• Journal of Astronomy and Space Sciences
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• 제16권1호
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• pp.61-68
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• 1999

GPS신호는 대류권을 지나면서 지연된다. 대류권에서의 신호지연은 건조공기에 의한 건조지연과 수증기에 의한 습윤지역으로 분리할 수 있다. 본 연구에서는 ’98년 5월 한달동안 대전, 수원에서 관측된 GPS자료를 최소자승법으로 처리하여 천장방향에 대한 총 대류권 신호지연값을 얻어내었다. 건조지연값은 지상기압을 정확하게 관측하면 얻어지므로 총대류권 지연양에서 건조지연값을 빼주면 천장방향의 습윤지연값을 얻게된다. 천장 습윤지연값은 대류층의 수증기양과 직접적으로 연관됨으로 수증기량을 측정하였고 결과의 신빙성을 검증하기 위해 오산에서 관측된 라디오존데 자료를 이용하여 계산한 대류권 수증기량과 비교하여 보았다. 그 결과 오산에서 가까운 수원의 경우 수증기량의 변화 경향이 라디오존데의 그것과 대체로 일치하였고 표준편차 3.68mm의 정도의 정확도를 보였다.

• 대한인간공학회지
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• 제36권1호
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• pp.23-36
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• 2017

Objective: This paper presents a study to evaluate the WBGT index for assessing the effects of a wide range of outdoor weather conditions on human responses. Background: The Wet Bulb Globe Temperature (WBGT) index was firstly developed for the assessment of hot outdoor conditions. It is a recognised index that is used world-wide. It may be useful over a range of outdoor conditions and not just for hot climates. Method: Four group experiments, involving people performing a light stepping activity, were conducted to determine human responses to outside conditions in the U.K. They were conducted in September 2007 (autumn), December 2007 (winter), March 2008 (spring) and June 2008 (summer). Environmental measurements included WBGT, air temperature, radiant temperature (including solar load), humidity and wind speed all measured at 1.2m above the ground, as well as weather data measured by a standard weather station at 3m to 4m above the ground. Participants' physiological and subjective responses were measured. When the overall results of the four seasons are considered, WBGT provided a strong prediction of physiological responses as well as subjective responses if aural temperature, heart rate and sweat production were measured. Results: WBGT is appropriate to predict thermal strain on a large group of ordinary people in moderate conditions. Consideration should be given to include the WBGT index in warning systems for a wide range of weather conditions. However, the WBGT overestimated physiological responses of subjects. In addition, tenfold Borg's RPE was significantly different with heart rate measured for the four conditions except autumn (p<0.05). Physiological and subjective responses over 60 minutes consistently showed a similar tendency in the relationships with the $WBGT_{head}$ and $WBGT_{abdomen}$. Conclusion: It was found that either $WBGT_{head}$ or $WBGT_{abdomen}$ could be measured if a measurement should be conducted at only one height. The relationship between the WBGT values and weather station data was also investigated. There was a significant relationship between WBGT values at the position of a person and weather station data. For UK daytime weather conditions ranging from an average air temperature of $6^{\circ}C$ to $21^{\circ}C$ with mean radiant temperatures of up to $57^{\circ}C$, the WBGT index could be used as a simple thermal index to indicate the effects of weather on people. Application: The result of evaluation of WBGT might help to develop the smart clothing for workers in industrial sites and improve the work environment in terms of considering workers' wellness.

• 한국작물학회지
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• 제41권4호
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• pp.411-419
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• 1996

보리입모중 벼 파종에 있어서 보리짚 시용에 따른 경운방법과 질소시용량별 관개수중에 용출된 각 성분함량 변화를 검토하였던 바, 그 결과를 요약하면 다음과 같다. 1. pH는 무경운재배에서는 시비수준간 차리가 없었으나 경운재배에서는 컸으며, 10일까지는 시비수준이 높을수록 pH가 높았으나 그 이후는 비슷하였다. 2. EC는 무경운에 비해 경운재배에서 높았으며, 경운의 유 ㆍ무에 관계없이 시비수준이 높을수록 EC도 높았다. 시기별로 보면 10일에 최고수준에 도달하였다가 그 후 감소경향이나, 20일에는 초기와는 달리 시비수준이 높을수록 EC가 감소하였고, 그 감소폭은 경운재배에서 컸다. 3. 용존산소는 무경운에 비해 경운에서 높았으며, 시비량이 많을수록 낮은 경향을 보였다. 경운방법별로는 무경운에서는 시용후일수가 경과됨에 따라 다소 증가하는 경향이었으며, 무처리에 비해 매우 낮았으나, 경운재배에서는 초기에 매우 높고 10일에 급격히 감소하였으며 그 후 다시 증가하였다. 4. NH$_4$-N는 경운의 유 ㆍ무에 관계없이 시비수준이 높을수록 높았으나, 20일에는 시비량간 차이는 없었다. 경운방법간에는 무경운에서는 10일까지 높고 그 후 감소를 보였으나 경운에서는 초기(5일)에 매우 높았다가 급격히 감소하였고, 15일에 다시 감소하였으나 20일에는 거의 발현되지 않았다. NO$_3$-N는 무경운에서는 처리일수 및 시비수준간의 차이가 매우 컸으며, 10일에 최고수준을 보였고, 그 후 20일까지 급격히 감소하였다. 경운구에서는 처리일수가 경과함에 따라 감소경향을 보였으나, 시비수준간 차이는 보이지 않았다. 5. PO$_4$$^{3-}$ 은 경운재배에 비해 무경운재배에서 높았으며, 두처리 모두 시비수준이 높을수록 높았으나, 무경운재배에 비하여 경운재배에서는 시일의 경과에 따라서도 차이가 크지 않았고 함량도 낮았다. 6. 양이온함량은 모두 경운 유 ㆍ무에 관계없이 시비수준이 높을수록 높은 경향을 보였고, 10일에 최고수준을 보인 후 완만한 감소를 나타냈으며, $K^{+}$, $Ca^{2+}$에 비해 $Mg^{2+}$이 보다 낮은 함량을 보였다.

• 한국수자원학회논문집
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• 제33권5호
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• pp.537-550
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• 2000

본 연구에서는 낙동강 진동지점에서 일유출량을 예측하기 위하여 신경망모형이 제시되었다. 신경망모형의 구조는 CASE 1(5-5-1)과 CASE 2(5-5-5-1)로 구성하였으며, 은닉층의 수에 따라 두 가지의 모형으로 분류하였다. 각 신경망모형은 광역최소점과 훈련임계치에 수렴하는데 기존의 역전파훈련 알고리즘(BP) 보다 뛰어난 Fletcher-Reeves 공액구배 역전파훈련 알고리즘(FR-CGBP)과 축적된 공액구배 역전파훈련 알고리즘(SCGBP)을 이용하였다. 그리고 모형의 훈련과 검증을 위하여 이용된 자료는 풍수년, 평수년, 갈수년 풍수년+평수년, 풍수년+갈수년, 평수년+갈수년 및 풍수년+평수년+갈수년으로 구분하여 구성하였다. 모형의 훈련과정에서 각 자료를 이용하여 최적 연결강도와 편차가 결정되어 졌으며, 동시에 일유출량이 계산되어졌다. 예측오차의 통계분석을 통하여 풍수년+갈수년의 자료를 제외하고는 훈련결과가 양호한 것으로 나타났다. 모형의 검증에는 모형의 훈련을 통해 산정된 CASE 1 의 SCGBP 알고리즘의 연결강도와 편차를 이용하였으며, 검증의 결과는 훈련결과처럼 만족스러운 것으로 분석되었다. 또한 본 연구에서 선정한 신경망모형과 비교검토하기 위하여 다중회귀분석모형을 적용하여 일유출량을 예측하였으며, 그 결과 신경망모형이 다소 우수한 결과를 나타내는 것으로 분석되었다. 이와 같이 신경망모형은 조직적인 접근법, 매개변수의 감소 및 모델을 개발하는데 소모되는 시간을 줄일수 있는 장점이 있다.

• 한국산림과학회지
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• 제99권2호
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• pp.251-257
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• 2010

Influences of environment (indicated by plant associations) and forest management practices on the distribution of Armillaria spp. and genets (vegetative clones) were investigated. A total of 142 isolates of Armillaria was collected from various host trees on pristine and managed sites (thinned and/or fertilized) growing in relatively wet and dry environments in eastern Washington, U.S.A. The incidence of Armillaria spp. was significantly higher in the relatively wetter sites than the relatively drier sites, as indicated by plant associations. However, no differences in Armillaria occurrence were found among different forest management practices (control vs. thinned vs. thinned and fertilized) within both wetter and drier sites. Incidence of Armillaria was significantly different among conifer and shrub species. The highest proportion with Armillaria was found on grand fir (Abies grandis). Based on pairing tests and rDNA sequencing, the 142 isolates were comprised in a total of 20 genets representing three Armillaria species. More diverse Armillaria spp. were found in both relatively wetter and relatively drier sites within the undisturbed control plots, compared to plots disturbed by forest management practices. The results from this study provide baseline information toward understanding how environment and forest management practices influence incidence and diversity of Armillaria species and genets.

• 환경영향평가
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• 제12권2호
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• pp.73-86
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• 2003

In this study, we performed 8 times of water quality sampling and continuous measurement of flow to identify wastewater flow characteristics for wastewater treatment basins of Namyangju city. The field survey has been conducted 6 times in dry weather period and 2 times in wet weather period. Each survey conducted 24-hr water quality sampling in the interval of 2-hr. From the analysis of flow data and water quality data, the following conclusions can be drawn. For Namyangju-1 station, which represents residential and commercial mixed area, flow rises early in the morning before office-going hour and moves up and down within narrow range, and lasted after office-leaving hour, resulting from continuous commercial activity. In case of Namyangju-5 station representing community and Namyangju- 6 station representing residential area, the flow immediately falls down after rising early in the morning and later rises again at the office-leaving hour, and arrives at peak flows around late evening. In the analysis of wastewater characteristics for weekdays and weekends, without landuse types the flow rate of weekends is higher than that of weekdays because it reflects population, being not contributed to generate wastewater during the working hours of weekdays, stay home and produce wastewater for weekends period.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.461-464
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• 1992

A survey of the cholesterol content of eggs obtained from commercial sources in Korea was conducted. Eggs from 17 different strain birds were obtained from the Poultry Random Sample Test Station at Ansung, Kyonggi province. Yolk cholesterol contents, determined by the colorimetric procedure, were obtained from three consecutively laid eggs from birds of about 63 weeks of age. The overall mean of cholesterol value was 17.25 mg/g of wet yolk and ranged from 16.40 to 18.18 mg/g yolk. Analysis of t-test between white shell eggs and brown shell eggs showed no difference in cholesterol content: however, the white shell eggs were somewhat high in cholesterol (17.41 vs. 17.08 mg/g yolk). Significant differences (p<0.05) were found in yolk cholesterol contents among strains within the breed.

• 전기학회논문지
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• 제65권10호
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• pp.1786-1791
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• 2016

The damage has occurred inside the semiconductor pattern When using conventional wet station for semiconductor. It was used for electrolytic ion water generator in order to prevent damage to the semiconductor pattern. It was designed and developed a flow path electrode and the mesh electrode to check the efficiency of the electrode. And It confirmed the expected results through the simulation of the flow path. and ORP were measured in accordance with the current and voltage of mesh electrode and flow paht electrodes. Flow path electrode 22A is 3V, up to pH 9.8, the value of ORP-558mV was measured and the mesh electrode was measured up to pH 9.8, ORP -350mV.

• 한국농공학회지
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• 제31권4호
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• pp.72-80
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• 1989

Various analyses were made to investigate the stochastic structure of the daily rainfall in Korea. Records of daily rainfall amounts from 1951 to 1984 at Chinju Metesrological Station were used for this study. Obtained results are as follows : 1. Time series of the daily rainfall at Chinju were positively, serially correlated for the lag as large as one day. 2. Rainfall events, defined as a sequence of consecutive wet days separated by one or more dry days, showed a seasonal variation in the occurrence frequency. 3. The marginal distribution of event characteristics of each month showed significant dif- ferences each other. Events occurred in summer had longer duration and higher magnitude with higher intensity than those of events occurred in winter. 4. There were significant positive correlations among four event characteristics ; dura- tion, magnitude, average intensity, and maximum intensity. 5. Correlations among the daily rainfall amounts within an event were not significant in general. 6. There were no consistant significancy in identity or difference between the distribu- tions of daily rainfall amounts for different days within events. 7. Above mentioned characteristics of daily rainfall time series must be considered in building a stochastic model of daily rainfall.

• 한국해양공학회지
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• 제9권1호
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• pp.120-131
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• 1995

Numerical simulations on the suspended sediment transport in the Nakdong Estuary are carried out Uncoupled flow model and diffusion model of which the governing equations are two-dimensional depth integrated equations are used int his study. Four cases are tested in this numerical simulations in which the Gaduk waterway open boundary condition and Nakdong Estuary barrage boundary condition are considered as the boundary conditions. The simulated results are compared with the measured data which were obtained by NEDECO at hadan site on 1981.2.19. and by Dong-A university at one station in the study area on 1993.4.3. and show a good agreement with them. The construction of the Nakdong Estuary Barrage may affect to reduce the current near Jinudo an Daemadeung and the suspended sediment inflowed from the upstream in the wet season seems to be transported to the Dadae.