용접구조물의 파괴거동을 분석하기 위해서는 용접중의 열전달 해석, 잔류응력 해석, 그리고 파괴해석이 같이 병행되어야 한다. 잔류응력이 존재하면 J-적분은 적분 경로에 관계없이 일정한 값을 갖는 특성을 잃게 된다. 그러므로 용접부의 J-적분 해석을 위해서는 별도의 프로그램을 개발하여야 한다. 본 연구에서는 균열선단에서의 J-적분을 계산하기 위한 이론식 및 프로그램을 개발하였으며 적용사례로 박판 및 후판의 다층용접에 대한 J-적분값을 계산하였다.

The heat transfer performance of R - 11 vapor condensing on integral fin tubes has been studied using fin tubes having the fin density from 748 to 1654 fins per meter. Electric heater supplied heat energy to the boiler to generate R - 11 vapor over the range of 25-60W. Condensation rates of each tubes were tested under the condition of cooling water flow rate from 400l/h to 2500l/h. For the seven fin tubes tested, the best performance has been obtained with a tube having a fin density of 1417fpm and a fin height of 1.3mm. This tube has yielded a maximum value of the heat transfer coefficient of 16500W/m2K, at a vapor to wall temperature difference of 3K. Experimental results of integral fin tubes have been compared with available predictive models such as Beatty - Katz's analysis, Webb's analysis, Sukhatme's analysis and Rudy's empirical relation. The experimental results were shown to be in good agreement with that of the Sukhatme's analysis.

One of the main problems in evaluating complex objects, such as an ill-defined system, is how to treat ambiguous aspect of the evaluation. Due to the Complexity and ambiguity of the objects, many types of evaluation attributes should be identified based on the rational dsision. One of these attributes is an analytical hierarchy process (AHP). the weight of evaluation attribtes in AHP however comes from the probability measure based on the additivity. Therefore, it is notapplicable to the objects which have the property of non-additivity. In the previous studies by other researchers they intriduced the Hierarchical Fuzzy Integral method or mergd AHP and fuzzy measure for the analysis of the overlaps among the evaluation objects. But, they need more anlyses in terms of transformation of the probability measure into fuzzy measure which fits for the additivity and overlapping coefficient which affects to the fuzzy measure. Considering these matters, this paper deals that, ⅰ) clarifying the relation between the fuzzy and probability measure adopted in AHP, ii) calculating directly the family of fuzzy measure from the overlapping coefficient and probability measure. A simple algorithm for the calculation of fuzzy measures and set family of those from the above results is also proposed. Finally, the effectiveness of the algorithm developed by applying this to the problems for estimation of safety in ship berthing and for evaluation of ports in competition is verified. This implied that the new algoritnm gives better description of the system evaluation.

이차원 선형탄성파괴역학 문제에서 인장모우드 상태의 응력확대계수를 명료하게 산정할 수 있는 독립적 적분경로에 근거를 둔 새로운 J-적분 균열모델이 제안되었다. 이 방법은 p-수렴 개념에 기초를 두며 기존의 유한요소 컴퓨터코드에 쉽게 적용할 수 있다. 본 연구에서는 균열선단에서의 응력상태가 조사되었으며, 균열선단으로부터 떨어진 정규거리로 표현되는 서로 다른 적분경로에 따라 J-적분치가 유한요소해석시 Rice의 이론처럼 경로에 독립적인 해를 얻을 수 있는지 분석되었다. 세가지 수치예제인 중앙균열판, 일변균열판과 양변균열판과 양변균열판의 p-수렴 해석결과가 종래의 h-수렴법에 의한 해석결과와 비교되었으며, 또한 이 결과는 제안된 방법의 정확성과 수치적 안정성을 보여주고 있다.

본연구는 DSC (dynamic run)의 Barrett method Integral mdthod DGEBA/MDA/MN(malononitrile) DSC DSC pre exponential factor, kinetic parameter 들을 구할 수 있었다.

This work studies for boiling and condensation heat transfer performance of trapezoidally shaped integral-fin tubes having fin densities from 748fpm to 1654fpm. For comparison, tests are made using a plain tube having the same inside and outside diameter as that of the root of fins of finned tubes. Hahne's theoretical model and Webb's theoretical model are used to predict the R-11 boiling heat transfer coefficient and condensing heat transfer coefficient respectively for plain tube and all integral-fin tubes. Experiments are carried out using R-11 as working fluid. This work is limited to film-wise condensation and pool boiling on the outside surface of plain tube and 4 low integral-fin tubes. In case of condensation, the refrigerant condenses at saturation state of 32℃ on the outside tube surface cooled by coolant and in case of boiling. the refrigerant evaporates at saturation state of 1bar on the outside tube surface. The amount of non-con-densable gases in the test loop is reduced to a negligible value by repeated purging. The actual boiling and condensing processes occur on the outside tube surfaces. Hence the nature of this surface geometry affects the heat transfer performances of condenser and evaporator in refrigerating system. The condensation heat transfer coefficient of integral-fin tube is enhanced by both extended tube surface area and surface tension. The ratio of the condensation heat transfer coefficients of finned to plain tubes is greater than that of surface area of finned to plain tubes, while ratio of the boiling heat transfer coefficient of finned to plain tubes shows reverse result. As a result, low integral-fin tube can be used in condenser more effectively than used in evaporator.

본 연구에서는 양쪽크랙 인장시험편을 이용한 평면응력 파괴인성치 J 하(1C)를 검토하기 위하여, 두께 4.5mm 일반구조용 압연강판(SS41)을 균질화 및 연화처리하고 각각의 경우에 대하여 크랙비가 0.55, 0.65, 0.75인 시험편을 준비하여 J 하(1C) 및 저항곡선의 거동을 고찰하였다. 얻어진 결과를 요약하면 다음과 같다. 1) 양쪽 크랙 인장시험편을 사용하여 J 하(1C)를 구한 값은 한계하중에 의한 방법이 Rice가 제안한 방법보다 크게 나타남을 알 수 있다. 2) Rice가 제안한 방법으로 J 하(1C)는 실험한 크랙비 범위 0.55-0.75에서 거의 일정한 값을 나타내고 저항곡선의 기울기는 크랙비에 따라 증가하였다. 3) Rice가 제안한 방법으로 [SS41의 J 하(1C)의 평균값은 모재는 22.8kgf/mm, 균질화 처리재는 24.7kgf/mm, 연화처리재는 26.9kgf/mm를 얻었다

Unlike normal wheels, the Mecanum wheel enables omni-directional movement regardless of the orientation of a mobile robot. In this paper, a robust trajectory tracking control method is developed based on the dynamic model of the Mecanum wheel mobile robot in order that the mobile robot can move along the given path in the environment with disturbance. The method is designed using the impedance control to make the mobile robot to track the path, and the integral sliding mode control for robustness to disturbance. The good performance of the proposed method is verified using the MATLAB /Simulink simulation and also through the experiment on an actual Mecanum wheel mobile robot. In both the simulation and the experimentation, we make the mobile robot move along a reference trajectory while maintaining the robot's orientation at a constant angle to see the characteristics of the Mecanum wheel.

기존 거더 형식의 교량이나 슬래브 교량에서는 신축이음장치, 받침, 역T형 교대 및 별도의 접속슬래브 구조를 이루는 시스템으로 이루어져 있다. 이러한 시스템은 신축이음부의 빈번한 파손으로 인한 비용증가, 모멘트 재분배가 낮은 구조로 인한 내구성 감소 등의 문제가 있다. 상기의 문제를 개선하기 위해 일체식 및 반일체식 복합 교량을 제안하고 구조해석을 통해 안전성을 검토하였다. 검토결과 단면강성은 작 지만 접속슬래브와 본체 구조가 연속 강결된 다연속‧ 프레임 구조계 형성과 상부구조의 경간과 단면강성의 균형으로 인하여 모멘트재분배와 힘전달이 확실하게 이루어져 기존교량에 비해 구조안전성 높은 구조임을 확인하였다.

In order to lengthen the integral abutment bridge (IAB), pile-to-pilecap performance is one of the most important parts of the bridge since IABs have no expansion joints. Therefore, this study intended to develop four new types of pile-to-pilecap connections to improve the IAB performance using numerical analysis. Developed connections allow larger displacement and successfully control the crack generations.

In this paper, an exact reshaping method for the motor dynamics of a flexible-joint robot is proposed using an integral manifold approach. Obtaining the exact model for both motor-side and linkside dynamics of a flexible-joint robot is difficult due to its under-actuated nature and complex dynamics. Despite the simple structure of the motor-side dynamics, they are difficult to model accurately for a flexible-joint robot due to motor disturbances, especially when speed reducers such as harmonic drives are installed. An integral manifold feedback control (IMFC) is proposed to reshape the motor dynamics. Based on the integral manifold approach, it is theoretically proved that the IMFC reshapes motor dynamics exactly even with bounded disturbances such as motor friction. The performance of the proposed IMFC is verified experimentally using a single degree-of-freedom flexible-joint robot under gravity conditions.

In this paper, studied on the continuous Up and Down Prestressed Concrete (UD PSC) girder bridge in which the reinforced concrete pier cap is integral with the part of girders in superstructure were performed. In previous studies, it is known that the structural behavior of continuous UD PSC girder bridge is quite different compared to the one of the bridges with conventional bearings or shoes to support the loading from girders. Nevertheless, it has hardly been studied about the structural behavior of bridge with UD PSC girder. Therefore, in this study, various static behaviors of continuous UD PSC girder bridge with integral pier cap have been analyzed using numerical method.

Pile-abutment connection in integral abutment bridge is vulnerable to cyclic thermal load and seismic load. However, research about reinforcement detail for this connection has merely been conducted throughout the world, and no codes stipulate specifications for this connection. Therefore, this study intended to investigate crack patterns due to bridge movement. Previous integral abutment bridge research utilized 2D finite element analysis. However, this study analyzed transverse responses of integral abutment bridge using 3D finite element analysis.

건설환경의 지속적인 변화로 인하여 교량 건설비용의 최소화뿐만 아니라 공용기간중의 유지관리를 포함한 전체 비용의 최소화 및 최적화의 요구가 증가하고 있다. 이러한 이유로 교량의 상부구조에서 하부구조로 힘을 전달하기 위해 사용되는 교량받침 대신에 스터드나 연결철근 등과 같은 연결재를 사용하여 교량의 상부구조와 하부구조를 라멘식으로 일체화 시킨 교량형식이 제시되고 있다. 이 논문은 교량의 상부구조 형식을 연속 UD PSC 거더로 하여 철근콘크리트 교각과 일체화 시킨 교각일체형 연속 UD PSC 거더교를 대상으로 한다. 교각일체형 연속 UD PSC 거더교는 라멘교 형식과 거더교 형식을 결합한 교량으로 일반 받침형식의 교량과 상이한 거동특성을 나타낸다. 하지만 거동 특성에 대해 명확히 규명되어 있지 않다. 따라서 본 논문에서는 해석적 방법을 이용하여 교각일체형 연속 UD PSC 거더교의 동적거동 특성을 분석하고 2, 3경간 교각일체형 연속 UD PSC 거더교에 적용할 수 있는 충격계수 산정식을 제시하였다.

Cold stress at the seedling stage is a major threat to rice production. Cold tolerance is controlled by complex genetic factors. We used an F7 recombinant inbred line (RIL) population of 123 individuals derived from the cross of a cold-tolerant japonica and a cold-sensitive indica cultivars, for QTL mapping. Phenotypic evaluation of the parents and RILs in an 18/8oC (day/night) cold-stress regime showed continuous variations for cold tolerance or sensitivity. Six QTLs for seedling cold tolerance were identified on chromosomes 1, 2, 4, 10, and 11 with percent phenotypic variation (R2) ranging from 6.1% to 16.5%. Three main-effect QTLs (qSCT1, qSCT4, and qSCT11) were detected in all cold-tolerant RILs which explained high sum of phenotypic variation (SPV) ranging from 27.1% to 50.6%. Two QTLs (qSCT1 and qSCT11) on chromosomes 1 and 11 were fine mapped. The marker In1-c3 from ORF LOC_Os01g69910 of the BAC clone B1455F06 encoding calmodulin-binding transcription activator (CAMTA) and another marker, In11-d1 from ORF LOC_Os11g37720 (Duf6 gene) of the BAC clone OSJNBa0029K08, co-segregated with seedling cold tolerance. These two InDel markers amplified 241-bp and 158-bp alleles, respectively, in cold-tolerant RILs, and in the cold-tolerant donor Jinbu, which were absent in cold-sensitive parent BR29 and cold-sensitive RILs.

237Np is very important material in the fission products of nuclear reactors. Resonance integral(RI) tests of this material is necessary to check between the experiments and the evaluated data. Such feedback to the evaluated data is very important to correct data and improve of codes. The RI for the 237Np(n,γ)238Np reaction were measured by using the 46-MeV electron linear accelerator (linac) at the Research Reactor Institute, Kyoto University (KURRI). The measurement was performed in the energy region from 0.005 eV and 10 keV. RI obtained as 804.7 barns, compared with those of the evaluated data in JENDL-4.0 and Mughabghab.

해상에서 해양사고를 예방하고 통항안전성을 증대시키기 위해 연안 VTS와 항행보조시설이 적극 검토되고 있으나 막대한 비용과 예산이 든다. 따라서 연안해역에 통항 안전성을 평가하여 우선순위를 결정해야하고 통항 안전성평가는 조선자의 관점에서 평가되어야 한다. 한편, 인간의 사고에는 많은 형태의 애매함이 존재하기 때문에 이러한 애매함을 반영하기 위해 본 연구에서는 퍼지측도와 쇼케적분을 이용하였다. 본 연구의 목적은 퍼지측도와 쇼케적분을 이용하여 조선부담감의 관점에서 평가모델을 개발하고 우리나라 연안해역을 8개로 나누고 연안 VTS와 항행보조시설 설치의 우선순위를 결정하기 위한 평가를 실시하였다.