Computer Studies Made Simple : Information Technology : Preliminary Investigations

Computer Studies Made Simple : Information Technology

Preliminary Investigation:

A thorough investigation of a system is done in this phase.

Following steps are taken in order to achieve this:

 1.System Identification:

This phase is used to justify the need of a new system.

It is the single most important step in further development of a system.

2.System Scope :

The overall scope of a system is recognized and identified at this stage

3.Alternate Solutions :

Alternative sources for development of a system are identified after discussion and 

meetings with clients,customers and suppliers etc

4.Feasibility Studies

This is conducted to determine whether the proposed system would be effective for a 

particular organization in terms of its affordability and acceptability keeping in view the 

financial, and other constraints

5.Preliminary Plan

Also called as feasibility Report,is submitted to the managers and Organizers for 

approval.

It may have one of the following outcomes:

Approval

Modification

Complete Rejection

Dermatology Made Simple : Fungal Infections of the skin

Fungal Infections of Scalp:

Etiology / Causative Organisms

These are most frequently caused by Tinea capitis.

Major fungal Pathogens include:

Trichophyton

Microsporum

Epidermophyton

Clinical presentation:

These may present in one of following ways:

Scaling

Alopecia (Hair Loss)

Yellow crusts on the scalp.

Grey patches

Pustules

Kerion : Boggy inflamed pustular lesion on the scalp.

Investigations:

Scalp brushings must be taken to isolate fungal pathogens.

Management:

Systemic Antifugnals are usually needed as topical antifungals are unable to penetrate the affected areas.

Griseofulvin

Has minimal side effects.

Most effective for Microsporum Infections.

Dose is 10 mg / kg if over 1 month of age

Terbinafine:

Most effective against Tinea Tonsurans.

Dose : depends on the weight of the patient

< 20 kg : 62.5 mg

20 – 40 mg : 125 mg

  Ø  40 kg : 250 mg OD



TTinea Capitis involving Scalp

Computer Studies Made Simple : System Development Life Cycle / SDLC

System Development Life Cycle / SDLC :

This refers to a series of steps taken in order to develop a system.

The following series of steps are taken:

1.Preliminary Investigation:

This is the first phase in SDLC in which initial analysis of a system is performed.

The following aspects are analysed:

System identification

System Scope

Alternative Solutions

Feasibility Study

Preliminary Plan

2.System Analysis:

A detailed analysis and study of current system is undertaken to investigate the working of a system and 

ways of making improvements.

It includes the following aspects:

Need Analysis

Data Gathering

Data Analysis

Analysis Report

3.System Design:

In this stage,logical and physical model of a new system is designed.

This design is made keeping in mind to fulfil criteria devised in Analysis Phase

4.Coding Phase:

Actual development of the System takes place in this stage.

Different modules and programmes are designed.These modules are then intergrated at a later stage.

5.Testing:

In this phase,the system is thoroughly tested in order to identify and errors.

6.Implementation:

In this stage,hardware,software and other files are installed in the system after testing has been completed.

It canbe done in one of the methods below:

Parallel Implementation

Phased Implementation

Pilot Implementation

Direct Implementation

7.Maintenance:

In this phase,a system is monitored and steps aretaken to ensure that a system is fulfilling its objectives.

It includes the following meausures/steps:

Taking steps to update and improve effectiveness of a system.

Identifying and rectifying any problems identified in the system.

Computer Studies Made Simple : Devices used to connect networks of computers

Devices used to connect networks of computers:

Different devices to connect networks of computer are as follows:

1.Router

2.Gateway

3.Bridges

Router:

A router is a device that connects multiple networks that’s use similar or different protocols.

It manages the best route between any two communication networks.

It consists of hardware and software.

The hardware canbe a network server or a separate computer.

The software includes operating system and routing protocol.

Routers are used when several networks are connected together.

They can connect networks of different countries.

They transfer data in less time.

Gateway:

A gateway is a device that connects two or more networks with different types of protocols.

Two different type of networks require a gateway to communicate with each other.

It is an intelligent device as it converts data according to the protocol.

For example,the computers on a LAN require gateway to access the internet.

Bridges:

A bridge is a device that connects two network segments.

It is used to connect similar types of networks.

When a bridge receives a signal,it determines the segment where the signal should be sent.

It reads the addresses of sending and receiving computers.

If both the computers are in the same segment,bridge doesnot pass the signal to the other segment.

It reduces network traffic and increases network performance.  

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