• 한국습지학회지
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• 제21권3호
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• pp.215-223
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• 2019

본 연구에서는 낙동강 주요 지류를 대상으로 상관분석, 주성분 및 요인분석, 군집분석과 같은 통계분석을 통해 수질 특성을 분석하였다. 유기물질과 영양물질은 높은 상관관계를 가지고 있으며 봄철 및 가을철에 높게 나와 해당 계절에 대한 집중적인 수질 관리가 필요한 것으로 나타났다. 주성분 및 요인분석 결과 전체 분산의 82%를 유기물질, 영양물질, 자연, 기상 등 4개의 주성분으로 설명할 수 있으며 BOD, COD, TOC, TP 항목이 주요 영향요인으로 분석되었다. 군집분석 결과 계절별 유기물, 영양물질의 오염도를 고려하여 4개의 군집으로 분류하였으며 금호강 유역은 사계절 높은 오염특성을 나타내고 있었다. 따라서 지류 하천의 효과적인 수질 관리를 위해서는 시공간적 특성을 고려한 대책이 필요하며 다변량 통계기법은 수질 관리 및 정책 수립에서 유용하게 활용 가능할 것으로 분석되었다.

• 한국조사연구학회지:조사연구
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• 제9권1호
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• pp.69-85
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• 2008

층화는 표본설계 단계에서 예비정보를 활용하는 대표적인 방법으로 대부분의 전국 단위의 표본설계에서 널리 활용된다. 층화의 효율을 극대화시키기 위해서는 조사목적에 부합되는 적절한 층화변수를 선택하는 것이 매우 중요하다. 하나의 표본을 통해 여러 개의 관심변수를 동시에 조사하는 다목적조사에서 다변량 층화변수가 있을 때 층화 전략을 세우는 것은 매우 복잡한 양상을 띤다. 본 연구에서는 관심변수의 수가 매우 많은 다목적조사를 위한 층화전략을 다룬다. 층화를 위해 구체적으로 사용하는 통계적 도구는 요인분석과 군집분석 등의 다변량 통계기법인데, 먼저 요인분석을 통해 적절한 층화변수들을 선정한 후 그 변수들을 이용하여 군집분석을 통해 층화를 하는 전략을 소개한다. 본 연구에서는 구체적으로 해양수산부의 어업비계통생산량조사를 위한 표본설계에서의 층화과정을 다룬다.

• 한국조경학회지
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• 제13권1호
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• pp.43-66
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• 1985

Korea needs proper and rational public policies on conservation and use of forest land and other natural resources because of the accelerating expansion of national land developments in recent years. Unfortunately, there is no systematic planning system to support the needs. Generally, forest land use planning needs suitability analysis based on efficient land classification system. The goal of this study was to classify a forest land using multivariate satistical methods. A case study was carried out in winter of 1983 on a mountainous area higher than 100m above sea level located at Mt. Kwanak in Anyang -city, Kyung-gi-do (province). The study area was 19.80 km$^2$wide and was divided into 1, 383 Operational Taxonomic Units (OTU's) by a 120m$\times$120m grid. Fourteen descriptors were identified and quantified for each OTU from existing national land data : elevation, slope, aspect, terrain form, geologic material, surface soil permeability, topsoil type, depth of the solum, soil acidity, forest cover type, stand size class, stand age class, stand density class, and simple forest soil capability class. For this study, a FORTRAN IV program was written for input and output map data, and the computer statistics packages, SPSS and BMD, were used to perform the multivariate statistical analysis. Fourteen variables were analyzed to investigate the characteristics of their fire quench distribution and to estimate the correlation coefficients among them. Principal component analysis was executed to find the dimensions of forest land characteristics, and factor scores were used for proper samples of OTU throughout the study area. In order to develop the classes of forest land classification based on 102 surrogates, cluster and discriminant analyses of principal descriptor variable matrix were undertaken. Results obtained through a series of multivariate statistical analyses were as follows ; 1) Principal component analysis was proved to be a useful tool for data selection and identification of principal descriptor variables which represented the characteristics of forest land and facilitated the selection of samples.

• Biomolecules & Therapeutics
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• 제21권6호
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• pp.470-475
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• 2013

Ultraviolet (UV) radiation is a major environmental factor that leads to acute and chronic reactions in the human skin. UV exposure induces wrinkle formation, DNA damage, and generation of reactive oxygen species (ROS). Most mechanistic studies of skin physiology and pharmacology related with UV-irradiated skin have focused on proteins and their related gene expression or single-targeted small molecules. The present study identified and analyzed the alteration of skin metabolites following UVB irradiation and topical retinyl palmitate (RP, 5%) treatment in hairless mice using direct analysis in real time (DART) time-of-flight mass spectrometry (TOF-MS) with multivariate analysis. Under the negative ion mode, the DART ion source successfully ionized various fatty acids including palmitoleic and linolenic acid. From DART-TOF-MS fingerprints measured in positive mode, the prominent dehydrated ion peak (m/z: 369, M+H-$H_2O$) of cholesterol was characterized in all three groups. In positive mode, the discrimination among three groups was much clearer than that in negative mode by using multivariate analysis of orthogonal partial-least squares-discriminant analysis (OPLS-DA). DART-TOF-MS can ionize various small organic molecules in living tissues and is an efficient alternative analytical tool for acquiring full chemical fingerprints from living tissues without requiring sample preparation. DART-MS measurement of skin tissue with multivariate analysis proved to be a powerful method to discriminate between experimental groups and to find biomarkers for various experiment models in skin dermatological research.

• 한국환경과학회지
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• 제5권1호
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• pp.15-23
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• 1996

During the last two decades, many industrial complexes for heavy and chemical industries have been established along the Korean coastline, thereby increasing the pollution materials burden on the coastal environment of seawater. Masan Bay is one of the most polluted coastal areas in Korea and the main soures of pollutants are domestic and industrial wastewater from Masan, Changwon. This study was aimed to evaluate relationships among the physicochemical parameters in the bottom water of Masan bay and to examine environmental factors affecting to pollutions of seawater by factor analysis. 'rife factor loading, 1 is showed higher increasing inclination after 1989 year in station 1. The variance of pollutant materials is showed 43.7% in which the coastal inflow water is indicated external loadings(factor 1 : NO3--N, TN, factor 4 : SiO2-Si) corresponded to domestic sewage, industrial wastewater, and earth-sands in the bottom water of Masan bay And the internal loadings(factor 2 : SS, salinity, factor 3 . W.T., DO) are explained 33.8%'corresponded the phenomena of sedimentary layer and oxygen concentration. Therefore, The external loadings are explained by the higher factor pollutantal variance in Masan bay.

• 한국생활과학회지
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• 제7권2호
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• pp.63-73
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• 1998

To get well-fitted ready-made clothings with beautiful silhouettes, it's better to classify body forms into several forms and to assign sizing within each form than to grade just based on body size regardless of body styles. This study illucidated the importance of drop value in the results of surveying the current values of sizing and grading. Therefore, it's meaningful to get the classification of body form with appropriate distribution of drop values of the body, and the distribution of drop value and the frequency of each form is very helpful to name the combined sizing or coverage of ready-made clothes. This study aimed at classifying body forms with various drop values using multivariate analysis for sizing and grading. Factor analysis and cluster analysis were done using measured values from 346 unmarried women. The results are as follows: 1. The factor which explains body forms was obtained by factor analysis, and the representative major 18 items which have important roles in classifying body forms were selected among the measured values with high factor loading and communality. 2. The body forms were classified into 8 groups based on the charateristics, frequencies and distributions of them obtained from cluster analysis. 3. Each classified body form showed conspicuous difference in drop value and the difference of body form mainly resulted from the difference between waist and hip rather than the difference between bust circumference and waist in Korean unmarried women.

• Radiation Oncology Journal
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• 제11권2호
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• pp.337-346
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• 1993

This is a retrospective cohort analysis of 58 patients who treated with postoperative radiation therapy following radical hysterectomy and bilateral pelvic adenectomy for early stage carcinoma of uterine cervix between January 1988 and December 1990 at department of radiation oncology, Keimyoung University Hospital. Sixteen percent of patients (9/58) had chemotherapy. Most patients were FIGO I b (47 patients), and FIGO I a and II a were one and ten patients, respectively. The median follow-up periods were 48.5 months. The indications for radiation therapy included pelvic lymph node metastasis, large tumor size, deep stromal invasion, lymphovascular invasion, positive surgical margin, endometrial invasion and parametrial invasion. Eighty five percent of the patients had more than one risk factor. The actuarial overall five year survival rate (5 YSR) and five year disease free survival rate (5 YDFSR) were $89.5\%,\;and\;87.8\%,$ respectively. Their overall recurrence rate was $12.1\%,$(758). Distant metastasis was the most common cause of treatment failure $(71.4\%:5/7).$ The univariate analysis of prognostic factors affecting to five year survival rate disclosed pelvic lymph node status (negative: $95.5\%,\;positive:69.2\%,$ p=0.006) and hemoglobin level $(\le11 :75\%,>11g/dl:93.3\%,p=0.05)$ as significant factor. The age status was marginally significant $(\le40:96.0\%,\;>\;40:84.3\%p=0.15).$ Multivariate analysis clarified three independent prognostic factors: pelvic lymph node metastasis (p=p.006), hemoglobin level (p=0.015) and age (p=0.035). Multivariate analysis of prognostic factor affecting to five year disease free survival rate disclosed pelvic lymph node status (p=0.0078) and status of surgical margin (p=0.008). Complications relating to radiotherapy were $10.3\%,(6/58).$ There were no severe major complication requiring surgical intervention or a long hospital stay. It is our opinion that the benefit of postoperative pelvic radiotherapy may be gained in such a high risk patient population with acceptible morbidity.

• 한국디지털건축인테리어학회논문집
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• 제11권2호
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• pp.51-60
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• 2011

Although the comparative advantage of cities is emphasized in the context of transition into an information-oriented society and globalization, it is difficult to define the concept and evaluate the status of each city. There have been many studies and appraisals on urban competitiveness with common features of subjective standards by researchers. This study aims at extracting determinants of competitive advantage of location by not normative but data-based approach, and deals with panel data concerning 21 cities in capital region. Factor Analysis, a kind of multivariate methods, is taken up for the purpose and results in various findings. Time-serial 5-factor models constructed by the analysis show temporal variability in the determinants and have non-exhaustive and overlapped categories. This study also finds that 'educational base' is emphasized as a leading determinant and 'health, welfare and public services' factor is getting more important. The other potential factor explaining variables such as college and museum is also emerging, which is considered as an element to attract people from outside. And the fact that traditionally expected factors regarding industrial or productive basis is not drawn out indicates the other way of thinking on the relationship between the essential function of cities and industrial foundation.

• 한국식품조리과학회지
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• 제20권4호
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• pp.371-379
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• 2004

The purpose of this study was to identify factors associated with high satisfaction with foodservices in family restaurant. Accordingly, this study surveyed questionnaire concerning 20 measures of foodservice as well as major subject descriptors. The result of this study were as follows. KMO and Bartlett's test statistics showed that the data fitted factor analysis well. Results of factor analysis, average variance extracted estimates and shared variance showed that the convergent and discriminant validitys of 3 factors are supported, and cronbach's alpha showed that the internal consistency of 3 factors is supported. It was found that expensive groups, except gender groups and frequency of purchase groups, were differentially associated with high levels of overall satisfaction with foodservices. Multivariate analyses showed that satisfaction with service factor was the best predictor of overall satisfaction, followed by facilities factor. Three factors emerged from the logistic regression analysis as predictors of level of overall satisfaction. Overall, approximately 77% of university students could be correctly classified as being satisfied or unsatisfied. Finally, the results of the study provide some insights into the market-oriented types of foodservice marketing strategies or tactics to enable family restaurant to effectively manage and more competitive.

• 한국빅데이터학회지
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• 제5권2호
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• pp.135-143
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• 2020

본 논문은 농식품 소비자패널 데이터에서 소비자의 유형을 나눌 때에 변수간 연관성이 많은 장바구니 분석에서 전처리 방법과 차원축소의 방법을 제안한다. 군집분석은 다변량 자료에서 관측 개체를 몇 개의 군집으로 나눌 때 널리 사용되는 분석기법이다. 하지만 여러 개의 변수가 연관성을 가진 경우에는 차원축소를 통한 군집분석이 더 효과적일 수 있다. 본 논문은 1,987 가구를 대상으로 조사한 식품소비 데이터를 K-means 방법을 사용하여 군집화하였으며, 군집을 나누기 위해 17개의 변수를 선정하였고, 17개의 다중공선성 문제와 군집을 나누기 위한 차원축소의 방법 중 주성분 분석과 요인분석을 비교하였다. 본 연구에서는 주성분분석과 요인분석 모두 2개의 차원으로 축소하였으며 주성분분석에서는 3개의 군집으로 나뉘었지만 분석하고자 하였던 소비 패턴에 대한 군집의 특성이 잘 나타나지 않았으며 요인분석에서는 분석가가 보고자 하는 소비 패턴의 특징이 잘 나타났다.