• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.4
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• pp.21-28
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• 2009

Most of domestic shipyards are located at coastal regions which are affected by typhoons nearly every year. For effectiveness of shipbuilding, shipyards contain many facilities which are light-weighted and affected dominantly by wind. In the present paper, we analyze various wind fields over a shipyard including surrounding topology and structures to evaluate the structural safety of the facilities posed in the strong wind. Extreme wind speed for a study region was estimated by typhoon Monte Carlo simulation and then used for inlet wind speed for CFD analysis for wind load on the facilities. Considering geometrical wind effects, we assess the surface pressure of the elements as the pressure factor, the ratio of surface pressure to dynamic pressure. The results show that the simulated wind speed is greater than the design wind speed for the some facilities because of the shipyard's geometry. It also shows that surrounding topography in coastal area is needed to be considered and adjustment for design wind speed at wind load standard application is necessary for mooring ship and industry facilities.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.1
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• pp.109-116
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• 2005

Wind power and photovoltaic(PV) systems are getting into the spotlight as substitute energy. But problem is happened stability by speed change of wind and the power output of the sun's ray. The power output amount according to velocity of wind power system. System breakdown can happen at change of sudden velocity, typhoon and night. This paper shows a automatic tail safety brake controller based on feedback control using wind velocity. The operation of automatic tail safety controller verified by manual test. PV system is a energy change system by temperature of sun's ray and cell. Maximum power point tracking(MPPT) is used in PV systems to maximize the photovoltaic array output power. In existed PV system is low output and changeable DC voltage for boost and filtering the buck-boost converter use. But, this paper established deformed DC-DC converter. Changed Buck-boost converter's unlined output current to line output current using DC-DC converter. This is effect that reduce ripple of output current. Proved through an output waveform comparison experiment. Finally, tail safety brake controller is established to wind turbine system for stability elevation and DC-DC converter is established on PV system for stability output.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.338-347
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• 2023

Jinhae Bay, characterized by frequent runaway ships and strong winds during typhoon attacks, poses a high risk of maritime accidents such as ship collisions and groundings. This study aims to determine a safe separation distance between ships in the Jinhae Bay anchorage, considering the unique environmental characteristics of the Korean sea area. Analysis revealed that an average of 100-200 ships anchor in the typhoon avoidance area in Jinhae Bay during typhoon attacks, with approximately 70% of ships experiencing anchor dragging owing to strong external forces exceeding 25 m/s wind speeds. In this study, we analyzed and presented the separation distances between ships during anchoring operations based on domestic and international design standards, separation distances between ships used as actual typhoon shelters in Jinhae Bay, and appropriate safe distances for ships drifting under strong external forces. The analysis indicated that considering the minimum criteria based on the design standards and emergency response time, a minimum safe distance of approximately 400-900 m was required. In cases where ample space was available, the separation distance was recommended to be set between 700 to 900 m. The findings of this study are anticipated to contribute to the development of guidelines for establishing safe separation distances between ships seeking refuge from typhoons in Jinhae Bay in the future.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.150-157
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• 2019

This study was carried out to investigate at the micrometeorology change of the orchard according to the net installation. Two weather stations were installed at the inside of the anti-insect nets(2 mm, 4 mm), one was installed at the outside(control). They were observed the temperature, humidity, wind speed and solar radiation from April to September 2018. Daily mean temperature at the experimental group was higher than control group by $0.2^{\circ}C$. Daily mean humidity at the experimental group was higher than control group by 3.5 to 4.7%. Daily mean the solar radiation at the experimental group(2 mm) was lower than control group by 50%. The wind speed was decreased from 12% to 50% of the external wind speed at 4 mm, and from 25% to 59% at 2 mm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.150-154
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• 2001

도로 및 철도에서 발생하는 소음을 저감시키기 위해 설치되는 방음벽은 흡음률, 투과손실 등과 같은 음향성능 외에도 태풍과 같은 강풍에 견딜 수 잇는 구조성능이 확보되어야 한다. 따라서, 본 논문에서는 지역별 특성 및 풍속을 고려한 풍압을 산정하는 방법을 소개하고, 풍압에 의한 방음판의 구조해석을 수행하였다. 또한, EN 1794-1의 규정에서 정하는 시험방법에 따른 방음판의 하중변형량 시험을 통하여 방음판의 구조성능을 평가하였다.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.107-119
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• 2003

Serious damages occurred in Yeongdong area of Gangwondo by typoon Rusa in August, 2002. Therefore, this study intends to investigate and analyse the characteristics of landslide having occurred in Gangneung area. 11 sites including many features of landslide were selected and scales, soil properties and a state of vegatation of slopes were investigated. It can be concluded that rainfall intensity, the velocity of the wind, geomorphology, vegatation and forest fire etc. are considered as main factors affecting occurrence of landslides in this area.

• Atmosphere
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• v.22 no.4
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• pp.473-481
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• 2012

The objective methods estimating the radius of maximum wind (RMW) of tropical cyclones (TCs) are discussed using infraed (IR) imagery of geostationary satellite, and an alternative method is suggested that can estimate RMW in the TCs having eyes using IR imagery. The RMW-estimating methods are based on the characteristic structure of the eyewall of a tropical cyclone. RMW is dependent upon the radius of the eye and the distance from the center to the top of the most developed convective cloud. In order to test these methods, blackbody brightness temperature of Korean geostationary satellite, COMS (Communication, Ocean, and Meteorological Satellite) IR imagery are utilized in this study. The estimated RMWs are compared with surface winds of ASCAT (Advanced Scatterometer) of a polar orbiting satellite.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06c
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• pp.380-384
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• 2010

기후온난화, 국지성 호우 및 대규모 태풍으로 인한 피해가 증대되면서 사회 경제적 손실 또한 날로 증가하고 있어 재해로 인한 피해 발생가능성을 효율적으로 예측하는 모델을 통한 선제적 대응이 필요하다. 재난 재해의 위험성 분석 방법은 주로 확률 통계기법을 기반으로 하는 연구가 주류를 이루었으나, 본 논문에서는 포착된 현상의 데이터를 이용해 그 데이터를 지배하는 경험적 규칙성을 학습하고 획득하는데 다른 기법보다 탁월한 성능을 가진 신경망 모델을 적용하여 자연재해 피해예측 모델을 연구하였다. 1991년부터 2005년 사이에 우리나라에서 발생한 자연재해의 피해자료와 기상개황 자료를 이용하여 지역별 자연재해로 인한 피해를 예측하는 신경망 모델은 우리나라 232개 행정구역에 대하여 누적강우량과 최대풍속, 그리고 재해사상 발생 5일 이내의 선행강우량을 입력변수로 하고 총 피해액을 출력변수로 한다. 또한 학습을 통한 최적의 해를 찾기 위해 신경망의 매개변수 학습률, 모멘텀, 편의값을 유전자알고리즘으로 결정하여 학습을 수행 하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.14-22
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• 2017

The frequency and scale of natural disasters due to the abnormal climate phenomena caused by global warming have being increasing all over the world. Various natural disasters, such as typhoons, earthquakes, floods, heavy rain, drought, sweltering heat, wind waves, tsunamis and so on, can cause damage to human life. Especially, the damage caused by natural disasters such as the Earthquake of Japan, hurricane Katrina in the United States, typhoon Maemi and so on, have been enormous. At this stage, it is difficult to estimate the scale of damage due to (future) natural disasters and cope with them. However, if we could predict the scale of damage at the disaster response level, the damage could be reduced by responding to them promptly. In the present study, therefore, among the many types of natural disaster, we developed a function to estimate the damage due to wind waves caused by sea winds and waves. We collected the damage records from the Disaster Report ('91~'14) published by the Ministry of Public Safety and Security about wind waves and typhoons in the western coastal zone and, in order to reflect the inflation rate, we converted the amount of damage each year into the equivalent amount in 2014. Finally, the meteorological data, such as the wave height, wind speed, tide level, wave direction, wave period and so on, were collected from the KMA (Korea Meteorological Administration) and KHOA (Korea Hydrographic and Oceanographic Agency)'s web sites, for the periods when wind wave and typhoon damage occurred. After that, the function used to estimate the wind wave damage was developed by reflecting the regional characteristics for the 9 areas of the western coastal zone.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.5
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• pp.295-305
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• 2010

Although the rubble mound breakwaters in Korea have been damaged by typhoons almost every year, quantification of erosion of armor block have seldomly been made. In this paper, the damage of armor units is standardized by the relative damage. In the case where the number of damaged units is reported, it is divided by the total number of units to calculate the relative damage. In the case where the rehabilitation cost is reported, the relative damage is calculated by using its relationship with the present value of the past rehabilitation cost. The relative damage is shown to have strong correlations with the typhoon parameters such as nearest central air pressure and maximum wind speed at each site. On the other hand, the existing numerical methods for calculating the cumulative damage are compared with hydraulic model tests. The method of Melby and Kobayashi (1998) is shown to give a reasonable result, and it is used to calculate the relative damage, which is compared with the measured damage. A good agreement is shown for the East Breakwater of Yeosu Harbor, while poor agreement is shown for other breakwaters. The poor agreement may be because waves of larger height than the design height occurred due to strong typhoons associated with climate change so that the relative damage increased during the last several decades.