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关键词： Markov chains   queueing networks   blocking   enterprise JavaBeans  

摘要： We consider a form of blocking, which is typical in client-server systems including those implemented under the Enterprise JavaBean (EJB) specification. The novel feature is that tasks must wait for one of a number of parallel queues to clear its outstanding work. Thus, blocking time is the minimum of sojourn times at the parallel queues. Under certain simplifying assumptions, we solve this model for the probability distribution of blocking time and obtain a simple formula for its mean value. We then use this result in an aggregate server model of a larger queueing network in which further non-standard techniques are included to represent this form of blocking. We compare our approximate results against simulation data, obtaining good agreement for both system throughput and queue length probability distributions at equilibrium. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： graphic correlation   biostratigraphy   stratigraphy   computer simulation  

摘要： A combination of a stratigraphic simulation package (STRATA) and an evolutionary-ecological model (BIOSTRAT) can be used to simulate the distribution of species within a sequence stratigraphic framework. BIOMODULE is an extension of this model approach in that it facilitates the visualization and interpretation of those simulations and their input data. Environmental factors (e.g., sea-level changes or sedimentation rates) and ecological factors (preferred water depth, depth tolerance, abundance) that determine the spatial and temporal distribution of species are easily and quickly investigated. In addition, BIOMODULE can be used to compile the stratigraphic first and last appearances of those species and export them into available graphic correlation software packages (Conop9 and GraphCor). This can be used to test the graphic correlation technique and investigate its accuracy and precision under a range of different conditions (e.g., different stratigraphic architectures and sampling densities) since the true correlation of the different sections is already known. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： JAVA语言-程序设计  

关键词： Java语言   程序设计   操作系统   内核对象  

关键词： Personal   Java   程序设计   Windows   CE   Symbian  

摘要： 您想用Java来设计手机与PDA的应用程序,可是嫌J2ME MIDP功能太少,无法让您尽情发挥吗?笔者建议您试试Personal Java。Personal可以让您设计的Java程序得以在以Windows CE与Symblan OS为操作系统的机器上执行,包括市面上已经可以买到的PocketPC、Nokia 9210c、SonyE ricsson P800都是Personal Java可以发挥的范围。

关键词： Logo画面   Java语言   程序设计   初始化程序  

关键词： 动态编译   Java语言   编译程序   编译器   计算机  

关键词： Java   协议测试程序   URL   网络  

摘要： 通常 Java 程序定位和检索网络上的数据最简单的方法是使用 URL 类。那么,如何知道主机支持哪些协议呢?使用 URL 类不需要考虑具体的协议。但是,如果试图用一个不支持的协议创建 URL,所有的构造器都会触发 MalformedURLException 异常。正是因为触发异常,我们能够知道主机是否支持触发异常的协议!在 *** 类中包含了6种构造器,用于创建 URL 实例。本文中的示例,采用了其中的一个构造器,即,public URL(String protocol,String hostname,String file)throw MalformedURLException。在程序中。

关键词： 移动通信-携带电话机-JAVA语言-程序设计  

关键词： Java语言-程序设计