Reliability-based Evaluation of Load Carrying Capacity for a Composite Box Girder Bridge

김현중,김호경,박준용 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.3

The load carrying capacity of a composite open-top steel box girder bridge was evaluated, based on a reliability-based method, and potential differences from conventional approaches were evaluated. A practical analysis model was utilized in evaluating the Rating Factor (RF) after verification with a rigorous full finite element analysis model with solid and plate elements. The accuracy of the analysis models was validated in terms of displacements and distribution factors through static loading tests. Dynamic effects were also estimated from the dynamic loading tests. The load factors, proposed for the purpose of evaluation based on recently accumulated statistical data, were utilized in evaluating RF. The RFs were evaluated for maximum positive flexure, negative flexure,and shear regions along the bridge. The calculated RF with the load factors for evaluation purposes was higher by 35% than that with design load factors. The proposed method also produces a 29% increase in RF compared to the conventional allowable stress design approach. Consequently, the proposed reliability-based procedure would be expected to permit a more economical assessment of bridge performance to be made.

個別敎授法

김현중 경기대학교학생생활종합센타 1988 學生生活硏究 Vol.7 No.-

INDUSTIAL DESIGN 方法論에 關한 事例硏究 : 디자인 프로세스를 中心으로

金炫重 同德女子大學校 1984 同大論叢 Vol.14 No.1

Literature on design methods began to appear in most industrialized countries in the nineteen fifties and sixties. Before that time it was sufficient to know that designing was what architects, engineers, industrial designers and other did in order to produce the drawings needed by their clients and by manufacturers. Now filings are different. There are plenty of professional designers who doubt the procedures that they have been taugh to use and plenty of new methods that have been invented to replace the traditional ones. A common feature of both the criticisms of traditional methods and the proposals for new ones is the attempt to isolate tile essence of designing and to write it down as a standard method or recipe, that can be relied upon in all situations. One of the simplest and most common observation about designing, and one upon which many writers agree, is that it includes the three essential stage of analysis, synthesis, and evaluation. These can be described in simple words as 'breaking the problem into pieces','putting the pieces together in a new way'and 'testing to discover the consequences of putting the new arangement into practice' **Designing as a three-stage process (J. christopher Jones) The three stage are here named divergence, transformation and convergence. The chief characteristics of three stage process are as follows. A. Divergence 1. The objectives are unstable and tentative. 2. The problem boudary is unstable and undefined. 3. Evaluation is deferred. B. Transformation 1. The main objective is to impose, upon the results of a divergent search, a pattern that is precise enough to permit convergence to single design that must eventually be decided upon and fixed in every detail. 2. This is the stage when objectives, brief and problem boundaries are fixed, when critial variables are identified, when constraints are recognized, when opportunities are taken and when judgment are made. 3. It is also the stage when the problem is split up into sub-problems each of which is judged to be capable of solution in series, or in parallel, and in relytive isolation. C. Convergence 1. Persistence and rigidity of mind and method is a trirtue; flexibility and vagueness are to be shunned, 2. The snag is convergence is, of course, that unforeseen sub-problems prove to be critical, i.e. to be insoluble unless an earlier decision is changed, the causing recycling. 3. The models used to represent the range of alternatives remaining should become less abstract and more detailed during convergence. **The RIBA plan of work map of the design process The RIBA practice and management hand book tells us that the design process may be divided into four phases. A. Phase 1 assimilation The accumulation and ordering of general information and information specifically related to the problem in hand. B. Phase 2 general study The investigation of the nature of the problem. The investigation of possible solutions or means of solution. C. Phase 3 development The development and refinement of one or more of the tentative solutions isolated during phase 2. D. Phase 4. communication The communication of one or more solutions to people inside or outside the design team. **The Markus/Marver map of design process Markus and subsequenty Maver have developed and related RIBA maps of designing They argue that a complete picture of design method reguires both a "decision sequence'and "design process" or "morpholog" . hfarkus Markus and Maver suggest that we need to go through the decision sequence of analysis, sythesis, appraisal, and decision at increasingly detailed levels of the design process. Design problems and design solutions are inexorably interdependent. It is obviously meaningless to study solutions writhout reference to problems and reverse is equally fruitless. The more one tries to isolate and study designproblems the more important it becomes to refer to design solution. In design, design problem and design solutions has certain features as follows, it is worth pausing briefly here to summarise some of the important characteristics of design problems and solutions and the lessons that can be learnt about the nature of the design process itself. Design problems 1. Design problems cannot be comprehensively stated. 2. Design problems require subjective interpretation. 3. Design problems tend to be organized hierarchically. Design situation 1. There are an inexhaustible number of different solutions. 2. There are no optimal solutions to design problems. Design process 1. The process is endless. 2. There is no infallibly correct process. 3. The process involves finding as well as solving problems. 4. Design inevitably invelves subjective value judgement. 5. Design is a prescriptive activity. 6. Designers work in the context of a need for action.

IS-95 Reverse Link 규격의 Viterbi Decoder 설계

김현중,이찬호 崇實大學校 生産技術硏究所 2001 論文集 Vol.31 No.-

Recently, the Viterbi algorithm is widely used for the decoding of convolutional codes. This paper proposes a Viterbi decoder using the modified register exchange to reduce the amount of memory storing the survivor path information and to increase the decoding speed. The decoder complies IS-95 Reverse link specification with K=9, and code rate of 1/3. The decoder is designed using the Xilink Foundation tool and the operation is verified by simulations.

무정형 탄소의 입도분포에 따른 리튬이온이차전지의 탄소부극 특성

김현중,이철태 ( Hyun Joong Kim,Chul Tae Lee ) 한국공업화학회 1998 공업화학 Vol.9 No.5

K-GIC 의 합성 및 리튬이온이차전지에서의 부극특성

김현중,이철태 ( Hyun Joong Kim,Chul Tae Lee ) 한국공업화학회 1998 공업화학 Vol.9 No.5

슈퍼커패시터용 탄소에어로젤의 대량생산을 위한 솔-젤변수의 최적화

김현중,김원일,서동진,박태진,박형상 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.1

전기전도성을 가진 탄소에어로젤은 단위부피 당 높은 비표면적을 가져 전기이중층 커패시터의 전극으로 사용될 수 있는 이상적인 물질로 알려져 있다. 탄소에어로젤은 솔-젤 반응을 통해 유기젤을 합성한 후 초임계건조와 열분해를 거쳐 제조된다. 본 연구에서는 유기젤의 제조 시 초임계건조에 적합한 알코올류를 용매로 사용할 수 있으며, 페놀류나 Resorcinol보다 반응성이 우수하다고 알려진Phloroglucinol과 Formaldehyde를 출발물질로 사용하여 제조 조건에 따라 수시간에서 수일내에 젤화및 숙성을 거쳐 초임계건조가 가능한 솔-젤 제법을 개발하였다. 그 결과 솔-젤 변수의 변화에 따른 유기젤과 탄소에어로젤의 물성 변화를 유도하여 높은 비표면적을 가진 탄소에어로젤 물질을 제조할 수있었으며, 이러한 고비표면적의 탄소에어로젤은 최고 250 F/g의 높은 축전상수를 가짐으로써, 전기이중층 커패시터의 전극 물질로서 가능성을 보이고 있다. 이러한 탄소에어로젤의 대량생산시 솔-젤 변수 외에 유기젤의 용적 등이 탄소에어로젤의 물성변화에 영향이 있음을 알 수 있었으며, 탄소에어로젤의 대량생산을 위해 솔-젤 변수 및 기타 변수들을 최적화하였다.

리튬이온이차전지에서 결정성 탄소재료가 탄소부극 특성에 미치는 영향

김현중,이철태 ( Hyun Joong Kim,Chul Tae Lee ) 한국공업화학회 1998 공업화학 Vol.9 No.7

아크릴계 점착제의 박리강도와 점착부여제

김현중 서울대학교 농업개발연구소 1999 농업생명과학연구 Vol.3 No.-

The stability and performance (peel strength) of the acrylic copolymer and various modified rosin systems were investigated. The peel strength was measured over a wide range of scling rates, and the influence of the viscoelasticity of the PSA (pressure sensitive adhesive) was considered. In the case of miscible systems, the peak of peel strength (PSA performance) over wide peel rates was changed and modified systematically with increasing glass transition temperature of the blends. The peak of the peel strength for blended systems shifts toward the lower rate side as glass transition temperature (Tg) of the blend increased. The influence of esterification of the rosin on performance and stability against deterioration was greatly modified by blending with rosin of glycerol ester and rosin pentaerythritol ester. The failure mode of the blend varies with the combination with acrylic copolymer and modified rosin, and cohesive failure was found at a lower peel rate while interfacial failure was found at a high peel rate. A few systems where a single Tg could be measured, despite the fact that two phases were observed microscopically, were detected.

적성과 교수법

김현중 경기대학교학생생활종합센타 2000 學生生活硏究 Vol.17 No.-