AIM The purpose of this experiment is to assess whether the advantages of variable practice are due to schema formation or to enhanced information processing (contextual interference) alone. DESIGN The design involved a 2 (mode; cognitive and motor) x 5 (practice schedule; blocked, random, constant distance one, constant distance two, and constant distance three) between subjects design resulting in ten groups. One hundred participants were randomly chosen from Human Movement students at Australian Catholic University and assigned to each of the ten groups (n=10). The cognitive mode involved the participants having to recognise the appropriate target from three geometrical shapes (triangle, square or circle), the triangle being the target in every case. The motor mode involved the participants having to tap on the target among three boxes that was merely filled in. The experiment consisted of ninety (3 blocks of 30) acquisition trials followed by ten transfer trials to a novel movement. MAIN HYPOTHESIS It was hypothesised that if facilitated transfer to a novel target occurs through schema formation, then there would be no differences between the motor groups and their corresponding cognitive groups. However, if facilitated transfer to a novel target occurs through enhanced information processing, then there would be differences between the motor groups and their corresponding cognitive groups. RESULTS Statistical analysis revealed a contextual interference effect for participants involved in the cognitive mode, in that the cognitive blocked group outperformed the cognitive random group in acquisition, but the reverse was the case in transfer. In the motor mode, the motor blocked group outperformed the motor random group in acquisition, and repeated the performance in transfer. CONCLUSION The results appear to indicate that for simple motor tasks it is the amount of variability of practice that is important for transfer to a novel task, while for tasks with a cognitive component, the schedule of practice is critical.

Consumers’ perceptions of their resources in consumption tasks (that is, their abilities and endowments to perform consumption tasks) are many times not accurate. This misjudgement of resources negatively influences their performance in consuming or using products and services. Further, this carries on to influence consumers’ perceived value of products or services. In order to represent this phenomenon, consumer calibration is defined as the agreement between the subjective and objective assessment of consumer resources required in a consumption task. Therefore, it is crucial to discover the role of consumer calibration in the consumption experience. This paper proposes that consumer calibration occurs at two levels: of the task and of the self. Consumer task calibration refers to the extent of error in the task-required resource appraisal, whereas consumer self-calibration is the degree of accuracy in one’s self-perception of abilities. This systematic literature review is conducted to explore the relationships between consumer self and task calibration, on the one hand, and consumer value, on the other hand. After screening 2297 studies, based on their relevance and quality, forty texts in three main academic domains of Marketing, Psychology and Information Systems are selected for analysis and synthesis. The results reveal that subjective and objective assessments of consumer resources and task-required resources influence consumer value through their impact on functional performance and emotional consequences. The findings also suggest that, although a relationship between consumer task and self-calibration exists, their relationship with consumer value and their emotional consequences need further scrutiny. Consequently, a model for the effect of consumer calibration on consumer value is developed, based on the relationships established in the literature reviewed and the interpretation of the findings in the studies reviewed.

<p>Människan minns händelser och rörelser som hon själv genomfört bättre än de hon fått berättade för sig. Minnet för händelser och rörelser behandlas i det episodiska minnet. Multimodal memory theory är en teori om det episodiska minnet vilket bland annat behandlar förkunskapernas och modaliteternas betydelse för minneskapaciteten. Då människan genomför något används den motoriska modaliteten och då hon får höra något berättas används den verbala modaliteten. Det som har undersökts är om minnet och förståelsen för komplexa och tekniska lösningar påverkas av vilket modalitet som används vid inkodningen. Undersökningen visade inte någon skillnad på förståelse eller minneskapacitet för komplexa och tekniska lösningar, beroende av vilket modalitet som används vid inkodningen. En anledning till att undersökningen inte visade någon skillnad kan vara att mätredskapet var för trubbigt. Det är även möjligt att resultatet hade blivit ett annat om utformningen på experimentet hade varit annorlunda.</p>

In this study information-related activities engaged in by engineers during work task performance in the research and development centre at Sandvik Materials Technology AB are investigated. The purpose of the present study was to identify and achieve an understanding of the information-related activities performed by engineers during work task performance in a corporate context. The work task performance in focus is the task of writing a technical report.The study rests on methodological triangulation through the use of a work task diary, a semi-structured questionnaire and focus groups. In total 16 engineers participated in the study. The theoretical framework is based on theories of information in social practice, the information seeking process and the concept of task.The study presents results showing that engineers work in a highly complex information environment and their work task performance is to a high degree affected by situational attributes such as previous experience, type of work task, time, target group, and access to information. The results show that the information sources preferred by engineers have not changed over time; rather a change is seen in the type of sources. There is a distinct increase in the use of electronic sources; which in turn seem to affect the way engineers perceive accessibility. The study also shows that there are evident situational and contextual attributes affecting the information-related activities. Information needed to perform a work task is strongly related to data retrieved from experiments. There also seems to be an embedded tolerance for a low scientific level in technical reports, even though the scientific practice is the norm.This study also shows that the concept of work task forms a relevant basis for studies of information-related activities, particularly in combination with theories on information in social practice. The model of the work task process combined with a faceted classification of work tasks provides a sound methodological tool for the analysis of work tasks in different contexts.

A large number of studies in psychology and cognitive neuroscience suggest that the left and right cerebral hemispheres have differences in specialization of processing. The left hemisphere tends to be specialized for complex capacities such as language and numbers, whereas the right hemisphere typically shows advantages for visuospatial attention and recognition of nonverbal form. The present study was designed to investigate whether these functional cerebral asymmetries would extend to working memory tasks. It was hypothesized that the left hemisphere would have more advantage for accurate responses to a Number-based memory task, whereas the right hemisphere would be relatively advantaged for accurate responses on a Color-based memory task. For the Color-based memory task, we used a Corsi-Block memory task (4x4 grid). For the Number-based memory task, we used a string of 8 digits. In each case, to-be-remembered stimuli were constructed sequentially, such that participants (N = 39) had to form and maintain the image in working memory. Participants then compared these remembered stimuli with flashed images that appeared either on the left or right edge of the screen. We recorded the correct responses and the response time. The left hemisphere appears to be advantaged for accurate responses when the memory stimuli are numerical in nature, whereas the right hemisphere has more advantage for accurate responses on the color-memory task.

Computer simulations are an indispensable tool for scientists to gain new insights about nature. Simulations of natural phenomena are usually large, and limited by the available computer resources. By using the computer resources more efficiently, larger and more detailed simulations can be performed, and more information can be extracted to help advance human knowledge. The topic of this thesis is how to make best use of modern computers for scientific computations. The challenge here is the high level of parallelism that is required to fully utilize the multicore processors in these systems. Starting from the basics, the primitives for synchronizing between threads are investigated. Hardware transactional memory is a new construct for this, which is evaluated for a new use of importance for scientific software: atomic updates of floating point values. The evaluation includes experiments on real hardware and comparisons against standard methods. Higher level programming models for shared memory parallelism are then considered. The state of the art for efficient use of multicore systems is dynamically scheduled task-based systems, where tasks can depend on data. In such systems, the software is divided up into many small tasks that are scheduled asynchronously according to their data dependencies. This enables a high level of parallelism, and avoids global barriers. A new system for managing task dependencies is developed in this thesis, based on data versioning. The system is implemented as a reusable software library, and shown to be as efficient or more efficient than other shared-memory task-based systems in experimental comparisons. The developed runtime system is then extended to distributed memory machines, and used for implementing a parallel version of a software for global climate simulations. By running the optimized and parallelized version on eight servers, an equally sized problem can be solved over 100 times faster than in the original sequential version. The parallel version also allowed significantly larger problems to be solved, previously unreachable due to memory constraints. / UPMARC / eSSENCE

The task assignment problem is one of the fundamental combinatorial optimization problems. It has been extensively studied in operation research, management science, computer science and robotics. Task assignment problems arise in various applications of multi-robot systems (MRS), such as environmental monitoring, disaster response, extraterrestrial exploration, sensing data collection and collaborative autonomous manufacturing. In these MRS applications, there are realistic constraints on robots and tasks that must be taken into account both from the modeling perspective and the algorithmic perspective. From the modeling aspect, such constraints include (a) Task group constraints: where tasks form disjoint groups and each robot can be assigned to at most one task in each group. One example of the group constraints comes from tightly-coupled tasks, where multiple micro tasks form one tightly-coupled macro task and need multiple robots to perform each simultaneously. (b) Task deadline constraints: where tasks must be assigned to meet their deadlines. (c) Dynamically-arising tasks: where tasks arrive dynamically and the payoffs of future tasks are unknown. Such tasks arise in scenarios like searchrescue, where new victims are found dynamically. (d) Robot budget constraints: where the number of tasks each robot can perform is bounded according to the resource it possesses (e.g., energy). From the solution aspect, there is often a need for decentralized solution that are implemented on individual robots, especially when no powerful centralized controller exists or when the system needs to avoid single-point failure or be adaptive to environmental changes. Most existing algorithms either do not consider the above constraints in problem modeling, are centralized or do not provide formal performance guarantees. In this thesis, I propose methods to address these issues for two classes of problems, namely, the constrained linear assignment problem and constrained generalized assignment problem. Constrained linear assignment problem belongs to P, while constrained generalized assignment problem is NP-hard. I develop decomposition-based distributed auction algorithms with performance guarantees for both problem classes. The multi-robot assignment problem is decomposed into an optimization problem for each robot and each robot iteratively solving its own optimization problem leads to a provably good solution to the overall problem. For constrained linear assignment problem, my approaches provides an almost optimal solution. For constrained generalized assignment problem, I present a distributed algorithm that provides a solution within a constant factor of the optimal solution. I also study the online version of the task allocation problem with task group constraints. For the online problem, I prove that a repeated greedy version of my algorithm gives solution with constant factor competitive ratio. I include simulation results to evaluate the average-case performance of the proposed algorithms. I also include results on multi-robot cooperative package transport to illustrate the approach.

Habilitation - Universität, Saarbrücken, 2007. / Includes bibliographical references (p. [425]-451) and index.

Diss. no. 13564 techn. sc. SFIT Zurich. / Im Buchh.: Aachen : Shaker. Literaturverz.

Τα τελευταία χρόνια πολλοί ερευνητές της διδακτικής των μαθηματικών έχουν εστιάσει στον ρόλο της πολλαπλής επίλυσης προβλήματος (επίλυση προβλήματος με περισσότερους από έναν τρόπους) στην ανάπτυξη της μάθησης του αντικειμένου. Δύο είδη πολλαπλής επίλυσης προβλήματος που μπορούν να ενταχθούν στη διδακτική πρακτική είναι καταρχήν αυτό με βάση το αποκαλούμενο “πρόβλημα πολλαπλών επιλύσεων” (“multiple solution task”) (Leikin et al., 2006) και δεύτερον αυτό με απαρχή το “πρόβλημα διασύνδεσης” (“interconnecting task”) (Kondratieva, 2011). Η διπλωματική αυτή εργασία θα περιέχει μια κριτική παρουσίαση των ποιοτικών χαρακτηριστικών των δύο προαναφερθέντων ειδών προβλημάτων, στο πλαίσιο των βασικών προσεγγίσεων επίλυσης προβλήματος που ανέπτυξαν οι Schroeder & Lester (1989) και Mamona-Downs & Papadopoulos (2006), καθώς και τα αποτελέσματα μιας πρώτης διερευνητικής προσπάθειας εφαρμογής αυτής της διδακτικής πρακτικής, σε τρεις τάξεις μαθηματικών σε σχολεία των Πατρών. Στην διπλωματική εργασία παρουσιάζονται ερευνητικά αποτελέσματα, αναφορικά με τις αιτίες της μη συστηματικής ένταξης της πολλαπλής επίλυσης προβλήματος στη διδακτική πρακτική. Επιπλέον, αναφέρονται συγκεκριμένες διδακτικές προσεγγίσεις για την πραγμάτωση της πολλαπλής επίλυσης προβλήματος στη διδασκαλία των μαθηματικών. Τέλος, σχολιάζονται κριτικά επιλεγμένες απαντήσεις συμμετεχόντων στην έρευνα, που αναδεικνύουν αφενός τα ποιοτικά χαρακτηριστικά της πολλαπλής επίλυσης προβλήματος, αφετέρου τον προσεκτικό σχεδιασμό που απαιτεί αυτή η πρωτοεμφανιζόμενη στην ελληνική βιβλιογραφία διδακτική πρακτική. / In recent years many researchers of mathematics’ education have focused on the role of multiple problem solving (problem solving in more than one ways) in the development of subject knowledge. Two types of multiple problem solving, that can be integrated into teaching practice, are firstly the "multiple solution task" (Leikin et al., 2006) and secondly the "interconnecting task" (Kondratieva, 2011). This thesis contains a critical presentation of the qualitative characteristics of these two types of problems, within the framework of the basic problem solving approaches developed by Schroeder & Lester (1989) and Mamona-Downs & Papadopoulos (2006), and the results of a first exploratory effort to implement this teaching practice, in three mathematics’ classrooms in schools of Patras. In this thesis we present research results regarding the causes of non-systematic implementation of multiple problem solving in teaching practice. Moreover, we outline specific teaching approaches for the implementation of multiple problem solving in mathematics’ teaching. Finally, we critically comment selected responses of participants in the survey, that highlight both the qualitative characteristics of multiple problem solving and the careful planning that is required for this nascent teaching practice in the Greek literature.