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Kalyanasundaram, P.
- Evaluation Of 3D Network-On-Chip Architectures By Using Layers
Authors
Source
International Journal of Innovative Research and Development, Vol 2, No 5 (2013), Pagination:Abstract
SoC are widely used in high volume and high end application . Due to the exponential growth of the transistor the 2D chip fabrication technology is facing a lot of challenges. The NoC concept replaces design-specific global on chip wires with a generic on-chip interconnection network realized by specialized routers that connect generic processing elements . The architectural level, Networks on- Chip (NoC) has been proposed to address the complexity of interconnecting an ever-growing number of Intellectual Property (IP) blocks like DSP, Memories, I/O Ports, and Peripherals . 3D NoC is a promising choice for implementing scalable interconnection architectures. A design methodology that integrates floor planning where the IP blocks are implemented, routers assignment, and cycle-accurate NoC simulation is proposed to evaluate the performance of the 3D NoC. Let us consider 3D NoC where IP blocks are implemented in top and bottom layers and 3D NoC routers are implemented in the middle layer using mesh topology. The implementation of the 3D NoC routers on a separate layer offers an additional area that may be utilized to improve the network performance by increasing the number of virtual channels, buffers size, and mesh size. The scalability and predictability of NoCs enable designers to design increasingly complex systems, with large numbers of IP/cores and lower communication latencies for many applications. Experimental results show that increasing the number of virtual channels rather than the buffers size has a higher impact on network performance. Increasing the mesh size can significantly improve the network. The 3-layer architecture can offer significantly better network performance compared to the 2D architecture.
Keywords
3D NoC, 3D topology, TSVs, IP blocks, traffic rate, buffer size, network diameter.- Reliability of Detection of Small Defects in Noisy Weldments by Advanced Signal Processing and Pattern Recognition Techniques
Authors
1 Division for PIE & NDT Development, Indira Gandhi Centre for Atomic Research, Kalpakkam 630 102, IN
Source
Indian Welding Journal, Vol 20, No 2 (1988), Pagination: 340-343Abstract
Load bearing capacity of any structure for a given dimension can be increased by improving the reliability of detection of smaller defects in weldments. This is highly desirable in aeronautical and space industries where the overall weight of the structure is a major constraint as it decides the pay load capacity.
Maraging steels are widely used in space industries for fabrication of rocket motor casings. Conventional ultrasonic pulse echo technique is applied for defect detection in weldments. However, inspection by ultrasonic testing of top midsection of maraging steel weldments, which is acoustically noisy, poses problems for reliable detection of defects of size 3 mm long x 1 mm deep or less (a design requirement). This is because of small amplitude difference of echo signal (2dB) between the noise and defect signals. Reliability of detection of such defects is improved by adopting advanced signal processing and pattern recognition techniques, which in turn increases the load bearing capacity of the structures.
A developmental work was undertaken for reliable detection of small defects in maraging steel weldments. For this purpose, a fatigue crack of 3 mm x 1 mm size was created in top midsection of the maraging steel weldments representing expected weld defects formed during fabrication. This paper discusses the application of advanced techniques like, autocorrelation, cross power spectral analysis, demodulation and cluster analysis for detection of the simulated fatigue crack. By adopting these techniques 95% reliability has been achieved for the detection of the fatigue crack. The approach has been assessed for shop floor adaptability. The approach would yield considerable enhancement in the pay lead of space vehicle thus resulting in enhanced capability and effective utilization.
- NDE of High Temperature Stainless Steel Used in Biomass Gasifier
Authors
1 Department of Physics, Sethu Institute of Technology, Kariapatti-626106, IN
2 School of Energy, Madurai Kamaraj University, Madurai-625021, IN
3 Division for PIE & NDT Development, Indira Gandhi Center for Atomic Research, Kalpakkam-603102, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 30, No 1 (2008), Pagination: 1-7Abstract
A biomass gasifier was in operation for sometime and later failed near the weld portion. A portion of the sample near the failed region was cut and used for this investigation. Study based on ultrasonic velocity measurements, metallography and X-ray diffraction was carried out at different portions of samples of stainless steel used in the biomass gasifier. Precise ultrasonic velocity measurements were performed by pulse echo method using cross correlation technique. Longitudinal ultrasonic wave generating probes of 5 and 20 MHz were used. It is found that there is an increase in ultrasonic velocity in samples obtained from the exposed portion as compared to the virgin samples. Metallographic studies revealed that there is a microstructural reformation taking place due to prolonged temperature treatment at the regions away from the failed portion. Very near the failed portion, there is intergranular type crack propagation as a result of partial sensitization and embrittlement. X-ray diffraction study is in support of the metallographic observations. The increase in ultrasonic velocities in service exposed specimen with and without intergranular cracks was attributed to the continuous changes taking place in the microstructures. It is suggested that periodic monitoring of the critical parts especially the combustion zone by NDE techniques would help avoid premature failure of the biomass gasifier plant.Keywords
Ultrasonic Measurements, Biomass Gasifier, AISI Type 310 Stainless Steel, Microstructures, Characterization.- Damage Evaluation in High Temperature Stainless Steel Components Using Non-Destructive Techniques
Authors
1 Department of Physics, Thiagarajar College, Madurai-625009, IN
2 School of Energy, Madurai Kamaraj University, Madurai-625021, IN
3 Department of Physics, Alagappa University, Karaikudi-623001, IN
4 Non Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, IN