• 한국입자에어로졸학회지
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• 제13권2호
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• pp.97-104
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• 2017

In order to characterize atmospheric aerosols in Chungcheong area, black carbon concentration, which is known to be closely related to global warming, was measured and compared with $PM_{10}$, $PM_{2.5}$ concentrations and various meteorological parameters such as wind velocity and wind direction. Multi Angle Absorption Photometer (MAAP), a filter-based equipment, was used for the black carbon measurement, and the $PM_{10}$, $PM_{2.5}$ concentrations, wind velocity and wind direction were provided by the local monitoring stations. Black carbon concentration was monitored to be high in spring and winter but low in fall. $PM_{10}$ concentration was observed to be high when westerly wind was strong.

• 한국운동역학회지
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• 제15권3호
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• pp.117-132
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• 2005

It was to study a following research of "A Kinematic Analysis of Air-rolling-breakfall in Judo". The purpose of this study was to analyze the Center of Gravity(COG) variables when performing Air-rolling-breakfall motion, while passing forward over(PFO) to the vertical-hurdles(2m height, take off board 1m height) in judo. Subjects were four males of Y. University squad, who were trainees of the demonstration exhibition team, representatives of national level judoists and were filmed by four 5-VHS 16mm video cameras(60field/sec.) through the three dimensional film analysis methods.COG variable were anterior-posterior directional COG and linear velocity of COG, vertical directional COG and linear velocity of COG. The data collections of this study were digitized by KWON3D program computed The data were standardized using cubic spline interpolation based by calculating the mean values and the standard deviation calculated for each variables. When performing the Air-rolling-breakfall, from the data analysis and discussions, the conclusions were as follows : 1. Anterior-posterior directional COG(APD-COG) when performing Air-rolling-breakfall motion, while PFO over to the vertical-hurdles(2m height) in judo. The range of APD-COG by forward was $0.31{\sim}0.41m$ in take-off position(event 1), $1.20{\sim}1.33m$ in the air-top position(event 2), $2.12{\sim}2.30m$ in the touch-down position(event 3), gradually and $2.14{\sim}2.32m$ in safety breakfall position(event 4), respectively. 2 The linear velocity of APD-COG was $1.03{\sim}2.14m/sec$. in take-off position(event 1), $1.97{\sim}2.22m/sec$. gradually in the air-top position(event 2), $1.05{\sim}1.32m/sec$. in the touch-down position (event 3), gradual decrease and $0.91{\sim}1.23m/sec$. in the safety breakfall position(event 4), respectively. 3. The vertical directional COG(VD-COG) when performing Air-rolling-breakfall motion, while PFO to the vertical-hurdles(2m height) in judo. The range of VD-COG toward upward from mat was $1.35{\sim}1.46m$ in take-off position(event 1), the highest $2.07{\sim}2.23m$ in the air-top position(event 2), and after rapid decrease $0.3{\sim}0.58m$ in the touch-down position(event 3), gradual decrease $0.22{\sim}0.50m$ in safety breakfall position(event 4), respectively. 4. The linear velocity of VlJ.COG was $1.60{\sim}1.87m/sec$. in take-off position(event 1), $0.03{\sim}0.08m/sec$. gradually in the air-top position(event 2), $-4.37{\sim}\;-4.76m/sec$. gradual decrease in the touch-down position(event 3), gradual decrease and -4.40${\sim}\;-4.77m/sec$. in safety breakfall position(event 4), respectively. When performing Air-rolling-breakfall showed parabolic movement from take-off position to air-top position, and after showed vertical fall movement from air-top position to safety breakfall. In conclusion, Ukemi(breakfall) is safety fall method Therefore, actions need for performing safety fall movement, that decrease and minimize shock and impact during Air-rolling-breakfall from take-off board action to air-top position must be maximize of angular momentum, and after must be minimize in touch-down position and safety breakfall position.

• 한국해양학회지
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• 제12권2호
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• pp.75-81
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• 1977

피조개는 우리나라의 내만이나 내해의 비교적 수심이 깊은 곳에 사는 대형종으로 조개류 중에서 가장 값비싼 중요양식종이다. 이 종의 양식을 위한 관심이 컸고, 많은 노력도 해 왔으나 양식의 기본이 되는 종묘생산이 제대로 되지않아 그 양식은 언제나 형식에 지나지 않았다.

• 복식
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• 제52권2호
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• pp.139-150
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• 2002

The purpose of this study was to explore the effects of meteorological factors on sales of apparel products. Basic fiat came out daily meteorological data and sales data of apparel products in department store from 1998 to 2000. Four factors(the average temperature, rainfall, wind velocity, sunshine duration) from the nine meteorological factors were selected and were collected with Korea Meteorological Administration. Sales data were collected with business strategy department of H (department store in Seoul. The sales data were divided into six classifications, which are woman's wear, men's wear, children's wear, golf wear, sports wear, and inner wear. The results of this study were as follows: 1) Sales of apparel products were significantly correlated with the average temperature, rainfall, wind velocity, sunshine duration. Among the meteorological factors, temperature turned out to be the most influential in apparel sales and then the amount of rainfall, sunshine duration affected sales according to apparel classifications differently. 2) There were some differences among the apparel classifications in the effect of meteorological factors on the sales of apparel. In the spring. the higher the temperature was, the higher the sales of women's wear and golf wear were, but the lower the sales of children's wear, sports wear and inner wear were. In the summer, The higher the amount of rainfall was, the lower the sales of all the apparel classification were. The higher the temperature was, the higher the sales of sports wear were. In the fall, the lower the temperature was, the higher the sales of all the apparel classification except snorts wear were. In the winter, the meteorological factors had little effect on the sales of women's wear, men's wear and children's wear. The higher the temperature was, the higher the sales of golf wear were. The lower the temperature was, the higher the sales of sports wear were.

• 한국인터넷방송통신학회논문지
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• 제12권5호
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• pp.115-122
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• 2012

자동차 충돌해석은 다양한 형태로 구성되어 충돌중 차량에 대한 속도변화는 차량간의 충돌정도 또는 승객의 안전도를 평가하는 데 중요한 요소로 활용된다. 이로 인해 충돌해석 프로그램을 활용한 속도변화에 따른 결과치를 해석하는 방법이 필요하다. 본 연구에서는 PC-Crash 프로그램을 이용하여 노면의 마찰계수에 따라 차량속도에 따른 제동거리를 실제값과 해석값을 비교하여 마찰계수가 작을 때 오차가 큼을 알 수 있었고, 서로 다른 주 차량(MATIZ, SONATA 및 버스 적용)이 교차로에서 충돌하는 속도의 오차범위는 차량무게의 차이에 따라 최대오차는 1.2%, 1.8%, 3.1%으로 나타났다. 또한 인천대교 버스추락 사고를 재현하기 위하여 시뮬레이션을 한 결과로 다소 오차는 있었으나 사고 재구성을 검증할 수 있었다.

• Steel and Composite Structures
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• 제36권5호
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• pp.603-615
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• 2020

The present manuscript focuses on the flow and heat transfer of the dusty fluid along exponentially stretching cylinder. Enormous attempts are made for fluid flow along cylinder but the study of fluid behavior along exponentially stretching cylinder is discussed lately. Using appropriate transformations, the governing partial differential equations are converted to non-dimensional ordinary differential equations. The transformed equations are solved numerically using Shooting technique with Runge-Kutta method. The influence of the physical parameters on the velocity and temperature profiles as well as the skin fraction coefficient and the local Nusselt number are examined in detail. The essential observations are as the fluid velocity decreases but temperature grows with rise in particle interaction parameter, and both the fluid velocity and temperature fall with increase in mass concentration parameter, Reynold number, Particle interaction parameter for temperature and the Prandtl number.

• 대한원격탐사학회지
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• 제21권1호
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• pp.73-81
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• 2005

We construct improved geocentric digital elevation model (DEM), estimate tidal dynamics and ice stream velocity over Sulzberger Ice Shelf, West Antarctica employing differential interferograms from 12 ERS tandem mission Synthetic Aperture Radar (SAR) images acquired in austral fall of 1996. Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry profiles acquired in the same season as the SAR scenes in 2004 are used as ground control points (GCPs) for Interferometric SAR (InSAR) DEM generation. 20 additional ICESat profiles acquired in 2003-2004 are then used to assess the accuracy of the DEM. The vertical accuracy of the OEM is estimated by comparing elevations with laser altimetry data from ICESat. The mean height difference between all ICESat data and DEM is -0.57m with a standard deviation of 5.88m. We demonstrate that ICESat elevations can be successfully used as GCPs to improve the accuracy of an InSAR derived DEM. In addition, the magnitude and the direction of tidal changes estimated from interferogram are compared with those predicted tidal differences from four ocean tide models. Tidal deformation measured in InSAR is -16.7cm and it agrees well within 3cm with predicted ones from tide models. Lastly, ice surface velocity is estimated by combining speckle matching technique and InSAR line-of-sight measurement. This study shows that the maximum speed and mean speed are 509 m/yr and 131 m/yr, respectively. Our results can be useful for the mass balance study in this area and sea level change.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권3호
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• pp.177-185
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• 2000

In this study, the characteristics of various electricity and high resistivity ash collection were measured at superimposed nanosecond pulse energization. The pulse was generated through the hydrogen thyratron. Superimposed pulse was nanosecond duration pulse that had fast pulse rising time 100[ns], short pulse width 500∼850[ns] and pulse fall time 400∼750[ns]. The results of this study are summarized as followings; Frist, compared with the DC ESP(electrostatic precipitator), superimposed pulse ESP could induce higher peak voltage, and had the about 30[%] reduction of ESP collection area and 50∼80[%] reduction of power consumption. showing the same efficiency. Second, enhancement factor H had 1.9∼3.6 with the increase of migration velocity.

• 한국전문물리치료학회지
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• 제11권4호
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• pp.51-60
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• 2004

Falls are common, costly, and a leading cause of death among older adults. The major predisposing factors of a fall may include age-related deterioration in the dynamic system composed of auditory, somatosensory, vestibular, visual, musculoskeletal, and neuromuscular subsystems. Older adults with a history of frequent falls demonstrated significant reductions in gait velocity, muscle force production, and balance performance. These altered neuromechanical characteristics may be further exaggerated when faced with conflicting multisensory conditions. Despite the important contribution of multisensory function on the sensorimotor system during postural and locomotor tasks, it remains unclear whether multisensory intervention will produce dynamic balance improvement during locomotion in older adults with a history of frequent falls. Therefore, the purpose of this paper is to address important factors associated with falls in elderly adults and provide theoretical rationale for a multisensory intervention program model.

• 한국생산제조학회지
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• 제21권2호
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• pp.337-343
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• 2012

This work investigates the vibrational characteristics of the underground gas pipelines. Experiments were conducted to analyze the effects of various parameters on the vibrational characteristics from the emergency detection point of view. Influences of the various types of impact exerted on the pipe, height of free fall and measuring locations were analyzed. Especially, the difference between the vibrational signal generated by the direct impact on the pipe and the ambient noise was successfully identified. To validate the experimental observation, computer simulation was also performed with constant properties(elasticity, fluid velocity and internal pressure) which are directly conjectured from the accompanying experiment with a real pipe system.