• Title/Summary/Keyword: Under-Sampling

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Semiparametric Bayesian estimation under functional measurement error model

  • Hwang, Jin-Seub;Kim, Dal-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.2
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    • pp.379-385
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    • 2010
  • This paper considers Bayesian approach to modeling a flexible regression function under functional measurement error model. The regression function is modeled based on semiparametric regression with penalized splines. Model fitting and parameter estimation are carried out in a hierarchical Bayesian framework using Markov chain Monte Carlo methodology. Their performances are compared with those of the estimators under functional measurement error model without semiparametric component.

Microbial changes under packaging conditions during transport and comparison between sampling methods of beef

  • Yim, Dong-Gyun;Jin, Sang-Keun;Hur, Sun-Jin
    • Journal of Animal Science and Technology
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    • v.61 no.1
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    • pp.47-53
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    • 2019
  • This study was performed to evaluate the microbial and temperature changes of boxed beef during transport and distribution under vacuum and modified atmosphere packaging (MAP), and to compare between excision and swab sampling for 15 days. The top round and striploin (quality grade 1) from Hanwoo steers at 2 days post-slaughter were obtained from a local meat processing plants and chilled at $4{\pm}2^{\circ}C$ in a cold room. The boxes were transported under refrigeration ($4{\pm}2^{\circ}C$) to the laboratory within half an hour. Vacuum and MAP packs were subsequently taken out from cool boxes, and microbiological examinations were carried out at 0, 6, 12, and 24 h of storage time. MAP was more effective than vacuum packaging for the inhibition of total aerobic, lactic acid bacteria and Pseudomonas (p < 0.05). Microbial loads of swab methods were slightly lower than those of excision ones (p < 0.05). The results of this study could be utilized by meat consumers in future studies as well as by manufacturers to determine the ideal storage conditions for cool boxed meat, thus ensuring reduced economic losses due to spoilage.

An Improved Sample Design for Estimating the Usage of Copyrighted Music Works (노래연습장, 유흥·단란주점의 음악저작물이용 실태조사 개선안 연구)

  • Lee, Kay-O;Chung, Yeon-Soo
    • Communications for Statistical Applications and Methods
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    • v.19 no.3
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    • pp.315-331
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    • 2012
  • In this research, we estimated the number of hits per song and its sampling error from 11 (areas including Gangnam) based on log data compiling the number of hits collected from offline karaoke players in March 2011. Then, we calculated the monetary equivalent of the sampling error under the current system that distribute royalties from the karaoke players to copyright holders(song writers and arrangers) according to the estimated hits. Because of the small sample size, the estimated number of hits had a very large sampling error. This research proposes a more reasonable sample design to estimate the usage of copyrighted music works for a fair distribution of royalties by reducing sampling error.

Objective Bayesian Estimation of Two-Parameter Pareto Distribution (2-모수 파레토분포의 객관적 베이지안 추정)

  • Son, Young Sook
    • The Korean Journal of Applied Statistics
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    • v.26 no.5
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    • pp.713-723
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    • 2013
  • An objective Bayesian estimation procedure of the two-parameter Pareto distribution is presented under the reference prior and the noninformative prior. Bayesian estimators are obtained by Gibbs sampling. The steps to generate parameters in the Gibbs sampler are from the shape parameter of the gamma distribution and then the scale parameter by the adaptive rejection sampling algorism. A numerical study shows that the proposed objective Bayesian estimation outperforms other estimations in simulated bias and mean squared error.

Design of a 12b SAR ADC for DMPPT Control in a Photovoltaic System

  • Rho, Sung-Chan;Lim, Shin-Il
    • IEIE Transactions on Smart Processing and Computing
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    • v.4 no.3
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    • pp.189-193
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    • 2015
  • This paper provides the design techniques of a successive approximation register (SAR) type 12b analog-to-digital converter (ADC) for distributed maximum power point tracking (DMPPT) control in a photovoltaic system. Both a top-plate sampling technique and a $V_{CM}$-based switching technique are applied to the 12b capacitor digital-to-analog converter (CDAC). With these techniques, we can implement a 12b SAR ADC with a 10b capacitor array digital-to-analog converter (DAC). To enhance the accuracy of the ADC, a single-to-differential converted DAC is exploited with the dual sampling technique during top-plate sampling. Simulation results show that the proposed ADC can achieve a signal-to-noise plus distortion ratio (SNDR) of 70.8dB, a spurious free dynamic range (SFDR) of 83.3dB and an effective number of bits (ENOB) of 11.5b with bipolar CMOS LDMOD (BCDMOS) $0.35{\mu}m$ technology. Total power consumption is 115uW under a supply voltage of 3.3V at a sampling frequency of 1.25MHz. And the figure of merit (FoM) is 32.68fJ/conversion-step.

A Stratified Multi-proportions Randomized Response Model (층화 다지 확률화응답모형)

  • Lee, Gi-Sung;Park, Kyung-Soon
    • The Korean Journal of Applied Statistics
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    • v.28 no.6
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    • pp.1113-1120
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    • 2015
  • We propose a multi-proportions randomized response model by stratified simple random sampling for surveys of sensitive issues of a polychotomous population composed of several stratum. We also systemize a theoretical validity to apply multi-proportions randomized response model (Abul-Ela et al.' model, Eriksson's model) to stratified simple random sampling and derive the estimate and its dispersion matrix of the proportion of sensitive characteristic of population using the suggested model. Two types of sample allocations (proportional allocation and optimum allocation) are considered under the fixed cost. In efficiency, the Eriksson's model by stratified sampling are compared to the Abul-Ela et al.' model.

A Study on the Statistical Representativeness of Samples taken from Radioactive Soil (방사성 토양폐기물 시료의 통계적 대표성에 관한 연구)

  • Cho Han-Seok;Kim T.K.;Lee K.M.;Ahn S.J.;Shon J.S.
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.06a
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    • pp.151-157
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    • 2005
  • For the treatment of regulatory clearance of the soils, a procedure for the radionuclides and radioactivity concentration analysis is under development. A strategy for soil sampling including random sampling after homogenization and standardization was set up. Statistical representativeness is considered for not only sampling strategy but also sample size. In this study, designed sample size was designed with confidence interval and error bound of soil using the pilot samples which were taken following the sampling strategy.

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Determination of Siloxanes in Biogas by Solid-phase Adsorption on Activated Carbon

  • Kim, Nack-Joo;Chun, Seung-Kyu;Cha, Daniel K.;Kim, Cheal
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2353-2357
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    • 2013
  • The objective of this study was to develop a simple, less time-consuming and accurate sampling technique based on solid-phase sorption with activated carbon as the sorbents. The results from solid-phase sorption techniques were compared to that from a conventional solvent impinger-based technique to confirm the efficacy of the proposed method. The laboratory results indicated that the solid-phase sorption method was suitable for the determination of siloxanes as the measured concentrations were similar to that from a solvent impinge method. The data from solid-phase sorption method showed excellent recovery and reproducibility while the sampling was less labor intensive and less time consuming than the solvent impinge method. Following the laboratory tests, the solid-phase sorption technique was successfully applied to sampling biogas from a field site. This study shows that the activated carbon-based solid-phase sorption can be a reliable and less time-consuming option for the sampling and collection of siloxanes under various different landfill conditions.

A Performance Comparison of Sampling Rate Conversion Algorithms for Audio Signal (오디오 신호를 위한 표본화율 변환 알고리듬 성능 비교)

  • Lee Yong-Hee;Kim Rin-Chul
    • Journal of Broadcast Engineering
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    • v.9 no.4 s.25
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    • pp.384-390
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    • 2004
  • In this paper we compare the performance of 4 different algorithms for converting the sampling frequency of an audio from 44.1KHz to 48KHz. The algorithms considered here include the basic polyphase method. sine function based method. multi-stage method. and B-spline based method. For a fair comparison, the sampling rate converters using the 4 algorithms are redesigned under a high fidelity condition. Then, their H/W complexities are compared in terms of the computational complexity and the memory size. As a result, it is shown that the basic polyphase method and sine function based method outperform the other two in terms of the computational complexity, while the B-spline based method requires less memory than the others.

Sampling, Surveillance and Forecasting of Insect Population for Integrated Pest Management in Sericulture

  • Singh, R.N.;Maheshwari, M.;Saratchandra, B.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.8 no.1
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    • pp.17-26
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    • 2004
  • Pest monitoring through field surveys and surveillance helps in forecasting the population build up of pest. It reduces the load of pesticides application and forms the basis of Integrated Pest Management in sericulture. Common sampling techniques for quantifying pest populations and damage caused by them are reviewed emphasizing the need for quick and simple sampling methods. Various direct and indirect sampling methods for establishing pest populations are discussed and methods have been discussed to use indirect sampling method under IPM programme in sericulture. The use of pheromone lures and traps forms one of the important ingredients of integrated pest management, which calls for integration of all available methods in a cost effective and environmental friendly manner offering consistent efficacy. Silk-worms feed on the variety of silk host plants and spin cocoons. Each silk host plant is attacked in the field by number of insect pest species. Several pests are common to mulberry, tasar, oak tasar, muga and eri host plant but pest status and seasonal abundance differs from each crop. The key pests are serious perennially occurring persistent species which cause considerable yield loss every year on large areas and require control measure. Regular occurrence of minor pest is noticed but sudden increase in its population is not known. The occasional pests are sporadic but potential causing sufficient damage. Silk losses due to attack of all the pests have not been calculated. However, information on pest biology and ecology, and control practices being practiced is available but the period of outbreak of major pests and predators on silkworms and its host plant needs to be reinvestigated. Pest and predators forecasting based on surveillance information may provide an opportunity to minimize the losses, particularly to reduce expenditure involved in pest management.