This study performed a finite element stress analysis of pipe system connected by bellows based on APDL(ANSYS Parametric Design Language) customizing. The effects of different shapes of developed pipes for various parameters are studied using the finite element commercial package for this study. The structural behavior of complex pipe structures with bellows was also investigated to study the interactions between bellows and other parts. Based on the ANSYS APDL, the effect of initial axial and lateral displacements, and internal temperature and pressure on the Von Mises stress distribution is also analyzed.

This paper presents a foundation pile to steel column connection that can resist large magnitude of moment and that can be easy installed. The developed joint has spherical shape and it is given the name HAT joint to mean Hallow half-sphere steel joint. Four types of HAT joints are developed. Namely, H-type, T-type, P-type and K-type. In this paper I will talk about the performance assessment of T-type(Tube Column) and P-type(Pile Column) of HAT joints with finite element analysis and experiment on a full scale model is presented.

막대나 히스토그램과 같은 그래픽 요소는 통계자료의 탐색적 분석을 위한 정보 시각화 도구로 자주 활용되어왔다. 이에 비해단계구분도나 유선도와 같은 전통적 주제도는 지리참조된 통계자료의 공간 분포 및 패턴 분석을 위한 유용한 시각화 기법으로 인식되었다. 그러나 통계학 분야에서 최근 제안된 연결형 마이크로맵은 공간통계자료의 탐색적 분석을 위한 효과적인 시각화 도구로서 많은 관심을 받고 있다. 이에 본 연구는 서울특별시 자치구를 대상으로 생산된 공간통계자료를 시각화할 수 있는 연결형 마이크로맵을 R 프로그래밍 언어를 이용하여 구현하여 제시하였다. 그리고 본 연구는 기존 주제도와 차별적인 연결형 마이크로맵의 특징을 고찰하였다. 연결형 마이크로맵은 전통적 주제도의 한계를 해결하고 정보 손실을 최소화할 수 있는 효과적인 시각화 기법으로서 그 활용도가 높아질 것으로 기대된다.

본 연구에서는 사회적 자본이론을 적용하여 SNS(Social network service, 이하 SNS) 사용자들이 온라인을 통해 형성한 소셜 네트워크의 특성이 이들의 제품에 대한 관여도에 어떤 영향을 미치는지를 분석한다. 본 연구의 연구목적은 크게 두 가지이다. 첫 번째로는 SNS의 참여를 양적 참여(quantity)와 질적 참여(quality)로 나누었을 때 이들 각각이 사회자본의 형성에 어떤 영향을 주는지 알아보고자 한다. 또한, SNS의 사용이 전 세계적으로 보편화 되면서 소비자 행동으로 이어지는 SNS사용과 SNS에서 형성된 사회자본이 마케터들의 큰 관심을 받고 있다. 그래서 본 연구의 두 번째 연구목적은 SNS에서 형성된 사회자본의 형태(연결적 사회자본, 결속적 사회자본)에 따라 어떤 유형의 제품(실용적, 상징적)에 대한 관여도가 영향을 받는지를 밝히고, 또 이 두 가지 형태의 사회자본이 소비자 관여도에 있어서 상호작용이 존재하는지를 규명하는 것이다. 이를 위해 SNS 주 이용 층인 대학교 재학생(중국, 한국, 미국) 521명을 설문 조사하여 본 연구의 연구표본으로 사용하였다. 연구결과 SNS 참여와 사회자본의 형성 사이 관계를 보았을 때, SNS 양적 참여와 질적 참여 모두 연결적 사회자본의 형성에 긍정적 영향을 미쳤고 결속적 사회자본의 형성에 있어서는 질적 참여만이 유의미한 긍정적 영향을 미치는 것으로 검증 되었다. 그 다음으로 SNS에서 형성된 사회자본이 소비자 구매 행동으로 이어질 때 연결적 사회자본은 실용적 제품의 관여도에 긍정적인 영향을 미쳤고 결속적 사회자본은 실용적 제품의 관여도에 직접적 영향은 미치지 않았지만 연결적 사회자본과 실용적 제품 관여도 사이의 정의 관계를 강화하는 조절효과가 있는 것으로 나타났다. 또한, 결속적 사회자본은 상징적 제품 관여도에 긍정적인 영향을 미쳤고 연결적 사회자본은 상징적 제품 관여도에 직접적인 영향은 없지만 결속적 사회자본이 상징적 제품 관여도에 주는 긍정적인 영향을 강화하는 조절효과가 있는 것으로 나타났다.

사회기반시설물인 교량은 인적/물적 자원의 신속하고 원활한 이동을 위해 지장물을 극복하도록 설계/시공되는 구조물이다. 그러므로 교량의 교축방향으로 배열되는 교각의 형상과 규모는 지형의 제약을 받을 수밖에 없다. 이러한 교각의 형상과 규모는 지진하중의 전달경로를 결정하는 연결부분 배열과 함께 연결부분과 교각에 발생하는 작용력을 좌우하게 된다. 이 연구에서는 강재받침과 철근콘크리트 기둥을 연결부분과 교각으로 하는 일반교량을 대상으로 교각 및 강재받침 배열이 다른 해석모델을 설정하여 지진해석을 수행하였다. 해석결과로 구한 교각기둥과 강재받침의 강도/작용력 비로부터 각 해석모델의 연성파괴메카니즘을 구성하고 연결부분 및 교각 배열이 일반교량의 내진성능에 미치는 영향을 연성파괴메카니즘 구성 측면에서 제시하였다.

Generally, the Load of upper structures is transferred to concrete foundations through columns supporting them. So, the anchor connection system is usually adopted in order to connect the columns and the concrete foundations. To apply this system, the column-foundation connections need to be designed with enough stiffness. This study was experimentally conducted to effectively improve the structural detail of circular CFT column-foundation connections, to which axial and lateral load simultaneously apply. For this study, the test specimen with a general anchor and an anchor frame, and the specimens with the high-tension bolt and inner reinforcement were fabricated. In addition, double base plates were adopted to have the enough stiffness of connections. The behavioral characteristics and the failure mode were investigated and compared, and the improvement of structural detail of circular CFT column-foundation connections was suggested.

In Part I, we disccussed of joint between PHC pile and steel column in foundation of large space structures, one prototype of a joint of PHC pile to steel pipe column was suggested on the basis of analytical studies. In this paper, I explain the Joint of PHC pile to steel tube column and more detail of analysis

To overcome disadvantages of usual spread foundation in large space structure, some prototypes of a joint of the PHC pile to steel pipe column that directly connects a column to a PHC pile are analytically studied. With the consideration of strength requirement and stress concentration of joint of the PHC pile to column, we suggest the most appropriate one.

Shear wall systems behave as individual wall because of openings like window and elevator cage. When coupling beams are installed in shear walls, they will have high strength and stiffness so that be less damaged by lateral loads like earthquake. However, coupling beam is difficult construction method. And arranging reinforcement of slender coupling beams are especially hard. It is because the details of coupling beam provided by ACI 318 are complex. In this paper, experiments were conducted using coupling beams with 3.5 aspect ratio to improve the details of slender coupling beams provided by ACI 318. Two specimens were proposed for this study. One specimen applied with bundled diagonally reinforcement only. Another specimen applied both bundled diagonally reinforcement and High-Performance Fiber Reinforced Cementitious Composite (HPFRCC) so that coupling beams have half of transverse reinforcement. All specimen were compared with a coupling beam designed according to ACI 318 and were evaluated with hysteretic behaviors. Test results showed that the performance of two specimen suggested in this study were similar to that of coupling beam designed according to current criteria. And it was considered that simplification of the details of reinforcement would be available if transverse reinforcement was reduced by using bundled diagonally reinforcement and HPFRCC.

It is known that sewer problems are the major causes of road cave-in. The objective of this study is to analyze the risk of road cave-in due to storm sewer laterals. We investigated 174 storm sewer laterals using a zoom camera at O-dong area in Seoul. The causes of road cave-in were classified into five cases: breakage of rigid pipe, deformation of flexible pipe, out of pipeline alignment, changing pipe material or changing pipe diameter, and a poor linkage between lateral and sewer. In addition, all defects were sorted into five grades based on the severity rating at storm sewer laterals. In this study, the most fragile pipe materials were found to be concrete pipe and polyethylene pipe, which recorded 2.3 and 1.69 defect rates. With regard to the causes of road cave-in, deformation of flexible pipe has a large influence on road cave-in at present. On a long-term basis, the two causes, out of pipeline alignment and a poor linkage between lateral and sewer, could have more influence on road cave-in.

목 적 : 중증 외상환자나 급성 뇌졸중 환자와 같이 호흡이 불안정한 환자에 대한 MRI 검사가 증가하면서 인공호흡기 사용 환자의 영상 quality를 높이기 위한 여러 방법이 논의되었고, 연장관을 이용한 수동식 인공호흡기에 one-way valve를 기관지 삽입관에 직접 연결하는 방식이 가장 우수한 영상 quality를 만들어 낸다는 연구결과도 있었다. 하지만 기존의 연장관 연결 방식 사용 시 시간이 지날수록 환자의 호흡상태가 불량해지는 원인에 대한 정확한 인식이 부족하였고, 수동식 인공호흡기(Ambu)에 연결되어 있는 one-way valve를 분리사용 시 연장관과의 직경이 맞지 않는 등, 연결에 불편을 초래하여 이를 개선하고자 본 연구를 시작하게 되었다. 대상 및 방법 : 본원의 중증외상센터에 입원 중인 인공호흡기 치료 환자를 대상으로 수동식 인공호흡기에 연장관만을 연결하여 MRI검사를 시행하면서 동맥혈가스검사(ABGA)를 검사 초기에 3회 시행하였고, 검사 시작 30분후에 본원에서 제안한 연장관(one-way valve일체형)에 수동식 인공호흡기를 연결하여 동맥혈가스검사(ABGA)를 2회 재시행하여 전후의 혈액 속 산소량과 이산화탄소량을 측정하였다. (동맥혈가스 검사는 본원의 중증외상팀의 협조 아래 A-Line이 연결되어 있는 환자에게 시행되었다.) 결 과 : 기존의 수동식 인공호흡기에 연장관을 연결한 방법이 사용된 30분에서는 혈액 속 산소량과 이산화탄소량이 각각 300~200, 45~80으로 정상범위인 85~100, 35~45를 벗어나 급격하게 증가하는 양상을 볼 수 있었고, 호흡불안정으로 인해 영상의 quality가 떨어지는 결과가 나왔다. 이후 본원에서 제안한 one-way valve일체형 연장관이 사용된 검사에서는 혈액 속 산소량과 이산화탄소량이 모두 정상치를 보임을 알 수 있었고, 환자의 호흡이 안정되어 보다 높은 quality의 영상을 얻을 수 있었다. 결 론 : 잘못된 연장관 사용에 의해 환자가 배출한 이산화탄소가 외부로 배출되지 못하고 다시 환자에게 공급되면서, 혈액 속에 이산화탄소의 증가로 환자의 PH는 산성으로 바뀌며, 환자는 고통을 느끼게 되어, 뇌에서는 호흡 횟수를 증가시키도록 지시한다. 이러한 이산화탄소 Retention에 기인한 Expiration Time의 감소가 호흡불안정과 움직임에 의한 영상 quality의 저하로 이어진 것으로 사료된다. 본원에서 제안한 개선 방식에서는 혈액 속 산소량과 이산화탄소량이 적정하게 유지됨으로써 환자의 호흡도 안정되고, 영상의 quality 또한 높아 졌으며, 수동식 인공호흡기에 연결되어 있는 one-way valve의 위치를 바꾸는 경우보다 쉽고 빠르게 수동식 인공호흡기를 연결할 수 있어 환자의 안전과 영상의 quality 향상에 도움이 될 것으로 판단된다.

Due to the advantageous mechanical properties of the fiber reinforced polymeric plastics(FRP), their application in the construction industries is ever increasing trend, as a substitute of structural steel which is highly vulnerable under hazardous environmental conditions (i.e., corrosion, humidity, etc.). In this study, hybrid FRP-concrete composite pile (HCFFT) connection is suggested. The HCFFT is consisted of pultruded FRP unit module, filament wound FRP which is in the outside of mandrel composed of circular shaped assembly of pultruded FRP unit modules, and concrete which is casted inside of the circular tube shaped hybrid FRP pile. Therefore, pultruded FRP can increase the flexural load carrying capacity, filament wound FRP and concrete filled inside can increase axial load carrying capacity. In the study, connection capacity of HCFFT(small and mid size) is investigated throughout experiments and finite element method. From the results of experiments, we suggested the connection methods about HCFFT pile connection.

In this study, circular sectional concrete-filled tube(CFT) column-to-foundation connections were numerically investigated in order to improve their structural details. A inner reinforced specimen with high-tension bolts and inner deformed bars was adopted from a previous experimental study to make the numerical model. The validity of the numerical method was verified through comparing the experimental results with the analysis’s ones. In order to optimize design variables about the inner reinforced model, a number of numerical analyses were conducted for various variables. Finally, this study suggested the optimum variables about the reinforced circular sectional CFT column-to-foundation connections.

An experimental study on the structural behavior of connection types between approach slab and integral abutment has been done for three typical bar connections. Typical hinge style reinforcing bar detail for its connection is preferred in order to accommodate rotation of the approach slab among engineers. However, the straight horizontal bars can be used as connection detail accomodate structural capacity. Total six specimens with three types of rebar detail are tested for direct tensile and bending load. The characteristic structural behaviors are carefully monitored and all the strain gauge data obtained are analyzed. It is shown that the structural performance of all the specimens well exceed its design allowance. Several design suggestions are given based on careful reviews on the experiment.

PURPOSES: Safety consciousness can be the first factor to hinder the acceptance of design alternative, which moderates the applied design criteria in order to adapt the road to the natural terrain condition. METHODS : The method which enables to check the safety of design alternative by using design consistency concept is suggested. The method is based on the linked or interactive analysis between terrain and road alignment. Real design example is considered as a guide how to apply the method and the analysis result is discussed with the future research. RESULTS: Suggested method can be used for designers as a tool to review their design outputs can be safe as much as the original design. So, designers have the more objective judgement on their designs and have the confidence on their designs. CONCLUSIONS : The method is expected to be used as a tool to see the safety consciousness in an objective view, so any possible conflicts between designers and design-related personnels caused by the terrain-oriented design can be solved.

Fiber reinforced plastic (FRP) structural shapes are readily available in civil engineering applications. Among many manufacturing techniques used for FRP structural shapes, pultrusion process is one of the most widely used techniques in civil engineering applications. Pultrusion is a manufacturing process for producing continuous lengths of reinforced polymeric plastic structural shapes with constant cross-section. Pultruded composites are attractive for structural applications because of their continuous mass production with excellent mechanical properties. This paper presents the results of investigations pertaining to the bolted connection with two bolts for the pultruded FRP (PFRP) structural members. PFRP bolted connection tests were conducted with end distance to bolt diameter ratio (e1/db) and two types of bolt pattern such as horizontal (Pattern A) and vertical arrangement (Pattern B). As a result, it is found that the e1/db is recommended as the ratio of 4. In addition, it is also found that the bearing strengths at failure of the Pattern A and Pattern B have a similar value.

In everyday network changing field, permanent service is being an issue. Network disconnection phenomenon is directed to financial damage to service providers. Some companies guarantee on network maintenance, but there is a permitted limit according to their company regulations. If customers overuse the limitation, extra pay will be placed. Moreover, network disconnection affects critical in some fields with using network. Permanent service becomes indispensable in stock, finance, online game, and other fields. Additionally, it should be possible to pre-detect and block abnormal traffic area, improve network infrastructure secureness and optimization, and reduce damage recovery cost. MCS(Multi Connection System) can provide permanent service even if a connection is cut because it provides multi-connection. It can also isolate the attacker when it detects DDoS attack, so it provides smooth service. Also, the benefit from this structure is that the real server can be hidden so the service can be provided continuously. It prevents damages from network cutting, reduces management cost, maintains the best performance, and increases convenient on management and maintenance. Stable and continuous service can be provided with managing network through MCS.

The purpose of this study is to examine the effects of focus-on-form approach on learning connective ending '-느라고' of Korean language learners. Input enhancement and consciousness raising tasks were applied and compared as an effective way of this grammar instruction among various techniques of focus-on-form approach. The participants in the study are intermediate-level Korean language learners. They were divided into two groups, and teaching activities were provided undertaken based on two different methods. According to the results, significant differences were not found between the two methods, but the upper-level students had higher achievements than the lower-level students. Although no significant difference was found between the input enhancement and consciousness raising tasks, it was found that the focus-on-form approach can be recommended as a way to teach grammar effectively, especially it is effective for upper-level learners.

A methodology to evaluate the seismic performance of interface piping systems that cross the isolation interface in the seismically isolated nuclear power plant (NPP) was developed. The developed methodology was applied to the safety-related interface piping system to demonstrate the seismic performance of the target piping system. Not only the seismic performance for the design level earthquakes but also the performance for the beyond design level earthquakes were evaluated. Two artificial seismic ground input motions which were matched to the design response spectra and two historical earthquake ground motions were used for the seismic analysis of piping system. The preliminary performance evaluation results show that the excessive relative displacements can occur in the seismically isolated piping system. If the input ground motion contained relatively high energy in the low frequency region, we could find that the stress response of the piping system exceed the allowable stress level even though the intensity of the input ground motion is equal to the design level earthquake. The structural responses and seismic performances of piping system were varied sensitively with respect to the intensities and frequency contents of input ground motions. Therefore, for the application of isolation system to NPPs and the verification of the safety of piping system, the seismic performance of the piping system subjected to the earthquake at the target NPP site should be evaluated firstly.