Back at school, Indian teachers face a crisis of discipline, attendance and learning loss

Pupils in India are back in classrooms, but teachers face enormous problems with discipline, attendance, concentration and loss of learning. Daya Sajeevan, Sreehari Ravindranath and Ravichandra Krishna (Dream a Dream) talked to teachers in Karnataka about their students’ behaviour post-lockdown

Comparative study between Blair’s procedure of ankle fusion and arthroscopic ankle arthrodesis

Background: Our objective was to perform a comparative study in terms of functional outcome of Blair’s procedure of ankle fusion versus arthroscopic methods of ankle fusion.Methods: 25 patients that underwent arthroscopic ankle arthrodesis versus Blair’s procedure of ankle fusion were taken for study at government medical college, Srinagar (VCSGGIMS and R) from the duration 2015-2021. Clinical assessment was done foot and ankle disability index and visual analog scale score for pain. Radiological assessment was done by serial X-rays. Regular follow-ups were taken till one year.Results: Both modalities proved to be equally effective in terms of patient’s functional outcome. Our analysis showed that Blair’s procedure ankle fusion was associated with a lower fusion rate (OR 0.26, 95% CI 0.13-0.52, p=0.0002), longer tourniquet time (MD 16.49, 95% CI 9.46-23.41, p<0.00001), and longer length of stay (MD 1.60,95% CI 1.10-2.10, p<0.00001) compared to arthroscopic ankle fusion; however, there was no significant difference between two groups in terms of infection rate (OR 2.41, 95% CI 0.76-7.64, p=0.14), overall complication rate (OR: 1.54, 95% CI 0.80-2.96, p=0.20), and operation time (MD 4.09, 95% CI 2.4910.66, p=0.22).Conclusions: We found no significant difference between two groups in terms of infection rate, overall complication rate, and operation time. Further high quality randomized controlled trials that are adequately powered are required

Approaching the theoretical limits of a mesh NoC with a 16-node chip prototype in 45nm SOI

In this paper, we present a case study of our chip prototype of a 16-node 4x4 mesh NoC fabricated in 45nm SOI CMOS that aims to simultaneously optimize energy-latency-throughput for unicasts, multicasts and broadcasts. We first define and analyze the theoretical limits of a mesh NoC in latency, throughput and energy, then describe how we approach these limits through a combination of microarchitecture and circuit techniques. Our 1.1V 1GHz NoC chip achieves 1-cycle router-and-link latency at each hop and energy-efficient router-level multicast support, delivering 892Gb/s (87.1% of the theoretical bandwidth limit) at 531.4mW for a mixed traffic of unicasts and broadcasts. Through this fabrication, we derive insights that help guide our research, and we believe, will also be useful to the NoC and multicore research community

Propiedades y aplicaciones de Funciones Hipergeométricas Extendida

In this article, we study several properties of extended Gauss hypergeometric and extended confluent hypergeometric functions. We derive several integrals, inequalities and establish relationship between these and other special functions. We also show thaEn este artículo, estudiamos varias propiedades de las funciones hipergeométricas de Gauss extendidas y hipergeométricas confluentes extendidas. Derivamos varias integrales, desigualdades y establecemos una relación entre estas y otras funciones especial

Real-time Processor-in-Loop investigation of a modified non-linear state observer using sliding modes for speed sensorless induction motor drive in electric vehicles

Tracking performance and stability play a major role in observer design for speed estimation purpose in motor drives used in vehicles. It is all the more prevalent at lower speed ranges. There was a need to have a tradeoff between these parameters ensuring the speed bandwidth remains as wide as possible. This work demonstrates an improved static and dynamic performance of a sliding mode state observer used for speed sensorless 3 phase induction motor drive employed in electric vehicles (EVs). The estimated torque is treated as a model disturbance and integrated into the state observer while the error is constrained in the sliding hyperplane. Two state observers with different disturbance handling mechanisms have been designed. Depending on, how they reject disturbances, based on their structure, their performance is studied and analyzed with respect to speed bandwidth, tracking and disturbance handling capability. The proposed observer with superior disturbance handling capabilities is able to provide a wider speed range, which is a main issue in EV. Here, a new dimension of model based design strategy is employed namely the Processor-in-Loop. The concept is validated in a real-time model based design test bench powered by RT-lab. The plant and the controller are built in a Simulink environment and made compatible with real-time blocksets and the system is executed in real-time targets OP4500/OP5600 (Opal-RT). Additionally, the Processor-in-Loop hardware verification is performed by using two adapters, which are used to loop-back analog and digital input and outputs. It is done to include a real-world signal routing between the plant and the controller thereby, ensuring a real-time interaction between the plant and the controller. Results validated portray better disturbance handling, steady state and a dynamic tracking profile, higher speed bandwidth and lesser torque pulsations compared to the conventional observer

Generalización bivariada de la distribución kummer-beta

En este artículo, definimos la función de densidad de la generalización bivariada de la distribución Kummer-Beta. Estudiamos algunas de sus propiedades y casos particulares, así como las distribuciones marginales y condicionales. Para ilustrar el comportamiento de la función de densidad, mostramos algunos gráficos para diferentes valores de los parámetros. Finalmente, encontramos la distribución del producto de dos variables cuya distribución conjunta es Kummer-Beta bivariada y utilizamos la distribución beta como una aproximación. Además, con el fin de comparar la distribución exacta y la aproximada de este producto, mostramos algunos gráficos. Se presenta una aplicación a datos climáticos sobre niebla y neblina de Colombia.In this article, we study several properties such as marginal and conditional distributions, joint moments, and mixture representation of the bivariate generalization of the Kummer-Beta distribution. To show the behavior of the density function, we give some graphs of the density for different values of the parameters. Finally, we derive the exact and approximate distribution of the product of two random variables which are distributed jointly asbivariate Kummer-Beta. The exact distribution of the product is derived as an infinite series involving Gauss hypergeometric function, whereas the beta distribution has been used as an approximate distribution. Further, to show the closeness of the approximation, we have compared the exact distribution and the approximate distribution by using several graphs. An application of the results derived in this article is provided to visibility data from Colombia

Real-time analysis of a modified state observer for sensorless induction motor drive used in electric vehicle applications

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SCORPIO: A 36-Core Research Chip Demonstrating Snoopy Coherence on a Scalable Mesh NoC with In-Network Ordering

URL to conference programIn the many-core era, scalable coherence and on-chip interconnects are crucial for shared memory processors. While snoopy coherence is common in small multicore systems, directory-based coherence is the de facto choice for scalability to many cores, as snoopy relies on ordered interconnects which do not scale. However, directory-based coherence does not scale beyond tens of cores due to excessive directory area overhead or inaccurate sharer tracking. Prior techniques supporting ordering on arbitrary unordered networks are impractical for full multicore chip designs. We present SCORPIO, an ordered mesh Network-on-Chip(NoC) architecture with a separate fixed-latency, bufferless network to achieve distributed global ordering. Message delivery is decoupled from the ordering, allowing messages to arrive in any order and at any time, and still be correctly ordered. The architecture is designed to plug-and-play with existing multicore IP and with practicality, timing, area, and power as top concerns. Full-system 36 and 64-core simulations on SPLASH-2 and PARSEC benchmarks show an average application run time reduction of 24.1% and 12.9%, in comparison to distributed directory and AMD HyperTransport coherence protocols, respectively. The SCORPIO architecture is incorporated in an 11 mm-by- 13 mm chip prototype, fabricated in IBM 45nm SOI technology, comprising 36 Freescale e200 Power Architecture TM cores with private L1 and L2 caches interfacing with the NoC via ARM AMBA, along with two Cadence on-chip DDR2 controllers. The chip prototype achieves a post synthesis operating frequency of 1 GHz (833 MHz post-layout) with an estimated power of 28.8 W (768 mW per tile), while the network consumes only 10% of tile area and 19 % of tile power.United States. Defense Advanced Research Projects Agency (DARPA UHPC grant at MIT (Angstrom))Center for Future Architectures ResearchMicroelectronics Advanced Research Corporation (MARCO)Semiconductor Research Corporatio