• Title/Summary/Keyword: Safety Estimation

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A Study on the Real-Time Parameter Estimation of DURUMI-II for Control Surface Fault Using Flight Test Data (Longitudinal Motion)

  • Park, Wook-Je;Kim, Eung-Tai;Song, Yong-Kyu;Ko, Bong-Jin
    • International Journal of Control, Automation, and Systems
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    • v.5 no.4
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    • pp.410-418
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    • 2007
  • For the purpose of fault detection of the primary control surface, real-time estimation of the longitudinal stability and control derivatives of the DURUMI-II using the flight data is considered in this paper. The DURUM-II, a research UAV developed by KARI, is designed to have split control surfaces for the redundancy and to guarantee safety during the fault mode flight test. For fault mode analysis, the right elevator was deliberately fixed to the specified deflection condition. This study also mentions how to implement the multi-step control input efficiently, and how to switch between the normal mode and the fault mode during the flight test. As a realtime parameter estimation technique, Fourier transform regression method was used and the estimated data was compared with the results of the analytical method and the other available method. The aerodynamic derivatives estimated from the normal mode flight data and the fault mode data are compared and the possibility to detect the elevator fault by monitoring the control derivative estimated in real time by the computer onboard was discussed.

A Novel Enhanced Decision-Directed Channel Estimation Scheme in High-Speed Mobile Environments (고속 이동 전파환경에서 결정지향 채널 추정 기법의 개선)

  • Ren, Yongzhe;Park, Dong Chan;Kim, Suk Chan
    • Journal of Satellite, Information and Communications
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    • v.10 no.1
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    • pp.29-32
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    • 2015
  • It has been a big trend of the convergence technologies about communication systems and vehicular industry to improve safety and convenience. To achieve a number of infotainment vehicular applications, vehicles should transmit information with high reliability. A robust and accurate channel estimation scheme is of great importance to achieve the goal. In this paper, we present a novel enhanced decision-directed channel estimation scheme called FADP (Frequency Averaging Data Pilot) for dynamic time-varying vehicular channels in IEEE 802.11p. We use linear averaging filtering in frequency domain, and utilize the correlation characteristic of the channels between the adjacent two data symbols, update the CR in time domain to get more accuracy. Finally, analysis and simulation results reveal that compared with exist schemes, the proposed scheme has a good performance in mean square error (MSE) and bit error rate (BER).

Maximum Tolerated Dose Estimation with Dose De-Escalation Design in a Phase I Clinical Trials (제 1상 임상시험에서 용량 감량을 허용하는 MTD 추정법)

  • Jang, Eunah;Kim, Dongjae
    • The Korean Journal of Applied Statistics
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    • v.27 no.7
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    • pp.1115-1123
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    • 2014
  • The main purpose of phase I clinical trials is to estimate the Maximum Tolerated Dose (MTD), which minimizes side effect and assures safety of a new drug by evaluating the toxicity at each dose-level. The conventional MTD estimation methods is Standard method (Storer, 1989; Korn et al., 1994), Accelerated Titration Designs (Simon et al., 1997) and DM method (Dixon and Mood, 1948) etc. In this paper, MTD estimation method with de-escalation is suggested phase I clinical trials. The proposed MTD estimation method is compared to Accelerated Titration Designs, SM3 without de-escalation method and SM3 with de-escalation method using a Monte Carlo simulation.

Reactor Neutron Noise Analysis using AR Spectral Estimation (AR 스펙트럼 추정법을 이용한 원자로 중성자 잡음 신호 해석)

  • Sim, Cheul-Muu;Hwang, Tae-Jin;Baik, Heung-Ki
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.5
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    • pp.83-91
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    • 1997
  • A reactor vibration monitoring has been performed using neutron noise obtained from excore detectors for the safety operation, Traditionally, the spectral estimator based on Fourier analysis has been widely used in the noise analysis of the reactor system. If the bias is too severe, the resolution would not be adequate for a given application. One major motivation for the current interests in the parametric approach to spectral estimation is the apparent higher resolution achievable with these modern techniques. In considering an unbias, a consistency, an efficency, and a minimum lower bound of the statictic estimation, an AR model is appropriate for noise spectral estimation with sharp peaks but not deep valley. In order to select an appropriate model order, the lag value of autocorrleaton function is applied. Burg method to trace the vibration mode of RPV internal is the most sucuessful.

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Fault Tolerant Control of Sensor Fault of EPB System (EPB 시스템의 센서 고장 허용 제어 기법)

  • Lee, Won-Goo;Lee, Young-Ok;Jang, Min-Seok;Lee, Choong-Woo;Chung, Chung-Choo;Chung, Han-Byul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.4
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    • pp.8-17
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    • 2010
  • In this paper, a fault tolerant control against sensor faults of electric parking brake (EPB) is proposed. Fault tolerant control method of EPB system is strongly demanded since sensor faults can endanger a driver's safety. In this paper, a clamp force estimation method is presented using motor's armature current and angular velocity. Clamp force estimation method is applied for fault detection method with parity equations. The goal of the detection method is to detect and identify faults in encoder, current sensor, force sensor, and parking cable. And a switching logic for fault tolerant control against the three sensor faults is suggested. Experimental results show that the proposed force estimation method satisfies the specifications of EPB system. The effectiveness of the fault detection method is validated with experimental results. Although a single sensor fault happens, EPB system with the proposed fault detection method does not develop into a failure on subsystem or system level.

Study on the Development of Qualification for Fire Identification and Estimation (화재감식평가 자격개발에 관한 연구)

  • Lee, Su-Kyung;Kim, Young-Chul;Oh, Hyung-Sool;Jung, Ki-Sin;Song, Dong-Woo;Kim, Tae-Hoon
    • Fire Science and Engineering
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    • v.24 no.3
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    • pp.78-85
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    • 2010
  • Currently, there are various institutions performing fire investigation and identification, such as fire stations and police stations as well as institutes related to fire safety, etc. And the manpower working at the institutions reaches a large number of persons. But there is no objective index on the expertise of the persons. In this paper, we suggested the examination criteria through job analysis and the enforcement method of the exam system. And we developed suitable exam subjects and exam content specifications for qualification of fire identification and estimation that investigate a fire cause, combustion, escape circumstances and fire facilities at the scene of a fire, survey the fire damage and analysis fire cause, etc. It will increase the public trust to develop national technical qualification items of the fire identification and estimation engineer.

A Study on the Needs and Estimation of Users in the Playground of Child Care Facilities (보육시설의 실외놀이 환경에 대한 사용자 평가 및 요구조사)

  • Choi, Mock-Wha;Byun, Hea-Ryun
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2008.04a
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    • pp.386-392
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    • 2008
  • The purpose of this study is to clarify playground types by characteristics of playground environment in child care facilities, to analyze the needs and estimation of users according to playground types. The subjects of this study were care-givers, who assist outdoor play activities of children and manage safety in playground, to estimate adequateness of playground's environment to children's outdoor plays and to report needs. The data were collected by field measurement survey for clarification playground environments in 21 child care facilities and structured-questionnaire for estimation and needs of 181 care-givers in them. The major results showed the following. 1) The playgrounds were clarified to five type according to number of child and size of playground. The five types include A-type as large-scale facility/small-size playground, B-type as small-scale facility/large-size playground, C-type as small-scale facility/small-size playground, D-type as middle-scale facility/large-size playground, and E-type as large-scale facility/large-size playground. 2) The adequateness of playground environment of D-type were estimate higher than others. C-type were estimated lower than other types in size and outdoor play areas organization of playground. 3) The care-givers in D-type and E-type wanted to install various play equipments, but the care-giver in C-type didn't wanted to install play equipment. 4) The various outdoor play areas were needed in D-type.

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Estimation Algorithm of Vehicle Roll Angle and Control Strategy of Roll Mitigation Force Distribution (차량 롤 각 추정 알고리즘 및 롤 저감력 분배 제어 전략)

  • Chung, Seunghwan;Lee, Hyeongcheol
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.6
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    • pp.633-641
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    • 2015
  • The ROM (roll over mitigation) system is a next-generation suspension system that can improve vehicle-driving stability and ride comfort. Currently, mass-produced safety systems, such as ESC (electronic stability control) and ECS (electronic control suspension), enable measurements of longitudinal and lateral acceleration as well as yaw rate through inertial sensor clusters, but they lack direct measurements of the roll angle. Therefore, in this paper, a roll angle estimation algorithm from ESC system sensors and tire normal force has been proposed. Furthermore, this study presents a method for roll over mitigation force distribution between the front and rear of a ROM system. Performance and reliability of the roll angle estimation and roll over mitigation force distribution were investigated through simulations. The simulation results showed that the proposed control algorithm and strategy are reliable during vehicle rollovers.