• International Journal of Automotive Technology
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• 제7권4호
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• pp.423-439
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• 2006

This paper proposes a hybrid analytic method for the prediction of vibrational and acoustic responses of reverberant system in the medium-to-high frequency ranges by using the PFA(Power Flow Analysis) algorithm and SEA(Statistical Energy Analysis) coupling concepts. The main part of this method is the application of the coupling loss factor(CLF) of SEA to the boundary condition of PFA in reverberant system. The hybrid method developed shows much more promising results than the conventional SEA and equivalent results to the classical PFA for various damping loss factors in a wide range of frequencies. Additionally, this paper presents applied results of hybrid power flow finite element method(hybrid PFFEM) by formulating the new joint element matrix with CLF to analyze the vibrational responses of built-up structures. Finally, the analytic results of coupled plate structures and an automobile-shaped structure using hybrid PFFEM were predicted successively.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.73-78
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• 2004

In this research, the photoelastic experimental hybrid method with Hook-Jeeves numerical method has been developed: This method is more precise and stable than the photoelastic experimental hybrid method with Newton-Rapson numerical method with Gaussian elimination method. Using the photoelastic experimental hybrid method with Hook-Jeeves numerical method, we can separate stress components from isochromatics only and stress intensity factors and stress concentration factors can be determined. The photoelastic experimental hybrid method with Hook-Jeeves had better be used in the full field experiment than the photoelastic experimental hybrid method with Newton-Rapson with Gaussian elimination method.

• Journal of information and communication convergence engineering
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• 제7권3호
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• pp.253-257
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• 2009

As the value of B2B integration gets more importance and the business process becomes more complex, BPEL4WS standard has been focused for the solution of the problems which is based on web service technology. Many vendors implement the standard in their systems to integrate B2B and web service based inner-Enterprise Application(EA)s. But there is no way to use the standard to integrate non-web service based EAs, because the standard is designed only for Service Oriented Architecture (SOA) over web services. This paper proposes Hybrid Service Orchestration Framework to participate web services and also non-web service based EAs in the business process as a partner using BPEL4WS standard. The framework introduces Hybrid Service Architecture to represent non-web service based EAs as a service, so BPEL4WS could be used to integrate web services and non-web service based EAs. And the framework also introduces Hybrid Service Toolkit to support software level facilities. The paper also introduces Hybrid Orchestration System that is based on Hybrid Service Orchestration Framework.

• 한국자동차공학회논문집
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• 제12권5호
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• pp.101-107
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• 2004

Recently the objective of vehicle design was focused on the crash safety and the energy saving. For the energy saving vehicle structures must be light weight, but for the crash safety some energy absorbing elements must be added. In this paper hybrid structure which consists of a steel and a FRP was studied on the energy absorption characteristics under the impact load by finite element method. Test results of the other researchers were compared with that of computer simulation on this simple hybrid structure. Side rail of vehicle front structure was replaced with hybrid materials for the application of the vehicle structure. 35mph frontal crash simulation was performed with hybrid structure and with conventional steel structure. By the adoption of hybrid structure, the improvement of energy absorption characteristics and reduction of weight was observed under the frontal crash simulation.

• 대한소아치과학회지
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• 제30권2호
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• pp.263-271
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• 2003

본 연구는 All-In-One system의 적용 시간과 도포횟수에 따라 유치 상아질과 복합레진의 접착 강도와 혼성층에 어떤 영향을 미치는지를 규명하고자 Single bonding agent(Scotchbond Multi-Purpose Plus, 3M, USA)와 All-In-One system(Prompt-L pop, 3M ESPE, USA)를 사용하였고 수복용 레진으로 복합레진(Z-250, 3M, USA)를 사용한 결과 다음과 같은 결과를 얻을 수 있었다. 1. 전단 결합 강도는 Single bonding agent를 적용한 경우 All-In-One system을 적용한 군보다 유의하게 높게 나타났다(P<0.05). 2. Prompt L-pop을 2회, 3회 적용한 경우에 전단 결합 강도는 1회 적용한 군보다 유의하게 높게 나타났으며(P<0.05), 혼성층의 두께는 1회 적용군보다 2회, 3회 적용한 군에서 증가하였다. 3. Prompt L-pop을 15초 적용한 경우에 전단 결합 강도는 7초 적용한 군보다 유의하게 높게 나타났으며(P<0.05), 30초 적용군과는 차이가 없었다. 혼성층의 두께는 7초 적용군이 가장 얇고, 15초군과 30초군에서는 차이가 없었다. 4. Single bonding agent를 이용한 경우 두터운 $2-4{\mu}m$의 혼성층이 관찰된 반면, All-In-One bonding system(Prompt L-pop, 3M ESPE, USA)에서는 비교적 얇은 혼성층($1-2{\mu}m$)이 형성되었다.

• Progress in Superconductivity
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• 제10권1호
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• pp.60-67
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• 2008

We present domestic efforts for superconducting fault current limiter (SFCL) application in the Korea Electric Power Corporation (KEPCO) grid and pending points at issue. KEPCO's decision to upgrade the 154 kV/22.9 kV main transformer from 60 MVA to 100 MVA cast a problem of high fault current in the 22.9 kV distribution lines. The grid planners supported adopting an SFCL to control the fault current. This environment friendly to SFCL application must be highly dependent upon the successful development of SFCL having specifications that domestic utility required. The required conditions are (1) small size of not greater than twice of 22.9 kV gas insulated switch-gear (GIS), (2) sustainability of current limitation without the line breaking by circuit breakers (CB) for maximum 1.5 seconds. Also, optionally, recommended is (3) the reclosing capability. Conventional resistive SFCLs do not meet (1) $\sim$ (3) all together. A hybrid SFCL is an excellent solution to meet the conditions. The hybrid SFCL consists of HTS SFCL components for fault detection and line commutation, a fast switch (FS) to break the primary path, and a limiter. This characteristic structure not only enables excellent current limiting performances and the reclosing capability, but also allows drastic reduction of HTS volume and small size of the cryostat, resulting in economic feasibility and compactness of the equipment. External current limiter also enables long term limitation since it is far less sensitive to heat generation than HTS. Semi-active operation is another advantage of the hybrid structure. We will discuss more pending points at issues such as maintenance-free long term operation, small size to accommodate the in-house substation, passive and active control, back-up plans, diagnosis, and so on.

• Journal of Welding and Joining
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• 제34권2호
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• pp.22-29
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• 2016

Recently, Application of composite materials are increased in transport area for weight reduction. Also, Related technical developments have been implemented actively at domestic and abroad. In particular, The carbon fiber has high strength and ultra light property higher than stainless steel, aluminum, GFRP as Eco-friendly material. Carbon fiber contribute to improving the environmental effect such as fuel saving, expansion of loadage, reducing the exhaustion of carbon dioxide through the weight reduction of transport area. In addition, The carbon fiber is applied to the ship in the area of race yacht, luxury cruise boat as weight reduction and high added-value materials, but there is limited application for general boat because price of carbon fiber is very expensive. For the weight reduction of general boat hull, being used as structure materials, glass fiber and carbon fiber are applied to hull with form of hybrid composite materials, but application of domestic and research for development are incomlete. In this study, An evaluations of mechanical strength property and fatigue strength are performed on composite materials by hybrid weaving of glass fiber and carbon fiber and composite materials forming method by hybrid forming.

• Smart Structures and Systems
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• 제26권3호
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• pp.373-390
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• 2020

Hybrid simulation (HS) is a versatile tool for structural performance evaluation under dynamic loads. Although real structural responses are often multiple-directional owing to an eccentric mass/stiffness of the structure and/or excitations not along structural major axes, few HS in this field takes into account structural responses in multiple directions. Multi-directional loading is more challenging than uni-directional loading as there is a nonlinear transformation between actuator and specimen coordinate systems, increasing the difficulty of suppressing loading error. Moreover, redundant actuators may exist in multi-directional hybrid simulations of large-scale structures, which requires the loading strategy to contain ineffective loading of multiple actuators. To address these issues, lately a new strategy was conceived for accurate reproduction of desired displacements in bi-directional hybrid simulations (BHS), which is characterized in two features, i.e., iterative displacement command updating based on the Jacobian matrix considering nonlinear geometric relationships, and force-based control for compensating ineffective forces of redundant actuators. This paper performs performance validation and application of this new mixed loading strategy. In particular, virtual BHS considering linear and nonlinear specimen models, and the diversity of actuator properties were carried out. A validation test was implemented with a steel frame specimen. A real application of this strategy to BHS on a full-scale 2-story frame specimen was performed. Studies showed that this strategy exhibited excellent tracking performance for the measured displacements of the control point and remarkable compensation for ineffective forces of the redundant actuator. This strategy was demonstrated to be capable of accurately and effectively reproducing the desired displacements in large-scale BHS.

• ETRI Journal
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• 제33권1호
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• pp.13-17
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• 2011

A highly miniaturized on-chip $180^{\circ}$ hybrid employing periodic ground strip structure (PGSS) was realized on a silicon radio frequency integrated circuit. The PGSS was placed at the interface between $SiO_2$ film and silicon substrate, and it was electrically connected to top-side ground planes through the contacts. Owing to the short wavelength characteristic of the transmission line employing the PGSS, the on-chip $180^{\circ}$ hybrid was highly miniaturized. Concretely, the on-chip $180^{\circ}$ hybrid exhibited good radio frequency performances from 37 GHz to 55 GHz, and it was 0.325 $mm^2$, which is 19.3% of a conventional $180^{\circ}$ hybrid. The miniaturization technique proposed in this work can be also used in other fields including compound semiconducting devices, such as high electron mobility transistors, diamond field effect transistors, and light emitting diodes.

• 한국자동차공학회논문집
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• 제10권6호
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• pp.166-170
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• 2002

A hybrid structure composed of magnesium and steel is Instrument Panel structure used for the basement of cockpit module components. For that reason, A hybrid structure has to be designed for satisfying components assembly design facility and styling. There are various models of If like steel structure assembly, however having been applied normally, but magnesium structure assembly selected far saving weight down. This paper introduces a hybrid structure having advantages between steel and magnesium structure and presents a CAE technical solution based on a development project. furthermore, it provides desired direction of the future development is suggested.