• Title/Summary/Keyword: systematic sampling

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Choosing an optimal connecting place of a nuclear power plant to a power system using Monte Carlo and LHS methods

  • Kiomarsi, Farshid;Shojaei, Ali Asghar;Soltani, Sepehr
    • Nuclear Engineering and Technology
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    • v.52 no.7
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    • pp.1587-1596
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    • 2020
  • The location selection for nuclear power plants (NPP) is a strategic decision, which has significant impact operation of the plant and sustainable development of the region. Further, the ranking of the alternative locations and selection of the most suitable and efficient locations for NPPs is an important multi-criteria decision-making problem. In this paper, the non-sequential Monte Carlo probabilistic method and the Latin hypercube sampling probabilistic method are used to evaluate and select the optimal locations for NPP. These locations are identified by the power plant's onsite loads and the average of the lowest number of relay protection after the NPP's trip, based on electricity considerations. The results obtained from the proposed method indicate that in selecting the optimal location for an NPP after a power plant trip with the purpose of internal onsite loads of the power plant and the average of the lowest number of relay protection power system, on the IEEE RTS 24-bus system network given. This paper provides an effective and systematic study of the decision-making process for evaluating and selecting optimal locations for an NPP.

Fish Community Structure in the Pyeongchanggang River

  • Choi, Jun-Kil
    • Animal Systematics, Evolution and Diversity
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    • v.27 no.2
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    • pp.151-158
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    • 2011
  • Fish community structure in the Pyeongchanggang River was investigated from April to November 2009. About 900 individuals representing 24 species from eight families at six sites in the Pyeongchanggang River were collected. It was similar to the 2001's survey and it was less than 2006's survey. The Korean endemic species, Zacco koreanus was the most abundant, whereas subdominant species were native species, such as Pungtungia herzi, Zacco platypus, Rhynchocypris kumgangensis and Rhynchocypris oxycephalus. Three endangered species were collected at the sampling area, Acheilognathus signifier (relative abundance [RA] 0.9%), Pseudopungtungia tenuicorpa (RA 1.4%), and Cottus koreanus (RA 3.6%). One natural monument species, Hemibarbus mylodon, was included. According to the analysis of ecological indicator characteristics, the relative proportion of tolerant species was 6.3% (57 individuals), whereas the proportion of sensitive species was 65.9% (593 individuals). Species evenness, richness and diversity indices decreased gradually through the month from April to November during the study. Community indices in Pyeongchanggang River showed a high evenness index (J'>0.6), a low level of species richness (R<3.5) and a medium level of diversity (1.5

A Systematic Comparison of Time Use Instruments: Time Diary and Experience Sampling Method (생활시간 연구를 위한 측정도구의 비교 : 경험표집법과 시간일지)

  • Jeong, Jae-Ki
    • Survey Research
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    • v.9 no.1
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    • pp.43-68
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    • 2008
  • This study compares two instruments for time use study: The time diary and the Experience Sampling Method (ESM), While previous studies show that the ESM and the full-diary are similar with respect to aggregate estimates, No previous study has examined the concordance rates of individual records from both instruments. Based on the subsamples who completed both instruments during the same time period from 500 family studies conducted by the Alfred P. Sloan Center on Parents, Children, and Work at the University of Chicago, we systematically compares the two instruments and evaluates their relative strengths. The results suggest that time diaries provide less biased time use estimates. and that compared to the time diary, the ESM provides a more detailed description of everyday life. The implications of further researches are discussed.

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Application of Quality Statistical Techniques Based on the Review and the Interpretation of Medical Decision Metrics (의학적 의사결정 지표의 고찰 및 해석에 기초한 품질통계기법의 적용)

  • Choi, Sungwoon
    • Journal of the Korea Safety Management & Science
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    • v.15 no.2
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    • pp.243-253
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    • 2013
  • This research paper introduces the application and implementation of medical decision metrics that classifies medical decision-making into four different metrics using statistical diagnostic tools, such as confusion matrix, normal distribution, Bayesian prediction and Receiver Operating Curve(ROC). In this study, the metrics are developed based on cross-section study, cohort study and case-control study done by systematic literature review and reformulated the structure of type I error, type II error, confidence level and power of detection. The study proposed implementation strategies for 10 quality improvement activities via 14 medical decision metrics which consider specificity and sensitivity in terms of ${\alpha}$ and ${\beta}$. Examples of ROC implication are depicted in this paper with a useful guidelines to implement a continuous quality improvement, not only in a variable acceptance sampling in Quality Control(QC) but also in a supplier grading score chart in Supplier Chain Management(SCM) quality. This research paper is the first to apply and implement medical decision-making tools as quality improvement activities. These proposed models will help quality practitioners to enhance the process and product quality level.

Analysis of Measured Acceleration Data to Obtain Dynamic Characteristics of Bridges (교량의 동적 특성 분석을 위한 가속도 데이터의 해석)

  • 이선구;이성우
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.111-121
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    • 1995
  • In Extracting the dynamic parameters for estimating the load carrying capacity and integrity of bridges, both the instrumentation and the processing the data plays important role . When the fixed point can not be secured, it is difficult and expensive to measure dynamic displacements. Even if the displacement is obtained through the integration of the acceleration data, the results can be quite different from the real behavior, because the main frequency contents can be leaked during discretized data processing. The instrumentation is used for measurements, and every measurement involves error and uncertainty, such as systematic, conformance, environmental, observational, sampling, and ranmom error. Systematic and conformance error can be remedied through the proper sellection and installation of the instruments, but sampling and random errors could not have been corrected properly and it becomes the limitation for using acceleration data. In this paper, the errors which can be occurred in numerical processing of dynamic data are referred, and the method to sellect proper sampling rate for the structural frequency range are proposed. Using the proposed method, the displacement response of the structures can be economically obtained from the measured acceleration record, and this procedure can be used properly to estimate the integrity of the bridges and infrastructures subjected to dynamic loads.

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Design of an 8-bit 100KSPS Cyclic Type CMOS A/D Converter with 1mW Power Consumption (1mW의 전력소모를 갖는 8-bit 100KSPS Cyclic 구조의 CMOS A/D 변환기)

  • Lee, Jung-Eun;Song, Min-Kyu
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.9
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    • pp.13-19
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    • 1999
  • This paper describes a design of an 8-bit 100KSPS 1mW CMOS A/D Converter. Using a novel systematic offset cancellation technique, we reduce the systematic offset voltage of operational amplifiers. Further, a new Gain amplifier is proposed. The proposed A/D Converter is fabricated with a $0.6{\mu}m$ single-poly triple-metal n-well CMOS technology. INL and DNL is within ${\pm}1LSB$, and SNR is about 43dB at the sampling frequency of 100KHz. The power consumption is $980{\mu}W$ at +3V power supply.

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Systematic Forecasting Bias of Exit Poll: Analysis of Exit Poll for 2010 Local Elections (출구조사의 체계적인 예측 편향에 대한 분석: 2010년 지방선거 출구조사를 중심으로)

  • Kim, Young-Won;Choi, Yun-Jung
    • Survey Research
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    • v.12 no.3
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    • pp.25-48
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    • 2011
  • In this paper, we overview the sample design, sampling error, non-response rate and prediction errors of the exit poll conducted for 2010 local elections and discusses how to detect a prediction bias in exit poll. To investigate the bias problem in exit poll in regional(Si-Do) level, we analyze exit poll data for 2007 presidential election and 2006 local elections as well as 2010 local elections in Korea. The measure of predictive accuracy A proposed by Martin et al.(2005) is used to assess the exit poll bias. The empirical studies based on three exit polls clearly show that there exits systematic bias in exit poll and the predictive bias of candidates affiliated to conservative party (such as Hannara-Dang) is serious in the specific regions. The result of this study on systematic bias will be very useful to improving the exit poll methodology in Korea.

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Development Directions of Service Standards for Senior Congregate Housing

  • You Byung-Sun;Hong Hyung-Ock
    • International Journal of Human Ecology
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    • v.6 no.2
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    • pp.73-83
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    • 2005
  • The purpose of this study was to analyze the needs of future users for services at senior congregate housing and to look into the development directions of the service standards for senior congregate housing. A survey was conducted among middle-aged people in their fifties, who lived in Seoul, using the systematic random sampling method. The final sample included 498 respondents. The survey was conducted from November 3, 2003 to November 14, 2003. The results of this study were as follows. Firstly, as the need for housing services were high, it was quite clear that various services at senior congregate housing should be provided. Secondly, a service differentiation strategy should be proposed to meet the characteristics of the users. Thirdly, it was hereby suggested that service standards should be established in the following manner considering the relationship between the needs for services and the income level directly influencing the provision of services: 'Basic services' to be provided regardless of income, 'Optional services' to be selectable among the preferable services per income level, and 'Supportive services' to be provided for low-income people.

Prevalence Rate and Factors of Myopia in Preschool Children (서울시 학령전기 아동의 근시 유병률과 관련요인)

  • Kim Shin-Ja
    • Journal of Korean Academy of Nursing
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    • v.35 no.2
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    • pp.390-398
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    • 2005
  • Purpose: This study was aimed at providing basic data for developing a nursing intervention program which enables systematic and correct visual acuity care by discovering out visual acuity conditions, prevalence rate of myopia, and the factors related to myopia with Preschool children. Method: The subjects of this study consisted of 519 children between 3 and 6 years of age from 12 kindergartens in Seoul which were selected through multiple cluster sampling. Myopia was defined as the spherical equivalent (SE) of more than -0.5 diopters (D) in the right eye. The data was analyzed by t-test, 2-test, ANOVA, and logistic regression by using the SAS program. Result: The prevalence rate of myopia was $8.7\%$. the odds ratio of child myopia when one parent had myopia was 2.2 times higher than when neither parent had myopia. The odds ratio of child myopia when reading more than three books per week was 0.27 times higher than reading less than three books. Conclusion: Myopia should be continuously and intensively managed from the age of 3.

Achieving Local Residents' Support for Tourism Development through Community Satisfaction and Government Trust

  • Trinh, Thi Anh;Kim, Hyun-Jung
    • Culinary science and hospitality research
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    • v.22 no.1
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    • pp.96-107
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    • 2016
  • The purposes of the study are (1) to explore relationships amongst attitudes to positive/negative tourism impacts, community satisfaction, government trust, and support for tourism development and (2) to provide practical implications for policy makers how they can gain residents' support by increasing community satisfaction and government trust, which are resulted from attitudes to tourism impacts. A questionnaire is self-administered to local residents using a systematic sampling method in Ninh Hai Commune, Hoa Lu District, Ninh Binh Province, Vietnam. The results indicate community satisfaction and government trust are core factors of support for tourism development. The study highlights that to attain community satisfaction and government trust, the policy makers should especially increase positive socio-cultural and environmental impacts and minimize negative economic impacts on the community simultaneously.