一种具有时延保证的无线网络机会调度算法

提出了一种针对下一代无线网络的机会调度算法(PFQ-OS),其目标是提高无线网络中时间敏感业务的时延性能.由于时延性能同时依赖于资源分配算法和无线信道的传输容量,通过在传统分组公平排队(PFQ)策略中引入搜索半径(SR),并使用最大相对信噪比(Max-rSNR)准则,能够在提供有保证的服务时间基础上,提高每个用户的吞吐量.基于对PFQ-OS算法时延性能的理论分析,发现用户的时延性能直接由SR决定,为了使每个用户的时延性能均得到提高,有必要限定SR的取值.在此基础上我们提出了一个合理的时延性能目标,并设计了一个实际可行的迭代过程.通过大量的仿真对PFQ-OS算法的性能进行了详细的分析.     

一种提供QoS保证的公平跨层资源分配方案

提出了一种基于正交频分多址接入（orthogonal frequency division multiple access, OFDMA）系统的跨层资源分配方案。在保证各种业务服务质量（quality of service, QoS）要求的基础上,以获取系统最大吞吐量为目标,兼顾用户之间资源分配的比例公平性。该方案充分考虑了媒体接入控制（media access control, MAC）层各种业务的QoS要求和无线信道的大尺度衰落特性,将MAC层的分组调度与物理层的资源分配进行联合设计,MAC层根据物理层分配给每个用户的时变信道容量进行分组调度,物理层根据MAC层中各用户的队列状态信息为每个用户分配信道资源。仿真结果表明,该方案可以满足多用户各种业务的QoS要求,与采用等功率分配的依赖信道状态的分组调度（channel state dependent packet scheduling, CSDPS）算法相比可以提高系统下行总吞吐量,且较好地改善具有不同路径损耗的用户之间的公平性。     

一种基于业务优先级的跨层资源分配算法

提出了一种多用户MIMOOFDM系统中满足多种业务用户QoS需求的跨层自适应资源分配算法.利用各种业务的优先级在发送功率一定的条件下以吞吐量最大化为目标首先分配子载波,再分配子载波的出特和功率,最后分配空间子信道的比特和功率.仿真结果表明提出的算法能够根据信道条件在满足各种业务用户QoS需求的情况下动态的分配资源,而且能够有效的提高系统的吞吐量.     

一种针对无线多媒体业务的基于联合的缓存和调度的功率节省算法

一种有效的节省移动终端功率损耗的方法是在保证用户服务质量的前提下,尽可能的将无线网络接口(WNI)切换至休眠状态.然而我们发现,在多媒体业务流的分组到达间隔非常短的情况下,这个策略并不十分有效.提出了一个新的功率节省算法JBS.通过在基站设置一个整形代理,对多媒体分组进行缓存,JBS很好的解决了分组到达间隔较短对功率节省性能的不利影响.进一步,通过使用我们设计的功率节省的机会调度器POS,JBS能够使系统中每个多媒体用户获得较高的吞吐量,并得到很好的分组时延性能.对JBS的性能进行了细致的仿真,结果表明JBS能够在保证用户服务质量的前提下有效降低WNI的功率损耗.     

基于时间敏感软件定义网络的工业互联网时延优化方案

大规模工业通信网络中不同优先级的数据流量共同传输会导致网络拥塞、时延增大等问题，基于时间敏感软件定义网络(time sensitive software defined network, TSSDN)框架，提出一种网络时延优化方案。在数据链路层对工业网络中不同优先级的数据流量设计分类整形调度的增强型时间感知整形器(enhanced-time awareness shaper, E-TAS)算法，缩短网络排队时延，将最高优先级同步实时数据采取流预留的方式、将次优先级非同步实时数据采取帧抢占的方式进行调度，将低优先级非实时数据按其调度权重进行公平调度，同时在网络层结合使用基于时延的Dijkstra算法，缩短网络数据的传播时延。仿真结果表明，所提方案有效保证了不同优先级数据流量的时延要求，实现了网络总时延性能的优化。     

一种支持多用户QoS的跨层资源分配策略

提出了一种多用户OFDM系统中支持QoS的跨层资源分配策略。在MAC层采用有限长用户缓存模型,推导了丢包率要求引起的用户速率限制条件,将其作为跨层信息指导物理层资源分配过程。根据等待时延对用户进行分级,在保证所有用户QoS的前提下为高级用户优先分配子载波和功率。仿真表明,在报文到达率较高的情况下该策略既保证了吞吐量,又降低了系统丢包率。     

高速crossbar调度中的队列均衡及其仿真研究

提出一种简单、有效、硬件易实现的队列长度均衡策略，能够明显改善高速crossbar调度算法在非均匀业务流下的吞吐量和时延等性能．以典型的高速crossbar调度算法iSLIP为例，在各种非均匀业务流下对该均衡策略进行了仿真研究，结果表明：使用该均衡策略后，iSLIP吞吐量能够最多可以提高20％以上，并且时延性能得到大大改善。对于其它高速crossbar调度算法，该均衡策略具有类似的性能改善效果。     

无线多跳网络中基于QoS的自适应拥塞控制方案

提出的无线多跳网络中基于服务质量(QoS:Quality of service)的自适应拥塞控制方案是从两个方面实现拥塞控制和QoS保证的.一方面,通过控制路由请求过程,为实时业务选择时延较短的路由,为非实时业务选择时延较长的路由来控制拥塞并保证QoS.另一方面,按照QoS等级减小邻居结点的转发业务来增加拥塞结点占用信道的概率,从而消除拥塞并保证QoS.该方案的特点在于综合考虑了拥塞控制和QoS保证,能在控制拥塞的过程中提高服务的QoS质量.论文建立了路由发现成功率、端到端时延和丢包率的性能分析模型,并对提出的方案进行了性能分析.性能分析和仿真结果表明我们提出的方案能够有效的控制拥塞,并保证实时业务的QoS.     

一种关联时效的OFDM系统调度算法仿真

在OFDM系统中,目前主流的调度算法在考虑缓冲区的时候,都默认其为无限大,并且每类业务的包大小都是固定的,这些假设不完全符合实际情况,使得算法的实用性不高.在考虑有限缓冲和包大小不固定的基础上,更实际性地考虑各类业务的时延需求,提出了一种新的调度算法,即在兼顾有限缓冲和包大小不固定的同时,用一个时间效用函数来表示业务被服务的紧迫性,进而通过调度保证各类业务的数据包在它所能承受的最大时延范围内传输数据,从而保证各类业务的时延约束.     

Multi-power multi-radio传感网中联合调度、信道和功率分配的最优路由策略

研究了multi-power multi-radio无线传感器网络中联合调度、信道和功率分配的最优路由问题,并利用线性规划方程设计了该问题的最优路由方案,同时联合解决了链路调度、信道和功率分配问题.然后针对最优路由问题的NP复杂性,设计了有效的多项式时间解决方案.实验结果表明,提出的联合优化的路由方案能有效地减小端到端的传输时延和能量消耗.     

The 12th International Conference on Service Systems and Service Management ICSSSM'15

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Enterprise resource planning implementation decision & optimization models

To study the uncertain optimization problems on implementation schedule, time-cost trade-off and quality in enterprise resource planning (ERP) implementation, combined with program evaluation and review technique (PERT), some optimization models are proposed, which include the implementation schedule model, the timecost trade-off model, the quality model, and the implementation time-cost-quality synthetic optimization model. A PERT-embedded genetic algorithm (GA) based on stochastic simulation technique is introduced to the optimization models solution. Finally, an example is presented to show that the models and algorithm are reasonable and effective, which can offer a reliable quantitative decision method for ERP implementation.     

A calculus for services innovation

Innovation in the services area - especially in the electronic services （e-services） domain - can be systematically developed by first considering the strategic drivers and foci, then the tactical principles and enablers, and finally the operational decision attributes, all of which constitute a process or calculus of services innovation. More specifically, there are four customer drivers （i.e., collaboration, customization, integration and adaptation）, three business foci （i.e., creation-focused, solution-focused and competition-focused）, six business principles （i.e., reconstruct market boundaries, focus on the big picture not numbers, reach beyond existing demand, get strategic sequence right, overcome organizational hurdles and build execution into strategy）, eight technical enablers （i.e., software algorithms, automation, telecommunication, collaboration, standardization, customization, organization, and globalization）, and six attributes of decision informatics （i.e., decision-driven, information-based, real-time, continuously-adaptive, customer-centric and computationally-intensive）. It should be noted that the four customer drivers are all directed at empowering the individual - that is, at recognizing that the individual can, respectively, contribute in a collaborative situation, receive customized or personalized attention, access an integrated system or process, and obtain adaptive real-time or just-in-time input. The developed process or calculus serves to identify the potential white spaces or blue oceans for innovation. In addition to expanding on current innovations in services and related experiences, white spaces are identified for possible future innovations; they include those that can mitigate the unforeseen consequences or abuses of earlier innovations, safeguard our rights to privacy, protect us from the always-on, interconnected world, provide us with an authoritative search engine, and generate a GDP metric that can adequately measure the growing knowledge economy,     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

正August 10-14,2015Beijing,China The International Congress on Industrial and Applied Mathematics(IClAM)is the premier international congress in the field ofapplied mathematics held every four years under the auspices ofthe International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists and entrepreneurs fiom around the world will gather in Beijing,China for the 8th IClAM to be held at     

论生物系统中的功能不守恒性

根据能量守恒定律，能量一次转换所做的总功应等于输入的总能量。但在生物系统中，能量的转换是多次的，其总功之和大于系统输入的总能量，此现象称之为功能不守恒性。能量转换效率越高，功能差别越大。能量通过细胞水平的多次转换，总功可提高至2倍左右。能量通过生态系统水平多次转换，总功可提高至1．4倍左右。通过系统内各子系统能流之和称为序能，反映了系统有序性大小，它取决于系统输入总能量和能量转换效率。根据序能原理，用GDP^2／9(GDP为国内生产总值，Q为能量总输入)反映人类社会功能和效率，要比单纯用GDP更客观。绿色GDP应同时考虑使GDP^2／Q增长最大和使自然生态系统的序能最大。人的经济行为和动物的行为对策也符合序能原理。     

Dealing with Human Relations in Chinese Systems Practice

This paper is about the Wuli, Shili, Renli (WSR) systems methodology. An important concept within this, Renli, has been developed from Confucian philosophy to clarify to Chinese researchers the necessity of dealing with human relations in systems practice. At present, the only formal means of operationalizing Renli that people are exploring in China is to import from the West methods for organizing debate. However, the concept of Renli suggests that more is needed than methods alone. In particular, facilitation skills are required. It is argued that the development of facilitation skills can be enhanced if researchers can gain both theoretical and practical knowledge of group dynamics, and engage in activities of self-reflection to look at, and alter, their own roles in these dynamics and the wider sociopolitical system. There are therefore three aspects to Renli: the use of systems methods for organizing debate, the acquisition of facilitation skills, and self-reflection geared toward the development of facilitation skills and enhanced critical awareness of the politics of intervention.     

云环境中邮件服务器面向传输的优化设计

随着云计算的发展,新的应用不断涌现,但电子邮件服务依然占有着重要的地位.邮件服务器是一种I/O密集的应用.在云计算时代,越来越多的用户邮件保存在服务器端,邮件在从客户端传输到服务器端之前,邮件或者邮件的部分内容在服务器端可能已经存在.基于这种现象,提出了一种方案,通过引入计算的代价来降低通信量,从而提高邮件服务器的处理能力.对电子邮件的格式和SMTP协议进行了扩充,引入了附件和正文分离传输的模式.在邮件传输时,客户端先计算附件的散列值,并作为正文的一部分传输到服务器端,服务器端再根据散列值来判断附件是否需要传输.     

金工工艺的优化设计

运用价值工程与运筹工程理论, 在金工工艺单项设计指标优化的基础上, 对其设计指标也进行了全面优化。     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

正August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists