• 제목/요약/키워드: Knowledge-Intensity

검색결과 232건 처리시간 0.028초

3차원 균열의 응력확대계수에 대한 해석의 자동화 (Automation of Analysis for Stress Intensity Factor of 3-D Cracks)

  • 이준성
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 춘계학술대회 논문집
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    • pp.496-500
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    • 1997
  • This paper describes an automated system for analyzing the stress intensity factors(SIFs) of three-dimensional (3D) cracks. A geometry model, i.e.a solid containing one or several 3D cracks is defined. Several distributions of local node density are chosen, and then automatically superposed on one another over the geometry model by using the fuzzy knowledge processing. Nodes are generated by the bucketing method, and ten-noded quadratic tetrahedral solid elements are generated by the Delauuay triangulation techniques. The singular elements such that the mid-point nodes near crack fornt are shifted at the quarter-points are automatically placed along the 3D crack front. THe complete finite element (FE) model generated, i.e the mesh with material properties and boundary conditions is given to one of the commercial FE codes, and a stress analysis is performed. The SIFs are calculated using the displacement extrapolation method. To demonstrate practical performance of the present system, a semi- elliptical surface crack in a plate subjected to tension is solved.

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복사 버너의 연소특성에 관한 실험적 연구 (An Experimental Study on Combustion Characteristics of Radiant Burner)

  • 위재혁;이대래;김영수;전충환
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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    • pp.19-25
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    • 2006
  • Energy efficient and low pollution combustion systems the use gaseous fuels have been in great demand in recent year. Radiant burner in many different forms are emerging as very desirable combustion systems for same reason. Porous radiant burners are used in drying, preheating and curing, and in other type of materials processing and manufacturing processes. However, little knowledge is available about the operating characteristics and the structure of flames in porous ceramic fiber radiant burners. The objective of the present work is to investigate the global performance characteristics of the ceramic fiber burner. A detailed study which includes the spectral intensity, gas temperature, radiation efficiency and global pollutant emissions. Another objective is to study the flame structure of the ceramic fiber burner by measuring the local gas temperature. The results indicate that ceramic fiber burner do offer a 19-44% gain in radiant efficiency. The ceramic fiber burner exhibit significant spectral intensity peaks in the band at $2.0-2.5{\mu}m$. The local temperature distribution inside the mat and near the mat surface as a function of the equivalence ratio can be reasonably interpreted by the relation of the heat balance in the mat and movement of the reaction zone. Nox emission from ceramic fiber burner is less than 25ppm throughout the operating range.

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산간분지에서 주택밀도의 결정인자로서 태양광도의 영향력 평가 (Evaluating Explanatory Power of Solar Intensity as Determining Factor of Housing Density in Intermontane Basin)

  • 엄정섭
    • 한국지역지리학회지
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    • 제15권6호
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    • pp.689-706
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    • 2009
  • 주택입지에 영향을 미치는 공간변수의 우선순위를 평가하는 과정은 일부 전문가의 경험과 직관에 의존해 온 것이 사실이다. 산간 분지에서 주택(134채)의 밀도와 태양광도 관련 공간변수의 상관성을 파악하기 위해 다중공간 회귀분석 기법이 활용되었다. 전통적인 이론에서 주택 입지를 설명하는 전형적인 변수인 고도, 경사, 도로에 대한 접근성 등은 주택밀도에 대한 영향력에서 주요 변수로서 역할을 하지 못하였다 동지의 일사량과 일조시간이 산간분지에서 주택밀도를 설명할 수 있는 결정적인 변수였다. 산간분지에서 주택 입지가 전통적인 이론에서 제시하는 고도, 경사 등 이상적인 지형특성보다는 그림자로 인한 음지를 피하는 것을 최우선 순위로 고려하는 것이 확인되었다.

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Effects of Material Modulus on Fracture Toughness of Human Enamel, a Natural Biocomposite

  • Mishra, Dhaneshwar;Yoo, Seung-Hyun
    • 비파괴검사학회지
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    • 제31권3호
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    • pp.287-293
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    • 2011
  • The enamel, the upper layer of a tooth has remarkable capability of bearing severe loading on the tooth. The fracture behavior is important to understand the mechanism of load bearing and it could be very useful for developing new materials. Non-destructive evaluation of such materials will also benefit from this knowledge. The graded microstructures of enamel were modeled by finite element analysis software and the J-integrals and the stress intensity factors were evaluated as the fracture parameters. The results show that these parameters are location dependent. Those values increase when measured in the direction of dentine enamel junction. This finding matched well with experiments and implies many useful understanding of biomaterials and applications to new materials.

Implementation of 2D Active Shape Model-based Segmentation on Hippocampus

  • Izmantoko, Yonny S.;Yoon, Ho-Sung;Adiya, Enkhbolor;Mun, Chi-Woong;Huh, Young;Choi, Heung-Kook
    • 한국멀티미디어학회논문지
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    • 제17권1호
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    • pp.1-7
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    • 2014
  • Hippocampus is an important part of brain which is related with early memory storage and spatial navigation. By observing the anatomy of hippocampus, some brain diseases effecting human memory (e.g. Alzheimer, schizophrenia, etc.) can be diagnosed and predicted earlier. The diagnosis process is highly related with hippocampus segmentation. In this paper, hippocampus segmentation using Active Shape Model, which not only works based on image intensity, but also by using prior knowledge of hippocampus shape and intensity from the training images, is proposed. The results show that ASM is applicable in segmenting hippocampus from whole brain MR image. It also shows that adding more images in the training set results in better accuracy of hippocampus segmentation.

Parametric Blind Restoration of Bi-level Images with Unknown Intensities

  • Kim, Daeun;Ahn, Sohyun;Kim, Jeongtae
    • IEIE Transactions on Smart Processing and Computing
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    • 제5권5호
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    • pp.319-322
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    • 2016
  • We propose a parametric blind deconvolution method for bi-level images with unknown intensity levels that estimates unknown parameters for point spread functions and images by minimizing a penalized nonlinear least squares objective function based on normalized correlation coefficients and two regularization functions. Unlike conventional methods, the proposed method does not require knowledge about true intensity values. Moreover, the objective function of the proposed method can be effectively minimized, since it has the special structure of nonlinear least squares. We demonstrate the effectiveness of the proposed method through simulations and experiments.

Wavelet based Feature Extraction of Human Face

  • Kim, Yoon-ho;Lee, Myung-kil;Ryu, Kwang-ryol
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2001년도 춘계종합학술대회
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    • pp.656-659
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    • 2001
  • Human have a notable ability to recognize faces, which is one of the most common visual feature in our environment. In regarding face pattern, just like other natural object, a geometrical interpretation of face is difficult to achieve. In this paper, we present wavelet based approach to extract the face features. Proposed approach is similar to the feature based scheme, where the feature is derived from the intensity data without detecting any knowledge of the significant feature. Topological graphs are involved to represent some relations between facial features. In our experiments, proposed approach is less sensitive to the intensity variation.

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A Study on the Market of Imported Medical Devices in Myanmar

  • Bae, Hong Kyun
    • 무역상무연구
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    • 제64권
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    • pp.213-237
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    • 2014
  • The medical-device market of Myanmar in the recent Asian region is where the influences of Thailand, China, India and Singapore are being shown considerably with the lift-up of economic sanctions by America and the West. However, although the global capital and liberalization have widened the openness and the international concerns, the relative Myanmar's medical environment demands an active assistance and improvement. The study, recognizing the importance of Medical-Devices and their market conditions emerging as key business for knowledge-based industry, aims to obtain consequential meaningful suggestions, pursuant to relative export-concentration and sustainable market growth of Medical Devices, by analyzing inter-nation trade intensity for key Medical Device items. To do so, this study selected 8 nations in total by reviewing three points: core Medicine-advanced countries, geographically adjacent countries to Myanmar, and relative export-concentration.

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Wavelet based Feature Extraction of Human face

  • Kim, Yoon-Ho;Lee, Myung-Kil;Ryu, Kwang-Ryol
    • 한국정보통신학회논문지
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    • 제5권2호
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    • pp.349-355
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    • 2001
  • Human have a notable ability to recognize faces, which is one of the most common visual feature in our environment. In regarding face pattern, just like other natural object, a geometrical interpretation of face is difficult to achieve. In this paper, we present wavelet based approach to extract the face features. Proposed approach is similar to the feature based scheme, where the feature is derived from the intensity data without detecting any knowledge of the significant feature. Topological graphs are involved to represent some relations between facial features. In our experiments, proposed approach is less sensitive to the intensity variation.

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철도레일의 파괴 및 피로에 대한 안전도평가 및 잔류수명계산 (The Evaluation of Safety and Remaining Life on Fracture and Fatigue in Rail Steel)

  • 박용걸
    • 한국안전학회지
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    • 제10권2호
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    • pp.120-128
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    • 1995
  • The fatigue failure of rail is a principal source of derailment accidents. The reduction of fatigue failures can be achieved by Intensive track maintenance and periodic safety assessments for the railway. For the safety assessments, it is required to have more accurate knowledge for fatigue behavior such as the crack initiation, propagation, crack growth rate and the remaining service life in rail. In this paper, the mean stress effects for the fatigue behavior of rail steel are studied. For this study, the fatigue test is conducted and some equations for fatigue evaluation are applied and compared. From the results, we can see that the fatigue crack growth rate is the more increased as the men stress Is the more increased, the mean stress effect is represented well by the combination of stress intensity factor range and maximum stress intensity factor and Crooker and Range's equation represented by ${\Delta}K, K_{max}$ is the best fit for fatigue evaluation and safety assessment of rail.

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