There are several previous studies in which machine learning algorithms are used to predict how fault-prone a piece of code is. This thesis takes on a slightly different approach by attempting to predict how long a piece of code will remain unmodified after being written (its “lifetime”). This is based on the hypothesis that frequently modified code is more likely to contain weaknesses, which may make lifetime predictions useful for code evaluation purposes. In this thesis, the predictions are made with machine learning algorithms which are trained on open source code examples from GitHub. Two different machine learning algorithms are used: the multilayer perceptron and the support vector machine. A piece of code is described by three groups of features: code contents, code properties obtained from static code analysis, and metadata from the version control system Git. In a series of experiments it is shown that the support vector machine is the best performing algorithm and that all three feature groups are useful for predicting lifetime. Both the multilayer perceptron and the support vector machine outperform a baseline prediction which always outputs the mean lifetime of the training set. This indicates that lifetime to some extent can be predicted based on information extracted from the code. However, lifetime prediction performance is shown to be highly dataset dependent with large error magnitudes.

The purpose of the study is partly to identify and describe the conditions that arenecessary for ICT4D projects using open source software to become successful, but also toidentify what possibilities and difficulties come with a greater openness. The result of thisstudy can be used as guidance when planning and executing ICT4D projects. The study applies a qualitative method with an abductive approach. Thematerial of the study was collected by interviewing five people, who are working within thefield of ICT4D. The conditions, that are required for open source based ICT4D projects to besuccessful, mainly focus on the importance of a wide competence, local ownership,simplicity, more collaboration and a higher degree of awareness. Further the conclusion canbe drawn that the free nature of open source can imply larger possibilities to local adjustment,the spread of initiatives, and collaboration between participants. It can also lead to a reductionof government-controlled information. Open development, meaning increased participationwith the intended users, collaboration between organizations, and a larger transparency in thedevelopment process, can have a positive influence on the sustainability and scalability of aproject. The difficulties that a greater openness can imply mainly focus on the dependencythat can arise between different parties, but also the omission of the local context and thecosts that can occur when developing with open source.

Denna uppsats undersöker upptagandet av öppen mjukvara genom en flerfallstudie på svenska IT-företag. Den använder semistrukturerade intervjuer för att kartlägga de uppfattningar om open source som finns hos ledande personer på företagen och försöker fastställa deras engagemang och kunskapsnivå. Som teorigrund för att utforma frågor och analysera intervjuer har bland annat Rogers och Attewells teorier om spridande och upptagande av innovationer använts. Resultaten visar att företagen värderar tryggheten som en relation till leverantören erbjuder och att organisationens interna förutsättningar ofta påverkar valet av mjukvara, i större utsträckning än kvaliteten på öppen mjukvara.

Software users have become more conscious of security. More people have access to Internet and huge databases of security exploits. To make secure products, software developers must acknowledge this threat and take action. A first step is to perform a software security analysis. The software security analysis was performed using automatic auditing tools. An experimental environment was constructed to check if the findings were exploitable or not. Open source projects were used as reference to learn what patterns to search for. The results of the investigation show the differences in the automatic auditing tools used. Common types of security threats found in the product have been presented. Four different types of software security exploits have also been presented. The discussion presents the effectiveness of the automatic tools for auditing software. A comparison between the security in the examined product and the open source project Apache is presented. Furthermore, the incorporation of the software security analysis into the development process, and the results and cost of the security analysis is discussed. Finally some conclusions were drawn.

In this thesis work, we try to enhance an industry work simulator by developing a Free and Open source fault injecting and monitoring application. We present our experiences and ideas while participating in a work simulation. We implement some of these ideas to further enhance the simulation. We also try to connect these experiences to the fields of Human Com- puter Interaction (HCI), Computer Supported Cooperative Work (CSCW) and Ubiquitous Computing. / This thesis is mainly about developing a Fault injecting and Monitoring (FIM) application for supporting Work simulation environment. / Mobile number: 0739225562 (Sweden) vikas.vikky@gmail.com

Open-source software is becoming a gradually more popular as a software development method; some of the most successful softwares are for example: the Linux operating system, Mozilla, Apache web server and openoffice.org. Open source softwares viewed by many as being very good in terms of their usage, reliability, performance and market share. Mostly open source software developer focus on functionality and different feature of the software; on the other hand they ignore the user centric design requirement. In this thesis the importance of the usability in Open source applications, such as Openoffice.org are described and how usability can be measured by assessing user performance such as, satisfaction, effectiveness and acceptability. Openoffice.org is a freely available office suite in different operating system and with different languages. The OpenOffice.org 3.0 feature set is similar to the feature set of Microsoft Office 2003. It has word processing, spreadsheet and presentation applications all together within a common suite. But still this application suite is not much familiar among common users that cause a major usability threat for usability studies. The basic purposed of this thesis was to find out the issues and users satisfaction regarding this Openoffice.org. Empirical method of usability assessment such as thinks aloud, Questionnaires and interviews were used. / Folkparkvagen 20 Lag 10 Ronneby 37240 Sweden Mobile number 0046-700183591

Business modelling (BM) is being used in commercial organizations of different sizes and industries all over the world as a tool to design, structure and analyse business processes and activities. Hence, advantages of BM can be exploited by public sector institutions (PSIs) as well. Adoption of open source software (OSS) is another phenomenon that started to spread from individual and corporate users to public environment. In Europe, it was successfully done in German municipalities and Swedish police. Moreover, guidelines on OSS public procurement were developed by the group of researchers led by R. A. Ghosh on the base of EU directives on software management. The aim of the current study is to combine two mentioned above tools (BM and OSS adoption) in one practical approach that could be used by municipalities. The main reason for doing this is obvious lack of findings in both theoretical and practical aspects though the subject is being broadly discussed and promoted. The overall purpose of the current research is to design an OSS based business model for Kivos municipalities that can be later generalized to other public organizations, probably even in other countries. The specific feature of this business modelling is that it is created upon value and relationships instead of issues related to money which is more common for BM. The current study is an exploratory and inductive qualitative research where case study was chosen as a research strategy. Data collection was conducted using the following techniques: literature review – for secondary data collection, and communication (interview and survey) – for primary data collection. Theoretical framework includes literature (sources providing both general and specific information related to the subject of interest. All gathered information was interpreted and analysed through the instrumentality of enterprise modelling or simply summarised and discussed verbally. On the base of interpreted results of theoretical and empirical studies desired OSS based business relationships model was designed and described for Kivos municipalities. It is based on value which in particular case implies sharing information, knowledge and experience as well as mutual assistance and reliable interaction between participants of relationships existing in OSS environment.

For years, game companies have been using different programs for the creation of the newest most inspiring games. A short presentation about different programs used for game art is provided with key aspects in developing art for games in character production. One aim is to showcase the potential of open-source programs. Two projects with two different characters were created for games testing the workflow between open-source, free application and also commercial programs. The results of the projects are discussed and then the document focuses on explaining what the negative side of open-source programs is and why they should not be used. After the discussion, a conclusion is made explaining the similarities and differences between open-source and commercial programs.

The understanding of the physics of the Coherent Structures and their interaction with the remaining fluid motions is of paramount interest in Turbulence Research. <p>Indeed, recently had been suggested that separating and understanding the the different physical behavior of Coherent Structures and "uncoherent" background might very well be the key to understand and predict Turbulence. Available understanding of Coherent Structures shows that their size is considerably larger than the turbulent macro-scale, making permissible the application of Large Eddy Simulation to their simulation and study, with the advantage to be able to study their behavior at higher Re and more complex geometry than a Direct Numerical Simulation would normally allow. Original purpose of the present work was therefore the validation of the use of Large Eddy Simulation for the study of Coherent Structures in Shear-Layer and the its application to different flow cases to study the effect of the flow topology on the Coherent Structures nature.<p>However, during the investigation of the presence of Coherent Structures in numerically generated LES flow fields, the aging in house Large Eddy Simulation (LES) code of the Environmental & Applied Fluid Dynamics Department has shown a series of limitations and shortcomings that led to the decision of relegating it to the status of Legacy Code (from now on indicated as VKI LES legacy code and of discontinuing its development. A new natively parallel LES solver has then been developed in the VKI Environmental & Applied Fluid Dynamics Department, where all the shortcomings of the legacy code have been addressed and modern software technologies have been adopted both for the solver and the surrounding infrastructure, delivering a complete framework based exclusively on Free and Open Source Software (FOSS ) to maximize portability and avoid any dependency from commercial products. The new parallel LES solver retains some basic characteristics of the old legacy code to provide continuity with the past (Finite Differences, Staggered Grid arrangement, Multi Domain technique, grid conformity across domains), but improve in almost all the remaining aspects: the flow can now have all the three directions of inhomogeneity, against the only two of the past, the pressure equation can be solved using a three point stencil for improved accuracy, and the viscous terms and convective terms can be computed using the Computer Algebra System Maxima, to derive discretized formulas in an automatic way.<p>For the convective terms, High Resolution Central Schemes have been adapted to the three-dimensional Staggered Grid Arrangement from a collocated bi-dimensional one, and a system of Master-Slave simulations has been developed to run in parallel a Slave simulation (on 1 Processing Element) for generating the inlet data for the Master simulation (n - 1 Processing Elements). The code can perform Automatic Run-Time Load Balancing, Domain Auto-Partitioning, has embedded documentation (doxygen), has a CVS repository (version managing) for ease of use of new and old developers.<p>As part of the new Frame Work, a set of Visual Programs have been provided for IBM Open Data eXplorer (OpenDX), a powerful FOSS Flow visualization and analysis tool, aimed as a replacement for the commercial TecplotTM, and a bug tracking mechanism via Bugzilla and cooperative forum resources (phpBB) for developers and users alike. The new M.i.O.m.a. (MiOma) Solver is ready to be used again for Coherent Structures analysis in the near future. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

Abstract This thesis explores whether usability cost-benefit analysis is helpful when applied to commercial and open source software (OSS) development contexts. First, the thesis examines the differences and commonalities among the existing usability cost-benefit analysis models. The results indicate that there are considerable variations in the usability cost-benefit analysis literature in how the different categories of usability costs and benefits are identified and documented. Second, the thesis examines how well the existing usability cost-benefit considerations fit into practice in closed source software development. The results indicate that there are considerable risks of failure when using usability cost-benefit considerations in the commercial development context, when the inherent costs of usability activities become apparent, concrete, and measurable. Conversely, the potential benefits of better usability remain vague, uncertain, and unconvincing to the management. In order to build better usability cost-benefit models and minimize the potential that the models have unforeseen inherent risks, as outlined in this thesis, researchers should focus strongly on bringing forward the possible benefits of usability instead of focusing on the costs of designing and implementing user interfaces that would be realized in any case, regardless of the usability activities. Third, the thesis identifies the parallels and differences between open source software development and closed source software development in order to identify how usability costs and benefits fit into OSS development. The usability costs and benefits specific to OSS development are reflected in the experiences of bringing usability into the OSS development context. The results indicate that it is possible to fit usability cost-benefit considerations into the OSS development context, even though there are no apparent financial or resource factors to be considered. Furthermore, to fit usability cost-benefit considerations into the OSS development context, the philosophy, principles, hierarchical structure, community structure, and characteristics of OSS development must be considered. Usability cost-benefit considerations that fit into the OSS development context might help convince core developers that usability activities are important and should be integrated into the project roadmap. / Tiivistelmä Väitöskirjassa tutkitaan käytettävyyden kustannus-hyöty -analyysin soveltamista kaupalliseen ja avoimen lähdekoodin ohjelmistojen (OSS) ohjelmistokehitykseen. Tutkimuksessa tarkastellaan ensin käytettävyyden kustannus-hyöty -analyysimallien eroja ja yhteisiä piirteitä. Tulokset osoittavat käytettävyyden kustannus-hyöty -analyysimalleissa olevan huomattavia eroja siinä, miten eri käytettävyyden kustannuksia ja hyötyjä on tunnistettu. Toiseksi tutkimuksessa tarkastellaan miten hyvin nykyiset käytettävyyden kustannus-hyöty -analyysimallit sopivat käytännössä kaupallisten ohjelmistojen kehittämisessä. Tulokset osoittavat, että on olemassa huomattavia epäonnistumisen riskejä käytettäessä käytettävyyden kustannus-hyötynäkökohtia käytettävyystoimien oikeuttamiseen. Käytettävyyden kustannukset voivat tulla yrityksen johdon näkökulmasta konkreettisiksi ja mitattaviksi, kun taas mahdolliset paremman käytettävyyden hyödyt voivat jäädä epämääräisiksi, epävarmoiksi ja epäuskottaviksi. Parempien käytettävyyden kustannus-hyöty –mallien kehittämiseksi ja odottamattomien riskien minimoimiseksi mallien suunnittelussa tulisi keskittyä erityisesti paremman käytettävyyden tuomiin mahdollisiin etuihin, koska osa kustannuksista toteutuisi joka tapauksessa käytettävyystoimista riippumatta. Kolmanneksi tutkimuksessa tarkastellaan eroja ja yhtäläisyyksiä avoimen lähdekoodin ohjelmistojen kehittämisessä ja kaupallisessa suljetun lähdekoodin ohjelmistojen kehittämisessä, sekä miten käytettävyyden kustannukset ja hyödyt soveltuvat OSS kehityksessä käytettävyystoimien oikeuttamiseen. Käytettävyyden kustannuksia ja hyötyjä OSS -kehityksessä heijastetaan suhteessa kokemuksiin käytettävyystoimista OSS -projekteissa. Tulokset osoittavat, että on mahdollista soveltaa käytettävyyden kustannus-hyöty -näkökulmia OSS kehityksessä, vaikka OSS kehityksessä ei olekaan ilmeisiä huomioitavia taloudellisia tai resurssitekijöitä. Käytettävyyden kustannus-hyöty -näkökulmien soveltaminen OSS kehityksessä edellyttää OSS kehityksen filosofian, periaatteiden, hierarkkisen rakenteen, yhteisön rakenteen sekä OSS kehityksen ominaispiirteiden ottamista huomioon. OSS -kehitykseen paremmin soveltuvien käytettävyyden kustannus-hyöty –näkökulmien avulla voidaan vakuuttaa OSS -projektin pääkehittäjiä ja yhteisöä käytettävyystoimien tärkeydestä ja nämä toimet voidaan saada osaksi projektin ohjelmistokehitystä.