• 한국환경보건학회지
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• 제45권6호
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• pp.577-582
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• 2019

Objectives: The purpose of this survey was to assess the concentrations of heavy metals in the atmosphere of Pocheon City by measuring heavy metals in the industrial complex area and at the city air measuring station, and also to assess the degree of impact that the industrial area has on urban air quality. Methods: Sampling was carried out between February 2018 and November 2018 at two sites in the industrial complex and in the city air monitoring stations. Results: At the industrial complex in Pocheon City, air pollutant emitting businesses were emitting concentrations of fine dust (PM₁₀) between 45 and 60 ㎍/㎥ higher than in the city air. The daily maximum concentrations of lead (Pb), manganese (Mn), and cadmium (Cd) in the industrial complex are below the WHO recommendation standard (annual average), and the impact on the urban atmosphere is judged to be insignificant. Three to five percent of fine dust (PM₁₀) consists of metallic materials, and as the fine dust increased, metals were detected proportionally. Although cadmium (Cd) and beryllium (Be) were not detected in the city air in Pocheon and chromium (Cr), copper (Cu), and arsenic (As) were found to be 50 percent or less, it is deemed that copper (Cu) was detected at unusually high levels due to unknown air pollutants, which requires regular heavy metal measurement and cause verification. Conclusions: An analysis of the heavy metals in the industrial zone and the urban atmosphere in Pocheon City in this study showed that the linear relationship of heavy metals in the industrial zone, or the direct impact relationship, on the heavy metals in the urban atmosphere could not be estimated. The sampling device for equivalent assessment of particulate matter installed at air pollution monitoring stations is highly likely to be used for analysis of fine dust and heavy metals.

• Communications for Statistical Applications and Methods
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• 제14권3호
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• pp.593-600
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• 2007

Under repeated surveys, missing values often appear for various reasons and are replaced by new samples. It is investigated that the existing estimator in repeated survey by Jessen (1942), which has been originally developed for the new samples of fixed size, can be used in such situation where the size of new samples is random. It is shown that the proposed estimator has smaller variance than the sample mean.

• 대한의용생체공학회:의공학회지
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• 제12권3호
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• pp.191-202
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• 1991

This paper describes ECG data compression algorithm using neural network. As a learning method, we use back error propagation algorithm. ECG data compression is performed using learning ability of neural network. CSE database, which is sampled 12bit digitized at 500samp1e/sec, is selected as a input signal. In order to reduce unit number of input layer, we modify sampling ratio 250samples/sec in QRS complex, 125samples/sec in P & T wave respectively. hs a input pattern of neural network, from 35 points backward to 45 points forward sample Points of R peak are used.

• Macromolecular Research
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• 제11권5호
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• pp.393-397
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• 2003

By applying a configurational-bias Gibbs ensemble Monte Carlo algorithm, priority simulation results regarding the conformation of non-dilute polyelectrolytes in solvents are obtained. Solutions of freely-jointed chains are considered, and a new method termed strandwise configurational-bias sampling is developed so as to effectively overcome a difficulty on the transfer of polymer chains. The structure factors of polyelectrolytes in the bulk as well as in the confined space are estimated with variations of the polymer charge density.

• 한국대기환경학회지
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• 제26권4호
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• pp.357-366
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• 2010

The purpose of this study is to evaluate a method for the measurement of N,N-Dimethylformamide (DMF) and to apply the method to the ambient air samples. For the determination of DMF together with other general VOCs (e.g., benzene, toluene, and xylenes), adsorption sampling and thermal desorption with GC/MS was used in this study. The sampling and analytical approaches tested in this study showed a good repeatability and linearity with lower detection limits of less than 0.35 ppb. Field measurements were carried out at three industrial sites (Daegu-Seongseo, Siwha and Banwall industrial complexes) and one residential site in Daegu city during a period from October 2006 to November 2008. DMF was detected in 71.8% of the total samples from the Seongseo industrial complex, well known for textile industry. In contrast, DMF was detected in only 20.4% and 12.9% of all the samples from the other two sites in Banwall and Siwha industrial complexes, respectively. This implies that sources of DMF should be strongly associated with textile industry. The mean concentration of DMF also appeared to be the highest in Seongseo site (5.95 ppb), followed by a residential site in Daegu (3.28 ppb), Banwall (0.88 ppb) and Siwha (0.55 ppb). In this study, we demonstrated the environmental significance of DMF in urban ambient air. To our knowledge, the DMF measurement introduced in this paper is the first case of an official report in Korea.

• Journal of electromagnetic engineering and science
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• 제8권2호
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• pp.76-83
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• 2008

A low power(9 mW) highly-digitized 2.4 GHz receiver for sensor network applications(IEEE 802.15.4 LR-WPAN) is realized by a $0.18{\mu}m$ CMOS process. We adopted a novel receiver architecture adding an intermediate frequency (IF) level detection scheme to a low-power complex fifth-order continuous-time(CT) bandpass L:tl modulator in order to digitalize the receiver. By the continuous-time bandpass architecture, the proposed $\Sigma\Delta$ modulator requires no additional anti-aliasing filter in front of the modulator. Using the IF detector, the achieved dynamic range(DR) of the over-all system is 95 dB at a sampling rate of 64 MHz. This modulator has a bandwidth of 2 MHz centered at 2 MHz. The power consumption of this receiver is 9.0 mW with a 1.8 V power supply.

• Asian-Australasian Journal of Animal Sciences
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• 제25권11호
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• pp.1511-1514
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• 2012

Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells. Mean empirical statistical power was estimated for testing posterior mean estimate of combined genotype effect. A practical example for obtaining empirical statistical power estimates with a given sample size was provided under unbalanced designs. The empirical statistical powers would be useful for determining an optimal design when interactive associations of multiple loci with complex phenotypes were examined.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.877-884
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• 2002

This paper deals with a multi-stage TSK fuzzy modeling method by using Genetic Programming (GP). Based on the time sequence of sampling data the best structural change points of complex systems are detemined by using GP, and also the moving window is simultaneously introduced to overcome the excessive amount of calculation during the generating procedure of GP tree. Therefore, a multi-stage TSK fuzzy model that attempts to represent a complex problem by decomposing it into multi-stage sub-problems is addressed and its learning algorithm is proposed based on the Radial Basis Function (RBF) network. This approach allows us to determine the model structure and parameters by stages so that the problems ran be simplified.

• 한국조사연구학회지:조사연구
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• 제1권1호
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• pp.109-123
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• 2000

복잡한 확률표본설계를 기초로 수집된 데이터를 적법하게 분석하려면 반드시 조사설계를 고려하여 통계적 추론을 전개해야한다. 만일 설계를 무시하고 분석을 하면 각종 추정량의 분산이 과소추정되면 이 결과 제 1종 오류의 확률이 매우높아진다. 본고에서는 조사데이터를 전문적으로 분석하는 소프트웨어 패키지들을 소개하고 특히 SUDAAN 7.5판 과 SAS 8판의 분석 능력들에 대한 정보를 요약한다.

• Journal of the Korean Data and Information Science Society
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• 제25권3호
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• pp.523-531
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• 2014

설계효과는 새로운 표본설계를 계획하거나 기존 표본조사에 적용된 설계요소의 효율성을 평가하는데 널리 사용된다. 본 연구에서는 Gabler 등 (2006)이 제시한 설계효과모형을 층화이단집락추출의 표본설계로 이루어진 2013 식품소비행태조사에 응용하여 적용하였다. 조사결과를 통해 표본설계모형의 유용성과 적절성에 대해 논의하였다.