IGNOU MCA 3rd Semester Solved Assignment For 2016-2017 Session

MCS 032

What is class diagram ? Draw class diagram for Library Management System. 

Class diagram

In software engineering, a class diagram in the Unified Modeling Language (UML) is a type of static structure diagram that describes the structure of a system by showing the system's classes, their attributes, operations (or methods), and the relationships among objects.

• Classes

Classes represent an abstraction of entities with common characteristics. Associations represent the relationships between classes.

• Active Classes

Active classes initiate and control the flow of activity, while passive classes store data and serve other classes. Illustrate active classes with a thicker border.

• Visibility

Use visibility markers to signify who can access the information contained within a class. Private visibility, denoted with a - sign, hides information from anything outside the class partition. Public visibility, denoted with a + sign, allows all other classes to view the marked information. Protected visibility, denoted with a # sign, allows child classes to access information they inherited from a parent class.

• Associations

Associations represent static relationships between classes. Place association names above, on, or below the association line. Use a filled arrow to indicate the direction of the relationship.

• Multiplicity (Cardinality)

Place multiplicity notations near the ends of an association. 

• Constraint

Place constraints inside curly braces {}.

• Composition and Aggregation

Composition is a special type of aggregation that denotes a strong ownership between Class A, the whole, and Class B, its part. Illustrate composition with a filled diamond.

• Generalization

Generalization is another name for inheritance or an "is a" relationship. 
 

 

IGNOU MCA 3rd Semester Solved Assignment For 2016-2017 Session

MCS 031

Discuss some real world problems, to which the techniques given below are applicable. 

Discuss some real world problems, to which the techniques given below are applicable
(i) Divide & Conquer
(ii) Dynamic Programming
(iii) Greedy Approach

Divide and Conquer in real world

I am going to explain using real world systems around us

Government and Company: 

In real world, Government follows the divide and conquer approach to get all problem listed and resolve. Using State Leaders, District Leaders, Block Leader, Village Leader etc. 

Similar for the company, suppose someone purchased a Product from Cipla, and He received an outdated product from store. For this problem He can't complain directly to CEO of Cipla. 

CEO > Managers of different fields > Territorial Manager > Area Manager > Local Distributor > Then Local Shop/Store

By this chain they can easily find the problem and solved in mannered way. 

Simple word, We can solve a big problem in small pieces and solve it, after solving each merge them together. 

So basically, divide any big problem into smaller problems (to make our life easy), solve individual problems and combine the solution of small problems to get the solution to big problem. Note that sometimes, there is no need for combining solutions of small problems.

Dynamic programming in real life

Dynamic programming used to avoid repetitive work. That can be achieve by remembering partial results.

Real World Problem : Min-Num-Coins

(Gives the minimum number of coins for Given Amount)

In Automated shop, someone purchased goods of Rs. 389, After billing Machine start showing few combination of change to achieve the Amount 389. Customer will select a combination and give the money. Similar If customer paid 500 to pay 389 then Shopkeeper will also calculate the change with minimum coins.

Aircraft stand assignment to minimize walking

Gate scheduling is concerned with assigning flights to terminal or ramp positions, called gates. It is a key activity in airport operations. With the increase of civil air-traffic and the corresponding growth of airports in the past decades, the complexity of the task has increased significantly. At large international airports, several hundreds of flights must be handled per day.

Greedy Approach in real world

Interval scheduling is a class of problems in computer science, particularly in the area of algorithm design. The problems consider a set of tasks. Each task is represented by an interval describing the time in which it needs to be executed. For instance, task A might run from 2:00 to 5:00, task B might run from 4:00 to 10:00 and task C might run from 9:00 to 11:00. A subset of intervals is compatible if no two intervals overlap. For example, the subset {A,C} is compatible, as is the subset {B}; but neither {A,B} nor {B,C} are compatible subsets, because the corresponding intervals within each subset overlap.

The interval scheduling maximization problem (ISMP) is to find a largest compatible set - a set of non-overlapping intervals of maximum size. The goal here is to execute as many tasks as possible.