• 제목/요약/키워드: Negative moments

검색결과 98건 처리시간 0.024초

유전알고리즘에 의한 철근콘크리트 골조의 이산형 구조설계 (Discrete Structural Design of Reinforced Concrete Frame by Genetic Algorithm)

  • Ahn, Jeehyun;Lee, Chadon
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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    • pp.127-134
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    • 1999
  • An optimization algorithm based on Genetic Algorithm(GA) is developed for discrete optimization of reinforced concrete plane frame by constructing databases. Under multiple loading conditions, discrete optimum sets of reinforcements for both negative and positive moments in beams, their dimensions, column reinforcement, and their column dimensions are found. Construction practice is also implemented by linking columns and beams by group ‘Connectivity’between columns located in the same column line is also considered. It is shown that the developed genetic algorithm was able to reach optimum design for reinforced concrete plane frame construction practice.

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WEAK LAWS OF LARGE NUMBERS FOR WEIGHTED COORDINATEWISE PAIRWISE NQD RANDOM VECTORS IN HILBERT SPACES

  • Le, Dung Van;Ta, Son Cong;Tran, Cuong Manh
    • 대한수학회지
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    • 제56권2호
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    • pp.457-473
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    • 2019
  • In this paper, we investigate weak laws of large numbers for weighted coordinatewise pairwise negative quadrant dependence random vectors in Hilbert spaces in the case that the decay order of tail probability is r for some 0 < r < 2. Moreover, we extend results concerning Pareto-Zipf distributions and St. Petersburg game.

Electronic Structure and Magnetism of CrP/SrBi Interface: A First Principles Study

  • Bialek, Beata;Lee, Jae-Il
    • Journal of Magnetics
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    • 제12권3호
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    • pp.93-96
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    • 2007
  • We investigated the electronic structure and magnetic properties of zinc-blende CrP/SrBi interface by using the all-electron full-potential linearized augmented plane wave method within the generalized gradient approximation. It is found that the half-metallicity is destroyed when the two half-metals are in contact. Magnetic moments of the atoms forming the supercell differ considerably from the respective values obtained for the bulk structures of the two materials. Cr atoms being and not being in contact with Bi atoms have magnetic moment 3.43 and $2.69{\mu}_B$, respectively. Bi atoms lose their majority electrons which results in their negative polarization. Alkaline Sr atoms are very weakly negatively polarized. The spin distribution within the supercell is such that well separated regions of positive and negative polarization are seen, especially around the layer of P atoms being in contact with the layer of Sr atoms.

다이아프램이 고려된 ILM 교량 상부단면의 단순해석 및 최적설계조건 (Simplified Analysis of Superstructure Section Considering Diaphragm and Optimum Design Conditions for ILM Bridge)

  • 이환우;박용진
    • 한국전산구조공학회논문집
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    • 제27권5호
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    • pp.459-467
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    • 2014
  • ILM 교량은 압출되는 동안 상부의 단면이 지간의 중앙부와 지점부를 모두 통과한다. 따라서 발생되는 최대 정모멘트 및 최대 부모멘트를 효과적으로 제어하기 위해서 압출추진코를 이용한다. 이 연구에서는 압출중 상부구조물에 발생하는 휨모멘트를 계산할 수 있는 다이아프램이 고려된 단순 해석식을 개발하였다. 또한 다이아프램이 고려된 압출추진코의 최적설계조건에 관하여 분석하였다. 단순 해석식을 MIDAS Civil과 비교한 결과 대부분의 경우 0.5%이하의 오차를 가지는 정확성을 확인하였다. 다이아프램의 영향을 고려했을 경우와 고려하지 않았을 경우 사례교량에서 최대 13%의 휨모멘트 차이를 보였다. 또한, 단순 해석식에 적용시킬 등가 등단면의 단위중량 및 평균강성값을 결정할 수 있는 기준을 제시하였다. 이 연구에서는 ILM 교량의 압출중 역학특성으로 인하여 부모멘트 최소화 조건만을 사용하는 것이 압출추진코 최적설계를 위한 효과적인 방법으로 판단하였다.

편향하중 조건 보행시 인체의 적응 작용에 대한 분석 (Joint moments and muscle forces during walking with sided load as one of activities of daily living)

  • 김현동;손종상;김한성;김영호;임도형
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1709-1712
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    • 2008
  • The trunk is inclined to the loaded side when carrying an object as one of activities of daily living. As the reaction to this behavior the human body may be inclined to his/her trunk to unloaded side. The present study investigated the biomechanical effects of weight variation for sided load carriage during walking upon joint moments and muscle torques, through the tracker agent and joint driving dynamic analysis. To perform the experiment one male was selected as subject for the study. Gait analysis was performed by using a 3D motion analysis system. Thirty nine 14mm reflective markers, according to the plug-in marker set, were attached to the subject. We used BRG.LifeMOD(Biomechanics Research Group, Inc., USA), for skeletal modeling and inverse and joint driving dynamic simulation during one gait cycle. In walking with a sided load carriage, the subject modeled held the carriage with the right hand, which weighed 0, 5, 10, 15kg, 20kg respectively. The result of this simulation showed that knee and hip in the coronal plane were inclined to the loaded side and loaded side had larger moments as the sided load carriage was increased. On the other hand thoracic and lumbar in the coronal plane had larger negative values as the sided loaded carriage was increased. The thoracic and lumbar in the transverse plane also had larger values as the sided load was increased. And the several muscles of loaded side were increased as increasing sided load. It could be concluded that human body is adopted to side loaded circumstances by showing more biologic force. These results could be very useful in analysis for delivery motion of daily life.

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How Do the Banks Determine Regulatory Capital, Risk, and Cost Inefficiency in Bangladesh?

  • RAHMAN, Mohammad Morshedur;CHOWDHURY, Md. Ali Arshad;MOUDUD-UL-HUQ, Syed
    • The Journal of Asian Finance, Economics and Business
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    • 제7권12호
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    • pp.211-222
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    • 2020
  • This study examines simultaneous relationships between regulatory capital, risk, and cost-inefficiency for a sample of 30 commercial banks in Bangladesh from 2006 to 2018. To conduct the analysis, we used the Generalized Methods of Moments (GMM) in an unbalanced panel data framework. The empirical results show that there is a negative and significant relationship between capital regulation and credit, and overall risk. It is also evident from the results that the capital adequacy ratio is positively and significantly related to default risk and liquidity risk. Therefore, higher capitalized banks take an effort to prevent more credit risk and promote financial stability by reducing liquidity risk. Results also report that banks have been characterized as inefficient, less capitalized, and high risk. On the other hand, efficient banks are more stable but have a high level of liquidity risk. Besides, from the size of the bank, large banks are defined as having lower regulatory capital, are more risk seekers but stable with higher cost-efficiency. Notably, higher capitalized banks are more profitable and cost-efficient by reducing risk. Finally, this study also provides some insightful policy suggestions to the stakeholders.

Directors' Remuneration and Performance: Evidence from the Textile Sector of Bangladesh

  • AKTER, Sharmin;ALI, Md. Hossain;ABEDIN, Md. Thasinul;HOSSAIN, Balal
    • The Journal of Asian Finance, Economics and Business
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    • 제7권6호
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    • pp.265-275
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    • 2020
  • This study investigates the impact of board incentives as proxied by directors' remuneration on the financial performance of listed textile companies in Bangladesh. Using Generalized Method of Moments (GMM) and data pertaining to listed textile companies of Dhaka Stock Exchange (DSE) during the period from 2011 to 2017 (resulting in a total of 140 firm-year observations), we have estimated the firm performance equation involving directors' remuneration and board independence as the independent variables and some other control variables like firm age, size, leverage, and operating efficiency. The results reveal that there is a negative association between board remuneration and firm performance. In addition, this study finds no significant relationship between board independence and firm performance of the sample firms. Our findings suggest that higher pay to the board does not stimulate higher firm performance and, in turn, results in shareholders getting nothing in return from this and, hence, is a matter of great concern for them. Moreover, our results indirectly indicate that currently directors' remuneration in Bangladesh is not aligned with the firm performance, which has been emphasized in extant corporate governance literature. Besides, this paper further raises questions about the effectiveness of independent directors in the boards of textile firms in Bangladesh.

Point load actuation on plate structures based on triangular piezoelectric patches

  • Tondreau, Gilles;Raman, Sudharsana Raamanujan;Deraemaeker, Arnaud
    • Smart Structures and Systems
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    • 제13권4호
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    • pp.547-565
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    • 2014
  • This paper investigates the design of a perfect point load actuator based on flat triangular piezoelectric patches. Applying a difference of electric potential between the electrodes of a triangular patch leads to point loads at the tips and distributed moments along the edges of the electrodes. The previously derived analytical expressions of these forces show that they depend on two factors: the width over height (b/l) ratio of the triangle, and the ratio of the in-plane piezoelectric properties ($e_{31}/e_{32}$) of the active layer of the piezoelectric patch. In this paper, it is shown that by a proper choice of b/l and of the piezoelectric properties, the moments can be cancelled, so that if one side of the triangle is clamped, a perfect point load actuation can be achieved. This requires $e_{31}/e_{32}$ to be negative, which imposes the use of interdigitated electrodes instead of continuous ones. The design of two transducers with interdigitated electrodes for perfect point load actuation on a clamped plate is verified with finite element calculations. The first design is based on a full piezoelectric ceramic patch and shows superior actuation performance than the second design based on a piezocomposite patch with a volume fraction of fibres of 86%. The results show that both designs lead to perfect point load actuation while the use of an isotropic PZT patch with continuous electrodes gives significantly different results.

The Effect of Trade Integration on Business Cycle Synchronization in East Asia

  • NGUYEN, Vinh Thi Hong;HOANG, Thuy Thi Thanh;NGUYEN, Sang Minh
    • The Journal of Asian Finance, Economics and Business
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    • 제7권8호
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    • pp.225-231
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    • 2020
  • The paper aims to investigate the impact of trade integration on business cycle synchronization for the East Asian countries during 2005- 2017 based on the endogeneity hypothesis of Optimum Currency Area criteria. We test the determinants of business cycles by calculating bilateral trade, financial integration, and business cycle synchronization. Applying the system Generalized Method of Moments for dynamic panel data models, the results show that business cycle synchronization is highly associated with trade and financial integration. These findings confirm the endogeneity hypothesis that more trade integration will mitigate asymmetric shocks, and have a positive impact on the business cycle synchronization. The increased trade intensity and financial linkage lead to more correlated business cycles in East Asia. Apart from trade and financial integration, the trade structure differential, monetary policy similarity also influence the business cycle comovement. The significantly negative impact of trade structure differential on business cycle synchronization suggests that countries with less similar structures are more likely to undergo asymmetric shocks. The results also indicate that monetary policy matters for output comovement. This study recommends that the East Asian countries should focus on bilateral trade as well as financial integration with each other to reap benefits from the integration process.

FDI Spillover Effects on the Productivity of the Indian Pharmaceutical Industry: Panel Data Evidence

  • DESAI, Guruprasad;SRINIVASAN, Palamalai;GOWDA, Anil B
    • The Journal of Asian Finance, Economics and Business
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    • 제9권8호
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    • pp.109-121
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    • 2022
  • The study empirically examines the horizontal spillover effects of foreign direct investment (FDI) on the productivity of Indian pharmaceutical firms. Robust least squares and the Generalized Method of Moments estimators are applied for the firm-level panel data of Indian pharmaceutical companies whose shares were traded on the National Stock Exchange (NSE) and Bombay Stock Exchange (BSE). The information was collected from the Centre for Monitoring Indian Economy (CMIE) Prowess database from 2015 to 2019. Based on the regularity in data availability, the sample firms are limited to 112 companies, 100 of which are domestic firms and 12 international firms. Firms with more than 10 percent foreign equity are classified as FDI firms, while those with less than that are classified as domestic firms. Estimation results show that foreign ownership does not contribute to the productivity of domestic firms. Due to increased competition, the Indian pharmaceutical companies with foreign equity participation are not more productive than local ones. Moreover, the findings reveal a negative and insignificant horizontal spillover effect from FDI on the productivity of domestic enterprises. The absence of horizontal spillovers may be attributable to foreign enterprises' ability to prevent technological outflow to competitors in the same industry.