- Email: [email protected]
Reliability of nuclear power plants
BOOK R E V I E W S Examples and exercises in operations research A. Ghosal, S. G. Loo and N. Singh Gordon and Breach, London and New York, 1975. 262 pp. £8.50 The style of a usual textbook is to deal with the theory of a topic first, and then to elucidate the validity of the theory through examples and exercises. The style of this book is the reverse: techniques are taught through examples and exercises. The principal aim in writing this book is to satisfy queries of students at a lower level and users of OR who would refer to the book for solution of real-life problems. Thus the appetite of the reader is whetted on reading the preface, so that he turns eagerly to the table of contents. Combat analysis and Use of cybernetics look oddly out of place amongst the nine chapter titles but then every author has some idiosyncrasies. The first chapter has the familiar title of Model making in operational research, which augurs well. Moreover, the promise is maintained with the first example on page one being about the difficulty which the Royal Air Force had in sinking enemy submarines in 1941. One wonders whether those pioneering scientists in Coastal Command really did use a general function of five variables when time was at a premium. Thirteen pages later, the examples give way to exercises but the apprehensive reader who quickly scans ahead is reassured by the obvious existence of hints. However, these rapidly increase in complexity, so that before chapter one is concluded, the reader is told that a particular type of problem will be solved in chapter five. The second chapter of twenty-six pages is about the Application of statistical principles. The t-test, multiple regression, stratified sampling, analysis of variance, the chi-square distribution, evolutionary operations, the Poisson distribution, autogressive schemes, hypothesis tests, the Bayesian approach and other topics are encountered in a bewilderingly quick sequence. Then suddenly the puzzled reader realizes that this book is intended for use by university teachers of mathematics, who feel that their examples should have some practical relevance but who do not have any practical experience themselves. Iia chapter five, the Wiener-Hopf integral equation first encountered in chapter one is solved. Obviously the book is intended for teachers of brilliant, lower-level mathematics students !
A. Mercer
110
Models and systems in architecture and building Edited by, Dean Hawkes Construction Press, Lancaster, 1975. £9.50 Twenty-one papers presented at this conference, together with the closing discussion, are reproduced. At one extreme there are descriptions of some interesting case studies, particularly in the area of hospital design: at the other there are papers of a philosophical nature, full of jargon and difficult to follow. Apart from the immediately recognizable models in the environmental science area, the conference essentially attempts to assess the current situation with regard to computer-aided design in architecture. While the papers demonstrate that modelling and computing techniques are useful in certain cases in architectural design, nothing really new can be claimed to have been presented, and little confidence is given to the architect that they are techniques which may be incorporated into anything but the most expensive projects. The open discussion, although intended to be broad based, revolves around the usual enquiry into architectural education and practice. The book contains some good summaries of research in specific fields and should be useful to research workers.
N. T. Norman
Reliability of nuclear power plants Proceedings of IAEA Symposium, Innsbruck IAEA, Vienna, 1975. 750 pp. £20 The mathematical models used in reliability analysis are often thought to be rather specialized. However, writers such as Buckland ('Statistical assessment of the life characteristic', 1964) and Proschan and Serfiing ('Statistical analysis of life length', 1974) have shown, there is a large overlap between models used in biometry, manpower planning and reliability. Moreover, the optimizing of trade-offs between (say) capital costs and availability, or inspection costs and safety (both of which feature in nuclear power plant analysis) are examples of more general classes of cost/benefit problems. Therefore these proceedings of an IAEA Conference held in April 1975, although describing only nuclear power plant reliability work, should interest all mathematical modellers. First, they provide examples of the type of mathematical models currently used in
Appl. Math. Modelling, 1976, Vol 1, September
nuclear plant reliability work; second, they provide insight into the problems of establishing suitable data sources and standards, so as to set up correct models with realistic parameters; third, they illustrate the difficulties modellers face in getting their approach adopted in practical situations; fourth, the discussions highlight some of the outstanding modelling problems which remain to be tackled. Nine papers deal with reliability data collection and storage, and with the statistical analysis of such data to establish and parameterize suitable mathematical reliability models. Problems of data checking and paucity of detailed information are discussed. About thirty papers describe methods of analysis, with examples of their application to the prediction of the reliability of safety (and other) systems, and of system availability. The techniques include Markov processes, Monte Carlo simulation and fault-tree presentations using cut sets, as well as the more common probability methods for combining events. Most papers are sound, although the methods vary from the elegant to the downright primitive. A few papers (and some discussions) deal with the problems of optimization. (How much should you pay for high plant availability? How often should you inspect to ensure safety but avoid bankruptcy? Is it best to throw away failed parts or repair them?) These are important because they emphasize the difficulty of making optimum choices when the data are sparse. One very good paper derives an expression for component failure probability by modelling the basic physical processes of failure. This is an important area for further modelling, because in a developing technology valid failure data from past experience do not often exist. The final batch of papers contain background engineering details describing inspection techniques, operating and training programmes and quality assurance methods. These might prove useful to applied mathematicians working in the engineering industry and will be to those working in ivory towers t To sum up, many of these papers would be interesting to any mathematical modeller, although they will only be compulsory reading to workers in the reliability field. To such workers, most papers are more interesting for their field of application than for their originality. The book, therefore, would only be worth purchasing by reliability teams and0 libraries. Both should bear in mind R a t it is a £20 paperback in which 14 out of 48 papers are in a foreign language (11 French, 3 Russian).
D. Norman
A. Mercer
110
Models and systems in architecture and building Edited by, Dean Hawkes Construction Press, Lancaster, 1975. £9.50 Twenty-one papers presented at this conference, together with the closing discussion, are reproduced. At one extreme there are descriptions of some interesting case studies, particularly in the area of hospital design: at the other there are papers of a philosophical nature, full of jargon and difficult to follow. Apart from the immediately recognizable models in the environmental science area, the conference essentially attempts to assess the current situation with regard to computer-aided design in architecture. While the papers demonstrate that modelling and computing techniques are useful in certain cases in architectural design, nothing really new can be claimed to have been presented, and little confidence is given to the architect that they are techniques which may be incorporated into anything but the most expensive projects. The open discussion, although intended to be broad based, revolves around the usual enquiry into architectural education and practice. The book contains some good summaries of research in specific fields and should be useful to research workers.
N. T. Norman
Reliability of nuclear power plants Proceedings of IAEA Symposium, Innsbruck IAEA, Vienna, 1975. 750 pp. £20 The mathematical models used in reliability analysis are often thought to be rather specialized. However, writers such as Buckland ('Statistical assessment of the life characteristic', 1964) and Proschan and Serfiing ('Statistical analysis of life length', 1974) have shown, there is a large overlap between models used in biometry, manpower planning and reliability. Moreover, the optimizing of trade-offs between (say) capital costs and availability, or inspection costs and safety (both of which feature in nuclear power plant analysis) are examples of more general classes of cost/benefit problems. Therefore these proceedings of an IAEA Conference held in April 1975, although describing only nuclear power plant reliability work, should interest all mathematical modellers. First, they provide examples of the type of mathematical models currently used in
Appl. Math. Modelling, 1976, Vol 1, September
nuclear plant reliability work; second, they provide insight into the problems of establishing suitable data sources and standards, so as to set up correct models with realistic parameters; third, they illustrate the difficulties modellers face in getting their approach adopted in practical situations; fourth, the discussions highlight some of the outstanding modelling problems which remain to be tackled. Nine papers deal with reliability data collection and storage, and with the statistical analysis of such data to establish and parameterize suitable mathematical reliability models. Problems of data checking and paucity of detailed information are discussed. About thirty papers describe methods of analysis, with examples of their application to the prediction of the reliability of safety (and other) systems, and of system availability. The techniques include Markov processes, Monte Carlo simulation and fault-tree presentations using cut sets, as well as the more common probability methods for combining events. Most papers are sound, although the methods vary from the elegant to the downright primitive. A few papers (and some discussions) deal with the problems of optimization. (How much should you pay for high plant availability? How often should you inspect to ensure safety but avoid bankruptcy? Is it best to throw away failed parts or repair them?) These are important because they emphasize the difficulty of making optimum choices when the data are sparse. One very good paper derives an expression for component failure probability by modelling the basic physical processes of failure. This is an important area for further modelling, because in a developing technology valid failure data from past experience do not often exist. The final batch of papers contain background engineering details describing inspection techniques, operating and training programmes and quality assurance methods. These might prove useful to applied mathematicians working in the engineering industry and will be to those working in ivory towers t To sum up, many of these papers would be interesting to any mathematical modeller, although they will only be compulsory reading to workers in the reliability field. To such workers, most papers are more interesting for their field of application than for their originality. The book, therefore, would only be worth purchasing by reliability teams and0 libraries. Both should bear in mind R a t it is a £20 paperback in which 14 out of 48 papers are in a foreign language (11 French, 3 Russian).
D. Norman