• Journal of the Korean Society of Food Culture
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• v.27 no.6
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• pp.677-685
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• 2012

This study examined the job satisfaction and characteristics of dietitians working in an elderly health care facility. The subjects for the study were 116 dietitians who work in an elderly health care facility across the country. The following lists the items affecting the total satisfaction on each element of the job: the nature of work (4.20), coworkers (4.02), supervision (3.83), communication (3.81), pay (3.22), operating conditions (3.16), fringe benefits (3.05) and promotion (2.78). Regarding supervision, regular employees (3.90) had higher satisfaction than non-regular employees (3.11), and for fringe benefits, regular employees (3.10) had higher satisfaction than non-regular employees (2.52). Regarding fringe benefits, those with less than 10 years experience showed higher satisfaction than with more than 10 years'. In terms of the job characteristics, the following were found to affect job satisfaction: the task identity (3.33), variety (3.27), autonomy (3.18), feedback (3.05), friendship opportunities (3.01) and dealing with others (2.82) were listed in the highest order. For task identity, more than 41 years old (3.53) had a significantly higher score. Regarding diversity, graduate schools (3.37) had a significantly higher score. In terms of income, those earning more than 2 million won (3.37 and 3.26) showed higher scores in autonomy and friendship opportunities than those earning less than 1.5 million won (2.79 and 2.57).

• Journal of the HCI Society of Korea
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• v.14 no.2
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• pp.83-91
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• 2019

These days, virtually every mobile game has a daily quest system. Daily quest is a great tool that can attract game players by providing daily rewards as the player conducts designated missions. However, conducting similar tasks repeatedly has a risk of becoming tedious duties, and maintaining an enjoyable daily quest is critical in enhancing the overall experience of a game. Based on the awareness on the need for academic research on daily quest systems, this study categorized the types of quests systems implemented in the current mobile games, observed how preferred type differs by player's propensity, and analyzed how motivation of a player can be improved using quest types. The results are (1) the staged rewards after each clearance of a task improve a player's motivation, (2) players with high autonomy should be given a freedom to choose their own quests, and (3) players who values their playing skills higher are motivated by providing a feedback on the completion of a task.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.47-52
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• 2021

This research emphasized that the importance of key elements of job characteristics such as technical diversity, task identity, task importance, autonomy, and feedback. Moreover, it focused on verifying the effects of these five elements on turnover intention through Self-Efficacy. To verify this, an empirical analysis was conducted on employees of the service industry in China. Through empirical analysis, it was found that all five elements of job characteristics improve Self-Efficacy. Furthermore, Self-Efficacy was found to degrade the level of turnover intention. Furthermore, it has been verified that self-efficacy has a fully mediated effect in the relationship between the two elements(technical diversity, autonomy) of job characteristics and turnover intention. Through this research, it was revealed which elements of job characteristics had the greatest influence on self-efficacy. Finally, based on this research, we presented useful implications in human resource management to practitioners of Chinese service companies and Korean service companies seeking to enter China and future research directions were discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.179-187
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• 2018

This study purpose is to improve athletes by investigating the relation between the leadership behavior type of athletes and athlete satisfaction and exercise flow. The sampling method was non-probabilistic sampling method. The number of questionnaires was 381 for analyzing the data. SPSS/PC+ Window 21.0 version statistical program were used for analyzing the questionnaire answers. Frequency analysis, factor analysis, correlation analysis and multiple regression analysis were used. The study results are as follows. First, there were positive correlations between leadership behavior type of athletes and athlete satisfaction and exercise flow, but not between authoritative behavior of leader behavior type and exercise flow. Second, the effect of leadership behavior type of athletes on satisfaction of athletes was positive on social interaction related with training, instruction, and social support, on task execution related with training and instruction, and on coaching related with training, instruction, and positive feedback. Third, the effect of leadership behavior type of athletes on flow of exercise was positive on cognitive commitment related with training, instructions and positive feedback, and on behavioral commitment related with training, instructions, positive feedback, and social interaction. So, athletes will be able to perform good exercise skills if they come to the game in flowing exercise satisfaction and exercise.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.363-376
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• 2023

According to the COVID-19, development of various medical software based on IoT(Internet of Things) was accelerated. Especially, interest in a central software system that can remotely monitor and control ventilators is increasing to solve problems related to the continuous increase in severe COVID-19 patients. Since medical device software is closely related to human life, this study aims to develop central monitoring system that can remotely monitor and control multiple ventilators in compliance with medical device software development standards and to verify performance of system. In addition, to ensure the safety and reliability of this central monitoring system, this study also specifies risk management requirements that can identify hazardous situations and evaluate potential hazards and confirms the implementation of cybersecurity to protect against potential cyber threats, which can have serious consequences for patient safety. As a result, we obtained medical device software manufacturing certificates from MFDS(Ministry of Food and Drug Safety) through technical documents about performance verification, risk management and cybersecurity application.The purpose of this study is to conduct a usability assessment to ensure that ergonomic design has been applied so that the ventilator central monitoring system can improve user satisfaction, efficiency, and safety. The rapid spread of COVID-19, which began in 2019, caused significant damage global medical system. In this situation, the need for a system to monitor multiple patients with ventilators was highlighted as a solution for various problems. Since medical device software is closely related to human life, ensuring their safety and satisfaction is important before their actual deployment in the field. In this study, a total of 21 participants consisting of respiratory staffs conducted usability test according to the use scenarios in the simulated use environment. Nine use scenarios were conducted to derive an average task success rate and opinions on user interface were collected through five-point Likert scale satisfaction evaluation and questionnaire. Participants conducted a total of nine use scenario tasks with an average success rate of 93% and five-point Likert scale satisfaction survey showed a high satisfaction result of 4.7 points on average. Users evaluated that the device would be useful for effectively managing multiple patients with ventilators. However, improvements are required for interfaces associated with task that do not exceed the threshold for task success rate. In addition, even medical devices with sufficient safety and efficiency cannot guarantee absolute safety, so it is suggested to continuously evaluate user feedback even after introducing them to the actual site.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1742-1745
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• 1997

We have developed a highly responsible probing system for inspection of electrical properties of assemble PCB$_{s}$ (printed circuit boards). However, as the duration of the impact occurring between a probe and a solder joint on PCB is very short, it is very difficult to control the harmful peak impact force and the slip motion of the probe to sufficient level only by its vorce feedback control with high gains. To overcome these disadvantages of the prototype, it needs ot obtain some information of the solder joint in advance before the contact. In addition, to guarantee the reliability of the probing task, the probing system is required to measure several points around the probale target point at high speed. There fore, to meet such requirements, we propose a new noncontaet sensor capable of detecting simultaneously position and normal vectors of the multiple points around the probable target point in real time. By using this information, we can prepare a control strategy for stable contact motion on impact. In this paper, we described measuring priniciple, design, and development of the sensor. The effectiveness of the proposed sensor is verified through a series of experiments.s.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1786-1790
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• 2004

The main objective of this paper is to analyze the performance of various force control algorithms in improving and adjusting the compliance of industrial robots in contact with their environment. Some of fundamental force control algorithms such as sensorless control, impedance control and hybrid position/force control are theoretically analyzed and simulated for various situations of an environment, and then a series of experiments using them were performed. In this paper, a control scheme to use position control in implementing the impedance control was investigated in order to nullify the effect of joint friction. The new reference trajectory is generated using contact force feedback and original desired trajectory. And an inner position control loop is designed to provide accurate position tracking for the new reference trajectory and good disturbance rejection. Experiments to insert a peg in a hole (so-called the peg-in-a-hole task) were performed with HILS (hardware-in-theloop simulation) system based on the results of the analyses and simulations on the characteristics of each control algorithm. The experiments showed that various force control methods improved the performance of robots in close contact with the environment by adjusting their compliance with respect to an arbitrary set of coordinates.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.211-218
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• 1999

The traditional robot manipulators are actuated by continuous range of motion actuators such as motors or hydraulic cylinders. However, there are many applications of mechanisms and robotic manipulators where only a finite number of locations need to be reached, and the robot’s trajectory is not important as long as it is bounded. Binary manipulator uses actuators which have only two stable states. As a result, binary manipulators have a finite number of states. The number of states of a binary manipulator grows exponentially with the number of actuators. This kind of robot manipulator has some advantage compared to a traditional one. Feedback control is not required, task repeatability can be very high, and finite state actuators are generally inexpensive. And this kind of robot manipulator has a fault tolerant mechanism because of kinematic redundancy. In this paper, we solve the inverse kinematic problem of a binary parallel robot manipulator using neural network and test the validity of this structure using some arbitrary points m the workspace of the robot manipulator. As a result, we can show that the neural network can find the nearest feasible points and corresponding binary states of the joints of the robot manipulator

• Smart Structures and Systems
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• v.11 no.3
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• pp.315-329
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• 2013

The construction of an experimental nonlinear structural model with little cost and unlimited repeatability for vibration control study represents a challenging task, especially for material nonlinearity. This paper reports the design, analysis and vibration control of a nonlinear structural experiment platform with adjustable hinges. In our approach, magnetorheological rotary brakes are substituted for the joints of a frame structure to simulate the nonlinear material behaviors of plastic hinges. For vibration control, a separate magnetorheological damper was employed to provide semi-active damping force to the nonlinear structure. A dynamic neural network was designed as a state observer to enable the feedback based semi-active vibration control. Based on the dynamic neural network observer, an adaptive fuzzy sliding mode based output control was developed for the magnetorheological damper to suppress the vibrations of the structure. The performance of the intelligent control algorithm was studied by subjecting the structure to shake table experiments. Experimental results show that the magnetorheological rotary brake can simulate the nonlinearity of the structural model with good repeatability. Moreover, different nonlinear behaviors can be achieved by controlling the input voltage of magnetorheological rotary damper. Different levels of nonlinearity in the vibration response of the structure can be achieved with the above adaptive fuzzy sliding mode control algorithm using a dynamic neural network observer.

• The Journal of Korea Robotics Society
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• v.8 no.3
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• pp.186-196
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• 2013

Since its introduction (e.g., [4, 6]), virtual coupling technique has been de facto way to connect a haptic device with a virtual proxy for haptic rendering and control. However, because of the single dependence on spring-damper feedback action, this virtual coupling suffers from the degraded transparency particularly during contact tasks when large device/proxy-forces are involved. In this paper, we propose a novel virtual coupling technique, which, by utilizing passive decomposition, reduces device-proxy position deviation even during the contact tasks while also scaling down (or up) the apparent inertia of the coordinated device-proxy. By doing so, we can significantly improve transparency between multiple degree of freedom (possibly nonlinear) haptic device and virtual proxy. In other to use passive decomposition, disturbance observer of [3] is adopted to estimate human force with some dead-zone modification to avoid "winding-up" force estimation in the presence of device torque saturation. Some preliminary experimental results are also given to illustrate efficacy of the proposed technique.