第四方物流长期合作下的激励机制

考虑了第四方物流在协调及对第三方物流的培训、质量指导等方面的努力对第三方物流完成物流任务的影响,建立了第四方物流与第三方物流长期合作下的静态模型及动态模型,比较了相同期不同模型下各策略变量的影响因素,得出了第四方物流在动态模型下且努力水平调整系数大于零时能起到更好的激励效果的结论.     

基于信号传递模型的第四方物流分包及利益分配机制

在分析了第四方物流分包及利益分配重要意义的基础上,运用信号传递模型,研究了第四方物流分配任务及调整收益分配比例的问题.通过对结果的详细分析,得出了第四方物流的最优分配比例.     

第四方逆向物流资源优化配置问题研究

为了克服第三方物流在处理逆向物流时难以达到规模经济的问题,将第四方物流服务模型引入零散、不确定的逆向物流服务中,提出第四方物流模式下物流任务与物流资源的优化匹配问题,并对此进行了初步的探索.提出了两级物流资源优化配置策略,即首先将具有相似属性的零散的逆向物流任务进行聚类整合,再将整合后的物流任务与第三方物流资源进行优化匹配.以总成本最小和完成时间最短为目标,建立了逆向物流资源优化配置模型,设计了求解该模型的遗传算法,最后用实例验证了模型和算法的有效性,为第四方逆向物流服务模式的实用化奠定了基础.     

第四方物流及对物流规划功能的外包

随着企业与物流的发展，物流的规划决策外包越来越受到重视。介绍了一种解决物流规划功能外包问题的物流方案－－第四方物流，对其定义与工作方式进行了详细的介绍，并以实例证明，第四方物流能够进一步降低物流的成本，提高物流效率。     

第四方物流及其在我国的发展

供应链的日益复杂要求物流系统运作更加有效率。单纯的第三方物流已不能满足物流整合的需要，这样第四方物流的理论提出和实践应用逐渐被提上日程。首先对第四方物流的运作方式及解决方案的创新性进行了分析，随之提出我国发展这种新的物流方式的紧迫性，最后探讨了我国对此的基本措施和战略对策。     

武汉物流产业发展问题研究

基于对武汉的物流产业的历史背景,区位条件以及其现状理清的基础上,而将武汉的物流产业的发展方向定位于大力发展第三方物流,以及尝试发展第四方物流;并对发展第三方物流的条件以及必要性和尝试发展第四方物流的优势、劣势、风险性和必要性做出详细分析。     

第四方物流中基于多维权的有向图模型及算法

在简单介绍第四方物流概念的基础上，基于实际工程项目应用背景，指出第四方物流运作中的关键问题，建立了赋予多维权的有向图模型。就所选的模型，通过转化、简化一定的约束，进一步提出基于Dijkstra算法的求解方法。     

基于客户满意度最大化的4PL选择3PL的决策模型

基于物流客户的多样化、个性化要求,以最大程度提高客户满意度为目标,建立了一种基于客户满意度最大化的4PL选择3PL决策模型.利用此模型可以使第四方物流集成商满足其物流客户多样化、个性化的需求,为客户选择最为满意的方案.同时基于一个实例的分析,得出该模型能够帮助第四方物流为物流客户选择最为满意的物流方案.     

基于优先权编码机制带有随机需求的4PL路径问题

针对第四方物流客户对货物需求具有随时间或环境动态变化的特点,本文提出了带有随机需求的第四方物流路径问题。在分析随机需求的基础上,利用带有主观偏好的随机规划方法建立了相应的数学模型。鉴于该问题具有在多重图上选择约束最短路径的特征,提出了嵌入随机模拟的基于优先权双列编码机制的混合遗传算法。实验结果表明,对于相同的交货期,运输费用会随着设置信水平的升高而增加。     

基于CVaR的两阶段第四方逆向物流网络设计模型

研究了具有风险规避特性的产品回收第四方逆向物流网络设计问题。首先,以条件风险值(CVaR)作为成本的风险度量指标,确定物流网络中的条件风险值成本;然后,以回收产品的数量和客户对再制造产品的需求量为随机变量,以总利润的期望值最大为目标建立两阶段随机规划模型;最后,采用引入自适应变异算子的遗传算法对该模型进行求解。通过具体算例说明了该模型能够有效地解决在风险因素影响下的第四方逆向物流的网络设计问题。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...