• Journal of the Korean Data and Information Science Society
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• 제28권4호
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• pp.743-754
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• 2017

두 제제의 생체이용률을 비교하여 동등성을 입증하는 생물학적 동등성 시험은 표준 $2{\times}2$ 교차설계를 원칙으로 하고 있으나, 최근에는 제제의 특성이 고변동성으로 인해 표준 $2{\times}2$ 교차설계를 사용할 경우 지나치게 많은 피험자가 필요하게 되면서, EMA나 MFDS 등에서는 $2{\times}2$ 교차설계를 확장한 $2{\times}4$, $4{\times}2$ 또는 $4{\times}4$ 등의 고차원 설계를 권장하고 있다. $2{\times}3$ 교차설계는 표준 $2{\times}2$ 교차설계에서 1기간을 확장한 설계로 불균형 설계이기는 하지만 $2{\times}4$ 교차설계와 비교해서 경제적, 윤리적 측면에서 장점을 갖고 있는 설계라 할 수 있다. 본 연구에서는 $2{\times}3$ 이중설계를 활용하는 생물학적 동등성 시험에서 설계의 통계적 특성을 고찰해 보고, 생물학적 동등성 평가를 위한 통계적 설계 및 추론 절차를 새롭게 개정된 의약품동등성시험기준을 적용하여 논의한다.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 춘계학술대회
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• pp.481-486
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• 2011

The research reviews three experimental designs which include Split Plot Design (SPD), Crossover Design (CD) and Replicated Design (RD) by using Latin Square Design (LSD). SPD (CRD, LSD) and SPD (LSD, RCBD) that are derived from (S:A)${\times}B{\times}C{\times}D$ and $A{\times}B{\times}C{\times}D$. In addition, (S:A)${\times}B{\times}C$, (S:A)${\times}C{\times}D$ and (S:A)${\times}B{\times}C{\times}D$ can be used to generate various LSD and CD models. Finally, Replicated LSDs are considered to increase the power of detectability.

• 생물정신의학
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• 제19권4호
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• pp.159-163
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• 2012

An appropriate research design for hypotheses and purposes leads to a good quality of research results. In this review article, we summarized the types of research methods and described the characteristics of clinical trials. Research designs are categorized into observational studies and experimental ones, depending on data collecting methods. In an observational study, there are cross-sectional, cohort and case-control studies. Parallel groups design and crossover trial studies are representative designs in a randomized controlled trial study, a kind of experimental study. Clinical researchers should understand the characteristics of clinical research designs including advantages and disadvantages and choose the suitable design according to their study purposes and the nature of collected data or subjects.

• 응용통계연구
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• 제18권1호
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• pp.159-171
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• 2005

최근 미국을 위시한 선진국에서 제제간의 생물학적 동등성을 판단하는 기준이 생체 이용률의 평균치를 비교하는 시험에서 분산까지 같이 고려하는 기준으로 바뀌고 있다. 처방성과 교차사용성을 의미하는 모집단과 개인 생물학적 동등성이 바로 그것이다. US FDA에서는 2 × 4 교차설계법을 활용해서 제제간의 생동성을 입증하는 것을 추천하고 있다. 현재 US FDA에서 제안하고 있는 모집단 생물학적 동등성 평가 방법은 통계적으로 문제점을 가지고 있어 최근 Lee, Shao & Chow(2002), Chow, Shao & Wang(2003), 그리고 McNally, Iyer & Mathew(2002)에 의해서 수정된 평가 방법들이 제안되고 있다. 본 연구 논문에서는 그동안 제제간의 생물학적 동등성 평가 설계법이였던 2×2 교차설계법을 이용해서 모집단 생물학적 동등성을 평가하는 방법을 논의하고 최근 제안된 방법들을 모의실험을 통해 비교하여 가장 적절한 방법론을 제안한다.

• Journal of the Korean Data and Information Science Society
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• 제24권6호
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• pp.1439-1448
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• 2013

확률화 블록계획법이나 교차된 이원분류표에 대한 분산분석과 오차제곱합의 성질은 널리 알려져있다. 본 논문에서는 인자에 따른 수준에 또 다른 인자들이 내포되어 있는 지분계획 특히 이단계 지분계획에 대하여 구조적 특징을 설명하고 오차제곱합의 성질에 대하여 살펴보았다. 또한 이단계 지분계획의 활용으로 크로스오버 계획을 소개하고 생물학이나 약학 등의 분야에서 많이 사용되는 동등성 검정의 신뢰구간 구축에 대하여 설명하였고 실제자료와 SPSS 통계 페키지를 이용하여 분석함으로서 응용성을 부각시켰다.

• Communications for Statistical Applications and Methods
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• 제23권6호
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• pp.543-553
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• 2016

The validity of statistical inference depends on proper randomization methods. However, even with proper randomization, we can have imbalanced with respect to important characteristics. In this paper, we introduce a method based on ranked auxiliary variables for treatment allocation in crossover designs using Latin squares models. We evaluate the improvement of the efficiency in treatment comparisons using the proposed method. Our simulation study reveals that our proposed method provides a more powerful test compared to simple randomization with the same sample size. The proposed method is illustrated by conducting an experiment to compare two different concentrations of titanium dioxide nanofiber (TDNF) on rats for the purpose of comparing weight gain.

• Journal of Preventive Medicine and Public Health
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• 제34권2호
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• pp.119-126
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• 2001

Air pollution epidemiologic studies are intrinsically difficult because the expected effect size at general environmental levels is small, exposure and misclassification of exposure are common, and exposure is not selective to a specific pollutant. In this review paper, epidemiologic study designs and analytic methods are described, and two nationwide projects on air pollution epidemiology are introduced. This paper also demonstrates that possible confounding issues in time-series analysis can be resolved and the impact on the use of data from ambient monitoring stations may not be critical. In this paper we provide a basic understanding of the types of air pollution epidemiologic study designs that be subdivided by the mode of air pollution effects on human health (acute or chronic). With the improvements in the area of air pollution epidemiologic studies, we should emphasize that elaborate models and statistical techniques cannot compensate for inadequate study design or poor data collection.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2006년도 추계 학술발표회 논문집
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• pp.43-48
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• 2006

In 2001 US FDA proposed a draft guidance for future in vivo bioequivalence studies. The guidance suggested specific criteria for new drug sponsors to show prescribability and switchability in bioequivalence testing for approval of generic drugs. However, there is less acceptance of the need to change statistical procedures and study designs from those currently used to assess the current criterion of average bioequivalence. The measures of population and individual bioequivalence testing are introduced and statistical procedures for them are discussed.

• Structural Engineering and Mechanics
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• 제55권2호
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• pp.399-411
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• 2015

The buckling equations of filament wound composite cylindrical shell are established. The coefficients $K_{ij}$ and $L_{ij}$ of the buckling equations are determined by solving the equations. The geometric analysis and the effective stiffness calculation for the fiber crossover and undulation region are respectively accomplished. Using the effective stiffness of the undulation region, the specific formulas of the coefficients ${K^{\prime}}_{ij}$ and ${L^{\prime}}_{ij}$ of the buckling equations are determined. Numerical examples of the buckling critical loads have been performed for the different winding angles and stacking sequences cylindrical shell designs. It can be concluded that the fiber undulation results in the less effect on the buckling critical loads $P_{cr}$. $P_{cr}$ increases with the thickness-radius ratio. The effect on $P_{cr}$ due to the fiber undulation is more obvious with the thickness-radius ratio. $P_{cr}$ decreases with the length-radius ratio. The effect on $P_{cr}$ due to the fiber undulation can be neglected when the ratio is large.

• 한국정밀공학회지
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• 제14권3호
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• pp.89-97
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• 1997

A genetic algorithm (GA) is a stochastic direct search strategy that mimics the process of genetic evolution. The GA applied herein works on a population of structural designs at any one time, and uses a structured information exchange based on the principles of natural selection and wurvival of the fittest to recombine the most desirable features of the designs over a sequence of generations until the process converges to a "maximum fitness" design. Principles of genetics are adapted into a search procedure for structural optimization. The methods consist of three genetics operations mainly named selection, cross- over and mutation. In this study, a method of finding the optimum topology of truss/beam structure is pro- posed by using the GA. In order to use GA in the optimum topology problem, chromosomes to FEM elements are assigned, and a penalty function is used to include constraints into fitness function. The results show that the GA has the potential to be an effective tool for the optimal design of structures accounting for sizing, geometrical and topological variables.variables.