Discrete Choices, Trade‐offs, and Advantages: Modeling Social Venture Opportunities and Intentions

[Excerpt] Our study is motivated by the fundamental question of whether social entrepreneurs differ from \u27traditional\u27 entrepreneurs. More concretely, is the way that aspiring entrepreneurs view social entrepreneurial opportunities different from the way they view more traditional (defined as primarily economic) entrepreneurial opportunities? Answering this question is critical to the advancement of the study of social entrepreneurship, and represents a powerful vehicle for demonstrating how the study of social entrepreneurship also advances our knowledge of traditional entrepreneurship

Testing of xtUML Models across Auto-Reflexive Software Architecture

Application of MDA in the software development enables a synchronization of the system models and corresponding source files used for the building of the executable version of a software system. Because of often use of manual modifications of some parts of code without equivalent changes in connected models, there is no guarantee that the output of the process of building of the target application will be consistent with the relevant design and implementation models. Possibility of generating of the source files from the models is a necessity, but not a sufficient condition in the process of development and modification of software systems synchronously with the changes in all related models.  More safe approach is building the target application with the use of an automated building process with nested steps for consistency verifications of all critical models and related source files and the usage of model compilers. This article describes the method and tools for extending the software process of building the target system using special files with specification of dependencies between models and source files. Such dependencies represent the core of the critical knowledge, and it is possible to make this knowledge an integral part of the proposed new software architecture

A secure client / server interface protocol for the electricity prepayment vending industry

Electricity prepayment systems have been successfully implemented by South Africa’s national electricity utility (Eskom) and local municipalities for more than 17 years. The prepayment vending sub-system is a critical component of prepayment systems. It provides convenient locations for customers to purchase electricity. It predominantly operates in an “offline” mode, however, electricity utilities are now opting for systems that operate in an “online” mode. “Online” mode of operation or online vending is when a prepayment token is requested from a centralised server that is remote from the client at the actual point of sale (POS). The token is only generated by the server and transferred to the POS client, once the transaction, the POS client and the payment mechanism has been authenticated and authorised. The connection between the POS client and the server is a standard computer network channel (like Internet, direct dial-up link, X.25, GPRS, etc) The lack of online vending system standardisation was a concern and significant risk for utilities, as they faced the problem of being locked into proprietary online vending systems. Thus the South African prepayment industry, lead by Eskom, initiated a project to develop an industry specification for online vending systems. The first critical project task was a current state analysis of the South African prepayment industry, technology and specifications. The prepayment industry is built around the Standard Transfer Specification (STS). STS has become the de-facto industry standard to securely transfer electricity credit from a Point of Sale (POS) to the prepaid meter. STS is supported by several “offline” vending system specifications. The current state analysis was followed by the requirements analysis phase. The requirements analysis confirmed the need for a standard interface protocol specification rather than a full systems specification. The interface specification focuses on the protocol between a vending client and vending server and does not specify the client and server application layer functionality and performance requirements. This approach encourages innovation and competitiveness amongst client and server suppliers while ensuring interoperability between these systems. The online vending protocol design was implemented using the web services framework and therefore appropriately named, XMLVend. The protocol development phase was an iterative process with two major releases, XMLVend 1.22 and XMLVend 2.1. XMLVend 2.1 is the current version of the protocol. XMLVend 2.1 addressed the shortcomings identified in XMLVend 1.22, updated the existing use cases and added several new use cases. It was also modelled as a unified modelling language (UML) interface or contract for prepayment vending services. Therefore, clients using the XMLVend interface are able to request services from any service provider (server) that implements the XMLVend interface. The UML modelled interface and use case message pairs were mapped to Web Service Definition Language (WSDL) and schema (XSD) definitions respectively. XMLVend 2.1 is a secure and open web service based protocol that facilitates prepayment vending functionality between a single logical vending server and ‘n’ number of clients. It has become a key enabler for utilities to implement standardised, secure, interoperable and flexible online vending systems. AFRIKAANS : Voorafbetaalde elektrisiteitstelsels is suksesvol deur Suid-Afrika se nasionale elektrisiteitsverskaffer (Eskom) en plaaslike munisipaliteite geïmplementeer vir meer as 17 jaar. Die Voorafbetaal verkoop-subsisteem is 'n esensiële komponent van voorafbetaal elektrisiteitstelsels. Dit laat gebruikers toe om elektrisiteit te koop by ‘n verskeidenheid van verkooppunte. In die verlede het hierdie stelsels meestal bestaan as alleenstaande verkooppunte maar elektrisiteitsverskaffers is besig om hulle stelsels te verander om in n aanlyn modus te werk. Aanlyn verkoop is wanneer 'n voorafbetaalkoepon versoek word vanaf ‘n sentrale bediener wat vêr verwydered is van die kliënt se verkooppunt. Die koepon word slegs gegenereer deur die bediener en gestuur aan die kliënt nadat die transaksie, die kliënt self, en die betaling meganisme, gemagtig is. Die koppeling tussen verkooppuntkliënt en die bediener is ‘n standaard kommunikasie kanaal, (byvoorbeeld; Internettoegang, direkte inbel skakel, X.25 en “GPRS”) Die gebrek aan 'n standaard vir aanlynverkoopstelsels was 'n bekommernis en beduidende risiko vir elektrisiteitsverskaffers, aangesien hulle ‘n probleem ondervind dat hulle ingeperk sal word tot ‘n eksklusiewe ontwerp vir so ‘n aanlynverkoopstelsel. Dus het die Suid Afrikaanse voorafbetaal industrie, gelei deur Eskom, 'n projek begin om 'n industriespesifikasie te ontwikkel vir aanlyn verkoopstelsels. Die eerste kritiese projek taak was 'n analise van die huidige stand van die Suid-Afrikaanse vooruitbetaling industrie, die tegnologie en spesifikasies. Die voorafbetaal sektor is gebou rondom die Standaard Oordrag Spesifikasie, bekend as “Standard Transfer Specification” (STS). STS word algemeen aanvaar as die industrie standaard vir die oordrag van elektrisiteit krediet vanaf 'n Verkooppunt na die voorafbetaalmeter. STS word ondersteun deur verskeie alleenstaande verkoopstelsel spesifikasies. Die analise vir die huidige status was opgevolg deur ‘n studie van die vereistes vir so ‘n stelsel. Die vereistes analise het die behoefte bevestig vir 'n standaard koppelvlak protokol spesifikasie, eerder as 'n nuwe spesifikasie vir ‘n volledige oorafbetaalstelsel. Dit bepaal alleenlik die protokol koppelvlak tussen 'n voorafbetaalkliënt en die bediener. Dit spesifiseer nie die program vlak funksionaliteit of prestasie vereistes, vir die kliënt en bediener nie. Hierdie benadering bevorder innovasie en mededingendheid onder kliënt- en bediener-verskaffers, terwyl dit nog steeds verseker dat die stelsels wedersyds aanpasbaar bly. Die aanlyn verkoopprotokol ontwerp is geïmplementeer met die webdienste raamwerk en staan bekend as XMLVend. Die protokol vir die ontwikkeling fase was 'n iteratiewe proses met die twee groot weergawes, XMLVend 1.22 en XMLVend 2.1. Die huidige weergawe van die protokol - XMLVend 2.1, adresseer die tekortkominge wat geïdentifiseer is met XMLVend 1.22, terwyl dit ook die bestaande gebruiksgevalle opdatteer en verskeie nuwe gebruiksgevalle byvoeg. Dit was ook geskoei as 'n verenigde modelleringtaal (UML) koppelvlak, of 'n kontrak, vir die voorafbetaal verkoopsdienste. Kliënte is daarom in staat om, met behulp van die XMLVend koppelvlak, dienste te versoek van enige diensverskaffer wat die XMLVend koppelvlak ondersteun. Die UML gemodelleerde koppelvlak- en gebruiksgevalle- boodskappare was gemodeleer in die Web Dienste Definisie Taal (WSDL) en skema (XSD) definisies onderskeidelik. XMLVend 2.1 is 'n sekure en oop webdienste-gebaseerde protokol wat dit moontlik maak om voorafbetaalfunksies te fasilliteer tussen 'n enkele logiese verkoopbediener en 'x' aantal kliënte. Dit het 'n sleutelrol aangeneem vir verskaffers om ‘n gestandaardiseerde, veilige, wedersyds-aanpasbare en buigsame aanlyn verkoopstelsels moontlik te maak. CopyrightDissertation (MSc)--University of Pretoria, 2010.Electrical, Electronic and Computer Engineeringunrestricte

A Model-Driven Architecture based Evolution Method and Its Application in An Electronic Learning System

Software products have been racing against aging problem for most of their lifecycles, and evolution is the most effective and efficient solution to this problem. Model-Driven Architecture (MDA) is a new technique for software product for evolving development and reengineering methods. The main steps for MDA are to establish models in different levels and phases, therefore to solve the challenges of requirement and technology change. However, there is only a standard established by Object Management Group (OMG) but without a formal method and approach. Presently, MDA is widely researched in both industrial and research areas, however, there is still without a smooth approach to realise it especially in electronic learning (e-learning) system due to the following reasons: (1) models’ transformations are hard to realise because of lack of tools, (2) most of existing mature research results are working for business and government services but not education area, and (3) most of existing model-driven researches are based on Model-Driven Development (MDD) but not MDA because of OMG standard’s preciseness. Hence, it is worth to investigate an MDA-based method and approach to improve the existing software development approach for e-learning system. Due to the features of MDA actuality, a MDA-based evolution method and approach is proposed in this thesis. The fundamental theories of this research are OMG’s MDA standard and education pedagogical knowledge. Unified Modelling Language (UML) and Unified Modelling Language Profile are hired to represent the information of software system from different aspects. This study can be divided into three main parts: MDA-based evolution method and approach research, Platform-Independent Model (PIM) to Platform-Specific Model (PSM) transformation development, and MDA-based electronic learning system evolution. Top-down approach is explored to develop models for e-learning system. A transformation approach is developed to generate Computation Independent Model (CIM), Platform-Independent Model (PIM), and Platform-Specific Model (PSM); while a set of transformation rules are defined following MDA standard to support PSM’ s generation. In addition, proposed method is applied in an e-learning system as a case study with the prototype rules support. In the end, conclusions are drawn based on analysis and further research directions are discussed as well. The kernel contributions are the proposed transformation rules and its application in electronic learning system

As pesquisas sobre sistemas generativos

As transformações da sociedade proporcionadas pela tecnologia digital nos impelem a estudar suas implicações no campo da arquitetura. Há algumas décadas, nota-se o impacto da adoção do desenho auxiliado por computador no que diz respeito à apresentação e representação de projetos, sendo que, nos últimos tempos, as ferramentas digitais tem assumido cada vez mais um papel ativo no processo de projeto. BIM, parametrização e sistemas generativos são temas ligados a esta transformação e ainda podem ser explorados no cenário brasileiro. Este estudo teve como objetivo verificar o panorama atual de pesquisas relacionadas aos Sistemas Generativos de Projeto, tema que, apesar de não ser exclusivamente digital, tem despertado maior interesse com as possibilidades oferecidas pelas novas ferramentas de projeto. Como método de trabalho foi adotada a Revisão Sistemática de Literatura (RSL) nas bases de dados Periódicos CAPES e CumInCAD. Através de uma consistente compilação das publicações direcionadas ao tema, feita a partir de combinações de palavras chave, buscou-se delinear o contorno do problema de pesquisa e identificar, entre outros, os principais agentes, métodos e técnicas, utilizados. A análise do material se deu em duas etapas, a princípio na amostra de artigos de interesse e posteriormente nas referências utilizadas por tais artigos. Com isso, foi possível identificar as principais publicações, autores, periódicos e eventos de área, bem como estabelecer direcionamentos para futuros trabalhos acadêmico-científico a partir do diagnóstico de tendências relativas a temas, métodos, softwares utilizados e resultados obtidos pelas publicações analisadas

How Do Business People Rank Requirements Representations for Information Systems?

The research question that summarises the primary research goals is: How do business people rank their intentions to use different requirements representations for information systems? An additional goal of the research is to understand the determinants that contribute to these intentions. Business people in this research are defined as working people who are not in an information systems role. The requirements representations evaluated were Prose Narrative, Image Narrative, Diagram Narrative and Video Narrative. The results of this research show that business people rank their intention to use the requirements representations in the following order: Prose Narrative, Image Narrative, Diagram Narrative and Video Narrative. The determinants that influence the intention to use a representation are: Job Performance, Effort, Attitude to a Representation, Social Influence, Facilitating Conditions, Self-Efficacy, Anxiety, Freedom of Choice, Experience, Age and Gender. This research shows that the influence of each of these determinants on the intention to use a representation is significantly different for each requirements representation

An interpretive case study into the application of software engineering theory

Even before software engineering was formally defined as a discipline, software projects were notorious for being behind schedule and over budget. The resulting software systems were also often described as unreliable. Researchers in the field have, over the years, theorised and proposed many standards, methods, processes and techniques to improve software project outcomes. Based on allegorical evidence, however, it would seem that these proposals are often not applied in practice. This study was inspired by a desire to probe this general theme, namely of the extent to which (if at all) software engineering theory is adopted in practice. The core of this research is an interpretive case study of a software project in the financial services industry that ran from end 2006 to mid 2008. I was one of a team of approximately 20 developers, analysts and development managers working on the project, until I left the company in 2009. Results are reported in a two-phase fashion over several themes. Firstly, the literature of recommended software engineering practices relating to a particular theme is reviewed. This is regarded as the "theory". Thereafter, the observations and evidence collected from the interpretive study in regard to the relevant theme is presented and discussed. The first theme investigated is the notion of "project outcome". Definitions of successful and failed software projects are considered from the perspective of the various stakeholders. Also considered are factors that contribute to project success or failure. After examining how case study participants viewed the project’s outcome, it is argued that the project could neither be labelled as a complete success nor as a complete failure. Two areas were identified as problematic: the requirements gathering process; and the system architecture that had been chosen. Improvements in these areas would arguably have most benefitted the project’s outcome. For this reason, recommended practices were probed in the literature relating both to requirements engineering and also to software architecture design. The case study project was then evaluated against these recommended practices to determine the degree to which they were implemented. In cases where the recommended practices were not implemented or only partially implemented, a number of reasons for the lack of adoption are considered. Of course, the conclusions made in this study as to why the recommended practices were not implemented cannot be naïvely generalized to the software engineering field as a whole. Instead, in line with the interpretive nature of the study, an attempt was made to gain in depth knowledge of a particular project, to show how that project’s individual characteristics influenced the adoption of software engineering theory, and to probe the consequences of such adoption or lack thereof. The study suggested that the complex and individual nature of software projects will have a substantial influence on the extent to which theory is adopted in practice. It also suggested that the impact such adoption will have on a project’s outcome will be critically influenced by the nature of the software project. CopyrightDissertation (MSc)--University of Pretoria, 2012.Computer Scienceunrestricte