• Title/Summary/Keyword: computational algorithm

Search Result 4,412, Processing Time 0.027 seconds

A Transcoding Algorithm between EVRC and G.729A (EVRC와 G.729A 간의 상호부호화)

  • Kwon Goo-Rak;Ko Sung-Jea
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.43 no.3 s.309
    • /
    • pp.54-60
    • /
    • 2006
  • This paper presents an effective algorithm for transcoding between the Enhanced Variable Rate Codec(EVRC) and G.729A. The simplest way to communicate between heterogeneous speech networks is the cascade connection of two different codecs, called tandem coding. However, tandem coding not only produces high computational loads, but also makes long delay, These problems can be solved by using the transcoding algorithm. The proposed algorithm consists of LSP (Line Spectral Pair) conversion, pitch delay conversion and algorithm for reduction of delay. Experimental results show the proposed algorithm produces lower computational complexity, shorter algorithm delay, and similar speech quality when compared with the tandem algorithm.

A Direct Expansion Algorithm for Transforming B-spline Curve into a Piecewise Polynomial Curve in a Power Form. (B-spline 곡선을 power 기저형태의 구간별 다항식으로 바꾸는 Direct Expansion 알고리듬)

  • 김덕수;류중현;이현찬;신하용;장태범
    • Korean Journal of Computational Design and Engineering
    • /
    • v.5 no.3
    • /
    • pp.276-284
    • /
    • 2000
  • Usual practice of the transformation of a B-spline curve into a set of piecewise polynomial curves in a power form is done by either a knot refinement followed by basis conversions or applying a Taylor expansion on the B-spline curve for each knot span. Presented in this paper is a new algorithm, called a direct expansion algorithm, for the problem. The algorithm first locates the coefficients of all the linear terms that make up the basis functions in a knot span, and then the algorithm directly obtains the power form representation of basis functions by expanding the summation of products of appropriate linear terms. Then, a polynomial segment of a knot span can be easily obtained by the summation of products of the basis functions within the knot span with corresponding control points. Repeating this operation for each knot span, all of the polynomials of the B-spline curve can be transformed into a power form. The algorithm has been applied to both static and dynamic curves. It turns out that the proposed algorithm outperforms the existing algorithms for the conversion for both types of curves. Especially, the proposed algorithm shows significantly fast performance for the dynamic curves.

  • PDF

Adaptive Frame Rate Up-Conversion Algorithms using Block Complexity Information

  • Lee, Kangjun
    • Journal of Korea Multimedia Society
    • /
    • v.21 no.8
    • /
    • pp.813-820
    • /
    • 2018
  • This paper proposes new frame rate up-conversion algorithms. Adaptive motion estimation based on block complexity information are used to obtain more accurate motion vectors. Because the information on block complexity is extracted from the motion estimation prediction size from the original frame, additional computational complexity is not imparted. In experimental results, the proposed algorithms provide robust frame interpolation performance for whole test sequences. Also, the computational complexity of the proposed algorithm is reduced to a benchmark algorithm.

Predictive Control of Structural Vibration Subject to Wind Loads (풍하중에 대한 구조진동의 예측제어)

  • 최창근;권대건;이은진
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1996.10a
    • /
    • pp.29-36
    • /
    • 1996
  • A procedure for the predictive control for structural vibration control in building subject to wind loads is presented. The building motions are modeled by the first mode of the response. Wind velocities are generated by the simulation using power spectral density function. Predictive control algorithm is the discrete-time formulation and that is developed as a control strategy that computes the control signal which makes the predicted process output equal to a desired process output. Results on the reduction of the dynamic response and control effectiveness of the algorithm are presented and discussed.

  • PDF

Real-time Aircraft Parameter Estimation using LWR

  • Song,Yongkyu;Hong, Sung-Kyung
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.141.4-141
    • /
    • 2001
  • In this paper the Local Weighted Regression LWR technique is applied to the estimation of aircrcraft parameters. The method consists In improving the Local Weighted Regression LWR technique by adding a data Retention-and-Deletion RD strategy. The improvement comes with reduced computational effort since the two techniques can share their main computational procedures. The purpose of the study was to establish if the proposed algorithm could provide fast and reliable real-time estimations, with accuracy comparable to other well-known off-line identification schemes. The algorithm was tested using specific parameter estimation maneuvers and flight data of the NASA F/A-18 HARV. The results were compared with both the estimation obtained from ...

  • PDF

An efficient algorithm for generalized SS/TDMA scheduling with satellite cluster

  • Kim, Sehun;Kim, Soo-Hyun
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 1994.04a
    • /
    • pp.13-20
    • /
    • 1994
  • We consider the satellite cluster scheduling problem which is one of the most interesting problems in satellite communication scheduling area. This problem is known to be NP-complete and a couple of heuristic algorithms had been developed. In this paper, we suggest another algorithm for this problem which has the same computational complexity as the best existing one and provides much better solution quality. Extensive computational simulation results are reported.

Automatic Tetrahedral Mesh Generation using 3-D Operators (3-D 오퍼레이터를 이용한 사면체 요소망의 자동 생성)

  • 권기연;채수원;이병채
    • Korean Journal of Computational Design and Engineering
    • /
    • v.9 no.1
    • /
    • pp.27-34
    • /
    • 2004
  • A tetrahedral mesh generation scheme using 3-D operators has been presented. The proposed scheme employs new 3-D operators such as rearranging and modified finishing operators in addition to the previous trimming, wedging, digging, splitting and finishing operators. These new operators have been introduced in order to increase the stability of mesh generation process. Check processings with surrounded element edges and faces have also been optimized by employing a searching algorithm. Sample meshes are constructed to demonstrate the mesh generating capability of the proposed algorithm.

A HYBRID METHOD FOR REGULARIZED STRUCTURED LINEAR TOTAL LEAST NORM

  • KWON SUNJOO
    • Journal of applied mathematics & informatics
    • /
    • v.18 no.1_2
    • /
    • pp.621-637
    • /
    • 2005
  • A hybrid method solving regularized structured linear total least norm (RSTLN) problems, which have highly ill-conditioned coefficient matrix with special structures, is suggested and analyzed. This scheme combining RSTLN algorithm and separation by parts guarantees the convergence of parameters and has an advantages in reducing the residual norm and relative error of solutions. Computational tests for problems arisen in signal processing and image formation process confirm that the presenting method is effective for more accurate solutions to (R)STLN problem than the (R)STLN algorithm.

INVERSE PROBLEM FOR A HEAT EQUATION WITH PIECEWISE-CONSTANT CONDUCTIVITY

  • Gutman, S.;Ramm, A.G.
    • Journal of applied mathematics & informatics
    • /
    • v.28 no.3_4
    • /
    • pp.651-661
    • /
    • 2010
  • We consider the inverse problem of the identification of a piecewise-constant conductivity in a bar given the extra information of the heat flux through one end of the bar. Our theoretical results show that such an identification is unique. This approach utilizes a "layer peeling" argument. A computational algorithm based on this method is proposed and implemented. The advantage of this algorithm is that it requires only 3D minimizations irrespective of the number of the unknown discontinuities. Its numerical effectiveness is investigated for several conductivities.

Dynamic analysis of structures using linearized alogrithm for material nonlinearity (선형화 알고리듬을 이용한 재료적 비선형 구조물의 동적해석)

  • 심재수;임선묵
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1993.04a
    • /
    • pp.53-60
    • /
    • 1993
  • Nonlinear equation of motion due to material nonlinearity of structure is transformed to linear equation of motion by treating the nonlinear elastic force term as an applied force. The solution in a time step is carried out by iterative linear dynamic analysis. The present simple algorithm is varidated by several examples .The results show that this algorithm is and efficient.

  • PDF