• Title/Summary/Keyword: survey and estimation errors

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Design-Based Small Area Estimation for the Korean Economically Active Population Survey (시군구 실업자 총계 추정을 위한 설계기반 간접추정법)

  • 정연수;이계오;이우일
    • The Korean Journal of Applied Statistics
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    • v.16 no.1
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    • pp.1-14
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    • 2003
  • In this study, we suggest the method of small area estimation based on the Economically Active Population Survey (EAPS) data in producing unemployment statistics for the local self-government areas (LSGAs) within large areas. The small area estimators considered are design-based indirect estimators such as the synthetic and composite estimators. The jackknife mean square error was used as a measure of accuracy of such small area estimators. The total unemployed and jackknife mean square errors of the 10 LSGAs within the large area of ChoongBuk region are derived from the estimation procedure suggested in this study, using EAPS data of December 2000. The reliability of small area estimators was assessed using the relative bias values and relative root mean square errors of these estimators. We find that under the current Korean EAPS system, the composite estimator turns out to be much more stable than other estimators.

A Review on the Sampling Design for Energy Consumption Survey in Agricultural Sector (농업부문 에너지 소비량 조사를 위한 표본설계)

  • Kim, Yean-Jung;Kim, Bae-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.9
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    • pp.411-417
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    • 2017
  • It is necessary to determine the current and future energy consumption by farm households for the rational specification of energy related policy in the Korean agricultural sector. Especially, It is important to identify the consumption by source of energy and by the crops. On the other hand, the world has tried to reduce the production of greenhouse gases and, in line with this, the Korean government established related legislations to contribute to this reduction (30% reduction in emissionsby 2020). The reduction target of the agricultural sector is specified as 5.2% of the national total. This study focuses on sampling design to determine the energy consumption and emission of greenhouse gases, and suggests several alternatives to improve the confidence level and to make a dent survey and estimation errors. The population for the energy consumption survey of the agricultural sector was derived from agricultural census data. In the case of commodities with high skewness, we cut the sample range to within the statistical significant range. The number of samples in each class is specified using the Neyman allocation method and 95% significance level. The estimation results are compared with the population to verify the statistical significance and several management methods of sampling errors are suggested.

Modified inverse moment estimation: its principle and applications

  • Gui, Wenhao
    • Communications for Statistical Applications and Methods
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    • v.23 no.6
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    • pp.479-496
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    • 2016
  • In this survey, we present a modified inverse moment estimation of parameters and its applications. We use a specific model to demonstrate its principle and how to apply this method in practice. The estimation of unknown parameters is considered. A necessary and sufficient condition for the existence and uniqueness of maximum-likelihood estimates of the parameters is obtained for the classical maximum likelihood estimation. Inverse moment and modified inverse moment estimators are proposed and their properties are studied. Monte Carlo simulations are conducted to compare the performances of these estimators. As far as the biases and mean squared errors are concerned, modified inverse moment estimator works the best in all cases considered for estimating the unknown parameters. Its performance is followed by inverse moment estimator and maximum likelihood estimator, especially for small sample sizes.

Comparison of Univariate Kriging Algorithms for GIS-based Thematic Mapping with Ground Survey Data (현장 조사 자료를 이용한 GIS 기반 주제도 작성을 위한 단변량 크리깅 기법의 비교)

  • Park, No-Wook
    • Korean Journal of Remote Sensing
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    • v.25 no.4
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    • pp.321-338
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    • 2009
  • The objective of this paper is to compare spatial prediction capabilities of univariate kriging algorithms for generating GIS-based thematic maps from ground survey data with asymmetric distributions. Four univariate kriging algorithms including traditional ordinary kriging, three non-linear transform-based kriging algorithms such as log-normal kriging, multi-Gaussian kriging and indicator kriging are applied for spatial interpolation of geochemical As and Pb elements. Cross validation based on a leave-one-out approach is applied and then prediction errors are computed. The impact of the sampling density of the ground survey data on the prediction errors are also investigated. Through the case study, indicator kriging showed the smallest prediction errors and superior prediction capabilities of very low and very high values. Other non-linear transform based kriging algorithms yielded better prediction capabilities than traditional ordinary kriging. Log-normal kriging which has been widely applied, however, produced biased estimation results (overall, overestimation). It is expected that such quantitative comparison results would be effectively used for the selection of an optimal kriging algorithm for spatial interpolation of ground survey data with asymmetric distributions.

Application of In-direct Estimation for Small Area Statistics (소지역 통계분석기법의 활용-도소매업 및 서비스업 통계조사 사례연구-)

  • 김영원;성나영
    • Proceedings of the Korean Association for Survey Research Conference
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    • 2000.06a
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    • pp.57-73
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    • 2000
  • Small area estimation is becoming important in survey sampling due to a growing demand for reliable small area statistics. In estimating means, totals, and other parameters for small areas of a finite population, samplie sizes for small areas are typically small because the overall sample size is usually determined to provide specific accuracy at a much higher level of aggregation than that of small area. The usual direct estimators that use the only information which is gotten from the sample in a given small area provide unreliable estimates. However, indirect estimators utilize the information from the areas related with a given small area, that is borrow strength from other related areas, and so give more accurate estimates than direct estimators. In this paper we investigate small area estimation methods such as synthetic, composite and empirical best linear unbiased prediction estimator, and apply them to real domestic data which is from the Survey of Hotels and Restaurants in In-Chon as of 1996 and then evaluate the performance of these methods by measuring average squared errors. This evaluation shows that indirect estimators, which are small area estimation methods, are more efficient direct estimator.

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Application of In-direct Estimation for Small Area Statistics (소지역 통계 생산을 위한 추정방법)

  • Kim, Young-Won;Sung, Na-Young
    • Journal of the Korean Data and Information Science Society
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    • v.11 no.1
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    • pp.111-126
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    • 2000
  • Small area estimation is becoming important in survey sampling due to a growing demand for reliable small area statistics. In estimating means, totals, and other parameters for small areas of a finite population, samplie sizes for small areas are typically small because the overall sample size is usually determined to provide specific accuracy at a much higher level of aggregation than that of small area. The usual direct estimators that use the only information which is gotten from the sample in a given small area provide unreliable estimates. However, indirect estimators utilize the information from the areas related with a given small area, that is, borrow strength from other related areas, and so give more accurate estimates than direct estimators. In this paper we investigate small area estimation methods such as synthetic, composite and empirical best linear unbiased prediction estimator, and apply them to real domestic data which is from the Survey of Hotels and Restaurants in In-Chon as of 1996 and then evaluate the performance of these methods by measuring average squared errors. This evaluation shows that indirect estimators, which are small area estimation methods, are more efficient than direct estimator.

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Estimation of Geometric Error Sources of Suspension Bridge using Survey Data (측량 데이터를 이용한 현수교의 형상오차 원인 추정)

  • Park, Yong Myung;Cho, Hyun Jun;Cheung, Jin Hwan;Kim, Nam Sik
    • Journal of Korean Society of Steel Construction
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    • v.19 no.3
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    • pp.313-321
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    • 2007
  • The study discussed in this paper presents a method of estimating sources of geometric errors in suspension bridges in use, based on geometric survey data. A geometric error is defined as the difference between the survey data and the design geometry of a main cable. It is assumed that the geometric error in a suspension bridge is caused by the variations in the weight of the stiffening girder and the deformation of the anchorage foundations due to the creep of soil. The variations in the girder weight and the deformation of the foundation were estimated by constructing a matrix of factors that affect suspension bridges due to the variations. To check the validity of the proposed method, it was applied to the Kwang-An Bridge, and the sources of geometric errors in the bridge were estimated using the survey data.

Robust Pitch Detection Algorithm for Pathological Voice inducing Pitch Halving and Doubling (피치 반감 배가를 유발하는 병적인 음성 분석을 위한 강인한 피치 검출 알고리즘)

  • Jang, Seung-Jin;Choi, Seong-Hee;Kim, Hyo-Min;Choi, Hong-Shik;Yoon, Young-Ro
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1797-1798
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    • 2007
  • In field of voice pathology, diverse statistics extracted form pitch estimation were commonly used to assess voice quality. In this study, we proposed robust pitch detection algorithm which can estimate pitch of pathological voices in benign vocal fold lesions. we also compared our proposed algorithm with three established pitch detection algorithms; autocorrelation, simplified inverse filtering technique, and nonlinear state-space embedding methods. In the database of total pathological voices of 99 and normal voices of 30, an analysis of errors related with pitch detection was evaluated between pathological and normal voices, or among the types of pathological voices. According to the results of pitch errors, gross pitch error showed some increases in cases of pathological voices; especially excessive increase in PDA based on nonlinear time-series. In an analysis of types of pathological voices classified by aperiodicity and the degree of chaos, the more voice has aperiodic and chaotic, the more growth of pitch errors increased. Consequently, it is required to survey the severity of tested voice in order to obtain accurate pitch estimates.

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Species Identification and Noise Cancellation Using Volume Backscattering Strength Difference of Multi-Frequency (다중 주파술의 체적산란강도 차이를 이용한 에코그램 내에서의 종 분리와 잡음 제거)

  • KANG Donhyug;SHIN Hyoung-Chul;KIM Suam;LEE Yoonho;HWANG Doojin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.5
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    • pp.541-548
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    • 2003
  • Species identification in hydroacoustic survey is one of the key requirements to estimate biomass of organism and to understand the structure of zooplankton community. Feasibility of species identification using two frequencies (38 and 120 kHz) was investigated on the basis of mean volume backscattering strength difference (MVBS). Virtual echogram technique was applied to two frequencies data sets that obtained from surveys in the Antarctic Ocean and Yellow Sea. Virtual echogram method using MVBS revealed the possibility of species identification, which species identification relying on visual scrutiny of single frequency acoustic data resulted in significant errors in biomass estimation. Through noise cancellation using MVBS, much of the acoustic noise caused by acoustic instruments could be removed in new virtual echogram, and the biomass estimation and data quality was improved.

Effects of Maximum Probe Spacing of Soil Resistivity Survery on Substation Grounding Analysis (변전소 접지설계를 위한 대지저항율 측정시 전극간 최대간격이 접지해석에 미치는 영향)

  • 정길조;곽희로;최종기
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.8
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    • pp.382-386
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    • 2001
  • Presently, typical maximum probe spacing of soil resistivity survey(Wenners 4 pin method) is 20 m in case of 154 K substation grounding design of KEPCO. This paper examined the effects of maximum probe spacing of wenner method on the equivalent soil modeling and the accuracy of grounding resistance measurement by comparing the calculated FOP(Fall-of-Potential) curves of various soil models with the measured one at 154kV H substation. The comparison results showed that the inaccurate estimation of deep soil resistivity, which is caused from the short probe spacing of soil resistivity survey, can produce large errors on measurement of grounding resistance. In this paper a quantitative analysis of FOP at H substation has been presented.

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