A comparative study to measure the sagittal condylar inclination using mechanical articulator, virtual articulator and jaw tracking device

Liya Ma,Fei Liu,Jiansong Mei,Jiarui Chao,Zhenyu Wang,Jiefei Shen 대한치과보철학회 2023 The Journal of Advanced Prosthodontics Vol.15 No.1

Purpose. To compare the sagittal condylar inclination (SCI) in dentate individuals measured by the different methods with mechanical articulator (MA), virtual articulator (VA), and a jaw tracking device (JTD) system. Materials and methods. A total of 22 healthy dentate participants were enrolled in this study. For MA workflow, the SCI was obtained by a semi-adjustable articulator with protrusive interocclusal records. The SCI was also set on a VA by aligning intraoral scan (IOS) with cone beam computed tomography (CBCT) and facial scan (FS), respectively. These virtual workflows were conducted in a dental design software, namely VAIOS-CBCT and VAIOS-FS. Meanwhile, a JTD system was also utilized to perform the measurement. Intraclass correlation was used to assess the repeatability within workflows. The bilateral SCI values were compared by Wilcoxon matched-pairs signed rank test for each workflow, and Kruskal-Wallis test and post hoc p-value Bonferroni correction were used to compare the differences among four workflows. The agreement of VAIOS-CBCT, VAIOS-FS, and JTD compared with MA was evaluated by Bland-Altman analysis. Results. Intraclass correlation of the SCI revealed a high degree of repeatability for each workflow. There were no significant differences between the left and right sides (P > .05), except for VAIOS-CBCT (P = .028). Significant differences were not found between MA and VAIOS-FS (P > .05). Bland-Altman plots indicated VAIOS-CBCT, VAIOS-FS, and JTD were considered to substitute MA with high 95% limits of agreement. Conclusion. The workflow of VAIOS-FS provided an alternative approach to measure the SCI compared with MA.

Axial Hole Air-Entraining Cooling Technique of Radial-Flow Turbines

Ma Chao,Zhang Jianjian,Wang Ningning,Zhu Zhifu 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.5

In response to the continually increasing thermal load caused by the rising gas temperature in the inlet of radial-flow turbines, this paper proposes the use of axial hole air-entraining cooling to cool the turbine shaft and turbo wheel back-disc. The cooling effect of this technique, as well as its influence on the aerodynamic performance of turbines, were investigated through numerical simulations. The results demonstrate that the axial hole air-entraining cooling technique can significantly improve the local cooling efficiency of the turbine back-disc. Under a blowing ratio of 0.25 %, the local cooling efficiency increased by 154 %, and the temperature decreased by up to 233 K. The maximum temperature on the surface of the turbine shaft at the floating bearing location decreased significantly, thus reducing the coking risk of the lubricating oil. When the blowing ratio was within 0.5 %, the impact of this cooling technique on the overall turbine performance was negligible.

Carrageenan Oligosaccharides Extend Life Span and Health Span in Male Drosophila Melanogaster by Modulating Antioxidant Activity, Immunity, and Gut Microbiota

Chao Ma,Qiaowei Li,Xianjun Dai 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.1

Carrageenan oligosaccharide (CAO), the hydrolysate of carrageenan from marine red algae, is used as a prebiotic additive or medical material. In this study, male Drosophila melanogaster was used as an animal model to explore the possibility that CAO can extend the life span through its relationship with antioxidation, immunity, and gut microbiota in vivo. The results show that a certain amount of CAO effectively prolonged the average life span and improved the climbing vitality and fecundity of male Drosophila. In addition, 0.125% CAO in the diet significantly increased the activity of Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and catalase (CAT), reduced the content of malondialdehyde (MDA), and significantly repressed the expression of nuclear factor kappa B (NF-κB) gene in old male Drosophila tissues. In the intestinal microbiota analysis, 0.125% CAO in the diet increased the diversity of gut microbiota and improved the abundance of Commensalibacter at the genus level in Drosophila on the 40th day. The above results indicated that CAO supplementation could extend the life span of male Drosophila by improving antioxidant activity, immunity, and by regulating intestinal microflora.

A Study on the Design Principle of Battery Capacity for x-EVs

Chao Ma,Minseok Song,Kiyun Jeong,Hyunsoo Kim 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

Memory-based Human Postural Regulation Control: An Asynchronous Semi-Markov Model Approach

Chao Ma,Hang Fu,Wei Wu 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.10

This article investigates the human postural regulation problem from the dynamical system perspective, which is also applicable for human-like robotics. More precisely, since the dynamical human posture parameters may change caused by varying load or environment abrupt, the semi-Markov jump process is employed to model the human standing postural dynamics with multiple modes. Furthermore, a novel memorized regulation strategy is developed for guaranteeing the stable standing such that the past memory information can be well utilized. In particular, the asynchronous regulation procedure is considered for better describing the human postural model with mismatched jumping modes. By model transformation and stochastic analysis, mode-dependent regulation criteria with state feedback model are established by convex optimization approach, based on which the mode-dependent regulation gains are designed accordingly. Finally, the feasibility and effectiveness of our proposed regulation strategy is verified via an illustrative example of quiet upright standing posture.

A Study on Real Time Based Equivalent Fuel Economy Calculation Algorithm for Green Car

Chao Ma(마차오),Jinhyun Park(박진현),Sung-ho Hwang(황성호),Hyunsoo Kim(김현수) 한국자동차공학회 2012 한국자동차공학회 부문종합 학술대회 Vol.2012 No.5

In this paper, a real time based equivalent fuel economy (EFE) calculation algorithm is presented for green car which consists of the conventional engine, motor and battery. The real time based EFE algorithm calculates the equivalent fuel economy using the parameters directly received from the engine, motor and battery. It is expected that the real time based algorithm can be used for estimation of the fuel economy in real time driving, and on-line virtual interface driving environment as well as off-line evaluation environment for the development and evaluation of the green car.

Development of HEV Simulator for Module Design

Chao Ma,Jian Ji,Sungmin Kim,Hyunsoo Kim 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

Hybrid electric vehicle (HEV) simulator is developed to evaluate the performance of the HEV sub-modules. First, dynamic model of the HEV powertrain is constructed by using Cruise for Toyota Prius. For the simulation, control algorithms are developed by using MATLAB/Simulink. Using the Cruise simulator and MATLAB/Simulink control algorithms, cosimulation environment is developed. In addition, a graphical user interface (GUI) is developed for sub-modules of the HEV by using MATLAB/GUIDE. The component performance such as power flow, power loss is investigated in the GUI environment. It is expected that co-simulator developed in this study can be used in design of the sub-modules for HEV.

CCL12 induces trabecular bone loss by stimulating RANKL production in BMSCs during acute lung injury

Ma Chao,Gao Juan,Liang Jun,Wang Feizhen,Xu Long,Bu Jinhui,He Bo,Liu Guangpu,Niu Ru,Liu Guangwang 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

In the last three years, the capacity of health care systems and the public health policies of governments worldwide were challenged by the spread of SARS-CoV-2. Mortality due to SARS-CoV-2 mainly resulted from the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Moreover, millions of people who survived ALI/ARDS in SARS-CoV-2 infection suffer from multiple lung inflammation-induced complications that lead to disability and even death. The lung-bone axis refers to the relationship between lung inflammatory diseases (COPD, asthma, and cystic fibrosis) and bone diseases, including osteopenia/osteoporosis. Compared to chronic lung diseases, the influence of ALI on the skeleton has not been investigated until now. Therefore, we investigated the effect of ALI on bone phenotypes in mice to elucidate the underlying mechanisms. In vivo bone resorption enhancement and trabecular bone loss were observed in LPS-induced ALI mice. Moreover, chemokine (C-C motif) ligand 12 (CCL12) accumulated in the serum and bone marrow. In vivo global ablation of CCL12 or conditional ablation of CCR2 in bone marrow stromal cells (BMSCs) inhibited bone resorption and abrogated trabecular bone loss in ALI mice. Furthermore, we provided evidence that CCL12 promoted bone resorption by stimulating RANKL production in BMSCs, and the CCR2/Jak2/STAT4 axis played an essential role in this process. Our study provides information regarding the pathogenesis of ALI and lays the groundwork for future research to identify new targets to treat lung inflammation-induced bone loss.

Prediction of Venous Trans-Stenotic Pressure Gradient Using Shape Features Derived From Magnetic Resonance Venography in Idiopathic Intracranial Hypertension Patients

Ma Chao,Zhu Haoyu,Liang Shikai,Chang Yuzhou,Mo Dapeng,Jiang Chuhan,Zhang Yupeng 대한영상의학회 2024 Korean Journal of Radiology Vol.25 No.1

Objective: Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology associated with venous sinus stenosis. This study aimed to develop a magnetic resonance venography (MRV)-based radiomics model for predicting a high trans-stenotic pressure gradient (TPG) in IIH patients diagnosed with venous sinus stenosis. Materials and Methods: This retrospective study included 105 IIH patients (median age [interquartile range], 35 years [27– 42 years]; female:male, 82:23) who underwent MRV and catheter venography complemented by venous manometry. Contrast enhanced-MRV was conducted under 1.5 Tesla system, and the images were reconstructed using a standard algorithm. Shape features were derived from MRV images via the PyRadiomics package and selected by utilizing the least absolute shrinkage and selection operator (LASSO) method. A radiomics score for predicting high TPG (≥ 8 mmHg) in IIH patients was formulated using multivariable logistic regression; its discrimination performance was assessed using the area under the receiver operating characteristic curve (AUROC). A nomogram was constructed by incorporating the radiomics scores and clinical features. Results: Data from 105 patients were randomly divided into two distinct datasets for model training (n = 73; 50 and 23 with and without high TPG, respectively) and testing (n = 32; 22 and 10 with and without high TPG, respectively). Three informative shape features were identified in the training datasets: least axis length, sphericity, and maximum three-dimensional diameter. The radiomics score for predicting high TPG in IIH patients demonstrated an AUROC of 0.906 (95% confidence interval, 0.836– 0.976) in the training dataset and 0.877 (95% confidence interval, 0.755–0.999) in the test dataset. The nomogram showed good calibration. Conclusion: Our study presents the feasibility of a novel model for predicting high TPG in IIH patients using radiomics analysis of noninvasive MRV-based shape features. This information may aid clinicians in identifying patients who may benefit from stenting.

A Study on Control Algorithm and Energy Management Strategy for GM-Volt Plug-in HEV

Chao Ma,Jian Ji,Woulsun Choi,Hyunsoo Kim 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

In this paper, a study was performed on the control algorithm and energy management strategy for plug-in HEV. GM-Volt plug-in HEV was selected as the target vehicle, which is capable of driving in Charge depleting (CD) mode with only motor working and Charging sustaining (CS) mode with engine and motor working together. First, powertrain model of GM-Volt was derived. Based on the dynamic model, detailed component control algorithms for CD mode and CS mode were developed. In addition, an energy management strategy was developed from the viewpoint of fuel economy, using the battery state of charge. Drive mode determination algorithm in CD mode was also developed based on the vehicle velocity and wheel torque. Using the dynamic model of and control algorithm for GMVolt plug-in HEV, simulations were performed. Based on the simulation results, an analysis was performed, and it was found that the electric drive range and fuel economy were different with the official values. It was considered due to the transmission loss such as clutch/brake loss and oil pump loss that were not considered in this study.