• 국제초고층학회논문집
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• 제7권4호
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• pp.343-362
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• 2018

A simplified spring connection modelling approach for steel flush endplate beam-to-column connections in fire has been developed to enable realistic behaviour of connections to be incorporated into full-scale frame analyses at elevated temperature. Due to its simplicity and reliability, the proposed approach permits full-scale high-temperature frame analysis to be conducted without high computational cost. The proposed simplified spring connection modelling approach has been used to investigate the influence of connection ductility (both axial and rotational) on frame behaviour in fire. 2D steel and 3D composite frames with a range of beam spans were modelled to aid the understanding of the differences in frame response in fire where the beam-to-column connections have different axial and rotational ductility assumptions. The modelling results highlight that adopting the conventional rigid or pinned connection assumptions does not permit the axial forces acting on the connections to be accurately predicted, since the axial ductility of the connection is completely neglected when the rotational ductility is either fully restrained or free. By accounting for realistic axial and rotational ductilities of beam-to-column connections, the frame response in fire can be predicted more accurately, which is advantageous in performance-based structural fire engineering design.

• 복합신소재구조학회 논문집
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• 제5권4호
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• pp.24-35
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• 2014

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.

• 전자통신동향분석
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• 제30권4호
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• pp.120-128
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• 2015

최근 인터넷의 거대화와 더불어 기본적으로 ISP의 오버헤드를 최소화하는 요구사항을 만족시켜 줄 수 있는 역추적기술 보장에 큰 비중을 두고 있으며, 현재 또는 차세대 인터넷에서 적용 가능한 역추적기술이 필요하다. 본 논문은 사이버 표적공격(Advanced Persistent Threats: APT)에 적용 가능한 역추적(Traceback)기술에 대한 동향을 살펴본다. 특히 기존 IP 및 TCP Connection 기반 역추적방법 중 Network 기반 Connection 추적기술인 Timing-based Approach에 대해서 상세히 살펴보며 아울러 본 논문에서 제안하는 Netflow 기반의 ON-OFF 모델 확장을 통한 Timing-based Connection Traceback Approach의 기술적 적용을 통하여 공격 시스템의 위치와 실제 해킹을 시도하는 해커의 위치가 서로 다르다 하더라도 실제 해커의 위치인 공격 근원지를 추적할 수 있는 기술적 가능성 및 전망을 소개한다.

• KIEAE Journal
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• 제10권6호
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• pp.159-165
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• 2010

The composite frame system suggested in this paper consists of steel reinforced concrete beam encased with structural tee and precast concrete column. This system has advantages such as reduction of materials, CO2 emissions and waste. To commercialize the new composite frame system, it is necessary to develop connections that can effectively connect each member. Therefore, a hybrid connection that has steel type connection and reinforced concrete together is utilized to connect easily at the composite frame system. To evaluate the structural performance of the composite frame system, an experimental investigation is presented. In this study, the flexural moment capacity of the composite frame was determined using the strain compatibility approach. The strain compatibility approach can be used to predict the flexural moment capacity at each limit state. As a result, all elements of the beam to column connection are represented to fully interact between each other. The specimens show errors of -1.9% in the yield limit state and 0.9% at the maximum load limit state. Also, testing shows that beam to column connections have characteristics of semi-rigid connection as per Eurocode 3.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.558-564
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• 2006

When vehicles pass the connection between the bridge and earthwork, the difference of both sections' stiffness produces an increasing wheelload. As a consequence, it results in the excessive vibration of vehicles and the damage of bearing system. In general, steel plate girder railway bridges without ballast track have larger stiffness than the bridge with ballast, and produces larger impulse on the bridge superstructure. Thus, it is necessary to reduce the differences of both stiffness. This study presents parametric studies on the behavior of plate girder bridges and their tracks by means of various stiffnesses and the length of approach zone. The results of numerical study showed that the smaller the stiffness of both sides and the longer the length of approach zone, the variation of wheelload becomes smaller. Hence, it gives less burden into the plate girder bridges and their tracks. It is expected that the results of parametric study can be used as a preliminary data for the determination of economical length on the approach zone and the stiffness of both sides.

• 한국전자거래학회지
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• 제4권3호
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• pp.235-246
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• 1999

There have been several approaches to integrating heterogeneous database systems in enterprises. Due to their inherent limitations, however, it has been difficult to apply them to actual situations in enterprises. In this paper, we propose EasyConnection, a system that is based on the flexible and extensible architecture and overcomes the limitations of the previous approaches, EasyConnection consists of Wrappers, Sharing Manager, and Clients, and the connections among these components are based on CORBA. It can also be used as the information management mechanism for such application systems as ERP, PDM, and EAI.

• Structural Engineering and Mechanics
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• 제81권6호
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• pp.737-750
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• 2022

Timber-Concrete Composite construction system consists of combining timber beam or deck and concrete with different connectors. Different fastener types are used in Timber-Concrete Composite systems. In this paper, the effects of two types of fasteners on structural behavior are compared. First, the notches were opened on timber beam, and combined with reinforced concrete slab by fasteners. This system is called as Notched Connection System. Then, timber beam and reinforced concrete slab were combined by new type designed fasteners in another model. This system is called as Notched-Slab Approach. Two laboratory models were constructed and bending tests were performed to examine the fasteners' effectiveness. Bending test results have shown that heavy damage to concrete slab occurs in Notched Connection System applications and the system becomes unusable. However, in Notched-Slab Approach applications, the damage concentrated on the fastener in the metal notch created in the slab, and no damage occurred in the concrete slab. In addition, non-destructive experimental measurements were conducted to determine the dynamic characteristics. To validate the experimental results, initial finite element models of both systems were constituted in ANSYS software using orthotropic material properties, and numerical dynamic characteristics were calculated. Finite element models of Timber-Concrete Composite systems are updated to minimize the differences by manual model updating procedure using some uncertain parameters such as material properties and boundary conditions.

• 한국통신학회논문지
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• 제27권4B호
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• pp.338-344
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• 2002

This paper proposes a transient (predictive) connection admission control (CAC) scheme using the transient quality of service (QoS) measure for CDMA cellular systems with bursts On-Off sources. We need an approximate and bounded approach for real-time CAC applications. We derive the transient outage probability as the QoS measure using the Chernoff bound and the refuted large deviation approximation. Numerical results show that the predictive CAC is a promising approach for the multicell CDMA systems.

• Journal of Chest Surgery
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• 제23권4호
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• pp.764-768
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• 1990

Congenitally corrected transposition of great arteries is a congenital cardiac anomaly with ventriculoarterial discordant connection and atrioventricular discordant connection. A 8-year-old girl had congenitally corrected transposition of the great arteries with ventricular septal defect and pulmonary valvular stenosis. By transaortic approach, ventricular septal defect was closed and pulmonary valvotomy was performed by transpulmonary approach. No heart block or aortic insufficiency developed postoperatively.

• 대한조선학회논문집
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• 제46권5호
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• pp.510-519
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• 2009

Ship structure is composed of the welded mixture members which are plate and stiffeners. Ship structure is also influenced by variable loadings such as wave and inertia load. There have been several fatigue damage problems on the connection between longitudinal and transverse web due to wide usage of high tensile steel and adoption of wide web space to improve shipbuilding productivity. It is impossible to estimate the fatigue lives for all connection details through refined fatigue analysis. It is necessary to use the simplified approach for the fatigue life estimation of the connection details. PLUS analysis, which is suggested by the classification society, is one of the simplified approaches and is widely adopted to get fatigue lives for the connection details along whole cargo hold area. However, ship building yards still have difficulties to get fatigue lives due to large amount of calculation and time even if this approach reduce the time and amount of calculation. This paper treats the computing system developed to reduce efforts of estimating the fatigue lives. The influence factors of mean shear stress and local dynamic pressure are easily calculated and fatigue lives for all hot spots can be estimated automatically by the developed computing system. It is possible to reduce computing time and efforts to get the fatigue lives for the connection details between longitudinals and transverse webs along the ship. This system was applied to get fatigue lives on the connection details of a VLCC and verified the availability.