Metaheuristic-designed systems for simultaneous simulation of thermal loads of building

Chang Lin,Junsong Wang 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.29 No.5

Water cycle algorithm (WCA) has been a very effective optimization technique for complex engineering problems. This study employs the WCA for simultaneous prediction of heating load (LH) and cooling load (LC) in residential buildings. This algorithm is responsible for optimally tuning a neural network (NN). Utilizing 614 records, the behavior of the LH and LC is explored and the captured knowledge is then used to predict for 154 unanalyzed building conditions. Since the WCA is a population-based algorithm, different numbers of the searching agents were tested to find the most optimum configuration. It was observed that the best solution is discovered by 500 agents. A comparison with five newly-developed benchmark optimizers, namely equilibrium optimizer (EO), multi-tracker optimization algorithm (MTOA), slime mould algorithm (SMA), multi-verse optimizer (MVO), and electromagnetic field optimization (EFO) revealed that the WCANN predicts the desired parameters with considerably larger accuracy. Obtained root mean square errors (1.4866, 2.1296, 2.8279, 2.5727, 2.5337, and 2.3029 for the LH and 2.1767, 2.6459, 3.1821, 2.9732, 2.9616, and 2.6890 for the LC) indicated that the most reliable prediction was presented by the proposed model. The EFONN, however, provided a more time-effective solution. Lastly, an explicit predictive formula was elicited from the WCANN.

Setup and Performance of a Combined Hardware-in-loop and Software-in-loop Test for MMC-HVDC Control and Protection System

Chang Lin,Dong Liu,Xueguang Wu,ZhiyuanHe,Weihua Wang,Wei Li 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Despite the rapid development of VSC-HVDC technology, the practical experience to operate modular multi-level converter (MMC) has not yet been sufficiently accumulated. Real-time simulation is one of the most efficient approaches to verify the control and protection (C & P) scheme under various contingencies. With the increasing number of sub-modules, the accurate simulation of the MMC-HVDC becomes more difficult, as it requires larger computing resources and more complex interface between the test platform and the C&P system hardware devices. This paper proposes an application of real-time simulation, which combines the hardware-in--loop (HIL) and software-in-loop (SIL) approach to test a control and protection system for MMC-based HVDC links. In the proposed system, a pole control and protection (PCP) will be tested using the HIL approach, while the valve base controller (VBC) is tested using the SIL method. The setup of the test rig and performance is demonstrated in this paper.

MicroRNA-206 Protects against Myocardial Ischaemia-Reperfusion Injury in Rats by Targeting Gadd45β

Changlin Zhai,Qang Qian,Guanmin Tang,Bingjiang Han,Huilin Hu,Dong Yin,Haihua Pan,Song Zhang 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.12

MicroRNAs are widely involved in the pathogenesis of cardiovascular diseases through regulating gene expression via translational inhibition or degradation of their target mRNAs. Recent studies have indicated a critical role of microRNA-206 in myocardial ischaemia-reperfusion (I/R) injury. However, the function of miR-206 in myocardial I/R injury is currently un-clear. The present study was aimed to identify the specific role of miR-206 in myocardial I/R injury and explore the underlying molecular mechanism. Our results revealed that the expres-sion level of miR-206 was significantly decreased both in rat I/R group and H9c2 cells subjected to hypoxia/reoxygenation (H/R) compared with the corresponding control. Overexpression of miR-206 observably decreased infarct size and inhibited the cardiomyocyte apoptosis induced by I/R injury. Furthermore, bioinformatics analysis, luciferase activity and western blot assay proved that Gadd45beta (growth arrest DNA damage-inducible gene 45beta) was a direct target gene of miR-206. In addition, the expression of pro-apoptotic-related genes, such as p53, Bax and cleaved caspase3, was decreased in association with the down-regulation of Gadd45beta. In summary, this study demonstrates that miR-206 could protect against myocardial I/R injury by targeting Gadd45beta.

DISTURBANCE ATTENUATION FOR A CLASS OF DISCRETE-TIME SWITCHED SYSTEMS WITH EXPONENTIAL UNCERTAINTY

Changlin Li,Fei Long,Guohui Ren 대한수학회 2011 대한수학회지 Vol.48 No.4

The disturbance attenuation problem for a class of discrete-time switched linear systems with exponential uncertainties via switched state feedback and switched dynamic output feedback is investigated, respectively. By using Taylor series approximation and convex polytope technique, exponentially uncertain discrete-time switched linear system is transformed into an equivalent switched polytopic model with additive norm bounded uncertainty. For such equivalent switched model, one designs its switching strategy and associated state feedback controllers and dynamic output feedback controllers so that whole switched model is asymptotical stabilization with H-infinity disturbance attenuation based on switched Lyapunov function and LMI approach. Finally, two numerical examples are presented to illustrate our results.

Vibration analysis of FG porous rectangular plates reinforced by graphene platelets

Changlin Zhou,Zhongxian Zhan,Ji Zhang,Yuan Fang,Vahid Tahouneh 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.2

The aim of this study is to investigate free vibration of functionally graded porous nanocomposite rectangular plates where the internal pores and graphene platelets (GPLs) are distributed in the matrix either uniformly or non-uniformly according to three different patterns. The elastic properties of the nanocomposite are obtained by employing Halpin-Tsai micromechanics model. The GPL-reinforced plate is modeled using a semi-analytic approach composed of generalized differential quadrature method (GDQM) and series solution adopted to solve the equations of motion. The proposed rectangular plates have two opposite edges simply supported, while all possible combinations of free, simply supported and clamped boundary conditions are applied to the other two edges. The 2-D differential quadrature method as an efficient and accurate numerical tool is used to discretize the governing equations and to implement the boundary conditions. The convergence of the method is demonstrated and to validate the results, comparisons are made between the present results and those reported by well-known references for special cases treated before, have confirmed accuracy and efficiency of the present approach. New results reveal the importance of porosity coefficient, porosity distribution, graphene platelets (GPLs) distribution, geometrical and boundary conditions on vibration behavior of porous nanocomposite plates. It is observed that the maximum vibration frequency obtained in the case of symmetric porosity and GPL distribution, while the minimum vibration frequency is obtained using uniform porosity distribution.

DISTURBANCE ATTENUATION FOR A CLASS OF DISCRETE-TIME SWITCHED SYSTEMS WITH EXPONENTIAL UNCERTAINTY

Li, Changlin,Long, Fei,Ren, Guohui Korean Mathematical Society 2011 대한수학회지 Vol.48 No.4

The disturbance attenuation problem for a class of discretetime switched linear systems with exponential uncertainties via switched state feedback and switched dynamic output feedback is investigated, respectively. By using Taylor series approximation and convex polytope technique, exponentially uncertain discrete-time switched linear system is transformed into an equivalent switched polytopic model with additive norm bounded uncertainty. For such equivalent switched model, one designs its switching strategy and associated state feedback controllers and dynamic output feedback controllers so that whole switched model is asymptotical stabilization with H-in nity disturbance attenuation base on switched Lyapunov function and LMI approach. Finally, two numerical examples are presented to illustrate our results.

MicroRNA-206 Protects against Myocardial Ischaemia-Reperfusion Injury in Rats by Targeting Gadd45β

Zhai, Changlin,Qian, Qang,Tang, Guanmin,Han, Bingjiang,Hu, Huilin,Yin, Dong,Pan, Haihua,Zhang, Song Korean Society for Molecular and Cellular Biology 2017 Molecules and cells Vol.40 No.12

MicroRNAs are widely involved in the pathogenesis of cardiovascular diseases through regulating gene expression via translational inhibition or degradation of their target mRNAs. Recent studies have indicated a critical role of microRNA-206 in myocardial ischaemia-reperfusion (I/R) injury. However, the function of miR-206 in myocardial I/R injury is currently unclear. The present study was aimed to identify the specific role of miR-206 in myocardial I/R injury and explore the underlying molecular mechanism. Our results revealed that the expression level of miR-206 was significantly decreased both in rat I/R group and H9c2 cells subjected to hypoxia/reoxygenation (H/R) compared with the corresponding control. Overexpression of miR-206 observably decreased infarct size and inhibited the cardiomyocyte apoptosis induced by I/R injury. Furthermore, bioinformatics analysis, luciferase activity and western blot assay proved that $Gadd45{\beta}$ (growth arrest DNA damage-inducible gene $45{\beta}$) was a direct target gene of miR-206. In addition, the expression of pro-apoptotic-related genes, such as p53, Bax and cleaved caspase3, was decreased in association with the down-regulation of $Gadd45{\beta}$. In summary, this study demonstrates that miR-206 could protect against myocardial I/R injury by targeting $Gadd45{\beta}$.

Vibrational characteristics of multi-phase nanocomposite reinforced circular/annular system

Zhou, Changlin,Zhao, Yi,Zhang, Ji,Fang, Yuan,Habibi, Mostafa Techno-Press 2020 Advances in nano research Vol.9 No.4

The vibrational characteristics of Multi-Phase Nanocomposite (MPC) reinforced annular/circular plate under initially stresses are presented using the state-space formulation based on three-dimensional elasticity theory (3D-elasticity theory) and Differential Quadrature Method (DQM). The MPC reinforced annular/circular plate is under initial lateral stress and composed of multilayers with Carbon Nanotubes (CNTs) uniformly dispersed in each layer, but its properties change layer-by-layer along the thickness direction. The State-Space based Differential Quadrature Method (SS-DQM) is presented to examine the frequency behavior of the current structure. Halpin-Tsai equations and fiber micromechanics are used in the hierarchy to predict the bulk material properties of the multi-scale composite. A singular point is investigated for modeling the circular plate. The CNTs are supposed to be randomly oriented and uniformly distributed through the matrix of epoxy resin. Afterward, a parametric study is done to present the effects of various types of sandwich circular/annular plates on frequency characteristics of the MPC reinforced annular/circular plate using 3D-elasticity theory.

Application Research of Linear Programming on Mining Outliers of Time Series

Yingying Min,Changlin Ao 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.2

Based on data mining of outliers of time series, current studies have developed many methods, but there exist certain disadvantages for each method. This paper developed the method of mining outliers of time series based on linear programming model, verified high efficiency through an actual case and make up for the shortcoming of other methods.

Empirical likelihood for partially linear varying-coefficient models with missing response variables and error-prone covariates

Chuanhua Wei,Changlin Mei 한국통계학회 2012 Journal of the Korean Statistical Society Vol.41 No.1

In this study, the empirical likelihood method is applied to the partially linear varyingcoefficient model in which some covariates are measured with additive errors and the response variable is sometimes missing. Based on the correction-for-attenuation technique, we define an empirical likelihood-based statistic for the parametric component and show that its limiting distribution is chi-square distribution. The confidence regions of the parameters are constructed accordingly. Furthermore, a simulation study is conducted to evaluate the performance of the proposed method.