Context. The effective generation of test data is regarded as very important in the software testing. However, mature and effective techniques for generating string test data have seldom been explored due to the complexity and flexibility in the expression form of the string comparing to other data types. Objectives. Based on this problem, this study is to investigate strengths and limitations of existing string test data generation techniques to support future work for exploring an effective technique to generate string test data. This main goal was achieved via two objectives. First is investigating existing techniques for string test data generation; as well as finding out criteria and Classes-Under-Test (CUTs) used for evaluating the ability of string test generation. Second is to assess representative techniques through comparing effectiveness and efficiency. Methods. For the first objective, we used a systematic mapping study to collect data about existing techniques, criteria, and CUTs. With respect to the second objective, a comparison study was conducted to compare representative techniques selected from the results of systematic mapping study. The data from comparison study was analysed in a quantitative way by using statistical methods. Results. The existing techniques, criteria and CUTs which are related to string test generation were identified. A multidimensional categorisation was proposed to classify existing string test data generation techniques. We selected representative techniques from the search-based method, symbolic execution method, and random generation method of categorisation. Meanwhile, corresponding automated test generation tools including EvoSuite, Symbolic PathFinder (SPF), and Randoop, which achieved representative techniques, were selected to assess through comparing effectiveness and efficiency when applied to 21 CUTs. Conclusions. We concluded that: search-based method has the highest effectiveness and efficiency in three selected solution methods; random generation method has a low efficiency, but has a high fault-detecting ability for some specific CUTs; symbolic execution solution achieved by SPF cannot support string test generation well currently due to possibly incomplete string constraint solver or string generator.

Context: Software startups are newly created companies with no operating history and are extremely fast in producing cutting-edge technologies. These companies develop software un- der highly uncertain conditions, tackling fast growing markets with severe lack of resources. Startups present an unique combination of characteristics which pose several challenges to the software development activities, creating interesting problems for software engineers. However, despite the increasing economical importance and the high failure rate, there are only a few sci- entific studies attempting to address software engineering (SE) issues, especially for early-stages startups. In a context where a wrong decision can easily lead the entire business to failure, the support of SE can contribute to foster performances of startups and making a big impact on a large number of companies. Objective: In view of a lack of primary studies, the first step to attending the software development strategies with scientific and engineering approaches is by an understanding of the startups’ behavior. For this reason this research aims to understand how software development strategies are engineered by practitioners, in the period of time that goes from idea conception to the first open beta release of the software product. Methods: This research combines a systematic review of the state-of-the-art with a cross- sectional case study conducted in 13 web startups recently founded and distributed in di↵erent geographic areas and market sectors. A grounded theory approach guided the execution of a sys- tematic mapping study, integrated with semi-structured interviews and follow-up questionnaires to explore the state-of-practice. Results: We selected, classified and evaluated 37 relevant studies. The systematic review revealed that the studies which constitute the body of knowledge are generally not rigorously designed and executed, make use of inconsistent terminology, and cover only small samples of startups. Moreover, we extrapolated concepts from the case study to form a theoretical model, explaining the underlying phenomenon of software development in early-stage startups. The model is grounded in the empirical data and its explanatory power was further validated through a systematic procedure. Finally we proposed a multi-faceted evolutionary model to describe the dynamics of the software development after the first product release. Conclusions: The research provided a wide set of evidences fostering the understanding of how software development is structured and executed, from idea conception to the first release. The results revealed the urgent priority of startups of releasing the product as quickly as possi- ble to verify the product/market fit and to adjust the business and product trajectory according to the early collected user feedbacks. Nevertheless, the initial gain obtained in speeding-up the development by low-precision and product-centric engineering activities is counterbalanced by the need of restructuring the product and the workflows before setting o↵ for further grow. In fact, when user requests and company’s size start to increase startups face an initial and temporary drop-down in productivity, creating the need of mitigation strategies to find a sweet spot between being fast enough to enter the market early while controlling the amount of accu- mulated technical debt. The conclusions can be generalized with a good degree of confidence to the majority of early-stage software startups involved in the production of innovative products, especially for web and mobile applications.

Developing and maintaining software is a difficult task, and finding effective methods of understanding software is more necessary now than ever with the last few decades seeing a dramatic climb in the scale of software. Appropriate visualisations may enable greater understanding of the datasets we deal with in software engineering. As an aid for sense-making, visualisation is widely used in daily life (through graphics such as weather maps and road signs), as well as in other research domains, and is thought to be exceedingly beneficial. Unfortunately, there has not been widespread use of the multitude of techniques which have proposed for the software engineering domain. Tag clouds are a simple, text-based visualisation commonly found on the internet. Typically, implementations of tag clouds have not included rich interactive features which are necessary for data exploration. In this thesis, I introduce design considerations and a task set for enabling interaction in a tag cloud visualisation system. These considerations are based on an analysis of challenges in visualising software engineering data, and the perceptive influences of visual properties available in tag clouds. The design and implementation of interactive system Taggle based on these considerations is also presented, along with its broad-based evaluation. Evaluation approaches were informed by a systematic mapping study of previous tag cloud evaluation, providing an overview of existing research in the domain. The design of Taggle was improved following a heuristic evaluation by domain experts. Subsequent evaluations were divided into two parts - experiments focused on the tag cloud visualisation technique itself, and a task-based approach focused on the whole interactive system. As evidenced in the series of evaluative studies, the enhanced tag cloud features incorporated into Taggle enabled faster visual search response time, and the system could be used with minimal training to discover relevant information about an unknown software engineering dataset.

Developing and maintaining software is a difficult task, and finding effective methods of understanding software is more necessary now than ever with the last few decades seeing a dramatic climb in the scale of software. Appropriate visualisations may enable greater understanding of the datasets we deal with in software engineering. As an aid for sense-making, visualisation is widely used in daily life (through graphics such as weather maps and road signs), as well as in other research domains, and is thought to be exceedingly beneficial. Unfortunately, there has not been widespread use of the multitude of techniques which have proposed for the software engineering domain. Tag clouds are a simple, text-based visualisation commonly found on the internet. Typically, implementations of tag clouds have not included rich interactive features which are necessary for data exploration. In this thesis, I introduce design considerations and a task set for enabling interaction in a tag cloud visualisation system. These considerations are based on an analysis of challenges in visualising software engineering data, and the perceptive influences of visual properties available in tag clouds. The design and implementation of interactive system Taggle based on these considerations is also presented, along with its broad-based evaluation. Evaluation approaches were informed by a systematic mapping study of previous tag cloud evaluation, providing an overview of existing research in the domain. The design of Taggle was improved following a heuristic evaluation by domain experts. Subsequent evaluations were divided into two parts - experiments focused on the tag cloud visualisation technique itself, and a task-based approach focused on the whole interactive system. As evidenced in the series of evaluative studies, the enhanced tag cloud features incorporated into Taggle enabled faster visual search response time, and the system could be used with minimal training to discover relevant information about an unknown software engineering dataset.

Muslim groups in Karlstad are rarely visible online. There is also no previous research about them. Through an interview-based mapping study, I want to research what activities take place in Muslim mosques in Karlstad. The aim of the study is to document and analyze Muslim activities. This study is included in a research project at Karlstad University: Karlstad’s mosque - negotiations on Islam in Värmland. It aims to illuminate Islam’s development in Värmland from various aspects. Religious change and religion collision are theoretical starting points for the study. The results of this study show that three congregations are active in Karlstad: Islamiska Kulturföreningen [sunni], Bosniska Islamiska Kulturföreningen [sunni] and Mahdi Al Montazar [shia]. They established their congregations since 1990s. They are dependent on their main organizations and do not cooperate with other Muslim associations. Members of the congregation are very important for the organization’s existence. The result indicates that the religious activities of groups are not affected by data-based communication. Different branches work for their own community and have different views about Islam. In a Christian society, these Muslim congregations try to adapt to the rules of majority society in different ways. They find new ways to practise their religion. Minority groups want to preserve their own cultural and religious traditions through the mosque building or association board. It will be a way to be included and recognized by the majority.

As software engineering is a socio-technical research field, there is a myriad of research strategies and data sources that researchers need to consider when designing their studies. These choices determine different tradeoffs in terms of generalizability, realism, and control, among other aspects of research quality. It is not possible to create a perfect study, so these strengths and weaknesses are acceptable at the study level; however, when a research community's collective body of work suffers from an imbalance in these tradeoffs it can negatively impact overall research quality. Through this thesis, I investigate the research strategies and data sources that are used by the software engineering research community, and reflect on how this may affect aspects of research quality in our collective body of work. I apply Runkel and McGrath's models of research strategies and data sources to the software engineering domain through a systematic mapping study of three years of International Conference on Software Engineering (ICSE) proceedings and a mixed-methods survey of the authors of these papers. I found that a majority of papers report computational studies relying on trace measures rather than active human participation, showing an imbalance where generalizability and realism are prioritized over control. Through my survey, I confirmed that researcher participants explicitly prioritized realism and generalizability over control, impacting their research design choices. This imbalance in prioritization has the potential to lead to a collective failure to control for extraneous factors in the measurement of human behavior in software development, and without understanding what causes the behaviors we measure, we cannot fully understand why certain approaches and techniques work better than others, thus slowing our ability to advance as a research domain. Therefore, I present a call to action for the community to critically examine and discuss the issues raised by this research, and implement changes to increase the quality and diversity of our future work as a community. / Graduate / 2019-08-08

[pt] Contexto: Embora o desenvolvimento de software seja uma atividade humana, a pesquisa em Engenharia de Software (ES) concentra-se principalmente em processos e ferramentas, esquecendo-se dos fatores humanos por trás. Ainda quando explorados, os pesquisadores não tem adotado adequadamente referencial da psicologia para entender melhor os fatores humanos em ES, bem como dos instrumentos psicométricos, que visam medir algum tipo de fator humano. Objetivo: Nosso objetivo é apresentar uma visão geral e reflexões sobre o uso dos instrumentos psicométricos na pesquisa da ES em relação a personalidade. Método: Foi realizado um mapeamento sistemático da literatura para gerar um catálogo dos instrumentos psicométricos utilizados. Resultados: Esta dissertação contribui com a atualização de um estudo secundário existente para cobrir cinquenta anos de pesquisa em ES (de 1970 a 2020). Observamos discrepâncias remanescentes entre um dos instrumentos mais popularmente adotado (MBTI) e as recomendações existentes na literatura sobre o seu uso. Conclusão: A adoção de instrumentos psicométricos relativos a personalidade em ES precisa ser aprimorada. Trabalhos futuros nos direcionam a analisar a literatura mapeada sob a ótica de especialistas e pesquisadores das ciências sociais. / [en] Context: Although software development is an inherently human activity, research in Software Engineering (SE) has focused mostly on processes and tools, thus failing to recall the human factors behind it. Even when explored, researchers typically do not properly use the psychological background to understand better human factors in SE, such as the psychometric instruments, which aim to measure human factors. Objective: Our goal is to present an overview and reflections on psychometric instruments in SE research regarding personality. Method: We conducted a systematic mapping of the literature to generate a catalog of the psychometric instruments used. Results: This dissertation contributes with an update of an existing secondary study to cover fifty years of SE research (1970 to 2020). We observed remaining discrepancies between one of the most popular adoption instruments (MBTI) and existing recommendations in the literature on the use of this instrument. Conclusion: The findings lead us to conclude that the adoption of psychometric instruments regarding personality in SE needs to be improved. Future work directs us to analyze the mapped literature under the lens of social science specialists and researchers.

Modern automotive systems increasingly depend on camera sensors to gather safetycriticaldata used in driver-assisting features of the system. These features can consist offor example, lane-keeping assist and automatic braking where the sensors register objectswithin certain distances. When these camera sensors gather information, the time of theimage is critical for the calculation of speeds, distances, and size of any potential registeredobject in the frame. Limitations of bandwidth and computing in such vehicles creates aneed to use special cameras that do not capture the whole image simultaneously but insteadcapture the images piecewise. These cameras are called rolling shutter cameras. Thisputs pressure on defining when an image was captured when different parts of the imagewere captured at different points in time. For this thesis, this point in time is defined as thechronological middle point in between the camera starting to capture an image and when ithas collected the final part of it. This thesis performs a mapping-study to evaluate methodsto verify the timestamp of an image generated from rolling shutter cameras. Further, thisthesis proposes a new method using multiple digital clocks and presents its performanceusing a proof-of-concept implementation to prove the method’s ability to accurately representtime with sub-millisecond accuracy.

Submitted by PPG Ci?ncia da Computa??o (ppgcc@pucrs.br) on 2017-12-11T16:00:35Z No. of bitstreams: 1 Gianlucca_Oliveira_Puglia_dis.pdf: 2043630 bytes, checksum: f7fc70f33d1d15b56eded8458fbed2fa (MD5) / Approved for entry into archive by Tatiana Lopes (tatiana.lopes@pucrs.br) on 2017-12-18T11:25:26Z (GMT) No. of bitstreams: 1 Gianlucca_Oliveira_Puglia_dis.pdf: 2043630 bytes, checksum: f7fc70f33d1d15b56eded8458fbed2fa (MD5) / Made available in DSpace on 2017-12-18T11:49:55Z (GMT). No. of bitstreams: 1 Gianlucca_Oliveira_Puglia_dis.pdf: 2043630 bytes, checksum: f7fc70f33d1d15b56eded8458fbed2fa (MD5) Previous issue date: 2017-03-21 / As tecnologias de mem?rias n?o-vol?teis s?o uma grande promessa na ?rea de arquitetura de computadores e ? esperado que sejam poderosas ferramentas para solucionar os problemas referentes a manipula??o eficiente de dados dos dias de hoje. Estas tecnologias prov?m alta performance e acesso em granularidade de bytes com a distinta vantagem de serem persistentes. Por?m, afim de explorar estas tecnologias em todo seu potencial, os sistemas e arquiteturas de hoje precisam buscar meios de se adaptar a esta nova forma de acessar dados e de superar os desafios que v?m com ela.Trabalhos existentes na ?rea j? prop?em m?todos para adaptar as arquiteturas existentes para o uso de NVM bem como formas inovadoras de empregar estas mem?rias em futuras aplica??es. No entanto, o suporte dos sistemas operacionais a estas solu??es, ainda que existente, ainda ? muito limitado. Neste trabalho, n?s apresentamos duas varia??es da chamada de sistema msync, modeladas para explorar as caracter?sticas das tecnologias de NVM e garantir consist?ncia para os dados dos usu?rios. Ambas s?o solu??es simples que permitem aos usu?rios definirem checkpoints de seus arquivos usando a sintaxe comum de sistemas de arquivos. N?s implementamos e testamos estes m?todos sobre o sistema operacional Linux utilizando como base um sistema de arquivo nativamente voltado a NVM. Nossos resultados mostram que estes mecanismos s?o capazes de garantir a integridade dos arquivos mesmo na presen?a de falhas no sistema enquanto mant?m uma performance razo?vel. / Upcoming non-volatile memory technologies are a big promise in computer architecture and are expected to be powerful tools to address today?s issues regarding efficient data manipulation. They provide high performance and byte granularity while also having the distinct advantage of being persistent. However in order to explore these technologies to their full potential, existing systems and architecture must adapt to this new way of working with data and workaround the challenges that come with it. Existing work in the area already proposes methods to adapt existing architecture to NVM as well as innovative ways to employ these memories in future applications. However operating system support to such NVM-enabled solutions, although existent, still very limited. In this work, we present two variations of the existing mmap system call, designed to both explore NVM characteristics and provide user data consistency. Both are very simple solutions that allow users to control the persistence and define checkpoints to their files while using the common mapped file syntax. We have implemented and tested these methods over Linux using a NVM file system as our base. Our results show that these mechanisms can ensure file integrity in the presence of system failures while also providing a reasonable performance.

Nowadays, autonomous driving revolution is getting closer to reality. To achieve the Autonomous driving the first step is to develop the Advanced Driver Assistance System (ADAS). Driver-assistance systems are one of the fastest-growing segments in automotive electronics since already there are many forms of ADAS available. To investigate state of art of development of ADAS towards Autonomous Driving, we develop Systematic Mapping Study (SMS). SMS methodology is used to collect, classify, and analyze the relevant publications. A classification is introduced based on the developments carried out in ADAS towards Autonomous driving. According to SMS methodology, we identified 894 relevant publications about ADAS and its developmental journey toward Autonomous Driving completed from 2012 to 2016. We classify the area of our research under three classifications: technical classifications, research types and research contributions. The related publications are classified under thirty-three technical classifications. This thesis sheds light on a better understanding of the achievements and shortcomings in this area. By evaluating collected results, we answer our seven research questions. The result specifies that most of the publications belong to the Models and Solution Proposal from the research type and contribution. The least number of the publications belong to the Automated…Autonomous driving from the technical classification which indicated the lack of publications in this area.