Simulating discrete event systems with UML and JAVA

Summary  The main readership are students in the field of informatics. In most parts, other interested scientists from environmental disciplines get some insights in the field of environmental modelling and software. The book can be recommended broadly. With the last chapter ‘Simulation in Practice’, this work may also be useful for commercial application. With chapter 14, the authors contribute to the increasingly important topic of E-Learning.     

A survival-analysis-based simulation model for Russian wheat aphid population dynamics

A simulation model for Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), populations is built by integrating survival-analysis-based development and survivor functions and the same-shape reproduction distribution model in the framework of Leslie [Leslie, P.H., 1945. On the use of matrices in certain population mathematics. Biometrika 33, 183–212] matrix structure. Survival analysis is utilized to model both the development and survival of RWA populations, and the Cox (1972) proportional hazards model is fitted with the data sets from our laboratory observation of 1800 RWA individuals under 25 factorial combinations of five temperature regimes and five barley plant-growth stages. Rather than using simple age-specific survivor rates as in the traditional Leslie matrix, the survivor functions based on survival analysis describe age-specific, temperature and plant stage-dependent RWA survival probabilities. Similarly, a probability model from survival analysis to estimate the probability that an individual will reach mature adult stage is utilized to describe the development process; this makes the transition from nymphal stage to mature adult stage dependent on RWA age as well as temperature and plant-growth stage.Inspired by the same-shape distribution and rate-summation approach for modeling insect development, a similar approach for modeling insect reproduction under variable temperature is developed. This new same-shape reproduction distribution model incorporates individual variation in reproduction capability, as well as the effects of RWA age, temperature and plant-growth stage. Consequently, the same-shape reproduction distribution model replaces the simple age-specific fecundities in Leslie matrix model. To the best of our knowledge, this work is the first to introduce survival analysis to simulation modeling in entomology and ecology and also the first to integrate our newly developed same-shape reproduction distribution model into application.     

通过英特网进行基于虚拟现实的矿山安全模拟培训

良好的人员素质和有效的救护策略是矿山灾害处理过程中最关键的要素。在矿山生产过程中完全避免伤害是很难做到的 ,甚至在救护过程中 ,突发事件也时有发生。应用目前计算机技术及信息网络技术相结合的系统综合手段 ,通过英特网采用基于虚拟现实的方法 ,对矿山人员进行模拟培训具有逼真、有效、经济、快速的特点和重要的实用价值。这种培训方式是减少矿山事故率和死亡率的很好手段 ,并且能使各大矿井之间互相学习 ,扬长避短     

Modelling effects of chemical exposure on birds wintering in agricultural landscapes: The western burrowing owl (Athene cunicularia hypugaea) as a case study

We describe an ecotoxicological model that simulates the sublethal and lethal effects of chronic, low-level, chemical exposure on birds wintering in agricultural landscapes. Previous models estimating the impact on wildlife of chemicals used in agro-ecosystems typically have not included the variety of pathways, including both dermal and oral, by which individuals are exposed. The present model contains four submodels simulating (1) foraging behavior of individual birds, (2) chemical applications to crops, (3) transfers of chemicals among soil, insects, and small mammals, and (4) transfers of chemicals to birds via ingestion and dermal exposure. We demonstrate use of the model by simulating the impacts of a variety of commonly used herbicides, insecticides, growth regulators, and defoliants on western burrowing owls (Athene cunicularia hypugaea) that winter in agricultural landscapes in southern Texas, United States. The model generated reasonable movement patterns for each chemical through soil, water, insects, and rodents, as well as into the owl via consumption and dermal absorption. Sensitivity analysis suggested model predictions were sensitive to uncertainty associated with estimates of chemical half-lives in birds, soil, and prey, sensitive to parameters associated with estimating dermal exposure, and relatively insensitive to uncertainty associated with details of chemical application procedures (timing of application, amount of drift). Nonetheless, the general trends in chemical accumulations and the relative impacts of the various chemicals were robust to these parameter changes. Simulation results suggested that insecticides posed a greater potential risk to owls of both sublethal and lethal effects than do herbicides, defoliants, and growth regulators under crop scenarios typical of southern Texas, and that use of multiple indicators, or endpoints provided a more accurate assessment of risk due to agricultural chemical exposure. The model should prove useful in helping prioritize the chemicals and transfer pathways targeted in future studies and also, as these new data become available, in assessing the relative danger to other birds of exposure to different types of agricultural chemicals.     

山地林火蔓延模型的研究

建立了有风速有坡度条件下的林火蔓延模型,并进行了模拟山丘条件下的数值计算和实验模拟。通过对计算结果和实验结果的分析比较,获得了模拟山地条件下的一些流场变化规律,为进一步预测林火行为为奠定了基础,同时也证明了采用该模型的必要性。     

基于GIS的地震次生火灾蔓延范围模拟

地震次生火灾对人类的危害极大。笔者首先在对阻止火蔓延的因素进行分析以及对以往调查资料分析的基础上,确定了阻止火蔓延的距离与建筑物结构及防火类型的关系。然后,在阻止火蔓延距离的基础上,确定了地震次生火灾蔓延范围模拟的方法以及流程。最后,以汕头市为例,对地震次生火灾蔓延范围进行了模拟。通过对地震次生火灾蔓延范围的研究,为地震应急救灾提供了决策的科学依据。     

Computer simulations help determine safe vertical boom speeds for roof bolting in underground coal mines

PROBLEM: Incident investigation reports do not usually contain enough information to aid in studying boom arm vertical speed for roof bolting machines to determine the impact that appendage speed had on an operator's risk of experiencing a contact. Laboratory experiments with human subjects are also not feasible because of safety and ethical issues. METHOD: Researchers successfully developed a three-dimensional computer model that uses virtual human simulation software as the primary means to gather contact data when the boom arm touches the operator's hand, arm, head, or leg. RESULTS: Data analysis of roof bolter simulations shows that the speed of the boom arm is the most important factor in determining the risk of an operator making contact. Regardless of other variables, contact incidents were always greater when the bolter arm was moving up, greater on the hand, and greater for the boom arm part of the machine. The reason why the subject experiences more contacts when the boom arm is moving up rather than down is that more risky behaviors occur during drilling and bolting when the boom arm is ascending. Based on the data collected, boom speeds greater than 13 in/sec result in a substantial increase in risk to the roof bolter operator of making contact. Speeds less than or equal to 13 in/sec are associated with a more modest relative risk of making contact, which represents a decrease in potential hazard. IMPACT ON INDUSTRY: The use of such information can be quite helpful in making recommendations to machine design and task procedures to reduce the likelihood that roof bolter operators will experience injury due to contact with a moving roof bolting machine's boom arm.     

Risk communication in emergency response to a simulated extreme flood

Risk communication in flood incident management can be improved through developing hydrometeorological and engineering models used as tools for communicating risk between scientists and emergency management professionals. A range of such models and tools was evaluated by participating flood emergency managers during a 4-day, real-time simulation of an extreme event in the Thamesmead area in the Thames estuary close to London, England. Emergency managers have different communication needs and value new tools differently, but the indications are that a range of new tools could be beneficial in flood incident management. Provided they are communicated large model uncertainties are not necessarily unwelcome among flood emergency managers. Even so they are cautious about sharing the ownership of weather and flood modelling uncertainties.     

基于悬浮体系的大跨度铁路斜拉桥减震控制方案模拟分析

本文提出了基于悬浮体系的大跨度斜拉桥结构减震控制方案。用El Centro波模拟计算了采用非正常使用状态下,斜拉桥悬浮体系的空间动力反应,尤其是控制截面的内力反应,并与其它约束条件下的结构动力反应进行了对比,证实了采用悬浮体系,实现大跨铁路斜拉桥主动减震控制的可行性;进而利用联想记忆智能化混合结构控制算法,进一步优化结构控制效果,通过仿真计算说明了采用该控制算法实施控制的有效性;最后概略介绍了准备实施模拟试验的控制驱动装置方案,给出了本文的小结。     

矿井火灾计算机模拟研究

介绍了国内外矿井火灾计算机模拟技术发展的历史和现状。将现有的矿井火灾计算机摸拟方法分为稳态模拟、一维瞬态模拟和多维瞬态模拟，并对其特点进行了分析和评