• Title/Summary/Keyword: Parameter Studies

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Estimation of State-of-charge and Sensor Fault Detection of a Lithium-ion Battery in Electric Vehicles (전기자동차용 리튬이온전지를 위한 SOC 추정 및 센서 고장검출)

  • Han, Man-You;Lee, Kee-Sang
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.8
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    • pp.1085-1091
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    • 2014
  • A model based SOC estimation scheme using parameter identification is described and applied to a Lithium-ion battery module that can be installed in electric vehicles. Simulation studies are performed to verify the effect of sensor faults on the SOC estimation results for terminal voltage sensor and load current sensor. The sensor faults should be detected and isolated as soon as possible because the SOC estimation error due to any sensor fault seriously affects the overall performance of the BMS. A new fault detection and isolation(FDI) scheme by which the fault of terminal voltage sensor and load current sensor can be detected and isolated is proposed to improve the reliability of the BMS. The proposed FDI scheme utilizes the parameter estimation of an input-output model and two fuzzy predictors for residual generation; one for terminal voltage and the other for load current. Recently developed dual polarization(DP) model is taken to develope and evaluate the performance of the proposed FDI scheme. Simulation results show the practical feasibility of the proposed FDI scheme.

Output-only modal parameter identification of civil engineering structures

  • Ren, Wei-Xin;Zong, Zhou-Hong
    • Structural Engineering and Mechanics
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    • v.17 no.3_4
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    • pp.429-444
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    • 2004
  • The ambient vibration measurement is a kind of output data-only dynamic testing where the traffics and winds are used as agents responsible for natural or environmental excitation. Therefore an experimental modal analysis procedure for ambient vibration testing will need to base itself on output-only data. The modal analysis involving output-only measurements presents a challenge that requires the use of special modal identification technique, which can deal with very small magnitude of ambient vibration contaminated by noise. Two complementary modal analysis methods are implemented. They are rather simple peak picking (PP) method in frequency domain and more advanced stochastic subspace identification (SSI) method in time domain. This paper presents the application of ambient vibration testing and experimental modal analysis on large civil engineering structures. A 15 storey reinforced concrete shear core building and a concrete filled steel tubular arch bridge have been chosen as two case studies. The results have shown that both techniques can identify the frequencies effectively. The stochastic subspace identification technique can detect frequencies that may possibly be missed by the peak picking method and gives a more reasonable mode shapes in most cases.

A 3-DOF forced vibration system for time-domain aeroelastic parameter identification

  • Sauder, Heather Scot;Sarkar, Partha P.
    • Wind and Structures
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    • v.24 no.5
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    • pp.481-500
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    • 2017
  • A novel three-degree-of-freedom (DOF) forced vibration system has been developed for identification of aeroelastic (self-excited) load parameters used in time-domain response analysis of wind-excited flexible structures. This system is capable of forcing sinusoidal motions on a section model of a structure that is used in wind tunnel aeroelastic studies along all three degrees of freedom - along-wind, cross-wind, and torsional - simultaneously or in any combination thereof. It utilizes three linear actuators to force vibrations at a consistent frequency but varying amplitudes between the three. This system was designed to identify all the parameters, namely, aeroelastic- damping and stiffness that appear in self-excited (motion-dependent) load formulation either in time-domain (rational functions) or frequency-domain (flutter derivatives). Relatively large displacements (at low frequencies) can be generated by the system, if required. Results from three experiments, airfoil, streamlined bridge deck and a bluff-shaped bridge deck, are presented to demonstrate the functionality and robustness of the system and its applicability to multiple cross-section types. The system will allow routine identification of aeroelastic parameters through wind tunnel tests that can be used to predict response of flexible structures in extreme and transient wind conditions.

Systematic Review for the Development of the Clinical Study with Economical Assessment Protocol on Facial palsy (얼굴마비의 임상연구병행 경제성평가 프로토콜 개발을 위한 체계적 문헌고찰연구)

  • Gong, Na-Gyeong;Seo, Eunsung;Seon, Ji-Hye;Kim, Nam-Kwen
    • The Journal of Korean Medicine
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    • v.38 no.1
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    • pp.46-55
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    • 2017
  • Objectives: The aim of this study is reviewing the literature to extract the key parameter, study design, perspective, cost-effectiveness index and find the calibration parameter for the clinical study with economical evaluation protocol on facial palsy. Methods: Literature search is performed using PUBMED for literature published from January 2000 to December 2016. We included randomized controlled trials(RCTs) and modelling study with economic assessment in which human participated. Results: As a result of literature search, the 198 articles were found. After reviewing the title, abstract and full text, the 5 articles were selected. Selected articles are classified into 4 RCT studies dealing with quality of life and 1 CEA(cost-effectiveness analysis) study. Conclusions: We found reliable key parameters, calibration parameters and elements of economical assessment study, which might be necessary factors for developing research protocol of clinical trial with economic evaluation about facial palsy patients.

A STUDY ON THE DIFFUSE ATTENUATION COEFFICIENT OF DOWN-WELLING IRRADIANCE AROUND THE YELLOW SEA

  • Min, Jee-Eun;Ahn, Yu-Hwan;Ryu, Joo-Hyung;Lee, Kyu-Sung
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.459-462
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    • 2006
  • The diffuse attenuation coefficient for down-welling irradiance ($K_d$) is an important parameter for ocean studies including remote sensing applications. For the vast ocean, ocean color remote sensing is the only possible means to get the fine-scale measurements of $K_d$. To develop a technique of estimating $K_d$ from remotely sensed data, the following underwater optical parameters (absorption coefficient (a), attenuation coefficient (c), scattering coefficient (b), diffuse attenuation coefficient ($K_d$), etc.) have been studied. For this research we conducted the field campaign around the Yellow Sea at $8{\sim}9$ June, 2006. We obtained a set of underwater optical parameter data: down-welling irradiance ($E_d$), up-welling irradiance ($E_u$) and up-welling radiance ($L_u$) using TriOS optical sensors and a, c coefficient using Spectral Absorption and Attenuation Meter (AC-S). We then derived $K_d$ values from $E_d$ for each depth.

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STM Studies of Keggin-type and Wells-Dawson-type Heteropolyacid Catalysts (Keggin 형 및 Wells-Dawson 형 헤테로폴리산 촉매의 STM 연구)

  • Park, Gyo Ik;Barteau, Mark A.;Jung, Ji Chul;Song, In Kyu
    • Korean Chemical Engineering Research
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    • v.47 no.2
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    • pp.163-168
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    • 2009
  • Negative differential resistance(NDR) behaviors of Keggin-type and Wells-Dawson-type heteropolyacids with cation, heteroatom, and polyatom substitutions were investigated by scanning tunneling microscopy. A reliable correlation between NDR peak voltage and reduction potential of heteropolyacid catalysts was established. It was found that more reducible heteropolyacid catalyst showed NDR behavior at less negative voltage, regardless of the structural difference. Thus, NDR peak voltage of heteropolyacid catalyst could be utilized as a single correlating parameter for the reduction potential of heteropolyacid catalyst.

Studies on the Application of Weibull Distribution to Forestry (II) - Estimation of Parameter by Gamma Function - (Weibull 분포(分布)를 응용(應用)한 임학연구(林學硏究)(II) - Gamma함수(函數)에 의한 parameter의 추정(推定) -)

  • Yun, Jong Wha
    • Journal of Korean Society of Forest Science
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    • v.61 no.1
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    • pp.1-7
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    • 1983
  • In the estimation of diameter distribution in a stand using Weibull distribution function, the calculation method of experimental distribution was presented in previous paper. This study was to estimate the diameter distribution of Korean pine stands by Weibull distribution which represents Gamma function, with mean diameter and mean basal-area diameter of the random sample trees. The results obtained fitted the diameter distribution in experimental stands. Thus, this method appears to be used for the estimation of diameter distribution in a stand as well as for the analysis and prediction of stand construction for the future.

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Uncertainty Analysis of Parameters of Spatial Statistical Model Using Bayesian Method for Estimating Spatial Distribution of Probability Rainfall (확률강우량의 공간분포추정에 있어서 Bayesian 기법을 이용한 공간통계모델의 매개변수 불확실성 해석)

  • Seo, Young-Min;Park, Ki-Bum;Kim, Sung-Won
    • Journal of Environmental Science International
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    • v.20 no.12
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    • pp.1541-1551
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    • 2011
  • This study applied the Bayesian method for the quantification of the parameter uncertainty of spatial linear mixed model in the estimation of the spatial distribution of probability rainfall. In the application of Bayesian method, the prior sensitivity analysis was implemented by using the priors normally selected in the existing studies which applied the Bayesian method for the puppose of assessing the influence which the selection of the priors of model parameters had on posteriors. As a result, the posteriors of parameters were differently estimated which priors were selected, and then in the case of the prior combination, F-S-E, the sizes of uncertainty intervals were minimum and the modes, means and medians of the posteriors were similar to the estimates using the existing classical methods. From the comparitive analysis between Bayesian and plug-in spatial predictions, we could find that the uncertainty of plug-in prediction could be slightly underestimated than that of Bayesian prediction.

Analysis of the spectroscopic characteristics of Ground color images using a digital camera (디지털 카메라를 활용한 컬러 지상영상의 분광학적 특성 분석)

  • Ko, In-Chul;Seo, Su-Young
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2010.06a
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    • pp.137-144
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    • 2010
  • Ground digital image data obtained by using DSLR camera can be used to the ground photogrammetry and spatial modeling. Intensity of each pixel in digital video images is the most important parameter to generate digital image. Therefore, it is needed to estimate the parameters and spectral characteristics of digital cameras in order to take more definite intensity data. In this study, using the Sony DSC-F828 DSLR camera, seven digital images are obtained by the continuous shooting. (frame rate, 0.38 seconds). And then extract the value of the intensity from RGB band of each digital color photographs to confirm difference of intensity between frames. The purpose of this study is to confirm spectral characteristics and changes and to estimate correlation through the analysis of statistical in each pixel of R, G, B band.

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Size dependent bending analysis of micro/nano sandwich structures based on a nonlocal high order theory

  • Rahmani, Omid;Deyhim, Soroush;Hosseini, S. Amir Hossein
    • Steel and Composite Structures
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    • v.27 no.3
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    • pp.371-388
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    • 2018
  • In this paper, a new model based on nonlocal high order theory is proposed to study the size effect on the bending of nano-sandwich beams with a compliance core. In this model, in contrast to most of the available sandwich theories, no prior assumptions are made with respect to the displacement field in the core. Herein the displacement and the stress fields of the core are obtained through an elasticity solution. Equations of motion and boundary conditions for nano-sandwich beam are derived by using Hamilton's principle and an analytical solution is presented for simply supported nano-sandwich beam. The results are validated with previous studies in the literature. These results can be utilized in the study of nano-sensors and nano-actuators. The effect of nonlocal parameter, Young's modulus of the core and aspect ratio on the deflection of the nano-sandwich beam is investigated. It is concluded that by including the small-scale effects, the deflection of the skins is increased and by increasing the nonlocal parameter, the influence of small-scale effects on the deflections is increased.