• International Journal of Internet, Broadcasting and Communication
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• v.6 no.2
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• pp.17-19
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• 2014

Now is the applications are using WSN for environmental monitoring and surveillance applications, intelligent transportation systems, monitoring, disaster recovery, and the structure used in the field. Also, the low cost of the communication and control functions can be provided, in particular management of smart grid demand may be used in many applications. In this paper, WSN in smart grid is based on the building blocks of smart grid management system proposed for the fuzzy demand.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.639-646
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• 2000

Estimation for the vibration behavior of a nuclear fuel rod with its supporting structure called spacer grid has been made by the both of experimental and analytical methods in order to compare the supporting performance of two kinds of the spacer grids which have been newly developed. For the analytical method the fuel rod was modeled as a beam continuously supported by the springs of the spacer grid, and ABAQUS computer code was utilized. After a modal testing was performed for the fuel rod supported by five spacer grids, two results has been compared to justify and compensate the both methods. It has been found that the spring design of the spacer grid could give significant effect to natural frequency and vibration amplitude of the fuel rod.

• 한국전산유체공학회:학술대회논문집
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• 1997.10a
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• pp.38-42
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• 1997

A multiblock grid generation has been applied to a Navier-Stokes design procedure of a axial-flow compressors. A multiblock structure simplifies the creation of structured H-grids about complex turbomachinery geometries and facilitate the creation of a grid in the tip flow region. The numerical algorithm adopts the combination of the algebraic and elliptic method to create the internal grids efficiently and quickly. The input module is made of the results of the preliminary design, i.e., flow-path, aerodynamic conditions along the spanwise direction, and the blade profile data. The final grids generated from each module of the system are used as the preprocessor for the performance prediction of the sectional blade, the blade-stacking process and the three-dimensional flow simulation inside the blade passage. Application to the blade design of the LP compressor was demonstrated to be very reliable and practical in support of design activities. This customized system are coupled strongly with the design procedure of the turbomachinery cascades using the Navier-Stokes technique.

• Journal of computational fluids engineering
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• v.10 no.2
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• pp.15-20
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• 2005

Numerical investigations have been performed to examine the effects of the computational grids on the prediction of the flow characteristics inside the turbine cascades. Three kinds of grid system based on H-type grid are applied to the high-turning transonic turbine rotor blades and comparisons with the experimental data and the numerical results of each grid structure have been done. In addition, the grid sensitivity on the estimation of the blade performances has been investigated.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.857-862
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• 2003

Numerical investigations have been performed to examine the effects of the computational grids on the prediction of the flow characteristics inside the turbine cascades. Three kinds of grid system based on H-type grid are applied to the high-turning transonic turbine rotor blades and comparisons with the experimental data and the numerical results of each grid structure have been done. In addition, the grid sensitivity on the estimation of the blade performances has been investigated.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.5
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• pp.417-422
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• 2008

In this paper, a novel DC/DC low-voltage high-current converter circuit is proposed to improve the efficiency of power converter used in the grid-connected fuel-cell generator system. We proposed a novel high efficiency grid-connected power conditioning system for RPG fuel cell. On the result of that, the loss of system was decreased rapidly by driving stack within the condition of maximum efficiency. The peak currents of the current-type inductor and the transformer's coil are reduced by synchronizing switching frequency of Buck-type converter is increased twice as the Push-Pull converter's switching frequency. The novel structure of DC/DC converter is able to realize ZVS-ZCS in fuel-cell system is proposed. The proposed switching component of Push-Pull converter has the ZVS and ZCS function by using the circuit of new passive clamp.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.563-566
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• 2011

Smart grid electrical energy network is constructed in the additional network concept can be viewed with the power and IT. In order to build samrt grid networks the communication requirements should be defined definitely with implementing structure on communication network. In this paper, we introduces smart grid technology and network perspective on the requirements based on ITU-T standards.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.329-330
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• 2012

The rising popularity of renewable energy sources resulted in development of the units of higher rated powers, where the large-scale plants and grid-connected type solar power systems are increased. Therefore, the importance of grid stabilization, which depends on each country or system-type, has been strengthened by different grid-codes or certifications. In this paper, the control scheme of three-phase photovoltaic system is enhanced, where both injected active and reactive powers are simultaneously controlled with the consideration of the certification of the Germany Association of Energy and Water Industries (BDEW). Experimental results are shown to verify the theoretical analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.470-475
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• 2019

This paper deals with a 30kW grid-connected PCS (Power Conversion System) for an Oscillating Water Column (OWC) wave-power generation system. Wave power generation in marine energy is suitable for Korea with the characteristics of a peninsula with three sides facing the sea. In the case of coastal disasters, wave generators can act as a breakwater to reduce damage, and can be integrated with other marine power generation systems to increase efficiency. Wave power generation systems are classified into various types, such as oscillating bodies, OWC, and overtopping according to the operation principle, and they can also be classified into two types according to the installation method: a fixed structure and floating structure. This paper proposes a 30kW grid-connected PCS topology and model for OWC wave power generation that is structurally stable with a turbine and generator that are relatively easy to maintain, and then provide a control method required for grid connection, including DC link voltage control. Simulation verification was performed to verify the proposed PCS.

• Journal of architectural history
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• v.11 no.4 s.32
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• pp.99-115
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• 2002

Centered on Durand and Le Corbusier, this study analyses the changing status of the grid and axis in modern architecture. In the Renaissance, the taxis grid operated as a contour grid, defining the elements and space of the building as part of closed harmonized world. In his Pre'cis des lec., ons d'architecture, Durand provides the most explicit demonstration of a new modem grid in which its lines function as spatial and structural axes. In principle these axes are coordinates for the placements of a priori elements but in Beaux-Arts practice, as Durand himself acknowledged, they involve a simultaneous process in which the spatial axis sets up the basic parti and the structural axis is developed into the building's poche'. As a coordinate, Durand's grid provides a place for the 'subject' to enter the architectural process. At the same time, it is the object of the subject's gaze, the dense site of the subject's transformative actions. Though Le Corbusier is noted for his frequent attacks on the academic system, his architecture should be seen within the continuity of the classical tradition. He redefines the Beaux-Arts axis as a moving and seeing observer, and continues the discipline of the plan, the essential discipline of the Beaux-Arts system. In his dialectics, an intellectual scheme which extends to his commentators, the intention and will of the subject must come in tune with the objective material form of the building. Like Durand, Le Corbusier's axis provides the medium for the subject to enter. Unlike the Beaux-Arts system, however, Le Corbusier's mobile subject no longer has a holistic view of the building previously provided by the central axis. If there is a parti for Le Corbusier, it consists of the domino grid as a potential, but nonetheless, tangible form. In comparison with the Beaux-Arts structural grid, his gaze no longer lingers on their lines because they no longer constitute a formal process tied to the development of a thick articulated structure. Le Corbusier's grid constitutes a 'loose' form, one that breaks down the hierarchical nature of the Beaux-Arts system.