• Spatial Information Research
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• 제20권1호
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• pp.81-90
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• 2012

지리적 공간상에서 발생하는 대부분의 현상은 서로 인접한 곳에서 유사한 값을 가지는 특성이 있다. 이는 공간자기상관성과 관련이 있으며 공간분석의 존재 이유를 나타내는 개념이다. 또한 지리적 공간상에서 위치에 따라 값의 분포가 다양한 패턴을 보이게 된다. 이러한 패턴은 공간적 변이를 내포하고 있다. 즉, 특정 위치에서 항상 같은 값을 관찰할 수 있다고 단정하기는 불가능하기 때문에 이러한 변이는 본질적으로 확률론적 특성을 지닌다. 이러한 공간자료의 특성들을 무시하고 일반적 통계분석 등을 수행할 경우 공간자기상관성으로 인하여 통계분석에서 가정하는 자료 값들 간 독립성이 위배되고 분석결과는 왜곡될 가능성이 크다. 그러므로 공간자료 분석을 위해서는 공간자기상관성과 확률론적 변이를 적절하게 반영할 수 있는 수단이 필요하다. GIS는 공간적 위치정보를 처리하는데 적합하고 공간통계학은 공간적 변이를 다루는데 유용하다. 따라서 GIS를 기반으로 공간통계학을 통합하는 분석방식은 공간자료의 특성들을 고려하여 유의미한 분석을 하기에 적합한 장점이 있다. 본 연구의 목적은 공간자료 분석에 있어서 공간통계학과 GIS를 결합하는 접근방식의 유용성을 논의하고 실증적 사례분석을 통하여 구체적 활용성을 살펴보는 것이다. 이를 위하여 공간통계학을 주요 방법론으로 활용하는 공간역학(spatial epidemiology) 분야를 예시적으로 살펴보았다. 구체적으로는 공간검색통계량을 이용하여 미국 Erie 및 Niagara 카운티(New York 주) 내의 유방암 발생의 공간적 군집패턴 분석 논의하였다.

• 한국건강관리협회지
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• 제4권1호
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• pp.1-11
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• 2006

"본 논문은 대한외과학회지 2006년 제70권제1호에 실렸던 논문으로 대한외과학회 편집위원회 승인을 득하고 본 협회지에 게재함. Purpose: Malnutrition has been frequently reported for patients on their admission to the hospital and it has been associated with an increase in morbidity, mortality and the length of the hospital stay. Although a number of screening tools have been developed to identify those patients at risk for malnutrition, there is no' gold standard' for defining malnutrition and the malnourished patients remain largely unrecognized. The aim of this study is to evaluate the efficacy of a nutritional screening tool for use in Dankook University Hospital. Methods Nutritional evaluation was performed for 53 patients who were admitted to the department of surgery and internal medicine between October and December 2004. The screening tool was completed by the ward nurse and the nutritional support team nurse on the same patients within24 hours of admission. The nutritional support team nurse performed the full assessment. The screening sheet included 4 questions regarding body mass index, recent unintentional weight loss, food intake and disease severity. Each answer was scored and a total of 5 was tested as the criterion fey malnutrition. The full assessment included current body weight, recent weight loss, triceps skinfold thickness, mid-arm muscle circumference, serum albumin)in and total lymphocyte count. Malnutrition was defined by 3 or more values below the reference values. The reliability of the screening tool was assessed using kappa statistic. Sensitivity, specificity and accuracy were calculated to evaluate the validity of the screening tool. The receiver operating characteristic(ROC) curve was drawn to choose a cutoff valve that maximizes sensitivity and specificity. Results' The level of agreement between the ward nurse and the NST nurse was good for BMI and food intake and moderate for weight loss and disease severity. The full assessment identified7 patients(13.2%) as malnourished. The screening sheet had a sensitivity of 86% and a specificity of 80%. According to the ROC curve, a score of 5 points provided the best validity. Conclusion The nutritional screening tool is reliable when completed by different observers and it is valid for nutritional assessment.

• 유통과학연구
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• 제20권9호
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• pp.47-59
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• 2022

Purpose: This study aims to analyze a triangulation model: 1) the effect of entrepreneurship education (EE) on entrepreneurship knowledge (EK) and entrepreneurship mindset (EM) and 2) the effect of EK on EM. Entrepreneurship education is a medium and pedagogical tool to cultivate EK and EM with the purpose enhancing of students who will be interested in entrepreneurial activities. Knowledge of adequate entrepreneurship is a stimulus strategic tool to develop the entrepreneurial mindset of students. Research design, data, and methodology: There were 278 respondents from Business and Non-Business both Indonesian and Malaysian students. The research design was quantitative and evaluated three hypotheses by PLS-SEM using WarpPLS v.7 software. Statistic descriptive for respondent used SPSS IBM v.26. Results: The results showed that the three hypotheses had supported with a significant level of p-value < 0.001. It's meant EE enhanced both EK and EM. Furthermore, increasing EM was not only by EE, but also EM could be increased through EK. Conclusions: The novelty of this research contributes to filling the knowledge gap in the development of pedagogy in the pursuit of entrepreneurship using a triangulation model of the relationship among EE, EK, and EM.

• 한국시스템다이내믹스연구
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• 제8권2호
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• pp.175-190
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• 2007

Stock market volatility largely depends on firms' value and growth opportunities. However, with the globalization of world economy, the effect of the synchronization in major countries is gaining its importance. Also, domestically, the business cycle and cash market of the country are additional factors needed to be considered. The main purpose of this research is to attest the application and usefulness of System Dynamics as a general stock market forecasting tool. Throughout this research, System Dynamics suggests a conceptual model for forecasting a KOSPI(Korea Composite Stock Price Index), taking the factors of the composite stock price indexes in traditional researches. In conclusion of this research, System Dynamics was proved to bean appropriate model for forecasting the volatility and direction of a stock market as a whole. With its timely adaptability, System Dynamic overcomes the limit of traditional statistic models.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.300-302
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• 2008

For the evaluation of wind resources, numerical simulation was carried out as a tool for establishing wind map around the korean peninsula. Initial and boundary condition are given by 3 hourly RDAPS(Regional Data Assimilation and Prediction System) data of KMA(Korea Meteorology Administration) and high resolution terrain elevation land cover(30 seconds) data from USGS(United States Geological Survey). Furthermore, Data assimilation was adopted to improve initial meteorological data with buoy and QuikSCAT seawinds data. The simulation was performed from 2003 to 2006 year. To understand wind data correctly in complex terrain as the korean peninsula, at this research, Wind map was classified 4 categories by distance from coastline and elevation.

• Communications for Statistical Applications and Methods
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• 제24권5호
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• pp.481-492
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• 2017

This paper investigates a convergence rate of a test statistics given by two scale sampling method based on $A\ddot{i}t$-Sahalia and Jacod (Annals of Statistics, 37, 184-222, 2009). This statistics tests for longitudinal data having the existence of long memory dependence driven by fractional Brownian motion with Hurst parameter $H{\in}(1/2,\;1)$. We obtain an upper bound in the Kolmogorov distance for normal approximation of this test statistic. As a main tool for our works, the recent results in Nourdin and Peccati (Probability Theory and Related Fields, 145, 75-118, 2009; Annals of Probability, 37, 2231-2261, 2009) will be used. These results are obtained by employing techniques based on the combination between Malliavin calculus and Stein's method for normal approximation.

• 응용통계연구
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• 제15권2호
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• pp.415-421
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• 2002

통계적분석에서 가장 대표적인 가정이 정규성 가정이므로 데이터의 정규성 검정은 매우 중요하다. 이 논문에서는 정규성 검정을 위해 경제학에서 소득분배의 불균형에 관한 척도로 널리 이용되는 Lorenz curve를 변형한 새로운 플롯과 검정통계량을 제시한다. 그리고 제한한 검정을 W검정 (Shapiro and Wilk (1965)), Lorenz curve를 이용한 TL검정(Kang and Cho (1999))과 몬테칼로 방법을 이용하여 검정력을 비교한다. 제안된 검정이 특별한 대립분포의 경우를 제외하고는 대부분 검정력이 높았다.

• 한국재난정보학회 논문집
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• 제4권2호
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• pp.124-136
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• 2008

The systematic information management of chemical accidents has been required as a tool for the policy making, system improvement and release of information concerning accident prevention. However, there is not yet a systematic chemical accidents tracking system in Korea, which make confusion among the related government agencies and the parties to accidents that the related statistics are different from each others. In this study, We developed the Chemical Accident Tracking System (CATS) using chemical accident classification which was made up of 12 upper classes, 70 middle classes, 272 lower classes. The CATS is mainly consist list up module, reporting module, searching and statistic module, etc. The CATS is expected to be applied to the information tracking and database system for chemical accidents and improve its manageability.

• Communications for Statistical Applications and Methods
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• 제22권5호
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• pp.495-506
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• 2015

Volatility is a variation measure in finance for returns of a financial instrument over time. GARCH models have been a popular tool to analyze volatility of financial time series data since Bollerslev (1986) and it is said that volatility is highly persistent when the sum of the estimated coefficients of the squared lagged returns and the lagged conditional variance terms in GARCH models is close to 1. Regarding persistence, numerous methods have been proposed to test if such persistency is due to volatility shifts in the market or natural fluctuation explained by stationary long-range dependence (LRD). Recently, Lee et al. (2015) proposed a residual-based cumulative sum (CUSUM) test statistic to test volatility shifts in GARCH models against LRD. We propose a bootstrap-based approach for the residual-based test and compare the sizes and powers of our bootstrap-based CUSUM test with the one in Lee et al. (2015) through simulation studies.

• Journal of Preventive Medicine and Public Health
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• 제43권1호
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• pp.9-17
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• 2010

Objectives: Parkinson's disease is one of the most common neurodegenerative diseases in the elderly population. In order to estimate the prevalence of Parkinson's disease in the community, the application of a good screening tool is essential. We evaluated the validity and reliability of a Parkinson's disease screening questionnaire and propose an alternative measure to improve its validity for use in community surveys. Methods: We designed the study in a three-phase approach consisting of a screening questionnaire, neurologic examination, and confirmatory examination. A repeated survey was administered to patients with disease detected in the community and on 150 subjects. We examined internal consistency using Cronbach's alpha test, test-retest reliability using the kappa statistic, and validity using sensitivity, specificity, and ROC curves. Unadjusted odds ratios were utilized for the estimation of weights for each questionnaire item. Results: The Cronbach's alpha of the questionnaire was 0.708. The kappa statistic for test-retest reliability was good to generally fair in most of the items. When newly proposed weighting scores were used, the optimum cut-off value was 7/8. When cut-off value was 5/6 for surveying prevalence in a community, the sensitivity was 0.98, and the specificity was 0.61, with simultaneous improvement in reliability. Conclusions: We recommend 5/6 as the ideal cut-off value for the survey of PD prevalence in community. This questionnaire designed for the Korean community could help future epidemiologic studies of PD.