• Title/Summary/Keyword: state matrix

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The Rheological Behaviors of Solid-Liquid Transfer Emulsion (고상-액상 전이형 에멀젼의 레올로지 거동)

  • Park, Byeong-Gyun;Han, Jong-Sub;Lee, Sang-Min;Lee, Cheon-Koo;Yoon, Moung-Seok
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.31 no.2 s.51
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    • pp.135-140
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    • 2005
  • A solid state emulsion haying high velocity gradient shows two important transition ranges in the plot of storage modulus(G') as a function of shear strain, when the state is changed from solid to liquid. However, a solid state emulsion having low velocity gradient shows only one apparent transition range when the change from solid to liquid state takes place. The result implies the importance of the surface properties in the solid state emulsion. The addition of water phase in the solid state emulsion reduces the modulus in the modulus in the surface transition range by increasing interfacial friction and weakening the matrix. The addition of pigments increases the modulus in the modulus in the surface transition range by reinforcing the matrix, when there is no wafer phase in the solid state emulsion. When the solid state emulsion has water phase, however, the addition of pigments decreases the modulus in the modulus in the surface transition range.

A study on the speaker adaptation in CDHMM usling variable number of mixtures in each state (CDHMM의 상태당 가지 수를 가변시키는 화자적응에 관한 연구)

  • 김광태;서정일;홍재근
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.3
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    • pp.166-175
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    • 1998
  • When we make a speaker adapted model using MAPE (maximum a posteriori estimation), the adapted model has one mixture in each state. This is because we cannot estimate a number of a priori distribution from a speaker-independent model in each state. If the model is represented by one mixture in each state, it is not well adadpted to specific speaker because it is difficult to represent various speech informationof the speaker with one mixture. In this paper, we suggest the method using several mixtures to well represent various speech information of the speaker in each state. But, because speaker-specific training dat is not sufficient, this method can't be used in every state. So, we make the number of mixtures in each state variable in proportion to the number of frames and to the determinant ofthe variance matrix in the state. Using the proposed method, we reduced the error rate than methods using one branch in each state.

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Matrix completion based adaptive sampling for measuring network delay with online support

  • Meng, Wei;Li, Laichun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.7
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    • pp.3057-3075
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    • 2020
  • End-to-end network delay plays an vital role in distributed services. This delay is used to measure QoS (Quality-of-Service). It would be beneficial to know all node-pair delay information, but unfortunately it is not feasible in practice because the use of active probing will cause a quadratic growth in overhead. Alternatively, using the measured network delay to estimate the unknown network delay is an economical method. In this paper, we adopt the state-of-the-art matrix completion technology to better estimate the network delay from limited measurements. Although the number of measurements required for an exact matrix completion is theoretically bounded, it is practically less helpful. Therefore, we propose an online adaptive sampling algorithm to measure network delay in which statistical leverage scores are used to select potential matrix elements. The basic principle behind is to sample the elements with larger leverage scores to keep the traits of important rows or columns in the matrix. The amount of samples is adaptively decided by a proposed stopping condition. Simulation results based on real delay matrix show that compared with the traditional sampling algorithm, our proposed sampling algorithm can provide better performance (smaller estimation error and less convergence pressure) at a lower cost (fewer samples and shorter processing time).

Performance Improvement of Reduced Order Extended Luenberger Observer(ROELO) based Sensorless Vector Control Fed by Matrix Converter With Non-linearity Modeling (비선형모델을 이용한 matrix convertor로 구동되는 축소차원 확장 루엔버거 관측기기반의 유도전동기 센서리스 벡터제어의 성능개선)

  • Lee Kyo-Beum
    • The Transactions of the Korean Institute of Power Electronics
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    • v.10 no.4
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    • pp.363-372
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    • 2005
  • This paper presents an improved sensorless vector control system for high performance induction motor drives fed by a matrix converter with non-linearity compensation. The nonlinear voltage distortion that is caused by commutation delay and on-state voltage drop in switching devices is corrected by a new matrix converter model. A Reduced Order Extended Luenberger Observer (ROELO) is employed to bring better response in the whole speed operation range and a method to select the observer gain is presented. Experimental results are shown to illustrate the performance of the proposed system.

A Novel Compressed Sensing Technique for Traffic Matrix Estimation of Software Defined Cloud Networks

  • Qazi, Sameer;Atif, Syed Muhammad;Kadri, Muhammad Bilal
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.10
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    • pp.4678-4702
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    • 2018
  • Traffic Matrix estimation has always caught attention from researchers for better network management and future planning. With the advent of high traffic loads due to Cloud Computing platforms and Software Defined Networking based tunable routing and traffic management algorithms on the Internet, it is more necessary as ever to be able to predict current and future traffic volumes on the network. For large networks such origin-destination traffic prediction problem takes the form of a large under- constrained and under-determined system of equations with a dynamic measurement matrix. Previously, the researchers had relied on the assumption that the measurement (routing) matrix is stationary due to which the schemes are not suitable for modern software defined networks. In this work, we present our Compressed Sensing with Dynamic Model Estimation (CS-DME) architecture suitable for modern software defined networks. Our main contributions are: (1) we formulate an approach in which measurement matrix in the compressed sensing scheme can be accurately and dynamically estimated through a reformulation of the problem based on traffic demands. (2) We show that the problem formulation using a dynamic measurement matrix based on instantaneous traffic demands may be used instead of a stationary binary routing matrix which is more suitable to modern Software Defined Networks that are constantly evolving in terms of routing by inspection of its Eigen Spectrum using two real world datasets. (3) We also show that linking this compressed measurement matrix dynamically with the measured parameters can lead to acceptable estimation of Origin Destination (OD) Traffic flows with marginally poor results with other state-of-art schemes relying on fixed measurement matrices. (4) Furthermore, using this compressed reformulated problem, a new strategy for selection of vantage points for most efficient traffic matrix estimation is also presented through a secondary compression technique based on subset of link measurements. Experimental evaluation of proposed technique using real world datasets Abilene and GEANT shows that the technique is practical to be used in modern software defined networks. Further, the performance of the scheme is compared with recent state of the art techniques proposed in research literature.

Threshold Voltage Instability in a-Si:H TFTs and the Implications for Flexible Displays and Circuits

  • Allee, D.R.;Venugopal, S.M.;Shringarpure, R.;Kaftanoglu, K.;Uppili, S.G.;Clark, L.T.;Vogt, B.;Bawolek, E.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1297-1300
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    • 2008
  • Electrical stress degradation of low temperature, amorphous silicon thin film transistors is reviewed, and the implications for various types of flexible circuitry including active matrix backplanes, integrated drivers and general purpose digital circuitry are examined. A circuit modeling tool that enables the prediction of complex circuit degradation is presented.

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A Quantitative Performance Index for an Input Observer (II) - Analysis in Steady-State - (입력관측기의 정량적 성능지표 (II) -정상상태 해석-)

  • Jung, Jong-Chul;Lee, Boem-Suk;Huh, Kun-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.10
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    • pp.2067-2072
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    • 2002
  • The closed-loop state and input observer is a pole-placement type observer and estimates unknown state and input variables simultaneously. Pole-placement type observers may have poor performances with respect to modeling error and sensing bias error. The effects of these ill-conditioning factors must be minimized for the robust performance in designing observers. In this paper, the steady-state performance of the closed-loop state and input observer is investigated quantitatively and is represented as the estimation error bounds. The performance indices are selected from these error bounds and are related to the robustness with respect to modeling errors and sensing bias. By considering both transient and steady-state performance, the main performance index is determined as the condition number of the eigenvector matrix based on $L_2$-norm.

The Analysis of The Kalman Filter Noise Factor on The Inverted Pendulum (도립진자 모델에서 칼만 필터의 잡음인자 해석)

  • Kim, Hoon-Hak
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.5
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    • pp.13-21
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    • 2010
  • The Optimal results of Kalman Filtering on the Inverted Pendulum System requires an effective factor such as the noise covariance matrix Q, the measurement noise covariance matrix R and the initial error covariance matrix $P_0$. We present a special case where the optimality of the filter is not destroyed and not sensitive to scaling of these covariance matrix because these factors are unknown or are known only approximately in the practical situation. Moreover, the error covariance matrices issued by this method predict errors in the state estimate consistent with the scaled covariance matrices and not the issued state estimates. Various results using the scalar gain $\delta$ are derived to described the relations among the three covariance matrices, Kalman Gain and the error covariance matrices. This paper is described as follows: Section III a brief overview of the Inverted Pendulum system. Section IV deals with the mathematical dynamic model of the system used for the computer simulation. Section V presents a various simulation results using the scalar gain.

CONVERGENCE ANALYSIS OF THE EAPG ALGORITHM FOR NON-NEGATIVE MATRIX FACTORIZATION

  • Yang, Chenxue;Ye, Mao
    • Journal of applied mathematics & informatics
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    • v.30 no.3_4
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    • pp.365-380
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    • 2012
  • Non-negative matrix factorization (NMF) is a very efficient method to explain the relationship between functions for finding basis information of multivariate nonnegative data. The multiplicative update (MU) algorithm is a popular approach to solve the NMF problem, but it fails to approach a stationary point and has inner iteration and zero divisor. So the elementwisely alternating projected gradient (eAPG) algorithm was proposed to overcome the defects. In this paper, we use the fact that the equilibrium point is stable to prove the convergence of the eAPG algorithm. By using a classic model, the equilibrium point is obtained and the invariant sets are constructed to guarantee the integrity of the stability. Finally, the convergence conditions of the eAPG algorithm are obtained, which can accelerate the convergence. In addition, the conditions, which satisfy that the non-zero equilibrium point exists and is stable, can cause that the algorithm converges to different values. Both of them are confirmed in the experiments. And we give the mathematical proof that the eAPG algorithm can reach the appointed precision at the least iterations compared to the MU algorithm. Thus, we theoretically illustrate the advantages of the eAPG algorithm.

In-situ Synthesis of Cu-TiB2 Nanocomposite by MA/SPS

  • Kwon, Young-Soon;Kim, Ji-Soon;Kim, Hwan-Tae;Moon, Jin-Soo;D.V Dudina;O.I. Lomovsky
    • Journal of Powder Materials
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    • v.10 no.6
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    • pp.443-447
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    • 2003
  • Nano-sized $TiB_2$ was in situ synthesized in copper matrix through self-propagating high temperature synthesis (SHS) with high-energy ball milled Ti-B-Cu elemental mixtures as powder precursors. The size of $TiB_2$ particles in the product of SHS reaction decreases with time of preliminary mechanical treatment ranging from 1 in untreated mixture to 0.1 in mixtures milled for 3 min. Subsequent mechanical treatment of the product of SHS reaction allowed the $TiB_2$ particles to be reduced down to 30-50 nm. Microstructural change of $TiB_2$-Cu nanocomposite during spark plasma sintering (SPS) was also investigated. Under simultaneous action of pressure, temperature and electric current, titanium diboride nanoparticles distributed in copper matrix move, agglomerate and form a interpenetrating phase composite with a fine-grained skeleton.