• 제목/요약/키워드: Weather-conditions

검색결과 1,812건 처리시간 0.025초

이상기후에 따른 농작물의 수확량 및 재해발생 확률의 추정 (Simulating Crop Yield and Probable Damage From Abnormal Weather Conditions)

  • 임상준;박승우;강문성
    • 한국농공학회지
    • /
    • 제39권6호
    • /
    • pp.31-40
    • /
    • 1997
  • Potential impacts for unfavourable weather conditions and the assessment of the magnitudes of their adverse effects on crop yields were studied. EPIC model was investigated for its capability on crop yield predictions for rice and soybean. Weather generationmodel was used to generate long-term climatic data. The model was verified with ohserved climate data of Suwon city. Fifty years weather data including abnormal conditions were generated and used for crop yield simulation by EPIC model. Crop yield probability function was derived from simulated crop yield data, which followed normal distribution. Probable crop yield reductions due to abnormal weather conditions were also analyzed.

  • PDF

Probabilistic Assessment of Total Transfer Capability Using SQP and Weather Effects

  • Kim, Kyu-Ho;Park, Jin-Wook;Rhee, Sang-Bong;Bae, Sungwoo;Song, Kyung-Bin;Cha, Junmin;Lee, Kwang Y.
    • Journal of Electrical Engineering and Technology
    • /
    • 제9권5호
    • /
    • pp.1520-1526
    • /
    • 2014
  • This paper presents a probabilistic method to evaluate the total transfer capability (TTC) by considering the sequential quadratic programming and the uncertainty of weather conditions. After the initial TTC is calculated by sequential quadratic programming (SQP), the transient stability is checked by time simulation. Also because power systems are exposed to a variety of weather conditions the outage probability is increased due to the weather condition. The probabilistic approach is necessary to evaluate the TTC, and the Monte Carlo Simulation (MCS) is used to accomplish the probabilistic calculation of TTC by considering the various weather conditions.

온실의 냉난방부하 산정을 위한 외부기상자료 비교분석 (Comparative Analysis of Weather Data for Heating and Cooling Load Calculation in Greenhouse Environmental Design)

  • 남상운;신현호;서동욱
    • 생물환경조절학회지
    • /
    • 제23권3호
    • /
    • pp.174-180
    • /
    • 2014
  • Standard weather data available to greenhouse environmental design are limited in most regions of the country. So, instead of using standard weather data, in order to find the method to build design weather data for greenhouse heating and cooling, design outdoor weather conditions were analyzed and compared by TAC method and frequency analysis using climatological normal and thirty years from 1981 to 2010 hourly weather data provided by KMA and standard weather data provided by KSES. Average TAC values of outdoor temperature, relative humidity and insolation using thirty years hourly weather data showed a good agreement with them using standard weather data. Therefore, in regions which are not available standard weather data, we suggest that design outdoor weather conditions should be analyzed using thirty years hourly weather data. Average of TAC values derived from every year hourly weather data during the whole period can be established as environmental design standards, and also minimum and maximum of them can be used as reference data.

기상특성에 따른 교통사고 안전성 평가지표 개발 (고속도로를 대상으로) (Development of Traffic Accident Safety Index under Different Weather Conditions)

  • 박준태;홍지연;이수범
    • 대한교통학회지
    • /
    • 제28권1호
    • /
    • pp.157-163
    • /
    • 2010
  • 기상상태에 따른 교통사고발생 및 사고심각도는 밀접한 관계가 있음이 잘 알려져있다. 최근고속도로에서 교통 안전성 평가지표 및 시스템의 개발은 사고 치명도를 줄이고자 접근하는 것이다. 본 연구에서는 도로선형 요소와 기상 상태를 고려한 교통사고 영향 요인을 분석하여 규명하고자 한다. 기상상태요인과 도로요인과의 교통사고 발생 관계를 규명하기 위하여 과거사고이력자료를 이용하여 판별분석을 수행하였으며 눈, 맑음, 비, 안개, 흐림의 5가지 유형에 대해 도로 구성요소인 노면과 경사도를 통해 구분하였다. 그 결과 콘크리트 노면과 하향경사 3%이상인 구간에서 각 기상상태 별 사고영향이 다르며 이러한 주행환경에서는 시정거리의 감소와 정지거리의 증가가 주행 위험요인으로 발생할 수 있는 구간이다. 본 연구에서는 기상악화시 콘크리트 노면과 하향경사가 형성된 구간이 평상시 보다 주행시 주의를 필요로 하는 구간임을 분석하였으며 분류함수의 계수 비교를 통해 영향지표를 개발하였다.

Impact of temperature cycling on fracture resistance of asphalt concretes

  • Pirmohammad, Sadjad;Kiani, Ahad
    • Computers and Concrete
    • /
    • 제17권4호
    • /
    • pp.541-551
    • /
    • 2016
  • Asphalt pavements are exposed to complex weather conditions and vehicle traffic loads leading to crack initiation and crack propagation in asphalt pavements. This paper presents the impact of weather conditions on fracture toughness of an asphalt concrete, prevalently employed in Ardabil road networks, under tensile (mode I) and shear (mode II) loading. An improved semi-circular bend (SCB) specimen was employed to carry out the fracture experiments. These experiments were performed in two different weather conditions namely fixed and cyclic temperatures. The results showed that consideration of the impact of temperature cycling resulted in decreasing the fracture toughness of asphalt concrete significantly. Furthermore, the fracture toughness was highly affected by loading mode for the both fixed and cyclic temperature conditions studied in this paper. In addition, it was found that the MTS criterion correctly predicts the onset of fracture initiation although this prediction was slightly conservative.

F급 항공기 교체공항 선정을 위한 기상분석 (An Weather Analysis for Selection of the Aircraft Category F's Alternative Airport)

  • 김영철;김도현
    • 한국항공운항학회지
    • /
    • 제20권4호
    • /
    • pp.70-75
    • /
    • 2012
  • This paper is part of the research about the selection and justification of Jeju international airport as an aircraft category 'F' alternative airport, which is the results of an weather analysis based on meteorological statistics. As the results of the study, it has been only 1 day per year (58minutes) that weather conditions of Incheon and Jeju international airports, from January 2006 to June 2011, are below landing weather minimums of each airport at the same times. This means that these airports are not within the same meteorological region, which is against the current orthodoxy. In addition, it is very rare that weather conditions of Jeju international airports are below landing weather minimums when Incheon international airport is below landing weather minima. It shows that the meteorological characteristics of these regions differ widely and the designation of Jeju international airport as an alternative airport is scientifically reasonable.

Energy Modeling of a Supertall Building Using Simulated 600 m Weather File Data

  • Irani, Ali;Leung, Luke;Sedino, Marzia
    • 국제초고층학회논문집
    • /
    • 제8권2호
    • /
    • pp.101-106
    • /
    • 2019
  • Assessing the energy performance of supertall buildings often does not consider variations in energy consumption due to the change of environmental conditions such as temperature, pressure, and wind speed associated with differing elevations. Some modelers account for these changing conditions by using a conventional temperature lapse rate, but not many studies confirm to the appropriateness of applying it to tall buildings. This paper presents and discusses simulated annual energy consumption results from a 600 m tall skyscraper floor plate located in Dubai, UAE, assessed using ground level weather data, a conventional temperature lapse rate of $6.5^{\circ}C/km$, and more accurate simulated 600 m weather data. A typical office floorplate, with ASHRAE 90.1-2010 standards and systems applied, was evaluated using the EnergyPlus engine through the OpenStudio graphical user interface. The results presented in this paper indicate that by using ground level weather data, energy consumption at the top of the building can be overestimated by upwards of 4%. Furthermore, by only using a lapse rate, heating energy is overestimated by up to 96% due to local weather phenomenon such as temperature inversion, which can only be conveyed using simulated weather data. In addition, sizing and energy consumption of fans, which are dependent both on wind and atmospheric pressure, are not accurately captured using a temperature lapse rate. These results show that that it is important, with the ever increasing construction of supertall buildings, to be able to account for variations in climatic conditions along the height of the building. Adequately modeling these conditions using simulated weather data will help designers and engineers correctly size mechanical systems, potentially decreasing overall building energy consumption, and ensuring that these systems are able to provide the necessary indoor conditions to maintain occupant comfort levels.

생성형 대형 언어 모델(LLM) 활용 영상 데이터의 날씨 환경 자동 인식 및 분류 방법 (Generative LLM-based Automatic Classification and Annotation of the Weather environment in Image datasets)

  • 주형진;송한빈;김시호
    • Journal of Platform Technology
    • /
    • 제12권5호
    • /
    • pp.71-78
    • /
    • 2024
  • 생성형 대형 언어 모델(LLM)을 활용하여 기후 환경을 포함하는 영상 데이터의 이미지-텍스트 쌍 데이터를 생성하는 방법을 제안하였다. 다양한 악천후 상황을 나타내는 이미지를 수집하고, 해당 이미지의 기후 조건을 텍스트로 설명하는 방법을 구현하였다. 제안하는 기술은 악천후 빈도와 자율주행 차량에 미치는 영향을 분석하여 자율주행 운행 가능 조건을 판단하는 데 필요한 악천후 조건을 정확하게 분류할 수 있도록 지원한다. 이를 통해 기상 데이터의 품질을 높이고 기상 예측 시스템의 성능을 향상해 자율주행 기술의 안전성과 신뢰성을 크게 향상할 수 있음을 입증하였다. 실험 결과, 제안한 방법이 Precision, Recall, F1-score의 세 가지 정량지표 모두 가장 높은 성능을 보였다. LLM을 활용한 이미지-텍스트 쌍 데이터 생성은 기상 데이터 품질과 자율주행 차량의 안전성을 크게 높이며 자율주행 기술 발전에 중요한 역할을 할 것으로 기대된다.

  • PDF

날씨·조명 판단 및 적응적 색상모델을 이용한 도로주행 영상에서의 이정표 검출 (Road Sign Detection with Weather/Illumination Classifications and Adaptive Color Models in Various Road Images)

  • 김태형;임광용;변혜란;최영우
    • 정보처리학회논문지:소프트웨어 및 데이터공학
    • /
    • 제4권11호
    • /
    • pp.521-528
    • /
    • 2015
  • 도로주행 영상에서의 객체 검출에 관한 기존의 연구들은 날씨 및 조명 상태에 따른 객체 검출의 어려움 때문에 대부분 맑은 날씨의 영상을 대상으로 연구가 진행되었다. 본 논문에서는 도로주행 영상의 다양한 날씨 및 조명 상태를 먼저 판단하고, 이를 기반으로 도로 이정표에 대한 색상모델을 설정하여 이정표 객체를 찾는 방법을 제안한다. 제안한 방법은 5종류의 도로 이미지 특징을 이용하여 맑음, 흐림, 비, 야간, 역광으로 날씨 및 조명 상태를 먼저 분류하고, 각각의 상태에서 대상 이정표 색상의 픽셀값의 범위를 추출하여 GMM(Gaussian Mixture Model)을 생성하고 이를 객체 추출에 사용한다. 날씨 및 조명이 다양하게 변하는 도로주행 영상에 제안한 방법을 적용하여 이정표 영역이 안정적으로 찾아지는 것을 확인할 수 있었다.

A Study on Weather Data for Air Conditioning Equipment Design Report I - Weather Data in Busan from 1970 through 2003

  • Kim Jong-Ryeol;Kum Jong-Soo;Choi Kwang-Hwan
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • 제14권1호
    • /
    • pp.1-6
    • /
    • 2006
  • For the purpose of processing weather data for air conditioning equipment de sign in Busan area Korea, this study collected weather observations made by Busan weather Administration from 1970 to 2003, and then established external conditions for heating and air-conditioning design. For changes of temperature in external conditions for design, the highest temperature had little changed, whereas the lowest had been on the rise as the years went by through the 1970s, 1980s, 1990s, and 2000s, but insolation has a little lessened. Absolute humidity does not show a significant change but an incessant rise.