• Journal of the Korea Furniture Society
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• v.28 no.3
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• pp.156-168
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• 2017

The digital information society that developed along with the 21st century is the 'Open-source Making Movement' which produces collective intelligence through open-source sharing and digital manufacturing tools, which is called 'Makers Movement'. The purpose of this paper is to analyze the case of Makers Movement in furniture design through 'IKEA Hacking' which arose simultaneously with the Makers Movement, and to study and present the prospect and direction of furniture design in the change of manufacturing industry. In this study, four design features were compared with IKEA hacking cases along with the establishment of 'community' which is a feature of Makers Movement. Four characteristics are first customized design, second derivative design through open source, third long -Tail effect design, and fourth, design using digital manufacturing tools. The prospect and direction of furniture design through this study are as follows: first, democratization of furniture design manufacturing, second job creation, third, coexistence of large and small enterprises, fourth promotion of various new technologies, and fifth, discovery of various furniture designers through 'Open System Organization'.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.1095-1099
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• 2017

A fission source can act as a stabilization element in coupled Monte Carlo simulations. We have observed this while studying numerical instabilities in nonlinear steady-state simulations performed by a Monte Carlo criticality solver that is coupled to a xenon feedback solver via fixed-point iteration. While fixed-point iteration is known to be numerically unstable for some problems, resulting in large spatial oscillations of the neutron flux distribution, we show that it is possible to stabilize it by reducing the number of Monte Carlo criticality cycles simulated within each iteration step. While global convergence is ensured, development of any possible numerical instability is prevented by not allowing the fission source to converge fully within a single iteration step, which is achieved by setting a small number of criticality cycles per iteration step. Moreover, under these conditions, the fission source may converge even faster than in criticality calculations with no feedback, as we demonstrate in our numerical test simulations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1602-1610
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• 2018

Induction heating can convert electrical energy to thermal energy with high conversion efficiency and quick heating. Currently, a current source rectifier/inverter-fed parallel resonant circuit is widely used as an induction heating power supply for forging applications. However, the conventional induction heating power supplies composed of phase-controlled rectifier and SCR inverter have low efficiency and low power factor at input side, and require additional starting circuitry. So this paper proposes new induction heating power supply topologies for forging applications which have high power factor, high efficiency, and large output power. It also suggests detailed design guideline.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.259-260
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• 2006

• Proceedings of the Korean Vacuum Society Conference
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• 2002.02a
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• pp.173-173
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• 2002

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.79-86
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• 2005

The apparent source spectrum of the Fukuoka earthquake is estimated at the seismic basement by removing from the observed spectra at Korean seismic stations the path and site responses that were previously revealed through inversion process applied to large spectral D/B accumulated until 2004. The approximate source spectrum is also estimated by using data recorded near the epicenter from various Japanese seismic networks and compared with the Korean source spectrum. The comparison result shows that there is good agreement among source spectra estimated based on the data from seismic networks of Korea at large distances (190km

• Journal of the Korean Geophysical Society
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• v.8 no.1
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• pp.15-21
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• 2005

The apparent source spectrum of the Fukuoka earthquake is estimated at the seismic basement by removing from the observed spectra at Korean seismic stations the path and site responses that were previously revealed through inversion process applied to large spectral D/B accumulated until 2004. The approximate source spectrum is also estimated by using data recorded near the epicenter from various Japanese seismic networks and compared with the Korean source spectrum. The comparison result shows that there is good agreement among source spectra estimated based on the data from seismic networks of Korea at large distances (190 km

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.3-4
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• 2011

This paper presents a survey of floating power supply based on bootstrap operation for three-level voltage-source inverters. The floating power supply for upper switches is achieved by the bootstrap capacitor charged during on-time of the switch underneath. Hence, a large number of bulky isolated DC/DC power supplies for each gate driver are reduced. The Pspice simulation results show the behavior of bootstrap devices and the performance of bootstrap capacitor voltage.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.629-631
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• 2004

The proposed output buffer is presented for driving large-size LCD panels. This output buffer is designed by adding some simple circuitry to the conventional two-stage operational amplifier. The proposed circuit is simulated in a high-voltage 0.35um CMOS process with HSPICE. The simulated result is more improved settling time than that of conventional one.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.505-508
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• 2000

A coreless printed circuit board(PCB) transformer is employed in a contactless energy transfer circuit that achieves an efficient power conversion at the presence of a considerable airgap between the source and the load side. A half-bridge series resonant converter is selected as the contactless energy transfer circuit in order to minimize the detrimental effects of large leakage inductance small magnetizing inductance and poor coupling coefficient of the coreless PCB transformer. The operation and performance of the proposed contactless power converter are verified on a 7 W experimental circuit that provides an 18V/0.4A output from a 210-370 V input source.