• 제목/요약/키워드: Rising Time

검색결과 982건 처리시간 0.029초

The research on static and dynamic mechanical properties of concrete under the environment of sulfate ion and chlorine ion

  • Nie, Liangxue;Xu, Jinyu;Bai, Erlei
    • Computers and Concrete
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    • 제20권2호
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    • pp.205-214
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    • 2017
  • The Hydraulically driven test system and ${\Phi}100mm$ split Hopkinson pressure bar(SHPB) test device were employed to research the quasi-static and dynamic mechanical properties of concrete specimens which has been immersed for 60 days in sodium sulfate (group S1) and sodium chloride (group S2) solution, the evolution of their mass during corrosive period was explored at the same time, and the mechanism of performances lost was analyzed from the microscopic level by using scanning electron microscope. Results of the experimental indicated that: their law of mass both presents the trend of continuous rising during corrosive period, and it increases rapidly on the early days, the mass growth of group S1 and group S2 in first 7 days are 76.78% and 82.82% of their total increment respectively; during the corrosive period, the quasi-static compressive strength of specimens in two groups are significantly decreased, both of which present the trend of increase first and then decrease, the maximum growth rate of group S1 and group S2 are 7.52% and 12.71% respectively, but they are only 76.23% and 82.84% of specimens which under normal environment (group N) on day 60; after immersed for 60 days, there were different decrease to dynamic compressive strength and specific energy absorption, and so as their strain rate sensitivities. So the high salinity environment has a significant effect of weaken the quasi-static and dynamic mechanical performance of concrete.

CUDA를 이용한 Convolutional Neural Network의 효율적인 구현 (Efficient Implementation of Convolutional Neural Network Using CUDA)

  • 기철민;조태훈
    • 한국정보통신학회논문지
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    • 제21권6호
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    • pp.1143-1148
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    • 2017
  • 현재 인공지능과 딥 러닝이 사회적인 이슈로 떠오르고 있는 추세이며, 다양한 분야에 이 기술들을 응용하고 있다. 인공지능 분야의 여러 알고리즘들 중에서 각광받는 방법 중 하나는 Convolutional Neural Network이다. Convolutional Neural Network를 적은 양의 데이터에서 이용하거나, Layer의 구조가 복잡하지 않은 경우에는 학습시간이 길지 않아 속도에 크게 신경 쓰지 않아도 되지만, 학습 데이터의 크기가 크고, Layer의 구조가 복잡할수록 학습시간이 상당히 오래 걸린다. 이로 인해 GPU를 이용하여 병렬처리를 하는 방법을 많이 사용하는데, 본 논문에서는 CUDA를 이용한 Convolutional Neural Network를 구현하였으며, 비교에 사용한 Framework/Program들 보다 학습속도가 빨라지고 큰 데이터를 학습 시키는데 더욱 효율적으로 진행하도록 한다.

Developing a semi-automatic data conversion tool for Korean ecological data standardization

  • Lee, Hyeonjeong;Jung, Hoseok;Shin, Miyoung;Kwon, Ohseok
    • Journal of Ecology and Environment
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    • 제41권3호
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    • pp.78-84
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    • 2017
  • Recently, great demands are rising around the globe for monitoring and studying of long-term ecological changes. To go with the stream, many researchers in South Korea have attempted to share and integrate ecological data for practical use. Although some achievements were made in the meantime, we still have to overcome a big obstacle that existing ecological data in South Korea are mostly spread all over the country in various formats of computer files. In this study, we aim to handle the situation by developing a semi-automatic data conversion tool for Korean ecological data standardization, based on some predefined protocols for ecological data collection and management. The current implementation of this tool works on only five species (libythea celtis, spittle bugs, mosquitoes, pinus, and quercus mongolica), helping data managers to quickly and efficiently obtain a standardized format of ecological data from raw collection data. With this tool, the procedure of data conversion is divided into four steps: data file and protocol selection step, species selection step, attribute mapping step, and data standardization step. To find the usability of this tool, we utilized it to conduct the standardization of raw five species data collected from six different observatory sites of Korean National Parks. As a result, we could obtain a common form of standardized data in a relatively short time. With the help of this tool, various ecological data could be easily integrated into the nationwide common platform, providing broad applicability towards solving many issues in ecological and environmental system.

Influence of Sustain Pulse-Width on the Electrical and Optical characteristics in AC-PDPs

  • Jeong, Y.W.;Cho, T.S.;Kim, T.Y.;Choi, M.C.;Ahn, J.C.;Jeong, J.M.;Lim, J.Y.;Choi, S.H.;Chong, M.W.;Kim, S.S.;Ko, J.J.;Kim, D.I.;Lee, C.W.;Kang, S.O.;Cho, G.S.;Choi, E.H.
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 디스플레이 광소자 분야
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    • pp.155-158
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    • 2000
  • Influence of sustain pulse-width on electro-luminous efficiency is experimentally investigated for surface discharge of AC-PDP. A square pulse with variable duty ratio and rising time of 300 ns has been used in the experiment. It is found that the firing voltage is decreased as the pulse-width is increased from 2 ${\mu}s$ to 8 ${\mu}s$ with sweeping frequency range of 10 kHz to 50 kHz. It has been found that the optimal sustain pulse-width is in the range of $3{\sim}4{\mu}s$ under driving frequency range of 30 kHz and 50 kHz, based on observation of memory coefficient, wall charge, and wall voltage as well as luminous efficiency.

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유교적 가족윤리의 해체 전기(前期: 1880년대 초부터 1919년 3.1 운동이전까지)에 있어서의 가족윤리 실상 (The State of the Family Ethics in the Period of the Early Deconstruction of Confucian Family Ethics (From the Beginning of 1880's to the 3.1 movement of 1919))

  • 이정덕
    • 대한가정학회지
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    • 제38권7호
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    • pp.133-152
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    • 2000
  • This study was inquire into the state of the family ethics during the period of the beginning of 1880′s to the 3.1 independence movement of 1919 which has been the black period in the history of Korean family ethics. The research was conducted by analyzing the newspapers, magazines, related literature and articles of the period. It was the beginning of the 1860′s and by the "Cheondo-Kyo" (the Religion of the Heavenly) way that the issues regarding the equality of sexes as the central concern of the modem family ethics came to be the object of the social discourse for the first time in Korean history. The social discourse had come to be positively activated around 1900, when the intellectuals of the "Korean enlightenment" had begun to the feel necessity of the modernization of Korean socialite and the importance of the women education as the essential part of it. However, the activation of the social discourse itself, especially with the newspapers of that period did not mean the changes of the traditional Confucian family ethics, but the discourse of the modernizing forces had become the seeds for changing the family ethics of the Korean people. The made chauvinistic nature of the family ethics of the period was not so much different from those of the preceeding patriarch societies, but the state of the family ethics during the period are characterized by several social phenomenon such as the rising needs of using the "Hangle"(Korean alphabet) instead of Chinese character for the equal education of the both sexes, increasing practices of the early marriage, customs of trade marriage in accordance with the demand of excessive weeding presents, and regarding social consciousness of the traditional family ethics as patriotics attitude against the Christian rejection of the ancestor worship ritual.

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온침 시술 시 생체 조직 내 열분포 분석에 관한 연구 (Thermal Distribution in Living Tissue during Warm Needling Therapy)

  • 김종연;이종수
    • 한방재활의학과학회지
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    • 제24권3호
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    • pp.111-119
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    • 2014
  • Objectives This study aims to analyze a thermal distribution in biological living tissue during warm needling therapy by using a finite element method. The analysis provides an understanding of warm needling's efficacy and safety. Methods A model which consisted of four-layered tissue and stainless steel needle was adopted to analyze the thermal distribution in living tissue with a bioheat transfer analysis. The governing equation for the analysis was a Pennes' bioheat equation. A heat source characteristic of warm needling therapy was obtained by previous experimental measurements. The first analysis of the time-dependent temperature distribution was conducted through points on a boundary between the needle and the tissue. The second analysis was conducted to visualize the horizontal temperature distribution. Results When heat source's peak temperatures was above $500^{\circ}C$ and temperature rising rates were relatively slow, the peak temperature at skin surface exceeded a threshold of pain and tissue damage ($45^{\circ}C$), whereas when the peak temperature was around $400^{\circ}C$, the peak temperature at the skin surface was within a safe limit. In addition, the conduction of combustion energy from the moxa was limited to the skin layer around the needle. Conclusions The results suggest that the skin layer around the needle can be heated effectively by warm needling therapy, but it appears to have little effect at the deeper tissue. These findings enhance our understanding of the efficacy and the safety of the warm needling therapy.

철근공사의 공장가공 현황분석과 활성화 방안 (Analysis of re-bar manufacturing system in plant and its facilitate method)

  • 조훈희;강태경;박현용;윤석헌;허영기;박우열
    • 한국건설관리학회논문집
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    • 제8권1호
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    • pp.57-65
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    • 2007
  • 철근 공장가공은 현장가공에 비하여 가공의 정밀도를 향상시킬 수 있을 뿐 아니라 철근의 절단 손실을 줄일 수 있는 장점이 있다. 최근 도심지 공사의 증가로 야적장이 부족하고 숙련된 현장 노무인력의 확보가 어려워짐에 따라 향후 철근의 공장가공 방식은 점차 확대될 것으로 예상된다. 본 연구에서는 철근가공 공장방식의 중요성을 인지하고 그간의 연구들이 배근작업과 전문건설업체를 중심으로 이루어졌다는 점에 착안하여 18개 철근가공 공장을 대상으로 실태조사를 실시하였다. 실태조사 결과를 토대로 철근공장가공 활성화를 위한 방안으로 철근가공 형상 표준화, 시공성이 반영된 배근상세도 작성 및 철근 가공형상표 산출 업무 전산화, 배근작업의 표준화와 ADC기반의 철근자재 추적시스템을 개발을 제안하였다.

Kitan 해협의 유동 및 수질구조에 관한 연구 (A Study on the structures of flow and water quality in the Kitan strait)

  • 허재영;김한구
    • 한국해안해양공학회지
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    • 제15권4호
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    • pp.259-268
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    • 2003
  • Kitan 해협을 포함하는 Seto내해(inland sea)에서는 COD, 인 등에 관한 총량규제가 실시됨에도 불구하고 적조현상과 빈산소 수괴 현상이 매년 발생하고 있는데, 그 원인으로서 저니로부터의 용출과 부영양화에 따른 1차 생산의 증가가 주목되고 있다 또한 최근의 조사결과는 수질오염의 원인이 되는 질소와 인과 같은 영양염이 육지뿐만 아니라 태평양으로부터도 유입되고 있다는 것을 보여주고 있다. 본 연구에서는 Osaka만과 Kii수로를 연결하는 Kitan해협에 있어서 유동구조와 물질수송구조의 실태를 명확히 밝히기 위해 현지관측을 실시하였으며, 기 출판된 자료와 함께 연구대상 해역의 오염원인을 규명하고자 하였다. 현지조사는 1999년부터 2002년 사이에 걸쳐 실시되었으며, 자료의 획득은 각 계절을 대표하는 2월, 5월, 8월, 11월에 각각 이루어졌다.

석회암 내 방사상 발파균열을 예측하기 위한 동적파괴과정 해석법의 입력물성 결정법에 관한 연구 (Determining Parameters of Dynamic Fracture Process Analysis(DFPA) Code to Simulate Radial Tensile Cracks in Limestone Blast)

  • 김현수;강형민;정상선;김승곤;조상호
    • 화약ㆍ발파
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    • 제31권2호
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    • pp.6-13
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    • 2013
  • 최근 채석장 및 광산의 파쇄설비로부터 발생되는 소음 및 분진에 의한 민원과 환경적인 문제가 대두되고 있으며, 이러한 파쇄설비를 지하공동으로 옮기는 사례가 증가하고 있다. 파쇄설비 및 가공시설을 갱내에 설치하기 위해서는 넓은 공간의 굴착이 이루어져야 하고, 대형공동 주변암반의 안정성이 확보되어야 한다. 지하공동 주변암반의 안정성은 굴착 시공 시 발생되는 굴착손상영역과 밀접한 관계가 있어, 최종파단면을 형성시키는 최외곽 발파공에 대한 정밀한 설계가 필요하다. 본 연구에서는 석회석 지하광산에서 대형공동 및 영구갱도 굴착시 발생 가능한 발파균열길이 및 손상영역을 예측하기 위한 수치해석기법을 제안하였다. 먼저 석회암블록에 대한 발파실험을 수행하고 발생된 인장균열수 및 길이를 분석하여, 동적파괴과정해석코드의 주요 입력변수인 평균 미시적 인장강도를 결정하였다.

녹색성장을 위한 기능성 재킷의 프로토타입에 관한 연구 (A Study of a Prototype Functional Jacket for Green Growth)

  • 김미현;김선영
    • 한국의류학회지
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    • 제35권1호
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    • pp.104-114
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    • 2011
  • There is rising interest in green energy, energy efficient equipment, and products as countries show increased interest in 'Low Carbon and Green Growth'. The cellphone has become one of the essential influences on modem people beyond the meaning itself by the release and the commercialization of the Smartphone. Thus, it considers that the introduction of fashion for cellphones and digital devices to be always on should be a quite natural design attempt for humans to wear clothes at all times. In addition, outdoor activities increase as the population enjoys more sports and leisure time that requires the development of specialized outwear such as the development of a functional jacket. This specialized field is associated with higher value-added businesses. This study made a prototype of a functional jacket equipped with solar cells that established a system of a fashion design that is harmonious with green growth as a plan to measure of fashion design for green growth. The objects of this study are as follow: First, the study seeks a design method for green growth. Second, it makes a prototype to present the improved design method. Third, it presents the establishment of a design system that considers green growth and the concrete measures practical for the system. It established the design system and made the prototype of functional jacket equipped with solar cells, LED, and digital devices as a measure of design for green growth based on the improvement plan of the design that the problems had been supplemented for. Previous studies were mainly about prototypes that attempted to equip mobile digital devices as a study of smart wear; however, this study leaves the issue of power supply for a follow-up study that is different from preceding studies.