• 방송공학회논문지
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• 제5권1호
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• pp.130-138
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• 2000

본 논문에서는 인터넷/인트라넷 환경에 사용할 수 있으며 인터넷 방송 기능을 제공하는 푸시 시스템을 개발하면서 다수 사용자를 수용하기 위한 방안을 연구하였다. 특히 사용자 접속에 따른 푸시서버의 부하량 증가와 접속빈도에 의한 푸시서버의 분산효과를 분석하였다. 분산된 상태에서 채널을 공유하기 위한 방법으로 공통채널과 지역채널로 구분하여 푸시서버마다 공통채널을 복제하는 방식으로 대규모 사용자를 분산 수용하면서 정보 취득에 어려움이 없도록 하였으며 분산 푸시서버에서 채널연동을 효과적으로 수행하기 위한 알고리즘을 고안하게 되었다.

• 한국통신학회논문지
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• 제25권9B호
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• pp.1635-1640
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• 2000

본 논문에서는 기본파를 억제시키고 2차 고조파가 주 발진신호로 동작되는 18GHz 대역의 push-push 발진기를 semi-MMIC 형태로 설계 및 제작하였다. 마이크로스트립 선로를 포함하는 passive component는 semi-insulating GaAs 기판위에 MMIC 공정을 이용하여 구현하고, Chip 형태의 P-HEMT, 저항, 캐패시터를 Au wire-bonding에의해 연결하였으며, via-hole 대신 접지면을 회로 주변에 구성하여, back-side와 wire-bonding하였다. 실험 결과 -10.5 dBm의 출력 전력 특성을 얻었으며, 기본 주파수 억압은 -17.3 dBc/Hz의 특성을 보였다. 위상 잡음은 100kHz offset에서 -97.7 dBc/Hz를 얻었다.

• 한국위성정보통신학회논문지
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• 제12권2호
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• pp.33-37
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• 2017

본 논문에서는 새로운 신뢰성 있는 푸쉬풀 컨버터를 제안하였다. 제안된 컨버터는 기존의 푸쉬풀 컨버터에 비해 두 개의 다이오드가 추가된 구조를 갖는다. 이 추가된 다이오드로 인해서 푸쉬풀 컨버터의 두 개의 MOSFET 스위치 중에 한 개가 켜진 상태이면 다른 MOSFET는 자동으로 오프 상태를 유지한다. 그러므로 컨버터가 매우 큰 전기적인 노이즈 환경에 있더라도 두 개의 스위치가 켜지면서 회로가 단락되는 것을 막을 수 있다. 본 논문에서는 100 kHz의 스위칭 주파수를 갖는 컨버터를 노이즈 환경에서 PLECS 소프트웨어로 시뮬레이션하였다. 시뮬레이션 결과 컨버터 스위치의 전류는 $20{\mu}sec$의 전기적인 노이즈 환경에서 10 % 정도 증가한다. 그러나, 컨버터는 단락현상이 없이 신뢰성 있게 동작한다.

• The Journal of Korean Physical Therapy
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• 제28권3호
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• pp.195-200
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• 2016

Purpose: This study was designed to evaluate the effects of the different condition of leg support surface on the upper extremity and core muscle activity during the push-up exercise. Methods: Fifteen healthy subjects that were practicable push-ups were recruited in this study. Subjects were instructed the push-up exercise in the different condition of the leg support surface. Each condition of support surface was set to the high and lower, and the unstable and stable condition. Muscle activation was measured by using the surface electromyography (EMG), and recorded from the triceps brachii, serratus anterior, latissimus dorsi, rectus abdominis, abdominal external oblique, and erector spinea muscle. Results: In the results of experiments, there was no significant difference of muscle activation in upper extremity between the high unstable and high stable support surface. By contrast, muscle activation of the rectus abdominis and abdominal external oblique was significantly higher in the low unstable support surface, compared with those of the low stable support surface. It is well known that the core muscle was important to stabilization of trunk stability. Conclusion: This result demonstrates that the low and unstable support surface for the lower extremity was suited for training of core muscle for trunk stabilization during the push-up exercise.

• 대한물리의학회지
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• 제4권4호
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• pp.269-274
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• 2009

Purpose：The purpose of this study is an interval palmar width according to change of muscle activation under push-up movement. Methods：Three, this study participation normal young adult (male 3, mean age ; 24yaers). The subject performed maximum contraction under push-up movement. EMG activaty patterns is measured with three different width. The EMG activity of pectoralis major and latissimus dorsi were measured using surface electromyography. Results：EMG activation of pectoralis major and latissimus dorsi following of push-up was shown significant difference(p<.05). Also, experiment value was agree with calculation value and width of shoulder position was minimum of pectoralis major and latissimus dorsi muscle activity. Conslusion：RMS values in case of fretum and wide width of the hands on Latissimus Dorsi are shown muscle activity $132{\mu}V$ and $173.5{\mu}V$, respectively. Especialy, RMS value in terms of wide width of the hands on muscles is shown very enhanced muscle activity. It is suggest that interval palmar width of the hands on pectoralis major and latissimus dorsi in push-up movement was effective to intensify of the muscle activity.

• 한국식생활문화학회지
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• 제24권4호
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• pp.401-412
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• 2009

The aims of study were to provide basic data for the internationalization of Contract Foodservice Management Companies (CFMC) and to gain a better understanding of internal push-and-pull factors through in-depth interviews. The interviewees were managers of four large CFMCs and one small-to-medium CFMC. The non-structured interview format employed an interview guide of open-ended questions. All interviews were digitally recorded and notes were taken simultaneously by an interview assistant. The narrative data analysis involved transcription, coding, classification by categories, and content analysis. Eighty-eight codes were generated from the interview analyses, and the subordinate variables uncovered included seven push factors, eight pull factors, one interactive factor, and 10 internal dynamics. These factors will be useful in further studies of the internal operations of specific CFMCs, and more generally, the practical condition of the industry.

• 유통과학연구
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• 제16권9호
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• pp.65-77
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• 2018

Purpose - A trading area is very closely related to consumer life. A trading area is a cultural and social space that consumes culture and promotes human relationships as well as an economic space where consumers live their daily lives. In this context, a trading area research should be conducted objectively and empirically because it deals with the activities of consumer's life. The purpose of this study is to identify the intrinsic psychological motivation(push motivation) caused when consumers visit a trading area and to demonstrate how the push motivation for a trading area influence on consumer's flow, satisfaction, revisit intention. Research design, data, and methodology - In order to develop research hypotheses for this study, the development procedures for push motivation scale are as follows; (1) generating initial pool of items based on previous studies, (2) expert judgement to evaluate content and face validity, and (3) assessing convergent and discriminant validity using confirmatory factor analysis. In order to achieve these purposes, online surveys were conducted on frequent or familiar visitors to the trading areas around the Gangnam, Kunkuk University and Hongik University Station. Among the 1,343 questionnaires collected, 1,157 cases were analyzed by using SPSS 22.0 and SmartPLS 3.0 statistical package program, except for 186 responses in which responses were judged to be unfaithful. Results - The push motivation was classified into five sub-dimensions of excitement/stimulus, rest/relaxation, exit/refreshing, knowledge/learning and human relationship promotion as multidimensional and complex factors composed of individual and social-related dimensions. The excitement/stimulus and human relationship promotion of push motivation have positive effects on satisfaction. However, all dimensions of the push motivation have positive effects on flow. And flow has a positive effect on satisfaction and revisit intention. Meanwhile, the mediation test using boostrapping shows that flow plays a full mediating role in the relationship between rest/relaxation, exit/refreshing, knowledge/learning and satisfaction, but a partial mediating rol e between excitement/stimulus, human relationship promotion and satisfaction. Finally, satisfaction plays a partial mediating role between flow and revisit intention. Conclusions - This study shows that the push motivation is multidimensional and compositive depending on the situation of a consumer. In addition, it is found that the human relationship promotion(a social-related motivation) has a much more important effect on flow and satisfaction than other push motivations of individual dimensions. It also shows that satisfaction increases when consumers are being flowed at their visit and degree of revisit intention also grows as satisfaction increases. As implications of this study, a marketer should try to understand consumer's visit motivation at first and then develop factors that increase their flow, satisfaction, revisit intention. It also requires a marketer to approach subjects on a trading area more objectively and empirically based on the psychology and behavior of consumers, in order to establish a proper and efficient strategy on development of a trading area.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.624-631
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• 2017

본 연구의 목적은 머리 전방 자세 성인에 대하여 8주간 슬링에서의 푸쉬업 플러스 운동이 근활성도와 폐기능에 어떠한 영향을 미치는지 알아보고자 하였다. 총 16명의 머리 전방 자세 성인이 모집 되었고 대조군과 실험군으로 각 8명씩 배정 되었다. 슬링에서의 니푸쉬업 플러스와 안정한 면에서 니푸쉬업 플러스 운동을 2015년 7월 6일부터 8월 28일까지 8주간 나누어 시행하였고 주 3회 실시하였다. 머리 척추각을 측정시 두군에서 (p<0.001)의 증가를 보였고 머리 회전각 측정시 대조군에서 (p<0.05), 실험군에서 (p<0.001)의 감소를 보였다. 두 군에서 근활성도는 위 등세모근(p<0.001)의 감소와 앞톱니근, 아래 등세모근의(p<0.001)의 증가를 나타내었고 폐기능 측정시 대조군에서(p<0.01), 실험군에서(p<0.001)의 증가를 보였다. 결론적으로 푸쉬업 플러스 운동은 머리 전방 자세를 개선시키고 호흡근들의 활성화를 높일뿐더러 폐기능 강화에 효과적이며 슬링에서의 푸쉬업 플러스 운동이 머리 전방 자세의 개선에는 더욱 효과적이지만 폐기능에는 유의한 차이가 없었다. 따라서 슬링에서의 푸쉬업 플러스 운동은 머리 전방자세 성인의 자세 개선과 폐기능에 효과적인 운동으로 추천 된다.

• 대한물리의학회지
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• 제11권3호
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• pp.49-54
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• 2016

PURPOSE: This study was implemented to measure the muscle activity of muscles surrounding shoulder during push-up exercise according to the slope angle. METHODS: This study has research subject consisting of 25 normal male adults without neurologic or musculoskeletal injury in shoulder part. EMG was used as a tool for measuring muscle activity and four muscles including upper trapezius (UT), middle trapezius (MT), Lower Trapezius (LT), and Serratus Anterior (SA) were chosen for measuring the muscle activity of muscles surrounding shoulder. Tilting table slope was set at $0^{\circ}$, $30^{\circ}$, $45^{\circ}$, and $60^{\circ}$ and push-up motion was performed three time for each case to use the average value. The measured value was used after generalization process to create %RVC value where the measured value was standardized by using $0^{\circ}$ as a standard. RESULTS: There was a difference of muscle activity according to the tilting table slope during push-up exercise. In UT, MT, and SA, there was no significant $0^{\circ}$ and $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$. But there was significant $30^{\circ}$ and $45^{\circ}$. LT was significant difference between $45^{\circ}$ and $60^{\circ}$ (p<.05). CONCLUSION: There are cases where push-up exercise should be selectively implemented due to shoulder problems. According to this results between $0^{\circ}$ and $30^{\circ}$, push up will be able to more effectively exercise. Applying proper angle of tilting table for push-up to patients who have difficulties in performing motions along with physical consumption can deliver effective and easy exercise program.

• 한국산업보건학회지
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• 제16권3호
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• pp.290-301
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• 2006

A push pull hood system is frequently applied to control contaminants evaporated from an open surface tank. Efficiency of push pull hood system is affected by various parameters, such as, cross draft, vessel shapes, tank surface area, liquid temperature. A previous work assisted by flow visualization technique qualitatively showed that a strong cross draft blown from the pull hood to push slot could destroy a stable wall-jet on the surface of tank, resulting in the abrupt escape of smoke from the surface. In this study, the tracer gas method was applied to determine the effect of cross-draft on the capture efficiency qualitatively. A new concept of capture efficiency was introduced, that is, linear efficiency. This can be determined by measuring the mass of tracer gas in the duct of pull hood while the linear tracer source is in between push slot and pull hood. By traversing the linear tracer source from the push slot to the pull hood, it can be found where the contaminant is escaped from the tank. Total capture efficiency can be determined by averaging the linear efficiencies. Under the condition of cross-draft velocities of 0, 0.4, 0.75, 1.05 and 1.47m/s, total capture efficiencies were measured as 97.6, 95.4, 94.6, 92.7 and 70.5% respectively. The abrupt reduction of efficiency with cross-draft velocity of 1.47m/s was due to the destruction of tank surface wall-jet by the counter-current cross-draft. The same phenomenon was observed in the previous flow visualization study. As an alternative to overcome this abrupt efficiency drop, the 20% increase of hood flow rates was tested, resulting in 20% efficiency increase.