• 디지털융복합연구
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• 제13권8호
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• pp.495-502
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• 2015

본 연구는 빙상 선수를 대상으로 외발점프 훈련 시 하지관절 운동역학 변인의 차이를 분석함으로써 무릎테이핑의 효과를 알아보고자 하였다. 연구결과 다음과 같은 결론을 얻었다. 점프높이는 테이핑 후 높은 것으로 나타났지만 테이핑에 따른 차이는 없는 것으로 나타났다. 상승 시 좌 우, 전 후 최대충격력은 테이핑 후 감소되는 것으로 나타났고, 수직 최대충격력은 테이핑 후 증가된 것으로 나타났다. 착지에서 테이핑 후의 좌우 최대충격력은 감소되었으나 전 후, 수직 최대 충격력은 증가된 것으로 나타났다. 상승과 하강 시 테이핑 후 충격량의 감소가 크게 나타났다. 상승 시 테이핑 후 무릎관절의 신전, 외번모멘트에서 감소가 나타났다. 착지에서 테이핑 후 무릎관절의 굴곡모멘트는 감소했지만 내번모멘트는 테이핑 후 증가된 것으로 나타났다. 무릎테이핑이 선수들의 부상예방과 운동수행능력에 도움을 줄 수 있을 것으로 판단되며 스포츠의학과의 융복합연구가 필요할 것으로 판단된다.

• 한국운동역학회지
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• 제15권2호
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• pp.31-39
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• 2005

The Purpose of this study was to reveal the biomechanical difference of two soccer footwear(soft ground footwear and hard ground footwear). Secondly, the purpose of this study was to clarify how each type of soccer footwear effects soccer players, which will provide scientific data to coaches and players, to further prevent injuries and to improve each players capacity. The result of comparative analysis of two soccer footwear can be summarized as below. The comparison of the very first braking force at walking found distinctive factors in the statistical data(t=3.092, p<.05). Braking impulse of two difference footwear showed distinctive factors in the statistical data(t=2.542, p<.05). In comparing GRFz max(N), the result showed a statistically significant difference in the two soccer footwear at running(t=2.784, p<.05). In the maximum braking impulse(t=2.774, p<.05) and propulsive impulse for antero-posterior direction, there was a statistically significant difference between the two soccer footwear at running. In the maximum braking force(t=3.270, p<.05) and propulsive force(t=4.956, p<.05) for antero-posterior direction, there was a statistically significant difference between the two soccer footwear at running. Significant differences were not found in moment(rotational friction) with two difference soccer footwear(moment max; t=2.231, moment min; t=1.784).

• International Journal of Fluid Machinery and Systems
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• 제9권4호
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• pp.300-306
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• 2016

A twin unidirectional impulse turbine for wave energy conversion has been suggested in our previous study, and the performance under unsteady flow has been investigated by quasi-steady analysis. In the present study, the performance of twin impulse turbine under unsteady flow condition has been investigated by unsteady analysis of Computational fluid dynamics. As a result, the mean efficiency of twin unidirectional impulse turbine under unsteady flow is lower than the maximum efficiency of unidirectional impulse turbine. Moreover, it is verified that airflow goes backward in the reverse turbine in low flow rates.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.484-485
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• 2007

This paper describes the series-gap characteristics of transmission line arrester with switching and lightning impulse flashover test. The transmission line arrester exhibited external gap because it is must not flashover with switching impulse on the other hand it is must flashover with lightning impulse. In accordance, minimum and maximum length of series-gap was determinated with these tests. As gap length is increased flashover voltage was increased in the range of 315.4 kV~496.3 kV and negative polarity exhibited a high voltage. As a result, It was thought tat the series-gap length of transmission line arrester exhibited in the range of 580 mm~1100 mm.

• 한국의류산업학회지
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• 제16권6호
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• pp.879-887
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• 2014

Consumers often act impulsively when making internet purchases. Triggered by easy access to products, lack of social pressure, and absence of delivery impediments, impulse buying frequently occurs in the context of internet shopping. This study tests the structural equation model of the impulse buying process for fashion products when internet shopping and examines impulse buying process differences between Korean and Chinese consumers. A total of 985 usable questionnaires were obtained from college students. Data were analyzed by structural equation model analysis using a correlation matrix with a maximum likelihood by AMOS 21.0. Results showed that increased internet browsing by consumers resulted in more impulse buying as mediated by the urge to buy; in addition, more impulse buying by consumers resulted in a higher consumer satisfaction experience. Pure impulse buying created more important antecedents of satisfaction than the promotion-oriented impulse buying. Impulse buying showed a high similarity between Korean and Chinese consumers; however, increased influence from promotion activities resulted in more fashion product impulse buying for Chinese consumers versus Korean consumers. We confirm that one of the outcomes of the impulse buying process is impulse buying product satisfaction. Korean and Chinese consumers also present similarities and differences in fashion product impulse buying. A managerial implication is discussed for retailers of fashion products to develop strategies to increase consumer browsing and subsequently trigger impulse buying accompanied with consumer satisfaction.

• 한국의류산업학회지
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• 제19권3호
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• pp.280-288
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• 2017

This study tested how the mobile impulse buying(m-impulse buying) of fashion products was related to shopping motives and mobile applications(apps) browsing in the context of mobile shopping. A total of 316 self-administered questionnaires were obtained from college students who had experienced m-impulse buying of fashion products during the most recent six months. A structural equation model using a correlation matrix with maximum likelihood was estimated for examining the relationships among shopping motives(e.g., hedonic shopping motive and utilitarian shopping motive), apps browsing, and m-impulse buying of fashion products(e.g., fashion-oriented impulse buying and pure impulse buying) by AMOS 21.0. Findings showed that hedonic shopping motive and utilitarian shopping motive had significant effects on apps browsing in their mobile shopping. Apps browsing had a significant effect on fashion-oriented impulse buying, but did not significantly effect on pure impulse buying of fashion products. Additionally, the hedonic shopping motive had directly significant effects on both fashion-oriented impulse buying and pure impulse buying, whereas the utilitarian shopping motive significantly effected on only the pure impulse buying of fashion products in their shopping. This study suggests that the hedonic shopping motive played an important role to determine the m-impulse buying of fashion products and the utilitarian shopping motive played a role in activating apps browsing relevant to mobile shopping for fashion products. Managerial implications are discussed for retailers related to the fashion products in mobile shopping.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권9호
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• pp.456-465
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• 2001

In this paper, breakdown voltages in $SF_6-N_2$ mixtures were experimentally investigated to understand characteristics of dielectric strength and physical phenomena in nonuniform field disturbed by a needle shape protrusion. The test voltages are the lightning impulse$(\pm1.2/44 \mus)$ and the damped oscillatory impulse$(\pm400 ns / 0.83 MHz)$ voltages which can be occurred by the operation of disconnecting switches in gas-insulated switchgears(GIS). The effects of the polarity and wave shape of the test voltages, and the gas pressure on the V-t characteristics were in detail examined. The V-t characteristic curves were measured in different two ways : (1) one is the method by taking the maximum voltage recorded at or prior to breakdown against the time to breakdown, that is, the Procedures recommended in IEC 60060-1, (2) the other is the method by taking the voltage at the instant of chopping against the time to breakdown. As a result, the V-t characteristics of $SF_6-N_2$ mixtures in nonuniform electric field were significantly affected by the polarity and wave shape of the applied voltages. The positive breakdown voltages resulted in lower breakdown voltages in the time ranges considered, and the V-t curves for the negative oscillatory impulse voltage were extended over the longer time range. For the lightning impulse voltages, the V-t curves obtained by IEC Pub. 60060-1 were nearly same with the V-t curves obtained by the voltage at the instant of chopping against the time to breakdown. It is clear that the actual breakdown voltages were much lower than the maximum voltages appearing at or prior to breakdown because of the displacement current produced as a result of the dV/dt during the oscillatory transient voltage app1ication. The scattering of the negative actual breakdown voltages was much larger than that of the positive.

• 한국운동역학회지
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• 제12권1호
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• pp.193-204
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• 2002

The purpose of this study was to investigate the effect of martial art type and target height on the ground reaction force factors during Dollyuchagi motion. Data were collected using force plate. Five Taekwondo players and five Hapkido players were tested during Dollyuchagi motion to three different target heights(0.8, 1.2, 1.6 m). After analysis of kinetics using force plate data, maximum vertical ground reaction force was 1.62~2.44 BW, and impulse was $0.66\sim1.01 BW{\cdot}s$. Even though there was no difference for maximum ground reaction forces and impulse between Hapkido and Taekwondo, as target height was higher, impulse increased. Anterior-posterior and vertical ground reaction forces at kicking foot take-off were greater with target height, although there was no difference for medio-lateral force with target height. At impact there was significant difference for anterior-posterior ground reaction force between Hapkido and Taekwondo players. Taekwondo players' force (range, -0.23~-0.26 BW) was greater than Hapkido players's force (range, -0.08~-0.14 BW).

• 전기학회논문지
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• 제60권5호
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• pp.1005-1010
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• 2011

The accidents caused by dielectric instability have been increasing in power grid. It is important to enhance the dielectric reliability of a high voltage apparatus to reduce the damage from electrical hazards. To develop an electrically reliable high voltage apparatus, the experimental study on the electrical breakdown field strength is indispensable, as well as theoretical approach. In this paper, the lightning impulse breakdown characteristics considering utilization factors are studied for the establishment of insulation design criteria of an high voltage apparatus. The utilization factors are represented as the ratio of mean electric field to maximum electric field. Dielectric experiments are performed by using several kinds of sphere-plane electrode systems made of stainless steel. As a result, it is found that dielectric characteristics are affected by not only maximum electric field intensity but also utilization factors of electrode systems. The results are expected to be applicable to designing the air-insulated high voltage apparatuses.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1146-1149
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• 2004

A new developed impulse current test system(100kV, 250kJ)is presented, which can carry out all impulse current and performance tests on surge arrester sections with rated voltage up to 12kV according to IEC 60099-4(2001). The maximum achievable peak value is 200kA for the impulse current $4/10{\mu}s$ and 60kA for the $30/80{\mu}s$ and $8/20{\mu}s$. The long duration current impulse is realized from class 1 to class 5. The digital transient recorder(4 channels 60MS/S 10bit) is used for measuring AC voltage, impulse current, reference voltage and leakage current. The complex control, measuring, evaluation and data storage system is controlled by one industrial PC system.