The accuracy of dependency analysis in static architecture compliance checking

Architecture compliance checking (ACC) is an approach to verify conformance of implemented program code to high‐level models of architectural design. Static ACC focuses on the modular software architecture and on the existence of rule violating dependencies between modules. Accurate tool support is essential for effective and efficient ACC. This paper presents a study on the accuracy of ACC tools regarding dependency analysis and violation reporting. Ten tools were tested and compared by means of a custom‐made benchmark. The Java code of the benchmark testware contains 34 different types of dependencies, which are based on an inventory of dependency types in object oriented program code. In a second test, the code of open source system FreeMind was used to compare the 10 tools on the number of reported rule violating dependencies and the exactness of the dependency and violation messages. On the average, 77% of the dependencies in our custom‐made test software were reported, while 72% of the dependencies within a module of FreeMind were reported. The results show that all tools in the test could improve the accuracy of the reported dependencies and violations, though large differences between the 10 tools were observed. We have identified 10 hard‐to‐detect types of dependencies and four challenges in dependency detection. The relevance of our findings is substantiated by means of a frequency analysis of the hard‐to‐detect types of dependencies in five open source systems. © 2016 The Authors. Software: Practice and Experience Published by John Wiley & Sons, Ltd.     

楔形海域声矢量场分析

海洋环境中的声传播是水声学研究领域的一个经典问题.在传统的研究中,关心的主要是声压场.随着矢量水听器的出现,不仅是声压场,介质质点振速场也受到极大关注.应用虚源法分析了ASA基准楔形模型中谐和点源的三维质点振速场.基于Deane和Buckingham给出的声场声压表达式,文中推导了三维质点振速的积分公式,并应用数值积分的方法计算了声场声压与质点振速,分析了它们的传播损失和相位差以及不同方向声强的衰减过程.结果表明,即使在远距离上,声压与质点振速的相位差并不为零.     

种群分类粒子群改进算法研究

针对粒子群算法在陷入局部最优时难于跳出的缺陷,提出一种改进的粒子群算法.该算法首先利用粒子适应值的统计规律对粒子进行分类,对属于不同类别的粒子采用不同的进化模型,对于利用完全模型进化的粒子,采用动态调整学习因子的方法,从而大大提高了算法的优化效率和优化精度.通过反复实验分析,得出学习因子随着进化推进的最优变化规律,并给出了学习因子的最佳函数表达式.仿真结果表明,利用改进的PSO算法优化4种具有代表性的基准函数,无论是在优化精度方面还是在优化效率方面,均较以往提出的PSO算法在性能上有本质的提高.     

基于"基准分析"模式的福建城市竞争力评价分析

首先分析国内外城市竞争力评价理论和评价方法,在此基础上构建了城市综合竞争力评价模型,从城市化水平竞争力、城市规模竞争力、城市经济竞争力、基础设施竞争力、人居环境竞争力5个方面共选取16项指标,对福建省城市整体综合竞争力进行评价,并对综合竞争力的情况进行SWOT分析。最后提出了进一步提升福建省城市综合竞争力的对策。     

基于PSO-SVM的电网调度电厂耗煤基准值滚动预测

电网调度在做电煤供应分级预警的研究制定和对各电厂负荷经济分配时常会用到耗煤基准值,它对于监测电厂未来存煤使用天数,制定合理发电调度计划具有重要作用。目前常用的耗煤基准测算方法很少,主要是通过对历史数据进行简单的数学计算作为未来耗煤基准预测值,误差较大。提出了结合实际需求、面向电网调度的基于粒子群优化支持向量机的火电厂耗煤基准值滚动预测方法,选取电网下典型的3个电厂,经过数据分析处理与试验比对,结果表明基于粒子群优化支持向量机模型能很好地对耗煤基准值进行滚动测试及预测更新,进而可以为电网调度部门推测各个电厂存煤可用天数和建立电厂存煤预警机制,制定发电调度计划提供数据支撑。     

改进的万有引力搜索算法在边坡稳定分析中的应用

基于万有引力搜索算法(GSA)提出了一种改进的万有引力搜索算法(MGSA)。针对GSA在处理优化问题时会出现发散的情况,通过限制粒子的速度同时更改算法中的参数来改善这一问题。算法改进后显著提高了GSA中粒子的探索能力与开发能力,可以获得较强的优化能力。采用MATLAB对8个测试基准函数进行仿真实验,并将该方法引入到边坡稳定分析中。对于边坡稳定性分析,利用MGSA搜索出临界滑动面并结合极限平衡法计算出相应的最小安全系数。结果表明:与GSA法及其他方法相比,MGSA在求解最危险滑动面安全系数时具有更好的优化性能。     

零件机械加工工艺设计原则的探讨

对机械加工工艺设计中的主要原则进行论述,提供一些有价值的资料,以便对合理编制零件的加工工艺起到一定的帮助。     

基于量子策略的布谷鸟搜索算法研究

针对基本布谷鸟搜索算法存在局部搜索能力较弱、收敛速度偏慢和精度较低等缺点,文中研究了基于量子策略的布谷鸟搜索算法。借助于量子策略使布谷鸟的寻巢搜索行为具有多样性,并在此基础上提出3种改进局部搜索能力的措施:引入惯性权值、自适应减小鸟窝主人发现外来鸟蛋的概率、随机扰动增量的优化,并通过对两类基准测试函数的寻优结果对比,证明提出的改进融合算法精度更高,且具有更大的优势。     

基于ESN的污水处理过程优化控制

针对污水处理过程能耗过高的问题,提出了一种基于状态回声网络(ESN)的在线优化控制方法。建立了污水处理过程预测模型,实现性能指标的预测;根据系统的状态以及预测的性能指标,采用ESN实时优化控制变量的设定值;将优化后的设定值传送给底层控制器进行跟踪控制。将ESN优化控制方法在污水处理过程基准仿真模型(BSM1)上进行了验证,实验结果表明,该方法不但能够满足出水水质的要求,而且降低了污水处理过程运行成本。     

Method for rating energy performance of public buildings

This paper discussed a comparative study of several state-of-art methods for determining building energy consumption benchmark. A new approach, which combined the idea of “building benchmark” and “operational benchmark” in its rating system, was proposed. A case study was conducted which applied the proposed approach to benchmarking an existing office building in Tianjin. Besides, the calculation of benchmarks of the reference building model and real building model using the rating method in eQUEST was also considered. Furthermore, the simulation results of the reference building model were taken as the baseline to divide real office buildings into different energy performance grades.