• Title/Summary/Keyword: the cause of wind

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A Sunglasses Design to Prevent Snow Blindness at High Altitude (설맹 방지를 위한 고소등반용 선글라스 디자인)

  • Choi, Byung-Jin;Jang, Joon-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.4
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    • pp.19-22
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    • 2007
  • Recently, the population of people exploring High Mountain trekking or expedition is increasing as an increase in the backpackers. Many accidents occurring at High Mountain above 6,000 m are the results of snow blindness. The damage of cornea and/or retina is direct cause of snow blindness. The UV intensity increases on the hand, along with the altitude caused by decrease in the atmospheric pressure, on the other hand the reflections by bright snow at high mountain area. And it increases approximately 3 times and 4 times higher than the ground level at altitude of 4,000 m and 8,000 m, respectively. The use of sunglasses is more favorable than goggles for the protection of snow blindness at High Mountains. The eye frames that have high mechanical strength and the plastic lenses which can protect UV 100% are recommended. The attachable shielding pads are needed to prevent the incident UV light reflected or scattered from the gap between glasses frame and face. The sunglasses must have flexible and long temples to wind the ears adequately for the prevention of detachment during climbing and it is recommended that the metal frame to be coated with plastics to prevent the eye surroundings from frostbite.

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Effect of Hydro-meteorological and Surface Conditions on Variations in the Frequency of Asian Dust Events

  • Ryu, Jae-Hyun;Hong, Sungwook;Lyu, Sang Jin;Chung, Chu-Yong;Shi, Inchul;Cho, Jaeil
    • Korean Journal of Remote Sensing
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    • v.34 no.1
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    • pp.25-43
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    • 2018
  • The effects of hydro-meteorological and surface variables on the frequency of Asian dust events (FAE) were investigated using ground station and satellite-based data. Present weather codes 7, 8, and 9 derived from surface synoptic observations (SYNOP)were used for counting FAE. Surface wind speed (SWS), air temperature (Ta), relative humidity (RH), and precipitation were analyzed as hydro-meteorological variables for FAE. The Normalized Difference Vegetation Index (NDVI), land surface temperature (LST), and snow cover fraction (SCF) were used to consider the effects of surface variables on FAE. The relationships between FAE and hydro-meteorological variables were analyzed using Z-score and empirical orthogonal function (EOF) analysis. Although all variables expressed the change of FAE, the degrees of expression were different. SWS, LST, and Ta (indices applicable when Z-score was < 0) explained about 63.01, 58.00, and 56.17% of the FAE,respectively. For NDVI, precipitation, and RH, Asian dust events occurred with a frequency of about 55.38, 67.37, and 62.87% when the Z-scores were > 0. EOF analysis for the FAE showed the seasonal cycle, change pattern, and surface influences related to dryness condition for the FAE. The intensity of SWS was the main cause for change of FAE, but surface variables such as LST, SCF, and NDVI also were expressed because wet surface conditions suppress FAE. These results demonstrate that not only SWS and precipitation, but also surface variables, are important and useful precursors for monitoring Asian dust events.

Design of The Autopilot System of vessel using Fuzzy Algorithm (퍼지제어 알고리즘을 이용한 선박의 자율운항 시스템 설계)

  • 이민수;추연규;이광석;김현덕;박연식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.7
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    • pp.1509-1513
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    • 2003
  • The autopilot system of vessel is proposed to take service safety and security, to elevate service efficiency, to decrease labor and to improve working environment. Ultimate purpose of the proposed system is to minimize the number of crew by guaranteeing economical efficiency of shipping service. Recently, the research is being achieved to compensate various nonlinear parameters of vessel and apply it to course keeping control, track keeping control, roll-rudder stabilization, dynamic ship positioning and automatic mooring control etc. using optimizing control technique. Relation between rudder angle controlled by steering machine of vessel and ship-heading angle, and load condition of ship is nonlinear, which affects various parameters of shipping service. The speed and direction of waves, velocity and quantity of wind, which also cause the non-linearity of it. Therefore the autopilot system of ship requires the robust control algorithm can overcome various non-linearity. On this paper, we design the autopilot system of ship, which overcomes nonlinear Parameters and disturbance of it using Fuzzy Algorithm, evaluate the proposed algorithm and its excellence through simulation.

The Study about the Comparison of Korean-Western Medicine on Atopic Dermatitis and Food Allergy (아토피 피부염과 음식물 알레르기에 대한 동서의학적 고찰)

  • Noh, Hyeon-Min;Park, Sung-Gu;Heo, Eun-Sun;Jo, Eun-Hee;Park, Min-Cheol
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.30 no.2
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    • pp.86-99
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    • 2017
  • Objectives : The purpose of this study is to compare atopic dermatitis and food allergy of Korean Medicine with those of western medicine. Methods : We examined the relationship between atopic dermatitis and food allergy mainly in digestive system abnormalities through literature review. Results : Food allergy is classified into categories such as diarrhea, abdominal pain and cough caused by retention of undigested food(食積) and pimples(癮疹) in Korean medicine. The side effects caused by specific immune reactions occur repeatedly due to exposure to specific food allergen or retention of undigested food. Atopic dermatitis and food allergy are often coexisting and deeply related. Digestive system abnormalities can result not only in indigestion but also in immune function abnormalities. Food allergies are known to cause atopic dermatitis and the influx of food antigens exacerbates atopic dermatitis. This corresponds to atopic dermatitis due to abnormal digestive system(脾胃) accompanied by fever(熱), wind(風), and weakness(虛) with focusing on dampness(濕). A typical example of the relationship between atopic dermatitis and food allergy in Korean medicine is Tae-yeul (胎熱). Tae-yeul refers to atopic dermatitis caused by a sensitization to reaction to the dietary antigens of the mother through the placenta during the fetal life with a unusual genetic disposition. Conclusions : We compared korean medicine with western medicine for atopic dermatitis and food allergy. Atopic dermatitis caused by abnormal immune function due to ingestion of food antigen corresponds to dermatitis due to retention of undigested food(食積), digestive system(脾胃臟) problems in korean medicine.

Analysis of Clutter Effects in a Weather Radar (기상 레이다에서의 클러터 영향 분석)

  • Lee, Jonggil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.9
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    • pp.1641-1648
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    • 2016
  • A weather radar estimates Doppler frequency and width of Doppler spectrum from the received weather signal which represents the return echoes from rain or dust particles in a corresponding area. These estimates are very important parameters since they are directly related to precipitation, wind velocity and degree of turbulence. Therefore, these estimated values should be highly reliable to obtain accurate weather information. However, the echoes of a weather radar include both the weather signal and the clutter which occurred from ground reflection or moving objects, etc. The existence of the clutter in the echoes may cause serious errors in the estimation of weather-related parameters. Therefore, in this paper, models are developed to represent the weather signal and the clutter for the purpose of analyzing estimation errors caused by the strong clutter echoes. Using these models, various return echoes according to the weather signal and clutter power are simulated to analyze the effects of the clutter.

Design of The Autopilot System of vessel using Fuzzy Algorithm (퍼지제어 알고리즘을 이용한 선박의 자율운항 시스템 설계)

  • 이민수;추연규;이광석;김현덕;박연식
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.801-804
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    • 2003
  • The autopilot system of vessel is proposed to take service safety sorority, to elevate service efficiency, to decrease labor and to improve working environment. Ultimate purpose of it is to minimize the number of crew by guaranteeing economical efficiency of shipping service. Recently, the research is being achieving to compensate various nonlinear parameters of vessel and apply it is course keeping control, track keeping control, roll-rudder stabilization, dynamic ship positioning and automatic mooring control etc. using optimizing control technique. Relation between rudder angle controlled by steering machine of vessel and ship-heading angle, and load condition of ship are nonlinear, which affect various parameters of shipping service. The speed and direction of waves, velocity and quantity of wind, which also cause the non-linearity of it. Therefore the autopilot system of ship requires the robust control algorithm can overcome various non-linearity. On this paper, we design the autopilot system of ship, which overcome nonlinear parameters and disturbance of it using Fuzzy Algorithm, evaluate the proposed algorithm and its excellence through simulation

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A Review of Clinical Researches on Socheongryong-Tang (소청룡탕의 임상연구 분석)

  • Kim, Won-Bae;Seok, Eun-Joo;Jeon, Su-Yeon;Jeong, Jong-Kil;Lee, Soong-In
    • Herbal Formula Science
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    • v.26 no.1
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    • pp.43-57
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    • 2018
  • Objective : This study's purpose was to review the clinical studies of Socheongryong-Tang. Method : We searched papers about Socheongryong-Tang using KISS, KTKP, PUBMED, Embase, Science Direct, and the key words "Socheongryong-Tang", "Shoseiryuto", "Xiao Qing Long Tang", and "Minor Green-Blue Dragon Decoction" were used. Papers not matched with inclusion criteria were excluded. Until today, there have been 143 studies on the effects of asthma, allergic rhinitis, common cold, eczema and other various effects of Socheongryong-Tang. Of these, 15 were classified as clinical research papers. Results : There were 4 cases of asthma, 2 cases of allergic rhinitis, 2 cases of common cold, 1 case of pneumonia in patients with dementia, 1 case of eczema, 1 case of drug interaction study, 1 case of ephedrine drug removal, 3 cases of side effects causing pneumonia. Conclusion : It can be seen that Socheongryong-Tang has established the basis for application for the purpose of asthma, allergic rhinitis, wind-cold type cold, preventing pneumonia in patients with dementia, dyshidrotic eczema. On the other hand, considering three cases that cause side effects of pneumonia, it is necessary to confirm whether or not the symptoms of pneumonia are certainly progressing when observing the progress of the patient.

Analysis and Prediction of (Ultra) Air Pollution based on Meteorological Data and Atmospheric Environment Data (기상 데이터와 대기 환경 데이터 기반 (초)미세먼지 분석과 예측)

  • Park, Hong-Jin
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.4
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    • pp.328-337
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    • 2021
  • Air pollution, which is a class 1 carcinogen, such as asbestos and benzene, is the cause of various diseases. The spread of ultra-air pollution is one of the important causes of the spread of the corona virus. This paper analyzes and predicts fine dust and ultra-air pollution from 2015 to 2019 based on weather data such as average temperature, precipitation, and average wind speed in Seoul and atmospheric environment data such as SO2, NO2, and O3. Linear regression, SVM, and ensemble models among machine learning models were compared and analyzed to predict fine dust by grasping and analyzing the status of air pollution and ultra-air pollution by season and month. In addition, important features(attributes) that affect the generation of fine dust and ultra-air pollution are identified. The highest ultra-air pollution was found in March, and the lowest ultra-air pollution was observed from August to September. In the case of meteorological data, the data that has the most influence on ultra-air pollution is average temperature, and in the case of meteorological data and atmospheric environment data, NO2 has the greatest effect on ultra-air pollution generation.

Analysis of Hebei Spirit Collision Accident by Simulation (시뮬레이션에 의한 허베이스피리트호-삼성바지선 충돌사고 분석)

  • Kim, Sun-Young;Lee, Gyeong-Joong;Park, Se-Kil;Kim, Yeon-Gyu;Lee, Moon-Jin;Son, Nam-Sun;Gong, In-Young;Kim, Mi-Hyun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2011.06a
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    • pp.85-86
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    • 2011
  • On 7 December 2007, the Hebei Spirit, a 260,000 dwt VLCC, anchored near Korea's Daesan Port, was collided with a passing crane-carrying barge Samsung1, which was under tow of two tugs Samsung T5 and Samho T3. In this study, the behaviour of Hebei Spirit at the time of the accident has been reproduced and analyzed by simulation. This study precedes the study for the investigation of any available countermeasures for Hebei Spirit to prevent the accident. The simulation has been done only for Hebei Spiri and the motion of Samsung barge is just given with recorded AIS data. Dynamic characteristics of Hebei Spirit have been modeled based on empirical data and her sea trial data. Effects of current, wave and wind are also estimateed using empirical formula. Considering uncertainty of environmental condition and control of Hebei Spirit, simulation has been done by varying engine control method and holding power coefficients of the anchor. Finally, based on simulations, the most plausible scenario on the state of anchor and engine control could cause real accidents.

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A Study on Behavior Characteristics of Volatile Organic Compound Caused by Ventilation in a Room (통풍에 의한 휘발성 유기화합물의 실내 거동 특성에 대한 연구)

  • Kim, Jang-Woo;Chung, Jin-Do
    • Journal of Environmental Science International
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    • v.15 no.11
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    • pp.1011-1016
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    • 2006
  • Recently, volatile organic compound(VOC) has been noted as a main cause of air pollution. VOC, with its toxic and offensive odor, is hazardous to health. Furthermore indoor, underground and hish-rise buildings are preferable living spaces. People spend more than 80% of the day indoor, so indoor air pollution is a matter of importance. In Korea, from 2004, 10 types of indoor pollutants in public facilities have been identified. However, there is no standard for individual VOC, so the regulation has not yet effectively been carried out. In this study, we have studied on the diffusion of Benzene in a room using a numerical analysis for various air-controlled conditions consisted of door, window and ventilation system. This study investigates spatial concentration distribution and time-history of room-averaged benzene concentration for several cases. The results of this study show that when the room is ventilated by a small fan only for 30 minutes, the average concentration of benzene is decreased a very little, thus the impact to human body would be serious compared to the case of natural ventilation by window and door, In the case of natural ventilation by window and door, if the wind speed is higher than 0.5m/s, it takes small than 4 minutes for benzene to spread to the target concentration of $1.2mg/m^3$.