• Title/Summary/Keyword: Local Characteristics

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An Experimental Study on Heat Transfer Characteristics with Turbulent Swirling Flow Using Uniform Heat Flux in a Cylindrical Annuli

  • Chang, Tae-Hyun;Lee, Kwon-Soo
    • Journal of Mechanical Science and Technology
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    • v.17 no.12
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    • pp.2042-2052
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    • 2003
  • An experimental study was performed to investigate heat transfer characteristics of turbulent swirling flow in an axisymmetric annuli. The static pressure, the local flow temperature, and the wall temperature with decaying swirl were measured by using tangential inlet conditions and the friction factor and the local Nusselt number were calculated for Re=30000∼70000. The local Nusselt number was compared with that obtained from the Dittus-Boelter equation with swirl and without swirl. The results showed that the swirl enhances the heat transfer at the inlet and the outlet of the test tube.

Attenuation of S-waves in the Gyungsang Basin: Results of 1997 ~2000 Earthquake Data Analysis (경상분지에서의 S파 감쇠 : 1997-2000 지진자료 분석결과)

  • 이정모;김태경;조봉곤
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.09a
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    • pp.52-56
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    • 2001
  • In order to get information on more reliable S-wave attenuation characteristics in the Gyeongsang Basin, local earthquake data compiled during the period of years 1997~2000 are analyzed using spectral smoothing technique. Total 421 seismograms recorded at 12 local stations by 68 earthquakes of local magnitudes equal to or greater than 1.4 are examined. Among them, 155 records with good S/N ratio were analyzed. As results, statistically well constrained attenuation characteristics are fecund. Those are; (1) 0.000158362 < $x_{q}$-value (0.000196474) < 0.000234586, (2) 0.00657 < $x_{s}$-value (0.01061) < 0.01465, and (3) 1158 < Q-value (1383) < 1716, where the upper and low limits are values with 95% confidence level. We obtained remarkably well constrained $X_{s}$-value which has not been determined previously. The results can be used as input data far ground motion computations in earthquake engineering.ing.g.

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The Effects of a University Cooperation Project on Urban Regeneration for Recovery of Commercial Supremacy

  • Ryu, Tae-Chang;Sung, Chang-Soo
    • Journal of Distribution Science
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    • v.14 no.10
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    • pp.29-38
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    • 2016
  • Purpose - This research examines the effects of local universities on urban regeneration to recover commercial supremacy in the original urban area and provides clear information on the "University Cooperation Project for Traditional Market." Research design, data, and methodology - The "University Cooperation Project for Traditional Market" started in 2015. This study was conducted focusing on 22 places selected in 2015 and the project content in those locations. Results - This study analyzes the link to urban regeneration and spreads the concept along with theoretical consideration of university cooperation for traditional markets. Additionally, it promotes policies to help propel the project based on characteristics of the region. Conclusions - A differentiated project should be created, with characteristics of the region reflected, and detailed programs developed and implemented resulting in meaningful achievement from the perspective of members of the local community, who may have deviated from existing perspectives. Additionally, opportunities should be established for the direct application of young consumer ideas through experimental business to regenerate the traditional market (commercial supremacy), the center of the local economic society.

An Experimental Study on Swirling Flow with Heat Transfer in the Horizontal Circular Annuli

  • Chang Tae-Hyun
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.3
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    • pp.260-274
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    • 2005
  • An experimental investigation was performed to study the characteristics of turbulent swirling flow in the cylindrical annuli. The swirl angle measurements were performed by flow visualization technique using smoke and dye liquid. By using the particle image velocimetry method. this study has found the time-mean velocity distribution and turbulent intensity with swirl for Re=20,000. 30.000. 50.000. and 70,000 along longitudinal sections. The results appear to be physically reasonable. Other experimental study was performed to investigate heat transfer characteristics of turbulent swirling air flow in axisymmetric annuli. The static pressure. the local air flow temperature, and the wall temperature with decaying swirl were measured by using thermocouples and the friction factor and the local Nusselt number were calculated for Re=30,000. 50,000 and 70000. The local Nusselt number was compared with that obtained from the Dittus-Boelter equation with swirl and without swirl, respectively. The results showed that the swirl enhances the heat transfer at the inlet and the outlet of the test tube.

Value Co-creation Types according to Co-creation Execution Phase : Focusing on Regional Brand (Co-creation 실행 단계에 따른 Value Co-creation 유형 : 지역브랜드를 중심으로)

  • Ryou, An Young;Son, Won Jun
    • Journal of Korea Multimedia Society
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    • v.24 no.3
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    • pp.481-493
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    • 2021
  • Regional brands are recognized for their importance as one of the local public relations policies, but only the methods promoted by local government officials and outside experts are revealing limitations in self-reliance and sustainability. In order for a regional brand to succeed, it is necessary to develop and manage a brand that fits the characteristics of the region together with various stakeholders including residents. In this study, it was confirmed that regional brand evaluation indicators may vary depending on the stage of co-creation in the design process for regional brand development, and the type of value co-creation was determined through a classification method using the results of the evaluation index. According to the results of the study, the type of value co-creation that fits the local situation and characteristics can be derived by adjusting the stage of co-creation execution in the design process.

Fluctuation Characteristics of Radial Void Fraction in Vertical Concentric Annuli (수직동심환상관에서 반경방향 보이드율의 변동특성)

  • Son B.J.;Kim I.S.;Kim M.C.
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.16 no.5
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    • pp.516-524
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    • 1987
  • This paper presents experimental data of fluctuation characteristics of local void fraction of air-water two-phase flow which are associated with the flow pattern, annular gap size and radial location in vertical concentric annuli with coefficient of skewness and kurtosis. The annular gap widths are 13mm, 11mm, and 9mm for a 38m inner diameter as the lucite outer tube. A electrical conductivity probe was used to measure the local void fraction and traversed diametrically from inner wall to outer wall using radial increments of 2mm. It was shown that distribution of the coefficient of skewness and kurtosis, which is related that the one is the asymmetry and the other peakness of local void fraction distribution was influenced by flow pattern, annular gap size and radial location.

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Deposition Characteristics of the Sandbar and Estimation of the Mass Transport Flux in the Nakdong Estuary (낙동강 하구역의 사주 퇴적특성과 물질수송플럭스 산정)

  • YOON RAN-SAM;LEE IN-CHEOL;Ryu CHEONG-RO
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.131-137
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    • 2004
  • This paper is intended as an investigation of the deposition characteristics and mass transport flux estimation in the Nakdong estuary. In order to understand the effects of the tidal current circulation which influenced to an estuary terrain change, the seawater circulation calculation by the use of 2D numerical model for the three cases of without riverflow, mean and flood riverflow quantity condition practiced and each sectional net-flux of water quantity between sandbars(so called, dung) estimated. It may be that an estuary terrain change due to the large scale construction and reclamation at the Nakdong estuary influence to the long-time deposition characteristics. by the revim for the old research, we know that the development of the local sandbars has been moved toward the east-side from the west-side estuary area after the construction of the Nakdong river dike, at present the strong-acted location is the Bakhap-dung of the front sea of Tadea. The seawater circulation pattern at this large scale area of tidal flat bring on a change due to the water quantity outflowing from the Nakdong river. Base on the calculated results for the section net-flux of water quantity, we see that the accumulating action very strong at the local sea around Jangjado, Bakhapdung and Tadae for the case of flood riverflow quantity condition, but at the local sea around Jinudo for the another cases. Consequently, it is emphasized that in the Nakdong estuary the main sensitive regions which influenced from the discharge of riverflow were the local sea around Jangjado, Bakhapdung, Tadae and Jinudo.

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A Study on Spatial Structure Analysis for Comprehensive Rural Clustered Villages Development Area using the Space Syntax Method Technique (Space Syntax를 이용한 농촌마을종합개발사업 권역의 공간구조분석에 관한 연구)

  • Lee, Haeng-Wook;Kim, Young-Joo;Choi, Soo-Myung
    • Journal of Korean Society of Rural Planning
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    • v.10 no.4 s.25
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    • pp.19-28
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    • 2004
  • In order to revitalize rural areas fundamentally through multifunctional utilization of their resources, it should be necessary to prepare the rational development plan to the areal characteristics and conditions, and the first priority of its planning works should be given to spatial planning. The space syntax method, a powerful objective and quantitative analysis tool on the relationship between social and spatial characteristics, was introduced in this study. Five Comprehensive Rural Clustered Villages Development Areas in the Jeonnam-province were selected as case study areas, of which total area's and included villages' spatial variables were measured and analyzed. Rural villages analyzed in this study have the spatial structure badly systematized and much complicated, which results from low integration and deep spatial depth of them. And, by virtue of relatively many axial lines, there should be few differences between villages in terms of local integration, connectivity and control, while being significant difference in terms of global integration showing the whole areal characteristics. Intelligibility, the correlation coefficient between connectivity(local variable) and integration(global one) is low, which means that the spatial structure of the study areas is difficult for visitors to understand the area or village well. Spatial configuration analysis results in the case study areas showed that each development area has a unique spatial structure and is differentiated in terms of not only local spatial variables but also global spatial variables. Therefore, global and local characteristics should be considered in spatial analysis of development areas.

An Adaptive Histogram Equalization Based Local Technique for Contrast Preserving Image Enhancement

  • Lee, Joonwhoan;Pant, Suresh Raj;Lee, Hee-Sin
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.15 no.1
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    • pp.35-44
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    • 2015
  • The main purpose of image enhancement is to improve certain characteristics of an image to improve its visual quality. This paper proposes a method for image contrast enhancement that can be applied to both medical and natural images. The proposed algorithm is designed to achieve contrast enhancement while also preserving the local image details. To achieve this, the proposed method combines local image contrast preserving dynamic range compression and contrast limited adaptive histogram equalization (CLAHE). Global gain parameters for contrast enhancement are inadequate for preserving local image details. Therefore, in the proposed method, in order to preserve local image details, local contrast enhancement at any pixel position is performed based on the corresponding local gain parameter, which is calculated according to the current pixel neighborhood edge density. Different image quality measures are used for evaluating the performance of the proposed method. Experimental results show that the proposed method provides more information about the image details, which can help facilitate further image analysis.