• 제목/요약/키워드: Expanding Area

검색결과 656건 처리시간 0.022초

확장 면적을 이용한 안정된 증발 마이크로채널 시스템의 설계 (Design of Stable Evaporative Micro-channel Systems Using Expanding Area)

  • 이희준
    • 대한기계학회논문집B
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    • 제35권8호
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    • pp.831-838
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    • 2011
  • 마이크로채널 표면의 핵에서 생성된 기포는 물을 작동유체로 이용하는 경우 채널의 좁은 단면적에 의해 압착되어 유동불안정성을 유발한다. 직관 마이크로채널에서 압착된 기포는 관성 유동의 역방향인 채널 상류로 진행한다. 마이크로채널에서 역방향 유동을 없애기 위해 채널 하류의 단면적을 확장시키는 것이 효과적이다. 그 이유는 압착된 기포의 전후단 계면의 표면장력에 의한 압력차이가 계면의 반지름에 역비례해서 자연적으로 기포가 채널 하류로 이동하려는 힘이 발생하기 때문이다. 확장 증발 마이크로채널에서 정적 유동불안정성 모델이 제시되었으며, 실험으로 모델을 검증하였다. 또한, 안정된 확장 시스템을 설계하기 위해 국부 설계 개념을 도입하였다. 검증된 모델과 개념을 바탕으로 안정된 확장 증발 마이크로채널 설계를 성공적으로 수행하였다.

상정사고를 고려한 배전용 변전소 신,증설 계획 수립 (Planning for Construction and Expanding of Distribution Substation Considering Contingency)

  • 최상봉;김대경;정성환
    • 대한전기학회논문지:전력기술부문A
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    • 제50권7호
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    • pp.303-308
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    • 2001
  • This paper presents algorithm to plan construction and expanding of substation considering contingency accidents by proposing utilization factor according to configuration of substation bank system. In this paper, firstly, proper sphere of supply area by each district which could be standardized with respect to its supply capacity is established under assumption of long term load forecasting. Secondly, goal of utilization ratio based on configuration of substation bank was set to keep reliability by remaining sound bank when it happen to one bank accidents. Finally, it is set up for optimal construction and expanding of substation considering economy and reliability simultaneously about substation to exceed these ratio. To verify proposed algorithm, at first, after adopting a part of Kangnam area in Seoul as area for testing, it is divided into several regions for this area according to power branches of power utility. Secondly, by deriving correlation factor between load demand and economic indicators in these region respectively, the regional load forecasting was performed with economic growth and city plan scenario. Finally, based on the predicted load demand by region and land use data which is identified from air-photographic, the load demand by district was predicted. Also, planning for substation considering contingency is formulated to expand taking into account computing utilization factor which is based on configuration of substation bank respectively.

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레이저 빔 단면확대를 이용한 나노 복화(複畵)공정의 패턴 정밀도 향상에 관한 연구 (Fabrication of Precise Patterns using a Laser Beam Expanding Technique in Nano-Replication Printing (nRP) Process)

  • 박상후;임태우;양동열;이신욱;공홍진
    • 한국정밀공학회지
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    • 제22권1호
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    • pp.175-182
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    • 2005
  • A laser beam expanding technique is employed to fabricate precise nano-patterns in a nano-replication printing (nRP) process. In the nRP process, some patterns can be fabricated in the range of several microns inside on a polymerizable resin by using a volume-pixel (voxel) matrix that is transformed from a two-tone bitmap figure file. The liquid monomers are polymerized by means of a two-photon-absorption (TPA) phenomenon that is induced by a femtosecond (fs)-pulse laser. The yokels are generated consecutively to merge into adjoining yokels in the process of fabricating a pattern. The resolution of a fabricated pattern can be obtained under the diffraction limit of a laser beam by the two-photon absorbed polymerization (TPP). In this work, a beam-expanding technique has been applied to enlarge a working area and to fabricate precise patterns. Through this work, a working area is expanded by the technique as much as 2.5 times compared with a case of without a beam expanding technique, and precision of outside patterns is improved.

Study on Change in Landscape Structure over Time in Suburban Area by Using GIS -Case Study of Kawachinagano City, Osaka-

  • Kaga, Horoyuki;Izaki, Noriaki;Shimomura, Yasuhiko;Masuda, Noboru
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • 제1호
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    • pp.67-74
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    • 2001
  • Now that importance of landscape planning unique to each area is emphasized, it is necessary to conduct landscape planning by taking advantage of natural environments unique to each ares, because its natural environments are regarded as one of the assets the area possesses. This study targets at Kawachinagano City, Osaka, one of the residential areas that I not only rich in natural and historical elements, but also has been rapidly growing. The purposes of this study are to evaluate change in landscape structure over time by analyzing relation between landform and pattern of expanding the built-up area at three time points of 1932, 1967, and 1994 with GIS (ARC/INFO 7.0.3, ARC/View 3.0 (ESRI)), as well as to make some suggestions for planning landscape unique to the area. Data on main ridges, sub ridges, main rivers, and other landform were read from the elevation map, and data on woodland, and parks and open spaces (having more than 3 ha area) were read from the existing land use map. The data were used to understand the natural structure of the city from topographic viewpoint. Next, the existing land use map prepared with data on the built-up area and urban axes consisting of roads and streets were overlaid on the elevation map in order to understand relation between pattern of expanding the built-up area and the natural structure.

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순창고추장의 팽창 원인 효모의 분리 및 특성 (Isolation and Characterization of a Volume-Expanding Yeast from Sunchang Gochujang)

  • 이경자
    • 한국식품영양학회지
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    • 제12권4호
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    • pp.339-343
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    • 1999
  • A strain of gas-producing and volume-expanding yeast was isolated from Gochujang made in Sunchang by the traditional ways and was identified to be a Saccharomyces sp. This yeast was detected only in malt among the several ingrediants of Gochujang which means that the volume-expanding yeast comes into Gochujang at the time of making products through malt one of the major ingredients. However boiling of the malt-saccharified rice could not prevent the occurrence of the volume-expanding yeast in Gochuj-ang. This yeast was contained in the range of 5.67∼7.75 log10CFU/g in products made and aged between 1 monty and 3 year in Sunchang area.

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HI Shells and Supershells in the I-GALFA HI 21-cm Line Survey

  • 박금숙;구본철
    • 천문학회보
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    • 제36권2호
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    • pp.112.2-112.2
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    • 2011
  • We carry out a systematic study of HI shells and supershells in the first Galactic quadrant (l = $32^{\circ}$ to $77^{\circ}$, b = $-10^{\circ}$ to $10^{\circ}$) using the "Inner-Galaxy Arecibo L-band Feed Array (I-GALFA)" HI 21-cm survey data. The high-resolution (3.'4) and high sensitivity (0.2 K) of the survey provide us an opportunity to exploit the true nature of the sources detected in previous low-resolution studies and also to detect faint and/or small shells that were not detectable before. Our work is composed of three parts: (1) confirm the objects in the low-resolution (about 30') catalog of Heiles (1979), (2) search for fast-expanding HI shells associated with Galactic supernova remnants (SNRs), and (3) search for new shell structures. Among the 21 Heiles' supershells in the I-GALFA survey area, we confirm fourteen. The high resolution data reveal their complex morphology, and provide direct evidence for expansion in some sources. Among the 39 Galactic SNRs in the survey area, we find five with associated fast expanding HI shells, which is consistent with previous results. A remarkable result from the SNR study is the detection of HI gas at very high negative velocities in the SNR W44 that should be from the approaching part of the HI expanding shell. This is the first time to detect both the approaching and receding sides of an expanding shell in HI 21-cm emission line in SNRs. We have found 33 new shell candidates of angular sizes ranging from 0.5 to 6.5 degrees, half of which appear to be expanding. We summarize these results and discuss some individual interesting objects in detail.

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위성항법시스템의 전리층 보정 가능 영역 확장을 위한 인공 신경망의 성능 분석 (Performance Analysis of Artificial Neural Network for Expanding the Ionospheric Correction Coverage of GNSS)

  • 류경돈;소형민;박흥원
    • 한국항행학회논문지
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    • 제22권5호
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    • pp.409-414
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    • 2018
  • 광역 차분위성항법시스템의 서비스 영역을 기준국 네트워크 외부로 확장하기 위해서는 전리층 보정 정보의 외삽이 필수적이다. 본 논문에서는 전리층 보정 영역 확장을 위한 인공 신경망을 설계하고 이에 대한 성능분석을 수행하였다. 인공 신경망 입력으로 사용되는 일/년별 주기함수, 태양흑점개수, 자기장 인덱스(Ap)의 개별 요소들이 전리층 외삽 추정 성능에 미치는 영향을 분석하였다. 신경망의 구성에 있어서는 은닉 층의 수 및 뉴런 개수 변화에 따른 성능 분석을 수행하였다. 분석결과를 바탕으로 신경망을 구현하고 태양활동 극대기(2014년)의 고위도와 저위도 지역에서의 전리층 추정 결과를 보였다.

생태학적 접근을 통한 가사노동 사회화의 관련변수에 관한 연구 -서울시 거주하는 확대기 가정 주부를 중심으로- (An Ecological Study on the Socialization of Household Work -Focusing on the Expanding Stage of the Family Life cycle of Housewives-)

  • 윤영희;박미석
    • 가족자원경영과 정책
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    • 제1권1호
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    • pp.101-115
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    • 1997
  • This study was designed to examine the socialization of household work utilizing ecological theory. The main purposes were to identify the socialization level, and to predict the socialization of household work in term of the selected variables. The sample was drawn from housewives of expanding stage of family life cycle in Seoul. 518 respondents were analyzed using SPSS/PC+ statistical package. The results of this study were as follows: 1. Among the variables of food area, education of housewife, type of housing, family income, number of children had significant influence. 2. Among the variables of clothing area, family income was the only important variable. 3. Among the variable of housing area, number of household equipment, number of aids for household work, education of housewife, family income, attitude of housewife’s role, number of aids for household work had significant influence. 4. Among the varables of home management area, number of household equipment, family income, self control had significant influence. 5. Among the environment variables of household work, social-cultural environment had the most important effect on the socialization of household work.

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상정사고를 고려한 배전용 변전소 신,증설 계획 수립에 관한 연구 (A study on the planning for construction and expanding of distribution substation considering contingency)

  • 최상봉;김대경;정성환;배정효;하태현;이현구;한상용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 A
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    • pp.552-554
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    • 2000
  • This paper presents algorithm to plan construction and expanding of substation considering contingency accidents by proposing utilization factor according to configuration of bank system. In this paper, at first, proper sphere of supply area in each district which could be standardized with respect to its supply capacity is established under assumption which was made long term load forecasting in district respectively. Secondly, goal of utilization ratio according to configuration of substation bank was set to keep reliability by remaining sound bank when it happen to one bank accidents Finally, optimal construction and expanding of substation considering economy and reliability simultaneously about substation to exceed these ratio could be anticipated.

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부하예측에 의한 합리적인 배전용 변전소 증설계획 수립 (Planning for Reasonable Construction and Expanding of Distribution Substation By Load Forecasting)

  • 최상봉;김대경;정성환;배정효;하태현;이현구;김호용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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    • pp.92-94
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    • 2000
  • This paper presents algorithm to plan construction and expanding of substation considering contingency accidents by proposing utilization factor according to configuration of substation bank system. In this paper, above all, proper sphere of supply area by each district which could be standardized with respect to its supply capacity is established under assumption of long term load forecasting which was made by district respectively, and then goal of utilization ratio based on configuration of substation bank was set to keep reliability by remaining sound bank when it happen to one bank accidents. Finally it is set up for optimal construction and expanding of substation considering economy and reliability simultaneously about substation to exceed these ratio.

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