• 한국음향학회지
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• 제38권3호
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• pp.283-289
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• 2019

RLS(Recursive-least-squares) 알고리즘은 수렴성이 좋고, 수렴 후 오차 수준도 우수한 것으로 알려져 있다. 그러나 알고리즘 내에 역행렬 계산이 포함되어 수치적 불안정성을 나타내는 단점도 있다. 본 논문에서는 언급한 불안정성을 회피하기 위해서 역행렬이 없지만 수렴성이 유사한 알고리즘을 제안한다. 이를 위해서 기울기 평균 벡터를 사용한 가변 스텝 최소 자승 알고리즘을 사용한다. 또 시변 채널 추정에 우수한 성능을 내기 위해서 계산량이 적은 가변 망각인자를 도입한다. 시뮬레이션을 통해서 기존 RLS와의 성능을 비교하고 그 유사성을 보인다. 또 시변 채널에서 가변 망각인자의 우수성도 보인다.

• 대한간호학회지
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• 제38권2호
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• pp.344-352
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• 2008

Purpose: This study was to test the reliability and validity of a Drinking Refusal Self-Efficacy Questionnaire-Revised (DRSEQ-R) in Korean college students, Methods: The DRSEQ-R was designed to assess an individual's belief in their ability to refuse drinking alcohol by Oei et al. (2005) and consisted of three factors (social pressure, opportunity, and emotional relief). A methodological study design with an exploratory factor analysis for validity and correlation coefficients for reliability was used. DRSEQ-R was translated into Korean and a translation equivalency was obtained. DRSEQ-R was tested with a sample of 201 college students in Korea. The subjects consisted of 106 males and 95 females. Principal component factor analysis was used for construct validity and Cronbach's alpha was used to evaluate for internal consistency of the instrument. Results: The factor analysis showed three factors explaining 66.3% of total variance and the corresponding factors were emotional relief (48.01%), drinking contextual opportunity (11.18%), and social pressure (7.14%). The internal consistency was acceptable (Cronbach's alpha=.937). All three factors of DRSEQ-R negatively correlated with alcohol dependency and a heavy drinker showed a lower DRSEQ-R than a moderate drinker. Conclusion: Based on the findings, DRSEQ-R is a reliable and valid instrument to measure for drinking refusal self-efficacy in Korean college students.

• 한국간호교육학회지
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• 제14권2호
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• pp.262-272
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• 2008

Purpose: This study examined the validity and reliability of the Korean version of the Revised Process of Change for Weight Control Scale (POC-WCS) in adults with metabolic syndrome. Method: A methodological research design with an exploratory factor analysis for validity and correlational coefficients for reliability was used. The Korean version of the Revised POC-WCS was translated into Korean and a translation equivalency was obtained. It was tested with one hundred and fifty-one obese adults with metabolic syndrome in a university hospital. The data were analyzed using Cronbach's alpha and Guttman coefficients and a principal component factor analysis with SPSS/WIN 12.0. Result: The factor analysis identified eight factors explaining 64.7% of the total variance. The Korean version of the Revised POC-WCS included stimulus control (9 items), dramatic relief (6 items), reinforcement management (6 items), helping relationships (4 items), consciousness raising (3 items), self liberation (3 items), self reevaluation (3 items), and social liberation (4 items). The internal consistency was acceptable with Cronbach's alpha (.94) and Guttman coefficient (.92). Conclusion: The Korean version of the Revised POC-WCS had adequate validity and reliability in adults with metabolic syndrome. It can be used to assess the strategies and processes for weight control in a variety of populations with obesity.

• 분석과학
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• 제28권3호
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• pp.204-211
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• 2015

란탄족 착물은 독특한 발광 특성으로 인하여 많은 연구가 되고 있는 물질이다. 유로피움(III) β-디케토네이트 착물에 아민계열 또는 포스핀옥사이드계열 리간드를 추가로 배위 결합시켜 발광 효율을 비교하였으며, 아민계열 배위보다는 발광 효율 증진에는 포스핀옥사이드 계열이 더 좋은 추가 리간드임을 확인하였다. 그 중에서도 트리옥틸포스핀 옥사이드를 배위시켰을 때 가장 높은 발광효율이 관찰되었다. 추가로 배위될 수 있는 트리옥틸포스핀 옥사이드의 당량을 확인하기 위해서 ³¹P-NMR과 photoluminescence를 분석하였다. 유로피움(III) β-디케토네이트 화합물은 리간드의 입체장애에 따라 트리옥틸포스핀 옥사이드의 배위 당량은 1 개 또는 2 개가 가능함을 확인하였다.

• 한국대기환경학회지
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• 제30권6호
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• pp.519-530
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• 2014

Twenty four individual polycyclic aromatic hydrocarbon (PAH) compounds both in gas- and particle-phase were quantified in three tunnels (Namsan Tunnel 3, Jeongneung Tunnel, Bukak Tunnel) to characterize vehiculate emission of PAHs. Gas phase PAHs were dominant in tunnels which consisted of 85% of total PAHs concentrations. Naphthalene and 2-methyl naphthalene were the most abundant gas phase PAH compounds, while the concentrations of fluoranthene and pyrene were highest in the particle phase. Most (96%) of the gas phase PAH compounds consisted of two- and three-aromatic rings whereas most of the particle phase PAHs were in four and five-rings (67%) in tunnels. Average BaP-eq concentrations of PAHs in the particle phase ($20.8{\pm}11.6ngm^{-3}$) was about twenty fold higher than that in the gas phase ($1.6{\pm}0.6ngm^{-3}$). It means that the particle phase PAHs has more adverse health effect than the gas phase PAHs even though the concentrations of the particle phase PAHs were lower than those of the gas phase PAHs. Compared to previous studies reporting diagnostic ratios for specific PAH compounds, the profile of individual PAH compounds measured in this study reflected well for the vehiculate emissions. We reported, for the first time, on the results of the profile of individual PAH compounds measured in tunnels for both gas and particle phases.

• 한국토양비료학회지
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• 제45권1호
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• pp.107-111
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• 2012

Eight marine sediments from Busan port in Korea were annually analyzed to examine the concentration distribution of dioxins from 2006 to 2010. Yearly mean concentration of dioxins ranged from 186.3 to $383.3pg\;g^{-1}$ in real values and 5.087 to 8.541 pg-TEQ (Toxicity equivalency) based on dry weight of samples. The dioxin concentration at the site near fishing market was the highest concentration among all sampling sites. Also the dioxin concentration at the sites with various pollutant sources such as large ships, sewage influx and thermal power station as well as fishing market was higher than that of the sites without specific pollutant sources. Another main factor that affects the dioxin concentration is topography characteristics of the bay. The bay has relatively high dioxin concentration because of the lack of the pollutant diffusion. This study demonstrated that the dioxin concentration in the site with pollutant sources and the lack of the pollutant diffusion was relatively high as compared with the other sites. As a result of contribution ratio of dioxin congeners, OCDD (Octachlorodibenzodioxin) in all sites was major contributor in real value, in contrast, dioxin congeners in TEQ values were dominated by 2,3,4,7,8-PeCDF.

• 대한수의학회지
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• 제48권1호
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• pp.39-48
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• 2008

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are ubiquitous and can contaminate the food chain. A study monitoring PCDD/Fs in imported meat was conducted at the National Veterinary Research and Quarantine Service (NVRQS, Republic of Korea) in order to maintain food safety from the bioaccumulative PCDD/Fs. Seventeen PCDD/Fs with toxic equivalency factors (TEFs) established by World Health Organization (WHO, 1998) were analyzed in imported beef, pork, and chicken by high resolution gas chromatography/mass spectrometry (HR-GC/MS). Results of the monitoring for the last 5 years are presented. The levels of PCDD/Fs were similar to other studies except two unusually high concentrations in pork and beef. Excessive levels greater than the Korean provisional maximum residue limit of PCDD/Fs were found in a sample of pork imported from Chile and a sample of beef imported from U.S, and those products were rejected and returned. There was no obvious trend or differences with respect to time or origin of meat in this study.

• 한국해양환경ㆍ에너지학회지
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• 제10권2호
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• pp.86-92
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• 2007

본 연구는 E-screen assay를 이용해서 광양만 연안해역 퇴적물의 에스트로겐 활성분포를 정량적으로 평가하고 화학분석 결과와 비교 검토하고자 하였다. 가장 높은 에스트로겐 활성을 보인 지점은 산업단지와 섬진강 유입구에 인접한 G6, G8 이었다. E-screen assay로 얻어진 이러한 결과는 다성분 동시분석 결과와도 일치하였다. 특히 GY6, GY8 지점의 RPE는 90% 이상으로 강한 에스트로겐 작용을 나타내어 full agonist 지점으로 확인되었다. 또한 이들 지점은 EEQ가 각각 35.6 ng/g, 14.6 ng/g로 타 지점에 비해 낮아 에스트로겐 활성 효능이 상대적으로 높을 것으로 판단된다. 이러한 결과로부터, 산업단지와 섬진강 유역에 인접한 지점들을 광양만 연안 해역의 내분비계 교란 물질의 유입원으로 추정할 수 있다. 한편, 에스트로겐 활성도와 화학오염물질과의 비교결과는 상관성이 없는 것으로 나타났다.

• 분석과학
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• 제12권1호
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• pp.61-67
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• 1999

도시쓰레기 소각로의 배출가스 중 다이옥신(Dioxins, PCDDs/PCDFs), chlorobenzenes(CBs) 및 chlorophenols(CPs)를 측정 분석하고, 각 시설에 대한 다이옥신 및 전구물질의 배출 패턴을 조사하였다. 대형쓰레기 소각로의 배출가스 중 다이옥신류의 농도를 독성등가환산(Toxic Equivalent, TEQ) 농도로 평가한 결과 오염화퓨란류(Pentachlorofurans, PeCDFs), 육염화퓨란류(Hepxachlorofurans, HxCDFs) 및 칠염화퓨란류(Heptachlorofurans, HeCDFs)가 전체의 76.24%, 60.84%를 차지하는 것으로 나타났으며, chlorophenols은 2,4,6-trichlorophenol(TCP), 2,3,4,6-tetrachlorophenol(TeCP) 및 pentachlorophenol(PeCP)이, chlorobenzens은 1,2,4,5-tetrachlorobenzene(TeCB) 및 hexachlorobenzene(HxCB)의 형태로 주로 배출되는 것으로 나타났다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 Asia Navigation Conference
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• pp.129-138
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• 2004

Recently, maintenance of clean ocean is very important issue. One part of the issue strongly relates to the safe navigation of vessels. Most parts of safe navigation depend on the mariner's competencies. STCW was established to guarantee the sufficient mariner's competencies. However the code dose not indicate the each necessary competency clearly. Therefore, the understandings on STCW are not same among training institutes, and each training institute interprets them individually and executes them. As a result, it makes big differences among the institutes concerning training methods and contents and the assessment on mariner's competencies. The countries in EU have paid attention on this issue and the activities enhance the rational assessment of competencies through METNET. In order to execute the rational assessments, it is necessary to clarify the techniques being assessed. And it means the necessity to clarify the necessary techniques for safe navigation and to assess the competencies to achieve them, and then we can attain the objectives of STCW. In this paper, the necessary techniques for achievement of safe navigation are discussed and the methods of assessment of competencies are proposed. As we apply proposed assessment system, we can get the mariner's competency quantitatively and continuously through training period. Then we can know the trend of the competency that is the learning process. By clarifying the learning process of the techniques, we can decide the necessary training time to achieve the competencies. Furthermore, we can discuss the issues on conversion between training onboard and simulator used training by analysing the learning processes.