• 제목/요약/키워드: Minimum sampling

검색결과 314건 처리시간 0.025초

우수유출 모형을 이용한 합류식하수관로시스템의 월류량, 월류빈도 산정 기준 결정 연구 (Criteria for calculation of CSO volume and frequency using rainfall-runoff model)

  • 이건영;나용운;류재나;오재일
    • 상하수도학회지
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    • 제27권3호
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    • pp.313-324
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    • 2013
  • It is widely known that untreated Combined Sewer Overflows (CSOs) that directly discharged from receiving water have a negative impact. Recent concerns on the CSO problem have produced several large scale constructions of treatment facilities, but the facilities are normally designed under empirical design criteria. In this study, several criteria for defining CSOs (e.g. determination of effective rainfall, sampling time, minimum duration of data used for rainfall-runoff simulation and so on) were investigated. Then this study suggested a standard methodology for the CSO calculation and support formalized standard on the design criteria for CSO facilities. Criteria decided for an effective rainfall was over 0.5 mm of total rainfall depth and at least 4 hours should be exist between two different events. An Antecedent dry weather period prior to storm event to satisfy the effective rainfall criteria was over 3 days. Sampling time for the rainfall-runoff model simulation was suggested as 1 hour. A duration of long-term simulation CSO overflow and frequency calculation should be at least recent 10 year data. A Management plan for the CSOs should be established under a phase-in of the plan. That should reflect site-specific conditions of different catchments, and formalized criteria for defining CSOs should be used to examine the management plans.

농지 공간격자 자료의 층화랜덤샘플링: 농업시스템 기후변화 영향 공간모델링을 위한 국내 농지 최적 층화 및 샘플 수 최적화 연구 (A stratified random sampling design for paddy fields: Optimized stratification and sample allocation for effective spatial modeling and mapping of the impact of climate changes on agricultural system in Korea)

  • 이민영;김용은;홍진솔;조기종
    • 환경생물
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    • 제39권4호
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    • pp.526-535
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    • 2021
  • 공간 샘플링은 공간모델링 연구에 활용되어 샘플링 비용을 줄이면서 모델링의 효율성을 높이는 역할을 한다. 농업분야에서는 기후변화 영향을 예측하고 평가하기 위한 고해상도 공간자료 기반 모델링에 대한 연구 수요가 빠르게 증가하고 있으며, 이에 따라 공간 샘플링의 필요성과 중요성이 증가하고 있다. 본 연구는 국내 농지 공간샘플링 연구를 통해 농업분야 기후변화연구의 공간자료 활용의 효율성을 제고하고자 하였다. 본 연구는 층화랜덤샘플링을 기반으로 하였으며, 1 km 해상도의 농지 공간격자자료 모집단(11,386개 격자)에 대해서 RCP 시나리오별(RCP 4.5/8.5) 연대별(2030/2050/2080년대) 공간샘플링을 설계하였다. 국내 농지는 기상 및 토양 특성에 따라 계층화 되었으며, 샘플링 효율 극대화를 위해 최적 층화 및 샘플 배정 최적화를 수행하였다. 최적화는 작물수량, 온실가스 배출량, 해충 분포 확률을 포함하는 16개 목표 변수에 대해 주어진 정밀도 제한 내에서 샘플 수를 최소화하는 방향으로 진행되었다. 샘플링의 정밀도와 정확도 평가는 각각 변동계수(CV)와 상대적 편향을 기반으로 하였다. 국내 농지 공간격자 모집단 계층화 및 샘플 배정 및 샘플 수 최적화 결과, 전체 농지는 5~21개 계층, 46~69개 샘플 수 수준에서 최적화되었다. 본 연구결과물들은 국내 농업시스템 대표 공간격자로써 널리 활용될 수 있을 것으로 기대된다. 또한, 기후변화 영향예측 공간모델링 연구들에 활용되어 샘플링 비용 및 계산 시간을 줄이면서도 모델의 효율성을 높이는 데에 기여할 수 있다.

Use of Fast Transfer Analysis Cartridges for Cervical Sampling and Real Time PCR Based High Risk HPV Testing in Cervical Cancer Prevention - a Feasibility Study from South India

  • Vijayalakshmi, Ramshankar;Viveka, Thangaraj Soundara;Malliga, JS;Murugan, Kothandaraman;Kanchana, Albert;Arvind, Krishnamurthy
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권14호
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    • pp.5993-5999
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    • 2015
  • Background: Molecular testing for human papillomavirus (HPV) is the most objective and reproducible of all cervical cancer screening tests and also less demanding in terms of training and quality assurance. However, there is an impending need for cost effective molecular HPV testing methods with sampling ease, easy storage measures and minimum turn around times suitable for a low resource setting. Objective : Our aim was to evaluate the feasibility of using a fast transfer analysis (FTA) mini elute cartridge for cervical sampling to identify high risk HPV by real time PCR and to compare molecular HPV testing and Pap cytology testing to predict histologically confirmed cervical precancer (CIN 2+ lesions) in a cervical cancer prevention program. Materials and Methods: This was conducted as a pilot study (n=200) on women sampled using FTA mini elute cartridges, genotyped by two different real time PCR assays, detecting 13 high risk HPV (HR HPV) species, including HPV16 along with its physical DNA status. Results obtained from each of the tests were compared and analysed using suitable statistical tests. Results: With FTA mini elute cartridge samples HR HPV positivity was seen in 48/200 (24%). Of these, presence of HPV 16 DNA was observed in 28/48 (58.3%) women. High risk HPV was positive in 20% (37/185) of women with benign cytology and 73.3% (11/15) of women with abnormal cytology findings. A very significant correlation (${\chi}^2=22.090$ ; p=0.000) was observed between cytology and HR HPV findings showing an increasing trend of HR HPV prevalence in 50% (1/2) of LSIL, 75% (3/4) of HSIL and 100% (3/3) of SCC. Of the CIN 2+ lesions identified by histopathology, 88.9% (8/9) had HR HPV. A significant association (${\chi}^2=11.223$ ; p=0.001) of HR HPV and histopathologically confirmed CIN 2+ lesions was found. Sensitivity of the two tests were comparable but specificity of Pap testing was better (90.7% vs 70.4%) to predict histopathologically diagnosed cervical precancers. Conclusions: The current study explored the feasibility of using a FTA mini elute cartridge for cervical sampling for the first time in India as a part of a community based cervical cancer prevention program. We suggest that FTA based sampling is suitable and feasible for real time based HPV testing. Molecular HR HPV testing can be more sensitive and useful to identify high risk women requiring Pap testing which is more specific to detect histologically confirmed cervical precancer.

고농도 오존 예측을 위한 향상된 변환 기법과 예측 성능 평가 (Modified Transformation and Evaluation for High Concentration Ozone Predictions)

  • 천성표;김성신;이종범
    • 한국지능시스템학회논문지
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    • 제17권4호
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    • pp.435-442
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    • 2007
  • 대기중의 고농도 오존의 피해를 줄이기 위해서, 고농도 오존 발생 전에 미리 오존 농도를 예측하기 위한 연구가 진행되었다. 하지만, 고농도 오존은 그 발생 빈도가 매우 희소하고, 대기 오존 생성 과정이 매우 비선형적이며 복잡한 특징이 있다. 이러한 특징을 극복하고 보다 정확한 예측 모델을 개발하기 위하여, 본 논문에서는 다양한 데이터 처리 기법을 도입하였다. 데이터 전처리과정에서 FCM(Fuzzy C-mean) 방법을 이용하여 오존 농도별 데이터 클러스터링을 시도하였으며, 결측 또는 비정상 데이터를 처리할 목적으로 Rejection 표본 추출법을 이용하였고, 모델의 입력과 출력의 상관관계를 향상시키기 위해서 로그 변환기법을 응용하였다. 오존 예측을 위한 모델링 기법은 DPNN(Dynamical Polynomial Neural Networks)을 이용하였으며, 최소 바이어스 판별법(Minimum Bias Criterion)으로 최적화된 모델을 선택하였다. 끝으로, 본 논문에서는 로그 변환기법이 예측 모델에 미치는 영향을 보이기 위해서 입력 데이터를 두 개의 집합으로 나누어 다양한 방법으로 예측 결과를 평가했다. 결과적으로 계절적 영향에 의해 특정 분포를 가지는 오존 관련 데이터에 있어서 로그 변환 방법이 모델의 성능을 향상시킬 수 있다는 것을 보였다.

Prevalence and Predictors of Complementary Feeding Practices Among Children Aged 6-23 Months in Indonesia

  • Siti, Nurokhmah;Lucinda, Middleton;Aryono, Hendarto
    • Journal of Preventive Medicine and Public Health
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    • 제55권6호
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    • pp.549-558
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    • 2022
  • Objectives: Poor complementary feeding practices have consistently contributed to the burden of child undernutrition in Indonesia. This study aimed to estimate the prevalence and predictors of the time of the introduction of solid, semi-solid, and soft foods (ISSSF), minimum dietary diversity (MDD), minimum meal frequency (MMF), and minimum acceptable diet (MAD). Methods: We analyzed 4804 last-born infants aged 6-23 months from the 2017 Indonesia Demographic and Health Survey, which employed multistage cluster random sampling. The outcomes were calculated based on the 2021 World Health Organization/United Nations Children's Fund guidelines. The predictors of the 4 complementary feeding indicators were assessed using multivariate Poisson regression with robust variance adjusting for potential confounders and study design. Results: The prevalence of ISSSF, MDD, MMF, and MAD was 86.1%, 54.3%, 71.8%, and 37.6%, respectively, with younger children less likely to meet 3 out of the 4 outcomes. Parental education, the presence of a birth attendant, and maternal media consumption were among the predictors of MDD and MAD. Children from families with higher income were more likely to meet MDD than those from low-income households (adjusted prevalence ratio [aPR], 1.16; 95% confidence interval [CI], 1.05 to 1.28). Living in an urban area was positively associated with MMF (aPR, 1.09; 95% CI, 1.04 to 1.15) and MAD (aPR, 1.12; 95% CI 1.02 to 1.24). In eastern regions, the prevalence of children achieving MDD and MAD was lower than in those living in Java and Bali. Conclusions: It is crucial that more attention and efforts are made to improve the recommended practices throughout Indonesia, since the prevalence of adequate complementary feeding practices remains low.

A Model-based 3-D Pose Estimation Method from Line Correspondences of Polyhedral Objects

  • Kang, Dong-Joong;Ha, Jong-Eun
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.762-766
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    • 2003
  • In this paper, we present a new approach to solve the problem of estimating the camera 3-D location and orientation from a matched set of 3-D model and 2-D image features. An iterative least-square method is used to solve both rotation and translation simultaneously. Because conventional methods that solved for rotation first and then translation do not provide good solutions, we derive an error equation using roll-pitch-yaw angle to present the rotation matrix. To minimize the error equation, Levenberg-Marquardt algorithm is introduced with uniform sampling strategy of rotation space to avoid stuck in local minimum. Experimental results using real images are presented.

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스펙트럼차에 기초한 LSP 추출방법 (An LSP Extraction Method Based on the Spectral Difference)

  • 김홍국
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1993년도 학술논문발표회 논문집 제12권 1호
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    • pp.253-258
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    • 1993
  • In this paper, we propose a new method to extract the line spectrum pair (LSP) frequencies. When speech signal is analyzed by the autocorrelation method, the spectral difference in the logarithmic spectra of the model at steps p and p-1 oscillates. There are p-1 frequency points where the values of the spectral dfference take on either maximum or minimum between 0 and half sampling frequency. We show that these frequencies are excatly the LSP frequencies of order p-1, which can be found by searching the frequencies where the spectral difference reaches either maxima or minima. also, the LSP frequencies of order p can be obtained from this spectral difference. In this case, we derive the expression governing the pth order LSP frequencies. The efficient search for finding the LSP frequencies of order p can be done by proving the property that the LSP frequencies of order p and p-1 are interlaced with each other.

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지역사회 청소년의 리더십기술 (A Study on Youth Leadership Skill of Community Youth)

  • 이채식;박은식
    • 농촌지도와개발
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    • 제13권1호
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    • pp.135-147
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    • 2006
  • The purpose of this study were to analyze youth leadership skill of rural youth and to suggest implication for rural youth development. The study was carried out questionnaire. To analyze youth leadership skill of rural youth, the data were collected from 196 rural youth by stratified random sampling. The SPSSWIN / ver12.0 was used for analyzing data with t-test, ANOVA, and factor analysis. The major findings of this study were as follows; 1) Average of youth leadership skill is 91.42, minimum is was 61, maximum is 130, 2)When it comes to youth leadership skill, it is higher in highly educated youth and higher economic status, 3)When it comes to youth leadership skill, it is higher in farming size, extending in three years, promise of farming successor. Conclusionally, the study suggests community youth should be offered more educational experience for developing youth leadership.

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Quality of service management for intelligent systems

  • Lee, Sang-Hyun;Jung, Byeong-Soo;Moon, Kyung-Il
    • International journal of advanced smart convergence
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    • 제3권2호
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    • pp.18-21
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    • 2014
  • A control application requirements currently used is very low, such as packet loss rate, minimum delay on sensor networks with quality of service (QoS) requirements some packet delivery guarantee. This paper is the sampling period at the end of the actuator and sensor data transfer related to the Miss ratio for each source sensor node, use the controller and the internal ANFIS. The proposed scheme has the advantages of simplicity, scalability, and General. Simulation results of the proposed scheme can provide QoS support in WSANs.

불소를 이용한 상수관망 수리해석의 검증 및 보정 (Verification and Calribration of Hydraulic Analysis of Water Supply System Using Fluoride Tracer)

  • 주대성;박노석;박희경;오정우
    • 상하수도학회지
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    • 제12권2호
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    • pp.76-82
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    • 1998
  • It is necessary to calculate the accurate velocity from the hydraulic model for the reliable prediction of water quality changes in water supply system. To verify the hydraulic analysis of the water supply system, fluoride was used as a tracer to calculate the travel time from the injection point to the sampling points. Results from this field experiment indicate that fluoride can be a good conservative tracer while it showed a little longitudinal dispersion along the pipe lines. And the velocity from the model was verified by these travel times and calibrated by changing the ratio of the unaccountable water. When the ratio of the unaccountable water. When the ratio of the unaccountable water was 20%, the error between the estimation of hydraulic model and the real travel time was minimum.

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