• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.223-226
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• 2001

In this paper, dc link ripple currents for three-phase ac/dc/ac PWM converters are analyzed in a frequency domain. The expression of the harmonic currents is developed by using switching functions and exponential Fourier series expansion. The dc link ripple currents with regard to power factor and modulation index are investigated. In addition, the effect of the displacement angle between the switching periods of line-side converters and load-side inverters on the do link ripple current is studied. The result of the do link current analysis is helpful in specifying the dc link capacitor size and its life time estimation.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.83-88
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• 2023

The increasing global average temperature and the emergence of various abnormal climate phenomena are already being experienced in reality. The problems arising from climate change are expanding and becoming catastrophic, despite the efforts of various organizations to prevent them. In order to avoid climate issues from becoming black elephants, we conducted interviews with emergency planning officer from various institutions to identify potential X-events caused by climate change. The results of analyzing the anticipated X-events by these emergency planning officer revealed a chain of ripple effects associated with their occurrence. This implies that once an X-event happens, its influence is broader and more significant. Through this study, we aim to share the understanding of the ripple effects of climate X-events with many people, raising awareness of the severity of climate issues. We hope that this will serve as a starting point for more institutions, individuals, and nations to make efforts in resolving climate problems, turning X-events into opportunities rather than crises.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1425-1435
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• 2013

The useful method for determining parameters of weighting functions used to design the $H_{\infty}$ current controller for attenuating the current ripple due to saliencies which SPMSM(Surface Permanent Magnet Synchronous Motor) also incorporates is described. To analyze the effect, the current ripple due to the structural and the saturation saliencies, the SPMSM model with nonlinear inductance function depending on the two independent variables, rotor position and stator current is simulated. After analysis, parameters of the weighting functions for $H_{\infty}$ current controller is selected to satisfy the robust stability, robust performance and specific performance in time and frequency domain by using the PSO(Particle Swarm Optimization) algorithm in the linear SPMSM model. Especially, the robust performance is proved that the selected weighting functions play a role in reducing the current ripple caused by the saliencies of SPMSM at the desired frequency range by the simple experiment.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.338-347
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• 2007

The purpose of this study was to analyze a ripple effect of the regions, Samcheok city, Goseong county and Donghae city, in Gangwon province by government aid for forest fire restoration through the input-output analysis. These regions were devastated by forest fire in 2000. Direct production inducement effect was higher than indirect production inducement effect except for construction industry. Income inducement effect similarly showed production inducement effect Indirect employment inducement effect was higher than direct employment inducement effect. The efficiency of government aid took a side view of three effects. Production inducement effect and income inducement effect in Donghae were more efficient than these in Samcheok and Goseong. Employment inducement effect in Samcheok was more efficient than it in Goseong and Donghae.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.159-161
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• 2007

$CO_2$ laser sees that is most suitable to get this effect through minimum formation damage and advantage that is root enemy of effect that happen in minimum cellular tissue depth of 0.1mm is stable living body organization or internal organs institution. Formation damage by ten can be related in formation's kind or energy density, length of evaporation time. If shorten evaporation time, surroundings cellular thermal damage 200 - because happen within 400ums laser beam in rain focus sacred ground surroundings cellular tissue without vitiation me by evaporation Poe of very small floor as is clean steam can. Application is possible to vulva cuticle cousins by a paternal aunt quantity, uterine cancer, cuticle tumor by laser system that $CO_2$ laser gets into standard in obstetrics and gynecology application. Because effect that super pulse output is ten enemies of laser if uniformity one pulse durations are short almost is decreased, most of all pulse module special quality of pulse style $CO_2$ laser for obstetrics and gynecology mode stabilization by weight very, in this research to get into short pulse duration and higher frequency density, do switching by high frequency in DC-DC Converter output DC's ripple high frequency to be changed, high frequency done current ripple amount of condenser for output filter greatly reduce can. Ripple of output approximately to Zero realization applying possible inductor realization through a special quality experiment do.

• Journal of Power Electronics
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• v.16 no.3
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• pp.832-839
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• 2016

In this study, the performance of a direct current (DC)-DC buck converter is analyzed in the presence of non-idealities in passive components and semiconductor devices. The effect of these non-idealities on the various design issues of a DC-DC buck converter is studied. An improved expression for duty cycle is developed to compensate the losses that occur because of the non-idealities. The design equations for inductor and capacitor calculation are modified based on this improved expression. The effect of the variation in capacitor equivalent series resistance (ESR) on output voltage ripple (OVR) is analyzed in detail. It is observed that the value of required capacitance increases with ESR. However, beyond a maximum value of ESR (r_c,max), the capacitor is unable to maintain OVR within a specified limit. The expression of r_c,max is derived in terms of specified OVR and inductor current ripple. Finally, these theoretical studies are validated through MATLAB simulation and experimental results.

• Journal of Information Management
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• v.41 no.3
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• pp.175-190
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• 2010

In order to enhance national science technology and to secure the origin of creative wealth, there is a need to offer accurate and high quality information with semantic technology. Semantic technology enables to significantly unify information and obtain the wanted information in an easier way. Also Semantic technology is a key technology of the next generation having great ripple effect on the whole of IT. In this paper, We analyze an economic ripple effects in terms of production inducement effect, added value inducement effect, import inducement effect, labor inducement effect of Semantic technology using an input-out analysis of the bank of Korea(2009). We also examine an economic propriety of Semantic technology.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.9
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• pp.525-531
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• 2004

This paper proposes inserted core type of slotless Permanent Magnet Linear Synchronous Motor(PMLSM) to improve its low thrust density. However, by inserting the core between windings of each phase, detent force is generated and it acts as thrust ripple. Furthermore, linear motors generate end effect making thrust ripple. So, this paper applies the neural network to minimize detent force and to maximize thrust. Also, sub-poles is placed at the end parts of the mover to compensate end effect. To confirm of calculation method's validity, the calculated results are compared with experimental results.

• Journal of Korea Port Economic Association
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• v.38 no.3
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• pp.53-68
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• 2022

In this study, the economic value and economic ripple effect of the Jeju Inland Port redevelopment project were estimated. The economic value was estimated from the viewpoint of amenity, the value of non-market goods such as landscape improvement, environmental improvement, and recreation effects. As a result of the estimation, the population was divided into Jeju Island and other regions and the individual's willingness to pay was estimated to be 2,952.9 won in Jeju Island and 4,722.8 won in other regions. On the other hand, the economic ripple effect of the Jeju Inland Port redevelopment project was estimated during the project period and after the completion of the economic ripple effect was estimated. As a result of the estimation, the production inducement value was KRW 84,387 million, the value-added inducement effect was KRW 37,292 million, and the employment inducement value was 5,846 employment when the (direct employment + indirect employment) effect was combined. After the end of the project period, as of 2022, there were 518,000 foreign tourists, and the value-added inducing effect was estimated to be about 149,885 million won.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.4
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• pp.41-49
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• 2007

This study aims to examine the ripple effect of the '119 Integrated Information System' for city disaster management on the local economy. The study was conducted in the area of Gyeongnam province, and the study method is the interdependence analysis based on the Input Coefficient drawn from Input-Output Tables in which Intermediary Transaction Tables drawn through RAS was taken advantage of to grasp the correlation among industries and regions in terms of the local economy, and the ripple effect of the changes of political exogenous variables on the local economy was divided to such elements as production, added value, and employment so as to attempt empirical analysis on the local economy system. To estimate the ripple effect on the local economy, three different amounts of the expected input were applied to the study respectively and the results are as follows: Some $28.7{\sim}42.4$ billion won for the production induction effect, some $7.5{\sim}11.4$ billion won for the added-value induction effect, some $103{\sim}157$ job openings for the employment induction effect, and some $3.8{\sim}5.7$ billion won for the income induction effect are expected to take place as the ripple effect on the local economy.