H-Infinity Shifting Control in a Dual-Speed Transmission for Electric Vehicle

Tan Senqi,Yang Jue,Khajepour Amir,Zhao Xinxin,Yu Wenhao 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.1

To improve the economic and comfort performance of pure electric vehicles (PEV), this paper proposes a novel H-infinity gear-shifting controller for dual-speed Transmissions (DST) to achieve a smooth and swift shifting when considering uncertain disturbances in system. Firstly, the structure as well as the working principle of the DST for PEV are introduced briefly and the mathematical model of the transmission is derived according to the Lagrange equation. Then the gear-shifting process is analyzed and the control problem is formulated according to the clutch status. Next, a robust Hinfinity controller is proposed to attenuate the vehicle jerk as well as the clutch sliding energy loss. Simulation results under different working conditions indicate the controller presented have better performance in limiting the effect of unknown external disturbances comparing to a calibrated proportional-integral derivative (PID) controller.

Improved Pupil-Size Diversity Technology for High-Resolution Imaging with Faint Objects

Xinxin Yang,Ge Ren,Haotong Ma,Qi Peng,Yufeng Tan,Jihong Wang 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.76 No.1

Phase aberration is one of the prime factors that degrade the quality of observed images. Pupil-size diversity technology (PSDT) is a newly developed post-processing method for aberration correction and image reconstruction. However, images reconstructed using PSDT suffer from massive grains when imaging astronomical faint objects, which extremely limits its further application. In this paper, we propose an improved PSDT with embedded denoising reprocessing to overcome this drawback. Diversity raw images, generated by modulating the size of the pupil, are firstly processed by blocking-matching and 3D filtering (BM3D), a state-of-art denoising algorithm. Then, the traditional PSDT can be employed to estimate the wavefront and reconstruct a high-resolution image. Both numerical simulations and experiment demonstrations show that our proposed strategy exhibits superior performance for aberrations correction and image restoration of faint objects in view of its efficiency and robustness. Being capable of realizing high-resolution imaging with faint objects, this proposed method may have important application prospects in the fields of astronomical object detection, remote sensing, \textit{etc.}

Synthesis, characterization and tribological performances of nano-CeO2/biodiesel carbon soot composites as a novel lubricant additive in polyalphaolefin

Chuan Li,Xinxin Wang,Qiangqiang Zhang,Xu Tan,Yefeng Liu,Honglin Li,Hao Liu,Enzhu Hu,Xianguo Hu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.126 No.-

This study fabricated nano-CeO2/biodiesel carbon soot (BCS) composites using the raw material BCS,which is the byproduct of biodiesel combustion and cerium salt and used as a novel lubricant additiveto PAO6 for steel/steel contact. Oleylamine modified nano-CeO2/BCS composites comprise abundant lipophilicgroups, and thus nano-CeO2/BCS composites exhibit good dispersion in PAO6. The tribologicalresults showed that nano-CeO2/BCS composites significantly improved the lubricating performances ofPAO6. In case of 0.1 wt% nano-CeO2/BCS composites dispersed in PAO6, the friction coefficient and wearvolume were reduced by 17.3 and 35.2%, respectively. The improved tribological properties were attributedto the composites rolling and forming of a lubricating film on the friction surface and the presence ofBCS and CeO2 in composites exerting a synergistic lubricating effect, which simultaneously improved thetribological properties of PAO6. This discovery contributes to the conversion of BCS into valuables andpromotes the high value utilization of BCS as a lubricating additive.

GelMA-based bioactive hydrogel scaffolds with multiple bone defect repair functions: Therapeutic strategies and recent advances

Bixia Zhou,Xulei Jiang,Xinxin Zhou,Wuyuan Tan,Hang Luo,Shaorong Lei,Ying Yang 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Currently, the clinical treatment of critical bone defects attributed to various causes remains a great challenge, and repairing these defects with synthetic bone substitutes is the most common strategy. In general, tissue engineering materials that mimic the structural, mechanical and biological properties of natural bone have been extensively applied to fill bone defects and promote in situ bone regeneration. Hydrogels with extracellular matrix (ECM)-like properties are common tissue engineering materials, among which methacrylate-based gelatin (GelMA) hydrogels are widely used because of their tunable mechanical properties, excellent photocrosslinking capability and good biocompatibility. Owing to their lack of osteogenic activity, however, GelMA hydrogels are combined with other types of materials with osteogenic activities to improve the osteogenic capability of the current composites. There are three main aspects to consider when enhancing the bone regenerative performance of composite materials: osteoconductivity, vascularization and osteoinduction. Bioceramics, bioglass, biomimetic scaffolds, inorganic ions, bionic periosteum, growth factors and two-dimensional (2D) nanomaterials have been applied in various combinations to achieve enhanced osteogenic and bone regeneration activities. Three-dimensional (3D)-bioprinted scaffolds are a popular research topic in bone tissue engineering (BTE), and printed and customized scaffolds are suitable for restoring large irregular bone defects due to their shape and structural tunability, enhanced mechanical properties, and good biocompatibility. Herein, the recent progress in research on GelMA-based composite hydrogel scaffolds as multifunctional platforms for restoring critical bone defects in plastic or orthopedic clinics is systematically reviewed and summarized. These strategies pave the way for the design of biomimetic bone substitutes for effective bone reconstruction with good biosafety.

Green Cooperative Sensing Scheme in Heterogeneous Networks

( Lifei Shen ),( Jian Liu ),( Xinxin Tan ),( Lei Wang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.2

Cognitive radio technology is still the key technology of future mobile communication systems. Previous studies have focused on improving spectrum utilization and less energy consumption. In this paper, we propose an Overhead Reduced Scheme (ORS) for green cooperative spectrum sensing. Compared to traditional cooperative sensing scheme, ORS scheme divides the sensing time into three time slots and selects the best multi-mode user to report decisions. In consideration of reporting channel deviation, we derive closed-form expressions for detection probability and false alarm probability of ORS scheme based on Rayleigh fading channel. Simulation results show that ORS scheme can improve the perception accuracy while reducing the perceived delay and energy consumption in the process of perception, so as to realize the green communication.

Clinical Evidence of Chemotherapy or Endocrine Therapy Maintenance in Patients with Metastatic Breast Cancer: Meta-analysis from Randomized Clinical Trials and Propensity Score Matching of Multicentre Cohort Study

Wei Ren,Yunfang Yu,Huangming Hong,Ying Wang,Quanlong Gao,Yongjian Chen,Peixian Chen,Jianli Zhao,Qiyun Ou,Dagui Lin,Tuping Fu,Yujie Tan,Chenchen Li,Xinxin Xie,Guolin Ye,Jun Tang,Herui Yao 대한암학회 2022 Cancer Research and Treatment Vol.54 No.4

Purpose This study aims to comprehensively evaluate the clinical efficacy of chemotherapy or endocrine therapy maintenance in metastatic breast cancer (MBC) patients. Materials and Methods The meta-analysis of randomized clinical trials (RCTs) and propensity score matching of multicenter cohort study evaluated MBC patients who underwent first-line chemotherapy or endocrine therapy maintenance. This study is registered with PROSPERO: CRD42017071858 and ClinicalTrials.gov: NCT04258163. Results A total of 2,867 patients from 15 RCTs and 760 patients from multicenter cohort were included. The results from meta-analysis showed that chemotherapy maintenance improved progression-free survival (PFS) (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.54 to 0.73; p < 0.001; moderate-quality evidence) and overall survival (OS) (HR, 0.87; 95% CI, 0.78 to 0.97; p=0.016; high-quality evidence) than observation. In the cohort study, for hormone receptor–positive MBC patients, chemotherapy maintenance improved PFS (HR, 0.67; 95% CI, 0.52 to 0.85; p < 0.001) and OS (HR, 0.55; 95% CI, 0.42 to 0.73; p < 0.001) compared with observation, and endocrine therapy maintenance also improved PFS (HR, 0.65; 95% CI, 0.53 to 0.80; p < 0.001) and OS (HR, 0.55; 95% CI, 0.44 to 0.69; p < 0.001). There were no differences between chemotherapy and endocrine therapy maintenance in PFS and OS (all p > 0.05). Regardless of the continuum or switch maintenance therapy, showed prolonged survival in MBC patients who were response to first-line treatment. Conclusion This study provided evidences for survival benefits of chemotherapy and endocrine therapy maintenance in MBC patients, and there was no difference efficacy between chemotherapy and endocrine therapy maintenance for hormone receptor–positive patients.