Retrieving and classifying instances of source code plagiarism

Automatic detection of source code plagiarism is an important research field for both the commercial software industry and within the research community. Existing methods of plagiarism detection primarily involve exhaustive pairwise document comparison, which does not scale well for large software collections. To achieve scalability, we approach the problem from an information retrieval (IR) perspective. We retrieve a ranked list of candidate documents in response to a pseudo-query representation constructed from each source code document in the collection. The challenge in source code document retrieval is that the standard bag-of-words (BoW) representation model for such documents is likely to result in many false positives being retrieved, because of the use of identical programming language specific constructs and keywords. To address this problem, we make use of an abstract syntax tree (AST) representation of the source code documents. While the IR approach is efficient, it is essentially unsupervised in nature. To further improve its effectiveness, we apply a supervised classifier (pre-trained with features extracted from sample plagiarized source code pairs) on the top ranked retrieved documents. We report experiments on the SOCO-2014 dataset comprising 12K Java source files with almost 1M lines of code. Our experiments confirm that the AST based approach produces significantly better retrieval effectiveness than a standard BoW representation, i.e., the AST based approach is able to identify a higher number of plagiarized source code documents at top ranks in response to a query source code document. The supervised classifier, trained on features extracted from sample plagiarized source code pairs, is shown to effectively filter and thus further improve the ranked list of retrieved candidate plagiarized documents.     

Keeping things different: coexistence within European markets for cleantech and biofuels

Environmental policy increasingly resorts to market-based instruments in order to meet sustainability objectives. The ‘carbon market’ instituted by the European Emissions Trading directive from 2003 is a canonical example, which has been described, and critiqued, as a delegation of policy objectives to market exchanges. In this paper, we examine the complex ways in which the operationalization of policy objectives and the organization of markets are intertwined, focusing on two other examples of European environmental regulation. The first one is the Integrated Pollution Prevention and Control directive from 1996, which defined the ‘best available techniques’ to curb emissions in air, water and soil. The second one is the Renewable Energy Directive from 2009, which introduced criteria for the definition of the sustainability of biofuels. Through the analysis of the design and implementation of these two directives, we identify a central concern for the coexistence of various objects, and various initiatives undertaken by European institutions, member states and private actors. We use the notion of coexistence to describe a European political and economic ordering that is inherently hybrid, and cannot be reduced to a mere delegation of policy objectives to the market, or a legal constraint imposed on all European actors. It grounds its political legitimacy and economic rationality on the distribution of roles and responsibilities across public and private actors, and on the ability to ‘keep things different’ according to local variabilities.     

Special Education in Ireland

ABSTRACT

Special education in Ireland can be understood only against the background of the general system of education which is briefly described at the beginning of this article. While some special provision dates back to the nineteenth century the great expansion of services has happened in the past 30 years. The form of provision reflects the characteristics of the general system. Ireland has no legislation governing special education and the future is not easy to read just now.     

Understanding the experiences of bilingual,Latino/a adolescents: Voices from gifted and general education

Eight gifted and eight general‐education students engaged in discussions regarding their observations of, experiences in, and recommendations for education. Six categories emerged through qualitative analysis of their conversations. These categories include: problem solving, task commitment, self‐perceptions, education, communication, and discrimination. Content within each category provides a glimpse into the students’ perceptions of their schooling experiences. The roles of ethnic identity development, identification with majority culture, adolescence, and gifted‐ness are examined and recommendations for future research are provided.     

An analysis of the relationship between the linear hammer speed and the thrower applied forces during the hammer throw for male and female throwers

The purpose of this study was to investigate the relationship between the cable force and linear hammer speed in the hammer throw and to identify how the magnitude and direction of the cable force affects the fluctuations in linear hammer speed. Five male (height: 1.88 +/- 0.06 m; body mass: 106.23 +/- 4.83 kg) and five female (height: 1.69 +/- 0.05 m; body mass: 101.60 +/- 20.92 kg) throwers participated and were required to perform 10 throws each. The hammer's linear velocity and the cable force and its tangential component were calculated via hammer head positional data. As expected, a strong correlation was observed between decreases in the linear hammer speed and decreases in the cable force (normalised for hammer weight). A strong correlation was also found to exist between the angle by which the cable force lags the radius of rotation at its maximum (when tangential force is at its most negative) and the size of the decreases in hammer speed. These findings indicate that the most effective way to minimise the effect of the negative tangential force is to reduce the size of the lag angle.     

Sequence-dependent rotation axis changes in tennis

The purpose of this study was to evaluate the role of rotation axes during a tennis serve. A motion capture system was used to evaluate the contribution of the potential axes of rotation (minimum inertia axis, shoulder-centre of mass axis and the shoulder-elbow axis) during the four discrete tennis serve phases (loading, cocking, acceleration and follow through). Ten ranked athletes (International Tennis Number 1–3) repeatedly performed a flat service aiming at a target on the other side of the net. The four serve phases are distinct and thus, each movement phase seems to be organised around specific rotation axes. The results showed that the limbs’ rotational axis does not necessarily coincide with the minimum inertia axis across the cocking phase of the tennis serve. Even though individual serving strategies were exposed, all participants showed an effect due to the cocking phase and changed the rotation axis during the task. Taken together, the results showed that despite inter-individual differences, nine out of 10 participants changed the rotation axis towards the minimum inertia and/or the mass axis in an endeavour to maximise external rotation of the shoulder to optimally prepare for the acceleration phase.     

Risks, rules, and roles

Summary Based on ten years of fieldwork with a focus on macro-micro linkages from organizational ethos and structure to language behavior and roleplaying, this report centers on institutional changes that affect cognitive, social, and linguistic development of youth. Argued here is the resilience of those young people who find their way to youth-based (as distinct from youth-serving) organizations during their out-of-school lives. These organizations provide an institutional force to fill the voids left by intergenerational communication and nurturance breakdowns and an absence of meaningful work for youth in community and family life. Part 1 gives an overview of areas of interaction, work, and support that institutions fail to give in post-industrial societies and sets up the framework to view the fact that some youth create an institutional force through youth-based organizations that take over key socialization roles. Here crossage peers become their own agents to create an ecology of learning significantly different from customary agents of transmissive socialization. Part 2 answers the questions of what happens in this ecology of learning, and how learning works in youth-based organizations that place high emphasis on the real work of production and performance. Within these organizations that offer a type of liminal zone between childhood and full entry into adult life, youth take risks, play roles, and set their own rules in order to achieve a group goal of excellence in performance. Part 3 looks at language use within these organizations and addresses the means by which youth-based organizations remain dynamic and responsive to the rapidly changing dimensions of youth needs. Part 4 sets out certain changes necessary in the thinking of adults about models of socialization and their role in helping to make possible learning ecologies young people will see as effective. Part 5 pulls together the macro and micro dimensions of the findings to highlight the importance of research on the ways that rules, roles, and risks play within the work of learning.

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Zusammenfassung Risiken, Regeln und Rollen. Jugendperspektiven zur Lernarbeit in der Gemeindeentwicklung Basierend auf zehn Jahren Feldforslchung mit dem Fokus auf den Makro-Mikro-Zusammenh?ngen zwischen organisationaler Struktur und dazugeh?rigem Ethos einerseits und Sprachverhalten und Rollenspiel andererseits konzentriert sich dieser Beitrag auf den institutionellen Wandel, der sich auf die kognitive, soziale und sprachliche Entwicklung der Jugend auswirkt. Auff?llig ist die Selbstbehauptungskraft derjenigen Jugendlichen, die in ihrer au?erschulischen Freizeit den Weg zu jugendzentrierten Einrichtungen finden. Diese Organisationen vermitteln eine institutionelle Macht, die die Leere der intergenerationellen Kommunikation, der Bildungsabbrüche und der fehlenden Aufgaben für Jugendliche im Familien- und Gemeindeleben füllt. Abschnitt 1 gibt zum einen einen überblick über Interaktionsbereiche, die Arbeit und Unterstützung, die Institutionen der postindustriellen Gesellschaft nicht geben, und zeigt dann auf, welche institutionelle Kraft manche Jugendliche durch Engagement in jugendzentrierten Initiativen entwickeln, denen Schlüsselfunktionen in ihrer Sozialisation zukommen. Hier werden altersgemischte Peergruppen ihre eigenen Interessenvertreter, um eigene Lernumgebungen zu schaffen, die sich signifikant von den herk?mmlichen, auf Stoffvermittlung bestehenden Ans?tzen unterscheiden. Teil 2 beantwortet die Fragen, was in diesen Lernumwelten geschieht und welch wichtigen Platz Lernen in diesen jugendzentrierten Einrichtungen mit ihrer deutlichen Betonung von ernsthafter produktorientierter Arbeit und Darstellung einnehmen. In diesen Projekten mit ihrem Angebot für den Zeitraum zwischen Kindheit und vollst?ndigem Eintritt in das Erwachsenenleben akzeptieren Jugendliche Risiken, spielen Rollen und setzen sich Regeln, um hervorragende Gruppenergebnisse, z. B. bei einer Theateraufführung, zu erreichen. Abschnitt 3 betrachtet die Sprache, die in diesen Organisationen benutzt wird, und benennt die Mittel, mit deren Hilfe jugendzentrierte Einrichtungen dynamisch bleiben und auf die raschen Wechsel der jugendlichen Bedürfnisse antworten. Teil 4 beschreibt einige notwendige ?nderungen im Denken der Erwachsenen hinsichtlich der Sozialisationsmodelle und beschreibt ihre Rolle für die effektive Gestaltung von Lernumgebungen für junge Menschen. Im fünften Abschnitt werden Forschungsergebnisse der Makro- und Mikroebene zusammengefasst, um die Wichtigkeit der Forschung zu unterstreichen, die darüber aufkl?rt, welche Rolle Regeln, Rollen und Risiken in der Lernarbeit spielen.