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排序方式: 共有6146条查询结果,搜索用时 15 毫秒
61.
提出了一种基于灰关联混合蛙跳算法的雷达波形设计方法,以混合蛙跳算法为主体,在局部更
新算子中引入遗传算法的遗传算子,并改进原始蛙跳算法的分组方法,丰富了种群的多样性,同时引入灰关联综合评价法则对适应度函数值加以关联度分析。文中以设计具有低自相关旁瓣和互相关特性的正交多相编码为例,将该算法用于雷达波形设计中。仿真结果表明使用本文算法产生
的波形具备较好的低自相关特性和互相关特性,表明了该算法是有效和可行的。 相似文献
62.
Dongyu Zhao Fan Fan Vladimir G. Chigrinov Hoi Sing Kwok Ben Zhong Tang 《Journal of the Society for Information Display》2015,23(5):218-222
Nowadays, liquid crystal displays (LCDs) with light‐emission are considered as energy‐efficient devices and are promising alternatives to conventional LCDs. To realize such possibility, strong fluorescent materials with a dichroic properties are required. Aggregate‐induced emission (AIE) is an unusual photophysical phenomenon shown by some luminogenic materials that will be highly emissive in their aggregate state. In this work, we studied the AIE effect of a luminescent liquid crystalline molecule TPE‐PPE in our LC system as a luminophore dopant. The result showed the excellent AIE effect that higher concentration of luminogen in the nematic LC host induced stronger luminescent intensity. Through exposure of a photoisomeriable alignment material sulfonic‐dye‐1, the photopatterning of a light‐emitting LC device was achieved with the use of the TPE‐PPE/nematic LC mixture. 相似文献
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64.
Ben W. Morrison Mark W. Wiggins Glenn Porter 《International journal of human-computer interaction》2013,29(4):297-316
This study examined trainee crime-scene investigators' preference for, and accuracy in using, four different computer-based decision support interface designs, each of which incorporated a different reduced processing information acquisition strategy. The interfaces differed on the basis of the number of options that could be considered simultaneously and the level of control that could be exercised over the number and sequence in which feature values were accessed. Forty trainee investigators completed six decision scenarios in which they were asked to acquire information and formulate a decision by selecting one of three options. The study comprised two phases, the first of which involved familiarizing participants with each of the four interface designs and collecting performance and subjective data. The second phase involved trainees selecting one of the four interfaces to engage in a fifth and sixth decision scenario involving high or low levels of time-pressure. The results indicated that the “all options, full control” interface was the preferred option in the low time-pressure condition. Although the strategy remained the most frequently selected in the high time-pressure condition, this preference was not significant. It was concluded that the perceptions of difficulty and the degree of user control over information acquisition were more important than perceived efficiency in the selection of computer-based interface designs. The outcomes have implications for the design of decision support systems. 相似文献
65.
This paper proposes a new nonlinear unknown input observer. The observer design approach utilizes the first order Taylor expansion. The observer gains are then obtained by a systematic method. In this paper, we added some improvements to this method. The developed approach also can enable observer design for a large class of differentiable nonlinear systems. The necessary and sufficient conditions for the existence of the observer are given. A numerical example is given to illustrate the attractiveness and the simplicity of the new design procedure. 相似文献
66.
徐奔 《数字社区&智能家居》2009,5(5):3478-3480
该文将二值水印嵌入到宿主图像的小波变换域的低频分量中,利用BP神经网络很好的非线性映射和自学习、自适应学习特点实现水印信息的盲提取,仿真实验结果表明该算法既能抵抗常规的图像处理攻击,也能抵抗一定程度的几何攻击,如JPEG压缩、剪切、加噪和滤波等,具有较好的鲁棒性和不可见性。 相似文献
67.
针对当前形势下炼油企业蒸汽动力系统存在的巨大改造潜力,提出了蒸汽动力系统改造的优化方法;该方法首先通过运行优化方案分析和系统设备诊断找出系统存在问题,然后通过专家知识系统提出一系列解决的方案,建立系统改造方案的超结构和考虑柔性调节的优化改造混合整数线性规划(MILP)模型,求解模型并确定最优的改造方案;文章最后部分给出了详细的案例分析,结果表明应用本文提出的改造优化策略方法确定的最佳改造方案可以为案例背景炼油企业蒸汽动力系统节约大约6%的运行费用,投资回收期约0.38年;本文提出的优化改造方法为推动炼油企业蒸汽动力系统的节能降耗提供了定的理论指导和技术支持. 相似文献
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70.
FENECIA: failure endurable nested-transaction based execution of composite Web services with incorporated state analysis 总被引:1,自引:0,他引:1
Neila Ben Lakhal Takashi Kobayashi Haruo Yokota 《The VLDB Journal The International Journal on Very Large Data Bases》2009,18(1):1-56
Interest in the Web services (WS) composition (WSC) paradigm is increasing tremendously. A real shift in distributed computing
history is expected to occur when the dream of implementing Service-Oriented Architecture (SOA) is realized. However, there
is a long way to go to achieve such an ambitious goal. In this paper, we support the idea that, when challenging the WSC issue,
the earlier that the inevitability of failures is recognized and proper failure-handling mechanisms are defined, from the
very early stage of the composite WS (CWS) specification, the greater are the chances of achieving a significant gain in dependability.
To formalize this vision, we present the FENECIA (Failure Endurable Nested-transaction based Execution of Composite Web services with Incorporated state Analysis) framework. Our framework approaches the WSC issue from different points of view to guarantee a high level of dependability.
In particular, it aims at being simultaneously a failure-handling-devoted CWS specification, execution, and quality of service
(QoS) assessment approach. In the first section of our framework, we focus on answering the need for a specification model
tailored for the WS architecture. To this end, we introduce WS-SAGAS, a new transaction model. WS-SAGAS introduces key concepts that are not part of the WS architecture pillars, namely, arbitrary nesting, state, vitality degree, and compensation, to specify failure-endurable CWS as a hierarchy of recursively nested transactions. In addition, to define the CWS execution
semantics, without suffering from the hindrance of an XML-based notation, we describe a textual notation that describes a
WSC in terms of definition rules, composability rules, and ordering rules, and we introduce graphical and formal notations. These rules provide the solid foundation needed to formulate the execution
semantics of a CWS in terms of execution correctness verification dependencies. To ensure dependable execution of the CWS, we present in the second section of FENECIA our architecture THROWS, in which the execution control of the resulting CWS is distributed among engines, discovered dynamically, that communicate
in a peer-to-peer fashion. A dependable execution is guaranteed in THROWS by keeping track of the execution progress of a
CWS and by enforcing forward and backward recovery. We concentrate in the third section of our approach on showing how the
failure consideration is trivial in acquiring more accurate CWS QoS estimations. We propose a model that assesses several
QoS properties of CWS, which are specified as WS-SAGAS transactions and executed in THROWS. We validate our proposal and show
its feasibility and broad applicability by describing an implemented prototype and a case study. 相似文献