본 연구에서는 강주형과 바닥판의 합성에 사용되는 전단연결재에 대한 연구를 위해 세계 각국에서 사용되는 설계기준과 연구사례를 분석하고 교량 바닥판에 작용하는 각종 수직하중으로 인해 강주형과 콘크리트 슬래브의 접촉면에 발생하는 수평방향의 전단력을 전달하는 이 연결재를 설치한 밀어내기 시험체에 대하여 전단실험을 수행하였으며, 이 시험을 통하여 철근 대신 FRP 철근이 배치된 Steel strap 바닥판의 전단열재 평가식을 제안하였다. 본 연구에서의 제안식은 도로교설계기준의 전단연결재 허용강도 대비 약 3배의 안전율을 가지고 있으며, 기존의 DIN 기준과 Viest 평가식과 비교하면 5%정도의 오차로 유사한 결과를 보여주었다.

In this paper, the finite element model updating method of the PSC bridge based on the static and dynamic data is verified through field experiment. The proposed method consists of two steps. First, update the rotational stiffness of the supports using the deflection and rotational displacement measurements that occur when the moving loads pass through the bridge. The stiffness of each member is updated by using the dynamic characteristics estimated from the acceleration measured by the ambient vibration test. The finite element model updated by the proposed method can predict the static and dynamic behavior of actual bridges through field experiment.

본 연구는 단경간 교량의 정적하중입력/변위출력관계를 이용한 새로운 교량 유한요소모델 개선 방법을 제안하였고, 실내 모형교량 실험을 통해 검증하였다. 기존의 유한요소모델개선기법은 실험으로부터 얻어진 모드계수와 유한요소모델로부터 예측된 모드계수가 유사해 지도록 유한요소모델을 개선하는데, 이 과정에서 구조계의 질량행렬에 대한 가정을 필요로 한다. 제안된 기법은 질량행렬을 가정하지 않고, 오 히려 질량행렬 추정을 가능하게 하는 장점을 가진다. 제안된 기법은 두 단계로 구성된다. 첫째, 정적 하중입력-변위응답으로부터 강성행렬을 개선하고, 둘째, 실측된 고유진동수를 이용하여 질량행렬을 개선한다. 실험검증을 위하여 실내 모형교량을 제작하였고, 제안된 기법을 이용하 여 모형교량의 탄성계수를 추정하였으며, Universal Testing Machine으로 부터 얻어진 탄성계수와 비교하였다. 또한 기존의 유한요소모델개 선기법으로 추정된 탄성계수와 비교하였다. 실험의 결과들로부터 제안된 기법이 합리적으로 탄성계수와 질량밀도를 추정하는 것이 관찰되었 고, 기존의 유한요소모델개선기법은 고차모드를 사용했을 때 상대적으로 큰 오차를 주는 것이 관찰되었다. 추가적으로 유한요소모델링 오차 에 대하여 토의하였다.

This study compares the steel column-base plate connections to improve the flexural capacity of small building. In addition, performance level was evaluated by example building. Analysis results, an additional reinforcement is required to the proposed steel column-base plate connection. And then, We should compared the impact of beam-column joints.

This study proposes a measurement method using angular sensors to measure deformation and displacement of bridges. The proposed measurement method consists of gyroscope sensors and data processor to transform angular to vertical displacement. This study contains experimental evaluation to verify the applicability of the proposed method. 4-points bending tests were conducted on a small-sized girder specimen. The displacements were measured with both conventional LVDT and gyroscope sensor to compare the accuracy of the proposed method. It is estimated that the method using gyroscope shows some noise in data, but the method using gyroscope has advantages to measure the vertical displacement. Therefore if the sampling rate and synchronizing problems can be approved, it can be a good alternative measuring method for the deformation of the bridges.

3D 게임에서 오브젝트의 위치를 파악하거나 사실감을 높이기 위하여 광원의 시점에서 정점 의 깊이 값을 계산하는 그림자 매핑 기법이 많이 사용된다. 그림자 맵의 깊이 값은 월드 좌표 를 통해 계산되기 때문에 월드 좌표가 변하지 않는 정적 오브젝트는 깊이 값을 갱신할 필요가 없다. 본 논문에서는, (1) 렌더링 속도를 향상시키기 위하여 한번만 저장하는 정적 오브젝트 깊 이 값과 매번 갱신하는 동적 오브젝트의 깊이 값을 다중 렌더 타겟을 이용하여 따로 관리한다. 또한 (2) 쿼터 뷰 기반 3D 게임에서 동적 오브젝트 그림자 품질을 높이기 위하여 광원의 위치 가 카메라를 따라다니며 동적 오브젝트에 가깝게 변동한다. 제안하는 방법의 효율성을 3D 게임 의 다양한 정적 및 동적 오브젝트 구성에 따른 실험을 통하여 검증하였다.

In this study, a novel bridge weigh-in-motion system based on pseudo-static deflection extracted from the measured dynamic displacement while a truck overpasses the bridge is proposed and its feasibility is experimentally verified through a series of driving tests with a heavy duty truck on an operating bridge.

In this Study, the performance of the connection of Transfer-beam system suggested in the previous study was evaluated by the quasi-static test. The test model was applied to Top and Seat Angle Connection and modified SAC Protocol. The performance of the connection obtained by quasi-static test was shown in P-Δ and M-θ curve graph.

원위치에서 공학적 정수의 산정을 위하여 지반특성에 따라 표준관입실험(SPT), 동적 콘관입실험(DCPT), 정적 콘관입실험(SCPT) 등 다양한 실험방법들이 적용되어 왔다. SPT 및 DCPT의 경우 실험방법이 간단한 반면 결과의 신뢰도는 낮으며, SCPT의 경우 실험결과의 신뢰성은 높으나, 대상현장에 따라 관입장비의 적용에 한계가 있어 왔다. 본 연구에서는 계장화된 동적 콘관입기(Instrumented Dynamic Cone Penetrometer, 이하 IDCP)를 개발하여 CPT의 적용이 어려운 현장의 지반특성을 파악하고자 하였다. IDCP는 원추형 선단부와 연결롯드, 그리고 두부로 구성되어 있으며, 선단부 및 두부에는 변형률계와 가속도계를 설치함으로써, 각 부분에서의 힘, 속도, 변위, 그리고 전달된 에너지를 측정할 수 있도록 하였다. IDCP의 관입을 위한 해머 및 관입장비는 대상현장에 따라 SPT 및 DCPT와 동일한 방식으로 적용되었다. IDCP를 이용한 실내 및 현장적용 실험결과, 동적관입에 따라 측정된 선단의 저항력은 두부로부터 선단으로 전달된 에너지의 손실에 대한 영향없이 대상지반의 강도분포를 우수하게 나타내고 있음을 보여주었다. 본 논문에서 개발된 IDCP는 기존 실험법의 한계점을 보완함으로써, 현장적용성이 우수하고, 정량적인 강도분포의 도출이 가능한 지반조사장비로 활용될 수 있을 것으로 예상된다.

Bacterial cellulose (BC) has played important role as new functional material for food industry and industrial products based on its unique properties. The interest in BC from static cultures has increased steadily in recent years because of its potential for use in medicine and cosmetics. In this study, we investigated culture condition for BC production by Acetobacter sp. F15 in static culture. The strain F15, which was isolated from decayed fruit, was selected on the basis of BC thickness. The optimal medium compositions for BC production were glucose 7%, soytone 12%, K2HPO4 0.2%, NaH2PO4ㆍ2H2O 0.2%, lactic acid 0.05% and ethanol 0.3%, respectively. The strain F15 was able to produce BC at 26℃-36℃ with a maximum at 32 ℃. BC production occurred at pH 4.5-8 with a maximum at pH 6.5. Under these conditions, a maximum BC thickness of 12.15 mm was achieved after 9 days of cultivation; this value was about 2.3-fold higher than the thickness in basic medium. Scanning electron micrographs showed that BC from the optimal medium was more compact than plant cellulose and was reticulated structure consisting of ultrafine cellulose fibrils. BC from the optimal medium was found to be of cellulose type I, the same as typical native cellulose.

There are many stringent environmental regulations on the management of waste electrical and electronic equipments(WEEE) in most developed countries. WEEE directive aims at increasing collection and recycling rate of WEEE whereas,while the restriction of the use of certain hazardous substances (RoHS) aims at restricting hazardous materials duringthe production of electrical and electronic equipment (EEE). TV housing rear covers consist of small portion of brominatedflame retardants (BFRs). Improper management and disposal of such waste can pose impacts on the environment andhuman health. In Korea, there are very few available statistical data regarding BFRs levels in TVs housing rear covers.In order to provide additional measures related to management of BFRs, there is a need for a quantitative material flowstudy on the amount of BFR found in TVs. This can be achieved by the aid of material flow analysis of the TV setsand by studying the Deca-BDE components present in the TV housing read covers. In this study, the relevant data werecollected from the statistical reports and through field site visits to the WEEE recycling facilities with surveys. Staticand dynamic material flow analysis (MFA) was conducted to determine material flow of BFRs (Deca-BDE) in themanagement of waste TVs. According to this study, in 2011, households in Korea use 73,821ton of TV sets of which23,592ton of waste TV sets were collected and recycled by municipalities and producers. Extended ProducerResponsibility (EPR) played a major role in recycling of WEEE. In this study, it was predicted that Deca-BDE in usestage would reach down to 51.73ton by 2016. In addition, the amount of Deca-BDE present at the disposal and recyclingstage is estimated to be approximately 2.45ton by 2018.

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.

This paper presents a new method for conveniently estimating static displacements of a structure based on its vibration data. In the proposed method, structural static displacements can be obtained using a normalized modal flexibility matrix assisted by a known mass perturbation method in order to overcome several shortcomings of existing displacement sensors such as the limitation on installation due to surrounding environments and the inconvenience to the public during static loading tests. For validating the feasibility of the proposed method, experimental validation was carried out on a simply-supported beam model. It was found that the proposed method can be an effective alternative to conventional static displacement estimation.

We investigated the quality characteristics of brewing brown rice vinegar through a traditional static fermentation process. Accordingly, we decided to compare the physicochemical characteristics of brewing vinegar at different temperatures and filtration methods. In four to five weeks’ time, the acetic acid fermentation exhibited the highest titratable acidity and then it eventually decreased. The titratable acidity was affected by the filtration method. It was revealed that the titratable acidity was higher in the forced filtration than the traditional filtration method. Various organic acids were detected in order to initialize the fermentation stage and as the fermentation progressed, only the acetic acid could be detected. The total free amino acid content was higher at a temperature of 30℃ than at 20℃. Moreover, the free amino acid content was dependent on the acetate content during the acetic fermentation process. The main bioactive substance of the γ-aminobutyric acid content was more than twice at a fermentation temperature of 30℃ compared to the fermentation temperature of 20℃. Furthermore, the total amino acid and essential amino acid content at a temperature of 30℃ was excellent. The quality of the brown rice vinegar via forced filtration method at a temperature of 30℃ was the most excellent. Based on these results, the fermentation temperature and the use of nuruks (fermenting agent) affected the quality of the brown rice vinegar, and an appropriate method to consider its purpose is required.

The object of this study is to evaluate static behavior of transverse connection of slab-type modular bridge. Especially, this paper focus on evaluation that shear key and tendon force affect bending strength of transverse connection of slab-type modules. We compared and examined the bending performance of connection through a structural test (4-point bending test). This experimental results show that bending strength of transverse connection of slab-type modules are influenced a number of shear key and amounts of tendon force. So in order to apply to modular construction, it is necessary to research in connection of slab-type modules.

Offshore plant structures must be secured of structural safety applying real-time monitoring technology because they are in a state of very poor ocean conditions. In this study, Fiber Bragg Grating (FBG), sensors were attached to the scaled model of offshore floating structure, and put in scaled model in the water tank, and then calculated strain after measuring scaled model's wavelength through optical spectrum analyzer

This study analyzes descriptive statistics and tests homogeneity hypothesis, and applies a posteriori comparison procedures among treatment levels for the response characteristics such as static response ratios, impact factors, natural frequencies of bridges according to structural types and service periods. This study is expected to help understand the difference among response characteristics of groups and provides the practical information for safety assessment and structural design.

To determine the type and dimension of modular deck, the parameter study was executed. Decks of three types were proposed and static tests were performed to verify the structural performance. From the test results, the full steel plate composite deck had about three times strength as the others.

To determine the type and dimension of modular deck, the parameter study was executed. Decks of three types were proposed and static tests were performed to verify the structural performance. From the test results, the full steel plate composite deck had about three times strength as the others.

Steel panel dampers are very economical, easy to maintain and widely used as vibration control devices for building structure. However, this dampers are fractured in the center part under repeated loading so that the strength degrades after attaining the maximum resisting capacity. This issue and other many problems had been pointed out by many researchers. In this paper, the performance of steel panel damper has been enhanced by introducing cover plates on the panel on both side so that the lateral out of plane buckling of panel was protected. Thus, the deformation behavior as well as its hysteretic characteristics of a newly proposed Out-of-plan buckling resisting steel damper (BRSD) were studied