• 제목/요약/키워드: Deterministic Analysis

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하이브리드 차량의 SOC 유지전략 방법 (Deterministic rule-based control classification for HEV)

  • 변상민;김범수;차석원
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 추계학술대회 논문집
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    • pp.357-360
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    • 2008
  • There are many control strategies for HEV in today. Expanding motor-driving and operating at good-efficient point in engine is the key of the HEV control to increase fuel economy. There are two types of HEV supervisory control. One is rule-based control and the other is optimization control. MAX-SOC control, thermostat control, baseline status control and state-machine control are in deterministic RBC. It is simple, but powerful and easy to apply in real-time circumstance. In this study, we analysis these four control strategies in RBC (Rule-based control) and identify the each advantage and disadvantage.

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Stochastic design charts for bearing capacity of strip footings

  • Shahin, Mohamed A.;Cheung, Eric M.
    • Geomechanics and Engineering
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    • 제3권2호
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    • pp.153-167
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    • 2011
  • Traditional design methods of bearing capacity of shallow foundations are deterministic in the sense that they do not explicitly consider the inherent uncertainty associated with the factors affecting bearing capacity. To account for such uncertainty, available deterministic methods rather employ a fixed global factor of safety that may lead to inappropriate bearing capacity predictions. An alternative stochastic approach is essential to provide a more rational estimation of bearing capacity. In this paper, the likely distribution of predicted bearing capacity of strip footings subjected to vertical loads is obtained using a stochastic approach based on the Monte Carlo simulation. The approach accounts for the uncertainty associated with the soil shear strength parameters: cohesion, c, and friction angle, ${\phi}$, and the cross correlation between c and ${\phi}$. A set of stochastic design charts that assure target reliability levels of 90% and 95%, are developed for routine use by practitioners. The charts negate the need for a factor of safety and provide a more reliable indication of what the actual bearing capacity might be.

전력계통의 고임피던스 고장으로부터 혼돈특성 추출에 관한 연구 (A Study on Extracting Chaotic Properties from High Impedance Faults in Power Systems)

  • 고재호
    • 한국지능시스템학회논문지
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    • 제9권5호
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    • pp.545-549
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    • 1999
  • Previous studies on high impedance faults assumed that the erratic behavior of fault current would be random. In this paper we prove that the nature of the high impedance faults is indeed a deterministic chaos not a random motion. Algorithms for estimating Lyapunov spectrum and the largest Lyapunov exponent are applied to various fault currents in order to evaluate the orbital instability peculiar to deterministic chaos dynamically and fractal dimensions of fault currents which represent geometrical self-similarity are calculated. In addition qualitative analysis such a s phase planes Poincare maps obtained from fault currents indicate that the irregular behavior is described by strange attractor.

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자갈궤도의 안정성 확보를 위한 확률론적 접근 방안에 대한 연구 (A Study on Probabilistic Approach Method for Stability of the Ballasted Track)

  • 이우철;최진유;임남형;이진옥
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.299-302
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    • 2008
  • The behavior of continuous welded rail tracks is directly affected by the following various parameters: rail size; track curvature; neutral temperature; misalignment; and ballast resistance. Most of these parameters are having the nature of random variables. Therefore, uncertainties exist in the buckling safety assessments. The evaluation of the buckling safety and the maintenance strategy based on the deterministic analysis are very inefficient since the value of deterministic parameters are selected in worst track condition. In this study, the probabilistic approach method were investigated considering the probabilistic distribution of major parameters such as the neutral temperature of rail and the ballast resistance.

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성능지표 선정을 통한 강인한 칼만필터 설계 (Robust Kalman Filter Design via Selecting Performance Indices)

  • 정종철;허건수
    • 대한기계학회논문집A
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    • 제29권1호
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    • pp.59-66
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    • 2005
  • In this paper, a robust stationary Kalman filter is designed by minimizing selected performance indices so that it is less sensitive to uncertainties. The uncertainties include not only stochastic factors such as process noise and measurement noise, but also deterministic factors such as unknown initial estimation error, modeling error and sensing bias. To reduce the effect on the uncertainties, three performance indices that should be minimized are selected based on the quantitative error analysis to both the deterministic and the stochastic uncertainties. The selected indices are the size of the observer gain, the condition number of the observer matrix, and the estimation error variance. The observer gain is obtained by optimally solving the multi-objectives optimization problem that minimizes the indices. The robustness of the proposed filter is demonstrated through the comparison with the standard Kalman filter.

확률론적 평가법과 결정론적 평가법에 의한 내진성능비교분석 (The Comparison of Seismic Capacities Of Two Approaches, Probabilistic Approach and Deterministic Approach)

  • 송정국;황규호;강선구;서용표;이종림
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2003년도 춘계 학술발표회논문집
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    • pp.101-109
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    • 2003
  • In evaluating the individual Plant Examination of Seismic Events, two methodologies, Seismic Probabilistic Risk Assessment(SPRA) and Seismic Margin Assessment(SMA) can be used. SPRA is based on the probubilistic approach and SMA is based on the deterministic approach in evaluating seismic capacities. In this paper, by evaluating the seismic capacities of the same component by these two approaches respectively, the correlation of two methodologies can be shown. In addition, the meaning of HCLPF(High Confidence of Low Probability of Failure) values that are inherent in these two methodologies is recognized by the quantitative comparison analysis.

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Binary Sequence Family for Chaotic Compressed Sensing

  • Lu, Cunbo;Chen, Wengu;Xu, Haibo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권9호
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    • pp.4645-4664
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    • 2019
  • It is significant to construct deterministic measurement matrices with easy hardware implementation, good sensing performance and good cryptographic property for practical compressed sensing (CS) applications. In this paper, a deterministic construction method of bipolar chaotic measurement matrices is presented based on binary sequence family (BSF) and Chebyshev chaotic sequence. The column vectors of these matrices are the sequences of BSF, where 1 is substituted with -1 and 0 is with 1. The proposed matrices, which exploit the pseudo-randomness of Chebyshev sequence, are sensitive to the initial state. The performance of proposed matrices is analyzed from the perspective of coherence. Theoretical analysis and simulation experiments show that the proposed matrices have limited influence on the recovery accuracy in different initial states and they outperform their Gaussian and Bernoulli counterparts in recovery accuracy. The proposed matrices can make the hardware implement easy by means of linear feedback shift register (LFSR) structures and numeric converter, which is conducive to practical CS.

STOCHASTIC CASHFLOW MODELING INTEGRATED WITH SIMULATION BASED SCHEDULING

  • Dong-Eun Lee;David Arditi;Chang-Baek Son
    • 국제학술발표논문집
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    • The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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    • pp.395-398
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    • 2011
  • This paper introduces stochastic cash-flow modeling integrated with simulation based scheduling. The system makes use of CPM schedule data exported from commercial scheduling software, computes the best fit probability distribution functions (PDFs) of historical activity durations, assigns the PDFs identified to respective activities, simulates the schedule network, computes the deterministic and stochastic project cash-flows, plots the corresponding cash flow diagrams, and estimates the best fit PDFs of overdraft and net profit of a project. It analyzes the effect of different distributions of activity durations on the distribution of overdrafts and net profits, and improves reliability compared to deterministic cash flow analysis.

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Modelling atomic relaxation and bremsstrahlung in the deterministic code STREAM

  • Nhan Nguyen Trong Mai;Kyeongwon Kim;Deokjung Lee
    • Nuclear Engineering and Technology
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    • 제56권2호
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    • pp.673-684
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    • 2024
  • STREAM, developed by the Computational Reactor Physics and Experiment laboratory (CORE) of the Ulsan National Institute of Science and Technology (UNIST), is a deterministic neutron- and photon-transport code primarily designed for light water reactor (LWR) analysis. Initially, the photon module in STREAM did not account for fluorescence and bremsstrahlung photons. This article presents recent developments regarding the integration of atomic relaxation and bremsstrahlung models into the existing photon module, thus allowing for the transport of secondary photons. The photon flux and photon heating computed with the newly incorporated models is compared to results obtained with the Monte Carlo code MCS. The incorporation of secondary photons has substantially improved the accuracy of photon flux calculations, particularly in scenarios involving strong gamma emitters. However, it is essential to note that despite the consideration of secondary photon sources, there is no noticeable improvement in the photon heating for LWR problems when compared to the photon heating obtained with the previous version of STREAM.

반응면 기법을 이용한 적층복합재료판의 신뢰성해석 (Reliability Analysis of laminated Composite Panel using Response Surface Method)

  • 방제성;김용협
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2001년도 추계학술발표대회 논문집
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    • pp.187-190
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    • 2001
  • Response surface method is applied to evaluate the reliability of laminated composite panels. Since the linear and nonlinear first-ply failure load are computed using deterministic finite element analysis, new probabilistic finite element analysis is not necessary. Tsai-Wu criterion is used to construct the limit state suface. Material properties, layer thickness and lamina strengths of laminated composite panel are treated as random design variables. feasibility and accuracy of current method is validated using Monte-Carlo method Which perform thousand times of finite element analysis directly.

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