The history of the waterfall model The waterfall model which is also referred as a linear sequential life cycle model was the first model to be developed. The waterfall model is a sequential design process used in software development processes in which progress is seen as flowing steadily downwards(like a waterfall) through the phases of conception‚ initiation‚ analysis‚ construction ‚testing‚ production/implementation and maintenance. The waterfall model creation originates in the manufacturing
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Drugs screen using Thin Layer Chromatography of basic illicit drugs Abstract The majority of evidence submitted to crime labs comes from drug-related crimes. Often‚ this evidence includes unidentified powders that may be illegal drugs. In order to prosecute individuals for possession of illegal substances‚ it is necessary for forensic scientists to positively identify any suspected drugs submitted to the laboratory. In addition‚ forensic toxicologists must determine the identity
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IT310 OSI Model In the early years of computer and network research and development many systems were designed by a number of companies. Although each system had its rights and were sold across the world‚ it became apparent as network usage grew‚ that it was difficult‚ to enable all of these systems to communicate with each other. In the early 1980s‚ the International Organization for Standardization (ISO) recognized the need for a network model that would help companies create
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Analysis models are model used in software development to help in understanding the application area being addressed by a system‚ before the stages of system design and coding are reached. In another word‚ analysis models describe the data handled in an application and the various processes by which it is manipulated. Analysis and Design models fulfill the same needs and provide the same sorts of benefit. Software systems that both analysis and design models are supporting or interacting with
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Chapter 2 Network Models Copyright © The McGraw-Hill Companies‚ Inc. Permission required for reproduction or display. Chapter 2: Outline 2.1 Protocol Layering 2.2 TCP/IP Protocol Suite 2.3 OSI Model 1.# 1 Chapter 2: Objective The first section introduces the concept of protocol layering using two scenarios. The section also discusses the two principles upon which the protocol layering is based. The first principle dictates that each layer needs to have two opposite tasks
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whole attempt to formalize the definition of business models when he wrote that " "Business Model" is one of those terms of art that were central to the Internet boom: it glorifies all manner of half baked plans. All it really meant was how you planned to make money." In an abstract of his paper "A Mesoscopic Approach to Business Models: Nano Research on Management" published in "Economic Issues in China" Dr. Junyi Weng stated that "Business Model‚ a well known important and extensively used term
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UNDERSTANDING THE OSI MODEL AND THE RELATIONSHIP WITH TCP/IP Table Of Contents Letter of Transmittal Abstract Table of Contents Written Presentation References Abstract The Open Systems Interconnection (OSI) model is a reference tool for understanding data communications between any two networked systems. It divides the communications processes into seven layers. Each layer both performs specific functions to support the layers above it and offers services to the layers below it. The
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SPIRAL MODEL The spiral model combines the idea of iterative development (prototyping) with the systematic‚ controlled aspects of the waterfall model. It allows for incremental releases of the product‚ or incremental refinement through each time around the spiral. The spiral model also explicitly includes risk management within software development. Identifying major risks‚ both technical and managerial‚ and determining how to lessen the risk helps keep the software development process under control
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Bohr and the Atomic Model Niels Bohr’s model of the hydrogen atom—first published 100 years ago and commemorated in a special issue of Nature—is simple‚ elegant‚ revolutionary‚ and wrong. Well‚ "wrong" isn’t exactly accurate—incomplete or preliminary are better terms. The Bohr model was an essential step toward an accurate theory of atomic structure‚ which required the development of quantum mechanics in the 1920s. Even in its preliminary state‚ the model is good enough for many calculations
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Mathematical model A mathematical model is a description of a system using mathematical language. The process of developing a mathematical model is termed mathematical modelling (also writtenmodeling). Mathematical models are used not only in the natural sciences (such as physics‚ biology‚ earth science‚ meteorology) and engineering disciplines (e.g. computer science‚artificial intelligence)‚ but also in the social sciences (such as economics‚ psychology‚ sociology and political science); physicists
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