• Title/Summary/Keyword: Sample sizes

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Studies on the Grain Size and Acid-consuming Capacity of Aiuminium-Hydroxide Gel (수산화(水酸化)알미늄. 겔의 Grain Size 와 제산도(制酸度)에 관(關)한 연구(硏究))

  • Roe, Tae-Sun
    • Journal of Pharmaceutical Investigation
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    • v.2 no.1
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    • pp.5-13
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    • 1972
  • There are some repels in which they studied on the change of acid-consuming capacity of aluminium hydroxide resulted from the passing of time. However, the relationship between grain sizes(particle sizes) and the acid-consuming capacity of dried aluminium hydroxide gel was not been studied. And studies on the grain sizes of aluminium hydroxide gel qualified by pharmacopoeia of Korea has not been reported. For the purpose of studying these two problems, the author prepared two-kinds of aluminium hydroxide gel as follows : $Na_2OAl_2O_3+CO_2------{\longrightarrow}Al(OH)_3{\cdots}{\cdots}{\cdots}$sample 1 $Al_2(SO_4)_318H_2O+6NaHCO_3{\longrightarrow}Al(OH)_3{\cdots}{\cdots}{\cdots}$sample 2 Both of sample 1 and 2 are found to be amorphous by X-ray diffraction methods, and their acid-consuming capacities were determined by the method of pharmacopeia of Korea. The grain size was measured by X-ray diffraction method, the particle sizes observed by electron microscopy, and the change of acid-consuming capacity with passing of time was determined by the method of pharmacopoeia of Korea. The results of these studies are summerized as follows: 1. The grain size was linearly enlarged as the time goes by. The aluminium hydroxide gel gradually crystallized in a certain period of time. 2. The acid-consuming capacity was in exponential function, decreased as the grain size of them enlarged. 3. One particle consists of tens of grains.4. Grinding the Sample obtained in any period of testing time in mortar did not change both their grain size and their acid-consuming capacity. 5. The grain size of dried aluminium hydroxide gel ought to be micronized less than $100{\AA}$ for maintaining the ability such as consumes 250m1 of 0. 1N-HC1 solution per Is of $Al(OH)_3$ described in pharmacopoeia of Korea.

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Comparison of Reliability Estimation Methods for Ammunition Systems with Quantal-response Data (가부반응 데이터 특성을 가지는 탄약 체계의 신뢰도 추정방법 비교)

  • Ryu, Jang-Hee;Back, Seung-Jun;Son, Young-Kap
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.6
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    • pp.982-989
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    • 2010
  • This paper shows accuracy comparison results of reliability estimation methods for one-shot systems such as ammunitions. Quantal-response data, following a binomial distribution at each sampling time, characterizes lifetimes of one-shot systems. Various quantal-response data of different sample sizes are simulated using lifetime data randomly sampled from assumed weibull distributions with different shape parameters but the identical scale parameter in this paper. Then, reliability estimation methods in open literature are applied to the simulated quantal-response data to estimate true reliability over time. Rankings in estimation accuracy for different sample sizes are determined using t-test of SSE. Furthermore, MSE at each time, including both bias and variance of estimated reliability metrics for each method are analyzed to investigate how much both bias and variance contribute the SSE. From the MSE analysis, MSE provides reliability estimation trend for each method. Parametric estimation method provides more accurate reliability estimation results than the other methods for most of sample sizes.

On Sample Size Determination of Bioequivalence Trials

  • Park, Sang-Gue
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.2
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    • pp.365-373
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    • 2007
  • Sample size determination plays an important role in designing a bioequivalence trial. Formulae of sample sizes based on Schuirmann's two one-sided tests procedures are given for bioequivalence studies with the $2{\times}2$ crossover design and two-sample parallel design. A practical discussion for the relationship among these formulae is given.

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Design of Variance CUSUM

  • Lee, Eun-Kyung;Hong, Sung-Hoon;Lee, Yoon-Dong
    • The Korean Journal of Applied Statistics
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    • v.22 no.6
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    • pp.1131-1142
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    • 2009
  • We suggest a fast and accurate algorithm to compute ARLs of CUSUM chart for controling process variance. The algorithm solves the characteristic integral equations of CUSUM chart (for controling variance). The algorithm is directly applicable for the cases of odd sample sizes. When the sample size is even, by using well-known approximation algorithm combinedly with the new algorithm for neighboring odd sample sizes, we can also evaluate the ARLs of CUSUM charts efficiently and accurately. Based on the new algorithm we consider the optimal design of upward and downward CUSUM charts for controling process variance.

A Study on the Development of Patterns for the Improvement of Fit of Brassiere - Comparative Analysis of Sample Brassiere with Products of Underwear Brands for 1924 Generation - (브래지어의 맞음새 향상을 위한 패턴개발 연구 -l924세대용 언더웨어 브랜드 시판제품과의 비교분석-)

  • Oh, Song-Yun;Choi, Hei-Sun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.5 s.164
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    • pp.729-741
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    • 2007
  • In order to examine the characteristics of brassiere products for the 1924 generation brands on the market and grasp problems, we selected three 'comparative brassieres', each one from among the 1924 underwear brands with the highest recognition and sales profit, and then designed a 'sample brassiere' pattern(75A) with a similar shape to the comparative brassieres. We set up the "New Cup Grading Rule" with a view of reflecting the wearing effect that was varied according to cup sizes, graded the sizes of 75AA and 75B with this method, and made the sample brassieres in three sizes. We conducted the wearing evaluation and body measurements of 9 subjects after analyzing the patterns and characteristics of the sample brassieres and three comparative brassieres. As a result of the wearing evaluation, the sample and comparative brassiere 2, the dimensions and shapes were appropriate for the 1924 generation consumers and expressed an overall natural silhouette, showed satisfactory results in the entire evaluation questions. On the other hand, the comparative brassiere 1 and 3 that tended toward making a big change in the physical characteristics got unsatisfactory evaluations in the dimensions of the cups, clothing pressure, and bust silhouette. As a result of observing the variation in body dimensions by body measurements when nude and when wearing each brassiere and then summing it up with the score of the wearing evaluation, it was proven that too much change in body shape can create a negative image by upsetting the balance of the whole silhouette. Therefore, it is desirable to develop brassiere products with proper dimensions and clothing pressure that can make a physical change that harmonizes the overall bust silhouette and the position and shape of the breasts.

Sample Size and Statistical Power Calculation in Genetic Association Studies

  • Hong, Eun-Pyo;Park, Ji-Wan
    • Genomics & Informatics
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    • v.10 no.2
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    • pp.117-122
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    • 2012
  • A sample size with sufficient statistical power is critical to the success of genetic association studies to detect causal genes of human complex diseases. Genome-wide association studies require much larger sample sizes to achieve an adequate statistical power. We estimated the statistical power with increasing numbers of markers analyzed and compared the sample sizes that were required in case-control studies and case-parent studies. We computed the effective sample size and statistical power using Genetic Power Calculator. An analysis using a larger number of markers requires a larger sample size. Testing a single-nucleotide polymorphism (SNP) marker requires 248 cases, while testing 500,000 SNPs and 1 million markers requires 1,206 cases and 1,255 cases, respectively, under the assumption of an odds ratio of 2, 5% disease prevalence, 5% minor allele frequency, complete linkage disequilibrium (LD), 1:1 case/control ratio, and a 5% error rate in an allelic test. Under a dominant model, a smaller sample size is required to achieve 80% power than other genetic models. We found that a much lower sample size was required with a strong effect size, common SNP, and increased LD. In addition, studying a common disease in a case-control study of a 1:4 case-control ratio is one way to achieve higher statistical power. We also found that case-parent studies require more samples than case-control studies. Although we have not covered all plausible cases in study design, the estimates of sample size and statistical power computed under various assumptions in this study may be useful to determine the sample size in designing a population-based genetic association study.

A Study on Elderly Women's Breast Types and Their Brassiere Sizes (노년여성(老年女性)의 유방형태(乳房形態) 분석(分析)과 브래지어 착용(着用) 치수분포(値數分布) 연구(硏究))

  • Park, Sung-Yi;Sohn, Hee-Soon
    • Journal of Fashion Business
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    • v.5 no.4
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    • pp.144-157
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    • 2001
  • The purpose of this study was to research on breast shape and size to suggest a brassiere sizing chart for elderly women. For this purpose 90 elderly women aged between 55 and 69 were sampled at random to review their breast types by age group, and thereby, suggest the basic measurements and production ratio of each brassiere size in reference to KS K 0070: 1999. The collected measurement data were processed statistically using the SPSS PC/WIN program for technical statistical analysis. The results of this study can be summarized as follows; 1. Analysis of Breast Measurements To find out difference among age groups, the 90 subjects were grouped into three(Group 1 ; aged 55 to 59, Group 2 ; aged 60 to 64, Group 3 ; aged 65 to 69). The results of the comparative analysis of anthropometric data from three groups show that getting older;- Various length measurements related to the drooping degree of breast were increased. It was found that the older group in their 65-69's had more drooping breasts than their 55-59's or 60-64's counterparts. Such findings suggests that older women's drooping can be corrected by a brassiere which serves to support the breasts. 2. Suggestions on a Brassiere Sizing For the basic measurements of brassiere parts for the elderly women, the correlation between underchest circumferences and cup sizes were analyzed. 3% or higher occurrences among the whole sample elderly women were included in the brassiere sizes. thus, the under-chest measurements were set at four intervals from 75 to 95, while the cup measurements were determined also at four intervals from "AAA" to "B" sizes. The resultant 6 sizes excluding the least frequent occurrences covered 73.2% of the sample elderly women actual breast sizes. As a consequence of reviewing the production ratio of each brassiere size for the women, it was found that the brassiere size of highest production ratio was "85A" (17.4%), followed by 80A (14.5%), 85AA 90A (10.1%) and 75A (8.7%) in their order.

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A New trace-driven Simulation Algorithm for Sector Cache Memories with Various Block Sizes (다양한 블럭 크기를 갖는 섹터 캐시 메모리의 Trace-driven 시뮬레이션 알고리즘)

  • Dong Gue Park
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.6
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    • pp.849-861
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    • 1995
  • In this paper, a new trace driven simulation algorithm is proposed to evaluate the bus traffic and the miss ration of the various sector cache memories, which have various sub-block sizes and block sizes and associativities and number of sets, with a single pass through an address trace. Trace-driven simulaton is usually used as a method for performance evaluation of sector cache memories, but it spends a lot of simulation time for simulating the diverse cache configurations with a long address trace. The proposed algorithm shortens the simulation time by evaluating the performance of the various sector cache configurations. which have various sub-block sizes and block sizes and associativities and number of sets , with a single pass through an address trace. Our simulation results show that the run times of the proposed simulation algorithm can be considerably reduced than those of existing simulation algorithms, when the proposed algorithm is miplemented in C language and the address traces obtained from the various sample programs are used as a input of trace-driven simulation.

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A Study on the Sizes of Ready-made Clothes to Export to China - Suggestion of Chinese Correspondent Sizes Based on Korean Women's Clothes - (중국수출(中國輸出) 여성기성복(女性旣成服)의 치수(値數)에 관(關)한 연구(硏究) - 한국(韓國) 여성복(女性服)을 중심(中心)으로 한 중국(中國) 여성복(女性服)의 대응치수(對應値數) 제시(提示)-)

  • Shim, Boo-Ja
    • Journal of Fashion Business
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    • v.8 no.4
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    • pp.1-21
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    • 2004
  • This research suggest the correspondent sizes of female ready-made clothes to export to China on the basis of those of Korean women's ready-made clothes. The following is the concrete coverage of this research: $\cdot$ Analyze the physical measurements and body types of the women in their 30s and 40s in the area of Ningbo, Jeolgang Province in China. $\cdot$ Compare the body measurements of Chinese and Korean women. $\cdot$ Hold compensation measurement by an basic torso pattern test to raise precision of the direct and indirect body measurements. $\cdot$ Establish the corresponding and representative sizes of women's ready-made clothes to go to China. $\cdot$ Make basic torso pattern and sample clothes reflecting representative sizes. $\cdot$ Hold adjustment and compensation through the wearing evaluation by Chinese consumers on the spot. $\cdot$ Finally suggest the correspondent sizes of women's ready-made clothes to export to China.

Determination of Sample Sizes for Plant Characteristics of Food Crops

  • Chang, Suk-Hwan
    • Journal of the Korean Data and Information Science Society
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    • v.9 no.1
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    • pp.57-62
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    • 1998
  • The minimum number of samples for the measurement of plant characteristics of major crops were calculated from the data obtained from the field experiments on rice, barley, wheat, soybean and sweet potato conducted by Kyungpuk Rural Development Administration.

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