• 제목/요약/키워드: global frame

검색결과 406건 처리시간 0.031초

전역적 정보를 이용한 샷 경계 검출 (Shot Boundary Detection Using Global Information)

  • 신성윤;신광성;이현창;진찬용;이양원
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2012년도 춘계학술대회
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    • pp.149-150
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    • 2012
  • 본 논문은 프레임 차이 값을 카메라에서 브레이크로 인해 발생하는 높은 유사 콘텐츠의 경계 추출을 허용하는 글로벌 의사 결정 트리를 기반으로 샷 경계 검출 방법을 제공합니다. 처음엔 프레임 사이의 차이 값은 지역 $X^2$-히스토그램과 정규화를 통해 계산됩니다. 다음으로, 차이 값 사이의 거리는 정규화를 통해 계산됩니다.

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평면골조의 최적내진설계를 위한 SA 알고리즘의 냉각스케줄 (Cooling Schedules in Simulated Annealing Algorithms for Optimal Seismic Design of Plane Frame Structures)

  • 이상관;박효선;박성무
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 봄 학술발표회논문집
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    • pp.458-465
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    • 2000
  • In the field of structural optimization simulated annealing (SA) algorithm has widely been adopted as an optimizer with the positive features of SA such as simplicity of the algorithm and possibility of finding global solution However, annealing process of SA algorithm based on random generator with the zeroth order structural information requires a large of number of iterations highly depending on cooling schedules and stopping criteria. In this paper, MSA algorithm is presented in the form of two phase annealing process with the effective cooling schedule and stopping criteria. With the application to optimal seismic design of steel structures, the performance of the proposed MSA algorithm has been demonstrated with respect to stability and global convergence of the algorithm

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Single-Run FRF 측정을 통한 실차 모달 시험 및 모드맵 검증 (Full Vehicle Modal Testing using Single-Run FRF Measurement and Mode Map Validation)

  • 이근수;정승균;김증한
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 추계학술대회논문집
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    • pp.387-388
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    • 2008
  • Finding reasonable flexural modes from the full vehicle modal testing has always been a difficult job to N&V engineers due to FRF inconsistency, nonlinearity, heavy damping and, in many cases, interactions between global body structural modes and massive isolate/non-isolated subsystem modes. This paper provides a brier overview of the mode map validation using single-run FRF measurement with highly sensitive accelerometers fur the full vehicle modal analysis and then it can be used to characterize the vehicle's global/local vibration performances, especially customer perceived "structural feel" typically below 40Hz.

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Hybrid evolutionary identification of output-error state-space models

  • Dertimanis, Vasilis K.;Chatzi, Eleni N.;Spiridonakos, Minas D.
    • Structural Monitoring and Maintenance
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    • 제1권4호
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    • pp.427-449
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    • 2014
  • A hybrid optimization method for the identification of state-space models is presented in this study. Hybridization is succeeded by combining the advantages of deterministic and stochastic algorithms in a superior scheme that promises faster convergence rate and reliability in the search for the global optimum. The proposed hybrid algorithm is developed by replacing the original stochastic mutation operator of Evolution Strategies (ES) by the Levenberg-Marquardt (LM) quasi-Newton algorithm. This substitution results in a scheme where the entire population cloud is involved in the search for the global optimum, while single individuals are involved in the local search, undertaken by the LM method. The novel hybrid identification framework is assessed through the Monte Carlo analysis of a simulated system and an experimental case study on a shear frame structure. Comparisons to subspace identification, as well as to conventional, self-adaptive ES provide significant indication of superior performance.

Calculation of Proton-Induced Reactions on Ti, Fe, Cu and Mo up to 60 MeV for TLA Application

  • Kim, Doohwan;Lee, Young-Ouk;Jonghwa Chang
    • Nuclear Engineering and Technology
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    • 제31권6호
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    • pp.595-607
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    • 1999
  • The reaction cross-sections of $^{nat}$Ti(p,X)$^{48}$ V, $^{nat}$Fe(p,X)$^{56}$ Co, $^{nat}$Cu(p,X)$^{65}$ Zn and $^{nat}$Mo(p,X)$^{96}$ Tc for TLA application are calculated in the frame of the ECIS-GNASH code system up to 60 MeV. The calculated results are compared with the experimental data taken from the EXFOR at the NEA Data Bank. A preliminary calculation with the global optical parameters of Varner et al. shows considerable differences from the experimental data at low energy range. The global optical parameters for the imaginary volume potential and the diffuseness of the imaginary potential are adjusted to achieve a better description of the experimental data in the vicinities of peak position below 16 MeV. 16 MeV.

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비억제 파라미터를 갖는 비선형 시스템의 전역 안정화 (A Global Regulation Method of Nonlinear Systems with Unbounded Parameters Under State Feedback Frame)

  • 구민성;최호림
    • 제어로봇시스템학회논문지
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    • 제22권3호
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    • pp.171-176
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    • 2016
  • In this paper, we consider a regulation problem of nonlinear systems under two triangular conditions where there possibly exist unbounded parameters in the systems. We propose a state feedback controller with dynamic gains in order to deal with unbounded parameters based on the condition of the time-varying rate of the growing parameter. The analysis of our control scheme is carried out by Lyapunov stability method. Our control method is verified by simulation results.

측지계변환에 따른 해양안전에 관한 연구 (A Study on the Ocean Safety According to the Geodetic Datum Transformation)

  • 고광섭;임정빈;임봉택
    • 해양환경안전학회지
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    • 제1권2호
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    • pp.39-52
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    • 1995
  • There are numerous mapping, charting, geodetic systems and electronic digital products defined in various local geodetic datum. It becomes a straight forward requirement to simplify the complexity by referencing all the products to a common reference globally. WGS-84 is well known as a state-of-the-art global reference system based on the use of data, techniques and technology available within American Defence Mapping Agency(DMA). Its parameters can be translated into more accurate maps, charts and geodetic positioning compared to others previously. Since Global Positioning System(GPS/NAVSTAR), which is asssociated with World Geodetic System(WGS-84)in reference frame, has been widely used, the unified geodetic system has been required for GPS users in many fields.

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Feasibility study of improved particle swarm optimization in kriging metamodel based structural model updating

  • Qin, Shiqiang;Hu, Jia;Zhou, Yun-Lai;Zhang, Yazhou;Kang, Juntao
    • Structural Engineering and Mechanics
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    • 제70권5호
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    • pp.513-524
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    • 2019
  • This study proposed an improved particle swarm optimization (IPSO) method ensemble with kriging model for model updating. By introducing genetic algorithm (GA) and grouping strategy together with elite selection into standard particle optimization (PSO), the IPSO is obtained. Kriging metamodel serves for predicting the structural responses to avoid complex computation via finite element model. The combination of IPSO and kriging model shall provide more accurate searching results and obtain global optimal solution for model updating compared with the PSO, Simulate Annealing PSO (SimuAPSO), BreedPSO and PSOGA. A plane truss structure and ASCE Benchmark frame structure are adopted to verify the proposed approach. The results indicated that the hybrid of kriging model and IPSO could serve for model updating effectively and efficiently. The updating results further illustrated that IPSO can provide superior convergent solutions compared with PSO, SimuAPSO, BreedPSO and PSOGA.

Nonlinear finite element model updating with a decentralized approach

  • Ni, P.H.;Ye, X.W.
    • Smart Structures and Systems
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    • 제24권6호
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    • pp.683-692
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    • 2019
  • Traditional damage detection methods for nonlinear structures are often based on simplified models, such as the mass-spring-damper and shear-building models, which are insufficient for predicting the vibration responses of a real structure. Conventional global nonlinear finite element model updating methods are computationally intensive and time consuming. Thus, they cannot be applied to practical structures. A decentralized approach for identifying the nonlinear material parameters is proposed in this study. With this technique, a structure is divided into several small zones on the basis of its structural configuration. The unknown material parameters and measured vibration responses are then divided into several subsets accordingly. The structural parameters of each subset are then updated using the vibration responses of the subset with the Newton-successive-over-relaxation (SOR) method. A reinforced concrete and steel frame structure subjected to earthquake loading is used to verify the effectiveness and accuracy of the proposed method. The parameters in the material constitutive model, such as compressive strength, initial tangent stiffness and yielding stress, are identified accurately and efficiently compared with the global nonlinear model updating approach.

F-투영법을 이용한 웨이블렛 신경망의 성장 알고리즘 (Growing Algorithm of Wavelet Neural Network using F-projection)

  • 서재용;김용택;조현찬;김용민;전홍태
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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    • pp.15-168
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    • 2001
  • In this paper, we propose growing algorithm of wavelet neural network. It is growing algorithm that adds hidden nodes using wavelet frame which approximately supports orthogonality in wavelet neural network based on wavelet theory. The result of this processing can be reduced global error and progresses performance efficiency of wavelet neural network. We apply the proposed algorithm to approximation problem and evaluate effectiveness of proposed algorithm.

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