• Title/Summary/Keyword: Estimate

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Observed Data Oriented Bispectral Estimation of Stationary Non-Gaussian Random Signals - Automatic Determination of Smoothing Bandwidth of Bispectral Windows

  • Sasaki, K.;Shirakata, T.
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.502-507
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    • 2003
  • Toward the development of practical methods for observed data oriented bispectral estimation, an automatic means for determining the smoothing bandwidth of bispectral windows is proposed, that can also provide an associated optimum bispectral estimate of stationary non-Gaussian signals, systematically only from an observed time series datum of finite length. For the conventional non-parametric bispectral estimation, the MSE (mean squared error) of the normalized estimate is reviewed under a certain mixing condition and sufficient data length, mainly from the viewpoint of the inverse relation between its bias and variance with respect to the smoothing bandwidth. Based on the fundamental relation, a systematic method not only for determining the bandwidth, but also for obtaining the optimum bispectral estimate is presented by newly introducing a MSE evaluation index of the estimate only from an observed time series datum of finite length. The effectiveness and fundamental features of the proposed method are illustrated by the basic results of numerical experiments.

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IRI estimation using analysis of dynamic tire pressure and axle acceleration

  • Zhao, Yubo;McDaniel, J. Gregory;Wang, Ming L.
    • Smart Structures and Systems
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    • v.19 no.2
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    • pp.151-161
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    • 2017
  • A new method is developed to estimate road profile in order to estimate IRI based on the ASTM standard. This method utilizes an accelerometer and a Dynamic Tire Pressure Sensor (DTPS) to estimate road roughness. The accelerometer measures the vertical axle acceleration. The DTPS, which is mounted on the tire's valve stem, measures dynamic pressure inside the tire while driving. Calibrated transfer functions are used to estimate road profile using the signals from the two sensors. A field test was conducted on roads with different quality conditions in the city of Brockton, MA. The IRI values estimated with this new method match the actual road conditions measured with Pavement Condition Index (PCI) based on the ASTM standard, images taken from an onboard camera and passengers' perceptions. IRI has negative correlation with PCI in general since they have overlapping features. Compared to the current method of IRI measurement, the advantage of this method is that a) the cost is reduced; b) more space is saved; c) more time is saved; and d) mounting the two sensors are universally compatible to most cars and vans. Therefore, this method has the potential to provide continuous and global monitoring the health of roadways.

The method of evaluating the validity in making the checklist of statistical method (통계기법 점검표 작성시 타당성 평가방법)

  • Lee, Sang-Bock;Kim, Mal-Sook
    • Journal of the Korean Data and Information Science Society
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    • v.9 no.2
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    • pp.323-336
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    • 1998
  • This thesis is to propose the method of evaluating the validity in stages on the design of a checklist based on the estimate theory of the validity on the design of a checklist and the method of evaluating the validity accordy to the purpose for usiug checklist and establish the standards of estimating the validity in stages on the checklist owing to the estimate theory with the journal, Journal of the Korean Society of Clothing and Textiles. We are emboding the statistical consulting server using the proposed estimate method of the validity and the followings we the questions to solve in future. First, there are many kinds of the statistical methods used in the fields of learing and applied technalogy. So we must establish the statistical standars required in each field and study and develope the special statistical checklists. Second, it is neded to systemize the estimate methods and standard on the validity by building the statistical consult DB, evaluate the researchers according to the degrees of statistical knowledge the validity of study design iud propose the delicate and generalized statistical methods appropriate to the ability of researchers.

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Pollutant Loading Estimates from Watershed by Rating Curve Method and SWMM

  • Jeon, Ji-Hong;Yoon, Chun-Gyeong
    • Korean Journal of Environmental Agriculture
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    • v.19 no.5
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    • pp.419-425
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    • 2000
  • Rating curve method and SWMM (Storm Water Management Model) were applied to estimate pollutant loading from Hwa-Ong watershed in Kyunggi-Do. Rating curves were derived from sampling sites and applied to the whole watershed. SWMM version 4.4 was calibrated by field data of sampling sites and applied to the whole watershed. The pollutant loading estimated by rating curve was slightly higher than the one by SWMM, but the difference was not significant considering diffuse pollution characteristics of wide variation. Land use effect of the subcatchments could not be incorporated logically in rating curve method and difficulty in extrapolation was experienced, therefore, the estimate by rating curve method was thought to be less confident. SWMM was satisfactory in estimation of pollution loading, and its great flexibility worked well to describe complex nonurban land uses. Neither of them could exactly describe complex natural phenomena, but SWMM was preferred in this study due to its flexibility and logical hydrologic processes including land use effects. Use of reasonable watershed model rather than rating curve method for watershed pollutant loading estimate can be more practical and is recommended.

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Influence of Offspring on Quality of Life among Cancer Patients and Survivors: Results from the Korean Longitudinal Study of Aging (KLoSA), 2008-2011

  • Kim, Jae-Hyun;Park, Eun-Cheol
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10531-10537
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    • 2015
  • Background: To examine whether offspring improve or reduce quality of life (QOL) among cancer patients and survivors. Materials and Methods: We used data from the Korean Longitudinal Study of Aging (KLoSA) from 2008 to 2011. There were 490 research subjects in our study: 245 cancer patients and survivors and 245 controls matched using propensity scores. Results: For cancer patients and survivors with no offspring, the QOL estimate was -2.831 lower (SE: 5.508, p-value: 0.623) than that of those with two offspring, while for those with five or more offspring, the QOL estimate was 7.336 higher (SE: 2.840, p-value: 0.036). For non-cancer patients and survivors with one child, the QOL estimate was -11.258 lower (SE: 2.430, p-value: 0.002) than that of those with two offspring, while for those with five or more offspring, the QOL estimate was -4.881 lower (SE: 2.484, p-value: 0.090). Conclusions: This article provides evidence for a beneficial effect of offspring upon QOL in cancer patients and survivors, indicating that offspring are important for them.

Capacity Optimization of Two-way Amplify-and Forward Relay Networks (Two-way 증폭과 전송 릴레이 네트워크의 용량 최적화)

  • Hanif, Mohammad Abu;Lee, Moon Ho;Park, Ju Yong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.1
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    • pp.27-33
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    • 2013
  • In this paper, we propose a pilot based channel estimation technique in two-way relay networks. We propose to transmit a pilot symbol together with the data symbol during transmission. In absence of Channel State Information (CSI), destination uses the pilot symbol to estimate the channel. In this system, the relay amplifies the pilot and the data symbol then forward them to the destination using amplify and forward (AF) protocol. We assume that the relay gain is fixed, so the relay does not need to estimate the channel, the destination only estimate the channel. We apply well-known Least-square (LS) and minimum mean-square error (MMSE) channel estimation methods to estimate the channel.

Comparative analysis of Bayesian and maximum likelihood estimators in change point problems with Poisson process

  • Kitabo, Cheru Atsmegiorgis;Kim, Jong Tae
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.1
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    • pp.261-269
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    • 2015
  • Nowadays the application of change point analysis has been indispensable in a wide range of areas such as quality control, finance, environmetrics, medicine, geographics, and engineering. Identification of times where process changes would help minimize the consequences that might happen afterwards. The main objective of this paper is to compare the change-point detection capabilities of Bayesian estimate and maximum likelihood estimate. We applied Bayesian and maximum likelihood techniques to formulate change points having a step change and multiple number of change points in a Poisson rate. After a signal from c-chart and Poisson cumulative sum control charts have been detected, Monte Carlo simulation has been applied to investigate the performance of Bayesian and maximum likelihood estimation. Change point detection capacities of Bayesian and maximum likelihood estimation techniques have been investigated through simulation. It has been found that the Bayesian estimates outperforms standard control charts well specially when there exists a small to medium size of step change. Moreover, it performs convincingly well in comparison with the maximum like-lihood estimator and remains good choice specially in confidence interval statistical inference.

Performance Comparison of Background Estimation in the Video (영상에서의 배경추정알고리즘 성능 비교)

  • Do, Jin-Kyu;Kim, Gyu-Yeong;Park, Jang-Sik;Kim, Hyun-Tae;Yu, Yun-Sik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.05a
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    • pp.808-810
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    • 2011
  • The background estimation algorithms had a significant impact on the performance of image processing and recognition. In this paper, background estimation algorithms were analysis of complexity and performance as preprocessing of image recognition. It was evaluated the performance of Gaussian Running Average, Mixture of Gaussian, and KDE algorithm. The simulation results show that KDE algorithm outperforms compared to the other algorithms.

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Implicit Treatment of Technical Specification and Thermal Hydraulic Parameter Uncertainties in Gaussian Process Model to Estimate Safety Margin

  • Fynan, Douglas A.;Ahn, Kwang-Il
    • Nuclear Engineering and Technology
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    • v.48 no.3
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    • pp.684-701
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    • 2016
  • The Gaussian process model (GPM) is a flexible surrogate model that can be used for nonparametric regression for multivariate problems. A unique feature of the GPM is that a prediction variance is automatically provided with the regression function. In this paper, we estimate the safety margin of a nuclear power plant by performing regression on the output of best-estimate simulations of a large-break loss-of-coolant accident with sampling of safety system configuration, sequence timing, technical specifications, and thermal hydraulic parameter uncertainties. The key aspect of our approach is that the GPM regression is only performed on the dominant input variables, the safety injection flow rate and the delay time for AC powered pumps to start representing sequence timing uncertainty, providing a predictive model for the peak clad temperature during a reflood phase. Other uncertainties are interpreted as contributors to the measurement noise of the code output and are implicitly treated in the GPM in the noise variance term, providing local uncertainty bounds for the peak clad temperature. We discuss the applicability of the foregoing method to reduce the use of conservative assumptions in best estimate plus uncertainty (BEPU) and Level 1 probabilistic safety assessment (PSA) success criteria definitions while dealing with a large number of uncertainties.

Recreational Physical Activity and Risk of Ovarian Cancer: a Meta-analysis

  • Zhou, Li-Min
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.13
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    • pp.5161-5166
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    • 2014
  • Our aim was to access the association between recreational physical activity (RPA) and risk of ovarian cancer (OC). The studies were retrieved from the PubMed and Embase databases up to February 20th, 2014. Risk ratios (OR) and 95% confidence intervals (CI) were used to estimate effect sizes. Random-effects or fixed-effects models were used to pool the data. The trim and fill method was applied for sensitivity analysis. Begg's rank correlation test and Egger's regression asymmetry test were employed to assess the publication bias. A total of 6 studies (435398 participants including 2983 OC patients) were included in this meta-analysis. The overall estimate indicated that there was weakly inverse association between RPA and OC risk (RR=0.90, 95%CI: 0.72-1.12, p=0.335). Meanwhile, for prospective cohort studies, a result consistent with the overall estimate was obtained (RR=1.12, 95% CI: 0.88-1.42, p=0.356). However, for case control studies, the pooled estimate of RR was 0.76 (95%CI: 0.64-0.90, p=0.002), indicating a clear significant association between RPA and OC risk. In addition, the sensitivity analysis indicated a significant link between RPA and risk of OC after removing Lahmann's study (RR=0.80, 95% CI: 0.68-0.93, p=0.004). No significant publication bias was found (Begg's test: p=1.00; Egger's test: p=0.817). In conclusion, our meta-analysis indicated a weakly inverse relationship between RPA and the occurrence of OC.