Requirements, design and business process reengineering as vital parts of any system development methodology

This thesis analyzes different aspects of system development life cycle, concentrating on the requirements and design stages. It describes various methodologies, methods and tools that have been developed over the years. It evaluates them and compares them against each other. Finally a conclusion is made that there is a very important stage missing in the system development life cycle, which is the Business Process Reengineering Stage

Towards an aspect weaving BPEL engine

This position paper proposes the use of dynamic aspects and the visitor design pattern to obtain a highly configurable and extensible BPEL engine. Using these two techniques, the core of this infrastructural software can be customised to meet new requirements and add features such as debugging, execution monitoring, or changing to another Web Service selection policy. Additionally, it can easily be extended to cope with customer-specific BPEL extensions. We propose the use of dynamic aspects not only on the engine itself but also on the workflow in order to tackle the problems of Web Service hot deployment and hot fixes to long running processes. In this way, composing aWeb Service "on-the-fly" means weaving its choreography interface into the workflow

Toward a document evaluation methodology: What does research tell us about the validity and reliability of evaluation methods?

Although the usefulness of evaluating documents has become generally accepted among communication professionals, the supporting research that puts evaluation practices empirically to the test is only beginning to emerge. This article presents an overview of the available research on troubleshooting evaluation methods. Four lines of research are distinguished concerning the validity of evaluation methods, sample composition, sample size, and the implementation of evaluation results during revisio

DATA SECURITY USING 2D CELLULAR AUTOMATA RULES

This paper deals with the secure transformation of text. Encryption is the most common method of hiding text from unauthorized access. Two popular ways of sending personal information in a secret way are Cryptography and Steganography. To hide the existence of the message as well as distorts the message itself using this method. LSB and ELSB are the advanced techniques used to hide text in the image. There are two levels to hide the secret information. In the first level of hiding text, data sent to images by using the password and in second level encryption of 2D Cellular Automata used to enhance more security. If one level of security technique is broken by third person then there will be one more level to provide security to that secret information. Encryption will do using 2 dimensional rules of Cellular Automata. The use of Cellular Automata rules is for the parallelism which provides high security during storing and communicating, higher compression ratio and higher encoding of data while comparing with the available security techniques

Analyzing Interaction Patterns to Verify a Simulation/Game Model

Thesis (Ph.D.) - Indiana University, School of Education, 2012In order for simulations and games to be effective for learning, instructional designers must verify that the underlying computational models being used have an appropriate degree of fidelity to the conceptual models of their real-world counterparts. A simulation/game that provides incorrect feedback is likely to promote misunderstanding and adversely affect learning and transfer. Numerous methods for verifying the accuracy of a computational model exist, but it is generally accepted that no single method is adequate and that multiple methods should be used. The purpose of this study was to propose and test a new method for collecting and analyzing users' interaction data (e.g., choices made, actions taken, results and feedback obtained) to provide quantified evidence that the underlying computational model of a simulation/game represents the conceptual model with sufficient accuracy. In this study, analysis of patterns in time (APT) was used to compare gameplay results from the Diffusion Simulation Game (DSG) with predictions based on diffusion of innovations theory (DOI). A program was written to automatically play the DSG by analyzing the game state during each turn, seeking patterns of game component attributes that matched optimal strategies based on DOI theory. When the use of optimal strategies did not result in the desired number of successful games, here defined as the threshold of confidence for model verification, further investigation revealed flaws in the computational model. These flaws were incrementally corrected and subsequent gameplay results were analyzed until the threshold of confidence was achieved. In addition to analysis of patterns in time for model verification (APTMV), other verification methods used included code walkthrough, execution tracing, desk checking, syntax checking, and statistical analysis. The APTMV method was found to be complementary to these other methods, providing quantified evidence of the computational model's degree of accuracy and pinpointing flaws that could be corrected to improve fidelity. The APTMV approach to verification and improvement of computational models is described and compared with other methods, and improvements to the process are proposed

Inverse software configuration management

Software systems are playing an increasingly important role in almost every aspect of today’s society such that they impact on our businesses, industry, leisure, health and safety. Many of these systems are extremely large and complex and depend upon the correct interaction of many hundreds or even thousands of heterogeneous components. Commensurate with this increased reliance on software is the need for high quality products that meet customer expectations, perform reliably and which can be cost-effectively and safely maintained. Techniques such as software configuration management have proved to be invaluable during the development process to ensure that this is the case. However, there are a very large number of legacy systems which were not developed under controlled conditions, but which still, need to be maintained due to the heavy investment incorporated within them. Such systems are characterised by extremely high program comprehension overheads and the probability that new errors will be introduced during the maintenance process often with serious consequences. To address the issues concerning maintenance of legacy systems this thesis has defined and developed a new process and associated maintenance model, Inverse Software Configuration Management (ISCM). This model centres on a layered approach to the program comprehension process through the definition of a number of software configuration abstractions. This information together with the set of rules for reclaiming the information is stored within an Extensible System Information Base (ESIB) via, die definition of a Programming-in-the- Environment (PITE) language, the Inverse Configuration Description Language (ICDL). In order to assist the application of the ISCM process across a wide range of software applications and system architectures, die PISCES (Proforma Identification Scheme for Configurations of Existing Systems) method has been developed as a series of defined procedures and guidelines. To underpin the method and to offer a user-friendly interface to the process a series of templates, the Proforma Increasing Complexity Series (PICS) has been developed. To enable the useful employment of these techniques on large-scale systems, the subject of automation has been addressed through the development of a flexible meta-CASE environment, the PISCES M4 (MultiMedia Maintenance Manager) system. Of particular interest within this environment is the provision of a multimedia user interface (MUI) to die maintenance process. As a means of evaluating the PISCES method and to provide feedback into die ISCM process a number of practical applications have been modelled. In summary, this research has considered a number of concepts some of which are innovative in themselves, others of which are used in an innovative manner. In combination these concepts may be considered to considerably advance the knowledge and understanding of die comprehension process during the maintenance of legacy software systems. A number of publications have already resulted from the research and several more are in preparation. Additionally a number of areas for further study have been identified some of which are already underway as funded research and development projects

Paradigms for the design of multimedia learning environments in engineering

The starting point for this research was the belief that interactive multimedia learning environments represent a significant evolution in computer based learning and therefore their design requires a re-examination of the underlying principles of learning and knowledge representation. Current multimedia learning environments (MLEs) can be seen as descendants of the earlier technologies of computer-aided learning (CAL), intelligent tutoring systems (ITS) and videodisc-based learning systems. As such they can benefit from much of the wisdom which emerged from those technologies. However, multimedia can be distinguished from earlier technologies by its much greater facility in bringing to the learner high levels of interaction with and control over still and moving image, animation, sound and graphics. Our intuition tells us that this facility has the potential to create learning environments which are not merely substitutes for "live" teaching, but which are capable of elucidating complex conceptual knowledge in ways which have not previously been possible. If the potential of interactive multimedia for learning is to be properly exploited then it needs to be better understood. MLEs should not just be regarded as a slicker version of CAL, ITS or videodisc but a new technology requiring a reinterpretation of the existing theories of learning and knowledge representation. The work described in this thesis aims to contribute to a better understanding of the ways in which MLEs can aid learning. A knowledge engineering approach was taken to the design of a MLE for civil engineers. This involved analysing in detail the knowledge content of the learning domain in terms of different paradigms of human learning and knowledge representation. From this basis, a design strategy was developed which matched the nature of the domain knowledge to the most appropriate delivery techniques. The Cognitive Apprenticeship Model (CAM) was shown to be able to support the integration and presentation of the different categories of knowledge in a coherent instructional framework. It is concluded that this approach is helpful in enabling designers of multimedia systems both to capture and to present a rich picture of the domain. The focus of the thesis is concentrated on the domain of Civil Engineering and the learning of concepts and design skills within that domain. However, much of it could be extended to other highly visual domains such as mechanical engineering. Many of the points can also be seen to be much more widely relevant to the design of any MLE.Engineering and Physical Sciences Research Counci

Guidelines for Testing Microservice-based Applications

Há uma tendência no desenvolvimento de software de adotar uma arquitetura baseada em microserviços. Apesar de vários benefícios como maior modularização, escalabilidade e manutenibilidade, esta abordagem levanta outros desafios para a organização. Ao aplicar este padrão de arquitetura, a estratégia de teste precisa de ser ajustada. Um sistema baseado em microserviços é inerentemente distribuído e pressupõe que os vários serviços estejam em constante comunicação entre si, através de conexões de rede, para responder aos requisitos de negócio. Testar um microserviço por si só é mais fácil, pois este está naturalmente isolado do resto do sistema, mas a execução de testes de integração torna-se mais complexa. A utilização de microserviços também oferece várias opções sobre onde e o que testar. Este trabalho tem o objetivo de estudar, comparar e sistematizar soluções e abordagens atuais para o desenvolvimento de testes em sistemas baseados em microserviços e propor um conjunto de diretrizes, métodos e boas práticas universais para facilitar o seu processo de testagem, ajudando as organizações a produzir testes com qualidade, mais valiosos e com menos custos. De modo a perceber os problemas e desafios enfrentados a testar microserviços, um projeto em forma de prova de conceito (PoC) e utilizando uma arquitetura baseadas em microserviços foi planeado, desenhado e testes, relativos a alguns casos de uso foram investigados. Também foram sugeridos um conjunto de indicadores que pretendem medir a qualidade e valor da estratégia de testes. Para cada indicador foi proposto onde pode ser recolhido, um racional com a explicação do seu propósito e uma escala de medida. Este trabalho concluiu que, apesar da existência de estratégias e frameworks de testes capazes de ajudar as organizações a testar as suas aplicações corretamente, é necessária a mentalidade certa para atingir uma estratégia de testes de qualidade. Deste modo, este trabalho propõe um conjunto de recomendações e boas práticas que promovem a mentalidade correta para desenhar e implementar testes sobre todas as camadas do sistema. São também sugeridos passos a seguir para definir e decompor cenários de teste, e soluções para os vários tipos de testes estudados. Assim, este trabalho pode também ser considerado uma base de conhecimento na área de testes em microserviços e ajudar a acelerar a sua adoção.There’s a trend in software development to adopt a microservice-based architecture. Despite several benefits such as increased modularization, scalability and maintainability, this approach brings other challenges to the table. When applying this architectural pattern, the testing strategy needs to be adapted. A microservice-based application presupposes that the various services that compose the system are communication with each other, across network boundaries, to fulfil business requirements and is inherently distributed. Testing a microservice by itself is easier, as it is naturally isolated from the rest of the system, but integration testing becomes more challenging. Microservices also offer several options about where and what to test. This work focus on studying, comparing, and systemizing current solutions and approaches for testing in microservice-based systems and proposing a set of universal guidelines, methods, and best practices to facilitate microservice-based application testing, helping organizations produce more valuable and quality tests with less costs. To understand the problems and challenges presented by microservices testing, a proof-ofconcept (PoC) project, using a microservice-based architecture, was designed and tests for some use cases were explored. Furthermore, indicators to measure test quality and value were proposed, describing it source, rational and measurement scale. This works concludes that, although many testing approaches and frameworks exist that can help organizations test their applications correctly, they need to be used with the right mindset. To achieved this, this work proposes a set of guidelines and best practices that promote the right mindset for designing and implementation tests at all system layers. It also proposes a workflow for test definition and decomposition, and solutions for the various studied testing types

Model checking web applications

The modelling of web-based applications can assist in capturing and understanding their behaviour. The development of such applications requires the use of sound methodologies to ensure that the intended and actual behaviour are the same. As a verification technique, model checking can assist in finding design flaws and simplifying the design of a web application, and as a result the design and the security of the web application can be improved. Model checking has the advantage of using an exhaustive search of the state space of a system to determine if the specifications are true or not in a given model. In this thesis we present novel approaches in modelling and verifying web applications' properties to ensure their design correctness and security. Since the actions in web applications rely on both the user input and the server status; we propose an approach for modelling and verifying dynamic navigation properties. The Spin model checker has been used successfully in verifying communication protocols. However, the current version of Spin does not support modelling time. We integrate discrete time in the Spin model to allow the modelling of realistic properties that rely on time constraints and to analyse the sequence of actions and time. Examining the sequence of actions in web applications assists in understanding their behaviour in different scenarios such as navigation errors and in the presence of an intruder. The model checker Uppaal is presented in the literature as an alternative to Spin when modelling real-time systems. We develop models with real time constraints in Uppaal in order to validate the results from the Spin models and to compare the differences between modelling with real time and with discrete time as in Spin. We also compare the complexity and expressiveness of each model checker in verifying web applications' properties. The web application models in our research are developed gradually to ensure their correctness and to manage the complexities of specifying the security and navigation properties. We analyse the compromised model to compare the differences in the sequence of actions and time with the secure model to assist in improving early detections of malicious behaviour in web applications