• Title/Summary/Keyword: Weather conditions

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Ship Detection Based on KOMPSAT-5 SLC Image and AIS Data (KOMPSAT-5 SLC 영상과 AIS 데이터에 기반한 선박탐지)

  • Kim, Donghan;Lee, Yoon-Kyung;Kim, Sang-Wan
    • Korean Journal of Remote Sensing
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    • v.36 no.2_2
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    • pp.365-377
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    • 2020
  • Continuous monitoring and immediate response is essential to protect the national maritime territory and maritime resources from the activities of illegal ships. Synthetic Aperture Radar (SAR) images with a wide range of images are effective for maritime surveillance asthe weather and day-night conditions rarely affect to image acquisition. However, an effective ship detection is not easy due to the huge data size of SAR images and various characteristics such as the speckle noise. In this study, the Human Visual Attention System (HVAS) algorithm was applied to KOMPSAT-5 to extract the initial targets, and the SAR-Split algorithm depending on the imaging modes was used to remove false alarms. The detected targets were finally selected by the Constant False Alarm Rate (CFAR) algorithm and matched with the ship's Automatic Identification System (AIS) information. Overall, the detected targets were well matched with AIS data, but some false alarms by ship wakes were observed. The detection rate was about 80% in ES mode and about 64% in ST mode. It is expected that the developed ship detection algorithm will contribute to the construction of a wide area maritime surveillance network.

Spatial Analysis of Skin Cancer Incidence in Iran

  • Pakzad, Reza;Ghoncheh, Mahshid;Pournamdar, Zahra;Pakzad, Iraj;Momenimovahed, Zohre;Salehiniya, Hamid;Towhidi, Farhad;Makhsosi, Behnam Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.33-37
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    • 2016
  • Skin cancer is one of the most common cancers worldwide, including in Iran. Variations in its incidence rate among geographical areas are due to various contributing factors. Since there has been a lack of studies on this topic in our country, the present spatial analysis of skin cancer incidence in Iran in 2009 was conducted using data from the cancer registry system for the country. The reported incidences of the disease were standardized on the basis of the World Health Organization population and the direct method. Then the data were inserted into the GIS software, and finally, using the analysis of hot spots (Getis-Ord Gi), high-risk areas were drawn. Provinces that were 1.9 SD higher or lower than the national average were considered hot spots or cold spots, with significance at the level of 0.05. In 2009, a total of 9,964 cases of skin cancer occurred, 3,696 in women and 6,268 in men (standardized incidence rates of 15.8 and 22.6, respectively). The results of the study showed that in men and women, the disease demonstrated high incidence in the central provinces and desert regions. In women, Yazd Province and in men, Qom Province had significant hot spots (p <0.05). While Isfahan, Markazi, Tehran and Kurdistan provinces were expected to be hot spots, the differences from the national average were not significant at the 0.05 level. As well, the provinces of Sistan Va Baluchistan, Kerman, and Hormozgan were identified as cold or low-risk disease regions (p <0.05). The central provinces of the country due to hot weather conditions, more solar radiation, and closer vicinity to the central desert of Iran demonstrated higher incidence rates for skin cancer, so further epidemiological studies into the etiology and early detection are essential in these areas.

Effect of Daytime Temperature on Fruit Cracking of Paprika Cultivars (착색단고추 품종별 주간온도가 열과 발생에 미치는 영향)

  • 최영하;권준국;이재한;강남준;조명환;손병구
    • Journal of Bio-Environment Control
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    • v.13 no.3
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    • pp.172-177
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    • 2004
  • This experiment was conducted to investigate the effect of daytime temperature on fruit crack-ing in the paprika cv. Fiesta and cv. Jubilee under soil culture experiment of vinyl house for two years from 2003 to 2004. The rate of cracked fruit was higher in cv. Fiesta than cv. Jubilee and was the highest at the high daytime temperature of $34\pm$$1^{\circ}C$. and then rapidly increased after April becomes better weather conditions. The flesh hardness and the rate of flesh dry weight were lower in cv. Fiesta than cv. Jubilee and were the lowest at the high daytime temperature of $34\pm$1$^{\circ}C$. but the thickness of flesh was thicker in cv. Fiesta than cv. Jubilee and was the thinnest at the high daytime temperature of $34\pm$$1^{\circ}C$. Inorganic matter contents of flesh was observed no difference to the cultivars and also the temperature treatments. Root condition in harvesting time was better in cv. Fiesta than cv. Jubilee and was not difference in temperature treatments. Therefore, the rate of cracked fruit showed up a positive correlation to the flesh hardness, flesh dry weight, flesh firmness and root condition, and has not correlation to the flesh thickness and inorganic matter con-tents. In conclusion, differences in cultivar sensitivity and the highest rate of cracked fruit in daytime temperature of $34\pm$$1^{\circ}C$ may be partly due to difference in flesh characteristic and root condition but additional factors may be involved.

Investigation on the Performance of Special Purpose Automotive Air-Conditioning System Using Dual Refrigeration Cycle (듀얼 냉동사이클을 이용하는 특수목적 자동차용 에어컨 시스템의 냉방성능에 관한 연구)

  • Seo, Jae-Hyeong;Bang, You-Ma;Lee, Moo-Yeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.4
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    • pp.213-220
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    • 2016
  • The objective of this study is to investigate the cooling performance of an air-conditioning system for a special purpose vehicle under tropical and severe weather conditions. In order to evaluate and compare the cooling performances, the dual refrigeration cycle using R-134a was tested on a special purpose vehicle with various refrigerant charge amounts and indoor temperatures. The cycle was tested considering indoor cooling speed and compression ratio (discharge pressure), and was optimized at the refrigerant charge amount of 1.5 kg and outdoor temperature of $40.0^{\circ}C$. The time to reach indoor temperature of $15.0^{\circ}C$ increased by 86.5% and 38.1%, at the indoor temperatures from $25.0^{\circ}C$ to $32.5^{\circ}C$ and from $32.5^{\circ}C$ to $40.0^{\circ}C$, respectively. In addition, with the increase in indoor temperature from $25.0^{\circ}C$ to $40.0^{\circ}C$, the cooling capacity increased by 7.3%, from 19.1 kW to 20.5 kW, but decreased by 7.0% from 4.67 to 5.1.

Optimal Micrositing and Annual Energy Production Prediction for Wind Farm Using Long-term Wind Speed Correlation Between AWS and MERRA (AWS와 MERRA 데이터의 장기간 풍속보정을 통한 풍력터빈 최적배치 및 연간에너지생산량 예측)

  • Park, Mi Ho;Kim, Bum Suk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.4
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    • pp.201-212
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    • 2016
  • A Wind resource assessment and optimal micrositing of wind turbines were implemented for the development of an onshore wind farm of 30 MW capacity on Gadeok Island in Busan, Republic of Korea. The wind data measured by the automatic weather system (AWS) that was installed and operated in the candidate area were used, and a reliability investigation was conducted through a data quality check. The AWS data were measured for one year, and were corrected for the long term of 30 years by using the modern era retrospective analysis for research and application (MERRA) reanalysis data and a measure- correlate-predict (MCP) technique; the corrected data were used for the optimal micrositing of the wind turbines. The micrositing of the 3 MW wind turbines was conducted under 25 conditions, then the best-optimized layout was analyzed with a various wake model. When the optimization was complete, the estimated park efficiency and capacity factor were from 97.6 to 98.7 and from 37.9 to 38.3, respectively. Furthermore, the annual energy production (AEP), including wake losses, was estimated to be from 99,598.4 MWh to 100,732.9 MWh, and the area was confirmed as a highly economical location for development of a wind farm.

Parameter Regionalization of Hargreaves Equation Based on Climatological Characteristics in Korea (우리나라 기후특성을 고려한 Hargreaves 공식의 매개변수 지역화)

  • Moon, Jang Won;Jung, Chung Gil;Lee, Dong Ryul
    • Journal of Korea Water Resources Association
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    • v.46 no.9
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    • pp.933-946
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    • 2013
  • The quantitative analysis of evapotranspiration (ET) is a key component in hydrological studies and the establishment of water resources planning. Generally, the quantitative analysis of ET is performed by the estimation method of potential or reference ET based on meteorological factors such as air temperature, wind speed, etc. Hargreaves equation is one of empirical methods for reference ET using air temperature data. In this study, in order to estimate more exact reference ET considering climatological characteristics in Korea, parameter regionalization of Hargreaves equation is carried out. Firstly, modified Hargreaves equation is presented after the analysis of the relationship between solar radiation and temperature. Secondly, parameter ($K_{ET}$) optimization of Hargreaves equation is performed using Penman-Monteith method and modified equation at 71 weather stations. Lastly, the equation for calculating $K_{ET}$ using temperature data is proposed and verified. As a result, reference ET from original Hargreaves equation is overestimated or underestimated compared with Penman-Monteith method. But modified equation in this study is more accurate in the climatic conditions of Korea. In addition, the applicability of the equation between $K_{ET}$ and temperature is confirmed.

Ubiquitous sensor network based plant factory LED lighting system development (유비쿼터스 센서 네트워크 기반의 식물공장 LED 조명 시스템 개발)

  • Yang, Heekwon;Shin, Minseock;Lee, Chankil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.845-848
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    • 2013
  • Due to intense climate changes and extreme weather conditions a noticeable decrease has been observed in the growth of certain plants. The indoor plant factories would have certain benefits including increase in crop yield, reduction in distribution cost, and maintains the healthy freshness level of the agricultural product. Recently, an artificial light source with optimum wavelength is spot lighted to fulfill the need of light for the indoor plant factories. The energy efficient light emitting diodes (LED) provide the essential light energy for the proper growth of indoor cultivated plants. This work focuses to utilize ubiquitous sensors network(USN) in providing suitable environment for the proper growth of agricultural product inside the indoor plant factory. The proposed system makes use of sensors and actuators, communicating each other through WPAN, ZigBee network. The proposed system obscured the traditional indoor plant factories with easy installation and wireless connectivity of the sensors and actuators along with eliminating the web of wires reducing the initial installation and maintenance cost.

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Development of Simulation Method to Design Rover's Camera System for Extreme Region Exploration (극한지 탐사 로버의 카메라 시스템 설계를 위한 시뮬레이션 기법 개발)

  • Kim, Changjae;Park, Jaemin;Choi, Kanghyuk;Shin, Hyu-Soung;Hong, Sungchul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.12
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    • pp.271-279
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    • 2019
  • In extreme environment regions, unmanned rovers equipped with various sensors and devices are being developed for long-term exploration on behalf of humans. On the other hand, due to the harsh weather conditions and rough terrain, the rover camera has limited visible distance and field of view. Therefore, the rover cameras should be located for safe navigation and efficient terrain mapping. In this regard, to minimize the cost and time to manufacture the camera system on a rover, the simulation method using the rover design is presented to optimize the camera locations on the rover efficiently. In the simulation, a simulated terrain was taken from cameras with different locations and angles. The visible distance and overlapped extent of camera images, and terrain data accuracy calculated from the simulation were compared to determine the optimal locations of the rover's cameras. The simulated results will be used to manufacture a rover and camera system. In addition, self and system calibrations will be conducted to calculate the accurate position of the camera system on the rover.

A Study on the Standard Test Method for Thermal Resistance of Military Textile Thermal Insulator for Winter Season (방한을 목적으로 하는 군용 섬유제품 충전재의 보온성 시험방법에 대한 표준화 연구)

  • Yeo, Yong-heon;Hong, Seong-don;Lee, Min-hee;Kim, Kyung-pil;Chung, Il-han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.9
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    • pp.492-500
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    • 2018
  • The performance evaluation of cold weather clothing is mainly carried out with thermal resistance. However, the results of the revised test method regarding the same specimen were decreased compare to previous one. In addition, there were deviations of the results among the authorized testing institutes according to the different interpretation of the KS test method. This makes it a considerable difficulty to the quality assurance of combat supplies. The purpose of this study is to minimize the variation of the results before and after the revision by analyzing the cause of the decrease in the heat insulation rate according to the revised test method. For this purpose, the difference between the test conditions before and after the revision of KS is analyzed and the possible results are reviewed. In addition, we want to minimize the result deviation between testing laboratories by analyzing the cause of the result deviation between test laboratories according to arbitrary interpretation of the standard. Based on this, we propose a standardized test method to prevent the decrease of the heat insulation rate by checking the pre-revision test method and the condition with the least deviation.

Development of Yeongdong Heavy Snowfall Forecast Supporting System (영동대설 예보지원시스템 개발)

  • Kwon, Tae-Yong;Ham, Dong-Ju;Lee, Jeong-Soon;Kim, Sam-Hoi;Cho, Kuh-Hee;Kim, Ji-Eon;Jee, Joon-Bum;Kim, Deok-Rae;Choi, Man-Kyu;Kim, Nam-Won;Nam Gung, Ji Yoen
    • Atmosphere
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    • v.16 no.3
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    • pp.247-257
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    • 2006
  • The Yeong-dong heavy snowfall forecast supporting system has been developed during the last several years. In order to construct the conceptual model, we have examined the characteristics of heavy snowfalls in the Yeong-dong region classified into three precipitation patterns. This system is divided into two parts: forecast and observation. The main purpose of the forecast part is to produce value-added data and to display the geography based features reprocessing the numerical model results associated with a heavy snowfall. The forecast part consists of four submenus: synoptic fields, regional fields, precipitation and snowfall, and verification. Each offers guidance tips and data related with the prediction of heavy snowfalls, which helps weather forecasters understand better their meteorological conditions. The observation portion shows data of wind profiler and snow monitoring for application to nowcasting. The heavy snowfall forecast supporting system was applied and tested to the heavy snowfall event on 28 February 2006. In the beginning stage, this event showed the characteristics of warm precipitation pattern in the wind and surface pressure fields. However, we expected later on the weak warm precipitation pattern because the center of low pressure passing through the Straits of Korea was becoming weak. It was appeared that Gangwon Short Range Prediction System simulated a small amount of precipitation in the Yeong-dong region and this result generally agrees with the observations.