• 제목/요약/키워드: sample number

검색결과 2,859건 처리시간 0.039초

제조용 충전물을 사용한 액체 크로마토그래피의 흡착특성 (Adsorption Characteristics of Liquid Chromatography with Preparative Packings)

  • 최용석;이종호;노경호
    • 공업화학
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    • 제9권3호
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    • pp.430-434
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    • 1998
  • 제조용 액체 크로마토그래피는 주로 생화학물질에서 유용성분을 분리하는 데 사용된다. 본 연구에서는 제조용 충전물($15{\mu}m$)이 채워진 역상 액체 크로마토그래피를 이용하여 sample size에 따른 흡착특성을 고찰하였다. 시료는 향미제인 5'-GMP이고 이동상은 $KH_2PO_4$ 수용액 20mM과 메탄올을 97:3 (vol.%)으로 혼합하여 사용하였다. 실험결과에 의하면 sample size가 증가해도 체류인자는 거의 일정하였지만 $1{\mu}g$ 이상에서는 peak의 모양이 비대칭성이 되었다. 또한 sample size가 증가함에 따라서 이론단수는 감소하였고 농도가 작은 경우 peak width가 크기 때문에 이론단수는 더 작았다. 본 실험조건에서 5'-GMP는 Freundlich 비선형흡착식에 비교적 잘 일치하였다.

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굽힘반복에 따른 슬랙스 무릎부위의 역학적특성 변화 (Mechanical Properties Change of the Slacks Knee Part by the Bending Time)

  • 이정숙;권헌선;성수광
    • 한국의류산업학회지
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    • 제6권4호
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    • pp.497-502
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    • 2004
  • The mechanical properties of jean slacks to the type of cutting lines in knee region and the bending time, after doing bending 0 times, 500 times, and 1500 times, the effects of whether or not cutting line, the fabric direction of the cutting area, and the number of cutting lines were investigated for tensile, shearing, compression, and mixing value of mechanical properties. The results are as follows: EM to bending times were larger in order of weft

치의학 연구에서의 표본크기 산출 (Sample size determination in dental research)

  • 임회정
    • 대한치과의사협회지
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    • 제52권9호
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    • pp.558-569
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    • 2014
  • Sample size determination is critical, but not easy to do. Sample size defined as the number of observations in a sample to be studied should be big enough to have a high likelihood of detecting a true difference between groups. Practical procedure for determining sample size, using $G^*$power and previous dental articles, was shown in this study. Examples involving independent t-test, paired t-test, one-way analysis of variance(ANOVA), and one-way repeated-measures(RM) ANOVA were used. The purpose of this study is to enable researchers with non-statistical backgrounds to use in practice freely available statistical software G*power to determine sample size and power.

의학연구에서 표본크기 계산 (Sample Size Calculation in Medical Research)

  • 박선일;오태호
    • 한국임상수의학회지
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    • 제29권1호
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    • pp.68-77
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    • 2012
  • Whenever planning a study design or preparing a research proposal it is highly recommended that investigators decide the optimum sample size that is required to yield an outcome of interest with a predetermined level of precision. This is because that, all else being equal, if a study with less than the optimum sample size would not detect the significance of differences in reality, and similarly, if a study with more than the optimum sample size will be costly. For these reasons, the majority of peer reviewed biomedical journals assess the adequacy of sample size requirements. The calculated sample size is used as a target number of samples to be collected to provide an estimate of the parameter with the desired and predetermined level of accuracy, and the sample size is a major determinant of the probability of detecting diseased animals from the population. There is no single method of calculating sample size for any given study design. In this context, the purpose of this article is to provide a collection of formulas and examples for some typical situations likely to be encountered in veterinary clinical practice and to highlight the importance of performing prospective sample size calculations when planning a research. Specifically, this paper is concerned with the basic principle of sample size calculation, and considerations for methodological applications were illustrated for a given data set. Also included in this paper is factors influencing sample size calculations using a statistically valid techniques. Appropriate methods to consider these factors are presented.

A Study on Microbial Contamination of Foods Exposed to Multiple Environments

  • KIM, Dan-Bee;CHA, Seong-Soo
    • 식품보건융합연구
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    • 제5권3호
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    • pp.35-40
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    • 2019
  • In this study, general bacterial counts and coliform counts, which are hygienic indicator microorganisms, were tested for candy, chocolate, and jelly which are easily available and enjoyed around. After dropping each sample on the desk, indoors, and outdoors, it is immediately collected, or washed and collected to confirm the myth of the 3-second rule. Immediately after removing the wrapping paper, each sample was dropped on the desk, indoors, and outdoors, and after 3 seconds from the moment of contact with the surface, and then collected in a sample bag using sterilized sanitary gloves. After the same operation, each sample was rinsed for 5 seconds using sterilized sanitary gloves and sterilized distilled water, and then collected in a sample bag. The number of bacteria detected in non-washing candies was 41 CFU/g at outdoor and the number of bacteria detected in non-washing chocolate was 76 CFU/g at outdoor. The number of bacteria detected in non-washing jellies was 79 CFU/g at outdoor. Coliform group was not detected in all samples. This showed good results at the level of m = 10,000 or less, which is an allowable value suggested in the Food Code. Also, effect of washing on contaminated food was confirmed. This result is remarkably low compared with the microorganism specimens shown in Food Code, and it is confirmed that contamination occurs but not high value. Therefore, the myth of the 3-second rule is true compared to the figures based on Food Code. However, it showed the characteristics of bacteria that could survive and cross-contaminate on dry food surfaces and emphasized the importance of hygiene through food contact to unsanitary surfaces to minimize the risk of food poisoning.

해표이진탕(解表二陳湯)이 흰쥐의 $SO_2$에 의한 호흡기손상(呼吸器損傷)에 미치는 영향(影響) (The Effects of Haepyoyijintang on the Pulmonary Injury caused by $SO_2$ in Rats)

  • 이경태;박동일
    • 대한한의학회지
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    • 제17권2호
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    • pp.178-190
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    • 1996
  • This experiment was performed in order to study the effects of Haepyoyijintang on the pulmonary injury caused by $SO_2$. Healthy adult male rats weighting about 250g were divided into 4 groups- the Normal group, the Control group, the group of Haepyoyijintang administration for 5 days after $SO_2$ gas exposure (Sample I ), and the group of Haepyoyijintang administration for 10 days before and for 5 days after $SO_2$ gas exposure (SampleⅡ). The results were obtained as follows; 1. In the total number of leucocyte, Sample I and Sample II decreased significantly compared with Control group. 2. In the erythrocyte sedimentation rate, Sample I and Sample Ⅱ decreased significantly compared with Control group. 3. In the lung weight, Sample I and Sample II decreased significantly compared with Control group. 4. In the lung TBA level, only Sample II decreased significantly compared with Control group. 5. In the tracheal glycoprotein level, Sample I and Sample II decreased significantly compared with Control group. According to the above results, Haepyoyijintang has significant effects on the pulmonary injury caused by $SO_2$ in rats.

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소자도담강기탕(蘇子導痰降氣湯)이 $SO_2$에 의한 흰쥐의 호흡기손상(呼吸器損傷)에 미치는 영향(影響) (The effect of Sojadodamgangkitang on the pulmonary injury caused by $SO_2$ in rats)

  • 박동일;김봉재
    • 대한한의학회지
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    • 제18권1호
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    • pp.344-356
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    • 1997
  • This experiment was performed in order to study the clinical effect of Sojadodamgangkitang on the pulmonary injury caused by $SO_2$. Healthy adult male rats weighing about 250g were divided into 4 groups-the Normal group, the Control group, the group of Sojadodamgangkitang administration for 5 days after $SO_2$ gas exposure(Sample I), and the group of Sojadodamgangkitang administration for 10 days before and for 5days after $SO_2$ gas exposure(Sample II). The results were obtained as. follows; 1. In comparison with Control group, Sample I and Sample II were revealed significant effect on the total number of leucocyte. 2. In comparison with Control group, Sample I and Sample II were revealed significant effect on. the erythrocyte sedimentation rate. 3. In the effect on the lung weight, Sample I and Sample II were revealed significantly. 4. In the effect on the lung TBA level, only Sample II was revealed significantly. 5. In the effect on the tracheal glycoprotein level, Sample I and Sample II were revealed significantly. According to above results, Sojadodamgangkitang had significant effect on the pulmonary injury caused by $SO_2$ in rats.

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무작위변량을 이용한 강우빈도분석시 내외삽오차에 관한 연구 (A Study on Error of Frequence Rainfall Estimates Using Random Variate)

  • 최한규;엄기옥
    • 산업기술연구
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    • 제20권A호
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    • pp.159-167
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    • 2000
  • In the study rainfall frequency analysis attemped the many specific property data record duration it is differance from occur to error-term and probability ditribution of concern manifest. error-term analysis of method are fact sample data using method in other hand it is not appear to be fault that sample data of number to be small random variates. Therefore, day-rainfall data: to randomicity consider of this study sample data to the Monte Carlo method by randomize after data recode duration of form was choice method which compared an assumed maternal distribution from splitting frequency analysis consequence. In the conclusion, frequency analysis of chuncheon region rainfall appeared samll RMSE to the Gamma II distribution. In the rainfall frequency analysis estimate RMSE using random variates great transform, RMSE is appear that return period increasing little by little RMSE incresed and data number incresing to RMSE decreseing.

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프린터 헤드 노즐분사 제어용 집적회로설계 (Design of an Integrated Circuit for Controlling the Printer Head Ink Nozzle)

  • 정승민;김정태;이문기
    • 한국정보통신학회논문지
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    • 제7권4호
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    • pp.798-804
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    • 2003
  • 본 논문에서는 프린터 head의 노즐분사제어를 위한 개선된 회로를 설계하였다. 기존 방식에 비하여 비하여 Pad 수를 줄임으로서 노즐 수를 확장시킬 수 있다. 제안된 회로는 사전검증을 위하여 먼저 20개의 노즐을 제어하는 sample 회로로 설계하고 FPGA를 이용하여 동작을 확인하였다. 320개의 노즐제어를 위한 전체회로는 sample 회로를 확장하여 ASIC Full Custom 설계방식을 통하여 설계한 뒤 로직 및 회로 simulation 검증을 하였다. 전체회로는 3$\mu\textrm{m}$ CMOS design rule을 적용하여 layout 및 chip으로 제작되었다.

On-line System Identification using State Observer

  • Park, Duck-Gee;Hong, Suk-Kyo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.2538-2541
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    • 2005
  • This paper deals one of the methods of system identification, especially on-line system identification in time-domain. The algorithm in this study needs all states of the system as well input to it for system identification. In this reason, Kalman filter is used for state estimation. But in order to implement a state estimator, the fact that a system model must be known is logical contradiction. To overcome this, state estimation and system parameter estimation are performed simultaneously in one sample. And the result of the system parameter estimation is used as basis to state estimation in next sample. On-line system identification comes, in every sample by performing both processes of state estimation and parameter estimation that are related mutually and recursively. This paper demonstrates the validity of proposed algorithm through an example of an unstable inverted pendulum system. This algorithm can be useful for on-line system identification of a system that has fewer number of measurable output than system order or number of states.

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