coupled devices

The purpose of this paper is to discuss applications of charge-coupled devices in signal processing systems. Both analog and digital CCD concepts are considered. Recent developments in high-speed (∼100 MHz) CCD's are discussed, and the uses of high-speed CCD and surface-acoustic wave (SAW) devices together are considered. Examples of the applications of CCD's in electro-optical systems, secure voice communication systems, sonar systems and radar systems are given. Finally, projections for future uses of CCD's in signal processing systems are presented.     

Invariant subspace methods in linear multivariable-distributed systems and lumped-distributed network synthesis

Linear multivariable-distributed systems and synthesis problems for lumped-distributed networks are analyzed. The methods used center around the invariant subspace theory of Helson-Lax and the theory of vectorial Hardy functions. State-space and transfer function models are studied and their relations analyzed. We single out a class of systems and networks with nonrational transfer functions (scattering matrices), for which several of the well-known results for lumped systems and networks are generalized. In particular we develop the relations between singularities of transfer functions and "natural modes" of the systems, a degree theory for infinite-dimensional finear systems and a synthesis via lossless embedding of the scattering matrix. Finally coprime factorizations for this class of systems are developed. These factorizations play an essential role in the development and show that properties of Hardy functions are of fundamental importance for this class of distributed systems as properties of rational functions are for lumped systems.     

Testing HDTV terrestrial broadcasting systems

The Advanced Television Test Center (ATTC) is a private sector, nonprofit organization created to undertake full, fair, and impartial testing of the various advanced television (ATV) systems that have been proposed as the United States terrestrial broadcast standard. Cable Television Laboratories (CableLabs) organized by the cable television industry operates, in cooperation with ATTC, a state-of-the-art laboratory testing facility capable of thoroughly evaluating the proposed ATV systems when transmitted by cable TV, including both coaxial cable and fiber-optic transmission. Presently there are six systems scheduled for test by the ATTC and CableLabs. The systems and their scheduled test dates are shown. One of the systems is an enhanced NTSC compatible system and the other five are high-definition television (HDTV) simulcast systems. Four of the simulcast systems are digital. Both objective and subjective tests of all six systems are discussed     

Regulation of Photovoltaic Voltage

Manufacturing systems changed towards higher degrees of automation in the 1980s. Today's manufacturing systems again face a fundamental change. One of the key matters of this change is going to be the modularity of tomorrow's manufacturing systems. This article analyzes the industrial and technological background of this change from the perspective of a large manufacturing company in the automotive, consumer goods and automation industry. A seminal definition of modularity for manufacturing systems is given. A new categorization of manufacturing systems based on the granularity of their modules is presented. Within this categorization manufacturing systems are divided into standard-machine-based production systems, cell-based production systems, workstation-based production systems, and unit-based production systems. Advantages and disadvantages of the different concepts are discussed with respect to future requirements. Finally, challenges and trends of the future manufacturing technology are outlined.     

Minimal-cost system reliability with discrete-choice sets for components

We focus on systems whose components come from discrete choice sets. In a choice set, the alternatives have increasing cost with increasing reliability. The objective is to ensure minimal cost for achieving a specified reliability for the systems under consideration. Earlier work restricted itself to series-parallel/parallel-series (S/P) systems and provided formulations and algorithms. However, these are not amenable for dealing with more general systems. In this paper, we develop alternative formulations and algorithms based on a dynamic programming approach, and these are generalized for S/P-reducible systems. The algorithms we obtain are pseudo-polynomial and possess fully polynomial approximation schemes. Moreover, the formulations & algorithms are amenable for further generalizations to k-out-of-n : G and k-out-of-n : G-reducible systems, though we cannot claim pseudo-polynomiality in these cases. The results of this paper are useful for developing reliable systems at minimum cost. As such, the formulation & algorithms are of vital interest for systems & reliability professionals & researchers.     

偏振器件在通信和传感中的应用

偏振器件是光纤通信和光纤传感系统中的重要器件.随着光纤光学的发展,偏振器件的应用越来越广泛,并且开发出了许多新的类型.为此总结了偏振器件在光纤通信及光纤传感领域中的应用,并对偏振器件的研究方向作了展望.     

Combining multiple matchers for fingerprint verification: A case study in biosecure network of excellence

We report on experiments for the fingerprint modality conducted during the First BioSecure Residential Workshop. Two reference systems for fingerprint verification have been tested together with two additional non-reference systems. These systems follow different approaches of fingerprint processing and are discussed in detail. Fusion experiments I volving different combinations of the available systems are presented. The experimental results show that the best recognition strategy involves both minutiae-based and correlation-based measurements. Regarding the fusion experiments, the best relative improvement is obtained when fusing systems that are based on heterogeneous strategies for feature extraction and/or matching. The best combinations of two/three/four systems always include the best individual systems whereas the best verification performance is obtained when combining all the available systems.     

WDM-based local lightwave networks. I. Single-hop systems

An overview of emerging all-optical networks is given. The characteristics and alternative architectures for single-hop systems are discussed. The characteristics of lightwave technology that facilitate the design of wavelength-division-multiplexing (WDM) networks are reviewed, and it is explained how WDM local networks can be built based on the single-hop and multihop approaches. Various categories of single-hop systems are discussed: experimental systems, systems based on no pretransmission coordination, and systems based on pretransmission coordination, which also require a separate control channel. A simple classification for single-hop systems is provided     

Antenna systems for broadband wireless access

Broadband wireless access along with evolving mobile Internet and multimedia services are driving the surge of research and development activities for future wireless communication systems. We provide an overview of antenna systems for broadband wireless communications and introduce some of the important issues surrounding them. The approach we use is to first provide a general framework of how antenna systems may be utilized in wireless communication systems and then describe the antenna systems themselves. In particular, we consider antenna systems for the base station, mobile station, and then finally multiple-input multiple-output antenna systems where antenna systems are utilized at both the base and mobile stations     

Consideration on three-dimensional visual communication systems

A novel head-tracking technique for a full-color stereoscopic video display system is presented. Using this head-tracking system, the stereoscopic area is increased by a factor of three and stabilized stereoscopic images are observed. Two kinds of large-size rear-projection stereoscopic display systems that do not require special glasses are proposed. Experimental tests, confirming the effectiveness of the proposed systems, are described. By incorporating these techniques into visual communication systems, such as TV telephone systems, video conference systems, or virtual reality systems, a very natural and accurate depth sensation which cannot be obtained by conventional systems that require the viewer to wear special glasses may be possible     

Synchronous digital transmission systems based on CCITT SDHstandard

The synchronous digital hierarchy (SDH) transmission systems developed by NTT are discussed. The advantages of SDH are detailed, stressing its simplified network structure and enhanced operations, administration, and maintenance functions. The layered architecture of the SDH systems is described. NTT's SDH fiber-optic transmission systems and digital radio transmission systems are presented     

Performance comparison of FFH and MCFH spread-spectrum systems withoptimum diversity combining in frequency-selective Rayleigh fadingchannels

The performance of frequency-hopping spread-spectrum systems employing noncoherent reception and transmission diversity is analyzed for frequency-selective Rayleigh fading channels. Two different types of transmission diversity systems, a fast frequency-hopping (FFH) system and a multicarrier frequency-hopping (MCFH) system, are investigated. In order to combine received signals from transmit diversity channels, the optimum diversity combining rule based on the maximum-likelihood criterion is developed. Probability of error equations are derived, and utilized to evaluate the performance of the two systems. The MCFH systems are found to outperform FFH systems when the channel delay spread is severe, while FFH systems are superior to MCFH systems when a channel varies rapidly. Furthermore, it is found that performance enhancement due to an increase of diversity order is more significant for MCFH systems than for FFH systems in frequency-selective fading channels. The effect of frequency-selective fading is also investigated in determining optimum frequency deviations of binary frequency-shift keying signals     

Coexistence of chaos-based and conventional digital communication systems of equal bit rate

Chaos-based communication systems represent a new category of spread-spectrum communication systems, whose working principle differs significantly from conventional direct-sequence and frequency-hopping spread-spectrum systems. However, like all other kinds of spread-spectrum systems, chaos-based systems are required to provide reasonable bit error performance in the presence of a narrow-band signal which can be generated from an intruder or a coexisting conventional communication system. In particular, the frequency band of this foreign narrow-band signal can fall within the bandwidth of the chaos-based system in question. Such a scenario may occur in normal practice when chaos-based systems are introduced while the conventional systems are still in operation. It is therefore important to examine the coexistence of chaos-based and conventional systems. The objective of this paper is to evaluate the performance of the chaos-based system when its bandwidth overlaps with that of a coexisting conventional system. In particular, the chaos-based systems under study are the coherent chaos shift keying (CSK) system and the noncoherent differential CSK (DCSK) system, whereas the conventional system used in the study employs the standard binary phase shift keying scheme. Also, both the chaos-based and conventional systems are assumed to have identical data rates. Analytical expressions for the bit-error rates are derived, permitting evaluation of performance for different noise levels, power ratios and spreading factors. Finally, results from computer simulations verify the analytical findings.     

Expert systems in oncology: concepts, problems, perspectives

The architecture and fields of application of the expert systems in oncology are described. These systems allow systematization, developing and realizing the approximate knowledge, heuristics and algorithms of the expert-oncologists by the computer systems for solution of optimization problems of diagnosis and treatment of cancer patients. Principles of the functioning of expert systems are considered through the examples of solutions of concrete problems in oncology. Intellectual possibilities of the man-machine interaction under clinical conditions are discussed. The vistas of technological development of expert systems in oncology are evaluated.