• Title/Summary/Keyword: Fast Computation

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Fast computation of Observation Probability for Speaker-Independent Real-Time Speech Recognition (실시간 화자독립 음성인식을 위한 고속 확률계산)

  • Park Dong-Chul;Ahn Ju-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.9C
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    • pp.907-912
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    • 2005
  • An efficient method for calculation of observation probability in CDHMM(Continous Density Hidden Markov Model) is proposed in this paper. the proposed algorithm, called FCOP(Fast Computation of Observation Probability), approximate obsewation probabilities in CDHMM by eliminating insignificant PDFs(Probability Density Functions) and reduces the computational load. When applied to a speech recognition system, the proposed FCOP algorithm can reduce the instruction cycles by $20\%-30\%$ and can also increase the recognition speed about $30\%$ while minimizing the loss in its recognition rate. When implemented on a practical cellular phone, the FCOP algorithm can increase its recognition speed about $30\%$ while suffering $0.2\%$ loss in recognition rate.

Measurement of $\beta_{eff}$ in the Fast Critical Assembly BFS and Validation of a $\beta_{eff}$ Computation Code, BETA-K

  • Kim, Taek-Kyum;Kim, Young-Il;Kim, Young-Jin
    • Nuclear Engineering and Technology
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    • v.31 no.4
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    • pp.401-407
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    • 1999
  • We have performed two experiments in the fast critical assembly BFS to measure the effective delayed neutron fraction $\beta$$_{eff}$ values and compared the results to validate the $\beta$$_{eff}$ computation code, BETA-K. Measurements of $\beta$$_{eff}$ were carried out in a metallic plutonium core and a metallic uranium core with Cf$^{252}$ source pseudo-reactivity method. Fission integrals and correction factors, which were used to obtain the experimental $\beta$$_{eff}$ values, were calculated by using the LMR core design computation code system of KAERI. BETA-K has been developed consistently with the hexagonal Nodal Expansion Method (NEM) and it used delayed neutron data of ENDF/B-VI. By comparing the computed $\beta$$_{eff}$ values with the measured ones, we found that the results from BETA-K agreed with the experimental values within the experimental error bound.ror bound.

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Fast Computation of the Visibility Region Using the Spherical Projection Method

  • Chu, Gil-Whoan;Chung, Myung-Jin
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.1
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    • pp.92-99
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    • 2002
  • To obtain visual information of a target object, a camera should be placed within the visibility region. As the visibility region is dependent on the relative position of the target object and the surrounding object, the position change of the surrounding object during a task requires recalculation of the visibility region. For a fast computation of the visibility region so as to modify the camera position to be located within the visibility region, we propose a spherical projection method. After being projected onto the sphere the visibility region is represented in $\theta$-$\psi$ spaces of the spherical coordinates. The reduction of calculation space enables a fast modification of the camera location according to the motion of the surrounding objects so that the continuous observation of the target object during the task is possible.

Improved Service Restoration technique by Using Dijkstra Algorithm in Distribution Systems (다익스트라 알고리즘을 이용한 배전계통의 향상된 사고복구 기법)

  • Kim, Nark-Kyung;Kim, Jae-Chul;Jeon, Young-Jae;Kim, Hoon
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.2
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    • pp.67-75
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    • 2001
  • This paper presents a fast and effective methodology for service restoration in large-scale distribution systems. The service restoration problem is formulated as a constrained optimization problem and requires the fast computation time and superior solution because the more unfaulted out-of-service area should be restored as soon as possible. The proposed methodology is designed to consider the fast computation time and priority service restoration by dijkstra algorithm and fuzzy theory in large-scale distribution systems. Simulation results demonstrate the validity and effectiveness of the proposed on a 26-bus and 140-bus system.

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Development of Nonlinear Inverter Model for Fast Dynamic Analysis of Electric Power Steering with PMSM Drive System (자동차 전자식 조향장치용 PMSM 구동 시스템의 신속한 동적해석을 위한 비선형 인버터 모델 개발)

  • Choi, Chin-Chul;Lee, Woo-Tiak;Hong, Jeong-Pyo
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1132-1133
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    • 2007
  • A circuit-domain model of PWM inverter provides accurate simulation results in consideration of detail switching characteristics. Although, a huge amount of computation time is demanded for the simulation results of several ten seconds, which is the required time to analyze system behaviors or control performances of Electric Power Steering(EPS) on real drive condition. This paper describes the nonlinear inverter model for fast dynamic simulation of EPS without the PWM concept through analyzing the effect of nonlinear switching characteristics like dead time, forward voltage drop and conduction resistance. Some inverter models including proposed model are compared from two standpoints which are computation time and accuracy. The comparison results show the usefulness of the developed model in order to develop the control algorithm through the fast prediction of system behaviors.

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DEVELOPMENT OF A CORE THERMO-FLUID ANALYSIS CODE FOR PRISMATIC GAS COOLED REACTORS

  • Tak, Nam-Il;Lee, Sung Nam;Kim, Min-Hwan;Lim, Hong Sik;Noh, Jae Man
    • Nuclear Engineering and Technology
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    • v.46 no.5
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    • pp.641-654
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    • 2014
  • A new computer code, named CORONA (Core Reliable Optimization and thermo-fluid Network Analysis), was developed for the core thermo-fluid analysis of a prismatic gas cooled reactor. The CORONA code is targeted for whole-core thermo-fluid analysis of a prismatic gas cooled reactor, with fast computation and reasonable accuracy. In order to achieve this target, the development of CORONA focused on (1) an efficient numerical method, (2) efficient grid generation, and (3) parallel computation. The key idea for the efficient numerical method of CORONA is to solve a three-dimensional solid heat conduction equation combined with one-dimensional fluid flow network equations. The typical difficulties in generating computational grids for a whole core analysis were overcome by using a basic unit cell concept. A fast calculation was finally achieved by a block-wise parallel computation method. The objective of the present paper is to summarize the motivation and strategy, numerical approaches, verification and validation, parallel computation, and perspective of the CORONA code.

Fast MOG Algorithm Using Object Prediction (객체 예측을 이용한 고속 MOG 알고리즘)

  • Oh, Jeong-Su
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.11
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    • pp.2721-2726
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    • 2014
  • In a MOG algorithm using the GMM to subtract background, the model parameter computation and the object classification to be performed at every pixel require a huge computation and are the chief obstacles to its uses. This paper proposes a fast MOG algorithm that partly adopts the simple model parameter computation and the object classification skip on the basis of the object prediction. The former is applied to the pixels that gives little effect on the model parameter and the latter is applied to the pixels whose object prediction is firmly trusted. In comparative experiment between the conventional and proposed algorithms using videos, the proposed algorithm carries out the simple model parameter computation and the object classification skip over 77.75% and 92.97%, respectively, nevertheless it retains more than 99.98% and 99.36% in terms of image and moving object-unit average classification accuracies, respectively.

A Study on the Fast Computational Algorithm for the Discrete Cosine Transform(DCT) via Lifting Scheme (리프팅 구조를 경유한 고속의 DCT 계산 알고리즘에 관한 연구)

  • Inn-Ho Jee
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.6
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    • pp.75-80
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    • 2023
  • We show the design of fast invertible block transforms that can replace the DCT in future wireless and portable computing application. This is called binDCT. In binDCT, both the forward and the inverse transforms can be implemented using only binary shift and addition operation. And the binDCT inherits all desirable DCT characteristics such as high coding gain, no DC leakage, symmetric basis functions, and recursive construction. The binDCT also inherits all lifting properties such as fast implementations, invertible integer-to-integer mapping, in-place computation. Thus, this method has advantage of fast implementation for complex DCT calculations. In this paper, we present computation costs and performance analysis between DCT and binDCT using Shapiro's EZW.

Algorithm and Implementation of Fast Multipole Boundary Element Method with Theoretical Analysis for Two-Dimensional Heat Conduction Problems (2차원 열전도 문제에 대한 Fast Multipole 경계요소법의 이론과 실행 알고리즘의 분석)

  • Choi, Chang-Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.5
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    • pp.441-448
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    • 2013
  • This paper presents the fast multipole boundary element method (FM-BEM) as a new BEM solution methodology that overcomes many disadvantages of conventional BEM. In conventional BEM, large-scale problems cannot be treated easily because the computation time increases rapidly with an increase in the number of boundary elements owing to the dense coefficient matrix. Analysis results are obtained to compare FM-BEM with conventional BEM in terms of computation time and accuracy for a simple two-dimensional steady-state heat conduction problem. It is confirmed that the FM-BEM solution methodology greatly enhances the computation speed while maintaining solution accuracy similar to that of conventional BEM. As a result, the theory and implementation algorithm of FM-BEM are discussed in this study.

An Auto-range Fast Bilateral Filter Using Adaptive Standard Deviation for HDR Image Rendering (HDR 영상 렌더링을 위한 적응적 표준 편차를 이용한 자동 레인지 고속 양방향 필터)

  • Bae, Tae-Wuk;Lee, Sung-Hak;Kim, Byoung-Ik;Sohng, Kyu-Ik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.4C
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    • pp.350-357
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    • 2010
  • In this paper, we present an auto-range fast bilateral filter (FBF) for high-dynamic-range (HDR) images, which increases computation speed by using adaptive standard deviations for range filter (RF) of FBF in iCAM06. Many images that cover the entire dynamic range of the scene with different exposure times are fused into one High Dynamic Range (HDR) image. The representative algorithm for HDR image rendering is iCAM06, which is based on the iCAM framework, such as the local white point adaptation, chromatic adaptation, and the image processing transform (IPT) uniform color space. FBF in iCAM06 uses constant standard deviation in RF. So, it causes unnecessary FBF computation in high stimulus range with broad and low distribution. To solve this problem, the low stimulus image and high stimulus image of CIE tri-stimulus values (XYZ) divided by the threshold are respectively processed by adaptive standard deviation based on its histogram distribution. Experiment results show that the proposed method reduces computation time than the previous FBF.