Dissertations / Theses on the topic 'Iterative and incremental development'

Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2014.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 138-142).
A means for reducing the risk for an on-orbit robotic servicing and assembly mission through the development of a series of testbeds that build successively upon one another is investigated. Robotic Servicing and Assembly (RSA) missions are believed to enable life extension programs for existing spacecraft while also enabling much larger and more complex satellites to be developed through on-orbit construction. Unfortunately, many of the new and innovative technologies required for RSA to be economically and technically feasible are still in their formative development stages. Consequently, such RSA missions are highly risk prone. This thesis investigates the development of an incremental and iterative testing facility which can be used to reduce these RSA risks by conducting demonstration testing in authentic operational environments while leveraging existing infrastructures to reduce the costs associated with testing. The Defense Advanced Research Project Agency's (DARPA) Phoenix project, a satellite repurposing mission, serves as an example of a full-scale flight mission requiring risk-reduction testing. The thesis presents research that shows how the newly developed testing facility, which expands on the Synchronized Position Hold Engage and Reorient Experimental Satellites (SPHERES) facility, can reduce the risk of many technologies required for Phoenix. In particular, testing is discussed and analyzed for the risk reduction of resource aggregation and physical reconfiguration technologies. This testing is both incremental and iterative in nature as part of two ground test programs and a flight program aboard the International Space Station. The testing progression matures these technologies from base principles tested in the ground environment at the MIT Space Systems Laboratory to the planned implementation aboard the International Space Station prior to the final flight mission. The newly developed testing facility is small in scale as compared to the final RSA flight satellites, so newly developed scaling laws are presented. This process relies on the scaling of testbed results using the combined application of hybrid scaling laws and nondimensional parameters. In doing so, the results from the new testing facility can be applied to the Phoenix mission to raise the probability of mission success.
by David Charles Sternberg.
S.M.

Context In the last centuries, we have been generating and building infrastructure at a faster pace than ever before. Simultaneously the costs for labor and construction sectors as road and house building is increasing. This provides room for autonomous machines. The development of infrastructure is accomplished through highly efficient and productive construction machinery that progressively modernizes to form the society. In order to increase the pace of development, both cars and industry are getting more and more automated. Volvo Construction Equipment is exploring the autonomous vehicle space. The new machines complement and perfect the human work with efficiency, reliability, and durability. There is however, a question of trust between the human workers and the autonomous machines, I will in this thesis investigate methods on how to develop trust through communication systems with autonomous machines.   Objectives To create recommendations and solutions for products that build trust between human and automated machines on a construction site.   Method Outcome is reached through a case study exploration with validated learning, meaning that it will incorporate learnings through prototype iterations.   Results The result evaluates how trust could be developed between humans and autonomous machinery at a construction site and how communication methods between these parties could be implemented while maintaining high levels of efficiency and safety.   Conclusion Findings in this thesis indicates that trust is developed over time with reliable systems that provide colleagues with updated information available at any time. The results can be introduced in both today’s and tomorrow’s construction sites at various levels of advanced technology.
Sammanhang De senaste hundra åren har vi gett upphov till att bygga infrastruktur i en snabbare takt än någonsin tidigare. Samtidigt ökar kostnaderna för både arbetskraft och byggsektorer som väg- och bostadsbyggnader. Denna situation ger utrymme för autonoma maskiner. Utvecklingen av infrastruktur sker genom effektiva och produktiva konstruktionsmaskiner som successivt moderniseras för att forma samhället. För att öka utvecklingstakten moderniseras både bilar och industri för att möta en mer automatiserad vardag.  Volvo Construction Equipment undersöker det autonoma fordonsutrymmet för nästa generations maskiner. Automationen kompletterar de nya maskinerna och fulländar det mänskliga arbetet med effektivitet, tillförlitlighet och hållbarhet.   Det finns dock en fråga om relationen mellan mänskliga arbetare och autonoma maskiner, jag kommer i denna avhandling undersöka metoder för hur man kan utveckla tillit genom kommunikationssystem mellan arbetare och autonoma maskiner.   Mål Att skapa rekommendationer och lösningar för produkter som bygger tillit mellan mänskliga och automatiserade maskiner på en byggarbetsplats.   Metod Resultatet uppnås genom användandet av fallstudie forskning kombinerat med validerande lärande. Detta innebär lärdomar med hjälp av en iterativ process utav prototyper som testas och valideras.   Resultat Resultatet utvärderar hur förtroende kan utvecklas mellan människor och autonoma maskiner på en byggarbetsplats. Hur kommunikationsmetoder mellan dessa parter skulle kunna genomföras samtidigt som hög effektivitet och säkerhet upprätthålls .   Slutsats Lärandet i denna avhandling tyder på att förtroendet utvecklas över tid med tillförlitliga system som ger medarbetare uppdaterad nödvändig information tillgänglig när som helst. Resultaten kan införas i både dagens och framtidens anläggningsplatser på olika nivåer av avancerad teknik.

Vissa delar är borttagan på grund av konfidentialitet.

ME310 Design Innovation at Stanford University

A modelagem é uma das atividades metodológicas presentes em processos de desenvolvimento de software e cumpre um papel relevante na fase de análise e projeto da solução. A linguagem de modelagem usual é a UML, porém ela é criticada por ser extensa e complexa. Outra possibilidade é fazer uso de diagramas livres, não existindo, entretanto, uma padronização nos elementos. Uma alternativa seria o uso da OPM, que representa a estrutura e comportamento de um sistema em um mesmo diagrama, utilizando uma notação única, além de possuir mecanismos intrínsecos para gerenciamento da complexidade. O objetivo deste trabalho é propor uma alternativa para modelagem de software em processos de desenvolvimento iterativo, incremental e ágil, visando aumentar a efetividade nesta atividade e colaborar na minimização das dificuldades encontradas nas atividades de análise e projeto de software, utilizando a OPM. A abordagem busca completude de modelagem, além de facilidade de compreensão e de aplicação e foi denominada PIASO – Projeto Iterativo, Incremental e Ágil de Software Utilizando a OPM. Uma avaliação da abordagem foi realizada por um grupo de 9 profissionais e os resultados mostraram que a percepção sobre a abordagem é que ela é fácil de entender e utilizar. Os dados obtidos com a avaliação mostraram que 67% dos participantes concordam que a abordagem seja de fácil entendimento e uso e 33% concordam parcialmente, além disso, os dados mostraram que a percepção quanto à utilidade da abordagem é positiva, 56% concordam que a abordagem seja útil e 36% concordam parcialmente. Finalmente, para ilustrar a utilização da abordagem, um estudo de caso foi executado, o qual indicou que para a visualização geral e modelagem da arquitetura do software o PIASO mostrou-se de fácil execução e interpretação, despendendo pouco tempo para sua realização, porém, para especificar algorítmos lógicos os diagramas da OPM não são tão eficazes. Outrossim, a característica iterativa da abordagem adaptou-se aos processos de desenvolvimento iterativos, incrementais e ágeis.
Modeling is one of the methodological activities in any software development process, mainly in the analysis and design phase. Usually the UML is used as modeling language, but it is criticized for being sprawling and complex. Informal visual conventions are also used, nevertheless, there is no single notation for the elements. OPM could be an alternative language because of its ability to express structure and behavior in a single diagram and complexity handling mechanisms. This paper presents a modeling approach using OPM in iterative, incremental and agile software development processes. The approach will intend to be not only complete, but easy to understand and apply. This approach was named PIASO, from the portuguese acronym for Iterative, Incremental and Agile Software Design using OPM. An evaluation of the approach was carried out by a group of professionals and the results show that the perception about the approach is that it is easy to understand and use. 67% out of the participants agreed that the approach is easy to understand and use and 33% agreed partially. In addition, the results show that the perception of the usefulness of the approach is positive, 56% out of the participants agreed that the approach is useful and 36% agreed partially. Finally, to illustrate the approach’s usage, a study case was performed, which indicated that for a software glance and architecture the PIASO was easy to execute and not time consuming, but to specify logical algorithms OPM diagrams are not so effective. Finally, PIASO’s iterative characteristic is naturally adapted to iterative, incremental, and agile software development processes.

The quality of a product depends on the quality of the underlying process is a well known fact. Software development organizations have been struggling to decrease their cost, increase their ROI, reduce time-to-market, and enhance the quality of their products. This all depends upon the improvement in the processes they are following inside their organizations. A number of software process improvement models exist in market, e.g., CMMI, SPICE and Automotive SPICE. But before an organization can improve its development and management processes, it is very important to know whether it is following the right processes. There exist a number of software development process models, mainly categorized into Traditional and Agile, which provide the step-by-step guidance to develop and manage the software projects.The current thesis presents a study of software process improvement models in automotive industry, their weaknesses and strengths and presents a comparison of how do they relate to each other. This thesis also explores some software development models which are more famous in automotive industry, and the applicability of process improvement models in conjunction with the Agile software development models. A case study was performed at an automotive software supplier organization to investigate the experience of combining Agile practices with organization’s company-tailored software development model that was incorporating Automotive SPICE standards.

In this study, a novel incremental ring rolling process used in production of rings with various cross sections is examined. A basic type of this process is investigated numerically, using commercial finite element programs
MSC Superform, MSC Marc. The user defined subroutines are also utilized for flexibility in modeling. The aim of modeling is to determine the material flow for geometrical analysis, strain/stress distribution for tool force analysis and residual stresses, in a cost effective way. The process has instabilities and requires large number of incremental stages to complete a full finite element simulation. The full models are reliable but costly hence the numerical studies are focused on reliable simplified models with lower computation time. Different approaches are developed: three-dimensional segment model, improved segment model, velocity coupling model. The results of these models are compared with experimentally verified full models. Numerical parameters such as mesh type, step size, convergence ratio are examined. After verification of the model different applications to of the process is developed and physical parameters affecting the process are discussed
such as the tool path .

This thesis is an evaluation and proposal for development for an alternative health care center in West Virginia. The Gesundheit Institute is based on the work of Dr. Hunter "Patch" Adams and his desire to create an alternative to the current model of health care. The Institute would not charge for services and will offer non-traditional as well as traditional methods of healing. By evaluating what is currently happening at the center and what the resources are, I propose to use an incremental approach to growth. The ideas would result in a series of smaller buildings developed over time as opposed to a single larger building. The thesis includes the design for the next major building, a community center/dining hall and a basic design for a series of sleeping quarters. It also includes the reworking of the master plan to better include issues integrating incremental growth and sustainable development.
Master of Architecture

South Africa is experiencing unprecedented population growth due to rapid urbanisation. This growth often overwhelms the current planning and developmental capacities of city-regions acutely impacting informal settlement areas. As a result the city's most vulnerable citizens experience poor service delivery and poor living conditions. This project proposal challenges the current approach to housing delivery and the upgrading of informal settlements in urban areas of South Africa. It is positioned within a complex informal housing environment with poor basic infrastructure and high exposure to the risk of fire and flooding in winter. Based on the research of this project, the Barney Molokana Section in Khayelitsha was selected as the conditions above were evident in this informal settlement. The project comprises three parts; the first is a proposal for an infrastructural intervention aimed to act as a settlement organisational device, the second is a public amenities building that promotes an active public interface and a didactic architecture and the third a series of support structures that further promote the concept of incremental housing development. The process learnt from existing spatial configurations and transformations within informal settlements allowed the working backwards to discover the minimal elements or support structures from which a settlement can grow incrementally.

This thesis concerns the general area of experimental benchmarking of Iterative Learning Control (ILC) algorithms using two experimental facilities. ILC is an approach which is suitable for applications where the same task is executed repeatedly over the necessarily finite time duration, known as the trial length. The process is reset prior to the commencement of each execution. The basic idea of ILC is to use information from previously executed trials to update the control input to be applied during the next one. The first experimental facility is a non-minimum phase electro-mechanical system and the other is a gantry robot whose basic task is to pick and place objects on a moving conveyor under synchronization and in a fixed finite time duration that replicates many tasks encountered in the process industries. Novel contributions are made in both the development of new algorithms and, especially, in the analysis of experimental results both of a single algorithm alone and also in the comparison of the relative performance of different algorithms. In the case of non-minimum phase systems, a new algorithm, named Reference Shift ILC (RSILC) is developed that is of a two loop structure. One learning loop addresses the system lag and another tackles the possibility of a large initial plant input commonly encountered when using basic iterative learning control algorithms. After basic algorithm development and simulation studies, experimental results are given to conclude that performance improvement over previously reported algorithms is reasonable. The gantry robot has been previously used to experimentally benchmark a range of simple structure ILC algorithms, such as those based on the ILC versions of the classical proportional plus derivative error actuated controllers, and some state-space based optimal ILC algorithms. Here these results are extended by the first ever detailed experimental study of the performance of stochastic ILC algorithms together with some modifications necessary to their configuration in order to increase performance. The majority of the currently reported ILC algorithms mainly focus on reducing the trial-to-trial error but it is known that this may come at the cost of poor or unacceptable performance along the trial dynamics. Control theory for discrete linear repetitive processes is used to design ILC control laws that enable the control of both trial-to-trial error convergence and along the trial dynamics. These algorithms can be computed using Linear Matrix Inequalities (LMIs) and again the results of experimental implementation on the gantry robot are given. These results are the first ever in this key area and represent a benchmark against which alternatives can be compared. In the concluding chapter, a critical overview of the results presented is given together with areas for both short and medium term further research.

Incremental Development System for Axiom Specified Objects (IDAX) is a prototype tool for the generation of test plans for objects in an OOPS environment. It is based on the concepts of up/down axiom specification of objects and is a continuation of the work performed by Dr. B. P. Zeigler in the software tool AXClass. IDAX extends AXClass to work with all of the objects in a given Hierarchical tree in parallel, rather than singly. On top of this, IDAX moves up one level of abstraction to allow for the incremental development of objects as well as the hierarchy. The final improvement made by IDAX is the introduction of a consistent and uniform user interface. This thesis first provides ample background for the concepts introduced by the paper and IDAX, a complete discussion on the contributions and limitations of the previous work, AXClass, and introduces the IDAX tool through a discussion of the new concepts, data abstraction, and a sample session. This makes the work a stand alone reference for the IDAX tool and the concepts from which it was derived.

Industrial control systems (ICS) play an extremely important role in the world around us. They have helped in reducing human effort and contributed to automation of processes in oil refining, power generation, food and beverage and production lines. With advancement in technology, embedded platforms have emerged as ideal platforms for implementation of such ICSes. Traditional approaches in ICS design involve switching from a model or modeling environment directly to a real-world implementation. Errors have the potential to go unnoticed in the modeling environment and have a tendency to affect real control systems. Current models for error identification are complex and affect the design process of ICS appreciably. This thesis adds an additional layer to ICS design: an Interface Abstraction Process (IAP). IAP helps in incremental migration from a modeling environment to a real physical environment by supporting intermediate design versions. Implementation of the IAP is simple and independent of control system complexity. Early error identification is possible since intermediate versions are supported. Existing control system designs can be modified minimally to facilitate the addition of an extra layer. The overhead of adding the IAP is measured and analysed. With early validation, actual behavior of the ICS in the real physical setting matches the expected behavior in the modeling environment. This approach to ICS design adds a significant amount of latency to existing ICSes without affecting the design process significantly. Since the IAP helps in early design validation, it can be removed before deployment in the real-world.
Master of Science

In highly iterative development processes, functionality is continuously added while existing faults are repaired simultaneously. Therefore, practitioners need means to predict the fault inflow, i.e. the number of faults at the a certain project stage, in order to allocate resources adequately. This study investigates the use of software reliability growth models (SRGMs) for predicting fault inflow. Additionally, a simple linear model is developed and compared to the SRGMs. The paper provides results from applying these models on fault data from three different industrial projects. One of the key findings of this study is that SRGMs are applicable for predicting fault inflow in highly iterative processes. Moreover, the results show that a linear model provides reasonably accurate predictions as well and therefore, represents a valid alternative to the SRGMs.

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2003.
Includes bibliographical references (p. 123-132).
In today's postindustrial society, considering connections between power, knowledge, and information is fundamental to promoting democracy and equity. This thesis examines current and potential uses of information technologies in community development work. It argues that while these technologies are vital to developing and implementing sound policy, they are also valuable tools for fostering greater community dialogue, encouraging broad collaboration, and building community capacity to effect sustained positive change. Research is specifically designed to inform a nascent university-community partnership between the Department of Urban Studies and Planning at the Massachusetts Institute of Technology in Cambridge, Massachusetts and Lawrence CommunityWorks, Inc., a community development corporation in Lawrence, Massachusetts. The goal of this multiyear partnership is to design, implement, and evaluate a neighborhood information system (NIS) as a strategy for empowering residents and supporting community development efforts in Lawrence. The approach of the thesis is to provide a theoretical and practical framework for this investigation. Technological advances, the devolution of social policy down to local agencies, and comprehensive community building efforts underscore the importance of information technologies in planning, organizing, and advocating for neighborhood change. Furthermore, the ability of citizens to access and use data and technology is fundamental to community empowerment. Quantitative and qualitative research methods are used to evaluate existing NIS and to document and inform the work in Lawrence. Findings suggest that while traditional NIS systems add value to public policy by providing access to reliable data, these systems fall short of building information literacy and technological fluency within neighborhoods. Citizen involvement, information and technology training, cross-cutting collaborations, and public agency partners are critical for successful and sustainable community-based technology projects. Recommendations for the Lawrence partnership emphasize the use of information technologies to support a network of formal and informal capacity building of residents, community leaders, community-based organizations, and institutions. Furthermore, given the widespread interest in the using information technologies to empower citizens, additional research into metrics and indicators of community capacity and community power is needed.
by Michelle Caulfield.
M.C.P.

Thesis (M.S.)--West Virginia University, 1999.
Title from document title page. Document formatted into pages; contains v, 80 p. : ill. Includes abstract. Includes bibliographical references (p. 33-35).

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
PROGRAMA DE EXCELENCIA ACADEMICA
Aplicações ubíquas estão inseridas em ambientes inteligentes integrados ao mundo físico e compostos de usuários com diferentes preferências, dispositivos heterogêneos e vários provedores de serviço e conteúdo. Além disso, essas aplicações são especializadas em oferecer serviços e conteúdos em qualquer lugar e momento, auxiliando os usuários em suas atividades diárias sem incomodá-los. Baseado nesse mundo idealizado, o paradigma em qualquer lugar e momento impõe alguns desafios para a comunidade de Engenharia de Software, tais como: heterogeneidade de dispositivos, ambientes distribuídos, mobilidade, satisfação de usuário, adaptação de conteúdo, sensibilidade de contexto, privacidade, personalização, transparência, invisibilidade e constante evolução das tendências tecnológicas. Visando lidar com esses novos desafios tecnológicos, é proposta uma abordagem orientada à reutilização de software para desenvolvimento incremental e sistemático de aplicações ubíquas intencionais. Foram escolhidos dois principais objetivos para conduzir a pesquisa dessa tese: (i) a construção de conjuntos de apoio, orientados à reutilização de software, com base em uma investigação detalhada de aplicações ubíquas e do paradigma de Sistemas Multi-Agentes Intencionais – ou seja, Desenvolvimento para Reutilização; e (ii) o desenvolvimento incremental e sistemático de aplicações ubíquas, dirigidas por Sistemas Multi-Agentes Intencionais, com base na abordagem orientada à reutilização de software – ou seja, Desenvolvimento com Reutilização. Algumas contribuições do nosso trabalho são: (i) uma arquitetura orientada à reutilização de software e baseada nos conjuntos de apoio – i.e. blocos de construção principalmente compostos de modelos conceituais, frameworks, padrões e bibliotecas – obtidos a partir da Engenharia de Domínio das Aplicações Ubíquas; (ii) uma Engenharia de Aplicações Ubíquas orientada à reutilização de software visando o desenvolvimento incremental e sistemático de aplicações ubíquas com base nos blocos de construção propostos; (iii) um modelo de raciocínio focado em regras condicionais de lógica nebulosa e no modelo Crença-Desejo-Intenção para melhorar a capacidade cognitiva dos agentes; (iv) um mecanismo específico, baseado em agentes intencionais, para lidar com questões de privacidade, balanceando privacidade e personalização bem como transparência e invisibilidade; (v) um catálogo que graficamente apresenta os principais requisitos não-funcionais ubíquos, as interdependências entre eles e formas de se operacionalizá-los com base na combinação de tecnologias tradicionais e emergentes; (vi) ontologias para permitir a construção dinâmica de interfaces e melhorar a comunicação e inter-operabilidade dos agentes de software; e (vii) um modelo de banco de dados dinâmico para carregar e recuperar os perfis ubíquos (ex. perfis de usuário, dispositivo, rede e contrato), melhorando o gerenciamento de dados em tempo de execução. A abordagem proposta foi avaliada desenvolvendo diferentes aplicações ubíquas (ex. aplicações ubíquas de comércio eletrônico e de clínica odontológica).
Ubiquitous applications are embedded in intelligent environments integrated into the physical world and composed of users with different preferences, heterogeneous devices and several content and service providers. Moreover, they focus on offering services and contents anywhere and at any time by assisting the users in their daily activities without disturbing them. Based on this idealized world, the anywhere and at any time paradigm poses some challenges for the Software Engineering community, such as: device heterogeneity, distributed environments, mobility, user satisfaction, content adaptability, context awareness, privacy, personalization, transparency, invisibility and constant evolution of technological trends. In order to deal with these new technological challenges, we propose a Reuse-Oriented Approach for Incremental and Systematic Development of Intentional Ubiquitous Applications. We have chosen two main goals that drive our research in this thesis: (i) the construction of reuse-oriented support sets based on an extensive investigation of ubiquitous applications and the Intentional-Multi-Agent Systems paradigm – i.e. Development for Reuse; and (ii) the incremental and systematic development of Intentional-Multi-Agent-Systems-driven ubiquitous applications based on the reuse-oriented approach – i.e. Development with Reuse. Some contributions of our work are: (i) a reuse-oriented architecture centered on support sets – i.e. building blocks mainly composed of conceptual models, frameworks, patterns and libraries – obtained from the Domain Engineering of Ubiquitous Applications; (ii) a reuse-oriented Ubiquitous Application Engineering for incremental and systematic development of intentional ubiquitous applications centered on the proposed building blocks; (iii) a reasoning engine focused on fuzzy conditional rules and the Belief-Desire-Intention model to improve the agents cognitive capacity; (iv) a specific mechanism based on intentional agents to deal with privacy issues by balancing privacy and personalization as well as transparency and invisibility; (v) a catalogue that graphically presents the main ubiquitous non-functionalrequirements, their interdependencies and ways to operationalize them based on the combination of traditional and emergent technologies; (vi) ontologies to allow the dynamic construction of interfaces and to improve the communication and inter-operability of software agents; and (vii) a dynamic database model to store and retrieve the ubiquitous profiles (e.g. user, device, network and contract profiles) by improving the data management on the fly. The proposed approach was evaluated by developing different ubiquitous applications (e.g. e-commerce and dental clinic ubiquitous applications).

“Despite a significant reduction in the percentage of population living in informal settlements from 2000 to 2014, the absolute number of people living in deplorable conditions has increased from 689 to 880 million people over the same period. Current policy and planning practice in developing countries has not been able to cope with such pervasive rapid urbanisation. By 2050 the United Nations predicts two-thirds of the global population will live in cities. Of which as many as one-third of this population could be living in informal settlements (slums). To address these unsustainable and undesirable trends in support of the disadvantaged and maintaining environmental sustainability, this minor dissertation conducts comprehensive research of contemporary policy and planning work to seek alternatives. The purpose of the literature review is to identify commonalities, differences, gaps of knowledge and constraints of current policies and planning practice currently used to plan and manage growth of cities. Analysis and findings then inform and add value in exploring parameters for a 'liveable’ or improved urbanism from that currently experienced in informal settlements. Historic global policies focusing on government led top down approaches to provide large scale low cost housing have not kept up with demand, although they remain popular politically. From these policy and planning failures, it is evident that a more inclusive and incremental approach better utilizing available human capital should be considered. Critical analysis of literature with an alternative urbanism and planning paradigm in mind emerges in the findings and conclusion in the form of recommended parameters for a new inclusive and incremental urbanism. Such urbanism is entirely possible provided the critical issues identified such as lack of political will and good governance can be mitigated. To dramatically improve the lives of millions will require a compelling vision and collaborative effort seldom seen in current policy and planning of developing countries. Despite the daunting task, this paper seeks to define a conceptual framework drawn from findings to mitigate issues and guide an alternative vision of the future. The alternative urbanism that emerges from the conceptual framework may fall somewhere between that of current informal settlements and current discourse such as smart cities’’

Controlling unsteady combustion induced gas flow fluctuations and the resultant motor vibrations is a very significant step in rocket motor design. It occurs when the unsteady heat release due to combustion happens to feed the acoustic oscillations of the closed duct forming a feed-back system. The resultant vibrations concerned may even lead to total failure of the rocket system unless analysed and tested thoroughly. This thesis aims developing a linear numerical analysis method for the growth rate of instabilities and possible mode shape of a liquid-propelled chamber geometry. In particular, A 3-D Helmholtz code, utilizing Culicks spatial averaging linear iterative method, is developed to find the form of deformed mode shapes iteratively to obtain possible effects of heat source and impedance boundary conditions. The natural mode shape phase is solved through finite volume discretization and the open-source eigenvalue extractor, ARPACK, and its parallel implementation PARPACK. The iterative method is particularly used for analyzing the geometries with complex shapes and essentially for disturbances of small magnitudes to natural mode shapes. The developed tools are tested via two simple cases, a duct with inactive flame and a Rijke tube, used as validation cases for the code particularly with only boundary contribution and heat contribution respectively. A sample 2-D and 3-D liquid-propelled combustion chamber is also analysed with heat sources. After comparing with the expected values, it is eventually proved that the method should be only used for determining the modes instability analysis, as to whether it keeps vibrating or decays. The methodology described can be used as a preliminary design tool for the design of liquid-propellant rocket engine combustors, rapidly revealing only the onset of instabilities.

It is important to manage iterative projects in a way to maximize quality and minimize cost. To achieve high quality, accurate project estimates are of high importance. It is challenging to predict the effort that is required to perform test activities in an iterative development. If testers put extra effort in testing then schedule might be delayed, however, if testers spend less effort then quality could be affected. Currently there is no model for test effort prediction in iterative development to overcome such challenges. This paper introduces and validates a dynamic Bayesian network to predict test effort in iterative software development. In this research work, the proposed framework is evaluated in a number of ways: First, the framework behavior is observed by considering different parameters and performing initial validation. Then secondly, the framework is validated by incorporating data from two industrial projects. The accuracy of the results has been verified through different prediction accuracy measurements and statistical tests. The results from the verification confirmed that the framework has the ability to predict test effort in iterative projects accurately.

Incremental development, software reuse, product families and component-based development seem to be the potent technologies to achieve benefits in productivity, quality and maintainability, and to reduce the risks of changes. These approaches have multiple and crosscutting impacts on development practices and quality attributes. Empirical studies in industry answer questions about why and when certain approaches are chosen, how these are applied with impact on single instances and how to generalize over classes or systems. Large, long-lived systems place more demands on software engineering approaches. Complexity is increased, systems should have the correct subset of functionality and be maintainable for several years to return the investment.

The research in this thesis is based on several empirical studies performed at Ericsson in Grimstad, Norway and in the context of the Norwegian INCO project (INcremental and COmponent-Based Software Development). A product family with two large-scale products that have been developed incrementally is described. The work aimed to assess the impact of development approaches on quality and improve the practice in some aspects. The research has been a mixed-method design and the studies use qualitative data collected from sources such as web pages, text documents and own studies, as well as quantitative data from company’s data repositories for several releases of one product. The thesis contains five main novel contributions:

C1. Empirical verification of reuse benefits. Quantitative analyses of defect reports, change requests and component size showed reuse benefits in terms of lower defect-density, higher stability between releases, and no significant difference in change-proneness between reused and non-reused components.

C2. Increased understanding of the origin and type of changes in requirements in each release and changes of software between releases. A quantitative analysis of change requests showed that most changes are initiated by the organization. Perfective changes to functionality and quality attributes are most common. Functionality is enhanced and improved in each release, while quality attributes are mostly improved and have fewer changes in form of new requirements.

C3. Developing an effort estimation method using use case specifications and the distribution of effort in different phases of incremental software development. The estimation method is tailored for complex use case specifications, incremental changes in these and reuse of software from previous releases. Historical data on effort spent in two releases are used to calibrate and validate the method.

C4. Identifying metrics for a combination of reuse of software components and incremental development. Results of quantitative and qualitative studies are used to relate quality attributes to development practices and approaches, and to identify metrics for a combination of software reuse and incremental development.

C5. Developing a data mining method for exploring industrial data repositories based on experience from the quantitative studies.

This thesis also proposes how to improve the software processes for incremental development of product families. These are considered minor contributions:

C6a. Adaptation of the Rational Unified Process for reuse to improve consistency between practice and the software process model.

C6b. Improving techniques for incremental inspection of UML models to improve the quality of components. A controlled industrial experiment is performed.

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
FUNDAÇÃO DE APOIO À PESQUISA DO ESTADO DO RIO DE JANEIRO
PROGRAMA DE EXCELENCIA ACADEMICA
BOLSA NOTA 10
A avaliação experimental de modelos de plasticidade incremental e a predição da vida à fadiga sobre cargas combinadas requer o uso de máquinas de testes multiaxiais. Neste trabalho é desenvolvida uma máquina tração-torção (MTT) para avaliar modelos de plasticidade incremental. Este sistema eletromecânico utiliza como atuadores principais dois motores de corrente contínua conectados a caixas de redução para gerar os carregamentos de tração axial e/ou torção. O projeto da MTT compreende a análise de sua integridade estrutural, seu dimensionamento, e o cálculo da vida à fadiga de seus principais componentes; o projeto e desenvolvimento de uma célula tração-torção (LTC - load torque cell); o desenvolvimento e implementação das técnicas de controle; e finalmente sua construção e avaliação. Uma técnica de controle PID por modos deslizantes (PID Sliding Mode control) foi especialmente desenvolvida para esta máquina, consistindo em aplicar um sinal de controle descontínuo que força o sistema a deslizar ao longo de uma superfície de convergência. Esta técnica de controle tem a capacidade de controlar continuamente a força axial e/ou o torque aplicado ao corpo de prova de maneira independente, o que permite gerar histórias de cargas não-proporcionais. Os métodos de controle são implementados em uma plataforma computacional em tempo real CompactRio. Deste modo, é possível gerar uma máquina de ensaios de fadiga multiaxial compacta, de fácil manuseio, que não precise de um sistema de controle complexo, e a um baixo custo. A máquina tração-torção foi projetada para atender a uma ampla gama de ensaios de fadiga multiaxial, com uma capacidade de força axial máxima de mais ou menos 200 kN e torque máximo de mais ou menos 1300 N.m. O desempenho da MTT foi avaliado experimentalmente através de ensaios de plasticidade incremental. Para tanto, foram usados corpos de prova de tração-torção para medir seus comportamentos sobre cargas multiaxiais. Ensaios de encruamento não-proporcional, ratcheting (fluência cíclica) multiaxial e ratcheting uniaxial foram realizados em corpos de prova de aço inox 316, aço 1020, alumínio 7075 e alumínio 6063 na MTT, assim como em uma máquina Instron de 100 kN. Um simulador de plasticidade incremental para carregamentos de tração-torção foi desenvolvido, incorporando o modelo de encruamento cinemático não-linear de Jiang-Sehitoglu, e o modelo incremental de encruamento não-proporcional de Tanaka. Os parâmetros do material foram calibrados a partir de ensaios experimentais, permitindo que as simulações fossem capazes de prever o comportamento do material sobre diferentes histórias de carregamento, assim como as taxas de encruamento não-proporcional e de ratcheting. Os experimentos e simulações confirmaram tanto a adequabilidade da MTT desenvolvida, quanto do simulador de plasticidade incremental implementado, baseado nos modelos não-lineares de Jiang-Sehitoglu e Tanaka.
The experimental evaluation of incremental plasticity models and fatigue life prediction under combined loads requires the use of multiaxial testing machines. In this work, an axial-torsion machine (MTT) was developed to evaluate incremental plasticity models. This electromechanical system uses as a main actuators two DC motors connected to gearboxes to generate the axial and/or torsion loads. The design of axial-torsion machine comprises the analysis of its structural integrity, its dimensioning and fatigue life prediction its major components; the design and development of a load torque cell – LTC; the development and implementation of control techniques, and finally, its construction and its performance evaluation. A PID Sliding Model control technique has been specially developed for this machine, which consists in applying a discontinuous control signal that forces the system to slide along a surface convergence. This control technique has the ability to control the axial force and/or torsion applied to specimen test in an independent manner, which allows to generate a non-proportional loading histories. The control methods are implemented on a computing platform in real time CompactRio. Thus, it s possible to developed a compact multiaxial fatigue testing machine, easy to handle, which does not require a complex control system, and at a low cost. The tensiontorsion machine was designed to meet a wide range of multiaxial fatigue tests, with a maximum capacity of axial force of more or less 200 kN and torque of more or less 1300 N.m. The MTT performance was evaluated experimentally by incremental plasticity testing. For this purpose, tensile / torsion specimens were used to measure their behavior under multiaxial loads. Testing of non-proportional hardening, multiaxial ratcheting and uniaxial ratcheting (cyclic creep) were performed on specimens of 316 stainless steel, 1020 steel, 7075 aluminum and 6351T6 aluminum in the MTT, as well as a Instron Machine of more or less 100 kN. A simulator of incremental plasticity to tensile-torsion loads has been developed, incorporating the non-linear kinematic hardening model of Jiang-Sehitoglu, and non-proportional hardening model of Tanaka. The material parameters were calibrated using experimental tests, allowing the simulations to predict the material behavior under different load histories, as well as rates of non-proportional hardening and ratcheting. The experiments and simulations confirmed both the suitability of the developed MTT, as well as the simulator of incremental plasticity implemented, based on non-linear models of Jiang-Sehitoglu and Tanaka.

A multi-agent system is a group of software or hardware agents that cooperate or compete to achieve individual or shared goals. A method for developing a multi-agent system must be capable of modelling the concepts that are central to multi-agent systems. These concepts are identified in a review of Agent Oriented Software Engineering methodologies. The rigorous development of complex systems using formal methods can reduce the number of design faults. Event-B is a formal method for modelling and reasoning about reactive and distributed systems. There is currently no method that guides the developer specifically in the modelling of agent-based concepts in Event-B. The use of formal methods is seen by some developers as inaccessible. This thesis presents an Incremental Development Process for the development of multi-agent systems in Event-B. Development following the Incremental Development Process begins with the construction of informal models, based on agent concepts. The informal models relate system goals using a set of relationships. The developer is provided with guidance to construct formal Event-B models based on the informal design. The concepts that are central to multi-agent systems are captured in the Event-B models through the translation from the goal models. The Event-B models are refined and decomposed into specifications of roles that will be performed by the agents of the system. Two case studies illustrate how the Incremental Development Process can be applied to multi-agent systems. An additional aid to the developer presented in this thesis is a set of modelling patterns that provide fault-tolerance for Event-B models of interacting agents.

Mestrado em Engenharia Mecânica
Esta dissertação de mestrado detalha o desenvolvido de uma interface gráfica para a máquina Single Point Incremental Forming - Aveiro (SPIF-A) com o objetivo de realização de diversas funções, nomeadamente a sua operação. Esta insere-se na unidade curricular Dissertação/Projeto/Estágio do segundo semestre do quinto ano do Mestrado Integrado em Engenharia Mecânica da Universidade de Aveiro. A SPIF-A é uma máquina de estampagem incremental que vem sendo desenvolvida por alunos, investigadores e professores do Departamento de Engenharia Mecânica da Universidade de Aveiro. O trabalho em seguida apresentado é a continuação deste mesmo projeto, sendo que o principal objetivo passou pelo desenvolvimento de uma interface gráfica para operação e monitorização da máquina. O projeto começou pela definição dos principais requisitos que a interface teria de cumprir. Em seguida, iniciou-se o desenvolvimento e o teste da interface gráfica numa instalação auxiliar, sendo a mesma mais tarde transferida e testada na instalação da SPIF-A. Foram realizados vários testes com a interface para detetar e corrigir o maior número possível de erros. Durante este período, foram também introduzidas algumas alterações no controlo da SPIF-A para melhorar a sua segurança e utilização. Para avaliar a facilidade e velocidade de operação da SPIF-A com a interface desenvolvida, produziram-se algumas peças usando o método antigo e a interface atual e registaram-se as principais diferenças. Para finalizar, foi revisto o design da interface para a tornar o mais amigável possível para o operador. Foi também criado um manual de utilização da interface, de modo a possibilitar uma rápida aprendizagem a um novo utilizador.
This master dissertation resumes the development of SPIF-A's graphical user interface with some required functions such as its operation and monitoring. The project is inserted in the curricular unit Dissertação/Projeto/Estágio of the second semester of the fth year of the Master's degree in Mechanical Engineering of the University of Aveiro. SPIF-A project is a single point incremental forming machine that has been developed by students, researchers and professors of the Department of Mechanical Engineering at the University of Aveiro. The work presented is the prolongation of this project, being the main goal the development of a graphical interface for operation and monitoring of the machine. Initially, the work focused in the de nition of the main requirements that the interface should ful ll as well as an analysis to its target users. Then, the interface development and testing started in a backup installation to prevent accidents due to programming errors, being later transfered to SPIF-A. Some tests were performed to detect and x as many errors as possible. During this period, some changes in SPIF-A's control were implemented to improve its security and operation. To validade the new interface performance, some parts were produced using both old and new methodologies and the main di erences were registered. Finally, the interface design was revised and a user's manual was written to facilitate the learning process for new users.

One of the main objectives of software development in scientific computing is efficiency. Being focused on highly specialized application domain, important software quality metrics, e.g., usability, extensibility ,etc may not be amongst the list of primary objectives. In this research, we have studied the design structures and iterative releases of scientific research software using Design Structure Matrix(DSM). We implemented a DSM partitioning algorithm using sparse matrix data structure Compressed Row Storage(CRS), and its timing was better than those obtained from the most widely used C++ library boost. Secondly, we computed several architectural complexity metrics, compared releases and total release costs of a number of open source scientific research software. One of the important finding is the absence of circular dependencies in studied software which attributes to the strong emphasis on computational performance of the code. Iterative release analysis indicates that there might be a correspondence between “clustering co-efficient” and “release rework cost” of the software.
x, 87 leaves : ill. ; 29 cm

The spatial legacy in South Africa has resulted in fragmented urban environments and development in peri-urban areas, such as Mamelodi, is often implemented with a top-down approach. The focus of development tends to be on connecting these hinterlands to the cities with affordable transportation and trying to satisfy needs for basic services and amenities as quickly as possible. This has resulted in the implementation of solutions that are not place specific but instead tend to be generic models implemented on a large scale. The danger therein lies that projects implemented might not be appropriate to communities and could become dysfunctional and underutilised. Part of the process of developing a solution should be the acknowledgement of the everyday in a specific community; the way in which space is produced, appropriated and the everyday rituals. The intention of this dissertation is to re-conceptualise what an art centre could be in the context of Mamelodi West, the historic centre of Mamelodi. Through an understanding of the everyday, what is generally considered a mono-functional program is re-imagined as a diverse intervention integrated into everyday life and ritual. The dissertation proposes one possible means of connecting isolated communities using the commonality of the need for both individual and collective expression of identity to cultivate gemeinschaft; address misconceptions of the value of the Arts and propose a way in which the spatial legacy can be redressed.
Dissertation (MArch (Prof))--University of Pretoria, 2020.
Architecture
MArch (Prof)
Unrestricted

Thesis: S.M. in Real Estate Development, Massachusetts Institute of Technology, Program in Real Estate Development in conjunction with the Center for Real Estate, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 58-61).
Smart buildings have grown from an increase in digital technologies that can sense, recognize and verify the experiences of the building and its inhabitants. Nascent literature has identified what it means to be considered smart. Buildings must respond to all three components of systems, performance, and service and has to have the following components: a) Smartness and technology awareness, b) economic and cost efficiency, c) personal and social sensitivity and d) environmental responsiveness. Yet, it is unclear whether these systems have any value to the users or its owners. This thesis studies the economic impact of Smart, Connected and Green buildings upon rents and transaction prices. Using numerous data sources, we identify buildings that offer at least one so-called "smart" amenity and link them with the building's achieved rent and transactions prices as well as to other so-called "innovation" amenities, like greenness and or fiber-lit connectivity. Results documented in this study suggest that buildings that offer a more integral solution (i.e. buildings that are Smart, Connected and Green) have a premium in both rents and transaction prices over similar office products. While products that offer a more disintegrated solution have a smaller premium or even no incremental value premium, with the exception of green only buildings that offers a premium by themselves. This study contributes to the vast literature on real estate innovation but explores particularly the recent commercial office products that are Smart Buildings.
by Alfredo Keitaro Bando Hano.
S.M. in Real Estate Development

[EN] The stupefying success of Artificial Intelligence (AI) for specific problems, from recommender systems to self-driving cars, has not yet been matched with a similar progress in general AI systems, coping with a variety of problems. This dissertation deals with the long-standing problem of creating more general AI systems, through the analysis of their development and the evaluation of their cognitive abilities. Firstly, this thesis contributes with a general-purpose learning system that meets several desirable characteristics in terms of expressiveness, comprehensibility and versatility. The system works with approaches that are inherently general: inductive programming and reinforcement learning. The system does not rely on a fixed library of learning operators, but can be endowed with new ones, so being able to operate in a wide variety of contexts. This flexibility, jointly with its declarative character, makes it possible to use the system as an instrument for better understanding the role (and difficulty) of the constructs that each task requires. The learning process is also overhauled with a new developmental and lifelong approach for knowledge acquisition, consolidation and forgetting, which is necessary when bounded resources (memory and time) are considered. Secondly, this thesis analyses whether the use of intelligence tests for AI evaluation is a much better alternative to most task-oriented evaluation approaches in AI. Accordingly, we make a review of what has been done when AI systems have been confronted against tasks taken from intelligence tests. In this regard, we scrutinise what intelligence tests measure in machines, whether they are useful to evaluate AI systems, whether they are really challenging problems, and whether they are useful to understand (human) intelligence. Finally, the analysis of the concepts of development and incremental learning in AI systems is done at the conceptual level but also through several of these intelligence tests, providing further insight for the understanding and construction of general-purpose developing AI systems.
[ES] El éxito abrumador de la Inteligencia Artificial (IA) en la resolución de tareas específicas (desde sistemas de recomendación hasta vehículos de conducción autónoma) no ha sido aún igualado con un avance similar en sistemas de IA de carácter más general enfocados en la resolución de una mayor variedad de tareas. Esta tesis aborda la creación de sistemas de IA de propósito general así como el análisis y evaluación tanto de su desarrollo como de sus capacidades cognitivas. En primer lugar, esta tesis contribuye con un sistema de aprendizaje de propósito general que reúne distintas ventajas como expresividad, comprensibilidad y versatilidad. El sistema está basado en aproximaciones de carácter inherentemente general: programación inductiva y aprendizaje por refuerzo. Además, dicho sistema se basa en una biblioteca dinámica de operadores de aprendizaje por lo que es capaz de operar en una amplia variedad de contextos. Esta flexibilidad, junto con su carácter declarativo, hace que sea posible utilizar el sistema de forma instrumental con el objetivo de facilitar la comprensión de las distintas construcciones que cada tarea requiere para ser resuelta. Por último, el proceso de aprendizaje también se revisa por medio de un enfoque evolutivo e incremental de adquisición, consolidación y olvido de conocimiento, necesario cuando se trabaja con recursos limitados (memoria y tiempo). En segundo lugar, esta tesis analiza el uso de tests de inteligencia humana para la evaluación de sistemas de IA y plantea si su uso puede constituir una alternativa válida a los enfoques actuales de evaluación de IA (más orientados a tareas). Para ello se realiza una exhaustiva revisión bibliográfica de aquellos sistemas de IA que han sido utilizados para la resolución de este tipo de problemas. Esto ha permitido analizar qué miden realmente los tests de inteligencia en los sistemas de IA, si son significativos para su evaluación, si realmente constituyen problemas complejos y, por último, si son útiles para entender la inteligencia (humana). Finalmente se analizan los conceptos de desarrollo cognitivo y aprendizaje incremental en sistemas de IA no solo a nivel conceptual, sino también por medio de estos problemas mejorando por tanto la comprensión y construcción de sistemas de propósito general evolutivos.
[CAT] L'èxit aclaparant de la Intel·ligència Artificial (IA) en la resolució de tasques específiques (des de sistemes de recomanació fins a vehicles de conducció autònoma) no ha sigut encara igualat amb un avanç similar en sistemes de IA de caràcter més general enfocats en la resolució d'una major varietat de tasques. Aquesta tesi aborda la creació de sistemes de IA de propòsit general així com l'anàlisi i avaluació tant del seu desenvolupament com de les seues capacitats cognitives. En primer lloc, aquesta tesi contribueix amb un sistema d'aprenentatge de propòsit general que reuneix diferents avantatges com ara expressivitat, comprensibilitat i versatilitat. El sistema està basat en aproximacions de caràcter inherentment general: programació inductiva i aprenentatge per reforç. A més, el sistema utilitza una biblioteca dinàmica d'operadors d'aprenentatge pel que és capaç d'operar en una àmplia varietat de contextos. Aquesta flexibilitat, juntament amb el seu caràcter declaratiu, fa que siga possible utilitzar el sistema de forma instrumental amb l'objectiu de facilitar la comprensió de les diferents construccions que cada tasca requereix per a ser resolta. Finalment, el procés d'aprenentatge també és revisat mitjançant un enfocament evolutiu i incremental d'adquisició, consolidació i oblit de coneixement, necessari quan es treballa amb recursos limitats (memòria i temps). En segon lloc, aquesta tesi analitza l'ús de tests d'intel·ligència humana per a l'avaluació de sistemes de IA i planteja si el seu ús pot constituir una alternativa vàlida als enfocaments actuals d'avaluació de IA (més orientats a tasques). Amb aquesta finalitat, es realitza una exhaustiva revisió bibliogràfica d'aquells sistemes de IA que han sigut utilitzats per a la resolució d'aquest tipus de problemes. Açò ha permès analitzar què mesuren realment els tests d'intel·ligència en els sistemes de IA, si són significatius per a la seua avaluació, si realment constitueixen problemes complexos i, finalment, si són útils per a entendre la intel·ligència (humana). Finalment s'analitzen els conceptes de desenvolupament cognitiu i aprenentatge incremental en sistemes de IA no solament a nivell conceptual, sinó també per mitjà d'aquests problemes millorant per tant la comprensió i construcció de sistemes de propòsit general evolutius.
Martínez Plumed, F. (2016). Incremental and developmental perspectives for general-purpose learning systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/67269
TESIS

The author Mike Davis has labelled our entire globe as a planet of slums. This hesis aims to provide some insights to the research field of slum rehabilitation, and thus contribution to efforts to make our globe slum free. The United Nations states that security of tenure is one of the essential preconditions for improvements in slums. The statement comes with support from academic research, which highlights the relation between secure tenure and a slums physical quality. Out of these messages two hypotheses are formulated and tested throughout the thesis; one theoretical, the other empirical. The theoretical section holds that tenure should be studied according to property rights and tenure status, that interventions for slum rehabilitation should support the dwellers efforts of incremental development, that tenure is granted in both the informal and formal land market, and that there are several causalities between secure tenure and the quality of housing and infrastructure. The case study examines 208 informal settlements in terms of their living conditions in the city of Pune, India. The thesis draws on empirical data in the form of a citywide slum survey that has been made available by the non-governmental organisations, Maharashtra Action League and CHF International, both of which operate in Pune. The empirical section reveals that secure tenure does not influence housing quality at all, that secure tenure just slightly influences available infrastructure in a settlement, and that urban planners are able to support a sustainable and incremental rehabilitation of slums by focusing on tenure security.

Thesis (MTech (Business Information Systems))--Cape Peninsula University of Technology, 2018.
Many software organisations using iterative software development approach use practices that relate to quality management. However, the quality management process has been inadequate. Despite many research studies conducted on quality management in iterative software product development none have adequately addressed the challenges and mitigation techniques to have an adequate process that leads to a quality software product. The objective of this study was to determine factors that affect the quality management process in iterative software development. The research followed a qualitative approach, a case of software organisation SasTech in Cape Town, South Africa. 22 interviews were conducted on three roles actively involved in the software product development process. These are product management, quality assurance and software developers. Themes were drawn from results and were tabulated. The duality of technology theory was used as a theoretical lens to data analysis. Several factors were identified to influence the software quality management process. These include planning, documentation, process ownership, technologies, testing, timelines and management support. Through the general proposed framework, facilities (human resources and technologies), interpretive schemes (architecture) and norms (practices) of software quality management can be institutionalised leading to adequate and effective quality management in iterative development for SasTech as well as other organisations in the same industry.

Cloud computing represents a fundamental change in the way organizations acquire technological resources (e.g., hardware, development and execution environments, applications); where, instead of buying them, they acquire remote access to them in the form of cloud services supplied through the Internet. Among the main characteristics of cloud computing is the allocation of resources in an agile and elastic way, reserved or released depending on the demand of the users or applications, enabling the payment model based on consumption metrics. The development of cloud applications mostly follows an incremental approach, where the incremental delivery of functionalities to the client changes - or reconfigures - successively the current architecture of the application. Cloud providers have their own standards for both implementation technologies and service management mechanisms, requiring solutions that facilitate: building, integrating and deploying portable services; interoperability between services deployed across different cloud providers; and continuity In the execution of the application while its architecture is reconfigured product of the integration of the successive increments. The principles of the model-driven development approach, the architectural style service-oriented architectures, and the dynamic reconfiguration play an important role in this context. The hypothesis of this doctoral thesis is that model-driven development methods provide cloud service developers with abstraction and automation mechanisms for the systematic application of the principles of model engineering during the design, implementation, and incremental deployment of cloud services, facilitating the dynamic reconfiguration of the service-oriented architecture of cloud applications. The main objective of this doctoral thesis is therefore to define and validate empirically DIARy, a method of dynamic and incremental reconfiguration of service-oriented architectures for cloud applications. This method will allow specifying the architectural integration of the increment with the current cloud application, and with this information to automate the derivation of implementation artifacts that facilitate the integration and dynamic reconfiguration of the service architecture of the cloud application. This dynamic reconfiguration is achieved by running reconfiguration artifacts that not only deploy / un-deploy increment's services and orchestration services between services of the increment with the services of the current cloud application; but also, they change the links between services at runtime. A software infrastructure that supports the activities of the proposed method has also been designed and implemented. The software infrastructure includes the following components: i) a set of DSLs, with their respective graphical editors, that allow to describe aspects related to the architectural integration, implementation and provisioning of increments in cloud environments; ii) transformations that generate platform-specific implementation and provisioning models; (iii) transformations that generate artifacts that implement integration logic and orchestration of services, and scripts of provisioning, deployment, and dynamic reconfiguration for different cloud vendors. This doctoral thesis contributes to the field of service-oriented architectures and in particular to the dynamic reconfiguration of cloud services architectures in an iterative and incremental development context. The main contribution is a well-defined method, based on the principles of model-driven development, which makes it easy to raise the level of abstraction and automate, through transformations, the generation of artifacts that perform the dynamic reconfiguration of cloud applications.
La computación cloud representa un cambio fundamental en la manera en la que las organizaciones adquieren recursos tecnológicos (p. ej., hardware, entornos de desarrollo y ejecución, aplicaciones); en donde, en lugar de comprarlos adquieren acceso remoto a ellos en forma de servicios cloud suministrados a través de Internet. Entre las principales características de la computación cloud está la asignación de recursos de manera ágil y elástica, reservados o liberados dependiendo de la demanda de los usuarios o aplicaciones, posibilitando el modelo de pago basado en métricas de consumo. El desarrollo de aplicaciones cloud sigue mayoritariamente un enfoque incremental, en donde la entrega incremental de funcionalidades al cliente cambia - o reconfigura - sucesivamente la arquitectura actual de la aplicación. Los proveedores cloud tienen sus propios estándares tanto para las tecnologías de implementación como para los mecanismos de gestión de servicios, requiriéndose soluciones que faciliten: la construcción, integración y despliegue de servicios portables; la interoperabilidad entre servicios desplegados en diferentes proveedores cloud; y la continuidad en la ejecución de la aplicación mientras su arquitectura es reconfigurada producto de la integración de los sucesivos incrementos. Los principios del enfoque de desarrollo dirigido por modelos, del estilo arquitectónico de arquitecturas orientadas a servicios y de la reconfiguración dinámica cumplen un papel importante en este contexto. La hipótesis de esta tesis doctoral es que los métodos de desarrollo dirigido por modelos brindan a los desarrolladores de servicios cloud mecanismos de abstracción y automatización para la aplicación sistemática de los principios de la ingeniería de modelos durante el diseño, implementación y despliegue incremental de servicios cloud, facilitando la reconfiguración dinámica de la arquitectura orientada a servicios de las aplicaciones cloud. El objetivo principal de esta tesis doctoral es por tanto definir y validar empíricamente DIARy, un método de reconfiguración dinámica e incremental de arquitecturas orientadas a servicios. Este método permitirá especificar la integración arquitectónica del incremento con la aplicación cloud actual, y con esta información automatizar la derivación de los artefactos de implementación que faciliten la integración y reconfiguración dinámica de la arquitectura de servicios de la aplicación cloud. Esta reconfiguración dinámica se consigue al ejecutar los artefactos de reconfiguración que no solo despliegan/repliegan los servicios del incremento y servicios de orquestación entre los servicios del incremento con los servicios de la aplicación cloud actual; sino también, cambian en tiempo de ejecución los enlaces entre servicios. También se ha diseñado e implementado una infraestructura software que soporta las actividades del método propuesto e incluye los siguientes componentes: i) un conjunto de DSLs, con sus respectivos editores gráficos, que permiten describir aspectos relacionados a la integración arquitectónica, implementación y aprovisionamiento de incrementos en entornos cloud; ii) transformaciones que generan modelos de implementación y aprovisionamiento; iii) transformaciones que generan artefactos que implementan la lógica de integración y orquestación de servicios, y scripts de aprovisionamiento, despliegue y reconfiguración dinámica específicos para distintos proveedores cloud. Esta tesis doctoral contribuye al campo de las arquitecturas orientadas a servicios y en particular a la reconfiguración dinámica de arquitecturas de servicios cloud en contextos de desarrollo iterativo e incremental. El principal aporte es un método bien definido, basado en los principios del desarrollo dirigido por modelos, que facilita elevar el nivel de abstracción y automatizar por medio de transformaciones la generación de artefactos que real
La computació cloud representa un canvi fonamental en la manera en què les organitzacions adquirixen recursos tecnològics (ej., maquinari, entorns de desplegament i execució, aplicacions) ; on, en compte de comprar-los adquirixen accés remot a ells en forma de servicis cloud subministrats a través d'Internet. Entre les principals característiques de la computació cloud els recursos cloud són assignats de manera àgil i elàstica, reservats o alliberats depenent de la demanda dels usuaris o aplicacions, possibilitant el model de pagament basat en mètriques de consum. El desenrotllament d'aplicacions cloud seguix majoritàriament un enfocament incremental, on l'entrega incremental de funcionalitats al client canvia - o reconfigura - successivament l'arquitectura actual de l'aplicació. Els proveïdors cloud tenen els seus propis estàndards tant per a les tecnologies d'implementació com per als mecanismes de gestió de servicis, requerint-se solucions que faciliten: la construcció, integració i desplegament de servicis portables; la interoperabilitat entre servicis desplegats en diferents proveïdors cloud; i la continuïtat en l'execució de l'aplicació mentres la seua arquitectura és reconfigurada producte de la integració dels successius increments. Els principis de l'enfocament de desenrotllament dirigit per models, de l'estil arquitectònic d'arquitectures orientades a servicis i de la reconfiguració dinàmica complixen un paper important en este context. La hipòtesi d'esta tesi doctoral és que els mètodes de desenrotllament dirigit per models brinden als desenvolupadors de servicis cloud mecanismes d'abstracció i automatització per a l'aplicació sistemàtica dels principis de l'enginyeria de models durant el disseny, implementació i desplegament incremental de servicis cloud, facilitant la reconfiguració dinàmica de l'arquitectura orientada a servicis de les aplicacions cloud. L'objectiu principal d'esta tesi doctoral és per tant de definir i validar empí-ricamente DIARy, un mètode de reconfiguració dinàmica i incremental d'arquitectures orientades a servicis per a aplicacions cloud. Este mètode permetrà especificar la integració arquitectònica de l'increment amb l'aplicació cloud actual, i amb esta informació automatitzar la derivació dels artefactes d'implementació que faciliten la integració i reconfiguració dinàmica de l'arquitectura de servicis de l'aplicació cloud. Esta reconfi-guración dinàmica s'aconseguix a l'executar els artefactes de reconfiguració que no sols despleguen/repleguen els servicis de l'increment i servicis d'orquestració entre els servicis de l'increment amb els servicis de l'aplicació cloud actual; sinó també, canvien en temps d'execució els enllaços entre servicis. També s'ha dissenyat i implementat una infraestructura programari que suporta les activitats del mètode proposat i inclou els següents components: i) un conjunt de DSLs, amb els seus respectius editors gràfics, que permeten descriure aspectes relacionats a la integració arquitectònica, implementació i aprovisionament en entorns cloud dels increments; ii) transformacions que generen models d'implementació i aprovisionament específics de la plataforma a partir dels models d'integració d'alt nivell; iii) transformacions que generen artefactes que implementen la lògica d'integració i orquestració de servicis, i scripts d'aprovisionament, desplegament i reconfiguració dinàmica específics per a distints proveïdors cloud. Esta tesi doctoral contribuïx al camp de les arquitectures orientades a servicis i en particular a la reconfiguració dinàmica d'arquitectures de servicis cloud en contextos de desenrotllament iteratiu i incremental. La principal aportació és un mètode ben definit, basat en els principis del desenrotllament dirigit per models, que facilita elevar el nivell d'abstracció i automatitzar per mitjà de transformacions la generació d'artefactes que r
Zuñiga Prieto, MÁ. (2017). Reconfiguración Dinámica e Incremental de Arquitecturas de Servicios Cloud Dirigida por Modelos [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86288
TESIS

Panel data analysis has become an important tool in applied econometrics and the respective statistical techniques are well described in several recent textbooks. However, for an analyst using these methods there remains the task of choosing a reasonable model for the behavior of the panel data. Of special importance is the choice between so-called fixed and random coefficient models. This choice can have a crucial effect on the interpretation of the analyzed phenomenon, which is demonstrated by an application on research and development spillover. (author's abstract)
Series: Forschungsberichte / Institut für Statistik

A new approach for the development of problem-solvers for combinatorial problems is proposed in this thesis. The approach combines incremental knowledge acquisition and probabilistic search algorithms, such as evolutionary algorithms, to allow a human to rapidly develop problem-solvers in new domains in a framework called HeurEAKA. The approach addresses a known problem, that is, adapting evolutionary algorithms to the search domain by the introduction of domain knowledge. The development of specialised problem-solvers has historically been labour intensive. Implementing a problem-solver from scratch is very time consuming. Another approach is to adapt a general purpose search strategy to the problem domain. This is motivated by the observation that in order to scale an algorithm to solve complex problems, domain knowledge is needed. At present there is no systematic approach allowing one to efficiently engineer a specialpurpose search strategy for a given search problem. This means that, for example, adapting evolutionary algorithms (which are general purpose algorithms) is often very difficult and has lead some people to refer to their use as a ???black art???. In the HeurEAKA approach, domain knowledge is introduced by incrementally building a knowledge base that controls parts of the evolutionary algorithm. For example, the fitness function and the mutation operators in a genetic algorithm. An evolutionary search algorithm ismonitored by a human whomakes recommendations on search strategy based on individual solution candidates. It is assumed that the human has a reasonable intuition of the search problem. The human adds rules to a knowledge base describing how candidate solutions can be improved, or why they are desirable or undesirable in the search for a good solution. The incremental knowledge acquisition approach is inspired by the idea of (Nested) Ripple Down Rules. This approach sees a human provide exception rules to rules already existing in the knowledge base using concrete examples of inappropriate performance of the existing knowledge base. The Nested Ripple Down Rules (NRDR) approach allows humans to compose rules using concepts that are natural and intuitive to them. In HeurEAKA, NRDR are significantly adapted to form part of a probabilistic search algorithm. The probabilistic search algorithms used in the presented system are a genetic algorithm and a hierarchical bayesian optimization algorithm. The success of the HeurEAKA approach is demonstrated in experiments undertaken on industrially relevant domains. Problem-solvers were developed for detailed channel and switchbox routing in VLSI design and traffic light optimisation for urban road networks. The problem-solvers were developed in a short amount of time, in domains where a large amount of effort has gone into developing existing algorithms. Experiments show that chosen benchmark problems are solved as well or better than existing approaches. Particularly in the traffic light optimisation domain excellent results are achieved.

Nowadays, many formal methods are used in the area of software development accompanied by a number of advanced theories and tools. However, more experiments are still required in order to provide significant evidence that will convince and encourage users to use, and gain more benefits from, those theories and tools. Event-B is a formalism used for specifying and reasoning about systems. Rodin is an open and extensible tool for Event-B specification, refinement and proof. The flash file system is a complex system. Such systems are a challenge to specify and verify at this moment in time. This system was chosen as a case study for our experiments, carried out using Event-B and the Rodin tool. The experiments were aimed at developing a rigorous model of flash-based file system; including implementation of the model, providing useful evidence and guidelines to developers and the software industry. We believe that these would convince users and make formal methods more accessible. An incremental refinement was chosen as a strategy in our development. The refinement was used for two different purposes: feature augmentation and structural refinement (covering event and machine decomposition). Several techniques and styles of modelling were investigated and compared; to produce some useful guidelines for modelling, refinement and proof. The model of the flash-based file system we have completed covers three main issues: fault-tolerance, concurrency and wear-levelling process. Our model can deal with concurrent read/write operations and other processes such as block relocation and block erasure. The model tolerates faults that may occur during reading/writing of files. We believe our development acts as an exemplar that other developers can learn from. We also provide systematic rules for translation of Event-B models into Java code. However, more work is required to make these rules more applicable and useful in the future

The ability to organize concepts (e.g., dog, chair) into efficient mental representations, i.e., categories (e.g., animal, furniture) is a fundamental mechanism which allows humans to perceive, organize, and adapt to their world. Much research has been dedicated to the questions of how categories emerge and how they are represented. Experimental evidence suggests that (i) concepts and categories are represented through sets of features (e.g., dogs bark, chairs are made of wood) which are structured into different types (e.g, behavior, material); (ii) categories and their featural representations are learnt jointly and incrementally; and (iii) categories are dynamic and their representations adapt to changing environments. This thesis investigates the mechanisms underlying the incremental and dynamic formation of categories and their featural representations through cognitively motivated Bayesian computational models. Models of category acquisition have been extensively studied in cognitive science and primarily tested on perceptual abstractions or artificial stimuli. In this thesis, we focus on categories acquired from natural language stimuli, using nouns as a stand-in for their reference concepts, and their linguistic contexts as a representation of the concepts’ features. The use of text corpora allows us to (i) develop large-scale unsupervised models thus simulating human learning, and (ii) model child category acquisition, leveraging the linguistic input available to children in the form of transcribed child-directed language. In the first part of this thesis we investigate the incremental process of category acquisition. We present a Bayesian model and an incremental learning algorithm which sequentially integrates newly observed data. We evaluate our model output against gold standard categories (elicited experimentally from human participants), and show that high-quality categories are learnt both from child-directed data and from large, thematically unrestricted text corpora. We find that the model performs well even under constrained memory resources, resembling human cognitive limitations. While lists of representative features for categories emerge from this model, they are neither structured nor jointly optimized with the categories. We address these shortcomings in the second part of the thesis, and present a Bayesian model which jointly learns categories and structured featural representations. We present both batch and incremental learning algorithms, and demonstrate the model’s effectiveness on both encyclopedic and child-directed data. We show that high-quality categories and features emerge in the joint learning process, and that the structured features are intuitively interpretable through human plausibility judgment evaluation. In the third part of the thesis we turn to the dynamic nature of meaning: categories and their featural representations change over time, e.g., children distinguish some types of features (such as size and shade) less clearly than adults, and word meanings adapt to our ever changing environment and its structure. We present a dynamic Bayesian model of meaning change, which infers time-specific concept representations as a set of feature types and their prevalence, and captures their development as a smooth process. We analyze the development of concept representations in their complexity over time from child-directed data, and show that our model captures established patterns of child concept learning. We also apply our model to diachronic change of word meaning, modeling how word senses change internally and in prevalence over centuries. The contributions of this thesis are threefold. Firstly, we show that a variety of experimental results on the acquisition and representation of categories can be captured with computational models within the framework of Bayesian modeling. Secondly, we show that natural language text is an appropriate source of information for modeling categorization-related phenomena suggesting that the environmental structure that drives category formation is encoded in this data. Thirdly, we show that the experimental findings hold on a larger scale. Our models are trained and tested on a larger set of concepts and categories than is common in behavioral experiments and the categories and featural representations they can learn from linguistic text are in principle unrestricted.

The appropriation of open space is a common and organic process that is constantly taking place in the contemporary South African city. The tabula rasa approach of Apartheid and modernist planning had little consideration for these natural spatial patterns. This dissertation argues for a democratic approach to architecture and space-making in the contemporary South African city, one that embraces diversity, multifunctionality, and the eventuality of incremental development. Drawing from theories such as Control of Complexity (Habraken 1987), Space as Ritual (van Rensburg & da Costa 2008), and Safe-to-Fail (Ahern 2011), the research explores the possibilities of designing for emergent and adaptable space as a tool for enablement in the context of Mamelodi. The inherited Apartheid spatial legacy of Mamelodi has led to the prevalence of monofunctional, medium density development that has limited economic opportunity and encouraged pendulum migration in search of employment. This presents the opportunity to introduce new scales of urbanity to the context, whilst still being sensitive and encouraging existing spatial functions and patterns.
Mini Dissertation MArch(Prof)--University of Pretoria, 2018.
Architecture
MArch(Prof)
Unrestricted