Design of a time-efficient video-goniophotometer combining bidirectional functions assessment for transmission and reflection

A detailed knowledge of the light distribution characteristics through advanced window systems is required to improve the visual comfort of the building's occupants while controlling the propagation of daylight in rooms and the solar gains. An innovative bidirectional goniophotometer has recently been set up for this purpose, using digital image capture and the projection of the emerging light on a diffusing screen. It therefore provides a continuous investigation of the bidirectional transmission figures in a time-efficient way. This instrument was converted into a double-purpose device, allowing both transmission and reflection measurements, which induced several strong constraints due to the conflict of incident and emerging light flux in reflection mode: on one hand the incident beam had to be restricted to the sample area only; on the other hand, as the screen obstructed the incoming light flux in some positions, a special opening in the latter was required. The practical answer to these constraints, detailed in this paper, proved to be reliable, appropriate and efficient.     

Forecast and evaluation of hot dry rock geothermal resource in China

Utilizing information from plate tectonics characteristics, volcanic activities, and geothermal anomaly, this paper identifies areas where hot dry rock (HDR) may exist as potential geothermal resource in China. Further investigations are also carried out in the paper based on results from regional tectonics, volcanic geology and lithology, as well as data from geothermal displays, geochemistry, geophysics, and shallow borehole temperature measurements. The study reveals several promising areas of HDR geothermal resource in China, including Tengchong of Yunnan province, Qiongbei of Hainan province, Changbaishan of Jilin province, Wudalianchi of Heilongjiang province, and the Southern Tibet area. A 3D static heat conduction model was developed to study the underground temperature gradient characteristics of the Rehai geothermal field in Tengchong and the Yangbajing geothermal field in Tibet. The model adopted is a geological block 10 km deep from the ground surface and 50 km wide in each of the horizontal directions (2500 km² area). The numerical simulation results in evaluations on the quantities of the HDR geothermal resource in Rehai and Yangbajing geothermal fields. The paper shows that there is abundant HDR geothermal resource with large exploitation value in China. If developed with a power capacity of 1×10⁸ kW, the Rehai and Yangbajing fields along would be able to generate electricity for 1560 years.     

从甘肃民勤生态危机反思石羊河流域水资源利用模式

民勤生态环境危机主要表现在:土地盐碱化、荒漠化日益严重,灾害性天气频繁发生等方面,这些都直接威胁着绿洲存亡。从绿洲生态危机对石羊河流域水资源利用模式进行了反思,指出了目前流域水资源利用中存在的问题,并提出了建议:实行流域水资源统一管理;建立合理的水权制度,适当调整水价;控制人口增长;加快外流域调水。     

内燃机气缸压力振动识别研究

本文应用数字信号处理技术研究了内燃机气缸压力对缸盖表面的激励作用，提出了借助于缸盖系统传递函数分离表面振动信号。识别气缸压力成份并复现示功图的方法。     

The Efficiency of Engineering Traffic Across Network Boundaries

With the arrival of wideband packet and circuit-oriented data services, it becomes a challenge to provide efficiently the desired quality of service for speech, packet data, and real-time data on a network. As these diverse networks will coexist, architectural studies on integrated heterogeneous networks suggest that a common radio resource manager be used to coordinate radio resource allocation between diverse network types. Initial studies show that supernets, which engineer traffic across wireless networks, are more efficient than operating separate cellular/wireless networks. Increased sharing occurs in supernets because a larger number of services compete for a larger pool of resources. If sharing can be shown to be efficient in general, then supernets should likewise be more efficient. This study decomposes the two-dimensional Markov chain to prove when sharing is beneficial and when it is not.     

数字电视用户管理模式探讨

近年来有线电视数字化已经在全国各地铺展开来,如何有效地进行数字电视用户管理成为一个新的课题摆在我们面前。主要介绍了三门县对数字电视用户管理模式的探索以及具体细节的探讨。     

IPv6标准现状及进展

对IPv6标准进行了分类,介绍了与IPv6标准化相关的国内外标准化组织以及在这些组织中IPv6标准化工作的进展,在此基础上对目前IPv6标准化工作的成熟度进行了分析总结。     

Technology standards-setting in the US wireless telecommunications industry: A study of three generations of digital standards development

This article focuses on the evolution of technology standards-setting in the US wireless telecommunications industry during the decades of the 1980s and 1990s. The purpose of this exploratory study is to understand and model the organizational process and environmental influences employed to develop three generations (i.e. second generation (2.0) Time Division Multiple Access (TDMA), second generation (2.5) Code Division Multiple Access (CDMA), and third generation (3.0) Wideband Code Division Multiple Access (WCDMA)) of de jure US wireless digital telecommunications standards. Through the use of a multi-case study approach, the research study focuses on inter-organizational strategic cooperation among wireless telecommunications firms proposing competitive technology designs in the standard development process. Based on data collected in these three case studies, wireless standard development models are “mapped” for the TDMA, CDMA and WCDMA technologies. Moreover, a generic, conceptual wireless technology standard development model is “mapped”, a further refinement of an earlier seminal model of telecommunications standard-setting. Finally, conclusions are reached, with both theoretical and practical implications, and suggested areas of future research (in the form of a set of research hypotheses) are presented.     

Information and Telecommunications Project for a Digital City: A Brazilian case study

Making information and telecommunications available is a permanent challenge for cities concerned to their social, urban and local planning and development, focused on life quality of their citizens and on the effectiveness of public management. Such a challenge requires the involvement of everyone in the city. The objective is to describe the information and telecommunications project from the planning of a digital city carried out in Vinhedo-SP, Brazil. It was built as a telecommunications infrastructure of the kind of “open access metropolitan area networks” which enables the integration of citizens in a single telecommunications environment. The research methodology was emphasized by a case study which turned to be a research-action, comprising the municipal administration and its local units. The results achieved describe, by means of a methodology, the phases, sub-phases, activities, approval points and resulting products, and formalize their respective challenges and difficulties. The contributions have to do with the practical feasibility of the project and execution of its methodology. The conclusion reiterates the importance of the project, collectively implemented and accepted, as a tool to help the management of cities, in the implementation of Strategic Digital City Projects, in the decisions of public administration managers, and in the quality of life of their citizens.     

DVD视盘播放设备

概述了DVD视盘及其播放设备（DVD视盘机）的一些基本概念,重点介绍了DVD视盘机的硬件和软件系统。