Ch. 1 Engineering Problem Solving

Contents I.Engineering in the Twenty-First Century II.Computing Systems: Hardware and Software III.An Engineering Problem-Solving Methodology IV.Homework

I. Engineering in the Twenty-First Century

RECENT ENGINEERING ACHIEVEMENTS In 1989, the National Academy of Engineering selected the 10 engineering achievements that it considered to be the most important accomplishments during the previous 25 years: Microprocessor Moon landing Application satellites CAD(Computer Aided Design)/CAM(Computer Aided Manufacturing) Jumbo jet Advanced composite materials CAT(Computer Axial Tomography) Genetic engineering Laser Optical fiber

GRAND CHALLENGES FOR THE FUTURE The Office of Science and Technology Policy in Washington, D.C. identified the grand challenges as part of a research and development strategy for high performance computing. Prediction of weather, climate, and global change Computerized speech understanding Human Genome Project Improvements in vehicle performance Enhanced oil and gas recovery

CHANGING ENGINEERING ENVIRONMENT strong communication skills for both oral presentations and for preparing written materials the design/process/manufacture path, which consists of taking an idea from a concept to a product cooperativeness in interdisciplinary team to understand world marketplace not only to analyze data, but synthesize a solution using many pieces of information to consider their solutions in their social context Engineers need:

II. Computing Systems: Hardware and Software

Computing Systems Computer: A machine that is designed to perform operations that are specified with a set of instructions called a program. Hardware: the computer equipment, such as the keyboard, the mouse, the terminal, the hard disk, and the printer. Software: the programs that describe the steps that we want the program to perform.

Computer Hardware CPU –Central Processing Unit –Processor + ALU(Arithmetic logic unit) Internal Memory –Read-only Memory(ROM) –Random-access Memory(RAM) External Memory –Hard-disk –Floppy-disk

Internal organization of a computer

Types of computer Personal Computer(PCs) –small inexpensive computers –commonly used in offices, homes, and laboratories –microcomputer Workstation –minicomputer or mainframe computer –small enough to fit on a desktop Super computer –the fastest computer

COMPUTER SOFTWARE

Operating System –provides an interface between the user and the hardware –in which the user can select and execute the application software –contains many utilities to perform functions such as printing files, copying files and listing files. ex) dir (on DOS), ls (on UNIX) …

Software tools word processor (Microsoft word, 한글 ) spread sheet (Lotus 1-2-3, Excel … ) database management system (dBase IV, Paradox, … ) CAD package (AutoCAD, AutoSketch, CADKEY, … ) mathematical computation tools and graphic tools (MATLAB, Mathmatica, MATHCAD, Maple)

Computer Languages machine language assembly language high-level language –Fortran –COBOL –Basic –Pascal –Ada –C++ –Java –C 4GL natural language

Executing a Computer Program 1.Compiling –source program –object program 2.Linking and Loading 3.Executing 4.Debugging

Compiling: –Translate high-level language into machine language –source program: the original program written by high-level language such as C –object program: the machine language version of source program Linking and loading –Linking: link the other necessary machine language statements to the object program –Loading: load the program into memory

Debugging –a process to correct errors(often called bugs) in a program –compile-time error: syntactic errors –run-time error: logic errors

Software Life-Cycle Phases Life Cycle Percent of Effort Definition3 Specification15 Coding and modular testing14 Integrated testing8 Maintenance60

III. An Engineering Problem-Solving Methodology

An Engineering Problem-Solving Methodology The process or methodology for problem solving that we will use throughout this course has five steps: 1.State the problem clearly 2.Describe the input and output information 3.Work the problem by hand (or with a calculator) for a simple set of data 4.Develop a solution and convert it to a computer program 5.Test the solution with a variety of data

1. PROBLEM STATEMENT Compute the straight-line distance between two points in a plane.

2. INPUT/OUTPUT DESCRIPTION I/O Diagram Point 1 Point 2 Distance between points

3. HAND EXAMPLE Let the points p 1 and p 2, have the following coordinates: p 1 = (1,5); p 2 = (4,7); distance = SQRT((side 1 ) 2 + (side 1 ) 2 ) = 3.61

Decomposition Outline 1.Give values to the two points. 2.Compute the lengths of the two sides of the right triangle generated by the two points. 3.Compute the distance between the two points, which is equal to the length of the hypotenuse of the triangle. 4.Print the distance between the two points 4. ALGORITHM DEVELOPMENT

/* */ /* Program chapter1_1 */ /* */ /* This program computes the */ /* distance between two points. */ #include int main(void) { /* Declare and initialize variables. */ double x1=1, y1=5, x2=4, y2=7, side_1, side_2, distance; /* Compute sides of a right triangle. */ side_1 = x2 - x1; side_2 = y2 - y1; distance = sqrt(side_1*side_1 + side_2*side_2); /* Print distance. */ printf("The distance between the two points is " "%5.2f \n",distance); /* Exit program. */ return (0); } /* */ Coding

5. TESTING The distance between the points is 3.61!!

VI. Homework Write a short report (2000 자 ) on one of these grand challenges by March 21: Prediction of weather, climate, and global change Computerized speech understanding Mapping of Human Genome Project Improvements in vehicle performance Enhanced oil and gas recovery