• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.195-198
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• 2001

To improve the properties of FRP composite materials, the hybrid prepreg with non-woven tissue (NWT) is developed. The hybrid prepreg consists of undirectional prepreg and NWT prepreg. The NWT prepreg is made by compounding the NWT and polymer resin, which is similar to the production method of FRP prepreg. The NWT has short fibers which are discretely distributed with in-plane random orientation. The stiffness and strength of NWT composites are lower than those of continuously fibrous composites. The strengthening technique and fabricating technique for the hybrid prepreg are described in this work. The mechanical characteristics of hybrid composites with NWT are discussed and compared with those of the FRP composites.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.100-108
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• 2003

This paper proposes a flywheel hybrid vehicle to solve the energy crisis problem by the exhaustion of a fossil fuel and air pollution for the conservation of environment. The proposed flywheel hybrid vehicle is composed of an accumulator and a flywheel as the energy generation and storage component and three variable displacement hydraulic pump/motors as the energy transfer devices. Flywheel has the characteristics of high energy density and easy energy absorption and consumption. The effectiveness of the energy-saving of the proposed flywheel hybrid vehicle is verified by simulation using Matlab/simulink. First of ail, analytical modeling for the flywheel hybrid vehicle is presented and simulations are performed based on the experimental efficiency data of a variable displacement pump/motor. The results of the simulation show that the effect of energy savings is realized by the proposed hybrid vehicle in 3 different city driving patterns.

• Journal of Power Electronics
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• v.3 no.1
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• pp.40-48
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• 2003

In this paper, a hybrid power system with photovoltaic/wind/diesel generators is proposed to solve the defect of stand-alone type power system in a remote area. A hybrid power system has a power-balanced controller to equilibrate generation power with a given load demand and which is composed of common DC power system. To execute a power-balanced control, a hybrid power system is assumed that all of power generators have the characteristics of an equivalent current-source and load sharing control technique must be needed at the same time. So this paper discusses the structure of power-balance control for hybrid power system. And through the results of simulation, the proposed scheme was verified.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.527-534
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• 2003

This paper presents the LRB-based hybrid base isolation systems employing additional active/semiactive control devices for seismic protection of cable-stayed bridges by examining the ASCE first generation benchmark problem for a cable-stayed bridge. In this study, ideal hydraulic actuators (HAs) and ideal magnetorheological dampers (MRDs) are considered as additional active and semiactive control devices, respectively. Numerical simulation results show that all the hybrid base isolation systems are effective in reducing the structural responses of the benchmark cable-stayed bridge under the historical earthquakes considered. The simulation results also demonstrate that the hybrid base isolation system employing semiactive MRBs is robust to the stiffness uncertainty of the structure, while the hybrid system with active HAs is not. Therefore, the LRB-based hybrid base isolation system employing MRDs could be more appropriate in real applications for full-scale civil infrastructures.

• Korean Journal of Social Welfare
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• v.62 no.3
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• pp.323-351
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• 2010

Through the biographical approach, the current research purports to reconstruct the Changeprocess of values and identities on the lives of the first-generation Korean-German females in Germany from the transnational perspective. Ten interviews were conducted, using Schutze's autobiographicalnarrative interview. Interview data were analyzed through the application of Schutze's autobiographical-narrative interview and Mayring's qualitative content analysis. Findings showed that on the onset of emigration, their values centered around hybrid collectivism. Their life in the process of emigration was characteristic of a shift to hybrid individualism. Furthermore, the life at beginning of emigration was found to be characterized by a singular regional identity. The process of emigration was shown to mark the conversion into dual identity, dual regional and dual national. Some theoretical and practical suggestions for the emigrants' welfare were finally offered that were associated with the process of values and identities changes in their life.

• Electronics and Telecommunications Trends
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• v.35 no.4
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• pp.1-10
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• 2020

Since the 1960s, semiconductor packaging technology has developed into electrical joining techniques using lead frames or C4 bumps using tin-lead solder compositions based on traditional reflow processes. To meet the demands of a highly integrated semiconductor device, high reliability, high productivity, and an eco-friendly simplified process, packaging technology was required to use new materials and processes such as lead-free solder, epoxy-based non cleaning interconnection material, and laser based high-speed processes. For next generation semiconductor packaging, the study status of two epoxy-based interconnection materials such as fluxing and hybrid underfills along with a laser-assisted bonding process were introduced for fine pitch semiconductor applications. The fluxing underfill is a solvent-free and non-washing epoxy-based material, which combines the underfill role and fluxing function of the Surface Mounting Technology (SMT) process. The hybrid underfill is a mixture of the above fluxing underfill and lead-free solder powder. For low-heat-resistant substrate applications such as polyethylene terephthalate (PET) and high productivity, laser-assisted bonding technology is introduced with two epoxy-based underfill materials. Fluxing and hybrid underfills as next-generation semiconductor packaging materials along with laser-assisted bonding as a new process are expected to play an active role in next-generation large displays and Augmented Reality (AR) and Virtual Reality (VR) markets.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.7
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• pp.18-25
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• 2005

In this study, the main focus is the simulation of acoustic wave scattering in trailing edge and the analysis of the generation mechanism of instability wave by the interaction of trailing edge, shear flow and initial disturbance. The numerical algorithm is based on CFD/CAA hybrid method with high-order computational aeroacoustic method. It is found that steady mean flow gradient terms play a crucial role on the generation of instability wave through the comparison of simulations of Simple Linearized Euler Equation and Full Linearized Euler Equation. Through the comparison with the results of Full Navier-Stokes Equation, it is reasonable and efficient to use the Full Linearized Euler Equation in the initial generation mechanism of the instability wave near the trailing edge.

• Advances in Energy Research
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• v.7 no.1
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• pp.67-84
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• 2020

Given the recent surge of interest towards utilization of renewable distributed energy resources (DER), in particular in remote areas, this paper aims at designing an optimal hybrid system in order to supply loads of a village located in Esfarayen, North Khorasan, Iran. This paper illustrates the optimal design procedure of a standalone hybrid system which consists of Wind Turbine Generator (WTG), Photo Voltaic (PV), Diesel-generator, and Battery denoting as the Energy Storage System (ESS). The WTGs and PVs are considered as the main producers since the site's ambient conditions are suitable for such producers. Moreover, batteries are employed to smooth out the variable outputs of these renewable resources. To this end, whenever the available power generation is higher than the demanded amount, the excess energy will be stored in ESS to be injected into the system in the time of insufficient power generation. Since the standalone system is assumed to have no connection to the upstream network, it must be able to supply the loads without any load curtailment. In this regard, a Diesel-Generator can also be integrated to achieve zero loss of load. The optimal hybrid system design problem is a discrete optimization problem that is solved, here, by means of a recently-introduced meta-heuristic optimization algorithm known as Lightning Attachment Procedure Optimization (LAPO). The results are compared to those of some other methods and discussed in detail. The results also show that the total cost of the designed stand-alone system in 25 years is around 92M€ which is much less than the grid-connected system with the total cost of 205M€. In summary, the obtained simulation results demonstrate the effectiveness of the utilized optimization algorithm in finding the best results, and the designed hybrid system in serving the remote loads.

• Fire Science and Engineering
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• v.31 no.4
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• pp.12-19
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• 2017

The present paper is a study on the performance characteristics of organic-inorganic hybrid flame retardants. MDF plywood has been used, that are being used for the interior decoration of building structures, to make the samples for experiment according to the existing or non-existing treatment of organic-inorganic hybrid flame resistants. Later, the experiment on the measurement of flame retardant performance using a $45^{\circ}$ flammability tester and the experiment on the measurement of combustion characteristic using a cone calorimeter have been proceeded to confirm the performance characteristic of organic-inorganic hybrid flame retardants. From the result of experiments, it has been confirmed that both organic-inorganic hybrid flame retardants have merits of inorganic and organic substances, and that heat resistance, durability and adhesiveness have been largely improved. The performance on the flame retardant has also appeared with excellent effect such as the reduced generation of combustion gas and the decreased generation of smoke.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.5
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• pp.80-92
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• 2017

The popularity of cloud computing has led to the emergence of various types of cloud services, and the hybrid cloud, a deployment model that integrates public cloud and private cloud and offset their shortcomings, is in the spotlight recently. However, the complexity of different clouds integration and the lack of related integration solutions have delayed the adoption of hybrid cloud and cloud strategy by companies and organizations. Therefore, in this paper, we propose a cloud integration mechanism to solve the integration complexity problem. The cloud integration mechanism proposed in this paper consists of integration script that solves the cloud integration by the script based on the hybrid cloud function, a process of creating and executing it, and a script creation model applying the software design pattern. By integrating the various cloud services, we can quickly generate scripts that meet the user's needs. It is expected that the introduction of hybrid cloud and the acquisition of cloud strategy can be accelerated through this proposed integration mechanism.