• Title/Summary/Keyword: 내/외부 유동

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Developing Cognition and Preference Contours of a City Image - A Case Study of Seongnam City - (도시이미지 인지와 선호등위선 개발 - 성남시를 대상으로 -)

  • Byeon, Jae-Sang
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.3
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    • pp.1-14
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    • 2010
  • Areas with negative images in cities can degrade the image of the city as a whole and slow the city's efforts to improve its image. The identification of such areas and the development of a city contour that charts the images of various areas in advance can help urban planners establish relevant strategies to ameliorate detrimental images of the city. This study intends to draw a contour of Seongnam City according to citizen's cognition levels of and preference for city area images and aim to shift the strategy of urban image planning from being results-oriented to being process-oriented. The results of this study are as follows: First, an analysis of the level of cognition of and preferences for Seongnam City's landmarks shows that the degree of cognition varies in different areas, whereas that of preferences remains similar; Second, the cognition and preference contour makes it easy to assess and diagnose city images; Third, the image management map, which merges the cognition contour with the preference contour, divides the city into four different areas. In order to manage city images, it follows that those areas with a high degree of cognition but low preference need to be classified and dealt with first. Further, this study shows that those areas with high cognition are the most populated and visited. Areas with high preference can become a strong candidate for being a landscape control point of a city, which adds to the usefulness of this study. The contour of Seongnam will contribute to networking sightseeing areas for visitors centered upon those places of high preference. It would appear that this type of networking will inspire a better image for the city.

Development of Numerical Method for Large Deformation of Soil Using Particle Method (입자법을 이용한 토사의 대변형 해석법 개발)

  • Park, Sung-Sik;Lee, Do-Hyun;Kwon, Min-Ho
    • Journal of the Korean Geotechnical Society
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    • v.29 no.12
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    • pp.35-44
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    • 2013
  • In this study, a particle method without using grid was applied for analysing large deformation problems in soil flows instead of using ordinary finite element or finite difference methods. In the particle method, a continuum equation was discretized by various particle interaction models corresponding to differential operators such as gradient, divergence, and Laplacian. Soil behavior changes from solid to liquid state with increasing water content or external load. The Mohr-Coulomb failure criterion was incorporated into the particle method to analyze such three-dimensional soil behavior. The yielding and hardening behavior of soil before failure was analyzed by treating soil as a viscous liquid. First of all, a sand column test without confining pressure and strength was carried out and then a self-standing clay column test with cohesion was carried out. Large deformation from such column tests due to soil yielding or failure was used for verifying the developed particle method. The developed particle method was able to simulate the three-dimensional plastic deformation of soils due to yielding before failure and calculate the variation of normal and shear stresses both in sand and clay columns.

Characteristics of Cooling Effect Depending on Operation of Forced Ventilation Systems in a Single-span Plastic Greenhouse (강제환기장치 사용에 따른 단동 플라스틱 온실 기온 강하 특성)

  • Kim, Seong-Heon;Kim, Hyung-Kweon;Kwon, Jin-Kyung;Lee, Si-Young
    • Journal of Bio-Environment Control
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    • v.31 no.3
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    • pp.143-151
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    • 2022
  • This study was carried out to investigate quantitative characteristics of the cooling effect in a single-span arch greenhouse with roll-up side vents depending on operation of circulation and exhaust fans during ventilation, in order to suggest a practical strategy regarding installation or operation of forced ventilation systems. The examination was conducted under 3 different ventilation conditions (side vents only, side vents + circulation fans, and side vents + circulation fans + exhaust fans). In each condition, variations of internal and external air temperatures and exogenous environmental factors were recorded during ventilation, and the cooling effects were investigated by comparing the normalized temperature difference (NTD) of each ventilation condition. In the morning time (11:00-12:00), a temporary peak in the temperature difference was observed at the beginning of ventilation regardless of ventilation methods. The time taken to the maximum NTD was decreased from 340 s to 110s, and the NTD was dropped from 1.158 to 1.037 as the more forced ventilation systems were operated. The more operations caused the passing time over specific NTD values reduced by 60% as the time was reduced from 1,030 s to 550 s at NTD = 0.8, 1,610 s to 915 s at NTD = 0.6, and 2,315 s to 1,360 s at NTD = 0.4. The temporary peak in NTD was not observed in the afternoon time (14:00-15:00) but it was dropped as quickly as the ventilation started. Also the more operations resulted in the passing time over specific NTD values reduced by 70% as the time was reduced from 560 s to 345 s at NTD = 0.8, from 825 s to 540 s at NTD = 0.6, and from 1,145 s to 810 s at NTD = 0.4. Conclusively, the intervention of the forced ventilation system is recommended in the morning time or in high thermal conditions to achieve more effective and economical ventilation.

Effects of Forced Molting and Storage Time on the Egg Quality (강제환우와 보존기간이 난질에 미치는 영향)

  • Oh, Hong-Rock;Lee, Bong-Duk;Lee, Soo-Kee;Liu, Xian-De;Yu, Dong-Jo
    • Korean Journal of Agricultural Science
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    • v.33 no.1
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    • pp.17-24
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    • 2006
  • An experiment was conducted to investigate the effects of forced molting and egg storage time on the various egg qualities. A total of 240 ISA Brown layers (60 wk of age) were employed as the unmolted treatment (Control). Two hundred and forty ISA Brown layers, molted at the age of 55 wk, were used as a forced molting treatment (T1), and the same number and strain of layers, molted at the age of 70 wk, were also used as the another forced molting treatment (T2). A total of 120 eggs were sampled from each treatment, and divided into six sets, 20 eggs per set. These six sets were stored for 1, 3, 6, 9, 12, and 15 days at $18^{\circ}C$ temperature, respectively. Eggs from T1 were collected from laying hens at the age of 68 wk, which started molting at 60 wk of age and achieved 50% egg production at 63 wk of age. Eggs from T2 were collected from hens at 82 wk of age, which started molting at 70 wk of age and achieved 50% egg production at 78 wk of age. The eggshell strength of T1 was significantly (p<0.05) higher than the Control and T2, and the storing periods did not affect the eggshell strength at all. Neither the forced molting nor the storing periods did not exert any consistent effect on the egg weight, eggshell thickness, eggshell color and egg yolk color. The albumin heights of T1 and T2 were significantly (p<0.05) lower than the Control, and it was remarkably reduced gradually as the storage periods increased in all three treatments. The Haugh unit showed very similar trends as the albumin height, indicating that both albumin height and Haugh unit were very much related to each other. In conclusion, the forced molting improves the eggshell strength, but decreases the albumin height and Haugh unit. The storage of eggs also decreases the albumin height and Haugh unit regardless of molting.

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A Study on Influence of Foodservice Managers' Emotional Intelligence on Job Attitude and Organizational Performance (급식관리자의 개인적 감성지능이 직무태도 및 조직성과에 미치는 영향)

  • Jung, Hyun-Young;Kim, Hyun-Ah
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.12
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    • pp.1880-1892
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    • 2010
  • The purposes of this study were to: a) provide evidence concerning the effects of emotional intelligence on job outcomes, b) examine the impacts of emotional intelligence on employee-related variables such as 'job satisfaction', 'organizational commitment', 'organizational performance', and 'turnover intention' c) identify the conceptual framework underlying emotional intelligence. A survey was conducted to collect data from foodservice managers (N=231). Statistical analyses were completed using SPSS Win (16.0) for descriptive analysis, reliability analysis, factor analysis, t-test, correlation analysis, cluster analysis and AMOS (16.0) for confirmatory factor analysis and structural equation modeling. The concept of emotional intelligence (EI) has been on the radar screens of many leaders and managers over the last several decades. The emotional intelligence is generally accepted to be a combination of emotional and interpersonal competencies that influence behavior, thinking and interaction with others. The main results of this study were as follows. The four EI (Emotional Intelligence) dimensions correlated significantly with age. The means of job satisfaction score were above the midpoint (3.04 point) scale. The organizational commitment score was above the midpoint (3.41 point) scale and was higher at 'loyalty' factor than 'commitment' factor. The means of organizational performance score were above the midpoint (3.34) scale. The correlations among the four EI (emotional intelligence) factors were significant with job satisfaction; organizational commitment, organizational performance and turnover intention. The test of hypothesis using structural equation modeling found that emotional intelligence produced positive effects on job attitude and job performance. Emotional intelligence enhanced organizational commitment, and in turn, managers' attitude produced positive effects on organizational performance; emotional intelligence also had a direct impact on organizational performance. This study has identified the effect of emotional intelligence on organizational performance and attitudes toward one's job.