基于微分博弈的供应链质量协调研究

文章以一个制造商和一个供应商所构成的两级供应链为研究对象,应用微分博弈的方法分析了四种不同的质量管理博弈情形下,制造商和供应商的最优质量管理策略、收益和整条供应链的总收益。研究结果表明,当制造商和供应商的收益分配比满足一定条件时,从Nash非合作质量管理博弈情形,到弱激励Stackelberg博弈情形,再到强激励Stackelberg博弈情形,最后到合作质量管理博弈情形,对于制造商、供应商以及整个供应链系统来说都是一种帕累托改进。所以,合作质量管理博弈情形是供应链质量管理所追求的最理想的情形,为了有效促进该情形的实现,文章应用Nash讨价还价模型对该情形下合作双方关于供应链系统的剩余利润分配进行了分析。最后,在对一家电风扇制造商的供应链进行调查来获得仿真数据的基础上,通过算例分析验证了理论推导的结果。     

Planning reform beyond planning: the debate on an integrated Environment and Planning Act in the Netherlands

Land-use plans serve a dual function. On the one hand, they are programmes for future development, plans for action. On the other hand, they have a regulative function in relation to construction and land use. This paper investigates how the interplay between these functions is playing a role in the current debate about the new integrated Environment and Planning Act (Omgevingswet) in the Netherlands. Initially, the government proposed abolishing local land-use plans and replacing them with a system of by-laws. However, this proposal did not survive the debate on this bill. This paper will shed light on the relationships between planning and regulation by analysing that debate.     

Modelling process robustness: a case study of centrifugal casting

A robust process minimises the effect of the noise factors on the performance of a product or process. The variation of the performance of a robust process can be measured through modelling and analysis of process robustness. In this paper, a comprehensive methodology for modelling and analysis of process robustness is developed considering a number of relevant tools and techniques such as multivariate regression, control charting and simulation within the broad framework of Taguchi method. The methodology as developed considers, in specific terms, process modelling using historical data pertaining to responses, inputs variables and parameters as well as simulated noise variables data, identification of the model responses at each experimental setting of the controllable variables, estimation of multivariate process capability indices and control of their variability using control charting for determining optimal settings of the process variables using design of experiment-based Taguchi Method. The methodology is applied to a centrifugal casting process that produces worm-wheels for steam power plants in view of its critical importance of maintaining consistent performance in various under controllable situations (input conditions). The results show that the process settings as determined ensure minimum in-control variability with maximum performance of the centrifugal casting process, indicating improved level of robustness.     

Load-Oriented Order Release (LOOR) revisited: bringing it back to the state of the art

In the workload control literature, the Load-Oriented Order Release (LOOR) approach has been neglected since its robustness was questioned at the end of the 1990s. This paper revisits LOOR and evaluates whether its performance can be improved in two ways. First, an intermediate pull release mechanism is added to avoid starvation between periodic release events. This mechanism was recently shown to be effective at improving the performance of a state-of-the-art release method known as LUMS COR. Second, an integer linear programming model is used to manage the trade-off between the timing and load balancing functions of order release. The two refinements are assessed using simulations of different shop configurations, which allow us to evaluate robustness. Results demonstrate that the refinements contribute to improving the performance of LOOR such that it can even outperform LUMS COR. Perhaps counter-intuitively, putting more emphasis on load balancing than on the urgency of individual orders is shown to lead to a lower percentage of tardy orders. Overall, the improvements mean that concerns about LOOR’s robustness are no longer valid – it now appears suitable for a wide range of shops found in practice.     

三点渐进式无模成形分析与数值模拟

渐进成形是一种金属板材快速无模成形方法。工具头挤压板材产生连续的局部变形,通过累积局部变形以达到整体成形。然而每一局部变形必然影响整体变形,所以对局部变形的控制就成为成形精度的关键。文章提出一种3点渐进式无模成形方法,可以很好的控制的局部变形。通过LS-DYNA模拟整个成形过程,并通过分析节点在成形过程中的位移变化,可以看出此方法对局部变形的控制效果,提高了成形精度。     

Analysis of the Bovine Spongiform Encephalopathy Maternal Cohort Study: the Discordant Case–Control Pairs

The progeny of the affected and non-affected dams in the bovine spongiform encephalopathy (BSE) cohort study were paired in terms of their farm of origin and approximate date of birth. This paper presents an exact logistic regression analysis that avoids modelling the differences between the pairs and so analyses only the discordant pairs. There is some evidence that the pairs in which the affected animal was born to the affected dam tend to be those in which the onset of BSE in the affected dam preceded or occurred soon after the calving. This suggests some occurrence of maternal transmission.     

一种谨慎自较正控制算法

本文给出了一种谨慎自校正控制算法。仿真实验表明,这种算法能够有效地降低由于参数估计的不确定性所引起的盲目控制,从而达到改善系统动态性能的目的。     

Inventory Systems with Unreliable Suppliers

The aim of this article is to establish the optimal control of a periodic-review inventory system with two suppliers. One of them delivers orders immediately, the other one is unreliable delivering the orders immediately only with probability p ∈ (0, 1). Two cases are considered. In the first case, it is possible to order any inventory amount from each of suppliers. In the second case, the system budget is restricted.