• Title/Summary/Keyword: rational curves

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Strength of Reinforced Concrete Members in Pure Torsion (순수(純粹)비틀림을 받는 철근(鐵筋)콘크리트 부재(部材)의 내력(耐力))

  • Shin, Hyun Mook;Kim, Eun Kyun;Kim, Seon Il
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.2
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    • pp.125-133
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    • 1988
  • To establish the rational design method, it is very important that predict accurately load-deformation response on reinforced concrete members. Torque-twist curves of reinforced concrete members in pure torsion were proposed recently by Collins and Hsu, etc. But, it is found that torsional strength of reinforced concrete members based on Hsu's theory is underestimated in the over-all load region except the ultimate state. In this paper, an attempt is made to present the higher-precision of torsional strength on arbitrary loading condition. For this purpose, constitutive equations are derived from which an estimate can be made of the torsional behavior of reinforced concrete members under the pure torsion. Tension stiffness of concrete in both the cracked and uncracked state have been considered. A softening effect that reduces the strength of the concrete by the diagonal cracking of concrete have been appropriately deliberated. Particularly, the experiments was done with 14 test beams to investigate the validity of theoretical analysis.

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A Study on the Traditional Aesthetic Consciousness Reflected on the Contemporary Fashion - Focused on Comparative Research for Korea and Japan - (현대(現代)패션에 반영(反映)된 전통(傳統) 미의식(美意識)의 연구(硏究) - 한국(韓國)과 일본(日本)의 비교연구(比較硏究)를 중심(中心)으로 -)

  • Yun, Bo-Yeun;Bae, Soo-Jeong
    • Journal of Fashion Business
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    • v.5 no.4
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    • pp.56-72
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    • 2001
  • The purpose of this study is to provide a philosophical basis for a rational, meaningful and systematic development of contemporary Korean fashion and culture industry. The study will begin by comparing traditional aesthetics of Japan and Korea and their respective influences in contemporary fashion design. Japanese aesthetic consciousness can be understood in terms of decorative beauty and undecorated beauty where traditional Korean aesthetic consciousness consists of aesthetic naturalism, beauty of mysticism and beauty of humor. Japanese aesthetic consciousness is generally inclined toward article fanciness, on the other hand, Korean aesthetic consciousness is inclined toward natural beauty. Both Japan and Korea reflect their traditional aesthetic consciousness in their contemporary fashion design. In Japan's case, traditional patterns have been applied to obi(帶, おび). And aesthetic naturalism can be seen in holes, tears and patches present, as well as rough and coarse texture used, in contemporary fashion design. In case of Korea, aesthetic naturalism can be seen in elegant naturally flowing curves and use of plain colored fabric used in fashion design. Beauty of mysticism can be seen in splendid primary colors from shaman ritual costumes, and fortune-telling hexagram patterns. Beauty of humor can be seen in outrageously exaggerated and distorted fit of clothes. The above comparative analysis, with respect to their formative elements, show that both Korean and Japanese contemporary fashion trends reflect and embody their respective traditional aesthetic consciousness. Japan is creating high-grade fashion design of temporal universality and contemporary appeal. Japan has done so by studying their aesthetic tradition from the point of view of philosophy and utilizing its formative elements. Korea, however, is in the middle of transition: Korea is caught between directly grafting traditional aesthetic designs onto contemporary fashion design and integrating the two according to their common internal spirit.

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Determination of Horizontal Coefficient of Consolidation from the Self-boring Pressuremeter Holding Test by Considering Pore Pressure Dissipation Trend (간극수압 소산경향을 고려한 자가굴착식 프레셔메터로부터의 수평압밀계수 결정법)

  • 김영상
    • Journal of the Korean Geotechnical Society
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    • v.20 no.3
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    • pp.151-159
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    • 2004
  • This paper describes a systematic way of identifying the horizontal coefficient of consolidation of clayey soil by applying an optimization technique to the early part of dissipation data measured from the self-boring pressuremeter strain holding test. An analytical solution developed by Randolph & Wroth (1979) was implemented in normalized form to express the build-up of excess pore pressures as a function of the rigidity index and subsequent dissipation of excess pore pressures around a pressuremeter Horizontal coefficient of consolidation was determined by minimizing the differences between theoretical and measured excess pore pressure curves over 50% degree of dissipation range using optimization technique. The effectiveness of the proposed back-analysis method was examined against the real fled performances obtained from pressuremeter strain holding tests at Gimje and Yangsan site. It is shown that the proposed back-analysis method can evaluates the rational horizontal coefficient of consolidation, which is similar to those obtained from the piezocone dissipation test. Furthermore, proposed method can evaluate appropriate coefficient of consolidation for soil under partially drained condition.

Probabilistic Analysis of Forced-Damped Torsional Vibration of Marine Diesel Propulsion Shafting Systems (선박디젤추진축계 감쇠강제비틂진동의 확률적 해석)

  • S.Y. Ahn;M.B. Krakovski
    • Journal of the Society of Naval Architects of Korea
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    • v.31 no.4
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    • pp.157-166
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    • 1994
  • Recently. the excessive diesel engine torsional excitation of typical energy saving ships has resulted in severe damages of the propeller shaft. Up to now the design and torsional vibration analysis of the marine diesel shafting system has been performed on the assumption that excitations are deterministic. But a diesel engine excitation varies randomly from cylinder to cylinder and from cycle to cycle, due to the imperfect operation of the engine components due to engine misfiring. consequently, a more rational analysis method for the propulsion shafting torsional vibration is required. In this paper probabilistic analysis method of the marine diesel engine shafting system under torsional vibration is presented. First a response surface representing maximum shear stresses in a shafting system is built. Then Monte Carlo simulation with subsequent approximation of the results by one of Pearson's curves, is performed. Some numerical results based on the proposed method are compared with t도 some numerical data available. They show acceptable agreements with the data.

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On Generating a Dynamic Price Formation System with Rationality -Application to U.S. Fisheries- (합리성을 가진 동태적 가격형성모형의 연구 -U.S. 수산자원에의 응용-)

  • Park, Hoanjae
    • Environmental and Resource Economics Review
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    • v.14 no.3
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    • pp.699-728
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    • 2005
  • This article is basically an extension of Barten(1993), Brown et al. (1995), Holt and Bishop's(2002) price formation system. A new dynamic price formation system is attempted considering full rationality of the consumers' side. The underlying idea of the new dynamic price formation system is that consumers are rational and farsighted and thus consider past and future consumptions in addition to current consumption to accept the prices traders called. In an empirical application, the U.S. commercial fish demand data are particularly interesting to this analysis in which the species are over fished, including many of the most valuable species. Especially, the grouper-snapper complex are under management jurisdiction of the National Marine Fisheries Council. In the empirical section, it shows how to adapt the model to estimate the marginal values to consumers of commercial fisheries. Since it is conceived of regulations as inducing movements along the marginal value curves, it is of growing importance to regional and national policy makers who are confronted with competing claims on diminishing fish stocks by commercial fisheries interests. It performs well and shows the plausible signs and magnitudes of price flexibilities and interaction among species. It further contributes to the general methodology of applied economics.

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Analysis of Hydraulic behavior in Unsaturated Soil Slope for the Boundary Condition and Hysteresis of SWCC (경계 조건과 불포화 함수 특성 곡선의 이력에 따른 불포화 토사 사면의 수리적 거동 분석)

  • Lee, Eo-Ryeong;Park, Hyun-Su;Park, Seong-Wan
    • Journal of the Korean Geotechnical Society
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    • v.39 no.1
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    • pp.15-25
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    • 2023
  • Recent weather changes have led to an increase in heavy rainfall resulting in frequent large-scale slope failures. To minimize damage to life and property, a measurement system is used in slope failure warning systems. However, understanding the slope failure behavior is difficult as the measurement system only measures a specific point. Therefore, numerical analysis must be p erformed with the measurement system. The soil water characteristic curve (SWCC) drying curve and boundary conditions that consider evapotranspiration and precipitation have been applied to numerical analysis, but the hysteresis of SWCC affects the numerical analysis results. To address this, a new evapotranspiration calculation method is proposed and applied to boundary conditions, and the measurement data are compared with the results of the numerical analysis. This method takes into account the different infiltration behaviors on evapotranspiration according to the drying and wetting curves of the SWCC, and allows for a more rational prediction of water movement on unsaturated slopes.

A Review on Ultimate Lateral Capacity Prediction of Rigid Drilled Shafts Installed in Sand (사질토에 설치된 강성현장타설말뚝의 극한수평지지력 예측에 관한 재고)

  • Cho Nam Jun;Kulhawy F.H
    • Journal of the Korean Geotechnical Society
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    • v.21 no.2
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    • pp.113-120
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    • 2005
  • An understanding of soil-structure interaction is the key to rational and economical design for laterally loaded drilled shafts. It is very difficult to formulate the ultimate lateral capacity into a general equation because of the inherent soil nonlincarity, nonhomogeneity, and complexity enhanced by the three dimensional and asymmetric nature of the problem though extensive research works on the behavior of deep foundations subjected to lateral loads have been conducted for several decades. This study reviews the four most well known methods (i.e., Reese, Broms, Hansen, and Davidson) among many design methods according to the specific site conditions, the drilled shaft geometric characteristics (D/B ratios), and the loading conditions. And the hyperbolic lateral capacities (H$_h$) interpreted by the hyperbolic transformation of the load-displacement curves obtained from model tests carried out as a part of this research have been compared with the ultimate lateral capacities (Hu) predicted by the four methods. The H$_u$ / H$_h$ ratios from Reese's and Hansen's methods are 0.966 and 1.015, respectively, which shows both the two methods yield results very close to the test results. Whereas the H$_u$ predicted by Davidson's method is larger than H$_h$ by about $30\%$, the C.0.V. of the predicted lateral capacities by Davidson is the smallest among the four. Broms' method, the simplest among the few methods, gives H$_u$ / H$_h$ : 0.896, which estimates the ultimate lateral capacity smaller than the others because some other resisting sources against lateral loading are neglected in this method. But it results in one of the most reliable methods with the smallest S.D. in predicting the ultimate lateral capacity. Conclusively, none of the four can be superior to the others in a sense of the accuracy of predicting the ultimate lateral capacity. Also, regardless of how sophisticated or complicated the calculating procedures are, the reliability in the lateral capacity predictions seems to be a different issue.