We present a compiler that takes high level signal and image processing algorithms described in MATLAB and generates an optimized hardware for an FPGA with external memory. We propose a precision analysis algorithm to determine the minimum number of bits required by an integer variable and a combined precision and error analysis algorithm to infer the minimum number of bits required by a floating point variable. Our results show that on an average, our algorithms generate hardware requiring a factor of 5 less FPGA resources in terms of the Configurable Logic Blocks (CLBs) consumed as compared to the hardware generated without these optimizations. We show that our analysis results in the reduction in the size of lookup tables for functions like sin, cos, sqrt, exp etc. Our precision analysis also enables us to pack various array elements into a single memory location to reduce the number of external memory accesses. We show that such a technique improves the performance of the generated hardware by an average of 35%.

We present an area and delay estimator in the context of a compiler that takes in high level signal and image processing applications described in MATLAB and performs automatic design space exploration to synthesize hardware for a Field Programmable Gate Array (FPGA) which meets the user area and frequency specifications. We present an area estimator which is used to estimate the maximum number of Configurable Logic Blocks (CLBs) consumed by the hardware synthesized for the Xilinx XC4010 from the input MATLAB algorithm. We also present a delay estimator which finds out the delay in the logic elements in the critical path and the delay in the interconnects. The total number of CLBs predicted by us is within 16% of the actual CLB consumption and the synthesized frequency estimated by us is within an error of 13% of the actual frequency after synthesis through Synplify logic synthesis tools and after placement and routing through the XACT tools from Xilinx. Since the estimators proposed by us are fast and accurate enough, they can be used in a high level synthesis framework like ours to perform rapid design space exploration.

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Fluid particle coalescence and breakage phenomena are important for optimal operation of many industrial process units. In particular, in bubble column reactors, the bubble size distribution determines the interfacial momentum, heat, and mass transfer fluxes through the contact area and may thus limit the overall process performance. To elucidate the mechanisms of the coalescence and breakage phenomena, extensive wellplanned model-based experimental investigations are required. In addition, a suitable modeling framework considering the microscopic phenomena is needed to interpret the data achieving extended understanding of the important mechanisms, enabling the formulation of more sophisticated mechanistic kernel functions. This article presents a combined multifluid-population balance model for describing the behavior of vertical bubbledriven flows in bubble columns. In the present modeling approach, the Maxwellian average transport equations for the disperse phase are formulated in terms of a density function. The main advantage of this novel modeling concept is that we obtain a set of transport equations expressed in terms of the set of internal coordinates. All the important moments like the void fraction, contact area, Sauter mean diameter, average disperse phase velocity, mean mass, and momentum fluxes, etc., can then be computed from the predicted density function in a post processing procedure. For model validation, the model predictions are compared to experimental data gathered from the literature. The agreement between the available data and the model predictions ais considered very good. It is concluded that the model is a viable tool for parameter fitting of novel coalescence and breakage kernels provided that sufficient experimental data are made available.

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BackgroundCognitive deficits in various domains have been consistently replicated in patients with schizophrenia. Most studies looking at the relationship between cognitive dysfunction and functional disability are from developed countries. Studies from developing countries are few. The purpose of the present study was to compare the neurocognitive function in patients with schizophrenia who were in remission with that of normal controls and to determine if there is a relationship between measures of cognition and functional disability.MethodsThis study was conducted in the Psychiatric Unit of a General Hospital in Mumbai, India. Cognitive function in 25 patients with schizophrenia in remission was compared to 25 normal controls. Remission was confirmed using the brief psychiatric rating scale (BPRS) and scale for the assessment of negative symptoms (SANS). Subjects were administered a battery of cognitive tests covering aspects of memory, executive function and attention. The results obtained were compared between the groups. Correlation analysis was used to look for relationship between illness factors, cognitive function and disability measured using the Indian disability evaluation and assessment scale.ResultsPatients with schizophrenia showed significant deficits on tests of attention, concentration, verbal and visual memory and tests of frontal lobe/executive function. They fared worse on almost all the tests administered compared to normal controls. No relationship was found between age, duration of illness, number of years of education and cognitive function. In addition, we did not find a statistically significant relationship between cognitive function and scores on the disability scale.ConclusionThe data suggests that persistent cognitive deficits are seen in patients with schizophrenia under remission. The cognitive deficits were not associated with symptomatology and functional disability. It is possible that various factors such as employment and family support reduce disability due to schizophrenia in developing countries like India. Further studies from developing countries are required to explore the relationship between cognitive deficits, functional outcome and the role of socio-cultural variables as protective factors.