After extensive research in the past decades, the design of field programmable gate array-based time-to-digital converters (TDC) with tapped delay line (TDL) architecture has become relatively ...mature, and the performance that can be achieved has also been reasonably high. This paper first presents a comprehensive analysis of measurement uncertainty of two different multi-interpolation TDL based TDCs. By executing multiple time interpolations within one clock cycle, the discrepancy between the resolution improvement and precision improvement is quantitatively analyzed. Therefore, the contributions of major error sources can be clearly understood, which is helpful for TDC designers to predict the performance that their TDCs can achieve. Thanks to the structural characteristics of TDL-TDCs and the build-in function of relatively placed macro (RPM) in Xilinx Vivado Design Suite, the implementations of these two TDCs can be packaged as intellectual property (IP) cores. Since the major building elements and their relative positions can be assigned with pre-established constraints, the high TDC performances can be maintained when the IP cores are instantiated. With the knowledge of TDC architectures and factors affecting performance introduced in this paper, end-users can easily configure the IP cores to meet their requirements without the need of knowing technique details.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In most of the industrial application, TIG welding is the most effective metal joining technique for mass production. In this research work, Al 7075 material is used to weld as bead-on-plate style. ...In this research investigation, the input parameters viz. Current (A), Welding speed (mm/min) and Welding time (s) are used to weld twenty different types of samples. The welding strength is measured by performing tensile strength test. The optimization technique has been accomplished using response surface methodology, which has most effective central composite method. Further, the most convincing parameter and contribution of process parameters has been evaluated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
MIG welding is used in automotive industries which helps in good opportunity to reduce production costs, decrease vehicle weight and improve the strength of sheet metal joining. In this project, the ...objective is to study welding parameters used in joining two dissimilar metals. Aluminum 6 series and aluminum 7 series with thickness both 6 mm was weld together using MIG welding with tailor welded blanks method. In this project the voltage(V), wire feed(F) and gas pressure(P) are maintained according to the material used for MIG welding. By using design expert software MIG welding parameters are optimized to obtain good tensile strength. Response surface methodology type is used to optimization to study the parameters of MIG WELDING.
Power electronics converters are a key component in high voltage direct current (HVDC) power transmission. The modular multilevel converter (MMC) is one of the latest topologies to be proposed for ...this application. An MMC generates multilevel output voltage waveforms which reduces the harmonics contents significantly. This paper presents a VHDL implementation of the capacitor voltage balancing control and level-shifted pulse width modulation (LSPWM) for MMC. The objective is to minimize the processing time with minimum gate counts. The design details are fully described and validated experimentally. An experiment is conducted on a small scale MMC prototype with two units of power cells on each arm. The test results are enclosed and discussed.
The chapter presents fundamental concepts and theories regarding airfoil lift and drag generation. It begins by presenting crucial definitions for use in airfoil theory. Ranging from the basics of ...Buckingham’s Π-theory to representation of forces moments to discussion of pressure distribution along the upper and lower surfaces of the airfoil and how it affects the growth of the boundary layer and, eventually, flow separation. Discussion of airfoil stall characteristics and ice-accretion problems are introduced with the basics of airfoil design theory. Then important geometric properties of airfoils are presented to help make the aircraft designer better rounded when comes to identifying various airfoil types, such as NACA airfoils, and understanding of their background. For this purpose, the section introduces a number of airfoils that have gained fame or notoriety in the history of aviation. This is followed by a discussion of the generation of forces and moments on the airfoil and how various outside agents, such as very high airspeeds, high angle-of-attack, deflection of control surfaces, and even surface contamination, affects their aerodynamic properties. Finally, it presents a method to help the designer select the proper airfoil for a new aircraft design.
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