tailieunhanh - ENVIRONMENTAL ENGINEER’S MATHEMATICS HANDBOOK - CHAPTER 4

Trong chương 3, chúng tôi chỉ ra rằng mô hình môi trường đã trở thành một công cụ quan trọng trong hộp công cụ của các kỹ sư môi trường được trang bị tốt. Sử dụng tương tự một, chúng tôi có thể nói rằng nếu một điển hình có tay nghề cao handyperson của hộp công cụ chứa một ratchet thiết lập ổ cắm và file đính kèm cờ lê một số khác nhau có kích thước, sau đó các trang bị tốt môi trường kỹ sư của hộp công cụ bao gồm một số mô hình môi trường. | Chapter 4 Algorithms and Environmental Engineering introduction In Chapter 3 we pointed out that environmental modeling has become an important tool within the well-equipped environmental engineer s toolbox. Using an analogy we can say that if a typical skilled handyperson s toolbox contains a socket set ratchet and several differently sized wrench attachments then the well-equipped environmental engineer s toolbox includes a number of environmental models socket set ratchets with a varying set of algorithms socket wrench attachments . Although a complete treatment or discussion of algorithms is beyond the scope of this book we do provide basic underlying explanations of what algorithms are and examples of their applications in cyber space to the real world . For those interested in a more complete discussion of algorithms many excellent texts are available on the general topic. We list several of these resources in the recommended reading section at the chapter s end. ALGORITHMS WHAT ARE THEY An algorithm is a specific mathematical calculation procedure. More specifically according to Cormen et al. 2002 an algorithm is any well-defined computational procedure that takes some value or set of values as input and produces some value or set of values as output. In other words an algorithm is a recipe for an automated solution to a problem. A computer model may contain several algorithms. According to Knuth 1973 the word algorithm is derived from the name al-Khowarizmi a ninth-century Persian mathematician. Algorithms should not be confused with computations. An algorithm is a systematic method for solving problems and computer science is the study of algorithms although the algorithm was developed and used long before any device resembling a modern computer was available the act of executing an algorithm that is manipulating data in a systematic manner is called computation. For example the following algorithm attributed to Euclid circa 300 . and thus known