• Title/Summary/Keyword: Wall following

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A Suggested Mechanism of Significant Stall Suppression Effects by Air Separator Devices in Axial Flow Fans

  • Yamaguchi, Nobuyuki
    • International Journal of Fluid Machinery and Systems
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    • v.4 no.1
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    • pp.57-66
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    • 2011
  • Radial-vaned air separators show a strong stall suppression effect in an axial flow fans. From a survey of existing literature on the effects and the author's data, a possible mechanism for the significant effects has been proposed here. The stall suppression is suggested to have been achieved by a combination of the following several effects; (1) suction of blade and casing boundary layers and elimination of embryos of stall, (2) separation and straightening of reversed swirling flow from the main flow, (3) induction of the fan main flow toward the casing wall and enhancement of the outward inclination of meridional streamlines across the rotor blade row, thus keeping the Euler head increase in the decrease in fan flow rate, and (4) reinforcement of axi-symmetric structure of the main flow. These phenomena have been induced and enhanced by a stable vortex-ring encasing the blade tips and the air separator. These integrated effects appear to have caused the great stall suppression effect that would have been impossible by other types of stall prevention devices. Thus the author would like to name the device "tip-vortex-ring assisted stall suppression device".

Magnetic Resonance Imaging in Thoracic Disease (흉부질환의 자기공명영상)

  • Song, Koun-Sik
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.4
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    • pp.345-352
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    • 1993
  • The role of magnetic resonance(MR) imaging in the evaluation of thoracic disease has been limited Nontheless, MR has inherent properties of better contrast resolution than CT allowing tissue-specific diagnosis. MR has capability of direct imaging in sagittal, coronal, and oblique planes which provide better anatomic information than axial images of CT such as lesions in the pulmonary apex, aorticopulmonary window, peridiaphragmatic region, and subcarinal region. MR is sensitive to blood flow making it an ideal imaging modality for the evaluation of cardiovascular system of the thorax without the need for intravenous contrast media. Technical developments and better control of motion artifacts have resulted in improved image quality, and clinical applications of MR imaging in thoracic diseases have been expanded. Although MR imaging is considered as a problem-solving tool in patients with equivocal CT findings, MR should be used as the primary imaging modality in the following situations: 1) Evaluation of the cardiovascular abnormalities of the thorax 2) Evaluation of the superior sulcus tumors 3) Evaluation of the chest wall invasion or mediastinal invasion by tumor 4) Evaluation of the posterior mediastinal mass, especially neurogenic tumor 5) Differentiation of fibrosis and residual or recurrent tumor, especially in lymphoma 6) Evaluation of brachial plexopathy With technical developments and fast scan capabilities, clinical indications for MR imaging in thorax will increase in the area of pulmonary parenchymal and pulmonary vascular imaging.

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A case of bullous lung disease disappeared spontaneously (자연소실의 경과를 보안 기포성 폐질환 1예)

  • Kim, Chong-Ju;Yong, Suk-Joong;Gang, Sin-Gu;Song, Gwang-Seon;Shin, Kye-Chul
    • Tuberculosis and Respiratory Diseases
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    • v.43 no.3
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    • pp.455-460
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    • 1996
  • In general, a bulla of the lung is large, air contained sac and it is more than 1cm in diameter, and its wall is well defined and less than 2mm thick. The natural course of bulla of the lung is said to follow a pattern of progressive deterioration. It is a progressive disease, and spontaneous resolution of bulla is very unusual. In the world only two cases of spontaneous resolution of bulla have been reported. We experienced a case of bullous lung disease complicated from miliary tuberculosis in which the bulla was disappeared spontaneously following bulla infection.

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A Study on Evaluation of Thermal Environment Following the Alleviation of the Limit on Number of Floors of Apartment Complexes (공동주택 건축물 층수완화에 따른 열환경 평가에 관한 연구)

  • Ryu, Ji-Won;Jung, Eung-Ho;Akira, Hoyano
    • Journal of the Korean housing association
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    • v.22 no.3
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    • pp.93-100
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    • 2011
  • The objective of this study is to provide basic objective data which can be utilized as an adjustment criterion for the alleviation of the limit on the number of floors of buildings by quantitatively evaluates the effect of the alleviation of the limit on the number of floors of buildings in apartment complexes on thermal environment of apartment complexes using data obtained from apartments in a class 2 general residential area. In this study, we carried out a thermal environment analysis utilizing the simulation of a virtual object area. The result is summarized as follows: The result of analyzing the entire surface temperature showed an equal decrease of surface temperature due to shadow in all scenarios and high floors showed a tendency of low surface temperature during daytime as the rate of shadow the high floors increase. This influences not only the surface temperature but also HIP and is judged to greatly contribute to the alleviation of the heat island effect. Also, the reason why HIP at high floors shows high values before sunrise and after sunset is thought to be because the concrete wall of the building maintains a high temperature during nighttime by absorbing and storing sunlight during daytime instead of reflecting it since it has low reflectance.

A Study on Characteristic of Visitor's Behavior and Circulation Path Type in Art Museum Exhibition Space (미술관 단위전시실의 경로선택 유형과 관람행동 특성에 관한 고찰)

  • Choi, Jun-Hyuck
    • Korean Institute of Interior Design Journal
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    • v.17 no.2
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    • pp.83-90
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    • 2008
  • This study attempts to understand the arrangement and spatial requisites of art pieces by materializing the visitors' path of movement in the exhibition space, as well as researching their behavior. The purpose of the research is to the guideline for planning the exhibition layout and visitors' circulation can be derived in order to correspond to the visitors' characteristic of movement and circulation-path choice. Although such guideline may have limited use, it is still significant enough to be studied. Taking three Korean art galleries as the subjects of research, this study observes the arrangement of art pieces, movement path of visitors, characteristics of the visitors' behavior and the duration time a visitor takes to view an art piece without moving around in order to understand the arrangement and spatial requisites of art pieces which correspond to the visitors' behavior. The following results have been drawn in this research and analysis; First, when there is an island type exhibition other than the ordinary on-the-wall display in the exhibition space, the visitors' choice of path changes. In short, an island type exhibition seems to be a factor that changes the visitors' path. Second, in the entrance of an exhibition space unit, most of the visitors seem to choose a path which moves counter-clockwise. Third, it is considered that well-known art pieces or art pieces with a big size shall not be displayed on the comer of the exhibition room.

Stability analyses of a cylindrical steel silo with corrugated sheets and columns

  • Sondej, Mateusz;Iwicki, Piotr;Wojcik, Michal;Tejchman, Jacek
    • Steel and Composite Structures
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    • v.20 no.1
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    • pp.147-166
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    • 2016
  • The paper presents comprehensive quasi-static stability analysis results for a real funnel-flow cylindrical steel silo composed of horizontally corrugated sheets strengthened by vertical thin-walled column profiles. Linear buckling and non-linear analyses with geometric and material non-linearity were carried out with a perfect and an imperfect silo by taking into account axisymmetric and non-axisymmetric loads imposed by a bulk solid following Eurocode 1. Finite element simulations were carried out with 3 different numerical models (single column on the elastic foundation, 3D silo model with the equivalent orthotropic shell and full 3D silo model with shell elements). Initial imperfections in the form of a first eigen-mode for different wall loads and from 'in-situ' measurements with horizontal different amplitudes were taken into account. The results were compared with Eurocode 3. Some recommendations for the silo dimensioning were elaborated.

Electron microscopic observations of the irradiation of ultra-violet ray on cryptococcus neoformans (자외선 조사처리에 의한 cryptococcus neoformans의 전자현미경적 관찰)

  • Hwang, Dong-Hoon;Koh, Choon, Myung;Choi, Tae-Joo;Lew, Joon
    • Korean Journal of Microbiology
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    • v.10 no.1
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    • pp.29-34
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    • 1972
  • The present study is of ultra-fine structure of Cryptococcus neoformans by means of electron microscopy and reveals the following : 1) In constrast to the bacteria, the normal Cryptococcus neofrmans contains nuclear enveloped with nuclear menbrane, mitochondria, endoplasmic reticulum, distinct cell wall and cell membrane, vacuoles and storage granules as observed in the eucaryotic cells. 2) In apparent cell walls and cell membrane with the appearance of electron transparent area (ETA) and changes of cell morphology were observed in the ultra-violet ray irradiated cell. 2) In apparent cell walls and cell membrance with the appreance of electron transparent area (ETA) and changes of cell morphology were observed in the ultra-violet ray irradiated cell. 3) Morphology changes and cytoplasmic element abnormality was increased with irradiated time. 4) Increase of electron transparent area was thought to be associated with degradation of cell.

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An study on the Space Composition of the Theme Park-style Shopping Center - Focused on Designed Projects by Jerde Partnership - (테마파크 형 쇼핑센터의 공간구성에 관한 연구 - 저드파트너쉽의 설계 작품을 중심으로 -)

  • Ha, Sung-Joo
    • Korean Institute of Interior Design Journal
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    • v.16 no.6
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    • pp.144-151
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    • 2007
  • The idea of shopping is changed from a purchase of merchandise to an experience of pleasure. This study is a space composition analysis for the introduction of theme in multi-plex shopping center design to reflect variable consumer trend and company marketing strategy, The study progressed through theoretical consideration and substance analysis about the shopping centers which had been designed by Jerd Partnership In Japan since 2000. The following is result. The path is a sole main street that is made of curve form, parallel and vertical circulating rout and movement of human being. It leads continuity. The node and landmarks have a circular court with typifier as powerful center, character of transition space and event for experience. It makes locational quality. The districts are composed of retail shops, restaurants and culture facilities and the edge is represented by closed vertical wall and parapet. It induces a domain. The characteristic of Jerde shopping center is an experience of theme environment through the path as betweenness with a story based on a main theme. It is mostly related nature or exotic element and is obviously represented at path and node. The node takes a round shape and bring about event as a court. The application of theme to the shopping center by Jerde has a significant meaning for place marketing.

An study on the Expressive Characteristics of Jerde Partnership's shopping center - Focused on Space Composition of Theme Park-style - (저드파트너쉽 쇼핑센터의 표현 특성에 관한 연구 - 테마파크형 공간구성을 중심으로 -)

  • Ha, Sung-Joo;Ha, Mi-Kyoung
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2007.11a
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    • pp.103-106
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    • 2007
  • The idea of shopping is changed from a purchase of merchandise to an experience of pleasure. This study is a space composition analysis for the introduction of theme in multi-plex shopping center design to reflect variable consumer trend and company marketing strategy. The study progressed through theoretical consideration and substance analysis about the shopping centers which had been designed by Jerd Partnership from 2000 in Japan. The following is result. The path is a sole main street that is made of curve form, parallel and vertical circulating rout and movement of human being. It leads continuity. The node and landmarks have a circular court with typifier as powerful center, character of transition space and event for experience. It makes locational quality. The districts are composed of retail shops, restaurants and culture facilities and the edge is represented by closed vertical wall and parapet. It induces a domain. The characteristic of Jerde shopping center is an experience of theme environment through the path as betweenness space with a story based on a main theme.

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A Semiological Interpretation of the Koreaness in Paris Park, Seoul (파리공원에 반영된 한국성의 기호학적 해석 -예름슬레우 모델을 중심으로-)

  • 김동찬;유재설;김성준
    • Journal of the Korean Institute of Landscape Architecture
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    • v.28 no.3
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    • pp.53-60
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    • 2000
  • Although built-environment has not only function but also socio-cultural meanings, the latter is neglected in the modernism. People don't have the identity of their place because they can't communicate with environment. Therefore, expressing the socio-curtural meanings in landscape is one of main issues after the modern era. The meanings of phenomena can be analyzed by the Semiology based on Structurism, the methodology which has been developed in Linguistics and Anthropology since 1900's. The purpose of this study is to adapt Helmslev's model that can effectively explain the meanings of built-environment and interpret the Koreaness, one of important meanings in contemporary urban park, Paris park. The following methods are used for achieving the purpose. 1. Adaptation of the Helmslev's model for interpreting the urban park. 2. Interpretation of the Paris park. 3. Making the types of interpretion of Paris park. The results are as followings: 1. Helmslev's model can explain the content and expression of the urban park in denotation and connotation. 2. Th socio-cultural meanings of Paris park are the relationship of France, Yan and Yin theory, philosophy of Samjae, king's authority. And they are expressed in the pattern of paving, the shape of mounds, fountain, and pond, a picture of the wall, colours of lightings and columns, and a mark of bollards.

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