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A cybernetics model of manufacturing execution system(MES CM) was proposed and studied from the viewpoint of cybernetics.Combining with the features of manufacturing system, the MES CM was modeled by"generalized modeling"method that is discussed in large-scale system theory.The mathematical model of MES CM was constructed by the generalized operator model, and the main characteristics of MES CM were analyzed. 相似文献
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To solve the resource-constrained multiple project scheduling problem (RCMPSP) more effectively, a method based on timed colored
Petri net (TCPN) was proposed. In this methodology, firstly a novel mapping mechanism between traditional network diagram
such as CPM (critical path method)/PERT (program evaluation and review technique) and TCPN was presented. Then a primary TCPN
(PTCPN) for solving RCMPSP was modeled based on the proposed mapping mechanism. Meanwhile, the object PTCPN was used to simulate
the multiple projects scheduling and to find the approximately optimal value of RCMPSP. Finally, the performance of the proposed
approach for solving RCMPSP was validated by executing a mould manufacturing example. 相似文献
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针对大连远洋运输公司的72,000T油轮"连安湖",根据实际算例,通过对船型、货油、水文气象等多方因素的考虑,采用FLUENT软件对油轮加热过程进行了流场模拟,通过软件计算得到,随着加热时间的增加,货油的温度缓慢的上升,货油传热的主要方式是对流换热,热传导作用相对较小,热流主要由底部热源面沿着对称面侧向上传递,而又由外侧低温处随着温度降低而向下传递,属于比较明显的自然对流换热方式。 相似文献
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2005年,我国国民经济继续保持高位增长,国内生产总值将超过15万亿元.对外开放进一步扩大,预计2005年进出口总额将超过13800亿美元,比2000年的4743亿美元增长1.9倍.作为对外贸易商品运输的大动脉,全国公路总里程超过190万公里,其中高速公路里程超过4万公里. 相似文献
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石油具有粘度大倾点高的特点,在通过油轮运输时需要适当加热与保温。为节约加热所用燃料,分析货油在油舱中传热模型并计算出合理的加热与自然冷却时间,根据不同的算法基于C#语言编写应用程序,通过对船型、货油、水文气象等多方因素的考虑,计算出针对货油加热与保温操作的方案。通过与两个航次实船采集数据对比可知,算法I和算法II的总体误差分别低于9%和12%,具有较高的准确性和合理性;通过计算软件,可以大量减少操作人员的工作量,并减少凭经验操作的失误和燃料浪费;水文气象条件对货油的传热尤其是船首货油舱有较大的影响。 相似文献
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对纤维碎石封层使用材料的参数如何确定进行了探讨,通过测力延度、落球试验、粘结强度等试验,对纤维沥青的最大拉应力、最大延度、与集料的粘附性能以及抗剪切能力进行了检测,最后阐述了纤维碎石封层施工参数的设计方法,可为同类型的施工提供借鉴。 相似文献
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An intelligent response surface methodology (IRSM) was proposed to achieve the most competitive metal forming products, in which artificial intelligence technologies are introduced into the optimization process. It is used as simple and inexpensive replacement for computationally expensive simulation model. In IRSM, the optimal design space can be reduced greatly without any prior information about function distribution. Also, by identifying the approximation error region, new design points can be supplemented correspondingly to improve the response surface model effectively. The procedure is iterated until the accuracy reaches the desired threshold value. Thus, the global optimization can be performed based on this substitute model. Finally, we present an optimization design example about roll forming of a "U" channel product. 相似文献
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