GaAs Mach－Zehnder型光波导开关／调制器

采用非对称Ｘ结耦合器代替传统的Ｙ分支器，研制了ＧａＡｓＭａｃｈ－Ｚｅｈｎｄｅｒ型２×２光开光，得到了小于－２２．４ｄＢ的串音比和１２Ｖ左右的开关电压，器件的波导传输损耗小于７ｄＢ／ｃｍ。预计该器件可广泛应用于ＧａＡｓ开关列阵及高速光调制等领域。     

Switching between tasks of unequal familiarity: The role of stimulus-attribute and response-set selection.

It has been reported that it is harder to switch to a strong, well-practiced task from a weaker, less-practiced task than vice versa. Three experiments replicated this surprising asymmetry and investigated how it is affected by a reduction in interference between tasks. Experiment 1 progressively delayed the onset of the stimulus attribute associated with the stronger task. Experiments 2 and 3 separated the response sets of the tasks. Both manipulations reduced, without eliminating, interference of the stronger with the weaker task but reversed the asymmetry of switch costs, resulting in a larger cost of switching to the weaker task. The results are interpreted in terms of a model of the interactions between control input, task strength, and task priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PHS数据通信技术的发展及业务运营探讨

文章概述了个人手持电话系统(PHS)的发展过程,对其最新技术进行了介绍,并在对PHS数据通信业务的发展及运营策略进行深入分析和探讨的基础上,展望了该业务的应用前景.     

光突发交换中的冲突解决协议

文章介绍了适合于在当前技术条件下的新交换技术-光突发交换，并对光突发交换中的各种冲突解决协议进行了阐述和对比．     

在道岔缺口超标报警系统中的软件设计

介绍了SED1335的性能及特点，重点阐述了它在道岔缺口超标报警系统中显示字符、汉字、构建友好界面的软件设计方法，提出了编写液晶显示程序的一些优良算法。     

Survey of switching techniques in high-speed networks and their performance

One of the most promising approaches for high speed networks for integrated service applications is fast packet switching, or ATM (asynchronous transfer mode). ATM can be characterized by very high speed transmission links and simple, hard-wired protocols within a network. To match the transmission speed of the network links, and to minimize the overhead due to the processing of network protocols, the switching of cells is done in hardware switching fabrics in ATM networks. A number of designs have been proposed for implementing ATM switches. Although many differences exist among the proposals, the vast majority of them are based on self-routeing multistage interconnection networks. This is because of the desirable features of multi-stage interconnection networks such as self-routeing capability and suitability for VLSI implementation. Existing ATM switch architectures can be classified into two major classes: blocking switches, where blockings of cells may occur within a switch when more than one cell contends for the same internal link, and non-blocking switches, where no internal blocking occurs. A large number of techniques have also been proposed to improve the performance of blocking and non-blocking switches. In this paper, we present an extensive survey of the existing proposals for ATM switch architectures, focusing on their performance issues.     

A high-capacity broadband packet switch architecture based on a multilink approach

Broadband packet networks based on asynchronous transfer mode (ATM) are expected to provide a wide range of services, including motion video, voice, data and image. When these networks become prevalent, some applications such as motion video and high-speed LAN interconnections will place a very large bit rate requirement on the channels. Currently, the physical layer supported by the synchronous optical network (SONET) allows the transmission of up to 2.4 Gbit/s with the OC-48 optical interface. However, it is not feasible for the electronic packet switch to route packets at this rate on a single link. In this paper we present a design of a broadband packet switch that uses multiple links in parallel to realize a high-speed channel. This implementation permits the switch to operate at the lower link rate, which can be at 150 Mbit/s, while having the ability to support a virtual circuit at a higher rate (up to 2.4 Gbit/s). The main contribution of the design is that packet sequence on a channel is still maintained even though packets are allowed to use any of the links belonging to the same channel. Besides allowing the switch to function at a slower rate than the transmission channel rate, the implementation of the multilinks benefits from statistical multiplexing gain. Analytical results show the performance advantages of multilink design with respect to delay, throughput and packet loss probability.     

一种新的带优先权控制的ATM交换结构

本文在Ｋｎｏｃｋｏｕｔ交换结构的基础上，探讨一种新的ＡＴＭ交换结构，使其本身带有优先权控制功能，以适应不同业务对信元丢失率及时延的不同要求。这种结构既能最大限度地有效利用系统资源，又能满足不同用户对业务质量的不同要求，并能降低交换结构复杂度。     

一种新型半桥不对称PW M控制变换器

介绍了一种适用于DC／DC半桥变换的不对称PWM控制方案，分析了电路的工作原理，给出了150W变换器的仿真波形和实验结论，结果表明，该控制方案能在恒定开关频率下对变换器实现高效率的软开关控制。     

用C++ Builder实现数字图像的平滑处理

介绍了图像增强技术中，空间域处理方法中的邻域平均法的原理、算法，及该原理在windows平台上以C＋＋ Builder为开发工具的具体程序实现。