• Title/Summary/Keyword: Weighting Function

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Executive function and Korean children's stop production

  • Eun Jong Kong;Hyunjung Lee;Jeffrey J. Holliday
    • Phonetics and Speech Sciences
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    • v.15 no.3
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    • pp.45-52
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    • 2023
  • Previous studies have established a role for cognitive differences in explaining variability in speech processing across individuals. In the case of perceptual cue weighting in the context of a sound change, studies have produced conflicting results regarding the relationship between executive function and the use of redundant cues. The current study aimed to explore this relationship in acoustic cue weighting during speech production. Forty-one Korean-speaking children read a list of stop-initial words and completed two tests that assess executive function, i.e., Dimensional Change Card Sorting (DCCS) and digit n-back. Voice onset time (VOT) and fundamental frequency (F0) were measured in each word, and analyses were carried out to determine the extent to which children's executive function predicted their use of both informative and less informative cues to the three pairs comprising the Korean three-way stop laryngeal contrast. No evidence was found for a relationship between cognitive ability and acoustic cue weighting in production, which is at odds with previous, albeit conflicting, results for speech perception. While this result may be due to the lack of task demands in the production task used here, it nevertheless expands the empirical ground upon which future work in this area may proceed.

$H{\infty}$ optimal controller robustness and performance improvement by frequency domain analysis of open loop transfer function (개루프 전달함수 주파수영역 해석에 의한 $H{\infty}$ 최적 제어기의 견실성 및 성능 개선)

  • Kim, Y.K.;Ryu, C.K.
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.761-763
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    • 1999
  • When the controller designed by the $H{\infty}$ control technique is applied to the object system, sometimes the controller does not satisfy the robust stability and robust performance but only satisfy the nominal performance. In this paper, we derive the region on the frequency response curve of the open-loop transfer function which satisfy the robustness and robust performance of the designed controller. We also derive the region for the suitableness of the weighting function on the frequency response curve of the weighting function. We showed that the robust stability and the robust performance of the $H{\infty}$ optimal control)or by applying the designed controller on an electromechanical actuator system could be improved by determining parameter ${\gamma}$ and weighting function gain ${\alpha}$ using the derived region.

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An In-depth Study on Applying Metric Weighting to Space Syntax (공간구문론에의 거리가중개념 적용에 관한 심층 연구)

  • Kim, Minseok;Piao, Gensong
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.12
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    • pp.49-54
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    • 2018
  • Applying metric(distance) factor as weighting to spatial syntax is known to not contribute to the explanatory power for the human movement behavior as compared to the geometric(angle) factor according to the negative results of several related studies. However, Kim & Piao (2017) assumed that there is not a problem of the metric factor itself but a problem of the way of applying the metric factor as weighting, and presented a new possibility of the metric factor as weighting by proposing and verifying the methods of applying the metric weighting, which are different from the existing ones. The purpose of this study is to propose advanced methods of applying the metric weighting to space syntax, and to verify whether they contribute to the improvement of explanatory power of space syntax analysis. In this paper, we propose functions for combined depth of distance-step that combine the distance-weighted depth function with the step depth function and apply them to axial segment analysis to check the improvement of explanatory power of them.

Design Optimization of Axial Flow Fan Using Genetic Algorithm (유전자 알고리즘을 이용한 축류 송풍기 설계최적화)

  • Yoo, In-Tae;Ahn, Cheol-O;Lee, Sang-Hwan
    • 유체기계공업학회:학술대회논문집
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    • 2003.12a
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    • pp.397-403
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    • 2003
  • In an attempt to solve multiobjective optimization problems, weighted sum method is most widely used for the advantage that a designer can consider the relative significance of each object functions by weight values but it can be highly sensitive to weight vector and occasionally yield a deviated optimum from the relative weighting values designer designated because the multiobjective function has the form of simple sum of the product of the weighting values and the object functions in traditional approach. To search the design solution well agree to the designer's weighting values, we proposed new multiobjective function which is the functional of each normalized objective functions and considered to find the design solution comparing the distance between the characteristic line and the ideal optimum. In this study, proposed multiobjective function was applied to design high efficiency and low noise axial flow fan and the result shows this approach will be effective for the case that the qualify of the design can be highly affected by the designer's subjectiveness represented as weighting values in multiobjective design optimization process.

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$H_\infty$ Optimal Controller Synthesis by the Frequency Domain Analysis of Weighting Function (가중함수의 주파수 영역 해석에 따른 $H_\infty$ 최적 제어기 구성)

  • Kim, Yong-Gyu;Ryu, Chang-Geun
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.37 no.2
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    • pp.8-15
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    • 2000
  • This study presents an H$_{\infty}$ optimal controller synthesis by the frequency domain analysis of weighting function. The main purpose of our study is to visualize weighting function domains and open loop transfer function domains that satisfy robustness and performance. Also we aim to simplify the iterative algorithm for H$\infty$ optimal controller synthesis. We report that the designed regulator by the proposed method in this paper satisfies the desired specifications and performance in spite of the plant uncertainty variation at any operating point.

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An Information-theoretic Approach for Value-Based Weighting in Naive Bayesian Learning (나이브 베이시안 학습에서 정보이론 기반의 속성값 가중치 계산방법)

  • Lee, Chang-Hwan
    • Journal of KIISE:Databases
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    • v.37 no.6
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    • pp.285-291
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    • 2010
  • In this paper, we propose a new paradigm of weighting methods for naive Bayesian learning. We propose more fine-grained weighting methods, called value weighting method, in the context of naive Bayesian learning. While the current weighting methods assign a weight to an attribute, we assign a weight to an attribute value. We develop new methods, using Kullback-Leibler function, for both value weighting and feature weighting in the context of naive Bayesian. The performance of the proposed methods has been compared with the attribute weighting method and general naive bayesian. The proposed method shows better performance in most of the cases.

Weighting Matrices of LQR and ILQR Controllers Considering Structural Energy (구조물의 에너지를 고려한 LQR 및 ILQR제어기의 가중행렬)

  • 민경원;이영철;박민규
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.6
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    • pp.49-53
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    • 2002
  • This paper provides the systematic procedure to determine the weighting matrices of optimal controllers considering structural energy. Optimal controllers consist of LQR and ILQR. The weighting matrices are needed first in the conventional optimal control design strategy. However, they are in general dependent on the experienced knowledge of control designers. Applying the Lyapunov function to total structural energy and using the condition that its derivative is negative, we can determine the weighting matrices without difficulty. It is proven that the control efficiency with using determined weighting matrices is achieved well for LQR and ILQR controllers.

Determining the Weighting Matrices of Optimal Controllers considering Structural Energy (구조물의 에너지를 고려한 최적제어기의 가중행렬 결정)

  • 민경원;이영철
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.03a
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    • pp.475-482
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    • 2002
  • This paper provides the systematic procedure to determine the weighting matrices of optimal controllers considering structural energy. Optimal controllers consist of LQR and ILQR. The weighting matrices are needed first in the conventional optimal control design strategy. However, they are in general dependent on the experienced knowledge of controll designers. Applying the Lyapunov function to the total structural energy and using the contrition that its derivative is negative, we can determine the weighting matrices without difficulty. It is proven that the control efficiency is achieved well for LQR and ILQR.

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Characteristics Analysis of Wide-Band One-Shot Beam as Variation of Weighting Width (가중치 폭 변화에 따른 광대역 단일빔 특성 분석)

  • 도경철;임근희손경식
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.1267-1270
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    • 1998
  • This paper analyzes the characteristics of wide-band one-shot beam formed by using all sensors of array at once, as variation of weighting width. Gaussian function is applied to each sensor as a role of weighting. As the results of the simulation for nested linear array having 17 sensors for each octave, as the width goes wider the directivity index(DI) becomes lower but more even and the variation of beamwidth becomes smaller. It is confirmed, therefore, that weighting width is carefully decided in consideration of DI level, DI stability and the beamwidth.

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Determination of the Weighting Parameters of the LQR System for Nuclear Reactor Power Control Using the Stochastic Searching Methods

  • Lee, Yoon-Joon;Cho, Kyung-Ho
    • Nuclear Engineering and Technology
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    • v.29 no.1
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    • pp.68-77
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    • 1997
  • The reactor power control system is described in the fashion of the order increased LQR system. To obtain the optimal state feedback gain vectors, the weighting matrix of the performance function should be determined. Since the contentional method has some limitations, stochastic searching methods are investigated to optimize the LQR weighting matrix using the modified genetic algorithm combined with the simulated annealing, a new optimizing tool named the hybrid MGA-SA is developed to determine the weighting parameters of the LQR system. This optimizing tool provides a more systematic approach in designing the LQR system. Since it can be easily incorporated with any forms of the cost function, it also provides the great flexibility in the optimization problems.

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