• Title/Summary/Keyword: Shape factor

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Radiation Flux Impact in High Density Residential Areas - A Case Study from Jungnang area, Seoul - (고밀도 주거지역에서의 복사플럭스 영향 연구 - 서울시 중랑구 지역을 대상으로 -)

  • YI, Chae-Yeon;KWON, Hyuk-Gi;Lindberg, Fredrik
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.4
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    • pp.26-49
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    • 2018
  • The purpose of this study was to verify the reliability of the solar radiation model and discuss its applicability to the urban area of Seoul for summer heat stress mitigation. We extended the study area closer to the city scale and enhanced the spatial resolution sufficiently to determine pedestrian-level urban radiance. The domain was a $4km^2$ residential area with high-rise building sites. Radiance modelling (SOLWEIG) was performed with LiDAR (Light Detection and Ranging)-based detailed geomorphological land cover shape. The radiance model was evaluated using surface energy balance (SEB) observations. The model showed the highest accuracy on a clear day in summer. When the mean radiation temperature (MRT) was simulated, the highest value was for a low-rise building area and road surface with a low shadow effect. On the other hand, for high-rise buildings and vegetated areas, the effect of shadows was large and showed a relatively low value of mean radiation temperature. The method proposed in this study exhibits high reliability for the management of heat stress in urban areas at pedestrian height. It is applicable for many urban micro-climate management functions related to natural and artificial urban settings; for example, when a new urban infrastructure is planned.

A Study of Evaluating Streetscape Green Environments to Improve Urban Street Green Spaces - A Case Study of Jeonju City - (도시가로녹지의 개선을 위한 녹화환경평가 연구 -전주시를 대상으로-)

  • Jeong, Moon-Sun;Lim, Hyun-Jeong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.3
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    • pp.55-71
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    • 2019
  • The purpose of this study is to propose an evaluation method to assess green environments of streetscapes to improve urban street green spaces in Jeonju City. Through a rapid assessment of urban street green spaces, we suggest an objective basis for expanding street green space as well as for adopting sustainable maintenance and improvement measures. We choose 12 sections of streetscapes (roads and sidewalks) to investigate existing street conditions which have more than four lanes and function as major road axes. Six large roads and six medium roads of Jeonju City center area are investigated as pilot assessment study sites. Site inventory checklists consist of environmental characteristics of streetscape, street tree status, and planting condition evaluation. Environmental characteristics of streetscapes are composed of physical and neighborhood factors. For instance, items for physical factors are types and width of road/sidewalks, paving materials, tree protection materials, and green strip. And surrounding landuse is a neighborhood factor. Assessment items for street tree status are street plant names (tree/shrubs/ground cover), size, and planting intervals. Planting condition evaluation items are tree shape, damage, canopy density, and planting types with existence of adjacent green space. Evaluation results are classified into three levels such as A(maintain or repair), B(greening enhancement), and C(structural improvement). In case of grade A, streetscapes have enough sidewalk width for maintaining green strip and a multi-layered planting(in large road only) with fairly good growing conditions of street trees. For grade B and C, streetscapes have a moderate level of sidewalk width with a single street tree planting. In addition, street tree growing conditions are appeared poor so that green enhancement or maintenance measures are needed. For median, only grade B and C are found as its planting growing foundations are very limited in space. As a result, acquiring enough sidewalk space is essential to enhance ecological quality of urban street green. Especially, it is necessary to have green strip with reasonable widths for plant growing conditions in sidewalks. In addition, we need to consider native species with multi-layer plant compositions while designing street green.

Analysis of bifurcation characteristics for the Seolmacheon experimental catchment based on variable scale of source basin (수원 유역의 변동성 규모를 기반으로 한 설마천 시험유역의 분기 특성 해석)

  • Kim, Joo-Cheol;Jung, Kwan Sue
    • Journal of Korea Water Resources Association
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    • v.54 no.5
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    • pp.289-299
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    • 2021
  • This study analyzes bifurcation characteristics of the Seolmacheon experimental catchment by extracting the shape variation of channel network due to variable scale of source basin or threshold area. As the area of source basin decreases, a bifurcation process of channel network occurs within the basin of interest, resulting in the elongation of channel network (increase of total channel length) as well as the expansion of channel network (increase of the source number). In the former case, the elongation of channel reaches overwhelms the generation of sources, whereas, in the latter case, the drainage path network tends to fulfill the inner space of the basin of interest reflecting the opposite trend. Therefore, scale invariance of natural channel network could be expressed to be a balanced geomorphologic feature between the elongation of channel network and the expansion of channel network due to decrease of source basin scale. The bifurcation structure of the Seolmacheon experimental catchment can be characterized by the coexistence of the elongation and scale invariance of channel network, and thus a further study is required to find out which factor is more crucial to rainfall transformation into runoff.

A Study on Structural Characteristics of Axial Fans Operating Speed Using Finite Element Analysis (유한요소해석을 이용한 축류팬 운전속도별 구조특성에 대한 연구)

  • Kook, Jeong-Keun;Cho, Byung-Kwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.593-601
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    • 2021
  • The axial fan is an element of a blower used for ventilation in various industrial fields. Many studies on aerodynamic performance have been conducted to assess axial fans using fluid dynamics. The subject was a large axial fan size, 1800 mm in diameter with 100 horsepower. The blower's axial fan consisted of blades, hubs, hub caps, and bosses are important components. The blade design has a great influence on the aerodynamic performance. 3D point data is extracted using an aerodynamic performance prediction program, and a 3D modeling shape is generated. The blades and hubs, which are important components, can be easily modified if processed by cutting owing to the environment in which blades and hubs are manufactured through die casting or gravity casting. In this study, the structural safety of components and the analysis results of weak areas at the rated operating speed of the axial fan were verified using the maximum stress and safety factor. The tip clearance reflected in the design was the rotation of the blade. To check whether there is interference with other components, the displacement result was derived to verify the structural safety of the axial fan.

Seeking for the Determinants of Entrepreneurship from National Level Data (국가 특성이 창업활동에 미치는 영향 실증 분석)

  • Kim, Hyung Jun;Min, Tae Ki;Wang, Jingbu;Schuler, Diana;Oh, Keun Yeob
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.6
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    • pp.55-65
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    • 2020
  • The purpose of this study is to empirically analyze the factors that affect start-up activities at the national level. Unlike most existing research about entrepreneurship at the individual level, this empirical analysis makes use of the total early-stage entrepreneurial activity(TEA) index at national level. This was developed by the Global Entrepreneur Monitor (GEM) as the measure for the degree of entrepreneurship of the countries. Based on the previous studies, not only national income level and unemployment rate, but also other factors including the cultural characteristics of the countries were included in our regression model. Using GEM's panel data, we found that the effectiveness of the factors depends on the stage of economic development. In particular, we found 'U-shape' relationship between the level of per capita income and entrepreneurship activity by the panel regression analysis using quadratic function. This analysis result can explicitly confirm what the existing literature have explained descriptively. Furthermore, the governmental support programs are shown to have significantly positive effects on the entrepreneurship or start-up activities in the factor-driven and efficiency-driven economies. On the contrary, those programs were not very helpful in the innovative economies. Lastly, this research suggests that the 'education and training' and the 'entrepreneurial culture' be the supportive norm for new business regardless of the economic development level.

Development and Validation of Digital Twin for Analysis of Plant Factory Airflow (식물공장 기류해석을 위한 디지털트윈 개발 및 실증)

  • Jeong, Jin-Lip;Won, Bo-Young;Yoo, Ho-Dong;Kim, Tag Gon;Kang, Dae-Hyun;Hong, Kyung-Jin
    • Journal of the Korea Society for Simulation
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    • v.31 no.1
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    • pp.29-41
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    • 2022
  • As one of the alternatives to solve the problem of unstable food supply and demand imbalance caused by abnormal climate change, the need for plant factories is increasing. Airflow in plant factory is recognized as one of important factor of plant which influence transpiration and heat transfer. On the other hand, Digital Twin (DT) is getting attention as a means of providing various services that are impossible only with the real system by replicating the real system in the virtual world. This study aimed to develop a digital twin model for airflow prediction that can predict airflow in various situations by applying the concept of digital twin to a plant factory in operation. To this end, first, the mathematical formalism of the digital twin model for airflow analysis in plant factories is presented, and based on this, the information necessary for airflow prediction modeling of a plant factory in operation is specified. Then, the shape of the plant factory is implemented in CAD and the DT model is developed by combining the computational fluid dynamics (CFD) components for airflow behavior analysis. Finally, the DT model for high-accuracy airflow prediction is completed through the validation of the model and the machine learning-based calibration process by comparing the simulation analysis result of the DT model with the actual airflow value collected from the plant factory.

Web viewer for sharing of prosthesis design between laboratory and clinic: Case report (웹뷰어를 이용한 기공실과 진료실 측 간의 보철물 설계 형태의 공유: 증례 보고)

  • Jang, Sung Won;Lee, Ho Jin;Kim, So-Yeun;Lee, Du-Hyeong
    • The Journal of Korean Academy of Prosthodontics
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    • v.60 no.3
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    • pp.276-282
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    • 2022
  • Close communication between clinicians and dental technicians is an important factor in providing successful prostheses. The exchange of opinions with laboratories has mainly been in the form of written prescriptions and a photos, but it has been reported that information transmission may be limited. Currently, as digital technology-based prosthesis fabrication is common, 3D image objects can be stored on the web and can be easily viewed through a mobile web browser. In this article, we introduce cases where the design of the prosthesis was improved by designing the prosthesis using CAD software and reviewing the prosthesis designed with the clinical side through a web viewer. Through this protocol, it was possible to improve the occlusal surface and crown contour, the opposing teeth condition, the size of the gingival embrasure, and the shape of pontic. The process of sharing, discussing, and modifying the prosthesis design with the clinician and technician through a web viewer contributes to reflecting the diversity of oral conditions and individualized needs, thereby helping to make functional and esthetic prostheses.

The Effect on Legibility of the Inner Space Width of Hangeul Characters: Focusing on the Outer Space Width (한글꼴의 속공간 넓이가 가독성에 미치는 영향: 외부 속공간을 중심으로)

  • Jeon, Eoun-Sun;Kim, Sung-Kye
    • The Journal of the Korea Contents Association
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    • v.22 no.7
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    • pp.498-510
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    • 2022
  • Among the various factors that form fonts, the concept of a new Korean font term called Inner Space Width was developed and the effect of changes in fonts applied to readability was analyzed. [Experiment 1] An empirical analysis was attempted on how the Korean-shaped Outer Space Width affects readability among the texts. Among the factors that make up the paragraph, Outer Space Width by letter size, letter size, letter spacing, letter spacing, and letter shape was composed of Yoon Myung-jo 110-160 and Inner Space Width of Yoon Myung-jo 110 was the widest at 26.83%. [Experiment 2] In-depth interviews with experts were conducted to derive factors and evaluation indicators constituting the inner space. Inner Space Width is evaluated as a complex factor that affects preference and fatigue, and is related to understanding and speed. This study empirically reviewed the effect on readability using the concept of Inner Space Width in the absence of existing research on Hangul-shaped fast space, and is expected to be actively used in the development of fonts in the future.

A Study on the Comedic Acting Methods in the Play - Focusing on Character of Kim Seo-Young - (연극 <코트>에 나타난 희극적 연기 방법 연구 - 김서영 역을 중심으로 -)

  • Kim, Seok
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.4
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    • pp.89-100
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    • 2021
  • Comedy has been popular since ancient Greece. In order to visualize comedy more effectively, the actor's acting acts as an important factor. Then active discussion is needed on how actors can actually shape their comedic performance. I would like to approach comedic acting methods, focusing on the character of Kim Seo-young in the play . This researcher played the character of Kim Mi-young, and the characteristics of comedic acting include exaggeration, repetition, fast tempo, changing tone, and exaggerated physical behavior. Comedic acting comes from a dissonance of reactions. This is because unexpected reactions to stimuli can cause audience laughter. Comedic acting is also important in exaggeration and repetition, which must be based on true acting. The fast tempo of the act and the changing tone of the words also affect comedic acting expressions, and the embodiments of 'slapstick' and 'group dance', which are characteristics of farce acting, play an important role in causing audience laughter. In order for these characteristic elements to show comic effects, the actor's true acting must be the basis. What is important in comedic acting is understanding the narrative flow and features of the text and expressing it accurately. Comedic effects can be sufficiently represented if an actor truly expresses his means and faithfully demonstrates what the text requires. It is hoped that such research will help explore various acting arts, the acting education field, and the theater creation process.

Estimation of the Hydrological Design Frequency of Local Rivers Using Bayesian Inference and a Sensitivity Analysis of Evaluation Factors (평가인자 가중치에 대한 베이지안 추론과 민감도 분석을 통한 적정 하천설계빈도 결정)

  • Ryu, Jae Hee;Kim, Ji Eun;Lee, Jin-Young;Park, Kyung-Woon;Kim, Tae-Woong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.5
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    • pp.617-626
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    • 2022
  • In Korea, annual precipitation and its variability have gradually increased since modern meteorological observations began, and the risk of disasters has also been increasing due to significant regional variations and recent abnormal climate conditions. Given that damage from storms and floods mainly occurs around rivers, it is crucial to determine the appropriate design frequency for river-related projects. This study examined existing design practices used to determine hydrological design frequencies and suggested a new method to determine appropriate design frequencies. The study collected available data pertaining to seven evaluation factors, specifically the basin areas, shape parameters, channel slopes, stream orders, backwater effect reaches, extreme rainfall frequencies, and urbanized flood inundation areasfor 413 local rivers in Chungcheongnam-do in Korea. The estimated weights for areas of extreme rainfall frequencies and urbanized flood inundation were found to be 18, having a great effect on determining the design frequency. Compared with the established design frequency in previous government reports, the estimated design frequency increased for 255 rivers and decreased for 158 rivers.