• Proceedings of the Acoustical Society of Korea Conference
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• 1992.06a
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• pp.137-140
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• 1992

실내 바닥슬래브의 휨진동에 의한 음향방사문제에 대하여 유한요소법을 적용하여 검토하였다. 단순한 형상의 판이 휨진동하여 자유공간에 음을 방사하는 문제에 대해서는 이론적인 해를 구할 수 있으나, 임의형상의 판이 휨진동하여 실내에 음을 방사하는 문제에 대해서는 검토되지 않았다. 따라서 본 연구에서는 이와같은 문제를 단순화한 해석법으로서 먼저 유한요소법을 이용하여 판의 휨진동에 대한 고유모드의 상대변위를 구하고, 다음 상대변위를 진동속도로 변환한 결과를 입력조건으로 하여 유한요소법에 의한 3차원 음장해석을 하였다. 그 결과 실내 바닥슬래브의 휨진동에 의한 음향방사파워는 슬래브의 진동모드, 실내음향모드 및 벽흡음율 등의 조건에 따라 크게 변화된다는 것을 확인하였다.

• Journal of Korea Port Economic Association
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• v.27 no.2
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• pp.111-136
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• 2011

This article aims to reveal the relative influences to the Brand Power and Performance of Factors that comprise the port brand assets in order to control and manage the ports. And also this Paper want to suggest the useful strategies and implications for the improvement of Brand Power by comparing the level of brand competitiveness of Incheon Port with those of other Korean ports that are in competitive relation. In this research we can find out that the components of port brand asset are awareness level, image, service quality, and satisfaction of relation. And among those 4 factors, recognition level and satisfaction of relation are very significant relation factors for the loyalty in Incheon Port. In comparison study between Incheon and Pyungtack Ports, satisfaction of relation is revealed as especially significant factor for the customers that show highly effective management performances and we can find that, in Busan Port, image and service quality are significant as well.

• Management & Information Systems Review
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• v.29 no.3
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• pp.23-50
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• 2010

This study is that the manufacturer's sales policy power appeared on the source of local distributors through the sale willingness impact on research for coexistence between the manufacturer and dealer sales for developing policy. Dealers in terms of the sale of regional sales willingness says "manufacturers and retailers to connect to the regional distribution on the path to regional sales representative for manufacturers based on trust companies that supply products or products manufactured by local retailers for about a unilateral will sale whether the continued willingness and indicates the degree of business". This study topics are the results of this measure will sell a total of 24 entries are four factors. In variety sales policy of each power source, First, sales policy in Reward Power, compensatory power as the manager of promotion support, sales support and sales activities will significantly impact respectively. Second, sales policy of Coercive Power, reduction of credit limits act as an element of discontent and the sales will appear in the negative hypothesis of the influence was partially supported. Third, sales policy in Referent Power, the information trust, the most significantly impact of trade policy, respectively. Fourth, sales policy in Professional Power, delay time delivery of goods, sales of our product and sales knowledge will have a significantly effect appear to be related.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.162-169
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• 2020

This study was conducted from November 25 to December 4, 2019, to unmask differences in physical fitness based on the weight class of high school Ssirum elite-players. A total of 28 high school Ssirum elite-players were compared and analyzed by measuring physical factors (muscle strength/power, agility, anaerobic power, aerobic ability, flexibility, and isokinetic muscle function) by weight class. Data were analyzed using SPSS ver. 23.0. One-way ANOVA was used for comparison between groups. There was no difference by weight class in terms of grip strength, sit-ups, sergeant jump, long jump, flexibility, side step, and reaction time. Evaluation of back muscle strength revealed that the group with more than 100 kg had greater strength than lower weight categories, whereas it was lower in the sit-ups, 20 m shuttle run and the relative values anaerobic power. Considering isokinetic muscle function, no difference was observed between the groups of back muscle strength and knee joint. The results of this study indicate that amongst the high school Ssirum elite-players, there is no difference in muscle power, flexibility, agility, and anaerobic average power per body weight, isokinetic trunk strength, and knee flexion strength, when evaluated according to weight class.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.773-778
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• 2020

In this paper, we analyzed the effects of musical stimuli on humans in performing mathematical tasks through EEG measurements. The musical stimuli were divided into preferred music and non-preferred music, and mathematical tasks were divided into memorization task and procedure task. The data measured in the EEG experiments was divided into frequency bands of Theta, SMR, and Mid-beta because of the concentration. In our results, preferred music causes more positive emotional response than no music and non-preferred music regardless of the type of mathematical task.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.434-434
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• 2010

Axial type 가상음극발진기를 이용하여 전극의 기하학적 구조와 고출력 마이크로파의 출력 특성을 분석하고, 최대 파워의 조건에 대한 전자기기 효과를 알아보았다. 고출력 마이크로파 발생 장치인 Vircator는 강렬한 상대론적 전자빔 발생장치로 최대전압 600 kV, 최대전류 88 kA, 펄스폭 60 ns의 특성을 가진다. Anode와 cathode의 간격은 4 mm로 최적화 하였고, 이 조건에서 마이크로파의 출력 특성을 분석하여 보았을 때 WR-137 수신안테나에서 최대 출력143 MW와 5.4 GHz의 진동수를 측정하였다. 출력 효율을 증가시키기 위해서 도파관 중앙에 폭이 10 mm인 반사판을 사용하였고, 그 결과 반사판이 공진구조에 기여하여 정상파(standing wave)를 형성하여 마이크로파 출력 효율 향상하여 WR-137에서 최대 549 MW의 출력을 보였다. 향상된 마이크로파의 출력을 이용하여 각도와 거리를 변화해 가며 컴퓨터와 전자소자로 제작된 회로에 대해 전자기기 효과 실험을 실시하였다. 그 결과 컴퓨터의 경우 $0^{\circ}$ 1 m에서 hard kill 상태가 되었다. 전자소자 회로의 경우는 $0^{\circ}$ 30 cm에서 hard kill의 상태로 되었다. 또한 면적 대비 출력 파워로 비교 했을 경우 약 $0.484\;{\mu}J$의 마이크로파의 영향임을 확인할 수 있었다.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.78-86
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• 2014

In this paper, a novel intensity-based fiber optic vibration sensor using a mass-spring structure, which consists of four serpentine flexure springs and a rectangular aperture within a proof mass, is proposed and its feasibility test is given by the simulation and experiment. An optical collimator is used to broaden the beam which is modulated by the displacement of the rectangular aperture within the proof mass. The proposed fiber optic vibration sensor has been analyzed and designed in terms of the optical and mechanical parts. A mechanical structure has been designed using theoretical analysis, mathematical modeling, and 3D FEM (Finite Element Method) simulation. The relative aperture displacement according to the base vibration is given using FEM simulation, while the output beam power according to the relative displacement is measured by experiment. The simulated sensor sensitivity of $15.731{\mu}W/G$ and detection range of ${\pm}6.087G$ are given. By using reference signal, the output signal with 0.75% relative error shows a good stability. The proposed vibration sensor structure has the advantages of a simple structure, low cost, and multi-point sensing characteristic. It also has the potential to be made by MEMS (Micro-Electro-Mechanical System) technology.

• Journal of Korean Society of Steel Construction
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• v.23 no.5
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• pp.595-606
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• 2011

This study was conducted to investigate the seismic behavior of steel member resisting frames considering the relative stiffness of the connection and beams. Six-story steel moment frames were designed to study the seismic behavior. The connections were classified into Double Web-Angle connections (DWAs), Top- and Seat-angles with double Web-angles (TWSs), FEMA-Test Summary No. 28, Specimen ID: UCSD-6 (SAC), and Fully Restrained (FR). The rotational stiffness of the semi-rigid connections was estimated using the Three-Parameter Power Model adopted by Chen and Kishi. The relative stiffness, which is the ratio of the rotational stiffness of the connections to the stiffness of the beams, was used. Push-over, repeated loading, and time history analysis were performed for all the frames. The seismic behavior of each frame was analyzed with the story drift, plastic hinge rotation, and hysteretic energy distribution.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.2
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• pp.251-256
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• 2008

Many researchers are studying about human Brain-Computer Interface(BCI) that it based on electroencephalogram(EEG) signals of multichannel. The researches of EEG signals are used for detection of a seizure or a epilepsy and as a lie detector. The researches about an interface between Brain and Computer have been studied robots control and game of using human brain as engineering recently. Especially, a field of brain studies used EEG signals is put emphasis on EEG artifacts elimination for correct signals. In this paper, we measure EEG signals as human emotions and divide it into five frequence parts. They are calculated related the percentage of selecting range to total range. the calculating values are compared standard values by Bayesian Network. lastly, we show the human face avatar as human Emotion.

• Journal of the Korean Society of Safety
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• v.23 no.3
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• pp.65-70
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• 2008

Electroencephalogram(EEG) would be the most objective psychophysiological research technique on human errors though few research has been taken yet. This study aimed to get characteristics of human error while committing simple Odd-Ball tasks by utilizing the power spectrum technique of EEG data. Each experiment was composed of 3 tasks with different rules, and three young undergraduate students participated in this study as paid subjects. The result showed that subject and the interaction of subject and task factors were statistically significant on variation of power of $\alpha$ and $\beta$ bands which implied there would exist groups with homogeneity in their response. And though the variation of band powers due to task factors were not so great as to get statistical significance, it implied that the task requiring decoding process would be more strange to human beings than the task merely requiring psychological recall process.