• Title/Summary/Keyword: Joint property

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Development of a Vision System for the Measurement of the Pendulum Test (진자검사 계측을 위한 영상 시스템의 개발)

  • Kim, Chul-Seung;Moon, Ki-Wook;Lee, Soo-Young;Eom, Gwang-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.4
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    • pp.817-819
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    • 2007
  • The purpose of this work is to develop a measurement system of the pendulum test with minimal restriction of experimental environment and little influence of noise. In this work, we developed a vision system without any line between markers and a camera. The system performance is little influenced by the experimental environment, if light are sufficient to recognize markers. For the validation of the system, we compared knee joint angle trajectories measured by the developed system and by the magnetic sensor system during the nominal pendulum test and the maximum speed voluntary knee joint rotation. The joint angle trajectories of the developed system during both tests matched well with those of the magnetic system. Therefore, we suggest the vision system as an alternative to the previous systems with limited practicality for the pendulum test.

Watertightness Property Evaluation of Rain-Block System (개폐식 대공간 구조물에서 지붕 맞댐부 우수차단 시스템의 수밀성 평가에 관한 연구)

  • Kim, Yun-Ho;Baek, Ki-Youl;Kim, Jong-Su;Lee, Sun-Gyu;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.13-16
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    • 2010
  • This study is an Investigation on the Watertightness Properties of Rain-Block System on the Sliding-Roof Joint of Large-Span Membrane Structures. In this experimental, we test the watertightness performance of joint part of sliding door in roof of large span membrane structure(for pilot project) under environment of rain and wind. A shape of rain water blocking systems of joint part in sliding door verifies the defects and effects of water leakage prevention in precipitation with the wind conditions. For obtaining watertightness of large span membrane structures, it is necessary quality of joints and performance, and quality of membrane material of a retractable roof as well as a closed roof. Also, for obtaining quality in joints, it is essential to make a watertightness guideline for design of large-span membrane.

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A Study on Biomimetic Composite for Design of Artificial Hip Joint (인공 관절 설계를 위한 바이오미메틱 복합재료에 관한 연구)

  • 김명욱;윤재륜
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 1999.11a
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    • pp.234-238
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    • 1999
  • This study suggests the design of the functionally gradient composite, [0/90/0/core]$_s$ cross-ply laminate, to prevent stress concentration induced from the difference of rigidity between the bone and the artificial hip joint and to reinforce the wear property of the surface and the expectation of their mechanical properties. First, the four-point bending test is done about wet bones and dry bones to know the mechanical properties of the cortical bones. In result, the wet bone shows the viscoelastic behavior and the dry bone shows the elastic behavior. Moreover, we expect the properties of the proposed gradient composites as a function of carbon fiber volume fraction in each layer to apply Halpin-Tsai equation, CLPT(classical laminate plate theory), and Bernoulli beam theory etc. and decide the thickness ratio of each lamina in order to match Young's modulus of the anisotropic cortical bone with the proposed gradient composites.

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Overlapped Subband-Based Independent Vector Analysis

  • Jang, Gil-Jin;Lee, Te-Won
    • The Journal of the Acoustical Society of Korea
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    • v.27 no.1E
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    • pp.30-34
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    • 2008
  • An improvement to the existing blind signal separation (BSS) method has been made in this paper. The proposed method models the inherent signal dependency observed in acoustic object to separate the real-world convolutive sound mixtures. The frequency domain approach requires solving the well known permutation problem, and the problem had been successfully solved by a vector representation of the sources whose multidimensional joint densities have a certain amount of dependency expressed by non-spherical distributions. Especially for speech signals, we observe strong dependencies across neighboring frequency bins and the decrease of those dependencies as the bins become far apart. The non-spherical joint density model proposed in this paper reflects this property of real-world speech signals. Experimental results show the improved performances over the spherical joint density representations.

Entropy and Average Mutual Information for a 'Choseong', a 'Jungseong', and a 'Jongseong' of a Korean Syllable (한글 음절의 초성, 중성, 종성 단위의 발생확률, 엔트로피 및 평균상호정보량)

  • 이재홍;오상현
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.9
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    • pp.1299-1307
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    • 1989
  • A Korean syllable is regarded as a random variable according to its probabilistic property in occurrence. A Korean syllable is divided into a 'choseong', a 'jungseong', and a 'jongseong' which are regarded as random variables. From the cumulative freaquency of a Korean syllable all possible joint probabilities and conditional probabilities are computed for the three ramdom variables. From the joint probabilities and the conditional probabilities all possible joint entropies and conditional entropies are computed for the three random varibles. Also all possible average mutual informations are calculated for the three random variables. Average mutual informatin between two random variables hss its biggest value between choseong and jungseong. Average mutual information between a random variable and other two random variables has its biggest value between jungseong and choseong-jongseong.

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Microstructures and mechanical properties with the different Sc content of AA2519 FSW joint (스칸듐(Sc) 함량이 다른 2519 알루미늄 합금 마찰교반접합부의 미세조직 및 기계적 특성)

  • Lee, Chang-Yong;Choe, Don-Hyeon;Pyo, Seong-Eun;Yeon, Yun-Mo;Jeong, Seung-Bu
    • Proceedings of the KWS Conference
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    • 2007.11a
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    • pp.345-347
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    • 2007
  • The microstructures and mechanical properties with the different Sc content of AA2519 FSW joint were investigated in this study. The sound FSW joints were obtained under applied all welding conditions such as the Sc content and the tool rotation speed. The grain size of the stir zone decreased slightly with increasing the Sc content. And the ultimate tensile strength increased and elongation decreased with increasing the Sc content. The intermetallic compound contained the Sc is considered to bring out the improvement of mechanical property in FSW joint.

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A Study on the Alternative Method of Video Characteristics Using Captioning in Text-Video Retrieval Model (텍스트-비디오 검색 모델에서의 캡션을 활용한 비디오 특성 대체 방안 연구)

  • Dong-hun, Lee;Chan, Hur;Hyeyoung, Park;Sang-hyo, Park
    • IEMEK Journal of Embedded Systems and Applications
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    • v.17 no.6
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    • pp.347-353
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    • 2022
  • In this paper, we propose a method that performs a text-video retrieval model by replacing video properties using captions. In general, the exisiting embedding-based models consist of both joint embedding space construction and the CNN-based video encoding process, which requires a lot of computation in the training as well as the inference process. To overcome this problem, we introduce a video-captioning module to replace the visual property of video with captions generated by the video-captioning module. To be specific, we adopt the caption generator that converts candidate videos into captions in the inference process, thereby enabling direct comparison between the text given as a query and candidate videos without joint embedding space. Through the experiment, the proposed model successfully reduces the amount of computation and inference time by skipping the visual processing process and joint embedding space construction on two benchmark dataset, MSR-VTT and VATEX.

Effect of shield gas on the characteristics of $CO_2$ laser welded 600MPa grade high strength steel (600MPa급 자동차용 고장렬강판의 $CO_2$ 레이저 용접부의 특성에 미치는 보호가스의 영향)

  • Han Tae-Kyo;Lee Bong-Keun;Kang Chung-Yun
    • Laser Solutions
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    • v.7 no.2
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    • pp.19-26
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    • 2004
  • The effect of shield gas on the weldability, mechanical properties and formability of CO2 laser weld joint in 600MPa grade high strength steel was investigated. Bead on plate welds were made under various welding speed and shield gas. Tensile test was carried out under the load of perpendicular and parallel direction to the weld line, Formability of the joint was evaluated by Erichsen test. As the welding speed increases, the porosity fraction decreases. The porosity fraction in the joint used Ar-$50\%He$ mixed gas as a shield gas was lower than that of the joint used Ar gas. Hardness at the weld metal of full penetrated joint was nearly equal to that of water quenched raw metal. In a tensile test under a perpendicular load to the weld axis, strength and elongation of joint produced by optimum condition were nearly equal to those of base metal. However, the strength of joint in a tensile test under a parallel load to weld axis was higher than that of raw metal, but the elongation of joint was lower than that of raw metal. Elongation and formability were further increased by the method of using Ar+He mixed gas as a shield gas as compared with Ar gas. Formabilities of joints were recorded ranging from $58\%\;to\;70\%$ of that of base metal with different shield gases.

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