• 제목/요약/키워드: Number of Sample

검색결과 2,895건 처리시간 0.034초

제한된 수의 Sensor를 이용한 Averaged MUSIC의 효율성에 관한 연구 (A Study on the Effectiveness of Averaged MUSIC Using Limited Number of Sensors)

  • 김영집
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1993년도 학술논문발표회 논문집 제12권 1호
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    • pp.206-209
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    • 1993
  • The main purpose of this paper is to verify the effectiveness of a high resolution direction finding method, so called the‘averaged MUSIC’. This method uses a new sample array covariance matrix that consists of diagonal components obtained by taking averages of the diagonal component values of the sample covariance matrix for the MUSIC. The paper shows that the proposed method performs higher resolved direction-of-arrival estimation and better resolution probability than the MUSIC in such cases as low signal-to-noise ratio, when the number of sensors used is finite, based on the statistical analysis.

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고차원 자료의 재현성과 표본 수 (Reproducibility and Sample Size in High-Dimensional Data)

  • 서원석;최지아;정형철;조형준
    • 응용통계연구
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    • 제23권6호
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    • pp.1067-1080
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    • 2010
  • 임상시험을 위한 표본 수 산정방법에 대해 지금까지 많은 방법이 개발되었고 현재 국내외 임상시험 기관에서 이 방법들을 토대로 표본 수를 산정하고 있다. 하지만 마이크로어레이칩 을 이용한 실험에 필요한 표본 수 산정에 대한 연구는 아직 미비하여 제대로 이용되지 않고 있다. 본 연구의 목적은 마이크로어레이 실험에 필요한 표본 수를 산정하는 데 있어 실제 마이크로어레이 자료의 재현성에 대한 정보를 이용하여 그 지침을 제공하는데 있다. 재현성 비교에서는 5가지 검정방법 즉, Fold change, Two-sample t-test, Wilcoxon rank-sum test, SAM, LPE 방법 별로 재현성을 측정하였다. 발현 값의 표준화 방법에 있어서는 MAS5, RMA 두 가지로 세분화 하였으며 반복수에 따라 상위 20개 또는 100개 유전자에 대한 일치성도 측정하였다. 또한, 표본수를 산정하는데 있어 기존에 제시한 방법에 현실적인 정보를 이용하여 좀 더 세분화하여 실험에 필요한 표본수를 산정해 보았다.

A Heuristic Approach for Approximating the ARL of the CUSUM Chart

  • Kim, Byung-Chun;Park, Chang-Soon;Park, Young-Hee;Lee, Jae-Heon
    • Journal of the Korean Statistical Society
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    • 제23권1호
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    • pp.89-102
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    • 1994
  • A new method for approximating the average run length (ARL) of cumulative sum (CUSUM) chart is proposed. This method uses the conditional expectation for the test statistic before the stopping time and its asymptotic conditional density function. The values obtained by this method are compared with some other methods in normal and exponential case.

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EFFICIENT REPLICATION VARIANCE ESTIMATION FOR TWO-PHASE SAMPLING

  • 김재광
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2002년도 추계 학술발표회 논문집
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    • pp.327-332
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    • 2002
  • Variance estimation for the regression estimator for a two-phase sample is investigated. A replication variance estimator with number of replicates equal to or slightly larger than the size of the second-phase sample is developed. In these cases, the proposed method is asymptotically equivalent to the full jackknife, but uses smaller number of replications.

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Multi-Level Skip-Lot Sampling Plan-Average Fraction Inspected Properties

  • In-Suk Lee;Gyo-Young Cho;Hae-Rim Kim
    • Communications for Statistical Applications and Methods
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    • 제3권2호
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    • pp.151-159
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    • 1996
  • The general formulas of average fraction inspected, average sample number and average outgoing quality in n-level skip-lot sampling plan are derived. Average sample number and average outgoing quality of a reference plan, three-level, five-level and ten-level skip-lot sampling plans are compared.

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식중독균의 검출을 위한 시료전처리 및 핵산기반의 분석기술 (Sample Preparation and Nucleic Acid-based Technologies for the Detection of Foodborne Pathogens)

  • 임민철;김영록
    • 산업식품공학
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    • 제21권3호
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    • pp.191-200
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    • 2017
  • There have been great efforts to develop a rapid and sensitive detection method to monitor the presence of pathogenic bacteria in food. While a number of methods have been reported for bacterial detection with a detection limit to a single digit, most of them are suitable only for the bacteria in pure culture or buffered solution. On the other hand, foods are composed of highly complicated matrices containing carbohydrate, fat, protein, fibers, and many other components whose composition varies from one food to the other. Furthermore, many components in food interfere with the downstream detection process, which significantly affect the sensitivity and selectivity of the detection. Therefore, isolating and concentrating the target pathogenic bacteria from food matrices are of importance to enhance the detection power of the system. The present review provides an introduction to the representative sample preparation strategies to isolate target pathogenic bacteria from food sample. We further describe the nucleic acid-based detection methods, such as PCR, real-time PCR, NASBA, RCA, LCR, and LAMP. Nucleic acid-based methods are by far the most sensitive and effective for the detection of a low number of target pathogens whose performance is greatly improved by combining with the sample preparation methods.

혈장 시료 풀링을 통한 신약 후보물질의 흡수율 고효율 검색기법의 평가 (Evaluation of a Sample-Pooling Technique in Estimating Bioavailability of a Compound for High-Throughput Lead Optimazation)

  • 이인경;구효정;정석재;이민화;심창구
    • Journal of Pharmaceutical Investigation
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    • 제30권3호
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    • pp.191-199
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    • 2000
  • Genomics is providing targets faster than we can validate them and combinatorial chemistry is providing new chemical entities faster than we can screen them. Historically, the drug discovery cascade has been established as a sequential process initiated with a potency screening against a selected biological target. In this sequential process, pharmacokinetics was often regarded as a low-throughput activity. Typically, limited pharmacokinetics studies would be conducted prior to acceptance of a compound for safety evaluation and, as a result, compounds often failed to reach a clinical testing due to unfavorable pharmacokinetic characteristics. A new paradigm in drug discovery has emerged in which the entire sample collection is rapidly screened using robotized high-throughput assays at the outset of the program. Higher-throughput pharmacokinetics (HTPK) is being achieved through introduction of new techniques, including automation for sample preparation and new experimental approaches. A number of in vitro and in vivo methods are being developed for the HTPK. In vitro studies, in which many cell lines are used to screen absorption and metabolism, are generally faster than in vivo screening, and, in this sense, in vitro screening is often considered as a real HTPK. Despite the elegance of the in vitro models, however, in vivo screenings are always essential for the final confirmation. Among these in vivo methods, cassette dosing technique, is believed the methods that is applicable in the screening of pharmacokinetics of many compounds at a time. The widespread use of liquid chromatography (LC) interfaced to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) allowed the feasibility of the cassette dosing technique. Another approach to increase the throughput of in vivo screening of pharmacokinetics is to reduce the number of sample analysis. Two common approaches are used for this purpose. First, samples from identical study designs but that contain different drug candidate can be pooled to produce single set of samples, thus, reducing sample to be analyzed. Second, for a single test compound, serial plasma samples can be pooled to produce a single composite sample for analysis. In this review, we validated the issue whether the second method can be applied to practical screening of in vivo pharmacokinetics using data from seven of our previous bioequivalence studies. For a given drug, equally spaced serial plasma samples were pooled to achieve a 'Pooled Concentration' for the drug. An area under the plasma drug concentration-time curve (AUC) was then calculated theoretically using the pooled concentration and the predicted AUC value was statistically compared with the traditionally calculated AUC value. The comparison revealed that the sample pooling method generated reasonably accurate AUC values when compared with those obtained by the traditional approach. It is especially noteworthy that the accuracy was obtained by the analysis of only one sample instead of analyses of a number of samples that necessitates a significant man-power and time. Thus, we propose the sample pooling method as an alternative to in vivo pharmacokinetic approach in the selection potential lead(s) from combinatorial libraries.

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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

첨가물을 달리한 구운 유과 반대기의 품질 특성 (Quality Characteristics of Baked Yugwabandagi with Different Additives)

  • 차경옥;한은주
    • 동아시아식생활학회지
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    • 제25권3호
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    • pp.492-501
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    • 2015
  • To improve the shortcomings of baked Yugwa 0.5, 1.0, 1.5 and 2.0% natural ind igestible materials,- (gellan gum, glucomannan and carrageenan) were each treated with glutinous rice-baked Yugwa was processed, and quality imprpvements were deducted. Baked Yugwa with natural additives,- (gellan gum, glucomannan and carrageenan) was compared,- to additional test results with sample 1.5%(w/w) additives,- The one showing the highest preference from the sensory test was the acid number reference group at $2.19{\pm}0.42$, while the sample groups,- with different additives, were lower than the reference group by $1.48{\pm}0.39$ to $1.67{\pm}0.68$. The peroxide number reference group showed the highest preference of $49.34{\pm}0.42$, whereas the sample groups, with different additives, showed lower preferences than the reference group by $36.72{\pm}$0.42 compared to the sample group of glucomannan 1.5% (w/w), $32.45{\pm}0.59$ compared to the sample group of gellan gum 1.5%(w/w), and $28.65{\pm}0.56$ compared to the sample group of carrageenan 1.5% (w/w). According to the preference test targeting employees of Korean cake, manufacturers, there was no significant difference in color and flavor among all groups, whereas the sample group of carrageenan 1.5% (w/w) showed the highest scores in items of taste, texture and overall-preference, and also sample groups of glucomannan 1.5% (w/w) and gellan gum 1.5% (w/w) scored higher than the reference group. Baked Yugwa with 1.5% (w/w) additives of carrageenan, glucomannan and gellan gum have higher marketability by decreasing deterioration caused by oxidation of existing deep fried Yugwa and by improving the solid texture of baked Yugwa.

A Time Truncated Two-Stage Group Sampling Plan for Weibull Distribution

  • Aslam, Muhammad;Jun, Chi-Hyuck;Rasool, Mujahid;Ahmad, Munir
    • Communications for Statistical Applications and Methods
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    • 제17권1호
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    • pp.89-98
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    • 2010
  • In this paper, a two-stage group sampling plan based on the time truncated life test is proposed for the Weibull distribution. The design parameters such as the number of groups and the acceptance number in each stage are determined by satisfying the producer's and consumer's risks simultaneously when the group size and the test duration are specified. The acceptable reliability level is expressed by the ratio of the true mean life to the specified life. It was demonstrated from the comparison with single-stage group sampling plans that the proposed plan can reduce the average sample number or improve the operating characteristics.