Rozprawy doktorskie na temat „Collaborative programming”

Software systems are getting larger and more complex, while the requirements are becoming vaguer and more rapidly changing. These trends make current software development more and more likely a team work. To integrate multiple developers into a coherent structured management process and make team software development a positive-sum game for both higher productivity and better quality, many team soft ware development methodologies have been proposed and practised. An emerging methodology is collaborative programming, which allows a group of programmers to work together on the same source code for design, implementation of individual components, and integration of individual components. Compared with other team software methodologies that only address needs in some phases or situations, collaborative programming is more adaptive to the variety of different phases or situations in a team software development process. A core technical component in collaborative programming is collaborative editing, which allows a group of programmers to view and edit the same source code. To support different phases or situations in an Internet-based collaborative programming process, collaborative editing must meet the requirements of supporting unconstrained, responsive, real-time collaborative editing; unconstrained, syncretic, non-real-time collaborative editing; and smooth, flexible switching between real-time and non-real-time collaborative editing. This thesis research contributes several novel techniques to address these requirements, and an Internet-based collaborative programming environment to integrate those techniques. These research contributions have advanced state-of-the-art technologies on col laborative editing for supporting Internet-based collaborative programming. First, we contribute a collaborative highlighting gestural communication technique for unconstrained, responsive, real-time collaborative editing. This technique is particularly effective in improving the quality of real-time interaction on text-based source code documents. The contribution to the operational transformation technology is the extension of the technology to support group awareness. It includes a package of operational transformation functions and transformation control algorithms for consistency maintenance in collaborative highlighting, and a flexible undo solution that has the capability of undoing any highlighting operation at any time. Second, we contribute a flexible operation-based merging technique for unconstrained, syncretic, non-real-time collaborative editing, which is efficient and has the capability of textually integrating all changes, and automatically detecting and resolving syntactic conflicts according to application-dependent user-specified policies. The contribution to the operational transformation technology is the extension of the technology to support unconstrained, syncretic, non-real-time collaborative editing. Its includes a log compression algorithm, a textual merging algorithm, and a syntactic merging algorithm. Moreover, we contribute a flexible notification technique to support flexible collaborative editing: unconstrained, responsive, real-time collaborative editing; uncon strained, syncretic, non-real-time collaborative editing; and smooth, flexible switching between them. The contribution to the operational transformation technology is the extension of the technology to support flexible collaborative editing. It includes a new transformation control algorithm that has a linear time complexity, two notification algorithms that support propagation and acceptance of any notifications at any time, and a notification propagation protocol that is efficient for both real-time and non-real-time collaborative editing.

Software systems are getting larger and more complex, while the requirements are becoming vaguer and more rapidly changing. These trends make current software development more and more likely a team work. To integrate multiple developers into a coherent structured management process and make team software development a positive-sum game for both higher productivity and better quality, many team soft ware development methodologies have been proposed and practised. An emerging methodology is collaborative programming, which allows a group of programmers to work together on the same source code for design, implementation of individual components, and integration of individual components. Compared with other team software methodologies that only address needs in some phases or situations, collaborative programming is more adaptive to the variety of different phases or situations in a team software development process. A core technical component in collaborative programming is collaborative editing, which allows a group of programmers to view and edit the same source code. To support different phases or situations in an Internet-based collaborative programming process, collaborative editing must meet the requirements of supporting unconstrained, responsive, real-time collaborative editing; unconstrained, syncretic, non-real-time collaborative editing; and smooth, flexible switching between real-time and non-real-time collaborative editing. This thesis research contributes several novel techniques to address these requirements, and an Internet-based collaborative programming environment to integrate those techniques. These research contributions have advanced state-of-the-art technologies on col laborative editing for supporting Internet-based collaborative programming. First, we contribute a collaborative highlighting gestural communication technique for unconstrained, responsive, real-time collaborative editing. This technique is particularly effective in improving the quality of real-time interaction on text-based source code documents. The contribution to the operational transformation technology is the extension of the technology to support group awareness. It includes a package of operational transformation functions and transformation control algorithms for consistency maintenance in collaborative highlighting, and a flexible undo solution that has the capability of undoing any highlighting operation at any time. Second, we contribute a flexible operation-based merging technique for unconstrained, syncretic, non-real-time collaborative editing, which is efficient and has the capability of textually integrating all changes, and automatically detecting and resolving syntactic conflicts according to application-dependent user-specified policies. The contribution to the operational transformation technology is the extension of the technology to support unconstrained, syncretic, non-real-time collaborative editing. Its includes a log compression algorithm, a textual merging algorithm, and a syntactic merging algorithm. Moreover, we contribute a flexible notification technique to support flexible collaborative editing: unconstrained, responsive, real-time collaborative editing; uncon strained, syncretic, non-real-time collaborative editing; and smooth, flexible switching between them. The contribution to the operational transformation technology is the extension of the technology to support flexible collaborative editing. It includes a new transformation control algorithm that has a linear time complexity, two notification algorithms that support propagation and acceptance of any notifications at any time, and a notification propagation protocol that is efficient for both real-time and non-real-time collaborative editing.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Computing and Information Technology
Full Text

Users who can program computers can use their computer more effectively than those who can not. While much research has examined how to help users easily program computers, two methods that show promise have not yet been thoroughly investigated in the context of children's programming environments. The first method provides users with multiple representations of a computer program. Providing multiple representations lets users choose a representation close to their own mental model of computer programming and helps them transfer their knowledge from one domain to another. The second method provides support for collaboration. When users collaborate they build a shared understanding of a computer program and they can learn from teachers and more competent peers. This thesis presents an investigation into these two methods: collaborative and multiple-notation programming environments for children. Our target users are children aged eight to twelve years. The contributions described in this thesis are: providing an analysis of how programming environments use different representations of computer programs; describing two evaluations (one of collaboration and one of multiple notations), and introducing our programming environment, Mulspren. The analysis describes three cognitive gulfs that can create problems for users when programming and identifies eight factors related to notation use that risk creating these gulfs. The first evaluation finds that children can read and understand a conventional-style notation faster than an English-like notation, but that they prefer the English-like notation. The second evaluation finds that the type of collaboration support present in a collaborative environment does not reliably affect how well children learn to solve a puzzle. The analysis and two evaluations influenced the design of our programming environment: Mulspren. Mulspren users can interact with two different notations at the same time, and can move between the notations seamlessly. We call this programming style 'dual notation programming.'

Extreme programming is an agile software development process, which has gained a lot of publicity the last couple of years. It has also brought Pair Programming into new light. Research and experiments have shown that the usage of Pair Programming can increase the quality in software development. People who used Pair Programming are usually satisfied using it and they are also more confident in their solutions. Having a pair colleague is not redundancy, people bring the best out of each other and they produce better solutions. Wages for employees are today heavy costs for companies but quality and time aspects in software development become more and more important. A quantitative survey has been conducted among professionals and students, both with and without Pair Programming experience. People surveyed have very low resistance from the start when using Pair Programming. They actually find benefits from it compared to being singles, but they think it should not be used on every task and at every time. This report investigates if Pair Programming is a technique to increase quality and productivity within software development. We also address business related aspects compared to the usage of Pair Programming as well as management aspects to see if we can find other synergy effects from the use of Pair Programming.
Denna rapport undersöker om Parprogrammering är en teknik för att höja kvalitén och produktiviteten inom mjukvaruutvecklingen. Vi belyser även relaterade areor och jämför dessa med Parprogrammering för att se om vi kan finna synergieffekter från användandet av Parprogrammering. Vi har gjort en undersökning både bland professionella och studenter, både med och utan Parprogrammeringserfarenhet. De som svarat har väldigt lågt motstånd till att använda Parprogrammering. De anser att det finns fördelar med att använda Parprogrammering jämfört med att arbeta själv, men de anser att tekniken inte kan användas hela tiden på alla delmoment.
Nöjesv 6 294 77 Sölvesborg 0708-422240

In this project a collaboration multimedia toolkit, JSCMT (Java Synchronized Collaborative Multimedia Toolkit) was developed which is intended to connect a group of people located in different geographical locations who are working on the same project.

This thesis documents the creation of a family literacy program developed with, and for, a Haida community on the Northwest Coast of British Columbia. The field of family literacy is juxtaposed with the historical and contemporary school experiences of the community and presented as a means of addressing the imbalance between Indigenous and Western knowledge systems currently offered through the public education system. Both Indigenous and Western research methods are utilized through a process designed to involve the community in the reconstruction of an already-existing community family literacy program, PALS (Parents as Literacy Supporters). The metaphor of a circle, representing the six Haida values of interconnectedness, seeking wise counsel, reciprocity, balance, respect, and responsibility, is used to guide the research in addition to serving as the foundation for a new, culturally responsive, version of PALS.

The purpose of this investigation was to examine the effects of collaborative learning strategies on formulating solutions to linear programming word problems that were designed to incorporate problem-solving skills. Forty-six students majoring in business at a small southwest college in Virginia participated in the study. After an instruction session, a study period, and a question and answer discussion, participants completed the test instrument based upon random assignment to three treatment groups. These included individual study with individual test taking (control), paired study with individual test taking, and paired study with paired test taking. All participants returned in 17 days to complete a posttest individually having received no further instruction in linear programming theory. The following null hypothesis was examined: No differences in treatment means measuring problem-solving abilities would be found based on students' test and posttest scores using two treatment groups of collaborative study, with collaborative or individual test taking, and a control group of individual study with individual test taking. After satisfying the assumptions of no difference in ability in the treatment groups, establishing significant influence of ability on test score and posttest score variables, and establishing homogeneity of regression, an analysis of covariance (ANCOVA) was used to test the null hypothesis. The null hypothesis was rejected. Treatment had a significant effect on the variance for the test score variable, F = 3.92, p < .05, and for the posttest score variable, F = 4.44, p < .05. Newman-Keuls post hoc test showed significant differences in the adjusted means of the test score variable between the individual study with individual test taking group (72.22) and the paired study with paired test taking group (87.86). For the posttest score variable, the Newman-Keuls post hoc test revealed significant differences between the adjusted means of the individual study with individual test taking group (36.25) and the paired study with individual test taking group (59.20), and between the adjusted means of the individual study with individual test taking group (36.25) and the paired study with paired test taking group (55.77). Implications of findings and recommendations for further research were discussed.
Ph. D.

Business team collaboration in the future will increasingly take place in an environment where everything is potentially distributed. Traditional group support systems have been LAN-based and have not ported easily to distributed, Internet-based products. Rather, distributed group support systems require new architectures if they are to support the same type of real-time, high-collaboration environments that traditional systems have. This dissertation describes the development of a server architecture and programming model to support the rapid application development of real-time, distributed, and collaborative applications. Since the efficiency, robustness, and scalability of these applications are handled by the server, complex applications can be developed in very short production cycles. Background literature presented in the dissertation includes a taxonomy of distributed networking and data sharing methods, models of dialog independence, and messaging methods. Many different prototype and real systems are presented, analyzed, and compared with the Collaborative Server in this dissertation. The Systems Development methodology is applied to this research domain. A prototype system-the “Collaborative Server”-is developed, including a unique data persistence and replication scheme based upon a central Property object. Properties are created in hierarchical trees to form the “scaffolding” for collaborative applications. Each Property governs a single value, or datum, and controls the access, replication, security, viewing, locking, and persistence of its value. Properties are layered with predefined or custom child indices. A new systems development methodology, based upon the Waterfall method but tailored for the Collaborative Server, is presented. The efficiency and effectiveness of this methodology is analyzed using a simulated example and two case studies. The research contribution of this dissertation is the Collaborative Server. The basis of this server is the Property concept, including the methodology changes it effects, the efficiencies and application stability it produces, and the specialized messaging system it allows. Required programmer knowledge is significantly reduced when applications are built upon the Collaborative Server. In addition, the presented examples and case studies show significant decreases in code size and in time-to-market for their respective applications.

Programming practices are used to improve various attributes of the coding process. Pair and Mob Programming are two practices that involve multiple developers collaboratively working on the same tasks and share multiple advantages and disadvantages. The aim of this project is to identify common advantages and disadvantages of the two practices as well as some attributes that differentiate the two and help in the process of deciding which programming practice should be used for a task. The first method used to answer the research questions was a literature review that should find and list the pros and cons of Mob and Pair Programming. A second method used were interviews with industry practitioners, whose perspectives and experiences will validate the previous results, add new attributes to the practices and identify differences and factors that encourage the use of one or the other practice. The findings of the project consist of positive and negative aspects of using any of the two programming practices and a set of attributes that should be considered when deciding whether to adopt Mob or Pair Programming for the task at hand.

Pendant très longtemps, l'automatisation a été assujettie à l'usage de robots industriels traditionnels placés dans des cages et programmés pour répéter des tâches plus ou moins complexes au maximum de leur vitesse et de leur précision. Cette automatisation, dite rigide, possède deux inconvénients majeurs : elle est chronophage dû aux contraintes contextuelles applicatives et proscrit la présence humaine. Il existe désormais une nouvelle génération de robots avec des systèmes moins encombrants, peu coûteux et plus flexibles. De par leur structure et leurs modes de fonctionnement ils sont intrinsèquement sûrs ce qui leurs permettent de travailler main dans la main avec les humains. Dans ces nouveaux espaces de travail collaboratifs, l'homme peut être inclus dans la boucle comme un agent décisionnel actif. En tant qu'instructeur ou collaborateur il peut influencer le processus décisionnel du robot : on parle de robots collaboratifs (ou cobots). Dans ce nouveau contexte, nous faisons usage de guides virtuels. Ils permettent aux cobots de soulager les efforts physiques et la charge cognitive des opérateurs. Cependant, la définition d'un guide virtuel nécessite souvent une expertise et une modélisation précise de la tâche. Cela restreint leur utilité aux scénarios à contraintes fixes. Pour palier ce problème et améliorer la flexibilité de la programmation du guide virtuel, cette thèse présente une nouvelle approche par démonstration : nous faisons usage de l'apprentissage kinesthésique de façon itérative et construisons le guide virtuel avec une spline 6D. Grâce à cette approche, l'opérateur peut modifier itérativement les guides tout en gardant leur assistance. Cela permet de rendre le processus plus intuitif et naturel ainsi que de réduire la pénibilité. La modification locale d'un guide virtuel en trajectoire est possible par interaction physique avec le robot. L'utilisateur peut déplacer un point clé cartésien ou modifier une portion entière du guide avec une nouvelle démonstration partielle. Nous avons également étendu notre approche aux guides virtuels 6D, où les splines en déplacement sont définies via une interpolation Akima (pour la translation) et une 'interpolation quadratique des quaternions (pour l'orientation). L'opérateur peut initialement définir un guide virtuel en trajectoire, puis utiliser l'assistance en translation pour ne se concentrer que sur la démonstration de l'orientation. Nous avons appliqué notre approche dans deux scénarios industriels utilisant un cobot. Nous avons ainsi démontré l'intérêt de notre méthode qui améliore le confort de l'opérateur lors de la comanipulation
For a very long time, automation was driven by the use of traditional industrial robots placed in cages, programmed to repeat more or less complex tasks at their highest speed and with maximum accuracy. This robot-oriented solution is heavily dependent on hard automation which requires pre-specified fixtures and time consuming programming, hindering robots from becoming flexible and versatile tools. These robots have evolved towards a new generation of small, inexpensive, inherently safe and flexible systems that work hand in hand with humans. In these new collaborative workspaces the human can be included in the loop as an active agent. As a teacher and as a co-worker he can influence the decision-making process of the robot. In this context, virtual guides are an important tool used to assist the human worker by reducing physical effort and cognitive overload during tasks accomplishment. However, the construction of virtual guides often requires expert knowledge and modeling of the task. These limitations restrict the usefulness of virtual guides to scenarios with unchanging constraints. To overcome these challenges and enhance the flexibility of virtual guides programming, this thesis presents a novel approach that allows the worker to create virtual guides by demonstration through an iterative method based on kinesthetic teaching and displacement splines. Thanks to this approach, the worker is able to iteratively modify the guides while being assisted by them, making the process more intuitive and natural while reducing its painfulness. Our approach allows local refinement of virtual guiding trajectories through physical interaction with the robots. We can modify a specific cartesian keypoint of the guide or re- demonstrate a portion. We also extended our approach to 6D virtual guides, where displacement splines are defined via Akima interpolation (for translation) and quadratic interpolation of quaternions (for orientation). The worker can initially define a virtual guiding trajectory and then use the assistance in translation to only concentrate on defining the orientation along the path. We demonstrated that these innovations provide a novel and intuitive solution to increase the human's comfort during human-robot comanipulation in two industrial scenarios with a collaborative robot (cobot)

A growing number of enterprise applications on the Internet ranging from banking transactions to business management make use of real-time collaboration. Simultaneous access from any device to any set of applications shared among many users is a hot area of research and development. This thesis designed a thick-client for real-time collaboration supporting the applications development and interoperability. It introduces a new programming paradigm, algorithms and protocols to bring real-time collaboration to a web-based platform. Its component-oriented metamorphic architecture supports a run-time scalable multi-desktop environment connecting client applications through automated remote procedure call and the object request broker pattern while providing new mechanisms for dynamic resource loading. The new architecture supports unsolicited server control actions on the client using an event model to simulate interruptions and sustained user-activity during network failure. Results obtained validate the correctness of the approach and the feasibility of an extensible web-based platform for real-time collaboration.

The primary purpose of this study was to examine the perceptions of southern Alberta nurse educators regarding the concept of collaborative programming as one way of working towards baccalaureate entry into nursing practice (EP 2000). Specifically, answers to the following questions were sought: 1. To what extent do nurse educators support the EP 2000 mandate, and why do they hold these views? 2. To what extent do nurse educators support the concept of collaborative programming, and why do they hold these views? 3. What programming alternatives do nurse educators perceive as desirable for working towards baccalaureate entry to practice? 4. What are the perceived barriers and facilitators to developing a collaborative program? 5. What factors may influence a nurse educator's perception of collaborative programming? A questionnaire was developed and distributed to 112 full-time nurse educators in four dimploma nursing programs (DNP) and two baccalaureate nursing programs (BNP) in southern Alberta. Completed returns numbered 74 (66%). Descriptive statistics, content analysis and the Chi Square statistical test were used to analyze the data. Lewin's (1951) force field theory was used as a guide in inteerpretation of the data findings. The major findings of the study were as follows: 1. Generally, nurse-faculty perceived the system of nursing education to be inadequate in meeting the health care needs of society; in providing for education and career mobility; and in the kind and amount of communication between its educational components. 2. A majority of BNP and DNP faculty support the EP 2000 mandate. Each group identified the need to upgrade professional standards and educational requirements to better serve society (consumers, patients, hospitals, marketplace demands and the profession) and better meet the increased intellectual, technical and judgemental demands required by the expanded roles in nursing practice. 3. A majority of the BNP and DNP faculty support the development of collaborative baccalaureate programsprovi for reasons ranging from professional benefits to pragmatic and economic aspects. However, there were a number of ambiguities and contradictions in the participants' responses. 4. Restricted provincial funds, lack of government support for EP 2000, concerns regarding the academic qualifications of diploma faculty to deliver university transfer courses, the need to protect existing program territoriality, and difficulties in mobilizing inter-institutional processes were perceived as barriers influencing the development of collaborative programs. The EP 2000 position statements, the increased student demands for baccalaureate education, and a desire to retain the strengths and resources of diploma education were preceived as facilitators. 5. The participants' type of employing institution affected certain perceptions of collaborative programming and the baccalaureate as entry to nursing practice. It was concluded that less overt resistance to collaborative programming was found than might have been predicted, given the slow movement in the province toward planned collaboration. The base seems to exist for a concerted, organized, regional effort in this direction, provided that serious attention is paid to the issues identified by the respondents. Finally, the data provide a foundation for developing on educational process and action steps to enhance progress toward collaboration as one option for facilitating EP 2000. Recommendations were presented for nursing education and future research.
xi, 138 leaves ; 28 cm

A new generation of industrial robots have been growing in numbers in the past years. These are called collaborative robots and instead of replacing an operator to perform a job task, this robot works in collaboration with the operator. ABB's most recent robot is a collaborative, dual arm, small part, assembly robot called YuMi. The programming of industrial robots is complex and requires a professional with a high level of expertise and several years of experience to perform. ABB currently investigate how to make the programming of YuMi easier for operators with limited previous programming knowledge. To support ABB in their work, the goal of this thesis is to create a concept for a highly usable interactive device aimed for programming the workflow of a collaborative robot. To reach the goal, a literature review and a case study have been conducted. The literature review reveals previous attempts in making industrial robot programming easier and insights about what have been successful. During the case study, experts working with YuMi and potential future operators were interviewed and the outcome of the case study is a prototype of a tablet device interface. The method used in the case study is a User-Centered Design process called Focused Rapid Contextual Design.

Mob programming is a collaborative software development method that has gained increasing attention in both industry and research. While the focus of mob programming is on the benefits of teams programming together, there are also potential benefits for other aspects of the software development process. However, there is a lack of research on the use of the method outside the domain of programming. This study explores user-centred design (UCD) in mob programming through a case study of three software development teams at Sveriges Television, a Swedish public broadcasting company. Results show that the teams use the method for a variety of tasks in their daily work, calling for a rebranding of the method to mob development to encompass the broader scope. The integration of UCD is analysed through the principles of user-centred agile software development. The results indicate that a revision of these principles is needed to include the cross-functional and social factors that mob development adds to the software development process.

Students struggle with learning to program. In recent years, not only has there been a dramatic drop in the number of students enrolling in IT and Computer Science courses, but attrition from these courses continues to be significant. Introductory programming subjects traditionally have high failure rates and as they tend to be core to IT and Computer Science courses can be a road block for many students to their university studies. Is programming really that difficult — or are there other barriers to learning that have a serious and detrimental effect on student progression? In-class experiments were conducted in introductory programming units to confirm our hypothesis that that pair-programming would benefit students' learning to program. We investigated the social and cultural barriers to learning programming by questioning students' perceptions of confidence, difficulty and enjoyment of programming. The results of paired and non-paired students were compared to determine the effect of pair-programming on learning outcomes. Both the empirical and anecdotal results of our experiments strongly supported our hypothesis.

This thesis explores the benefits of using Building Information Modeling (BIM) during the programming and conceptual design phase of a project. The research was based on a case study undertaken dealing with the decisions and assumptions made during the design phases of the Center for Science at Cal Poly San Luis Obispo. The project team used a traditional approach to project plan development. The finding of this study was that the project process would have greatly benefited utilizing BIM tools and a collaborative team approach in the programming and conceptual design phase. Because decisions made early in the project have enormous implications to aesthetics and cost, the increase in analysis of design options afforded by the use of BIM tools would have minimized inaccurate, incomplete and unreliable information, and allowed the design team to work in a more efficient, collaborative manner transmitting through all phases of the project.

Dans la collaboration entre transporteurs, plusieurs transporteurs forment une alliance pour échanger leurs demandes de transport dans le but d'améliorer la rentabilité. Dans cette thèse, nous avons étudié la planification collaborative de transport entre transporteurs de charges partielles. Plus concrètement, nous avons étudié trois sous-problèmes soulevés dans cette planification collaborative: le problème de ramassage et de livraison avec fenêtres de temps, profits et demandes réservées, le problème de détermination de gagnants dans l'échange combinatoire, et le problème de génération d'enchère.Ces trois sous-problèmes sont les problèmes clés pour la planification collaborative de transport parmi des transporteurs, et ils sont peu étudiés dans la littérature. Nous avons établi les nouveaux modèles de programmation mathématique pour ces problèmes et développé des heuristiques efficaces pour trouver des solutions très proches de leurs optimums dans un temps de calcul raisonnable. Les heuristiques proposées sont plus performantes que les solveurs commerciaux (GUROBI, CPLEX) non seulement en termes de la qualité de solution, mais aussi en termes du temps de calcul
In carrier collaboration, multiple carriers form an alliance to exchange their delivery requests for the purpose of improving profitability. In this thesis, we have studied the collaborative transportation planning (CTP) among less-than-truckload (LTL) carriers. More concretely, we have studied three sub-problems raised in this collaborative planning: the pickup and delivery problem with time windows, profits, and reserved requests (PDPTWPR), the winner determination problem (WDP) in carrier collaboration via combinatorial exchange (CE), and the bid generation problem (BGP).These sub-problems are the key issues for collaborative transportation planning among carriers, and they are rarely studied in the literature. We have established new mathematical programming models for these problems and developed efficient heuristics to find solutions close to their optimums in a reasonable computational time. The heuristics proposed are more efficient than commercial solvers (GUROBI, CPLEX) not only in terms of solution quality, but also in terms of computation time

This study investigated the students&rsquo
perceptions about the web-based learning environment in the blended learning environment in terms of web-based instruction, online collaborative learning and the online instructor. The study tried to show the contributions of the web-based instruction in traditional face-to-face instruction. In this case study, Programming Languages II Course (CEIT211), a undergraduate course at Computer Education and Instructional Technology Department (CEIT), at Middle East Technical University, at the 2002-2003 Spring semester, was delivered as blended learning with a new web site. Totally 65 subjects, 2nd year CEIT students, attended the course in the term and participated to the study. The course was delivered via traditional face-to-face instruction and supported with the web site. At the end of the semester, three questionnaires were administrated in order to understand the students&rsquo
perceptions about web-based learning environment in terms of web-based instruction, online collaborative learning and online instructor. The time spent on the web site and the numbers of messages posted to forum were other data sources in this study. The data were statistically analyzed. The quantitative data showed that the students&rsquo
perceptions about web-based instruction and online instructor were positive, but online collaborative learning perceptions are about neutral. Beside the research questions, some design considerations in the blended learning case were presented. The study results may be used in evaluation of the blended learning environment for the instructor and for the department, may show a direction in the future design of the course.

As unmanned vehicle capabilities have matured, the design and development of autonomous collaborative Systems-of-Systems (SoS) has gained increased attention. This has been motivated by the indication that significant improvements in overall effectiveness may be possible by employing many systems in cooperation with one another. However, as the potential combinations of vehicles, subsystems, and operational concepts becomes increasingly large, a systematic approach is needed for designing and analyzing alternatives. Furthermore, the discrete nature of the problem can cause variations in effectiveness that are counter-intuitive, such as a point of diminishing returns as the number of systems grows. Systems-of-systems are hierarchical in nature, consisting of top-level mission requirements that are decomposed into system- and subsystem-level performance measures. The overarching research objectives of this dissertation are to show that the analysis of alternatives should be performed at varying levels of the SoS hierarchy and to provide novel means for performing those analyses. In particular, it has been postulated that a formulation built on an energy-based approach to multi-level analysis of SoS components will enable more accurate and transparent subsystem and system trade-offs. Various steps of the design process are established and argued for or against, and significant focus is placed on the analysis of alternatives. The foundation of the new method is laid on structured SoS engineering principles. The full substance comes together by incorporating unique aspects developed within this dissertation. A new virtual experimentation approach is presented for creating sensor performance representations that are functions of vehicle operations. The sonar equation is used as a baseline sensor model for comparison against the new virtual experimentation method. Dozens of forward-looking and side-scan sonar experiments are designed, and data is provided to show the extent to which typical sensor modeling over-predicts performance without vehicle operations considered. In addition, comparisons are made between possible representations of vehicle performance. An underwater vehicle sizing and synthesis process is developed to enable comparisons between system-level component modeling approaches. The experiments attest to significant gaps in accuracy when performing sensor and operational trade-offs without energy-based modeling of the collaborative vehicles. Finally, a heuristic path-planning algorithm is formulated, and mixed-integer linear programming is used to choose between alternative SoS designs. The developed method is demonstrated through a representative example problem: a group of unmanned underwater vehicles (UUVs) operating in a collaborative fashion to search for underwater objects. The example scenario provides an application for illustrating the phenomenon discussed in regards to the analysis of alternatives of collaborative SoS. The significance of providing more or less analytic detail is traced and the effect on mission requirements is quantified. Counter-intuitive results are highlighted, such as the observation that the increased energy required for systems to effectively collaborate can often out-weigh the benefits gained in overall mission effectiveness.

Un système de systèmes est un système dont les composants sont eux-mêmes des systèmes indépendants, tous communiquant pour atteindre un objectif commun. Lorsque ces systèmes sont mobiles, il peut être difficile d'établir des connexions de bout-en-bout. L'architecture mise en place dans de telles situations est appelée réseau tolérant aux délais. Les données sont transmises d'un système à l'autre – selon les opportunités de communication, appelées contacts, qui apparaissent lorsque deux systèmes sont proches – et disséminées dans l'ensemble du réseau avec l'espoir que chaque message atteigne sa destination. Si une donnée est trop volumineuse, elle est découpée. Chaque fragment est alors transmis séparément.Nous supposons ici que la séquence des contacts est connue. On s'intéresse donc à des applications où la mobilité des systèmes est prédictible (les réseaux de satellites par exemple). Nous cherchons à exploiter cette connaissance pour acheminer efficacement des informations depuis leurs sources jusqu'à leurs destinataires. Nous devons répondre à la question : « Quels éléments de données doivent être transférés lors de chaque contact pour minimiser le temps de dissémination » ?Nous formalisons tout d'abord ce problème, appelé problème de dissémination, et montrons qu'il est NP-difficile au sens fort. Nous proposons ensuite des algorithmes pour le résoudre. Ces derniers reposent sur des règles de dominance, des procédures de prétraitement, la programmation linéaire en nombres entiers, et la programmation par contraintes. Une partie est dédiée à la recherche de solutions robustes. Enfin, nous rapportons des résultats numériques montrant l'efficacité de nos algorithmes
Systems of systems are supersystems comprising elements which are themselves independent operational systems, all interacting to achieve a common goal. When the subsystems are mobile, these may suffer from a lack of continuous end-to-end connectivity. To address the technical issues in such networks, the common approach is termed delay-tolerant networking. Routing relies on a store-forward mechanism. Data are sent from one system to another – depending on the communication opportunities, termed contacts, that arise when two systems are close – and stored throughout the network in hope that all messages will reach their destination. If data are too large, these must be split. Each fragment is then transmitted separately.In this work, we assume that the sequence of contacts is known. Thus, we focus on applications where it is possible to make realistic predictions about system mobility (e.g. satellite networks). We study the problem of making the best use of knowledge about possibilities for communication when data need to be routed from a set of systems to another within a given time horizon. The fundamental question is: "Which elements of the information should be transferred during each contact so that the dissemination length is minimized"?We first formalize the so-called dissemination problem, and prove this is strongly NP-Hard. We then propose algorithms to solve it. These relies on different dominance rules, preprocessing procedures, integer-linear programming, and constraint programming. A chapter is dedicated to the search for robust solutions. Finally experimental results are reported to show the efficiency of our algorithms in practice

Metacognition in collaborative learning settings is an emerging topic in research on metacognition. This study focused on the development of metacognitive skills during pair programming in order to enhance knowledge productivity. Pair programming entails collaboration between two programmers, each fulfilling a specific role during the execution of the programming task, and has recently been used in educational contexts as a teaching and learning strategy to improve learning in computer programming (DeClue, 2003:49; Preston, 2006b:16). In this study the outcomes of collaborative learning during pair programming are referred to as knowledge productivity, which is measured against the criteria of enhanced knowledge construction, enhanced problem-solving skills, conceptual changes in individual perspectives, commitment to work with the other member of the pair, and application of the results of the learning process (Tillema & Van der Westhuizen, 2006:51,55). To investigate the influence of a metacognitive teaching and learning approach to pair programming on knowledge productivity, a repeated-measures experiment with a control group was conducted among a number of Grade 11 learners who had been implementing pair programming in the learning of Information Technology at secondary school level. At the beginning of the study both groups completed two questionnaires, one on metacognition and the other on knowledge productivity. At the same stage, a number of randomly selected participants from each group were interviewed on the same two topics, using a semi-structured interview approach. This procedure was repeated three months later, without any intervention. During the intervention phase, the experimental group implemented a set of self-directed metacognitive questions that they had to answer while doing a pair programming task. These self-directed metacognitive questions form part of a metacognitive teaching and learning strategy suggested by the researcher. The members of the experimental group also kept a journal to describe how the self-directed questions directed their thinking during the execution of the pair programming task. At the end of the experimental period, the mo questionnaires on metacognition and knowledge productivity were completed by both groups again, supported by the interviews of the same selected participants. The results derived from the empirical study showed that the knowledge productivity of learners programming in pairs can be enhanced by implementing a metacognitive teaching and learning strategy. The metacognitive teaching and learning strategy implemented during this study was then adapted to make it suitable for use by teachers and learners during pair programming.
Thesis (Ph.D. (Education)--North-West University, Potchefstroom Campus, 2010.

We develop a detailed, large-scale, airspace planning and collaborative decision-making model (APCDM), that is part of an $11.5B, 10-year, Federal Aviation Administration (FAA)-sponsored effort to increase U.S. National Airspace (NAS) capacity by 30 percent. Given a set of flights that must be scheduled during some planning horizon, we use a mixed-integer programming formulation to select a set of flight plans from among alternatives subject to flight safety, air traffic control workload, and airline equity constraints. Novel contributions of this research include three-dimensional probabilistic conflict analyses, the derivation of valid inequalities to tighten the conflict safety representation constraints, the development of workload metrics based on average (and its variance from) peak load measures, and the consideration of equity among airline carriers in absorbing the costs related to re-routing, delays, and cancellations. We also propose an improved set of flight plan cost factors for representing system costs and investigating fairness issues by addressing flight dependencies occurring in hubbed operations, as well as market factors such as schedule convenience, reliability, and the timeliness of connections. The APCDM model has potential use for both tactical and strategic applications, such as air traffic control in response to severe weather phenomenon or spacecraft launches, FAA policy evaluation, Homeland Defense contingency planning, and military air campaign planning. The model is tested to consider various airspace restriction scenarios imposed by dynamic severe weather systems and space launch Special Use Airspace (SUA) impositions. The results from this model can also serve to augment the FAAâ s National Playbook of standardized flight profiles in different disruption-prone regions of the National Airspace.
Ph. D.

This project extended COLLDESIGN, an interactive collaborative modeling tool that was developed by Mr. Hara Totapally. The initial version included a collaborative framework comprised of configurable client and server components. This project accomplished a complete implementation of the Class Diagram view. In addition, extending the framework, text messaging and audio conferencing features have been implemented to allow for real-time textual and audio communication between team members working on a particular project. VideoClient is the GUI of the application.

Les réseaux de capteurs sans fil est une technologie nouvelle dont les applications s'étendent sur plusieurs domaines: militaire, scientifique, médicale, industriel, etc. La collaboration entre les noeuds capteurs, caractérisés par des capacités minimales en termes de capture, de transmission, de traitement et d'énergie, est une nécessité pour réaliser des tâches aussi complexes que la collecte des données, le pistage des objets mobiles, la surveillance des zones sensibles, etc. La contrainte matérielle sur le développement des ressources énergétiques des noeuds capteurs est persistante. D'où la nécessité de l'optimisation logicielle dans les différentes couches de la pile protocolaire et du système d'exploitation des noeuds. Dans cette thèse, nous approchons le problème d'optimisation d'énergie pour les applications collaboratives via les méthodes de sélection des capteurs basées sur la prédiction et la corrélation des données issues du réseau lui-même. Nous élaborons plusieurs méthodes pour conserver les ressources énergétiques du réseau en utilisant la prédiction comme un moyen pour anticiper les actions des noeuds et leurs rôles afin de minimiser le nombre des noeuds impliqués dans la tâche en question. Nous prenons l'application de pistage d'objets mobiles comme un cas d'étude. Ceci, après avoir dresser un état de l'art des différentes méthodes et approches récentes utilisées dans ce contexte. Nous formalisons le problème à l'aide d'un programme linéaire à variables binaires dans le but de trouver une solution générale exacte. Nous modélisons ainsi le problème de minimisation de la consommation d'énergie des réseaux de capteurs sans fil, déployé pour des applications de collecte de données soumis à la contrainte de précision de données, appelé EMDP. Nous montrons que ce problème est NP-Complet. D'où la nécessité de solutions heuristiques. Comme solution approchée, nous proposons un algorithme de clustering dynamique, appelé CORAD, qui adapte la topologie du réseau à la dynamique des données capturées afin d'optimiser la consommation d'énergie en exploitant la corrélation qui pourrait exister entre les noeuds. Toutes ces méthodes ont été implémentées et testées via des simulations afin de montrer leur efficacité
Wireless Sensor Networks is an emerging technology enabled by the recent advances in Micro-Electro-Mechanical Systems, that led to design tiny wireless sensor nodes characterized by small capacities of sensing, data processing and communication. To accomplish complex tasks such as target tracking, data collection and zone surveillance, these nodes need to collaborate between each others to overcome the lack of battery capacity. Since the development of the batteries hardware is very slow, the optimization effort should be inevitably focused on the software layers of the protocol stack of the nodes and their operating systems. In this thesis, we investigated the energy problem in the context of collaborative applications and proposed an approach based on node selection using predictions and data correlations, to meet the application requirements in terms of energy-efficiency and quality of data. First, we surveyed almost all the recent approaches proposed in the literature that treat the problem of energy-efficiency of prediction-based target tracking schemes, in order to extract the relevant recommendations. Next, we proposed a dynamic clustering protocol based on an enhanced version of the Distributed Kalman Filter used as a prediction algorithm, to design an energy-efficient target tracking scheme. Our proposed scheme use these predictions to anticipate the actions of the nodes and their roles to minimize their number in the tasks. Based on our findings issued from the simulation data, we generalized our approach to any data collection scheme that uses a geographic-based clustering algorithm. We formulated the problem of energy minimization under data precision constraints using a binary integer linear program to find its exact solution in the general context. We validated the model and proved some of its fundamental properties. Finally and given the complexity of the problem, we proposed and evaluated a heuristic solution consisting of a correlation-based adaptive clustering algorithm for data collection. We showed that, by relaxing some constraints of the problem, our heuristic solution achieves an acceptable level of energy-efficiency while preserving the quality of data

We develop and evaluate two significant modeling concepts within the context of a large-scale Airspace Planning and Collaborative Decision-Making Model (APCDM) and, thereby, enhance its current functionality in support of both strategic and tactical level flight assessments. The first major concept is a new severe weather-modeling paradigm that can be used to assess existing tactical en route flight plan strategies such as the Flight Management System (FMS) as well as to provide rerouting strategies. The second major concept concerns modeling the mediated bartering of slot exchanges involving airline trade offers for arrival/departure slots at an arrival airport that is affected by the Ground Delay Program (GDP), while simultaneously considering issues related to sector workloads, airspace conflicts, as well as overall equity concerns among the airlines. This research effort is part of an $11.5B, 10-year, Federal Aviation Administration (FAA)-sponsored program to increase the U.S. National Airspace (NAS) capacity by 30 percent by the year 2010. Our innovative contributions of this research with respect to the severe weather rerouting include (a) the concept of â Probability-Netsâ and the development of discretized representations of various weather phenomena that affect aviation operations; (b) the integration of readily accessible severe weather probabilities from existing weather forecast data provided by the National Weather Service (NWS); (c) the generation of flight plans that circumvent severe weather phenomena with specified probability levels, and (d) a probabilistic delay assessment methodology for evaluating planned flight routes that might encounter potentially disruptive weather along its trajectory. Given a fixed set of reporting stations from the CONUS Model Output Statistics (MOS), we begin by constructing weather-specific probability-nets that are dynamic with respect to time and space. Essential to the construction of the probability-nets are the point-by-point forecast probabilities associated with MOS reporting sites throughout the United States. Connections between the MOS reporting sites form the strands within the probability-nets, and are constructed based upon a user-defined adjacency threshold, which is defined as the maximum allowable great circle distance between any such pair of sites. When a flight plan traverses through a probability-net, we extract probability data corresponding to the points where the flight plan and the probability-net strand(s) intersect. The ability to quickly extract this trajectory-related probability data is critical to our weather-based rerouting concepts and the derived expected delay and related cost computations in support of the decision-making process. Next, we consider the superimposition of a flight-trajectory-grid network upon the probability-nets. Using the U.S. Navigational Aids (Navaids) as the network nodes, we develop an approach to generate flight plans that can circumvent severe weather phenomena with specified probability levels based on determining restricted, time-dependent shortest paths between the origin and destination airports. By generating alternative flight plans pertaining to specified threshold strand probabilities, we prescribe a methodology for computing appropriate expected weather delays and related disruption factors for inclusion within the APCDM model. We conclude our severe weather-modeling research by conducting an economic benefit analysis using a k-means clustering mechanism in concert with our delay assessment methodology in order to evaluate delay costs and system disruptions associated with variations in probability-net refinement-based information. As a flight passes through the probability-net(s), we can generate a probability-footprint that acts as a record of the strand intersections and the associated probabilities from origin to destination. A flight planâ s probability-footprint will differ for each level of data refinement, from whence we construct route-dependent scenarios and, subsequently, compute expected weather delay costs for each scenario for comparative purposes. Our second major contribution is the development of a novel slot-exchange modeling concept within the APCDM model that incorporates various practical issues pertaining to the Ground Delay Program (GDP), a principal feature in the FAAâ s adoption of the Collaborative Decision-Making (CDM) paradigm. The key ideas introduced here include innovative model formulations and several new equity concepts that examine the impact of â at-least, at-mostâ trade offers on the entire mix of resulting flight plans from respective origins to destinations, while focusing on achieving defined measures of â fairnessâ with respect to the selected slot exchanges. The idea is to permit airlines to barter assigned slots at airports affected by the Ground Delay Program to their mutual advantage, with the FAA acting as a mediator, while being cognizant of the overall effect of the resulting mix of flight plans on air traffic control sector workloads, collision risk and safety, and equity considerations. We start by developing two separate slot-exchange approaches. The first consists of an external approach in which we formulate a model for generating a set of package-deals, where each package-deal represents a potential slot-exchange solution. These package-deals are then embedded within the APCDM model. We further tighten the model representation using maximal clique cover-based cuts that relate to the joint compatibility among the individual package-deals. The second approach significantly improves the overall model efficiency by automatically generating package-deals as required within the APCDM model itself. The model output prescribes a set of equitable flight plans based on admissible trades and exchanges of assigned slots, which are in addition conformant with sector workload capabilities and conflict risk restrictions. The net reduction in passenger-minutes of delay for each airline is the primary metric used to assess and compare model solutions. Appropriate constraints are included in the model to ensure that the generated slot exchanges induce nonnegative values of this realized net reduction for each airline. In keeping with the spirit of the FAAâ s CDM initiative, we next propose four alternative equity methods that are predicated on different specified performance ratios and related efficiency functions. These four methods respectively address equity with respect to slot-exchange-related measures such as total average delay, net delay savings, proportion of acceptable moves, and suitable value function realizations. For our computational experiments, we constructed several scenarios using real data obtained from the FAA based on the Enhanced Traffic Management System (ETMS) flight information pertaining to the Miami and Jacksonville Air Route Traffic Control Centers (ARTCC). Through our experimentation, we provide insights into the effect of the different proposed modeling concepts and study the sensitivity with respect to certain key parameters. In particular, we compare the alternative proposed equity formulations by evaluating their corresponding slot-exchange solutions with respect to the net reduction in passenger-minutes of delay for each airline. Additionally, we evaluate and compare the computational-effort performance, under both time limits and optimality thresholds, for each equity method in order to assess the efficiency of the model. The four slot-exchange-based equity formulations, in conjunction with the internal slot-exchange mechanisms, demonstrate significant net savings in computational effort ranging from 25% to 86% over the original APCDM model equity formulation. The model has been implemented using Microsoft Visual C++ and evaluated using a C++ interface with CPLEX 9.0. The overall results indicate that the proposed modeling concepts offer viable tools that can be used by the FAA in a timely fashion for both tactical purposes, as well as for exploring various strategic issues such as air traffic control policy evaluations; dynamic airspace resectorization strategies as a function of severe weather probabilities; and flight plan generation in response to various disruption scenarios.
Ph. D.

L’étude de la planification entre partenaires coopérant au sein d’une chaine logistique au niveau tactique fait l’objet de cette thèse. Le présent travail se focalise plus particulièrement sur la coordination des processus de planification des activités de transport et de production, autour d’une nouvelle approche fondée sur la théorie des jeux. Deux situations de coopération sont considérées, selon le caractère homogène ou hétérogène des partenaires ; ainsi une première étude est menée sur un ensemble d’opérateurs de transport pour ensuite être étendue à la relation entre l’entreprise manufacturière et les transporteurs qui travaillent avec elle. L’expérimentation s’appuie sur des modèles mathématiques en programmation linéaire pour simuler les processus de planification des différents groupes de partenaires (également appelés coalitions), un protocole de coopération utilisant certaines propriétés liées à la théorie des jeux et sur une répartition équitable des gains / coûts telle que préconisée par la valeur de Shapley. Les modèles et l’ensemble du protocole sont appliqués à deux cas d’étude basés sur des jeux de données réalistes
This thesis focuses on the collaboration between partners inside supply chain at the tactical level of planning. This work aims to develop a new approach based on game theory to solve the problem of coordinating processes concerned by production and transportation planning decision making. Two types of coalitions cooperative games are implemented according to the nature of partners: the cooperation between homogeneous partners concerns multiple transport operators while the other case is more on the relationships between heterogeneous partners including one manufacturer and multiple transport operators. The coordination is supported by mathematical models implemented in linear programming which simulate the planning process within the various possible pools of partners, also called “coalitions”. These models are used in a gains/costs sharing protocol between the partners which is based on the Shapley value. Some basic properties are checked in order to verify if the cooperation is valid. The models and the protocol are assessed on theoretical test cases based on realistic data sets

During the past few years, pair-programming is a programming technique that has received an increasing amount of attention in the teaching of computer programming skills. Pair programming can briefly be described as a programming situation in which two persons sit at one computer and execute the task together. Although much research has been done on the advantages and disadvantages of pair programming, the assessment of computer skills acquired in pairs still remains a problem. The perception exists that pair assessment is not a reliable indicator of students' computer programming abilities. The purpose of the study was to determine whether (1) the results of programming skills assessed in pairs correlate with those of programming skills assessed individually, and (2) to investigate students' perceptions of pair and individual assessment. To reach these objectives, a literature study was performed to investigate pair programming as programming technique and the assessment of programming skills acquired in pairs. The empirical study has revealed that a positive relation exists between programming skills assessed in pairs and programming skills assessed individually. Furthermore, it was found that in general students' perceptions concerning pair assessment have changed positively. Based on the results arising from the empirical study, guidelines were suggested for the facilitation and assessment of pair programming skills.
Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2008.

Web-based collaborative learning is becoming an increasingly popular educational paradigm as more individuals who are geographically isolated seek higher education. As such students do not meet face to face with their peers and teachers, support for collaboration becomes extremely important. Successful collaboration means asking questions to gain a better understanding of the main concepts, elaborating and justifying opinions and sharing and explaining ideas. When group members' combined skills are sufficient to complete the learning task, effective group work can result in greater overall achievement than individual learning. Intelligent Tutoring Systems (ITS) have been shown to be highly effective at increasing students' performance and motivation. They achieve their intelligence by representing pedagogical decisions about how to teach as well as information about the learner. Constraint based tutors are a class of ITSs that use Constraint-based Modelling(CBM) to represent student and domain models. Proposed by Ohlsson, CBM is based on learning from performance errors, and focuses on correct knowledge. In this thesis, we present COLLECT-UML, a collaborative constraint-based ITS that teaches object-oriented analysis and design using Unified Modelling Language (UML). While teaching how to design UML class diagrams, COLLECT-UML also provides feedback on collaboration. Being a constraint-based tutor, COLLECT-UML represents the domain knowledge as a set of syntax and semantic constraints. However, it is the first system to also represent a higher-level skill such as collaboration using the same formalism. We started by developing a single-user ITS that supported students in learning UML class diagrams. The system was evaluated in a real classroom, and the results showed that students' performance increased significantly. We then extended the system to provide support for collaboration as well as domain-level support. The enhancement process included implementation of the shared workspace, modification of the pedagogical module to support groups of users, designing and implementing a group-modelling component, and developing a set of meta-constraints which are used to represent an ideal model of collaboration. The effectiveness of the system was evaluated in two studies. In addition to improved problem-solving skills, the participants both acquired declarative knowledge about effective collaboration and did collaborate more effectively. The participants enjoyed working with the system and found it a valuable asset to their learning. The results, therefore, show that CBM is an effective technique for modelling and supporting collaboration in computer-supported collaborative learning environments.

Empresas estão procurando reduzir seus custos e aumentar seu desempenho e competitividade. Neste cenário de redução de custos, a logística colaborativa pode ser uma aliada. Numa rede complexa, onde embarcadores muitas vezes nem sabem da existência de outros embarcadores com demandas complementares, existe um potencial de sinergia e redução de custos através da diminuição de deslocamentos de veículos sem carga, ou seja, deslocamentos para reposicionar os veículos. Visando essa redução, o Problema de Cobertura de Rotas (PCR), que tem como objetivo cobrir rotas no mínimo custo, une as demandas de frete de vários embarcadores e tenta minimizar os deslocamentos sem cargas (reposicionamentos), reduzindo assim o custo total de toda a rede dos embarcadores envolvidos. Esta pesquisa propõe um modelo e uma heurística para resolver, em grande escala através de programação paralela, uma expansão do PCR.
Companies are looking to reduce costs and improve performance and competitiveness. In this cost-cutting scenario, collaborative logistics can be an ally. In a complex network where shippers often do not know of the existence of other shippers with complementary demands, there is potential for synergy and cost savings by reducing unloaded travelling of vehicles, i.e, the distance and time to reposition the vehicles\'. Towards that reduction, the Lane Covering Problem (LCP), which aims to cover at least cost routeslinks the various shippers\' demands of freight and tries to minimize operations without loads (repositioning), thus reducing the total cost of the entire network for involved shippers. This research proposes a model and an heuristic to solve, in large-scale through parallel programming, an expansion of the PCR.

en català:

Un camp de recerca important dins del paradigma del Computer-Supported Collaborative Learning (CSCL) és la importància en la gestió eficaç de la informació d'esdeveniments generada durant l'activitat de l'aprenentatge col·laboratiu virtual, per a proporcionar coneixement sobre el comportament dels membres del grup. Aquesta visió és especialment pertinent en l'escenari educatiu actual que passa d'un paradigma tradicional - centrat en la figura d'un instructor magistral - a un paradigma emergent que considera els estudiants com actors centrals en el seu procés d'aprenentatge. En aquest nou escenari, els estudiants aprenen, amb l'ajuda de professors, la tecnologia i els altres estudiants, el que potencialment necessitaran per a desenvolupar les seves activitats acadèmiques o professionals futures.
Els principals aspectes a tenir en compte en aquest context són, primer de tot, com dissenyar una plataforma sota el paradigma del CSCL, que es pugui utilitzar en situacions reals d'aprenentatge col·laboratiu complexe i a llarg termini, basades en el model d'aprenentatge de resolució de problemes. I que permet al professor una anàlisi del grup més eficaç així com donar el suport adequat als estudiants quan sigui necessari.
En segon lloc, com extreure coneixement pertinent de la col·laboració per donar consciència i retorn als estudiants a nivell individual i de rendiment del grup, així com per a propòsits d'avaluació.
L'assoliment d'aquests objectius impliquen el disseny d'un model conceptual d'interacció durant l'aprenentatge col·laboratiu que estructuri i classifiqui la informació generada en una aplicació col·laborativa en diferents nivells de descripció. A partir d'aquesta aproximació conceptual, els models computacionals hi donen resposta per a proporcionar una extracció eficaç del coneixement produït per l'individu i per l'activitat del grup, així com la possibilitat d'explotar aquest coneixement com una eina metacognitiva pel suport en temps real i regulat del procés d'aprenentatge col·laboratiu.
A més a més, les necessitats dels entorns CSCL han evolucionat en gran mesura durant els darrers anys d'acord amb uns requisits pedagògics i tecnològics cada cop més exigents. Els entorns d'aprenentatge col·laboratius virtuals ara ja no depenen de grups d'estudiants homogenis, continguts i recursos d'aprenentatge estàtics, ni pedagogies úniques, sinó que exigeixen una forta personalització i un alt grau de flexibilitat. En aquest nou escenari, les organitzacions educatives actuals necessiten estendre's i moure's cap a paradigmes d'ensenyament altament personalitzats, amb immediatesa i constantment, on cada paradigma incorpora el seu propi model pedagògic, el seu propi objectiu d'aprenentatge i incorpora els seus propis recursos educatius específics.
Les demandes de les organitzacions actuals també inclouen la integració efectiva, en termes de cost i temps, de sistemes d'aprenentatge llegats i externs, que pertanyen a altres institucions, departaments i cursos. Aquests sistemes llegats es troben implementats en llenguatges diferents, suportats per plataformes heterogènies i distribuïdes arreu, per anomenar alguns dels problemes més habituals. Tots aquests problemes representen certament un gran repte per la comunitat de recerca actual i futura. Per tant, els propers esforços han d'anar encarats a ajudar a desenvolupadors, recercaires, tecnòlegs i pedagogs a superar aquests exigents requeriments que es troben actualment en el domini del CSCL, així com proporcionar a les organitzacions educatives solucions ràpides i flexibles per a potenciar i millorar el rendiment i resultats de l'aprenentatge col·laboratiu. Aquesta tesi proposa un primer pas per aconseguir aquests objectius.
An important research topic in Computer Supported Collaborative Learning (CSCL) is to explore the importance of efficient management of event information generated from group activity in collaborative learning practices for its further use in extracting and providing knowledge on interaction behavior.
The essential issue here is first how to design a CSCL platform that can be used for real, long-term, complex collaborative problem solving situations and which enables the instructor to both analyze group interaction effectively and provide an adequate support when needed. Secondly, how to extract relevant knowledge from collaboration in order to provide learners with efficient awareness and feedback as regards individual and group performance and assessment. The achievement of these tasks involve the design of a conceptual framework of collaborative learning interaction that structures and classifies the information generated in a collaborative application at several levels of description. Computational models are then to realize this conceptual approach for an efficient management of the knowledge produced by the individual and group activity as well as the possibility of exploiting this knowledge further as a metacognitive tool for real-time coaching and regulating the collaborative learning process.
In addition, CSCL needs have been evolving over the last years accordingly with more and more demanding pedagogical and technological requirements. On-line collaborative learning environments no longer depend on homogeneous groups, static content and resources, and single pedagogies, but high customization and flexibility are a must in this context. As a result, current educational organizations' needs involve extending and moving to highly customized learning and teaching forms in timely fashion, each incorporating its own pedagogical approach, each targeting a specific learning goal, and each incorporating its specific resources.
These entire issues certainly represent a great challenge for current and future research in this field. Therefore, further efforts need to be made that help developers, technologists and pedagogists overcome the demanding requirements currently found in the CSCL domain as well as provide modern educational organizations with fast, flexible and effective solutions for the enhancement and improvement of the collaborative learning performance and outcomes. This thesis proposes a first step toward these goals.

Índex foliat:
The main contribution in this thesis is the exploration of the importance of an efficient management of information generated from group activity in Computer-Supported Collaborative Learning (CSCL) practices for its further use in extracting and providing knowledge on interaction behavior. To this end, the first step is to investigate a conceptual model for data analysis and management so as to identify the many kinds of indicators that describe collaboration and learning and classify them into high-level potential categories of effective collaboration. Indeed, there are more evident key discourse elements and aspects than those shown by the literature, which play an important role both for promoting student participation and enhancing group and individual performance, such as, the impact and effectiveness of students' contributions, among others, that are explored in this work. By making these elements explicit, the discussion model proposed accomplishes high students' participation rates and contribution quality in a more natural and effective way. This approach goes beyond a mere interaction analysis of asynchronous discussion in the sense that it builds a multi-functional model that fosters knowledge sharing and construction, develops a strong sense of community among students, provides tutors with a powerful tool for students' monitoring, discussion regulation, while it allows for peer facilitation through self, peer and group awareness and assessment.
The results of the research described so far motivates the development of a computational system as the translation from the conceptual model into a computer system that implements the management of the information and knowledge acquired from the group activity, so as to be efficiently fed back to the collaboration. The achievement of a generic, robust, flexible, interoperable, reusable computational model that meets the fundamental functional needs shared by any collaborative learning experience is largely investigated in this thesis. The systematic reuse of this computational model permits a fast adaptation to new learning and teaching requirements, such as learning by discussion, by relying on the most advanced software engineering processes and methodologies from the field of software reuse, and thus important benefits are expected in terms of productivity, quality, and cost.
Therefore, another important contribution is to explore and extend suitable software reuse techniques, such as Generic Programming, so as to allow the computational model to be successfully particularized in as many as situations as possible without losing efficiency in the process. In particular, based on domain analysis techniques, a high-level computational description and formalization of the CSCL domain are identified and modeled. Then, different specific-platform developments that realize the conceptual description are provided. It is also explored a certain level of automation by means of advanced techniques based on Service-Oriented Architectures and Web-services while passing from the conceptual specification to the desired realization, which greatly facilitates the development of CSCL applications using this computational model.
Based on the outcomes of these investigations, this thesis contributes with computational collaborative learning systems, which are capable of managing both qualitative and quantitative information and transforming it into useful knowledge for all the implicated parties in an efficient and clear way. This is achieved by both the specific assessment of each contribution by the tutor who supervises the discussion and by rich statistical information about student's participation. This statistical data is automatically provided by the system; for instance, statistical data sheds light on the students' engagement in the discussion forum or how much interest drew the student's intervention in the form of participation impact, level of passivity, proactivity, reactivity, and so on. The aim is to provide both a deeper understanding of the actual discussion process and a more objective assessment of individual and group activity.
This information is then processed and analyzed by means of a multivariate statistical model in order to extract useful knowledge about the collaboration. The knowledge acquired is communicated back to the members of the learning group and their tutor in appropriate formats, thus providing valuable awareness and feedback of group interaction and performance as well as may help identify and assess the real skills and intentions of participants. The most important benefit expected from the conceptual model for interaction data analysis and management is a great improvement and enhancement of the learning and teaching collaborative experiences.
Finally, the possibilities of using distributed and Grid technology to support real CSCL environments are also extensively explored in this thesis. The results of this investigation lead to conclude that the features provided by these technologies form an ideal context for supporting and meeting demanding requirements of collaborative learning applications. This approach is taken one step further for enhancing the possibilities of the computational model in the CSCL domain and it is successfully adopted on an empirical and application basis. From the results achieved, it is proved the feasibility of distributed technologies to considerably enhance and improve the collaborative learning experience. In particular, the use of Grid computing is successfully applied for the specific purpose of increasing the efficiency of processing a large amount of information from group activity log files.

Agile Software Development has gained popularity with their people centric view and their common practices for developing software in today&rsquo
s volatile business world where change on requirements is unavoidable. However
the efficiency of the project depends on the communication and the collaboration of the team, which are supported by the co-location of the team. But in some cases colocation of the team cannot be realized, thus agile processes should also support distributed teams. This point was observed by Kircher, Jain, Corsaro, and Levine [31] and they suggested Distributed eXtreme Programming (DXP) after they prepared a study using offthe- shelf software products in order to replace the effect of face-toface communication on the efficiency of the application of agile processes with the aid gathered from tool support. In this study some available tool support for distributed agile software development is investigated and a tool is developed and presented in order to support software configuration management as well as increasing collaboration and communication of the team. The tool is then evaluated from a user&rsquo
s perspective and it is compared with some available software configuration management tools.

Growing memory capacities and the increasing number of cores on modern hardware enforces the design of new in-memory indexing structures that reduce the number of memory transfers and minimizes the need for locking to allow massive parallel access. However, most applications depend on hard durability constraints requiring a persistent medium like SSDs, which shorten the latency and throughput gap between main memory and hard disks. In this paper, we present our winning solution of the SIGMOD Programming Contest 2011. It consists of an in-memory indexing structure that provides a balanced read/write performance as well as non-blocking reads and single-lock writes. Complementary to this index, we describe an SSD-optimized logging approach to fit hard durability requirements at a high throughput rate.