The Impact of Population Aging on Housing Demand in China Based on System Dynamics

In recent years, the proportion of China's elderly population is gradually increasing, and the real estate market is changing dramatically. Consequently the impact of population aging on housing demand has become increasingly prominent. On the theoretical basis of the relationship between population aging, family structure and housing demand, this paper firstly constructs a system dynamics model of the impact of population aging and family structure on housing demand in China. Then,the model is simulated, and several scenarios of population, family structure, and real estate policies are set up. The main conclusions of this paper are as follows: China's population will rise at first and then decrease, reaching a peak of 1.401 billion by 2023. As the proportion of elderly population increases, the degree of population aging is becoming increasingly serious. The size of the family will gradually shrink to 2.39 people per household in 2050. The housing demand will increase first and then decrease. Through the results of scenario simulation, this paper puts forward the following suggestion to effectively balance the housing demand in China: Completely relaxing family planning policies,imposing a real estate tax, canceling the pre-sale policy, and raising the loan rate.     

仿真网格原型系统SimGrid-HLA的设计与实现

在分析作战效能仿真评估系统功能的基础上，结合三方利益相关人：想定开发方、运行管理方和模型管理方的实际需求，提出基于HLA的仿真网格系统三层结构，该结构分为应用层、HLA/RTI层和模型层三层。并对其原型系统SimGrid-HLA的主要组成部分：模型注册器、索引管理器和方案管理器进行了详细的分析设计，该原型系统完成模型信息的注册、发现、管理以及方案编辑执行。SimGrid-HLA原型是对仿真网格的初步尝试，为大规模军事仿真的开展途径进行了有效探索。     

基于贝叶斯修正的多阶段情景元素生成

针对证券市场中资产未来收益的不确定性问题,本文基于随机波动率模型刻画了资产未来收益的情景元素,得到了资产未来收益分布的情景树,并在此基础上进一步采用贝叶斯理论修正了情景概率,最后利用国际证券市场的股票指数数据对模型进行了验证.算例结果表明,基于随机波动率模型的情景元素生成模型得到的情景元素质量良好,贝叶斯方法修正后的情景概率也与真实市场情况更贴合.     

基于SD模型的水生态承载力模拟优化与例证

提出了系统动力学和投影寻踪法的水生态承载力模拟和优选方法,以常州市为例进行实证研究. 采用情景分析法,从节水和污染控制方面,设计了零方案,节水方案,污染控制低方案,污染控制中方案和污染控制高方案等5个情景方案. 通过Vensim DSS软件建立SD （system dynamics）模型和模拟仿真平台,模拟了2020年常州市水生态承载力,得到5种情景方案的模拟结果. 采用遗传投影寻踪法,对5种情景方案进行优选,推荐方案为污染控制高方案,在该方案下,2020年常州市可承载的人口数量为481万人,GDP总量可达到6094亿元,相应的水资源开发利用率为48.8%,最大水环境容量利用率为100%,要达到以上水生态承载力目标,必须提高水资源利用效率,降低重点污染行业增长速度,增加污水治理投资金额,提高污水处理率等. 研究结果为评估水生态承载力提供了理论依据,为研究区水生态环境保护和经济社会发展提供了决策参考.     

PERSPECTIVES ON URBAN WATER INFRASTRUCTURE IN CHINA FOR THE 21~(ST) CENTURY: SDMUWEIC MODEL

Based on system dynamics approach, SDMUWEIC model is developed in order to evaluate future dynamics of urban water infrastructure development in China. Firstly, this paper presents the basic structure and characteristics of the model, focusing on water infrastructure's dynamic relationships with population increase, economic development, water resources shortage and water conservation practices. Secondly, model veracity and robustness tests based on behavior reproduction and uncertainty analyses are illustrated. Thirdly, based on the model, future patterns of China's urban water infrastructure investment requirements are simulated, and effectiveness of two different policy scenarios are evaluated. Finally, conclusions and policy implications are drawn, allowing insights into China's sustainable water infrastructure policies and managements.     

突防弹与EKV对抗数字仿真系统设计与实现

为更好进行机动突防及拦截仿真研究,设计了一个弹道导弹与大气层外动能拦截器（EKV）攻防对抗的数字仿真系统。在统一的空间与时间中,建立了弹道导弹的飞行状态模型、拦截导引模型、剩余飞行时间估计、脱靶量计算等系统算法模块,并对目标机动突防、比例与最优导引拦截等想定进行数字仿真。结果表明：该系统可在多种对抗环境下检测攻防性能,采用模块化设计便于算法升级或想定变换,为拦截、规避性能评估,攻防对抗策略研究等提供性能测试平台。

Abstract：

To research on missile maneuver and intercepting simulations better, a numerical simulation system for onrushing missile versus intercepting EKV was set up. With the same coordinate system and clock, the ballistic missile flight state model, EKV guidance model, the time-to-go estimation algorithm and miss distance calculation algorithm were all accomplished. At last, the scenarios that target maneuver, interceptor guided by proportional navigation （PN） and by optimal guidance law （OGL） were simulated in the simulation system. It indicates that the system can run well in such scenarios. It is designed by modularization that makes it easy to upgrade algorithm or scenario. The system provides a nice performance test flat roof to the missile maneuver, intercepting and drawing a counterplot.     

考虑多种因素的一类三寡头R&D投入系统复杂性研究

建立了新兴产业中一个带有技术溢出和内生需求的动态三寡头RD投入博弈模型,着重讨论了决策调整速度和技术溢出率对于模型复杂性的影响。通过三维稳定域研究了模型的纳什均衡点对于决策调整速度和技术溢出率的稳定性,通过二维分岔图对模型的局部分岔进行了分析研究,发现如果决策调整速度过快,系统会通过flip或N-S分岔失去稳定,并最终走向混沌。同时研究了RD投入调整速度和技术溢出率造成的系统失稳对于各寡头利润的影响程度,发现系统失稳对于各方利润的影响不尽相同,控制技术溢出率,可以确保合作的两个寡头的利润优势。对该模型进行了全局分岔分析,发现寡头们的每一次决策值都不可以盲目的过高。     

基于SPEAR Ⅱ的Kerberos协议安全性分析

Kerberos认证是云计算安全采用的信息安全技术之一,对Kerberos协议进行形式化验证可以有效发现和避免协议设计缺陷和攻击。采用一种自动安全协议建模和分析工具SPEAR Ⅱ对Kerberos协议的安全性进行了分析。首先设计了窃听、重放和篡改攻击场景并分析了以上场景中通信主体的特点,在此基础上提出推理假设,然后通过SPEAR Ⅱ中基于Prolog的分析引擎从协议假设条件推导到协议目标。结果表明,Kerberos协议可以抵抗窃听和重放攻击,保护合法用户密钥的安全,但在篡改攻击下,若信任主体被攻陷,则攻击者可以通过伪造密钥骗取合法用户的信任,并与合法用户建立通信。     

巡航导弹弹载干扰机性能分析与仿真

为精确分析巡航导弹弹载干扰机的干扰性能,建立了考虑电波传输损耗、干扰天线特性、雷达接收机性能、巡航导弹雷达反射面积的干扰与探测的对抗模型,并在雷达天线指向导弹而弹载干扰机天线不一定指向雷达的最坏情形下,对不同的干扰压制比、干扰天线与雷达天线夹角、干扰频率、目标雷达反射面积下的干扰机最小干扰距离进行了仿真,精确得出巡航导弹弹载干扰机在不同作战环境下的干扰能力。     

国民经济动员仿真演练情景生成与调度

国民经济动员仿真演练涉及的参演单位众多,流程复杂,组织机构结构不确定,要求仿真演练系统框架能够适应较大的变化,具有较高的通用性。现有的基于EBAT的团队训练方法扩展性和重用性较差,不能很好的满足国民经济动员仿真演练的通用性需求。为了解决这一问题,在EBAT的基础上提出了一种通用的情景生成与调度框架。同时,针对演练情景的描述、生成与调度等核心问题提出了相应的解决方案。这种框架设计灵活、可扩展性强,提高了系统的通用性,并且已经在国民经济动员仿真演练中得到了实际应用,其有效性得到了验证。     

网络模拟器中分层路由协议的问题及改进

网络模拟被广泛地应用在网络研究领域,以测试和评价网络协议的性能。在目前被广泛使用的网络模拟器ns中,分层路由协议只能静态地计算路由,而不能在模拟的过程中动态适应网络拓扑的变化。本文首先深入分析了ns分层路由协议实现中的不足,然后介绍了一个经典的分层动态路由协议,给出了其在ns中的实现框架和细节,最后是模拟结果和性能分析。     

随机能力规划的Scenario模型及其决策风险分析

为研究随机环境下的生产能力扩张问题,采用Scenario方法,建立了市场需求量和产品价格为随机变量的多计划期能力规划决策模型.其中考虑了两种情况：一是能力投资方案不随市场需求的随机实现而变化的预报型模型,二是投资方案可以跟踪市场需求随机实现的适应型模型. 算例研究比较了这两种模型的决策效果.进一步,使用下方风险分析,探讨了随机能力扩张的投资决策风险,建立了考虑期望收益风险的预报型能力规划决策模型.该模型在随机规划中加入了一个期望下方风险约束,以反映决策者的风险偏好,基于算例讨论了考虑风险和不考虑风险时的决策差异.     

水环境危机下北京市水资源供需平衡系统动力学仿真研究

本文利用系统动力学研究了水环境危机背景下的北京市水资源供需平衡问题.首先,将北京市水资源供需平衡系统划分为两个主要的子系统进行建模分析.其次,基于供需平衡模型,建立了水资源供需平衡系统动力学仿真模型.最后,在仿真对比分析基础上,提出了缓解北京市水资源供需矛盾的方案.     

Application of Scenario-based Approaches in Leadership Research: An Action Research Intervention as Three Sets of Interlinked Practices

This article illustrates how scenario planning (SP) and scenario analysis as can be conceptualised as practices contributing to an action research (AR) investigation of leadership development. The project described in this article was intended to strengthen leadership capacity in Australia’s rapidly changing aged care and community care sector. A research team comprising academics from three universities and managers from two faith-based not-for-profit organisations providing aged and community care participated in this study. As part of the research, two sets of scenario-based workshops were held: the first, to identify possible futures using SP; and the second, to deal with plausible scenarios these organisations are likely to face with the changes happening in the aged care environment in Australia by using scenario analysis. Although the researchers did not consider a link between practice theory and AR during the SP phase, practice theory became useful during the scenario analysis phase. The article includes a brief literature review followed by a discussion on the relationship between AR and practice theory. The processes used in the two sets of scenario workshops are then described in detail along with the data collected and analysed. The article concludes with some reflections on the use of scenarios in practice as well as an acknowledgment that practice theory would be useful in investigating leadership capability development.     

基于收益-风险双目标规划的随机能力扩张模型

能力扩张问题是指在不同计划期,根据不断增长的市场需求,调整生产能力,使产能与需求合适匹配以寻求企业盈利的最佳表现.能力扩张涉及长期的产能投资,是生产领域的战略决策问题.当面对不确定需求时,这一决策任务变得十分复杂,需要从回报与风险两个角度评估能力扩张方案的性能.本文基于Scenario树描述多阶段的随机需求,从而建立随机环境下能力扩张问题的Scenario决策模型.其中考虑两个决策目标:最大化利润和最小化期望下方风险,因而形成了一个双目标规划问题.为求解该问题,基于二进制粒子群优化技术,提出了双目标优化的粒子群算法.算例表明该算法可以得到近似Pareto前沿,且能揭示利润与风险的同向变化关系.     

Coordination of a fashion and textile supply chain with demand variations

Owing to the changing fashion trends and a volatile market situation,demand in fashion and textile (FT) industry is unpredictable and could vary and change completely in a short time,which makes it more difficult to coordinate a FT supply chain.A change in product preference due to fashion trends is the main reason why the demand of FT industry shows more variations than other industries.In this paper,we use a well known contract,the all-unit quantity discount policy(AQDP),to coordinate a FT supply chain with certain demand,and we further consider it under the demand variations scenario to investigate whether it can still coordinate the supply chain.In detail,before the selling season,an AQDP is provided by the manufacturer to the retailer,and under which the FT supply chain coordination achieved with a certain demand.During the selling season,demand variation is realized after an abrupt changing of fashion trends,therefore,the manufacturer may need to revise the original AQDP to insure the supply chain is still coordinated.Utilizing the mechanism design theory,we prove that:(i) while the traditional AQDP can coordinate the supply chain when no demand variations,it cannot always coordinate the supply chain after the demand variations;(ii) when the AQDP fails,we can use the proposed capacitated linear pricing policy(CLPP) to achieve a new coordination;(iii) a more dominant decision maker,who can set a higher profit goal,is favorable to stabilization of the supply chain system under demand variations.Numerical examples are proposed also to show our results.     

建筑业与房地产业发展的互动机理及效应仿真

采用系统动力学原理和方法,从投入与产出角度提出了建筑业与房地产业发展的动力机制和动力模型。根据我国1992年至2007年建筑业、房地产业及宏观经济发展的历史数据,模拟和预测了我国建筑业、房地产业发展现状及发展趋势;改变建筑业投资,模拟并预测其对建筑业、房地产业的影响效应。设定金融危机对建筑业和房地产业的影响参数,模拟并预测其对建筑业和房地产业的影响程度;在此基础上,设定建筑业增加3万多亿投资的参数,模拟金融危机情形下增加建筑业投资对建筑业和房地产业的拉动效应。研究结果证明,建筑业与房地产业发展互动影响效应明显;在金融危机的情形下,对建筑业增加投资,能有效促进建筑业及房地产业等关联产业的持续增长,促进GDP的持续上涨。     

空间目标天基监视分布式仿真系统设计

以HLA在航天系统仿真领域的广泛应用为背景,设计了基于HLA的空间目标天基监视分布式仿真系统。在系统架构层面,设计数据层、模型层、任务层的分层结构。在系统设计方面,设计仿真控制成员、天基监视成员、光学载荷成员、空间目标成员和视景仿真成员,建立天基监视系统中的轨道动力学及机动模型、姿态动力学与控制模型、载荷指向及目标成像模型。在系统实现方面,基于RTI进行系统集成。应用Vega Prime和OpenGL实现天基监视视景仿真和光学成像仿真,完成空间目标天基监视任务的仿真验证。     

案例驱动的社区应急疏散准备规划启动时机识别

有效的应急疏散准备规划是提升应急疏散能力的关键.已有研究关注规划的理论建模及工作机理,忽略了何时启动规划,即应急疏散准备规划的启动时机识别这一重要问题.社区是城市应急管理的基层组织,是实施应对的基本单元.面向城市社区,阐述如何基于案例驱动实现社区应急疏散准备规划的启动时机识别.考虑到不同社区的案例适用性不同,通过社区特征相似性度量和适用度概率分配选择适用案例;以灾害情景要素特征为指标,运用聚类算法生成用于启动时机识别的模拟灾害情景组;根据案例建立模拟情景与预期疏散效果之间的联系,生成启动时机的识别结果.最后,通过对广东省社区的调查用例分析来验证该案例驱动方法的可行性.     

燃料电池客车CAN通信协议仿真

参照SAEJ1939协议设计了燃料电池客车的CAN通信协议，并利用CANoe进行仿真以评估其性能。结合整车和各个节点（电机、DC／DC、燃料电池和蓄电池）的数学模型，通过仿真对比了定周期、周期有误差、事件触发、有错误帧以及最坏情况等情况下总线负载变化，验证了协议的正确性和有效性。为车载网络实时通信系统的实际设计提供了参考依据，能降低开发成本并缩短开发周期。