• Steel and Composite Structures
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• 제18권1호
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• pp.135-148
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• 2015

The cutout hole locating at the place of rib-to-diaphragm welded connection is adopted to minimize the restraint, which is caused by the floor-beam web to rib rotation at the support due to the unsymmetrical loads in orthotropic deck. In practice, an inevitable problem is that there is a large number of welding joint's cracks formed at the edge of cutout hole. In this study, a comparative experiment is carried out with two types of cutout hole, the circular arc transition and the vertical transition. The fatigue life estimation of specimens is investigated with the application of the structural hot spot stress approach by finite element analyses. The results are compared with the ones of the fatigue tests which are carried out on these full-scale specimens. Factors affecting the stress range are also studied.

• 대한수학회지
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• 제36권5호
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• pp.959-1008
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• 1999

This paper considers foundational issues related to connections in the tangent bundle of a manifold. The approach makes use of second order tangent vectors, i.e., vectors tangent to the tangent bundle. The resulting second order tangent bundle has certain properties, above and beyond those of a typical tangent bundle. In particular, it has a natural secondary vector bundle structure and a canonical involution that interchanges the two structures. The involution provides a nice way to understand the torsion of a connection. The latter parts of the paper deal with the Levi-Civita connection of a Riemannian manifold. The idea is to get at the connection by first finding its.spary. This is a second order vector field that encodes the second order differential equation for geodesics. The paper also develops some machinery involving lifts of vector fields form a manifold to its tangent bundle and uses a variational approach to produce the Riemannian spray.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 봄 학술발표회논문집
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• pp.397-404
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• 2000

The research of the computer-aided analysis and design of steel structures has continuously evolved. Despite the importance of connection in steel structures, the design process of connections is inefficient in present. The purpose of this study is to help engineer in connection design process. In this paper, prototype of automatic connection design module in integrated system for steel structures is proposed. The main methodology is based on bottom-up approach to simplify and formalize product model. Expert system is used to help engineer for selecting steel connection type. Object-oriented analysis and modeling will improve the expansion of knowledge-base. The design for connection was done according to the design specifications of connections of AISC

• 한국공작기계학회논문집
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• 제12권4호
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• pp.50-56
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• 2003

Most engineering products contain more than one component. Failure occurs either at the connection itself or in the component at the point of attachment of the connection in many engineering structures. The allocation and design of connections such as bolts, spot-welds, adhesive etc. usually play an important role in the structure of multi-components. Topology optimization of connection component provides more practical solution in design of multi-component connection system. In this study, a topology optimization based on density distribution approach has been applied to optimal location of fasteners such as T-shape, L-shape and multi-component connection system. From the results, it was verified that the number of iteration was reduced, and the optimal topology was obtained very similarly comparing with ESO method. Therefore, it can be concluded that the density distribution method is very suitable for topology optimization of multi-component structures.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.15-20
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• 2003

Most engineering products contain more than one component. Failure occurs either at the connection itself or in the component at the point of attachment of the connection in many engineering structures. The allocation and design of connections such as bolts, spot-welds, adhesive etc. usually play an important role in the structure of multi-components. Topology optimization of connection component provides more practical solution in design of multi-component connection system. In this study, a topology optimization based on density distribution approach has been applied to optimal location of fasteners such as T-shape, L-shape and multi-component connection system. From the results, it was verified that the number of iteration was reduced, and the optimal topology was obtained very similarly comparing with ESO method. Therefore, it can be concluded that the density distribution method is very suitable for topology optimization of multi-component structures.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2003년도 종합학술대회 논문집
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• pp.172-177
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• 2003

As the electronic commerce in industry is spreading rapidly, the invitation and investment of e-marketplace is becoming a necessary condition for the industry's competition power insurance and existence. The successful conditions of e-marketplace are many supplier, many buyer, a globalism through the association and cooperation of a foreign marketplace. For that, the connection action inter industries and marketplaces is very necessary, In a condition of the study about the systematic connection type's classification is not exist, the paper aims at classifying the connection type that influences of e-marketplace playing a leading role. So, the connection type classifies into the list offering type, the trade mediation type, the supplementation type, the collaboration type, the information linking type. When we go ahead with a e-marketplace's plan, the paper will guide how to approach and analyze it.

• 인터넷정보학회논문지
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• 제2권5호
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• pp.81-91
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• 2001

XML은 웹에서 구조화된 정보나 반-구조화된 정보를 교환하고 저장하는데 있어서 하나의 표준 마크업 언어로 채택되고 있는 추세이다. 웹을 통한 정보교환에 있어서, XML 메시지의 소스 데이터는 Legacy 데이터베이스에 저장되어 있기 때문에 XML 응용과 데이터베이스 시스템과의 원활한 연계가 요구되어진다. 이를 위하여 Oracle8i와 9i 및 Informix 그리고 SQL2000과 같은 DBMS들은 XML을 취급하기 위하여 자신의 DBMS들을 확장하고 있다. 그러나 이러한 방법은 플랫폼-종속적이며 DBMS-종속적이다. 따라서 원활한 XML 응용과 데이터베이스 시스템과의 연계를 위해서는 플랫폼-독립적이며 DBMS-독립적인 연계방안이 요구된다. 이에 따라 본 논문에서는 XML응용과 기존의 데이터베이스 시스템과의 원활한 연계를 위하여. XML DTD를 토대로 관계형 데이터베이스 스키마를 설계하기 위한 미들웨어 컴포넌트를 설계하였다.

• Journal of Construction Engineering and Project Management
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• 제3권4호
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• pp.12-19
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• 2013

Green Frame is an environmentally friendly column-beam system composed of composite PC members that can increase buildings' life spans while reducing resource consumption. Typically, connections of PC and RC columns occur at the boundaries of each floor, which is at the upper section of slabs, causing the boundary of each floor to generate the maximum moment. Although it is not optimal in terms of structural safety to connect members at a location where the moment is high, this approach is highly adopted due to its constructability. We propose that a superior approach that employs the concept of connecting columns at the low bending moment zone can be applied to quickly and safely install green columns, the main structural members of Green Frame. Connection of green columns at the low bending moment zone can be classified into three techniques, depending on the method of reinforcing the joints, which have different connection characteristics and construction methods. Research is needed to compare the features of each method of reinforcing the joints so that the most appropriate column connection method can be chosen for the site conditions. This study aims to confirm the structural safety of the connection component at the low bending moment zone and to compare and analyze the construction duration, unit price, quality and safety performance of each column connection method. The study results are anticipated to activate the use of composite precast concrete and to be used as development data in the future.

• Computers and Concrete
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• 제14권4호
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• pp.463-477
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• 2014

The modelling approach in the case of connections in precast buildings is specific. The assembly of the constitutive parts of the connection requires the inclusion of contact definitions in the model. In addition, the material non-linearity including the influence of the spatial stress distribution should be taken into account where appropriate. Here a complex model of a beam-to-column dowel connection is presented. Experiments on the analysed connection were performed within the framework of the European project SAFECAST (Performance of Innovative Mechanical Connections in Precast Building Structures under Seismic Conditions). Several material and interaction parameters were investigated and the influence of each of them was evaluated. The set of parameters which gave the best match with the experiments was chosen.

• International journal of advanced smart convergence
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• 제12권4호
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• pp.55-62
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• 2023

Slotted-Aloha (S-Aloha) has been widely employed in random access networks owing to its simple implementation in a distributed manner. To enhance the throughput performance of the S-Aloha, connection-based slotted-Aloha (CS-Aloha) has been proposed in recent years. The fundamental principle of the CS-Aloha is to establish a connection with a short-sized request packet before transmitting data packets. Subsequently, the connected node transmits long-sized data packets in a batch of size M. This approach efficiently reduces collisions, resulting in improved throughput compared to the S-Aloha, particularly for a large M. In this paper, we address the short-term fairness of the CS-Aloha, as quantified by Jain's fairness index. Specifically, we evaluate how equitably the CS-Aloha allocatestime slots to all nodes in the network within a finite time interval. Through simulation studies, we identify the impact of system parameters on the short-term fairness of the CS-Aloha and propose an optimal transmission probability to support short-term fairness.