Unit 9 Computer virus Text 1 Virus Introduction Viruses will cause much confusion. Even some virus\experts\will misinform the cause of the virus. Let's define what we mean by virus a virus is a program that reproduces its own code by attaching itself to other executable files

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 4.1 Slide 4.1.1 Today ' s topics In this lecture, we are going to take a careful look at the kinds

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 8.1 Slide 8.1.1 Review: data abstraction In this lecture we are going to introduce a new data type, a data abstraction consists of: specifically to deal with symbols. This may sound a bit odd, but

Unit 1 COMPUTER TECHNOLOGIES Vocabulary 1 (paragraph 1-2) 1. ingredient.成分,因素 2. digital computer数字计算机 3. inherent adj.固有的,内在的 4. storage capacity存储容量 5. image processing图象加工,图象处理 6. real-time process control实时过程控制 7. time consuming adj.耗费时间的

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 30.1 Slide 30l1 In this lecture, we are going to go back to several themes that 6.001: Structure and Interpretation of we have been exploring over the past few weeks, and stitch

1 Induction Recall the principle of induction: Principle of Induction. Let P(n) be a predicate. If ·P(0) is true,an for all nE N, P(n) implies P(n+1), then P(n) is true for all nE N As an example let's try to find a simple expression equal to the following sum and then use induction to prove our guess correct 1·2+2·3+3:4+…+n·(mn+1) To help find an equivalent expression, we could try evaluating the sum for some small n and(with the help of a computer) some larger n sum

6.001 Structure and Interpretation of Computer Programs. Copyright o 2004 by Massachusetts Institute of Technology 6.001 Notes: Section 7.1 Slide 7.1.1 In the past few lectures, we have seen a series of tools for helping us create procedures to compute a variety of Good programming practices

Recursion-breaking an object down into smaller objects of the same typeis a ma- jor theme in mathematics and computer science. For example, in an induction proof we establish the truth of a statement()from the truth of the statement P(n-1). In pro- gramming, a recursive algorithm solves a problem by applying itself to smaller instances

• Teaching staffs • Textbook and Grading • Course Schedule • Motivation • Suggested reading – Preface xvii~xx • Bit and Byte • Context is very important • Understand machine representations of numbers • Information storage • Bit level manipulation • Suggested reading

Introduction to Probability Probability is the last topic in this course and perhaps the most important. Many Igorithms rely on randomization. Investigating their correctness and performance re- quires probability theory. Moreover, many aspects of computer systems, such as memory