Rough set optimization method was applied to design the worm gear in valve actuator. The superfluous constraints are reduced based on the methodology of rough set at the model of optimization that was established. The importance of each constraint condition and the coordination of the objective function can be got. Through example it can be seen that the optimal scheme made worm gear accord wit...

The integer word-length optimization known as range analysis (RA) of the fixed-point designs is a challenging problem in high level synthesis and optimization of linear-time-invariant (LTI) systems. The analysis has significant effects on the resource usage, accuracy and efficiency of the final implementation, as well as the optimization time. Conventional methods in recursive LTI systems suffe...

IMPORTANCE Transcatheter aortic valve replacement (TAVR) is an effective treatment option for high-risk patients with severe aortic stenosis. Different from surgery, transcatheter deployment of valves requires either a balloon-expandable or self-expandable system. A randomized comparison of these 2 systems has not been performed. OBJECTIVE To determine whether the balloon-expandable device is...

a new method of optimization on linear parabolic solar collectors using exergy analysis is presented. a comprehensive mathematical modeling of thermal and optical performance is simulated and geometrical and thermodynamic parameters were assumed as optimization variables. by applying a derived expression for exergy efficiency, exergy losses were generated and the optimum design and operating co...

We have performed a shape optimization of the disc in an industrial double-eccentric butterfly valve using the effect analysis of design variables to enhance the valve performance. For the optimization, we select three performance quantities such as pressure drop, maximum stress, and mass (weight) as the responses and three dimensions regarding the disc shape as the design variables. Subsequent...

the purpose of this research is to investigate thermoeconomic optimization and exergy analysis of transcritical co2 refrigeration cycle with an ejector. after modeling thermodynamic equations of elements and considering optimization parameters of emerging temperature of gas of cooler (tgc) , emerging pressure of cooler's gas (pgc) , and evaporative temperature (tevp) , optimization of targ...

In this paper, the effect of the Intake Valve Deactivation (IVDA) on engine performance is investigated in detail. Based on an optimization platform with Genetic Algorithm (GA) and engine thermodynamic model, the characteristics of the engine volumetric efficiency and pumping loss were studied under the cam-drive, Single Intake Valve (SIV) and Dual Intake Valves (DIV) operating modes, and the e...

The seismic performance of nuclear power valve is one the important indexes to measure its safety and reliability. analysis, thermal stress calculation, fatigue analysis experimental verification a class I three-way are carried out. Firstly, natural frequency, strain high temperature pressure analyzed. Secondly, calculation methods put forward. Finally, through frequency sweep test valve, opera...

This paper presents clonal selection algorithm to solve the Dynamic Economic Dispatch Problem (DEDP) of generating units considering valve point loading effects. It determines the optimal operation of units with predicted load demand over a certain period of time with an objective to minimize total production cost while the system is operating with ramp rate limits. This paper presents DED base...

BACKGROUND New generation devices for transfemoral aortic valve replacement were optimized on valve positioning and reduction of residual aortic regurgitation. We compared 30-day, 12-month, and 24-month outcomes of the Boston Scientific Lotus valve (Lotus) and the balloon-expandable Edwards Sapien 3 (ES3) valve. Primary end point was all-cause mortality or disabling stroke within 12 months. M...