• Journal of The Korean Association of Information Education
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• v.14 no.3
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• pp.341-353
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• 2010

The purpose of the present study is to verify the structural relationship among on-line task value, university support, satisfaction, learning persistence in Cyber University. For this study, W cyber university in Korea was chosen to conduct web survey. A hypothetical model was proposed, which was composed of on-line task value, university support as exogenous variables, satisfaction, learning persistence as endogenous variables. And satisfaction have been suggested as intervening endogenous variables. The result of this study is as follows: First, on-line task value and university support affect satisfaction. Second, university support and satisfaction affect learning persistence. Lastly, satisfaction mediated on-line task value, university support and learning persistence.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.413-427
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• 2022

The purpose of this study was to improve and verify task value and academic self-efficacy of university students with metaverse gamification teaching method combining flipped learning and project-based learning. The subjects in this study were 16 university students majoring in counseling psychology who engaged in K university in cheong-ju. The subjects were assigned to the experimental group or the comparison group. The experimental group received the proposed metaverse gamification teaching method combining flipped learning and project-based learning while comparison group received teacher-centered learning. The dependent variables in this study were task value and academic self-efficacy. Each variable was assessed before class, after the end of the class. At the end of the class, the experimental group engaged statistically significantly higher levels of task value and academic self-efficacy than the comparison group. The findings of this study suggest that this metaverse gamification teaching method combining flipped learning and project-based learning is effective at improving task value and academic self-efficacy.

• ETRI Journal
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• v.42 no.5
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• pp.748-760
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• 2020

MapReduce is a framework that can process huge datasets in parallel and distributed computing environments. However, a single machine failure during the runtime of MapReduce tasks can increase completion time by 50%. MapReduce handles task failures by restarting the failed task and re-computing all input data from scratch, regardless of how much data had already been processed. To solve this issue, we need the computed key-value pairs to persist in a storage system to avoid re-computing them during the restarting process. In this paper, the task failure resilience (TFR) technique is proposed, which allows the execution of a failed task to continue from the point it was interrupted without having to redo all the work. Amazon ElastiCache for Redis is used as a non-volatile cache for the key-value pairs. We measured the performance of TFR by running different Hadoop benchmarking suites. TFR was implemented using the Hadoop software framework, and the experimental results showed significant performance improvements when compared with the performance of the default Hadoop implementation.

• The Journal of Korean Association of Computer Education
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• v.15 no.4
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• pp.61-77
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• 2012

The purpose of this study was to examine the structural relationship among task value, self-efficacy, classroom goal structure, and academic emotions(enjoyment, fear, boredom) for promoting self-regulated learning in e-learning course. The results showed that task value, self-efficacy, class goal structure influenced academic emotions and self-regulated learning, and enjoyment had mediation effects among exogenous variables and self-regulated learning. The findings offer implications of facilitating self-regulated learning while considering academic emotions.

• Journal of the Korean Society of Safety
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• v.21 no.5 s.77
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• pp.103-111
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• 2006

The purpose of this study was to analyse the relationships between cognitive abilities and driving characteristics of elderly drivers. Driving characteristics of elderly and younger drivers who were driving a fixed base driving simulator vehicle were examined. Participants consisted of 12 drivers over age 65 (the 'older' group) and 12 drivers between the ages of 25 and 55 (the "younger" group). As indices of cognitive ability, critical flicker fusion frequency (CFF) tests and cognitive reaction tests were given before the driving task. CFF was also tested after the simulated driving task for both groups. Cognitive reaction tests, which were composed of speed estimation tests, multiple choice reaction tests and obstacle avoidance tests, were developed by the Korean Road Traffic Safety Authority in 2003. CFF values between the two groups exhibited significant differences both before and after the task, with a p-value less than 0.01 and a t-value of -3.01 before the test and a p-value less than 0.031 and a t-value of -2.35 after the test. Older drivers' CFF values were lower than those of the younger. However, there was no difference in older or younger driver CFF values before and after the task within the same group. Except for the multiple choice reaction test, there was no difference in cognitive reaction test results between the two groups. The elderly drivers made more errors though they did not differ from the younger drivers in reaction times. At the simulated driving task the reaction time of the elderly driver was longer than that of the younger; however, the driving speed of the elderly was lower and the number of collisions greater. There was a positive correlation (r=.496) between the number of errors in the multiple choice reaction test and the number of collisions in the driving task. Therefore, it was identified that critical attributes contributing to automobile crashes involving elderly drivers included cognitive difficulty in judging and responding to complex situations.

• Journal of Institute of Convergence Technology
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• v.6 no.2
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• pp.9-13
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• 2016

Robot usually requires spline motion to move through multiple knots. In this paper, catmull-rom spline method is applied to the trajectory planning of industrial robot in task space. Centripetal catmull-rom is selected to avoid self-intersection and slow motion which can be occurred in uniform and chordal spline. The method to set two control points are proposed to satisfy velocity conditions of initial and final knots. To optimize robot motion, time scaling method is presented to minimize margin between real robot value and maximum value in velocity and acceleration. The simulation results show that the proposed methods are applied to trajectory planning and robot can follow the planned trajectory while robot motion does not exceed maximum value of velocity and acceleration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.559-564
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• 1994

Recently, a visual servoing for an eye-in-hand robot has become an interesting problem. A distance between a camera and a task object is very useful information for visual servoing. In the previous works for visual servoing, the distance can be obtained from the difference between a reference and a measured feature value of the object such as area on image plane. However, since this feature depends on the object, the reference feature value must be changed when other task object is taken. To overcome this difficulty, this paper presents a novel method for visual servoing. In the proposed method, a blur is used to obtain the distance. The blur, one of the most important features, depends on the focal length of camera. Since it is not affected by the change of object, the reference feature value is not changed although other task object is taken. In this paper, we show a relationship between the distance and the blur, and define the feature jacobian matrix based on camera defocusing to operate the robot. A series of experiments is performed to verify the proposed method.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.3
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• pp.6-15
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• 1992

This paper proposes a method for the global optimization of redundancy over the whole task period for a kinematically redundant robot. The necessary conditions based on the calculus of variations for an integral type cost criterion result in a second-order differential equation. For a cyclic task, the periodic boundary conditions due to conservativity requirements are discussed. We refine the two-point boundary value problem to an initial value adjustment problem and suggest a numerical search method for providing the conservative global optimal solution using the gradient projection method. Since the initial joint velocity is parameterized with the number of the redundancy, we only search the parameter value in the space of as many dimensions as the number of degrees of redundancy. We show through numerical examples that multiple nonhomotopic extremal solutions and the generality of the proposed method by considering the dynamics of a robot.

• The Mathematical Education
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• v.60 no.3
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• pp.341-362
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• 2021

The purpose of this study is to explore the qualitative characteristics of pre-service teachers' motivation while they are participating in group activities for developing mathematical essay assessment problem and revising it. For this purpose, we analyzed individual factors about group learning activities as well as contextual factors about practical competency (in developing and revising mathematical essay assessment problem through collecting data of student responses to the problem). As results of data analyses, autonomy, among individual factors regarding group learning activities, was one of the main characteristics in attainment value, utility value, and intrinsic value, whereas task, authority, and grouping, among contextual factors regarding practical competency, appeared to have a positive impact on task value. These results suggest how to think of specific ideas and articulate them in designing a curriculum to develop student-evaluation expertise for pre-service teachers.

• 전자공학회논문지 IE
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• v.49 no.2
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• pp.65-74
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• 2012

The purpose of this study is to verify the prediction of mastery-approach goal orientation, task value, and self-regulated learning strategy on academic satisfaction and achievement of cyber engineering university students. For this study, 219 engineering students of H cyber university who enrolled in the spring semester of 2011 was chosen and completed web surveys. A hypothetical model proposed included mastery-approach goal orientation, task value, and self-regulated learning strategy as predictors, and academic satisfaction and achievement as criteria variables. The results of this study through multiple regression analysis indicated that task value(${\beta}$=.401) and self-regulated learning strategy(${\beta}$=.401) predicted significantly on academic satisfaction. In addition, self-regulated learning strategy(${\beta}$=.301) and mastery-approach goal orientation(${\beta}$=.196) predicted significantly on academic achievement. The result of this study suggested that mastery-approach goal orientation, task value, and self-regulated learning strategy should be considered for improving academic satisfaction and achievement in cyber engineering education.