• Title/Summary/Keyword: model errors

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A BAYESIAN APPROACH TO THE IMPERFECT INSPECTION MODEL

  • Park, Choon-Il
    • Journal of applied mathematics & informatics
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    • v.6 no.2
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    • pp.589-598
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    • 1999
  • Classification errors are included in sampling -with -re-placement model where items are sampled from a Bernoulli process. Bayesian imperfect inspection model is considered. In addition con-jugate prior and predctive densities for imperfect inspection model are obtained.

STATIONARY $\beta-MIXING$ FOR SUBDIAGONAL BILINEAR TIME SERIES

  • Lee Oe-Sook
    • Journal of the Korean Statistical Society
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    • v.35 no.1
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    • pp.79-90
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    • 2006
  • We consider the subdiagonal bilinear model and ARMA model with subdiagonal bilinear errors. Sufficient conditions for geometric ergodicity of associated Markov chains are derived by using results on generalized random coefficient autoregressive models and then strict stationarity and ,a-mixing property with exponential decay rates for given processes are obtained.

Comparative Daylighting Performance Analysis of Offices in 1/10, 1/5 Scale Models and Mock-up Model (실물대모형 및 1/5, 1/10축소모형의 자연채광 성능평가에 관한 비교분석)

  • Baik, Seung Heon;Kim, Jeong Tai
    • KIEAE Journal
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    • v.6 no.4
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    • pp.25-32
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    • 2006
  • Mock-up model can be applied to measure accurate performance data but difficult to apply the variables in experiment. There can be a slight experiment errors in Scale model, but various parameters can be applied for a objective experiment. This paper aims to compare the daylighting performance in 1, 1/5, 1/10 scale model of offices and analyze the experiment errors to certificate the influence of model experiment. To analyse daylighting performance, a comparison of a Mock-up model, sized $12.0m(w){\times}7.2m(l){\times}3.7m(h)$, designed for experimentation of daylighting systems and its 1:5, 1:10 scale model. It has an identical configuration of reference room and the test room. For the test room, the lightshelf system was designed as Micro-4 reflective material. To assess work plane illuminance and light factor, photometric sensors of each room were installed at work-plane(6 points) and exterior horizontal illuminance (1 point). And luminance of window, rare of the room was measured under clear sky. It is to be monitored by Agilent data logger, photometric sensor Li-cor and the Radiant Imaging ProMetric 1400. Comparisons with a light factor, increase-decrease ratio and luminance are discussed.

Dialogue Strategies to Overcome Speech Recognition Errors in Form-Filling Dialogue (양식 채우기 대화에서 음성 인식 오류의 보완을 위한 대화 전략)

  • Kang Sang-Woo;Lee Song-Wook;Seo Jung-Yun
    • Korean Journal of Cognitive Science
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    • v.17 no.2
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    • pp.139-150
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    • 2006
  • Speech recognition errors cause fatal results in a spoken dialogue system. When a system can not determine the speech-act of u utterance due to speech recognition errors, a dialogue system has a difficulty in continuing conversation. In this paper, we propose strategies for sub-dialogue generation by inferring the speech-act of an utterance with patterns of recognition errors on the field of form-filling dialogue. We used the proposed method on a plan-based dialogue model, corrected 27% of incomplete tasks, and acquired overall 89% of task completion rate.

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Compensation of SDINS Navigation Errors Using Line-Of-Sight Vector (시선벡터를 이용한 관성항법장치의 보정기법)

  • Lim, You-Chol;Yim, Jong-Bin;Lyou, Joon
    • Proceedings of the IEEK Conference
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    • 2003.07c
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    • pp.2521-2524
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    • 2003
  • Since inertial sensor errors which increase with time are caused by initial orientation error and sensor errors (accelerometer bias and gyro drift bias), the accuracy of these devices, while still improving, is not adequate for many of today's high-precision, long-duration sea, aircraft, and long-range missile missions. This paper presents a navigation error compensation scheme for Strap-Down Inertial Navigation System (SDINS) using Line-Of-Sight(LOS) vector from star sensor. To be specific, SDINS error model and measurement equation are derived, and Kalman filter is implemented. Simulation results show the bounded-ness of position and attitude errors.

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Calibation and Compensation for the Kinematic Error in Robot Manipulatior (로봇의 기구학적 오차측정과 보상에 관한 연구)

  • 이종신;임성호;조희상;이의훈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.545-549
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    • 1993
  • This paper presents the method of calibrating and compensating for the kinematic errors in robot manipulators. A calibration model is developed to represent any geometric errors in the manipulator's structure. A calibration jig is used to find the values of these kinematic errors in the end-effector's position and a calibration algormined for a SSR-6 robot manipulator developed by Samsung Heavy Industry, Daeduk R & D Center. Through this experiment the maximun kinematic error is reduced from 10mm to 0.4mm

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A Study of TCP Performance with Snoop Protocol over Fading Wireless Links

  • Cho, Yang-Bum;Cho, Sung-Joon
    • Journal of information and communication convergence engineering
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    • v.2 no.4
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    • pp.214-218
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    • 2004
  • In this paper, we have analyzed TCP performance over wireless correlated fading links with and without Snoop protocol. For a given value of the packet error rate, TCP performance without Snoop protocol is degraded as the fading is getting fast (i.e. the user moves fast). When Snoop protocol is introduced in the base station, TCP performance is enhanced in most wireless environments. Especially the performance enhancement derived from using Snoop protocol is large in fast fading channel. This is because packet errors become random and sporadic in fast fading channel and these random packet errors (mostly single packet errors) can be compensated efficiently by Snoop protocol's local packet retransmissions. But Snoop protocol can't give a large performance improvement in slow fading environments where long bursts of packet errors occur. Concerning to packet error rate, Snoop protocol results in the highest performance enhancement in the channel with mid-high values of packet error rate. This means Snoop protocol cannot fully fulfill its ability under too low or too high packet error rate environments.

Inversion of Geophysical Data with Robust Estimation (로버스트추정에 의한 지구물리자료의 역산)

  • Kim, Hee Joon
    • Economic and Environmental Geology
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    • v.28 no.4
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    • pp.433-438
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    • 1995
  • The most popular minimization method is based on the least-squares criterion, which uses the $L_2$ norm to quantify the misfit between observed and synthetic data. The solution of the least-squares problem is the maximum likelihood point of a probability density containing data with Gaussian uncertainties. The distribution of errors in the geophysical data is, however, seldom Gaussian. Using the $L_2$ norm, large and sparsely distributed errors adversely affect the solution, and the estimated model parameters may even be completely unphysical. On the other hand, the least-absolute-deviation optimization, which is based on the $L_1$ norm, has much more robust statistical properties in the presence of noise. The solution of the $L_1$ problem is the maximum likelihood point of a probability density containing data with longer-tailed errors than the Gaussian distribution. Thus, the $L_1$ norm gives more reliable estimates when a small number of large errors contaminate the data. The effect of outliers is further reduced by M-fitting method with Cauchy error criterion, which can be performed by iteratively reweighted least-squares method.

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Diagnostic System of Modeling Errors Generated from IGES CAD Data Exchange (IGES CAD 데이터의 교환에서 오류 진단 시스템)

  • Park, Sang-Ho;Park, Jong-Wook;Han, Soon-Heung;Choi, Young;Yang, Jung-Sam;Lee, Byung-Hoon
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.10
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    • pp.218-225
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    • 2003
  • A diagnostic system has been developed which reports modeling errors generated when exchanging CAD data using IGES (Initial Graphics Exchange Specification) format. The system determines whether the CAD data contains errors. It also helps to define the criteria for determining the integrity and interoperability of CAD data with downstream applications of another CAD/CAM/CAE/PDM systems. The methodology of our algorithms is to analyze IGES model data by identifying errors and anomalies with respect to the diagnosis of geometry and topology. The GUI (Graphic User Interface) of the developed system helps users to input values and to visualize diagnostic results at real time.

A Study on the Effects of Motion Errors for Acceleration/Deceleration Types (가감속 형태에 叫른 운동오차의 영향에 대한 연구)

  • 신동수;곽경남;정성종
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.671-677
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    • 1996
  • This paper proposes a study on the effects of motion errors for acceleration/ deceleration types. The proposed motion errors are consisted of two errors : one due to transient response of servomechanism and the other due to gain mismatching of positioning servo motor. They are derived from using laplace transformation for the block diagram of general purpose feed drive system. In order to minimize them, the paper proposes second order polynomial regression model by using orthogonal array method which describes one of experimental methodolgies. The validity and reliability of the study was veri lied on a vertical machining center equipped with FANUC 0MC through a series of experiments and analyses.

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