This paper applies integrated system modeling and control design process to a continuously variable valve timing (VVT) actuator system that has different control input and cam position feedback sample rates. Due to high cam shaft torque disturbance and high actuator open-loop gain, it is also difficult to maintain the cam phase at the desired constant level with an open-loop controller for syst...

Feedforward A/F control in turbocharged gasoline engines with variable valve timing requires knowledge of exhaust manifold pressure, Pe. Physical conditions in the manifold make measurement costly, compelling manufacturers to implement some form of on-line estimation. Processor limitations and the calibration process, however, put constraints on estimator complexity. This paper assesses the fea...

Engines equipped with a means to actuate air flow at the intake valve can achieve superior fuel economy performance in steady state. This paper shows how modern nonlinear design techniques can be used to control such an engine over a wide range of dynamic conditions. The problem is challenging due to the nonlinearities and delays inherent in the engine model, and the constraint on the air flow ...

The current article presents a method to reconstruct the mean velocity field of cyclic flow for an input parameter value that has not been measured, allowing number tests be reduced. It is applied tumble gasoline engine following Miller cycle. New engines often include variable valve timing (VVT) systems maximize efficiency such over-expanded cycles different operating points. reconstruction wa...

It is important to diagnose and treat diseases of the aortic valve. Untreated aortic valve disease can eventually result in heart failure, severe infection, and even sudden death. Some patients present with severe symptoms, whereas others have few, if any symptoms. The diagnosis may be made on a routine physical examination. Regular medical follow-up, treatment to prevent infection of the valve...

The timing of prophylactic ascending aortic aneurysm surgery in the setting of bicuspid aortic valve disease is complex, with multiple factors influencing the decision. The 2014 ACC/AHA Valve guidelines recommend prophylactic replacement of the aortic root and/or ascending aorta once the aortic diameter exceeds 5.5 cm. This aortic size threshold for surgery is at a larger diameter than had been...