• 제목/요약/키워드: Bubble Burst

검색결과 8건 처리시간 0.021초

폴리우레탄 코팅 장갑의 기포로 인한 불량 현상에 대한 고찰과 개선 (A Study on Defects Due to Air Bubbles in the PU-Coating Gloves and Enhanced Molds to Reduce the Defects)

  • 김용우
    • 한국공작기계학회논문집
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    • 제16권5호
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    • pp.55-62
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    • 2007
  • With the developments in knitting, manufacturing, and polymers, coated gloves have been evolved in a way to maximize occupational safety and functionality. In this paper, we have considered the PU-coating process for the glove knitted by Dyneema to reduce the occurrence of the defects due to air bubble. This paper classifies the types of defect due to air bubble and traces their forming mechanisms. The air between coating layer of glove and mold's surface forms the defects if it is not evacuated fully in the process of submerging into water. The defects can be suppressed or avoided by forming air-evacuating path on the surface of the molds.

독립공리 설계기법을 이용한 LCD 세정노즐의 최적설계 (Optimal Design of Water Jet Nozzles Utilizing Independence Design Axiom)

  • 신현석;이종수
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1240-1247
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    • 2003
  • Water jet nozzle for LCD has been used as a wet cleaning process in many industries. It is necessary for the nozzle to consider cleaning effect and flux. In this paper, we applied the bubble dynamic theory(Rayleight-Plesset equation) to improve the cleaning efficiency. Generally, Rayleigh-Plesset equations for cavitation bubbles are used in analyzing computer simulation for caviting flows. Burst of bubbles causes potential energies and we can use these energies to remove organic and inorganic compounds on the LCD. Therefore, it is necessary to analyze the bubble generations and axiomatic design by computational fluid dynamics(CFD). By comparing the weight matrix of neural networks to the design matrix of axiomatic design, we propose methods to verify designs objectively. The optimal solution could be deduced by the regression analysis using the design parameters.

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경제충격 시기의 한계소비성향 분석 - FIML 마코프-스위칭 모형 이용 (Marginal Propensity to Consume with Economic Shocks - FIML Markov-Switching Model Analysis)

  • 윤재호;이주형
    • 한국산학기술학회논문지
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    • 제15권11호
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    • pp.6565-6575
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    • 2014
  • 본 논문에서 Hamilton의 마코프-스위칭 모형을 연립방정식으로 확장한 FIML 마코프-스위칭 모형을 제시해 보았다. 본 논문의 FIML 마코프-스위칭 모형을 LIML 마코프-스위칭 모형 등과 비교하면 LIML 마코프-스위칭 모형은 FIML 마코프-스위칭 모형의 특별한 경우이며 FIML 마코프-스위칭 모형은 연립방정식으로 확장된 일반화된 모형 형태를 띄게 된다. 본 논문의 FIML 마코프-스위칭 모형을 Campbell and Mankiw 소비함수에 적용해 본 결과, 2008년 부동산 거품 붕괴와 같은 경제충격 시기의 한계소비성향은 매우 민감도가 높아진다는 것을 알 수 있다.

1993~2002년 일본불황에 대한 연구 (An Analysis on Japanese Recession Between 1993 and 2002)

  • 윤형모
    • 국제지역연구
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    • 제13권2호
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    • pp.168-188
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    • 2009
  • 일본은 과거 10년(1993-2002) 동안 버블붕괴로 극심한 경기침체기를 경험하였다. 최근 미국에서도 유사한 현상이 발생하였고, 그 여파로 세계 각국이 불경기를 겪고 있다. 본 연구의 목적은 과거 일본 경기침체기를 분석하여 현재 미국 등 여러 나라의 경제 불황을 탈출할 수 있는 방법을 모색하는데 있다. 과거 문헌자료에 의하여 나타난 시사점은 정부부채에는 최적 상태가 존재하고, 경기회복을 위한 정책은 실시 시점이 중요하다는 것이다. VAR 모형과 State Space Model에 의한 통계적 분석으로부터는 다음과 같은 결과가 도출되었다. 정부 재정지출의 경기부양에 대한 영향은 단기적이며 미약했다. 조세는 생산에 장기적이며 부정적 영향을 준다. 그러므로 정부부채 감소를 위한 증세(增稅)는 신중히 실시되어야 한다. 재정지출의 효과는 정책이 발표된 후 반년의 시차를 두고 효과가 나타나는 반면, 조세증가는 공시와 동시에 민간소비와 투자를 감소시키고 그 영향도 길며 크다.

유르스나르의 문학작품에 나타난 미국의 영향 (The American influence on the literary works of Yourcenar)

  • 오정숙
    • 비교문화연구
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    • 제37권
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    • pp.157-183
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    • 2014
  • Although Marguerite Yourcenar, a representative French woman writer, lived 47 years in the United States from 1939 to 1987, the American influence on her life has not been studied either at home or abroad. The purpose of this study is to examine chronologically the American influence on the following three literary works of Yourcenar: The Little Mermaid (1942), River Deep, Dark River (1966) and Recluse (1982). The Little Mermaid is a drama, presented in musical format, about the identity crisis and inner conflict of Yourcenar. Unlike the little mermaid who burst like a bubble in Hans Christian Andersen's fairy tale, Yourcenar associates her death with the image of ascension. River Deep, dark river is a translation of the Negro spiritual expressing the suffering of African Americans. Recluse, her last novel, deals with the life story of a simple man living in nature on a small island. This novel shows Yourcenar's desire for a pure world that is not defiled by human greed. Yourcenar sponsored major human rights organizations and environmental groups in her life, and donated her entire fortune for human rights and the protection of Wild Fauna and Flora. The American influence on the literary works of Yourcenar can be summarized as a "great turning point", because she was transformed from a humanistic writer into an intellectual actor.

일본 분양아파트의 생활서비스프로그램 운영실태 사례 연구 (A Case Study on the Operation and Management of Community Service Programs in Japanese Condominiums)

  • 강순주
    • 한국실내디자인학회논문집
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    • 제20권2호
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    • pp.85-93
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    • 2011
  • The Japanese housing market has implemented management and operation systems of community service ahead of the Korean market. This paper examines case studies of Japanese community services by reviewing related studies, studying homepages, and conducting in-depth interviews with management staff. The goal of this study is to find marketing strategies and the proper management practices in preparation for the upcoming low-fertility and aging society. The results of this study are as follows: 1) After Japan's bubble economy burst in 1985, so called that incorporated various community facilities with life services were introduced to the Japanese housing market in order to cope with the diversifying family types and lifestyles. This new trend was also due in part to customers' increasing demands for convenient urban condominiums. 2) In Japan, many developers and construction companies have run the management of community service programs and created new business models in collaboration with other affiliated companies. However, many of these programs have been found even more successful and reliable when the facility management companies collaborate with local service providers instead of relying solely on affiliated companies. 3) The early stage of life services began with "front-desk services", but these have evolved into more upgraded "concierge services" that can provide residents with tailored services and conveniences. Furthermore, some of the service providers have encouraged resident participation in the process of designing and implementing their community services. 4) In Korea, most construction companies and developers are still oriented toward providing hardware such as spaces and facilities in developing their community services. Therefore, companies with high market reputations must seek alternative ways to maintain and enhance their brand values by implementing new approaches in collaboration with both affiliated companies and local service providers. This can be done by finding new notions of managing and operating community services through research and development.

LATEST RESULTS OF THE MAXI MISSION

  • MIHARA, TATEHIRO
    • 천문학논총
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    • 제30권2호
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    • pp.559-563
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    • 2015
  • Monitor of All-sky X-ray Image (MAXI) is a Japanese X-ray all-sky surveyer mounted on the International Space Station (ISS). It has been scanning the whole sky since 2009 during every 92-minute ISS rotation. X-ray transients are quickly found by the real-time nova-search program. As a result, MAXI has issued 133 Astronomer's Telegrams and 44 Gamma-ray burst Coordinated Networks so far. MAXI has discovered six new black holes (BH) in 4.5 years. Long-term behaviors of the MAXI BHs can be classified into two types by their outbursts; a fast-rise exponential-decay type and a fast-rise flat-top one. The slit camera is suitable for accumulating data over a long time. MAXI issued a 37-month catalog containing 500 sources above a ~0.6 mCrab detection limit at 4-10 keV in the region ${\mid}{b}{\mid}$ > $10^{\circ}$. The SSC instrument utilizing an X-ray CCD has detected diffuse soft X-rays extending over a large solid angle, such as the Cygnus super bubble. MAXI/SSC has also detcted a Ne emission line from the rapid soft X-ray nova MAXI J0158-744. The overall shapes of outbursts in Be X-ray binaries (BeXRB) are precisely observed with MAXI/GSC. BeXRB have two kinds of outbursts, a normal outburst and a giant one. The peak dates of the subsequent giant outbursts of A0535+26 repeated with a different period than the orbital one. The Be stellar disk is considered to either have a precession motion or a distorted shape. The long-term behaviors of low-mass X-ray binaries (LMXB) containing weakly magnetized neutron stars are investigated. Transient LMXBs (Aql X-1 and 4U 1608-52) repeated outbursts every 200-1000 days, which is understood by the limit-cycle of hydrogen ionization states in the outer accretion disk. A third state (very dim state) in Aql X-1 and 4U 1608-52 was interpreted as the propeller effect in the unified picture of LMXB. Cir X-1 is a peculiar source in the sense that its long-term behavior is not like typical LMXBs. The luminosity sometimes decreases suddenly at periastron. It might be explained by the stripping of the outer accretion disk by a clumpy stellar wind. MAXI observed 64 large flares from 22 active stars (RS CVns, dMe stars, Argol types, young stellar objects) over 4 years. The total energies are $10^{34}-10^{36}$ erg $s^{-1}$. Since MAXI can measure the spectrum (temperature and emission measure), we can estimate the size of the plasma and the magnetic fields. The size sometimes exceeds the size of the star. The magnetic field is in the range of 10-100 gauss, which is a typical value for solar flares.

요세바 고도부키에서의 시공간과 로컬리티의 변화 (The Changes of Timespace and Locality in the Yoseba, Kotobuki)

  • 조현미
    • 한국지역지리학회지
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    • 제22권2호
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    • pp.383-396
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    • 2016
  • 요세바는 일용직노동자에게 있어서 구직과 구인의 공간이면서 거주공간이기도 하다. 일용직노동자의 삶을 좌우하는 가장 중요한 요소는 경기의 변화이며, 경기의 변화는 국가 혹은 국제관계의 영향을 받을 수밖에 없다. 그리고 노동자의 삶을 둘러싼 거주환경은 노동자의 경제적 상황에 민감하게 반응하면서 변화하므로 역시 국가적이며 국제적이다. 요세바 고도부키라는 지역형성에 직접적인 영향을 준 것은 제2차 세계대전의 종식이다. 도시재건사업이 활발히 전개되기 시작하면서 고도부키 지역은 전국각지에서 몰려온 노동자로 활기를 띠게 된다. '한국전쟁특수'를 통한 경제부흥 시기를 거쳐 석유파동으로 인한 세계적인 경제공황에 따른 경기침체로 일본의 내수경제도 침체하게 되고, 경기침체의 여파는 노동시장에도 직접적인 영향을 주게 되었다. 또한 거품경제의 붕괴로 인한 장기적인 경제불황으로 노동시장의 활기도 점차 식어가면서 한때 일본경제의 역군이었던 노동자들은 더 이상 제 역할을 담당하지 못한 채 고령화 되어갔다. 고령의 노동자들이 생활보호를 받게 되면서 도야경영자들은 도야를 보수하기 시작했고, 장애자와 고령자를 위한 개호업자들이 줄지어 들어서면서 고도부키는 다시 변화하기 시작했다. 요세바 고도부키에 있어서 로컬리티 변화에 작용한 역사적 시간들은 구성원인 노동자의 삶에 있어서는 미시적으로 작용한 시간들이지만 그 시간들에는 국민국가의 내셔널 시간과 글로벌 시간이 중층적으로 상호작용하면서 연계되어 있음을 확인할 수 있다.

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