COMPREHENSIVE SOLUTION TO THEORETICAL QUESTIONS : SOFTWARE VERIFICATION AND VALIDATION In software project management, software testing, and software engineering, verification and validation (V&V) is the process of checking that a software system meets specifications and that it fulfills its intended purpose. It may also be referred to as software quality control. It is normally the responsibility of software testers as part of the software development lifecycle. Validation. The assurance that a product, service, or system meets the needs of the customer and other identified stakeholders. It often involves acceptance and suitability with external customers. Contrast with verification. Verification. The evaluation of whether or not a product, service, or system complies with a regulation, requirement, specification, or imposed condition. It is often an internal process. Contrast with validation. Design Models and Processes An engineering design is a model of the product or structure to be engineered. The model is used to • Evaluate suitability of proposed product/system • Communicate proposed product to others An engineering design process describes a set of steps for constructing an engineering design. SPIRAL MODEL AND INCREMENTAL MODEL: The spiral model is a risk-driven process model generator for software projects. Based on the unique risk patterns of a given project, the spiral model guides a team to adopt elements of one or more process models, such as incremental, waterfall, or evolutionary prototyping. Iterative and Incremental development is any combination of both iterative design or iterative method and incremental build model for development. The combination is of long standing and has been widely suggested for large development efforts Evolutionary prototyping Evolutionary Prototyping (also known as breadboard prototyping) is quite different from Throwaway Prototyping. The main goal when using Evolutionary Prototyping is to build a very robust prototype in a structured manner and constantly refine it. The reason for this is that the Evolutionary prototype, when built, forms the heart of the new system, and the improvements and further requirements will be built. Throwaway prototyping Also called close-ended prototyping.Throwaway or Rapid Prototyping refers to the creation of a model that will eventually be discarded rather than becoming part of the final delivered software. After preliminary requirements gathering is accomplished, a simple working model of the system is constructed to visually show the users what their requirements may look like when they are implemented into a finished system ENTITY AND ENTITY TYPE : A set of entities that have the same attributes is called an entity type. Each entity type in the database is described by a name and a list of attributes. For example an entity employee is an entity type that has Name, Age and Salary attributes DE-NORMALIZATION In computing, denormalization is the process of attempting to optimize the read performance of a database by adding redundant data or by grouping data.[1][2] In some cases, denormalization is a means of addressing performance or scalability in relational database software. A denormalized data model is not the same as a data model that has not been normalized, and denormalization should only take place after a satisfactory level of normalization has taken place and that any required constraints and/or rules have been created to deal with the inherent anomalies in the design. For example, all the relations are in third normal form and any relations with join and multi-valued dependencies are handled appropriately. SQL statements are traditionally divided into the following logical categories: Data definition statements. These data definition language (DDL) statements can declare, rename, modify, or destroy objects in the local database. Data manipulation statements. These data manipulation language (DML) statements can retrieve, insert, delete, or modify data values. There are four basic SQL Operations or SQL Statements. SELECT – This statement selects data from database tables. UPDATE – This statement updates existing data into database tables. INSERT – This statement inserts new data into database tables. DELETE – This statement deletes existing data from database tables. IN DBMS Physical Level View: Physical representation of the DB on the computer. How the data is stored in the database. Logical Level View: The logical structure of the entire database as seen by DBA. What data is stored in the databas A bottleneck can occur in the user network or storage fabric or within servers where there is excessive contention for internal server resources, such as CPU processing power, memory, or I/O (input/output). As a result, data flow slows down to the speed of the slowest point in the data path. This slow down affects application performance, especially for databases and other heavy transactional applications, and can even cause some applications to crash. Difference between microprocessor and microcontroller Microprocessor is an IC which has only the CPU inside them i.e. only the processing powers such as Intel’s Pentium 1,2,3,4, core 2 duo, i3, i5 etc. These microprocessors don’t have RAM, ROM, and other peripheral on the chip. A system designer has to add them externally to make them functional. Application of microprocessor includes Desktop PC’s, Laptops, notepads etc. But this is not the case with Microcontrollers. Microcontroller has a CPU, in addition with a fixed amount of RAM, ROM and other peripherals all embedded on a single chip. At times it is also termed as a mini computer or a computer on a single chip. Today different manufacturers produce microcontrollers with a wide range of features available in different versions. Some manufacturers are ATMEL, Microchip, TI, Freescale, Philips, Motorola etc. Shrink Wrapped Software Shrink Wrapped Software is a term often used to describe software that is sold as a commodity. While a great deal of software is bespoke and only intended to be used by a limited audience, shrink wrapped software often has a broader appeal to a wider user base, be it industry specific, a niche market, or for general usage Custom software (also known as bespoke software or tailor-made software) is software that is specially developed for some specific organization or other user. As such, it can be contrasted with the use of software packages developed for the mass market, such as commercial off-the-shelf (COTS) software, or existing free software. Star The type of network topology in which each of the nodes of the network is connected to a central node with a point-to-point link in a hub and spoke fashion, the central node being the hub and the nodes that are attached to the central node being the spokes Ring The type of network topology in which each of the nodes of the network is connected to two other nodes in the network and with the first and last nodes being connected to each other, forming a ring – all data that is transmitted between nodes in the network travels from one node to the next node in a circular manner and the data generally flows in a single direction only. ROUTING AND FORWARDING : Both of these are used in the network layer for the purpose of data sending on different paths.In the forwarding network layer function, the data or packet is transferred form one incoming link and then reached to the other outgoing link, the main thing is that all these transfer of packets is done within a single router. When any packet reach at the input link of the router, then router must have to transfer the packet to its correct output link. On the other hand the routing function is used to send the packets form one pc to another pc within two different routers. Its means that routing occur between the two routers of network, their combined communication by means of routing protocols decide the routes or paths, that packets would acquire, on their journey from source to destination. It is the responsibility of the network layer that, it would decide the appropriate path for the packet, for sending it to its desired receiver In packet-switching, the packets are sent towards the destination irrespective of each other. Each packet has to find its own route to the destination. There is no predetermined path; the decision as to which node to hop to in the next step is taken only when a node is reached. Each packet finds its way using the information it carries, such as the source and destination IP addresses. In circuit-switching, this path is decided upon before the data transmission starts. The system decides on which route to follow, based on a resource-optimizing algorithm, and transmission goes according to the path. For the whole length of the communication session between the two communicating bodies, the route is dedicated and exclusive, and released only when the session terminates.
Posted on: Sun, 06 Apr 2014 04:21:35 +0000
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