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101.
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Simonetta Balsamo Vittoria De Nitto Person Paola Inverardi 《Performance Evaluation》2003,51(2-4):269-288
A review is carried out on how queueing network models with blocking have been applied so far into the performance evaluation and prediction of Software Architectures (SA). Queueing network models with finite capacity queues and blocking have recently been introduced and applied as more realistic models of systems with finite capacity resources and population constraints. Queueing network models have been often adopted as models for the evaluation of software performance. Starting from our own experience, we observe the need of a more accurate definition of the performance models of SA to capture some features of the communication systems. We consider queueing networks with finite capacity and blocking after service (BAS) to represent some synchronization constraints that cannot be easily modeled with queueing network models with infinite capacity queues. We investigate the use of queueing networks with blocking as performance models of SA with concurrent components and synchronous communication. Queueing theoretic analysis is used to solve the queueing network model and study the synchronous communication and performance of concurrent software components. Our experience is supported by other approaches that also propose the use of queueing networks with blocking. Directions for future research work in the field are included. 相似文献
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针对动力厂35t/h锅炉的工艺控制要求,选用SUPMAX500集散控制系统。介绍了系统的软、硬件构成及其具体实施方法。 相似文献
105.
介绍一种针对正、余弦旋转变压器—数字转换器(RDC)模块,用复杂可编程逻辑器件(CPLD)技术实现伺服轴角编码电路设计的方案。分析了轴角编码器系统中14XSZ系列旋转变压器—数字转换器的原理、轴角粗精组合原理及轴角纠错原理。详细介绍了CPLD的内部功能电路、CPLD轴角粗精组合和纠错实现电路,以及CPLD的工作时序图。提出了利用CPLD实现轴角粗精组合处理的方案,并通过了实际系统运行的考验,证明该方案可行。 相似文献
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Youngjoong Ko Sooyong Park Jungyun Seo Soonhwang Choi 《Information and Software Technology》2007,49(11-12):1128-1140
In order to efficiently develop large-scale and complicated software, it is important for system engineers to correctly understand users’ requirements. Most requirements in large-scale projects are collected from various stakeholders located in various regions, and they are generally written in natural language. Therefore, the initial collected requirements must be classified into various topics prior to analysis phases in order to be usable as input in several requirements analysis methods. If this classification process is manually done by analysts, it becomes a time-consuming task. To solve this problem, we propose a new bootstrapping method which can automatically classify requirements sentences into each topic category using only topic words as the representative of the analysts’ views. The proposed method is verified through experiments using two requirements data sets: one written in English and the other in Korean. The significant performances were achieved in the experiments: the 84.28 and 87.91 F1 scores for the English and Korean data sets, respectively. As a result, the proposed method can provide an effective function for an Internet-based requirements analysis-supporting system so as to efficiently gather and analyze requirements from various and distributed stakeholders by using the Internet. 相似文献
109.
对湘潭电厂存在已久的胶球清洗装置收球率低的问题进行了深入探讨,结合电厂对胶球清洗系统的改造、试验过程,分析并提出了影响胶球清洗装置清洗效果及收球率的诸多原因及其解决方法。 相似文献
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