• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.438-442
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• 2003

For an efficient sliding mode control system stability and chattering avoidance should be guaranteed. A continuation method using boundary layer is well known as one solution for this. However since not only model uncertainties and disturbances but also control task itself is variable. it is practically impossible to set controller parameters - control discontinuity, control bandwidth, boundary layer thickness - in advance. In this paper first an adaptation law of control discontinuity is introduced to assure system stability and then fuzzy logic based tuning algorithm of design parameters is applied based on monitored performance indices of tracking error, control chattering, and model precision. In the end maximum control bandwidth not exciting unmodeled dynamics and minimum control discontinuity, boundary layer thickness making system stable and free of chattering are found respectively. This eliminates control chattering and enhances control accuracy as much as possible under given control situation. In order to demonstrate the validity of the proposed algorithm safe headway maintenance control for autonomous transportation system is simulated. The control results show that the proposed algorithm guarantees system stability all the time and tunes control parameters consistently and in consequence implements an efficient control in terms of both accuracy and actuator chattering.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.2
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• pp.91-99
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• 2013

An autonomous unmanned underwater vehicle is a type of marine self-propelled robot that executes some specific mission and returns to base on completion of the task. In order to successfully execute the requested operations, the vehicle must be guided by an effective navigation algorithm that enables it to avoid obstacles and follow the best path. Architectures and principles for intelligent dynamic systems are being developed, not only in the underwater arena but also in related areas where the work does not fully justify the name. The problem of increasing the capacity of systems management is highly relevant based on the development of new methods for dynamic analysis, pattern recognition, artificial intelligence, and adaptation. Among the large variety of navigation methods that presently exist, the dynamic window approach is worth noting. It was originally presented by Fox et al. and has been implemented in indoor office robots. In this paper, the dynamic window approach is applied to the marine world by developing and extending it to manipulate vehicles in 3D marine environments. This algorithm is provided to enable efficient avoidance of obstacles and attainment of targets. Experiments conducted using the algorithm in MATLAB indicate that it is an effective obstacle avoidance approach for marine vehicles.

• Journal of Korean Academy of Nursing
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• v.30 no.2
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• pp.293-306
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• 2000

Providing care to the dementia elderly with behavioral problem is a major issue in nursing homes today. This study was aimed to explore the nursing staffs′ response to aggressive dementia patients, and the effect that the aggressive behavior had on Nsgstaff. The interviews used a semi-structured questionnaire are were carried out from May to July, 1999. The subjects were 23 nursing personnel working in the nursing homes for dementia elderly. The result are as follows; 1. The types of aggressive behavior cited by the subjects was "physical", "linguistic", and "sexual". 2. The factors that caused the behavior were "symptoms of disease", "under- conditioning", "context of nursing care", "unsatisfied need", "relationship to other patients", "change of outer environment", and "invasion of one′s own privacy". 3. The response of the subjects were "unhappiness", "stress", "anger", "exaggeration", "anxiety", and "fear". 4. The management strategies listed by nursing personnel used to alleviate aggressive behavior were "ignorance" "patience" "leaving the area" "soothing sounds" "verbal punishment" "restriction and isolation" and "various management skill appliance" "adaptation". 5. The effect that aggressive behavior and were "disturbance of relationship to elderly" "decline in the amount and quality of nursing care" "interruption of task performance" "job exhaustion" "desire to leave the job" "physical impact" "stress on the cognition of others" "anxiety about health and one own future" "interference to family life′. The findings of this study will be useful in understanding the difficulties of nursing personnel when confronting the aggressive behavior of dementia partients. It also is useful as basic data in preparing efficient intervention program for these difficulties.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.221-230
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• 1999

Automobile horn's psychoacoustic characteristic and significance as a anturalistic signal of danger makes it a valuable auditory stimulus to study such psychophysiological responses as startle, orienting and defense reactions. However, comparison and differentiation of physiological responses to commercially available horns is a complicated task due to small contrast of technical features of horns and influence of such processes as habituation on physiological outcome with increased number of auditory stimulation trials. In the study on 10 college students we performed comparative analysis of tonic and phasic reactivity of physiological responses mediated by autonomic nervous system in order to identify role of habituation and decrement of autonomic responsivity, as well as possibility o differentiate subjectively most and least preferred and subjectively more appropriate horns according to physiological manifestations. It was showed that electrodermal and cardiovascular reactivity have concurrent patterns of adaptation to repeated stimulation, namely skin conductance variables habituated, cardiac reactivity failed to show signs of habituation, while vascular component of response were facilitated demonstrating marked sensitization. Differentiation of Physiological responses to horns with respect to their subjective rating scores was possible, however electrodermal reactivity was effective only at the first block of trials, while phasic and tonic cardiovascular reactivity differentiate responses during whole course of experiment. There are discussed possible autonomic mechanisms involved in mediation of observed results.

• Journal of Microbiology and Biotechnology
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• v.21 no.3
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• pp.243-251
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• 2011

The gene bolA was discovered in the 80's, but unraveling its function in the cell has proven to be a complex task. The BolA protein has pleiotropic effects over cell physiology, altering growth and morphology, inducing biofilm formation, and regulating the balance of several membrane proteins. Recently, BolA was shown to be a transcription factor by repressing the expression of the mreB gene. The present report shows that BolA is a transcriptional regulator of the dacA and dacC genes, thus regulating both DD-carboxypeptidases PBP5 and PBP6 and thereby demonstrating the versatility of BolA as a cellular regulator. In this work, we also demonstrate that reduction of cell growth and survival can be connected to the overexpression of the bolA gene in different E. coli backgrounds, particularly in the exponential growth phase. The most interesting finding is that overproduction of BolA affects bacterial growth differently depending on whether the cells were inoculated directly from a plate culture or from an overnight batch culture. This strengthens the idea that BolA can be engaged in the coordination of genes that adapt the cell physiology in order to enhance cell adaptation and survival under stress conditions.

• Science of Emotion and Sensibility
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• v.15 no.3
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• pp.381-388
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• 2012

The purpose of this study is to check if LED lighting can be used as general lighting and examine the color rendering property of full color RGB LED lighting. CRI is one of the important properties of evaluating lighting. However the present CRI does not fully evaluate LED lightings. Firstly, the performance of a simple task was compared other than comparing CRI values for different lighting. For experimental preparation three types of lightings were used; standard D65 fluorescent tube, general household fluorescent tube, and RGB LED lighting. All three lightings show high error for Purple-Red. All three lightings show similar error for all hues and prove that color discrimination is not affected by the lighting. This proves that LED could be used as general lighting. Secondly, problems of the conventional CIE CRI method are considered and new models are suggested for the new lighting source. Each of the models was evaluated with visual experiment results obtained by the white light matching experiment. The suggested model is based on the CIE CRI method but replaces the color space model by CIELAB, color difference model by CIEDE2000, and chromatic adaptation model by CAT02.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.1019-1029
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• 2021

The study aims to investigate the impact of psychological climate, self-resilience, Organizational Citizenship Behaviour (OCB) and job stress on employee performance during Covid-19 pandemic. This paper also attempts to find out the mediating role of OCB and job stress in this context. A confirmatory survey was conducted on 316 employees of several institutions in Indonesia who worked from home during Covid-19 for a minimum period of 2 months. The research revealed that 1) PC has significant and positive influence on OCB and performance; 2) Self resilience have positive and significant influence on performance; 3) PC and self-resilience have a negative influence on job stress; 4) there are insignificant relationship between self-resilience on OCB; OCB and job stress on performance; 5) PC and self-resilience have no indirect influence on performance through OCB and job stress. The findings of this study reveal that organizations expected to have strategic approach in order to handle Covid-19 pandemic in different work patterns that are required to carry out routine office tasks from home, including handling stress as a fast adaptation for both employees and organizations that have a routine task from home.

• Journal of the Korea Safety Management & Science
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• v.23 no.4
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• pp.121-133
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• 2021

The composition of human resources in industrial sites is becoming global. In Korea, too, the proportion of foreign members in all industrial fields and production sites is increasing. This is the reason why an approach that reflects this reality is needed in the basic unit of competitive sources. Competitiveness starts with value creation, and this progresses through field innovation. Through empirical analysis of this study, it was analyzed that South Korea members showed active actions and attitudes in developing, promoting, and realizing ideas when they strongly recognized the real meaning of empowerment given by leaders. On the other hand, it was found that foreign members do not know the meaning of empowerment itself, so they are often unable to play an active role in the development, promotion, and realization of ideas. In fact, it was analyzed that foreign members generally did not experience positive interactions with LMX and were exposed to simple tasks and controls. In other words, they are being discriminated against in terms of communication problems, compensation system, and work environment. In particular, this phenomenon is exacerbated in the case of small and medium-sized enterprises (SMEs). Situational response to foreign workers through improvement of LMX and empowerment should be evaluated as a key management task in a situation where productivity improvement and job unit innovation are urgently needed.

• Journal of Internet Computing and Services
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• v.25 no.3
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• pp.9-18
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• 2024

Digital therapy has emerged as a novel treatment modality, propelled by advancements in information and communication technology. In the last five years, there has been a substantial surge in research publications addressing digital therapeutics (DTx) interventions, signaling a sustained upward trajectory in this field. The dynamic nature of computer science, marked by continuous innovation and development, underscores the need for agile adaptation to rapid changes. Consequently, computer science education is compelled to offer students insights into the latest trends. This research endeavors to contribute to the evolving landscape by developing textbooks that impart knowledge about DTx, an integration of information technology. The study focuses on the application of these textbooks to elementary and middle school students in South Korea. The instructional materials have been carefully organized to enable students to learn about the principle of Attention Deficit Hyperactivity Disorder (ADHD) DTx at the elementary level and the DTx that can prevent and address the digital drama at the middle school level. Based on the application of the textbook, students who received instruction using the textbook showed statistically significant improvements in all subcategories of creative problem-solving ability, including idea modification, visualization, task focus, analogy, idea generation, and elaboration (p<.01). Additionally, there were statistically significant changes in students' self-efficacy before and after using the textbook, with negative efficacy decreasing, and positive efficacy and social efficacy increasing (p<.001).

• Journal of Gifted/Talented Education
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• v.24 no.2
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• pp.289-312
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• 2014

The purpose of this study is to develop academic resilience scale for gifted youth. We extracted the pilot questionnaire of 101 items from open-ended questions with 178 scientifically gifted students and literature review. Item analysis and exploratory factor analysis were also carried out with data of 240 gifted youth. Finally, 11 factors from which 42 items were extracted and validated through the confirmatory factor analysis involving 444 gifted youth throughout the nation. The names of the extracted factors were sense of purpose, self-understanding, educational aspirations, academic self-regulation, task commitment, attribution for success (ability), attribution for success (effort), the interpersonal relationship (friend), the interpersonal relationship (parent), the interpersonal relationship(teacher), and optimism. The results show that all of the path coefficient and construct reliability, AVE (Average Variance Extracted), and coefficient of determination were all acceptable. The result of the study indicated that Academic Resilience Scale for Gifted Youth was positively and significantly correlated with School Adaptation Scale and Resilience Scale. However it was negatively correlated with Academic Burnout Scale, and it was statistically significant. Thus, Academic Resilience Scale for Gifted Youth demonstrated satisfactory internal validity and external validity. The results of the present study suggests theoretical and practical implications of the newly developed Academic Resilience Scale for Gifted Youth.