• Sleep Medicine and Psychophysiology
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• v.14 no.1
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• pp.42-48
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• 2007

Introduction: Detrended fluctuation analysis (DFA) is used as a way of studying nonlinearity of EEG. In this study, DFA is applied on sleep EEG of normal subjects to look into its nonlinearity in terms of EEG channels and sleep stages. Method: Twelve healthy young subjects (age：$23.8{\pm}2.5$ years old, male：female=7：5) have undergone nocturnal polysomnography (nPSG). EEG from nPSG was classified in terms of its channels and sleep stages and was analyzed by DFA. Scaling exponents (SEs) yielded by DFA were compared using linear mixed model analysis. Results: Scaling exponents (SEs) of sleep EEG were distributed around 1 showing long term temporal correlation and self-similarity. SE of C3 channel was bigger than that of O1 channel. As sleep stage progressed from stage 1 to slow wave sleep, SE increased accordingly. SE of stage REM sleep did not show significant difference when compared with that of stage 1 sleep. Conclusion: SEs of Normal sleep EEG showed nonlinear characteristic with scale-free fluctuation, long-range temporal correlation, self-similarity and self-organized criticality. SE from DFA differentiated sleep stages and EEG channels. It can be a useful tool in the research with sleep EEG.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.394-403
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• 2019

This research focuses on the perception of security screeners using a full body scanner at airport which had been newly introduced to terminal 2 of Incheon Int'l airport. To accomplish the purpose of research, this paper used UTAUT (Unified Theory of Acceptance and Use of Technology) model. Through an empirical analysis, it was proven the factors consisting of technological acceptance and how those factors affect both organizational innovation at airport and job satisfaction of security screeners. According to an empirical analysis, it was found out all the factors of technological acceptance have a significant effect on both organizational innovation and job satisfaction. However, only the effort expectation was shown to have a significant negative effect on the two dependant variables contrary to the other variables (performance expectation, behavioral intention and self efficacy. It was also proven organizational innovation had a moderating effect between technological acceptance and job satisfaction. Such results suggested organizational innovation at airport security division is necessary to enhance job satisfaction using a newly introduced full body scanner.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.560-567
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• 2007

컴퓨터 에이전트가 우리의 일상에 미치는 영향력이 커지고 에이전트와의 상호작용이 대인 상호작용과 유사하게 변화할수록, 업무적 효율성보다 에이전트와의 상호작용에서 사용자가 겪게 되는 심리적 사회적 경험이 중요해진다. 사용자의 긍정적인 심리적 경험을 유도하기 위해 에이전트와 사용자의 상호작용에서 사회적 실재감(social presence)을 증진시키고자 하는 연구가 이루어져 왔다. 이러한 연구들에서는 에이전트의 언어적/비언어적 커뮤니케이션에 대인적 요소를 적용함으로써 사회적 실재감을 증진시키고자 하였다. 본 연구에서는 대인관계에서 매우 중요한 커뮤니케이션 요소인 상호적 자기노출(self-disclosure)이 사용자들의 사회적 실재감 인식과 에이전트 평가, 사용자 경험에 있어 어떠한 효과를 갖는지 살펴보고, 또한 개인의 성격변인인 애착유형(attachment styles)은 어떠한 영향을 미치는지 살펴보았다. 또한 사회적 실재감이 에이전트 평가와 사용자 경험에 대한 효과를 매개하는지 알아보았다. 실험 결과 에이전트와의 상호적 자기노출 교환은 사회적 실재감을 증진시키고 에이전트에 대한 호의적 평가와 긍정적인 사용자 경험을 유도하였으며, 향후 상호작용 의사를 증진시켰다. 또한 피험자의 애착유형에 따라 사회적 실재감, 에이전트 평가, 사용자 경험, 향후 상호작용 의사가 다르게 나타났다. 종속변인에 대한 자기노출 교환과 애착유형의 효과는 지각된 사회적 실재감에 의해 매개되는 것으로 나타났다. 본 연구의 결과는 에이전트 설계에 커뮤니케이션적 측면이 중요하게 고려되어야 함을 시사한다. 또한 에이전트가 사용자들에게 미치는 심리적 효과는 사용자의 성격 특성에 따라 다르게 나타날 수 있다는 것을 시사한다.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.116-120
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• 2011

For the train positioning system currently applied in high-speed MAGLEV train systems, it is classified into absolute positioning systems which discontinuously detect train positions, and relative positioning systems which continuously detect train positions. In this paper we analyze the configuration model and the numerical model of the absolute positioning system applied in TRANSRAPID which is a representative high-speed MAGLEV train, and design the two configuration models specific to the recognition structures of absolute positioning systems. We also verify the compatibility of the design models of absolute positioning system through simulation using MATLAB and propose the optimal configuration model of absolute positioning systems for high-speed MAGLEV train system.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.487-497
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• 2014

This study was to examine the effect of the Self-efficacy Promotion Exercise Program to the elderly hypertensive with Stage 1. This research was the quasi-experimental study. The Self-efficacy Promotion Exercise Program combined to Aerobic exercise which is incrementally at a level of 40~60% HRmax and the source of the Self-efficacy Promotion Exercise. This research was carried out to experimental(33 patients) and control(32 patients), 60 minutes per day, 3 times a week for 12 weeks. The Self-efficacy Promotion Program was effect on enhancing the general(p<.001) and exercise self-efficacy(p<.001), the self-care behaviors(p<.001) and decreasing the systolic blood pressure(p<.001) to the elderly hypertensives. The 12 weeks Self-efficacy Promotion Exercise Program will be considering to useful for various care settings to the elderly hypertensives.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.615-625
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• 2023

This study was attempted to improve the mental and psychological health of nursing students through the intervention of positive psychological programs using complementary alternative therapy. This study applied a Non-equivalent control group pre-test and post-test design to verify the effects of negative emotions, career decision making self-efficacy, self-compassion, and flourish in nursing students. The experimental group is the students who received the positive psychology program using complementary and alternative therapy, and the control group is the students who did not receive the program. The collected data were analyzed using the SPSS Version 21.0 program. The experimental group showed higher career decision making self-efficacy, self-compassion, and flourish scores and lower negative emotion scores than the control group that did not participate in the education. After applying the positive psychology program using complementary and alternative therapy, it contributed to the expansion of the nursing intervention area using complementary and alternative therapy by reporting positive research effects on career decision making self-efficacy, self-compassion, and flourish.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.2
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• pp.141-148
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• 2011

This study presents the optimal grouping technique of columns which groups together columns of similar shortening trends to improve the efficiency of column shortening compensation. Here, Kohonen's self-organizing feature map which can classify patterns of input data by itself with unsupervised learning was used as the optimal grouping algorithm. The Kohonen network applied in this study is composed of two input neurons and variable output neurons, here the number of output neuron is equal to the column groups to be classified. In input neurons the normalized mean and standard deviation of shortening of each columns are inputted and in the output neurons the classified column groups are presented. The applicability of the proposed algorithm was evaluated by applying it to the two buildings where column shortening analyses had already been performed. The proposed algorithm was able to classify columns with similar shortening trends as one group, and from this we were able to ascertain the field-applicability of the proposed algorithm as the optimal grouping of column shortening.

• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.88-92
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• 2009

Granulocytic sarcoma is a rare extramedullary tumor composed of immature granulocytic precursors. Usually, granulocytic sarcoma is seen in association with acute myeloid leukemia, or other myeloproliferative disorders. Rarely, it may manifest as a primary presentation before the onset of systemic disease in acute myeloid leukemia. The clinical suspicion of granulocytic sarcoma based on imaging findings is important for the management of the patient especially when systemic disease of acute myeloid leukemia is not confirmed as in our case. We report the MR findings of a granulocytic sarcoma in the left leg mimicking hemorrhagic abscess in a patient with acute myeloid leukemia. We believe that MRI can be a helpful diagnostic method of making a differential diagnosis of granulocytic sarcoma in a patient with leukemia, and this can be done by analyzing the signal intensity and the enhancement pattern.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.137-140
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• 2011

시설의 안전성 평가에 대한 연구는 안전성에 영향을 주는 데이터를 정량화하여 획일적인 자동 수행하는 안전관리가 주를 이루고 있다. 이와 달리 자율수행은 수집 된 상황 정보나 상태 데이터를 이용하여 안전성을 예측하고 사고 위험성을 경보하여 사고를 예방 할 수 있다. 본 연구에서는 다양한 시설물 중에서 가스배관의 부식에 대한 판단을 위해서 신경망의 대표적 비지도학습인 자기조직화지도를 적용한다. SOM의 적용에서는 주변효과를 보완하기 위해서 관계적관점지도로 맵을 구성한다. 학습 할 데이터는 가스배관의 방식전위이다. 배관의 부식상태를 확인하기 위하여 수집 된 데이터인 방식전위에는 부식에 대한 위험요인이 내재되어 있다. 학습 후 새로운 데이터가 입력되면 각 상태 군집의 중심뉴런과 맵핑된 뉴런의 유사도를 측정하여 배관의 부식상태를 결정한다. 제안 된 방법으로 판단 된 결과를 기존에 사람이 판단한 결과와 비교하여 검증한다. 이를 통해 배관의 부식상태를 자율적이고 신속하게 판단하여 지능화 된 가스배관 관리로 활용한다.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.2
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• pp.117-122
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• 2000

The fractal image compression is based on the self-similarity that some area in an image is very similar to others. This compression method offers high compression ratio and fast decompression, but it has very long encoding time. To cut-off the encoding time, most researches give a restriction on domain blocks to be compared with a range block or make an effective search sequence of the domain blocks for a range block. However, most of them take much encoding time yet. In this research, we propose an algorithm that greatly reduces the encoding time by considering the coherence between range blocks. This algorithm first classifies all range blocks into some groups using the coherence between range blocks, and then searches corresponding domain blocks only for the key block of each group. If this scheme is joined in a prior work of the other fractal compression algorithm, it will give a great effectiveness to encoding time.