Computer Science Articles - Page 54 of 62

ProblemGenerate RE for a given finite automata by using the state elimination method.SolutionThere are two methods for converting a Deterministic Finite Automata (DFA) to Regular expression (RE).Arden's Theorem Method.State Elimination Method.The given automata is as follows−Step 1Initial state is A that has an incoming edge.So, we have to create a new initial state qi as follows−Step 2Initial state is B that has an incoming edge.So, we have to create a new final state qf as given below−Step 3Now, try to eliminate all intermediate states one by one.First eliminate state AThere is a path from state qi to B via A.So, ... Read More

ProblemGiven a Finite Automata, we need to convert the Finite Automata into equivalent Regular Expression using the State Elimination Method.Step 1 − Initial state q1 has incoming edge. So, create a new initial state qi.Step 2 − Final state q2 has outgoing edge. So, create a new final state.Step 3 − Start eliminating intermediate states one after another.If there is path going to qi to q2 via q1So after eliminating q1 we can connect a direct path from qi to q2 having costε .c*.a=c*aThere is a loop on q2 using state qiSo after eliminating state q1 we can draw a ... Read More

There are two methods for converting a Deterministic Finite Automata (DFA) to Regular expression (RE). These methods are as follows −Arden's Theorem Method.State Elimination Method.Now, let us learn about the state elimination method used in TOC.State Elimination MethodStep 1Initial state of DFA does not have any incoming edge.If there exists any incoming edge to the initial state, then we need to create a new initial state which has no incoming edge to it.An example about the relation between incoming edge and initial state is given below−Step 2There must be only one final state in DFA.If there exist multiple final states ... Read More

ProblemConstruct a regular expression for the given finite automata.SolutionStep 1 − Let us write down the equation.q1=q1a+ εq1 is the start state and ε will be added as the input a which is coming to q1 from q1.Hence, we writeState=source state of input * input coming to itStep 2 − Similarly, q2=q1b+q2bq3=q2aStep 3 − Let us simplify q1 first.q1=q1a+ εwe can re-write it as follows−q1= ε +q1aWhich is similar to R=Q+RP which has a solution as follows−R=QP*Step 4 − Assuming R=q1, Q= ε, P=aWe get q1 = ε.a* since ε.R=Rq1=a*Step 5 − Substituting values of q1 in q2 we get, ... Read More

There are two methods for converting a Deterministic Finite Automata (DFA) to Regular expression (RE). These methods are as follows −Arden's Theorem Method.State Elimination Method.Let us understand the Arden's Theorem method in detail.Arden's TheoremLet P and Q be the two regular expressions.If P does not contain null string, then the following equation in R, viz R = Q + RP, Which has a unique solution by R = QP*Here, The finite automata (FA) does not have epsilon moves.It must have only initial state q1.Its states are q1, q2, q3, ....qn. The final state may be some qi where i QP* ... Read More

There are two methods for converting a Deterministic Finite Automata (DFA) to Regular expression (RE). These methods are as follows −Arden's Theorem Method.State Elimination Method.Let us understand the Arden's Theorem method in detail.Arden's TheoremLet P and Q be the two regular expressions.If P does not contain null string, then the following equation in R, viz R = Q + RP, Which has a unique solution by R = QP*Here, The finite automata (FA) does not have epsilon moves.It must have only initial state q1.Its states are q1, q2, q3, ....qn. The final state may be some qi where iRead More

The basic definitions of the fundamental concepts in the Theory of Computation (TOC) along with the relevant examples are explained below −SymbolSymbols simply call it as a character.It is an atomic unit, such as a digit, character, lowercase letter, etc. Sometimes it is also a word. The formal language does not deal with the “meaning” of the symbols.For example, a, b, c, ……………z0, 1, 2, …………..9+, -, *, %, …………special characters.AlphabetThe set of characters is called as the alphabet.An alphabet is a finite, non-empty set of symbols. It is denoted by Σ or E.For example, Σ ={0, 1} set of ... Read More

In computer science and information technology, the terms data and information are frequently used as if they are synonyms, but in reality, they are quite different from each other. The most fundamental difference between the two is that data is the collection of raw facts and figures, while information is the processed data that have a meaning for a user. Read this article to find out more about "data" and "information" and how these two terms are different from each other. What is Data? Data is a collection of raw facts and figures that can be processed by any computing ... Read More

In the context of computer systems, a program or task in execution is called a process. In modern computers, several types of processes are used. The process of selecting one process from a bunch of processes and assigning it to the processor for execution is referred to as scheduling. The component of the system that accomplish this task is called a scheduler. There are two main types of schedulers, namely, Long−Term Scheduler and Short−Term Scheduler. In this article, we will discuss the important differences between long−term scheduler and short−term scheduler. But before that, let's start with some basics of long−term ... Read More

CRT and LCD are both display devices. CRT is an old technology whereas LCD is modern one. One major difference between CRT and LCD is in the technology used for image formation. The CRT display produces an image by using an electron beam, while LCD display produces an image on the screen using liquid crystal display. What is a CRT? CRT stands for Cathode Ray Tube. CRT displays produce an image on the screen by using a sharp beam of electrons that is highly focused to hit a phosphor screen present in front of the tube. The important components of ... Read More