计算机电信集成技术及其发展

本文介绍了计算机电信集成技术及其进展，特别详尽分析了它的三种实现形式：点对点形式、交换机－计算机形式、客户／服务器形式。     

Physiological cost of energy-equivalent noise exposures with a rating level of 85 dB(A):: Hearing threshold shifts associated with energetically negligible continuous and impulse noise

In industry continuous or impulse noise does not occur exclusively; rather it is a combination of both. If low-level continuous noise or impulse noise (below 120 dB) is added to an already existing high-level continuous noise this often numerically causes no essential increase in the rating level. Yet, it cannot be expected that also aural strain of these exposures is always negligible. Therefore, in a cross-over test series, ten male subjects (Ss) were exposed to white noise of 94 dB(A) for 1 h (TS I), energy-equivalent to an 8 h-rating level L_Ard of 85 dB(A). In a second test series (TS II) the same exposure was combined with 900 energetically negligible 5-ms impulses with a noise level of 113 dB(A) which increased the rating level by only 0.4 dB. The noise exposure of TS I and TS II was followed by an idealized resting phase in a soundproof cabin. In a third test series (TS III) the continuous noise of 94 dB(A) / 1 h was followed by 3 h of white noise at 70 dB(A). Such an additional load increases the L_Ard by merely 0.1 dB to 85.1 dB(A). In all three test series, the noise-induced temporary threshold shift (TTS₂) and its restitution were measured. The continuous noise exposure of 94 dB(A) for 1 h was associated with a TTS₂ of around 20 dB which disappeared completely after about 2 h. The additional impulse noise caused a small increase in the TTS₂ and a prolongation of the restitution time. The maximum mean temporary threshold shift for the group increased only slightly (from 22.5 to 25.9 dB, which nevertheless can be statistically proven at a significance level of p 0.99). Yet, more importantly, the restitution time increased from 126 to 175 min, i. e. 3 h, which can be statistically proven at a significance level of p0.95. The TTS₂-values of TS III did not differ significantly from those resulting from TS I. That was expected as the conditions up to that point in time were identical. But due to the additional subsequent exposure, the mean restitution time increased considerably from 126 min up to 240 min (4 h). The mean total physiological cost represented by the integrated restitution temporary threshold shift (IRTTS) increased in TS II by approximately 40% and in TS III even by 140%.

Relevance to industry

The results of the study show that levels of noise which have no influence on the rating level which traditionally is calculated according to the energy-equivalence principle are often of great importance, as they can lead to considerably prolonged restitution times. Therefore, the purely energy-equivalent determination of the rating level of both impulse noise and low sound levels can lead to an underestimation of latent problems so that over time a reversible TTS can evolve into a permanent threshold shift. The results are also of importance for the acoustic design of break rooms for noise-exposed workers. There should be conditions that allow an undisturbed restitution of hearing.     

基于SHDSL的IAD接入技术

单线对高比特率数字用户线(SHDSL)支持利用现有铜线对进行上、下行速率对称的宽带数据接入(在相类似的技术中,其性能最佳)。综合接入设备(IAD)完成各种网络终端的统一接入,并将这些话音、数据等多种业务融合在一起,统一实现各自的功能。将这两项技术完美地结合,可为NGN提供一种全新地宽带接入方式。文章主要分析了基于SHDSL的IAD接入的网络结构、SHDSL功能模型、用户数据的映射和封装,以及基于SHDSL的IAD技术应用前景。     

基于FPGA的RapidIO核接口芯片的设计和实现

新型嵌入式系统采用基于交叉开关的互连模式，用于系统互连的交叉开关是以RapidIO协议为核心的。RapidIO协议是一个点对点、包交换的协议。通过对RapidIO协议的研究，掌握了实现该协议的关键技术。使用Xilinx公司的FPGA(可编程门阵列)芯片实现基于RapidIO核的终端设备，并通过软件仿真和硬件实验系统对其功能进行验证。     

Technological aspects on the fabrication of silicon-based optical accelerometer with ARROW structures

The fabrication and characterization of an optical accelerometer based on silicon technology and using BESOI wafers is presented. Instead of the standard total internal reflection (TIR) waveguides, AntiResonant Reflecting Optical Waveguides (ARROW) have been used. On the basis of a quad beam accelerometer design, a sensing waveguide has been placed on the seismic mass. Its misalignment with the waveguides located at the frame allows measuring the acceleration. The mechanical structure has been designed so as to have a span of 2 μm, that should provide with a sensitivity of 4.6 dB/g. Reference waveguides measured by end-fire coupling have low radiation and insertion losses (0.3 and 2.5 dB, respectively). High insertion losses are observed due to imperfections in polishing when V-grooves with glass anodic bonding are used. This fact causes the reduction of its sensibility to 2.3 dB/g.     

基于现场总线的TSI和TDM一体化设计

本文率先提出了采用现场总线技术将汽轮机监视装置和瞬态数据管理系统整合的思想。设计了汽轮机监视装置和瞬态数据管理一体化系统的体系结构，通过基于CAN的令牌总线网络解决了系统间互联通信中的关键技术问题——介质共享访问解决方案。     

Flood control management system for reservoirs

Flood disaster is one of the most damaging natural disasters in China, with annual average losses more than 200 billion yuan in recent years. After 1995 floods in the Liaohe River and 1998 floods in the Yangtze River, the governments from national to local have realized that the flood control operation of reservoirs can play a major role in alleviating flood losses but there are some problems in flood control management for reservoirs. Most of the existing flood control management systems for reservoir were established for special purposes and are lack of data share and communication with governments, it is very difficult for decision-making departments to get real-time information in short time. Thus, a national programming about flood control management system for reservoirs is presented. The paper is a summary of the outcome of national programming about the flood control management system for reservoirs in China. The background, objectives, main challenges and main contents of the programming are introduced. The main focus is on the issues of the software integration flood control management system for reservoirs. Emphasis is concentrated on the flowchart design of the system and its core components. The current system can be applied to a river control center or a single reservoir because of using the national standard databases and easily integrated into the national flood control system in the future. An application system is briefly introduced in order to understand the system.     

CMOS集成电容湿度传感器

CMOS集成湿度传感器是利用MEMS技术基于CMOS工艺的新型传感器，将传感器结构与接口电路集成在同一块片子上，具有体积小，价廉、可靠性高等优点，利于批量生产和系统集成。主要介绍了湿度传感器的工作原理和一些常用感湿介质，如多孔硅、聚酰亚胺、空气的感湿特性，比较了几种流行的湿度传感器结构以及接口信号处理电路像开关电容电路、多谐振荡电路之间的优缺点。最后给出了微系统集成的概念，并对CMOS集成湿度传感器的应用前景进行了展望。     

Thermal dilatation in functional tolerancing

Functional tolerancing is classically based onto dimension chains to respect functional requirements. Tolerance synthesis deals with dimensions optimization in order to maximize tolerances. This method is classically used taking into account only geometrical defaults. Mechanisms concerned with significant variation of temperature in different stages of functioning, require taking into account thermal expansion. This expansion has a direct impact onto clearances and dimensions of the mechanism. The purpose of this paper is to consider thermal expansion of parts integrated within functional tolerancing. In particular, this paper will compare the effects of tolerancing, thermal expansion and uncertainties of temperature in order to know if uncertainties must be included in the tolerance chain or can be neglected as second order. A basic experimental mechanism is used to show this method and the differences between the two approaches.     

基于多代理的分布式可集成MES框架研究

分析了敏捷制造模式下对MES的要求，给出了支持敏捷制造的基于多代理的分布式可集成MES框架，框架由三层组成，MES核心层完成通用的MES功能，外部系统抽象层是与MES交互的外部系统的抽象，适配器层完成了框架与外部系统的连接，详细地描述各层中代理的功能以及它们之间的交互，并给出了基于JADE的系统实现。