• Title/Summary/Keyword: S-N approach

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Extension of a semi-analytical approach to determine natural frequencies and mode shapes of a multi-span orthotropic bridge deck

  • Rezaiguia, A.;Fisli, Y.;Ellagoune, S.;Laefer, D.F.;Ouelaa, N.
    • Structural Engineering and Mechanics
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    • v.43 no.1
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    • pp.71-87
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    • 2012
  • This paper extends a single equation, semi-analytical approach for three-span bridges to multi-span ones for the rapid and precise determination of natural frequencies and natural mode shapes of an orthotropic, multi-span plate. This method can be used to study the dynamic interaction between bridges and vehicles. It is based on the modal superposition method taking into account intermodal coupling to determine natural frequencies and mode shapes of a bridge deck. In this paper, a four- and a five-span orthotropic roadway bridge deck are compared in the first 10 modes with a finite element method analysis using ANSYS software. This simplified implementation matches numerical modeling within 2% in all cases. This paper verifies that applicability of a single formula approach as a simpler alternative to finite element modeling.

Dynamic Voltage Scaling Using Average Execution Time in Real Time Systems (실시간 시스템에서 태스크별 평균 실행 시간을 활용한 동적 전압 조절 방법)

  • 방철원;김용석
    • Proceedings of the IEEK Conference
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    • 2003.07d
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    • pp.1379-1382
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    • 2003
  • Recently, mobile embedded systems used widly in various applications. Managing power consumption is becoming a matter of primary concern because those systems use limited power supply. As an approach reduce power consumption, voltage can be scaled down. according to the execution time and deadline. By reducing the supplying voltage to 1/N power consumption can be reduced to 1/N. DPM-S is a well known method for dynamic voltage scaling. In this paper, we enhanced DPM-S by using average execution time aggressively. The frequency of processor is calculated based in average execution time instead of worst case execution time. Simulation results show that our method achieve up to 5% energy savings than DPM-S.

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A probabilistic analysis of Miner's law for different loading conditions

  • Blason, Sergio;Correia, Jose A.F.O.;Jesus, Abilio M.P. De;Calcada, Rui A.B.;Fernandez-Canteli, Alfonso
    • Structural Engineering and Mechanics
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    • v.60 no.1
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    • pp.71-90
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    • 2016
  • In this paper, the normalized variable V=(log N-B)(log ${\Delta}{\sigma}-C$-C), as derived from the probabilistic S-N field of Castillo and Canteli, is taken as a reference for calculation of damage accumulation and probability of failure using the Miner number in scenarios of variable amplitude loading. Alternative damage measures, such as the classical Miner and logarithmic Miner, are also considered for comparison between theoretical lifetime prediction and experimental data. The suitability of this approach is confirmed for it provides safe lifetime prediction when applied to fatigue data obtained for riveted joints made of a puddle iron original from the Fao bridge, as well as for data from experimental programs published elsewhere carried out for different materials (aluminium and concrete specimens) under distinct variable loading histories.

Generalizations of Ramanujan's Integral Associated with Infinite Fourier Cosine Transforms in Terms of Hypergeometric Functions and its Applications

  • Qureshi, Mohammad Idris;Dar, Showkat Ahmad
    • Kyungpook Mathematical Journal
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    • v.60 no.4
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    • pp.781-795
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    • 2020
  • In this paper, we obtain an analytical solution for an unsolved definite integral RC (m, n) from a 1915 paper of Srinivasa Ramanujan. We obtain our solution using the hypergeometric approach and an infinite series decomposition identity. Also, we give some generalizations of Ramanujan's integral RC (m, n) defined in terms of the ordinary hypergeometric function 2F3 with suitable convergence conditions. Moreover as applications of our result we obtain nine new infinite summation formulas associated with the hypergeometric functions 0F1, 1F2 and 2F3.

Bottom-up Approach: the Effects of Performing Arts Fostering Program, Chang-jak-san-shil (상향식접근(bottom-up approach)이론을 이용한 창작산실육성지원사업의 효과연구)

  • Kim, InSul;Shin, Hyesun;Lee, Heungjae
    • Review of Culture and Economy
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    • v.19 no.2
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    • pp.97-120
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    • 2016
  • This study aims to identify how performing artists in Korea, who are the target beneficiaries of the Arts Council Korea's Performing Arts Fostering Program, Chang-jak-san-shil(CJSS), would perceive and assess the current state of CJSS and its effects. To do so, this paper has adopted a bottom-up approach as a theoretical lens for policy evaluative analysis. This research engages with qualitative research design by conducting a series of in-depth interviews and FGIs with 28 participants in total. The interview participants consist of CJSS grantees(n=21) and peer-review panels(n=7) based on the intension to enhance objectivity and reliability of the study. Results of the data analysis suggest that the grant program still carries pressing needs to achieve a success as follows: providing post-program support, enhancing transparency of the panel appointment process and the peer review process, reflecting different nature of each arts discipline, and having more open communications with arts professionals. Based on these findings, this paper will provide and discuss about policy implications which can contribute to the performing arts domain at large.

Free vibrational behavior of perfect and imperfect multi-directional FG plates and curved structures

  • Pankaj S. Ghatage;P. Edwin Sudhagar;Vishesh R. Kar
    • Geomechanics and Engineering
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    • v.35 no.4
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    • pp.367-383
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    • 2023
  • The present paper examines the natural frequency responses of the bi-directional (nx-ny, ny-nz and nz-nx) and multidirectional (nx-ny-nz) functionally graded (FG) plate and curved structures with and without porosity. The even and uneven kind of porosity pattern are considered to observe the influence of porosity type and porosity index. The numerical findings have been obtained using a higher order shear deformation theory (HSDT) based isometric finite element (FE) approach generated in a MATLAB platform. According to the convergence and validation investigation, the proposed HSDT based FE model is adequate to predict free vibrational responses of multidirectional porous FG plates and curved structures. Further a parametric analysis is carried out by taking various design parameters into account. The free vibrational behavior of bidirectional (2D) and multidirectional (3D) perfect-imperfect FGM structure is examined against various power law index, support conditions, aspect, and thickness ratio, and for the curvature of curved structures. The results indicate that the maximum non-dimensional fundamental frequency (NFF) value is observed in perfect FGM plates and curved structures compared to porous FGM plates and curved structures and it is maximum for FGM plates and curved structures with uneven kind of porosity than even porosity.

An Information-Intensive Approach to the Molecular Pharmacology of Cancer

  • John N. Weinstein;Timothy G. Myers;Patrick M. O′Connor;Stephen H. Friend;Albert J. Fornace Jr;Kurt W. Kohn;Tito Fojo;Susan E. Bates;Lawrence V. Rubinstein;N. Leigh Anderson;John K. Buolamwini;Wiliam W. van Osdol;Anne P. Monks;Dominic A. Scudiero;Edward A. Sausville;Daniel W. Zaharevitz;Barry Bunow;Vellarkda N. Viswanadhan;Georage S. Johnson;Robert E. Wittes;Kennety D. Paull
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2001.08a
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    • pp.139-149
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    • 2001
  • Since 1990, the National Cancer Institute(NCI) has screened more than 60.000 compounds against a panel of 60 human cancer cell lines. The 50-percent growth-inhibitory concentration (GI$_{50}$) values encode unexpectedly rich, detailed information on mechanisms of drug action and drug resistance. Each compound's pattern is like a fingerprint, essentially unique among the many billions of distinguishable possibilities. These activity patterns are being used in conjunction with molecular structural features of the tested agents to explore the NCI's database of more than 460, 000 compounds, and they are providing insight into potential target molecules and modulators of activity in the 60 cell lines. For example, the information is being used to search for candidate anticancer drugs that are not dependent on intact p53 suppressor gene function for their activity. It remains to be seen how effective this information-intensive strategy will be at generating new clinically active agents.s.

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Fatigue Life Prediction of Non-Load-Carrying Cruciform Welded Joint using Master S-N Curve based on Structural Stress Approach (구조응력기반 마스터 피로 선도를 이용한 하중 비전달형 십자 필렛 용접조인트의 피로예측)

  • Kwak, Si-Young
    • Journal of Welding and Joining
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    • v.33 no.6
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    • pp.49-54
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    • 2015
  • Welding process is of importance to assemble products or structures, but also the process is structural weakness due to stress concentration in welding joint. The fatigue design of welded joint requires time & labor consuming fatigue test because the fatigue life is various according to the depth of joint, joint type and load type etc. In fatigue design codes, they guide to classify welding joints with their shape( BS7608, IIW Documents) and provide fatigue assessment information. In terms of numerical method for fatigue analysis, it is also difficult to decide the stress peak in joint because of mesh sensitivity which means that stress value is varies with element type or size on stress concentration zone. Hot-spot method is used generally, but Battelle of United States proposed Master S-N Curve based on structural stresses converted by mechanical equilibrium theory. In this research, we extracted master S-N curve from Battelle's fatigue test DB including test data of various welding joints to apply on Non-Load-Carrying cruciform Joint. Comparing fatigue results between the case of using normal stress and case of structural stress cor the cruciform Joint, The suggested Battelle method showed successive results.

Properties and low loss packing of LiNbO3 optical modulator for a broadband optical communications (광 대역 광 통신을 위한 LiNbO3 광 변조기 소자의 저손실 패키징 및 특성에 관한 연구)

  • Yun, Hyeong Do;Lee, Han Yeong;Lee, Gyeong Sik
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.38 no.5
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    • pp.35-35
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    • 2001
  • 광대역 초고속 광변조기소자 패키지와 연계되는 주요 문제점인 die feature, pigtailing, suppression of RF package resonance, RF launcher approach, termination approach의 5가지 특성을 차례로 분석한 후 우수한 특성이 나올 수 있도록 소자를 패키징하였다. Microcoax에 의해 패키징된 변조기의 전기적 특성인 S21은 10㎓ 이상까지 -3㏈ 이상의 파워를 유지하였고, $S_{11}$은 18㎓까지 -l5㏈를 유지하였다. 10㎓까지 광파워는 최대값으로부터 3㏈ 이상 떨어지지 않았고 50km 전송실험 후 소광비는 약 10.6㏈, 지터 값은 3.2ps로 양호한 값을 나타내어 패키징을 원만히 해결해야만 변조기의 변조 능력은 10㎓ 이상이 됨을 알 수 있다.

LAYOUT VERIFICATION METHOD FOR DESIGNING AND MANUFACTURING OF LCOS/AM OLED MICRODISPLAY BACKPLANES

  • Smirnov, A.G.;Koukharenko, S.N.;Volk, S.V.;Zayats, A.M.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.112-116
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    • 2006
  • In this presentation we will describe two core elements, which combination gives a new approach to layout verification; they are a computational algorithm for modeling of photolithographical processes and a method for physical layout verification that uses output contours of that algorithm. Utilization of this approach allows to improve the quality of LCOS/AM OLED backplanes physical verification, because it considers discrepancies between mask features and printed contours on a wafer.

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