• Title/Summary/Keyword: random sampling

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Comparison of Simple Random Sampling and Two-stage P.P.S. Sampling Methods for Timber Volume Estimation (임목재적(林木材積) 산정(算定)을 위(爲)한 Simple Random Sampling과 Two-stage P.P.S. Sampling 방법(方法)의 비교(比較))

  • Kim, Je Su;Horning, Ned
    • Journal of Korean Society of Forest Science
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    • v.65 no.1
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    • pp.68-73
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    • 1984
  • The purpose of this paper was to figure out the efficiencies of two sampling techniques, a simple random sampling and a two-stage P.P.S. (probability proportional to size) sampling, in estimating the volume of the mature coniferous stands near Salzburg, Austria. With black-and-white infrared photographs at a scale 1:10,000, the following four classes were considered; non-forest, young stands less than 40 years, mature beech and mature coniferous stands. After the classification, a field survey was carried out using a relascope with a BAF (basal area factor) 4. For the simple random sampling, 99 points were sampled, while for the P.P.S. sampling, 75 points were sampled in the mature coniferous stands. The following results were obtained. 1) The mean standing coniferous volume estimate was $422.0m^3/ha$ for the simple random sampling and $433.5m^3/ha$ for the P.P.S. sampling method. However, the difference was not statistically significant. 2) The required number of sampling points for a 5% sampling error were 170 for the two stage P.P.S. sampling, but 237 for the simple random sampling. 3) The two stage P.P.S. method reduced field survey time by 17% as compared to the simple random sampling.

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Fast Generation of Binary Random Sequences by Use of Random Sampling Method

  • Harada, Hiroshi;Kashiwagi, Hiroshi
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10b
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    • pp.240-244
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    • 1992
  • A new method for generation of binary random sequences, called random sampling method, has been proposed by the authors. However, the random sampling method has the defect that binary random sequence can not be rapidly generated. In this paper, two methods based on the random sampling method are proposed for fast generation of binary random sequences. The optimum conditions for obtaining ideal binary random sequences are derived.

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On desirable conditions for a random number used in the random sampling method

  • Harada, Hiroshi;Kashiwagi, Hiroshi;Takada, Tadashi
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10b
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    • pp.1295-1299
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    • 1990
  • A new method called random sampling method has been proposed for generation of binary random sequences. In this paper, a new concept, called merit factor Fn, is proposed for evaluating the randomness of the binary random sequences generated by the random sampling method. Using this merit factor Fn, some desirable conditions are investigated for uniform random numbers used in the random sampling method.

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A Random Sampling Method for Generation Adequacy Assessment Including Wind-Power (풍력발전을 포함한 시스템의 발전량 적정성 평가를 위한 비순차 샘플링 방법)

  • Kim, Gwang-Won
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.5
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    • pp.45-53
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    • 2011
  • This paper presents a novel random sampling method for generation adequacy assessment including wind-power. Although a time sequential sampling has advantages than a random sampling in its assessment results, it takes long assessment time. Therefore, an effective random sampling method for generation adequacy assessment is highly recommended to get specific reliability indices quickly. The proposed method is based on the Monte-Carlo simulation with state sampling and it can be applied to generation adequacy assessment with other intermittent power sources.

An Exploration on Random Sampling Telephone Survey -The Case of the Ulsan Mayoral Election in 2002- (임의표집법에 의거한 전화조사의 시도 -2002년 울산시장선거의 경우-)

  • No, Kyu-Hyung;Khang, Hung-Soo;Han, Cheol-Soo
    • Survey Research
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    • v.3 no.2
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    • pp.77-90
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    • 2002
  • This study reports the results of a random sampling telephone survey conducted in the case of the Ulsan mayoral election 2002. We interview at least five times to a respondent who is randomly selected by means of the birthday method from a randomly sampled telephone number list of 1,233 households, We analyze the result of interviewing, such as absence and promise. And we compare the demographic variables of the surveyed sample and those of the population and we also compare the randomly selected sample's voting preference with outcome of the election in various ways. Finally, we discuss difficulty of random sampling with the birthday method and suggest some technical tips to conduct random sampling telephone survey.

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A Study on economically optimal Determination of the Parameters of the Stratified Random Sampling (확률추출에 의한 층별 샘플링의 경제성에 관한 연구)

  • 황의철;이영식
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.13 no.21
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    • pp.81-90
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    • 1990
  • In stratified random sampling a simple random sample must be taken in each stratum to reduce the maximum gain in precision given the minimum cost. The purpose of this paper is to deal with the propertics of the estimates and variances and obtain the economic design of stratified random sampling through the optimum allocation of the sample sizes. In addition, the between stratum variation and the within stratum variation is stratifying the population are described.

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Design and Implementation of Teaching Simple Random Sampling by Using Constructivism and Information Technology

  • Han Beom Soo;Han Kyung Soo
    • Communications for Statistical Applications and Methods
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    • v.12 no.1
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    • pp.229-240
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    • 2005
  • This study described the application of constructivism and information technology for teaching simple random sampling. We considered more student's participation, more interaction, and more flow in their introductory statistics class. In addition, we presented a web-based teaching and learning system for simple random sampling to demonstrate.

Comparison of Latin Hypercube Sampling and Simple Random Sampling Applied to Neural Network Modeling of HfO2 Thin Film Fabrication

  • Lee, Jung-Hwan;Ko, Young-Don;Yun, Il-Gu;Han, Kyong-Hee
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.4
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    • pp.210-214
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    • 2006
  • In this paper, two sampling methods which are Latin hypercube sampling (LHS) and simple random sampling were. compared to improve the modeling speed of neural network model. Sampling method was used to generate initial weights and bias set. Electrical characteristic data for $HfO_2$ thin film was used as modeling data. 10 initial parameter sets which are initial weights and bias sets were generated using LHS and simple random sampling, respectively. Modeling was performed with generated initial parameters and measured epoch number. The other network parameters were fixed. The iterative 20 minimum epoch numbers for LHS and simple random sampling were analyzed by nonparametric method because of their nonnormality.

RANDOM SAMPLING AND RECONSTRUCTION OF SIGNALS WITH FINITE RATE OF INNOVATION

  • Jiang, Yingchun;Zhao, Junjian
    • Bulletin of the Korean Mathematical Society
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    • v.59 no.2
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    • pp.285-301
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    • 2022
  • In this paper, we mainly study the random sampling and reconstruction of signals living in the subspace Vp(𝚽, 𝚲) of Lp(ℝd), which is generated by a family of molecules 𝚽 located on a relatively separated subset 𝚲 ⊂ ℝd. The space Vp(𝚽, 𝚲) is used to model signals with finite rate of innovation, such as stream of pulses in GPS applications, cellular radio and ultra wide-band communication. The sampling set is independently and randomly drawn from a general probability distribution over ℝd. Under some proper conditions for the generators 𝚽 = {𝜙λ : λ ∈ 𝚲} and the probability density function 𝜌, we first approximate Vp(𝚽, 𝚲) by a finite dimensional subspace VpN (𝚽, 𝚲) on any bounded domains. Then, we prove that the random sampling stability holds with high probability for all signals in Vp(𝚽, 𝚲) whose energy concentrate on a cube when the sampling size is large enough. Finally, a reconstruction algorithm based on random samples is given for signals in VpN (𝚽, 𝚲).

Effects of Call-back Rules and Random Selection of Respondents: Statistical Re-analysis of R&R’s Ulsan Survey Data. (전화조사에서 재통화 규칙준수와 응답자 임의선택의 영향 - R&R 울산 사례의 통계적 재분석 -)

  • 허명회;임여주;노규형
    • The Korean Journal of Applied Statistics
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    • v.16 no.2
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    • pp.247-259
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    • 2003
  • In Korea, quota sampling is mainly adopted in telephone surveys, instead of random sampling which requires call-back procedure and random selection of respondent within households. The contact mode based on the se $x^{*}$age quotas is economically more advantageous and less time-consuming. However, it lacks theoretical ground for valid statistical inference, so that it is hardly accepted in academic circles despite of widely spread practice. Subsequently, survey theoreticians argued that random sampling-based telephone surveys should be tried. In response, Research & Research (R&R), a private research company in Seoul, executed atelephone survey by random sampling mode for the prediction of 2002 Ulsan City Mayor Election. The aim of this case study is to find out various effects of the call-back rule with random selection of respondents by statistically re-analyzing R&R’s Ulsan Survey Data.s by statistically re-analyzing R&R’s Ulsan Survey Data.