• Steel and Composite Structures
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• v.32 no.4
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• pp.497-507
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• 2019

Exposed column base connections are used in low- to mid-rise steel moment resisting frames. This paper is to investigate the effect of the base plate thickness on the exposed column base connection strength, stiffness, and energy dissipation. Five specimens with different base plate thickness were numerically modelled using ABAQUS software. The numerical model is able to reproduce the key characteristics of the experimental response. Based on the numerical analysis, the critical base plate thickness to identify the base plate and anchor rod yield mechanism is proposed. For the connection with base plate yield mechanism, the resisting moment is carried by the flexural bending of the base plate. Yield lines in the base plate on the tension side and compression side are illustrated, respectively. This type of connection exhibits a relatively large energy dissipation. For the connection with anchor rod yield mechanism, the moment is resisted through a combination of bearing stresses of concrete foundation on the compression side and tensile forces in the anchor rods on the tension side. This type of connection exhibits self-centering behavior and shows higher initial stiffness and bending strength. In addition, the methods to predict the moment resistance of the connection with different yield mechanisms are presented. And the evaluated moment resistances agree well with the values obtained from the FEM model.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.61-62
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• 2007

Network control platform (NCP) and quality of service switch (QSS) are developed to realize centralized control and management technology, which is essential for guaranteeing traffic engineering and service quality in the next generation network. This paper presents high-speed connection management mechanism to enhance connection setup delay of the existing SNMP interface between NCP and QSS. We built up a connection management platform in the laboratory environment to validate the realization of the proposed mechanism.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.507-510
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• 2001

HTTP/1.1 standard reduces latencies and overhead from closing and re-establishing connections by supporting persistent connections as a default, which encourage multiple transfers of objects over one connection. HTTP/1.1, however, does not define explicitly connection-closing time but specifies a certain fixed holding time model. This model may induce wasting server's resource when server maintains conn ection with the idle-state client that requests no data for a certain time. This paper proposes the mechanism of a heuristic connection management supported by the client-side under persistent HTTP, in addition to HTTP/1.1's fixed holding time model on server-side. The client exploits the tag information within transferred HTML page so that decides connection-closing time. As a result, the mechanism allows server to use server's resource more efficiently without server's efforts.

• Journal of information and communication convergence engineering
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• v.8 no.6
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• pp.682-686
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• 2010

In this paper, we propose the fast wakeup and connection mechanisms for various energy saving schemes in order to improve QoS. First, we offer the interconnection of heterogeneous access networks via the Media Independent Information Server/Service (MIIS). Then, we propose the fast wakeup and connection mechanism for multi-interface communication systems. The proposed novel mechanism focuses on the fast provision of incoming service destined to the interface currently in energy saving mode by using MIIS-assisted interconnection. We further evaluate the performance of proposed mechanism through the numerical and experimental analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.865-866
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• 2010

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.402-412
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• 2017

The convergence of broadcasting and telecommunication technologies is a key issue of the ubiquitous networks. So this paper offers the convergence of integrated telecommunication networks and broadcasting system, Advanced Terrestrial Digital Multimedia Broadcasting (AT-DMB), and the interconnection of them via the Media Independent Information Server/Service (MIIS). Then, this paper proposes the fast wakeup and connection mechanism with concepts for improving QoS and energy efficiency simultaneously. In the proposed convergence network, our mechanism places the key on the minimization of both the incoming service delay destined to a turned-off interface by using the broadcasting network and the additional energy consumption. This paper further evaluates the performance of proposed mechanism through the numerical and experimental analysis and has confirmed the decrease of both service delay and energy consumption.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.355-357
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• 2001

HTTP/1.1 standard reduces latencies and overhead from closing and re-establishing connections by supporting persistent connections as a default, which encourage multiple transfers of objects over one connection. HTTP/1.1, however, does not define explicitly connection-closing time but specifies a certain fixed holding time model. This model may induce wasting server’s resource when server maintains connection with the idle-state client that requests no data for a certain time. This paper proposes the mechanism of a heuristic connection management supported by the client-side under persistent HTTP, in addition to HTTP/1.1’s fixed holding time model on server-side. The client exploits the tag information within transferred HTML page so that decides connection-closing time. As a result, the mechanism allows server to use server’s resource more efficiently without server’s efforts.

• ETRI Journal
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• v.39 no.3
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• pp.345-352
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• 2017

Traffic management is a highly beneficial mechanism for satisfying quality-of-service requirements and overcoming the resource scarcity problems in networks. This paper introduces an optimal connection admission control mechanism to decrease the packet loss ratio and end-to-end delay in cognitive radio sensor networks (CRSNs). This mechanism admits data flows based on the value of information sent by the sensor nodes, the network state, and the estimated required resources of the data flows. The number of required channels of each data flow is estimated using a proposed formula that is inspired by a graph coloring approach. The proposed admission control mechanism is formulated as a semi-Markov decision process and a linear programming problem is derived to obtain the optimal admission control policy for obtaining the maximum reward. Simulation results demonstrate that the proposed mechanism outperforms a recently proposed admission control mechanism in CRSNs.

• The KIPS Transactions:PartC
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• v.14C no.6
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• pp.525-536
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• 2007

Network Control Platform(NCP) and Qualify of Service Switch(QSS) are being developed to realize centralized control and management technology, which is essential for guaranteeing traffic engineering and service quality in a next generation network. This paper adopts a parallel mechanism, and a thread and object pool to achieve high-speed connection management in the existing SNMP interface between NCP and QSS. We built up a connection management test-bed in laboratory environment to validate the functionality of high-speed connection management. We also measured and analyzed a performance of connection setup delay and a completion ratio using the test-bed. We ascertain that the parallel mechanism and the object pool are the most important performance parameters to achieve high-speed connection management in the SNMP interface between NCP and QSS.

• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.835-843
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• 2002

The goal of this paper is to understand the stress-transfer mechanism of concrete-filled tubular column to H-beam connection with external T stiffener through the elasto-plastic finite element method and to offer basic data for the design of T stiffener. For the accuracy, analysis results are compared with experimental results. It makes use of several stress and strain indices to understand the stress-transfer mechanism of connection. An alternative plan that decreases the stress concentration of beam flange to horizontal stiffener connection is proposed through the elasto-plastic finite element method.