Adaptive Extraction Method for Phase Foreground Region in Laser Interferometry of Gear

Xian Wang,Yichao Zhao,Chaoyang Ju,Chaoyong Zhang 한국광학회 2023 Current Optics and Photonics Vol.7 No.4

Tooth surface shape error is an important parameter in gear accuracy evaluation. When tooth surface shape error is measured by laser interferometry, the gear interferogram is highly distorted and the gray level distribution is not uniform. Therefore, it is important for gear interferometry to extract the foreground region from the gear interference fringe image directly and accurately. This paper presents an approach for foreground extraction in gear interference images by leveraging the sinusoidal variation characteristics shown by the interference fringes. A gray level mask with an adaptive threshold is established to capture the relevant features, while a local variance evaluation function is employed to analyze the fluctuation state of the interference image and derive a repair mask. By combining these masks, the foreground region is directly extracted. Comparative evaluations using qualitative and quantitative assessment methods are performed to compare the proposed algorithm with both reference results and traditional approaches. The experimental findings reveal a remarkable degree of matching between the algorithm and the reference results. As a result, this method shows great potential for widespread application in the foreground extraction of gear interference images.

Mangiferin ameliorates cardiac fibrosis in D-galactose-induced aging rats by inhibiting TGF-β/p38/MK2 signaling pathway

Jing Cheng,Chaoyang Ren,Renli Cheng,Yunning Li,Ping Liu,Wei Wang,Li Liu 대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.3

Doxorubicin-Loaded CuS Nanoparticles Conjugated with GFLG: A Novel Drug Delivery System for Lymphoma Treatment

Ying Jiang,Chaoyang Guan,Xu Liu,Yushan Wang,Huaqin Zuo,Tian Xia,Peipei Xu,Jian Ouyang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.1

Doxorubicin (DOX) plays an important part in lymphoma treatment. However, various side effects on normal tissues restrict its clinical use. Nanocarriers connected by Gly–Phe–Leu–Gly (GFLG) can be equipped with the advantages of nanoparticles (NPs), their enhanced permeability and retention (EPR) effect, and surface modifiability. Nanocarriers can also be specifically enzymatically hydrolyzed by cathepsin (Cath) B, a kind of enzyme highly expressed in tumor cells. In this work, we proposed a novel drug delivery system comprising GFLG conjugated with copper sulfide (CuS) NPs loaded with DOX. The system, designated as CuS-GFLG-DOX, could be used for NP-based targeted combination chemotherapy. Results showed that the drug delivery system had an appropriate diameter, good dispersibility, high encapsulation efficiency and high drug loading. The system also exhibited an excellent targeting of lymphoma cells and an enhanced antitumor activity. The possible pathway to induce cytotoxic effects was Bcl-2/caspase-mediated apoptosis pathway. In conclusion, CuS-GFLG-DOX could precisely deliver drugs to lymphoma cells and could be a novel and promising therapeutic option for lymphoma.

Low Chattering Trajectory Tracking Control of Non-singular Fast Terminal Sliding Mode Based on Disturbance Observer

Jiqing Chen,Chaoyang Zhao,Qingsong Tang,Xu Liu,Zhikui Wang,Chengzhi Tan,Jiahua Wu,Teng Long 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.2

The improvement of the performance of the multi-joint manipulator control system is of great significance to improve the level of industrial automation. The existing sliding mode control methods are difficult to ensure the high-precision and fast-tracking of joints of a manipulator to the desired trajectory under low chattering control input. Therefore, a non-singular fast terminal sliding mode control method based on a nonlinear disturbance observer is proposed. In addition, a new non-singular fast terminal sliding mode surface is designed. The performance comparison method of the sliding mode surface proves its better control quality. Aiming at the problem of serious chattering, the nonlinear disturbance observer technology, and saturation function method are introduced to effectively weaken the chattering. Finally, taking the 3-DOF manipulator as the research object, a comparative simulation experiment is carried out in the MATLAB / Simulink environment. The results show that under the uncertainty of modeling error, external disturbance, and joint friction, the designed control method not only solves the problems of singular control input and serious chattering but also realizes the high-precision and fast-tracking of each joint to the desired trajectory. Thus, the effectiveness and feasibility of the design method are verified. The improvement of the performance of the multi-joint manipulator control system is of great significance to improve the level of industrial automation. The existing sliding mode control methods are difficult to ensure the high-precision and fast-tracking of joints of a manipulator to the desired trajectory under low chattering control input. Therefore, a non-singular fast terminal sliding mode control method based on a nonlinear disturbance observer is proposed. In addition, a new non-singular fast terminal sliding mode surface is designed. The performance comparison method of the sliding mode surface proves its better control quality. Aiming at the problem of serious chattering, the nonlinear disturbance observer technology, and saturation function method are introduced to effectively weaken the chattering. Finally, taking the 3-DOF manipulator as the research object, a comparative simulation experiment is carried out in the MATLAB / Simulink environment. The results show that under the uncertainty of modeling error, external disturbance, and joint friction, the designed control method not only solves the problems of singular control input and serious chattering but also realizes the high-precision and fast-tracking of each joint to the desired trajectory. Thus, the effectiveness and feasibility of the design method are verified.

Computational design towards energy efficient optimization in overconstrained robotic limbs

Gu Yuping,Wang Ziqian,Feng Shihao,Sun Haoran,Lu Haibo,Pan Jia,Wan Fang,Song Chaoyang 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.5

Legged robots are constantly evolving, and energy efficiency is a major driving factor in their design. However, combining mechanism efficiency and trajectory planning can be challenging. This work proposes a computational optimization framework for optimizing leg design during basic walking while maximizing energy efficiency. We generalize the robotic limb design as a four-bar linkage-based design pool and optimize the leg using an evolutionary algorithm. The leg configuration and design parameters are optimized based on user-defined objective functions. Our framework was validated by comparing it to measured data on our prototype quadruped robot for forward trotting. The Bennett robotic leg was advantageous for omni-directional locomotion with enhanced energy efficiency.

A comparison of the fracture resistances of endodontically treated mandibular premolars restored with endocrowns and glass fiber post-core retained conventional crowns

Guo, Jing,Wang, Zhiming,Li, Xuesheng,Sun, Chaoyang,Gao, Erdong,Li, Hongbo The Korean Academy of Prosthodonitics 2016 The Journal of Advanced Prosthodontics Vol.8 No.6

PURPOSE. This in-vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post-core retained crowns. MATERIALS AND METHODS. Thirty mandibular premolars were assigned into three groups (n=10): GI, intact teeth; GE, teeth with endocrowns; GC, teeth with conventional post-core supported crowns. Except for the teeth in group GI, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. Both endocrowns and conventional crowns were fabricated from lithium-disilicate blocks using a CEREC 3D CAD/CAM unit. All specimens were subjected to thermocycling and then to $45^{\circ}$ oblique compressive load until fracture occurred. The fracture resistance and failure mode of each specimen were recorded. Data were analyzed with one-way ANOVA and LSD Post Hoc Test (${\alpha}=.05$). RESULTS. The fracture resistances of GE and GC were significantly lower than that of GI (P<.01), while no significant difference was found between GE and GC (P=.702). As of the failure mode, most of the specimens in GE and GC were unfavorable while a higher occurrence of favorable failure mode was presented in GI. CONCLUSION. For the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. Both of the two methods cannot rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have.

The Specific Case Analysis of Biomineralization Induced by Sulfate Reducing Bacteria

( Hongwei Liu ),( Shuang Qin ),( Chaoyang Fu ),( Fei Xiao ),( Deli Wang ),( Xia Han ),( Tianli Wang ),( Hongfang Liu ) 한국부식방식학회(구 한국부식학회) 2017 Corrosion Science and Technology Vol.16 No.6

The effects of sulfate reducing bacteria (SRB) on the corrosion and scaling of the Q235 carbon steel has been investigated in the simulated sewage water and oil field gathering pipelines production water, using scanning electron microscopy (SEM), energy dispersive x-ray spectrometry (EDS), and three-dimensional stereoscopic microscope. Results indicated that the concentration of SRB reached the maximum value on the ninth day in simulated sewage water with a large amount of scaling on the surface of specimen. In oil field gathering pipelines, a large amount of scaling and mineralization of mineral salts and thick deposition of extracellular polymeric substance (EPS) layers were also observed on the surface of specimen. The thickness of biofilm was about 245 μm within 30 days. After adding microbicides, the thickness of corrosion products film was only up to 48 - 106 μm within 30 days, suggesting that SRB could induce biomineralization. Under-deposit corrosion morphology was uniform in the absence of microbicides while local corrosion was observed in the presence of microbicides.

Mangiferin ameliorates cardiac fibrosis in D-galactose-induced aging rats by inhibiting TGF-β/p38/MK2 signaling pathway

Cheng, Jing,Ren, Chaoyang,Cheng, Renli,Li, Yunning,Liu, Ping,Wang, Wei,Liu, Li The Korean Society of Pharmacology 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.2

Aging is the process spontaneously occurred in living organisms. Cardiac fibrosis is a pathophysiological process of cardiac aging. Mangiferin is a well-known C-glucoside xanthone in mango leaves with lots of beneficial properties. In this study, rat model of cardiac fibrosis was induced by injected with 150 mg/kg/d D-galactose for 8 weeks. The age-related cardiac decline was estimated by detecting the relative weight of heart, the serum levels of cardiac injury indicators and the expression of hypertrophic biomakers. Cardiac oxidative stress and local inflammation were measured by detecting the levels of malondialdehyde, enzymatic antioxidant status and proinflammatory cytokines. Cardiac fibrosis was evaluated by observing collagen deposition via masson and sirius red staining, as well as by examining the expression of extracellular matrix proteins via Western blot analysis. The cardiac activity of profibrotic TGF-β1/p38/MK2 signaling pathway was assessed by measuring the expression of TGF-β1 and the phosphorylation levels of p38 and MK2. It was observed that mangiferin ameliorated D-galactose-induced cardiac aging, attenuated cardiac oxidative stress, inflammation and fibrosis, as well as inhibited the activation of TGF-β1/p38/MK2 signaling pathway. These results showed that mangiferin could ameliorate cardiac fibrosis in D-galactose-induced aging rats possibly via inhibiting TGF-β/p38/MK2 signaling pathway.

A comparison of the fracture resistances of endodontically treated mandibular premolars restored with endocrowns and glass fiber postcore retained conventional crowns

Jing Guo,Zhiming Wang,Xuesheng Li,Chaoyang Sun,Erdong Gao,Hongbo Li 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.6

PURPOSE This in-vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post-core retained crowns. MATERIALS AND METHODS Thirty mandibular premolars were assigned into three groups (n=10): GI, intact teeth; GE, teeth with endocrowns; GC, teeth with conventional post-core supported crowns. Except for the teeth in group GI, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. Both endocrowns and conventional crowns were fabricated from lithium-disilicate blocks using a CEREC 3D CAD/CAM unit. All specimens were subjected to thermocycling and then to 45° oblique compressive load until fracture occurred. The fracture resistance and failure mode of each specimen were recorded. Data were analyzed with one-way ANOVA and LSD Post Hoc Test (α=.05). RESULTS The fracture resistances of GE and GC were significantly lower than that of GI (P<.01), while no significant difference was found between GE and GC (P=.702). As of the failure mode, most of the specimens in GE and GC were unfavorable while a higher occurrence of favorable failure mode was presented in GI. CONCLUSION For the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. Both of the two methods cannot rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have.

Back-stepping Fault-tolerant Control for Morphing Aircraft Based on Fixed-time Observer

Xiaohui Liang,Qing Wang,Bin Xu,Chaoyang Dong 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.12

In this paper, the problem of the back-stepping fault-tolerant control (FTC) based on fixed-time observer is addressed for the morphing aircraft with model uncertainties, external disturbances, and actuator faults. First, thelongitudinal dynamics for the morphing process are presented, and the control-oriented models subject to undesired malfunctions are established. Second, the fixed-time observer is designed for offering estimations of compounddisturbances, including system uncertainties, disturbance, and malfunction information. Especially, the observer errors could converge to zero by the proposed observer within a settling time, which is independent of the system’sinitial conditions. Then, a back-stepping FTC strategy based on the observations is proposed for the altitude and velocity subsystem, and the stability of the close loop system would be guaranteed by the proposed controller despite the actuator failures. Furthermore, to eliminate the effects of the “explosion of complexity” of the backstepping method, a modified dynamic surface is applied to compute derivatives of virtual laws. Finally, the numerical simulations verify the effectiveness of the proposed control approach.