An investigation of latency prediction for NoC-based communication architectures using machine learning techniques

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. Due to the increasing number of cores in Systems on Chip (SoCs), bus architectures have suffered with limitations regarding performance. As applications demand higher bandwidth and lower latencies, buses have not been able to comply with such requirements due to longer wires and increased capacitance. Facing this scenario, Networks on Chip (NoCs) emerged as a way to overcome the limitations found in bus-based systems. Fully exploring all possible NoC characteristics settings is unfeasible due to the vast design space to cover. Therefore, some methods which aim to speed up the design process are needed. In this work, we propose the use of machine learning techniques to optimise NoC architecture components during the design phase. We have investigated the performance of several different ML techniques and selected the Random Forest one targeting audio/video applications. The results have shown an accuracy of up to 90% and 85% for prediction involving arbitration and routing protocols, respectively, and in terms of applications inference, audio/video achieved up to 99%. After this step, we have evaluated other classifiers for each application individually, aiming at finding the adequate one for each situation. The best class of classifiers found was the Tree-based one (Random Forest, Random Tree, and M5P) which is very encouraging, and it points to different approaches from the current state of the art for NoCs latency prediction

The Investigation of the Oxidation Kinetics of Phosphotungsten Suboxide

Dark blue colored phosphotungsten suboxide, which has the characteristics of phosphate tungsten oxide bronze, is formed during the thermal decomposition of ammonium phosphotungstate hydrate (APTH) in inert gas atmosphere. The aim of this study is to investigate the oxidation kinetics of phosphotungsten suboxide at isothermal conditions. Pellets prepared from phosphotungsten suboxide powder that were preheated at 1173 K temperature in inert gas atmosphere were used in the oxidation experiments. The sensitive measurement of weight increases was determined by the microelectronic microbalance. The oxidation reaction was carried out in the temperature range of 690 and 778 K and oxygen partial pressure range of 0.04 and 0.21 bar. The effects of gas flow rate, temperature, and oxygen partial pressure on the reaction rate were determined. The rate equation was derived by applying the "Nucleation and Growth Kinetics" model. The reaction rate was found to be of 0.94 order with respect to oxygen partial pressure, and the activation energy was 159 kJ mol(-1)

The Use of Oxalic Acid as a Chelating Agent in the Dissolution Reaction of Calcium Molybdate

In this study, the dissolution behavior of calcium molybdate (CaMoO4) was investigated in oxalic acid (H2C2O4) solution. The effects of stirring speed, temperature, H2C2O4 concentration, and particle size on the dissolution reaction of CaMoO4 were determined. The dissolved quantities of molybdenum and calcium were analyzed quantitatively by ICP-OES. Fractional conversion of CaMoO4 vs time and concentration of calcium vs time diagrams were plotted. It was observed that at constant temperatures and lower H2C2O4 concentrations, the dissolution increased by increasing H2C2O4 concentration, but at higher H2C2O4 concentrations, the effect of H2C2O4 concentrations was negligible. The dissolution reaction of CaMoO4 in H2C2O4 solution was performed in two steps as series-parallel type reaction. In the first step, CaMoO4 reacted with H2C2O4 to form the water-soluble calcium aqua oxalato molybdate (Ca[MoO3(C2O4)(H2O)]) intermediate chelate product. In the second step, the intermediate chelate, Ca[MoO3(C2O4)(H2O)], reacted with the reactant, H2C2O4, to yield water-soluble hydrogen oxalato dimolybdate chelate (H-2[(MoO3)(2)(C2O4)]) and insoluble CaC2O4H2O as final products. It was found that 500 rpm was enough to eliminate the resistance of liquid film layer that surrounds the solid particles. It was concluded that the optimum temperature was 313 K (40 A degrees C) and the optimum concentration of H2C2O4 was 1 kmol m(-3) to obtain high conversion during the dissolution of CaMoO4