• Korean Journal of Child Studies
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• v.28 no.5
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• pp.209-220
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• 2007

This study explored the effects of self efficacy, classroom contextual characteristics and help-avoidance attitudes on academic help-seeking behavior. Participants were 210 4th grade students. Data were analyzed by Pearson's correlation coefficient and multiple regression analysis through the SPSSWIN 12.0. Results showed that students' self efficacy, perception of teacher behavior and goal orientations were positively related to help-seeking behaviors. Help-avoidance attitudes were negatively related to help-seeking behaviors. Cognitive efficacy and social-emotional efficacy facilitated help-seeking behaviors. Help-seeking behaviors were influenced by teacher's supportive help and expectation. Mastery goal orientations and performance-approach goal orientations promoted help-seeking behaviors but performance-avoidance goal orientations impeded help-seeking behaviors. Autonomous intention attitudes expedited help-seeking behaviors but intention based on ability diminished help-seeking behaviors.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.3
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• pp.272-281
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• 2013

Traffic Collision Avoidance System (TCAS) is designed to enhance safety in aircraft operations, by reducing the incidences of mid-air collision between aircraft. The current version of TCAS provides only vertical resolution advisory to the pilots, if an aircraft's collision with another is predicted to be imminent, while efforts to include horizontal resolution advisory have been made, as well. This paper introduces a collision resolution algorithm, which includes both vertical and horizontal avoidance maneuvers of aircraft. Also, the paper compares between the performance of the proposed algorithm and that of algorithms with only vertical or horizontal avoidance maneuver of aircraft.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.146-154
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• 2004

Evaluating the risk of collision quantitatively plays a key role in developing the expert system of navigation and collision avoidance. This study suggested and developed a new approach to the evaluation by using the sech function as an alternative to the existing methods of appraising the collision risk. This study also investigated and built up theoretically how to determine the gradient coefficients in this approach and suggested the appropriate values as much as applicable. Finally this study analyzed thoroughly how to determine the threshold function of avoiding time and developed the appropriate equation.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.1
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• pp.75-84
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• 2013

In this paper, the guidance law for formation flight and collision avoidance of multiple Unmanned Aerial Vehicle (UAV)s is proposed. To construct the physically comprehensible guidance law for formation flight, the virtual structure approach is used. To develop a guidance law for collision avoidance considering both other UAVs and unknown static obstacles, a geometric approach using information such as a relative position vector is utilized. Through the Lyapunov theorem, the stability of the proposed guidance law is proved. To combine guidance commands, the concept of the elastic weighting factor inspired by the elastic behavior of shape memory polymer, which tends to regain its original shape after deformation, is introduced. By using the concept of elastic weighting factor, multiple UAVs are able to cope actively with the situation of a collision between both UAVs and static obstacles during the formation flight. To verify the performance of the proposed method, numerical simulations are performed.

• 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 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.

• 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.

• 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.

• 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 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.