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关键词： Dry dual clutch transmission   Starting sliding mode variable structure control   Real-time optimization   Simulation  

摘要： This paper researches the coordination of control between an engine and clutch at the system level to adequately reflect a driver's intention and improve the starting performance of a vehicle equipped with a dry dual clutch transmission (DCT). Four-degree-of-freedom (DOF) starting dynamic equations are established for a dry DCT with a single intermediate shaft, and a two-DOF model of the sliding friction process and a single-DOF in-gear model of stable operation are obtained after simplifying these equations. Taking advantage of predictive control and a genetic algorithm, target tracing curves of the engine's speed and the vehicle's velocity are optimally specified online, and the starting sliding mode variable structure (SMVS) coordinating control strategy is designed to track these curves. The starting performance of a prototype car equipped with a dry DCT is simulated under different starting cases on the MATLAB/Simulink software platform. The simulation results show that the designed SMVS coordinating controller not only embodies driver intention and effectively improves the dry DCT car's starting performance but is also highly robust when subjected to variations in the vehicle parameters.

关键词： Adhesion   Mechanosensing   Master equation   Durotaxis   F-actin   Myosin   Cytoskeletal dynamics   Multiscale modeling   Monte Carlo simulation  

摘要： Microenvironmental mechanics play an important role in determining the morphology, traction, migration, proliferation, and differentiation of cells. A stochastic motor-clutch model has been proposed to describe this stiffness sensitivity. In this work, we present a master equation-based ordinary differential equation (ODE) description of the motor-clutch model, from which we derive an analytical expression to for a cell's optimum stiffness (i.e., the stiffness at which the traction force is maximal). This analytical expression provides insight into the requirements for stiffness sensing by establishing fundamental relationships between the key controlling cell-specific parameters. We find that the fundamental controlling parameters are the numbers of motors and clutches (constrained to be nearly equal), and the time scale of the on-off kinetics of the clutches (constrained to favor clutch binding over clutch unbinding). Both the ODE solution and the analytical expression show good agreement with Monte Carlo motor-clutch output, and reduce computation time by several orders of magnitude, which potentially enables long time scale behaviors (hours-days) to be studied computationally in an efficient manner. The ODE solution and the analytical expression may be incorporated into larger scale models of cellular behavior to bridge the gap from molecular time scales to cellular and tissue time scales.

关键词： Cardiovascular disease   Electrocardiography   QRS-T angle   T-wave axis   Type 2 diabetes  

摘要： Frontal plane T-wave axis and QRS-T angle are novel electrocardiographic ventricular repolarization parameters that have been scarcely evaluated in type 2 diabetes. The aim was to investigate the factors associated with these parameters of abnormal ventricular repolarization in a cross-sectional analysis of 594 patients with type 2 diabetes. Clinical, laboratory, 2D-echocardiographic, ambulatory blood pressure (BP) monitoring, aortic pulse wave velocity (PWV) and carotid ultrasonographic data were obtained. Digital 12-lead ECG was recorded, and frontal plane T-wave axis and QRS-T angle were automatically measured. T-wave axis was considered abnormal if > 75A degrees or < 15A degrees and QRS-T angle if a parts per thousand yen73A degrees in men and a parts per thousand yen67A degrees in woman. Associations were assessed by bivariate tests and multivariate logistic regressions. One hundred and four (20.9 %) patients had abnormal T-wave axis, and 84 (14 %) had increased QRS-T angle. Patients with abnormal ventricular repolarization were older and had greater prevalence of micro- and macrovascular diabetic complications than patients with normal repolarization. They had higher office and ambulatory BPs, greater prevalence of the non-dipping pattern, and greater left ventricular mass, aortic PWV and carotid intima-media thickness. On multivariate analysis, abnormal ventricular repolarization parameters were independently associated with left ventricular hypertrophy, non-dipping pattern, higher ambulatory systolic BPs, glycated hemoglobin and common carotid intima-media thickness, and with the presence of coronary artery disease. In conclusion, abnormal frontal plane T-wave axis and QRS-T angle are independently associated with several markers of pre-clinical atherosclerotic disease;whether these associations represent additional cardiovascular risk in type 2 diabetes shall be confirmed in prospective studies.

摘要： A wide range of invasive pathological outcomes originate from the loss of epithelial phenotype and involve either loss of function or downregulation of transmembrane adhesive receptor complexes, including Ecadherin (Ecad) and binding partners beta-catenin and alpha-catenin at adherens junctions. Cellular pathways regulating wild-type beta-catenin level, or direct mutations in beta-catenin that affect the turnover of the protein have been shown to contribute to cancer development, through induction of uncontrolled proliferation of transformed tumor cells, particularly in colon cancer. Using single-molecule force spectroscopy, we show that depletion of beta-catenin or the prominent cancer-related S45 deletion mutation in beta-catenin present in human colon cancers both weaken tumor intercellular Ecad/Ecad bond strength and diminishes the capacity of specific extracellular matrix proteins including collagen I, collagen IV, and laminin V to modulate intercellular Ecad/Ecad bond strength through alpha-catenin and the kinase activity of glycogen synthase kinase 3 (GSK-3 beta). Thus, in addition to regulating tumor cell proliferation, cancer-related mutations in beta-catenin can influence tumor progression by weakening the adhesion of tumor cells to one another through reduced individual Ecad/Ecad bond strength and cellular adhesion to specific components of the extracellular matrix and the basement membrane.

关键词： 汽车   自动离合器   模糊自适应控制   刹车辅助  

摘要： 文章针对现有汽车电子自动离合器存在的缺点,设计了一套汽车电子自动控制离合器系统。该系统以单片机为控制核心,通过采集汽车的各种行车信息,运用模糊自适应算法得到合适的PWM调速信号控制机械执行机构,并配以刹车辅助控制,实现了离合器的平稳、可靠控制,提高了驾驶的舒适性和便利性。