• Journal of Korean Neurosurgical Society
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• 제30권6호
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• pp.761-768
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• 2001

Objective : To describe the underlying causes, surgical results, and prognostic factors in thoracic stenosis causing myelopathy, retrospective analysis for 28 cases of thoracic stenosis with surgery was performed Materials & Method : Twenty-eight patients(male, 15 ; female, 13) who underwent decompressive surgery for thoracic stenosis between 1987 and 1997 were analyzed. The mean age was 49 and the mean follow-up was 30.6 months. Statistical analysis with $SPSS^{(R)}$ was performed. Chi-square test was used for the analysis of relationship between subjects and multivariate analysis with general linear model was used to find prognostic factors. Result : Degenerative spondylosis was the most common cause, and three cases were associated with systemic diseases. Decompressive laminectomy was done in 23 cases, anterior decompression in four cases, and combined decompression in one case. Ossification of ligamentum flavum was found in 18 cases, facet hypertrophy in 13, ossification of posterior longitudinal ligament in six, and ventral spur in four. Postoperatively, 16 patients improved functionally and 4 patients worsened. The group of which initial symptom duration was less than two years showed better result(p=0.003). The group with sufficient decompression and no additional proximal stenosis had better outcome(p=0.002, p=0.001). Conclusion : Chronic myelopathy caused by thoracic stenosis can be reversible with appropriate decompression.

• 한국컴퓨터정보학회논문지
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• 제19권10호
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• pp.125-133
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• 2014

본 논문에서는 호텔경영을 위한 인공신경망 기반의 부도예측 모형을 개발한다. 부도예측 모형은 호텔에서 관리하는 사업장의 사업성과 이터를 바탕으로 부도 가능성을 평가하여 호텔 전체사업의 부도를 예측하는 특징을 가진다. 부도예측을 위한 전통적인 통계기법은 다변량 판별분석이나 로짓분석 등이 있는데, 본연구는 이들보다 우수한 예측정확성을 갖는 인공신경망 기법을 이용해서 연구를 진행하였다. 이를 위해 우선 우수기업 100개와 도산기업 100개를 선정하여 전체 실험데이터를 구성하고, 뉴로쉘이라는 인공신경망 도구를 이용하여 부도예측모형을 구성하였다. 본 모형 설계와 실험은 서비스드 레지던스 호텔에서 관리하는 각 브랜치의 부도예측과 재무건전성을 판단하기에 효율성이 높아 호텔 경영의 의사결정에 많은 도움이 될 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권5호
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• pp.1839-1843
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• 2015

Background: MicroRNAs are a class of noncoding RNAs which regulate multiple cellular processes during tumor development. The purpose of this report is to investigate the clinicopathological and prognostic significance of miR-218 in human gliomas. Materials and Methods: Quantitative RT-PCR (qRT-PCR) was conducted to detect the expression of miR-218 in primary normal human astrocytes, three glioma cell lines and 98 paired glioma and adjacent normal brain tissues.Associations of miR-218 with clinicopathological variables of glioma patients were statistically analyzed. Finally, a survival analysis was performed using the Kaplan-Meier method and Cox's proportional hazards model. Results: The expression level of miR-218 in primary normal human astrocytes was significantly higher than that in glioma cell lines (p<0.01). Also, the expression level of miR-218 in glioma tissues was significantly downregulated in comparison with that in the adjacent normal brain tissues (p<0.001). Statistical analyses demonstrated that low miR-218 expression was closely associated with advanced WHO grade (p=0.002) and low Karnofsky performance score (p=0.010) of glioma patients. Kaplan-Meier analysis with the log-rank test showed that patients with low-miR-218 expression had poorer disease-free survival and overall survival (p=0.0045 and 0.0124, respectively). Multivariate analysis revealed that miR-218 expression was independently associated with the disease-free survival (p=0.009) and overall survival (p=0.004) of glioma patients. Conclusions: Our results indicate that miR-218 is downregulated in gliomas and that its status might be a potential valuable biomarker for glioma patients.

• 응용통계연구
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• 제31권1호
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• pp.109-122
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• 2018

임계값을 기준으로 그 보다 작은 값은 로그정규분포(lognormal distribution; LN)를, 큰 값은 일반화파레토분포(generalized Pareto distribution; GPD)를 따르는 합성 분포를 LN-GPD 합성분포라 한다. Scollnik (2007)은 LN-GPD 합성분포가 로그정규분포와 GPD를 합성 시킴으로써 자료의 손실 없이 꼬리가 두꺼운 분포에서 좋은 적합력을 가진다고 밝혔다. 본 논문에서는 시간에 따라 변하는 LN-GPD 평균모형을 다루었으며 방법론으로는 국소 다항최대우도법을 기반으로 추정하는 방법에 대해서 연구하였다. 시간에 따라 변하는 분포를 추정함으로써 자료에 대한 훨씬 자세한 이해가 가능하며 이는 곧 상담원 배치나 자원배분과 같은 운영관리에 큰 도움을 줄 수 있다. 본 연구는 GPD 분포만을 고려한 Beirlant와 Goegebeur (2004)를 확장하여 절삭한 로그정규분포를 추가하여 자료의 손실 없이 자료의 특징을 살펴볼 수 있다는데도 의의가 있다. 모의실험을 통해 제안한 방법론의 적절함을 살펴 보았고 실증 자료 분석으로 이스라엘 은행의 콜센터 서비스 시간에 대해 분석하여 상담원 배치와 관련된 흥미로운 결과를 찾을 수 있었다.

• 농촌계획
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• 제11권4호
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• pp.47-57
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• 2005

The goal of this research is to evaluate landscape-ecological characteristics of watersheds in the Nakdong River Basin by using Geogaphic Information System (GIS) and landscape indices for integation of spatio-temporal informations and multivariate statistical techniques for quantitative analysis of forest landscape. Fragmentation index and change matrix techniques using factor analysis and grid overlay method were used to efficiently analyze and manage huge amount of information for ecological-environmental assessment (land-cover and forest landscape patterns). According to the results based on the pattern analysis of land-cover changes using the change detection matrix between 1980s and 1990s, addition on 750km$^2$ became urbanized areas. The altered 442.04km$^2$ was agricultural areas which is relatively easy for shifting of land-use, and 205.1km$^2$ of forests became urbanized areas, and average elevation and slope of the whole altered areas were 75m and 4$^{\circ}$. On the other hand, 120km$^2$ of urban areas were changed into other areas (i.e., agricultural areas and green space), and fortunately, certain amount of naturalness had been recovered. But still those agricultural areas and fallow areas, which were previously urban areas, had high potential of re-development for urbanization due to their local conditions. According to the structural analysis of forest landscape using the landscape indices, the forest fragmentation of watersheds along the main stream of the Nakdong River was more severe than my other watersheds. Furthermore, the Nakdong-sangju and Nakdong-miryang watersheds had unstable forest structures as well as least amount of forest quantity. Thus, these areas need significant amount of forest through a new forest management policy considering local environmental conditions.

• 박물관보존과학
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• 제2권
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• pp.69-76
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• 2000

본 연구는 동남해안 및 도서지방의 신석기시대 주칠토기 23점에 대한 과학적 분석의 일환으로서 먼저 태토성분, 소성온도, 안료성분 및 안료두께를 분석한 데에 이어 태토성분에 대한 통계적인 고찰 및 경도분석을 통한 안료성분의 역할을 보강하여 재정리한 것이다. 유도결합플라즈마분광기(ICP-AES)와 엑스선형광분석기(XRF)를 사용하여 태토의 성분분석을 실시하였고, 이 분석결과에 대한 다변량해석(PCA : 주성분분석법)을 수행한 결과, 토기의 태토는 범방, 욕지도, 나머지 지역의 3개 군으로 분류되었다. 또 태토와 안료의 경도를 토기 표면으로부터 깊이별로 측정한 결과, 산화철이 다량 포함된 안료층의 경도가 태토층보다 높았고 이를 통해 산화철이 고온소성시 경도를 크게 하는 역할을 했음을 알 수 있었다. 또한 안료층의 경도가 태토층 보다 높은 것은 안료층도 소성되었음을 의미하는 것으로, 토기성형시 안료를 먼저 바른 후 토기가 구워졌음을 유추해 볼 수 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.1965-1967
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• 2013

Background: To obtain the maximum additional information about the prognosis of gastric cancer, we compared CA-50 with other previously defined markers. Materials and Methods: This hospital based study was carried out in the Department of Biochemistry of Nepalese Army Institute of Health Sciences between $1^{st}$ July 2012 and $31^{st}$ December 2012. The variables collected were age, gender, AFP, CEA, CA19-9, and CA50, assayed with ELISA reader for all cases. The cut off values for serum AFP, CEA, CA19-9, and CA-50 were 10 ${\mu}g/l$, 10 ${\mu}g/l$, 37 U/ml, and 20 U/ml, respectively according to the manufacturer's instructions. Approval for the study was obtained from the institutional research ethical committee. Results: Of the 40 examined patients, 13 patients had tumors located in the upper third of the stomach, 6 patients had tumors in the middle third, 16 patients had tumors in the lower third, and 5 patients had tumors occupying two-thirds of the stomach or more. The distribution of lymph node staging of the patients was as follows: 7 patients belonged to N0, 9 patients to N1 stage, 10 patients to N2 stage, and 14 patients to N3 stage. The statistical method of Cox proportional hazards using multivariate analysis also illustrated that tumor markers including CEA (2.802), CA19-9 (2.690), CA50 (2.101), were independent prognostic factors, as tumor size (1.603), and lymph node stage (1.614). Conclusions: The tumour markers now available, like CEA, CA 19-9 and CA 50, chiefly perceive advanced gastric cancer. The preoperative rise in those tumour marker level have a prognostic significance and may be clinically helpful in choosing patients for adjuvant management.

• Journal of Ginseng Research
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• 제42권1호
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• pp.57-67
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• 2018

Background: Ginseng contains many small metabolites such as amino acids, fatty acids, carbohydrates, and ginsenosides. However, little is known about the relationships between microorganisms and metabolites during the entire ginseng fermentation process. We investigated metabolic changes during ginseng fermentation according to the inoculation of food-compatible microorganisms. Methods: Gas chromatography mass spectrometry (GC-MS) datasets coupled with the multivariate statistical method for the purpose of latent-information extraction and sample classification were used for the evaluation of ginseng fermentation. Four different starter cultures (Saccharomyces bayanus, Bacillus subtilis, Lactobacillus plantarum, and Leuconostoc mesenteroide) were used for the ginseng extract fermentation. Results: The principal component analysis score plot and heat map showed a clear separation between ginseng extracts fermented with S. bayanus and other strains. The highest levels of fructose, maltose, and galactose in the ginseng extracts were found in ginseng extracts fermented with B. subtilis. The levels of succinic acid and malic acid in the ginseng extract fermented with S. bayanus as well as the levels of lactic acid, malonic acid, and hydroxypruvic acid in the ginseng extract fermented with lactic acid bacteria (L. plantarum and L. mesenteroide) were the highest. In the results of taste features analysis using an electronic tongue, the ginseng extracts fermented with lactic acid bacteria were significantly distinguished from other groups by a high index of sour taste probably due to high lactic acid contents. Conclusion: These results suggest that a metabolomics approach based on GC-MS can be a useful tool to understand ginseng fermentation and evaluate the fermentative characteristics of starter cultures.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.643-648
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• 2005

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3075-3079
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• 2014

Background: The relationship between body mass index(BMI) and outcomes after chemoradiotherapy(CRT) has not been systematically addressed. The purpose of this study was to evaluate the effect of BMI on survival in patients with esophageal squamous cell carcinoma (ESCC). Materials and Methods: Sixty ESCC cases were retrospectively reviewed in this study. Patient overall survival(OS) and disease-free survival (DFS) were compared between two groups (BMI< $24.00kg/m^2$ and $BMI{\geq}24.00kg/m^2$). Results: There were 41 patients in the low/normal BMI group (BMI< $24.00kg/m^2$) and 19 in the high BMI group ($BMI{\geq}24.00kg/m^2$). No significant differences were observed in patient characteristics between these. We found no difference in 2-year OS and DFS associated with BMI (p=0.763 for OS; p=0.818 for DFS) using the Kaplan-Meier method. Univariate analysis revealed that higher clinical stage was prognostic for worse 2-year OS and DFS, metastasis for 2-year OS, lymph node status for 2-year DFS, while age, gender, smoking, drinking, tumor location and BMI were not prognostic. There were no differences in the 2-year OS (hazard ratio=1.117; p=0.789) and DFS(hazard ratio=1.161; p=0.708) between BMI groups in multivariate analysis, whereas we found statistical differences in the 2-year OS and DFS associated with clinical stage, gender and tumor infiltration (p<0.04), independent of age, smoking, drinking, tumor location, the status of lymph node metastases and BMI. Conclusions: BMI was not associated with survival in patients with ESCC treated with CRT as primary therapy. BMI should not be considered a prognostic factor for patients undergoing CRT for ESCC.