• Title/Summary/Keyword: Bad weather

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A Fuzzy Neural-Network Algorithm for Noisiness Recognition of Road Images (도로영상의 잡음도 식별을 위한 퍼지신경망 알고리즘)

  • 이준웅
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.5
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    • pp.147-159
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    • 2002
  • This paper proposes a method to recognize the noisiness of road images connected with the extraction of lane-related information in order to prevent the usage of erroneous information. The proposed method uses a fuzzy neural network(FNN) with the back-Propagation loaming algorithm. The U decides road images good or bad with respect to visibility of lane marks on road images. Most input parameters to the FNN are extracted from an edge distribution function(EDF), a function of edge histogram constructed by edge phase and norm. The shape of the EDF is deeply correlated to the visibility of lane marks of road image. Experimental results obtained by simulations with real images taken by various lighting and weather conditions show that the proposed method was quite successful, providing decision-making of noisiness with about 99%.

Analysis of Response to Major Oil Spills in the Korean Coastal Waters

  • Yun Jong-Hwui;Yoon Yeong-Suk;Ko Seong-Jung
    • Proceedings of KOSOMES biannual meeting
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    • 2004.05b
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    • pp.65-72
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    • 2004
  • With data of historical spill from vessels occurred in korean coastal waters, the author analyze the causes of spill and evaluate response technique adopted during spill. It is found that the majority of spill caused by operational failure, bad weather, violation of navigation rule and hull defect. As a result of evaluation of response measures, it is suggested that responsible agency establishes criteria for various response options and standards of tier response time and capability according to the size of spill.

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Power Network's Operation Influence Analysis of Wind Power Plant in Jeju island (제주지역 풍력발전기에 의한 전력계통운영 영향분석)

  • Kim, Young-Hwan;Choi, Byung-Chun;Jang, Si-Ho;Kim, Se-Ho;Jwa, Jong-Geun
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.127-129
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    • 2005
  • Construction of wind power plant is increasing rapidly because Jeju island is known as the most suitable place for wind power plant. Rut wind power plant is difficult electric power control and it has a rapid electric power fluctuation. Such a problem has a bad influence on electric power network in small electric network like Jeju. Therefore, we forecast the amount of wind power plant construction by weather information and the rate of utilization for existing facility. We investigate the contribution degree for electric Power demand, economic effect, the case of power network influence. So we forecast influence of wind power plant for Jeju power network's operation in the near future.

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An Accelerated Life Test of LED Lights for Aviation Taxiway (항공유도로등화용 LED 광원의 가속수명시험)

  • Min, Kyong-Chan;Yun, Yang-Gi;Kim, Myung-Soo
    • Journal of Applied Reliability
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    • v.11 no.2
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    • pp.127-140
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    • 2011
  • This paper presents an accelerated life test of aviation taxiway lights installed in the airport to help safe navigation of airplanes at night or in bad weather. Recently halogen lamps of taxiway lights are replaced by LED ones and their reliability needs yet to be verified. Thus, effective test conditions are designed reflecting the failure modes and mechanisms from the previous studies on LED, which include the accelerated degradation process. The test is performed under the temperature $70^{\circ}C$ and $90^{\circ}C$ for two types of LED lights, taxiway center line lights(TCLL) and taxiway edge lights (TEDL). The failure time data were analyzed using lognormal distribution and Arrhenius model to find the life-stress relationship, acceleration factor and life characteristics under the normal condition temperature $30^{\circ}C$.

Beam Stabilization Beamforming Technique for Hull-Mounted Sonar Performance Enhancement (선저고정형 소나의 탐지성능 향상을 위한 빔 안정화 빔형성 기법)

  • Ryu, Young-Woo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.3
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    • pp.129-137
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    • 2008
  • Hull-Mounted Sonar(HMS) has been the main equipment to detect and track underwater threats like torpedoes and enemy submarines. The HMS has short warming-up time and is employable independently with sea-state and weather condition. But these bad environmental condition and ship maneuvering make ship's roll and pitch. Ship's roll and pitch make unstability of sensor position, then cause degradation of the HMS performance. In this paper, we will show how the unstability influences the HMS performance, propose the 'Beam Stabilization Beamforming Technique' to overcome these phenomenon. And present the effectiveness of proposed technique by comparing with conventional beamforming result.

A Study on the Survivability Assessment System of Damaged Ships (손상선박의 생존성 평가 시스템에 관한 연구)

  • Lee, Dong-Kon
    • Journal of the Society of Naval Architects of Korea
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    • v.40 no.2
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    • pp.34-40
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    • 2003
  • Ship damage due to maritime casualties lead to marine pollution, loss of life and properties. The maritime casualties come from the rough sea and bad weather condition generally. Therefore the large-scaled casualties will be derived from loss of structural strength and stability due to the progressive flooding and enlargement of damage by the effect of wave and wind. The improvement of damage survivability is very important in maritime safety This paper described the damage survivability assessment system which can be evaluate and improve the ship safety in consideration of loading, sea and damage condition. The components of the system and decision criteria for damage stability and structural safety is established. The ship modeler and behavior analysis program in wave is developed. Finally further research work is also discussed.

Oceanography in the Waters Adjacent to Kamchatka and Kurile islands in the Northwestern Pacific - II (북서태평양 명태 어장의 해황 - 2 . 기후의 특성 -)

  • Han, Young-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.13 no.1
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    • pp.17-25
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    • 1977
  • For four calender years (1971-1974), daily observations of weather conditions (air temperature, humidity, wind speed, wind direction, cloud amount, fog, precipitation etc.) at six stations in the north western Pacific Ocean are used to calculate mean monthly values and to check extra-conditions. At Petropavlosk and Miko'skoe, where indicate the characteristics of modified continental climate, the temperature and humidity are high in summer, and Iow in winter. At A Dak and She Mya, where indicate the characteristics of warm current type maritime climate, humidity is high in all season and annual range of air temperature is nearly negligible. At Simusir and Vasi!' eva, where indicate the characteristics of cold current type maritime climate, humidity is high in all season and annual range of air temperature is $15^{\circ}C.$ As dry cooling power is relatively high in winter, working condition on deck is bad. Most of fogs are advection fog in the area of cold current type climate in summer.

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A Study on the Alternate Airport Selection Critreia (대체공항 선택요인에 관한 연구)

  • Jo, E.K.;Kim, B.J.
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.7 no.1
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    • pp.77-89
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    • 1999
  • The atmosphere condition at Kimpo International Airport occasionally prevents the aircraft from landing and forces them to fly to an alternate airport, especially in October and November during a year. Many airlines designated foreign airports instead of Korean airports as alternate airports in the case of the bad weather condition preventing use of Kimpo Airport. This paper addresses 1) economic comparison of candidates for the alternate airport, 2) what are the criteria for the alternate airport selection and the relative importance among the criteria and 3) evaluation of candidates for alternate airport using Brown and Gibson's pair-wise comparison method. It is found to be possible to reduce costs related alternate flight by 36% using Korean airports rather than using Japan's Hukuoka Airport. However, airlines weigh more on the factors such as service level of ground handling, accommodation for passengers and ground access convenience than costs. Among Korean airports, Kimhae International Airport is found the most favorable airport as the alternate airport for Kimpo International Airport.

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A Study on the Image Based Traffic Information Extraction Algorithm in Bad Weather (악천후시의 영상기반 교통정보 추출에 관한 연구)

  • Lee, Deuk-Jae;U, Jang-Myeon;Choi, Gyu-Dam;Choi, Gi-Ho
    • 한국ITS학회:학술대회논문집
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    • 2002.11a
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    • pp.169-172
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    • 2002
  • 차량검출에 관한 연구는 교통량 관측을 위해서 가장 기본적이고 필수적인 요소이다. 영상을 기반으로 한 교통 정보 시스템은 다른 방식을 이용하는 시스템들과 비교했을 때 여러가지 두드러진 장점을 가지고 있다. 하지만 일반적인 영상기반 시스템에서는 기상상태에 관해서 민감하게 반응하지 못하는 단점이 있다. 악천후가 발생하는 환경에서 영상의 노이즈는 차량의 교통정보 추출에 있어서 심각한 성능의 저하를 야기할 수 있다. 본 논문에서는 차량검출과 함께 기상 상태에 대해 영향을 덜 받는 향상된 차량정보 추출 방식을 제안 하였다. 제안된 방법은 에지를 기반으로 추출된 차량영상으로부터 비나 눈으로 인한 악천후 때문에 생긴 영상 잡음을 제거 하는 방식으로 기존의 방식에 비해 차량검출 정확도의 오류가 감소되었다. 본 논문에서 제안한 robust 한 차량검출 방법을 기반으로 하여 차량추적, 차량계수, 차종분류, 그리고 속도측정을 수행하여 각 도로의 부하르 나타내는 데 사용되는 차량 흐름과 관련되 여러 가지 교통 정보들을 추출하는데 응용될 수 있다.

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Development of Millimeter wave Radar System for an Automobile (차량용 밀리파 레이더 시스템의 개발)

  • 박홍민;이규한;최진우;신천우
    • Proceedings of the IEEK Conference
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    • 2001.06e
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    • pp.25-28
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    • 2001
  • This paper introduce a millimeter-wave radar system. As Fig 1 shows, This system consists of millimeter-wave radar front-end and digital signal processing parts through receive waves regarding up-coming obstacles. The system works as follow process; (1) Generate regular tripodal waves using the FMCW pulse generator (2) Transmit/Receive waves regarding up-coming obstacles (3) Analog filtering (4) FIFO memory interface (5) FFT(Fast Fourier Transform) (6) Calculation of distance / speed between cars (7) Object display and calibration. We have progress to solve the problem like as increase of traffic accidents causing damage and injuries due to the increased number of motor vehicles and long distance driving, and Need for a device to help drivers who are in trouble due to bad weather conditions. We are expect to Take the lead as a core technology in the ITS industry and to develop circuit and signal processing technologies related to millimeter-wave bandwidth.

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