• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.878-878
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• 2012

도시개발에 따른 인구증가와 강수의 계절적 편중 등으로 인하여 우리나라의 수자원량은 부족한 실정이다. 따라서 이러한 수자원을 효율적으로 이용하기 위해서는 유역의 가용 수자원량의 파악과 이에 따른 최적배분이 필요하다. 이러한 하천유량은 우량이나 수위와 같이 연속관측이 어렵기 때문에 관측치가 한정되어 있는 것이 일반적이며 자연하천에서 실시간으로 유량자료를 생산하는 것은 많은 인력과 장비, 경비가 필요하게 된다. 따라서 본 연구에서는 유량자료의 생산에 있어서 시간과 비용의 경제성 등을 고려하고 좀 더 효율적인 방법을 찾기 위하여 낙동강 유역의 제 1지류인 금호강 유역 내에 위치한 동촌 수위관측소의 유량자료를 이용하여 상류에 위치한 금호 단포교 지점을 미계측 유역이라 가정한 후 유량추정방법에 따른 적용성 검토를 위해 강우-유출모형인 SWAT(Soil and Water Assessment Tool)과 유역면적만을 활용하는 비유량법(Drainage-area ratio method), 유출에 영향을 주는 지형인자를 이용하는 지역회귀방법(Regional regression method)을 적용하여 그 타당성을 비교하였다. 모의된 결과, 동촌 금호 단포교 지점의 연간 상하류 유량비교에서 유량반전은 없었으며 비유량법의 유량추정에서는 높은 상관성을 보였으나 2008년과 2009년의 가뭄으로 인하여 강우-유출모형의 유량추정에서는 낮은 상관성을 보여주었다. 지역회귀방법에서는 수위관측소별 유황자료를 종속변수로 유역면적, 유역평균경사, 유로연장을 독립변수로 하는 회귀식을 산정하여 비교하였으나 본 연구에서는 사용된 자료수가 적고 수리구조물을 이용한 회귀수량 등으로 인하여 갈수량이 실측유량과는 다소 차이가 발생하였다. 미계측 유역의 유량추정시에는 자료의 축척기간과 연도별로 안정된 호우사상, 유역의 적절한 배분에 따라 결과치가 좌우되며 본 연구에서 사용된 유량추정은 관측 자료를 기초로 한 간접적인 방법들이였다. 결과적으로 금호강 유역의 동촌 지점을 이용하여 유량추정방법들을 적용해본 결과 비유량법과 강우-유출모형을 사용하는 것이 적정하였으나 관측 자료의 축적기간이 길고 상하류 간의 유량이 안정된 유역에서는 지역회귀방법의 적용으로도 안정된 유량을 산정할 것이라고 판단된다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.142-149
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• 1995

This study was conducted to investigate the relationships between yearly variation of climatic components and yearly variations of productivity in monoculture cotton. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components from the four varieties(Kinggus, Yongdang local. 113-4, 380) were collected from 1978 to 1992 in Mokpo area. The meteorological data gathered at the Mokpo Weather Station for the same period were used to find out the relationships between climatic components and productivity. Yearly variation of the amount of precipitation and number of stormy days in July are large with coefficients of the variations(C.V)84.89 and 97.05%, respectively, while yearly variation, of the average temperature, maximum temperature, minimum temperature from May to Sep. are relatively small. Seed cotton yield before frost in Sep. and Oct. very greatly with C.V. of 68.77, 78.52%, respectively. Number of boll bearing branches and lint percentage show more or less small in C.V. with 11.77 and 19.13%, respectively and flowering date and boll opening date show still less variation. Correlation coefficients between precipitation in May and number of boll bearing branches, duration of sunshine in July and number of bolls per plant, maximum temperature in July and total seed cotton before the frost in Sep., Oct., and Nov. evaporation in Aug. are positively sig-nificant at the 1% level. There are highly significantly positive correlated relationships among yield(total seed cotton) and yield components. Total seed cotton yield(Y) can be predicted by multiple regression equation with independent variables of climatic factors in July such as monthly averages of average temperature($X_1$), maximum temperature($X_2$) and minimum temperature($X_3$), monthly amount of precipitation ($X_4$), evaporation($X_5$), monthly average of relative humidity($X_6$), monthly hours with sunshine($X_7$) and number of rainy days($X_8$). The equation is estimatedas Y =-1080.8515 + 144.7133$X_1$+15.8722$X_2$ + 164.9367$X_3$ + 0.0802$X_4$ + 0.5932$X_5$ + 11.3373$X_6$ + 3.4683$X_7$- 9.0846$X_8$. Also, total seed cotton yield(Y) can be predicted by the same method with climatic components in Aug., Y =2835.2497 + 57.9134$X_1$ - 46.9055$X_2$ - 41.5886X$_3$ + 1.2559$X_5$ - 21.9687$X_6$ - 3.3763$X_7$- 4.1080$X_8$- 17.5586$X_9$. And the error between observed and theoretical yield were less with approached linear regression.

• The Korean Journal of Pesticide Science
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• v.14 no.2
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• pp.133-137
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• 2010

A field investigation was carried out for two years to analyze yield loss due to soybean anthracnose caused by Colletotrichum truncatum and to determine its economic threshold limit. Anthracnose severity in terms of % diseased pods was negatively correlated with yield, number of normal seeds per plant and number of pods per plant, and positively correlated with % abnormal seeds with correlation coefficients of -0.85, -0.78, -0.64, and 0.80, respectively. A simple linear regression model was obtained as Y=-1.7781X+164.22 with $R^2$=0.8092, when the soybean yields (Y) were predicted using anthracnose severity (X) as an independent variable. The yield levels could be predicted as high as 80.92%. Based on this equation, spray threshold without economic considerations was estimated as 6.9 in % pods infected with anthracnose. Economic threshold limit and economic spray threshold able to compensate the costs of fungicide sprays were determined as 11.9% and 9.5%, respectively.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.389-402
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• 2011

Previous research on the management of health care organization has heavily focused on health care quality and operational efficiency, whereas this research deals with flexibility, an important strategic priority in the field of operations management. Particularly, this research analyzes the effects that internal and external resources of volume and product flexibilities have on the organization's financial performance. Survey data from various types of sampled domestic hospitals have been collected using the developed questionnaire and analyzed with a regression model. The results show that volume flexibility based on internal resources has not only main effects but also interaction effects with internal and external resources of product flexibility. However, volume flexibility based on external resources is not shown to have any effect on performance. The explanation and managerial implications from the results are discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.19
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• pp.32-38
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• 1975

In order to clarify the effect of underchannel drainage and culture on the ill-drainage paddy fields, the experiment was carried out at different amounts of fertilizer and planting space under the culvert. It had been found that the effect of underchannel drainage on the ill-drainage paddy field was very efficacious, and planting density was more effective on yield than the amount of fertilizer applied.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1052-1056
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• 2004

본 연구에서는 유역내 홍수량 실측지점의 연최대 홍수량 자료 계열을 빈도 분석하여 지표 홍수량 빈도 곡선을 작성하고, 연 평균 홍수량과 유역 특성 인자간의 상관관계식을 유도하여 미계측 지점의 연평균 홍수량에 상응하는 확률 홍수량을 추정할 수 있는 방법을 개발하였다. 대상유역은 홍수자료가 풍부하고 신뢰성 있는 한강유역으로 선정하였으며, 유역의 홍수량은 댐 건설로 인하여 댐 건설 이전의 홍수량에 비하여 줄어들기 때문에 실측 유량자료의 빈도해석을 통한 홍수량 산정시에는 댐과 같은 수공구조물 건설의 영향으로 유역의 조건이 변경됨에 따라 유량자료의 불연속이 발생하는 것을 고려하였다. 한강유역의 홍수빈도 분석시 최적 확률분포형은 Gumbel 분포형으로 채택되었으며, 비 확률홍수빈도곡선을 작성한 결과 유역면적가 단위홍수량 상관성은 0.83정도로 모두 상관성을 보였으며, 지점별 주요지형인자와 연평균홍수량은 높은 상관성을 보이고, 연평균홍수량과 주요지형인자간의 회귀분석을 동하여 산정된 홍수량과 기존 하천정비 기본계획에 수록되어 있는 계획홍수량을 비교검토 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.511-511
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• 2015

국가적 측면에서 수자원의 효율적 관리는 국민의 안전 등 중요한 요소이며, 이를 위하여 수자원 장기 계획을 필요로 한다. 설계홍수량의 적정성 판단 및 첨두홍수량의 파악은 수자원 계획에 꼭 필요한 요소이다. 이를 산정하기 방법으로는 "설계홍수 추정 지침서(1993, 국토교통부)"에서 제시한 비유량법을 활용한 추정공식을 제시한 바 있다. 하지만, 기존에 제시된 비유량 산정 공식의 경우 유역면적 하나만을 매개변수로 하는 회귀식이기 때문에 급변하고 있는 강우 패턴 등의 반영이 어려울 것으로 판단되었으며, 특히 도시화 및 기후변화의 영향으로 인한 불투수면적의 증가와 집중호우 등의 극치수문사상이 발생됨에 따라 기존의 비유량법에 의해 첨두홍수량을 추정할 경우 많은 차이가 있을 것으로 예상된다. 또한, 하천기본계획 및 소하천정비종합계획 등 대부분의 하천관련 정비계획에서는 단위도법에 의해 산정된 홍수량을 계획홍수량으로 결정하고 있으며 비유량법에 의한 첨두홍수량은 계획홍수량의 적정성 검증 정도로만 활용하고 있으며 신뢰성에 의문이 제기되고 있는 실정이다. 따라서 도시유역을 대상으로 최근 수립된 하천기본계획 등의 계획홍수량 자료를 수집하고, 기존 비유량공식을 적용한 결과를 비교 검토하여 비유량 적용의 적정성을 판단하며 개선방안을 모색하고자 한다.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.2
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• pp.115-122
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• 1981

Data for this study were obtained from Burley 21 (Nicotiana tabacum L.) grown under various densities on the field in 1978 and 1979 at the Jeonju Experiment Station, Korea Ginseng & Tobacco Research Institute. Interrelations between yield and its components were statistically studied by correlation, regression, and pathway analysis. Correlation of yield with plant population was significant and positive. Quadratic functions for yield vs. plant population and the length of the largest leaf were fitted to the data. Multiple recession equation between yield and its components (leaf number ($X_1$), a leaf area ($X_5$), weight per unit leaf area ($X_9$), plant population ($X_14$)), was significant at the 5% level. Measuring the relative importance of its components on yield, plant population was 49.5%, weight per unit leaf area 25.3%, a leaf 15.6%, and leaf number 9.8%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.70-77
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• 2016

The object of this study was to evaluate the effects of climatic elements on potato yield and create a model for estimating the potato yield. We used 35 yield data of Sumi variety produced in mulching cultivation from 17 regions over 11 years. According to the results, some climatic elements showed significant level of correlation coefficient with marketable yield of potato. Totally 22 items of climatic elements appeared to be significant. Especially precipitation for 20 days after planting (Prec_1 & 2), relative humidity during 11~20 days after planting (RH_2), precipitation for 20 days before harvest (Prec_9 & 10), sunshine hours during 50~41 days before harvest (SH_6) and 20 days before harvest (SH_9 & 10), and days of rain during 10 days before harvest (DR_10) were highly significant in quadratic regression analysis. 22 items of predicted yield ($Y_i=aX_i{^2}+bX_i+c$) were induced from the 22 items of climatic elements (step 1). The correlations between the predicted yields and marketable yield were stepwised using SPSS, statistical program, and we selected a model (step 2), in which 4 items of independent variables ($Y_i$) were used. Subsequently the $Y_i$ were replaced with the equation in step 1, $aX_i{^2}+bX_i+c$. Finally we derived the model to predict the marketable yield of potato as below. $$Y=-336{\times}DR_-10^2+854{\times}DR_-10-0.422{\times}Prec_-9^2+43.3{\times}Prec_-9\\-0.0414{\times}RH_-2^2+46.2{\times}RH_-2-0.0102{\times}Prec_-2^2-7.00{\times}Prec_-2-10039$$.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.95-108
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• 1999

Field experiments were conducted in the 101 tobacco fields(51 fields in 1985 and 50 fields in 1986) of chief tobacco producing counties of Chungbuk province(Jincheon, Eumseong, Goesan, and Joongweon counties), Chungnam province(Cheonweon county), and Kyongbuk province (Cheongdo, Seongju, and Andong counties) for two years from 1985 to 1986 in order to evaluate soil fertility using chemical properties and soil map database. Pot experiments also on the same soils were conducted and the results were compared to those of field experiments. The yield of tobacco in the plots of no fertilization was considered as a basic factor representing the soil fertility and was evaluated by nineteen independent variables, that was 9 chemical properties and 10 soil map databases. These independent variables were classified into two groups, 11 quantitative indexes and 9 qualitative indexes, and were analyzed by multiple linear regression(MLR) of SAS by REG and GLM models. The yield of tobacco in the plot of no fertilization showed high variations, e.g. the difference between minimum and maximum yields was about 5.0-5.5 times in the pot experiment and 8.2-14.9 times in the field experiment. The indexes indicating close link between yield of tobacco and soil chemical indexes, was selected but it was not well matched by the years or between pot and field experiments. Also, the standardized partial regression coefficients of quantitative indexes for the yield of field were less than 1.0, suggesting that it is difficult to develop an available single index for the evaluation of soil fertility. Evaluation for the soil fertility of field by MLR was better than that of single regression and it was gradually improved by adding chemical properties, quantitative indexes, and qualitative indexes of soil map. For example, the coefficient of determination ($R^2$) of MLR for the yield of 1985 was increased to 0.422 with chemical indexes, 0.503 by addition of quantitative indexes, and 0.633 by the additional adding of qualitative indexes of soil map, compared to 0.244 of single index, $NO_3-N$ content of soil. Consequently, it is assumed that this approach by MLR with quantitative and qualitative indexes including chemical properties and soil map databases was available as an evaluation model of soil fertility for tobacco field.