• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.681-687
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• 2017

We investigated the potential for wind-power generation using the wind produced by express trains. We built equipment to detect the wind velocity, including wind meters and a data analyzer. We considered various conditions that might change the wind. First, we measured the velocity and duration of the wind at three locations distinguished by the presence of a tunnel and a valley landscape. We analyzed the changes in the wind according to the geometric conditions. Also, we analyzed the changes in the wind according to three different heights relative to the train. We also compared the wind produced by a KTX train and an SRT train. Finally, we used the results to derive the wind power energy harvested from the wind and discuss the expected utility.

• Fire Science and Engineering
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• v.28 no.5
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• pp.37-43
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• 2014

In the case of interior fire in an apartment building, contamination of vestibule area by fire smoke before air fan operating when fire doors are open makes the evacuation of people very difficult. In order to investigate the effect of heat release rate (HRR) and interior opening on fire flow velocity, numerical simulations using Fire Dynamics Simulator were carried out. In simulations, actual dimensions and configuration of an apartment building were considered and interior leakage and HRR were varied. From simulation results, it was found that fire flow velocity distribution is significantly influenced by HRR and interior opening resulting in the change of the location of a neutral plane. Also, it is shown that there is a larger difference of the fire flow velocity between upper and lower part of the fire door when the neutral plane becomes closer to the ceiling.

• Journal of the Korean earth science society
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• v.41 no.6
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• pp.658-669
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• 2020

The horizontal-to-vertical spectral ratio (HVSR) analysis is conducted to estimate the site amplification effect and the thickness of the sedimentary layer beneath the measurement site. We investigated the effects of meteorological variations (wind and precipitation rate) and sensor burial depths on HVSR analysis. The HVSR results were unstable when seismographs were exposed on the ground. The HVSR results of ambient noise data measured under strong winds were also unstable. It is recommended to measure the ambient noise at wind speeds of <3 m s-1. Stable HVSR results were obtained when seismographs were buried, regardless of the precipitation rates. The results of this study provide the best observations and optimal weather conditions required to acquire accurate and reliable HVSR results.

• Journal of the Korean Institute of Navigation
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• v.24 no.3
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• pp.113-122
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• 2000

본 논문에서는 손상선박의 안전대책에 관한 연구의 일환으로서, 황천항행중인 선박이 충돌, 좌초 등 원인에 의해 조종불능이 되었을 때를 가상하고, 예선ㆍ피예선계의 침로안정성에 미치는 풍향, 풍속, 예항삭의 길이의 영향을 이론적으로 검토하고, 풍압하에서 피예선을 다른 안전한 장소로의 예항에 대하여 하나의 지침을 주는 것을 목적으로 한다. 여기에서 실선은 Hulk carrier와 Passenger liner를 모델로 삼았고 외력으로서는 파도가 충분히 발달되지 않은 바람이 부는 초기상태 혹은 저속으로 항행하는 상태를 고려하여 바람의 영향만을 취급하며 피예선은 조타를 하지 아니한다.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.198-199
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• 2004

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.1 no.1
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• pp.21-31
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• 1989

본 연구에서는 경사진 hot-wire probe 의 특성값을 구하고 열선풍속계의 응답식으로부터 수평원통관내에서 3차원 흐름의 속도성분과 난류 강도 그리고 전단 응력을 pitot tube의 결과와 비교 연구하였다. 또한, 속도 및 난류 강도에 관한 유도된 식을 swirling flow에도 적용하여 만족한 결과를 얻었다.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.181-185
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• 2003

the effect if atmosphere is more important in the West sea of Korea than in other seas because of shallow water and heat storage if the water. The serial oceanographic observation data and coastal station data from NFRID, and the atmosphere data from KMA were used in order to find out the relationship between them The highest water temperature, salinity and weather factor were recorded in Aug, and the lowest of them in Feb. As the water deepens, the maximum time leg in water temperature and the minimum time leg in salinity. Water temperature have the maximum in Oct, the minimum in Apr at 75m of the 311-07 station with 100m depth water temperature (WT)-air temperature, WT-precipitation (Preci.) and salinity (Sal)-wind speed (WS) were in direct proportion, but WT-WS, Sal-AT and Sal-Preci in inverse proportion Water temperature and salinity I-ave time leg at the same depth the maximum had more the delay of $2\~4$ months at a depth if 20 meters than at the surface in all stations except for salinity at 307-05.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.41-46
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• 2015

This study was conducted to evaluate the use of biological monitoring to determine the factors that influence the effects of exposure to pyrethroid pesticides among highland cabbage farmers. Urine was collected from farmers who was cultivating Chinese cabbage in the relatively highground in Gangwon-do the morning following pesticide application and was analyzed for cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcy-clopropane carboxylic acid (DCCA) and 3-(2,2-dibromovinyl)-2,2-dimethyl cyclopropane carboxylic acid (DBCA). Factors affecting exposure to pesticides, such as wind speed, spraying location, and the use of protective gear, were also investigated. Statistical analysis was performed by the Kruskal-Wallis test. Our analysis indicated that highland cabbage farmers were exposed to a higher level of pesticides than the general public or other types of farmers. When the wind speed was low, workers who sprayed pesticides were exposed to a higher level of pesticides compared to the exposure level in an assistant. However, there was no difference in exposure between the two when wind speed was high.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.1
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• pp.59-65
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• 2011

The aerodynamic power and torque of wind turbines are extremely nonlinear. Therefore, the overall dynamic behavior of a wind turbine exhibits nonlinear characteristics that are dependent on the magnitude of the wind speed. The nonlinear aerodynamic characteristics of the wind turbine also affect the characteristics of the control system of the wind turbine. Therefore, the analysis of the nonlinear aerodynamic characteristics of wind turbine is essential in designing the wind-turbine controller. In this study, the nonlinear aerodynamic characteristics and the effects of these characteristics on the closed-loop pitch system with PI controller for an 1-mass model of the wind turbine are investigated above rated power.

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.303-310
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• 2012

We carried out the power performance evaluation for 1.5 MW${\times}$2 by using anemometer installed on WTGS(Wind Turbine Generator System) in the wind farm at Shi-hwa bang-a-mu-ri. In this paper, we compared and analyzed the performance of guaranteed output and measured output of WTGS which includes output curve, output coefficient, AEP(Annual Energy Product) and availability, etc.. The power performance of WTGS was optimized in the low wind speed sections(3 m/s ~ 10 m/s) and the measured output was more produced by AEP 109 % and availability 112 % than the guaranteed output. In addition, we could also cut the high cost of testing WTGS performance by using anemometer as a substitute for weather mast.