Resource conflict detection and removal strategy for nondeterministic emergency response processes using Petri nets

Correctness of an emergency response process specification is critical to emergency mission success. Therefore, errors in the specification should be detected and corrected at build-time. In this paper, we propose a resource conflict detection approach and removal strategy for emergency response processes constrained by resources and time. In this kind of emergency response process, there are two timing functions representing the minimum and maximum execution time for each activity, respectively, and many activities require resources to be executed. Based on the RT_ERP_Net, the earliest time to start each activity and the ideal execution time of the process can be obtained. To detect and remove the resource conflicts in the process, the conflict detection algorithms and a priority-activity-first resolution strategy are given. In this way, real execution time for each activity is obtained and a conflict-free RT_ERP_Net is constructed by adding virtual activities. By experiments, it is proved that the resolution strategy proposed can shorten the execution time of the whole process to a great degree.     

双重重压下六国化工盈利能力分析及突围之路探析

2012年下半年以来，由于市场不景气导致中国化工行业产品价格下降，而成本却不断攀升，企业盈利能力不容乐观，六国化工也不例外。文章对六国化工进行了介绍，并利用杜邦体系分析法等盈利能力指标对其分析，进而提出了相关建议，以便于六国化工找到突破困境的途径，获得持久的竞争优势及长期可持续发展。     

The Big Family: Informal Financing of Small‐ and Medium‐Sized Businesses by Guanxi

Guanxi facilitates interaction between companies and people in Confucian societies. Does this type of social construct still play the key role, when the entrepreneurs live in Western societies? The objective of this article is to verify the impact of Guanxi on the capacity of small and medium‐sized businesses accessing financial resources informally. To this end, data collected from small Chinese entrepreneurs active in the principal business center of Brazil were used. From nonparametric tests, the results suggest that: (1) different levels of Guanxi allow small and medium‐sized businesses to access informal financial resources; (2) different types of informal financing are mostly used, or judged to be more significant, depending on the level of Guanxi of the entrepreneur in terms of parental and nonfamily ties; and (3) unlike the Western literature on the financial cycles of start‐ups, this type of informal financing can extend beyond the initial stage of the business. © 2014 Wiley Periodicals, Inc.     

高等学校统计学专业人才培养新探

本文通过对我国高等学校统计学专业人才培养所存问题的分析,从培养目标定位、优化课程体系、构建统计学"自主-互动"创新型课堂教学模式等方面,对高等学校统计学专业人才培养提出建议.     

A Brief Survey of Modern Optimization for Statisticians

Modern computational statistics is turning more and more to high‐dimensional optimization to handle the deluge of big data. Once a model is formulated, its parameters can be estimated by optimization. Because model parsimony is important, models routinely include non‐differentiable penalty terms such as the lasso. This sober reality complicates minimization and maximization. Our broad survey stresses a few important principles in algorithm design. Rather than view these principles in isolation, it is more productive to mix and match them. A few well‐chosen examples illustrate this point. Algorithm derivation is also emphasized, and theory is downplayed, particularly the abstractions of the convex calculus. Thus, our survey should be useful and accessible to a broad audience.     

慕课视野下高职院校的教学模式改革研究

在互联网高度普及的情况下,慕课作为一种新的知识传播手段,必然会带来教学模式的变化,对于高职教育也不例外。本文分析了纯慕课教学模式与传统教学模式的优劣,然后针对高职教育及高职学生的自身特点来构建高职混合慕课教学模式,以及应用该教学模式来有效提高高职学生的学习兴趣与学习效率、提高高职教师的教学水平和教学效率。     

统筹城乡发展中农民权益保障问题思考——以成都改革为对象的分析

农民问题的核心是农民的权益保障问题。论文对成都统筹城乡改革中有关农民权益保障,包括经济权益、社会权益、政治权益的基本情况进行了调研分析,在经验归纳的基础上指出,在坚持中国共产党及其政府作为制度的整体设计者与公共资源的主体供给者前提下,从农民的权益诉求出发,落实并保障农民的权益。     

学生管理创新应用研究

教师肩负着教育引导学生,培养他们树立正确的世界观、道德观、人生观、价值观的重任,化学教师如何在教学工作中融入传统教育的管理与创新应用,似乎一直是个比较难解的题。为此,笔者通过多年教学中总结的一些经验与同行分享。希望有更多的人关注在理化生等理科学科中,对学生进行有效引导与教育,帮他们走上成才之路。     

上部覆盖层下伏页岩一类潜在滑坡演化变形机制分析

为研究上部覆盖层下伏页岩这一类型的滑坡失稳变形,需要确定其变形的潜在影响因素,从定量角度上分析这一类型滑坡灾害的变形演化问题。以容县六王镇西流河潜在滑坡为研究对象,借助钻孔勘探、室内试验和地质调绘,详细分析了西流河滑坡的工程地质概况,并推测其可能的变形演化机制,然后利用Geostudio数值软件建立西流河滑坡的渗流模型,模拟其在不同降雨工况下的渗流规律。研究发现:西流河滑坡在持续降雨过程中稳定性系数从1.224逐步降低至1.09,稳定性系数不断下降,滑坡体内由垂直入渗逐步转化沿滑动带稳定渗流;当遭遇极端暴雨情况(50年重现期)时,滑坡体内稳定渗流场显著增厚,饱和滑带土增多,滑坡安全储备达到极限。由此可以得出:上部覆盖层下伏页岩一类滑坡变形演化过程主要分滑坡体上部覆盖层堆积阶段,垂直入渗至页岩富水软化阶段和稳定渗流至潜在滑动带软化蠕变这3个阶段;其中上部覆盖层的高渗透性和下伏页岩的隔水特征是导致页岩风化带软化蠕变和稳定渗流场形成的关键因素。研究结果为上部覆盖层下伏页岩这一类滑坡影响因素的研究提供了一些证据,对研究滑坡演化变形机制具有借鉴意义。     

多级政府级次下的经济增长与财政支出规模优化研究

笔者在巴罗经济增长模型的基础上,建立了一个两级政府提供公共物品的经济增长数理模型,说明政府级次划分对经济增长绩效的影响.并采用计量分析的方法,分别对我国中央政府与地方政府财政事权划分的合理性、最优事权划分标准进行了检验与测算.