Test Generation And Regression Testing Q1 what is the test selection problem? , Test Adequacy: Answer: It is essential to choose tests that meet the four criteria of sensitivity, standardization, reliability and validity. It is very difficult to achieve the standards required if an organization tries to develop its own test batteries, unless it employs a qualified psychologist or obtains professional advice from a member of the British Psychological Society. This organizati on, with the support of the reputable test suppliers, exercises rigorous control over who can use what tests and the standard of training required and given. Particular care should be taken when selecting personality tests a bout. Doitthere are a lot of charlatans yourself tests are always suspect unless they have been properly validated and realistic norms have been established. They should not be used. Q2 what is Test Generation from Predicates? Answer: We propose a new technique for automatic genera tion of test cases for predicates. Earlier we proposed an efficient and effective test generation strategy for Boolean expressions. We now extend this strategy to predicates. Our new strategy addresses a number of issues, including: analysis of dependencie s between relational expressions in a predicate P; generation of test constraints for P based on the detection of Boolean and relational operator faults in P; and generation of actual tests according to the generated test constraints for P. We propose the use of constraint logic programming (CLP) to automate test data generation for a predicate. Furthermore, we propose an incremental approach to apply CLP techniques to solve a constraint system. Since our technique is specificationbased, it can facilitate for actual tests. Q3 what is fault model? Answer: A fault model generation of expected outputs is an engineering model of something that could go wrong in the construction or operation of a piece of equipment. From the model, the designer or user can then predict the consequences of this particular fault. Fault models can be used in almost all branches of engineering. Static faults, which give incorrect values at any speed and sensitized by performing only one operation:
. the stuck-at fault model. A signal, or gate output, is stuck at a 0 or 1 value, independent of the inputs to the circuit. the bridging fault model. Two signals are connected together when they should not be. Depending on the logic circuitry employed, this may result in a wired-OR or wired-AND logic function. Since there are O(n^2) potential bridging faults, they are normally restricted to signals that are physically adjacent in the design. the transistor faults. This model is used to describe faults for CMOS logic gates. At transistor level, a transistor maybe stuck-short or stuck-open. In stuck-short, a transistor behaves as it is always conducts (or stuck-on), and stuck-open is when a transistor never conducts current (or stuck-off). Stuck-short will produce a short between VDD and VSS. The open fault model. Here a wire is assumed broken, and one or more inputs are disconnected from the output that should drive them. As with bridging faults, the resulting behavior depends on the circuit implementation. A fault model, falls under one of the following assumptions: single fault assumption: only one fault occur in a circuit. if we define k possible fault types in our fault model the circuit has n signal lines, by single fault assumption, the total number of single faults is k×n. multiple fault assumption: multiple faults may occur in a circuit. Q4 what are difference between Control Flow Data- Flow? Answer: If we discuss the SSIS architecture then it is vital for you to understand these two terms, Data flow, and Control flow. One excellent way to know about both terms is to check out the working of components and how they are connected together. For the Control Flow, the task is the smallest piece of work that you have to complete on priority. If a particular task is not completed as needed, then you cannot switch to other tasks. For the Data Flow, Data source, destination, and the data transformation are the major components and their functioning is highly different from a task. When Data is transformed into anything meaningful, it is done on the basis of logic how are components connected together, data management, etc. Both Control Flow and Data Flow work similar to an objective of processing objects and there are connectors to make a bridge among them. Still, there is an ocean of differences between both of the terms. For example, you cannot pass the data among components using control flow but it works as a task coordinator only. Here are some of the major objectives of the control flow. It helps in orchestrating workflows. It is more process-oriented. It can help in executing tasks either serially or parallelly. It helps in processing data synchronously. As we have discussed earlier, tasks in the control flow are majorly designed to execute either serially or parallelly. Further, it is possible to divide a task into multiple branches that can be executed in parallel one by one. Here,you can also define the priority about which task to be executed first. For example, if there are a few tasks that are connected in a linear fashion, then they can be serialized and only one task has to be executed at one time. On the other side, Data Flow can split, merge, or branch tasks for parallel processing but it is absolutely different from the Control Flow in SSIS. Here are some of the most important features of Data Flow in SSIS. It is more information-oriented, not based on processes. It can group data together based on logic and transforming it into meaningful content. Multiple data batches can be coordinated for effective processing. Data is extracted from the source and loaded to the destination later. The major difference between control flow and data flow in SSIS is that Control Flow can execute only one task at a time in a linear fashion. On the other hand, Data Flow can perform multiple transformations at the same time. So this was it on SSIS control flow vs data flow, now let’s understand how data packets are executed in SSIS. Q5 what is Combinatorial Designs? Answer: Combinatorial design theory is the part of combinatorial mathematics that deals with the existence, construction and properties of systems of finite sets whose arrangements satisfy generalized concepts of balance and/or symmetry. These concepts are not made precise so that a wide range of objects can be thought of as being under the same umbrella. At times this might involve the numerical sizes of set intersections as in block designs, while at other times it could involve the spatial arrangement of entries in an array as in sudoku grids.
Combinatorial design theory can be applied to the area of design of experiments. Some of the basic theory of combinatorial designs originated in the statistician Ronald Fisher's work on the design of biological experiments. Modern applications are also found in a wide gamut of areas including finite geometry, tournament scheduling, lotteries, mathematical chemistry, mathematical biology, algorithm design and analysis, networking, group testing and cryptography. Given a certain number n of people, is it possible to assign them to sets so that each person is in at least one set, each pair of people is in exactly one set together, every two sets have exactly one person in common, and no set contains everyone, all but one person, or exactly one person? The answer depends on n. This has a solution only if n has the form q2 + q + 1. It is less simple to prove that a solution exists if q is a prime power. It is conjectured that these are the only solutions. It has been further shown that if a solution exists for q congruent to 1 or 2 mod 4, then q is a sum of two square numbers. This last result, the Bruck–Ryser theorem, is proved by a combination of constructive methods based on finite fields and an application of quadratic forms. When such a structure does exist, it is called a finite projective plane; thus showing how finite geometry and combinatorics intersect. When q = 2, the projective plane is called the Fano plane.
Anurag
Comments
Post a Comment