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CPSC 1105 Review for Final Exam. The exam is scheduled for Saturday, May 7 10:30 AM to 12:30 PM. Topics for the Exam. Digital Technology (Chapter 1) Hardware Concepts (Chapter 2) Software Concepts (Chapter 3) The Internet (Chapter 4) Information Security (Chapter 6 )
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CPSC 1105Review for Final Exam The exam is scheduled forSaturday, May 7 10:30 AM to 12:30 PM
Topics for the Exam • Digital Technology (Chapter 1) • Hardware Concepts (Chapter 2) • Software Concepts (Chapter 3) • The Internet (Chapter 4) • Information Security (Chapter 6) • Databases (Chapter 8) • Artificial Intelligence (Chapter 11)
Structure of the Exam • Questions will beMultiple ChoiceFill in the blankShort answer (maybe) • There will be about 40 to 50 questions.
1. Digital Technology • A computer combines hardware and software. • The main components are the CPU, memory, disk system, display monitor, and other I/O devices. • A program is read from the disk, executed on the CPU, takes input from the keyboard, and produces output on a display device.
Digital Technology (Data storage) • Everything stored or processed on a modern computer is represented in digital form. • Characters are stored in a coded form, usually one of the following two:ASCII – an 8-bit code common in the U.S.Unicode – a 16-bit code used for international applications. • Numbers are stored in binary form.
Digital technology (File System) • All modern computers have a sophisticated file system, in which files are organized into folders, and folders included in other folders. • Each file will have an extension that indicates the type of the file and hence the program to be used to process that file data. • Often Windows will be set not to display the file type. This can cause problems.
Digital Technology (File Types) • Here are some common file types. • DOC, DOCX Microsoft Word document • XLS, XLSX Microsoft Excel • PPT, PPTX Microsoft PowerPoint • WMA, MP3 Files containing digitized audio • BMP, JPG Files with digitized graphic data • HTM Web pages
2. Hardware • Modern computers are built from transistors, each acting as an on/off switch to handle the binary (1 or 0) data. • These transistors are organized into integrated circuits, each containing millions of transistors. • The CPU performs all of the calculations for the computer. Modern CPU chips are often multicore, with more than 1 CPU on a chip.
Hardware (Multicore) • For advertising reasons, multiple CPUs on a CPU chip are called cores. • A quad-core CPU is a single integrated circuit with four CPUs (called cores) on it. • Windows can divide the work to be done by the computer into two or four sets of tasks and keep each core busy. • A computer is named after its CPU. A Pentium computer is one with a Pentium CPU.
Hardware (Graphical Processors) • Graphics processing units (GPUs) are a result of the video gaming industry. • A GPU functions to generate graphical data to be displayed on a video monitor. • Recently we have discovered how to use a GPU as a very fast numerical processor to solve difficult simulation problems.
Hardware (Major Components) • The motherboard is the primary circuit of a computer into which all major components are connected. • The motherboard has slots for the CPU, memory, and connections to external devices. • The motherboard contains a small number of busses, each used to transmit data & control.
Hardware (Busses) • Here are a few busses on the motherboard. • The memory bus connects the CPU to primary memory. • The graphics bus connects the CPU to the GPU, which handles the graphics display. • There are at least two sets of I/O busses, one faster one for the disk and one slower one for devices such as the keyboard.
Hardware (Fetch/Execute Cycle) • Programs are executed by being copied from a disk into primary memory of the computer. • The program in memory is run using the fetch/execute cycle. • Each instruction is fetched from memory and executed by the CPU.
3. Software • Software is often divided into two types:system software and applications software. • System software allows the computer to function in a simple way. It includes the OS (Operating System) and device drivers (software to manage the I/O devices). • Application software is used for specific tasks: MS-Word for word processing, etc.
Software • Software may be acquired in several ways. • Commercial software is purchased in a store or over the Internet. It is standard software such as Windows, MS-Office, etc. • Software can be custom developed for a given company; e.g., the hotel management system developed for Hilton Hotels, Inc. • Software is also written by students as a part of their school assignments.
Software (Cloud Computing) • The term “cloud computing” refers to the use of the global Internet as a giant computer. • The program you run in the cloud may execute on another computer and access data on even another computer. • The better term is “software as a service”; just get the results without knowing what is used to produce those results.
Software Licenses • A software license is a legal document defining the terms of use for that software. • Commercial software is never purchased; one buys only a license to use that software. • With few exceptions, the license requires that the program be run on exactly one computer. • With few exceptions, the license prohibits creation of additional copies of the software. • Most companies are rather aggressive in defense of their license rights. Don’t make copies.
4. The Internet • The global Internet is a collection of networks that are connected to each other with routers. • This connection of networks is called “inter-networking”, hence the name. • The Internet is only loosely managed. • A router is a device connected to more than one network to allow messages to be passed between the individual networks.
The Internet • The function of the Internet is to allow an application on one computer to access an application on another computer. • For example, a web browser may contact a server program running on another computer. • The term “protocol” refers to a set of rules and conventions that allows different computers to communicate.
The Internet: TCP/IP • The most common protocol is called “TCP/IP”. • The IP protocol allows different computers to communicate over the Internet. • The TCP protocol provides reliable data transfer between applications. • The TCP obviously uses the IP to provide the communication between computers.
The Internet: Client/Server • The primary mode of interaction over the Internet is called “client/server”. • In client/server, the client computer requests services from the server computer; e.g., ane-mail client requests data from the server. • The term “P2P” stands for peer-to-peer. In this, two computers take turns as client and server.
The Internet: IP Address • Each device attached to the global Internet is identified by a 24-bit binary number called the IP address. • This is conventionally represented as four sets of decimal numbers in the range 0 to 255. • The IP address for the Columbus State server is 168.26.193.117 (Don’t memorize this.)
Internet: The DNS • The Domain Name for a device connected to the Internet is a logical name by which to refer to it. It is easier to memorize. • The Columbus State University main server is now called www.ColumbusState.edu • The DNS (Domain Name System) maintains tables for translating the domain name to the unique IP address associated with it.
Internet: Structure of a Domain Name • Consider www.ColumbusState.edu • The last three letters, “edu” identify this as an educational institution. • Other large domains are as follows:COM commercial institutionsORG non-profit institutionsMIL the U.S. militaryGOV the U.S. government • There are many others.
Internet: More Structure • Within the DNS, the last two parts of the name are unique to an institution. • Consider again www.ColumbusState.edu • The part “ColumbusState.edu” is registered to Columbus State University and may not be used by anyone else. • The first part “www” identifies a specific server used by CSU.
The Internet Cookie • The term “cookie” refers to a small file stored on a client computer by a server. • The cookie is used by the server computer to identify the user for future sessions. • For example, the Mapquest site keeps a cookie on my computer to identify the last map I requested. • Cookies can be considered as security problems.
6. Information Security • Information and information assets must be protected from attack. • The three basic services are: • Confidentiality – keep information from those who should not access it. • Integrity – keep information safe from unauthorized modification • Availability – make information easily available to those who are authorized to access it.
Information Security: Authentication • Authentication is an important part of control of access to information. • Authentication is based on who you are or what you have. • Password authentication is the most common. • Biometric authentication is based on some physical attribute, such as a fingerprint.
Encryption • Encryption refers to methods for converting a plaintext that is easily readable by humans into a ciphertext that cannot be read without the key, which will reveal the plaintext. • Encryption is the process of converting the plaintext to ciphertext. • Decryption is the process of converting the ciphertext back to its original plaintext.
Encryption Keys • One way to prevent unauthorized access to encrypted material is to use a given key for only a short time. • The time during which one key is used is called a session. The key for that session is called a session key. • The encryption used by the Internet to secure a web session is very strong.
Backup • The term “backup” refers to creation of multiple copies of important files. • There are two common backup types. • A total backup will copy every file in a specified folder or directory. • An incremental backup will copy only those files that have changed since the last backup.
Computer & Network Security • Network security focuses on protection of a computer against those threats that are presented over a network. • The most common network is the Internet. • The same facilities that make the Internet so productive also make computers attached to the Internet vulnerable to attack. • The attacks are commonly achieved by software, generically called “malware”.
Information Security: Malware • There are two main classes of malware: viruses and worms. • A computer virus is a segment of code that must be inserted into a working program in order to achieve its affect, which includes copying itself into other working programs. • A worm is a free-standing segment of code that can propagate independently.
Information Security: Firewalls • A firewall acts as a barrier between an interior network and the global Internet to protect the interior network from attack. • A firewall may be implemented only in software or as a combination of hardware and software. • A firewall inspects data packets for harmful content, and blocks those violating security policy. It may block outgoing packets.
Wireless security • For the sake of convenience, we now employ many wireless devices to connect our computers to networks. • These broadcast our data packets using radio waves. These can be intercepted and misused by malicious hackers. • Malicious hackers can also gain access to a wireless network and use its facilities for their own use, often to the detriment of the owner.
Vulnerabilities and Patches • From an information security viewpoint, a vulnerability is mistake in a program that will allow a malicious hacker to attack a system. • Software developers continuously discover vulnerabilities and issue software upgrades to address those. These are called “patches”. • Part of good system management is timely application of all suggested patches.
Antivirus Software • The purpose of antivirus software is to locate malware, both viruses and worms, on a computer and remove that malware. • In antivirus terminology, a patch is a revision of the antivirus software to include coverage of newly discovered malware. • It is very important to use antivirus software to protect every computer.
Fraud and Phishing • One goal of malicious hackers is to gain your personal identifying information and use it. • Some of the targeted information includes bank account numbers, credit card numbers, and the passwords to access those accounts. • The term “phishing” refers to the use of an apparently valid web site to induce you to divulge information that should be private.
Sample phishing attack • You may get an e-mail apparently from your bank asking you to go to a web page and verify your password and account number. • This web site will appear to be that of your bank. It is not. • Once the hacker has access to your account information, you can say “goodbye” to your money.
8. Databases • A database is a collection of data organized to meet the needs of a specific user. • Modern databases are built from a collection of tables. Each table holds a specific and narrowly defined collection of data. A database table resembles a spreadsheet. • Databases use queries and reports to answer questions posed by users.
Database Management Systems • A database has two parts: the data and the DBMS (Database Management System) used to organize and report on the data. • The primary function of a database is to answer questions. • A query is a specific question. It is posed in a structured language called SQL (Structured Query Language). • A report is a more general presentation of a collection of related data.
Database: Tables • Data are stored in database tables. • The table has rows and columns. • Each row in a table holds one record, such as student name and address information. • Each row in a table must have a unique key used to identify the row in the table. Your student ID number is a good example. • Each column in a table represents an attribute: name, street address, city, state, etc.
11. Artificial Intelligence • The field of artificial intelligence (AI) focuses on new ways to solve many problems that are not solved by mathematical-style algorithms. • Examples of algorithms: long division, taking the square root, solving a quadratic, etc. • AI focuses on production of software that appears to exhibit intelligence, though not necessarily human intelligence.
AI: Expert Systems • An expert system is a rule-based software system that attempts to solve problems in the same way as human experts do. • Medical diagnosis is a good example of expert behavior that has been mimicked by expert systems. • Generally, an expert system is built on a large database of facts and a set of rules for using those facts.
AI: Neural Nets • The study of computational neural nets was motivated by the fact that the human brain easily solves puzzles that resist standard algorithmic solution. • Feature extraction is a good example. Look at a picture. Do you see a dog in the picture?This is easy for humans, hard for computers. • Neural nets have met with some success.
AI: Robotics • AI also includes the investigation of robots that can sense their environment and react to it appropriately. • Here, a robot is not trying to mimic human intelligence as it has many extra tools it can use: radar to measure distance, etc. • Factory robots are not considered intelligent, in that they follow pre-programmed moves.