摘要:

This paper presents three approaches to minimize and eliminate scrap from stamping a single shape arranged in a single row or double rows on strip raw materials. In the first approach, interlocking shapes are generated. Although such shapes are scrap-free, they require congruent lines in the design. At the early stages of the design process, a skilful designer can compromise between functional features and symmetric features to improve nesting. The second approach is to characterize a shape by parallel lines bounding it. Specifically, the method to find a minimum area parallelogram that encloses a given convex shape is discussed. The result gives the optimum arrangement of a convex shape in single row. The third approach involves the nesting of a given shape in a specified pattern. Three computational algorithms for the single and double row arrangements are given. The double row arrangement includes a half-turn or a mirror reflection. The three approaches are all based on the concept of interlocking shapes and they can readily be implemented on a small computer. Depending on the design environment and the piece shape, one of the approaches can be used.

ISSN:0020-7543    

DOI:10.1080/00207547908919616

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

This paper presents a combined quantitative and qualitative (subjective) approach to the plant layout problem. The two objectives, which may be conflicting, are minimizing the material handling cost and maximizing a closeness rating measure. A heuristic algorithm is developed which results in a discrete efficient frontier set, including only 'efficient layouts’. By specifying the different weights, or range of weights, for these goals, the 'best’ solution (layout) is generated.

ISSN:0020-7543    

DOI:10.1080/00207547908919617

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The problem considered here is how to allocate n exponential tasks to two available servers. The servers may be placed in a series or parallel configuration, and arrivals are assumed to be Poisson. In general, this gives rise to a network of queues with Erlang service times. Alternative designs are examined using various approximation methods and simulation for several values of n and different utilization rates. If the workers must be placed in tandem, the rule of balancing the work of the two stations is found to be optimal for all cases considered. If it is possible to place the servers in a parallel configuration, each performing all n tasks, the average total waiting time can be substantially reduced.

ISSN:0020-7543    

DOI:10.1080/00207547908919618

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The start-up period of flow line operation is investigated in this study. Mathematical functions representing time-dependent start-up phenomena-—manufacfcuring progress and early failure of equipment—are described and incorporated in a stochastic model of the system. A set of performance measures capable of describing start-up characteristics is presented. The model is applied to several example configurations to evaluate the approach and to identify salient features of the start-up period. Primary contributions of the paper are (1) the modelling approach which might be applied to study start-up phenomena (manufacturing progress and early failure of equipment) and (2) description of several results which are expected to characterize flow line start-up operations in general.

ISSN:0020-7543    

DOI:10.1080/00207547908919619

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

This work deals with the measurement and analysis of torque and thrust in drilling mild steel using twist drills. Force and torque measurements were carried out using a specially designed two-component piezoelectric dynamometer. The dynamometer was both statically and dynamically calibrated, and techniques for increasing the measuring accuracy and reducing cross-interference were employed.

ISSN:0020-7543    

DOI:10.1080/00207547908919620

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

When fixed reordering costs and/or carrying rates are not known, efficient instead of optimal order quantities may be calculated by allocating the available reordering capacity to storage items such that the implied inventory investment is minimized, or vice versa. Static versions of this problem have been discussed in detail elsewhere. The present paper develops an algorithm suitable for calculation of efficient order quantities under conditions of dynamic multi-item demands.

ISSN:0020-7543    

DOI:10.1080/00207547908919621

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

When fixed reordering costs and/or carrying rates are not known, efficient instead of optimal order quantities may be calculated by allocating the available reordering capacity to storage items such that the implied inventory investment is minimized, or vice versa. Static versions of this problem have been discussed in detail elsewhere. The present paper develops an algorithm suitable for calculation of efficient order quantities under conditions of dynamic multi-item demands.

ISSN:0020-7543    

DOI:10.1080/00207547908919622

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Graphical Evaluation and Review Technique (GERT) has been applied to the analysis of the discrete conveyor model for service time distributions which are general but bounded and where there is no storage at work stations and no recirculation. The model is described by states with the Markovian property. The GERT analysis gives a visual representation of the conveyor system and useful information in the conveyor system design.

ISSN:0020-7543    

DOI:10.1080/00207547908919623

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

This paper presents an algorithm for finding an improved machine-based lower bound of make-span by introducing the concept of maximum effective preprocessing time for a machine. The usefulness is indicated by developing machino-based lower bounds without presequence of jobs. Numerical examples illustrate the improvement in the value of machine-based bound which in turn improves the global lower bound for permutation flows hop problems only.

ISSN:0020-7543    

DOI:10.1080/00207547908919624

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0020-7543    

DOI:10.1080/00207547908928105

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor