• Title/Summary/Keyword: Aspect of transition

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Effect of Aspect Ratio and Inclination on Natural Convection in Circular Trapezoidal Cavities (부채형 공간내의 자연대류에 대한 간격비와 경사각의 영향)

  • 배태열;배대석;권순석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.11
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    • pp.2181-2188
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    • 1992
  • Two-dimensional natural convection within a circular trapezoidal cavity with parallel cylindrical top and bottom walls at different temperatures and two adiabatic side walls has been solved by finite-difference methods. This study has been conducted to evaluate the effects of aspect ratio and inclination in the natural convection for various Rayleigh numbers. The minimum average Nusselt number occurs at the point of transition from a conductive heat transfer to a convective heat transfer. Numerical results are compared to experimental results with qualitatively good agreement.

Pressure Drop and Heat Transfer Characteristics of Internal Flow of the Rectangular Tube for Automobile Heat Exchanger (차량용 열교환기 사각관 내부 흐름에서 압력강하 및 열전달 특성)

  • Kang, Hie-Chan;Jun, Gil-Woong;Kim, Kwang-Il
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.489-492
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    • 2006
  • The present work was performed to investigate the thermal and hydraulic characteristics of flow inside the plain and turbulator flat tubes for the automobile application. The pressure drop and heat transfer coefficient at laminar, transition and turbulent regimes were studied experimentally and numerically. The flow transition was confirmed by flow visualization and quantitative data. It is proposed equations for the friction and heat transfer coefficient in the fully developed laminar flow inside rectangular tube as function of aspect ratio.

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A study on ITZ percolation threshold in mortar with ellipsoidal aggregate particles

  • Pan, Zichao;Wang, Dalei;Ma, Rujin;Chen, Airong
    • Computers and Concrete
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    • v.22 no.6
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    • pp.551-561
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    • 2018
  • The percolation of interfacial transition zone (ITZ) in cementitious materials is of great importance to the transport properties and durability issues. This paper presents numerical simulation research on the ITZ percolation threshold of mortar specimens at meso-scale. To simulate the meso-scale model of mortar as realistically as possible, the aggregates are simplified as ellipsoids with arbitrary orientations. Major and minor aspect ratios are defined to represent the global shape characteristics of aggregates. Some algorithms such as the burning algorithm, Dijkstra's algorithm and Connected-Component Labeling (CCL) algorithm are adopted for identification of connected ITZ clusters and percolation detection. The effects of gradation and aspect ratios of aggregates on ITZ percolation threshold are quantitatively studied. The results show that (1) the ITZ percolation threshold is mainly affected by the specific surface area (SSA) of aggregates and shows a global decreasing tendency with an increasing SSA; (2) elongated ellipsoidal particles can effectively bridge isolated ITZ clusters and thus lower the ITZ percolation threshold; (3) as ITZ volume fraction increases, the bridging effect of elongated particles will be less significant, and has only a minor effect on ITZ percolation threshold; (4) it is the ITZ connectivity that is essentially responsible for ITZ percolation threshold, while other factors such as SSA and ITZ volume fraction are only the superficial reasons.

Quantitative Research about a Suitable Hanok Type Based on the Local Characteristics by Geographic Information - Focused on Special Architectural District for Hanok Promotion in Suwon Hwaseong Fortress - (지역 특성에 적합한 한옥유형 도출을 위한 정량적 연구 - 수원 한옥촉진 특별건축구역을 대상으로 -)

  • Kim, Wan
    • Journal of the Korean housing association
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    • v.26 no.2
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    • pp.21-28
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    • 2015
  • The purpose of this paper is to estimate and deduct appropriate Hanok type within Suwon Hwaseong Fortress in which formula Hanok type has not remained. To do so, urban change according to chronology is analyzed and architectural aspect of transition is collected. By using geographic information in Suwon Hwaseong Fortress, present urban structural density, status of architecture and chronological aspect of transition in one-story buildings is surveyed. Through these data, appropriate Hanok form and density to the area is suggested. As a result, Hanok with two or more stories is economically suitable because its average plottage is excessively narrow. And back trowelling is desirable to construct walls in some concentrated areas with Hanok through arrangement of construction. Also in the other building sites, Hanoks are formed by a standard for separation to the property line. However it is necessary that exist standard about separation of property line is institutionally alleviated.

A Study on the Formative Characteristics on Hollywood Actresses' makeup - Focused on from 1920s to 2000s - (할리우드 여배우의 메이크업 조형특성 연구 - 1920년대부터 2000년대까지 -)

  • Kim, Eun-Sil;Bae, Soo-Jeong
    • Journal of Fashion Business
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    • v.15 no.5
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    • pp.195-219
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    • 2011
  • The purpose of the study is to analyze Hollywood actresses' makeup in formative characteristics and see the transition of the change for the usage as the fundamental materials to develop the future makeup field academy with the focus focused from 1920s to 2000s when the cosmetic industry began in earnest. The content of the study is to see the transition of the change by analyzing makeup of each era in formative aspect after seeing the transition of the makeup change in the social background by classifying by 10 years from 1920s to 2000s with related literature as the center in the theoretical background. The method of the study is to analyze makeup in formative aspect with total 180 pieces of pictures selected by two experts among their photos by selecting four actresses by each era and analyze Hollywood actresses' advertisement pictures which can be called as beauty icons at that time. Analysis frame to analyze the formativeness established new classification frame based on theories of Marian L. Davis, Marilyn Revell Delong, and Kang to analyze line, shape, texture, and decoration, and researcher's analysis frame was prepared based Munsell's color circle, tone analysis of P.C.C.S color system, and Kang's makeup color name to analyze colors. The result of the study is like below. Generally 20s and 30s highlighted line of eyebrows, 40s naturalness, 50s and 60s highlighted eye makeup, and from 70s makeup was focused on health, in 80s colorful makeup was boom, and 90s and 2000s has shown characteristics focused on texture of face.

Significance of Contrast Enema in One-stage Transanal Endorectal Pull-through Operation for Hirschsprung Disease (히르슈슈프룽병의 One-stage Transanal Endorectal Pull-through 술식에서 대장조영술의 의의)

  • Shin, Man Sik;Lee, Mi Jung;Kim, Myung Joon;Hong, Young Ju;Chang, He Kyung;Han, Seok Joo;Oh, Jung-Tak
    • Advances in pediatric surgery
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    • v.18 no.2
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    • pp.75-82
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    • 2012
  • In one-stage transanal endorectal pull-through operation (TERPT) for Hirschsprung disease, preoperative evaluation by contrast enema (CE) is important tool in aspect of planning of surgical procedure as well as diagnosis. This study was to evaluate the significance of CE for identifying the extent of aganglionic bowel. A retrospective analysis was performed in 40 patients who underwent TERPT between 2003 and 2011. The authors reviewed the CE studies and their correlation with pathologic extent of aganglionosis. Total 66 contrast enemas were performed in 40 patients. Twenty patients underwent single CE, but 20 patients required multiple CEs. In single CE group, 17 had clear radiographic transition zone, but 3 had less definite transition zone. In multiple CE group, 17 patients who had equivocal finding in first or second CE had definite radiographic transition zone, but 3 patients of this group had less definite radiographic transition zones. Overall, 34 patients (85%)had clear radiographic transition zone by single or repeated CE. One (2.9%) out of 34 patients with clear radiographic transition zone had discordance between radiographic and pathologic transition zone. In contrast 4 (66.7%) out of 6 patients with equivocal radiographic transition zone had discordance between radiographic and pathologic transition zone. Observation of clear radiographic transition zone is important in preparation of TERPT, and repeated CE is helpful to reduce the discordance between radiographic and pathologic transition zone. Awareness of the possibility of discordance is also important if radiographic transitional zone is not clear.

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A Study on The Spatial Organization of Public Area in Silver Town (실버타운 사례를 통한 공용공간 구성에 관한 연구)

  • Choi, Ung;Lee, Sang-Ho
    • Korean Institute of Interior Design Journal
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    • v.15 no.2 s.55
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    • pp.91-98
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    • 2006
  • The aged population increasing rapidly, the population rate of over 65 years old was over 7.5% in 2000 in Korea and it means that Korea is aging society. Increasing participation of woman in public affairs, becoming a nuclear family and increasing old aged people who want to stand alone brought about more the old households. But the aged welfare accommodation are still insufficient and more facilities accommodating the aged should be built. 80.5% of people according to poll by the Ministry of Health and Welfare responded the support of the aged is a serious problem in Korea. This result indicates the reality that the system for the aged are unsatisfied. Although these situations made a new concept of 'silver-town' of the welfare facility for the aged, it is under a transition in the aspect of the social system and the architectural aspect as well. This study will select good examples among facilities in the metropolitan area, analysis space and propose resonable program.

The Impact of Information Systems Integration on Organization

  • Juhn, Sung-Hyun
    • Asia pacific journal of information systems
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    • v.7 no.2
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    • pp.225-266
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    • 1997
  • A Causal Transition Model of the IT impact on organization is proposed. The model is based upon the premise that the IT impact is a multi-phase, multi-realm phenomenon, and that the IT impact in one organizational realm logically transpires to another realm, thus forming complex causal webs among them. Two exploratory research studies, the one qualitative and the other quantitative, were conductea to validate the model in a setting involving major structural reorganization of the organizations' IT function. The research results provide support for the general theory structure of the model. The findings include: ⅰ) the IT impact manifests on multiple organizational realms, with different degrees of strength, ⅱ) the impact on the realms follow a particular causal transition path among them, and ⅲ) the IT impact manifests on and through the information processing aspect of work. The results, however, indicate that people's perception of the IT impact is strongly mitigated by the IT relevance of work, and that the organization is affected as much by the structural arrangement surrounding and accompanying the IT as by the technology itself, suggesting that the IT impact is an organizational phenomenon as well as a technological phenomenon. The implications of the research results are discussed at the end.

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Experimental study of the Concentric Cylinder Flow with Various Axial Slit Wall (다양한 축방향 홈이 있는 동심원통 내부 유동에 대한 실험적 연구)

  • Lee, Sang-Hyuk;Kim, Hyoung-Bum
    • 한국가시화정보학회:학술대회논문집
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    • 2007.11a
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    • pp.123-127
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    • 2007
  • The effect of axial slit wall of outer cylinder on Taylor-Couette flow was experimentally investigated. The axial slits were azimuthally located along the inner wall of outer cylinder and the number of slits was 6, 9 and 18. The radius ratio and aspect ratio of the experimental models was 0.825 and 48, respectively. We used PIV method to measure the flow field and applied refractive index matching method to resolve the image distortion due to the complex model geometry. The results showed the effect of slit on the flow transition is increased as the number of slit increased. When the model has 6 slits, there were hardly the effect of axial slit wall and the flow transition happened at the same Reynolds number of plain smooth wall model case.

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