一种基于SMS的干放站远程监控系统

随着手机应用资费的不断下调及其通讯网络的不断完善,应用手机短消息(SMS)来进行远程监控具有很广阔的应用前景.本文对GSM网络的SMS的原理与操作进行了探讨,对基于SMS的干放站远程监控系统的实现方案、系统的组成、干放站控制器端软件设计及实现等进行了论述.本系统具有较好的可移植性,只需修改相应的通信协议,就可适用于其它行业远程设备的监控.     

基于GPRS/SMS燃气调压站远程监控系统的设计与实现

为了灵活高效地实现对燃气调压站的监控,设计了一种基于GPRS/SMS混合通讯的燃气调压站远程监控系统;系统主要由远程监控终端、无线传输网络和监控中心组成,远程监控终端主要负责数据的采集和调压控制,并分别与监控中心和手机终端建立连接,监控中心通过GPRS网络,实现数据的接收、报警和参数设置,SMS在实现上述功能的同时还可以设置终端与监控中心的通信参数;应用结果表明系统可以实现数据实时传输和准确报警,具有运行稳定可靠、操作简单和功耗低等特点。     

基于TCP/IP协议的远程配置与监控系统

主要介绍了一种基于TCP／IP协议的远程配置与监控系统，包括它的功能和特点以及该系统的软、硬件实现方法。该系统采用服务器／客户端模式，利用TCP／IP协议通过Internet网络实现设备工作参数的远程配置和设备运行状态的远程监视和控制，将该系统用于全IP移动通信系统基站的远程配置和监控，结果显示该系统能够很好地完成基站的远程配置和监控功能。     

基于SMS和Windows Mobile的手持式地理信息汇报系统①

介绍一种基于SMS和Windows Mobile的手持式地理信息汇报系统,探讨了一种利用目前现成的移动通信设施实现对带有GPS定位功能的手持智能设备持有者监控的系统。本系统利用目前流行的短信系统（SMS）作为数据传输手段,传送手持智能设备持有者的地理信息数据。使用SMS传输数据通信可靠,费用低廉,且覆盖范围广。     

基于Web的嵌入式设备监控模型的设计与实现

研究并实现了一种基于Web技术的嵌入式没备监控模型,使管理者可以通过Internet利用Web浏览器完成对现场设备的远程访问、监控和维护等操作,实现了异构设备之间的跨平台互访。对TCP／IP协议进行约简,实现了一个thin TCP／IP协议栈,为嵌入式设备提供了网络接口,实现了与Internet的无缝连接。嵌入式没备网关将TCP／IP协议与嵌入式设备监控协议之间的格式进行转换,实现了远程用户对现场设备的透明访问,具有智能化和远程管理的特点。通过对该模型性能的测试,结果表明基于Web的远程监控方式可以满足监控任务的需要,而且能有效降低监控运行维护成本、提高运行维护效率,具有实际应用价值。     

基于SMS通用型远程无线监控系统的实现

SMS服务可以使用移动设备发送和接收文本信息,通讯费用低廉,使用方便,可靠性高。基于GSM移动通信网络的SMS服务功能,正不断向工业远程监控领域扩展,利用这项服务,对传统的单台工业设备系统实施远程网络监控越来越有必要。文中讲述了用GSM MODEM实现基于SMS的通用远程无线监控的具体硬件组成结构和软件编程方法,通过采用PLC通用的信号输入方式设计了数据采集电路,解决了监控系统的通用性问题,实现了使用手提电话或计算机对一般工业设备的远程无线监控。     

基于IEEE 802.11b和CDMA网的多路监控系统的设计与实现

提出了一种基于IEEE 802.11b和CDMA网的远程监控系统,监控现场设备之间通过无线局域网相连接,监控现场设备与远程控制设备之间通过CDMA2000-1X移动通信网和Internet网相连接,可通过后台软件、Web服务器和手机短信等多路方式进行远程监控。阐述了该系统的总体结构,给出了基于嵌入式技术的软硬件实现方案,并进行了测试。结果表明,本监控系统具有不受现场布线束缚、监控设备可自由移动、监控手段灵活多样等优点。     

数控设备的开放式远程监控系统

设计一种基于Web技术的嵌入式数控设备远程监控系统,使传统的测试和控制设备转变为具备以TCP/IP为底层通信协议、Web技术为核心的基于Internet的网络监控设备,使管理者可以通过Internet完成对现场设备的远程访问、监控和维护等操作,实现了异构设备之间的跨平台互访,实现开放式远程监控.     

基于SMS的无线远程监控中心系统设计与实现

为了经济简便的实现对无人值守设备的遥测、遥控，提出基于SMS的无线远程监控系统．首先给出了一个监控系统的组网结构，然后介绍了该监控系统监控中心的设计，最后重点阐述了监控中心软件的设计和实现．所设计和实现的基于SMS的无线远程监控中心系统可以作为一个基本模式，应用于多种领域．     

基于IEEE 802.11b和CDMA网的多路监控系统的设计与实现

提出了一种基于IEEE 802.11b和CDMA网的远程监控系统,监控现场设备之间通过无线局域网相连接,监控现场设备与远程控制设备之间通过CDMA2000-1X移动通信网和Internet网相连接,可通过后台软件、Web服务器和手机短信等多路方式进行远程监控.阐述了该系统的总体结构,给出了基于嵌入式技术的软硬件实现方案,并进行了测试.结果表明,本监控系统具有不受现场布线束缚、监控设备可自由移动、监控手段灵活多样等优点.     

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.     

Modelling and / for / by simulation

Various aspects of the close interconnection of the two tasks ‘Modelling a System’ and ‘Simulating a System’, shall be discussed for continuous systems. Some typical examples from different areas of application will be given in order to provide some insight into this matter. Then the importance of implicit programming will be discussed shortly which allows for a ‘one-to-one-mapping’ of the system block structure on the simulation program. Some remarks on available simulation tools will complete the discussions.     

Properties and performance modelling of finite buffer M/G/1/K networks

Finite buffer, single-server queueing systems and networks are difficult to analyze since the length of time a customer spends in the system does not follow the Markovian property. A two-moment approximation schema is developed for the probability distribution of M/G/1/K systems and extended to the analysis of M/G/1/K   queueing networks. The general purpose of this paper is to develop a flexible and practical transform-free approach for computing the probability distribution and performance measures of the system as well as identify the underlying properties of these systems. It is shown that for most performance measures, a sigmoid or S-shaped curve with an inflection point at ρ=1$\rho =1$ appears as K→∞$K\to \infty$. This has direct implications for the analysis and optimization of such systems. The performance modelling of the M/G/1/K queueing networks of general topologies along with extensive numerical results accompany the paper along with the linear concave performance measures for these systems.     

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.     

The M/M/c/N queue with balking and reneging

In this paper, a truncated multi-channel queue with reneging and general balk function is considered. The steady-state distribution of the number of units in the system is derived. The expected number of units in both the system and the queue are also obtained. Some previously published results are shown to be special cases of the present results.     

Geom/G/1/n system with LIFO discipline without interrupts and constrained total amount of customers

Consideration was given to the discrete-time queuing system with inversive servicing without interrupts, second-order geometrical arrivals, arbitrary (discrete) distribution of the customer length, and finite buffer. Each arriving customer has length and random volume. The total volume of the customers sojourning in the system is bounded by some value. Formulas of the stationary state probabilities and stationary distribution of the time of customer sojourn in the system were established.     

Maximum entropy and the G/G/1/N queue

Summary A new hybrid analytic framework, based on the principle of maximum entropy, is used to derive a closed form expression for the queue length distribution of a G/G/1 finite capacity queue. It is shown that Birth-Death homogeneous recursions for a single resource queue are special cases of maximum entropy one-step transitions which can be applied either in an operational or stochastic context. Furthermore, an equivalence relationship is used to analyse two-stage cyclic queueing networks with general service times, and favourable comparisons are made with global balance and approximate results. Numerical examples provide useful information on how critically system behaviour is affected by the distributional form of interarrival and service patterns. Comments on the implication of the work to the performance analysis and aggregation of computer systems are included.Some of the material included in this paper has been presented to the Performance '86 and ACM Sigmetrics 1986 Joint Conference on Computer Modelling, Measurement and Evaluation, May 28–30, 1986, University of North Carolina, USA     

Steady state analysis and computation of the GI/M/1/L queue with multiple working vacations and partial batch rejection

This paper analyzes a finite-buffer bulk-arrival bulk-service queueing system with multiple working vacations and partial batch rejection in which the inter-arrival and service times are, respectively, arbitrarily and exponentially distributed. Using the supplementary variable and the embedded Markov chain techniques, we obtain the waiting queue-length distributions at pre-arrival and arbitrary epochs. We also present Laplace–Stiltjes transform of the actual waiting-time distribution in the queue. Finally, several performance measures and a variety of numerical results in the form of tables and graphs are discussed.