REFU: Redundant Execution with Idle Functional Units, Fault Tolerant GPGPU architecture

The General-Purpose Graphics Processing Units (GPGPU) with energy efficient execution are increasingly used in wide range of applications due to high performance. These GPGPUs are fabricated with the cutting-edge technologies. Shrinking transistor feature size and aggressive voltage scaling has increased the susceptibility of devices to intrinsic and extrinsic noise leading to major reliability issues in the form of the transient faults. Therefore, it is essential to ensure the reliable operation of the GPGPUs in the presence of the transient faults. GPGPUs are designed for high throughput and execute the multiple threads in parallel, that brings a new challenge for the fault detection with minimum overheads across all threads. This paper proposes a new fault detection method called REFU, an architectural solution to detect the transient faults by temporal redundant re-execution of instructions using the idle functional execution units of the GPGPU. The performance of the REFU is evaluated with standard benchmarks, for fault free run across different workloads REFU shows mean performance overhead of 2%, average power overhead of 6%, and peak power overhead of 10%

Spatial Distribution Patterns for Identifying Risk Areas Associated with False Smut Disease of Rice in Southern India

False smut disease (FSD) of rice incited by Ustilaginoidea virens is an emerging threat to paddy cultivation worldwide. We investigated the spatial distribution of FSD in different paddy ecosystems of South Indian states, viz., Andhra Pradesh, Karnataka, Tamil Nadu, and Telangana, by considering the exploratory data from 111 sampling sites. Point pattern and surface interpolation analyses were carried out to identify the spatial patterns of FSD across the studied areas. The spatial clusters of FSD were confirmed by employing spatial autocorrelation and Ripley’s K function. Further, ordinary kriging (OK), indicator kriging (IK), and inverse distance weighting (IDW) were used to create spatial maps by predicting the values at unvisited locations. The agglomerative hierarchical cluster analysis using the average linkage method identified four main clusters of FSD. From the Local Moran’s I statistic, most of the areas of Andhra Pradesh and Tamil Nadu were clustered together (at I > 0), except the coastal and interior districts of Karnataka (at I < 0). Spatial patterns of FSD severity were determined by semi-variogram experimental models, and the spherical model was the best fit. Results from the interpolation technique, the potential FSD hot spots/risk areas were majorly identified in Tamil Nadu and a few traditional rice-growing ecosystems of Northern Karnataka. This is the first intensive study that attempted to understand the spatial patterns of FSD using geostatistical approaches in India. The findings from this study would help in setting up ecosystem-specific management strategies to reduce the spread of FSD in India

Power loss analysis in altered tooth-sum spur gearing

The main cause of power loss or dissipation of heat in case of meshed gears is due to friction existing between gear tooth mesh and is a major concern in low rotational speed gears, whereas in case of high operating speed the power loss taking place due to compression of air-lubricant mixture (churning losses) and windage losses due to aerodynamic trial of air lubricant mixture which controls the total efficiency needs to be considered. Therefore, in order to improve mechanical efficiency it is necessary for gear designer during gear tooth optimization to consider these energy losses. In this research paper the power loss analysis for a tooth-sum of 100 altered by ±4% operating between a specified center distance is considered. The results show that negative altered tooth-sum gearing performs better as compared to standard and positive altered tooth-sum gearing

Power loss analysis in altered tooth-sum spur gearing

The main cause of power loss or dissipation of heat in case of meshed gears is due to friction existing between gear tooth mesh and is a major concern in low rotational speed gears, whereas in case of high operating speed the power loss taking place due to compression of air-lubricant mixture (churning losses) and windage losses due to aerodynamic trial of air lubricant mixture which controls the total efficiency needs to be considered. Therefore, in order to improve mechanical efficiency it is necessary for gear designer during gear tooth optimization to consider these energy losses. In this research paper the power loss analysis for a tooth-sum of 100 altered by ±4% operating between a specified center distance is considered. The results show that negative altered tooth-sum gearing performs better as compared to standard and positive altered tooth-sum gearing

Axial-flow compressor analysis under distorted phenomena at transonic flow conditions

Today, the turbomachinery engineering plays a vital role in the field of air breathing propulsion, most importantly the components like compressor, turbine and its possible numerical strategies to improve the overall efficiency especially in the transonic flow conditions. The main objective of this paper is to address the numerical solution for most uncertain problem like unsteady and non-uniform flow across the axial-flow compressor. The axial-flow compressor distorted flow problem is modeled and analyzed by means of a systematic three-dimensional numerical approach. Particularly, the rotor inflow instability implications of an axial compressor stage are carried out. Geometry is created using ROTOR-37 coordinates for numerical analysis and the results are validated in contradiction of experimental data available from literature, by imposing various combinations of Mach numbers from 0.8 to 1.2 and the engine mass flow rate of incoming air. The results highlighted that the rotor blade main distortion effect was noticed at near the tip region and as well as the hub corners of the blade. Numerical simulations also revealed that due to the distortion influence, the stream flow separation on pressure side of the blade is more. Moreover, these calculated figures have more significance for better aero-mechanical features of axial-flow compressor

Spatial Distribution Patterns for Identifying Risk Areas Associated with False Smut Disease of Rice in Southern India

False smut disease (FSD) of rice incited by Ustilaginoidea virens is an emerging threat to paddy cultivation worldwide. We investigated the spatial distribution of FSD in different paddy ecosystems of South Indian states, viz., Andhra Pradesh, Karnataka, Tamil Nadu, and Telangana, by considering the exploratory data from 111 sampling sites. Point pattern and surface interpolation analyses were carried out to identify the spatial patterns of FSD across the studied areas. The spatial clusters of FSD were confirmed by employing spatial autocorrelation and Ripley’s K function. Further, ordinary kriging (OK), indicator kriging (IK), and inverse distance weighting (IDW) were used to create spatial maps by predicting the values at unvisited locations. The agglomerative hierarchical cluster analysis using the average linkage method identified four main clusters of FSD. From the Local Moran’s I statistic, most of the areas of Andhra Pradesh and Tamil Nadu were clustered together (at I > 0), except the coastal and interior districts of Karnataka (at I < 0). Spatial patterns of FSD severity were determined by semi-variogram experimental models, and the spherical model was the best fit. Results from the interpolation technique, the potential FSD hot spots/risk areas were majorly identified in Tamil Nadu and a few traditional rice-growing ecosystems of Northern Karnataka. This is the first intensive study that attempted to understand the spatial patterns of FSD using geostatistical approaches in India. The findings from this study would help in setting up ecosystem-specific management strategies to reduce the spread of FSD in India