• Title/Summary/Keyword: The weighting factor

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Improvement of Rejection Performance using the Lip Image and the PSO-NCM Optimization in Noisy Environment (잡음 환경 하에서의 입술 정보와 PSO-NCM 최적화를 통한 거절 기능 성능 향상)

  • Kim, Byoung-Don;Choi, Seung-Ho
    • Phonetics and Speech Sciences
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    • v.3 no.2
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    • pp.65-70
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    • 2011
  • Recently, audio-visual speech recognition (AVSR) has been studied to cope with noise problems in speech recognition. In this paper we propose a novel method of deciding weighting factors for audio-visual information fusion. We adopt the particle swarm optimization (PSO) to weighting factor determination. The AVSR experiments show that PSO-based normalized confidence measures (NCM) improve the rejection performance of mis-recognized words by 33%.

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Modified parity space averaging approaches for online cross-calibration of redundant sensors in nuclear reactors

  • Kassim, Moath;Heo, Gyunyoung
    • Nuclear Engineering and Technology
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    • v.50 no.4
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    • pp.589-598
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    • 2018
  • To maintain safety and reliability of reactors, redundant sensors are usually used to measure critical variables and estimate their averaged time-dependency. Nonhealthy sensors can badly influence the estimation result of the process variable. Since online condition monitoring was introduced, the online cross-calibration method has been widely used to detect any anomaly of sensor readings among the redundant group. The cross-calibration method has four main averaging techniques: simple averaging, band averaging, weighted averaging, and parity space averaging (PSA). PSA is used to weigh redundant signals based on their error bounds and their band consistency. Using the consistency weighting factor (C), PSA assigns more weight to consistent signals that have shared bands, based on how many bands they share, and gives inconsistent signals of very low weight. In this article, three approaches are introduced for improving the PSA technique: the first is to add another consistency factor, so called trend consistency (TC), to include a consideration of the preserving of any characteristic edge that reflects the behavior of equipment/component measured by the process parameter; the second approach proposes replacing the error bound/accuracy based weighting factor ($W^a$) with a weighting factor based on the Euclidean distance ($W^d$), and the third approach proposes applying $W^d$, TC, and C, all together. Cold neutron source data sets of four redundant hydrogen pressure transmitters from a research reactor were used to perform the validation and verification. Results showed that the second and third modified approaches lead to reasonable improvement of the PSA technique. All approaches implemented in this study were similar in that they have the capability to (1) identify and isolate a drifted sensor that should undergo calibration, (2) identify a faulty sensor/s due to long and continuous missing data range, and (3) identify a healthy sensor.

An Indirect Adaptive Pole placement Controller Using a Discrete Adaptive Observer with Exponenrial Data weighting (지수 함수적 가중 특성의 적응 관측기를 이용한 간접 극배치 적응 제어기)

  • Kim, Jong-Hwan;Park, Dong-Jo;Jeon, Jeong-Yeol
    • Proceedings of the KIEE Conference
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    • 1990.07a
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    • pp.43-46
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    • 1990
  • A general scheme for a discrete adaptive observer having exponetial weighting properties is presented for a single-input single-output linear system. In this scheme, all the past measurement data are weighted esponetially both with the weighting factor and the stable matrix F. This observer is then implemented in the design of an indirect adaptive pole placement contoller. To increase nemerical stability in getting the controller parameter, a recusive algorithm is introduced. It is shown that the overall control scheme is globally stable with the persistent excition

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Optimum Design of Vehicle Powertrain Mounting System (자동차용 파워트레인 마운팅 시스템의 최적설계)

  • Kim, J.H.;Lee, S.J.;Lee, W.H.;Kim, J.R.
    • Journal of Power System Engineering
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    • v.14 no.3
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    • pp.33-38
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    • 2010
  • Technology of vehicle industry has been developing and it is required a better vehicle performance than before. Therefore, the consumers are asking not only an economic efficiency, functionality, polished design, ride comfort and silence but also a driving stability. The ride comfort, silence and driving stability are influenced by the size of vehicle and various facilities. But the principal factor is a room noise and vibration sensed by a driver and passenger. Thus, the NVH of vehicle has been raised and used as a principal factor for evaluation of vehicle performance. The primary objective of this study is an optimized design of powertrain mounting system. To optimized design was applied MSC.Nastran optimization modules. Results of dynamic analysis for powertrain mounting system was investigated. By theses results, design variables was applied 12 dynamic spring constant. And the weighting factor according to translational displacement and rotational displacement applied 3 cases. The objective function was applied to minimize displacement of powertrain. And the design variable constraint was imposed dynamic spring constant ratio. The constraint of design variable for objective function was imposed bounce displacement for powertrain.

Flowrate Integration Errors of Multi-path Ultrasonic Flowmeter using Weighting Factors (가중계수에 의한 다회선 초음파유량계의 유량적분오차)

  • Lee, Ho-June;Hwang, Shang-Yoon;Kim, Kyoung-Jin
    • The KSFM Journal of Fluid Machinery
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    • v.7 no.5 s.26
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    • pp.7-12
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    • 2004
  • Multi-path ultrasonic flowrate measuring technology is being received much attentions from a variety of industrial fields to exactly measure the flowrate. Multi-path ultrasonic flowmeter has much advantage since it has no moving parts and little pressure loss. It offers good accuracy, repeatability, linearity and turn-down ratio can be over 1:50. The present study investigates flowrate integration errors using weighting factors. A theoretical flow model uses power law to describe a fully developed velocity profiles and wall roughness is changed. Gaussian, Chebyshev, and Tailor methods are used to integrate line-average velocities. The obtained results show that Chebyshev method in 2, 4-path arrangement and Gaussian method in 3, 5-path arrangement are not affected for wall roughness changes.

Topology Design of a Structure with a Specified Eigenfrequency (주어진 고유주파수를 갖는 구조물의 위상최적설계)

  • Lee, Jong-Hwan;Min, Seung-Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.7
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    • pp.1210-1216
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    • 2003
  • Topology optimization is applied to determine the layout of a structural component with a specified frequency by minimizing the difference between the specified structural frequency and a given frequency. The homogenization design method is employed and the topology design problem is solved by the optimality criteria method. The value of a weighting factor in the optimality criteria plays an important role in this topology design problem. The modified optimality criteria method approximated by using the binomial expansion is suggested to determine the suitable value of the weighting factor, which makes convergence stable. If a given frequency is set as an excited frequency, it is possible to avoid resonance by moving away the specified structural frequency from the given frequency. The results of several test problems are compared with previous works and show the validity of the proposed algorithm.

Determination and application of the weights for landslide susceptibility mapping using an artificial neural network

  • Lee, Moung-Jin;Won, Joong-Sun;Yu, Young-Tae
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.71-76
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    • 2003
  • The purpose of this study is the development, application and assessment of probability and artificial neural network methods for assessing landslide susceptibility in a chosen study area. As the basic analysis tool, a Geographic Information System (GIS) was used for spatial data management. A probability method was used for calculating the rating of the relative importance of each factor class to landslide occurrence, For calculating the weight of the relative importance of each factor to landslide occurrence, an artificial neural network method was developed. Using these methods, the landslide susceptibility index was calculated using the rating and weight, and a landslide susceptibility map was produced using the index. The results of the landslide susceptibility analysis, with and without weights, were confirmed from comparison with the landslide location data. The comparison result with weighting was better than the results without weighting. The calculated weight and rating can be used to landslide susceptibility mapping.

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An Experimental Study onthe Endurance Characteristics of the Dynamic Absorber for Vibration Reduction of 4WD Vehicle's Powertrain (4륜구동 자동차의 동력기관에서 진동저감을 위한 동흡진기의 진동내구에 대한 실험적 연구)

  • 사종성;김찬묵
    • Journal of KSNVE
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    • v.9 no.6
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    • pp.1166-1172
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    • 1999
  • This paper is the experimental study on the endurance characteristics of the dynamic absorber for the vibration reduction of the 4WD(4 Wheel drive) vehicle's powertrain. Employing the vehicle speed, natural frequencies of damper, modal testing results of powertrain and the weighting factor, the improved endurance test conditions are suggested to enlarge the life time of the dynamic absorber. The test results show that the life time of the dynamic absorber for Z-direction(up and down) has no problems, but the characteristics of X-direction (fore and after) will be sensitive to endurance characteristics of dynamic absorber.

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Fuzzy-Bayes Fault Isolator Design for BLDC Motor Fault Diagnosis

  • Suh, Suhk-Hoon
    • International Journal of Control, Automation, and Systems
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    • v.2 no.3
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    • pp.354-361
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    • 2004
  • To improve fault isolation performance of the Bayes isolator, this paper proposes the Fuzzy-Bayes isolator, which uses the Fuzzy-Bayes classifier as a fault isolator. The Fuzzy-Bayes classifier is composed of the Bayes classifier and weighting factor, which is determined by fuzzy inference logic. The Mahalanobis distance derivative is mapped to the weighting factor by fuzzy inference logic. The Fuzzy-Bayes fault isolator is designed for the BLDC motor fault diagnosis system. Fault isolation performance is evaluated by the experiments. The research results indicate that the Fuzzy-Bayes fault isolator improves fault isolation performance and that it can reduce the transition region chattering that is occurred when the fault is injected. In the experiment, chattering is reduced by about half that of the Bayes classifier's.

Capillary Hysteresis Model in Unsaturated Flow : State of the Art

  • Park, Chan-Kun;Sonu, Jun-Ho
    • Korean Journal of Hydrosciences
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    • v.4
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    • pp.33-49
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    • 1993
  • The Purpose of this study is to classify existing hysteresis models and to discuss a possibility of a new type of the hysteresis model. The existing hysteresis models are classified into three types: the interpolation model, the scaling model and the domain model, of which only domain model is to simulate hysteresis curves based on the theoretical approach, It is useful to develop a hysteresis model that requires only one branch of hysteresis curves for the model calibration because obtaining hysteresis curves by experiments is expensive and time-concept by many investigators, however their models are not successful to accurately simulate real data of Rubicon Sandy Loam and Dune Sand. There is a possibility that a new model is based on the dependent domain concept considering the weighting factor, $P_a$($\theta$), which accounts for the pore blockage effect against air entry. Conclusively, a new model where the weighting factor $P_a$($\theta$) in Model III-1 (Mualem, 1984) reduces to a known variable through an appropriate method is an alternative model which required only one branch of main curves for the model calibration.

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