摘要:

The purpose of this paper is to illustrate a new technique useful in modelling complex production systems—GERT network analysis. The primary contribution of this paper is to describe how complex production systems with queueing characteristics can be analysed using network techniques. Using this approach, a wide class of production systems can be easily represented in graphical form and analysed using a FORTRAN based simulation programme hereafter known as GERTS III-Q. Each production model is constructed by drawing a queueing network composed of directed branches and logical nodes, and the analysis phase is implemented through the use of GERTS III-Q. The input to the programme iB a description of the network in terms of its nodes and branches, along with control information for setting up the simulation conditions. The objective of GERTS III-Q is to provide an easily under-stood, rapid access analysis tool useful in studying large complex production networks which possess queueing characteristics.

ISSN:0020-7543    

DOI:10.1080/00207547508942993

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Difficulties in recognition of planarity of graphs in the context of layout problems are reviewed. A problem oriented linear string representation for trees and the concept of grammar are then introduced as basic tools for symbolic computation of trees and planar graphs. A heuristic method to solve the layout problem is next discussed and the need of optimal algorithmic techniques is pointed out. Finally the application of list processing techniques for manipulation by computer is suggested.

ISSN:0020-7543    

DOI:10.1080/00207547508942994

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

This paper analyses a multi-stage cyclic queueing system in which there are alternate service and transit Btagea. The service times are negative exponentially distributed, but it is shown that the transit time distributions may be any of a whole range of types, from constant to negative exponential. It is also shown that the production rate of the system does not depend on the individual mean transit times, hut only on the sum of these mean transit times. An explicit expression for the average production rate is derived and used in two examples, (i) a two-stage earthmoving project, and (ii) a four-stage asphalt paving project, to obtain regions of optimal haul fleet size, in the parameter space, so as to minimize the cost of the system.

ISSN:0020-7543    

DOI:10.1080/00207547508942995

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Temperature gradients in high speed steel tools used to turn iron, titanium and nickel have been measured using a method based on the structural changes in high speed steel heated to temperatures over 560°C. The relationship between temperature gradient, cutting speed and feed rate have been demonstrated through the heat affected region close to the cutting edge. The most emphatic feature of the results is that each of the three metals imposed its own and greatly different pattern of temperature distribution within the tool. It was shown that this controls some of the basic wear processes which limit the rates of metal removal. When cutting iron there was a relatively cool zone close to the cutting edge in the most highly stressed region, while the hottest part was well back from the edge; the temperature gradients were very Bteep. When cutting titanium the higher temperatures were much closer to the cutting edge, and the total heated region was smaller, while the temperature gradients were again very steep. When cutting nickel the tool edge was at least as hot as elsewhere in the heat affected area, and temperature gradients.near the edge were much less steep. The results have Televance to the understanding of tool wear, the design of cutting tools and the application of cutting lubricants.

ISSN:0020-7543    

DOI:10.1080/00207547508942996

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The paper describes the surface roughness measurement of spark erosion reference standards by means of digital technique, enabling a comprehensive assessment of roughness parameters. Using digital and Fourier analysis, parameters have been evaluated in terms of density and slope distribution, Abbott curve, power spectrum, auto-correlation functions, etc. The commonly used Ra, Rms and Rt have been calculated as per the ISO standard on the mean line (M) system. The effects of standard ISO-double RC and the suggested phase-corrected filters on the roughness parameters, waviness in particular, have also been discussed.

ISSN:0020-7543    

DOI:10.1080/00207547508942997

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The one-bole test was developed to provide a situation in which unlike that in the Purdue peghoard and similar teste, the reach, grasp, move and position elements were consistent and their rate of improvement measurable. Results support the hypothesis tlmt measurements of rate of learning or of performance after 600 cycles of practice have a higher concurrent and predictive validity of production output than measurements of initial performance on the test. The one-hole test has a mean predictive validity of 0-75 (N = 228) between test scores and rate of learning in the training school; and a mean concurrent validity of 0-66 [N = 307) between test scores and mean production performance of experienced operators. Norms (N = 1422), reliabilities (W=158) and correlation of the one-hole test scores with anthropometric measurements, personality, intelligence, age and other manual dexterity tests are discussed.

ISSN:0020-7543    

DOI:10.1080/00207547508942998

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:0020-7543    

DOI:10.1080/00207547508942999

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:0020-7543    

DOI:10.1080/00207547508943002

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor