Optimal LQG Control for Networked Control Systems with Remote and Local Controllers

Xiao Liang,Juanjuan Xu,Xiao Lu,Qingyuan Qi,Haixia Wang,Rong Gao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.1

We consider the finite horizon optimal LQG control problem for networked control systems with a remote controller, a local controller and communication channels with packet dropouts and transmission delays. The local controller can directly observe state signals and send them to the remote controller via a packet-dropout channel. Then the remote controller sends the received measurement signals to the local controller. Afterwards, the two controllers operate the plant through a delayed channel. The contributions of this paper are as follows: Firstly, at the side of the remote controller, we develop an optimal estimator to show that the separation principle holds. Secondly, we derive a non- homogeneous relationship between the state and the costate of systems in virtue of the maximum principle. Finally, a necessary and sufficient condition for the optimal control problem is derived in terms of the two coupled Riccati equations. Numerical examples are employed to illustrate the theoretical results.

Erector spinae plane block for spinal surgery: a systematic review and meta-analysis

( Xiao Liang ),( Weilong Zhou ),( Yuchao Fan ) 대한통증학회 2021 The Korean Journal of Pain Vol.34 No.4

Background: Although the erector spinae plane block has been used in various truncal surgical procedures, its clinical benefits in patients undergoing spinal surgery remain controversial. The aim of this meta-analysis was to evaluate the clinical benefits of erector spinae plane block in patients undergoing spinal surgery. Methods: We searched the Cochrane Library, PubMed, EMBASE, and China National Knowledge Infrastructure for randomized controlled trials comparing the erector spinae plane block with a nonblocked control for spinal surgery. Results: Twelve studies encompassing 696 subjects were included in our systematic review and meta-analysis. We found that the erector spinae plane block decreased postoperative pain scores and opioid consumption in the postoperative and intraoperative periods. Moreover, it prolonged the time to the first rescue analgesic, reduced the number of patients who required rescue analgesia, and lowered the incidence of postoperative nausea and vomiting. However, it did not exhibit efficacy in decreasing the incidence of urinary retention and itching or shortening the length of hospital stays, or the time to first ambulation. Conclusions: Erector spinae plane block improves analgesic efficacy among patients undergoing spinal surgery compared with nonblocked controls; however, there is insufficient evidence regarding the benefits of erector spinae plane block for rapid recovery.

Twin models for high-resolution visual inspections

Xiao Liang,Seyedomid Sajedi,Kareem A. Eltouny 국제구조공학회 2023 Smart Structures and Systems, An International Jou Vol.31 No.4

Visual structural inspections are an inseparable part of post-earthquake damage assessments. With unmanned aerial vehicles (UAVs) establishing a new frontier in visual inspections, there are major computational challenges in processing the collected massive amounts of high-resolution visual data. We propose twin deep learning models that can provide accurate highresolution structural components and damage segmentation masks efficiently. The traditional approach to cope with high memory computational demands is to either uniformly downsample the raw images at the price of losing fine local details or cropping smaller parts of the images leading to a loss of global contextual information. Therefore, our twin models comprising Trainable Resizing for high-resolution Segmentation Network (TRS-Net) and DmgFormer approaches the global and local semantics from different perspectives. TRS-Net is a compound, high-resolution segmentation architecture equipped with learnable downsampler and upsampler modules to minimize information loss for optimal performance and efficiency. DmgFormer utilizes a transformer backbone and a convolutional decoder head with skip connections on a grid of crops aiming for high precision learning without downsizing. An augmented inference technique is used to boost performance further and reduce the possible loss of context due to grid cropping. Comprehensive experiments have been performed on the 3D physicsbased graphics models (PBGMs) synthetic environments in the QuakeCity dataset. The proposed framework is evaluated using several metrics on three segmentation tasks: component type, component damage state, and global damage (crack, rebar, spalling). The models were developed as part of the 2nd International Competition for Structural Health Monitoring.

Volume Compatibility of Interlayer Treatment Materials with Roller-Compacted Concrete

Xiaoliang Zhu,Yuxin Gao,Wenjing Song,Jingjing Xu,Chengyang Li,Zhaoheng Guo,Fang Chen,Rui Zhang 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.3

Interlayer is the weakest plane of the entire roller-compacted concrete (RCC) structure and is easily deteriorated under the pressure of water and other environmental factors. Shearing force induced by the different shrinkage in interlayer part is the main reason for that poor performance of the RCC. In this paper, the deformation of RCC concrete and interlayer treatment mortar with supplementary cementitious materials (SCMs, including fly ash and silica fume) and double expansive resources admixtures (HME, containing calcium sulphoaluminate (CSA) and CaO) were studied. Deformation of concrete (produced RCC) and interlayer treatment materials was modeled and compared. Porosity characters of interlayer treatment materials and water absorption of interlayer-treated RCC samples were tested. Results showed that the HME significantly reduced the shrinkage of mortar and the deformation difference degree between layers was shortened. Modified interlayer treatment materials with HME could modify the macroscopic properties of RCC, the low porosity of interlayer and water absorption of interlayer-treated RCC was resulted. The suitable HME content is necessary in interlayer treatment materials and which could improve the performance of RCC.

Parameter identification of the Bouc-Wen model for the magnetorheological damper using fireworks algorithm

Xiaoliang Chen,Liyou Xu,Shuai Zhang,Sixia Zhao,Kui Liu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

To solve the problems of low identification accuracy and complex identification methods in the Bouc-Wen model of the magnetorheological (MR) damper, a new parameter identification method using the fireworks algorithm (FWA) is proposed. According to the experimental results of the dynamic characteristics of the MR damper and the simulation data of the Bouc-Wen model, the FWA is used to identify the seven parameters of the Bouc-Wen model. On the basis of the relationship between the identification results and the command current, the current-controlled Bouc-Wen model (I-Bouc-Wen model) is constructed and compared with the experimental results under different sinusoidal excitation frequencies. Compared with the genetic algorithm (GA), differential evolution (DE) algorithm, and particle swarm optimization (PSO) algorithm, the FWA has the advantage of faster convergence, shorter calculation time, and higher stability in solving the parameter identification problem of the highly nonlinear hysteretic model. Under three harmonic excitations, the average calculation accuracies of the IBouc-Wen model reache 88.64 %, 90.45 %, and 81.28 %, respectively, and the dynamic characteristic curve of the model is in basic agreement with the experimental results. It can be used for the subsequent controller design and simulation research and lay a foundation for applying the parameterized model of the MR damper in vibration reduction control.

Development of Fluorescent Turn-On Sensor for Selective Detection of Cu2+ in Aqueous Solution

XiaoLiang Li,YongWu He,Kyung-Il Ahn,양성익 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

FABRICATION OF NANOPOROUS CHITOSAN MEMBRANES

XIAOLIANG WANG,XIANG LI,ELEANOR STRIDE,MOHAN EDIRISINGHE 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2010 NANO Vol.5 No.1

Naturally derived biopolymers have been widely used for biomedical applications such as drug carriers, wound dressings, and tissue engineering scaffolds. Chitosan is a typical polysaccharide of great interest due to its biocompatibility and film-formability. Chitosan membranes with controllable porous structures also have significant potential in membrane chromatography. Thus, the processing of membranes with porous nanoscale structures is of great importance, but it is also challenging and this has limited the application of these membranes to date. In this study, with the aid of a carefully selected surfactant, polyethyleneglycol stearate-40, chitosan membranes with a well controlled nanoscale structure were successfully prepared. Additional control over the membrane structure was obtained by exposing the suspension to high intensity, low frequency ultrasound. It was found that the concentration of chitosan/surfactant ratio and the ultrasound exposure conditions affect the structural features of the membranes. The stability of nanopores in the membrane was improved by intensive ultrasonication. Furthermore, the stability of the blended suspensions and the intermolecular interactions between chitosan and the surfactant were investigated using scanning electron microscope and Fourier transform infrared spectroscopy (FTIR) analysis, respectively. Hydrogen bonds and possible reaction sites for molecular interactions in the two polymers were also confirmed by FTIR analysis.

Effect of collagen hydrolysate obtained from leather waste on the setting, hydration and crystallization process of gypsum

Xiaoliang Ding,Bangquan Wei,Rui Dai,Hui Chen,Zhihua Shan 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.110 No.-

The disposal of leather waste has always been a huge challenge facing the tannery. Thus, the effectiveconversion of leather waste into value-added products can help the leather industry achieve green andsustainable development. In the paper, we utilized collagen hydrolysate (CH) obtained from leatherwaste as a protein retarder for gypsum and the effect of CH on the setting, hydration and crystallizationprocess of gypsum was analyzed. The results showed the addition of CH delayed the increase in hydrationdegree and release of hydration heat during the hydration process of gypsum, and this delay action wasmore remarkable as more CH was introduced. Moreover, CH could postpone the crystallization of dihydrategypsum from a micro perspective. TG/DSC, FTIR, XRD, and SEM analysis indicated that the presenceof CH inhibited the hydration reaction hemihydrate gypsum and the formation of dihydrate gypsum butover time the hemihydrate gypsum was completely hydrated at last. Finally, the retardation mechanismof CH on the gypsum was investigated by adsorption and zeta potential measurements. Adsorption andzeta potential measurement results demonstrated that CH could inhibit the hydration process of hemihydrategypsum by adsorbing on the gypsum particle, thereby achieving the retarding effect.

Glomalin in Alpine Soil Along an Tibetan Altitudinal Gradient is Highly Correlated with Hyphae Growth but Not Community Composition of Arbuscular Mycorrhizal Fungi

Xiaoliang Li,Xiaobu Cai,Xiaolin Li,Junling Zhang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Precipitating tunable-emission CsPb(Cl/Br)3 QDs in boro-germanate glass for wide-color-gamut liquid crystal displays

Xiaoliang Pang,Xuejie Zhang,Bingfu Lei,Haoran Zhang 한국정보디스플레이학회 2019 Journal of information display Vol.20 No.4

Embedding CsPbX3 (X = Cl, Br, I) perovskites QDs in inorganic glass matrix via in-situ crystallization has been regarded as a feasible strategy to improve their stability against water, heat, and light irradiation. However, the tunable-emission range of these CsPbX3-nanocrystals-embedded glasses is still narrow, insufficient to cover a wide color gamut. Herein, a simple synthetic method was developed in this study to obtain the tunable-emission CsPb(Cl/Br)3 quantum dots (QDs) in boro-germanate glass (CsPb(Cl/Br)3 QDs@glass) by controlling the molar ratio of PbBr2/PbCl2. With the increase of the PbBr2 concentration from 1.6 to 3.2 mol%, the emission wavelength of CsPb(Cl/Br)3 QDs@glasses can be shifted from 448 to 485 nm, and the corresponding photoluminescence quantum yield (PLQY) increases from 0.61 to 24.43%. In addition, the CsPb(Cl/Br)3 QDs@glass exhibits impressing promotion of thermal stability, photostability, and water resistance due to the excellent protective function of the glass matrix. As a proof-of-concept experiment, a LED device was fabricated by employing the optimal CsPb(Cl/Br)3 QDs@glass with a commercial 375nmUVchip, yielding an intense cyan light. All the results indicate that the investigated CsPb(Cl/Br)3 QDs@glasses may find promising applications as color convertors in wide-color-gamut liquid crystal displays (LCDs).