Software product lines and variability modeling : A tertiary study

Context: A software product line is a means to develop a set of products in which variability is a central phenomenon captured in variability models. The field of SPLs and variability have been topics of extensive research over the few past decades. Objective: This research characterizes systematic reviews (SRs) in the field, studies how SRs analyze and use evidence-based results, and identifies how variability is modeled. Method: We conducted a tertiary study as a form of systematic review. Results: 86 SRs were included. SRs have become a widely adopted methodology covering the field broadly otherwise except for variability realization. Numerous variability models exist that cover different development artifacts, but the evidence is insufficient in quantity and immature, and we argue for better evidence. SRs perform well in searching and selecting studies and presenting data. However, their analysis and use of the quality of and evidence in the primary studies often remains shallow, merely presenting of what kinds of evidence exist. Conclusions: There is a need for actionable, context-sensitive, and evaluated solutions rather than novel ones. Different kinds of SRs (SLRs and Maps) need to be better distinguished, and evidence and quality need to be better used in the resulting syntheses. (C) 2019 The Authors. Published by Elsevier Inc.Context: A software product line is a means to develop a set of products in which variability is a central phenomenon captured in variability models. The field of SPLs and variability have been topics of extensive research over the few past decades. Objective: This research characterizes systematic reviews (SRs) in the field, studies how SRs analyze and use evidence-based results, and identifies how variability is modeled. Method: We conducted a tertiary study as a form of systematic review. Results: 86 SRs were included. SRs have become a widely adopted methodology covering the field broadly otherwise except for variability realization. Numerous variability models exist that cover different development artifacts, but the evidence is insufficient in quantity and immature, and we argue for better evidence. SRs perform well in searching and selecting studies and presenting data. However, their analysis and use of the quality of and evidence in the primary studies often remains shallow, merely presenting of what kinds of evidence exist. Conclusions: There is a need for actionable, context-sensitive, and evaluated solutions rather than novel ones. Different kinds of SRs (SLRs and Maps) need to be better distinguished, and evidence and quality need to be better used in the resulting syntheses. (C) 2019 The Authors. Published by Elsevier Inc.Context: A software product line is a means to develop a set of products in which variability is a central phenomenon captured in variability models. The field of SPLs and variability have been topics of extensive research over the few past decades. Objective: This research characterizes systematic reviews (SRs) in the field, studies how SRs analyze and use evidence-based results, and identifies how variability is modeled. Method: We conducted a tertiary study as a form of systematic review. Results: 86 SRs were included. SRs have become a widely adopted methodology covering the field broadly otherwise except for variability realization. Numerous variability models exist that cover different development artifacts, but the evidence is insufficient in quantity and immature, and we argue for better evidence. SRs perform well in searching and selecting studies and presenting data. However, their analysis and use of the quality of and evidence in the primary studies often remains shallow, merely presenting of what kinds of evidence exist. Conclusions: There is a need for actionable, context-sensitive, and evaluated solutions rather than novel ones. Different kinds of SRs (SLRs and Maps) need to be better distinguished, and evidence and quality need to be better used in the resulting syntheses. (C) 2019 The Authors. Published by Elsevier Inc.Peer reviewe

Representing Variability in Software Architecture

Software Architecture is a high level description of a software intensive system that enables architects to have a better intellectual control over the complete system. It is also used as a communication vehicle among the various system stakeholders. Variability in software-intensive systems is the ability of a software artefact (e.g., a system, subsystem, or component) to be extended, customised, or configured for deployment in a specific context. Although variability in software architecture is recognised as a challenge in multiple domains, there has been no formal consensus on how variability should be captured or represented. In this research, we addressed the problem of representing variability in software architecture through a three phase approach. First, we examined existing literature using the Systematic Literature Review (SLR) methodology, which helped us identify the gaps and challenges within the current body of knowledge. Equipped with the findings from the SLR, a set of design principles have been formulated that are used to introduce variability management capabilities to an existing Architecture Description Language (ADL). The chosen ADL was developed within our research group (ALI) and to which we have had complete access. Finally, we evaluated the new version of the ADL produced using two distinct case studies: one from the Information Systems domain, an Asset Management System (AMS); and another from the embedded systems domain, a Wheel Brake System (WBS). This thesis presents the main findings from the three phases of the research work, including a comprehensive study of the state-of-the-art; the complete specification of an ADL that is focused on managing variability; and the lessons learnt from the evaluation work of two distinct real-life case studies

Do you eat 'pasta' for dessert and 'tender' your clothes? A comparison of cross-language activation in Turkish and Spanish learners of English

Màster de Lingüística Aplicada i Adquisició de Llengües en Contextos Multilingües, Departament de Llengües i Literatures Modernes i d'Estudis Anglesos, Universitat de Barcelona. Curs: 2021-2022. Tutor: Joan Carles Mora Bonilla[eng] The present study investigates whether L1 Turkish and L1 Spanish learners of English experience cross-language activation when recognising words that share spelling but differ in meaning across languages, i.e., interlingual homographs (IHs). Two primed lexical decision tasks in English were employed to examine if primes semantically related to the target IH’s L1 meaning – e.g., arena (sand in Spanish) preceded by beach – would entail shorter reaction times. Additionally, this study examines if typological differences between participants’ L1 (Turkish or Spanish) and L2 (English) influence L2 word recognition, a rather understudied relationship. Results from both experiments revealed dual-language activation, as participants recognised interlingual homographs significantly slower than control words. However, no significant differences were found between the Turkish and Spanish group, thus, language typology did not have a significant effect on L2 visual word recognition. Moreover, no cross-language semantic priming effects were found, as IHs were processed slower than control words, which did not hold a semantic relationship with their primes. Importantly, the results from this study support the language-non-selective hypothesis, i.e., the notion that L2 word recognition entails co-activation of languages, even in monolingual settings

Technologies for climate change adaptation: agricultural sector

This Guidebook presents a selection of technologies for climate change adaptation in the agricultural sector. A set of twenty two adaptation technologies are showcased that are primarily based on the principals of agroecology, but also include scientific technologies of climate and biological sciences complemented with important sociological and institutional capacity building processes that are required to make adaptation function. The technologies cover monitoring and forecasting the climate, sustainable water use and management, soil management, sustainable crop management, seed conservation, sustainable forest management and sustainable livestock management. Technologies that tend to homogenize the natural environment and agricultural production have low possibilities of success in conditions of environmental stress that are likely to result from climate change. On the other hand, technologies that allow for, and indeed promote, diversity are more likely to provide a strategy which strengthens agricultural production in the face of uncertain future climate change scenarios. In this sense, the twenty two technologies showcased in this Guidebook have been selected because they facilitate the conservation and restoration of diversity while at the same time providing opportunities for increasing agricultural productivity. Many of these technologies are not new to agricultural production practices, but they are implemented based on assessment of current and possible future impacts of climate change in a particular location. Agro-ecology is an approach that encompasses concepts of sustainable production and biodiversity promotion and therefore provides a useful framework for identifying and selecting appropriate adaptation technologies for the agricultural sector. The Guidebook provides a systematic analysis of the most relevant information available on climate change adaptation technologies in the agriculture sector. It has been compiled based on a literature review of key publications, journal articles, and e-platforms, and by drawing on documented experiences sourced from a range of organizations working on projects and programmes concerned with climate change adaptation technologies in the agricultural sector. Its geographic scope is focused on developing countries where high levels of poverty, agricultural production, climate variability and biological diversity currently intersect. Key concepts around climate change adaptation are not universally agreed. It is therefore important to understand local contexts – especially social and cultural norms - when working with national and sub-national stakeholders to make informed decisions about appropriate technology options. Thus, decision-making processes should be participative, facilitated, and consensus-building oriented and should be based on the following key guiding principles: increasing awareness and knowledge, strengthening institutions, protecting natural resources, providing financial assistance and developing context-specific strategies. For decision-making the Community–Based Adaptation framework is proposed for creating inclusive governance that engages a range of stakeholders directly with local or district government and national coordinating bodies, and facilitates participatory planning, monitoring and implementation of adaptation activities. Seven criteria are suggested for the prioritization of adaptation technologies: (i) The extent to which the technology maintains or strengthens biological diversity and is environmentally sustainable; (ii) The extent to which the technology facilitates access to information systems and awareness of climate change information; (iii) Whether the technology support water, carbon and nutrient cycles and enables stable and/or increased productivity; (iv) Income-generating potential, cost-benefit analysis and contribution to improved equity; (v) Respect for cultural diversity and facilitation of inter-cultural exchange; (vi) Potential for integration into regional and national policies and can be scaled-up; (vii) The extent to which the technology builds formal and information institutions and social networks. Finally, recommendations are set out for practitioners and policy makers: • There is an urgent need for improved climate modelling and forecasting which can provide a basis for informed decision-making and the implementation of adaptation strategies. This should include traditional knowledge. • Information is also required to better understand the behaviour of plants, animals, pests and diseases as they react to climate change. • Potential changes in economic and social systems in the future under different climate scenarios should also be investigated so that the implications of adaptation strategy and planning choices are better understood. • It is important to secure effective flows of information through appropriate dissemination channels. This is vital for building adaptive capacity and decision-making processes. • Improved analysis of adaptation technologies is required to show how they can contribute to building adaptive capacity and resilience in the agricultural sector. This information needs to be compiled and disseminated for a range of stakeholders from local to national level. • Relationships between policy makers, researchers and communities should be built so that technologies and planning processes are developed in partnership, responding to producers’ needs and integrating their knowledge

Adaptation autonomique d'applications pervasives dirigée par les architectures

The autonomic adaptation of software application is becoming increasingly important in many domains, including pervasive field. Indeed, the integration fo different application resources (physical devices, services and third party applications) often needs to be dynamic and should adapt rapidly and automatically to changes in the execution context. To that end, service-oriented components offer support for adaptation at the architectural level. However, they do not allow the formalisation of all the design constraints that must be guaranteed during the execution of the system. To overcome this limitation, this thesis modeled the design, deployment and runtime architectures. Also, it proposes to establish links between them and has developed algorithms to check the validity of an execution architecture with respect to its architectural design. This led us to consider the entire life cycle of components and to define a set of concepts to be included in architectures supporting variability. This formalisation can be exploited both by a human administrator and by an autonomic manager that has its knowledge base increased and structured. The implementation resulted in the realization of a knowledge base, providing a studio (Cilia IDE) for the design, deployment and supervision of dynamic applications, as well as an autonomic manager that can update the structure of pervasive applications. This thesis has been validated using a pervasive application called “Actimetry”, developed in the FUI~MEDICAL project.La problématique d'adaptation autonomique prend de plus en plus d'importance dans l'administration des applications modernes, notamment pervasives. En effet, la composition entre les différentes ressources de l'application (dispositifs physiques, services et applications tierces) doit souvent être dynamique, et s'adapter automatiquement et rapidement aux évolutions du contexte d'exécution. Pour cela, les composants orientés services offrent un support à l'adaptation au niveau architectural. Cependant, ils ne permettent pas d'exprimer l'ensemble des contraintes de conception qui doivent être garanties lors de l'exécution du système. Pour lever cette limite, cette thèse a modélisé les architectures de conception, de déploiement et de l'exécution. De plus, elle a établi des liens entre celle-ci et proposé des algorithmes afin de vérifier la validité d'une architecture de l'exécution par rapport à son architecture de conception. Cela nous a conduits à considérer de près le cycle de vie des composants et à définir un ensemble de concepts afin de les faire participer à des architectures supportant la variabilité. Notons que cette formalisation peut être exploitée aussi bien par un administrateur humain, que par un gestionnaire autonomique qui voit ainsi sa base de connaissances augmentée et structurée. L'implantation a donné lieu à la réalisation d'une base de connaissance, mise à disposition d'un atelier (Cilia IDE) de conception, déploiement et supervision d'applications dynamiques, ainsi que d'un gestionnaire autonomique capable de modifier la structure d'une application pervasive. Cette thèse a été validée à l'aide d'une application pervasive nommée >, développée dans le cadre du projet FUI~MEDICAL

Bilişim paylaşımı ile gerçek zamanlı üretim planlama ve kontrol sistemi tasarımı

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Dijital teknolojilerin yaygınlaşması ve hayatın her alanına girmesi ihtiyaçların bireysel kapsamda ele alınmasını sağlamış, rekabeti kişiye özgü çözüm ve ürün üretme boyutuna taşımıştır. Buna bağlı olarak, üretim sistemlerinin gelişimi de çeşitliliği artırmaya ve yönetmeye yönelik olarak devam etmektedir. Bu gelişim ve dönüşüm süreci temel taşlarından birisi kitlesel özelleştime (mass - customization) olan dördüncü sanayi devrimi (Endüstri 4.0) olarak adlandırılmıştır. Dünyanın Endüstri 4.0'a ayak uydurabilmesi için üretim ortamında çeşitliliği ve çeşitliliğe bağlı olarak meydana gelecek değişkenliği yönetebilmesi gerekmektedir. Üretim ortamında, değişkenliğin yönetilebilmesi için geliştirilen yöntemler değişkenlikleri stok tutarak veya zaman toleransları ile çalışarak yönetmektedirler. Bu durum verimliliğin azalmasına ve birim başına düşen sabit maliyetin artmasına neden olmaktadır. Çalışmada, klasik yaklaşımların olumsuz yönlerinen arındırılmış bir üretim planlama yaklaşımı ve modeli önerilmiştir. Önerilen modelin değişkenliklerden etkilenmemesi için model değişken olan miktar parametresi yerine, değişkenliklerden daha az etkilenecek olan zaman parametresi üzerine kurulmuştur. Modelde stok seviyesi yerine stoğun tükenmesine kalan süreye dikkat edilmekte, çizelgeleme sürecinde de üretimin tamamlanmasına kalan süreye ve termin tarihine göre önceliklendirme yapılmaktadır. Model zaman hedeflerine bağlı çalığtığından gerçek zamanlı bir modeldir. Üretim modeli nin gerçek zamanlı olması değişkenliklerden, miktar tabanlı yaklaşıma göre, çok az etkilenmesini sağlamıştır. Yapılan kıyaslama çalışmalarıyla gerçek zamanlı planlama sisteminin üretim ortamındaki değişkenliklerden etkilenmediği ve emniyet stoksuz ortamda, gecikmeleri azaltarak üretimin tamamlanmasını sağladığı ortaya konmuştur. Üstelik bu çıktılar O(n) zaman karmaşıklığına sahip, kısa sürede, sonlanan algoritmalarla elde edilmiştir. Modelin uygulanması algoritmik olarak kolay olsa da, gerçek zamanlı olduğundan, gerçek zamanlı olarak belirlenen işlem döngüsü içerisinde güncel stok ve üretim verisine ihtiyaç duyulmaktadır. Bu veriler Endüstri 4.0 teknolojileriyle elde edilebilen veriler olduğundan, gerçek zamanlı üretim modeli modern üretim sistemlerinde uygulanabilir bir modeldir. Modelin üretim sistemine katkısı, sistemi aynı anda hem itme hem de çekme sistemi gibi çalıştırabilmesidir. Bu sayede üretim sistemi iki biçimde de çalışabilmektedir. Verimli olan stretejiye dinamik olarak geçmek de stok maliyetinin %90'dan fazla azalmasını sağlamıştır.Spread of digital technology in every slice of life provides that the needs have been addressed within the individual scope and also it increases competition to the level of both individual solution and personal production. Accordingly, the development of production systems continues to enhance for managing the diversity. One of the milestones of this development and transformation process is mass customization called the fourth industrial revolution, Industry4.0. Enterprises should be able to overcome with the diversity and variability due to diversity in the production environment in order to keep pace with Industry 4.0. The methods improved in attempt to cope with variability in the production, are keeping inventory or working with time tolerances. In this case, efficiency decreases and overhead cost per unit increases in. A novel production planning approach and a model which is eliminated from negative aspect of conventional methods has been proposed, in this study. The proposed model is based on a time parameter less affected by the variances rather than the quantity in order to avoid being influenced by the changes. The remaining time to stock-out instead of inventory level is taken into account in this model, and prioritization is proceed according to the time remaining to complete the production and due date in the scheduling process. Thus, the model based on a time parameter is a real-time model. Being real-time provides, the model, to be affected from variances less than quantity based methods. It is presented that the real-time model is not affected by the variances in the manufacturing environment, and provides completing manufacturing process with less delays by using no safety stock. Besides, an algorithm having O(n) time complexity provides this result. Though the application of model is easy as algorithmically, the model, being real-time, requires the live inventory and production data within the determined time cycle. Because the data can be gained by the cyber-physical technologies of Industry 4.0, real-time model can be applied to modern production systems. The contribution of this model to production systems is that the model assimilates manufacturing systems as pull or push system at the same time. Selecting the productive strategy dynamically enables the decrease of more than 90% inventory cost

Quality of service differentiation for multimedia delivery in wireless LANs

Delivering multimedia content to heterogeneous devices over a variable networking environment while maintaining high quality levels involves many technical challenges. The research reported in this thesis presents a solution for Quality of Service (QoS)-based service differentiation when delivering multimedia content over the wireless LANs. This thesis has three major contributions outlined below: 1. A Model-based Bandwidth Estimation algorithm (MBE), which estimates the available bandwidth based on novel TCP and UDP throughput models over IEEE 802.11 WLANs. MBE has been modelled, implemented, and tested through simulations and real life testing. In comparison with other bandwidth estimation techniques, MBE shows better performance in terms of error rate, overhead, and loss. 2. An intelligent Prioritized Adaptive Scheme (iPAS), which provides QoS service differentiation for multimedia delivery in wireless networks. iPAS assigns dynamic priorities to various streams and determines their bandwidth share by employing a probabilistic approach-which makes use of stereotypes. The total bandwidth to be allocated is estimated using MBE. The priority level of individual stream is variable and dependent on stream-related characteristics and delivery QoS parameters. iPAS can be deployed seamlessly over the original IEEE 802.11 protocols and can be included in the IEEE 802.21 framework in order to optimize the control signal communication. iPAS has been modelled, implemented, and evaluated via simulations. The results demonstrate that iPAS achieves better performance than the equal channel access mechanism over IEEE 802.11 DCF and a service differentiation scheme on top of IEEE 802.11e EDCA, in terms of fairness, throughput, delay, loss, and estimated PSNR. Additionally, both objective and subjective video quality assessment have been performed using a prototype system. 3. A QoS-based Downlink/Uplink Fairness Scheme, which uses the stereotypes-based structure to balance the QoS parameters (i.e. throughput, delay, and loss) between downlink and uplink VoIP traffic. The proposed scheme has been modelled and tested through simulations. The results show that, in comparison with other downlink/uplink fairness-oriented solutions, the proposed scheme performs better in terms of VoIP capacity and fairness level between downlink and uplink traffic