• 응용통계연구
• /
• 제23권5호
• /
• pp.883-890
• /
• 2010

Since Fisher's exact test is conducted conditional on the observed value of the margin, there are two kinds of the exact power, the conditional and the unconditional exact power. The conditional exact power is computed at a given value of the margin whereas the unconditional exact power is calculated by incorporating the uncertainty of the margin. Although the sample size is determined based on the unconditional exact power, the actual power which Fisher's exact test has is the conditional power after the experiment is finished. This paper investigates differences between the conditional and unconditional exact power Fisher's exact test. We conclude that such discrepancy is a disadvantage of Fisher's exact test.

• 약학회지
• /
• 제24권2호
• /
• pp.117-122
• /
• 1980

A new application of high pressure liquid chromatography for the determination of fenitrothion and cis- and trans-neopynamin in insecticidal preparations was investigated. Optimum conditions for a good separation and determination were determined; solvent system: dichloromethane + n-hexane = 17 + 83; Bow rate: 0.5ml/min; column: u-porasil ($4mm{\times}3Ocm$); absorbance wavelength: 254nm; 0.05 AUFS and sample size: 30 ul. Recovery of fenicrothion, cis- and trans-neopynamin from mixed artificial preparations was 99.6%, 99.7% and 99.8% respectively. Also reproducibility tests showed that the coefficient of variation was 0.89% for fenitrothion, 0.74% cis-neopynamin and 1.1% for trans-neopynamin. There was no interference with insecticidal preparation containing DDVP, allethrin, S-421 and kerosene. HPLC method was rapid, accurate and it gave better reproducibility and higher sensitivity than any other analytical method. It was considered that HPLC could be greatly applied to the analysis of fenitrothion and neopynamin in insecticidal preparations.

• Bulletin of the Korean Chemical Society
• /
• 제27권3호
• /
• pp.413-418
• /
• 2006

Sodium hyaluronate (NaHA), water soluble polymer having ultra-high molecular weight, is characterized by using on-line frit inlet asymmetrical flow field-flow fractionation (FI-AFlFFF) and multiangle light scattering (MALS). This study demonstrates the capability of power programming FI-AFlFFF for the separation of NaHA and the applicability of FI-AFlFFF with MALS for the characterization of molecular weight distribution and their structural information. Since sample injection and relaxation in FI-AFlFFF are achieved by using hydrodynamic relaxation, separation of high molecular weight polymers can be achieved smoothly without halting the separation flow. Experiments are carried out with the two different NaHA products (a raw NaHA sample and a thermally degraded NaHA product) and molecular weight distribution and conformations in solution are determined. Influence of sample filtration on the change of molecular weight distribution is also discussed.

• Journal of the Korean Wood Science and Technology
• /
• 제43권1호
• /
• pp.25-35
• /
• 2015

본 연구에서는 국산 침엽수재의 육안 등급구분과 허용응력설정에 관한 국내의 학술논문을 정리하였다. 국립산림과학원 고시(KFRI 1995-27, KFRI 2000-39, KFRI 2007-3, KFRI 2009-1)를 활용하여 국산 낙엽송재의 육안 등급 구분한 연구를 비교한 결과 등급구분 비율이 연구자마다 상이했다. 보다 신뢰할 수 있는 등급구분 분류를 위해서 공증된 목재이용 기관에서 숙련된 연구자에 의한 등급구분을 시행하여야 할 것으로 사료된다. 허용응력설정에 관한 연구를 고찰한 결과, 연구자 마다 허용응력산출 방법이 ASTM D 245, KS F 2152, JAS 1990으로 모두 상이했다. 이는 침엽수 구조용재(KS F 3020)에서 기준허용응력을 제시하고 있지만 허용응력을 산출하는 명확한 방법이 제시되어 있지 않기 때문인 것으로 나타났다. 따라서 공식적인 허용응력 결정방법이 제정되어야 할 것으로 사료된다.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2002년도 학술발표회 발표논문집
• /
• pp.337-340
• /
• 2002

The purpose of this study is to evaluate the loss volume of base soil materials with the grain size range of filter materials for agricultural reservoir. The test results show that the loss volume is increased with the hydraulic pressure, and the amount of loss volume for same sample is different with the filter range.

• 응용통계연구
• /
• 제12권1호
• /
• pp.175-190
• /
• 1999

생존시간을 비교하기 위한 임상시험에서는 생존기간과 관련된 위험인자들을 고려한 층화된 연구설계가 종종 요구된다. 이 경우 필요한 표본수가 결정은 층이 없는 경우에 비하여 다양한 연구상황과 복잡한 표본수의 산출 절차를 수반한다. 본 논문에서는 층이 있는 경우 생존시간을 비교할 때 필요한 표본수를 결정하는 방법들을 실례와 함께 설명하고, 연구자가 주어진 상황하에서 적절한 방법을 선택하는데 도움이 될 수 있도록, 다양한 상황을 설정하여 이에 대한 표본수를 비교하였다.

• 대한화학회지
• /
• 제43권4호
• /
• pp.430-437
• /
• 1999

흐름주입 분석법(FIA)에 의한 간접 요오드화 UV 검출법으로 총 잔류염소를 신속하게 정량하는 방법을 연구하였다. FIA장치를 최적화하기 위해 용리액의 pH, 요오드화 이온의 농도, 혼합 및 반응코일의 길이,시료주입량 및 유속, 온도 및 검출파장에 대한 변화를 관찰하였다. pH 8.3에서 하이포아염소산 이온은 요오드화 이온을 선택적으로 산화시키고 자신은 염화이온으로 환원되었다. 방해이온을 제거하기 위한 가리움제로서 에틸렌다이아민이 가장 좋은 효율을 나타내었다. 하이포아염소산 이온의 검정곡선은 0.03-0.3 mg/L의 농도 범위에서 0.999이상의 직선성을 나타내었고, 검출한계는 0.007 mg/L이었다. 이러한 분석조건하에서 몇몇 전주근교 상수중 총 잔류염소의 농도를 정량하였다.

• Near Infrared Analysis
• /
• 제1권2호
• /
• pp.35-39
• /
• 2000

The purpose of this research was to find out suitable soil sample preparation and sample holding tools for NIR reflection radiation for estimating soil components. NIR reflectance was scanned at 2nm intervals from 1,100 to 2,500nm with an InfraAlyzer 500(Bran+Luebbe Co.). Coarse(2.0mm) and fine(0.5mm) soil sample and various sample holding tools were used to obtain mean diffuse reflection of the soil for the calibration and validation of the calibration set in estimating moisture, organic matter and total nitrogen of the soils. Multiple linear regression was used to obtain the best correlation of NIR spectroscopy method. Correlation of NIR spectroscopy method. Correlation of NIR spectra for finely and coarsely sized soil did not show much difference. The standard errors of prediction(SE) using different types of sample holding tools for organic matter, total nitrogen and soil moisture were better than 0.765, 0.041 and 0.63% respectively. From the results it can be concluded that NIR spectroscopy with flow type cell could be used as a fast routine testing method in quantitative determination of organic matter, total nitrogen and soil moisture.

• Bulletin of the Korean Chemical Society
• /
• 제27권2호
• /
• pp.231-236
• /
• 2006

A novel sample pretreatment technique, headspace hanging drop liquid phase microextraction (HS-LPME) was studied and applied to the determination of flavors from solid clove buds by gas chromatography-mass spectrometry (GC-MS). Several parameters affecting on HS-LPME such as organic solvent drop volume, extraction time, extraction temperature and phase ratio were investigated. 1-Octanol was selected as the extracting solvent, drop size was fixed to 0.6 $\mu$L. 60 min extraction time at 25 ${^{\circ}C}$ was chosen. HS-LPME has the good efficiency demonstrated by the higher partition equilibrium constant ($K_{lh}$) values and concentration factor (CF) values. The limits of detection (LOD) were 1.5-3.2 ng. The amounts of eugenol, $\beta$-caryophyllene and eugenol acetate from the clove bud sample were 1.90 mg/g, 1.47 mg/g and 7.0 mg/g, respectively. This hanging drop based method is a simple, fast and easy sample enrichment technique using minimal solvent. HSLPME is an alternative sample preparation method for the analysis of volatile aroma compounds by GC-MS.

• 품질경영학회지
• /
• 제11권1호
• /
• pp.44-50
• /
• 1983

The main factors of determining the Control Line of the Control Chart can be classified as follows: 1) sample size (n), 2) the factor that determines the spread of Control Limits (B), (3) sampling frequency (h). The determination of these factors can be explained according to the extent that occurrences of assignable cause should be detected. The purpose of this paper are two: one is for composing a model of which use should be designated for economic decision on the size of these factors leading to the Control Line of the Control Chart, the other is about what influence increasing or decreasing condition, according to changeability of the size of these factors, of expect cost can have on the economy when the Control Chart is used.