• 아동학회지
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• 제23권4호
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• pp.1-20
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• 2002

The subjects of this study of the development of concepts of pretense and of false beliefs were 168 3-, 4-, 5-, and 6-year-olds. There were 2 significant main effects for age and type of task both for pretend and false belief tasks. The older children performed pretend tasks and false belief tasks at a higher level than the younger children. Performance on pretend tasks was higher with alternatives than without them. On false belief tasks, there were differences in performance among the change of location, the change of content and the second order false belief tasks. Correlations between understanding of pretense and false beliefs were relatively high. These results suggest that the relationship between children's understanding of pretense and false belief varied by types of tasks.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권8호
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• pp.594-601
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• 2004

We analyze checkpoint strategy for multiple real-time periodic tasks with hard deadlines. Real-time tasks usually have deadlines associated with them. For multiple real-time tasks, checkpoint strategy considering deadlines of all tasks is very difficult to derive. We analyze the problem of checkpoint placement for such multiple periodic tasks. In our strategy, the interval between checkpoints is determined for each task considering its deadline. An approximated failure probability over a specified interval is derived. Then the number of checkpoints for each task is selected to minimize the approximated failure probability. To show the usefulness of our strategy, error bound between the exact and the approximated failure probability is estimated, which is revealed to be quite small.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권9호
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• pp.4349-4371
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• 2019

Moldable parallel tasks are widely used in different areas, such as weather forecast, biocomputing, mechanical calculation, and so on. Considering the deadline and the speedup, scheduling moldable parallel tasks becomes a difficulty. Past work majorly focuses on the LA (List Algorithms) or OMA (Optimizing the Middle Algorithms). Different from prior work, our work normalizes execution time and makes all tasks have the same scope in normalized execution time: [0,1], and then according to the normalized execution time, a method is used to search for the reference execution time without considering the deadline of tasks. According to the reference execution time, we get an initial scheduling result based on AFCFS (Adaptive First Comes First Served) policy. Finally, a heuristic approach is used to improve the performance of the initial scheduling result. We call our method HSRET (a Heuristic Scheduling method based on Reference Execution Time). Comparisons to other methods show that HSRET has good performance in AWT (Average Waiting Time), AET (Average Execution Time), and PUT (Percentages of Unfinished Tasks).

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1996년도 춘계학술대회논문집
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• pp.253-258
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• 1996

Virtual reality environment system is expected to be used as a new user interface tool oweing to its high immersiveness and high interactivity. To use VR interface effectively, we should identify the characteristics of the three-dimensional control tasks as if we did in two-dimensional graphic user interface environments. As a first step, we validated Fitts'law for the three-dimensional pointing tasks with the two input devices, Spaceball and Spacemouse. Different from the two-dimensional control tasks, VR pointing tasks needed inclusion of a new variable, size of the moving object, to Fitts'law. The modified

• 대한인간공학회지
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• 제16권1호
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• pp.85-96
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• 1997

This article reviews the effects of VDT tasks on multiple resources for processing and storage in short-term working memory. MD and PD method were introduced toevaluate the modalities (auditory-visual) in the multiple resources model. The subjects conducted 2 sessions of 50 minites VDT tasks. Before, between and after VDT tasks, MD, PD task performance scores and CFF(critical flicker frequency0 values were measured. The review suggested that the modalities of human information processing in working memory were affected by VDT tasks with different task contents.

• 대한인간공학회지
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• 제7권2호
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• pp.3-13
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• 1988

For health and welfare of VDT workers in VDT tasks, there has been serious efforts to establish guidelines for VDT tasks in several countries. In this study the author reviewed those guidelines and related researches in relation to health problems of VDT tasks and then suggested some minimal conditions or some key items of VDT task dimensions to protect VDT workers in performing their VDT tasks.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제29권3호
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• pp.281-300
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• 2015

본 연구의 목적은 스토리텔링 수학 교과서 개발과 학교 현장에서 스토리텔링 교과서 활용의 방향성을 제시하기 위해, 2009 개정 교육과정에 따른 중학교 2학년 수학 교과서 5종을 연구 대상으로 수학 과제 유형에 따른 인지적 노력 수준, 답안 유형, 스토리텔링 유형을 분석하였다. 연구 결과, 첫째, 수학 과제의 인지적 노력 수준은 공통적으로 모든 교과 내용 영역에서 PNC(Procedures without Connections) 과제가 가장 많은 비중을 차지하였고, 수학적 내용 과제에서는 인지적 노력이 낮은 수준의 과제(Low-Level)가 많았고, 수학적 활동 과제에서는 인지적 노력이 높은 수준의 과제(High-Level)가 더 많았다. 둘째, 학생들에게 요구하는 답안 유형은 모든 영역에서 단답형이 가장 많았고, 수학적 내용 과제의 대부분은 단답형, 수학적 활동 과제는 단답형과 설명형이 많았다. 마지막으로 스토리텔링의 유형은 실생활 연계형이 가장 많은 비중을 차지하고 있었고, 수학적 활동 과제의 수가 수학적 내용 과제의 수보다 휠씬 적었다. 그러나 스토리텔링 유형이 반영된 과제에서는 수학적 활동 과제의 비율이 수학적 내용 과제의 비율보다 더 높았다. 이러한 연구 결과를 바탕으로 향후 다른 학년의 스토리텔링 수학 교과서를 개발하고 학교 현장에 적용할 때, 수학 과제 유형에 따른 인지적 노력 수준, 답안 유형, 스토리텔링 유형에 대해서 균형성과 다양성을 고려해야할 필요성을 제시할 수 있다.

• 아동학회지
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• 제38권1호
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• pp.117-126
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• 2017

Objective: The purpose of this study was to investigate young children's nonsymbolic magnitude comparison ability according to ratio limit and task condition. Methods: The participants included 40 3-year-old children, 42 4-year-old children, and 41 5-year-old children recruited from 4 childcare centers located in Seoul, Korea. All magnitude comparison tasks were composed of image material tasks and concrete material tasks. In addition, each magnitude comparison task varied with the ratio of the two quantities; 0.5 ratio, 0.67 ratio, 0.75 ratio. Results and Conclusion: The results revealed that 3-, 4-, and 5-year-old children could perform nonsymbolic magnitude comparison tasks without learning experiences. Also, 3-, 4-, and 5-year-old children could perform concrete material tasks better than image material tasks in nonsymbolic magnitude comparison tasks. Furthermore, children's performance on nonsymbolic magnitude comparison tasks indicated the ratio signature of the approximate number system. Children have a degree of numerical capacity prior to formal mathematics instruction. Also, children were influenced by task conditions or sense stimulus when they processed numerical information. Furthermore, the approximate number system can be used in understanding the ordinality of number.

• 대한가정학회지
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• 제42권6호
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• pp.137-149
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• 2004

This research analyzed the tasks performed by firm's consumer department, evaluation, and efficiency of those tasks. In addition, regression analysis was employed to find what factors influence the level of evaluation and efficiency of tasks performed by firm's consumer department. Research results summarized as follows. First, two thirds of the appropriate amount of resources and systems for the consumer department were equipped and the score of evaluating for consumer counseling tasks was high. Second, the amounts of resources and systems being equipped by the firm's consumer department were greater in insurance companies and firms with more employees, firms with 70% to 100% female employees in the consumer department, firms that listed their stocks, and firms with the consumer department located higher than the second floor. Third, the score of evaluating the tasks performed by the firm's consumer department was greater in firms that listed their stocks, owned great resources and systems, and had a higher degree of work satisfaction. Finally, the task of consumer counseling performed by the consumer department turned out to be effective in firms that listed their stocks, were recently established, and owned necessary resources and systems.

• 한국멀티미디어학회논문지
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• 제8권12호
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• pp.1589-1596
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• 2005

The imprecise real-time system provides flexibility in scheduling time-critical tasks. Most scheduling problems of satisfying both 0/1 constraint and timing constraints, while the total error is minimized, are NP complete when the optional tasks have arbitrary processing times. Liu suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on uniprocessors for minimizing the total error. Song et al suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on multiprocessors for minimizing the total error. But, these algorithms are all off-line algorithms. On the other hand, in the case of on line scheduling, Shih and Liu proposed the NORA algorithm which can find a schedule with the minimum total error for a task system consisting solely of on-line tasks that are ready upon arrival. But, for the task system with 0/1 constraint, it has not been known whether the NORA algorithm can be optimal or not in the sense that it guarantees all mandatory tasks are completed by their deadlines and the total error is minimized. So, this paper suggests an optimal algorithm to search minimum total error for the imprecise on-line real-time task system with 0/1 constraint. Furthermore, the proposed algorithm has the same complexity, O(N log N), as the NORA algorithm, where N is the number of tasks.