• 대한치과의사협회지
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• 제55권6호
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• pp.413-422
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• 2017

Purpose: The aim of this study was to confirm the validity of the $Cariview^{TM}$, test in adults by assessing correlations between $Cariview^{TM}$, scores and caries experience using a quantitative light-induced fluorescence (QLF) technique. Methods: This retrospective cross-sectional study included 111 patients aged 19-64 years who visited a dental clinic in Seoul from 2015 to 2016, and underwent the $Cariview^{TM}$, test and had their teeth photographed with the Qraycam. Plaque was scraped with sterilized cotton swabs, and then placed in a culture medium and incubated at $37^{\circ}C$ for 48 h. Finally, the degree of color change was evaluated, and scored on a 0-100 point scale. Caries experience index included not only cavitated lesions but also early caries that were detected on white and fluorescence images. Participants were divided into low, moderate and high caries risk groups according to the $Cariview^{TM}$, score, and caries experience was compared between risk groups using ANCOVA. Spearman correlation coefficients were calculated to analyze the associations between $Cariview^{TM}$, scores and caries indices. Result: The mean age of the participants was 40 years, and the mean $Cariview^{TM}$, score was $53.6{\pm}20.7$. The WDMFT and the DMFT indices significantly increased with caries risk, and this increase was significantly different between the low- and high-risk groups. The $Cariview^{TM}$, test scores were significantly correlated with the WDMFT (r = 0.28, P = 0.003) and DMFT (r = 0.29, P = 0.002) indices. Conclusion: The $Cariview^{TM}$, test could be a clinically useful and simple method for assessing caries risk in adults.

• Journal of Korean Neurosurgical Society
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• 제49권3호
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• pp.147-152
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• 2011

Objective : The aim of this study was to evaluate the reliability and validity of the Pediatric Functional Assessment of Cancer Therapy Questionnaire Brain Tumor Survivor (version 2.0) Aged 13 years and older (Parent Form) (pedsFACT-BrS parent of adolescent). Methods : The pedsFACT-BrS parent of adolescent was translated and cross-culturally adapted into Korean, following standard Functional Assessment of Chronic Illness Therapy (FACIT) methodology. The psychometric properties of the pedsFACT-BrS parent of adolescent were evaluated in 170 brain tumor patient's mothers (mean age=43.38 years). Pretesting was performed in 30 mothers, and the results indicated good symptom coverage and overall comprehensibility. The participants also completed the Child Health Questionnaire Parent Form 50 (CHQ-PF-50), Neuroticism in Eysenck Personality Questionnaire, and Karnofsky score. Results : In validating the pedsFACT-BrS parent of adolescent, we found high internal consistency, with Cronbach's ${\alpha}$ coefficients ranging from 0.76 to 0.94. The assessment of test-retest reliability using intraclass correlation coefficient revealed satisfactory values with ICCs ranging from 0.84 to 0.93. The pedsFACT-BrS for parent of adolescent also demonstrated good convergent and divergent validities when correlated with the Child Health Questionnaire Parent Form 50 (CHQ-PF-50) and the Neuroticism in Eysenck Personality Questionnaire. The pedsFACT-BrS parent of adolescent showed good clinical validity, and effectively differentiated between clinically distinct patient groups according to the type of treatment, tumor location, shunt, and Karnofsky score of parent proxy report. Conclusion : We confirmed that this reliable and valid instrument can be used to properly evaluate the quality of life of Korean adolescent brain tumor patients by their parents' proxy report.

• 한국산학기술학회논문지
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• 제17권1호
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• pp.264-273
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• 2016

본 연구는 우리나라 청소년이 경험하는 구취증상과 스트레스 및 심리상태간의 구조적 관계를 검증하는데 목적을 두었다. 이를 위해 2010 한국청소년건강실태조사 원자료를 활용하였고 연구대상자는 중 고등학생 3,689명(남학생 1,805명, 여학생 1,884명)이었다. 단변량 분석에서 확인된 구취와 관련된 요인은 경로모형에서 통제변수로 설정하여 투입하였고, 구취증상과 스트레스, 그리고 우울감, 불안, 긴장, 적대감으로 측정된 심리상태와의 관계와 그 경로를 검증하였다. 분석결과, 구취증상 경험이 있는 청소년은 27.4% 이었고, 경로모형을 검증한 결과에서는 구취증상${\rightarrow}$스트레스(${\beta}=0.083$, P<0.001), 구취증상${\rightarrow}$우울(${\beta}=0.067$, P<0.001), 구취증상${\rightarrow}$불안(${\beta}=0.072$, P<0.001), 구취증상${\rightarrow}$긴장(${\beta}=0.072$, P<0.001), 구취증상${\rightarrow}$적대감(${\beta}=01.074$, P<0.001)로 가는 경로가 유의하게 나타났다. 또한 구취증상은 스트레스를 매개로 우울, 불안, 긴장, 적대감에 부정적인 영향을 미치는 간접효과를 확인할 수 있었다. 결론적으로 구취를 예방하는데 있어 스트레스와 다양한 심리적인 요소도 고려되어야 할 것이며 구취가 있는 청소년에게서 심리적 지지를 위한 지원과 강화방안이 논의되어야 할 것이다.

• 한국표면공학회지
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• 제52권6호
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• pp.283-288
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• 2019

MCrAlY overaly coatings are used as oxidation barrier coatings to prevent degradation of the underlying substrate in high temperature and oxidizing environment of the hot section of gas turbines. Therefore, oxidation resistance in high temperature is important property of MCrAlY coatings. Also, coefficients of thermal expansion (CTE) of MCrAlY have middle value of that of Ni-based superalloys and oxides, which have the effect of preventing the delamination of the surface oxides. Cyclic oxidation test is one of the most useful methods for evaluating the high temperature durability of coatings used in gas turbines. In this study, NiCoCrAlY overlay coatings were formed on Inconel 792(IN 792) substrates by vacuum plasma spraying process. Vacuum plasma sprayed NiCoCrAlY coatings and IN 792 susbstrates were exposed to 1000℃ one-hour cyclic oxidation environment. NiCoCrAlY coatings showed lower weight gain in short-term oxidation. In long-term oxidation, IN 792 substrates showed higher weight loss due to delamination of surface oxide but NiCoCrAlY coatings showed lower weight loss. X-ray diffraction (XRD) analysis showed α-Al2O3 and NiCr₂O₄ was formed during the cyclic oxidation test. Through cross-section observation using scanning electron microscopy (SEM) and electron back scatter diffraction (EBSD) analysis, thermally grown oxide (TGO) layer composed of α-Al₂O₃ and NiCr₂O₄ was formed and the thickness of TGO increased during 1000℃ cyclic oxidation test. β phase in upper side of NiCoCrAlY coating was depleted due to oxidation of Al and outer beta depletion zone thickness also increased as the cyclic oxidation time increased.

• 한국산업정보학회논문지
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• 제13권1호
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• pp.76-86
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• 2008

본 연구는 IT제조업 사업체 규모별 총요소생산성을 추정하고, 총요소생산성 결정요인을 분석한다. 분석 자료로는 $1990{\sim}2004$년 기간의 시계열 자료와 4개 그룹으로 구분된 사업체 규모의 횡단면 자료를 결합한 패널자료 등을 사용하였다. $1991{\sim}1997$년 총요소생산성 증가율은 사업체 규모에 상관없이 정(+)의 값을 보였으나, $1998{\sim}2004$년에는 300인 이상 사업체를 제외하고는 음(-)의 값으로 전환되었다. IT제조업의 총요소생산성 결정변수로 거시변수와 정책변수를 고려하였는데 전체 사업체를 대상으로 분석한 결과, 매출액 증가율은 7개 모형 모두에서 유의하게 정(+)의 값을 나타내 실행에 의한 학습 대량생산 등 규모의 경제 효과가 존재함을 나타냈다. 하지만 IT자본스톡, 정책금융지원 개방도 등 변수는 일부 모형에서만 유의하게 나타나 사업체 규모별로 총요소생산성에 미치는 효과가 다를 여지를 남겼다. 이에 사업체 규모별 총요소생산성 증가율 결정요인 분석을 한 결과 정책금융지원과 개방도가 총요소생산성 증가율에 정(+)의 효과를 가지고, 사업체 규모가 클수록 매출액 증가로 인한 비용절감, 표준화 등 규모의 경제 효과를 보는 것으로 나타났다. 또한 300인 이상 대규모 사업체의 경우 IT자본스톡이 생산성 향상에 도움을 주는 것으로 분석되었다.

• 대한화학회지
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• 제36권1호
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• pp.87-94
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• 1992

본 연구는 폴리스티렌(PS), 폴리메틸메타크릴레이트(PMMA), 및 폴리부타디엔(PB) 등 동종 중합체들(homopolymers), 그리고 폴리스티렌-폴리메틸메타크릴레이트 block 혼성중합체들(SM block copolymers) 및 스티렌-폴리부타디엔 star shaped 혼성중합체들(PS-PB star shaped copolymers)을 선택하여 다리걸친 폴리스티렌 겔 상에서의 용리거동을 비교 조사하였다. 선택한 이동상으로는 테트라히드로퓨란(THF), 톨루엔(TOL), 클로로포름(CHL), 메틸렌클로라이드(MC), 테트라히드로퓨란-시클로헥산(CH) 혼합용매의 5가지 시스템이며, 이동상 변화에 따른 시료들의 hydrodynamic 부피와 머무른 부피 사이에 플롯의 이동에 관한 현상을 조사하였으며, 또한 시료의 머무름을 예측하기 위해 다중 다단계 회귀분석(multiple stepwise regression analysis)을 수행한 결과, 각 중합체들에 대한 적절한 크기 파라미터를 찾았다. 또한, network-limited 분리 메카니즘에 의해 GPC에서 시료와 겔사이의 상호작용에 대한 분포계수 $K_p$를 각 이동상 시스템에서 구하였는데, PS와 PB의 kp값은 거의 1에 가까운 값을 나타내었고 PMMA인 경우는 적합 용매에서는 분자량이 증가할수록 $K_p$값은 다소 감소하였으나 부적합 용매에서는 분자량이 증가함에 따라 $K_p$값은 함께 증가하였다. 혼성중합체의 $K_p$값은 조성 및 분자량에 따라 달라짐을 알 수 있었고, 이로부터 SM block 혼합중합체의 형태는 무작정상(random phase)을 가지는 것으로 예측된다. 아울러 $K_p$값을 이용하여 동종중합체 및 폴리스티렌 혼성중합체들의 분자량을 측정하기 위해 이들의 새로운 머무름 파라미터$(V_r-V_o)/K_p$와 log[η]M을 플룻을 한 결과 좋은 직선성을 보이는 하나의 보편적 검정곡선을 얻었다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권7호
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• pp.913-921
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• 2019

Objective: The objectives of this study were to compare identified informative regions through two genome-wide association study (GWAS) approaches and determine the accuracy and bias of the direct genomic value (DGV) for milk production traits in Korean Holstein cattle, using two genomic prediction approaches: single-step genomic best linear unbiased prediction (ss-GBLUP) and Bayesian Bayes-B. Methods: Records on production traits such as adjusted 305-day milk (MY305), fat (FY305), and protein (PY305) yields were collected from 265,271 first parity cows. After quality control, 50,765 single-nucleotide polymorphic genotypes were available for analysis. In GWAS for ss-GBLUP (ssGWAS) and Bayes-B (BayesGWAS), the proportion of genetic variance for each 1-Mb genomic window was calculated and used to identify informative genomic regions. Accuracy of the DGV was estimated by a five-fold cross-validation with random clustering. As a measure of accuracy for DGV, we also assessed the correlation between DGV and deregressed-estimated breeding value (DEBV). The bias of DGV for each method was obtained by determining regression coefficients. Results: A total of nine and five significant windows (1 Mb) were identified for MY305 using ssGWAS and BayesGWAS, respectively. Using ssGWAS and BayesGWAS, we also detected multiple significant regions for FY305 (12 and 7) and PY305 (14 and 2), respectively. Both single-step DGV and Bayes DGV also showed somewhat moderate accuracy ranges for MY305 (0.32 to 0.34), FY305 (0.37 to 0.39), and PY305 (0.35 to 0.36) traits, respectively. The mean biases of DGVs determined using the single-step and Bayesian methods were $1.50{\pm}0.21$ and $1.18{\pm}0.26$ for MY305, $1.75{\pm}0.33$ and $1.14{\pm}0.20$ for FY305, and $1.59{\pm}0.20$ and $1.14{\pm}0.15$ for PY305, respectively. Conclusion: From the bias perspective, we believe that genomic selection based on the application of Bayesian approaches would be more suitable than application of ss-GBLUP in Korean Holstein populations.

• 지질공학
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• 제31권4호
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• pp.561-577
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• 2021

Barton and Choubey(1977)가 제안한 10개의 표준 거칠기 단면을 3차원으로 확장하여 모든 단면의 거칠기가 일정한 3차원 표준 거칠기 절리 모형을 제작하였다. 석고를 사용하여 이 절리 모형을 복제하여 절리시료를 제작하였고, 복제된 절리시료에 직접전단시험을 실시하여 표준거칠기 단면에 부여된 절리 거칠기계수(JRC)를 검증하였다. 먼저 절리 시료의 JRC, 절리면압축강도(JCS)와 기본마찰각(𝜙_b)을 이용하여 Barton (1973)의 전단강도 기준식에서 절리의 전단강도를 추정하고, 직접전단시험에서 측정된 전단강도와 비교하였다. 직접전단시험에서 측정된 전단강도는 1번과 4번 표준 거칠기를 제외한 8개 시료에서 Barton의 기준식에서 추정된 전단강도보다 낮았고, JRC가 큰 시료에서 차이가 더욱 크게 나타났다. 직접전단시험 결과를 역해석하여 JRC, JCS 그리고 𝜙_b의 적절성을 검토하였고, JRC의 문제점으로 인하여 측정된 전단강도가 추정된 전단강도보다 낮은 것으로 판명되었다. 역해석으로 구한 표준 거칠기 단면의 JRC 값인 JRC_m은 JRC보다 전반적으로 낮은 값을 보이지만 JRC와 상관성이 매우 높은 직선의 관계를 나타내었다. 위의 결과를 종합하여 표준 거칠기 단면의 정확한 JRC_m을 제시하였고, JRC_m과 JRC의 상관관계를 제시하였으며, Barton의 전단강도 기준식을 수정하여 제안하였다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1615-1615
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• 2001

During the past ten years, Near Infrared Spectroscopy has been successfully applied to the analysis of a great variety of agriculture products. Previous works (Morra et al., 1991; Salgo et al., 1998) have shown the potential of this technology for soil analysis, estimating different parameters just with one single scan. The main advantages of NIR applications in soils are the speed of response, allowing the increase of the number of samples analysed to define a particular soil, and the instantaneous elaboration of recommendations for fertilization and soil amendment. Another advantage is to avoid the use of chemical reagents at all, being an environmentally safe technique. In this paper, we have studied a set of 129 soil samples selected from representative glasshouse soils from Southern Spain. The samples were dried, milled, and sieved to pass a 2 mm sieve and then analysed for organic carbon, total nitrogen, inorganic nitrogen (nitrate ammonium), hygroscopic humidity, pH and electrical conductivity in the 1:1 extract. NIR spectra of all samples were obtained in reflectance mode using a Foss NIR Systems 6500 spectrophotometer equipped with a spinning module. Calibration equations were developed for seven analytical parameters (ph, Total nitrogen, organic nitrogen, organic carbon, C/N ratio and Electric Conductivity). Preliminary results show good correlation coefficients and standard errors of cross validation in equations obtained for Organic Carbon, Organic Nitrogen, Total Nitrogen and C/N ratio. Calibrations for nitrates and nitrites, ammonia and electric conductivity were not acceptable. Calibration obtained for pH had an acceptable SECV, but the determination coefficient was found very poor probably due to the reduced range in reference values. Since the estimation of Organic Carbon and C/N ratio are acceptable NIIRS could be used as a fast method to assess the necessity of organic amendments in soils from Mediterranean regions where the low level of organic matter in soils constitutes an important agronomic problem. Furthermore, the possibility of a single and fast estimation of Total Nitrogen (tedious determination by modifications of the Kjeldahl procedure) could provide and interesting data to use in the estimation of nitrogen fertilizer rates by means of nitrogen balances.

• Fisheries and Aquatic Sciences
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• 제26권2호
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• pp.105-116
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• 2023

Improved fish post-harvest technologies (IFPT) have been promoted as more efficient methods of fish processing, preservation, and value addition than the traditional methods prevalent in developing countries. The adoption rates, however, do not appear to be convincing. The purpose of this study was to determine the socio-demographic and psychological factors that influence intention of Kenyan farmed fish traders to use IFPT. The technology acceptance model (TAM) was used to properly explain the impact of TAM constructs such as perceived usefulness (PU), perceived ease of use (PEOU), and attitude (ATT), as well as socio-demographic factors such as gender, age, education level and fish trading experience on traders' intention to use the technologies. A cross-sectional survey was conducted to collect data using a semi-structured questionnaire from 146 traders in Busia, Siaya and Kakamega counties. At a significance level of p = 0.05, a linear regression model was used to examine the socio-demographic and psychological determinants of the traders' behavioral intention to use the improved technologies. The regression analysis revealed that PU (β = 0.443; p = 0.000), PEOU (β = 0.364; p = 0.000) and ATT (β = 0.615; p = 0.000) influence traders' intention to use IFPT, with ATT having the highest influence on intention. However, the traders' socio-demographic characteristics have no effect on their intention to use the technologies, as the coefficients for gender (β = 0.148; p = 0.096), age (β = 0.016; p = 0.882), level of education (β = -0.135; p = 0.141) and fish trading experience (β = 0.017; p = 0.869) are all insignificant. These findings show that the traders intend to use IFPT and will use them when it is in their best economic interests.