Accelerating Faceting Wide-Field Imaging Algorithm with FPGA for SKA Radio Telescope as a Vast Sensor Array.

The SKA (Square Kilometer Array) radio telescope will become the most sensitive telescope by correlating a huge number of antenna nodes to form a vast array of sensors in a region over one hundred kilometers. Faceting, the wide-field imaging algorithm, is a novel approach towards solving image construction from sensing data where earth surface curves cannot be ignored. However, the traditional processor of cloud computing, even if the most sophisticated supercomputer is used, cannot meet the extremely high computation performance requirement. In this paper, we propose the design and implementation of high-efficiency FPGA (Field Programmable Gate Array) -based hardware acceleration of the key algorithm, faceting in SKA by focusing on phase rotation and gridding, which are the most time-consuming phases in the faceting algorithm. Through the analysis of algorithm behavior and bottleneck, we design and optimize the memory architecture and computing logic of the FPGA-based accelerator. The simulation and tests on FPGA are done to confirm the acceleration result of our design and it is shown that the acceleration performance we achieved on phase rotation is 20× the result of the previous work. We then further designed and optimized an efficient microstructure of loop unrolling and pipeline for the gridding accelerator, and the designed system simulation was done to confirm the performance of our structure. The result shows that the acceleration ratio is 5.48 compared to the result tested on software in gridding parts. Hence, our approach enables efficient acceleration of the faceting algorithm on FPGAs with high performance to meet the computational constraints of SKA as a representative vast sensor array.

Comparison of right and left trans-radial catheterization for coronary angiography and intervention in patients with Acute myocardial infarction.

OBJECTIVE: To compare the clinical characteristics between the right and left radial approach in treating acute myocardial infarction, helping physicians make treatment strategies correctly. METHODS: The patients admitted at our institution and undergoing percutaneous coronary angiography and interventional procedures by left or right radial approach between November 2013 and July 2016 were retrospectively reviewed. The access time, compression time, ambulation time, the amount of contrast material used, fluoroscopy time, interventional procedural time, the number of catheters used, the percentage of procedures completed using the assigned approach and the major vascular complications were recorded and compared between the two groups. RESULTS: There were no significant differences in access time, compression time, the amount of contrast material used, number of catheters used as well as the time to ambulation between the two groups (p>0.05), but the fluoroscopy time and interventional procedural time were significantly longer in right radial approach group than those in left radial approach group (p<0.05). The left radial approach group presented with a higher percentage of procedures completed using the assigned approach than that of right radial approach group (p<0.05). CONCLUSION: The left radial approach has more advantages than right radial approach in treating acute myocardial infarction.