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1.
钱学森的现代科学技术体系与综合集成方法论 总被引:17,自引:2,他引:15
文章介绍了钱学森提出的现代科学技术体系和综合集成方法论。现代科学技术体系是横向上由11个科学技术部门、纵向上由三个层次,即基础理论、技术科学和应用技术所构成的矩阵式结构;综合集成方法论是由"从定性到定量综合集成方法"和"从定性到定量综合集成研讨厅体系"所构成。文章还讨论了它们在实践中的应用。 相似文献
2.
《振动与冲击》2018,(20)
近年来,随着纳米制造业的发展,一维材料因其优异的物理性能,广泛应用于各类力电光热纳米器件。基于弦振动理论研究了考虑原子纵向位移的单原子链纳米线横向振动控制方法,针对单原子链类弦结构,采用模态叠加法,建立了单原子链横向振动的动力学方程,提出了一种单原子链横向振动固有角频率的计算方法,并得到了轴向力控制电压量子极限。考虑原子链的边界条件与振动结构的对称性,利用非线性方程组的迭代方法,得到原子的纵向位移。研究发现:纳米线轴向张力与链的长度是影响单原子链纳米线的固有角频率和共振频率的主要因素,通过控制单原子链两端的压电块轴向位移,可以改变原子链的轴向张力和单原子链的长度,从而改变原子链的固有频率。研究为单原子链谐振器和滤波器等分子器件研发制造提供理论基础和计算方法。 相似文献
3.
(上接2O10《塑料包装》第6期)第三章双向拉伸聚酯薄膜生产设备与工艺第七节横向拉伸(TDO)铸片经过纵向拉伸后随即进入横向拉伸机进行拉幅操作。横拉机主要由烘箱、链夹、导轨、静压箱、EPC(导边器)、链条张紧装置、夹子开闭器、 相似文献
4.
沥青混凝土路面接缝按平面位置分为纵向和横向接缝,按接缝性质又分为冷接缝和热接缝两种。对横向冷接缝处理技术进行讨论,为类似工程提供借鉴。 相似文献
5.
介绍了国家CIMS工程技术中心(CIMSERC)业已完成的仿真支撑环境。它由三部分组成,即用于CIMS横向集成及支持生产计划与控制的一体化制造仿真软件IMSS,用于CIMS纵向集成的递阶控制仿真器AHCSE,及支持CAD/CAPP/CAM与加工过程集成的加工过程仿真器MPS。从功能、关键技术及性能评价三方面分别对各部分进行了介绍。 相似文献
6.
传动轴的纵向振动影响横向弯曲振动的稳定性及振幅,使轴端的花键微动摩擦及磨损。根据质心运动定理和Galerkin法建立和求得非惯性系下倾斜两端支承传动轴的纵向运动方程。在此基础上,用多尺度法求得纵向运动方程的一次近似解,并进一步求得纵向位移,分析了纵向振动的规律等。研究表明传动轴的非共振的纵向振动是小振幅、振幅按指数规律衰减、渐进稳定的振动,稳态纵向振动的振幅很小。传动轴的重力和偏心质量产生的惯性力引起纵向振动。传动轴的纵向振动无法消除,对传动轴的安全性构成威胁的可能性很小。 相似文献
7.
(上接2010《塑料包装》第6期)第三章双向拉伸聚酯薄膜生产设备与工艺第七节横向拉伸(TDO)铸片经过纵向拉伸后随即进入横向拉伸机进行拉幅操作.横拉机主要由烘箱、链夹、导轨、静压箱、EPC(导边器)、链条张紧装置、夹子开闭器、调幅装置、加热系统、润滑系统、驱动装置等组成. 相似文献
8.
基于车辆/轨道耦合动力学理论,分析对比了选用两种方案转向架情况下机车动力学特性,以及对牵引销结构冲击的影响。以某型米轨机车为例,结合国外山区线路特征,使用动力学软件SIMPACK构建车轨耦合动力学模型。通过模拟实际线路工况分析发现直线工况下由于牵引销纵向自由间隙的存在,在较差线路上高速运行时,由于轨道纵向激励的影响使得牵引销受到较大的纵向冲击,原始方案三个牵引销按顺序最大纵向力分别为165kN、197kN和167kN;改进后方案的牵引销纵向力最大值为165kN、141kN和186kN。小半径曲线工况下原始方案牵引销与横向止档发生剧烈碰撞,第二位牵引销所受的横向冲击最大,达到259kN,而考虑车轮磨耗时,冲击将达到785kN。改进方案牵引销横向冲击较小,均未超过45kN。结果表明:通过小半径曲线时,牵引销产生的巨大横向力可能是造成牵引销固定螺栓松动、剪断的原因。在较差线路上,轨道不平顺造成的纵向冲击这也可能引起该问题。 相似文献
9.
在一个供应商之间信息不共享的二阶供应链系统中,研究不同类型的供应链延迟交货惩罚因子的设定对供应商交货响应时间决策的影响,并基于此建立一种供应商与供应商的交货时间协同机制。文章以集中决策下供应链最佳交货响应时间为目标值,分别找出了横向及纵向延迟交货惩罚因子的值,制造商可以通过此种方式设定这两种惩罚因子的值,使供应商与供应商之间主动采取相同的并与供应链最优决策一致的交货期,数值分析表明,采用本文提出的协同机制还可以调整供应链总成本在三者之间的分配。同时文章提出增加纵向延迟惩罚因子有利于促进供应链横向关系的和谐这一新观点。 相似文献
10.
以精益思想为核心,结合ISA-95集成标准,对变速箱装配车间人员、设备、物料、质量、生产等的核心业务进行分析,提出了以MES为核心的数字化转型建设方案,实现了企业内部横向、纵向与端到端的集成,为其他装配制造离散型企业提供了以MES为核心的智能车间建设思路. 相似文献
11.
An automated method based on the curve chain was proposed for dimensioning
of engineering drawings for the mechanical products. According to the internal relation
between the features of 3D model feature and elements of 2D drawing, the curve chain was
established to reflect the geometric topological structure between the elements. It divides
the dimensions into the absolute dimensions within the cure chain and the relative
dimensions between the curve chains. The parallel and lengthy relationship between the
drawing elements of the constructed X and Y parallel matrix was solved to remove
redundant elements in the curve chain and labeled the absolute dimensions of the remaining
valid elements. The average minimum weight coefficient was introduced to judge the
dependence on the relative dimensions between curve chains. Through the analysis of the
overlap between the circular rectangular areas, including all the absolute dimensions of the
curve chains, overlapping curve chains were merged, and their dimensions were rearranged
to avoid the cross interference between them. The method was seamlessly integrated into
the drafting module of product design software NX, and it developed an automated
dimensioning system. The examples show that the system has excellent interactivity and
robustness in the dimensioning of product engineering drawings. The dimension
information is complete, accurate and reliable. 相似文献
12.
Kannan Govindan 《国际生产研究杂志》2013,51(13):3808-3835
Vendor-managed inventory (VMI) represents the methodology through which the upstream stage of a supply chain (vendor) takes responsibility for managing the inventories at the downstream stage (customer) based on previously agreed limits. VMI is another method by which supply chains can be managed, and, owing to centralised decision-making and constant information sharing, the benefits are much higher than in traditional supply chain case. However, there exists a lack of research that identifies the dimensions of VMI, benefits of VMI, methods, and levels used in the VMI environment. The focus of this paper is to explore the existing literature on VMI, to categorise it according to the criteria evaluated, and to present a systematic review. In this study, we have classified the review into three categories such as dimension-based, methodology-based, and level-based. From the thorough literature review, we have identified six dimensions of VMI: namely, inventory, transportation, manufacturing, general benefits, coordination/collaboration, and information sharing. In addition, there are, three methodological classifications: modelling, simulation, and case studies. Finally, we will consider the level-based classification. Based on the review, several recommendations that improve the performance of VMI are presented. 相似文献
13.
为减少药品价值链系统价值载体的“价值-价格偏离”,实现系统形式化知识表达与优化重构,从药品价格-价值“形成、流动、传递与实现”的视角,构建了药品价值链系统闭环结构模型;基于该模型,运用S BOX理论分别将系统结构与运行机理转化为本体结构列表和语义推理规则,构建了可重构药品价值链系统知识模型。推理算例实验表明,本模型能有效计算不同药品价值链结构下价值载体在原料采购、制造、批发、零售等各价值链环节的“价值-价格偏离量”,进而实现价值链系统优化重构,可为抑制药品价格过高提供理论支持。 相似文献
14.
Erik Hofmann 《国际生产研究杂志》2017,55(17):5108-5126
The bullwhip effect is causing inefficiencies in today’s supply chains. This study deals with the potential of big data on the improvement of the various supply chain processes. The aim of this paper is to elaborate which characteristic of big data (lever) has the greatest potential to mitigate the bullwhip effect. From previous research, starting points for big data applications are derived. By using an existing system dynamics model, the big data levers ‘velocity’, ‘volume’ and ‘variety’ are transferred into a simulation. Overall, positive impacts of all the big data levers are elaborated. Findings suggest that the data property ‘velocity’ relatively bears the greatest potential to enhance performance. The results of this research will help in justifying the application of big data in supply chain management. The paper contributes to the literature by operationalising big data in the control engineering analyses. 相似文献
15.
Typically, supply chain members are dependent on each other to manage various resources and information. The conflicting objectives
and lack of coordination between supply chain members may often cause uncertainties in supply and demand. The basic elements
of coordination theory like interdependency, coherency and mutuality may help in effective flow of information and material
between the dependent supply chain members. Supply chain contract can be an effective coordination mechanism to motivate all
the members to be a part of the entire supply chain. There are different types of supply chain contracts such as buy back
and quantity flexibility contracts. Supply chain performance may be substantially improved by properly designing the contracts
to share risks and rewards. The objective of this paper is to explore the applicability of coordination elements through an
analytical model in three-level (Manufacturer-distributor-retailer) serial supply chains using contracts. The model evaluates
the impact of supply chain contracts on various performance measures. The impact of some contract may be on some specific
performance measure only, which helps managers to choose the type of contract if there is an objective of improving certain
performance measure before hand. In three-level supply chains, the contracts are designed at two distinct interfaces: Manufacturer-distributor
and distributor-retailer. The model demonstrates the complexity in evaluating the decision variables of three level supply
chains. The proposed model is a novel approach to apply coordination theory at various levels of supply chain. The model also
presents how the coordination elements are related to each other in various coordination cases. 相似文献
16.
由于供应链的动态性和复杂性对系统性能的影响日趋明显,供应链系统的动力学和复杂性问题正在成为供应链设计、分析、优化和管理研究的一个热点。不同领域的学者一般仅关注供应链系统动力学和复杂性问题中的某些方面,而很少从更广泛的视角去观察分析这些问题及其相互联系。目前还没有就这些基本问题进行完整综述的文献报道。通过对该领域相关研究文献的分析和归纳,总结出供应链系统动力学和复杂性基本问题的框架内容,力图对供应链系统的动力学和复杂性有一个整体认识。 相似文献
17.
在供应链链间竞争的背景下,研究三级竞争供应链的纳什均衡结构。利用非线性规划、纳什博弈和Stackelberg博弈理论,分析了2条三级竞争供应链的渠道选择问题,求解了3种情景:全分布式结构;全一体化结构和混合结构(一条供应链为一体化,另一条为分布式)下的决策变量的最优解,并分别依据3种决策标准,即制造商利润最大化、渠道利润最大化和供应链系统利润最大化,分析了不同决策标准下供应链纳什均衡结构。研究表明,三级竞争供应链的纳什均衡结构,依赖于产品之间的替代系数及决策标准,并且当供应链链间的竞争强度较大时,无论何种决策准则下,全分布式结构均为供应链的纳什均衡结构。 相似文献
18.
目的 轨道维护工程机械是典型的复杂产品,根据用途需要自行研发制造,致使内室人机交互成为设计研究的难点。方法 根据轨道维护工程机械运动行驶、静态作业和移动作业三种形式,以及作业人员组和作业机械组两部分结合的行业现状,从界面、通道和用户三个方面,分析轨道维护工程机械的多类型界面组合、多通道信息传递和多用户行为协同的人机交互特点。依据开发过程的系统特性,界定轨道维护工程机械内室人机交互的概念,构建设计原则,并提出内室人机交互设计模型。结论 轨道维护工程机械内室设计以作业工况为核心,具有轨道交通和工程机械双重属性。内室人机交互既要符合轨道行业标准,也要顺应作业规范要求,结合工业设计与人机工程满足人机交互的作业工况。最后对磁浮轨道维护车内室人机交互进行设计应用,为理论与实践研究提供参考。 相似文献
19.
This study seeks to better understand the role of supply chain analytics (SCA) on supply chain planning satisfaction and operational performance. We define the architecture of SCA as the integration of three sets of resources, data management resources (DMR), IT-enabled planning resources and performance management resources (PMR), from the perspective of a resource-based view. Based on the data collected from 537 manufacturing plants, we test hypotheses exploring the relationships among these resources, supply chain planning satisfaction, and operational performance. Our analysis supports that DMR should be considered a key building block of manufacturers’ business analytics initiatives for supply chains. The value of data is transmitted to outcome values through increasing supply chain planning and performance capabilities. Additionally, the deployment of advanced IT-enabled planning resources occurs after acquisition of DMR. Manufacturers with sophisticated planning technologies are likely to take advantage of data-driven processes and quality control practices. DMR are found to be a stronger predictor of PMR than IT planning resources. All three sets of resources are related to supply chain planning satisfaction and operational performance. The paper concludes by reviewing research limitations and suggesting further SCA research issues. 相似文献