• 제목/요약/키워드: Closed Bottoms

검색결과 11건 처리시간 0.025초

액체과냉도가 하부폐쇄 수직환상공간 내부의 풀비등 열전달에 미치는 영향 (Effect of Liquid Subcooling on Pool Boiling Heat Transfer in Vertical Annuli with Closed Bottoms)

  • 강명기
    • 대한기계학회논문집B
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    • 제29권2호
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    • pp.239-246
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    • 2005
  • Effects of subcooling on pool boiling heat transfer in vertical annuli with closed bottoms have been investigated experimentally. For the test, a tube of 19.1mm diameter and the water at atmospheric pressure have been used. Three annular gaps of 7.05, 18.15, and 28.20 have been tested in the subcooled water and results of the annuli are compared with the data of a single unrestricted tube. The increase in pool subcooling results in much change in heat transfer coefficients. At highly subcooled regions, heat transfer coefficients for the annuli are much larger than those of a single tube. As the heat flux increases and subcooling decrease, a deterioration of heat transfer coefficients is observed at the annulus of 7.05mm gap. Single-phase natural convection and liquid agitation are the governing mechanisms for the single tube while liquid agitation and bubble coalescence are the major factors at the bottom closed annuli.

하부폐쇄 환상공간의 외부 튜브길이가 풀비등에 미치는 영향 (Effects of Outer Tube Length on Pool Boiling in an Annulus with Closed Bottoms)

  • 강명기
    • 대한기계학회논문집B
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    • 제30권8호
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    • pp.749-755
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    • 2006
  • To improve pool boiling heat transfer in an vertical annulus with closed bottoms, the length of an outer tube has been changed from 0.2m to 0.6m. For the test, a heated tube of 19.1mm diameter and water at atmospheric pressure have been used. Annular conditions are made using glass tubes fabricated around the heated tube. The gap size of the annulus is 3.65mm. To elucidate effects of the outer tube length on heat transfer results of the annulus are compared with the data of a single unrestricted tube and the annulus with wider gap size of 6.35mm. Throughout the tests much higher heat transfer coefficients are observed for the annulus of 3.65mm gap size comparing to the other two cases. The change in the outer tube length results in much variation in heat transfer coefficients. Moreover, with shortening the length of outer tube the possibility of the CHF occurrence can be removed.

돌궐 의복 형태 연구 (A Study on the Style of Clothing of Turk)

  • 양예은;채금석
    • 한국의상디자인학회지
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    • 제19권2호
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    • pp.63-78
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    • 2017
  • The purposes of this study was to study Turkic clothing traditions as a way to shed light on cultural development via the interactions among different tribes along the Silk Road, the close correlations between the surroundings of the Turks and their costumes, and the root of Turkic culture through literature studies and empirical studies. The study results are as follows. First, the Turks were nomadic equestrian tribes in the north that dominated the cold dry steppes from the $6^{th}$ to $8^{th}$ century A.D., when they expanded their influence to Dongbei, China to the east, and Turkistan (Central Asia) to the west. The Turks formed a nomadic lifestyle and culture suited to a cold dry climate, and interacted with various other tribes via the Silk Road, while exchanging and sharing different cultural aspects. Second, given that the Turkic garments constitute a two-piece style, which is a category of the basic nomadic costume of northern tribes, and that the artifact materials manifest jackets, overcoats, pants and skirts, the garments are categorized into tops and bottoms. The tops are sub-categorized into jackets and overcoats. The bottoms are sub-categorized into pants and skirts. In light of the necklines of tops, jackets have round necklines, while overcoats have V-necklines, round necklines and lapel collars. The bottoms include narrow-legged pants, wide-legged pants and closed-hem pants. Drapery skirts are worn at the waist. Third, the Turkic V-neckline overcoat is comparable to the Huns' silk overcoat, which illustrates the ethnic link between the two tribes. Also, the Turkic narrow- and wide-legged pants are consistent with the Huns' silk pants discovered in Noin Ula. The Turkic costumes are mostly tight fitting, suitable for the nomadic lifestyle in a cold, dry climate. Also, additional patches must be attached to the crotch points of pants due to the equestrian lifestyle.

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아두이노 센서를 이용한 케겔 운동 시스템 설계 (Kegel Exercise System Using an Arduino sensor)

  • 차제희;장종욱
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2015년도 추계학술대회
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    • pp.198-201
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    • 2015
  • 아두이노와 압력센서를 이용하여 현대인의 관심사인 건강관리 프로그램을 만드는 것이 목적이다. 현재 한국에는 총 420만명의 요실금 환자가 있을 것으로 추정된다. Information Technology와 Bio Technology의 융합을 통해 이러한 환자들이 쉽고 간단하며 가장 효과적인 골반저근운동(이하 케겔운동) 을 할 수 있도록 유도하여 요실금, 발기부전 등을 치료, 예방한다. 현재 시중에 판매되는 케겔 의료기기는 전기적 자극을 강제로 주어 운동을 해야 하는 시스템으로 하의를 탈의하고 폐쇄된 공간에서 Femcon Therapy를 주로 사용 하였으며 이는 시간제약, 공간제약, 위생적인 제약 등의 문제가 있다. 본 연구는 이러한 제약에서 벗어나 하의를 탈의하지 않고 공간과 위생의 제약에서 벗어나 BT와 IT를 융합한 케겔(Kegel) 의료기를 설계 하였다.

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중년여성의 수트 착용 형태미를 위한 형태 구성요인의 조합에 관한 연구 (A Study on the Combination of Suit Details for Image of Classic Style Suits-Middle Aged Women′s Body Construct)

  • 위은하;김옥진
    • 복식문화연구
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    • 제8권5호
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    • pp.726-740
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    • 2000
  • The purpose of this study is to evaluate the combination of suit details through visual evaluation which helps compensating the classic style suits-middle aged women's body construct for their more attractive fashion styles. The styles of the evaluated suits are formal and classical. The designs of evaluated suits are manipulated in 40 different kinds by the essential elements such as collars, necklines(tailored collars, soutien collars, stand collars, round necklines, V-necklines, etc.), bottoms(slacks, skirts), pocket (flap pocket, none) and opening(opened, closed). The data evaluated by a multiple ranking test were analyzed by paired t-test, ANOVA and Duncan's multiple raged test. The results are summarized as follows : 1. A middle aged woman on skirts suits look more graceful, more elegant, and a bit more refined than that on slacks suits. 2. A middle aged woman wearing a jacket with flap pockets on looks more balanced, and graceful than when wearing with no pockets. 3. Wearing closed jackets looks more balanced and graceful than on opened jackets. 4. The types of collar·necklines can be called the details which put much influence on Image effects. Putting on tailored collar suits is the most graceful, refined, balanced and harmonious case than any others.

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중년여성의 체형에 적합한 수트의 형태구성요인의 조합에 따른 시각 효과 (The Visual Effect in combination of Suit Details on Classic Style Suits-Middle Aged Womens Body Construct)

  • 위은하;김옥진
    • 한국의류학회지
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    • 제25권3호
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    • pp.525-536
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    • 2001
  • The purpose of this study is to evaluate the combination of suit details through visual evaluation which helps compensating middle aged womens body defects for their more attractive fashion styles. In this study, styles of the evaluated suits are formal and classical. The designs of evaluated suits are manipulated in 40 different kinds by the essential elements such as collars, necklines(tailored collars, soutien collars, stand collars, round necklines, V-necklines), bottoms(slacks, skirts), pocket(flap pocket, none) and opening(opened, closed). The data evaluated by a multiple ranking test were analyzed by mean, paired t-test, ANOVA and Duncans multiple raged test. The results are summarized as follows: 1) The classic style suits-middle aged womans body construct looks better when she is wearing it with the combination of suit details; opened tailored collar jacket with flap pocket or non-pocket, opened stand collar jacket with non-pocket, closed soutien collar and round neckline jacket with non-pocket, closed V-neckline jacket with flap pocket or non-pocket on slacks. 2) The middle aged woman wearing slacks looks smaller in upper body, longer in lower part of her body and taller as a whole than when wearing a skirt suit. And Opened jacket makes a middle aged woman be seen with less appeared abdomen than that on closed jacket. The stand calar and round neckline jacket with non-flap pockets makes her look smaller in upper body and hip. 3) With tailored, soutien, stand collar jacket, it looks slimmer in a neck, narrower in shoulder, smaller in upper body, and taller than on a round neckline and V-neckline jacket.

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하부 유로단면적이 수직 환상공간 내부 풀비등열전달에 미치는 영향 (Effects of Bottom Inflow Area on Pool Boiling Heat Transfer in a Vertical Annulus)

  • 강명기;유주식
    • 대한기계학회논문집B
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    • 제31권7호
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    • pp.604-610
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    • 2007
  • To investigate effects of the inflow area on pool boiling heat transfer in a vertical annulus, the inflow area at its bottom has been changed from 0 to $1060.3mm^2$. For the test, a heated tube of 34 mm diameter and water at atmospheric pressure have been used. To elucidate effects of the inflow area on heat transfer results of the annulus are compared to the data of a single unrestricted tube. The change in the inflow area at the bottom of the annulus results in much variation in heat transfer coefficients. When the inflow area is $113.1mm^2$ the deterioration point of heat transfer coefficients gets moved up to the higher heat fluxes because of the convective flow at the bottom regions.

외부 튜브 길이가 긴 수직 환상공간 내부의 풀비등 열전달 (Pool Boiling Heat Transfer in a Vertical Annulus with a Longer Outside Tube)

  • 강명기
    • 대한기계학회논문집B
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    • 제36권8호
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    • pp.775-782
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    • 2012
  • 수직으로 설치된 하부폐쇄 환상공간 내부의 풀비등 열전달 메카니즘을 알기 위하여 환상공간의 튜브 길이를 0.3m와 0.6m 사이에서 변경하였다. 실험을 위해 0.2m의 가열 길이를 갖는 직경 19.1mm인 스테인리스강 튜브와 대기압 상태 하에 있는 물을 사용하였다. 외부 튜브 길이가 열전달에 미치는 영향을 분명하게 살펴보기 위해 환상공간에 대한 결과를 환상공간이 없는 단일튜브에 대한 결과와 서로 비교하였다. 동일 열유속에서 외부튜브 길이의 증가는 틈새간격이 3.5mm인 경우에는 열전달계수의 증가하지만 틈새간격이 15.5mm인 경우에는 열전달계수가 감소하였다. 이러한 경향의 주된 원인은 액체교란의 차이로서 설명된다.

출구유로 단면적이 수직 환상공간 내부의 풀비등에 미치는 영향 (Effects of Outflow Area on Pool Boiling in Vertical Annulus)

  • 강명기
    • 대한기계학회논문집B
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    • 제37권4호
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    • pp.377-385
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    • 2013
  • 출구유로 단면적이 수직 환상공간 내부의 풀비등 열전달에 미치는 영향을 규명하기 위하여 세 가지 서로 다른 유동제한장치를 실험적으로 연구하였다. 가열 튜브는 매끈한 표면을 가지는 스테인리스강이며 대기압 상태 하에 있는 물을 사용하였다. 환상공간의 하부유로 조건은 개방과 폐쇄된 경우 두 가지를 모두 고려하였으며 유동제한장치를 설치한 환상공간에 대한 결과를 유동제한장치가 없는 환상공간에 대한 결과와 서로 비교하였다. 출구유로 단면적을 축소하는 것은 열전달의 감소를 초래하지만, 출구 유로가 아주 작은 경우 열전달계수가 증가하는 경우도 관찰되었다. 이러한 경향은 기포군집의 형성과 이동에 따른 액체교란의 차이로서 설명되며, 유동대류, 맥동류 발생, 기포 군집 하부의 미세층증발이 중요한 열전달 기구인 것으로 확인하였다.