• Journal of Advanced Marine Engineering and Technology
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• v.35 no.2
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• pp.224-231
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• 2011

Heating and/or cooling of the channel with pin-fin structure is a promising choice for the efficient heat transfer. Complex pin-fin structure shows highly irregular behavior like porous media. This study shows the numerical analysis on the characteristic of heat transfer and pressure drop of a channel with pin-fin structure. It predicts the experimental data quite well at the high porosity region with large diameter. Low porosity activates the rigorous flow disturbance and, consequently, the enhanced heat transfer. However, the concept of optimum design should be carefully reviewed because the pressure drop is also increased with decreasing porosity at low porosity region.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.91-98
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• 2022

In this study, Pukyong National University's floating population survey and analysis were conducted using Raspberry Pie, an open source hardware, and object detection algorithms based on deep learning technology. After collecting images using Raspberry Pie, the person detection of the collected images using YOLO3's IMAGEAI and YOLOv5 models was performed, and Haar-like features and HOG models were used for accuracy comparison analysis. As a result of the analysis, the smallest floating population was observed due to the school anniversary. In general, the floating population at the entrance was larger than the floating population at the exit, and both the entrance and exit were found to be greatly affected by the school's anniversary and events.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.2
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• pp.75-88
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• 2017

This study analyzed wind flows based on spatial and geomorphological characteristics of Daegu Metropolitan City. A three-stage analysis was performed, starting with a comparison of meteorological relationships between local wind direction (synoptic wind) and local wind flow. In the second stage the study area was subdivided into districts and suburban districts to analyze the relative change of local wind flow. In stage three, the formation of wind corridor for local wind flow, wind flow for the entire urban space, and spatial relationships between flows were verified comparatively using KLAM_21. Three results are notable, the first of which is a low correlation between synoptic wind of a region, and local wind, flow in terms of meteorology. Secondly, observations of local wind flow at five downtown districts and two suburban districts showed that there were diverse wind directions at each measurement point. This indicates that the spatial and geomorphological characteristics of areas neighboring the measurement points could affect the local wind flow. Thirdly, verifying the results analyzed using KLAM_21, compared to Atomatic Weather System(AWS) measurement data, confirmed the reliability of the numerical modelling analysis. It was determined that local wind flow in a city performs a spatial function and role in ameliorating the urban heat island phenomena. This indicates that, when an urban planning project is designed, the urban heat island phenomena could be ameliorated effectively and sustainably if local wind flow caused by immediate spatial and geomorphological characteristics is confirmed systematically and techniques are intentionally applied to connect the flows spatially within areas where urban heat islands occur.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.5
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• pp.1272-1281
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• 1990

A numerical study to predict the contamination behavior in a room being contaminated has been performed. The room with one inlet and three exits, which maintained same pressure at the ceiling, has been chosen as test model. Six sets of calculation have been performed, for one, two or three contamination sources of 1*10$^{-4}$ kg$_{c}$/s strength at two different velocities(0.2m/s, 20m/s). Numerical results show that the number the contamination concentration near the first source increased by every 20%-30% of the maximum concentration for each increase of the contamination source.e.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1997.11a
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• pp.229-234
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• 1997

밀폐공간내에서 일어나는 자연대류 열전달은 태양열 집열판, 연료탱크, 원자로의 핵반응로, 초전도 자성체의 냉각 및 건물이나 방의 효율적인 열설계, 화재시의 안전대책등 공업적으로 그 응용성이 매우 광범위하고 다양하게 생활주변에서 흔히 볼 수 있다. 밀폐공간내에 경계층 유동이 존재할 경우, 이 경계층 흐름은 일반적으로 외부유동에서의 경계층 유동과는 달리 코어영역(Core region)에서의 흐름과 서로 밀접한 관계가 있다. (중략)

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.3
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• pp.77-84
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• 2015

The key objective of this research is to review the effectiveness of spatial regression to identify the influencing factors of spatial distribution patterns of floating population. To this end, global and local spatial autocorrelation test were performed using seoul floating population survey(2014) data. The result of Moran's I and Getis-Ord $Gi^*$ as used in the analysis derived spatial heterogeneity and spatial similarities of floating population patterns in a statistically significant range. Accordingly, Geographically Weighted Regression was applied to identify the relationship between land use attributes and population floating. Urbanization area, green tract of land of micro land cover data were aggregated in to $400m{\times}400m$ grid boundary of Seoul. Additionally public transportation variables such as intersection density transit accessibility, road density and pedestrian passage density were adopted as transit environmental factors. As a result, the GWR model derived more improved results than Ordinary Least Square(OLS) regression model. Furthermore, the spatial variation of applied local effect of independent variables for the floating population distributions.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.2
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• pp.171-177
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• 1984

균일하게 분포된 내부발열을 갖는 유체가 든 경사진(수평에서 45.deg.까지)정사각형 단면의 밀폐 공간 내에서의 2차원 자연대류 유동 및 열전달에 관한 수치적인 연구가 수행되었다. 4개 벽면온 도가 동일한 경계조건에서 내부발열로 인한 자연대류 유동이 Rayleigh수 1.5*$10^{5}$까지는 층 류유동 영역의 가정하에서 수치적으로 수렴되었다. 경사진 밀폐 공간에서의 유동형태 및 온도분 포는 수평인 경우에 비하여 윗쪽 벽면 근처에서 그 상이점이 많이 나타났다. 경사각도가 증가함 에 따라 평균 열전달율이 아랫쪽 벽과 오른쪽 벽에서 증가하였고 왼쪽 벽에서 감소하였으며 윗 쪽 벽에서는 거의 일정하였다.다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2009.04a
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• pp.262-264
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• 2009

국내 마케팅 시장은 전체 분야에 걸쳐 출혈경쟁이 이뤄지고 있다. 이와 같은 환경에서 기업들이 올바른 의사결정을 통해 경쟁력을 확보하려면 시장의 잠재력을 정량적으로 파악하는 노력이 필요하다. 특히, 배후지의 인구, 직장인, 그리고 유동인구 규모 등은 시장의 잠재력을 판단하는 기본 정보다. 배후지의 인구와 직장인 정보는 국가통계 자료 등을 활용하거나 기타 추정방법에 의해 산정되어 활용되고 있다. 하지만, 유동인구에 관한 정보는 실제 거리에 나가 인구를 측정하여 활용하는 방안 외에는 마땅한 추정방법이 없는 실정이다. 이러한 이유로 유동인구가 매출에 직접적인 영향을 주는 기업들은 많은 시간과 인력을 투입하여 유동인구 수를 측정하고 있다. 하지만, 비용적인 측면에서 한계가 있다. 본 연구에서는 Point 기반의 인문사회 Spatial DB를 활용하여 전국단위의 유동인구를 추정하는 방법론을 제안했다. 또한, 유동인구 정보에는 연령 및 성별 비율까지 추정하여 다양한 활용이 가능하도록 하였다.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.1
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• pp.12-28
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• 2024

This study aims to identify the trend of changes in tourist floating population before and after COVID-19 in major tourist destinations in Jeju Island through spatial analysis. Seongsan-eup and Andeok-myeon in Jeju Island were selected as the research area, and the research period was set at 1 year before and 2 years after the COVID-19 outbreak. For the analysis, mobile floating population data was refined and processed to calculate floating population distribution and floating population increase/decrease data. This was converted into spatial data and an overlay analysis was performed with location data of major tourist attractions. As a result of the analysis, it was confirmed that the floating population of indoor tourist attractions and small facilities decreased immediately after COVID-19, and that in open coastal areas or large facilities, the floating population decreased less or actually increased. In conclusion, in tourism development, it is necessary to identify changes in floating population according to the characteristics of tourist facilities, and it is necessary to develop tourism facilities and strategies that can respond to risk situations such as pandemics when developing tourist destinations.

• Journal of the Korean Society for information Management
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• v.30 no.4
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• pp.93-110
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• 2013

During the last decade, increasing use of technology that facilitates information access has changed academic library services. The emergence of information commons is one of the key changes. Most previous studies on information commons have focused on its conception and role. Whereas, considering information commons as a spatial service, this study aims to examine the influence of information commons on user traffic patterns within the library and perception of the library. As the information commons grew into main library service space and facility, it is necessary to explore what influences information commons have on the behavior and recognition of users. Two methods were used. First, observation method was used to record traffic pattern and user behavior. Second, twenty undergraduates and twelve graduates were interviewed regarding the use and recognition of the information commons and the library. The results of the study show that the traffic patterns were different between undergraduate students and graduate students; the location and structure of facilities influences their movement and behaviors; and the recognition of information commons tends to affect the perception of the entire library. The findings may help librarians improve and plan for library spaces to meet user demands.