A data dictionary contains a set of precise and accurate definitions of all DFDs, data elements and data structures.
The following rules are followed in constructing a data dictionary:
a) The terms used to describe data structures are always in capital letters.
b) Multiple word names are hyphenated.
c) Names assigned should be straight forward and user-oriented.
d) There should [...]
Data Dictionary
Questionnaire
Questionnaires are special-purpose documents that allow the analysis to collect information and opinions from respondents. When it is impossible because of time, distance or cost constraint, to interview all the desired people involved in a system, then the analyst may consider the use of a questionnaire. This is a more structured and formal method of [...]
Tangible and intangible Costs and Benefits
Tangible benefits means that benefit which is definite and can be determined in advance. Tangible cost means that it is known and can be estimated quite accurately. For example, the cost of salary of employees, the expense of specific piece of equipment, would be tangible cost.
Intangible cost refers to something which we know exists, but [...]
COST – BENEFIT ANALYSIS
Cost –benefit analysis is a tool for evaluating the effectiveness of the project. It may be used by the management to decide as to what extent benefits outweigh the costs. The costs associated with the proposed business system are the expenses arising from developing, installing, training and implementing the systems. The benefits are the advantages [...]
cost per unit
The chartered institute of Management Accounts, London, defined a unit of cost as “a unit of product or service in relation to which costs are ascertained’. A cost unit is a devise for the purpose of breaking up or separating costs into smaller subdivisions. These smaller sub-division are attributed to product or services to determine [...]
CELL PHONE CAN READ YOUR LIPS
The prototype device could allow people to conduct silent phone conversations. The technology measures the tiny electrical signals produced by muscles used when someone speaks.
The device can record these pulse even when a person does not audibly utter any words and use then to generate synthesized speech in another handset.
“I was taking a train and [...]
MIND- READING
Devices allowing people to write letters or play pinball using just the power of their brains have become a major draw at the worlds biggest high tech fair. Huge crows at the CeBIT fair gathered round a man sitting at a pinball table wearing a cap covered in electrodes attached to his head, who controlled [...]
THE SKIN
It is the tissue covering the flesh of the body. It has two layers, the top one called the Epidermic or scarf skin and Dermis or true skin. The later is richly supplied with blood vessels. The skin is designed to –
1. Protect the body .
2. Act as an organ of excretion by means of the sweat [...]
Mineral composition of the human body
1. major element percentage gram/70kg weight
Calcium 1.5 to 2.2 1050-1540
Phosphorus 0.8 to 1.2 560-840
Potassium 0.35 245
Sulphur 0.25 175
Sodium 0.15 105
Chlorine 0.15 105
Magnesium 0.05 35
2. minor element
Iron 0.004 2.8
Manganese 0.003 0.21
Copper 0.00015 0.105
Iodine 0.00004 0.024
ATOMIC COMPOSITION OF THE HUMAN BODY
ELEMENT PERCENTAGE OF
TOTAL ATOMS
HYDROGEN 63
OXYZEN 25.5
CARBON 09.5
NITROGEN 01.4
CALCIUM 0.31
PHOSPHORUS 0.22
CHLORINE 0.09
POTASSIUM 0.06
SULPHUR 0.05
SODIUM 0.05
MAGNESIUM 0.01
ALL OTHER 0.01