CYBER SECURITY - BMC106 (Questions with Answer) of AKTU

1. What is information assurance and how is it provided?(Ans:Information assurance is defined a the set of measures applied to protect information systems and the information of an organization. It ensures availability, integrity, confidentiality and non repudiation of an organization's information and information system. IA infact the management of risk in relation of processing, transmitting or storing data or information, which means to protect information and information system from accessing, misusing, disclosing, disrupting, destructing and modifying in an unlawful manner.) 
2. Describe security risk analysis?(Ans: Risk analysis is a continuous process that require you to constantly monitor the measures employed to maintain security of your system at present. Process of security risk analysis involves the following three key elements: impact statement, effectiveness measure and recommended countermeasures.  )
3. How do you classify the information system in general? (Ans: there are three basic categories   1. operation support system(Transaction processing system, process control system, Enterprise collaboration System ), 2. knowledge based system (expert system, knowledge Management System), 3. management support system.(management information system, decision support system) ).
4. What is the public key encryption ? Explain.(Ans: in public key encryption two keys are used to encrypt and decrypt data. the key used to encrypt the data is known as public key, and the key used to decrypt the data is known as the private key.you need to generate the public key and private key to use public key encryption. the public key is then made available to anybody who wants to send data. sender can use public key to encrypt data and send the encrypted data to destination. you need to use private key which remains hidden from sender to decrypt data.)
5. What are the security threats? Discuss.(Ans: viruses(polymorphic, stealth, retroviruses, multipartite, armored, companion, phage, macro viruses),  Trojan horses, Logic bombs, worms, spoofing(ip spoofing, content spoofing, caller id spoofing, email spoofing), Trapedoor, email viruses, Macro viruses, Malicious software, deniel of service attacks)
6. How we can use firewall to make secure our application? (Ans: Packet filter, Application level gateway, circuit level gateway, proxy server)
7. What is the process of developing secure information system?
8. What do you understand by security structure and design?
9. Describe the intellectual property issue (IPR).
10. Write a short note on the copyright Act.         
11. What is the information security? Explain cyber crime and Cyber security in this reference.
12. What is intellectual property? Explain with example.
13. Elaborate the difference between security and threats and explain web security.
14. Draw the digrametical approach to make difference between symmetric and asymmetric cryptography.
15. How tunneling takes place in virtual private network (VPN)? Explain the advantage of VPN.
16. How you can say that intrusion detection system is the backbone of information system? Justify  along with its categories.
17. Elaborate cyber crime play a vital role against person , property and government to protect all valuable information and rights.
18. What are the different technologies used for the security of data and application? explain the vulnerabilities.
19. Explain and diffrentiate between integrating security at the implementation phase and the development phase.
20. What is the data security considerations? explain in this reference data back up security, data archival security and data disposal considerations.
21. Explain in what situation semiconductor law comes in consideration and how it differs from patent law?
22. What is the application security? define it in the case of vendor challenges and user challenges for application security.
23. Explain the concept of cryptography by using the diagrammatic approach of it. define the transformation method of it.
24. Elaborate the term access control. What is include in authorization process for (File, Program, data Rights) and explain the all type of controls.
25. Explain the information system resource and activities and what may be the reason of failure of it.

MCA OOS UNIT 4 & UNIT 5

Inheritance

C++ strongly supports the concepts of reusability.

Once a class has been written and tested, it can be adopted b other programmers to suit their requirements.

This is basically done by creating new classes reusing the properties of the existing once.

The mechanism of deriving a new class from an old one is called inheritance.

The old class is referred as base class and the new one is called the derived or subclass.

Hierarchical Inheritance

Multilevel Inheritance

Multiple Inheritance

Hybrid Inheritance

Single Inheritance

A class can also inherit properties from more than one class or from more than one level .

A derived class with only one base class is called single inheritance and one with several base classes is called multiple inheritances.

The traits of one class may be inherited by more than one class. This process is called as hierarchical inheritance.

The mechanism of deriving a class from another derived class is known as multilevel inheritance.




Syntax 

class  derived_ class-name : visibility-mode  base class_name
{
---------------//
---------------//members of derived class
--------------//
} ;

Single Inheritance Example :Single Inheritance is method in which a derived class has only one base class.

#include <iostream.h>
class Value 
  {
    protected:
      int val;
    public:
      void set_values (int a)
        { val=a;}
  };
class Cube: public Value 
  {
    public:
     int cube()
       { return (val*val*val); }
  };
int main () 
 {
   Cube cub;
   cub.set_values (5); //object of cube class inherit the 

                         function of Value class 
   cout << "The Cube of 5 is::" << cub.cube() << endl;
   return 0;
 }

Multiple Inheritance Example: Multiple Inheritance is a method by which a class is derived from more than one base class.

#include <iostream.h>
using namespace std;
class Square
  {
    protected:
     int l;
    public:
     void set_values (int x)
      { l=x;}
  };
class CShow 
  {
    public:
     void show(int i);
  };

void CShow::show (int i) 
 {
   cout << "The area of the square is::" << i << endl;
 }

class Area: public Square, public CShow
  {
   public:
    int area()
      { return (l *l); }
  };
int main () 
{
  Area r;
  r.set_values (5);
  r.show(r.area());
  return 0;
}

Hierarchical Inheritance Example: Hierarchical Inheritance is a method of inheritance where one or more derived classes is derived from common base class.

#include <iostream.h>
class Side
  {
    protected:
      int l;
    public:
      void set_values (int x)
        { l=x;}
  };
class Square: public Side
  {
    public:
      int sq()
      { return (l *l); }
  };
class Cube:public Side
  {
   public:
     int cub()
      { return (l *l*l); }
  };
int main () 
  {
    Square s;
    s.set_values (10);
    cout << "The square value is::" << s.sq() << endl;
    Cube c;
    c.set_values (20);
    cout << "The cube value is::" << c.cub() << endl;
    return 0;
  }

Multilevel Inheritance Example: Multilevel Inheritance is a method where a derived class is derived from another derived class.

#include <iostream.h>
class mm
  {
    protected:
      int rollno;
    public:
      void get_num(int a)
        { rollno = a; }
      void put_num()
        { cout << "Roll Number Is:\n"<< rollno << "\n"; }
  };
class marks : public mm
  {
    protected:
      int sub1;
      int sub2;
    public:
      void get_marks(int x,int y)
        {
           sub1 = x;
           sub2 = y;
        }
      void put_marks(void)
        {
          cout << "Subject 1:" << sub1 << "\n";
          cout << "Subject 2:" << sub2 << "\n";
        }
   };
class res : public marks
   {
     protected: 
       float tot;
     public:
       void disp(void)
          {
            tot = sub1+sub2;
            put_num();
            put_marks();
            cout << "Total:"<< tot;
          }
   };
int main()
   {
     res std1;
     std1.get_num(5);
     std1.get_marks(10,20);
     std1.disp();
     return 0;
  }

Hybrid Inheritance Example: Hybrid Inheritance is a method where one or more types of inheritance are combined together and used.




#include <iostream.h>
class mm
  {
    protected:
      int rollno;
    public:
      void get_num(int a)
       { rollno = a; }
      void put_num()
       { cout << "Roll Number Is:"<< rollno << "\n"; }
  };
class marks : public mm
  {
   protected:
     int sub1;
     int sub2;
   public:
     void get_marks(int x,int y)
       {
         sub1 = x;
         sub2 = y;
       }
     void put_marks(void)
       {
          cout << "Subject 1:" << sub1 << "\n";
          cout << "Subject 2:" << sub2 << "\n";
      }
  };

class extra 
  {
    protected:
      float e;
    public:
    void get_extra(float s)
      {e=s;}
    void put_extra(void)
      { cout << "Extra Score::" << e << "\n";}
  };

class res : public marks, public extra{
   protected: 
     float tot;
   public:
     void disp(void)
       {
         tot = sub1+sub2+e; 
         put_num();
         put_marks();
         put_extra();
         cout << "Total:"<< tot;
       }
 };

int main()
 {
   res std1;
   std1.get_num(10);
   std1.get_marks(10,20);
   std1.get_extra(33.12);
   std1.disp();
   return 0;
 }
When a base class is privately inherited by a derived class, public members of the
base class become private members of the derived class and therefore the public
member of the base class can only be accessed by the member functions of the derived class. They are inaccessible to the object of the derived class. 
A public member of a class can be accessed by its own objects using dot operator.

The result is that no member of the base class is accessible to the object of the derived class.

Visibility of Inherited members:

MCA-512 (UNIT V) - Dot Net Framework and C# (Assembly)

Assembly an Introduction

An assembly is a small logical collection of classes that contains the metadata of an application and components and resources that enable you to create an application. An assembly is one of the main components of the .NET framework and it is developed during the Runtime. An assembly provides the CLR with the metadata, which describes types, members, and references in your code. The runtime uses the metadata to locate and load classes, lay out instances in memory, generate native code, and enforce security.

It contains a manifest for executing a Microsoft Intermediate Language-based code (MSIL) at the CLR.Before the advent of the .NET platform, the business logic was implemented in the COM component. The main problem with COM is that it is tightly coupled with the operating system. When you deploy a COM component on a system, it copies the related .dll or .exe file to a specific location and makes an entry for the file in the registry. In COM, every component is uniquely identified in the registry through a Globally Unique Identifier (GUID).

DLL-hell Problem

COM-based systems are prone to the classic dll-hell problem. You cannot modify a component after it is deployed without affecting existing clients. COM provides a mechanism to register and access multiple versions of a component in the registry, but the operating system does not provide a mechanism to prevent an earlier version of a .dll from accidentally overwriting a newer version.

Needs for Assemblies
The assembly handles the operating system dependency and DLL-hell problems because it is a self-describing unit. You can maintain two versions of the same assembly on the same system.

COM-based systems are prone to the classic dll-hell problem. You cannot modify a component after it is deployed without affecting existing clients. COM provides a mechanism to register and access multiple versions of a component in the registry, but the operating system does not provide a mechanism to prevent an earlier version of a .dll from accidentally overwriting a newer version.The assembly handles the operating system dependency and DLL-hell problems because it is a self-describing unit. You can maintain two versions of the same assembly on the same system.

When Microsoft developed the .NET platform, the operating system dependency and the dll-hell problems were a major focus and it wanted to remove the coupling between the platform and the registry. The metadata of an application resides in the application itself and provides multiple versions of applications on the same system because each version maintains its own metadata.

 Assembly Advantages

- Easy Deployment: Allows you to deploy a .NET component on a client computer with a simple Xcopy command.

- Side-by-side Execution: Allows other applications to use assemblies in addition to the primary application.

- Operating System Independence: Allow you to port assemblies to any operating system that supports a .NET common runtime environment.

Structure of an Assembly

A .NET assembly consists of assembly metadata and the assembly manifest contains the type information, resources, and the MSIL code to implement type metadata in an assembly. The manifest is an important component of an assembly. The assembly manifest contains the following:

- Identity Information: Identifies the assembly uniquely by the combination of four properties:

assembly name, assembly version, culture, and strong name.

- File List Information: Includes types and declarations defined in another file. Every assembly is made up of one or more files. The manifest maintains a list of files that make up the assembly. The manifest maps the file containing the types and declarations to the file containing the declaration and implementation of an application.

- Identity Information:  Identifies the assembly uniquely by the combination of four properties:

assembly name, assembly version, culture, and strong name.

- File List Information: Includes types and declarations defined in another file. Every assembly is made up of one or more files. The manifest maintains a list of files that make up the assembly. The manifest maps the file containing the types and declarations to the file containing the declaration and implementation of an application.

- Referenced Assembly Information: Includes the information of references to other assemblies. In application development, you can develop various components that are spread across various assemblies.

- Exported Type References: Includes information about the functions and types that are exported and available to other assemblies. The components of other assemblies may refer to the methods and properties in the current assembly.

- Type Metadata: Provides the description of each class type. The manifest includes the name of each class type exported from the assembly and the information about the file containing its metadata.
- Resources: Includes resources such as bitmaps that you can integrate into a manifest. The assembly's resource section contains information on the resources the application uses.

- MSIL Code: Contains the compiled code in the MSIL format. The manifest is the system information about the assembly. The .NET platform compiles code written in a CLS-compliant language to an Intermediate Language (IL). The MSIL compiler compiles the source code to an IL form. When the .Net-based code is executed, the just-in-time compiler of the .NET runtime compiles the IL code to the executable form. The runtime loads the compiled code segment in memory and executes it. As a result, the system stores the complete compiled code as part of the assembly in IL format and recompiles and executes it. This happens only once between the loading and unloading of the .NET runtime.

Types of Assemblies

There are two types of assemblies, single-file and multi-file assemblies. In the .NET platform there is no difference between the two. Based on the structure, constraints, and requirements of the development team, you can choose either type of assembly.

                Single-File Assembly
                Multi-File Assembly

Single-File Assembly-A single-file assembly stores the manifest, type metadata, IL, and resources in a single file. You can use this approach for simple applications when you need to develop an assembly for a small-scale deployment.

Multi-File Assembly: For example, you can have different modules related to the system administration functionality, developed over a period of time. Using the multi-file assembly feature of .NET, you can group all administration functionality modules into an assembly to facilitate component versioning and maintenance.

Scope of Assemblies

Assemblies can either contain a private or a public scope, based on the level of access required by the clients who access it. The manifest contains information regarding the scope of an assembly.
               

•                          Private Assembly

•                          Shared Assembly

Private Assembly- Assemblies are private in scope if only one application can access them. Private assemblies are only available to clients in the same directory structure as the assembly. As a result, the .NET assembly resides in the same directory structure as the client executable. You can use a private assembly when it is specific to a client application and no other client application refers to it.

Shared Assembly-When an assembly such as a system assembly contains features shared by various applications, standard deployment techniques discourage the use of private assemblies. As a result, you need to maintain a copy of the assembly for each client application. You can also register the assembly in the Global Assembly Cache (GAC), so that all client applications refer to one copy of the assembly. This type of assembly is called a shared assembly. The side-by-side execution feature of the .NET platform enables you to register multiple versions of the same assembly in GAC.

Global Assembly Cache(GAC): GAC is a repository of assemblies used by multiple applications on a system. When you install the .NET runtime on a system, it creates a cache, which can be used to store assemblies.

 Advantages
The advantages of storing an assembly as a shared assembly in GAC are:
- Multiple Applications: Allows you to access an assembly from one location, GAC. If multiple applications use the same assembly, instead of keeping a copy of the assembly in each application folder, you can store a shared assembly in GAC.

- Automatic Search Location: Enables the client application to easily access an assembly stored in GAC. When the runtime searches for an assembly, GAC is the default location it searches.

Security: Ensures that only the system administrator can modify permissions of the folder. The GAC is always installed in the system folder. It inherits the permissions and Access Control Lists (ACLs) present in the system folder. As a result, you can protect GAC from unauthorized modifications.

- Side-by-side Versioning: Enables you to maintain multiple versions of the same application on a system. Private assemblies enable you to maintain a copy of the assembly in every client application folder. When a new version of an assembly is released, instead of updating the assemblies in all client applications, you can maintain multiple versions of the assembly in a central location, GAC. Client applications can refer to various versions of assemblies in GAC.

Disadvantage of Storing an Assembly in GAC

In a private assembly, you can use a simple Xcopy operation for deployment, which you cannot use for GAC-based assemblies. The assembly has to be physically registered in the GAC of client computers. For example, assemblies stored in the GAC should have the same assembly name and file name, which means that you should save assembly name abc as abc.exe or abc.dll.

Best Answers of a interview question, "What is your weakness?"

What is your weakness is a simple question but has a lot of significance. This question has to be answered well and by this the employer guages your temperament. So, prepare well to make it your strength during the interview.

few example of such type of Questions:-

"My weakness is I get irritated when my group member refuse to bear their responsibility."

"I get fed up when anyone discourage me."

"I Believe people blindly at first sight." 

"Can't tolerate the disturbance during work time."

"I do not feel comfortable until i finish my work."

"very friendly in behavior."

"It is very much difficult for me to say 'NO' to someone."

"I am an analyzer. Sometimes in leisure time i start doing analysis on people's sayings."

"My weakness is doing mistake once and my strength is I will never do done mistake again"

i can not trust the person with-in shortly.

TOP MCA/ENGINEERING COLLEGE IN NCR/GHAZIABAD

Ajay Kumar Garg Engineering College, Ghaziabad-120  –Reputed college in engineering with excelent academic environment.in top 10 from many years.it offers M. Tech course also.

Hi-Tech Institute of Engineering & Technology, Ghaziabad- 60 - Reputed college with excelent academic environment ............................provides  technical certfication with degree………………Nice placement..(100 %  in MCA )

ABES Engineering College, Ghaziabad-60- it’s a reputed engineering college with many awards in university level ……for their excelent performance.

Institute of Management Studies, Ghaziabad-120- a well known name in institutations…many campus …excelent infrastructure..

MASTER OF COMPUTER APPLICATION (MCA)/CAREER AFTER B.Sc./BCA/GRADUATION/CAREER IN IT INDUSTRY

The Master of Computer Applications (MCA) is a postgraduate degree in computer application streams awarded in India since 1982. Full time MCA programmes normally take three academic years. The primary emphasis in MCA curriculum is on the development of diverse types of application software rather than designing computer hardware and systems software, which is generally within the domain of engineering majors. More than one thousand institutions provide MCA courses in India with an annual intake of more than 55000 students.

Entrance into an MCA programme requires a bachelors degree from any field of computer science such as a BCA (Bachelor in Computer Application). The course of study covers a variety of topics in the computer programming and designing fields, and can prepare people for a wide variety of computer science related professions

 Structure of the Curriculum

There are two streams in computer education. One of them is the Engineering stream leading to the B.E./B.Tech degree and the other an application stream leading to the MCA degree.

In the B.E./ B.Tech course the primary emphasis is on designing computer hardware and systems software. Designing embedded systems, designing peripherals and interfacing them to a computer and use of computers in signal processing would be some of the other areas of interest to B.E. students.

The primary emphasis in MCA on the other hand, is on designing information systems for various organizations such as banks, insurance companies, hotels, hospitals etc. Development of application software in diverse areas where computers are used will be the main function of MCA graduates. Thus in the MCA curriculum hardware, system software and embedded system design are not emphasised. The major thrust is on giving the students a sound background in computing, business functioning and mathematics relevant to information technology. Thus the curriculum has these three streams of courses each semester running concurrently. In computing, students learn best by doing. A strong laboratory component is a part of the curriculum. The laboratories, besides supplementing the theory course should also expose the student to the use of the latest software tools.

Every MCA student is required to spend one semester in an industry developing a software system.It is suggested that the student periodically report back to the college and present a seminar on the work being done by him.

MCA Course Pre-requisites and Period

MCA is a three year (6 semester) course. The students entering MCA must have a B.C.A./B.Sc./ B.Com/B.A. degree with Mathematics as one of the subjects at 10+2 level or at graduation. Of the 6 semesters one semester is to be spent in an industry developing a software system.

The MCA programme is planned to have 5 theory subject plus two laboratories each semester. The curriculum has a strong core covering information technology, business management and mathematics.

CAREER AFTER B.Sc./BCA/BBA

        If you have strong will then you can achieve your dream that you see in your open eyes. Don’t hesitate don’t shy to say “yes i can”. For your bright future and stable career nothing is important besides your strong will and a proper guidance.

        Lots of full time and part time professional courses are available in various institutes. It is must to you search your soul that what you like or what is your nature. Don’t do that which is trend of mass. Do conversation with yourself and find a real option for you.

For career guidance mail at     bhaskersharma@india.com

Solved Theoretical Questions on CBNST paper (MCA-212) in MTU.

1. Explain how floating point numbers are stored in computers. What factors affect their accuracy and range?
2. What do you understand by machine epsilon of a computer? Explain.(ANS:
   We know that a computer has a finite word length, so only a fixed number of digits is stored and used during computation. Hence, even in storing an exact decimal number in its converted form in the computer memory, an error is introduced. This error is machine dependent and is called machine epcilon.
                        Error = True Value – Approximate Value
   In any numerical computation we come across the following types of errors: inherent errors, rounding errors.
   )
3. With the help of suitable example ,show that associative law of addition may not valid in numerical computation.(ANS: 
   When we perform the arithmetic operations with numbers in normalized floating point mode, the numbers have to be truncated to fit the 4 digit mantissa of our hypothetical computer.
   This leads the results with wide disparity. In fact associative law do not yield valid results in floating point.
   EX:      (L + M) – N =/= (l- N) + M            (=/=  not equal to)
   
   
   Let       L          =          .6776E1,         M         =          .6667E1
   and      N         =          .6755E1)
4. Write a computer program in a language of your choice which implements bisection method to compute real root of the equation 3x + sinx -e^x = 0 in an interval.
5. Under what conditions, newton raphson method become linearly convergent? explain .(ANS: When there are two or more roots that are close together then it may take many iterations before the iterates get close enough to one of them for the quadratic convergence to be apparent. it become linerarly convergent.)
6. What do you mean by truncation error? explain with examples. (ANS: 
   Example. Find the truncation error for e^x at x =1/5if
   (i) The first three terms are retained in expansion.
   (ii) The first four terms are retained in expansion.
   Sol. (i) Error = True value – Approximate value
   
   
    =   (1+ x+ x²/ !2 + x³ / !3 + - - - -) –(1+ x+ x²/ !2)
    =  x³ / !3  +  x⁴ / !4  +  x⁵ / !5 + - - -
   Put x= 1/5
   
   
   Error       =  .008/6 + .0016/24 + .00032/120 + - -
       =  .0013333 + .0000666 + .0000026 + ...
       =  .0014025
   (ii) Similarly the error for case II may be found.)
7. Explain the diffrence between a single step and a multistep method used  for solving  diffrential equations.(ANS:
    Single-step methods (such as Euler's method) refer to only one previous point and its derivative to determine the current value. Methods such as Runge-Kutta take some intermediate steps (for example, a half-step) to obtain a higher order method, but then discard all previous information before taking a second step. Multistep methods attempt to gain efficiency by keeping and using the information from previous steps rather than discarding it. Consequently, multistep methods refer to several previous points and derivative values.)
8. Obtain the globle truncation error term of trapazoidal method of integration.(ANS: Accuracy is affected by two sources of error, namely rounded off error and truncation error. The major cause for loss of accuracy is truncation error. this arises because of the use of a truncated Taylor Series. The total truncation error is any iteration step will consist of two components the propagated truncation error and the truncation error introduced by the step itself. The truncation introduced by the step itself is known as local truncation error and the sum of the propagated error and local error is called the global truncation error. )
9. What do you understand by stability of a method in context of solutions to diffrential equations.(ANS: The uncertainty exist in all stages of numerical processing. There are many situation where even a single operation may  magnify the round off errors of a level that completely runs the result. A computation process in which the cumulative effect of all input errors in grossly magnified is said to be numerically unstable. As we know a mathematical model can be solved either by analytical methods or by numerical methods when a problem itself is sensitive to small changes in its parameters. It is almost impossible to make a numerically stable method for its solution.when several parameters are involved , we may have instability with respect to some parameter and stability with others. in this case we should use the partial derivatives to estimate to total changes .  )
10. Describe the various type of frequency charts.
11. Differentiate between interpolating polynomial obtained for a set of data.
12. Described the following terms 

• Standard deviation
• level of significance
• type II errors
• moving avrages
• variaance 
• ANOVA

   13. What is chi squar test?

   14. Short notes on (I) use of statistical methods in quality control(ANS: 
STATISTICAL QUALITY CONTROL

A quality control system performs inspection, testing and analysis to ensure that the quality of the products produced is as per the laid down quality standards. It is called “Statistical Quality Control” when statistical techniques are employed to control, improve and maintain quality or to solve quality problems. Building an information system to satisfy the concept of prevention and control and improving upon product quality requires statistical thinking.

Statistical quality control (S.Q.C.) is systematic as compared to guess-work of haphazard process inspection and the mathematical statistical approach neutralizes personal bias and uncovers poor judgement. S.Q.C. consists of three general activities:

(1) Systematic collection and graphic recording of accurate data

(2) Analyzing the data

(3) Practical engineering or management action if the information obtained indicates significant

      deviations from the specified limits.

Modern techniques of statistical quality control and acceptance sampling have an important part to play in the improvement of quality, enhancement of productivity, creation of consumer confidence, and development of industrial economy of the country.

The following statistical tools are generally used for the above purposes:

(i) Frequency distribution. Frequency distribution is a tabulation of the number of times a given quality characteristic occurs within the samples. Graphic representation of frequency distribution will show:

(a) Average quality

(b) Spread of quality

(c) Comparison with specific requirements

(d) Process capability.

(ii) Control chart. Control chart is a graphical representation of quality characteristics, which indicates whether the process is under control or not.

(iii) Acceptance sampling. Acceptance sampling is the process of evaluating a portion of the product/material in a lot for the purpose of accepting or rejecting the lot on the basis of conforming to a quality specification.

It reduces the time and cost of inspection and exerts more effective pressure on quality improvement than it is possible by 100% inspection. It is used when assurance is desired for the quality of materials/products either produced or received.

(iv) Analysis of data. Analysis of data includes analysis of tolerances, correlation, analysis of variance, analysis for engineering design, problem solving technique to eliminate cause to troubles. Statistical

methods can be used in arriving at proper specification limits of product, in designing the product, in purchase of raw-material, semi-finished and finished products, manufacturing processes, inspection, packaging, sales, and also after sales service.

ADVANTAGES OF STATISTICAL QUALITY CONTROL

1. Efficiency. The use of statistical quality control ensures rapid and efficient inspection at a minimum cost. It eliminates the need of 100% inspection of finished products because the acceptance sampling in statistial quality control exerts more effective pressure for quality improvement.

2. Reduction of scrap. Statistial quality control uncovers the cause of excessive variability in manufactured products forecasting trouble before rejections occur and reducing the amount of spoiled work.

3. Easy detection of faults. In statistical quality control, after plotting the control charts (X, R, P, C, U) etc., when the points fall above the upper control limits or below the lower control limit, an indication of deterioration in quality is given. Necessary corrective action may then be taken

immediately.

4. Adherence to specifications. So long as a statistical quality control continues, specifications can be

     accurately predicted for the future by which it is possible to assess whether the production processes

     are capable of producing the products with the given set of specifications.

5. Increases output and reduces wasted machine and man hours.

6. Efficient utilization of personnel, machines and materials results in higher productivity.

7. Creates quality awareness in employees. However, it should be noted that statistical quality

    control is not a panacea for assuring product quality.

8. Provides a common language that may be used by designers, production personnel, and inspectors in arriving at a rational solution of mutual problems.

9. Points out when and where 100% inspection, sorting or screening is required.

10. Eliminates bottlenecks in the process of manufacturing.  It simply furnishes ‘perspective facts’ upon which intelligent management and engineering action can be based. Without such action, the method is ineffective. Even the application of standard procedures is very dangerous without

adequate study of the process.)

 (II) Analysis of variance

   15. Write a computer program in C language of your choice for finding out a real root of equation f(x)=0  by newton raphson method .

   16. Explain the order of convergence of a solution and prove that newton raphson method is second degree covergent. 

    17. Define absolute, relative and percentage errors.if x is rounded off to three decimal digits where 

          x=0.005998, calculate the above errors.
(ANS: Absolute error.

Absolute error is the numerical difference between

the true value of a quantity and its approximate value.

Thus, if X is the true value of a quantity and X′ is its approximate

value, then | X – X′ | is called the absolute error ea.

       

                        ea = | X – X′ | = | Error |

Relative error.

The relative error er is defined by

er = |Error | /True value = (X – X’) / X

where X is true value and |X – X’| is error.

Percentage error.

Percentage error ep is defined as

ep = 100 er = 100 |(X – X’) / X|)

    18. Short notes on : 

                   1. an attribute and a variable (ANS: Such types of data whose magnitude can not be measured are called attributes. Examples of such phenomenon are blindness, insanity, sickness, etc. In such a case an observer cannot measure the magnitude of the data. He can only study the presence or absence of a particular quantity in a group.

On the other hand if the measurement of magnitude of data is possible, such types of data are called as variable. For example height, income or marks of student.)

                   2. a discrete variable and a continuous variable                         (ANS: ·         Quantities which can take any numerical value within a certain range are called continuous variables. For example, the height of a child at various ages is a continuous variable since, as the child grows from 120 cm to 150 cm, his height assumes all possible values within the limit.

·         Quantities which are incapable of taking all possible values are called

discontinuous or discrete variables. For example, the number of rooms in

a house can take only the integral values such as 2, 3, 4, etc.)

                   3. Relative frequency and comulative frequency (ANS: When the frequency of a group is consider with respect to the other group, frequencies are called as relative frequency. when the frequency of a group also includes the frequency of other group is called as cumulative frequency. )

                   4. Histogram and pi- charts

                   5. frequency curve and frequency polygon         (ANS: FREQUENCY POLYGON

If the various points are obtained by plotting the central values of the class intervals as x co-ordinates and the respective frequencies as the y co-ordinates, and these points are joined by straight lines taken in order, they form a polygon called Frequency Polygon.

FREQUENCY CURVE

If through the vertices of a frequency polygon a smooth freehand curve is drawn, we get the Frequency Curve. This is done usually when the class-intervals are of small widths.)

   19. Explain how numerical solution differ from analytical solution.   (ANS: If you want to find a solution to the set of equations. The best is when you can use calculus, trigonometry, and other math techniques to write down the solution. Now you know absolutely how the model will behave under any circumstances. This is called the analytic solution, because you used analysis to figure it out. It is also referred to as a closed form solution. 

But this tends to work only for simple models. For more complex models, the math becomes much too complicated. Then you turn to numerical methods of solving the equations, such as the Runge-Kutta method. For a differential equation that describes behavior over time, the numerical method starts with the initial values of the variables, and then uses the equations to figure out the changes in these variables over a very brief time period. Its only an approximation, but it can be a very good approximation under certain circumstances. 

A computer must be used to perform the thousands of repetitive calculations involved. The result is a long list of numbers, not an equation. This long list of numbers can be used to drive an animated simulation, as we do with the models presented here. )

   20. What are the different type of error that may arise in numerical computations? describe.

  21.  Differentiate between accuracy and precision. (ANS:

• Accuracy is how close a measured value is to the actual (true) value
• Precision is how close the measured values are to each other)

  22. What do you understand by numerically unstable procedure.?(ANS: Numerical stability is an important notion in numerical analysis. An algorithm is called numerically stable if an error, whatever its cause, does not grow to be much larger during the calculation. This happens if the problem is well-conditioned, meaning that the solution changes by only a small amount if the problem data are changed by a small amount. To the contrary, if a problem is ill-conditioned, then any small error in the data will grow to be a large error.

A numerical method for solving a mathematical problem is considered stable if the sensitivity of the numerical answer to the data is no greater than in the original mathematical problem. Stable problems are also called well-posed problems. If a problem is not stable, it is called unstable or ill-posed.

A problem f(x, y) = 0 is said to be stable if the solution y depends in a continuous way on the variable x.)

  23. Differentiate between interpolation and curve fitting.                                      (ANS:  

Interpolation is the art of reading between the lines of the table

x:  x0    x1    x2 ...... xn

y:  y0    y1    y2 ...... yn

It also means insertion or filling up intermediate terms of the series. Thus the process of finding the value of y corresponding to any value of x = xi between x0 and xn is called interpolation.

Hence interpolation is the technique of estimating the value of a function for any intermediate value of the independent variable, while the process of computing the value of the function outside the given range is called extrapolation.

Curve fitting

Let there be two variables x and y which give us a set of n pairs of numerical values (x1, y1), (x2, y2).......(xn, yn). In order to have an approximate idea about the relationship of these two variables, we plot these n paired points on a graph, thus we get a diagram showing the simultaneous variation in values of both the variables called scatter or dot diagram. From scatter diagram, we get only

an approximate non-mathematical relation between two variables.

Curve fitting means an exact relationship between two variables by algebraic equations. In fact, this relationship is the equation of the curve. Therefore, curve fitting means to form an equation of the curve from the given data. Curve fitting is considered of immense importance both from the point of view of theoretical and practical statistics.

Theoretically, curve fitting is useful in the study of correlation and regression. Practically, it enables us to represent the relationship between two variables by simple algebraic expressions, for example, polynomials, exponential, or logarithmic functions.