• Title/Summary/Keyword: State Transformation

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Microstructural modeling of two-way bent shape change of composite two-layer beam comprising a shape memory alloy and elastoplastic layers

  • Belyaev, Fedor S.;Evard, Margarita E.;Volkov, Aleksandr E.;Volkova, Natalia A.;Vukolov, Egor A.
    • Smart Structures and Systems
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    • v.30 no.3
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    • pp.245-253
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    • 2022
  • A two-layer beam consisting of an elastoplastic layer and a functional layer made of shape memory alloy (SMA) TiNi is considered. Constitutive relations for SMA are set by a microstructural model capable to calculate strain increment produced by arbitrary increments of stress and temperature. This model exploits the approximation of small strains. The equations to calculate the variations of the strain and the internal variables are based on the experimentally registered temperature kinetics of the martensitic transformations with an account of the crystallographic features of the transformation and the laws of equilibrium thermodynamics. Stress and phase distributions over the beam height are calculated by steps, by solving on each step the boundary-value problem for given increments of the bending moment (or curvature) and the tensile force (or relative elongation). Simplifying Bernoulli's hypotheses are applied. The temperature is considered homogeneous. The first stage of the numerical experiment is modeling of preliminary deformation of the beam by bending or stretching at a temperature corresponding to the martensitic state of the SMA layer. The second stage simulates heating and subsequent cooling across the temperature interval of the martensitic transformation. The curvature variation depends both on the total thickness of the beam and on the ratio of the layer's thicknesses.

Validation of Reference Genes for Quantitative Real-Time PCR in Bovine PBMCs Transformed and Non-transformed by Theileria annulata

  • Zhao, Hongxi;Liu, Junlong;Li, Youquan;Yang, Congshan;Zhao, Shuaiyang;Liu, Juan;Liu, Aihong;Liu, Guangyuan;Yin, Hong;Guan, Guiquan;Luo, Jianxun
    • Parasites, Hosts and Diseases
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    • v.54 no.1
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    • pp.39-46
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    • 2016
  • Theileria annulata is a tick-borne intracellular protozoan parasite that causes tropical theileriosis, a fatal bovine lymphoproliferative disease. The parasite predominantly invades bovine B lymphocytes and macrophages and induces host cell transformation by a mechanism that is not fully comprehended. Analysis of signaling pathways by quantitative real-time PCR (qPCR) could be a highly efficient means to understand this transformation mechanism. However, accurate analysis of qPCR data relies on selection of appropriate reference genes for normalization, yet few papers on T. annulata contain evidence of reference gene validation. We therefore used the geNorm and NormFinder programs to evaluate the stability of 5 candidate reference genes; 18S rRNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ACTB (${\beta}-actin$), PRKG1 (protein kinase cGMP-dependent, type I) and TATA box binding protein (TBP). The results showed that 18S rRNA was the reference gene most stably expressed in bovine PBMCs transformed and non-transformed with T. annulata, followed by GAPDH and TBP. While 18S rRNA and GAPDH were the best combination, these 2 genes were chosen as references to study signaling pathways involved in the transformation mechanism of T. annulata.

Design of state space pole assignment self-tuning controller for MIMO systems using RPE method (RPE 방법을 이용한 다입출력 시스템의 상태공간 극배치 자기동조 제어기 설계)

  • 강석종;전기준
    • 제어로봇시스템학회:학술대회논문집
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    • 1986.10a
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    • pp.90-94
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    • 1986
  • This paper describes expansion of the state space pole assignment self-tuning control of SISO systems with system noise and abservation noise to that of MIMO systems. Resursive Prediction Error method is used for both parameter and state estimation in the block controllable canonical form. This simplifies the state feedback law by eliminating the online computation of transformation matrix.

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Transformation Method for a State Machine to Increase Code Coverage (코드 커버리지를 높이기 위한 상태 머신 변환 방법)

  • Yoon, YoungDong;Choi, HyunJae;Chae, HeungSeok
    • Journal of KIISE
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    • v.43 no.9
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    • pp.953-962
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    • 2016
  • Model-based testing is a technique for performing the test by using a model that represents the behavior of the system as a system specification. Industrial domains such as automotive, military/aerospace, medical, railway and nuclear power generation require model-based testing and code coverage-based testing to improve the quality of software. Despite the fact that both model-based testing and code coverage-based testing are required, difficulty in achieving a high coverage using model-based testing caused by the abstraction level difference between the test model and the source code, results in the need for performing model-based testing separately. In this study, to overcome the limitations of the existing model-based testing, we proposed the state machine transformation method to effectively improve the code coverage using the protocol state machine, one of the typical modeling methods is used as the test model in model-based testing, as the test model. In addition, we performed a case study of both systems and analyzed the effectiveness of the proposed method.

A simple data assimilation method to improve atmospheric dispersion based on Lagrangian puff model

  • Li, Ke;Chen, Weihua;Liang, Manchun;Zhou, Jianqiu;Wang, Yunfu;He, Shuijun;Yang, Jie;Yang, Dandan;Shen, Hongmin;Wang, Xiangwei
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2377-2386
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    • 2021
  • To model the atmospheric dispersion of radionuclides released from nuclear accident is very important for nuclear emergency. But the uncertainty of model parameters, such as source term and meteorological data, may significantly affect the prediction accuracy. Data assimilation (DA) is usually used to improve the model prediction with the measurements. The paper proposed a parameter bias transformation method combined with Lagrangian puff model to perform DA. The method uses the transformation of coordinates to approximate the effect of parameters bias. The uncertainty of four model parameters is considered in the paper: release rate, wind speed, wind direction and plume height. And particle swarm optimization is used for searching the optimal parameters. Twin experiment and Kincaid experiment are used to evaluate the performance of the proposed method. The results show that the proposed method can effectively increase the reliability of model prediction and estimate the parameters. It has the advantage of clear concept and simple calculation. It will be useful for improving the result of atmospheric dispersion model at the early stage of nuclear emergency.

Effects of Bainitic Transformation Temperature and Stress State on the Formability of C-Mn-Si TRIP Steels (C-Mn-Si계 변태유기소성강의 성형성에 미치는 베이나이트 변태온도 및 응력상태의 영향)

  • Jun H. S.;Oh J. H.;Park C. G.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.156-160
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    • 2001
  • The effects of TRansformation Induced Plasticity(TRIP) phenomena on the plastic deformation of 0.2C-1.5Si-1.5Mn multiphase steels have been investigated at various heat treatment and stress conditions. In order to estimate the formability, the hole expansion(HE) tests and the tensile tests were carried out. The formability evaluated from the uni-axial tensile tests was quite different from the formability measured from multi-axial HE-tests. Consequently, the formability in the multi-axial stress state decreased due to the extinction of the retained austenite relatively at earlier deformation stage and the production of irregular α' martensite. However, the defects of TRIP-steels were initiated exactly at the boundary between transformed martensite and ferrite matrix regardless of stress state. In addition, new experimental formula is proposed in order to predict the multi-axial formability of the TRIP steels from the results of uniaxial tensile test.

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Unscented Transformation According to Scaling Parameter for Motor Drive without Position Sensor (위치 센서 없는 전동기 구동장치를 위한 스케일링 파라미터에 따른 무향 변환)

  • Moon, Cheol;Kwon, Young-Ahn
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.6
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    • pp.174-180
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    • 2016
  • This paper study about an unscented Kalman filter with a variety type of unscented transformation to estimate state values for speed control without position sensor of a permanent-magnet synchronous motor. The principles of an unscented transformation and unscented Kalman filter are examined and their application is explained. Generally the mapping process can be divided into two type, such as a basic and a general form according to a scaling parameter. And computation time, the number of samples, and weights about samples are different from each other. But, there is no little information on the scaling parameter value how this value influences the system performance. Simulation and experimental results show the validity of the designed unscented transformation performance with the various scaling parameter values for sensorless motor drive.

Transformation of Schwertmannite to Goethite and Related Behavior of Heavy Metals (슈베르트마나이트-침철석 전이 및 이와 관련된 중금속의 거동)

  • Kim, Heon-Jung;Kim, Yeong-Kyoo
    • Journal of the Mineralogical Society of Korea
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    • v.24 no.2
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    • pp.63-71
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    • 2011
  • The mineral phases precipitated in the swamp built for the treatment of the mine drainage of the Dalsung Mine were investigated to reveal the mineralogical changes from schwertmannite to goethite and related behavior of heavy metals. Our XRD results show that most schwertmannite were transformed to goethite except the small portions of the samples in the uppermost part. No significant morphological changes were observed in the samples during mineral transformation by SEM, indicating that this transformation process occurred not from dissolution-precipitation process, but in solid state. Among heavy metals sorbed or coprecipitated in the mineral phases, Pb and Cu concentrations were relatively higher compared with their concentrations in the mine drainage. The relative concentrations of other heavy metals show similar values. The heavy metal concentration in the minerals do not show noticeable differences from uppermost schwertmannite to lower goethite samples, indicating the transformation process without any leaching or additional sorption of heavy metals in the solid state.

SAMPLE ENTROPY IN ESTIMATING THE BOX-COX TRANSFORMATION

  • Rahman, Mezbahur;Pearson, Larry M.
    • Journal of the Korean Data and Information Science Society
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    • v.12 no.1
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    • pp.103-125
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    • 2001
  • The Box-Cox transformation is a well known family of power transformation that brings a set of data into agreement with the normality assumption of the residuals and hence the response variable of a postulated model in regression analysis. This paper proposes a new method for estimating the Box-Cox transformation using maximization of the Sample Entropy statistic which forces the data to get closer to normal as much as possible. A comparative study of the proposed procedure with the maximum likelihood procedure, the procedure via artificial regression estimation, and the recently introduced maximization of the Shapiro-Francia W' statistic procedure is given. In addition, we generate a table for the optimal spacings parameter in computing the Sample Entropy statistic.

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