• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1161-1166
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• 2007

This paper proposes the Elastic Force application on the obstacle avoidance of the Silvermate Robot. The method deals with the problem associated with the Silvermate robot driving to a goal configuration as avoiding obstacles. The initial trajectory of a robot is determined by a motion planner, and the trajectory modification is accomplished by adjusting the control points. The control points are obtained based on the elastic force approach. Consequently the trajectory of a robot is incrementally modified to maintain a smooth and adaptive trajectory in an environment with obstacles. The suggested algorithm drivers the robot to obstacle avoid in real-time. Finally, the simulation studies are carried out to illustrate the effectiveness of the proposed approach

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.33-40
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• 2007

This paper proposes the Elastic force application on the obstacle avoidance of Silvermate robots. The method deals with the problem associated with a Silvermate robot driving to a goal configuration as avoiding obstacles. The initial trajectory of a robot is determined by a motion planner, and the trajectory modification is accomplished by adjusting the control points. The control points are obtained based on the elastic force approach. Consequently the trajectory of a robot is incrementally modified to maintain a smooth and adaptive trajectory in an environment with obstacles. The suggested algorithm drives the robot to avoid obstacle in real-time. Finally, The simulation studies are carried out to illustrate the effectiveness of the proposed approach.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.2
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• pp.169-178
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• 1997

This paper presents a new solution approach to moving obstacle avoidance problem of a robot. A new concept, avoidability measure(AVM) is defined to describe the state of a pair of a robot and an obstacle regarding the collision between them. As an AVM, virtual distance function(VDF) is derived as a function of three state variables: the distance from the obstacle to the robot, outward speed of the obstacle relative to the robot, and outward speed of the robot relative to the obstacle. By keeping the virtual distance above some positive limit value, the robot avoids the obstacle. In terms of the VDF, an artificial potential is constructed to repel the robot away from the obstacle and to attract the robot toward a goal location. At every sampling time, the artificial potential field is updated and the force driving the robot is derived from the gradient of the artificial potential field. The suggested algorithm drives the robot to avoid a moving obstacle in real time. Since the algorithm considers the mobility of the obstacle and robot as well as the distance, it is effective for moving obstacle avoidance. Some simulation studies show the effectiveness of the proposed approach.

• Journal of Korea Game Society
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• v.20 no.4
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• pp.21-32
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• 2020

The study took online game users' need for affect (approach/avoidance) and social norms (subjective/descriptive) into account and examined how these variables affected their attitude (utilitarian/hedonic) toward online games and their flow experience. Results from the hierarchical multiple regression analysis showed that, game users' approach affect and subjective norm had significant impacts on their utilitarian attitude, while their approach/avoidance affect and subjective norm had on their hedonic attitude toward onine games. Plus, the avoidance affect, subjective norm, and utilitarian/hedonic attitudes of game users had significant impacts on their flow experience.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.1
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• pp.112-119
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• 2011

This paper introduces a technique for calculating the degree of collision risk used in collision avoidance system of AUVs. The collision risk will be reckoned with the fuzzy inference, which uses TCPA(Time of the Closest Point of Approach) and DCPA(Distance of the Closest Point of Approach) as factors. A method to obtain TCPA and DCPA for 3-dimension is suggested. The degree of collision risk is provided to collision avoidance system, and is verified the effectiveness through simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.321-324
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• 2003

There are two steps to solve the self-collision avoidance problems for redundant manipulators. First, all links are regarded as cylinders. and then the collisions should be checked among all pairs of the links. Between two cylinders. we can get the collision information derived from the concept or configuration space obstacle in real time. Therefore. it is possible to detect the links where collisions are likely in real time by setting the risk radius which is larger than actual radius. Second. the configuration control points (CCP) should be placed at the ends of the detected links. A cost function is the sum of the distances between the CCPs. To maximize the cost function means the links go far away each other without self-collisions.

• Journal of Korean society of Dental Hygiene
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• v.12 no.1
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• pp.167-178
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• 2012

Objectives : The purpose of this research is to examine the effects of the goal achievement orientation of the students in dental-hygiene practice classes on their self-efficacy and on their adaptation to and satisfaction with their major. Methods : A survey was conducted among the dental-hygiene students in schools located in the Daegu region on October 24-31, 2011. A total of 212 accomplished questionnaires were gathered as sources of final analytical data. Statistical analysis was conducted on the collected data, using the SPSS 19.0 program. Results : 1. The students who had good personal relationships(p=.000) and who chose their major and school based on their aptitude(p=.029) were found to have a higher degree of satisfaction than those who did not have good personal relationships and who did not choose their major and school based on their aptitude. 2. Self-confidence(p=.004), self-control efficacy(p=.000), mastery approach(p=.000), and performance approach(p=.003) were found to have positive correlations with major adaptation while task difficulty preference(p=.000) was found to have a negative correlation with the same. 3. Self-confidence(p=.004), self-control efficacy(p=.000), mastery approach(p=.000), and performance approach(p=.045) were also found to have a positive correlation with major satisfaction while task difficulty preference(p=.000) was found to have a negative correlation with the same. 4. Mastery approach(p=.000) in goal achievement orientation was found to have a positive effect on self-efficacy while mastery avoidance(p=.001) was found to have a negative effect on the same. Mastery avoidance showed the greatest effect on self-confidence(p=.000) while mastery approach showed the greatest effect on self-control efficacy(p=.000) and task difficulty preference(p=.000). 5. In goal achievement orientation, mastery approach(p=.000) was found to have a positive effect on major adaptation while mastery avoidance was found to have a negative effect on the same. Meanwhile, with regard to self-efficacy, self-control efficacy(p=.037) and task difficulty preference(p=.008) were found to have positive effects on major adaptation. 6. In the case of major satisfaction, mastery approach(p=.000) in goal achievement orientation was found to have a positive effect on it, and in self-efficacy, self-control efficacy(p=.038) and task difficulty preference(p=.002) were found to have positive effects on it. Conclusions : Accordingly, to raise the level of the dental-hygiene students' adaptation to and satisfaction with their major, the students should be given appropriate tasks so that they can raise their mastery goal, and they should be encouraged to raise their approach goal rather than their avoidance goal. In addition, the students should be provided assistance in setting self-expectations and in developing confidence in their capabilities.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.6
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• pp.379-388
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• 2018

In this study, we propose a new approach to impliment autonomous travelling of mobile robot based on obstacle avoidance and voice command. Obstacle Avoidance technology of mobile robpot. It has been used in wide range of different robotics areas to minimize the risk of collisions. Obstacle avoidance of mobile robots are mostly applied in transportation systems such as aircraft traffic control, autonomous cars etc. Collision avoidance is a important requirement in mobile robot systems where they all featured some kind of obstacle detection techniques in order to avoid colliding. In this paper it was illustrated the reliability of voice command and obstacle avoidance for autonomous travelling of mobile robot with two wheels as the purpose of application to the manufacturing process by simulation and experiments.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.8 s.179
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• pp.2131-2142
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• 2000

As recent production facilities are usually operated with unmanned material-handling system, the development of an efficient schedule with deadlock avoidance becomes a critical problem. Related researches on deadlock avoidance usually focus on real-time control of manufacturing system using deadlock avoidance policy. But little off-line optimization of deadlock-free schedule has been reported. This paper presents an optimization method for deadlock-free scheduling for Job-Shop system with no buffer. The deadlock-free schedule is acquired by the procedure that generates candidate lists of waiting operations, and applies a deadlock avoidance policy. To verify the proposed approach, simulation resultsare presented for minimizing makespan in three problem types. According to the simulation results the effect of each deadlock avoidance policy is dependent on the type of problem. When the proposed LOEM (Last Operation Exclusion Method) is employed, computing time for optimization as well as makespan is reduced.

• Asia-Pacific Journal of Business
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• v.14 no.4
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• pp.233-254
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• 2023

Purpose - This study aims to verify whether the effect of tax avoidance on corporate value is non-linear in the Korean financial markets. Design/methodology/approach - This study believes that the cause of the inconsistent empirical analysis results of previous studies that verified the relationship between tax avoidance and firm value may be an error in assuming linearity, and verifies whether a nonlinear relationship exists. The sample company in this study is a December settlement corporation listed on the Korean stock market, and the analysis period is from 2000 to 2021. In the empirical analysis model, Tobin's Q is used as a proxy for corporate value, tax avoidance is used as the main independent variable, and a regression model is designed with corporate size, growth rate, and debt ratio set as control variables. Findings - As a result of the empirical analysis, it can be confirmed that there is an inverted U-shaped nonlinear relationship between tax avoidance and corporate value. In the additional analysis using Ohlson (1995) firm valuation model for the robustness of the results of the empirical analysis, the same nonlinear value relationship between tax avoidance can be confirmed. Research implications or Originality - This study is considered to be meaningful in that it verifies the non-linear relationship of tax avoidance, which has not been attempted in previous studies. The meaning of the inverted U-shaped nonlinear relationship presented in this study is that corporate tax avoidance acts as a factor that increases corporate value up to a certain level, but rather becomes a factor that decreases corporate value when it exceeds a critical point. These results are expected to provide new perspectives and perspectives on tax avoidance to companies belonging to the Korean capital market.