I/O级网络通信程序设计

用微机操作CAMAC设备举例,具体描述I/O级网络通信的步骤和程序,首先在单机操作下设计完成CAMAC设备的接口程序,然后在服从TCP/IP协议的前提下,使用Windows sockets技术在Windows环境下进行I/O级网络通信,在网络通信程序方面双方是用客户机和服务器的方式参与的.     

基于Pro/E二次开发的辅助布线技术

针对Pro/E布线模块在线缆建模过程中无法进行干涉检查、线缆信息输出等功能缺失问题,在Pro/E平台上,对Pro/E简单布线技术、线缆干涉调整、信息管理和参数化建模技术进行研究,提出线缆干涉调整和信息输出策略。结合Visual Studio环境下的Pro/E二次开发技术,开发一个具有上述功能的辅助布线系统,验证了技术的可行性。     

C/S到B/S模式转换的技术研究

随着Internet技术的兴起,致使更多的企业着手将C/S模式向B/S模式迁移。针对传统软件复用技术,对现有C/S模式的遗留系统进行分析,提出一种由C/S模式到B/S模式转换的方法。采用虚拟应用技术和.NET框架下的UIA技术,使用XML文件作为信息交换的载体,实现浏览器对C/S软件的远程操作,利用现有资源完成B/S结构的开发,并且无需修改源C/S软件的代码,体现模式的平台无关性,具有界面统一性、高度可扩展性以及易维护性等特征。实验结果表明,该方法在Windows XP的计算器中得到成功应用。     

一种基于AJAX技术的B/S与C/S混合构架模式

在分析当前客户机/服务器(C/S)与浏览器/服务器(B/S)混合架构模式与AJAX技术的基础上,提出了一种新的混合架构模式,这种架构模式基于Web服务技术和AJAX技术,统一了B/S与C/S的前台交互方式,融合了两种模式的优点,有效地实现了服务器端共享,增强了此类系统的可维护性与可扩展性。在此模式指导下,设计了动力学应用平台的架构,为类似此种架构的系统实现提供了一定参考。     

PowerBuilder应用从C/S模式向B/S模式的移植

把C/S模式下的PB应用平滑地移植到Web上来的方法,以WindowsActiveX和WindowsPlugin技术为例介绍采油成本管理系统的移植过程。     

基于Modbus/TCP的分布式污水处理系统

以Modicon公司PLC为例讨论了Modbus/TCP协议并描述了一种基于它的污水处理分布式监控系统平台,并给出了组通讯技术和PLC实时网页构建技术的具体实现,提高了Internet/Intranet环境下测控污水处理数据的实时性。     

基于COM/DCOM的分布式数据库系统的研究

本文针对目前存在的数据库系统,提出一种基于COM/DCOM集成技术下的多种异构数据库下的数据访问控制系统模型,该方案利用COM/DCOM解决系统的分布性和异构性,有效地集成了各种分布的、异构的数据库系统。     

C/S模式下Word文档的存取技术

介绍了C/S(Client/Server)模式下,以Delphi为开发工具,利用Oracle数据库实现Word文档存储和读取操作的基本原则和技术.     

基于MATLAB/xPC的快速原型技术的应用

本文结合具体实例,详细阐述了在MATLAB/xPC技术框架下,针对研华公司的接口设备ADAM5000成功开发了驱动程序模块,并将该模块和MATLAB/xPC技术成功应用于一个完整的计算机实时控制系统。     

C/S模式下Word文档的存取技术

介绍了C/S(Client/Server)模式下,以Delphi为开发工具,利用Oracle数据库实现Word文档存储和读取操作的基本原则和技术。     

M/G/c/K blocking probability models and system performance

An exact solution for the M/G/c/K model is only possible for special cases, such as exponential service, a single server, or no waiting room at all. Instead of basing the approximation on an infinite capacity queue as is often the case, an approximation based on a closed-form expression derivable from the finite capacity exponential queue is presented. Properties of the closed-form expression along with its use in approximating the blocking probability of M/G/c/K systems are discussed. Extensive experiments are provided to test and verify the efficacy of our approximate results.     

Complex random sample scheduling and its application to an N/M/F/Fmax problem

“Complex Random Sample Scheduling(CRSS)” was proposed in this paper as an efficient heuristic method for solving any permutation scheduling problems. To show the effectiveness of the proposed CRSS, it was applied to an N-job, M-machine, permutation flowshop scheduling problem to minimize makespan, N/M/F/F_max. Numerical experiments made it clear that the proposed CRSS provides a schedule very close to the near-optimal schedule obtained by the existing promising heuristic methods such as taboo search and simulated annealing, within less computation time than these heuristic methods.     

On the M/Ck/1 queue

We obtain the exact analytic expression of the probability distribution of the number of units in a single server queue with Poisson arrivals and Coxian service time distribution (notated as M/C_k/1). A recursive procedure for calculating this probability distribution is given. The well-known queues M/E_k/1 and M/D/1 are re-derived as special cases of the M/C_k/1 queue. Finally, the cases of M/C₂/1 and M/C₃/1 are fully worked out.     

Asymptotic analysis and simple approximation of the loss probability of the GI/M/c/K queue

We consider the GI^X/M/c/K queues with partial rejection or total rejection, and find an asymptotic behavior of loss probability of the GI^X/M/c/K queue as K tends to infinity. The asymptotic loss probability is expressed only in terms of the roots of the characteristic equation and the boundary probabilities of the corresponding GI^X/M/c queue. Numerical examples show that the asymptotic loss probability is a quite accurate approximation for the loss probability of the GI^X/M/c/K queue even when the system capacity K is moderate.     

Sn1-xFexOy: a new material with high carbon monoxide sensitivity

The preparation method and the sensing properties (sensitivity and selectivity to interfering gases) towards carbon monoxide of the new ternary compound Sn_1-xFe_xO_y deposited in the form of thin films, are presented in this paper. The metal of the VIIIB group is introduced with concentrations in the range 0<x<25 at %. Thin films are sputtered using the RGTO (rhotaxial growth and thermal oxidation) technique. This technique consists of metal deposition onto a substrate maintained at a temperature higher than the metal melting point and metal oxidation by means of an annealing cycle in pure oxygen. Particular emphasis is given to the relations between some preparation parameters of the material, namely the atomic percentage ofiron or the annealing cycle, and to the sensor sensitivity towards CO and other interfering gases like C₂H₅OH, H₂ and NO_x diluted in dry air. A sensitivity S=(G_gas-G_air)/G_air=3.5 towards 10 ppm of CO has been measured: the kinetic characteristics of the sensors are also presented, together with the working mechanism.     

IR uncooled bolometers based on amorphous Ge/sub x/Si/sub 1-x/O/sub y/ on silicon micromachined structures

In this work, we present the fabrication of bulk micromachined microbolometers made of amorphous germanium-silicon-oxygen compounds (Ge/sub x/Si/sub 1-x/O/sub y/) grown by reactive sputtering of a Ge/sub 0.85/Si/sub 0.15/ target. We describe the complete procedure for fabricating thermally isolated microbolometers consisting of Ge/sub x/Si/sub 1-x/O/sub y/ sensing films deposited on sputtered silicon dioxide membranes suspended over a silicon substrate. The electrical properties of the sensitive material are set by controlling the deposition parameters of the sputtering technique. Under optimum deposition conditions, Ge/sub x/Si/sub 1-x/O/sub y/ layers with moderate electrical resistivity and thermal coefficient at room temperature as high as -4.2% /spl middot/ K/sup -1/ can be obtained. Isolated structures measured at atmospheric pressure in air have a thermal conductance of 3 /spl times/ 10/sup -6/ W /spl middot/ K/sup -1/ and a thermal capacitance of 6/spl middot/10/sup -9/ W /spl middot/ s /spl middot/ K/sup -1/, yielding a response time of 1.8 ms. Bolometers with an IR responsivity of 380 V /spl middot/ W/sup -1/ and a NEDT of 3.85 K at 100 nA bias current are obtained. The use of sputtered films allows designing a fully low-temperature fabrication process, wholly compatible with silicon integrated circuit technologies.     

PECVD-SiOxNy films for large area self-sustained grids applications

In this work we study the structural properties and mechanical stress of silicon oxynitride (SiO_xN_y) films obtained by plasma enhanced chemical vapor deposition (PECVD) technique at low temperatures (320 °C) and report the feasibility of using this material for the fabrication of large area self-sustained grids. The films were obtained at different deposition conditions, varying the gas flow ratio between the precursor gases (N₂O and SiH₄) and maintaining all the other deposition parameters constant. The films were characterized by ellipsometry, by Fourier transform infrared (FT-IR) spectroscopy and by optically levered laser technique to measure the total mechanical stress. The results demonstrate that for appropriated deposition conditions, it is possible to obtain SiO_xN_y with very low mechanical stress, a necessary condition for the fabrication of mechanically stable thick films (up to 10 μm). Since this material (SiO_xN_y) is very resistant to KOH wet chemical etching it can be utilized to fabricate, by silicon substrate bulk micromachining, very large self-sustained grids and membranes, with areas up to 1 cm² and with thickness in the 2–6 μm range. These results allied with the compatibility of the PECVD SiO_xN_y films deposition with the standard silicon based microelectronic processing technology makes this material promising for micro electro mechanical system (MEMS) fabrication.     

On the overflow processes from the PH1 + PH2/M/S/K queue with two independent PH-renewal inputs

This paper presents an analysis of overflow processes from a PH₁ + PH₂/M/S/K queue having two independent phase type renewal input streams. Both the superposed overflow process and individual overflow processes for the PH₁- and PH₂-streams are analyzed using first passage time distributions for the number of customers in the system. Each overflow process is characterized as a Markov renewal process. The nth moment of the number of customers in an infinite server group to which these overflows have been offered is derived using a theory for the MR/M/∞ queue with a Markov renewal input. The numerical examples for means and variance-to-mean ratios (peakednesses) of the individual overflow streams are given for an H₂ + H₂/M/S/S queue with interrupted Poisson inputs, which is a vital model for telephone network planning. In addition, overflow traffic characteristics are discussed by using these examples.     

Randomized control of T-policy for an M/G/1 system

We study an M/G/1 queueing system with a server that can be switched on and off. The server can take a vacation time T after the system becomes empty. In this paper, we investigate a randomized policy to control a server with which, when the system is empty, the server can be switched off with probability p and take a vacation or left on with probability (1 − p) and continue to serve the arriving customers. For this system, we consider the operating cost and the holding cost where the operating cost consists of the system running and switching costs (start up and shut down costs). We describe the structure and characteristics of this policy and solve a constrained problem to minimize the average operating cost per unit time under the constraint for the holding cost per unit time.     

Gas-sensing property and mechanism of CaxLa1−xFeO3 ceramics

LaFEO₃ and Ca_xLa_1−xFeO₃ ceramic powders have been prepared by the coprecipitation method from La(NO₃)₃, Fe(NO₃)₃ and Ca(NO₃)₂ aqueous solutions. The orthorhombic perovskite phases of LaFeO₃ and Ca_xLa_1−xFeO₃ are characterized by X-ray diffraction patterns. The sensors fabricated with those powders have high sensitivity to alcohol. Partial substitution of La³⁺ in LaFeO₃ with Ca²⁺ can enhance the sensitivity of the materials to reducing gases. The resistance of an LaFeO₃ sensor in air, vacuum and alcohol-containing air has been measured. Complex impedance spectroscopy has been used to try and analyse the gas-sensing mechanism. According to the experimental results, it can be deduced that the surface adsorptive and lattice oxygen govern the sensing properties of LaFeO₃ and Ca_xLa_1−xFeO₃ ceramics.