• Title/Summary/Keyword: measurement models

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ON-LINE DYNAMIC SENSING OF SHIP'S ATTITUDE BY USE OF A SERVO-TYPE ACCELEROMETER AND INCLINOMETERS

  • Tanaka, Shogo;Nishifuji, Seiji
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.162-165
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    • 1995
  • For an accurate on-line measurement of the ship's attitude the paper develops an intelligent sensing system which uses one servo-type accelerometer and two servo-type inclinometers appropriately located on the ship. By considering the dynamics of the servo-controlled rigid pendulums of the inclinometers, linear equations for the rolling and pitching of the ship are derived separately from each other. Moreover, one accelerometer is used for extracting the heaving signal. Through the introduction of linear dynamic models and the linear observation equations for the heaving, rolling and pitching, the on-line measurement of the three signals can be reduced to the state estimation of the linear dynamic systems. A bank of Kalman filters is adaptively used to achieve the on-line accurate state estimation and to overcome changes in parameters in the linear dynamic models.

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A Study on the Computation and Application of Sound Power Level for Road Traffic Noise (도로교통소음 음향파워레벨 산정과 응용에 관한 연구)

  • 김득성;오진우;홍세화;이기정;장서일
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.527-534
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    • 2004
  • This study is a paper relating to between road traffic noise(RTN) and sound power level(PWL). At present to prediction of RTN is used to many experimental models and prediction methods. RTN is computed PWL using existing experimental models and prediction methods. Then, computed PWL is compared with it of measurement value, in them, it is selected model most similar to measurement value. And then, this results will watch for make Noise Map, as application field applied to computed results.

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Design of Adaptive Fuzzy IMM Algorithm for Tracking the Maneuvering Target with Time-varying Measurement Noise

  • Kim, Hyun-Sik;Kim, In-Ho
    • International Journal of Control, Automation, and Systems
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    • v.5 no.3
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    • pp.307-316
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    • 2007
  • In real system application, the interacting multiple model (IMM) based algorithm operates with the following problems: it requires less computing resources as well as a good performance with respect to the various target maneuvering, it requires a robust performance with respect to the time-varying measurement noise, and further, it requires an easy design procedure in terms of its structures and parameters. To solve these problems, an adaptive fuzzy interacting multiple model (AFIMM) algorithm, which is based on the basis sub-models defined by considering the maneuvering property and the time-varying mode transition probabilities designed by using the mode probabilities as the inputs of the fuzzy decision maker whose widths are adjusted, is proposed. To verify the performance of the proposed algorithm, a radar target tracking is performed. Simulation results show that the proposed AFIMM algorithm solves all problems in the real system application of the IMM based algorithm.

Adaptive Bilinear Lattice Filter(II)-Least Squares Lattice Algorithm (적응 쌍선형 격자필터 (II) - 최소자승 격자 알고리즘)

  • Heung Ki Baik
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.29B no.1
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    • pp.34-42
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    • 1992
  • This paper presents two fast least-squares lattice algorithms for adaptive nonlinear filters equipped with bilinear system models. The lattice filters perform a Gram-Schmidt orthogonalization of the input data and have very good numerical properties. Furthermore, the computational complexity of the algorithms is an order of magnitude snaller than previously algorithm is an order of magnitude smaller than previously available methods. The first of the two approaches is an equation error algorithm that uses the measured desired response signal directly to comprte the adaptive filter outputs. This method is conceptually very simple`however, it will result in biased system models in the presence of measurement noise. The second approach is an approximate least-squares output error solution. In this case, the past samples of the output of the adaptive system itself are used to produce the filter output at the current time. Results of several experiments that demonstrate and compare the properties of the adaptive bilinear filters are also presented in this paper. These results indicate that the output error algorithm is less sensitive to output measurement noise than the squation error method.

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Analysis of Ground Impedance of a Ground Rod Using Circuit Models (회로모델을 이용한 봉상전극 접지임피던스의 분석)

  • Lee, Bok-Hee;Lee, Tae-Hyung;Eom, Ju-Hong
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.05a
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    • pp.95-99
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    • 2004
  • A systematic approach of measurement, modeling and analysis of grounding system impedance in the field of lightning protection systems is presented. The measurement and analysis of ground impedance are based on a computer aided technique. The magnitude and phase of ground impedance were measured and analyzed by the modified fall-of-potential method and the proposed computer program algerian using the waveforms of the test current and potential rise. The theoretical analysis of ground impedance were performed with the equivalent circuit models, and the theoretical results were compared with the measured data.

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Predicting the shear strength parameters of rock: A comprehensive intelligent approach

  • Fattahi, Hadi;Hasanipanah, Mahdi
    • Geomechanics and Engineering
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    • v.27 no.5
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    • pp.511-525
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    • 2021
  • In the design of underground excavation, the shear strength (SS) is a key characteristic. It describes the way the rock material resists the shear stress-induced deformations. In general, the measurement of the parameters related to rock shear strength is done through laboratory experiments, which are costly, damaging, and time-consuming. Add to this the difficulty of preparing core samples of acceptable quality, particularly in case of highly weathered and fractured rock. This study applies rock index test to the indirect measurement of the SS parameters of shale. For this aim, two efficient artificial intelligence methods, namely (1) adaptive neuro-fuzzy inference system (ANFIS) implemented by subtractive clustering method (SCM) and (2) support vector regression (SVR) optimized by Harmony Search (HS) algorithm, are proposed. Note that, it is the first work that predicts the SS parameters of shale through ANFIS-SCM and SVR-HS hybrid models. In modeling processes of ANFIS-SCM and SVR-HS, the results obtained from the rock index tests were set as inputs, while the SS parameters were set as outputs. By reviewing the obtained results, it was found that both ANFIS-SCM and SVR-HS models can provide acceptable predictions for interlocking and friction angle parameters, however, ANFIS-SCM showed a better generalization capability.

Application of AIG Implemented within CLASS Software for Generating Cognitive Test Item Models

  • SA, Seungyeon;RYOO, Hyun Suk;RYOO, Ji Hoon
    • Educational Technology International
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    • v.23 no.2
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    • pp.157-181
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    • 2022
  • Scale scores for cognitive domains have been used as an important indicator for both academic achievement and clinical diagnosis. For example, in education, Cognitive Abilities Test (CogAT) has been used to measure student's capability in academic learning. In a clinical setting, Cognitive Impairment Screening Test utilizes items measuring cognitive ability as a dementia screening test. We demonstrated a procedure of generating cognitive ability test items similar as in CogAT but the theory associated with the generation is totally different. When creating cognitive test items, we applied automatic item generation (AIG) that reduces errors in predictions of cognitive ability but attains higher reliability. We selected two cognitive ability test items, categorized as a time estimation item for measuring quantitative reasoning and a paper-folding item for measuring visualization. As CogAT has widely used as a cognitive measurement test, developing an AIG-based cognitive test items will greatly contribute to education field. Since CLASS is the only LMS including AIG technology, we used it for the AIG software to construct item models. The purpose of this study is to demonstrate the item generation process using AIG implemented within CLASS, along with proving quantitative and qualitative strengths of AIG. In result, we confirmed that more than 10,000 items could be made by a single item model in the quantitative aspect and the validity of items could be assured by the procedure based on ECD and AE in the qualitative aspect. This reliable item generation process based on item models would be the key of developing accurate cognitive measurement tests.

Errors in Recorded Information and Calibration of a Catchment Modelling System(I) - Analysis of Measurement Errors in Recorded Information - (기록치 오차와 유역모형의 검정(I) - 기록치 내의 측정 오차 분석 -)

  • Kyung Sook Choi;James E. Ball
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.5
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    • pp.110-116
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    • 2003
  • A catchment modelling system is the summation of the numerous hydrologic, hydraulic and other process models necessary to simulate the response of a catchment to a storm event. Differences between the recorded catchment response and that predicted by a catchment modelling system can arise from structural errors within the catchment modelling system, evaluation errors in the control parameters, or measurement errors in the recorded data being used to assess the reliability of the evaluation of the control parameters. Presented herein is an investigation of the potential measurement errors within the recorded information, which was considered to occur from instrument error in the ultra sonic flow monitor. This investigation was undertaken using three available rating curves at the Musgrave Avenue Stormwater System in Centennial Park, Sydney, developed by Abustan (1997), Water Board (1994), and using Manning's equation.

On-line Static Load Modeling using Measurement Data (측정데이터를 이용한 실시간 정적 부하모델링)

  • Park, Sang-Hyun;Chung, Dong-Hyun;Kang, Sang-Gyun;Lee, Byong-Joon;Kwon, Sae-Hyuk
    • Proceedings of the KIEE Conference
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    • 2006.11a
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    • pp.282-284
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    • 2006
  • In this paper, Static load models are developed using measurement based approach which is fundamental for on-line load modeling. The measurement data can be acquired from PMU(phasor measurement units). On the assumption that we have on-line measurement data, a scheme which is for Static load model capable to apply SCADA/EMS is developed. The Least Squares criterion is used for minimizing between measured and simulated data. In this manner, On-line Static load modeling algorithm can be developed. In this paper, a scheme that simple Static load model is applied for On-line load modeling is studied.

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Compensation of errors caused by resonance vibration of measurement system in impact force measurement

  • Usui, Y.;Miyazawa, S.;Sawai, N.
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.593-596
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    • 1994
  • When a force impulse acting on a massive and plex object is measured with a dynamometer, be resonant vibration of the measurement system often leads to serious inaccuracies. A more accurate measurement is obtained when the transfer function ,of the object-dynamometer system is used to compensate for the error in the dynamometer's output signal. The natural frequency and the damping coefficient of the transfer function are estimated by analyzing the waveform of the free damped vibration period after the loading of the force has ended. The residue of the system is determined such that the compensated force spectrum becomes smooth within a neighborhood of the natural frequency. The effectiveness of this signal processing method is experimentally tested on a hammer impulse, under the assumption that the hammer's high resonant frequency accurately models the problems encountered in force impact measurement. The compensation method is used to derive a improved estimate of the hammer impulse.

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