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공법의 개발 접근방법

  • 김문한
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2003년도 학술.기술논문발표회
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    • pp.1001-1004
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    • 2003
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전단지연 이론을 이용한 단섬유 형태의 SMA 보강 고분자 복합재료의 열변형 거동 해석 (Thermo-Mechanical Behavior of Short SMA Reinforced Polymeric Composite Using Shear tag Theory)

  • 정태헌;이동주
    • 대한기계학회논문집A
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    • 제23권6호
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    • pp.1001-1010
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    • 1999
  • Thermo-mechanical behavior of discontinuous shape memory alloy(SMA) reinforced polymeric composite has been studied using modified shear lag theory and finite element(FE) analysis with 2-D multi-fiber model. The aligned and staggered models of short-fiber arrangement are employed. The effects of fiber overlap and aspect ratio on the thermomechanical responses such as the thermal expansion coefficient are investigated. It is found that the increase of both tensile stress(resistance stress) in SMA fiber and compressive stress in polymer matrix with increasing aspect ratio is the main cause of low thermal deformation of the composite.

The Change of Water Quality In Osaka Bay during Recent 70 Years

  • Han, Dong-Jin;Yoon, Jong-Sung
    • 한국환경과학회지
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    • 제13권11호
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    • pp.1001-1007
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    • 2004
  • The rapid industrialization and urbanization in Osaka Bay have produced many serious water pollution problems since the 1960s. A symbolic phenomenon is algae bloom (red tide), which occurred 53 times in 1976. The special law was enacted in 1973 and a number of administrative steps were taken, such as cutting COD loading, reductions in phosphorus (P) and restriction of land reclamation. As a result, the pollution of Osaka Bay has gradually been reduced, and the environment has been improved to some extent. In this study, to analyze the relations between water qualities as well as a social, economic activity by the coastal zone, the water quality data in Osaka Bay of 70 years past since 1921 were collected. Data such as population, livestock, fertilizer, industrial product etc. were also collected for estimating nutrients flowing into bay from land. It was found that the water quality was changed of a similar trend of estimated nutrients load, with delay of about four or five years.

단기 측정용 오존 간이 측정기의 실험 챔버 내에서 성능에 관한 연구 (A Study on the Performance of a Short Term Ozone Passive Sampler in Experimental Chamber)

  • 정상진
    • 한국환경과학회지
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    • 제16권8호
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    • pp.1001-1009
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    • 2007
  • Passive sampler is a simple and cost-effective measuring equipment for ambient and indoor air pollution. We studied the performance of a short term (1 hour mean concentration) ozone passive sampler which was coated with a colorant (indigo carmine) to a filter substrate. Acetone and sulfamic acid added ozone passive sampler was investigated to measure short term mean ozone concentration. Ozone response and interference of criteria air pollutant($SO_2,\;NO_2$, CO) on a short term ozone passive sampler was tested through experimental chamber. The results show sulfamic acid added passive ozone sampler have good response in ozone exposure. Interference of $NO_2$ gas is larger than other two criteria gases.

영이 아닌 DC값을 가지는 Discrete Cosine Transform을 이용한 CT Reconstruction (CT Reconstruction using Discrete Cosine Transform with non-zero DC Components)

  • 박도영;유훈
    • 전기학회논문지
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    • 제63권7호
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    • pp.1001-1007
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    • 2014
  • This paper proposes a method to reduce operation time using discrete cosine transform and to improve image quality by the DC gain correction. Conventional filtered back projection (FBP) filtering in the frequency domain using Fourier transform, but the filtering process uses complex number operations. To simplify the filtering process, we propose a filtering process using discrete cosine transform. In addition, the image quality of reconstructed images are improved by correcting DC gain of sinograms. To correct the DC gain, we propose to find an optimum DC weight is defined as the ratio of sinogram DC and optimum DC. Experimental results show that the proposed method gets better performance than the conventional method for phantom and clinical CT images.

스마트 기기에서 유해 멀티미디어 콘텐츠 판별 메커니즘 및 성능 분석 (Study for Injurious Multimedia Contents Analysis Mechanism in Smart Devices)

  • 민순호;김석우;하경주;서창호
    • 정보보호학회논문지
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    • 제23권6호
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    • pp.1001-1006
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    • 2013
  • 본 논문에서는 최근 스마트폰과 지능형 로봇 분야에서 급속도로 확산되고 있는 유해 멀티미디어의 유해성을 판별하기 위해 유해정보 판별 메커니즘 및 판별 메커니즘 성능 분석에 대해서 설명한다. 이러한 판별 기술들을 기반으로 멀티미디어(이미지, 비디오) 기반의 개별 유해 특징 요소를 정의한다. 또한 시각적 특징을 모델링하여 유해 멀티미디어 콘텐츠의 유해성을 분석한다.

NPVSS-NLMS 알.고리즘과 온라인 선형 피드백 경로 모델링을 이용한 비선형 능동 소음 제어 (Nonlinear ANC using a NPVSS-NLMS algorithm and online modelling of an acoustic linear feedback path)

  • 서재범;남상원
    • 전기학회논문지
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    • 제59권5호
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    • pp.1001-1004
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    • 2010
  • Acoustic feedback and background noise variation can degrade the performance of an active noise control (ANC) system. In this paper, nonlinear ANC using a non-parametric VSS-NLMS (or NPVSS-NLMS) algorithm and online feedback path modeling is proposed, whereby the conventional linear ANC with online acoustic feedback-path modeling is further extended to nonlinear Volterra ANC with a linear acoustic feedback path. In particular, the step-size of the NPVSS-NLMS algorithm is controlled to reduce the effect of background noise variation in the ANC system. Simulation results demonstrate that the proposed approach yields better nonlinear ANC performance compared with the conventional nonlinear ANC method.