Block Replacement Policies with General Cost Structures

In this paper we investigate block replacement policies when the cosl structure associated with the operation of the system involves a cost c ₁ of replacement at failure, a cost c ₂ of preventive replacement, together with some discrete or continuous costs which are increasing with the age of the system.     

The Study of Cost Rate for Multiple Cold Standby System Replacement Policies

We consider a replacement policy for a multiple-component cold-standby system,and atfer we analyze this plicy,we want to get the mean total cost rate and the preventive policy to make it the lowest.In this system,the failure rate of the component in poeration is constant,and the inspection will control all the processes of the operation.The system is inspected at random points over time to determine whether it is to be replaced.During the process,the replacement decision is based on the number of failed components at the time of inspection.     

论资产评估中的重置成本

重置成本法是资产评估中的一种基本方法,但在运用时对重置成本的要素构成却并不明晰。针对现行重置成本法中重置成本的要素概念模糊及由此产生的在不同资产类型应用时要素构成不一致问题,文章从种类资产评估的重置成本,逐项分析并规范了重置成本的要素构成与内涵。     

Optimum Investment Policies for Diagnostic Equipment under a Limited Budget in Multistage Production Systems

1IntroductionAcommonrequirementofcompaniesfromtheirmaintenanceprogramsistohavethemaximumavailabilityoftheirproductionprocesses.ManufacturersnowhavediagnosticequipmentthatenablesthemtOmonitortheirpreductionprocessesatalltimes.Maintenanceplanning,there...     

Tool-Replacement Policies: Variations in Cost, Tool Quality, and Monitoring Rules

A computer simulation experiment was conducted to examine cutting-tool operating costs under varying conditions. The input variables included the level of tool quality (high versus low), cost structure (two cost structures were used), and tool-replacement policies incorporating four types of quality-control decision rules. The rate of tool deterioration, the length of tool life, and the stage of tool life at which significant deterioration began were all stochastically defined. A primary finding was that replacement policies incorporating quality-control decision rules were not significantly better than a strict interval-replacement policy for the cost structure and input variables used in the study. It was further demonstrated that the relative performance of the decision rules was not consistent for variations in input characteristics (tool quality) and cost structure.     

不惑之惑

我的父母似乎太随意。只因我生在雪天，就给我起了名字叫曹雪。一是大女性化，常有未见面者把我幻想成一位女士，甚至想入非非；二是让那八辈子之前就去了另一个世界的曹雪芹还出来沾我一光。连那该死的电脑也会自然联想起他。真是气煞人!老祖宗啊，今日为了创自己的品牌，休怪我曹雪无“芹”了!     

Dynamic Operational Policies in an Automated Warehouse

In this paper we consider the optimal relocation of pallets with a high expectancy of retrieval within each storage rack of an automated warehouse to meet the fluctuating, short-term throughput requirements imposed on the automated storage-retrieval machines. The prepositioning of these pallets closer to the input/output point of each rack during off-peak periods will reduce the expected travel time for the storage/retrieval machines during future peak periods of the planning horizon.

As the model has been abstracted from an actual operating environment, we first describe the environment in which the problem has been posed. We then exploit the special structure of the problem to develop conditions that an optimal relocation policy should satisfy. Based on these optimality conditions, we develop a very efficient optimal relocation algorithm. Finally, we present the performance of several relocation policies in the warehouse studied.     

碳政策下货运企业运营成本比较分析

考虑两种碳政策：碳交易、碳税,研究其对货运物流企业运营成本的影响。以总成本最小为目标,考虑车辆油耗与其载货重量的关系以及减少固定碳排放需要付出一定的机会成本,构建两阶段车辆路径优化模型,并设计遗传算法求解。数值分析显示两种碳政策的实施均增加了企业的经营成本,但促使企业减少碳排放;货运企业可以从两方面减少碳排放：1）减少固定碳排放,例如减少办公能耗与员工出差等;2）优化车辆性能,降低车辆的百公里综合油耗与提高车辆排放标准。     

Optimum planned maintenance with discounting

In this paper we treat the optimum ordering policy, in which when an ordered spare is delivered, it can be put into inventory until a prespecified time if the original unit is still operating. We apply the expected total discounted cost as a criterion of optimality, introducing, with an exponential discount rate, two types of lead times and several costs. It is shown that under certain conditions there exist optimum ordering policies minimizing that expected cost. Finally, the results in this paper include those in an earlier paper by Kaio and Osaki (1978) as special cases.     

具有随机提前期的库存模型中安全因子的优化

建立了一个二级配送系统库存模型,在零售商和供应商库存均采取连续检查控制策略假设下,针对零售商的提前期随供应商的缺货量随机波动这种情形,分析了供应商和零售商关于其安全因子的决策问题.分别求解并研究了双方在分散决策与合作决策的情形下的最优安全因子模型,并通过算例验证了模型的主要结论.     

考虑投标费用的联合体工程总承包商收益分配

为探讨前期投标费用对联合体工程总承包商收益分配的影响,以合约理论和博弈思想为基础,建立联合体工程总承包商的相关收益模型。对模型进行求解,并以变化的具体数据作为算例进行检验,结果表明项目前期投标费用如何在联合体成员之间进行分配不影响以后项目实施过程中项目优化设计的实现程度、项目总承包收益在联合体成员之间的最优分配比例,以及联合体成员各自可采取的进行项目优化设计的最优努力程度;同时,前期投标费用在联合体双方成员之间的合理分配比例与联合体成员单位知识投入的成本系数、效率系数以及项目总承包收益在联合体成员间的分配比例3个因素相关。     

Optimum structural design with stability constraints

This paper presents an optimization method based on optimality criterion for minimum weight of structures with stability requirements. A recurrence relation is derived and the method is explained in the context of the displacement method of finite element analysis. The incipient buckling of the structure is determined by a linear eigenvalue solution. The method is programmed for trusses and frames. Illustrative problems are given to show the applicability of the method of design of structures with a large number of design variables.     

Optimum design of an extended octagonal ring by goal programming

Extended octagonal rings are used in metal cutting dynamometers to measure cutting forces and torque. The controllable design variables are the thickness, radius and width of the ring. Normally the objectives of the design are to achieve high sensitivity and high rigidity which arc conflicting in nature. Therefore, both requirements cannot be achieved simultaneously. The goal programming technique is used to determine the optimum size of extended octagonal ring for various goal priorities with respect to sensitivity and rigidity     

Optimum tolerance allocation in mechanical assemblies using an interval method

Tolerance allocation methods serve as effective tools for design engineers to reduce the overall manufacturing cost of products. In every mechanical design, it is the design engineer’s task to assign tolerances to all dimensions and clearances to all joints in an assembly. This paper presents an optimum allocation method, based on interval analysis, for finding the optimum values of tolerances and clearances in mechanical assemblies that will not only minimize a stated objective function, but also satisfy the required functional and design constraints. The design constraints include dimensional requirements that the related parts must match relative to each other with a specified precision. Given a set of trial values of component tolerances and joint clearances, the present method utilizes the sequential quadratic programming method, Broyden–Fletcher–Goldfarb–Shanno quasi-Newton method and line search approaches to find the optimum values of tolerances and clearances. The effects of different cost function models on the manufacturing cost are also compared and discussed. Numerical examples are presented to illustrate the application of the method.     

Investigation of an Optimum Concentration for Nano-Silica Used as an Adhesive Bonding Strength Enhancer

In this paper, the effect of silica nanoparticles (nano-silica) on the bonding strength of reinforced adhesive joints was experimentally studied in five concentrations. A two-part epoxy-based adhesive (Araldite 2015) was used to bond the adherends as well as silica nanoparticles for strengthening purposes. Nano-silica was added into the adhesive by 1, 1.5, 2, 2.5 and 3 wt.%. Some adhesive joints with and without nanoparticles were tested under uniaxial loading to obtain their bonding strength. The results showed that the change in the bonding strength is a function of nanoparticles concentration. Furthermore, it was concluded that the addition of silica nanoparticles has a suitable effect on the joint strength at an optimum point, in which the joint strength takes its maximum value, and a further increase in the nanoparticles weight fraction causes the joint strength to decrease.     

容许借贷的消费投资策略的渐近特征

考虑了一个容许借贷的消费投资问题。投资者选择了无风险的债券和带有红利回报的风险股票。研究了不同效用函数下投资者最优策略当财富特别多或特别少时的渐近特征。     

Optimum rigid motion with one perspective view

One of the central problems in dynamic computer vision is the determination of motion from correspondence of points on the visible surface of a moving object obtained at two different times. In the problem we consider, the initial position of several feature points on some object is assumed to be known. Then at some later time instant the corresponding perspective projection of those points is given. The moving body may be nonrigid or the measurements may be corrupted with noise. In either case, we determine the multiplicity of possible solution for the best-fitting rigid motion. We show that whenever at least three point correspondences are given, there are at most two possible solutions for the best-fitting rigid motion if the object space is two-dimensional, while there are at most forty possible solutions if the object space is three-dimensional. In the latter case the number of possible solutions drops to four if three point correspondence are known, the body is rigid, and the measurements are noise-free. Several examples are worked out to illustrate our results.©1994 John Wiley & Sons Inc