Data Process

Data Processing

All through the different stages in civilization, man has always tried to look for ways to simplify work and to solve problems more efficiently. Many problems involved numbers and quantities, so man started looking for easier ways to count, to add, subtract, multiply and divide. As society has grown in both size and complexity, so have data that are generated by it through time.

Definition of Terms

Data – is defined as any collection of facts. Thus sales reports, inventory figures, test scores, customers’ names and addresses, and weather reports are all example of data.

Data Processing – is the manipulation of data into a more useful form. It is the modern name for paperwork and involves the collecting, processing, and distribution of facts and figures to achieve a desired result.

Categories of Data Processing

Mechanical Data Processing – use a combination of manual procedures and mechanical equipment. The system uses devices such as typewriters, sorters, calculators, collators, tabulators, duplicators and verifiers.

Electronic Data Processing – different types of input, output and storage devices may be interconnected to an electronic computer to process data.

DATA PROCESSING CYCLE

1. Input – In this step the initial data or input data is prepared in some convenient form for processing. The form will depend on the processing machine.

2. Processing – In this step the input data is changed, and usually combined with other information, to produce data in a more useful form.

3. Output – Here the results of the preceding processing steps are collected. The particular form of the output data depends on the use of the data

AREAS OF DATA PROCESSING

1. Business Data Processing (BDP) – is characterized by the need to establish, retain, and process files of data for producing useful information. Generally, it involves a large volume of input data, limited arithmetic operation, and relatively large volume of output. For example, a large retail store must maintain a record for each customer who purchases on account, update the balance owed on each account, and periodically present a bill to the customer for merchandise purchase.
2. Scientific Data Processing (SDP) – involves a limited volume of input and many logical or arithmetic calculations. Unlike business problems, most of the scientific problems are non – repetitive, requiring an “one-time” solution. For example in cancer research data on cancer patients (collected over a period of time) are analyzed by a computer to produce a possible cure.

DATA PROCESSING OPERATIONS

1. Recording – refers to the transfer of data into some form of document. It is related to the documentation of intermediate figures of facts resulting from calculations. For example in computing gross pay the number of hours worked are multiplied by the hourly rate to arrive at gross pay.

2. Verifying – since recording is usually a manual operation it is important that recorded data be carefully checked for any errors. This operation is called verifying. For example, typed reports are re-read for corrections.

3. Duplication – it is sometimes necessary or desirable to copy or duplicate data. This operation consists in reproducing the data into many forms or documents. Duplicating may be done while the data are being recorded manually or it may be done afterwards by some machine.

4. Classifying – this operation separates data into various categories identifying and arranging items with like characteristics into groups or classes is called classifying. This can be done by shortened predetermined method of abbreviation known as coding.

Three types of code uses are:

a. numeric – a person’s social security number or student ID number
b. alphabetic – grades such A, B and C or names of persons
c. alphanumeric – automobile license plate or course and year

5. Sorting – arranging data in specific order is sorting. After the data are classified it is usually necessary to arranges them in a predetermined sequence to facilitate processing. Sorting is done in an alphabetic or an numeric order.
6. Calculating – arithmetic manipulation of the data is known as calculating. It is a crucial phase of data manipulation because the outcome of this operation becomes part of the output. Example in the calculation of an employee’s payroll.

7. Summarizing and Reporting – in this operation a collection of data is condensed and certain conclusions from the data are represented in a meaningful format. To be of value data must often be condensed of sifted so that the resulting output will be clear, concise and effective.

8. Merging – this operation takes two or more sets of data all sets having been sorted by the same key and puts them together to form a single set of data. As an example sales reports from different store branches are merged to form an overall sales report for the whole business establishment.

9. Storing – placing similar data into files for future references is storing. Storage is done by any of the following methods.

10. Retrieving – recovering stored data and/or information when needed is the retrieving step.

11. Feedback – is the comparisons of output(s) and the goal set in advance; any discrepancy is analyzed, corrected, and fed back to the proper stage in the processing operation.

EQUIPMENT USED IN PROGRAMMING, BUSINESS DATA PROCESSING AND SECURITY

1. Barcode Readers – are also called a price scanner or point-of-sales (POS) scanner, is hand-held or stationary input device used to capture and read information contained in a barcode.

There are five basic kinds of barcode readers
a. Pen Wand – is the simplest barcode readers. It contains no moving parts and is known for its durability and low cost.
b. Slot Scanner – remains stationary and the item with the bar code on it is pulled by hand through the slot.
c. Charge Couple Device (CCD) Scanner – has a better read – range than the pen wand and is often used in retail sales. Typically a CCD scanner has a “gun” interface and has to be held no more than one inch from the bar code.
d. Image Scanner – also called a camera reader, uses a small video camera to capture an image of the bar code and then uses sophisticated digital image processing techniques to decode the barcode.
e. Laser Scanner – either hand held or stationary does not have to be close to the bar code in order to do its job. It uses s system of mirrors and lenses to allow the scanner to read the bar code regardless of orientation.

2. Magnetic Stripe Reader – also called a magstripe reader, is a hardware device that reads the information encoded in the magnetic stripe located on the back of a plastic badge.

3. Biometrics – generally the study of measurable biological characteristics. In computer security biometrics refers to authentications techniques that rely on measurable physical characteristics that can be automatically checked.

There are several types of biometric identification schemes:
a. face – the analysis of facial characteristics
b. fingerprint – the analysis of an individual’s unique fingerprints
c. hand geometry – the analysis of the shape of the hand and the length of the fingers
d. retina – the analysis of the capillary vessels located at the back of the eye
e. iris – the analysis of the colored ring that surrounds the eye’s pupil
f. signature – the analysis of the way a person sings his name
g. vein – the analysis of pattern of veins in the back of the hand and wrist
h. voice – the analysis of the tone, pitch, cadence and frequency of a person’s voice

NUMBER SYSTEM

The number system that we now use has provided mathematicians, engineers and scientist with a great advantage over those of previous civilizations. It has proven to be an important factor in the rap, advancement of modern science and technology. The earliest numerals which have been found consist of either vertical or horizontal marks. The decimal 1 is an example of this sort of symbol. Similarly the symbols for 2 and 3 consist of two and three vertical or horizontal marks respectively.

1. Unitary System – in counting the simplest system is no the decimal system but a one-to-one comparison between the objects to be counted and the count or tally. Thus a checker makes a single mark each time one bag of a shipment of cement bags delivered to a warehouse and keeps account of the delivery by tallying up the total number of marks. A long series of tallying marks is simplified by breaking up the long series of tallying marks into groups of five by making a diagonal stroke through each set of mark marks as ||||.
2. Decimal System – the decimal system for counting has been so widely used from time immemorial. It is based upon the ten fingers of man. This system is nothing more than a code where each distinct quantity is assigned a symbol. In the decimal system the following digits are used: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9.

DECIMAL – BINARY CONVERSION

Suppose that a value expressed as a decimal numeral is to be represented as a binary numeral for storage in the computer. The numeral must then be converted from decimal to binary. One approach is to use division – multiplication method. The rule is simple: To convert decimal whole numbers from base 10 to any other base, divide the number repeatedly by the value of the base to which the number is being converted. The division operation is repeated until the quotient is zero. The remainders – written in reverse of the order in which they were obtained from the new equivalent numeral.

The rule is applied in the following example to convert the decimal 139 to its binary equivalent.

Division Quotient Remainders
139/2 69 1
69/2 34 1
34/2 17 0
17/2 8 1
8/2 4 0
4/2 2 0
2/2 1 0
1/2 0 1

Therefore: 13910 = 100010112

The zero quotient indicates the end of the calculations. Observe that the remainders can only be 0 or 1, since the divisions are by 2. The sequence of the remainders from the bottom up, as indicated by the arrow yields the required binary equivalent. The value expressed by the decimal numeral 139 can thus be expressed by the binary numeral 10001011. Other decimal numerals can be converted to binary in a similar manner.

“Give more example and seatwork to the students regarding the decimal – binary conversion”

BINARY – DECIMAL CONVERSION

Binary numeral can be converted to decimal by the use of expanded notation. When this approach is used the position values of the original numeral are written out. The following examples illustrate the conversion of binary numbers to the decimal system.

a. 101 = 1x22 + 0x21 + 1x20 = 4 + 0 + 1 = 5

b. 1100 = 1x23 + 1x22 + 0x21 + 0x20 = 8 + 4 + 0 + 0 = 12

b. 100110 = 1x25 + 0x24 + 0x23 + 1x22 + 1x21 + 0x20 = 32 + 0 + 0 + 4 + 2 + 0 = 38

Since each power of two is weighted by either 0 or 1 the binary number is simply the sum of those place values in which the bit 1 appears. This sum at once gives us the decimal equivalent of the binary number. Sometimes it is necessary to indicate the subscript 2 to distinguish a binary number.

Decimal Number Binary Number
16s 8s 4s 2s 1s
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20 0 1 1 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 1 0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 1 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 1 0 0 0 0 1 0 0 0 1 1 0 0 1 0 1 0 0 1 1 1 0 1 0 0

CONVERSION OF FRACTIONS: DECIMAL TO BINARY

A decimal fraction may also be converted into an equivalent binary notation. The conversion be accomplished using several techniques. A much simpler method consists of repeatedly doubling the decimal fraction and noting the integral part of the product. The following are illustrative examples.

Convert the following decimal fractions to its binary equivalent: 0.375, 0.40625, 0.78125, and 0.390625.

a. Multiplications Integral Parts 0.375 x 2 = 0.75 0 0.75 x 2 = 1.5 1 0.5 x 2 = 1.0 1

Therefore: 0.37510 = 0.0112 b. Multiplications Integral Parts 0.40625 x 2 = 0.8125 0 0.8125 x 2 = 1.625 1 0.625 x 2 = 1.25 1 0.25 x 2 = 0.5 0 0.5 x 2 = 1.0 1

Therefore: 0.4062510 = 0.011012 CONVERTING DECIMAL NUMBERS WITH INTEGRAL AND FRACTIONAL PARTS INTO ITS BINARY EQUIVALENT

In the previous examples we have seen the fractional part of a decimal number is converted into its binary equivalent.

In the following examples the procedure of converting decimal numbers with integral and fractional parts into its binary equivalent are illustrated.

Ex 1: Convert the decimal number 24.625 to its binary equivalent.

1st Step: Convert the integral part. DIVISIONS QUOTIENT REMAINDERS 24/2 12 0 12/2 6 0 6/2 3 0 3/2 1 1 ½ 0 1 Therefore: 2410 = 110002

2nd Step: Converting the fractional part.

MULTIPLICATIONS INTEGRAL PARTS 0.625 x 2 = 1.25 1 0.25 x 2 = 0.5 0 0.5 x 2 = 1.0 1 Therefore: 0.62510 = 0.1012

3rd Step: The binary equivalent of 24.625 is simply the sum of these two equivalents. Thus 2410 + 0.62510 = 110002 + 0.1012 24.62510 = 11000.1012

SYSTEM LIFE CYCLE

A system life cycle is a collection of related components that serve a common purpose. In the topic that is being discussed today, System Life Cycle means that it is either a program or a collection of programs that had been designed to perform a particular task.

The Stages of a s System Life Cycle

Business Systems – or enterprise functions do not remain static for very long otherwise they would lose their effectiveness because they no longer meet or deliver what is expected of them. And because of this the system or function has to change in order to meet this new demand. When changes occur systems that are in place are eventually replaced or significantly altered to become a new system or an improved version.

The Initial Study

Any project or study is never started without any apparent reason. It must have been initiated by someone who has a need that has not yet been met hence the need for a new system, project or study. For our purpose since we are in the ICT environment, we will call this person who initiates a system or the person who has a need to be met as the user.

System Analysis and Design/Review of Programming Specifications Based on the feasibility report that the System Analyst (SA) has prepared, the SA will carry out a requirement analysis to find out what is needed to meet the needs of the user. The system analyst will use various techniques like the interview and the questionnaire to find out what has been done with the old system and what else needs to be done by the new system. The SA will closely work with the user to verify the accuracy of the findings.

Program Design

Just as an architect must design a building prior to actually beginning construction so too must a computer programmer design a program before writing the actual instructions that the computer must execute.

When designing a program the programmer first examines the entire problem to determine the task that must be accomplished to solve the problem. Once these tasks are identified the programmer begins to define the precise sequence in which the operations are to be performed by the computer.

Development

When the design is completed it is time to convert the design to workable programs that will be used by the computer. Under this stage two main activities take place:

a. File creation
b. Application program creation

Implementation

After adequate testing to find and solve the errors that may occur in the program implementation of the system takes place. This particular stage may involve the actual acquisition of hardware that is necessary to fully implement the program.

Documentation

Documentation is an integral part of all stages in the development of the program. This is to ensure that no steps are unnecessarily repeated and that should a problem arise within the program there would be a way to check how to solve this error in the program.

Review

After everything has been done and the system has been used for a sufficient length of time and emergencies and errors have been coped with and evaluation review must take place. The review must be carried out by a person who has not involved in the design and development phase so as to ensure that the review will be done objectively.

DATA AND DATA STRUCTURE

Data – may be defined as a collection of numbers, characters, words and phrases that are suitable in some manner for computer processing to produce useful information. Example of data include the balance in your bank account, the score you receive in a test, your home address, the number of students in a class, the price of an item in a sales invoice or the number of stocks in store’s inventory list.

Types of Data

Numeric data – sums of money, ages, distances and others. They are generally numbers expressed as numerals that can be read by computers to perform mathematical operations. Two types of numeric data
a. Integers – are whole numbers that are used to count things, example 1,2,3… they are used to count discreet objects like the number of fruits, cars, or books; they are also often used for precise values (example: the value 18 means exactly 18).
b. Real Numbers – may have a fractional or decimal part (e.g. 1.5 and 1 ¼; can be positive or negative;) they are used to measure things (e.g. the length of a bond paper or the amount of a grocery item in pesos and centavos).

Non – numeric data – are set of characters or letters as in a name, a group of letters and numbers as in a license plate and others. Three types of non – numeric data
a. Characters or strings – may consist of numbers, alphabets (letters) or alphanumerics. In order represent such strings in a computer program, quote (“) or apostrophes (‘) are needed, usually depending on the programming language being used (e.g. for the name Juan Dela Cruz to be used it must be ‘Juan Dela Cruz’). String values are stored as codes using the American Standard Code for Information Interchange (ASCII).
b. Logical Data – on the other hand consists only of two (2) values: True or False. This is usually used as a “switch” in most programs as they are used in decisions making (e.g. Did he pass the exam?)
c. Pointers – are used to store the addresses of variables used in most programs.
d. Dates – allow to use the arithmetic operation on calendar dates. This is the only non – numeric data classification than can be used in computations.

Identifiers – All data items used in a program needs to be “declared” before usage. Declaration means to state down the name given to each data item storage cell known as an “identifier.”

Constants – are “Read - Only” variables which contain fixed data values that cannot be changed during program run – time.

Variables – on the other hand may have their contents changed due to user input or the processing of data, during program run – time.

Data Processing

All through the different stages in civilization, man has always tried to look for ways to simplify work and to solve problems more efficiently. Many problems involved numbers and quantities, so man started looking for easier ways to count, to add, subtract, multiply and divide. As society has grown in both size and complexity, so have data that are generated by it through time.

Definition of Terms

Data – is defined as any collection of facts. Thus sales reports, inventory figures, test scores, customers’ names and addresses, and weather reports are all example of data.

Data Processing – is the manipulation of data into a more useful form. It is the modern name for paperwork and involves the collecting, processing, and distribution of facts and figures to achieve a desired result.

Categories of Data Processing

Mechanical Data Processing – use a combination of manual procedures and mechanical equipment. The system uses devices such as typewriters, sorters, calculators, collators, tabulators, duplicators and verifiers.

Electronic Data Processing – different types of input, output and storage devices may be interconnected to an electronic computer to process data.

DATA PROCESSING CYCLE

1. Input – In this step the initial data or input data is prepared in some convenient form for processing. The form will depend on the processing machine.

2. Processing – In this step the input data is changed, and usually combined with other information, to produce data in a more useful form.

3. Output – Here the results of the preceding processing steps are collected. The particular form of the output data depends on the use of the data

FLOWCHARTING AND PSUEDOCODING

When we are designing program logic each individual step may be illustrated through the use of a flowchart. A flowchart consists of a series of symbols that graphically represented the solution to problem. Some of the more commonly used symbols are show below.

As the programmer determines each step to be performed by the program the appropriate symbol is drawn. The task to be accomplished is written inside the symbol as a caption. When the program design is completed the flowchart that was drawn will provide a graphic representation of the steps that are needed to solve the problem. Some of the most commonly used symbols are show below.

Symbol Description

Input/Output
Indicates any function of an input/output device making data available for processing or causing information to be made available for use by people or other machines.

Decision
Documents appoint in the program where a comparison is to be made and alternative processing is to occur based upon the results of the comparison.

Flow Lines
Indicate direction of data flow

Preparation
This symbol is used in declaring and initializing identifiers or variables that will be used in the program. This is usually placed right after the Start terminal which indicates the beginning of the flow chart. Example Sum = 0, Average = 0, Name = “”

Processing
Represents one or more instructions that perform a processing function for the program. Examples of a processing function are addition, subtraction, multiplication, division and others.

On page Connector
Indicates an entry or an exit to another part of the program flowchart. It is also used to indicate the termination of a comparison operation.

Terminal
Documents that beginning or end of a program

Off Page Connector
Indicates continuation to or from another page

Annotation Symbol
Used when an additional description is appropriate

PSEUDOCODE

Also called Program Design Logic presents an alternative to flowcharting. While flowcharts represent logic in graphic form, PSEUDOCODE allows the programmer to represent his/her logic in an English–like manner.

Both forms of representing program logic have their own advantage and disadvantage. The flowchart seems to be best suited to programmers who need visual images to solve problems more clearly while the pseudocode would do well for people who like it neat and simple when they make their program

Some rules in pseudocode
• The pseudocode must be language dependent it must try to avoid the use of words peculiar to any programming language.
• Indent lines to make pseudocode easy to read and understand
• Show keywords in capital letters (e.g. FOR condition NEXT)
• Punctuation is optional
• End every IF with an ENDIF
• End every DO, DO FOR, DO WHILE and DO UNTIL with an ENDDO

Some advantages in using pseudocode:
a. It bridges the gap between human language and computer language.
b. It is an intermediate notation that allows expression of program logic in a straight forward easy to understand manner without burdening the programmer with syntax details.
c. It is easier to make changes in pseudocode than to make changes in the source code of an actual programming language

Examples of pseudocode
Problem:
1. Ask the user to type in his/her name, address and telephone number. Generate a print out that prints the user’s first name, city and telephone number.
Start
FN = First name LN = Last name Num_St = number and street City = City Tel = telephone number Input FN, LN Input Num_St, City Input Tel Print FN, City, Tel
End
2. Create the pseudocode for a program that will ask the user to input two numbers and have the program compute the sum of the numbers. The output should print the two numbers and their sum.
Start
Firstnum = first number Secnum = second number Input Firstnum Input Secondnum Sum = Firstnum + Secnum Print Firstnum Print Secnum Print Sum End
3. Write the psuedocode for a program that tells use if they are old enough to vote based on their age.
Start
Age = 0 Input Age If Age > 18 Then Print “Old enough to vote” Else Restart End if
End

Sample Flowcharts for the examples above:

1.

2.

3.

Activity for the students:
1. Create a pseudocode and a flowchart on how to compute for the sum and average of three random numbers.
2. Write the pseudocode of a program that will ask the user for input for the radius of a circle and have the program compute for its area.
3. Create a flowchart for a program that will ask for the user to input his/her age, and then determine if they can be given a discount depending on their age. The age discount table follows:
Age Discount
0-12 100 %
13-17 75%
18-34 50%
35-45 30%
46-64 50%
65-above 75%