• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.81-90
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• 2016

This study aims to investigate the association between stock performance and credit ratings, and credit rating changes using a sample of 1,691 KRX firm-years that acquire equity in the form of long-term bonds from 2002 to 2013. Previous U.S. literature is mixed with regard to the relation between credit ratings and stock price. On one hand, there is evidence of a positive relation between credit ratings and stock prices, an anomaly established in U.S. studies. On the other hand, the CAPM model suggests a negative relation between stock prices and credit ratings, implying that investors expect financial rewards for bearing additional risk. To our knowledge, we are the first to examine the relationship between stock price and default risk proxied by credit ratings in period t+1. We find a negative (positive) relation between credit ratings (risk) in period t+1 and stock returns in period t, suggesting that credit rating agencies do not consider stock returns as a metric with the potential to influence default risk. Our results suggest that market participants may prefer firms with higher credit risk because of expected higher returns.

• Journal of the Korean Electrochemical Society
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• v.4 no.3
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• pp.109-112
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• 2001

An activated carbon paste electrode was modified with the N-Hydroxysuccinimide(NHS) layer and applied to determine the dopamine in the presence of an excess ascorbic acid using square-wave voltammetry. The electrochemical properties of the modified electrode were examined in the solution containing dopamine/ascorbic acid using cyclic voltammetry(CV): the separation between the oxidation peaks of dopamine and ascorbic acid was largely dependent on the pH of the sample solution and became maximum at pH 4.0. Hence, the square-wave voltammetric determination of dopamine was carried out in a pH 4.0, 100mM phosphate buffer saline(PBS) containing 140mM NaCl. The detection limit and response slop were improved from $1.0{\mu}M\;to\;5.0\times10^{-2}{\mu}M\;and\;from\;0.93{\mu}A/{\mu}M\;to\;6.1{\mu}A/{\mu}M$, respectively, upon modification of the electrode surface by NHS.

• Journal of KSNVE
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• v.10 no.6
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• pp.1059-1066
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• 2000

In this paper. a new indirect feedback active noise control (ANC) scheme barred on the fundamental frequency estimation is proposed for systems with a harmonic noise. When reference signals necessary for feedforward ANC configuration are difficult to obtain, the conventional ANC algorithms for multi-tonal noise do not measure the reference signals but generate them with the estimated frequencies.$^{(4)}$ However, the beating phenomena, in which certain frequency components of the noise vanish intermittently, may make the adaptive frequency estimation difficult. The confusion in the estimated frequencies due to the beating phenomena makes the generated reference signals worthless. The proposed algorithm consists of two parts. The first part is a reference generator using the fundamental frequency estimation and the second one is the conventional feedforward control. We propose the fundamental frequency estimation algorithm using decision rules. which is insensitive to the beating phenomena. In addition, the proposed fundamental frequency estimation algorithm has good tracking capability and lower variance of frequency estimation error than that of the conventional cascade ANF method.$^{(4)}$ We are also able to control all interested modes of the noise, even which cannot be estimated by the conventional frequency estimation method because of the poor S/N ratio. We verify the performance of the proposed ANC method through simulations for the measured cabin noise of a passenger ship and the measured time-varying engine booming noise of a passenger vehicle.

• Journal of Pharmaceutical Investigation
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• v.31 no.4
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• pp.281-287
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• 2001

Rebamipide is a novel anti-gastric ulcer agent that has been reported to increase the synthesis of mucus, to increase the mucosal concentration of prostaglandin, and to promote rapid ulcer healing. The purpose of the present study was to evaluate the bioequivalence of two rebamipide tablets, $Mucosta^{TM}$ (Otsuka Korea Pharmaceutical Co., Ltd.) and $Rebamide^{TM}$ (Kyung Dong Pharmaceutical Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The rebamipide release from the two rebamipide tablets in vitro was tested using KP VII Apparatus II method at pH 6.8 dissolution media. Twenty normal male volunteers, $24.20{\pm}2.26$ years in age and $66.19{\pm}9.41\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one tablet containing 100 mg of rebamipide was orally administered, blood was taken at predetermined time intervals and the concentrations of rebamipide in serum were determined using HPLC method with fluorescence detector. The dissolution profiles of two rebamipide tablets were very similar at pH 6.8 dissolution media. Besides, the pharmacokinetic parameters such as $AUC_t$, $C_{max}\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters. The results showed that the differences in $AUC_t$, $C_{max}\;and\;T_{max}$ between two tablets based on the $Mucosta^{TM}$ were -2.57%, 5.77% and -1.47%, respectively. Minimum detectable differences $({\Delta})$ at ${\alpha}=0.05$ and $1-{\beta}=0.8$ were less than 20% (e.g., 12.62% and 17.63% for $AUC_t,\;and\;C_{max}$, respectively). The powers $(1-{\beta})$ at ${\alpha}=0.05$, ${\Delta}=0.2$ for $AUC_t\;and\;C_{max}$ were above 99.00% and 88.56%, respectively. The 90% confidence intervals were within ${\pm}20%$ (e.g., $-9.96{\sim}4.82$ and $-4.54{\sim}16.09$ for $AUC_t\;and\;C_{max}$, respectively). Two parameters met the criteria of KFDA for bioequivalence, indicating that $Rebamide^{TM}$ tablet is bioequivalent to $Mucosta^{TM}$ tablet.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.6
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• pp.584-597
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• 2011

In this paper, low-loss and high-power RF SP6T switch chips are designed, fabricated and measured for GSM/EGSM/DCS/PCS applications using WIN Semiconductors 0.5 ${\mu}m$ pHEMT process. We utilized a combined configuration of series and series-shunt structures for optimized switch performance, and a common transistor structure on a receiver path for reducing chip area. The gate width and the number of stacked transistors are determined using ON/OFF input power level of the transceiver system. To improve the switch performance, feed-forward capacitors, shunt capacitors and parasitic FET inductance elimination due to resonance are actively used. The fabricated chip size is $1.2{\times}1.5\;mm^2$. S-parameter measurement shows an insertion loss of 0.5~1.2 dB and isolation of 28~36 dB. The fabricated SP6T switch chips can handle 4 W input power and suppress second and third harmonics by more than 75 dBc.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.28-37
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• 2019

It is apparently clear that K-pop has been expanding its influence overseas, with its high growth rate. As a result, attempts have been made to analyze the characteristics of K-Pop in various academic fields. This research quantitatively used the participatory use process of K-Pop contents in voluntary participation and dissemination of the audience in the Trans-Media environment. The author examined the use of participatory K-Pop contents from the view point of reparability through big data content analysis. It has been revealed that K-Pop is spreading globally through social media, fans of various countries like to play K-Pop, and they make up their own content and form a participatory culture. In addition, we looked at when the moments of momentum in which participatory use is soaring were popular content and who was the publisher.

• Korean Journal of Clinical Pharmacy
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• v.18 no.1
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• pp.38-44
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• 2008

Rebamipide, ($\pm$)-2-(4-chlorobenzoylamino)-3-[2(1H)-quinolinon-4-yl] propionic acid, is used for mucosal protection, healing of gastroduodenal ulcers, and treatment of gastritis. It works by enhancing mucosal defense, scavenging free radicals and temporarily activating genes encoding cyclooxygenase-2. The purpose of the present study was to evaluate the bioequivalence of two rebamipide tablets, $Mucosta^{(R)}$ (Korea Otsuca Pharmaceuticals Co., Ltd.) and Mustar (Korean Drug Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of rebamipide from the two rebamipide formulations in vitro was tested using KP VIII Apparatus II method with pH 6.8 dissolution medium. Twenty six healthy male subjects, $23.46{\pm}2.63$ years in age and $66.62{\pm}8.97\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a single tablet containing 100 mg as rebamipide was orally administered, blood samples were taken at predetermined time intervals and the concentrations of rebamipide in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar in the tested dissolution medium. The pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated, and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, $Mucosta^{(R)}$ were -5.08, 3.52 and -9.71 % for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 (e.g., log 0.84$\sim$log 1.07 and log 0.90$\sim$log 1.17 for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Mustar tablet was bioequivalent to $Mucosta^{(R)}$ tablet.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.106-106
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• 2010

오일샌드는 비투멘(bitumen), 물, 점토, 모래의 혼합체로 이루어진 비재래형 탄화수소 자원으로 세계적인 고유가 시대에 큰 관심을 받고 있는 석유자원 중 하나이다. 오일샌드는 대부분이 캐나다 앨버타주에 분포하고 있으며 주요 저류층으로는 아스바스카(Athabasca), 콜드레이크(Cold Lake) 지역의 멕머레이층(McMurray Formation), 클리어워터층(Clearwater Formation), 그랜드래피드층(Grand Rapid Formation)과 피스리버(Peace River) 지역의 블루스카이층(Bluesky Formation), 게팅층(Gathing Formation)이 있다. 오일샌드 저류층은 고생대 탄산염 기반암 위에 하성-에스츄어리에 이르는 다양한 퇴적환경에서 형성되어 매우 복잡한 지질특성이 나타난다. 오일샌드 저류층의 효율적인 개발을 위해서는 저류층의 복잡한 지질학적 특성의 이해가 반드시 필요하다. 본 연구에서 캐나다 오일샌드 시추코어 분석 DB, 물리검층 자료, 현장 및 현생 시추코어를 통하여 오일샌드 저류층의 지질특성화 정보의 도출을 시도하였다. 우선 캐나다 앨버타 전역에 분포하는 시추공의 기본 정보(표고, 위경도, 층서별 최상부 심도, 생산광구명, 광구개발업체)를 제공하는 AccuMap DB 프로그램을 이용하여 광역적인 오일샌드 저류층의 분포 특성을 이해하고자 주요층서에 대한 고지형도 및 층후도를 생산광구별로 도면화하여 분석하였다. 또한 캐나다 ENCANA사와 국제공동연구의 일환으로 확보된 크리스티나 레이크(Christina Lake)광구의 현장 시추코어를 이용하여 코어의 상세기재, 비파괴 물성측정, 입도/비투멘 함유량 분석과 같은 다양한 실내 시추코어분석 실험을 수행 중이다. 비파괴 물성측정은 현장 시추코어의 물리적/화학적 특성을 파악하고자 MSCL(Multi sensor core logger)과 XRF 코어 스캐너(X-ray fluorescence core scaner)를 통해 이루어지며, 분석결과로 시추코어의 감마밀도(gamma density), P파 속도(P-wave velocity), 전기비저항(resistivity), 대자율(magnetic susceptibility) 및 색지수의 물성과 정량적 화학조성을 측정한다. 현장 시추코어의 일부는 유기용매를 이용하여 퇴적물 내의 비투멘을 완전히 추출하고 퇴적물 입도와 저류층 비투멘 함유량 측정에 이용되었다. 현장 시료 분석 결과들은 물리검층 자료와 대비를 통하여 저류층의 지질특성을 규명하는 연구에 이용될 예정이다. 마지막으로 오일샌드의 현생 유사 퇴적환경으로 알려진 서해 경기만 조간대에서 시추코어 퇴적물을 획득하여 상세 기재하였으며, 이를 통해 오일샌드 저류층의 퇴적 모델을 제시하고자 퇴적층서 연구를 진행 중이다. 향후 오일샌드 관련 시추코어의 분석 결과들이 종합되면 기존 보다 비투멘 회수효율을 향상시킬 수 있는 정밀한 오일샌드 저류층 지질모델을 수립할 수 있을 것으로 기대된다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.789-798
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• 2011

We carry out an experimental investigation to analyze the basic performance of NO(nitric oxide) storage in a lean phase and also analyze the NO reduction achieved by the spraying of reducing agents in the rich phase of the exhaust gas in an LNT(Lean NOx Trap). This is an after-treatment system used to reduce the NOx emissions from a diesel engine. If the stored NO is reduced, we measure the outlet concentration downstream of the LNT. The test LNT material used in the experiments is commercial LNT. After being canned into stainless-steel(SUS304), it was built in a micro bench-flow reactor. Compositions of feed gases, three heated and three no heated gases were sprayed upstream of the LNT to analyze the characteristics. We use various temperatures and space velocities as response variables.

• Archives of design research
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• v.15 no.2
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• pp.253-266
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• 2002

Web Based Instruction has its theoretical background in constructivism paradigm of education. According to social changes called information era and thanks to the sophisticated internet mechanism the constructivism in education has been dominant paradigm. In this paradigm information and knowledge are not merely given by a instructor facing the loaners. This system of instruction has n almost every field of discipline introduced. This article aims to examine how far WBI and constructivism are applicable for design education. Richard Branchia predicted that the learner oriented instruction method would become the dominant education system. He stressed an interactivity of the teacher and students. Upon this can the applicability of WBI for design education be affirmed. Furthermore, there is a dozen of successful cases like www.cyberartcenter.com) (www.digitalyeil.co.kr)', http://www.schooleweb.co.kr/, htp://www.startstudy.co.kr/among many others. This article suggests several ways to solve the problems web based design education faces, including the lesson should inevitably combine the outline and of online study.