• 제목/요약/키워드: winds

검색결과 933건 처리시간 0.024초

Mapping of Post-Wildfire Burned Area Using KOMPSAT-3A and Sentinel-2 Imagery: The Case of Sokcho Wildfire, Korea

  • Nur, Arip Syaripudin;Park, Sungjae;Lee, Kwang-Jae;Moon, Jiyoon;Lee, Chang-Wook
    • 대한원격탐사학회지
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    • 제36권6_2호
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    • pp.1551-1565
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    • 2020
  • On April 4, 2019, a forest fire started in Goseong County and lasted for three days, burning the neighboring areas of Sokcho. The strong winds moved the blaze from one region to another region and declared the worst wildfire in South Korea in years. More than 1,880 facilities, including 400 homes, were burnt down. The fire burned a total area of 529 hectares (1,307 acres), which involved 13,000 rescuers and 16,500 military troops to control the fire occurrence. Thousands of people were evacuated, and two people are dead. This study generated post-wildfire maps to provide necessary data for evacuation and mitigation planning to respond to this destructive wildfire, also prevent further damage and restore the area affected by the wildfire. This study used KOMPSAT-3A and Sentinel-2 imagery to map the post-wildfire condition. The SVM showed higher accuracy (overall accuracy 95.29%) compared with ANN (overall accuracy of 94.61%) for the KOMPSAT-3A. Moreover, for Sentinel-2, the SVM attained a higher accuracy (overall accuracy of 91.52%) than the ANN algorithm (overall accuracy 90.11%). In total, four post-wildfire burned area maps were generated; these results can be used to assess the area affected by the Sokcho wildfire and wildfire mitigation planning in the future.

A Review on the Building Wind Impact through On-site Monitoring in Haeundae Marine City: 2021 12th Typhoon OMAIS Case Study

  • Kim, Jongyeong;Kang, Byeonggug;Kwon, Yongju;Lee, Seungbi;Kwon, Soonchul
    • 한국해양공학회지
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    • 제35권6호
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    • pp.414-425
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    • 2021
  • Overcrowding of high-rise buildings in urban zones change the airflow pattern in the surrounding areas. This causes building wind, which adversely affects the wind environment. Building wind can generate more serious social damage under extreme weather conditions such as typhoons. In this study, to analyze the wind speed and wind speed ratio quantitatively, we installed five anemometers in Haeundae, where high-rise buildings are dense, and conducted on-site monitoring in the event of typhoon OMAIS to determine the characteristics of wind over skyscraper towers surround the other buildings. At point M-2, where the strongest wind speed was measured, the maximum average wind speed in 1 min was observed to be 28.99 m/s, which was 1.7 times stronger than that at the ocean observatory, of 17.0 m/s, at the same time. Furthermore, when the wind speed at the ocean observatory was 8.2 m/s, a strong wind speed of 24 m/s was blowing at point M-2, and the wind speed ratio compared to that at the ocean observatory was 2.92. It is judged that winds 2-3 times stronger than those at the surrounding areas can be induced under certain conditions due to the building wind effect. To verify the degree of wind speed, we introduced the Beaufort wind scale. The Beaufort numbers of wind speed data for the ocean observatory were mostly distributed from 2 to 6, and the maximum value was 8; however, for the observation point, values from 9 to 11 were observed. Through this study, it was possible to determine the characteristics of the wind environment in the area around high-rise buildings due to the building wind effect.

A Study on the Utilization of Urban Garden Design Derived from the Traditional Farming Method Gyeonjongbeop from the Joseon Period: Focused on Imwongyeongjeji Bolliji

  • Hong, In-Kyoung;Yun, Hyung-Kwon;Chae, Young;Lee, Sang-Mi;Jung, Young-Bin;Lee, Mi-Ra
    • 인간식물환경학회지
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    • 제23권4호
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    • pp.423-432
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    • 2020
  • Background and objective: Traditional farming is winning recognition as a sustainable alternative farming method. As urban farming increases in South Korea, it is crucial to develop more sustainable farming techniques. Gyeonjongbeop is the traditional farming method introduced in the Joseon period. This study was conducted to propose a productive garden model suitable for urban farming through the interpretation of traditional farming methods contained in Imwongyeongjeji Bolliji and to test the model on an actual field. Methods: Using the design and cropping system of Gyeonjongbeop as the research materials, we reviewed its tillage and cultivation and examined the applicability. We proposed a modified method by extracting parts applicable to urban farming. According to the methods, we created a garden with ridges and furrows, cultivated proper vegetables, and evaluated their growth. Results: Raphanus sativus, Allium fistulosum L., Brassica juncea, and Spinacia oleracea grown on ridges showed higher growth than those grown on a conventional flat field. The growth of Hordeum vulgare var. hexastichon and Triticum aestivum L. on furrows was also slightly higher. This proved that the method could make up for the deficiencies of barley and wheat that are weak against winds and cold and are easily destroyed by the spring rains. Conclusion: Ridge and furrow cultivation derived from Gyeonjongbeop can be an efficient urban farming system compared to the conventional cultivation in flat fields. The system can use fallow lands in winter for year-round urban farming. In addition, the application of the traditional farming system can enhance the humanistic value of urban farming.

딥러닝 기반 컨테이너 적재 정렬 상태 및 사고 위험도 검출 기법 (Shipping Container Load State and Accident Risk Detection Techniques Based Deep Learning)

  • 연정흠;서용욱;김상우;오세영;정준호;박진효;김성희;윤주상
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제11권11호
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    • pp.411-418
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    • 2022
  • 최근 항만에서는 부정확한 컨테이너 적재로 인해 컨테이너가 강풍에 쉽게 쓰러지는 컨테이너 붕괴 사고가 빈번이 발생하고 있으며 이는 물적 피해와 항만 시스템 마비로 이어지고 있다. 본 논문에서는 이런 사고를 미연에 방지하기 위해 딥러닝 기반 컨테이너 적재 상태 및 사고 위험도 검출 시스템을 제안한다. 제안된 시스템은 darknet 기반 YOLO 모델을 활용하여 컨테이너 상하의 코너캐스팅을 통해 컨테이너 정렬 상태를 실시간으로 파악하고 관리자에게 사고 위험도를 알리는 시스템이다. 제안된 시스템은 추론 속도, 분류 정확도, 검출 정확도 등을 성능 지표와 실제 구현 환경에서 최적의 성능을 보인 YOLOv4 모델을 객체 인식 알고리즘 모델로 선택하였다. 제안된 알고리즘인 YOLOv4가 YOLOv3보다 추론속도와 FPS의 성능 측면에서 낮은 성능을 보이기는 했지만, 분류 정확도와 검출 정확도에서 강력한 성능을 보임을 증명하였다.

2015년~2021년 한반도 고농도 미세먼지 사례의 유형분류에 따른 기상학적 특징 분석 (Analysis of Meteorological Characteristics by Fine Dust Classification on the Korean Peninsula, 2015~2021)

  • 지준범;조창래;김유준;박승식
    • 대기
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    • 제32권2호
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    • pp.119-133
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    • 2022
  • From 2015 to 2021, high-concentration fine dust episodes with a daily average PM2.5 concentration of 50 ㎍ m-3 or higher were selected and classified into 3 types [long range transport (LRT), mixed (MIX) and Local emission and stagnant (LES)] using synoptic chart and backward trajectory analysis. And relationships between the fine particle data (PM2.5 and PM10 concentration and PM2.5/PM10 ratio) and meteorological data (PBLH, Ta, WS, U-wind, and Rainfall) were analyzed using hourly observation for the classification episodes on the Korean Peninsula and the Seoul metropolitan area (SMA). In LRT, relatively large particles such as dust are usually included, and in LES, fine particle is abundant. In the Korean peninsula, the rainfall was relatively increased centered on the middle and western coasts in MIX and LES. In the SMA, wind speed was rather strong in LRT and weak in LES. In LRT, rainfall was centered in Seoul, and in MIX and LES, rainfall appeared around Seoul. However, when the dust cases were excluded, the difference between the LRT and other types of air quality was decreased, but the meteorological variables (Ta, RH, Pa, PBLH, etc.) were further strengthened. In the case of the Korean Peninsula, it is difficult to find a clear relationship because regional influences (topographical elevation, cities and coasts, etc.) are complexly included in a rather wide area. In the SMA, it is analyzed that the effects of urbanization such as the urban heat island centered on Seoul coincide with the sea and land winds, resulting in a combination of high concentrations and meteorological phenomena.

Wind-induced mechanical energy analyses for a super high-rise and long-span transmission tower-line system

  • Zhao, Shuang;Yan, Zhitao;Savory, Eric;Zhang, Bin
    • Wind and Structures
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    • 제34권2호
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    • pp.185-197
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    • 2022
  • This study aimed to analyze the wind-induced mechanical energy (WME) of a proposed super high-rise and long-span transmission tower-line system (SHLTTS), which, in 2021, is the tallest tower-line system with the longest span. Anew index - the WME, accounting for the wind-induced vibration behavior of the whole system rather than the local part, was first proposed. The occurrence of the maximum WME for a transmission tower, with or without conductors, under synoptic winds, was analyzed, and the corresponding formulae were derived based on stochastic vibration theory. Some calculation data, such as the drag coefficient, dynamic parameters, windshielding areas, mass, calculation point coordinates, mode shape and influence function, derived from wind tunnel testing on reducedscale models and finite element software were used in calculating the maximum WME of the transmission tower under three cases. Then, the influence of conductors, wind speed, gradient wind height and wind yaw angle on WME components and the energy transfer relationship between substructures (transmission tower and conductor) were analyzed. The study showed that the presence of conductors increases the WME of transmission towers and changes the proportion of the mean component (MC), background component (BC) and resonant component (RC) for WME; The RC of WME is more susceptible to the wind speed change. Affected by the gradient wind height, the WME components decrease. With the RC decreasing the fastest and the MC decreasing the slowest; The WME reaches the its maximum value at the wind yaw angle of 30°. Due to the influence of three factors, namely: the long span of the conductors, the gradient wind height and the complex geometrical profile, it is important that the tower-line coupling effect, the potential for fatigue damage and the most unfavorable wind yaw angle should be given particular attention in the wind-resistant design of SHLTTSs

Environment and Development of the Weather Monitoring Application in Kosovo

  • Shabani, Milazim;Baftiu, Naim;Baftiu, Egzon;Maloku, Betim
    • International Journal of Computer Science & Network Security
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    • 제22권8호
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    • pp.371-379
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    • 2022
  • The environment in Kosovo is a topic of concern for the citizens and the state because of the temperatures that affect the health of the citizens and the climate around the world. Kosovo's climate is related to its geographical position. Stretching in the middle latitude, Kosovo's climate depends on the amount of heat coming from the Sun, the proximity of the Adriatic Sea, the Vardar valley, the openness to the north. In order to better understand the climatic features of Kosovo, one must know the elements of the climate such as: sunshine, temperature, precipitation, atmospheric pressure, winds. The Meteorological Institute of Kosovo is responsible for measuring temperatures in Kosovo since 2014 and until now 12 meteorological stations have been operationalized with automatic measurement and real-time data transfer to the central system for data collection and archiving. The hydrometeorological institute lacks an application for measuring temperatures in all the countries of Kosovo. Software applications are generally built to suit the requirements of different governments and clients in order to enable easier management of the jobs they operate on. One of the forms of application development is the development of mobile applications based on android. The purpose of the work is to create a mobile application based on the Android operating system that aims to display information about the weather, this type of application is necessary and important for users who want to see the temperature in different places in Kosovo, but also the world. This type of application offers many options such as maximum temperature, minimum temperature, humidity, and air pressure. The built application will have real and accurate data; this will be done by comparing the results with other similar applications. Such an application is necessary for everyone, especially for those people whose daily work is dependent on the weather or even for those who decide to spend their vacations, such as summer or winter. In this paper, comparisons are also made within android applications for tablets, televisions and smart watches.

Lateral Resistance of Reinforced Light-Frame Wood Shear Walls

  • Hyung Woo LEE;Sang Sik JANG
    • Journal of the Korean Wood Science and Technology
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    • 제51권1호
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    • pp.58-66
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    • 2023
  • In light-frame timber construction, the shear wall is one of the most important components that provide resistance to lateral loads such as earthquakes or winds. According to KDS (Korea Design Standard) 42 50 10, shear walls are to be constructed using wood-based structural sheathing, with studs connected by 8d nails spaced 150 mm along the edge and 300 mm in the field. Even though small-scale residential timber building can be designed to exhibit seismic resistance using light-frame timber shear walls in accordance with KDS 42 50 10, only the abovementioned standard type of timber shear wall is available. Therefore, more types of timber shear walls composed of various materials should be tested to measure their seismic resistance, and the results should be incorporated into the future revision of KDS 42 50 10. In this study, the seismic resistance of shear walls composed of structural timber studs and wood-based structural sheathing with reinforced nailing is tested to evaluate the effects of the reinforcement. For the nailing reinforcement, shear wall specimens are constructed by applying nail spacings of 75-150 mm and 50-100 mm. For the shear wall specimens with one sheathing and reinforced nailing, the shear strengths are 1.7-2.0 times higher than that of the standard shear wall (nail spacing of 150-300 mm). The shear strength of the shear walls with sheathing on both sides is 2.0-2.7 times higher than that of the standard shear wall.

주요 고농서를 통한 조선시대의 도작기술 전개 과정 연구 VIII. 수확 저장 요령 (A Study on Transition of Rice Culture Practices during Chosun Dynasty through Old References. VIII. Harvest and Storage)

  • 이숭겸;구자옥;이은웅;이홍석
    • 한국작물학회지
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    • 제37권3호
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    • pp.299-303
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    • 1992
  • 농업기술의 일반적인 농법들과 마찬가지로, 우리나라의 벼 수확법이나, 저장법 또는 조제법도 고대 중국의 기술과 방법을 받아 형성되어 온 것으로 보인다. 그러므로 벼 수확법의 최적시기는 손실을 막기 위해서 적절한 배수를 하므로써 정해진 수확과 조제를 위한 효율적인 농구가 사용되었으며 또한 벼 저장을 위한 특이하고 창조적인 기술이 교육됨으로서 쉽게 익혀졌다. 그것은, 풍우를 막고 좋은 통기조건을 갖게 했다. 15세기, 16세기에 저장보리의 곤충해를 막기위해 물여뀌 처리 그리고 벼낟알의 탈락을 막기위해 수확기 즉시에 벼베기를 하는 것이 장려되었다. 17세기는 창조적인 기술이 없었다. 18세기, 19세기에 포장에서 저장할 때의 쥐에 의한 해를 방제하기 위한 방법들이 제시되었다. 또한 여러 수도 품종들의 생태학과 장기간의 저장기술에 관한 연구들이 지역적으로 수확의 적시를 취하기 위하여, 또한 적시에 협동적으로 일하기 위하여 필순적으로 강조되었다.

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2021년 3월 1-2일 영동지역 강설 사례 연구 (A Case Study of Snowfall Event over Yeongdong Region on March 1-2, 2021)

  • 안보영;임병환
    • 한국지구과학회지
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    • 제44권2호
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    • pp.119-134
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    • 2023
  • 본 연구는 2021년 3월 1일부터 2일까지 영동지역에 강설이 발생했던 사례의 종관적, 열역학적, 역학적 특성을 분석한 것이다. 분석에 사용한 자료는 AWS 관측자료, 지상일기도, ERA5 재분석 자료, 레윈존데, 천리안 2A 위성 자료, WISSDOM 자료 등이다. 사례 기간 영동지역 4개소에서 관측된 적설은 10 cm 이상으로 나타났으며, 북강릉(37.4 cm)에서는 가장 많은 적설을 보였다. 종관 분석결과, 동해상 및 영동지역 주변으로 중·상층 대기의 매우 차고 건조한 대기와 상대적으로 따뜻한 하층 대기의 온도 차이로 대류 불안정이 형성되어 북강릉 지역으로 대류운의 발달과 함께 강설이 나타났다. 특히 열역학적 및 운동학적 연직 분석에서, 하층에서 온위의 연직 경도에 의한 강한 바람과 한랭이류에 의한 대류 불안정이 영동지역의 강설 발생에 큰 역할을 한 것으로 판단된다. 이러한 결과는 레윈존데의 연직 분석에서도 확인할 수 있었다.