• Korean Journal of Culture and Social Issue
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• v.21 no.3
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• pp.299-315
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• 2015

This study examines correlations among factors that reportedly affect adjustment to military life: self esteem, locus of control,, social support and stress coping strategies. The study also attempts to validate the structural model to enhance understanding of the process of adjusting to the military life. The subjects of the study were 447 listed soldiers from private to sergeant currently stationed and serving in an army post in Gangwon-Do, Korea. The following tools were used for this study. Based on self-inventory questionnaires, evaluations were made regarding self esteem, locus of control, social support, stress management, adaptation to military life. Reliability of each criterion was evaluated based on reliability examination, correlations among parameters were analyzed, and the structural equation model was validated to verify the research model. The results of the study can be summarized as follows. First, internal control and self esteem have significant positive influence on social support and stress coping. Second, internal control and self esteem affect adjusting to military life through social support and active coping, two factors mediated in this study to act as parameters between self-esteem and internal control and military adaption. This study emphasizes intervention such as establishment of a social support system and training for taking necessary actions as limitations of studies dealing with internal traits and military adaptation. Since the subjects of this study were chosen from an army based in a single location for convenience' sake, it may be difficult to generalize the results to analyze the entire military.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1957-1968
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• 2013

This study figured out how could mobile contents quality factors, such as usefulness, accuracy, timeliness, entertaining, economic, security etc., affect satisfaction by user individuality using empirical analysis with an aim of finding difference in content quality factors which have an influence on mobile contents satisfaction by user characteristics in integrated view systemically. The result of analysis shows that usefulness has an influence on satisfaction in principle regardless of user characteristics. This study discovered that both of usefulness and entertaining are significant to satisfaction in the groups with high-user individuality. On the other hand, in the groups with low-user individuality both of usefulness and accuracy affect satisfaction. Findings show that contents preference can be different based on user characteristics. Implications are discussed and limitations are proposed based on empirical analysis.

• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.175-184
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• 2008

As defined by the experts, safety education is the basic method through which people can protect themselves from the dangers in workplace. Therefore, safety education is an important safety measure that can be effectively utilized in disaster prevention without any certain limit. The current practice of safety education in construction sites, however, is all formal and has no substance. Safety education became a mere boring time to workers since the material is not related to them, and does not reflect the individual personalities, which cannot induce voluntary participation of workers. Thus, it is vital to develop various safety education models suitable for individual personalities of construction workers. This study aims to provide the basic data necessary to establish safety education models according to individual personalities of construction workers. Based on the analysis of the preliminary stuff and interviews, the typical individual personalities of construction workers and safety education factors were examined, and the frameworks for each were established. Based on results of applying them to actual cases, directions to improve safety education in construction sites are presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.639-650
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• 2017

This study examined the role of trait anxiety in the relationships among academic contingencies of self-worth, self-esteem, academic help-seeking, and academic concealment. The participants were 254 male and female undergraduate students, and the analyses were conducted using PASW 18.0. The results were as follows. Anxiety was confirmed to be a mediating variable between the academic contingencies of self-worth, self-esteem, and academic concealment. That is, the academic contingencies of self-worth and self-esteem had an effect on academic concealment through anxiety. On the other hand, the academic contingencies of self-worth had a positive effect on anxiety. On the other hand, self-esteem had a negative effect on anxiety. The need to develop education and counseling approaches as a special intervention is discussed. The approaches are meant to reduce the academic self-worth and anxiety. In addition, it is important to promote self-esteem in education and counseling. The limitations and implication for further study are suggested.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.325-338
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• 2003

Video adaptation in response to dynamic resource conditions and user preferences is required as a key technology to enable universal multimedia access (UMA) through heterogeneous networks by a multitude of devices In a seamless way. Although many adaptation techniques exist, selections of appropriate adaptations among multiple choices that would satisfy given constraints are often ad hoc. To provide a systematic solution, we present a general conceptual framework to model video entity, adaptation, resource, utility, and relations among them. It allows for formulation of various adaptation problems as resource-constrained utility maximization. We apply the framework to a practical case of dynamic bit rate adaptation of MPEG-4 video streams by employing combination of frame dropping and DCT coefficient dropping. Furthermore, we present a descriptor, which has been accepted as a part of MPEG-21 Digital Item Adaptation (DIA), for supporting terminal and network quality of service (QoS) in an interoperable manner. Experiments are presented to demonstrate the feasibility of the presented framework using the descriptor.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.88-88
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• 2011

복합분자펌프는 기존의 터보분자펌프 turbine blade에 spiral grooved를 추가하여 초고진공(10-8 Pa)에서 저진공(330Pa)까지 넓은 압력범위에서 사용할 수 있고 이 펌프를 사용함으로서 완전 oil free한 진공시스템을 만들 수 있는 특징을 가지고 있다. 특히, 회전체를 비접촉으로 지지하는 자기베어링 방식을 적용함으로써, 진동은 극히 작고 베어링수명은 길면서 중저진공에 대한 배기속도가 크고 임의의 방향으로 접속이 가능하여 반도체 및 디스플레이 제조 공정과 같은 첨단산업의 다양한 분야에 쉽게 적용되고 있으며, 그 적용 분야와 시장은 계속 성장하고 있다. 고 진공과 배기 속도의 달성을 위해서, 고속으로 이동하는 격면과 기체분자를 충돌시켜, 기체 분자를 원하는 방향으로 유도하는 작동원리를 가지고 있다. 특히 공기분자의 밀도가 매우 낮은 희박가스 상태에서 고속 회전하는 blade로 공기분자를 쳐 내면서 작동됨으로써 날개의 상하 압력차에 의한 공기력보다도 날개의 고속회전이 매우 중요시 되고 압력으로는 10-1 Pa 이하의 분자영역에서 그 성능을 최고로 발휘 할 수 있다. 이러한 복합 펌프의 주요 장점은 다음과 같다. 1. 10-8 Pa (10-10torr)~10 Pa (1 torr) 까지 넓은 영역에서 배기가 가능하다. 2. 탄화수계의 대하여 높은 압축특성을 가지고 있고, 윤활유를 사용하지 않으므로 얻을 수 있는 진공상태가 고청정하다(oil free). 3. 정밀 5축제어 자기베어링으로 완전히 부상하여 회전함으로서 마모가 없고 진동이 최소화하였을 뿐만 아니라, 또한 운전음도 거의 없다. 4. 설치조건에 제한이 없고 고장이 거의 없다. 본 논문에서는 이러한 복합분자펌프의 개발을 위하여, 상기 연구기관에서 수행된 내용을 소개하고 있으며, 펌프 시스템의 기본 설계 및 자기베어링 시스템의 설계 결과 및 수치해석 결과를 나타내었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.2878-2885
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• 2012

In this study, the training and sporting equipment for leg rehabilitation featuring the MR fluids is proposed. The compact MR fluid brake is designed and manufactured to apply to the rehabilitation training and sporting mechanism. The resistance characteristic of the MR fluid brake is controllable by varying the magnetic field around the fluid. Under consideration of spatial limitation, design parameters which are related with the magnetic strength are determined to maximize to a torque using finite element method. The FE analysis is performed using a commercial code, ANSYS Workbench. The proposed brake device is manufactured, and its field-dependant torque is experimentally evaluated. When the electric current is supplied, the torque of the MR fluid brake is increased and the response is very fast. Depending on the strength of the current supply, torques of the MR fluid brake also increase similar to Bingham property of MR fluid.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3A
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• pp.311-318
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• 2008

We propose new pulse shapes for FCC-compliant ultra-wideband (UWB) radios. The projections onto convex sets (POCS) technique is used to optimize temporal and spectral shapes of UWB pulses under the constraints of all of the desired UWB signal properties: efficient spectral utilization under the FCC spectral mask, time-limitedness, and good autocorrelation. Simulation results show that for all values of the pulse duration, the new pulse shapes not only meet the FCC spectral mask most efficiently, but also have nearly the same autocorrelation functions. It is also observed that our truncated (i.e., strictly time-limited) pulse shapes outperform the truncated Gaussian monocycle in the BER performance of binary TH-PPM systems for the same pulse durations. The POCS technique provides an effective method for designing UWB pulse shapes in terms of its inherent design flexibility and joint optimization capability.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.2
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• pp.224-227
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• 2016

This paper proposes a design of W-band mm-wave wideband monopulse comparator using waveguide structure for applications. The main idea of proposed design is to combine a self-compensating phase shifter on $90^{\circ}$ hybrid for wideband $180^{\circ}$ hybrid. Using multiple conventional phase shifters, because of their narrow-band characteristics, tends to restrict working bandwidth of system including antennas. Proposed comparator could relieve the problem since it applies the self-compensating phase shifter. The comparator has waveguide structure so it shows excellent characteristic in loss. It also show wideband characteristic in amplitude and phase response between ports.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.277-283
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• 2020

In a concentric magnetic gear, which replaces the teeth of a mechanical gear with a permanent magnet, the polar ratio of the magnet that determines the reduction ratio affects the behavior of the magnetic gear dramatically. This study analyzed the density of transmission torque, the efficiency of torque considering the solid loss, and the torque quality, including the cogging characteristics using finite element analysis. When the pole number on the driving side was changed from two to five, it was confirmed that there was an optimal pole ratio, in which the transmission torque was maximized. Because eddy current generation density is proportional to the magnetic field, the transmission efficiency also shows a similar tendency to the transmission torque density, and the efficiency is more than 95% at a low gear ratio. The cogging characteristics due to the interaction of the permanent magnets with the limited number of poles are inversely proportional to the least common multiple between the number of magnets on the drive side and the number of modulator teeth. A test model was built for the transmission torque evaluation.