• Title/Summary/Keyword: critical moments

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Pressure Effects on the Hg-doped Heavy-fermion Superconductor $CeRhIn_5$ (Hg을 도핑한 무거운 페르미온 초전도체 $CeRhIn_5$의 압력에 따른 변화)

  • Seo, S.;Ju, S.;Bauer, E.D.;Thompson, J.D.;Park, T.
    • Progress in Superconductivity
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    • v.14 no.1
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    • pp.17-23
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    • 2012
  • The heavy-fermion compound $CeRhIn_5$ is a prototypical antiferromagnet where Ce 4f moments align antiferromagnetically below 3.8 K. When doped with Hg, the antiferromagnetic transition $T_N$ initially decreases, becomes flat, and increases again with further increasing Hg concentration. Here we report pressure effects on the electrical resistivity of a 0.45 % Hg-doped $CeRhIn_5$, where $T_N$ is 3.4 K and the magnetic structure is same as that of the undoped compound with Q=(1/2, 1/2, 0.298). With increasing pressure, $T_N$ is suppressed and a superconducting state emerges. The temperature dependence of the electrical resistivity near an optimal pressure shows a power-law behavior that deviates from a $T^2$ dependence, indicating presence of abundant quantum fluctuations near the optimal pressure.

Numerical analysis of stainless steel-concrete composite beam-to-column joints with bolted flush endplates

  • Song, Yuchen;Uy, Brian;Wang, Jia
    • Steel and Composite Structures
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    • v.33 no.1
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    • pp.143-162
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    • 2019
  • A number of desirable characteristics concerning excellent durability, aesthetics, recyclability, high ductility and fire resistance have made stainless steel a preferred option in engineering practice. However, the relatively high initial cost has greatly restricted the application of stainless steel as a major structural material in general construction. This drawback can be partially overcome by introducing composite stainless steel-concrete structures, which provides a cost-efficient and sustainable solution for future stainless steel construction. This paper presents a preliminary numerical study on stainless steel-concrete composite beam-to-column joints with bolted flush endplates. In order to ensure a consistent corrosion resistance within the whole structural system, all structural steel components were designed with austenitic stainless steel, including beams, columns, endplates, bolts, reinforcing bars and shear connectors. A finite element model was developed using ABAQUS software for composite beam-to-column joints under monotonic and symmetric hogging moments, while validation was performed based on independent test results. A parametric study was subsequently conducted to investigate the effects of several critical factors on the behaviour of composite stainless steel joints. Finally, comparisons were made between the numerical results and the predictions by current design codes regarding the plastic moment capacity and the rotational stiffness of the joints. It was concluded that the present codes of practice generally overestimate the rotational stiffness and underestimate the plastic moment resistance of stainless steel-concrete composite joints.

Some Aspects of Thai culture on the folktale "Pla Boo Thong" (태국 민담 <쁠라 부텅>류에 나타난 태국인의 문화적 특성)

  • Kim, Young Aih
    • The Southeast Asian review
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    • v.21 no.1
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    • pp.287-314
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    • 2011
  • There are many versions of the thai folktale "Pla Boo Thong" in Thailand, which is a typical type of stepmother story and in many ways resembles Cinderella story. This study, the author took 6 versions, some from books, some from internet. The main story of those 6 version is consist of the death of mother, stepmother and step sister, the maltreat of the stepmother to the heroine, tiding over the critical moments with the help of the dead mother and others, getting married with the king and happy of the heroine, death of the heroine by the slander of stepmother, posing as a queen of the stepsister, reincarnation of the dead heroine, meeting with the king again, and punishment and the stepmother and stepsister. The main theme of this narrative is a conflict in the polygamic family and is followed by the pattern of the Cinderella tale such as the distinct contrast of Good and Evil. This tale also teaches teachings of Buddha such as the punitive justice, the promotion of virtue and reproval of vice, and forgiveness. And otherwise it gives the people the courage and hope to overcome fortitude in their life.

Modified models predicting punching capacity of edge column-slab joints considering different codes

  • Hamdy A. Elgohary;Mohamed A. El Zareef
    • Structural Engineering and Mechanics
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    • v.89 no.4
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    • pp.363-374
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    • 2024
  • Significant changes have been made to estimate the punching shear capacity for edge column-slab joints in the latest editions of most current codes. The revised equations account for axial forces as well as moments conveyed to columns from slabs, which have a substantial impact on the punching resistance of such joints. Many key design parameters, such as reinforcement-ratio, concrete strength, size-effect, and critical-section perimeter, were treated differently or even ignored in various code provisions. Consequently, wide ranges of predicted punching shear strength were detected by applying different code formulas. Therefore, it is essential to assess the various current Codes' design-equations. Because of the similarity in estimated outcomes, only the ACI, EC, and SNiP are used in this study to cover a wide range of estimation ranges from highly conservative to unconservative. This paper is devoted to analyzing the techniques in these code provisions, comparing the estimated punching resistance with available experimental data, and finally developing efficient models predicting the punching capacity of edge column-slab connections. 63 samples from past investigations were chosen for validation. To appropriately predict the punching shear, newly updated equations for ACI and SNiP are provided based on nonlinear regression analysis. The proposed equations'results match the experimental data quite well.

Performance evaluation of underground box culverts under foundation loading

  • Bin Du;Bo Hao;Xuejing Duan;Wanjiong Wang;Mohammad Roohani
    • Geomechanics and Engineering
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    • v.38 no.4
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    • pp.397-408
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    • 2024
  • Buried box culverts are crucial elements of transportation infrastructure. However, their behavior under foundation loads is not well understood, indicating a significant gap in existing research. This study aims to bridge this gap by conducting a detailed numerical analysis using the Finite Element Method and Abaqus software. The research evaluates the behavior of buried box culverts by examining their interaction with surrounding soil and the pressures from surface foundation loads. Key variables such as embedment depth, culvert wall thickness, concrete material properties, foundation pressure, foundation width, soil elastic modulus, and friction angle are altered to understand their combined effects on structural response. The methodology employs a validated 2D numerical model under plane strain conditions. Parametric studies highlight the critical role of culvert depth (H) in influencing earth pressure and bending moments. Foundation pressure and width demonstrate complex interdependencies affecting culvert behavior. Variations in culvert materials' elastic modulus show minimal impact. It was found that the lower wall of the buried culvert experiences higher average pressure compared to the other two walls, due to the combined effects of the culvert's weight and down drag forces on the side walls. Furthermore, while the pressure distribution on the top and bottom walls is parabolic, the pressure on the side walls follows a different pattern, differing from that of the other two walls.

Bending Moment Calculation Method and Optimum Element Size for Finite Element Analysis with Continuum Elements (연속체 요소를 사용한 유한요소해석의 휨 모멘트 계산 방법 및 최적의 요소 크기)

  • Heo, Ji-Hye;Kim, Han-Soo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.1
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    • pp.9-16
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    • 2018
  • When designing a reinforced concrete member using nonlinear finite element analysis results, the bending moment at the critical section should be calculated. In this paper, a bending moment calculation method using the results of reinforced concrete finite element analysis(FEA) using continuum elements is presented and the optimum element size according to the order of the displacement function of the finite element is proposed. The bending moments calculated by integrating the stresses from the FEA are compared with the bending moments calculated using the static equilibrium conditions. In the method of integrating the stress, both the stress due to the reinforcing bar and the stress of the concrete are considered. In addition, various factors affecting the accuracy of the stresses calculated by the FEA were analyzed and the influence of the displacement function and the element size was verified. If the purpose of the analysis is to roughly observe the behavior of the members, it is appropriate to use the first order displacement function and the element size should be about 25% of the section height of the analytical model. When the bending moment of a member with high accuracy is required, it is suggested that the secondary displacement function be used and the element size be 12.5%.

Economic Effects of Policy Loans: Focusing on Alleviation Effect of Investment Liquidity Constraint (정책융자의 경제적 성과분석: 투자의 유동성 제약완화 중심으로)

  • Nam, Joo-ha
    • International Area Studies Review
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    • v.15 no.1
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    • pp.173-193
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    • 2011
  • Most of the research regarding economic effects of policy loans has thus far been focused on whether policy loans can improve the financial status or the management performance of small and medium enterprises (SMEs). Unlike previous researches, this study implemented an empirical analysis focused on the contribution of policy loans to easing the liquidity restriction of investment. To analyze whether investment liquidity restriction can be alleviated or not, this study attempted an empirical analysis utilizing the nonlinear Euler equation induced through optimization of investment and GMM (generalized method of moments) as its analysis methodology. With the SMEs that received policy financing from the Small and medium Business Corporation (SBC) in 2004, this study analyzed three years of panel data before(2001~2003) and after(2004~2006) receipt of policy loans. According to the empirical results, it appears that policy loans had effects on resolving liquidity restriction of investment, implying that policy financing eases the liquidity restriction of SME investment and would contribute to the growth and development of SMEs. Further, I checked robustness of empirical results using Tobin's q model. The empirical results also support that policy loans help to resolve liquidity constraint. With these results, it is understood that the critical view to date, which has emphasized the ineffectiveness of policy financing due to it having no or insignificant economic effects, may be wrong.

Forced Oscillation Wind Tunnel Test of a 50m Length Airship (50M급 비행선의 강제진동 풍동시험)

  • Chang,Byeong-Hee;Lee,Yung-Gyo;Ok,Ho-Nam
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.6
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    • pp.17-22
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    • 2003
  • An airship is statically unstable, because it has no wing, relatively small tails and a large hull. Hence, an accurate prediction of dynamic stability is critical. In this study, dynamic stability data of the 50m Length Airship were acquired through forced oscillation wind tunnel tests. The tests were done in Birhle Applied Research Inc's Lange Amplitude Multi-Purpose(BAR LAMP) Facility located in Germany. The tests were composed with 16 static runs and 26 dynamic runs. As results, it is obtained that dynamic characteristics of the airship depend on the sideslip angle, the angular rate and its direction as well as the angle of attack. Generally, three directional moments have damping, but the normal force, the side force, and the cross-derivatives are unstable. The dynamic derivatives are not sensitive to the control surfaces, but nonlinear to the sideslip angle.

Silhouette-based Motion Estimation for Movement Education of Young Children (유아의 동작 교육을 위한 실루엣 기반 동작 추정)

  • Shin, Young-Suk;Kim, Hey-Jeong;Lee, Jeong-Wuk;Lee, Kyoung-Mi
    • The Journal of the Korea Contents Association
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    • v.8 no.4
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    • pp.273-284
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    • 2008
  • Movements are a critical ability to young children's whole development, including physical, social/emotional, and cognitive development. This paper proposes the method to estimate movements suitable for young children's body conditions. The proposed method extracts a silhouette in each frame of videos that are obtained by deploying two video cameras by compensating illuminations, removing background and conducting morphology operations. And we extract silhouette feature values: an area, the ratio of length to width, the lowest foot position, and 7 Hu moments. Also, the area and movements of sub-area are used as local features. For motion estimation, we used probability propagation of the features extracted from the front and side frames. The proposed estimation algorithm is demonstrated for seven movements, walking, jumping, hopping, bending, stretching, balancing, and turning.

Power in Exhibitions: The Artworks and Exhibitions in the 1960s through the 1970s (전시와 권력: 1960~1970년대 한국 현대미술에 작용한 권력)

  • Kim, Hyung-Sook
    • The Journal of Art Theory & Practice
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    • no.3
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    • pp.9-34
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    • 2005
  • Contemporary Korean art in the 1960s and the 1970s reflects the social and political contexts in Korea from the 5 16 revolution through the Yoo Shin period. This paper investigates whether art has been free from power or not. It examines the power embedded in contemporary Korean art in the 1960s and the 1970s. This paper examines the historical moments of the Korean Art Exhibition, focusing on the complications between the abstract and figurative artworks of the 1960s. One of the significant art exhibitions since the 8 15 liberation of Korea, the Korean Art Exhibition witnessed conflict among Korean artists who wanted to have power in the art world of Korea. Institutional contradiction based on factionalism and conservatism prevailed in the Korean Art Exhibition was attacked by the avant-garde young artists in the 1960s. With the contact of Abstract Expressionism, young artists' generation participated in the The Wall Exhibition. This exhibition challenged and established moral principles and visualized individual expression and creation similar to the Informal movement in the West. In the world of the traditional painting of Korea, the Mook Lim Exhibition of 1960, organized by young artists of traditional painting, advocated the modernization of Soo Mook paintings. Additionally, abstract sculptures in metal engraving were the new trends in the Korean Art Exhibition. In the 1970s, the economic development and establishment of a dictatorial government made the society stiffen. Abstract expression died out and monochrome painting was the most influential in the 1970s. After the exhibition of Five Korean Artists, Five White Colors in the Tokyo Central Art Museum in 1976, monochrome paintings were formally discussed in Korea. 'Flatness' 'physicality of material' 'action' 'post-image' 'post-subjectivity' and 'oriental spirituality' were the critical terms in mentioning the monochrome paintings of the 1970s. 'Korean beauty' was discussed, focusing on the beauty of white which was addressed by not only Yanagi Muneyoshi but also the policy of national rehabilitation under the Yoo Shin government. At this time, the monochrome paintings of the 1970s in Korea, addressing art for art's sake, cutting of communication with the masses, and elitism, came to be authorized.

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