• 대한화장품학회지
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• 제21권2호
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• pp.129-139
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• 1995

FT-IR의 정량 법 중 Partial least-squares(PLS) 방법과 Multiple scattering correction(MSC) 방법을 이용한 계면활성제 분석의 타당성을 조사하기 위하여 LAS, MES 그리고 ELA-9을 이들 방법으로 정량 하였다. 계면활성제 표준품을 각각 다른 비율로, 50% 에탄올에 가열 용해 시킨 다음, 건조 시켜 액막법으로 IR 스펙트럼을 측정하였다. 얻어진 스펙트럼으로부터 Variance(분산 ) 스펙트럼을 구하고 이를 참고하여 여러 파수 영역에서 반복하여 검량선을 작성하고 상관계수를 구하였다. 1245-1130 cm -1 의 범위와 1070-1010 cm -1 범위의 파수를 선정한 결과 상관계수의 값이 모두 1.000이었다. 또한 정량 결과, 오차가 0.32%이하로써 매우 만족할 만한 결과를 얻었다. 따라서 FT-IR을 이용한 정량 법에서 PLS 방법과 MSC 방법은 계면활성제 분석에 유효하며, 본 정량 방법이 매우 간단하므로 품질관리 목적의 분석에 적합하다는 결론에 도달하였다.

• 약학회지
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• 제49권2호
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• pp.115-121
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• 2005

In this study, the performance of a portable NIR system and a FT NIR spectrometer were compared to determine water content of hairless mouse skin. The stratum corneum parts wer e separated from the epidermal tissues by trypsin solution. NIR diffuse reflectance spectra of hairless mouse skin were acquired using a fiber optic probe. In the near infrared, water molecules show two clear absorption bands at 1450 nm from first overtone of O-H stretching and 1940 nm from the combination involving O-H stretching and O-H deformation. It was found that the variations of O-H absorption band according to water content. Partial least squares regression (PLSR) was applied to develop a calibration model. The PLS model showed a good correlation between NIR predicted value and the absolute water content of separated hairless mouse skin, in vitro. For both the portable and the FT NIR spectrometer, These studies showed the possibility of a rapid and nondestructive skin moisture measurement using NIR spectroscopy. The portable NIR spectrometer with a photodiode arrays-microsensor could be more rapidly applied for the determination of water content with comparable accuracy with the performance of a FT spectrometer .

• 한국환경과학회지
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• 제29권5호
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• pp.445-455
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• 2020

Fine dust is one of the most critical environmental issues in Korea, and the government recognizes the need to establish customized reduction policies based on regional characteristics. Several studies on air pollutants investigate whether factories affect the distribution of fine dust in a particular region. However, understanding the impact of the entire industry sector requires further investigation. This study identifies the impacts of industrial characteristics on fine dust levels of 141 municipalities across Korea in 2016. A total of 23 variables were used, of which 12 referred to industries and 11 to general characteristics of each city. Due to the high correlation between independent variables, partial least squares (PLS) regression models were used. The analysis identified 14 significant variables for PM10 and 13 for PM2.5. Therefore, the results suggest that local industrial characteristics can significantly influence fine dust levels and provide suggestions for establishing customized reduction policies based on local characteristics.

• 한국작물학회지
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• 제63권4호
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• pp.360-377
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• 2018

The levels of 12 isoflavones were measured in soybean (Glycine max (L.) Merrill) sprouts of 68 genetic varieties from three countries (China, Japan, and Korea). The isoflavone profile differences were analyzed using data mining methods. A principal component analysis (PCA) revealed that the CSRV021 variety was separated from the others by the first two principal components. This variety appears to be most suited for functional food production due to its high isoflavone levels. Partial least squares discriminant analysis (PLS-DA) and orthogonal projections to latent structures discriminant analysis (OPLS-DA) showed that there are meaningful isoflavone compositional differences in samples that have different countries of origin. Hierarchical clustering analysis (HCA) of these phytochemicals resulted in clusters derived from closely related biochemical pathways. These results indicate the usefulness of metabolite profiling combined with chemometrics as a tool for assessing the quality of foods and identifying metabolic links in biological systems.

• 한국의류학회지
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• 제43권4호
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• pp.506-520
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• 2019

This study first investigates relationships among fashion consumer's positive emotion toward social value seeking activities (SVSA), enterprise image (EI), enterprise-perceived quality (EPQ), and purchase intention. Additionally, it demonstrates if the confirmed relationships are different in similar SVSA between social enterprise and cause-related marketing (CRM). An online experiment using a 2 (the implementation organization of social values: social enterprise vs CRM) ${\times}2$ (SVSA: support of vulnerable group vs environmental protection) factorial design was conducted to test the established hypotheses. Participants were randomly assigned to one of four conditions, and the collected data were analyzed using a partial least squares structure equation modeling (PLS-SEM) and partial least squares multi-group analysis (PLS-MGA). The results revealed that positive emotion toward SVSA directly influenced EI and purchase intention. EI and EPQ were identified as sequential mediators linking positive emotion toward SVSA and purchase intention. A finding for similarity in consumer response paths between social enterprises and CRM highlights that social enterprises need to develop a marketing strategy distinguished from CRM.

• Clinical and Experimental Pediatrics
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• 제65권2호
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• pp.90-97
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• 2022

Background: Stunting is affected by various factors from mother and child. Previous studies assessed only one or more influencing variables. Unfortunately, nor the significant influence of maternal and child factors nor the indicators contributing to maternal and child factors that affect the stunting incidence have ever been analyzed. Purpose: This study analyzed the effect of maternal and child factors on stunting and the significant indicators that shape the maternal and child factors that impact stunting. Methods: This was a case-control study. Overall, 132 stunted children and 132 nonstunted children in Purbalingga Regency, Central Java Province, participated in the research. Direct interviews and medical record reviews were conducted to assess the studied variables. The research data were tested using the partial least squares structural equation with a formative model. Results: Maternal factors directly affected the occurrence of stunting (t=3.527, P<0.001) with an effect of 30.3%. Maternal factors also contributed a significant indirect effect on stunting through child factors (t=4.762, P<0.001) with an effect of 28.2%. Child factors affected the occurrence of stunting (t=5.749, P<0.001) with an effect of 49.8%. The child factor was influenced by maternal factor with an effect of 56.7% (t=10.014, P<0.001). The moderation analysis results demonstrated that maternal and child factors were moderate predictive variables of stunting occurrence. Conclusion: Child factors have more significant and direct effects on stunting than maternal factors but are greatly affected by them.

• 분석과학
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• 제15권2호
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• pp.102-107
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• 2002

근적외선 분광광도법 (near infrared spectroscopy, NIRS)를 이용하여 의약품의 신속 정확한 분석법을 개발하였다. 제조회사에 따라 약효성분이 같고 유사한 부형제를 갖고 있는 페노바르비탈정제에서 페노바르비탈을 액체크로마토그래피로 분석한 분석치와 투과방식의 NIRS 의 부분최소자승법(partial least squares regression, PLSR) 으로 얻은 데이터와의 상관관계를 이용하여 검정선을 얻었다. 이 방법의 직선성, 정량범위, 재현성 등을 검토하여 본 분석법의 정확성을 검증하였다. 검정선의 상관계수는 0.9983이고 검정의 표준오차(SEC)는 0.14% 이였으며, 이 분석법의 시간별 및 날자별 정밀도인 CV 값은 각 각 0.45%과 0.56% 이다.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2004년도 학술발표논문집
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• pp.1-8
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• 2004

We address the problem of parameter estimation in multivariate distributions under ignorable non-monotone missing data. The factoring likelihood method for monotone missing data, termed by Robin (1974), is extended to a more general case of non-monotone missing data. The proposed method is algebraically equivalent to the Newton-Raphson method for the observed likelihood, but avoids the burden of computing the first and the second partial derivatives of the observed likelihood Instead, the maximum likelihood estimates and their information matrices for each partition of the data set are computed separately and combined naturally using the generalized least squares method. A numerical example is also presented to illustrate the method.

• Environmental Analysis Health and Toxicology
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• 제15권1_2호
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• pp.39-43
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• 2000

Linear alkyl sulfonates (LAS) constitute a large fraction of the surfactants used in cleaning processes in households, trade and industry Despite the industrial significance and the possible environmental impact of these compounds, the fast and inexpensive determination of LAS concentrations is still a difficult task. In this study, near infrared (NIR) spectroscopy which is a rapid spectroscopic analysis method compared with a traditional analytical method for the measurement of LAS concentration such as HPLC, GC and standard wet chemistry method. NIR spectra of LAS between 0.313 and 25.0% (w/v) in water were utilized to develop a calibration model. The best results (R ＝ 0.998, SEP ＝ 0.244% (w/v)) obtained by using partial least-squares regression with spectral data treatment and 2nd derivatization were comparable to the results (SEC ＝ 0.186% (w/v), SEP ＝ 0.206% (w/v)) obtained by using multiple linear least-squares regression (MLR). However, models based on derivative spectra have no significant advantage with MLR.

• Journal of applied mathematics & informatics
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• 제38권3_4호
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• pp.311-334
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• 2020

The solution of the elliptic partial differential equation has interface singularity at the points which are either the intersections of interfaces or the intersections of interfaces with the boundary of the domain. The singularities that arises in the elliptic interface problems are very complex. In this article we propose an exponentially accurate nonconforming spectral element method for these problems based on [7, 18]. A geometric mesh is used in the neighbourhood of the singularities and the auxiliary map of the form z = ln ξ is introduced to remove the singularities. The method is essentially a least-squares method and the solution can be obtained by solving the normal equations using the preconditioned conjugate gradient method (PCGM) without computing the mass and stiffness matrices. Numerical examples are presented to show the exponential accuracy of the method.