• 제목/요약/키워드: Cross-over trials

검색결과 37건 처리시간 0.021초

$3\times3$ 교차실험을 범주형 자료 분석을 위한 주변확률모형 (The Marginal Model for Categorical Data Analysis of $3\times3$ Cross-Trials)

  • 안주선
    • 응용통계연구
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    • 제14권1호
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    • pp.25-37
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    • 2001
  • 세 처리, 세 기간을 갖는 3$\times$3 교차실험에서 c($\geq$3)개의 범주를 가진 자료의 분석에 사용될 수 있는 주변확률모형을 제안한다. 이 모형은 Kenward and Jones(1991)의 결합확률 모형의 대조물 (counterpart)로 사용될 수 있고 2항 변수를 갖는 3$\times$3 교차실험에서 처리 효과를 분석하기 위한 Balagtas et al(1995)의 일변량주변로지트모형의 일반화이다. 세 종류의 링크변화를 사용하여 주변확률모형방정식의 구성된다. 링크변환행렬과 모형행렬을 구성하는 방법이 주어지고, 모수의 추정이 논의된다. 제안된 모형을 Kenward and Jones 자료의 분석에 응용한다.

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2×2 교차계획법에서 결측치가 있을 때의 결측치 처리 방법 비교에 관한 연구 (Comparison of Single Imputation Methods in 2×2 Cross-Over Design with Missing Observations)

  • 조보배;김동재
    • 응용통계연구
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    • 제28권3호
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    • pp.529-540
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    • 2015
  • 의과학 분야에서 교차계획법은 임상시험을 통한 두 처리의 비교 검정에 이용되고 있으며 생물학적 동등성 시험에 자주 이용되고 있다. $2{\times}2$ 교차계획법에서 2시기에 결측치가 발생했을 때 통상적으로 결측치가 발생한 개체를 삭제하고 모수적 검정을 한다. 하지만 소표본으로 진행되는 $2{\times}2$ 교차계획법에서 일부 관측치의 삭제가 통계적 분석에 크게 영향을 미칠 수 있다. 본 논문에서는 소표본으로 이루어지는 $2{\times}2$ 교차계획법에서 2시기에 결측치가 발생했을 때 단순대체법들을 적용한 후 Hills-Armitage (1979)의 모수적 검정법과 Koch (1972)와 Kim (1999)이 제안한 비모수적 검정법들의 제 1종오류와 검정력을 몬테카를로 모의실험(Monte-Carlo simulation)을 통하여 비교하였다.

Nonparametric Tests for 2×2 Cross-Over Design

  • Gee, Kyuhoon;Kim, Dongjae
    • Communications for Statistical Applications and Methods
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    • 제19권6호
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    • pp.781-791
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    • 2012
  • A $2{\times}2$ Cross-over design is widely used in clinical trials for comparison studies of two kinds of drugs or medical treatments. This design has many statistical methods such as Hills-Armitage's (1979) method or Koch's (1972) method. In this paper, we propose a nonparametric test for $2{\times}2$ Cross-over design based on a two-sample test suggested by Baumgartner et al. (1998). In addition, a Monte Carlo simulation study is adapted to compare the power of the proposed methods with those of previous methods.

구강건강에 이용되는 보완대체의학 치료: 무작위대조임상연구를 통한 문헌적 고찰 (Complementary and Alternative Medicine for Oral Health : a Literature Review of Randomized Controlled Clinical Trials)

  • 김다희;최광호;황의형;허광호;김용덕;신병철
    • 대한예방한의학회지
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    • 제18권3호
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    • pp.23-39
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    • 2014
  • Objective : This review aims at analyzing Complementary and Alternative Medicine (CAM) therapies, using for oral health to know current use of CAM in dental area by analyzing randomized controlled clinical trials (RCTs). Method : We searched the following 6 electronic databases until 1 July 2014. : Pubmed, Medline, Embase, Allied and Complementary Medicine Database(AMED), Cumulative Index to Nursing and Allied Health Literature(CINAHL), the Cochrane Library. We included parallel RCTs and cross-over RCTs that assessed the efficacy of CAM regardless of blinding and language. Results : A total of 154 RCT articles were included. There were 2-arm parallel study design(69.5%), 3-arm parallel study design(20.8%), 4-arm parallel study design(4.5%) and Cross-over design(5.2%). Complementary and alternative medicine RCTs in oral health tend to increase in the early-2000s and in the mid-2010s. In addition, 154 citations were classified according to diseases and interventions that categorized Natural Products studies(68.2%), Mind and Body Practices studies(31.8%). We classified in detail that vitamin and mineral therapies(29.9%), dietary supplements(24.7%), acupuncture(23.3%), Herbal medicine(13.6%), homeopathy (2.6%), energy therapies(2.6%), Massage(1.9%), biofeedback(0.6%), traditional medicine(0.6%). Conclusion : Increasing publications and diverse interventions regarding CAM for oral health is observed by analyzing RCTs from the literature review. Further studies are needed to be performed as systematic reviews to verify their effectiveness and the research to inquire into side effect.

건강한 성인 지원자를 대상으로 한 필로칼핀 저작정의 타액분비 유도 및 타액중 용출패턴 평가 (Evaluations on Salivary Flow Induction and Dissolution Patterns in Saliva of Pilocarpine Chewing Tablet in Healthy Human Volunteers)

  • 박경호
    • Journal of Pharmaceutical Investigation
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    • 제27권4호
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    • pp.331-335
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    • 1997
  • Xerostomia is caused by organic or functional changes affecting the salivary system at different levels. Patients suffering from xerostomia may also complain of an oral burning sensation, ulceration or soreness, difficulty in swallowing, and poor denture retention. And pilocarpine is administered orally to induce salivary secretion. In Seoul National University Hospital(SNUH) pharmacy, the pilocarpine chewing tablets are prepared and supplied to patients of xerostomia in request of the dental hospital in SNUH. And we tested the salivary flow induction and the dissolution patterns of these products in saliva by a double-blind, sequential cross-over trials to eight healthy human volunteers with placebo. The pilocarpine chewing tablet contained 5 mg of pilocarpine, and placebo consisted of same materials as test drug, but didn't contain pilocarpine. In vivo experiment, all subjects were instructed to chew as 60-80 times/min. Mixed saliva was collected in the ranges of intervals such as 0-2, 2-5, 5-10, 10-15, 15-20, 20-30, 30-45 and 45-60 min after pilocarpine chewing tablet or placebo administration. Saliva volume was measured in each collecting time interval, and saliva pilocarpine concentrations were determined by reversed phase HPLC. The 82.5 percent $(4.13{\pm}0.69\;mg)$ of pilocarpine was extracted from chewing tablets during mastication of 60-80 times per minute for 60 minutes. Among these dissolved amounts, 90 percent was extracted within 20 minutes. The salivary flow rates were more increased in a group who administered pilocarpine chewing tablet at the interval of 5-10, 10-15, 20-30 and 45-60 min rather than a placebo-group, but only extracted amount of pilocarpine at 45-60 min interval is significanly different between two groups (p<0.05). But total amounts of saliva secreted for 1 hour in two group-pilocarpine and placebo treated- were $46.36{\pm}9.72\;ml\;and\;39.09{\pm}7.81\;ml$, respectively, and were not significantly different between two groups.

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The amelioration of plasma lipids by Korean traditional confectionery in middle-aged women: A cross-over study with western cookie

  • Hong, Sun Hee;Kim, Mijeong;Woo, Minji;Noh, Jeong Sook;Lee, JaeHwan;Chung, Lana;Song, Yeong Ok
    • Nutrition Research and Practice
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    • 제10권6호
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    • pp.590-596
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    • 2016
  • BACKGROUND/OBJECTIVES: The purpose of this study was to examine whether plasma lipid profiles are affected differently by snack kinds with equal calorific values. SUBJECTS/METHODS: We compared a Korean traditional confectionery (dasik) with Western confectionery (cookie) in this regard. Controlled cross-over study consisted of two 3-week snack intake phases and for separating, a 2-week washout period (3-2-3) was carried out with 30 healthy women aged between 40-59 years old. Brown rice based Korean traditional confectionery and wheat flour based Western confectionery were used. The participants consumed either dasik or cookie every day for 3 weeks, providing 93 kcal a day. RESULTS: The total cholesterol (TC) in the dasik group had decreased significantly after 3 weeks (P < 0.05). Furthermore, in the dasik group, reduction in TC and low-density lipoprotein-cholesterol were greater than those in the cookie group (P < 0.05). CONCLUSIONS: Prioritizing functional snacks like dasik improves plasma lipid profiles; this may be useful information for individuals who cannot refrain from snacking.

The Role of Milk Products in Metabolic Health and Weight Management

  • Zemel, Michael B.
    • Journal of Dairy Science and Biotechnology
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    • 제28권1호
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    • pp.17-28
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    • 2010
  • A substantial body of evidence has emerged over the last decade in support of the novel concept that dietary calcium and dairy foods play an important role in regulating energy metabolism and thereby promote healthy weight management and reduce obesity risk. This concept has been demonstrated in experimental animals studies, cross-sectional and prospective population studies and a number of randomized clinical trials. Notably, the effects of dairy foods in weight management are more consistent than the effects of supplemental calcium across clinical trials, and calcium per se is responsible for approximately 40-50% of the effects of dairy. The calcium component is only effective in individuals with chronically low calcium intake, as it serves to prevent the endocrine response to low calcium diets which otherwise favors adipocyte energy storage; calcium also serves to promote energy loss via formation of calcium soaps in the gastrointestinal tract and thereby reduce fat absorption. The calcium-independent anti-obesity bioactivity of dairy resides primarily in whey. The key components identified to date are leucine and bioactive peptides resulting from whey protein digestion. The high concentration of leucine in whey stimulates a repartitioning of dietary energy from adipose tissue to skeletal muscle where it provides the energy required for leucine-stimulated protein synthesis, resulting in increased loss of adipose tissue and preservation of skeletal muscle mass during weight loss. Finally, dairy rich diets suppress the oxidative and inflammatory responses to obesity and thereby attenuate the diabetes and cardiovascular disease risk associated with obesity.

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테이블 균형맞춤 작업이 가능한 Q-학습 기반 협력로봇 개발 (Cooperative Robot for Table Balancing Using Q-learning)

  • 김예원;강보영
    • 로봇학회논문지
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    • 제15권4호
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    • pp.404-412
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    • 2020
  • Typically everyday human life tasks involve at least two people moving objects such as tables and beds, and the balancing of such object changes based on one person's action. However, many studies in previous work performed their tasks solely on robots without factoring human cooperation. Therefore, in this paper, we propose cooperative robot for table balancing using Q-learning that enables cooperative work between human and robot. The human's action is recognized in order to balance the table by the proposed robot whose camera takes the image of the table's state, and it performs the table-balancing action according to the recognized human action without high performance equipment. The classification of human action uses a deep learning technology, specifically AlexNet, and has an accuracy of 96.9% over 10-fold cross-validation. The experiment of Q-learning was carried out over 2,000 episodes with 200 trials. The overall results of the proposed Q-learning show that the Q function stably converged at this number of episodes. This stable convergence determined Q-learning policies for the robot actions. Video of the robotic cooperation with human over the table balancing task using the proposed Q-Learning can be found at http://ibot.knu.ac.kr/videocooperation.html.

PubMed에서 acupuncture와 tension-type headache and migrain로 검색한 최근 연구경향 (Systemic Review : The Study on acupuncture for tension-type headache and migrain in PubMed)

  • 김경민;변임정;우현수;이현종;하지영;김종덕;홍장무;이재동;이윤호;최도영
    • Journal of Acupuncture Research
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    • 제20권1호
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    • pp.191-201
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    • 2003
  • Objective : To research the trends of study related to tension-type headache and migrain with acupuncture in PubMed, and to establish the hereafter direction of acupuncture. for tension-type headache and migrain. Methods : We searched in PubMed, with tension-type headache, migrain and acupuncture limitted by abstract and enterz data 10 years. Results : 1. The pattern of the study was as follows: Review article(18), Clinical Trials(23), meta analysis(2) and rondomized controlled trials(16). We further estimated 23 articles. 2. Many of these studies provide equivocal results because of designs, sample size and the others, but in the majority of the trials were concludes that acupuncture offers benefits in the treatment of headache. 3. Acupuncture methods need individualization, a carefully selected placebo and cross-over design must have adequate time between the two treatment periods.

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생물학적 동등성 시험을 위한 2×k 교차설계법의 통계적 고려 (Some Statistical Considerations on 2×k Crossover Designs for Bioequivalence Trial)

  • 노소영;박상규
    • 응용통계연구
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    • 제26권4호
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    • pp.675-686
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    • 2013
  • 현재 우리나라 식품의약품안전청에서는 $2{\times}2$ 교차설계법을 기초로 제제간의 생물학적 동등성 평가를 수행하도록 규정하고 있다. 하지만 고변동성 제제의 생물학적 동등성 평가에서 $2{\times}2$ 교차설계법에 의한 시험은 지나치게 많은 피험자를 필요로 할 수 있어 윤리적이고 경제적인 고려가 필요하다는 논의가 이루어지고 있다. $2{\times}2$ 교차설계법을 대체할 수 있는 대안으로 $2{\times}4$ 교차설계법은 미국 및 유럽 등에서는 생물학적 동등성 평가에 광범위하게 사용되는 설계 방법이고, $2{\times}3$ 교차설계법도 $2{\times}2$$2{\times}4$ 교차설계법의 단점을 개선할 수 있는 효율적인 대안으로 관심이 많다. 본 연구에서는 $2{\times}4$$2{\times}3$ 교차설계법의 통계적 모형과 제시된 통계적 모형에 연계된 분산분석표를 유도한다. 현행 국내 생물학적 동등성 시험 규정에 의하면 $2{\times}4$$2{\times}3$ 교차설계법의 분산분석표는 반드시 제시되어야 하지만 아직 문헌상에 존재하지 않아 관련 연구에 기여할 것으로 생각된다. 또한 $2{\times}4$$2{\times}3$ 교차설계법에 기초한 피험자 계산을 $2{\times}2$ 교차설계법과 비교 제시하여 고변동성 제제의 생물학적 동등성 시험 연구에 적절한 시험 설계 선택에 정보를 제공한다.