• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.1996-2008
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• 2004

A seamless analysis of material behavior incorporating complex geometry and crack- tip modeling is one of greatly interesting topics in engineering and computational fracture mechanics fields. However, there are still large gaps between the industrial applications and fundamental academic studies due to a time consuming detailed modeling. In order to resolve this problem, a numerical method to calculate an energy release rate by virtual crack closure technique was proposed in this paper. Both free mesh method and finite element method have been utilized and, thereafter, robust local and global elements for various geometries and boundary conditions were generated. A validity of the proposed method has been demonstrated through a series of fracture mechanics analyses without tedious crack-tip meshing.

• Journal of Information Technology Services
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• v.10 no.2
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• pp.189-202
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• 2011

It is important issue how to evaluate the economic feasibility of computing factors in the real world when we build ubiquitous spaces. In this paper, we propose a simple model that can evaluate the economic feasibility of mobile RFID-based ubiquitous computing system which enables seamless communication between offline and online via embedded computing factors in the real world. To achieve this, we explore the meaning of mobile RFID system, the difference between our research and extant researches concerning the evaluation of economic feasibility in RFID system, and propose the so-called 'Tag-based Evaluation Model' (TEM) which is an evaluation model to access the economic feasibility of mobile RFID systems. We also analyze the TEM via simulation cases based on proposed model and discuss the future of TEM.

• Journal of Korean Society of Archives and Records Management
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• v.12 no.1
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• pp.79-94
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• 2012

The BMS(Bussiness Management System) included conferences, directions, memo system and operated bussiness classification based on. The high valued BMS contains many faulty functions managing records. A purpose of this study is analyzing BMS in archival science. Morever, this study deals with resolving problems for seamless flow managing records.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.4
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• pp.185-194
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• 2010

In this paper, we propose an application layer-based vertical handover management protocol, called multihoming RTP (mhRTP), for real-time applications with seamless mobility across heterogeneous wireless access networks. The proposed multi-homing RTP provides a soft handover by utilizing multiple available wireless access network interfaces simultaneously. The newly available path is dynamically added to the ongoing session by the mhRTP session manager. Also the decision making of QoS-improving or QoS-guaranteed handover is possible based on the estimation of available bandwidth in each candidate network. The performances of the proposed mhRTP have been analyzed through a series of simulations on OPNET network simulator. From the performance analysis, we confirmed that the proposed mhRTP can provide QoS-guaranteed vertical handover with efficient session managements.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.171-177
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• 2012

Network mobility support has been taken into consideration for users who have multiple terminals to enjoy the seamless connectivity. This paper proposes a network mobility support scheme in the LISP architecture. During the mobile router attachment, the EID-to-RLOC mapping database is refreshed in the map server. Furthermore, map update is developed to support smooth handoff for the mobile network. An analysis of performance is given by comparing the proposed scheme with NEMO.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.593-596
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• 2010

Currently, maritime information service is provided by a variety of equipments such as satellites, radar and VHF devices with independent standards and protocols. However, the increase of vessel traffic and development of global marine industries need an infrastructure providing seamless information transfer for the safety, security and protection of the marine environment. Therefore, we propose features and requirements of future VHF data systems and equipments as a component of e-Navigation.

• New & Renewable Energy
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• v.4 no.3
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• pp.51-57
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• 2008

The objective of this study is to develop and validate a compressed hydrogen storage system for fuel cell vehicles. The type3 composite cylinder consists of full wrapped composites on a seamless aluminum liner. The key technologies, including design, analysis, and optimized fabrication process for 350bar composite cylinder, were established and verified, and the facilities for fabrication and validation testing have been constructed. Prototype cylinders were fabricated and validated through burst test and ambient cycling test in accordance with international standard.

• Journal of the Korea Society for Simulation
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• v.13 no.3
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• pp.31-41
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• 2004

In this paper, we consider the strategy of Universal Mobile Telecommunication System (UMTS) and Wireless Local Area Network (WLAN) internetworking that provide the seamless vertical handover for mobile nodes. We propose Mobility Anchor Points (MAP) based UMTS/WLAN internetworking architecture to support the vertical handover. Also, on integrated UMTS/WLAN networks, we propose a vertical handover scheme that avoids the call blocking caused by the network resource shortage. We provide the numerical analysis to investigate the performance evaluation to the proposed scheme and compare the proposed scheme with the existing scheme.

• ETRI Journal
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• v.28 no.2
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• pp.131-144
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• 2006

This work demonstrates a dead-reckoning (DR) scheme for a low-cost land navigation system and a DR/GPS system design using the sigma point Kalman filter (SPKF). T hrough an observability analysis and some simulations, it is shown that the performances of a stand-alone DR system and DR/GPS system can be improved by employing the proposed DR scheme and SPKF. By using the designed DR scheme and filter, the stand-alone DR system does not have any undetectable errors occurring on the curve trajectory. And the DR/GPS system can provide a stable and seamless navigational solution even in the case where the initial heading estimation error is large, such as 160 degrees, or when the GPS signal is unavailable due to tunnels, buildings, and so on. Simulation results indicate a satisfactory performance of the proposed system.

• Journal of Power Electronics
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• v.17 no.6
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• pp.1611-1624
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• 2017

With the rapid development of microgrid technology, microgrid projects are no longer limited to laboratory demonstrations and pilot platforms. It shows greater value in practical applications. Hence, the smooth interaction between a microgrid and the main grid plays a critical role. In this paper, a control method based on active disturbance rejection control (ADRC) is proposed in order to realize seamless transitions between grid-connected and islanding operation modes and stable operation with variable loads. It is verified by simulations that the proposed ADRC-based method features better performance when compared to conventional proportional-integral-differential (PID) control. Meanwhile, the stability of the third-order extended state observer (ESO) in second-order ADRC is validated by using Lyapunov stability criteria.