• The Journal of Korea Robotics Society
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• v.16 no.2
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• pp.137-146
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• 2021

When controlling manipulator, degree of freedom is lost in singularity so specific joint velocity does not propagate to the end effector. In addition, control problem occurs because jacobian inverse matrix can not be calculated. To avoid singularity, we apply Deep Deterministic Policy Gradient(DDPG), algorithm of reinforcement learning that rewards behavior according to actions then determines high-reward actions in simulation. DDPG uses off-policy that uses 𝝐-greedy policy for selecting action of current time step and greed policy for the next step. In the simulation, learning is given by negative reward when moving near singulairty, and positive reward when moving away from the singularity and moving to target point. The reward equation consists of distance to target point and singularity, manipulability, and arrival flag. Dual arm manipulators hold long rod at the same time and conduct experiments to avoid singularity by simulated path. In the learning process, if object to be avoided is set as a space rather than point, it is expected that avoidance of obstacles will be possible in future research.

• Safety and Health at Work
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• v.9 no.4
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• pp.447-453
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• 2018

Background: Patient safety and accurate implementation of medication orders are among the essential requirements of par nursing profession. In this regard, it is necessary to determine and prevent factors influencing medications errors. Although many studies have investigated this issue, the effects of psychosocial factors have not been examined thoroughly. Methods: The present study aimed at investigating the impact of psychosocial factors on nurses' medication errors by evaluating the balance between effort and reward. This cross-sectional descriptive study was conducted in public hospitals of Tehran in 2015. The population of this work consisted of 379 nurses. A multisection questionnaire was used for data collection. Results: In this research, 29% of participating nurses reported medication errors in 2015. Most frequent errors were related to wrong dosage, drug, and patient. There were significant relationships between medications errors and the stress of imbalance between effort and reward (p < 0.02) and job commitment and stress (p < 0.027). Conclusion: It seems that several factors play a role in the occurrence of medication errors, and psychosocial factors play a crucial and major role in this regard. Therefore, it is necessary to investigate these factors in more detail and take them into account in the hospital management.

• Safety and Health at Work
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• v.13 no.4
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• pp.469-474
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• 2022

Background: Nowadays, counter-productive work behaviors (CWBs) have turned into a common and costly position for many organizations and especially health centers. Therefore, the study was carried out to examine and compare the demand-control-support (DCS) and effort-reward imbalance (ERI) models as predictors of CWBs. Methods: The study was cross-sectional. The population was all nurses working in public hospitals in Hamadan, Iran of whom 320 were selected as the sample based on simple random sampling method. The instruments used were Job Content Questionnaire, Effort-Reward Imbalance Questionnaire, and Counterproductivity Work Behavior Questionnaire. Data were analyzed using correlation and regression analysis in SPSS18. Results: The findings indicated that both ERI and DCS models could predict CWB (p ≤ 0.05); however, the DCS model variables can explain the variance of CWB-I and CWB-O approximately 8% more than the ERI model variables and have more power in predicting these behaviors in the nursing community. Conclusion: According to the results, job stress is a key factor in the incidence of CWBs among nurses. Considering the importance and impact of each component of ERI and DCS models in the occurrence of CWBs, corrective actions can be taken to reduce their incidence in nurses.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.1
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• pp.113-120
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• 2017

PURPOSE: The purpose of this study is to provide the basic data for developing the self-leadership program by identifying the effect of self-leadership on intrinsic motivation among physical therapy students. METHODS: One hundred physical therapy students in E university of Gyeonggido were recruited by convenience sampling from October 4 to 14, 2016. Of them, 89% were chosen and 79% were analyzed after excluding the cases with wrong answers. The survey, using Likert's five scales was conducted with fifteen items of intrinsic motivation (Cronbach's ${\alpha}$, .84) and thirty-five items of self-leadership (Cronbach's ${\alpha}$, .90). Frequency analysis, correlation analysis regression diagnostics, and multiple regression analysis were done with SPSS 20.0 Statistics program (IBM, Korea). RESULTS: The total score of Self-leadership was 3.61 and of substrategies was 4.05 (Natural reward strategy), 3.38 (Behavior-focus strategy), and 3.43 (Constructive thought pattern strategy), respectively. The score of intrinsic motivation was 3.43. The substrategy of Self-leadership indicated positive correlation with intrinsic motivation. The correlation values in higher order were .75 (Natural reward strategy), .66 (Behavior-focus strategy), and .61 (Constructive thought pattern strategy). The Constructive thought pattern strategy (t=5.18, p=.00) and Natural reward strategy (t=2.10, p=.38), except Behavior-focus strategy were effective on intrinsic motivation, according to the multiple regression analysis. CONCLUSION: Before stepping up to the next level of being a physical therapist, students must go through the educational program to improve the Constructive thought pattern strategy and Natural reward strategy.

• Journal of Technologic Dentistry
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• v.31 no.3
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• pp.47-58
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• 2009

Self-leadership means a person's ability to make his thought or behavior in a right way by controlling it himself. Strategies of the same leadership can be largely categorized into three, behavior focused, natural reward and constructive thought strategies. In this study, the foresaid styles of self-leadership strategy are discussed from the perspective of dental lab laboratories' business environment of Gyeongnam region. And accordingly, this researcher examined such strategy styles that dental lab managers, chief technicians and assistant technicians usually have. Results of the study can be summarized as follows. First, out of the self-leadership strategy styles, most remarkably found among the professional of dental technology was constructive thought strategy, followed by behavior-focused and natural reward strategies in order. In general, therefore, the professionals strongly tend to make their thoughts that can a positive effect on their work performance or in a constructive way. In other words, professional dental technicians are more likely to make efforts to persuade or persuade themselves to change their own unreasonable confidence or negative process in more positive way. Second, the extent to which constructive thought strategy is perceived was not different among dental lab managers, chief technicians and assistant technicians. While, behavior-focused and natural reward strategies were found most strongly perceived by dental lab managers, followed by chief and assistant technicians in order. This may be attributed to the fact that the higher professional dental technicians are in position, the higher they are in self-leadership, or in the ability to overcome crises by themselves and make their thought or behavior in a right way. Dental lab managers usually have lots of experiences in relation to behavior-focused or natural reward strategy. Therefore, they are very strongly capable of controlling themselves in order to overcome crises or make their thought or behavior in a right way. In contrast, assistant technicians are still having lots of trials and errors because they are less experienced and skilled. This suggests that chief technicians should make themselves fully capable as a medium that connects between dental lab managers and assistant technicians.

• Journal of the Korean Society for information Management
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• v.20 no.4 s.50
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• pp.67-90
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• 2003

When we introduce knowledge management system in our organization, first of all, we need to change the way of motivating the members so as to voluntarily activate knowledge sharing activity For this, it is very important to establish fair evaluation and adequate reward system about knowledge contribution. In this study, I hypothesized a desirable evaluation and reward model for knowledge contribution on the basis of analysis of documents and cases concerning them in domestic enterprises and R&D institutes that adopted knowledge management. Also, I took a survey to analyze the response of the members of KAERI (Korea Atomic Energy Research Institute) about the evaluation and reward for knowledge contribution. I expect that the analysis results of this study can be applied very usefully in R&B institutes that want to introduce knowledge management.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.534-549
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• 2015

This study was conducted in 2014 with Osong International Bio Industry Expo volunteers as the subjects of the study. The study has analyzed whether their participation motivation, participation satisfaction, and educational training have moderating effects between their motivation and satisfaction. The purpose is to offer implications for successfully holding large events in the future. The findings are as follows. First, the internal reward, a sub-factor of participation motivation, had statistically significant effects on the six elements of volunteering satisfaction. Second, the external reward, a sub-factor of volunteering motivation, had statistically significant effects on the four elements of volunteering satisfaction: self-satisfaction about their abilities; satisfaction in pursuing changes; satisfaction in the event and satisfying interests. However, their satisfaction in self-growth and in interactions were excluded from the volunteering satisfaction elements that were critically affected by the external reward. Third, the training had moderating effects between their internal reward and satisfaction in the event. Forth, the training had moderating effects between their external reward and satisfaction in the event.

• Journal of The Korean Association For Science Education
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• v.24 no.5
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• pp.843-850
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• 2004

This study investigated the effects of group processing in cooperative learning using task-oriented reward on students' science achievement, science learning motivation, and attitude toward science instruction. Eighth graders (N=58) selected from a middle school in Seoul, were randomly assigned to either the treatment or comparison group, and taught on the 'Separation of Mixture' over 8 class hours. The treatment group received cooperative learning using task-oriented reward containing group processing (GCL), while the comparison group received cooperative learning using task-oriented reward without group processing (CL). Significant interactions between the instruction and prior achievement level were found in the achievement and the attitude toward science instruction. High-level students in the GCL group performed better than those in the CL group, while low-level students in the CL group performed better than their counterparts.

• The Journal of the Korea Contents Association
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• v.10 no.12
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• pp.274-289
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• 2010

MMORPG makes up 25.9% of domestic market share in game industry, and it has become increasingly fierce in competition. Game developer and publisher make every effort to build customer e-loyalty to sustain their competitiveness. Thus, this paper examines the determinants of e-loyalty that reflect the features of MMORPG such as intensive and real-time interactivity. For this purpose, we selected interactivity, sense of community, reward and fun as the key antecedents of e-loyalty based on the extensive review of previous researches related to online game and Internet service usage. A total of 202 responses were used for analysis and the research results are as follow. The findings show that interactivity, sense of community and reward influence significantly on fun, then fun is positively related to e-loyalty. Also, interactivity and reward are proven to have a positive influence on sense of community, and sense of community mediates the effect of interactivity and reward on fun.

• The KIPS Transactions:PartA
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• v.10A no.3
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• pp.181-188
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• 2003

We propose a heuristic on-line scheduling algorithm for the IRIS (Increasing Reward with Increasing Service) tasks, which has low computation complexity and produces total reward approximated to that of previous on-line optimal algorithms. The previous on-line optimal algorithms for IRIS tasks perform scheduling on all tasks in a system to maximize total reward. Therefore, the complexities of these algorithms are too high to apply them to practical systems handling many tasks. The proposed algorithm doesn´t perform scheduling on all tasks in a system, but on (constant) W´s tasks selected by a predefined task selection policy. The proposed algorithm is based on task selection policies that define how to select tasks to be scheduled. We suggest two simple and intuitive selection policies and a generalized selection policy that integrates previous two selection policies. By narrowing down scheduling scope to only W´s selected tasks, the computation complexity of proposed algorithm can be reduced to O(Wn). However, simulation results for various cases show that it is closed to O(W) on the average.