Situation awareness in sea kayaking: towards a practical checklist

Ever-changing weather and sea conditions constitute environmental hazards that sea kayakers must pay attention to and act upon to stay safe. The aim of this study was to propose a tool to aid sea kayakers’ situation awareness (SA). We developed a checklist guided by theory on the concept of SA and expert problem detection, judgement and decision-making, along with knowledge concerning previous incidents and important risk factors in sea kayaking. The checklist consists of two parts: a guide to how paddlers can improve their SA and decision-making skills, and an overview of what critical factors should be evaluated before and during a sea kayak trip. We argue that the checklist may improve risk assessment and management among sea kayakers, help to prevent distress and future incidents, and ultimately potentially save lives. Finally, we wish to stimulate debate concerning risk management in sea kayaking and outdoor education.     

Cognitive-inspired domain adaptation of sentiment lexicons

Sentiment lexicons are essential tools for polarity classification and opinion mining. In contrast to machine learning methods that only leverage text features or raw text for sentiment analysis, methods that use sentiment lexicons embrace higher interpretability. Although a number of domain-specific sentiment lexicons are made available, it is impractical to build an ex ante lexicon that fully reflects the characteristics of the language usage in endless domains. In this article, we propose a novel approach to simultaneously train a vanilla sentiment classifier and adapt word polarities to the target domain. Specifically, we sequentially track the wrongly predicted sentences and use them as the supervision instead of addressing the gold standard as a whole to emulate the life-long cognitive process of lexicon learning. An exploration-exploitation mechanism is designed to trade off between searching for new sentiment words and updating the polarity score of one word. Experimental results on several popular datasets show that our approach significantly improves the sentiment classification performance for a variety of domains by means of improving the quality of sentiment lexicons. Case-studies also illustrate how polarity scores of the same words are discovered for different domains.     

Somersaulting techniques used in high-scoring and low-scoring Roche vaults performed by male Olympic gymnasts

The aim of this study was to compare the somersaulting techniques used in the 16 highest-scoring and 16 lowest-scoring Roche vaults. Our hypothesis was that the gymnasts performing the highest-scoring Roche vaults would demonstrate a better technique than those performing the lowest-scoring Roche vaults while on the horse (pushing off the horse more effectively), somersaulting (executing most of the required somersaults higher in flight), and landing (showing a greater control). A 16-mm motion picture camera, operating at 100 Hz, recorded the vaults during the official competition. The two-dimensional direct linear transformation was used for spatial reconstruction. The results of t-tests (P < 0.05) indicated that, compared with the low-scoring gymnasts, the high-scoring gymnasts had: (1) greater height of body centre of mass and a more fully extended body position at the horse take-off; (2) greater height of body centre of mass at the peak of post-flight, knee release, and touchdown on the mat; (3) greater horizontal and vertical displacements of body centre of mass, greater somersaulting rotation, and longer time from the knee release to mat touchdown; and (d) markedly smaller landing point deductions. In conclusion, a successful Roche vault is likely when the focus is on: (a) leaving the horse with a large vertical velocity in an extended body position to achieve a high trajectory of centre of mass by first extending the legs, then immediately pushing off the horse vigorously, using the muscles of the upper extremity; (b) grasping the knees immediately after the take-off from the horse, achieving the tightly tucked body position early during the ascent to the peak, and completing two-thirds of the required somersaults at a great height; (c) releasing the knees and extending the body above the top level of the horse; and (d) contacting the mat with a high body centre of mass position.     

Szenario-basierter Systemtest von Software-Produktfamilien

Zusammenfassung In der Produktfamilienentwicklung werden durch zwei Entwicklungsprozesse, Domain und Application Engineering, zun"achst wiederverwendbare Entwicklungsartefakte produziert, um diese anschlie?end zur Konstruktion von kundenspezifischen Applikationen einzusetzen. Die Wiederverwendbarkeit wird durch die explizite Definition der Variabilit"at der geplanten Applikationen einer Produktfamilie erzielt. Diese proaktive Wiederverwendung ist bisher in den konstruktiven Entwicklungsphasen realisiert, jedoch noch nicht im Test. Mit ScenTED (Scen_ario based TE_st Case D_erivation) wird in diesem Beitrag eine wiederverwendungsorientierte Technik zur Testfallerstellung f"ur den Systemtest, dem Test eines ausf"uhrbaren Systems gegen spezifizierte Use-Cases, von Produktfamilien vorgestellt. ScenTED basiert auf zwei Kernideen: der Erhaltung der Variabilit"at in Testf"allen und der Szenario-basierten Verfeinerung der Testf"alle. Durch die Erhaltung der Variabilit"at wird die Wiederverwendbarkeit von Testf"allen gesichert; die Szenario-basierte Verfeinerung erm"oglicht Nachvollziehbarkeit durch die durchg"angige Nutzung von Szenarien. In diesem Beitrag wird die ScenTED-Technik an einem Beispiel erl"autert und Erfahrungen aus dem industriellen Einsatz diskutiert.

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Product family engineering consists of two development processes: Domain engineering and application engineering. Reuseable artefacts are created in the domain engineering process. These artefacts are used for the creation of customer specific applications during the application engineering process. Reusability is achieved with the explicit definition of variability that specifies the potential applications of the product family. The proactive reuse has been realized in the construnction phases of the development process, but not within the test phases. We propose ScenTED (Scen_ario based TE_st Case D_erivation) for the creation of reusable test cases for a use case based system testing in product family engineering. ScenTED has two key ideas: The first is the preservation of variability in test cases and the second idea is the scenario-based refinement of test cases. The preservation of variability ensures the reusability of test cases. The scenario-based refinement enables the traceability from requirements to test cases. We present the ScenTED technique in this article with an example and discuss an industrial case study.

CR Subject Classification D2.5     

The Engagement Model of Opinion Leadership: Testing Validity Within a European Context

Explicating and measuring opinion leadership continues to bean important theoretical topic, as personal influence and interpersonaldiscussion are widely recognized as shaping public opinion andpolitical behavior. However, the concept of opinion leadershiparose out of empirical research conducted primarily within theUSA. Whether it may be applied to other national contexts remainsto be fully explicated. Furthermore, media information-seekingbehaviors of opinion leaders, such as newspaper use or televisionexposure, seem to be culturally contingent based upon the scantcross-national research to date. This paper examines the ecologicaland constructive validity of the engagement model of the opinionleadership developed within the USA. Employing the EuropeanSocial Survey, I apply this model to fifteen European nationsto assess its validity and explore how media information-seekingbehaviors of opinion leaders may vary across national contexts.The findings suggest that the model may be most valid in WesternEuropean nations. Furthermore, the media use and behaviors ofopinion leaders vary greatly across nations in Europe, thoughlevels of interpersonal political discussion and specific individualsocio-psychological traits do not.     

Parental perspectives of the role of school factors in school refusal

The aim of this study was to explore parents’ perspectives on the role of school factors in school refusal (SR). Semi-structured interviews were conducted with 17 parents who had experienced SR with their own child. They identified several school factors related to SR. Some of these findings suggest that students who are prone to SR need more predictability and more teachers’ support than they sometimes get in school. Their need for predictability seems to occur particularly during less structured activities and during transitions in school. Findings also imply that disruptive behavior among classmates and harsh management from teachers affects perceived predictability and support for SR-prone students. All parents expressed concern about bullying, and roughly a third of them reported that their child had been a victim of bullying. Insufficient adaptation of schoolwork was also mentioned relatively frequently. Parents emphasized that adaptation of schoolwork needs to be done in close cooperation with the student and parents to avoid negative differentiation from classmates or stigma. Finally, several parents commented that teachers and schools need more knowledge about SR and felt that schools needed a more coordinated approach to supporting students who are at risk of SR.