• 대한토목학회논문집
• /
• 제39권6호
• /
• pp.859-867
• /
• 2019

기상상황(폭염, 폭우, 한파, 폭설)은 대중교통 통행 및 이용 패턴에 영향을 미치는 중요한 변수 중의 하나이며, 시스템의 예측가능성과 안정성을 중시하는 교통분야에서 이러한 기상의 영향을 이해하는 것은 매우 중요한 요소중의 하나이다. 그러므로 본 연구에서는, 서울시를 대상으로 기상상황에 따른 대중교통 이용 변화를 분석하고 해석하고자 하였다. 먼저, 기상, 모바일폰통신, 대중교통카드 자료를 이용하여 각 기상 상황별 서울시 대중교통 이용 변화를 살펴보고, 가장 영향이 큰 폭설 상황을 기준으로 대중교통 이용패턴을 지역별로 분석하였다. 또한, 의사결정모델(Decision-tree Model)를 활용하여 각 영향 변수들 간의 복잡한 관계를 밝히고자 하였다. 분석결과, 폭설 시, 전체 통행에 대한 잠재수요는 감소하고, 대중교통으로의 수단 전환이 일어나는 것을 확인할 수 있었다. 또한, 강동 및 송파 지역과 강서, 구로, 양천, 영등포 지역은 대중교통 이용이 증가하였으며, 관악, 금천, 동작 지역은 상대적으로 큰 변화가 없는 것을 확인할 수 있었다. 마지막으로, 폭설 시 대중교통 출발량의 변화는 도보접근통행시간, 정류장 근처 주차 가용성 등이 중요한 역할을 하며, 도착량의 변화는 해당 도착지의 종사자 및 사업체 밀도와 밀접한 연관이 있다는 것을 알 수 있었다.

• 한국정보통신학회논문지
• /
• 제22권1호
• /
• pp.155-161
• /
• 2018

국지적인 기상 이변이나 강우 현상 등을 분석하고 예보하기 위해서는 지역별로 저고도 탐색이 가능한 다수의 단거리 기상 레이다들이 필요하다. 그러나 이러한 레이다들의 특성인 낮은 고각의 전자파 빔 때문에 지표면 및 해수면 클러터가 기상 반사 신호를 오염시킬 가능성이 매우 높다. 대부분의 지표면 클러터는 매우 낮은 도플러 주파수 부근에 집중되어 나타나므로 주파수 대역에서의 구분이 비교적 용이한 편이다. 그러나 해수면 클러터의 경우 도플러 주파수 점유대역이 기상조건에 따라 매우 넓게 나타날 수 있기 때문에 클러터의 제거가 매우 어려운 실정이다. 따라서 본 논문에서는 전자적인 고각 빔 조향을 위하여 수직 위상 배열 안테나 구조를 갖는 기상 레이다에서의 해수면 클러터 제거 성능 정도를 분석하였다. 또한 위상배열 안테나의 수신 빔 형성을 통하여 해수면 클러터의 제거가 적절하게 이루어질 수 있음을 보였다.

• 한국농공학회지
• /
• 제16권4호
• /
• pp.3555-3571
• /
• 1974

This experiment of which aim contribute to plan irrigation system so as to increase forage crop yields, was conducted to estimate evapotranspiration amount of forage crops and to find out system of consumed water in a pasture-ground. The results obtained by this study are as follows: 1. The general weather conditions which, were closely related to the evapotrannpiration of forage crops were nearly same as those of the average year with the exception that temperature of May and June were slightly low. 2. According to the investigation of potential evapotranspirations (P.E) or forage crops and its changes during growing periods, changes of tenday P.E. were high significant according to the harvesting period. P.E of Alfalfa of which yield was the largest was the biggest. Althrough the correlations between P.E. and meteorological factors were irregular oming to three-time harvesting, correlation between ten-day evapotraspiration amount and copper plated pan evaporation or solar radiation was high positive significant. 4. Predicting formulas of P.E. were led by weather factors, and also relatione between P.E. and weather factors were showed as figure. from the these formulas, P.E. may be calculated by weather factors. 5. Predicting formulas of P.E. were led by mean temperature and copper plated pan evaporation, and by mean temperature and solar radiation. As computed values and measured values showed in figure, these formulas were high signiflent. 6. In the total consumed soil water duration of 10 days which, was non-rain period from 12th to 21th of August, Alfalfa was the largest 48.1mm, second, Orchard grass 40.1mm and Fescue 37.6mm, and Ladino clover was the smallest 37.1mm, also, order of each forage crop yield amound. was same to the abov. Order of soil moisture extraction rate of soil layer of all the for forage crops dulation of ten-day was soil layer 1 which was largest, soil layer 2, 3, and 4 Reviewing the the first five-day and the second five day, in the first five-day, order of that of all the forage crops was same to the above, but in the second five-day, that of soil layer 2 or 3 was more than the of soil layer 1.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제11B권4호
• /
• pp.169-174
• /
• 2001

A novel simulation scheme of transient phenomenon for the photovoltaic (PV) generation system under the real weather conditions has been proposed in this paper. A grid connected PV array is simulated using PSCAD/EMTDC. The transient changes of the output current of PV array under the real weather conditions is described and the output current of DC/AC converter flowing through the utility power network is also analyzed with the PWM switching width. Moreover, the MPPT control of PV generation system is combined to the system during the simulation for the comparison purposes of the control schemes. The outcome of the simulation demonstrates the effectiveness of the proposed simulation scheme. The result shows that the cost effective verifying for the efficiency or availability and stability of PV generation systems and the comparison research of various control schemes like MPPT under the same real whether conditions are eventually possible.

• 한국태양에너지학회 논문집
• /
• 제29권5호
• /
• pp.81-87
• /
• 2009

Computer simulation of buildings and solar energy systems is being used increasingly in energy assessments and design.. Building designers often now predict the performance of buildings simulation programmes that require hourly weather data. However, not all weather stations provide hourly data. Climate prediction models such as HadCM3 also provide the daily average dry bulb temperature as well as the maximum and minimum. Hourly temperature values are available for building thermal simulations that accounts for future changes to climate. In order to make full use of these predicted future weather data in building simulation programmes, algorithms for downscaling daily values to hourly values are required. This paper describes a more accurate method for generating hourly temperature values in the South Korea that uses all three temperature parameters from climate model. All methods were evaluated for accuracy and stability in terms of coefficient of determination and cumulative error. They were compared with hourly data collected in Seoul and Ulsan, South Korea.

• 한국항공운항학회지
• /
• 제12권2호
• /
• pp.71-81
• /
• 2004

There are four methods of landing of B747-400 during the crosswind condition. Pilots can choose either one of them. Those are: Sideslip/Wing low, De-Crab during Flare, Touchdown in Crab, Combining Crab and Sideslip. They decide to use one method by what they have learnt before. During the flight, the pilots choose the method, which depends on the weather forecast, and then try to land according to it. However, the weather condition always changes. In other words, the weather during planning and landing can be different, which can provide a difference between the previously expected situation and the actual one. Therefore, it is very important for the pilots to have the situation awareness. This study shows the direction and the prevention to avoid those errors, which are based on actual landing data of B747-400.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2018년도 추계학술대회
• /
• pp.78-80
• /
• 2018

해상교통 환경변화에 부응하고 나아가 대형 해양사고 방지와 인명사고 예방을 위해 구축한 해양기상신호표지시스템을 기능 개선과 표준화된 설치 방법을 통해 표준화된 통합항로표지 관리운영시스템으로 운영하여 항로표지 유지관리에 있어서 효율적인 관리를 통해 해상교통 안전에 만전을 기하고자 한다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.113-115
• /
• 2003

The electric power industry throughout the world is undergoing considerable changes from the vertically integrated utility structure to the deregulated market. However, the deregulated electricity market is operated with respect to theory of economical efficiency, and therefore, the system operator requires data with fast contingency ranking for security of the bulk power system. This paper presents fast calculation method for determining contingency ranking using the weather dependant probabilistic risk index(PRI). The probabilistic risk index can be classified into normal weather and adverse weather. This paper proposes calculation method using the probabilistic risk index in determining contingency ranking requiring for security under the deregulated electricity market.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2017년도 추계 학술논문 발표대회
• /
• pp.175-176
• /
• 2017

Many problems in various aspects such as generation of plastic/dry contraction cracks and cold joints can be caused unless proper quality control measures are established in hot weather circumstances. Therefore, this study aimed to compare the crack patterns of concrete by applying a change in 3 surface curing methods such as a mono aluminum-deposited bubble sheet developed to reduce the temperature and cracks through reflection of heat in summer and a PE film and a surface exposure used generally to an actually constructed apartment slab. The study result confirmed that the best concrete crack reduction effect can be obtained with a mono aluminum-deposited bubble sheet.

• 환경생물
• /
• 제29권3호
• /
• pp.195-201
• /
• 2011

Today, the weather is changing continually, due to the progress of global warming. As the weather changes, the habitats of different organisms will change as well. It cannot be predicted whether or not the weather will change with each passing day. In particular, the biological distribution of the areas climate change affects constitutes a major factor in determining the natural state of indigenous plants; additionally, plants are constantly exposed to rhizobacteria, which are bound to be sensitive to these changes. Interest has grown in the relationship between plants and rhizopheric microorganisms. As a result of this interest we elected to research and experiment further. We researched the dominant changes that occur between plants and rhizospheric organisms due to global warming. First, we used temperature as a variable. We employed four different temperatures and four different sites: room temperature ($27^{\circ}C$), $+2^{\circ}C$, $+4^{\circ}C$, and $+6^{\circ}C$. The four different sites we used were populated by the following strains: Pinus densiflora, Pinus koraiensis, Quercus acutissima. We counted colonies of these plants and divided them. Then, using 16S rRNA analysis we identified the microorganisms. In conclusion, we identified the following genera, which were as follows: 24 strains of Bacillus, 6 Paenibacillus strains, 1 Pseudomonas strains. Among these genera, the dominant strains in Pinus densiflora was discovered in the same genus. Additionally, those of Pinus koraiensis and Quercus acutissima changed in both genus and strains which changed into the Bacillus genus from the Paenibacillus genus at $33^{\circ}C$.