• The Journal of the Acoustical Society of Korea
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• v.18 no.8
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• pp.42-47
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• 1999

In this paper, a mixture interacting multiple model (MIMM) algorithm is proposed to enhance speech contaminated by additive nonstationary noise. In this approach, a mixture hidden filter model (HFM) is used to model the clean speech and the noise process is modeled by a single hidden filter. The MIMM algorithm, however. needs large computation time because it is a recursive method based on multiple Kalman filters with mixture HFM. Thereby, a computationally efficient implementation of the algorithm is developed by exploiting the structure of the Kalman filtering equation. The simulation results show that the proposed method offers performance gain compared to the previous results in [4,5] with slightly increased complexity.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06d
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• pp.56-59
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• 1998

머리전달함수(Head-Related Transfer Function, HRTF)를 이용한 영상 음원법(Image Model Method, IMM)을 적용하여 3차원 음장을 제어하기 위한 요소결정 방법을 제안한다. 제어 요소들은 직방체 내부에서의 음 에너지에 관한 이론을 토대로 결정하였다. 각 제어요소를 3차원 음장 모델에 적용하고, 헤드폰을 사용하여 청취자에 의한 심리음향 실험한 결과, 제어된 음장에서는 음상의 두외 정위, 거리감, 공간감이 실내에서와 같이 자연스럽게 형성됨을 나타냈다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.1
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• pp.25-32
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• 2011

Measurement noise variance of the radar is one of the main inputs of a state estimator of surveillance data processing system for air traffic control and has influences on the accuracy performance of maneuvering target tracking. A method is presented of estimating measurement noise variances every frame of target tracking using likelihood functions of multiple IMM filter. The results by running of Monte Carlo simulation show that variances are estimated within 5% of errors compared with true values and the tracking accuracy performance is improved.

• The Journal of the Acoustical Society of Korea
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• v.21 no.4
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• pp.387-393
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• 2002

The enhancement technique of noise signal using mixture HFM (Midden Filter Model) are proposed. Given the parameters of the clean signal and noise, noisy signal is modeled by a linear state-space model with Markov switching parameters. Estimation of state vector is required for estimating original signal. The estimation procedure is based on mixture interacting multiple model (MIMM) and the estimator of speech is given by the weighted sum of parallel Kalman filters operating interactively. Simulation results showed that the proposed method offers performance gains relative to the previous results with slightly increased complexity.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.11-18
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• 2021

This paper shows the applicability of deep learning algorithm in predicting target position and getting correction value of impact point in order to improve the accuracy of naval gun firing. Predicting target position, the proposed model using LSTM model and RN structure is expected to be more accurate than existing method using kalman filter. Getting correction value of impact point, the another proposed model suggests a reinforcement model that manages factors which is related in ballistic calculation as data set, and learns using the data set. The model is expected to reduce error of naval gun firing. Combining two models, a ballistic calculation model for improving accuracy of naval gun firing based on deep learning algorithm was designed.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.2
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• pp.253-270
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• 2021

This survey provides research into developing knee braces to protect the knee against damage, reduce knee pain, and strengthen the knee. A total of 235 surveys were conducted from December 2019 to January 2020. The subjects were adults in their 20s and over who lived in the Seoul metropolitan area and had experience of using knee braces. In terms of age differences, subjects over 60 years of age purchased knee braces mostly to secure a reduction of pain (ROP), whereas subjects in their 20s and 30s purchased knee braces for physical shock protection (PSP). Subjects in their 40s and 50s purchased knee braces for improvement of muscle movement (IMM). There was no significant difference in shape, material, and locking method based on the reason for wearing the knee brace. These results show that it is conceivable and maybe preferable to produce different knee braces-with a variety of shapes, materials, and locking materials-according to the reason behind wearing a knee brace. Knee braces are worn currently without any differentiation despite the findings of this study. In particular, we argue the need for functional and differentiated development of knee braces specifically for PSP, ROP, and IMM.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.11
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• pp.1117-1124
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• 2011

An integrated fault detection and isolation method is proposed in this paper. The main objective of this paper is development fault detection, isolation and diagnosis algorithm based on the DKF (Decentralized Kalman Filter) and the bank of IMM (Interacting Multiple Model) filters using penalty scalar for both partial and total faults and the outlier detection algorithm for preventing false alarm also included. The proposed FDI (Fault Detection and Isolation) scheme is developed in four phases. In the first phase, the outlier detection filter is designed to prevent false alarm as a pre-filter. In the second phases, two local filters and master filter are designed to detect sensor faults. In the third phases, the proposed FDI scheme checks sensor residual to isolate sensor faults and 11 EKFs actuator fault models are designed to detect wherever actuator faults occur. In the last phases, four filters are designed to identify the fault type which is either the total fault or partial fault. The developed scheme can deal with not only sensor and actuator faults, but also preventing false alarm. An important feature of the proposed FDI scheme can decreases fault isolation time and figure out not only fault detection and isolation but also fault type identification. To verify the proposed FDI algorithm performance, the Simulator is also developed under the Matlab/Simulink environment.

• Interaction and multiscale mechanics
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• v.2 no.2
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• pp.189-207
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• 2009

Dynamics of the electric system for the toroidal drive under mechanical disturbance is presented. Using the method of perturbation, free vibrations of the electric system under mechanical disturbance are studied. The forced responses of the electric system to voltage excitation under mechanical disturbance are also presented. We show that as the time grows, the resonance vibration caused by voltage excitation still exists and the vibrations caused by mechanical disturbance are enlarged. The coupled resonance vibration caused by mechanical disturbance and voltage excitation is discussed. The conditions of the occurrence of coupled resonance are studied.

• Interaction and multiscale mechanics
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• v.3 no.1
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• pp.81-94
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• 2010

The steady state response of a rotating generalized thermoelastic solid to a moving point load has been investigated. The transformed components of displacement, force stress and temperature distribution are obtained by using Fourier transformation. These components are then inverted and the results are obtained in the physical domain by applying a numerical inversion method. The numerical results are presented graphically for a particular model. A particular result is also deduced from the present investigation.

• Interaction and multiscale mechanics
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• v.6 no.2
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• pp.197-210
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• 2013

A fundamental trend of processor architecture evolving towards exaflops is fast increasing floating point performance (so-called "free" flops) accompanied by much slowly increasing memory and network bandwidth. In order to fully enjoy the "free" flops, a numerical algorithm of PDEs should request more flops per byte or increase arithmetic intensity. A meshfree/GFEM approximation can be the class of the algorithm. It is shown in a GFEM without extra dof that the kind of approximation takes advantages of the high performance of manycore GPUs by a high accuracy of approximation; the "expensive" method is found to be reversely hardware-efficient on the emerging architecture of manycore.