• 제목/요약/키워드: "On-water"

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A Study of Interrelationships between the Effect of the Upwelling Cold Water and Sea Breeze in the Southeastern Coast of the Korean Peninsula (한반도 동남연안지역의 냉수대 영향과 해풍의 상호관련성 연구)

  • Lee, Hwa-Woon;Ji, Hyo-Eun;Lee, Soon-Hwan
    • Journal of Korean Society for Atmospheric Environment
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    • v.25 no.6
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    • pp.481-492
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    • 2009
  • The characteristic of cold water by upwelling in the southeast of the Korean Peninsula and the effect of sea breeze in this region are investigated. The coastal upwelling around the southeast coast of the Korea Peninsula is analyzed by using Coastal Oceanographic Data statistical analyses for 5 years were carried out. The period of an cold water event, on the average, was observed southwesterly wind events. The analysis suggests that strong and persistent southwesterly winds in period of an cold water play an important role of bring the moisture to the surface, generating persistent cyclone as jangma. In order to investigate the effect of cold water on sea breeze, we considered two case. First, Exp. 1 is not occurred coastal upwelling on sea breeze. Second, Exp. 2 is occurred cold water on sea breeze. Two experiments were completed separately to the effects of cold water by upwelling. The results show the sea breeze is stronger in Exp. 2, when the cold water occurs, and weaker in Exp. 1, when there is no cold water. In order to verify the effect of the sea breeze on the cold water by upwelling, on the intensification and change of direction of the prevailing wind, the sea breeze effectively intensify cold water condition.

Epidemiologic Investigation to Identify the Cause of an Infant Methemoglobinemia (서울 S지역에서 발생한 영아 메트헤모글로빈혈증 1례의 원인구명을 위한 역학조사)

  • Kim, Young-Yeul;Choi, Bo-Youl;Park, Hang-Bae;Kim, Min-Young;Yeo, In-Hak
    • Journal of Preventive Medicine and Public Health
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    • v.26 no.2 s.42
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    • pp.192-201
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    • 1993
  • Epidemiologic investigation was conducted on January, 1993 in Seoul to identify the cause of an infant methemoglobinemia. Field investigation of the area of outbreak, survey of household and family members, analysis of ground water, and blood tests of involved family members were performed. Following results were obtained On analyzing the quality of the ground water on patient's household high levels of nitrate was found indicating contamination of water as the cause of a methemoglobinemia outbreak. On analysing the quality of the ground waters on seven other places within the neighborhood five were contaminated by nitrate in concentration that exceeded the permissible limit implying presence nearby source of contamination. Sources of contamination were thought to be originating from human waste in conventional bathroom facilities, chicken manure used in nearby orchards and plant fields or fertilizers. But the results of water analysis with presence of bacteria or E.coli, concentration of potassium, phosphate and the past history of diarrhea among family members, chicken manure suggested the most possible source of contamination. To evaluate the health status of members in the neighborhood past history was reviewed revealing no prior existence of patient with cyanosis and 65 people in the neighborhood had normal levels of methemoglobin concentration in their blood. Conclusively, the ground water on patient's household was contaminated with nitrate and despite provision of adequate water supply, family members of the patient along with their distrust in the water supply system had used ground water as their source of drinking water resulting of methemoglobinemia. Many suburban area of Seoul and country side thought to be having similar problems concerning contaminated ground water supply and dormant outbreak of patients as a result of the drinking of the contaminated water. Epidemiologic investigation and water analysis of ground waters are advised.

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An Effect of the Salt Solution on the Water Tree Propagation in Polyethylene (폴리에틸렌 내에서 워터트리가 확산하는데 염용액이 미치는 영향)

  • Koo, Ja-Yoon
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.34 no.11
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    • pp.436-439
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    • 1985
  • An effect of the salt solution on the Water Tree Propagation was shown systematically from the actions of the salt concentration in deionized water. It may be able to suggest that the tree propagation is possibly to be connected with an intervention of the electrochemical or chemical actions of the salt solution on water tree propagation, which may likely depend on the growth level of the trees. We have pointed out that it is necessary to study the structure of water tree under the electrical stress.

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On the Evapotranspiration Model derived from the Meteorological Elements and Penman equation (Penman 식과 기상요소를 이용한 증발산모델에 관하여)

  • 이광호
    • Water for future
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    • v.6 no.2
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    • pp.6-11
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    • 1973
  • This paper include the hydrometeorological analyses of evapotranspiration which is import factor concerning the estimate of water budgest over a certain basin. Evapotranspiration model mode by the multiple regression analysis between the evapotranspiration measured on various kinds of ground cover (water, bare soil and lawn) and the other meteorological elements affecting the evapotranspiration process, and the simple regression analysis between the evapo transpiration measured on each ground cover and the evapotranspiration on water and vegetables calculated from the Penman equation. It is expected that the evapotranspiration models are a very useful formulae estimating ten days amounts or a month's amounts.

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A Study on the Media Coverage of Public Issue: Focusing on Drinking-Water Issues (공적 이슈에 대한 미디어 보도 분석: 수돗물 관련 기사를 중심으로)

  • Kim, Sung-Tae;Lee, Chang-Ho
    • Korean journal of communication and information
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    • v.39
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    • pp.40-68
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    • 2007
  • Despite many efforts to improve water and publicize Arisu, ordinary citizens' distrust in water is still intense. This study aims to analyze how newspapers, television and internet media in Korea covered water-related news, focusing on the type of articles, themes, news sources, and news values. As a result, the mostly mentioned theme in the media was the discussion about suitability of water as a drinking water, followed by impurified water, governmental policy on water, coverage on the water pipe, and result of examination of water quality. Also among newspapers, broadcasting, and the internet, the internet medium showed the most negative tone in covering water. Stories written by journalists with expertise were less than 1% whereas stories by ordinary journalists were mostly found. In conclusion, to cover public issues like water desirably, it is necessary to bring up journalists with expertise in environmental issues, to diversify news sources, and to do investigative reporting rather than reporting appealing to audience's amusement.

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Effect of Hydrophilic and Hydrophobic Finishes of Fabrics on the Stratum Corneum Water Content and Comfort Properties (직물의 친수 및 소수화 처리가 피부잔류수분량 및 쾌적감에 미치는 영향)

  • Kahng, Soo Ma;Kim, Eun Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.1
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    • pp.151-161
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    • 1993
  • The purpose of this study was to investigate the effect of hydrophilic finish for polyester (PET) fabric and hydrophobic finish for cotton fabric on the water transport and comfort properties. Polyester fabric was treated with 10% sodium hydroxide solution to impart hydrophilicity. Cotton fabric was sprayed with Scotch-gard$^{(R)}$ water and oil repellent finish to impart hydrophobicity. Porosity, air permeability, contact angle, wickability and water vapor transport rate (WVTR) were measured to determine the water transport properties of fabrics. To compare the comfort properties of treated and untreated fabrics, wear test was performed by putting fabric patches on the upper back: stratum corneum water content (SCWC), subjective wettedness and comfort rating were determined. The results were as follows: (1) The contact angle of water on treated polyester fabric was decreased and that of treated cotton fabric was increased. Also, the wickability of treated polyester fabric was increased and the wickability of cotton fabric was decreased. (2) Although each finish did not change porosity, the water vapor transport rate of treated polyester fabric was increased and that of treated cotton fabric was decreased slightly. (3) The results of stratum corneum water content measurements showed good agreement with the results of the contact angle and the wickability, i.e., the better the liquid water transport properties are, the less the stratum corneum water contents were resulted. (4) The realtionship of subjective wettedness or comfort and stratum corneum water content was independent. Therefore, it was concluded that human perception on the subjective wettedness or the comfort is affected by the skin contact of wet fabric rather than by the stratum corneum water content.

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Research on How to Set 3rd Phase Target Water Quality on the Boundary between Metropolitan Cities/Dos Specified in Nakdong River Basin (낙동강수계 3단계 광역시·도 경계지점 목표수질 설정 방법 연구)

  • Hwang, Ha Sun;Park, Ji Hyung;Kim, Yong Seok;Rhew, Doug Hee;Choi, Yu Jin;Lee, Sung Jun
    • Journal of Korean Society on Water Environment
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    • v.33 no.1
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    • pp.70-77
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    • 2017
  • Total Pollution Load Control (TPLC) is a system for managing the discharge load assigned by satisfying the Target Water Quality (TWQ) in Standard Flow Conditions (SFC). TWQ for a between Metropolitan Cities/Dos Specified (Cites/Dos TWQ) is very important to be the basis of each Unit Watershed TWQ. The purpose of this study was to establish a rational and scientific 'Calculation Metohd of Cites/Dos TWQ'. A methodology for the 3rd phase 'Cites/Dos TWQ' was proposed in this study based on review of the past phase (1rd and 2rd) 'Cites/Dos TWQ' in nakdong river. And utilized water quality model to estimate 3rd phase 'Cites/Dos TWQ' The allocation method of individual discharge sources are important for estimating 'Cites/Dos TWQ' In this case, the key point of the method of calculating the total allowable individual sources is the balance of the equity and the efficiency between individual sources of reduced pollutants. Thus, water quality shall be determined with regard to the current emission levels, the reduction capacity and the technical possibilities of individual sources. We estimate 3rd phase 'Cites/Dos TWQ' according to the 'Calculation Method of Cites/Dos TWQ'.

A Study on Typical Rates of Water-use for Primary School, Middle School and High School Facilities (초.중.고등학교 시설의 급수 사용량에 대한 연구)

  • Kim, Kyu-Saeng
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.510-515
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    • 2007
  • A Study on Typical Rates of Water-use for School Facilities has been carried out in this work. Water supply system is given much weight in school facilities. Therefore, it set up a basis efficiency using of water sources to calculate typical rates of water use. The results are summarized as follows ; 1) On the whole, typical rates of water-use was founded out 15 L / stu. d in pirmary school, 10 L / stu. d in middle school and 30L / stu. d in high school smaller than the existing it. It was rate of water-use change as season and Max. Rates of water-use was July. 2) I deem that school hours are 5 hour's in primary school, 7 hour's in middle school and 8 hour's in high school. It the concept of 1 hour that is lesson time 40 minutes and resting time 10 minutes in primary school, lesson time 45 minutes and resting time 10 minutes in middle school and lesson time 50 minutes and resting time 10 minutes in high school. 3) It is desired that we calculate the volume of pump and water tank throughout this concept and the size of water tank should be 1.5 times with taking pick load into consideration by this study on typical rate of water-use. 4) The amount of using water increases in gradually and I consider the life cycle of facilities is more than 10 years. As a result, I can forecast that the size will be insufficiency but I deem that if we devise a plan about parallel pumping on water tank space, we can cope with it. Also, it is expected that we can cut back the transport energy by controlling pump volume.

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A Study on the Automatic Measurement of Solid Content in Recycled Water in Ready Mixed Concrete Plant (레디믹스트 콘크리트 플랜트의 회수수 농도 측정 자동화에 관한 연구)

  • Choi, Young-Cheol;Moon, Gyu-Don;Cho, Bong-Seok
    • Journal of the Korean Society of Safety
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    • v.29 no.4
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    • pp.123-131
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    • 2014
  • Whole amount of waste water, approximately 921.6 liter, for cleaning a ready mixed concrete truck should be used to produce concrete as a mixing water or cleaning water. Recycling water for concrete mixing contains solids, which cause decrease in slump, air and compressive strengths, so it may influence on poor concrete quality. Therefore, it has been maintained to use recycling water with less than 3 percent of solids. Since no evaluation system has been constructed to directly reflect on variability of recycling water from ready mixed concrete plants, it is necessary to develop "Automatic recycling solid measuring system" for quality controls in real time. In this research, sensors measuring waste water concentration in ultrasonic and inductance methods were developed, and automatic system using the sensors were established. The accuracy of measurement sensors developed for recycling water based on various conditions of concentration was proved, and application limits were evaluated. Also, concentration of recycling water using sensors developed from ready mixed concrete plant was measured, and curing method verified the accuracy of the sensors. Moreover, measurement sensors for recycling water in various locations were installed to evaluate the effects on measuring method and spots. The automatic measuring system for recycling water concentration, which is developed in the research, will contribute to improve concrete quality safety through reliable solids maintenance.

Prediction of pollution loads in agricultural reservoirs using LSTM algorithm: case study of reservoirs in Nonsan City

  • Heesung Lim;Hyunuk An;Gyeongsuk Choi;Jaenam Lee;Jongwon Do
    • Korean Journal of Agricultural Science
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    • v.49 no.2
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    • pp.193-202
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    • 2022
  • The recurrent neural network (RNN) algorithm has been widely used in water-related research areas, such as water level predictions and water quality predictions, due to its excellent time series learning capabilities. However, studies on water quality predictions using RNN algorithms are limited because of the scarcity of water quality data. Therefore, most previous studies related to water quality predictions were based on monthly predictions. In this study, the quality of the water in a reservoir in Nonsan, Chungcheongnam-do Republic of Korea was predicted using the RNN-LSTM algorithm. The study was conducted after constructing data that could then be, linearly interpolated as daily data. In this study, we attempt to predict the water quality on the 7th, 15th, 30th, 45th and 60th days instead of making daily predictions of water quality factors. For daily predictions, linear interpolated daily water quality data and daily weather data (rainfall, average temperature, and average wind speed) were used. The results of predicting water quality concentrations (chemical oxygen demand [COD], dissolved oxygen [DO], suspended solid [SS], total nitrogen [T-N], total phosphorus [TP]) through the LSTM algorithm indicated that the predictive value was high on the 7th and 15th days. In the 30th day predictions, the COD and DO items showed R2 that exceeded 0.6 at all points, whereas the SS, T-N, and T-P items showed differences depending on the factor being assessed. In the 45th day predictions, it was found that the accuracy of all water quality predictions except for the DO item was sharply lowered.