- Email: [email protected]
Modeling and simulation
2
ELSEVIER
Computers and Electronics in Agriculture 18 (1997) 63-64
63
Computers and electronics in agriculture -
Book review Modeling and Simulation
H. Bossel (Editor) A.K. Peters, Wellesley; 1994, Hardback; 484 pp.; $59.95; ISBN I-56881-033-4 (A.K. Peters), ISBN 3-528-05419-o (Verlag Vieweg) Repeatability and reproducibility are important attributes which underpin the scientific approach to research. Agricultural research, and indeed other scientific research, is complicated and expensive, and it is not uncommon to limit the scope and thoroughness of useful research due to a finite size of resources such as test specimen, samples, and population. Modelling and simulation offer inexpensive methods for analysing the behaviour of a system under variable conditions and predicting possible real life outcomes. In studies involving living organisms or expensive equipment, or where the time required to obtain one set of data can be large, modelling and simulation provide useful tools to assist in the selection of the most important parameters for experimentation; they could also suggest alternative factors to consider. Though the outcomes may not be perfectly accurate, comparison of experimental and model simulation results can provide mechanistic insights into the basis of a phenomena. The book ‘Modeling and Simulation’ represents one of the excellent contributions to the literature on this rapidly expanding and important tool in research and commerce. The text is laid out in seven chapters plus an appendix of computer programme listings. In Ch. 1, Bossel introduces the concepts of systems, models, and simulation and provides an outline of the book chapters which correspond to the different stages of the modelling and simulation process. Ch. 2 discusses the development of the influence diagram (first sketch of the system structure) and its step-by-step differentiation into a working simulation model which enables reliable and precise information about the dynamic behaviour of a system to be produced. Ch. 3 takes a closer look at the modelling process and the description of dynamic systemls by their ‘state equations’. These provide more exact characterisation of the system and the final products are mathematical relations or an equivalent simulation diagram which can both be used as the basis for programming a simulation model. In Ch. 4, the book builds on the discussions on model development in the previous chapters and turns to the task of converting mathematical models into simulation models and computer programmes. Following the discussion and analysis, Bossel describes a simulation programme SIMPAS (simulation of processes and systems) 016%1699/97/$17.00 0 1997 Elsevier Science B.V. All rights reserved. PIISO168-1699(97)01318-5
54
Book
review
and an interactive graphical model environrnent STELLA. Both approaches are used throughout the following chapters to demonstrate the dynamics of real life problems. Evaluation of the system behaviour and of the simulation results is of central importance in modelling and simulation. In Ch. 5, Bossel uses three simulation models developed earlier to demonstrate the important aspects of such evaluation. The ‘systems zoo’ (Ch. 6) contains the complete documentation of some fifty simulation models, which represent different types of dynamic systems with their characteristic structures and behaviours, ranging from one to four state variables. These simulation models are embedded in the SIMPAS software which is included in a diskette accompanying the book. The final chapter (7) discusses the concept of mathematical systems analysis in a rather condensed form. The contents include an explanation of the systems concept, development of state equations for continuous and discrete systems, discussion of the linear.isation of non-linear state equations, and the definition of the conditions for equilibrium of the different system types. Readers who are not familiar with vector and matrix algebra, eigenvalues and eigenvectors, elementary calculus, and computer programming may find it difficult to follow some of the discussions in this chapter. In summary, the book ‘Modeling and Simulation’ is a well written and illustrated text. Each chapter begins with a detailed introduction to its contents and provides logical linkage with the contents of other chapters. The ‘summary of important results’ that concludes each chapter also enables the reader to reinforce the main discussions in the book. With the SIMPAS simulation software and the ‘systems zoo’ provided on the accompanying diskette, together with the program listings, in the appendix, the book offers a self-contained. and complete guide to the methods and mathematical background of modelling a.nd computer simulation of dynamic systems. Readers of ‘Computers and Electronics in Agriculture’ will find the book very relevant for applications in computer simulation of biological and agricultural systems. With rapid developments in computer modelling and simulation in parallel with the increasing capacity of modern electronic digital computers, computer modelling has been a useful tool to the solution of problems in many areas including arts, the bio-sciences, engineering, business and commerce. This rapid growth in diverse areas calls for a need to articulate the process of modelling and simulation so that students can learn the techniques and tools easily. The volulme discussed in this review represents one of the excellent contributions in this respect. Students and researchers in other diverse fiellds such as ecology, economics, and geography will also find the book informative and instructive. Department
L.U. Opara of Agricultural Engineering Massey University Palmerston North New Zealand
ELSEVIER
Computers and Electronics in Agriculture 18 (1997) 63-64
63
Computers and electronics in agriculture -
Book review Modeling and Simulation
H. Bossel (Editor) A.K. Peters, Wellesley; 1994, Hardback; 484 pp.; $59.95; ISBN I-56881-033-4 (A.K. Peters), ISBN 3-528-05419-o (Verlag Vieweg) Repeatability and reproducibility are important attributes which underpin the scientific approach to research. Agricultural research, and indeed other scientific research, is complicated and expensive, and it is not uncommon to limit the scope and thoroughness of useful research due to a finite size of resources such as test specimen, samples, and population. Modelling and simulation offer inexpensive methods for analysing the behaviour of a system under variable conditions and predicting possible real life outcomes. In studies involving living organisms or expensive equipment, or where the time required to obtain one set of data can be large, modelling and simulation provide useful tools to assist in the selection of the most important parameters for experimentation; they could also suggest alternative factors to consider. Though the outcomes may not be perfectly accurate, comparison of experimental and model simulation results can provide mechanistic insights into the basis of a phenomena. The book ‘Modeling and Simulation’ represents one of the excellent contributions to the literature on this rapidly expanding and important tool in research and commerce. The text is laid out in seven chapters plus an appendix of computer programme listings. In Ch. 1, Bossel introduces the concepts of systems, models, and simulation and provides an outline of the book chapters which correspond to the different stages of the modelling and simulation process. Ch. 2 discusses the development of the influence diagram (first sketch of the system structure) and its step-by-step differentiation into a working simulation model which enables reliable and precise information about the dynamic behaviour of a system to be produced. Ch. 3 takes a closer look at the modelling process and the description of dynamic systemls by their ‘state equations’. These provide more exact characterisation of the system and the final products are mathematical relations or an equivalent simulation diagram which can both be used as the basis for programming a simulation model. In Ch. 4, the book builds on the discussions on model development in the previous chapters and turns to the task of converting mathematical models into simulation models and computer programmes. Following the discussion and analysis, Bossel describes a simulation programme SIMPAS (simulation of processes and systems) 016%1699/97/$17.00 0 1997 Elsevier Science B.V. All rights reserved. PIISO168-1699(97)01318-5
54
Book
review
and an interactive graphical model environrnent STELLA. Both approaches are used throughout the following chapters to demonstrate the dynamics of real life problems. Evaluation of the system behaviour and of the simulation results is of central importance in modelling and simulation. In Ch. 5, Bossel uses three simulation models developed earlier to demonstrate the important aspects of such evaluation. The ‘systems zoo’ (Ch. 6) contains the complete documentation of some fifty simulation models, which represent different types of dynamic systems with their characteristic structures and behaviours, ranging from one to four state variables. These simulation models are embedded in the SIMPAS software which is included in a diskette accompanying the book. The final chapter (7) discusses the concept of mathematical systems analysis in a rather condensed form. The contents include an explanation of the systems concept, development of state equations for continuous and discrete systems, discussion of the linear.isation of non-linear state equations, and the definition of the conditions for equilibrium of the different system types. Readers who are not familiar with vector and matrix algebra, eigenvalues and eigenvectors, elementary calculus, and computer programming may find it difficult to follow some of the discussions in this chapter. In summary, the book ‘Modeling and Simulation’ is a well written and illustrated text. Each chapter begins with a detailed introduction to its contents and provides logical linkage with the contents of other chapters. The ‘summary of important results’ that concludes each chapter also enables the reader to reinforce the main discussions in the book. With the SIMPAS simulation software and the ‘systems zoo’ provided on the accompanying diskette, together with the program listings, in the appendix, the book offers a self-contained. and complete guide to the methods and mathematical background of modelling a.nd computer simulation of dynamic systems. Readers of ‘Computers and Electronics in Agriculture’ will find the book very relevant for applications in computer simulation of biological and agricultural systems. With rapid developments in computer modelling and simulation in parallel with the increasing capacity of modern electronic digital computers, computer modelling has been a useful tool to the solution of problems in many areas including arts, the bio-sciences, engineering, business and commerce. This rapid growth in diverse areas calls for a need to articulate the process of modelling and simulation so that students can learn the techniques and tools easily. The volulme discussed in this review represents one of the excellent contributions in this respect. Students and researchers in other diverse fiellds such as ecology, economics, and geography will also find the book informative and instructive. Department
L.U. Opara of Agricultural Engineering Massey University Palmerston North New Zealand