• Title/Summary/Keyword: 분해기법

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Diagonalized Approximate Factorization Method for 3D Incompressible Viscous Flows (대각행렬화된 근사 인수분해 기법을 이용한 3차원 비압축성 점성 흐름 해석)

  • Paik, Joongcheol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.3B
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    • pp.293-303
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    • 2011
  • An efficient diagonalized approximate factorization algorithm (DAF) is developed for the solution of three-dimensional incompressible viscous flows. The pressure-based, artificial compressibility (AC) method is used for calculating steady incompressible Navier-Stokes equations. The AC form of the governing equations is discretized in space using a second-order-accurate finite volume method. The present DAF method is applied to derive a second-order accurate splitting of the discrete system of equations. The primary objective of this study is to investigate the computational efficiency of the present DAF method. The solutions of the DAF method are evaluated relative to those of well-known four-stage Runge-Kutta (RK4) method for fully developed and developing laminar flows in curved square ducts and a laminar flow in a cavity. While converged solutions obtained by DAF and RK4 methods on the same computational meshes are essentially identical because of employing the same discrete schemes in space, both algorithms shows significant discrepancy in the computing efficiency. The results reveal that the DAF method requires substantially at least two times less computational time than RK4 to solve all applied flow fields. The increase in computational efficiency of the DAF methods is achieved with no increase in computational resources and coding complexity.

대두단백질 가수분해물의 쓴맛 펩타이드 구조와 특징

  • Lee, Cheol-Ho
    • Proceedings of the Korean Society of Life Science Conference
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    • 2001.06a
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    • pp.3-41
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    • 2001
  • 단백질의 부분 가수분해는 산성 음료에서의 용해도 증가, 환자들의 소화력과 알러지 내성의 개선, 다른 기능적 특성의 개발 등을 위하여 식품산업에 널리 이용되고 있다. 그러나 우유 단백질이나 대두 단백질과 같은 몇 가지 단백질들은 가수분해에 의하여 강한 쓴맛을 형성한다, 단백질 가수분해물의 쓴맛에 관한 연구는 1950년대 초에 시작되었으며, 여러 가지 원료로부터 쓴맛물질이 분리되었다. 이들 단백질 가수분해물의 쓴맛 물질은 올리고펩타이드로 알려져 있으며, 펩타이드 분자를 구성하는 소수성 아미노산의 존재와 밀접한 관계가 있는 것으로 보고되고 있다. 본 연구에서는 최근에 발달된 분석기술과 생명공학적 기법으로 E. coli에서 생산한 콩 단백질 단일 subunit를 이용하여 효소적 가수분해물의 분자구조를 확인하고자 하였다. 탈지대두박으로부터 115 glycinin와 E.coli떼서 발현된 proglycinin을 각각 90%, 97%의 정제도로 분리하여 이들 단백질을 trypsin으로 각각 가수분해하였다. 115 glycinin은 효소/기질 비 3%에서 4시간 가수분해에 의해 $14.0{\times}10^{-5}$ M quinine-HCI equivalent의 강한 쓴맛을 나타내었으며, 12%의 가수분해도(DH)를 나타내었다. 대두 단백질의 쓴맛 성분을 확인 위하여 이미 아미노산 서열이 밝혀진 11S glycinin과 proglycinin 가수분해물에서 GP-HPLC, $C_{18}$ RP-HPLC 등을 통하여 쓴맛 peptide들을 분리하였다. 각각의 분획은 다시 21개의 peptide로 분리되어 그 서열이 결정되었으며 이중 RP와 GI는 이미 알려진 쓴맛 dipeptide였고, LAGNQEQE, SAEFG, NALPE, KLHENIAR, GMIYPG 등이 주된 쓴맛 Peptide로 확인되었다. 이들은 11S glycinin의 5개의 subunit 중에서 그 위치가 확인되었다. Proglycinin 가수분해물에서도 11S glycinin과 같은 방법으로 7개의 쓴맛 peptide가 분리되었다. 이들은 $A_{1a}B_{1b}$의 아미노산 서열 중에서 37-42, 103-110, 164-167, 323-327, 367-373의 위치에 분포하고 있었으며, NALKPD, IYPGCPST, SlDT, HNIGQT, NAMFVPH의 서열을 나타내었다. 분리된 쓴맛 peptide 중에서 가장 쓴 두 분회의 peptide를 합성하여 관능 검사한 결과, NALPE는 매우 쓴맛을 내는 peptide로 확인되었다.

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The Relative Position Estimate of the Moving Distributed Sources Using the Doppler Scanning Technique (도플러 스캐닝 기법을 이용한 이동하는 다중 음원의 상대 위치 추적 기법)

  • 노용주;윤종락;전재진
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.5
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    • pp.446-454
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    • 2002
  • This paper presents the Doppler Scanning technique which enables us to detect the relative positions of moving distributed sources using Doppler frequency shift estimate when the moving source consists of distributed sources with different signature frequencies. Doppler frequency shifts of characteristic frequencies of machinery noise sources such as ship's generator and propeller, with tine along CPA (Closest Point of Approach of moving source) are unique, and can be functioned with respect to each source position. Therefore, this technique can be applied to estimate the relative geometrical positions between machinery noise sources. The Extended Kalman Filter (EKF) which has a high frequency resolution with high time resolution, is adopted for improving accuracy of Doppler frequency shift estimate geometric resolution of machinery positions since machinery noise sources show in general low frequency band characteristics with limited spacial distance. The performance of the technique is examined by the numerical simulations and is verified by the experiment using loudspeaker sources on the roof of the car.

Super Resolution Algorithm using TV-G Decomposition (TV-G 분해를 이용한 초해상도 알고리즘)

  • Eum, Kyoung-Bae;Beom, Dong-Kyu
    • Journal of Digital Contents Society
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    • v.18 no.8
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    • pp.1517-1522
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    • 2017
  • Among single image SR techniques, the TV based SR approach seems most successful in terms of edge preservation and no artifacts. But, this approach achieves insufficient SR for texture component. In this paper, we proposed a new TV-G decomposition based SR method to solve this problem. We proposed the SVR based up-sampling to get better edge preservation in the structure component. The NNE used the relaxed constraint to improve the NE. We used the NNE based learning method to improve the resolution of the texture component. Through experimental results, we quantitatively and qualitatively confirm the improved results of the proposed SR method when comparing with conventional interpolation method, ScSR, TV and NNE.

Matched Field Source Localization and Interference Suppression Using Mode Space Estimation (정합장 기반 표적 위치추정 시 모드공간 분석을 통한 간섭 신호 제거 기법)

  • Kim, Kyung-Seop;Seong, Woo-Jae;Pyo, Sang-Woo
    • The Journal of the Acoustical Society of Korea
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    • v.27 no.1
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    • pp.40-46
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    • 2008
  • Weak target detection and localization in the presence of loud surface ship noise is a critical problem for matched field processing (MFP) in shallow water. For stationary sources, each signal component of received signal can be separated and interference can be suppressed using eigen space analysis schemes. However, source motion, in realistic cases, causes spreading of signal energies in their subspace. In this case, eigenvalues of target and interfere signal components are mixed and hard to be separated with usual phone space eigenvector decomposition (EVD) approaches. Our technique is based on mode space and utilizes the difference in their physical characteristics of surface and submerged sources. Performing EVD for modal cross spectral density matrix, interference components in the mode amplitude subspace can be classified and eliminated. This technique is demonstrated with synthetic data, and results are discussed.

Projective Reconstruction from Multiple Images using Matrix Decomposition Constraints (행렬 분해 제약을 사용한 다중 영상에서의 투영 복원)

  • Ahn, Ho-Young;Park, Jong-Seung
    • Journal of Korea Multimedia Society
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    • v.15 no.6
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    • pp.770-783
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    • 2012
  • In this paper, we propose a novel structure recovery algorithm in the projective space using image feature points. We use normalized image feature coordinates for the numerical stability. To acquire an initial value of the structure and motion, we decompose the scaled measurement matrix using the singular value decomposition. When recovering structure and motion in projective space, we introduce matrix decomposition constraints. In the reconstruction procedure, a nonlinear iterative optimization technique is used. Experimental results showed that the proposed method provides proper accuracy and the error deviation is small.

A Module Decomposition Method for Object-Oriented Design (객체 지향 설계를 위한 모듈 분해방법)

  • Heo, Gye-Beom;Choe, Yeong-Geun
    • The Transactions of the Korea Information Processing Society
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    • v.2 no.3
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    • pp.299-313
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    • 1995
  • Object-Oriented design method decomposes the program into object that establish the relationship between objects. It is the technique of object centered decomposition unlike function oriented legacy system. Since existing Object- Oriented design method doesn't fully explain of the design method of module and decomposition, and need to implement the Object-Oriented software as a total system init. It has many problems that whole object design method and application programs should be analyzed for the understanding an Object-Oriented software component. Therefore, this study provides a procedure for Object-Oriented module design and criteria of decomposition to practically support the complex and large system development. Futhermore, it shows a consistency between design model and implementation through a case study applying these module decomposition criteria to the real system.

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An Acoustic Event Detection Method in Tunnels Using Non-negative Tensor Factorization and Hidden Markov Model (비음수 텐서 분해와 은닉 마코프 모델을 이용한 터널 환경에서의 음향 사고 검지 방법)

  • Kim, Nam Kyun;Jeon, Kwang Myung;Kim, Hong Kook
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.8 no.9
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    • pp.265-273
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    • 2018
  • In this paper, we propose an acoustic event detection method in tunnels using non-negative tensor factorization (NTF) and hidden Markov model (HMM) applied to multi-channel audio signals. Incidents in tunnel are inherent to the system and occur unavoidably with known probability. Incidents can easily happen minor accidents and extend right through to major disaster. Most incident detection systems deploy visual incident detection (VID) systems that often cause false alarms due to various constraints such as night obstacles and a limit of viewing angle. To this end, the proposed method first tries to separate and detect every acoustic event, which is assumed to be an in-tunnel incident, from noisy acoustic signals by using an NTF technique. Then, maximum likelihood estimation using Gaussian mixture model (GMM)-HMMs is carried out to verify whether or not each detected event is an actual incident. Performance evaluation shows that the proposed method operates in real time and achieves high detection accuracy under simulated tunnel conditions.

High Resolution Wideband Local Polynomial Approximation Beamforming for Moving Sources (이동하는 음원에 적합한 고분해능 광대역 LPA 빔형성기법)

  • Park Do-Hyun;Park Gyu-Tae;Lee Jung-Hoon;Lee Su-Hvoung;Lee Kyun-Kyung
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.1
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    • pp.1-10
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    • 2005
  • This paper presents a wideband LPA (local polynomial approximation) beamforming algorithm that is appropriate for wideband moving sources. The Proposed wideband LPA algorithm adopts STMV (steered minimum variance) method that utilizes a steered covariance matrix obtained from multiple frequency components in one data snapshot, instead of multiple data snapshots in one frequency bin. The wideband LPA cost function is formed using STMV weight vector. The Proposed algorithm searches for the instantaneous DOA and angular velocity that maximize the wideband LPA cost function. resulting in a higher resolution performance than that of a DS LPA beamforming algorithm. Several simulations using artificial data and sea trial data are used to demonstrate the performance of the Proposed algorithm.

Adjustment Program for Large Sparse Geodetic Networks (희박행렬의 기법을 이용한 대규모 측지망의 조정)

  • Lee, Young Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.11 no.4
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    • pp.143-150
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    • 1991
  • This paper presents an overview of a system of computer programs for the solution of a large geodetic network of about 2,000 stations. The system arranges the matrices in systematic sparse form which is applied to observation equations of RR(C)U (Row-wise Representation Complete Unordered) type and to normal equations of RR(U)U (Row-wise Representation Upper Unordered) type. The solution is done by a Modified Cholesky's algorithm in view of large networks. The implementation program are tested in PC-386 by korean new secondary networks, the results show that the sparse techniques are highly useful to geodetic networks in core-storage management and processing time.

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