• Title/Summary/Keyword: Sea weather

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A Study on the Application for WIPI Terminal of ENC Image Information (전자해도 이미지 정보의 WIPI 단말기 적용 기법 연구)

  • Ahn, Sung-Hwan;Jung, Sung-Hun;Choi, Hong-Seok;Yim, Jae-Hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.67-70
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    • 2005
  • As the demand of sea leisure increases recently, interest is converged sea safety and offer of quick and systematic information according to weather environment that change rapidly. Use of Electronic Navigational Chart(ENC) in the sea in offer of geography information through Mobile terminal was gone to level that run in PDA environment in domestic by bulky good physician data information and complicated processing way of island in the sea expression in sea, and is loaded in obligatory sailing equipment of ship yet and is used. In this paper, we develop server system that take charge index for offer of quick information through Restrictive resource management and Caching Technique, image conversion and database construction and fast search to service various marine leisure informations of Weather Data and so on and image information of ENC in the sea to Mobile portable phone terminal efficiently.

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A Study on Ship's Longitudinal Strength and Ship Handling in Heavy Weather (황천항해중의 대형선의 종강도와 조선에 관한 연구)

  • 윤점동;박석주
    • Journal of the Korean Institute of Navigation
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    • v.7 no.1
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    • pp.63-81
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    • 1983
  • A vessel encountered heavy weather is face to two kinds of danger ; the danger of upset due to the lack of stability and the lack of the longitudinal strength. Generally a small vessel is face to the former and the large vessel to the latter. Most of people do not consider the danger of upset by the latter but the former. But many ships missed at sea, the exact causes being not known. This pper investigated and analyzed the causes of accidents. The result was that the lohgitudinal strength of the hull is not enough to cope with heavy weather, and the particular cautions are needed to handle a ship in heavy weather.

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Investigation of sea skin surface effects and sea surface emissivity effects based on thermal infrared camera image

  • Tamba, Sumio;Yoshimori, Kyu;Inomata, Kazuya
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.657-662
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    • 2002
  • Sea surface temperatures (SSTs) estimated from satellite data are affected by various kinds of disturbance factors. In order to accurately estimate SSTs based on radiometric data observed by satellite, it is important to correct the effects by these disturbance factors. We obtained a huge data set of skin sea surface temperature images observed by a thermal infrared camera (TIC) in MUBEX Campaign. TIC installed on an observation vessel recorded sea surface skin temperature distribution under various weather conditions. Based on some special images observed by TIC, we estimated skin effects and effective sea surface emissivity. In this paper, we report the methods and results of these estimations.

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Estimation of spatial distribution of precipitation by using of dual polarization weather radar data

  • Oliaye, Alireza;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.132-132
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    • 2021
  • Access to accurate spatial precipitation in many hydrological studies is necessary. Existence of many mountains with diverse topography in South Korea causes different spatial distribution of precipitation. Rain gauge stations show accurate precipitation information in points, but due to the limited use of rain gauge stations and the difficulty of accessing them, there is not enough accurate information in the whole area. Weather radars can provide an integrated precipitation information spatially. Despite this, weather radar data have some errors that can not provide accurate data, especially in heavy rainfall. In this study, some location-based variable like aspect, elevation, plan curvature, profile curvature, slope and distance from the sea which has most effect on rainfall was considered. Then Automatic Weather Station data was used for spatial training of variables in each event. According to this, K-fold cross-validation method was combined with Adaptive Neuro-Fuzzy Inference System. Based on this, 80% of Automatic Weather Station data was used for training and validation of model and 20% was used for testing and evaluation of model. Finally, spatial distribution of precipitation for 1×1 km resolution in Gwangdeoksan radar station was estimates. The results showed a significant decrease in RMSE and an increase in correlation with the observed amount of precipitation.

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A Study on the Development of Moving Watched Chamber (다중식 가두리 개발에 관한 연구)

  • Hong, Bong-Ki;Kim, In-Chul
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.31 no.1
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    • pp.93-106
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    • 1995
  • This paper describes the development of moving watched chamber. For the most part, the watched chamber have been located in the inner-bay. But, there are many problems of sea-water pollution. Therefore, the watched chamber must be relocated to undeveloped coastal area. The watched chamber which is located in the bay has a bit of damage by bad weather. But, the moving watched chamber would be exposed to bad water. It is desirable to improve the system of chamber. If we make a good design of the moving watched chamber with studying of waves and hydrodynamics, it would be possible to culture fish at the coastal sea area. When a fixed system is changed into a movable one, we can obtain the following advantages: 1. The possibility of diminishing the sea water pollution, easying the overcrowded state in a inner-bay farm, and relieved of limitation caused by bad conditions such as waves, red tides and terrains. 2. It would be easy not only to move the watched chamber system in accordance with weather conditions or occurrence of red tides, but also to select good sites for watched chamber fishes. 3. Transportation and good supervision with the automated design system can results with the effectiveness which increases the amount of aquatic products.

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Identification of Impact Factors in Ship-to-Ship Mooring Through Sensitivity Analysis

  • Lee, Sang-Won;Lee, Hyeong-Tak;Kim, Dae-Gun;Cho, Ik-Soon
    • Journal of Navigation and Port Research
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    • v.43 no.5
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    • pp.310-319
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    • 2019
  • With the recent increase in the volume of liquid cargo transportation, there is a need for STS( Ship To Ship) globally. In the case of the STS mooring, the safety assessment should be conducted according to other criteria because mooring is different from the general mooring at the quay, but there is no separate standard in Korea. Thus in this study, STS mooring simulation and sensitivity analysis using OPTIMOOR program, the numerical analysis program, was conducted to identify the characteristics of the STS mooring. The target sea modeled the Yeosu port anchorage in Korea and the target ship was selected as the case of VLCC (Very Large Crude Oil Carrier)-VLCC. Through the numerical simulation and sensitivity analysis, the characteristics of STS mooring were identified. Also based on these results, we focused on establishing the standard for STS mooring safety assessment. Numerical simulation results show that the STS mooring safety can be changed according to a ship's cargo loading condition, pre-tension of mooring line, sea depth, encounter angle with the weather, and the weather condition. Additionally, the risk matrix is prepared to establish the safe external force range in the corresponding sea area. This result can be used to understand the mooring characteristics of STS and contribute to the revision of mooring safety assessment criteria.

An Assessment of Applicability of Heat Waves Using Extreme Forecast Index in KMA Climate Prediction System (GloSea5) (기상청 현업 기후예측시스템(GloSea5)에서의 극한예측지수를 이용한 여름철 폭염 예측 성능 평가)

  • Heo, Sol-Ip;Hyun, Yu-Kyung;Ryu, Young;Kang, Hyun-Suk;Lim, Yoon-Jin;Kim, Yoonjae
    • Atmosphere
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    • v.29 no.3
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    • pp.257-267
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    • 2019
  • This study is to assess the applicability of the Extreme Forecast Index (EFI) algorithm of the ECMWF seasonal forecast system to the Global Seasonal Forecasting System version 5 (GloSea5), operational seasonal forecast system of the Korea Meteorological Administration (KMA). The EFI is based on the difference between Cumulative Distribution Function (CDF) curves of the model's climate data and the current ensemble forecast distribution, which is essential to diagnose the predictability in the extreme cases. To investigate its applicability, the experiment was conducted during the heat-wave cases (the year of 1994 and 2003) and compared GloSea5 hindcast data based EFI with anomaly data of ERA-Interim. The data also used to determine quantitative estimates of Probability Of Detection (POD), False Alarm Ratio (FAR), and spatial pattern correlation. The results showed that the area of ERA-Interim indicating above 4-degree temperature corresponded to the area of EFI 0.8 and above. POD showed high ratio (0.7 and 0.9, respectively), when ERA-Interim anomaly data were the highest (on Jul. 11, 1994 (> $5^{\circ}C$) and Aug. 8, 2003 (> $7^{\circ}C$), respectively). The spatial pattern showed a high correlation in the range of 0.5~0.9. However, the correlation decreased as the lead time increased. Furthermore, the case of Korea heat wave in 2018 was conducted using GloSea5 forecast data to validate EFI showed successful prediction for two to three weeks lead time. As a result, the EFI forecasts can be used to predict the probability that an extreme weather event of interest might occur. Overall, we expected these results to be available for extreme weather forecasting.

A Study on Measuring Procedure and Analysis Technique of Ship Infrared Signature at Sea (해상에서 적외선신호의 계측절차 및 분석기법 연구)

  • Cho, Yong-Jin
    • Journal of Ocean Engineering and Technology
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    • v.23 no.3
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    • pp.53-58
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    • 2009
  • A scale model test for ship Infra-Red signature measurements at sea is impossible, because it is sensitive to the environment. Since we can't control the meteorological environment of the real sea, it can't be carried out with the desired maritime environments. Therefore, in the sea, we made measurements of the weather, operating conditions of the ship, and ship IR signatures under given conditions, and then analyzed them. Conversely, we compared the results of the test with a prediction for a given scenario condition. This paper describes the test items, procedures, and measuring instruments of the experiments at sea and the results from basic researches for methods of estimation and analysis of the measured data.