• 제목/요약/키워드: Reduced integration

검색결과 486건 처리시간 0.024초

외연적 적분 기법을 적용한 Fully Flexible Cell 분자 동영학 시뮬레이션 (Explicit time integration algorithm for fully flexible cell simulation)

  • 박시동;조맹효
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2006년도 정기 학술대회 논문집
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    • pp.389-394
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    • 2006
  • Fully flexible cell preserves Hamiltonian in structure, so the symplectic time integrator is applied to the equations of motion. Primarily, generalized leapfrog time integration (GLF) is applicable, but the equations of motion by GLF have some of implicit formulas. The implicit formulas give rise to a complicate calculation for coding and need an iteration process. In this paper, the time integration formulas are obtained for the fully flexible cell molecular dynamics simulation by using the splitting time integration. It separates flexible cell Hamiltonian into terms corresponding to each of Hamiltonian term, so the simple and completely explicit recursion formula was obtained. The explicit formulas are easy to implementation for coding and may be reduced the integration time because they are not need iteration process. We are going to compare the resulting splitting time integration with the implicit generalized leapfrog time integration.

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임의의 하중 하에서 축소시스템 구성을 통한 구조물의 동적 거동 연구 (Time Integration in Reduced System Constructed by Two-level Condensation Scheme)

  • 김현기;조맹효
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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    • pp.19-26
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    • 2004
  • This study constructs the reduced system by two-level condensation scheme. This scheme consists of two steps. First step selects the candidate area for the primary degrees of freedom by energy estimation in element level. In the second step, the primary degrees of freedom are selected by the sequential elimination scheme. The efficiency and reliability of this scheme is shown through the prediction of eigenvalues of a few numerical examples. Time integration in the reduced system can save the computing time effectively. The well-constructed reduced system can present the accurate behavior of the structure under arbitrary dynamic loads so much as the global system. Through the numerical example, the efficiency and reliability of the proposed scheme will be demonstrated.

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3-D Hetero-Integration Technologies for Multifunctional Convergence Systems

  • 이강욱
    • 마이크로전자및패키징학회지
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    • 제22권2호
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    • pp.11-19
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    • 2015
  • Since CMOS device scaling has stalled, three-dimensional (3-D) integration allows extending Moore's law to ever high density, higher functionality, higher performance, and more diversed materials and devices to be integrated with lower cost. 3-D integration has many benefits such as increased multi-functionality, increased performance, increased data bandwidth, reduced power, small form factor, reduced packaging volume, because it vertically stacks multiple materials, technologies, and functional components such as processor, memory, sensors, logic, analog, and power ICs into one stacked chip. Anticipated applications start with memory, handheld devices, and high-performance computers and especially extend to multifunctional convengence systems such as cloud networking for internet of things, exascale computing for big data server, electrical vehicle system for future automotive, radioactivity safety system, energy harvesting system and, wireless implantable medical system by flexible heterogeneous integrations involving CMOS, MEMS, sensors and photonic circuits. However, heterogeneous integration of different functional devices has many technical challenges owing to various types of size, thickness, and substrate of different functional devices, because they were fabricated by different technologies. This paper describes new 3-D heterogeneous integration technologies of chip self-assembling stacking and 3-D heterogeneous opto-electronics integration, backside TSV fabrication developed by Tohoku University for multifunctional convergence systems. The paper introduce a high speed sensing, highly parallel processing image sensor system comprising a 3-D stacked image sensor with extremely fast signal sensing and processing speed and a 3-D stacked microprocessor with a self-test and self-repair function for autonomous driving assist fabricated by 3-D heterogeneous integration technologies.

분리형 GPS/DR 통합 칼만 필터 구현 (An Implementation of a Decoupled GPS/DR Integration Kalman Filter)

  • 서흥석;성태경;이상정
    • 제어로봇시스템학회논문지
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    • 제6권10호
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    • pp.928-935
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    • 2000
  • In order to improve the performance of a GPS/DR integration system, the error sources of DR sensors should be modeled accurately, This results in the increases in the dimension of the integration filter and, consequently, computational load becomes large. To reduce the computational load, suggested in this paper is a decoupled GPS/DR integration scheme that consists of two cascaded Kalman filters. The GPS velocity output is used in the first filter to calibrate the DR sensor and to fix the velocity as well. The velocity from the first filter is fed to the second filter where the position is corrected using the GPS position output. Experimental results show that the proposed integration scheme has positioning performance comparable to the conventional coupled one, while its computation is reduced to about 2/3.

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감각통합훈련이 20대 대학생들의 균형능력에 미치는 효과 (Effects of Sensory Integration Training on Equilibrium Ability in the College Students of the Twenties)

  • 한종만;이우형
    • 대한정형도수물리치료학회지
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    • 제16권1호
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    • pp.37-42
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    • 2010
  • Purpose : The purpose of this study was to evaluate the influence of sensory integration training on equilibrium ability in the college students of the twenties. Methods : The sensory integration training group(male: n=10, female: n=9) was measured an equilibrium ability by Kinesthetic Ability Trainer(KAT) at pre-intervention and post-intervention in 4weeks. Results : Mean value of eye close both leg standing and eye close one leg standing tests of the sensory integration training group were significantly reduced among the intervention period(p<.05). Conclusion : We were found that sensory integration training could reduce mean value of eye close both leg standing and eye close one leg standing tests and improve a balance for the college students of the twenties.

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계산량과 정확도를 동시에 만족하는 eLoran/GPS 통합 항법 알고리즘 (The Integrated eLoran/GPS Navigation Algorithm for Reduced Calculational Complexity and High Accuracy)

  • 송세필;신미영;손석보;김영백;이상정;박찬식
    • 전기학회논문지
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    • 제60권3호
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    • pp.612-619
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    • 2011
  • Satellite navigation system such as GPS is becoming more important infrastructure for positioning, navigation and timing. But satellite navigation system is vulnerable to interferences because of the low received power, complementary navigation system such as eLoran is needed. In order to develop eLoran/GPS navigation system, integrated eLoran/GPS navigation algorithm is necessary. In this paper, new integrated eLoran/GPS navigation algorithm is proposed. It combines the position domain integration and the range domain integration to get accurate position with less computational burden. Also an eLoran/GPS evaluation platform is designed and performance evaluation of the proposed algorithm using the evaluation platform is given. The proposed algorithm gives an accuracy of the range domain integration with a computational load of the position domain integration.

A high precision direct integration scheme for non-stationary random seismic responses of non-classically damped structures

  • Lin, Jiahao;Shen, Weiping;Williams, F.W.
    • Structural Engineering and Mechanics
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    • 제3권3호
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    • pp.215-228
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    • 1995
  • For non-classically damped structures subjected to evolutionary random seismic excitations, the non-stationary random responses are computed by means of a high precision direct (HPD) integration scheme combined with the pseudo excitation method. Only real modes are used, so that the reduced equations of motion remain coupled for such non-classically damped structures. In the given examples, the efficiency of this method is compared with that of the Newmark method.

등방성 및 복합재 플레이트용 16절점 요소의 강성행렬 계산 (Evaluation of Stiffness Matrix of 3-Dimensional Elements for Isotropic and Composite Plates)

  • 윤태혁;김정운;이재복
    • 대한기계학회논문집
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    • 제18권10호
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    • pp.2640-2652
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    • 1994
  • The stiffness of 6-node isotropic element is stiffer than that of 8-node isotropic element of same configuration. This phenomenon was called 'Relative Stiffness Stiffening Phenomenon'. In this paper, an equation of sampling point modification which correct this phenomenon was derived for the composite plate, as well as an equation for an isotropic plate. The relative stiffness stiffening phenomena of an isotropic plate element could be corrected by modifying Gauss sampling points in the numerical integration of stiffness matrix. This technique could also be successfully applied to the static analyses of composite plate modeled by the 3-dimensional 16-node elements. We predicted theoretical errors of stiffness versus the number of layers that result from the reduction of numerical integration order. These errors coincide very well with the actual errors of stiffness. Therefore, we can choose full integration of reduced integration based upon the permissible error criterion and the number of layers by using the thoretically predicted error.

A Practical Exciter Model Reduction Approach For Power System Transient Stability Simulation

  • Kim, Soobae
    • 조명전기설비학회논문지
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    • 제29권10호
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    • pp.89-96
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    • 2015
  • Explicit numerical integration methods for power system transient stability simulation require very small time steps to avoid numerical instability. The EXST1 exciter model is a primary source of fast dynamics in power system transients. In case of the EXST1, the required small integration time step for entire system simulation increases the computational demands in terms of running time and storage. This paper presents a practical exciter model reduction approach which allows the increase of the required step size and thus the method can decrease the computational demands. The fast dynamics in the original EXST1 are eliminated in the reduced exciter model. The use of a larger time step improves the computational efficiency. This paper describes the way to eliminate the fast dynamics from the original exciter model based on linear system theory. In order to validate the performance of the proposed method, case studies with the GSO-37 bus system are provided. Comparisons between the original and reduced models are made in simulation accuracy and critical clearing time.

New Anisoparametric 3-Node Elements for Out-of-Plane Deformable Curved Beam

  • Kim, Moon-Joon;Min, Oak-Key;Kim, Yong-Woo;Moon, Won-Joo
    • Journal of Mechanical Science and Technology
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    • 제14권3호
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    • pp.272-282
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    • 2000
  • Based on numerical reduced minimization theory, new anisoparametric 3-node elements for out-of-plane curved beam are developed. The elements are designed to be free from spurious constraints. In this paper, the effect of the Jacobian upon numerical solution is analyzed and predicted through reduced minimization analysis of anisoparametric 3-node elements with different Jacobian assumption. The prediction is verified by numerical tests for circular and spiral out-of-plane deformable curved beam models. This paper proposes two kinds of 3-node elements with 7-DOF; one element employs 2-point integration for all strains, and the other element uses 3-point integration with a constant Jacobian within element for calculation of shear strain.

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