• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.410-415
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• 2013

This paper proposes a bidirectional platoon control law using a coupled distance error based on the backstepping-like feedback linearization control method for an interconnected mobile agent system with a string structure. Unlike the previous results where the single agent was controlled using the only own information without other agents, the proposed control law cannot show the only distance error convergence of each agent, but also the string stability of the whole system. Also, the control performances are improved by the proposed control law in spite of low performance of bidirectional control strategy in the previous results. The proposed bidirectional platoon control algorithm is based on the backstepping-like feedback linearization control method. The position errors between each agent and the preceding and the behind agents are coupled by weighted summation. By the proposed control law, the distance error of each agent can converge to zero while the string stability is guaranteed when the coupled errors can converge to zero. To this end, the back-stepping control method is employed. The pseudo velocity input is determined considering the kinematic relationship between agents and the string stability. Then, the actual dynamic control input is determined to make the actual velocity converge to the pseudo velocity input. The stability analysis and the simulation results of the proposed method are included in order to demonstrate the practical application of the proposed algorithm.

• Korea Journal of Hospital Management
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• v.14 no.4
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• pp.103-123
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• 2009

The purpose of this study is to investigate antecedents and consequences of perceived justice of performance appraisals, which is classified as distributive and procedural justice, in hospital organization. The results of this study are summarized as follows. First, for distributive justice of performance appraisals, the influential factors are the pertinence of performance appraisal method, the opportunity of self-reporting, the availability of performance appraisal, and the feedback of performance appraisal. For the procedural justice of performance appraisals, they are the leadership style of performance appraisers, the ratee-rater exchange relationship, the pertinence of performance appraisal method, the opportunity of self-reporting, and the feedback of performance appraisal. Second, the perceived justice weakly affects outcome variables, organizational commitment and job satisfaction. By these results, the performance appraisal system needs to be changed in order to enhance distributive justice through the improvement of suitable methods of the performance appraisal, the opportunity of self-reporting, the availability of performance appraisal, and the feedback of performance appraisals. If it is difficult to increase the level of distributive justice due to the environmental restrictions in hospitals, the way to enhance the procedural justice more than the distributive one should be considered.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.1
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• pp.41-52
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• 1992

An algorithm of transforming continuous-time state feedback gains into equivalent discrete-time feedback gains or vice versa is proposed using bilinear transformation. The proposed method is evaluated experimentally by an application control of a mobile crane system which is implemented by 16bits micro computer with A/D and D/A converters. It has been shown from the experimental result that the transformed feedback gains are virtually identical to the optimal discrete gain over range of significant sampling time. Since the transformed matrix is composed by a distinct relationship between continuous-time gain and discrete-time gain, it is noted that the proposed method can be regarded as an explicit gain transformation method compared to the other methods using series expansion.

• Journal of Korea Game Society
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• v.19 no.2
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• pp.135-144
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• 2019

This study examined the role of enjoyment in the relationship between perceived auditory feedback (PAF), which provides information about the situation during game play, and user experience factors. 100 undergraduates played a mobile game, 'Classy Royale' and took a survey about their user experience. As a result of analyzing the available data from 98 participants, PROCESS MACRO showed that PAF was positively associated with enjoyment, immersion, and intention to use; enjoyment mediated the effects of PAF on immersion and intention. These results can help game research and development regarding the functional value of audio factors.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.549-556
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• 2020

This paper proposes several suboptimal methods of designing a controller for a networked control system with state feedback where delay due to transmission error and transmission delay is modeled as a Markov process. A stability condition for a control system with Markov delay is found through an equivalent relationship that corresponding delay-dependent Lyapunov-Krasovskii functional has the same form of the Lyapunov function of an augmented control system. Several suboptimal methods of designing a controller from the stability condition are proposed to reduce complexity. A simple numerical experiment shows that a restricted subspace method which limits the search space of a matrix variable to a block diagonal form provides the best tradeoff between the complexity and performance.

• Management & Information Systems Review
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• v.21
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• pp.49-76
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• 2007

The main purpose of this study is to assess the relationship between communication satisfaction and group creativity. To achieve this purpose, this study has two objectives. First, I will identify the relationship between the satisfaction of communication and idea creation. Second, the relationship between communication satisfaction and problem solving activity will be statistically tested. The major findings of the study can be summarized as follows: First, Statistically significant positive relations were found between the communication satisfaction and idea creation. Especially, sub-construct for supervisor communication$({\beta}=0.14,\;p<.05)$, quality of media$({\beta}=0.13,\;p<.05)$, individual feedback$({\beta}=0.36,\;p<.001)$, organizational prospect$({\beta}0.31,\;p<.001)$ showed the statistically significant positive(+) relationship with construct in idea creation. Second, the measurement of communication satisfaction had showed statistically significant relationship with the problem solving activity. Especially, communication with supervisor$({\beta}=0.21,\;p<.05)$, quality of media$({\beta}=0.21,\;p<.001)$, organizational prospects$({\beta}=0.22,\;p<.001)$, and communication with subordinate$({\beta}=0.37,\;p<.001)$ showed the significant positive(+) relationship with problem solving activity construct. These consequences suggest that communication satisfaction of employee is effective in the improving the group creativity in organization. In the conclusion, this study present the satisfaction factor of employee communication as a incremental factor of group creativity.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.29.5-30
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• 2016

(1) The correlation between the mass of supermassive black holes (SMBHs) and the properties of their host galaxies suggests that SMBHs and host galaxies are closely linked in their formation and evolution. While the exact origin of their relationship is still under debate, theoretical models often invoke feedback from active galactic nuclei as a crucial mechanism for establishing the BH-host correlation. In the first part of my talk, I will present our efforts to find observational sign of the AGN feedback in young luminous AGNs. (2) While intermediate-mass black hole (IMBH) is thought be cosmologically important class to understand the link between stellar mass black holes and SMBHs, it is extremely rare in the present-day Universe. In the second part of this talk, I will report a Gemini/GMOS-N IFU study of an ultraluminous X-ray source in NGC 5252, which is a possible candidate of an off-nuclear non-stellar black hole.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2215-2217
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• 2004

In this paper, a systematic design approach based on the parallel distributed compensation technique is proposed for chaotifying a general continuous-time Takagi-Sugeno (TS) fuzzy system. The fuzzy parallel distributed compensation controller (FPDCC) is composed of the feedback gain and time-delay feedback. The verification of chaos in the controlled continuous-time TS fuzzy system is done by the following procedures. First, we establish an asymptotically approximate relationship between a time-delay continuous-time TS fuzzy system and a discrete-time TS fuzzy system. Then, Marotto theorem is applied. Therefore, the generated chaos is in the sense of Li and Yorke. The boundedness in the controlled continuous-time TS fuzzy system is also proven via its associated discrete-time TS fuzzy system.

• Korean System Dynamics Review
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• v.15 no.4
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• pp.61-84
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• 2014

This study aims to explore the development and application of a simulated skills package designed to improve nursing students' knowledge integration and their system thinking(ST) skills about congestive heart failure(CHF) and to identify the change in students' ST levels using a ST-based learning approach. A simulated learning support package was developed by nurse educators and ST experts. The developed program was implemented with 35 third-year nursing students from S university in Seoul. The subjects improved their ST skills regarding CHF after intervention. Mean test scores for students completing the program were significantly higher than pre-intervention scores, including measures of direction of causality, polarity of causal relationship, feedback loop, polarity of feedback loop (reinforcing, balancing) and time delay (t=2.26~6.53, p=.030~p<.001). It is suggested that more educational programs be developed on various topics in order for nursing students to improve their ST skills as well as knowledge integration in clinical nursing practicum packages.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.27.4-27.4
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• 2017

(1) The correlation between the mass of supermassive black holes (SMBHs) and the properties of their host galaxies suggests that SMBHs and host galaxies are closely linked in their formation and evolution. While the exact origin of their relationship is still under debate, theoretical models often invoke feedback from active galactic nuclei as a crucial mechanism for establishing the BH-host correlation. In the first part of my talk, I will present possible observational biases in the BH-host relation, and methods to overcome these biases. I will also report our efforts to find observational sign of the AGN feedback in high-z young luminous AGNs. (2) While intermediate-mass black hole (IMBH) is thought be cosmologically important class to understand the link between stellar mass black holes and SMBHs, it is extremely rare in the present-day Universe. In the second part of this talk, I will report a Gemini/GMOS-N IFU study of an ultraluminous X-ray source in NGC 5252, which is a possible candidate of an off-nuclear non-stellar black hole.