• Title/Summary/Keyword: Sample Size

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Decomposing the Effect of Population Changes on Crime Changes

  • Lee, Soochang;Jang, Cheolyeung
    • International Journal of Advanced Culture Technology
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    • 제9권1호
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    • pp.1-6
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    • 2021
  • This study aims to test the relationship between the change in population size and population composition and crime changes. The analytical model includes variables representing changes in population size and population composition, three dependent variables for crime changes, and three control variables. Changes in popuvpdllation size and population composition are measured by indicators such as population size, gender, age groups, and immigrants and foreign workers, and crime changes by felonious, burglary, and violent crime volumes. The sample includes 154 cities and counties in South Korea, and the sample period is from 2010 to 2017. As a result of the analysis, I examine that the decrease in the number of young and men are likely to lead to a decline in felonious and violent crimes, but a high rate of the elderly and the increasing racial heterogeneity are likely to accelerate the fear and worries about crimes.

대형자연시료를 이용한 광양점토의 압밀특성에 관한 실험적 연구 (Experimental Study on the Consolidation Characteristics of Kwang-Yang Clay by Large Block sampling)

  • 김종국;유성진;채영수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 지반공학 공동 학술발표회
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    • pp.429-436
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    • 2005
  • In this study, we have compared with the differences between the extent of sampling disturbance and consolidation characteristics by experiments, which are consolidation test and have been performed with Kwang-Yang clay samples. The effects on sampling disturbance to consolidation characteristics of soft clay have been inverstigated by using soil samples obtained from large block sampling and piston sampling methods. Through a few experiments, we've got important results which are that the consoilidation parameter of large block sample(Pc, Cc, Cv) is much larger than the value of parameter of piston sample. We've also found the fact that the large block sample using the large size sampler is much better than piston sample in the quality of goods to lessen the effects on disturbance of sampling. When compared to the parameter of consolidation along with the methods of experiment, we found that the result performed by large size consolidation test is the greatest one and CRS is much better than standard consolidation test to seek for proper parameter.

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Homogeneity in Case/Control Numbers and North Indian Caste Criteria in Cervical Cancer/Female Urology Genetic-Studies at a Premier Medical Research Institute in Lucknow, India

  • Pandey, Saumya;Chandravati, Chandravati
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권10호
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    • pp.6185-6187
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    • 2013
  • Cervical cancer has emerged as a major public health problem in Lucknow and New York in the $21^{st}$ century. Cancer genetic studies are essential to identify/stratify disease-susceptible individuals in a population-based cohort. Sample size homogeneity and North Indian caste in female urology genetic-studies are significant issues in meaningful interpretation of data. A review of scientific literature using Pubmed database was conducted, including an assessment of cervical cancer genetic studies conducted as part of the author's doctoral dissertation at a premier Lucknow-based medical research Institute. Sample size numbers and caste criteria in the North Indian cohort ($N{\leq}400$ subjects) were evaluated with homogeneity in the sample cohort data set(s). Subgroup caste-stratification of North Indian cohort is equally essential, for instance, Brahmin (e.g. Pandey), Vaishya (e.g. Mittal), Rajput (e.g. Singh) and Kshudra (e.g. Yadav) during the conception and design of genetics-based studies. Sample size homogeneity in histopathologically confirmed case and control numbers and caste-based stratification in a North Indian cohort is essential in single nucleotide polymorphism (SNP) studies in cervical cancer susceptible populations to draw more definitive conclusions.

Dispersion of Li[Ni0.2Li0.2Mn0.6]O2 Powder by Surfactant for High-power Li-ion Cell

  • Yun, Su-Hyun;Park, Yong-Joon
    • Bulletin of the Korean Chemical Society
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    • 제30권7호
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    • pp.1598-1602
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    • 2009
  • The particle size of Li[$Ni_{0.2}Li_{0.2}Mn_{0.6}]O_2$ cathode powder was controlled effectively by dispersion using lauric acid as a surfactant. The samples treated by lauric acid showed smaller particles of approximately half the original size compared to the particles of a pristine sample. A structural change due to the dispersion of Li[$Ni_{0.2}Li_{0.2}Mn_{0.6}]O_2$ powder was not detected. The rate performance of the Li[$Ni_{0.2}Li_{0.2}Mn_{0.6}]O_2$ cathode was improved by dispersion using lauric acid, which was likely due to the decrease of the particle size. In particular, a sample dispersed pristine powder using lauric acid (L2) presented a greatly enhanced discharge capacity and capacity retention at a high C rate. The discharge capacity of a pristine sample was only 133 m$Ahg^{-1}$ (3C rate) and 96 m$Ahg^{-1}$ (12C rate) at the tenth cycle. In contrast, the L2 electrode delivered higher discharge capacities of 160 m$Ahg^{-1}$ (3C rate) and 129 m$Ahg^{-1}$ (12C rate) at the tenth cycle. The capacity retention at a rate of 12C/2C was also enhanced from ~ 45% (pristine sample) to 57% (L2) by treatment with lauric acid.

실험계획법을 이용한 평문.암호문 식별방법의 표본크기 선택에 관한 연구 (On sample size selection for disernment of plain and cipher text using the design of experiments)

  • 차경준
    • 정보보호학회논문지
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    • 제9권4호
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    • pp.71-84
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    • 1999
  • 암호알고리즘 출력 때문에 대한 난수성 검정은 평문과 암호문 식별에 중요한 역할 을 하고 있다. 따라서 현재 많이 사용되고 있는 나수성 검정 방법들의 비교 및 분석은 필수적이라 할수 있 다. 또한 하 나의 검정방법을 이용하고자 할 때 평문과 암호문을 식별할수 있는 최소한의 데이터 크기 는 실시간 검 정 측면에서 많은 도움을 줄수 있을 것이다. 본 논문에서는 대표적인 몇 개의 난수성 검정 방법들에 대 하여 평문과 암호문 식별에 대한 성공률을 실험을 통하여 분석하고 실험계획법을 이용하여 주어진 표본 크기들 중에서 각 난수성 검정방법에 따른 하나의 최적의 표본크기를 제안한다.

면적조사 및 생산량조사 표본설계 (A Study on the Sample Design for Crop Area Survey and Product Survey in Korea)

  • 박홍래
    • Journal of the Korean Statistical Society
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    • 제14권2호
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    • pp.100-117
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    • 1985
  • This paper describes an outline of the sampling design for crop area survey and product survey in Korea. The design attempts to from a double statification, to obtain an efficient allocation of the sample and to reduce the sampling error by establishign crop concentrated strata. The optimum numbers of sample field and sample plot are investigated. The design is made it possible to reduce the sampling errors as well as to reduce the sample size further than the present survey.

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On Large Deviation of the Sample Medians

  • Hong, Chong-Sun
    • Journal of the Korean Statistical Society
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    • 제19권2호
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    • pp.122-127
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    • 1990
  • Consider the following problem in the large deviation theory. For constants $a_1, \cdots, a_p$ the tail probability $P(M_1 > a_1, \cdots, M_p > a_p)$ of the sample medians $(M_1, \cdots, M_p)$ is supposed to converge to zero as sample size increases. This paper shows that this probability converges to zero exponentially fast and estimates the convergence rates of the above tail probability of the sample medians. Also compare with the rates about the sample means.

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중형 공진주 시험기를 이용한 보조도상 재료의 동적특성 정량화 (Evaluation of Dynamic Properties of Subballast Materials Used in Korea Using Midsize Resonant Column Test Apparatus)

  • 임유진;신중훈;박경수;박재학;황정규
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.1214-1221
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    • 2011
  • It is an well-known fact that dynamic properties should be considered in design and maintenance of civil structures undergoing dynamic force such as rail track. For designing of the rail tack structures, dynamic properties of track bed soil such as shear modulus (G) and damping coefficients(D) obtained in small to medium range of shear strain must be known. In general, small size sample of D=5 cm and H=10cm has been used mostly for test convenience. However, ratio of largest particle diameter of the soil to sample diameter is very important and affects to the values of dynamic soil properties in track bed. In this study, an RC/TS test apparatus was built and was run for testing a medium size soil sample that can handle with compacted soil sample up to 10 cm diameter and 20 cm height.

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Design of an Ultra-Compact UHF Passive RFID Tag Antenna for a Medical Sample Tube

  • Lee, Jung-Nam;Hwang, Moon-Young;Lee, Sang-Il;Lee, Kwang-Chun;Park, Jong-Kweon
    • ETRI Journal
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    • 제34권6호
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    • pp.974-977
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    • 2012
  • In this letter, a small-sized ultra-high frequency (UHF) RFID tag antenna for a medical sample tube is proposed. The RFID tag antenna is designed and fabricated based on the circular loop antenna used in the UHF band (Korea standard, 917 MHz to 923.5 MHz). The tag antenna size is reduced using a circular meander stub. The antenna has a physical size of 8 mm, which is about ${\lambda}$/40 in electrical length. The proposed tag antenna is molded into a medical sample and multitag identification is performed.

낮은 모비율 추정을 위한 표본추출방법 (A sampling scheme for the estimation of low proportion)

  • 김지현
    • 응용통계연구
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    • 제8권1호
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    • pp.1-7
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    • 1995
  • 표본조사에서 추정하고자 하는 모비율이 낮으면 많은 표본을 추출해야 한다. 이 때 단위표본의 비용이 높아 추출할 수 있는 표본의 크기가 제한된다면 추정량의 분산을 줄일 수 있는 방법을 신중히 고려해야 할 것이다. 본 논문에서는 모집단에 대한 사전 정보가 있어 이를 이용하여 층화추출하는 경우에 층의 표본크기의 새로운 배분방법을 제안하고 기존의 배분방법들과 비교해 본다.

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