共查询到19条相似文献,搜索用时 62 毫秒
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大型工程项目庞大、建设任务种类繁多,往往需要几十家建筑企业提供专业化服务。在“互联网+”背景下,如何依据大型工程任务需求选择最合适的建造服务,以避免出现阶段分离、资源浪费与效率低下等问题至关重要。通过借鉴制造服务理念,本文在阐明大型工程建造服务内涵与特征的基础上,结合协同理论与最优化理论提出了基于协同效应与服务质量(quality of service,QoS)的服务组合选择框架,将大型工程“自上而下”分解为不同粒度的建造服务,明确服务单元间协同效应及QoS测度指标。以此构建大型工程建造服务组合选择优化模型,并利用改进遗传算法对模型求解。最后,以某桥梁工程统计数据为依据进行算例仿真,验证了模型的可行性。本文在“互联网+”背景下提出了大型工程建造服务组合选择方法,为未来工程实践中的管理决策及建造模式的转型升级提供理论参考。 相似文献
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传统Web服务发布与发现机制中,服务提供者和消费者仅以Web服务的功能性属性作为其发布和发现服务的依据,并没有考虑诸如价格、执行时间、可靠性等的非功能性属性,即QoS(Quality of Service)。提出一个基于QoS的Web服务发布和发现框架。该框架在传统Web服务三脚架构中引入QoS broker,以实现QoS信息的收集、测试、监控和管理;全面地从Web服务提供者、服务使用者和UDDI三个角度探讨支持QoS的服务发现和发布;实现QoS信息的动态收集、评估和管理,以确保Web服务发布和发现过程能够基于动态更新的QoS信息,使服务选择过程更加有效。 相似文献
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指出一种基于Petri网的Web服务组合的化简方法,此方法包括建模和化简两个阶段。首先,Petri网结合工作流模式建模Web服务组合:然后通过Petri网的三种性质(可达性,安全性以及死锁)定义出Web服务组合结构,最后运用流程化简规则化简Web服务组合。 相似文献
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提出一种基于QoS预测模型的选择方法,该方法不仅能够通过基于信誉度或BP网络的QoS预测模型较准确地查找到真正满足用户QoS需求的服务,而且能够在没有完全满足用户QoS需求服务的情况下,推荐尽量相似的服务以供用户作进一步选择。 相似文献
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Abstract We propose an optical scheme for the simultaneous measurement of the position and momentum of a single atom. The scheme involves the coupling of the atom of two light fields with different spatial and polarization characteristics. The proposed technique is closely related to the Arthurs-Kelly measurement scheme; the principal difference is that in the present case the values of the position and momentum are inferred from phase shifts in electromagnetic fields rather than from shifts in the position of a pointer. 相似文献
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In this paper, the most conservative Tsai–Wu failure envelopes are obtained for laminated composite considering material as well as ply angle uncertainty. The uncertainty analysis is performed using Monte Carlo simulation (MCS). The obtained failure envelopes are then used as the constraint functions to perform the minimum weight design optimization problem using particle swarm optimization (PSO). Results show increase in weight of the laminate from the deterministic results and it varies from 4% to 50% depending upon the stacking sequence and loading condition. Substantial effects of uncertainty on the failure envelope and optimal design are quantified. 相似文献
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提出了一种考虑屈曲的复合材料加筋壁板铺层顺序优化方法。基于复合材料加筋壁板屈曲载荷求解的能量法,系统推导了轴压载荷作用下复合材料加筋壁板蒙皮、筋条局部屈曲载荷的显示表达式,考虑了加筋壁板各板元之间的弹性支持作用及筋条下缘条的影响,引入工程法求解了加筋壁板整体屈曲载荷。基于国产自主结构分析软件HAJIF中的复合材料铺层工程数据库,以铺层参数为中间变量,利用本文提出的复合材料加筋壁板屈曲载荷求解方法,构建了考虑屈曲的复合材料加筋壁板铺层顺序优化设计流程并完成程序实现,将最小二乘法用于最优铺层顺序与工程铺层数据库的匹配。相比于传统有限元计算方法,本文提出的复合材料加筋壁板屈曲载荷求解方法具备较好的求解精度及求解效率。复合材料加筋壁板优化算例表明,采用本文提出的加筋壁板屈曲载荷分析及其优化方法,在结构重量不变的前提下,屈曲载荷提高约17%,且铺层顺序优化结果可直接从铺层工程数据库中提取并用于工程实际。 相似文献
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There is a need for identifying computing power hours and storage utilisation along with total cost optimisation. The present paper focuses on optimal selection of application loading process on the cloud services considering relevant factors. Using this model, small companies that plan to develop applications and use cloud services may determine cost and optimal selection of service by taking into account its own as well as provider’s perspectives into consideration. The paper consists of four stages. First stage deals with the estimation of required computing power hours in the planned duration. Second stage relates to the calculation of storage capacity. Third stage corresponds to the formation of multi objective goal programme to prioritise computing power hours and storage utilisation requirements of applications and optimise total cost of usage. Finally, fourth stage deals with the mixed integer non-linear programming to minimise total cost considering other variable factors. For small application developers who cannot afford in-house IT infrastructure, we find an optimal framework for allocating number of applications on cloud services such as Infrastructure as a Service and Platform as a Service. For ease in planning, the user company can quickly decide corresponding number of applications at appropriate services, and at the same time can reduce overall usage cost. With the help of proposed method, the service provider may keep a suitable inventory of cores to provide backup computing power and storage capacity. This adds value to developers also, as company can plan for their operations corresponding to the business growth. 相似文献
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考虑叶片停机位置大型风力机塔架风-沙致结构响应分析 总被引:1,自引:0,他引:1
强风停机状态下叶片位置会显著影响风力机塔架的绕流及稳定性能,尤其在沙尘暴极端天气条件下,沙粒的附着也会影响风的湍流特征并对塔架产生附加冲击力,现有工作均缺乏风-沙耦合作用对大型风力机体系气动性能及结构响应的探索.以南京航空航天大学自主研发的5 MW水平轴风力机体系为对象,以风-沙双向耦合算法为核心,基于CFD技术分别采... 相似文献
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We study the integrated logistics network design and inventory stocking problem as characterized by the interdependency of the design and stocking decisions in service parts logistics. These two sets of decisions are usually considered sequentially in practice, and the associated problems are tackled separately in the research literature. The overall problem is typically further complicated due to time-based service constraints that provide lower limits on the percentage of demand satisfied within specified time windows. We introduce an optimization model that explicitly captures the interdependency between network design (location of facilities, and allocation of demands to facilities) and inventory stocking decisions (stock levels and their corresponding stochastic fill rates), and present computational results from our extensive experiments that investigate the effects of several factors including demand levels, time-based service levels and costs. We show that the integrated approach can provide significant cost savings over the decoupled approach (solving the network design first and inventory stocking next), shifting the whole efficient frontier curve between cost and service level to superior regions. We also show that the decoupled and integrated approaches may generate totally different solutions, even in the number of located facilities and in their locations, magnifying the importance of considering inventory as part of the network design models. 相似文献
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<正> 服务业标准化是个全新的领域,说它新不仅仅是因为它与工业标准化、农业标准化相比出现较晚,更主要的还在于无论是它涵盖的范围,还是它需要研究与寻求技术支持的理论深度以及实践难度都是前所未有的,已有的标准化手段或方法难以满足它的实际要求,必须不断探索和创新。什么是服务业标准化?简单地说,就是通过对服务标准的制定和实施,运用标准化的原则和方法开展对服务对象的有效服务,以达到服务质量目标化,服务方法规范化,服务过程程序化,从而获得优质服务的过程。这些定义说起来简单,也 相似文献