HID LAMP 驅動을 위한 類似共振形 INVERTER에 관한 硏究

金光一,裵相俊 慶一大學校 1992 論文集 Vol.8 No.1

The cricuit of QRI(Quasi-Resonant Inverter) which is able to regulate frequency in the output voltage by the ZVS(Zero Volt Switching) was investigated. We found parameters in the circuit of QRI so that they have application to the HID(High Intensity Discharge) Lamp drive. Then we simulated that by personal computer and summarized the result of simulation.

經濟法序說

朴光緖 中央大學校 法政大學 學生會 1965 法政論叢 Vol.11 No.1

Corynebacterium hofmannii에 依한 전신감염 1예

문대혁,최강원,박석건,이광호 대한감염학회 1984 감염 Vol.16 No.1

Corynebacterium of hoffmannii is a part of normal pharyngeal flora. Human infection caused by C. hofmannii is very rare. All reported cases involve prosthetic or native cardiac valve. This patient sufered from chronic alcohlism, diabetes mellitus, and acute suppurative inflammation of brain, meninges and soft tissue. And he failed to show any clinical response to various antimicrobial therapy and died after discharge.

초등교원양성대학의 교육서비스품질과 학생만족도 및 충성도의 구조적 관계

곽민석(Kwag Min Seok),곽현규(Kwag Hyun Gyu) 학습자중심교과교육학회 2017 학습자중심교과교육연구 Vol.17 No.18

본 연구는 초등교원양성대학의 교육서비스품질과 학생만족도 및 충성도의 구조적관계를 분석하는데 그 목적이 있다. 모집단으로는 현재 전국교육대학교에 재학 중인 학생들을 선정하였고, 이 중 서울과 강원도, 충청도에 소재한 A대학교, B대학교, C 대학교 학생들을 2017년 6월 5일부터 23일까지 약 3주간 표본 집단으로 설정하여 연구를 진행하였다. 연구의 수행을 위해 설문지를 측정도구로써 사용하였으며, 총 234명의 자료를 분석하여 가설을 검증하였다. 자료 처리에는 Windows용 PASW 18.0과 AMOS 20.0 프로그램을 이용하였으며, 빈도분석, 신뢰도 분석, 확인적 요인분석, 상관관계분석, 구조방정식 모형분석을 통해 자료를 분석하였다. 본 연구의 결과는 다음과 같다. 첫째, 교육서비스품질은 학생만족도에 긍정적인 영향을 미치는 것으로 나타났다. 둘째, 교육서비스품질은 학생충성도에 영향을 미치지 않는 것으로 나타났다. 셋째, 학생만족도는 학생충성도에 긍정적인 영향을 미치는 것으로 나타났다. 마지막으로 교육서비스품질과 학생충성도 사이에서 학생만족도는 매개하는 것으로 나타났다. The current study was aimed to investigate the structural relationships among educational service quality, satisfaction, and loyalty. Data were drawn from 234 students in three different universities. PASW 18.0 for windows and AMOS 20.0 program were used for data processing. Data were analyzed using frequency analysis, reliability analysis, confirmatory factor analysis, correlation analysis, and structural equation modeling techniques. The results were as follows. First, educational service quality had a positive effect on satisfaction. Second, educational service quality did not affect loyalty. Third, satisfaction had a positive effect on loyalty. Lastly, satisfaction fully mediated the relationship between educational service quality and loyalty.

Construction and commissioning of a position-sensitive ionization chamber

Kwag, M. S.,Chae, K. Y.,Cha, S. M.,Kim, A.,Kim, M. J.,Lee, E. J.,Lee, J. H. 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.

<P>A position-sensitive ionization chamber has been constructed and commissioned at the Physics Department of Sungkyunkwan University to extract position information on incident charged particles for future nuclear reaction measurements. By utilizing the newly-designed position-sensitive anodes and the previously-commissioned portable gas-filled ionization chamber by Chae et al., position information on incident particles could be obtained. The device was tested with an Am-241 alpha-emitting source, and the standard deviation of the fitted Gaussian distribution was measured to be 1.76 mm when a collimator with a 2 mm hole was used.</P>

The Effect of Managerial Overconfidence on the Values of Equity and Firm: A Simulated Valuation Approach

Kwag, Seung Woog 한국상업교육학회 2020 상업교육연구 Vol.34 No.5

1) 기업은 줄곧 경영진 자기과신의 희생양이 되어 왔다. 미국을 비롯한 대부분의 국가 에서 경영진 자기과신은 기업의사결정의 핵심 요인으로서 각종 투자정보를 분석하고 평가하는 과정에 깊이 관여하며 기업가치 증대 활동을 위축시키는 원인으로 주목받았 다. 특히 인수대상기업의 가치를 평가하는 고난도 과업을 담당하는 경영진들 사이에 서 두드러진다. 본 논문은 경영진 자기과신이 기업가치에 미치는 영향을 가치평가모 형과 민감도 시뮬레이션을 활용하여 고찰한다. 가치평가모형으로는 배당할인모형과 자유현금흐름모형이 사용된다. 시뮬레이션분석 결과는 기업가치가 경영진 자기과신의 변화에 매우 민감하게 반응함을 여실히 보여준다. 배당성장모형을 적용했을 때 자기 과신은 자기자본의 가치를 정상가치보다 평균 약 4.5배 과대평가하는 오류를 유발했 다. 자유현금흐름모형의 경우에는 기업가치가 자기과신으로 인해 정상가치보다 평균 약 9.9배가 치솟았다. 경영진 자기과신이 기업경영에 긍정적으로 작용한다는 연구도 종종 보고되고 있지만 자기과신으로 인한 주식가치나 기업가치의 과대평가를 과소평 가해서는 안 된다. 주식시장의 검증을 거치며 과도한 가치평가의 오류가 수정되면 기 업가치는 큰 폭으로 감소하게 되고 그 피해는 고스란히 주주들의 몫이 되기 때문이 다. 따라서 경영진 자기과신은 기업이나 개인의 투자의사결정 시 적절히 할인되어야 하고 재무관리와 회계 교육 시 가치평가의 필수요인으로 다루어져야 한다. The corporate world has suffered a crisis of managerial overconfidence. In the United States and around the world, managerial overconfidence has been a key input of corporate decisions for decades. Managerial overconfidence affects how managers interpret the information they receive from various media and on- or off-line sources. Managerial overconfidence is particularly pronounced among managers of acquiring companies who face the difficult task of evaluating the takeover targets. The purpose of this article is to investigate the impact of managerial overconfidence on firm value through a valuation framework. To this end, we employ two conventional valuation models – the dividend discount model (DDM) and the free cash flow model (FCFM) - to reveal the valuation effect of managerial overconfidence. Simulated sensitivity analyses show that the propensity of firm value to managerial overconfidence changes rapidly when the degree of managerial overconfidence strengthens. The simulation results show that when the DDM is applied the overconfident value of equity is, on average, 4.5 times the non-overconfident value of equity. When the FCFM is simulated, the ratio of the overconfident value of firm to the non-overconfident value of firm becomes 9.9 times, a big jump from 4.51 times for the DDM case. Regardless of the evidence of its useful contributions, managerial overconfidence appears to be a value-destroying behavioral bias that needs to be properly and cautiously addressed in corporate and individual investments and in educational settings of finance and accounting.

Gating of NMDA receptor-mediated hippocampal spike timing-dependent potentiation by mGluR5

Kwag, Jeehyun,Paulsen, Ole Pergamon Press 2012 NEUROPHARMACOLOGY - Vol.63 No.4

<P>Hippocampal long-term potentiation (LTP) is believed to be important for learning and memory. Experimentally, the pairing of precisely timed pre- and postsynaptic spikes within a time window of ∼10 ms can induce timing-dependent LTP (tLTP), but the requirements for induction of tLTP change with development: in young rodents single postsynaptic spikes are sufficient to induce tLTP, whereas postsynaptic burst firing appears to be required in the adult. However, hippocampal neurons <I>in vivo</I> show theta-modulated single spike activities also in older hippocampus. Here we investigated the conditions for single spike pairing to induce tLTP at older CA3–CA1 synapses. We found that the pairing of single pre- and postsynaptic spikes could induce tLTP in older hippocampus when the postsynaptic neuronal membrane was depolarized and the pairing frequency exceeded ∼4 Hz. The spike frequency requirement is postsynaptic, as tLTP could still be induced with presynaptic stimulation at 1 Hz as long as the postsynaptic spike frequency exceeded ∼4 Hz, suggesting that postsynaptic theta-frequency activity is required for the successful induction of tLTP at older CA3–CA1 synapses. The induction of tLTP was blocked by an NMDA receptor antagonist and by the selective mGluR5 blockers, MPEP and MTEP, whereas activation of mGluR1 and mGluR5 by DHPG relieved the postsynaptic spike frequency requirement for tLTP induction. These results suggest that activation of mGluR5 during single-spike pairing at older CA3–CA1 synapses gates NMDA receptor-dependent tLTP.</P>

High Speed Data Link Design for Spaceborne Multi-Mode SAR Image Data Transmission

Kwag, Young-Kil The Korean Society of Remote Sensing 2001 大韓遠隔探査學會誌 Vol.17 No.4

A high speed dat link capability is one of the critical factors in determining the performance of the spacebome SAR system with high resolution. It is due to the strict requirement for the real-time transmission from a series of massive raw image data of spacebome SAR to the ground station in a limited time of mission. In this paper, based on the data link model characterized by the spacebome small SAR system, the high rate multi-channel data link module is designed including link storage, link processor, transmitter, and wide-angle antenna. The design results are presented with the performance analysis on the data link budget as well as the multi-mode data rate in association with the SAR imaging mode of operation from high resolution to the wide swath. The designed multi-channel architecture can be effectively used for the spacebome and airborne applications which requires to expand the high speed data link capability.

Beneficial and Detrimental Effects of Soil-Structure Interaction on Probabilistic Seismic Hazard and Risk of Nuclear Power Plant

Kwag, Shinyoung,Ju, BuSeog,Jung, Wooyoung Hindawi Limited 2018 Advances in civil engineering Vol.2018 No.-

<P>The purpose of this study is to investigate the soil-structure interaction (SSI) effect on the overall risk of a PWR containment building structure with respect to two failure modes: strength and displacement. The precise quantification of the risk within the seismic probabilistic risk assessment framework depends considerably on an accurate treatment of the seismic response analysis. The SSI effect is one of the critical factors to consider when accurately predicting structural responses in the event of an earthquake. Previous studies have been conducted by focusing more on the positive side of the SSI effects and the effects mainly on the seismic fragility result. Therefore, this paper presents the results of a study of the SSI effect on the overall risk. Also, the study relies on an emphasis on revealing a beneficial and a detrimental effect of the SSI by utilizing an example of the containment structure in three soil conditions and two main failure modes. As a result, the consideration of SSI shows a complete conflicting effect on the seismic fragility and risk results depending on two failure modes considered in this study. This has a positive effect regarding the strength failure mode, but this brings a negative effect regarding the displacement failure mode. The risk fluctuation width is particularly noticeable in the site having a considerable change in seismic hazard information such as Los Angeles on the western site of the US. Such results can be expected to be utilized in a future study for investigating the pros and cons of the SSI effect associated with various failure modes in diverse conditions.</P>

Arterial hyperintensity on BLADE fluid-attenuated inversion recovery images (FLAIR) in hyperacute territorial infarction: comparison with conventional FLAIR.

Kwag, Eujean,Lim, Soo Mee,Park, Ji Eun,Chae, In Hye Springer International 2014 EUROPEAN RADIOLOGY Vol.24 No.9

<P>To evaluate the utility of BLADE fluid-attenuated inversion recovery images (FLAIR) magnetic resonance (MR) imaging compared to conventional FLAIR for the detection of arterial hyperintensity (AH) in hyperacute territorial infarction.</P>