• 설비공학논문집
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• 제15권12호
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• pp.1028-1034
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• 2003

The objectives of this paper are to study the effect of key parameters on the cycle performance and capacity and to estimate the cost of latent and sensible energy transportation systems. The overall conductance (UA) of each component, the ambient temperature and the absorber inlet temperature are considered the key parameters. It is concluded that COP of the solution transportation using an absorption system (STA) at ambient temperature is 10% higher than that of the conventional sensible system. It is also found that the cost of STA system can be reduced 7.5 times to that of sensible energy transportation for one year of operation with 10 km transportation distance.

• 설비공학논문집
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• 제16권6호
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• pp.506-513
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• 2004

The objective of this paper is to evaluate the economic performance of latent and sensible energy transportation systems. LCC (Life-Cycle Cost) analysis is a practical method and a guideline for evaluating the economic performance of considered systems during the Life-Cycle Period. By comparing the LCC of alternatives, The most ideal alternative is determined which has the lowest LCC. It is concluded that the cost of STA (Solution Transportation Absorption system) can be reduced by 67% to that of sensible energy transportation for study period with 10 km transportation distance.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1317-1322
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• 2004

In this report, the heat transfer model of spray cooling on hot surface was developed by focusing on the effect of rebound motion of droplets. In the model, it was assumed that droplets rebound repeatedly on the hot surface and heat transfer upon droplet impact is proportional to sensible heat which heats up the droplets to the saturation temperature. In addition, to take account of the contribution of th heat flux upon impact of rebound droplets, it was assumed that the rebound droplets are distributed following the Gaussian distribution from 0 to L, which distance L is determined by maximum flight distance $L_{max}$. Also the calculated results were compared with existing experimental results.

• Journal of the Korean Statistical Society
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• 제24권2호
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• pp.439-451
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• 1995

Ranked data are widely used in the area of social sciences, for instance in polls and preference surveys, in which a number of objects (or stimuli) are evaluted and ranked by a panel of judges (or subject) according to their preference. We propose a graphical method for ranked data by quantifying objects and judges. In a plot for judges, the interpoint distances can be interpreted as Spearman or Kendall distance between two rankings given by respective judges. Similarly, we also construct a plot for objects with a sensible relationship to the previous plot for judges.

• 대한기계학회논문집B
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• 제29권2호
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• pp.287-293
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• 2005

In the present study, to determine the flow rate of droplets supplied to heat transfer surface after (j-1)th rebound, $D_X[j{\ge}2]^{\ast}$, it was assumed that the rebound droplets are distributed according to the Gaussian distribution from 0 to L, in which the flight distance L is determined by maximum flight distance $L_{max}$. We also assumed that $L_{max}$ is dependent on the air flow velocity and mean size of droplets. The local heat flux of a dilute spray in high temperature region was predicted using the newly evaluated $D_X[j{\ge}2]^{\ast}$. In addition, the predicted results by the present model were compared with the existing experimental data.

• 한국조경학회지
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• 제18권1호
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• pp.19-32
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• 1990

The perception of landscape structure can he formed mode clearly, with including an auditory stimulus to a visual aspect. The waterfall, as an landscape element, will be considered of not only it's function and structure in landscape architecture designing but also harmony with environment which it has been situated, and contribution to the public goad. The purpose of this study was to establish more 7rational and practical design theory for the construction of waterfall. The number of subjects investigated were 47 of waterfall located in Mt. Palgong. In this study, the acoustic character of the waterfalls were investigated as an excellent effect to mask easily sensible noises. The correlations between the structure of waterfalls and water 1a17ing sound, which were useful for waterfall design and construction, were examined. It was discovered that the position of double distance of waterfall height From the waterfall is significant in the visual and acoustic perception of waterfall.

• 대한기계학회논문집 C: 기술과 교육
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• 제3권3호
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• pp.175-181
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• 2015

전투차량의 내부는 혹서기에는 약 $80^{\circ}C$에 이를 만큼 고온 다습한 환경에 노출되어 감지거리를 측정하여 제어기에 신호를 전달하는 근접센서가 감지거리가 늘어나면서 결국에는 센서 자체의 금속물질을 인식하여 작동이 안되는 고장이 다발하여 원인분석 및 개선을 수행하게 되었다. 개선은 2차에 걸쳐 수행되었고 많은 시행착오를 거쳐 고온에 장기적으로 노출될 경우 고장이 발생된다는 것을 알아내어 개선방안을 도출한 결과, 이미터코일(Emitter Coil)을 한 개 더 추가하여 전압차이를 높여 감지 정확도를 향상시키고, 내부 몰딩 면적을 높여 진동 및 충격 내성을 강화하여 온도 및 습도 변화에 둔감하도록 설계개선을 하였다. 입증을 위해 고온 다습($85^{\circ}C$, 85%습도)한 환경챔버에서 136시간 내구시험을 실시하여 고장 발생이 없음을 확인하였다.

• 대한지리학회지
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• 제50권5호
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• pp.527-541
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• 2015

본 연구의 목적은 시간거리를 크게 단축시킨 고속철도 도입으로 우리나라 도시간 통행흐름에 나타나는 변화를 파악하는 것이다. 이를 위하여 도시간 통행을 담당하고 있는 대표 운송수단인 고속버스와 철도의 운송실적을 바탕으로 고속철도 개통 이전과 이후 각 운송수단의 도시간 통행흐름에 나타나는 변화를 분석한다. 먼저 중력모형을 적용하여 시간거리 매개변수에 대한 운송수단별 도시간 통행량의 관계 변화를 파악한다. 분석결과 고속버스를 이용하는 도시간 통행은 철도에 비해 시간거리에 덜 민감하며 고속철도 도입 이후 그 경향은 더 강화되는 경향을 보인다. 그러나 일반철도를 이용하는 도시간 통행은 시간거리에 좀 더 민감하게 반응하며 고속철도 도입 이후 그 경향은 더욱 강화되어 일반철도를 이용한 장거리 통행량은 점점 더 감소한다. 반면 고속철도를 이용한 도시간 통행량은 장거리 일수록 오히려 증가하는 추세를 보여 중력모형과는 상치되는 양상을 보인다. 더불어 교통인프라의 변화로 나타나는 운송수단별 통행흐름의 공간구조에 나타나는 변화를 파악하기 위하여 MST(Maximum Spanning Tree)기법을 적용하여 각 시점의 운송수단별 허브구조를 비교분석한 결과 고속버스와 일반철도를 이용한 통행흐름은 시간이 경과하면서 계층 수가 늘어나는 변화를 보이지만 고속철도의 경우는 2010년 까지도 서울과 부산을 1차위의 Hub로 하는 단순 계층구조를 나타낸다.

• Journal of Computing Science and Engineering
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• 제7권2호
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• pp.99-111
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• 2013

Approximating a divergence between two probability distributions from their samples is a fundamental challenge in statistics, information theory, and machine learning. A divergence approximator can be used for various purposes, such as two-sample homogeneity testing, change-point detection, and class-balance estimation. Furthermore, an approximator of a divergence between the joint distribution and the product of marginals can be used for independence testing, which has a wide range of applications, including feature selection and extraction, clustering, object matching, independent component analysis, and causal direction estimation. In this paper, we review recent advances in divergence approximation. Our emphasis is that directly approximating the divergence without estimating probability distributions is more sensible than a naive two-step approach of first estimating probability distributions and then approximating the divergence. Furthermore, despite the overwhelming popularity of the Kullback-Leibler divergence as a divergence measure, we argue that alternatives such as the Pearson divergence, the relative Pearson divergence, and the $L^2$-distance are more useful in practice because of their computationally efficient approximability, high numerical stability, and superior robustness against outliers.

• 한국환경과학회지
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• 제23권8호
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• pp.1481-1493
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• 2014

In order to understand the relation between the distribution of sea surface temperature and heavy snowfall over western coast of the Korean peninsula, several numerical assessments were carried out. Numerical model used in this study is WRF, and sea surface temperature data were FNL(National Center for Environment Prediction-Final operational global analysis), RTG(Real Time Global analysis), and OSTIA(Operational Sea Surface Temperature and Sea Ice Analysis). There were produced on the basis of remote sensing data, such as a variety of satellite and in situ observation. The analysis focused on the heavy snowfall over Honam districts for 2 days from 29 December 2010. In comparison with RTG and OSTIA SST data, sensible and latent heat fluexes estimated by numerical simulation with FNL data were higher than those with RTG and OSTIA SST data, due to higher sea surface temperature of FNL. General distribution of RTG and OSTIA SST showed similar, however, fine spatial differences appear in near western coast of the peninsula. Estimated snow fall amount with OSTIA SST was occurred far from the western coast because of higher SST over sea far from coast than that near coast. On the other hand, snowfall amount near coast is larger than that over distance sea in simulation with RTG SST. The difference of snowfall amount between numerical assessment with RTG and OSTIA is induced from the fine difference of SST spatial distributions over the Yellow sea. So, the prediction accuracy of snowfall amount is strongly associated with the SST distribution not only over near coast but also over far from the western coast of the Korean peninsula.