• 농촌계획
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• 제20권2호
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• pp.127-137
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• 2014

Self-sufficiency rate of food in South Korea is almost at the lowest level among OECD countries, and the decrease tend of farmland is expected to be continued. In this situation, the government has been revised the target self-sufficiency rate of food, and carried forward various policies in order to achieve it. One of those policies is the restoration business of idle farmland which is planned to carry forward after 2015. This study set up indicators evaluating effective use of idle farmland, and tried to apply in the field before carrying forward restoration business. The result of this study may be summarized as follows. First of all, it reset an evaluation indicator that was based on the evaluation indicator developed in order to set application directions of idle farmland. Next, it selected 30 idle farmlands with reset evaluation indicator among 11,635 which were inspected nationwide in 2012. Before applying indicator, it measured the condition of recycling such as accessibility of farmland, condition of irrigation and drainage system, land state, and surroundings by field investigation. Then, it calculated composite score in each target area through applying indicators, and verified the indicator by comparing calculated result with the one which was decided from field investigation. Finally, it carried out field investigation, correct and upgrade some problems of the standard of score calculation that was found during applying previously set evaluation indicator to target area, and established the final standard of calculation for evaluation indicator.

• 한국초지조사료학회지
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• 제36권3호
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• pp.223-236
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• 2016

The objective of this study was to construct Italian ryegrass (IRG) dry matter yield (DMY) estimation models in South Korea based on climatic data by locations. Obviously, the climatic environment of Jeju Island has great differences with Korean Peninsula. Meanwhile, many data points were from Jeju Island in the prepared data set. Statistically significant differences in both DMY values and climatic variables were observed between south areas of Korean Peninsula and Jeju Island. Therefore, the estimation models were constructed separately for south areas of Korean Peninsula and Jeju Island separately. For south areas of Korean Peninsula, a data set with a sample size of 933 during 26 years was used. Four optimal climatic variables were selected through a stepwise approach of multiple regression analysis with DMY as the response variable. Subsequently, via general linear model, the final model including the selected four climatic variables and cultivated locations as dummy variables was constructed. The model could explain 37.7% of the variations in DMY of IRG in south areas of Korean Peninsula. For Jeju Island, a data set containing 130 data points during 17 years were used in the modeling construction via the stepwise approach of multiple regression analysis. The model constructed in this research could explain 51.0% of the variations in DMY of IRG. For the two models, homoscedasticity and the assumption that the mean of the residuals were equal to zero were satisfied. Meanwhile, the fitness of both models was good based on most scatters of predicted DMY values fell within the 95% confidence interval.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제4권4호
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• pp.187-194
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• 2015

본 논문에서는 RGB-D 입력 영상들로부터 3차원 공간을 움직이는 카메라의 실시간 포즈를 효과적으로 추적할 수 있는 시각 주행 거리측정기를 제안한다. 본 논문에서 제안하는 시각 주행 거리 측정기에서는 컬러 영상과 깊이 영상의 풍부한 정보를 충분히 활용하면서도 실시간 계산량을 줄이기 위해, 특징 기반의 저밀도 주행 거리 계산 방법을 사용한다. 본 시스템에서는 보다 정확한 주행 거리 추정치를 얻기 위해, 카메라 이동 이전과 이동 이후의 영상에서 추출한 특징들을 정합한 뒤, 정합된 특징들에 대한 추가적인 정상 집합 정제 과정과 주행 거리 정제 작업을 반복한다. 또한, 정제 후 잔여 정상 집합의 크기가 충분치 않은 경우에도 잔여 정상 집합의 크기에 비례해 최종 주행 거리를 결정함으로써, 추적 성공률을 크게 향상시켰다. TUM 대학의 벤치마크 데이터 집합을 이용한 실험과 3차원 장면 복원 응용 시스템의 구현을 통해, 본 논문에서 제안하는 시각 주행 거리 측정 방법의 높은 성능을 확인할 수 있었다.

• 소성∙가공
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• 제23권8호
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• pp.501-506
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• 2014

Progressive shearing with blanking dies is commonly employed to produce large quantities of tiny sheet metal electronic parts. Sheet metal pins, which are narrow and long, that are sheared with a progressive die set are often twisted. The twist in the sheet metal pins, which usually occurs in the final shearing operation, generally decreases with increasing blank holding force. The blank holding forces in all shearing operations are not the same because of different shearing positions and areas. In the current study, the optimal layout of the springs in a progressive die set to minimize the twist of the sheet metal pin is proposed. In order to find the holding force acting on the tiny narrow blanks produced with the proposed springs during the shearing process, the equivalent area method is used in the structural analysis. The shearing of the sheet-metal pin was simulated to compute the twist angle associated with the blank holding force. The constraint condition satisfying the pre-set blank holding force from the previous shearing operations was imposed. A design of experiments (DOE) was numerically implemented by analyzing the progressive die structure and by simulating the shearing process. From the meta-model created from the experimental results and by using a quadratic response surface method (PQRSM), the optimal layout of the springs was determined. The twist of sheet metal pin associated with the optimal layout of the springs found in the current study was compared with that of an existing progressive die to obtain a minimal amount of twist.

• 자원환경지질
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• 제32권5호
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• pp.537-544
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• 1999

금소광산은 지질학적 특성에 따라 여러 다양한 유형으로 형성되며, 특정원소나 특정광물종이 농집된다. 그러므로 광물자원탐사는 지질자료와 함께 많은 지구화학적 및 지구물리자료를 종합하여 분석처리 할 필요가 있다. 최근 지구과학정보시스템(GIS)이라는 개념이 도입됨에 따라, 도입됨에 따라 다양한 지질자료를 보다 체계적으로 처리할수 있게 되었고 효율적인 광물자원탐사가 가능하게 되었다. 본 연구대상지역 (37:00N/28:30E∼37:20N/128:45E0은 국내의 대표적인 광대화로 알려진 태백산 지역으로 영남육괴의 변성암을 기반으로 하여, 조선계의 퇴적암과 중생대의 화강암으로 구성되어있다. 본 연구에서는 이러한 지질자료와 함께 기보고된 지구화학 및 지구물리 탐사자료들을 디지털화하고 이를 퍼지집합이론에 적용하여 데이터통합을 시도하였다. 본 연구의 결과초써 나타난 스카른 부존가능지역이 기존의 스카론 철광산으로 알려진 신예미 광산 위치와 잘 일치하고 있으며, 이는 본 연구에서 데이터 통합에 사용된 퍼지집합이론이 태백산 지역이 스카른 광상탐사에 효과적이었음을 시사한다.

• 대한토목학회논문집
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• 제6권4호
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• pp.1-9
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• 1986

본 논문에는 최적설계 시 설계변수를 미리 정해진 유한 개의 숫자로 구성된 집합에서 선택함으로써 규격부재를 사용하여 구조물을 최적설계하는 방법에 대한 연구 결과가 수록되었다. 본 연구에서는 일차로 설계변수가 연속적으로 변할 수 있는 경우의 연속최적해를 구한 후 이로부터 가까이 있으며 제한조건을 위배하지 않는 가최적해(Pseudo-optimum)을 주어진 설계변수의 집합으로부터 선택하고, 이를 개선하여 목적함수를 최소화하는 최종 불연속최적해를 찾는 방법을 사용하였으며, 이를 최척화 기법의 하나인 미분벡터 투영법 (Gradient Projection Method)과 결합하여 문제 해결을 시도하였다. 개발된 방법을 이용하여 응력, 변위 몇 생계변수 제약조건들이 포함된 각종 트러스 구조물을 설계한 결과 이 방법이 설계변수가 규격을 만족시켜야 하는 최적설계 문제에 광범위하게 적용될 수 있음이 밝혀졌다.

• 한국정보과학회논문지:시스템및이론
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• 제35권7호
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• pp.340-353
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• 2008

화풍을 효과적이고 객관적으로 기술하는 한 방법으로 팔레트 추출에 대한 수학적 모델을 제시한다. 이 모델에서는 팔레트를 허용 오차 범위 내에서 회화 작품의 영상을 표현할 수 있는 주요 색상의 집합으로 정의하고 색상 그룹핑과 주요 색상 추출의 두 단계를 거처 팔레트 색상을 추출한다. 색상 그룹핑은 주어진 회화에 대해 적응적으로 색의 분해능을 조절하여 각 회화 작품을 이루는 기초 색상을 추출하며 다음 주요 색상 추출 단계에서 이것과 이것이 차지하는 영역에 대한 정보를 바탕으로 K-Means 클러스터링 알고리즘을 적용하여 팔레트를 얻는다. 실험을 통해 유명 화가의 작품을 대상으로 RGB와 CIE LAB 색상 모델을 사용하여 추출한 팔레트를 3차원 색 공간에 표시하였다. 팔레트 색상의 거리를 사용한 화가 분류 실험과 실사 영상의 색채 변환 실험 통해 이 방법이 화풍 분석과 그래픽 분야에 적용될 수 있음을 확인하였다.

• 한국도로학회논문집
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• 제17권5호
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• pp.57-66
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• 2015

PURPOSES: Nighttime driving is very different from daytime driving because drivers must obtain nighttime sight-distances based on road lights and headlights. Unfortunately, nighttime driving conditions in Korea are far from ideal due to poor lighting and an insufficient number of road lights and inadequate operation and maintenance of delineators. This study is conducted to develop new standards for nighttime road visibility based on experiments of driver perception for nighttime visibility conditions. METHODS : In the study, perception level and satisfaction of nighttime visibility were investigated. A total of 60 drivers participated, including 34 older drivers and 31 young drivers. To evaluate driver perceptions of nighttime road visibility, fuzzy set theory was used because the conventional analysis methods for driver perception are limited in effectiveness for considering the characteristics of perception which are subjective and vague, and are generally expressed in terms of linguistic terminologies rather than numerical parameters. RESULTS : This study found that levels of nighttime visibility, as perceived by drivers, are remarkably similar to their satisfactions in different nighttime driving conditions with a log-function relationship. Older drivers evaluated unambiguously degree of nighttime visibility but evaluations by young drivers regarding it were unclear. CONCLUSIONS : A minimum value of brightness on roads was established as YUX 30, based on final analyzed results. In other words, road lights should be installed and operated to obtain more than YUX 30 brightness for the safety and comfort of nighttime driving.

• 패션비즈니스
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• 제15권3호
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• pp.22-31
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• 2011

In this study, to develop a bodice pattern for women aged 18~24 years, statistical analysis was conducted using the body measurements from 2004 Size Korea and wearing test was conducted. As a result, ease of the bust level to set a horizontal line was decided to be 4cm, that of front interscye line 0cm, and that of back interscye line 0.7~1cm. And the line which divides the horizontal baseline into halves set as the side line. The conversion formula for decision of the scye depth line in the pattern is B/6 + 3.3(cm) + ease (2.5cm), and if bust circumference is 91 or more, it should be 21cm, and if bust circumference is 76 or less, it should be 18.5cm. The back neck line width is 7cm, front neck line width 6.5cm(back neck line width -0.5cm), and front neck depth 8cm(back neck line width +1cm). The shoulder slope was set as a slope of the hypotenuse of a right-angled triangle, which went out 15cm out of the shoulder point and went down 6cm, with tan$21.7^{\circ}$. To develop a final research pattern, wearing test was performed on the primary research pattern for 21 women aged 18~24 years. As a result, the research pattern was evaluated to be significantly higher.

• 제어로봇시스템학회논문지
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• 제16권3호
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• pp.305-312
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• 2010

The aim of this study is to find an analytic solution to the problem of determining the optimal capacity of a batch-storage network to meet demand for finished products in a system undergoing joint random variations of operating time and batch material loss. The superstructure of the plant considered here consists of a network of serially and/or parallel interlinked batch processes and storage units. The production processes transform a set of feedstock materials into another set of products with constant conversion factors. The final product demand flow is susceptible to joint random variations in the cycle time and batch size. The production processes have also joint random variations in cycle time and product quantity. The spoiled materials are treated through regeneration or waste disposal processes. The objective function of the optimization is minimizing the total cost, which is composed of setup and inventory holding costs as well as the capital costs of constructing processes and storage units. A novel production and inventory analysis the PSW (Periodic Square Wave) model, provides a judicious graphical method to find the upper and lower bounds of random flows. The advantage of this model is that it provides a set of simple analytic solutions while also maintaining a realistic description of the random material flows between processes and storage units; as a consequence of these analytic solutions, the computation burden is significantly reduced. The proposed method has the potential to rapidly provide very useful data on which to base investment decisions during the early plant design stage. It should be of particular use when these decisions must be made in a highly uncertain business environment.