• 한국측량학회지
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• 제21권3호
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• pp.199-207
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• 2003

본 연구에서는 위성측위의 정확도를 평가하기 위해서 위성 데이터 수신에 장애가 없는 개활지역, 신호차단과 다중경로 오차를 유발하는 고층 건물 및 차량통행과 전주 등이 산재한 도심지역을 실험지로 선정하여, GPS/GLONASS, TS/RTK-GPS 결합관측의 적용성을 제시하고, 기존 정지관측기법과의 정확도 비교와 결합관측방법의 활용성을 검토한 결과, 먼저 정적상대측위는 대상지별로 GPS 단독, GPS/GLONASS 결합의 방법으로 도근점의 성과와 0∼0.006m의 오차를 보였고, 실시간 위성측위에서 모호정수(Ambiguity) 고정해를 얻지 못한 RTK-GPS와 TS의 결합의 경우에는 도심지에서는 0.010∼0.077m 였으며, 개활지에서는 0.008∼0.078m 오차를 보였다. 이 값은 축척 l/l,200 지적도에서 측선거리 l00m의 경우 연결허용오차 12cm보다 작으므로 실용성이 있다고 판단된다.

• 한국측량학회지
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• 제15권2호
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• pp.165-173
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• 1997

동적 DGPS 측위에 의해 결정된 투영중심 좌표를 이용한 결합 번들블럭조정은 높은 정확도를 가지게 되었으며, 지상좌표 표준편차가 $\pm$10cm 이내로 결정될 수 있다. 이러한 정확도 수준에서는 더 작은 오차 성분이 중요하게 되었으며, 이 가운데 중요한 것은 GPS-Antenna 위치 사이에서 시간의 함수로 투영중심을 보간하는 것이다. 선형보간은 비행기의 비선형 움직움을 고려하지 않는 반면 최소제곱 다항식에 의한 보간은 비행기의 거동이 더 정확하게 고려되고, 위성의 상실과 신호차단 등에 의한 GPS위치의 과대오차를 소거하여 준다. 본 연구대상지 RHEINKAMP에서 3초의 시간을 이용한 보간은 MAA의 6-7초의 시간간격을 이용한 보간과는 다르며, 이러한 GPS위치는 국부회귀 다항식에 의하여 과대오차로 확인되었고, 이것은 정확한 블럭조정을 위해서는 무시할 수 없다.

• 한국물환경학회지
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• 제25권4호
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• pp.615-623
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• 2009

The research of the determination of event mean concentration (EMC) was focussed combined sewer overflows and highway runoff in korea. But those of non-urban areas are few. In this study, EMC and unit loading on land use types in Nogok watershed were estimated by runoff loading of non-point source (NPS) on non-urban area. Two monitoring sites were equipped with an automatic velocity meter, flow meter, and water sampler. Monitoring was conducted at two monitering site during the rainy season. The results show that the EMC ranges in forest land use are 1.3~2.6 mg/L for BOD, 2.0~16.1 mg/L for SS, 0.1~2.1 mg/L for TN, and 0.12~0.49 mg/L for TP. The unit loading of NPS in this study was difficult to compare directly with that used conventionally because of the difference of field investigation. In near future, it needs to conduct more systematic and long-term research about NPS within the watershed. The results of this research can be used to estimate the total pollution load management system (TPLMS) program in korea.

• 한국습지학회지
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• 제12권3호
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• pp.39-47
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• 2010

최근 우리나라 농경지 면적은 해마다 감소하고 있는 추세이나 이러한 농업지역으로부터 발생되는 오염부하량은 오히려 증가하고 있는 실정이다. 농업지역으로부터 발생되는 오염물질 중 대부분은 비점오염원에 의해 배출되며 이는 주로 저농도이면서 넓은 지역에서 대량으로 배출되는 특성을 보인다. 본 연구의 목적은 농업지역 내 비점오염원을 관리하기 위한 방안으로 인공습지를 적용하여 수질정화효율을 분석함으로써 인공습지 적용가능성과 오염물질 제거기작, 설계인자 등을 제공함에 있다. 모니터링 결과를 토대로 수질분석을 실시하였으며 분석 결과, 유입수의 평균 농도 제거율은 TSS가 26 %, BOD가 28 %, TN이 16 %, TP가 39 %로 나타났다. 또한 국내 하천수질기준에 준하여 인공습지 유입수과 유출수의 수질을 비교해 본 결과 대부분의 항목에서 수질등급이 향상되었다.

• 한국수자원학회논문집
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• 제37권6호
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• pp.461-466
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• 2004

본 연구에서는 쇄파대에서 정현파의 쇄파에 대해 수리모형실험과 수치모형실험을 수행하였으며, 두 실험결과를 비교하였다. 수치해석 모형에서는 Reynolds 방정식을 지배방정식으로 사용하고 난류해석을 위해 $textsc{k}$-$\varepsilon$ 모델을 적용하였으며, 자유수면변위를 추적하기 위해 VOF기법을 사용하였다. 수리모형실험과 수치모형실험 모두 동일한 수심과 주기를 가질 경우, 입사파의 파고가 커질수록 쇄파발생 지점이 경사시작 지점으로부터 가까운 위치로 이동하는 경향을 보였다. 또한, 쇄파발생시 파고비(H/H$_{0}$)는 동일한 수심과 파고를 가질 경우, 주기가 커질수록 증가하는 경향을 보였다.

• 한국농공학회지
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• 제34권3호
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• pp.53-63
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• 1992

To investgate the fracture behavior of the steel fiber reinforced concreate, the specimens with different steel fiber contents of 0.0%, 0.5%, 1.0%, 1.5%, were made and notched with differents notch depth ratios of 0.0,0.2, 0.4, 0.6, and the three point bend tests were followed. Test results of 16 different types of above combined specimens were summarized as follows. 1.The load line deflection contents were found to increase 5%, 16%, 19%, respectively, compared to the unnotched specimen with the increased of initial notch depth ratio to 0.2,0.4, 0.6, respectively. 2.The frexural strength were found to decrease 14%, 16%, 21 %, respectively, compared to the unnotched specimen with the increase of initial notch depth ratio to 0.2, 0.4, 0.6,respectively. 3.The stress intensity factors of the steel fiber reinforced concrete were found to increase 1.1 1.5 1.9 times, respectively, compared to the concrete with no steel fiber content with the increase of fiber content to 0.5%, 1.0%, 1.5%, respectively. 4.The influence of the mass of the steel fiber reinforced concrete to the whole fracture energy was found to be minor with 6~8 % contribution. 5.The fracture energy of the steel fiber reinforced concrete, considering the load-deflection curve and concrete mass was found to be approximately 350-380kg m/m$^2$. 6.The regression analysis through the relationship between the compressive(Oc)/tensile (OT) strength and fracture energy(Gf) showed that the fracture energy of the steel fiber reinforced concrete could be predicted as follows. Gf= 19.2662 Oc - 3940.4 Gf= 246.876 OT- 6008.8

• 한국환경농학회지
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• 제31권2호
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• pp.113-121
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• 2012

BACKGROUND: The Doam watershed in Korea has been managed for the reduction and the prevention of non-point source pollution since 2007. Especially, the water quality of the Doam reservoir is a primary issue related to the Doam dam reoperation. We have carried out the modeling to evaluate the water quality based on suspended solids (SS) of the Doam watershed and the Doam reservoir. Two powerful hydrological and water quality models (HSPF and CE-QUAL-W2) were employed to simulate the combined processes of water quantity and quality both in the upland watershed of the Doam reservoir and the downstream waterbody. METHODS AND RESULTS: The HSPF model was calibrated and validated for streamflow and SS. The CE-QUAL-W2 was calibrated for water level, water temperature, and SS and was validated for the only water level owing to data lack. With the parameters obtained through the appropriate calibration, SS concentrations of inflow into and in the Doam reservoir were simulated for three years (2008, 2004 and 1998) of the minimum, the average, and the maximum of total annual precipitation during recent 30 years. The annual average SS concentrations of the inflow for 2008, 2004, and 1998 were 8.6, 10.9, and 18.4 mg/L, respectively and those in the Doam reservoir were 9.2, 13.8, and 21.5 mg/L. CONCLOUSION(s): The results showed that more intense and frequent precipitation would cause higher SS concentration and longer SS's retention in the reservoir. The HSPF and the CE-QUAL-W2 models could represent reasonably the SS from the Doam watershed and in the Doam reservoir.

• 한국작물학회지
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• 제47권
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• pp.107-123
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• 2002

This paper is intented to present a information of various aspects of quality related characteristics and standards for grades in maize. Maize is world's one of the three most popular cereal crops and a primary energy supplement and can contribute up to 30, 60, and 98% of the dairy diet's protein, net energy, and starch, respectively. Maize is also processed into industrial goods by wet or dry milling. Sweet corn is a leader among vegetable crops and its production for fresh or processing markets is a major industry in many countries. Over the years, the combined efforts of breeders and geneticists, biochemists, food scientists, and others have helped bring us to the point where we understand issues related to sweet corn quality. Traditional criteria for selecting corn hybrids have been based primarily on agronomic factors, including grain production, disease resistance, drought tolerance, and storage characteristics. Little emphasis has been placed on the quality and nutritional values of corn. Although there is widespread interest for value-enhanced corns have increased tremendously in the last five years, there is limited information available on the production and comparing the quality attributes of specialty grains with those of normal yellow dent corn. Most countries have developed national maize standards, aiming to provide a framework for trade, both internal and external. Where trading involves direct choice and price negotiation in front of the commodity, grading standards are rarely employed; quality is assessed visually and is influenced by end-use, and the price is determined more by local rather than national factors. The use of an agreed standard will provide an unambiguous description of the quality of the consignment and assist in the formation of a legally-binding contract. Standards can also be seen to protect consumers rights through setting limits to the amount of unsuitable or noxious material.

• 한국농공학회논문집
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• 제60권4호
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• pp.123-132
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• 2018

The purpose of this study was to evaluate the reduction effect of non point source (NPS) pollution in Haean highland agricultural catchment ($62.8km^2$) for 13 BMP scenarios under RCP (Representative Concentration Pathway) 4.5 and 8.5 scenarios. Under the present climate condition, the BMP (best management practices) reduction efficiency of SS (suspended solid), T-N (total nitrogen), and T-P (total phosphorus) showed +25.7%, +4.2%, and +16.1% for VFS (vegetative filter strip), +0.1%, +15.6%, and +5.7% for FC (fertilizer control), and +6.3%, -2.9%, and +3.9% for RSM (rice straw mulching) respectively. In general, effective was the best for SS and T-P reductions, and the FC was the best for T-N reduction. The negative effect of T-N on RSM was induced by increase in infiltration and solute transport to baseflow. Under the future climate change scenarios, the SS, T-N, and T-P reduction efficiency showed the range of +1.9~+11.6%, -1.9~+0.2%, and +5.3~+11.9% respectively. The 3 BMPs (VFS, FC, and RSM) application in the future showed negative and little differences (-0.5~+1.6%) for SS and T-N reduction efficiencies while T-P reduction efficiency showed +0.3~+7.6% comparing with the baseline period. To achieve an increase in the reduction efficiency of future SS and T-N by +2~+10%, the combined application of more than two BMPs is necessary.

• The International Journal of Costume Culture
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• 제2권2호
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• pp.60-70
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• 1999

The purposes of this study were to investigate preference and images of Korean traditional motifs, and to identify the relationship between them. The subjects consisted of 369 male and 356 female undergraduate students. The experimental materials used in this study were 48 stimuli and a questionnaire composed of 7-point semantic differential scales of 26 adjectives. Twelve motifs selected from 3 groups of Korean motifs were used as pattern design stimuli. Twelve repeated patterns were constructed from them to be applied on a CAD-simulated dress. The data were analyzed by ANOVA, Duncan's multiple range test, and regression. The major findings were as follows : 1. Category, composition type, and application object had a significant effect on the preference. Interpretation type has no significant effects on the preference independently, but it had interaction effects when combined with composition type, and category. Especially the composition type had a greater effect than the other variables on the preference. Cloud motif and its abstract and decorative type were found to be more related to the preference than the other category and interpretation type. On the basis of the analysis results, image charts and preference charts were developed. By combining information from the image chart and preference chart, motifs and images preferred by consumers may be selected and developed into new valuable designs. 2. The preference was affected mainly by 'quality'image followed by 'simplicity', 'interest', and 'modernity'image. The preference on pattern design was affected by 'quality', 'simplicity', 'interest', and 'interest', 'simplicity', and 'modernity'image in the order. The relationship between the preference and sensibility images has been represented by equations.