• Structural Engineering and Mechanics
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• 제43권1호
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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.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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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.

• Structural Engineering and Mechanics
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• 제60권1호
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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.

• Kyungpook Mathematical Journal
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• 제60권4호
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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.

• 문화경제연구
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• 제19권2호
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• pp.97-120
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• 2016

아무리 좋은 목적을 가진 정책이라도 본래 의도한 결과를 적절한 평가 및 보완과정 없이 단번에 실현하는 경우는 드물다. 이 논문은 '창작산실육성지원사업의 정책대상자인 예술가들은 동 사업의 효과와 문제점을 어떻게 바라보고 평가하는가?'를 연구문제로 설정하여, 정책집행과정연구의 한 방식인 상향식접근(bottom-up approach)이론을 통해 정책현장의 관점을 체계적으로 분석했다. 연구방법으로 초점집단면접(FGI)과 개인심층면접(PII)을 사용하였으며, 자료의 수집은 2015년 9월부터 약 3달간 진행되었다. 연구참여자는 총 28명으로 창작산실사업을 통해 지원받은 예술가그룹(n=21)과 심사에 참여했던 전문가그룹(n=7)으로 구성하여 직접적인 수혜자가 바라본 정책사업에 대한 인식과 평가를 보다 객관적으로 이해할 수 있도록 설계했다. 자료 분석결과, 일부 긍정적인 사업의 성과에 있어 공통의 합의점을 찾을 수 있었으나 작품지원 후 작품에 대한 사후지원, 유통 및 관리, 심의과정에 대한 공정성과 심의위원 위촉과정의 투명성, 단계별 심사의 장르적 특성을 반영한 유연한 설계 및 심의결과 공개를 통한 예술계와의 소통 등이 반드시 개선되어야 할 사항으로 도출되었다. 본 논문은 상향식접근이론을 준거로 예술지원사업의 정책대상자를 통해 공공기금의 적절한 운용과 이에 따른 예술계의 발전방향에 실질적이고 구체적인 제언을 도출하였다.

• Geomechanics and Engineering
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• 제35권4호
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• pp.367-383
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• 2023

The present paper examines the natural frequency responses of the bi-directional (n_x-n_y, n_y-n_z and n_z-n_x) and multidirectional (n_x-n_y-n_z) 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.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2001년도 제2회 생물정보학 국제심포지엄
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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.

• Journal of Welding and Joining
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• 제33권6호
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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.

• 한국항해항만학회지
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• 제35권1호
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• pp.31-38
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• 2011

오늘날 해상교역과 국제 혼승선박의 지속적인 증가로 선박의 안전운항을 위한 항로표지와 관련하여 우선 해사영어의 표준화 연구가 필요하다. 항로표지장비 및 용품 표준규격심의회 조직의 검토결과 현행 심의회의 활동만으로는 다양한 종류의 항로표지의 표준화를 충족시킬 수 없었고 실무적 진행을 위해서는 실무위원회가 항로표지의 종류별로 구성될 필요가 있기에, 조직원의 구성에 있어서는 표준규격 심의회의 유연성과 전문성을 조화시킨 민 관 학 연의 통합적 접근이 바람직하다. 항로표지와 관련해사영어의 표준화 방안의 연구결과에서 각과정마다 대상, 등급 및 학습목표가 제시 되었으며, 이 모든 과정에 적용될 수 있는 교육/훈련단계는 통역/커뮤니케이션의 근본원리를 적용한 난이도에 따라 구분되었다. 본 논문의 기여는 항로표지와 관련한 제도정비의 근본이 되는 관련해사영어의 우선적 표준화 방안을 제시하여 현재 해사분야에서 실무전문성이 결여된 시청각 영어교육훈련의 문제점을 해결하기 위한 최초의 방안구축에 있다.

• 대한전자공학회논문지SD
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• 제38권5호
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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.