基于Agent的网构软件模型研究

以开放网络环境下的网构软件需求为切入点，基于软件Agent的原理、方法和技术，系统分析了基于面向对象方法学的经典软件结构模型及其支撑技术的限制，提出了一种开放协同软件模型来作为网构软件的基础模型．结合其关键支撑技术的研究，提出了基于移动Agent的协同程序设计技术、多模式交互机制及基于Agent中间件模型和面向体系结构的协同程序设计方法，并探讨其在主流软件技术中的应用，初步形成了一种适合于开放网络环境需求的技术框架体系，在此基础上，提出了一条建立基于Agent的网构软件模型的技术途径，即网构软件模型=开放协同模型＋环境驱动模型＋智能可信模型，从而为进一步的研究工作奠定了基础．     

跨流域调水管理仿真的Agent结构模型

鉴于传统水资源开发配置和调度管理普遍采用系统动力学方法进行系统仿真，有一定局限性，采用复杂适应系统理论以及多Agent建模方法分析了跨流域调水管理过程的层次结构，结合南水北调东线水资源调度管理系统，设计了一种基于复杂适应系统仿真的Agent结构模型，并对Agent结构模型的形式化描述和特点进行分析，最后基于swarm仿真平台进行了仿真和验证。结果表明跨流域调水管理仿真的Agent结构模型可以协调好智能体的反应性和适应性，满足了跨流域调水管理复杂适应系统仿真中对Agent的不同要求。     

JXTA网络中资源搜索模型的研究与实现

本文改进了对等节点的功能分工和网络层次结构,并引入移动Agent技术,通过移动Agent在集合点之间传播查询通告,提出了一种基于JXTA技术和移动Agent的新资源搜索网络模型,并实现了一个建立在P2P网络上的使用移动Agent进行资源搜索的系统--AJMAS.实验结果表明.通过改进网络结构及相应的搜索策略,能够极大地提高网络的适应性和搜索速度.使基于JXTA协议的P2P网络不再仅仅是一种理论上的研究模型,它将具有很好的应用前景.     

攻防对抗仿真在武器装备体系论证中的若干问题研究

介绍了作为武器装备体系论证定量分析基础的攻防对抗仿真,分析了武器装备体系攻防对抗仿真和建模需要注意的几个问题,重点探讨了基于元模型、基于（智能体）Agent技术的复杂系统建模方法,研究了复杂系统的多分辨率建模,构建了基于HLA的武器装备体系攻防对抗仿真系统体系结构,提出了基于仿真的武器装备体系效能探索性评估方法的思路.     

量子测距辅助的网络RTK定位算法研究

针对在GPS网络载波相位实时动态差分(RTK)中短观测历元内,由位置精度因子(PDOP)变化缓慢引起的整周模糊度准确求解困难的问题,提出了采用量子高精度测距辅助整周模糊度的求解方法.采用Householder变换代替双差法,确保了用于求解整周模糊度的各个观测量之间的相互独立,提高了整周模糊浮动解的求解稳定性.数学分析和仿真结果验证了上述方法的准确性和有效性.     

一种基于证据理论的结构可靠性优化设计方法

针对包含认知不确定性的结构可靠性问题,提出了一种基于证据理论的可靠性优化设计方法.首先,在优化过程中基于代理模型对迭代点处各约束进行可靠性分析,计算其似真度;其次,通过证据变量均匀化方法构造了一种证据理论可靠性的近似梯度计算方法,从而可采用基于梯度的常规优化算法进行优化求解;最后,数值算例和工程算例表明了本方法的有效性.     

梯级水电站群长期发电优化调度多核并行随机动态规划方法

随机动态规划求解水电站群长期发电优化调度易产生"维数灾"问题,导致计算耗时急剧增加,求解效率降低.如何缓解维数灾和提高计算效率,一直是水库优化调度致力于研究的难点问题.在随机动态规划的并行性分析基础上,提出了基于Fork/Join并行框架的多核并行随机动态规划方法.该方法将单个时段内所有变量组合状态下的计算任务作为父任务,通过分治法递归分解为多个子任务,并平均分配到不同的内核同时计算实现细粒度并行求解.以澜沧江下游梯级水电站群为研究实例,建立了3个变量离散数不同的调度方案,并在多核环境下验证该方法的计算效率.结果表明,在2和4核环境下,该方法的计算耗时与串行方法相比,分别节省了约50%和70%,大幅度缩减计算耗时,可充分利用多核资源;同时,计算任务的规模越大,并行计算的耗时缩减幅度越大.因此,此方法为大规模水电系统优化调度提供了一种可行途径,其并行原理可为其他应用所借鉴.     

结构包含密集模态时主动振动控制中作动器/传感器的优化配置

分析了已有的作动器/传感器配置方法的不足,针对包含密集模态的挠性结构,分析其可控/可观度的特殊性,提出了针对密频系统的作动器/传感器优化配置准则.通过可控性Gram阵的分块解析形式,避免了求解高阶Lyapunov矩阵方程,并利用了轻阻尼疏频系统自然平衡的条件,降低了求解可控度,即可控性矩阵奇异值的计算量.在此基础上用遗传算法寻优,得到元件的优化配置方式.最后通过算例与另外两种基于可控度的优化配置方法对比,证明依本文方法配置密频系统的作动器/传感器,振动控制效果最优.     

需求-服务匹配视角下的技术型知识员工任务指派问题研究

基于服务系统中需求-服务匹配视角对具有多种能力、异质效率的技术型知识员工任务指派问题进行分析,提出任务执行窗和可并行任务组概念,建立多阶段的员工分配决策路径图;然后,以任务-员工效率匹配度为目标建立优化模型,并运用动态规划法进行模型求解,确定员工任务指派最优路径,实现员工最优配置;最后,通过算例进行验证。     

考虑质量设计的合同组批生产问题研究

针对在制定组批方案中可能会产生的质量浪费现象,在考虑质量设计因素的基础上,建立以质量离散度为优化目标的组批模型,进而设计出考虑质量设计的合同组批算法。该算法改进了粒子群算法以实现聚类组批,首先松弛设备容量限制,以合同的质量离散度最小为目标,运用粒子群算法进行聚类计算,得到初步的组批方案;然后考虑设备容量约束,基于质量离散度最小原则,对违背设备容量范围的批次进行修复调整,得到最终的组批方案。以某大型国有钢铁集团的无缝钢管厂为例,基于生产实际数据设计了数据实验,以质量离散度为评价指标,将本文算法与基本粒子群算法进行对比,探讨了批次数量对问题求解的影响。实验结果表明,本文提出的模型和算法是可行和有效的。     

Worker lipid stores decrease with outside-nest task performance in wasps: Implications for the evolution of age polyethism

Recent models of energetically efficient division of labor in eusocial insects predict that risky tasks will be performed by workers with low nutrient content. We measured changes in workers' nutrient stores (chloroform: methanol extractable lipids) in relation to age-based division of labor in the eusocial waspPolybia occidentalis to test this prediction. Distributions of age of first performance differed among task sets; tasks at increasing distance from the nest interior were performed later in life. However, individuals varied in the rate of passage through the task sequence. Weight of extractable lipids, corrected for differences in body weight, decreased with time elapsed since first performance of tasks outside the nest. Lipid content had a weaker negative relationship with adult age. Therefore, patterns of lipid decrease reflected individual differences in age polyethism. Age-based division of labor, with performance of risky tasks delayed until late in life by workers with depleted nutrient stores, may have evolved as an energy saving mechanism for insect colonies.     

Performance evaluation of the New Connecticut Leading Employment Index using lead profiles and BVAR models

The leading and coincident employment indexes for the state of Connecticut developed following the recession of the early 1990s fell short of expectations. This paper performs two tasks. First, it describes the process of revising the Connecticut Coincident and Leading Employment Indexes. Second, it analyzes the statistical properties and performance of the new indexes by comparing the lead profiles of the new and old indexes as well as their out‐of‐sample forecasting performance, using the Bayesian Vector Autoregressive (BVAR) method. The new coincident index shows improved performance in dating employment cycle chronologies. The lead profile test demonstrates that superiority in a rigorous, non‐parametric statistic fashion. The mixed evidence on the BVAR forecasting experiments illustrates that leading indexes properly predict cycle turning points and do not necessarily provide accurate forecasts except at turning points, a view that our results support. Copyright © 2006 John Wiley & Sons, Ltd.     

Flippases: still more questions than answers

Our understanding of flippase-mediated lipid translocation and membrane vesiculation, and the involvement of P-type ATPases in these processes is just beginning to emerge. The results obtained so far demonstrate significant complexity within this field and point to major tasks for future research. Most importantly, biochemical characterization of P₄-ATPases is required in order to clarify whether these transporters indeed are capable of catalyzing transmembrane phospholipid flipping. The β-subunit of P₄-ATPases shows unexpected similarities between the β- and γ-subunits of the Na⁺/K⁺-ATPase. It is likely that these proteins provide a similar solution to similar problems, and might have adopted similar structures to accomplish these tasks. No P₄-ATPases have been identified in the endoplasmic reticulum and it remains an intriguing possibility that, in this compartment, P_5A-ATPases are functional homologues of P₄-ATPases. Received 19 June 2008; received after revision 31 July 2008; accepted 15 August 2008     

Viral capsids: Mechanical characteristics,genome packaging and delivery mechanisms

The main functions of viral capsids are to protect, transport and deliver their genome. The mechanical properties of capsids are supposed to be adapted to these tasks. Bacteriophage capsids also need to withstand the high pressures the DNA is exerting onto it as a result of the DNA packaging and its consequent confinement within the capsid. It is proposed that this pressure helps driving the genome into the host, but other mechanisms also seem to play an important role in ejection. DNA packaging and ejection strategies are obviously dependent on the mechanical properties of the capsid. This review focuses on the mechanical properties of viral capsids in general and the elucidation of the biophysical aspects of genome packaging mechanisms and genome delivery processes of double-stranded DNA bacteriophages in particular. Received 14 October 2006; received after revision 18 December 2006; accepted 27 February 2007     

互联网时代语音识别基本问题

语音识别技术经过半个世纪的积累,于近年来达到大规模商用水平．本文概括了统计语音识别理论的发展状况,并单独介绍了深度神经网络在声学建模、语言建模、多语言共享、语义识别等方面的卓越性能．深度神经网络的性能优势引起了我们强烈的兴趣．通过回顾类人听觉信息处理对深度神经网络的改进作用,我们意识到,深度神经网络与类人听觉信息处理相结合,必将推进语音识别技术的进一步发展．反过来,深度神经网络技术在语音识别中的进步,也必将推动类人听觉信总、处理技术的进步．语音识别技术后续发展的重点是对深度神经网络的结构和训练算法的改进使之更好地实现类人听觉．最后,我们分析了采用深度神经网络模拟人类听觉的抗噪修复机理和听觉关注机理的可能性．     

基于LPC2132和μC／OS-Ⅱ的脑电检测系统设计

本文阐述了脑电检测系统的原理;系统由信号采集单元和以ARM7为核心的中央处理器LPC2132两大部分组成。信号采集单元承担了脑电信号的采集、放大滤波的任务。将处理过的脑电信号送入LPC2132芯片中,对脑电信号进行后续处理。LPC2132所实现的功能有：AD转换、数据存储、显示波形等。由于微处理器所承担的任务多且切换频繁,在内核植入了μC／OS-Ⅱ操作系统。本文详细阐述了在LPC2132微处理器中植入μC／OS-Ⅱ操作系统所要进行必要的设置和任务创建的步骤。     

Stress and putative endogenous ligands for benzodiazepine receptors: the importance of characteristics of the aversive situation and of differential emotionality in experimental animals.

The relationships between anxiety/stress, possible endogenous ligands for benzodiazepine receptors and the behavioral modification by drugs are discussed in this short review, including the specific characteristics of elements involved in those interactions, e.g. ones concerning the aversiveness of the stressful situation and the nature of the organism under investigation. These are important factors when considering aversive tasks, insofar as they may involve stressful conditions which differ in intensity and in the degree of control afforded the subject. These characteristics may well lead to differing functional effects on GABA-gated chloride channels or, in other words, to an incongruous balance between endogenous benzodiazepine receptor agonist and inverse agonist activity. This is not surprising, as it is well known that different forms of stressors often actually produce divergent behavioral, physiological and biochemical effects. This review also illustrates the necessity of taking into account the variable effects of stressors and/or drugs on animals differing in reactivity or emotionality, even in the case of 'non-selected' stocks. The implication is made that, by genetic and/or environmental manipulation of the emotional state of the animals used, it will be possible to obtain more clearly definable results in neuropharmacological and psychopharmacological studies.     

一种基于时序感知的社会网络节点集情境聚合方法

情境聚合是社会感知计算的主要研究工作之一,目前主要采用基于特征提取的方法,对社会的交流方式进行量化分析.但是大多数的研究中忽略了情境信息的时序性,针对社会感知计算中时序情境信息的聚合问题,首先对时序情境和计算情境的聚合过程进行探讨,提出基于时序扩展的计算情境元素,用于情境对象的聚合,并给出一种时序感知的社会网络节点集情境聚合方法.实验表明,该方法能够根据时间情境和计算情境元素的特点,把聚合对象划分为相对情境聚合对象和绝对情境对象,有效地对社会环境中的时序信息进行情境聚合.     

天宫一号基于控制力矩陀螺的智能多模自适应姿态控制系统设计与验证

天宫一号是目前我国在轨运行的体积最大、重量最重的载人航天器.它具有变构型、变参数的特性,采用控制力矩陀螺系统和喷气推进系统实现高精度、高稳定度姿态控制.本文通过对天宫一号控制对象参数缓变和跳变相结合特点的分析,规划了高可靠灵活的控制策略,设计了智能多模自适应姿态控制系统.利用智能控制中规则集设定多模自适应控制的指标切换函数分配,利用多模自适应控制算法建立多模型控制器实现不同控制对象,不同控制任务的姿态控制.天宫一号通过地面测试和物理仿真试验,最后发射在轨运行,与神舟八号、神舟九号、神舟十号载人飞船圆满完成交会对接任务,充分验证了姿态控制系统设计的正确性和有效性.该设计方法在解决大型航天器变构型、变参数组合体姿态控制方面有突出优点,在未来的载人航天领域空间站建设具有应用前景.     

Constructing Failure: Leonard Hayflick,Biomedicine, and the Problems with Tissue Culture

By examining the use of tissue culture in post-war American biomedicine, this paper investigates how scientists experience and manage failure. I study how Leonard Hayflick forged his new definition of failure and ways of managing it by refuting Alexis Carrel's definition of failure alongside his theory of the immortality of cultured cells. Unlike Carrel, Hayflick claimed that every vertebrate somatic cell should eventually die, unless it transformed into a tumour cell. This claim defined cell death, which had been a problem leading to a laboratory failure, as a normal phenomenon. On the other hand, permanent life, which had been considered a normal cellular characteristic, became a major factor causing scientific failure, since it implied malignant transformation that scientists hoped to control. Hayflick then asserted that his cell strains and method would partly enable scientists to manage this factor—especially that occurred through viral infection—alongside other causes of failure in routine tasks, including bacterial contamination. I argue that the growing biomedical enterprise fostered this work of Hayflick's, which had repercussions in both his career and the uses of cells in diverse investigations. His redefinition of failure in the age of biomedicine resulted in the broad dissemination of his cells, medium, and method as well as his long struggle with the National Institutes of Health (NIH), which caused his temporarily failed career.