Sequential defect correction for high-accuracy floating-point algorithms

1984 ◽  
pp. 186-202 ◽  
Author(s):  
Hans J. Stetter
Keyword(s):  
High Accuracy ◽  
Floating Point ◽  
Defect Correction

scholarly journals DESIGN OF A HIGH-SPEED HIGH-ACCURACY 2048-POINT FFT USING SINGLE-PRECISION FLOATING-POINT ADAPTIVE CORDIC ON FPGA

2018 ◽  
Vol 56 (6) ◽  
pp. 751
Author(s):  
Duc Hung Le
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
High Speed ◽  
High Accuracy ◽  
Experimental Results ◽  
Floating Point ◽  
Path Delay ◽  
Single Precision ◽  
Look Up Table ◽  
Speed Performance

In this paper, hardware design of a Fast Fourier Transform (FFT) core using Single-precision Floating-point Adaptive CORDIC is implemented on Altera Stratix IV FPGA. With FFT implementation, CORDIC is utilized for reducing the speed drawback of complex multiplication and the adaptive algorithm is proposed to decrease the iterations of conventional CORDIC. The experimental results of Adaptive CORDIC and 2048-point Radix-2 Multi-path Delay Commutator FFT designs are built and verified based on three kinds of Look-up Table that cost 16, 8 and 4 constant angles. As experimental results, there is a resource equivalence while it has a trade-off between speed performance and accuracy. In comparison, an adaptive CORDIC core based on Look-up Table of 16 constant angles, and 2048-point Radix-2 Multi-path Delay Commutator Fast Fourier Transform based on Adaptive CORDIC using Look-up Table of 16 constant angles are well responding to resource optimization, high-speed performance and high-accuracy of computations.

PERFORMANCE ESTIMATION OF LU FACTORISATION ON MESSAGE PASSING MULTIPROCESSORS

1992 ◽  
Vol 02 (01) ◽  
pp. 51-60 ◽  
Author(s):  
B. V. PURUSHOTHAM ◽  
A. BASU ◽  
P. S. KUMAR ◽  
L. M. PATNAIK
Keyword(s):  
Analytical Model ◽  
Execution Time ◽  
Message Passing ◽  
Distributed Memory ◽  
High Accuracy ◽  
Parallel Execution ◽  
Performance Estimation ◽  
Floating Point ◽  
Experimental Values ◽  
Single Processor

The paper proposes an analytical model for estimating the performance of Pipelined Ring algorithm for LU factorisation on any distributed memory message passing multiprocessor. Expressions for parallel execution time and speedup are derived from the computation-communication characteristics of the algorithm. Earlier methods on performance estimation of LU factorisation have been based on determining the number of floating point operations in the best and worst cases. The methodology proposed in this paper follows a different approach and estimates the performance of LU factorisation from a measurement of the execution time of the algorithm on a single processor and from a knowledge of the number of bytes communicated in different steps of the algorithm. The expression for parallel execution time of LU factorisation derived from the analytical model has been validated with experimental values obtained 011 a sixty-four transputer based multiprocessor. Results indicate that the methodology proposed in this paper can be used for estimating the execution time of Pipelined Ring algorithm for LU factorisation on any distributed memory message passing multiprocessor with high accuracy.

A New 1,000 kV Electron Microscope

1967 ◽  
Vol 25 ◽  
pp. 260-261
Author(s):  
M. Nishigaki ◽  
S. Katagiri ◽  
H. Kimura ◽  
B. Tadano
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
Basic Research ◽  
Chromatic Aberration ◽  
High Accuracy ◽  
Biological Specimen ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron

The high voltage electron microscope has many advantageous features in comparison with the ordinary electron microscope. They are a higher penetrating efficiency of the electron, low chromatic aberration, high accuracy of the selected area diffraction and so on. Thus, the high voltage electron microscope becomes an indispensable instrument for the metallurgical, polymer and biological specimen studies. The application of the instrument involves today not only basic research but routine survey in the various fields. Particularly for the latter purpose, the performance, maintenance and reliability of the microscope should be same as those of commercial ones. The authors completed a 500 kV electron microscope in 1964 and a 1,000 kV one in 1966 taking these points into consideration. The construction of our 1,000 kV electron microscope is described below.

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