• 생약학회지
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• 제41권4호
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• pp.303-307
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• 2010

To overcome the limit of morphological method for classification of herbal drug, a novel method to discriminate its origin using pyrolysis mass spectrometry-multivariate analysis was developed. This method was applied successfully to Scutellaria baicalensis Georgi, one of the most popular herbal drug in oriental countries. The ethylacetate soluble fractions were prepared by sonication from pulverized roots of S. baicalensis which were collected from various regions including Korea and China, and subjected to direct insertion probe (DIP) mass spectrometry to achieve mass spectra of pyrolizates of extracts. The probe temperature was elevated from $30^{\circ}C$ to $320^{\circ}C$ at increasing rate $64^{\circ}C/min$, and the average mass spectrum calculated from total ion chromatography (TIC) was obtained. The relative peak intensities versus m/z were subjected to SAS program, and the training set (9 from Korea origin and 22 from China origin) was clustered two groups as its origin. In the test set, 11 samples among total 13 test sample were successfully classified according to their origin by developed method with accuracy of 85%.

• 한국실내디자인학회논문집
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• 제13권6호
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• pp.132-139
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• 2004

This study is to a question in argument that existing theses about a trait spatial configuration of exhibition space were analyzed without appropriateness verification of analysis characteristics. Firstly, through theoretical studies of established thesis, validity twenty analysis characteristics was chosen by making an investigation into existing analysis characteristics. Secondly, through a subject of our investigation, forty-two exhibition space of nineteen museums and art museum at home and abroad, a distribution map of exhibition space was analyzed by multivariate analysis. As a result of this study : 1) Nine analysis characteristics which extracted through multivariate analysis was the principal analysis characteristics. 2) A scale was important characteristic for the classification of museum therefore a degree of space perception was ought to compare every one of similar scale museum. 3) When comparing a trait of spatial configuration at exhibition space, these characteristics came into effect on middle sized museums. 4) It was visually confirmed a trait of spatial configuration of each group between museum and art museum

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3219-3221
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• 2013

Background: This study used receiver operating characteristic (ROC) curves to screen Surveillance, Epidemiology and End Results (SEER) skin melanoma data to identify and quantify the effects of socioeconomic factors on cause specific survival. Methods: 'SEER cause-specific death classification' used as the outcome variable. The area under the ROC curve was to select best pretreatment predictors for further multivariate analysis with socioeconomic factors. Race and other socioeconomic factors including rural-urban residence, county level % college graduate and county level family income were used as predictors. Univariate and multivariate analyses were performed to identify and quantify the independent socioeconomic predictors. Results: This study included 49,999 parients. The mean follow up time (SD) was 59.4 (17.1) months. SEER staging (ROC area of 0.08) was the most predictive foctor. Race, lower county family income, rural residence, and lower county education attainment were significant univariates, but rural residence was not significant under multivariate analysis. Living in poor neighborhoods was associated with a 2-4% disadvantage in actuarial cause specific survival. Conclusions: Racial and socioeconomic factors have a significant impact on the survival of melanoma patients. This generates the hypothesis that ensuring access to cancer care may eliminate these outcome disparities.

• Geomechanics and Engineering
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• 제10권3호
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• pp.269-284
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• 2016

Simplified techniques based on in situ testing methods are commonly used to assess seismic liquefaction potential. Many of these simplified methods were developed by analyzing liquefaction case histories from which the liquefaction boundary (limit state) separating two categories (the occurrence or non-occurrence of liquefaction) is determined. As the liquefaction classification problem is highly nonlinear in nature, it is difficult to develop a comprehensive model using conventional modeling techniques that take into consideration all the independent variables, such as the seismic and soil properties. In this study, a modification of the Multivariate Adaptive Regression Splines (MARS) approach based on Logistic Regression (LR) LR_MARS is used to evaluate seismic liquefaction potential based on actual field records. Three different LR_MARS models were used to analyze three different field liquefaction databases and the results are compared with the neural network approaches. The developed spline functions and the limit state functions obtained reveal that the LR_MARS models can capture and describe the intrinsic, complex relationship between seismic parameters, soil parameters, and the liquefaction potential without having to make any assumptions about the underlying relationship between the various variables. Considering its computational efficiency, simplicity of interpretation, predictive accuracy, its data-driven and adaptive nature and its ability to map the interaction between variables, the use of LR_MARS model in assessing seismic liquefaction potential is promising.

• 한국산학기술학회논문지
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• 제17권1호
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• pp.538-543
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• 2016

고품질의 제품과 조업 안전을 확보하기 위해서는 적절한 실시간 공정 감시 및 진단 시스템이 설치되어있는 것이 무엇보다 중요하다. 공정 감시 시스템과 결합된 신뢰도 높은 진단 시스템은 공정에서 발생한 특별한 사건이나 사고의 근본적인 원인과 공정 변수를 알려준다. 본 연구에서는 다변량 통계 분석과 분류기법에 기반한 공정진단 체계를 제시한다. 이 진단시스템은 비선형 데이터 표현과 필터링을 통한 지능적 데이터 표현으로 구성되어 있다. 진단 성능을 평가하기 위해 사례연구를 수행하였으며 다른 방법론과의 결과를 비교하기 위하여 진단 결과와 미래값 추정 방법을 평가하였다. 그 결과 본 연구에서 비교된 진단 방법론들에 비해 신뢰도 높은 진단 결과를 얻을 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권2호
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• pp.1107-1110
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• 2013

Intrahepatic cholangiocarcinoma (ICC), one of the primary liver cancers, is frequent in the northeastern part of Thailand. Surgical resection remains the best method of treatment, but patients suffering from ICC usually present at a late stage of the disease. Studies of survival and prognostic factors after surgery remain rare. The aim here was to evaluate the survival rate and factors affecting the survival of patients with intrahepatic cholangiocarcinoma after surgery. The study used a retrospective cohort design. The subjects were 73 consecutive patients with ICC, who were admitted for surgery to Srinagarind Hospital, Khon Kaen University, during the period 2005-2009. The censoring date was 31 December, 2011, data being evaluated using uni- and multivariate analyses. Postoperative survival analysis was performed by the Kaplan-Meier method, and the Cox proportional hazard model was used to identify independent prognostic factors. The total follow-up time was 99 person-years. The total number of deaths was 59, giving a mortality rate of 59 per 100 person-years. The cumulative 1-, 3-, and 5-year survival rates were 52.1%, 21.7%, and 11.2%, respectively. The median duration of survival after resection was 12.4 months. Univariate analysis revealed stage of disease, lymph node metastasis, histological type, histological grade and macroscopic classification to be statistically significant (p-value<0.05) prognostic factors. In the multivariate analysis, only macroscopic classification was statistically significant (p-value<0.05). In conclusion, macroscopic classification was the only independent factor found to be significantly associated with survival following surgical treatment of ICC.

• 한국병원경영학회지
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• 제22권4호
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• pp.87-101
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• 2017

[Purpose] This study aims to classify of healthcare decline and analyze the corresponding health outcomes among cities in Korea. In pursuing the above, this paper gives the particular attention to draw policy implications. [Methodology/Approach] Public healthcare data of 81 cities between 2014 and 2015 was obtained from the National Medical Center of Korea. A matrix analysis, t-test, ANOVA and multivariate regression were applied. [Findings] The study results indicated that declining cities tend to have the most healthcare resources, compared to growing or maintaining cities. However, accessibility to healthcare appeared to be lower in declining cities. Based on the classification of cities on healthcare decline, 42 out of 81 cities were categorized as a maintain/improvement group, while 39 cities were characterized as decline/depression. The group with a decline/depression type has significantly more healthcare facilities than maintain/improvement type. In contrast, maintain/improvement cities indicated lower incidence of morbidity and mortality than decline/depression cities. Lastly, according to the multivariate regression analysis for the healthcare outcomes by the type of healthcare decline, incidence of morbidity and mortality tended to decrease as the number of healthcare workers, the proportion of people who have healthcare accessibility, and the Timely Relevance Index increased regardless of the number of medical facilities including hospital beds and special beds. [Practical Implications] In conclusion, focusing on the improvement of healthcare accessibility as well as staffing, rather than expanding facilities is essential to set the healthcare policies.

• Gut and Liver
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• 제12권6호
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• pp.674-681
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• 2018

Background/Aims: The cumulative surgery rate and postoperative relapse of intestinal Behçet's disease (BD) have been reported to be high. This study aimed to establish a scoring system based on follow-up endoscopic findings that can predict intestinal BD recurrence after surgery. Methods: Fifty-four patients with intestinal BD who underwent surgery due to bowel complications and underwent follow-up colonoscopy were retrospectively investigated. Their clinical data, including colonoscopic findings, were retrieved. Classification and regression tree analysis was used to develop an appropriate endoscopic classification model that can explain the postsurgical recurrence of intestinal BD most accurately based on the following classification: e0, no lesions; e1, solitary ulcer <20 mm in size; e2, solitary ulcer ${\geq}20mm$ in size; and e3, multiple ulcers regardless of size. Results: Clinical relapse occurred in 37 patients (68.5%). Among 38 patients with colonoscopic recurrence, only 29 patients had clinically relapsed. Multivariate analysis identified higher disease activity index for intestinal BD at colonoscopy (hazard ratio [HR], 1.013; 95% confidence interval [CI], 1.005 to 1.021; p=0.002) and colonoscopic recurrence (HR, 2.829; 95% CI, 1.223 to 6.545; p=0.015) as independent risk factors for clinical relapse of intestinal BD. Endoscopic findings were classified into four groups, and multivariate analysis showed that the endoscopic score was an independent risk factor of clinical relapse (p=0.012). The risk of clinical relapse was higher in the e3 group compared to the e0 group (HR, 6.284; 95% CI, 2.036 to 19.391; p=0.001). Conclusions: This new endoscopic scoring system could predict clinical relapse in patients after surgical resection of intestinal BD.

• 보존과학연구
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• 통권8호
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• pp.1-12
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• 1987

Fifty ancient Korean coins originated in Choson dynasty have been determined for 9 elements such as Sn, Fe, As, Ag, Co, Sb, Ir, Ru and Ni by instrumental neutron activation analysis and for 3 elements such as Cu, Pb, and Zn by atomicalsorption spectrometry. Bronze coins originated in early days of the dynasty contain as major constituents Cu, Pb and Sn approximately in the ratio 90 : 4 : 3, where as, those in latter days contain in the ratio 7 : 2 : 0. Brass coins which had begun in 17century contain as major constituents Cu, Zn and Pb approximately in the ratio 7 : 1: 1. The multivariate date have been analyzed for the relation among elemental contents through the variance-covariance matrix. The data have been fur theranalyzed by a principal component mapping method. As the results training set of 8class have been chosen, based on the spread of sample points in an eigenvector plotand archaeolgical data such as age and the office of minting.

• 한국통신학회논문지
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• 제21권1호
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• pp.251-268
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• 1996

In this paper, a higher-order feedforward neural network called ridge polynomial network (RPN) which shows good approximation capability for nonlnear continuous functions defined on compact subsets in multi-dimensional Euclidean spaces, is presented. This network provides more efficient and regular structure as compared to ordinary higher-order feedforward networks based on Gabor-Kolmogrov polynomial expansions, while maintating their fast learning property. the ridge polynomial network is a generalization of the pi-sigma network (PSN) and uses a specialform of ridge polynomials. It is shown that any multivariate polynomial can be exactly represented in this form, and thus realized by a RPN. The approximation capability of the RPNs for arbitrary continuous functions is shown by this representation theorem and the classical weierstrass polynomial approximation theorem. The RPN provides a natural mechanism for incremental function approximation based on learning algorithm of the PSN. Simulation results on several applications such as multivariate function approximation and pattern classification assert nonlinear approximation capability of the RPN.