The concrete-filled tube (CFT) column has the excellent structural performance. But it is difficult to connect with column and beam because of closed section. Its Solution, 2 members of ㄷchennel in which Internal diaphragm is installed were welded beforehand and the method of making Rectangular Steel Tube was proposed. According to upside and downside junction shape, Internal diaphragm suggested as symmetric specimen and asymmetric specimen. The upper and lower diaphragm of the Symmetric specimen used the same horizontal and The upper diaphragm of the Asymmetric specimen used the horizontal plate and the lower diaphragm used the vertically plate. In this research, 4 T-shape column to beam steps connections were tested with cyclic loading experiment in order to evaluate the structural capability of the offered connection. Symmetric specimens be a failure in 0.03rad from beam flange. And Asymmetric specimens be a failure in 0.05rad from column interface. The comparison results of All specimens shown similar to energy absorption capacity in 0.02rad.

본 논문에서는 단일 센서와 공간집속 신호처리 기술로 시간 역전과 인버스 필터링을 이용하여 이방성 평판에 서 충격 위치를 결정할 수 있는 탐상법을 다루었다. 유한 평면에서 굽힘 파의 운동 방정식을 유도하여, 그 식을 통해 얻어진 데이터를 기반으로 해석적인 시뮬레이션을 통해 시간 역전과 인버스 필터링의 시간 집속 효과를 확 인하고 충격 위치와 그 주변에서 신호의 공간 집속 효과를 관찰하고 충격 위치 결정에 영향을 미칠 수 있는 인자 들(총 수신시간, 샘플링 주파수)에 대해 살펴보았다. 그리고 충격원의 위치에 따른 2차원 결과를 제시하고, 실제 충격 위치를 정확하게 결정할 수 있음을 확인하였다. 여기서 제안한 방법은 기존의 충격 위치 결정법에 비해 많은 장점을 갖고 있다. 첫 번째로 단일 센서를 사용하는 것과 시험체의 형상과 물성을 몰라도 된다는 점이다. 또한 판 에서와 같이 분산성에 의한 다중모드 파동이 발생하는 경우에도 특정 모드나 주파수에 의존할 필요가 없다.

본 논문에서는 단일 센서와 공간집속 신호처리 기술로 시간 역전과 인버스 필터링을 이용하여 등방성 평판에 서 충격 위치를 결정할 수 있는 탐상법을 다루었다. 유한 평면에서 굽힘 파의 운동 방정식을 유도하여, 그 식을 통해 얻어진 데이터를 기반으로 해석적인 시뮬레이션을 통해 시간 역전과 인버스 필터링의 시간 집속 효과를 확 인하고 충격 위치와 그 주변에서 신호의 공간 집속 효과를 관찰하고 충격 위치 결정에 영향을 미칠 수 있는 인자 들(총 수신시간, 샘플링 주파수)에 대해 살펴보았다. 그리고 충격원의 위치에 따른 2차원 결과를 제시하고, 실제 충격 위치를 정확하게 결정할 수 있음을 확인하였다. 여기서 제안한 방법은 기존의 충격 위치 결정법에 비해 많 은 장점을 갖고 있다. 첫 번째로 단일 센서를 사용하는 것과 시험체의 형상과 물성을 몰라도 된다는 점이다. 또한 판 에서와 같이 분산성에 의한 다중모드 파동이 발생하는 경우에도 특정 모드나 주파수에 의존할 필요가 없다.

This paper presents experimental studies aiming at evaluation of structural behaviors of RC (Reinforced Concrete) beams externally strengthened with taper ended CFRPs(Carbon Fiber Reinforced Polymers). Experiments are performed with RC beams having different numbers of CFRP layers and length of each layer. The beams are subjected to four point-bending with simply supported condition. Test results of taper ended CFRPs and non-tapered CFRPs are compared and the better strengthening effect is observed from tapered ended CFRPs.

In Korea, most existing school buildings have been constructed with moment frames with un-reinforced infill walls designed only considering gravity loads. Thus, the buildings may not perform satisfactorily during earthquakes expected in Korea. In exterior frames of the building, un-reinforced masonry infill walls with window openings are commonly placed, which may alter the structural behavior of adjacent columns due to the interaction between the wall and column. The objective of this study is to evaluate the seismic performance of existing school buildings according to the procedure specified in ATC 63. Analytical models are proposed to simulate the structural behavior of columns, infill walls and their interaction. The accuracy of the proposed model is verified by comparing the analytical results with the experimental test results for one bay frames with and without infill walls with openings. For seismic performance evaluation, three story buildings are considered as model frames located at sites having different soil conditions ( ,  ,  ,  ,  ) in Korea. It is observed that columns behaves as a short columns governed by shear due to infill masonry walls with openings. The collapse probabilities of the frames under maximum considered earthquake ranges from 62.9 to 99.5 %, which far exceed the allowable value specified in ATC 63.

본 연구는 덕유산, 계방산의 가문비나무 군락의 보존을 위한 기초자료를 제시하기 위하여 종조성과 흉고직경급을 조사, 분석하였다. 두 조사지의 교목․아교목․관목층의 층위별 식생은 덕유산이 8, 20, 26종, 계방산이 12, 23, 33종으로 구성되어 있다. 층위별 중요치 분석 결과, 덕유산 교목층은 가문비나무, 사스래나무, 구상나무, 아교목층은 사스래나무, 신갈나무, 관목층은 조릿대가 중요치가 높았으며, 계방산의 교목층은 가문비나무, 사스래나무, 분비나무, 아교목층은 시닥나무, 부게꽃나무, 관목층은 미역줄나무의 중요치가 가장 높은 것으로 분석되었다. 조사구의 층위별 종다양도의 경우 교목층은 덕유산 0.779, 계방산 0.984, 아교목층은 덕유산 1.052, 게방산 1.161, 관목층은 덕유산 0.823, 계방산 1.304로 분석되었다. 흉고직경 분포에서는 덕유산지역의 가문비나무 개체군이 역J형의 유형이 나타나고 있어 당분간 가문비나무군락이 유지될 수 있을 것으로 판단된다.

The construction of a moment connection for a rectangular hollow section (RHS) column and a H-shaped beam is difficult because the RHS is a closed section. When a inner diaphragm is used for such a connection, in general, it is installed after cutting the HSS columns, which results in increased construction work. This paper suggests a new fabrication method to overcome such problems: An inner diaphragm is welded to inside a C-shaped section first, and then a column is fabricated by welding two C-shaped sections. This fabrication method is superior to a classic method in terms of constructibility. An experimental and a numerical study using Ansys 9.0 were performed in order to compare the strength of connections with respect to the presence of concrete, the corner shape of diaphragm, and the axis of loading. The experimental results including initial stiffness and ultimate loads are reported and the analytical results including load transfer mechanism, degree of stress concentration, and strain distribution are also reported.

본 연구는 2009 개정 교육과정에서 교과 집중이수제, 창의적 체험활동의 실질적 적용, 학교의 자율권 확대 등 획기적인 변화를 시도하였다. 이러한 변화에 따라 집중이수를 하게 된 도덕교육의 효과를 높이기 위해 3개 학년 도덕 교과서를 재구조화하고, 도덕 교과의 근간이 되는 인성 교육과 진로 체험중심 프로그램을 개발․적용함으로써 집중이수 학습 능력 신장을 극대화하고자 하였다. 연구의 목적을 효과적으로 달성하기위하여 첫째 3개 학년 교과서를 각 영역의 학습 목표와 부합한 내용, 학생들의 능력과 흥미를 고려하여 재구성하고자 하였다. 둘째 1학년 과정에서 집중이수제를 운영함에 따라 학생의 이해 수준에 맞도록 체험 중심의 학습 자료 및 자기주도 학습 방법 등 수업 방법을 개선하고자 하였다. 셋째 교과 내용에서 인성 함양과 진로 교육에 중점을 두고 다양한 학습 자료를 구안 적용하고자 하였다.

This study presents the effectiveness of a composite structure at improving blast resistance. The proposed composite structure consists of carbon fiber reinforced polymer (CFRP) and steel layers. While CFRP layer is used for blast energy reflection due to its high strength, steel layer is used for blast energy absorption due to its high ductility. A dynamic model is used to simulate the elastoplastic behavior of the proposed composite structure subject to blast load. Considering the magnitude variations of a blast event, the probability of failure of each layer is evaluated using reliability analysis. By assigning design probability of failure of each layer in the composite structure, the thickness of layers is optimized. A case study for the design of CFRP-steel composite structure subjected to an uncertain blast event is also presented.

In this study, the structural analysis for bellows joint of high-performance that can enhance the performance of seismic isolation piping was performed. Bellows joint is that the corrugated flexible piping is connected at the both sides of elbow. An one axis of the bellows joint fixed, and the other end of the axis changes the position from 0° to 315° for the radius displacement of 500 mm. Results obtained are as follows for this case in analysing of the maximum stress and plastic strain of the bellows joint. As the location of the base isolation displacement get farther from the fixed pipe, the bellows joint is pulled, and the maximum stress and plastic deformation is increased. And so the maximum stress occurs near the bellows at both ends of the elbow. Displacement in the 135° position, a maximum stress of 837 MPa and a plastic strain of 3.00% was the highest.

The researches related to active control systems utilizing superelastic shape memory alloys (SMA) have been recently conducted to reduce critical damage due to lateral deformation after severe earthquakes. Although Superelastic SMAs undergo considerable inelastic deformation, they can return to original conditions without heat treatment only after stress removal. We can expect the mitigation of residual deformation owing to inherent recentering characteristics when these smart materials are installed at the part where large deformation is likely to occur. Therefore, the primary purpose of this research is to develop concentrically braced frames (CBFs) with superelastic SMA bracing systems and to evaluate the seismic performance of such frame structures. In order to investigate the inter-story drift response of CBF structures, 3- and 6-story buildings were design according to current design specifications, and then nonlinear time-history analyses were performed on numerical 2D frame models. Based on the numerical analysis results, it can be comparatively verified that the CBFs with superelastic SMA bracing systems have more structural advantages in terms of energy dissipation and recentering behavior than those with conventional steel bracing systems.

본 연구는 기업지배구조가 자본구조에 미치는 영향을 실증적으로 다루었다. 기존 연구는 자본구조는 자본조달과정에서 기업가치 극대화를 위한 레버리지의 정태적 변화에 대해서 주로 다루었다. 또한 기업지배구조에 따라 부채와 보유현금 및 자본지출과 같은 재무구성요소의 특성분석에 치중하였다. 본 연구에서는 이러한 재무구성요소의 특성을 기업지배구조에 따라 자본구조에 유의한 차가 있는지를 규명하고자 하였다. 이를 위해 사용된 기업지배구조는 기존 선행 연구에서 검증된 외국인보유율, 사외이사구성비율, 대주주보유율, 배당수익률의 시계열자료와 이들 변수들을 반영한 G-Index 지수를 사용하였다. 연구결과, 기업지배구조를 상하그룹으로 분리하여 자본구조에 대한 특성을 분석하였을 때, 기업지배구조에 따라 자본구조에 차이가 있다는 것으로 나타났다. 즉, 기업지배구조가 양호한 상위그룹은 상충이론(trade-off theory)에 부합하는 자본구조를 갖고, 기업지배구조가 열악한 하위그룹은 자본조달순위이론(pecking order theory)에 부합하는 자본구조를 갖는 것으로 나타났다.

PURPOSES : Traffic accidents at intersections have been increased annually so that it is required to examine the causations to reduce the accidents. However, the current existing accident models were developed mainly with non-linear regression models such as Poisson methods. These non-linear regression methods lack to reveal complicated causations for traffic accidents, though they are right choices to study randomness and non-linearity of accidents. Therefore, to reveal the complicated causations of traffic accidents, this study used structural equation methods(SEM). METHODS : SEM used in this study is a statistical technique for estimating causal relations using a combination of statistical data and qualitative causal assumptions. SEM allow exploratory modeling, meaning they are suited to theory development. The method is tested against the obtained measurement data to determine how well the model fits the data. Among the strengths of SEM is the ability to construct latent variables: variables which are not measured directly, but are estimated in the model from several measured variables. This allows the modeler to explicitly capture the unreliability of measurement in the model, which allows the structural relations between latent variables to be accurately estimated. RESULTS : The study results showed that causal factors could be grouped into 3. Factor 1 includes traffic variables, and Factor 2 contains turning traffic variables. Factor 3 consists of other road element variables such as speed limits or signal cycles. CONCLUSIONS : Non-linear regression models can be used to develop accident predictions models. However, they lack to estimate causal factors, because they select only few significant variables to raise the accuracy of the model performance. Compared to the regressions, SEM has merits to estimate causal factors affecting accidents, because it allows the structural relations between latent variables. Therefore, this study used SEM to estimate causal factors affecting accident at urban signalized intersections.

PURPOSES : This study is to develop ISM for potential risk factor in School Zone. METHODS : Based on the literature review, the Analytic Hierarchy Process (AHP) has been used most widely. However, it is difficult to apply in practice because the AHP results have the characteristics of the independence between each element and the interlayer can not explain the interrelationship. The Network Analysis Process (ANP) is possible to analyze the relationship between the elements and the network through the feedback. But, the reliability of the analysis fall because of complicated pair of comparison, also it is difficult to solve the super matrix. In this study, the complicated relationship between each element is inquired through the Interpretive Structural Modeling (ISM). RESULTS : The methodology of ISM is developed to remove the children's potential risk factors in school zone. CONCLUSIONS : It is possible to remove the children's potential risk factors from low level to high level step by step and improve safety. Through this, risk factors can be removed from the low-level, and upper-level will automatically improve.

Nickel oxide was doped with a wide range of concentrations (mol%) of Aluminum (Al) by solvothermal synthesis;single-phased nano powder of nickel oxide was generated after calcination at 900oC. When the concentration of Al dopant wasincreased, the reduced intensity was confirmed through XRD analysis. Lattice parameters of the synthesized NiO powder weredecreased after treatment of the dopant; parameters were increased when the concentration of Al was over the doping limit(5mol% Al). The binding energy of Ni2+ was chemically shifted to Ni3+ by doping Al3+ ion, as confirmed by the XPS analysis.The tilted structure of the synthesized NiO with 5mol% Al dopant and the polycrystalline structure of the Ni0.75Al0.25O wereobserved by HR-TEM analysis. The electrical conductivity of the newly synthesized NiO was highly improved by Al dopingin the conductivity test. The electrical conductivity values of the commercial NiO and the synthesized NiO with 5mol% Aldopant (Ni0.95Al0.05O) were 1,400s/cm and 2,230s/cm at 750oC, respectively. However, the electrical conductivity of thesynthesized NiO with 10mol% Al dopant (Ni0.9Al0.1O) decreased due to the scattering of free-electrons caused by the largenumber of impurity atoms; the electrical conductivity of Ni0.9Al0.1O was 545s/cm at 750oC.

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.

Recently, ultrafine grained (ufg, typically 100 > d > 500 nm) Ti-Fe eutectic materials have been highlighted due to their extraordinarily high strength and good abrasion resistance compared to conventional coarse grained (cg, d > 1μm) materials. However, these materials exhibit limited plastic strain and toughness during room temperature deformation due to highly localized shear strain. Several approaches have been extensively studied to overcome such drawbacks, such as the addition of minor elements (Sn, Nb, Co, etc.). In this paper, we have investigated the influence of the addition of Gd and Y contents (0.3-1.0 at.%) into the binary Ti-Fe eutectic alloy. Gd and Y are chosen due to their immiscibility with Ti. Microstructural investigation reveals that the Gd phase forms in the eutectic matrix and the Gd phase size increases with increasing Gd content. The improvement of the mechanical properties is possibly correlated to the precipitation hardening. On the other hand, in the case of Ti-Fe-Y alloys, with increasing Y contents, primary phases form and lamellar spacing increases compared to the case of the eutectic alloy. Investigation of the mechanical properties reveals that the plasticity of the Ti-Fe-Y alloys is gradually improved, without a reduction of strength. These results suggest that the enhancement of the mechanical properties is closely related to the formation of the primary phase.

Recently, the demand for the miniaturization of package substrates has been increasing. Technical innovation has occurred to move package substrate manufacturing steps into CMP applications. Electroplated copper filled trenches on the substrate need to be planarized for multi-level wires of less than 10μm. This paper introduces a chemical mechanical planarization (CMP) process as a new package substrate manufacturing step. The purpose of this study is to investigate the effect of surfactant on the dishing and erosion of Cu patterns with the lines and spaces of around 10/10μm used for advanced package substrates. The use of a conventional Cu slurry without surfactant led to problems, including severe erosion of 0.58μm in Cu patterns smaller than 4/6μm and deep dishing of 4.2μm in Cu patterns larger than 14/16μm. However, experimental results showed that the friction force during Cu CMP changed to lower value, and that dishing and erosion became smaller simultaneously as the surfactant concentration became higher. Finally, it was possible to realize more globally planarized Cu patterns with erosion ranges of 0.22μm to 0.35μm and dishing ranges of 0.37μm to 0.69μm by using 3 wt% concentration of surfactant.

The purpose of this study is to investigate the crystalline structure and optical properties of (GaZn)(NO) powders prepared by solid-state reaction between GaOOH and ZnO mixture under NH3 gas flow. While ammoniation of the GaOOH and ZnO mixture successfully produces the single phase of (GaZn)(NO) solid solution within a GaOOH rich composition of under 50 mol% of ZnO content, this process also produces a powder with coexisting (GaZn)(NO) and ZnO in a ZnO rich composition over 50 mol%. The GaOOH in the starting material was phase-transformed to α-, β-Ga2O3 in the NH3 environment; it was then reacted with ZnO to produce ZnGa2O4. Finally, the exchange reaction between nitrogen and oxygen atoms at the ZnGa2O4 powder surface forms a (GaZn)(NO) solid solution. Photoluminescence spectra from the (GaZn)(NO) solid solution consisted of oxygen-related red-emission bands and yellow-, green- and blue-emission bands from the Zn acceptor energy levels in the energy bandgap of the (GaZn)(NO) solid solutions.

We developed an age-based spawner-recruit model incorporating environmental variables to forecast stock biomass and recruits of pelagic fish in this study. We applied the model to the Tsushima stock of jack mackerel, which is shared by Korea and Japan. The stock biomass of jack mackerel (Trachurus japonicus) around Korean waters ranged from 141 thousand metric tons (mt) and 728 thousand mt and recruits ranged from 27 thousand mt to 283 thousand mt. We hind-casted the stock biomass to evaluate the model performance and robustness for the period of 1987~2009. It was found that the model has been useful to forecast stock biomass and recruits for the period of the lifespan of fish species. The model is also capable of forecasting the long-term period, assuming a certain climatic regime.