• Title/Summary/Keyword: 반복정도

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2006년도 외항해운업계 주요 국내외 뉴스

  • Korea Shipowners' Association
    • 해운
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    • no.12 s.34
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    • pp.13-17
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    • 2006
  • 매년 연말에 가서 한해를 돌아보면, 다사다난하지 않았던 해가 없을 정도로 1년 동안에 많은 일들이 일어나고 잊혀지기를 반복한다. 2006년 한해에도 국내외에서 크고 작은 일들이 일어났으며, 이러한 일들이 신문지면을 장식했다. 지난 신문들을 들춰보면서 외항해운업계의 주요이슈들을 정리해 본다. (편집자 주)

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A Comparative Study on Formulation of Three-Dimensional Elastic-Plastic Finite Deformation Analysis for Prediction Large Deflection (강부재의 대변형 예측을 위한 3차원 탄소성 유한변위해석의 정식화에 대한 비교연구)

  • Jang, Gab-Chul;Chang, Kyong-Ho
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.4 s.22
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    • pp.53-61
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    • 2006
  • In th is paper, to predicting the large deformation and cyclic plastic behavior of steel members under loading, 3-Dimensional elastic-plastic FE analysis method is developed by using finite deformation theory and proposed cyclic plasticity model. finite deformation theory, described the large deformation, is formulated by using Updated-lagrangian formulation and Green's strain tensor, Jaumann's derivative of Kirchoff stress. Also, cyclic plasticity model proposed by author is applied to developed analysis method. To verification of developed analysis method, analysis result of steel plate specimen compare to the analysis result using infinitesimal deformation theory and test result. Also, load-displacement and deflection shape, analysis result of pipe-section steel column, compare to test result. The good agreement between analysis result and experiment result shown that developed 3-dimensional finite element analysis can be predict the large deformation and cyclic plastic behavior of steel members.

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Motion Adaptive Temporal Noise Reduction Filtering Based on Iterative Least-Square Training (반복적 최적 자승 학습에 기반을 둔 움직임 적응적 시간영역 잡음 제거 필터링)

  • Kim, Sung-Deuk;Lim, Kyoung-Won
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.5
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    • pp.127-135
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    • 2010
  • In motion adaptive temporal noise reduction filtering used for reducing video noises, the strength of motion adaptive temporal filtering should be carefully controlled according to temporal movement. This paper presents a motion adaptive temporal filtering scheme based on least-square training. Each pixel is classified to a specific class code according to temporal movement, and then, an iterative least-square training method is applied for each class code to find optimal filtering coefficients. The iterative least-square training is an off-line procedure, and the trained filter coefficients are stored in a lookup table (LUT). In actual noise reduction filtering operation, after each pixel is classified by temporal movement, simple filtering operation is applied with the filter coefficients stored in the LUT according to the class code. Experiment results show that the proposed method efficiently reduces video noises without introducing blurring.

Synthesis of PVA/PVP Hydrogel by Irradiation Crosslinking (방사선 가교에 의한 PVA/PVP 하이드로겔 제조 및 드레싱에의 응용)

  • 김태훈;노영창
    • Polymer(Korea)
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    • v.25 no.2
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    • pp.270-278
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    • 2001
  • Hydrogels for wound dressing were manufactured using poly(vinylalcohol)(PVA) and poly(N-vinylpyrrolidone)(PVP). The hydrogels were obtained by exposing to $^{60}$ Co${\gamma}$-rays after freezing and thawing of aqueous solutions of PVA and PVP to improve mechanical strength. Mechanical properties such as gelation, water absorptivity and gel strength were examined after repeating the \"freezing and thawing\" of PVA/PVP hydrogels, and then irradiating them at 40 kGy. The PVA/PVP ratio was in the range of 30:70 ~ 100:0, and the solid concentration of PVA/PVP was 20 wt%. The gelation and strength of hydrogels were much higher when \"freezing and thawing\" and the irradiation process were used than when only the irradiation process was utilized. In addition, the mechanical properties of PVA/PVP hydrogels after repetition of \"freezing and thawing\" are discussed. thawing\" are discussed.ssed.

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The Effect of Repetitive Compression on the Fatigue Properties of Foam for Footwear Mid-sole (반복압축이 스포츠화용 발포체의 피로특성에 미치는 영향)

  • Park, Cha-Cheol
    • Elastomers and Composites
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    • v.40 no.4
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    • pp.242-248
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    • 2005
  • To study the fatigue properties of three type of foams for footwear midsole, polyurethane(PU), phylon(PH) and injection phylon(IP) foams were prepared with different hardnesses. Three types of foams were repetitively compressed for 50,000 cycles at 50 rpm. Cell shapes of foams were deformed with repetitive compression. The extent of cell deformation of IP was larger than those of PH and PU. Permanent strain of foam was made by repetitively compressing the foam, and the extent of IP was larger than those of PU and PH. Maximum compression forces of three types of the foams were decreased with the repetitive compression, and IP had the largest decrease in compression load of foam with compression. Decreases in maximum compression force of three types of foams were increased with increase of the hardness of foam.

Changing Adaptive Behaviors of TV Drama Producers (환경변화에 따른 TV드라마 제작자의 적응행동변화)

  • Limb, Seong-Joon;Lee, Choonkeun;Choo, Seungyoup
    • The Journal of the Korea Contents Association
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    • v.12 no.12
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    • pp.627-638
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    • 2012
  • This study empirically examines the concept of dynamic capability to recombine the resources such as directors, writers, and actors in the TV drama industry which is one of the most knowledge-based and project-based organizations. Based on the extant literature, it is argued that an organization's usage pattern of critical resources could partly reflect its dynamic capability. This study attempted to verify the hypothesis that Korean TV drama producers would utilize the same resources less repeatedly in the period with more uncertain environment(2003-2009) than the period with more stable and predictable environment(1994-2002). Empirical results partially support the hypothesis, verifying that there are different usage patterns in employing directors between the two periods but that is not the case in employing writers and actors. Such results imply that project-based organizations repeatedly use the same resources in order to pursue efficiency in stable environments whereas they tend to use a variety of different resources in order to adapt to uncertain environments.

Channel Coding Algorithm using Absolute Mean Values for the Difference Values of Soft Output in Digital Mobile Communication System (디지털 이동통신 시스템에서 연판정 출력의 차이값에 대한 절대평균값을 이용한 채널부호화 알고리즘)

  • Jeong, Dae-Ho;Kim, Hwan-Yong;Lim, Soon-Ja
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.10
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    • pp.67-74
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    • 2007
  • Turbo code, a kind of channel coding technique, has ben used in the field of digital mobile communication system if the number of iterations is increased in the several channel environments, my further iteration results in very little improvement, and requires much delay and computation in proportion to the number of iterations. In this paper, it proposes an efficient stopping rules for the iteration process in turbo decoding. By using absolute mean values for the LLR difference values between the first and second decoder in the present decoding process, the proposed algorithm can largely reduce the average number of iterations without BER performance degradation in all SNR regions. As a result of simulation, the average number of iterations of proposed algorithm is reduced by about $18.25%{\sim}20.58%$ compared to SDR algerian in the lower SNR region, and is reduced by about $22.96%{\sim}28.74%$ compared to method using variance values of extrinsic information in the upper SNR region.

Study on Simple Repetitive Work and the Risks of Musculoskeletal Injuries (단순반복 작업유형별 근골격계 질환 발생특성과 예방 대책에 관한 연구)

  • 임완희
    • Journal of Korea Society of Industrial Information Systems
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    • v.9 no.1
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    • pp.24-35
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    • 2004
  • According to the results of this study, we found through preliminary research that most of the workers studied suffered from some sort of musculoskeletal injury, but did not obtain hospital treatment, which shows that although their work was the source of injury, they did not realize the significance of their injury. In addition, there were some subjects that did not even know what musculoskeletal injuries were and in order to solve such problems, companies need to educate their workers about musculoskeletal injuries and show the significance of the injuries. Also, there was a difference in rates of musculoskeletal injuries in different occupations, with higher rates of injury in esthetics, driving and packaging positions. This calls for the use of automated machinery and alteration of the working environment to make it more ergonomic according to the recommended improvement plan, and continuous effort and support on the part of the company in order to reduce the risk of musculoskeletal injuries.

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Efficient Iteration Control Method with low complexity and New Interleaver for Turbo Codes (터보 부호에서 낮은 복잡도를 갖는 효율적인 반복부호 제어기법과 새로운 인터리버)

  • 김순영;장진수;성락주;이문호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.8A
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    • pp.1254-1264
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    • 2000
  • In this paper, we propose a new turbo interleaver and an efficient iteration control method with low complexity for turbo decoding. Turbo codes has better performance as the number of iteration and the interleaver size increases. However, as the interleaver size is increased, it require much delay and computation for decoding. Thus we propose a new efficient turbo magic interleaver using the Magic square matrix. Simulation results show that the proposed interleaver realizes a good performance like GF, Mother interleaver proposed to IMT-2000. And as the decoding approaches the performance limit, any further iteration results in very little improvement. Therefore, we propose an efficient algorithm of decoding that can reduce the delay and computation. Just like the conventional stop criterion, it effectively stop the iteration process with very little performance degradation.

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Cyclic Hardening and Degradation Effects on Site Response during an Earthquake (지진시 지반의 반복경화/연화 현상에 의한 부지응답 특성 영향 연구)

  • Lee, Jin-Sun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.6
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    • pp.65-71
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    • 2008
  • A one-dimensional site response analysis program (KODSAP) was developed using cyclic soil behavior model by using the modified parallel IWAN model. The model is able to predict the cyclic hardening and degradation of soil through the adjustment of the internal slip stresses of its elements beyond the cyclic threshold, and satisfies Bauschinger's effect and the Masing rule in terms of its own behavior characteristics. The program (KODSAP) used the direct integration method in the time domain. The elasticity of the base rock was considered as a viscous damper boundary condition. The effects of cyclic hardening or degradation of soil on site response analysis were evaluated through parametric studies. Three types of analyses were performed to compare the effect of analysis and cyclic parameter on site response. The first type was equivalent linear analysis, the second was nonlinear analysis, and a third was nonlinear analysis using the cyclic hardening or degradation model.