Due to a high level of system ductility, steel moment resisting frames have been widely used for lateral force resisting structural systems in high seismic zones. Earthquake field investigations after Northridge earthquake in 1994 and Kobe earthquake in 1995 have reported that many steel moment resisting frames designed before 1990's had suffered significant damages and structural collapse. In this research, seismic performance assessment of steel moment resisting frames designed in accordance with the previous seismic provisions before 1990's was performed. Buckling-restrained braces and shear walls are considered for seismic retrofit of the reference buildings. Increasing stiffness and strength of the buildings using buckling-restrained braces and shear walls are considered as options to rehabilitate the damaged buildings. Probabilistic seismic performance assessment using fragility analysis results is used for the criteria for determining an appropriate seismic retrofit strategy. The fragility contour method can be used to provide an intial guideline to structural engineers when various structural retrofit options for the damaged buildings are available.

The growing conditions of barium nitrate Ba(NO3)2 single crystals using the aqueous solution method have been studied. Supersaturation can be calculated by measuring the temperature of the solution and its equilibrium temperature. Supersaturation of Ba(NO3)2 was 0.7% at 32.0˚C and about 3% at 34.0˚C. The obtained single crystals have three kind of morphology: tetrahedral, cubic, and, rarely, dodecahedral. The normal growth rate is proportional to the supersaturation; it is necessary to make the solution below 5% supersaturation in order to obtain transparent Ba(NO3)2 single crystals. The normal growth rate for 1ar11 faces was 2.51×10-6 mm/s for the 0.7% supersaturation condition (32.0˚C), 6.43×10-6 mm/s for the the condition of 3.0% supersaturation, and 7.01×10-6 mm/s for the condition of 5.0% supersaturation. The quality of the grown crystals depends on the nature of the seed, the cooling rate employed, and the agitation of the solution. The faces of the obtained crystals have been identified uising an X-ray diffractometer. The surface diffusion is responsible for the low growth rates of the 1ar11 faces.

The hollow slab has advantages that its self-weight does not greatly increase notwithstanding the increase of its thickness and its flexural performance does not significantly degrade in comparison with general reinforced concrete slab. However, the utilization of the hollow slab is currently being underestimated in spite of structural system that enables economic design of building and construction of eco-friendly structure. the significant reasons for this situation is that the method of structural analysis and design for hollow slab is not generalized. In this study, to consider practical compressive zone of hollow slab, the equation for its flexural strength is proposed by the volume of compressive stress block according to neutral axis location in hollow section assumed. Existing estimation method of flexural strength of hollow slab considering only compressive zone above hollow part is evaluated as the most conservative method and the method estimating flexural strength by two alternative cross-section of hollow slab is evaluated as more practical method.

In this paper, a finite element domain decomposition method using local and mixed Lagrange multipliers for a large scal structural analysis is presented. The proposed algorithms use local and mixed Lagrange multipliers to improve computational efficiency. In the original FETI method, classical Lagrange multiplier technique was used. In the dual-primal FETI method, the interface nodes are used at the corner nodes of each sub-domain. On the other hand, the proposed FETI-local analysis adopts localized Lagrange multipliers and the proposed FETI-mixed analysis uses both global and local Lagrange multipliers. The numerical analysis results by the proposed algorithms are compared with those obtained by dual-primal FETI method.

현행의 비정형 건축물과 고층 건축물의 풍하중 평가방법은 건축물의 진동모드로 선형모드를 사용하고, 1자유도 해석을 수행하기 때문에 고차모드 및 다자유도 해석에는 한계가 있다. 이러한 한계를 극복하기 위해 개발된 방법은 풍압적분법이다. 풍압적분법은 층별 풍력을 산출하는 방법으로 비정형 및 다자유도 해석을 가능하게 한다. 하지만 풍압적분법에 의해 다자유도 해석을 수행할 경우 그 유효성을 직접적으로 검증할 수 있는 방법이 없다. 따라서 선행연구에서는 풍압적분법의 유효성을 검증하기 위해 건축물의 진동모드로 선형모드를 선택하여 하나의 풍향에 대한 풍압적분법과 기존의 풍동실험방법(풍력실험, 공력진동실험)에 의해 산출된 풍응답을 비교하였고, 그 결과 각 실험에 의한 풍응답이 모두 유사하게 나타났다. 선행연구결과는 하나의 풍향에 대한 결과이므로, 본 연구에서는 풍압적분법의 적용성을 높이기 위해 풍향변화에 따른 풍압적분법의 유효성 검증연구를 수행하였다. 그 검증대상은 풍력실험에 의해 산출된 풍응답과 비교하였다.

본 연구는 풍력터빈으로 입사되는 연직풍속분포를 변화시킴으로써 풍력터빈 운전성능 향상을 위한 풍속전단 경감방법에 대한 것이다. 전산유체역학 소프트웨어인 FLUENT를 사용하여 풍력터빈의 풍상부에 설치한 전단제거 구조물 주위의 정상/비정상상태의 바람장 특성을 모사하였다. 전단제거 구조물의 형상은 펜스, 건물 또는 방풍림일 수 있다. 수치모의 결과에 의하면, 풍력터빈의 회전자 높이구간에서의 풍속전단이 확연하게 경감됨을 확인할 수 있는데, 이는 전단제거 구조물의 후단에서 발생한 유동박리 및 재순환에 의해 형성된 가상적 언덕의 풍속할증 효과 때문이다.

Recently, the optimisation of end-of-life (EOL) product remanufacturing processes has been highlighted. In particular, computer remanufacturing becomes important as the amount of disposed of computers is rapidly increasing. At the computer remanufacturing, depending on the selections of used computer parts, the value of remanufactured computers will be different. Hence, it is important to select appropriate computer parts at the reassembly. To this end, this study deals with a decision making problem to select the best combination of computer parts for minimising the total remanufacturing computer cost. This problem is formulated with an integer nonlinear programming model and heuristic search algorithms are proposed to resolve it.

Of many approaches to reduce motion analysis errors, the compensation method of anatomical landmarks estimates the position of anatomical landmarks during motion. The method models the position of anatomical landmarks with joint angle or skin marker displacement using the data of the so-called dynamic calibration in which anatomical landmark positions are calibrated in ad hoc motions. Then the anatomical landmark positions are calibrated in target motions using the model. This study applies the compensation methods with joint angle and skin marker displacement to three lower extremity motions (walking, sit-to-stand/ stand-to-sit, and step up/down) in ten healthy males and compares their performance. To compare the performance of the methods, two sets of kinematic variables were calculated using different two marker clusters, and the difference was obtained. Results showed that the compensation method with skin marker displacement had less differences by 30~60% compared to without compensation. And, it had significantly less difference in some kinematic variables (7 of 18) by 25~40% compared to the compensa- tion method with joint angle. This study supports that compensation with skin marker displacement reduced the motion analysis STA errors more reliably than with joint angle in lower extremity motion analysis.

At present, the significance of a new manufacturing system that can shift from ‘mass production’ and consider life cycles of a product is pointed out and extremely expected. In such a situation, it is recognized that the modular design, often called ‘unit design,’ is the important design methodology which realizes the new production system enabling ‘cost reduction,’ ‘flexible production of a multi-functional artifact,’ ‘settlement of an environmental issue,’ and so on. A module (unit) of a product is generally defined as ‘the parts group made into the sub-system from a certain specific viewpoint.’ So far, there have been many researches related to the modular design. However, they are often limited to a certain viewpoint (objective). This paper proposes a simple but effective method for multi-objective modular design. In the proposed method, a new design metric, called similarity index, is proposed to evaluate the modular design candidates from the multiple viewpoints.

The properties of SOFC unit cells manufactured using the decalcomania method were investigated. SOFC unit cell manufacturing using the decalcomania method is a very simple process. In order to minimize the ohmic loss of flattened tube type anode supports of solid oxide fuel cells(SOFC), the cells were fabricated by producing an anode function layer, YSZ electrolyte, LSM electrode, etc., on the supports and laminating them. The influence of these materials on the power output characteristics was studied when laminating the components and laminating the anode function layer between the anode and the electrolyte to improve the output characteristics. Regarding the performance of the SOFC unit cell, the output was 246 mW/cm2 at a temperature of 800˚C in the case of not laminating the anode function layer; however, this value was improved by a factor of two to 574 mW/cm2 due to the decrease of the ohmic resistance and polarization resistance of the cell in the case of laminating the anode function layer. The outputs appeared to be as high as 574 and 246 mW/cm2 at a temperature of 800˚C in the case of using decalcomania paper when laminating the electrolyte layer using the in dip-coating method; however, the reason for this is that interfacial adhesion was improved due to the dense structure, which leads to a thin thickness of the electrolyte layer.

이 연구는 한국한자한문교육학회에서 ‘漢字 語彙 敎育의 方法 摸索과 實行 方案’을 주제로 개최된 학술대회를 계기로 수행되었다. 개정된 한문과 교육과정에 따른 한자 어휘 교육의 실행 방안을 제안하기 위해, 중‧고교 교과 용어와 연계하 여 한자 어휘를 교육할 수 있는 방법을 모색해 보고자 한다. 우선 敎科 漢字 用語 에 대한 中․高校 學生들의 認識이 어떠한지 조사해 보고, 漢文科 敎育課程에서 한자 어휘, 특히 교과목 한자 어휘가 포함된 전문 용어를 어떻게 가르치도록 서술 되어 있는지 살펴보고, 한문 과목과 한문 외 과목의 교과서에서 한자 용어를 어떻게 수용하고 있는지 그 양상을 살펴본 후, 中․高校 敎科와 연계하여 학생들의 학습에 도움을 줄 수 있는 한자 어휘 교육 사례를 살펴보았다. 연구 결과, 각 교과에 나오는 개념어를 배울 때 漢字의 뜻을 좇아 풀이하는 방 식으로 배울 경우, 이해하기도 쉽고 기억에 오래 남는다는 사실을 학생들도 충분 히 알고 있었다. 또한, 교과 한자 용어를 강조해서 제시한 한문 교과서도 많지 않 을뿐더러, 타 과목 교과서에서 漢字를 노출시켜 교과 용어를 설명한 사례는 없음 을 알 수 있었다. 中․高校 敎科와 連繫한 漢字 語彙 敎育이 이루어지기 위해서는 각 교과의 교과서에서 한자 용어를 제시할 때 한문 축자 풀이 방식을 도입하여 제시할 필요가 있으며, 예비 교사들에게 ‘교과 한자’와 같은 강의 개설 및 운영을 통해 각 교과별 주요 한자 용어를 축자 풀이 방식으로 익힐 수 있는 기회를 제공할 필요가 있다.

Synthesis of RGO (reduced graphene oxide)-CdS composite material was performed through CBD (chemical bath deposition) method in which graphene oxide served as the support and Cadmium Sulfate Hydrate as the starting material. Graphene-based semiconductor photocatalysts have attracted extensive attention due to their usefulness for environmental and energy applications. The band gap (2.4 eV) of CdS corresponds well with the spectrum of sunlight because the crystalline phase, size, morphology, specic surface area and defects, etc., of CdS can affect its photocatalytic activity. The specific surface structure (morphology) of the photocatalyst can be effective for the suppression of recombination between photogenerated electrons and holes. Graphene (GN) has unique properties such as a high value of Young's modulus, large theoretical specific surface area, excellent thermal conductivity, high mobility of charge carriers, and good optical transmittance. These excellent properties make GN an ideal building block in nanocomposites. It can act as an excellent electron-acceptor/transport material. Therefore, the morphology, structural characterization and crystal structure were observed using various analytical tools, such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. From this analysis, it is shown that CdS particles were well dispersed uniformly in the RGO sheet. Furthermore, the photocatalytic property of the resulting RGO-CdS composite is also discussed in relation to environmental applications such as the photocatalytic degradation of pollutants. It was found that the prepared RGO-CdS nanocomposites exhibited enhanced photocatalytic activity as compared with that of CdS nanoparticles. Therefore, better efficiency of photodegradation was found for water purification applications using RGO-CdS composite.

본 논문은 1차원 자유경계문제 해석의 정확도 향상을 위해 이동최소제곱 차분법을 이용하여 이동경계의 위상변화를 implicit하게 추적하는 기법을 제시한다. 기존의 이동최소제곱 차분법은 이동경계의 위치를 explicit하게 진전시켜 반복계산 은 필요없지만 해의 정확도 감소를 피할 수 없었다. 그러나 본 연구에서 제시한 implicit 기법은 전체 계방정식이 비선형 시 스템이 되어 반복계산 과정이 필요하지만, 실제로 수치예제를 통해 검증해 본 결과 계산량의 큰 증가없이 해석의 정확도를 획기적으로 향상시켰다. 이동하는 미분불연속 특이성을 갖는 융해(melting)문제를 수치계산한 결과, implicit 이동최소제곱 차분법을 통해 2차정확도를 얻을 수 있음을 보였다.

논문은 2차원 선형탄성 직접 경계요소법에서 저매개변수 요소를 사용할 때 Kernel의 적분방법에 대하여 논의하였 다. 일반적으로 등매개변수 요소의 경우 형상함수로 통칭되는 해의 기저함수와 요소의 적분을 위해 사용되는 사상함수를 동일하게 사용한다. 그러나 본 논문에서는 사상함수의 차수를 낮게 취하여 순수기저절점을 도입하고 그때 직접 경계요소의 Kernel을 적분하기 위한 방법이 모색되었다. 일반적으로 경계요소법의 적분 Kernel의 경우 Log수치적분과 코쉬주치 (Cauchy principal value) 등을 통해 해결하는데, 본 논문에서는 대수적 조작을 통해 적분값의 정확도를 높일 수 있도록 새 로운 수식을 유도하였다. 본 연구에서 저매개변수 기반의 직접 경계요소에 대한 강건성과 정확도를 검증하기 위해 2차원 타원형 편미분방정식으로 표현되는 평면응력과 평면변형문제에 대해 적용하였다. 적용 예제로는 단순연결영역(simple connected region)의 대표적 문제인 캔틸레버보와 다중연결영역(multiple connected region)의 대표적인 문제인 개구부가 있는 사각평면에 대해 각각 수치해석을 수행한 결과 대폭적인 자유도의 감소에 비해 정확도 측면에는 기존의 방법과 차이 가 없음을 볼 수 있었다. 본 논문에서 제시된 방법은 기저함수 고차화 저매개변수 직접 경계요소법(subparametric high order boundary element)과 이에 기초를 둔 저매개변수 고차 이중경계요소법(subparametric high order dual boundary element)의 초석이 될 수 있을 것이다.

Since June 25th 1950, the beginning of the cold war (Korean war), Korean peninsula is still in a state of war. Officially South and North Korean government call a truceafter three years from the beginning day, however both countries are still having several combats in these days. So every Korean citizen male has duty for serving military duty and this lasts even after the serving regular military force, as reserved military. Although South Korea is very small country, the size of military is very large so informing all reserved military takes some time. Since this nation is confronting the enemy and considering the global potential threat, South Korean military needs expedite informing system to call up the reserved military to active duty. In this project, the current informing system has been analyzed and compared with the new method which is using social network service such as Twitter. However mobilization order is very critical. So in our new model there are two ways combined. Using twitter to inform and then use traditional ways to finish the order. This method will provide more efficient and accurate way to cover the call ups.

Risk Assessment to list possible safety disasters and their probability and severity is the starting point for effective safety management on construction project site. However, the safety managers in owners, construction supervisors, contractors, and sub-contractors still have difficulties in judging the priorities of safety activities and preparing responses to each potential safety disasters. Therefore, this study aimed to suggest a systematic method in assessing safety risk prior to commencement with the agreement of stakeholders. FMECA(failure mode effects and criticality analysis) was selected as a main assessment tool and it was modified according to the characteristics of construction projects and trades. Each risk is, firstly, evaluated with occurrence probability, possible loss and impacts to projects, and detections, and then risk priority number(RPN) is calculated. Subsequently, the managers of each stakeholder discuss the types, timing, and responsibilities of responses as a group decision-making process.

본 연구에서는 분자동역학 전산모사와 유한요소해석 기반의 균질화 기법을 통해 나노복합재의 열전도 특성을 정확하고 효율적으로 예측할 수 있는 순차적 멀티스케일 균질화 해석기법을 제안하였다. 나노입자의 크기효과가 나노복합재의 유효 열전도 특성에 미치는 영향을 조사하기 위해 크기가 다른 구형 나노입자가 첨가된 나노복합재의 열전도 계수를 분자동역 학 전산모사를 통해 예측했고, 그 결과 나노입자의 크기가 작아질수록 계면에서의 Kapitza열저항에 의해 나노복합재의 열 전도 계수가 점차 감소하는 것으로 나타났다. 이러한 나노입자의 크기효과를 균질화 해석모델을 통해 정확하게 묘사하기 위해 Kapitza 열저항에 의한 계면에서의 온도 불연속 구간과 고분자 기지가 높은 밀도를 가지며 흡착되는 유효계면을 추가 적인 상으로 도입하여 나노복합재를 입자, Kapitza 계면, 유효계면, 기지로 구성된 4상의 연속체 구조로 모델링하였다. 이 후 순차적 멀티스케일 균질화 해석기법을 통해 유효계면의 열전도 계수를 나노복합재의 열전도 계수로부터 역으로 예측 했으며, 이를 입자의 반경에 대한 함수로 근사하였다. 근사 함수를 토대로 다양한 입자 체적분율과 반경에 대한 나노복합 재의 유효 열전도 특성을 예측하였으며, 유효계면에 대한 매개변수 연구를 수행하였다.

모듈러 강교량 제작, 조립, 설계, 시공단계에서 상부모듈의 부품정보를 효율적으로 제공하고 교환하기 위하여 BIM (Building Information Modeling) 프로젝트에서 정보교환을 위하여 사용하는 국제표준인 IFC 모델을 활용한 부품정보 라이 브러리 구축방법을 제시하였다. 모듈러 강교량의 상부모듈을 구성하는 부품정보를 IFC 모델로 표현하기 위하여 의미론적 인 관점에서 기존 IFC 모델에서 부품정보를 표현할 수 있는 엔티티와 모듈러 강교량의 구성요소를 매칭하여 적용하였으 며, 구성요소의 역할을 구분하기 위하여 매칭한 엔티티의 타입을 적용하거나 사용자정의 타입으로 정의하였다. 또한, 부품 정보 라이브러리에서 부품 및 조립품의 정보를 해당단계에서 효율적으로 제공하기 위하여 조립체계를 네 단계의 상세수준 (LoD)으로 구분하여 정의하였으며, 이를 IFC 모델로 표현하기 위하여 새로운 속성정보를 정의하였다. 마지막으로, IFC 모 델과 매칭하여 정의한 정보를 실제 모듈러 강교량 상부모듈에 적용하여 IFC 기반의 시범 라이브러리 정보를 생성하였다.

When discussing about CSL literary activities, most researchers focus on paper materials and theories of second or foreign language teaching are rarely applied. In order to go beyond the limitations, in this study we would like to explore the literary teaching activities when combining the digital materials and task-basking teaching method in the CSL classroom. One CSL teacher and 6 German students are invited to participate in this study. After the practice of CSL curriculum with digital materials and task-based teaching method, two results are found. First, in terms of task-based teaching method the CSL teacher spent more time on explaining than on doing and evaluating the language tasks. Second, with regard to difficulty, the CSL teacher would choose to lecture the class and skip the literary and discussion activities if the contents of digital materials were difficult. Therefore, we conclude that the CSL digital materials can provide students more literary opportunities; however, the CSL teacher may not change his/her teaching method and literary activities because of the use of digital materials.

本文主张改变目前流行的搬用拼音文字教学法的汉字教学法。因为这种教学不合汉字汉语特点，忽视中国千百年来的传统经验。中国古代中文启蒙教学主张先利用汉字特点集中识字，然后读《杂字》学词，再读四言短语如《千字文》，再读经典语句如《贤文》，再读文言文如《论语》。学习者的精力用于书面语汇积累，快捷有效。本文倡议中文五步教学法的五步是： 集中识字→集中识词→集中读短语→集中读句→集中读文言文。 于此同时，学习者自读大量白话短文。（不必由教师教）有利培养独立阅读能力，调动兴趣，满足求知欲。 这样做是基于以下理论依据： 1、中文启蒙教学有其特殊性。 2、掌握书面语汇是学会中文的关键。 3、白话文可以自读。文言文要教。