• Title/Summary/Keyword: Best Point Estimate

Search Result 69, Processing Time 0.037 seconds

A Study on Analysis of Emitter Geolocation Coverage Area based on the Characteristics and Deployment of Sensors (센서 특성 및 배치를 고려한 에미터 위치탐지 영역 분석에 관한 연구)

  • Yang, Jong-Won;Park, Cheol-Sun;Jang, Won
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.9 no.1 s.24
    • /
    • pp.99-108
    • /
    • 2006
  • In this paper, we analyzed the characteristics of emitter geolocation coverage area within which the emitter lies with a specified probability based on the LOBs(Line of Bearing) of sensors. Stansfield and MSD algorithms were applied to calculate BPE(Best Point Estimate), EEP(Elliptical Error Probable) and CEP(Circular Error Probable), They used the weighting factors composed of ${\sigma}_{Phi}$ (bearing error), QF(quality factor), $P_{e}$ (probability being inside) to optimize the performance. The characteristics of EEP was investigated in the change of them and those of CEP was analyzed based on the deployment of sensors.

VARIANCE ESTIMATION OF ERROR IN THE REGRESSION MODEL AT A POINT

  • Oh, Jong-Chul
    • Journal of applied mathematics & informatics
    • /
    • v.13 no.1_2
    • /
    • pp.501-508
    • /
    • 2003
  • Although the estimate of regression function is important, some have focused the variance estimation of error term in regression model. Different variance estimators perform well under different conditions. In many practical situations, it is rather hard to assess which conditions are approximately satisfied so as to identify the best variance estimator for the given data. In this article, we suggest SHM estimator compared to LS estimator, which is common estimator using in parametric multiple regression analysis. Moreover, a combined estimator of variance, VEM, is suggested. In the simulation study it is shown that VEM performs well in practice.

Moments and Estimation From Progressively Censored Data of Half Logistic Distribution

  • Sultan, K.S.;Mahmoud, M.R.;Saleh, H.M.
    • International Journal of Reliability and Applications
    • /
    • v.7 no.2
    • /
    • pp.187-201
    • /
    • 2006
  • In this paper, we derive recurrence relations for the single and product moments of progressively Type-II right censored order statistics from half logistic distribution. Next, we derive the maximum likelihood estimators (MLEs) of the location and scale parameters of the half logistic distribution. In addition, we use the setup proposed by Balakrishnan and Aggarwala (2000) to compute the approximate best linear unbiased estimates (ABLUEs) of the location and scale parameters. Finally, we point out a simulation study to compare between the efficiency of the techniques considered for the estimation.

  • PDF

Analysis of Loss of Offsite Power Transient Using RELAP5/MOD1/NSC; II: KNU1 Design-Base Simulation (RELAP5/MOD1/NSC를 이용한 원자력 1호기 외부전원상실사고해석;II:설계기준사고)

  • Kim, Hyo-Jung;Chung, Bub-Dong;Lee, Young-Jin;Kim, Jin-Soo
    • Nuclear Engineering and Technology
    • /
    • v.18 no.3
    • /
    • pp.175-182
    • /
    • 1986
  • The KNUI (Korea Nuclear Unit 1) loss of offsite power transient as a design-base accident has been simulated using the RELAP5/MOD1/NSC computer code. The analysis is carried out using the best-estimate methodology, but the sequence and its assumptions are based on the evaluation methodology th at emphasizes conservatism. Important thermal-hydraulic parameters such as average temperature, steam generator level and pressurizer water volume are compared with the results in the KNU1 Final Safety Analysis Report (FSAR). The present analysis gives much lower RCS average temperature and pressurizer water volume, and much higher S/G water volume at the turnaround point, which may be considered to be additional improved safety margins. This is expected since the present analysis deals with the best-estimate thermal-hydraulic models as well as the initial conditions on a best-estimate basis. These additional safety margins may contribute to further validate the safety of the KNU1 in this type of accidents(Decrease in Heat Removal by the Secondary System).

  • PDF

Surface Extraction from Point-Sampled Data through Region Growing

  • Vieira, Miguel;Shimada, Kenji
    • International Journal of CAD/CAM
    • /
    • v.5 no.1
    • /
    • pp.19-27
    • /
    • 2005
  • As three-dimensional range scanners make large point clouds a more common initial representation of real world objects, a need arises for algorithms that can efficiently process point sets. In this paper, we present a method for extracting smooth surfaces from dense point clouds. Given an unorganized set of points in space as input, our algorithm first uses principal component analysis to estimate the surface variation at each point. After defining conditions for determining the geometric compatibility of a point and a surface, we examine the points in order of increasing surface variation to find points whose neighborhoods can be closely approximated by a single surface. These neighborhoods become seed regions for region growing. The region growing step clusters points that are geometrically compatible with the approximating surface and refines the surface as the region grows to obtain the best approximation of the largest number of points. When no more points can be added to a region, the algorithm stores the extracted surface. Our algorithm works quickly with little user interaction and requires a fraction of the memory needed for a standard mesh data structure. To demonstrate its usefulness, we show results on large point clouds acquired from real-world objects.

A REVIEW AND INTERPRETATION OF RIA EXPERIMENTS

  • Vitanza, Carlo
    • Nuclear Engineering and Technology
    • /
    • v.39 no.5
    • /
    • pp.591-602
    • /
    • 2007
  • The results of Reactivity-Initiated Accidents (RIA) experiments have been analysed and the main variables affecting the fuel failure propensity identified. Fuel burn-up aggravates the mechanical loading of the cladding, while corrosion, or better the hydrogen absorbed in the cladding as a consequence of corrosion, may under some conditions make the cladding brittle and more susceptible to failure. Experiments point out that corrosion impairs the fuel resistance for RIA transient occurring at cold conditions, whereas there is no evidence of important embrittlement effects at hot conditions, unless the cladding was degraded by oxide spalling. A fuel failure threshold correlation has been derived and compared with experimental data relevant for BWR and PWR fuel. The correlation can be applied to both cold and hot RIA transients, account taken for the lower ductility at cold conditions and for the different initial enthalpy. It can also be used for non-zero power transients, provided that a term accounting for the start-up power is incorporated. The proposed threshold is easy to use and reproduces the results obtained in the CABRI and NSRR tests in a rather satisfactory manner. The behaviour of advanced PWR alloys and of MOX fuel is discussed in light of the correlation predictions. Finally, a probabilistic approach has been developed in order to account for the small scatter of the failure predictions. This approach completes the RIA failure assessment in that after determining a best estimate failure threshold, a failure probability is inferred based on the spreading of data around the calculated best estimate value.

Design of Digital Controllers with Self-Validating Intelligent Sensors (Self-Validating 지능형 센서를 사용한 디지털 제어기의 설계)

  • 나승유;배희종
    • Proceedings of the IEEK Conference
    • /
    • 2000.06e
    • /
    • pp.51-54
    • /
    • 2000
  • We are concerned with processing methods of the measurement values of sensors in the control system. When some faults happen to sensor components, the measurement value of sensors cause the malfunction of the plant. So it is necessary to detect and reduce the influence of faults to control with reliability for the overall system. The sensor status must be always good for best demonstration of the controller performance. A self-validating sensor detects the sensor state from the measurement value, reconstruct a soft sensor and can improve reliability of the sensor. If sensor faults, the sensor is detected and reconstructed with the best estimate from its correlation to other sensors and historical data. It is applied to the control of a flexible link system with the sensor fault problems in the light sensor module for position to show the applicability. In this paper, we propose a digital controller which reduces deflection of the moving set-point by reconstructing output of a sensor when the sensor fault is detected.

  • PDF

Analysis of Runoff Characteristics of Non-point Sources Pollutant and Application of BMP Using BASINS/WinHSPF Model (BASINS/WinHSPF 모형을 이용한 비점오염물질 유출특성 분석과 최적관리기법 적용)

  • Kim, Min Joo;Kim, Tae Geun
    • Journal of Environmental Impact Assessment
    • /
    • v.23 no.2
    • /
    • pp.88-100
    • /
    • 2014
  • This study analyzed runoff characteristics of non-point sources pollutant and evaluated removal of pollution by BMP(Best Management Practice) using BASINS/WinHSPF model. Hourly meterological data including input data was provided from 2010 to 2011 year to run HSPF model in Miho stream watershed. As the results of calibration and validation of the model, the model could be successfully performed to simulate the flow and water quality parameters. The apprehensive area of non-point source pollution was chosen by non-point source pollution per area of a tributary to the Miho stream and applied constructed wetland in area chosen. Three scenarios were based on installation area of an constructed wetland and HSPF model would be applied to estimate the pollutant removals through the constructed wetland. The removal rates of pollutants through the constructed wetland were estimated with the runoff and water quality parameters by the comparisons of before and after the constructed wetland application.

A Fast Block Matching Algorithm Using Hierarchical Search Point Sampling (계층적인 탐색점 추출을 이용한 고속 블록 정합 알고리즘)

  • 정수목
    • Journal of the Korea Computer Industry Society
    • /
    • v.4 no.12
    • /
    • pp.1043-1052
    • /
    • 2003
  • In this paper, we present a fast motion estimation algorithm to reduce the computations of block matching algorithm for motion estimation in video coding. The proposed algorithm is based on Multi-level Successive Elimination Algorithm and Efficient Multi-level Successive Elimination Algorithms. The best estimate of the motion vectors can be obtained by hierarchical search point sampling and thus the proposed algorithm can decrease the number of matching evaluations that require very intensive computations. The efficiency of the proposed algorithm was verified by experimental results.

  • PDF

The Distribution Analysis of PM10 in Seoul Using Spatial Interpolation Methods (공간보간기법에 의한 서울시 미세먼지(PM10)의 분포 분석)

  • Cho, Hong-Lae;Jeong, Jong-Chul
    • Journal of Environmental Impact Assessment
    • /
    • v.18 no.1
    • /
    • pp.31-39
    • /
    • 2009
  • A lot of data which are used in environment analysis of air pollution have characteristics that are distributed continuously in space. In this point, the collected data value such as precipitation, temperature, altitude, pollution density, PM10 have spatial aspect. When geostatistical data analysis are needed, acquisition of the value in every point is the best way, however, it is impossible because of the costs and time. Therefore, it is necessary to estimate the unknown values at unsampled locations based on observations. In this study, spatial interpolation method such as local trend surface model, IDW(inverse distance weighted), RBF(radial basis function), Kriging were applied to PM10 annual average concentration of Seoul in 2005 and the accuracy was evaluated. For evaluation of interpolation accuracy, range of estimated value, RMSE, average error were analyzed with observation data. The Kriging and RBF methods had the higher accuracy than others.