Presence Of Heterogeneous System Research Articles

Improved scheduler for multi-core many-core systems

Over the years, presence of heterogeneous system has dominated the area of concurrent job execution. Heterogeneous system is the natural choice as it can be designed with the legacy system. Scheduling, on such systems, is an important activity as it affects the job execution characteristic. Heterogeneity introduces many challenges for the efficient job execution. Heterogeneity in core architecture introduces the possibility of heterogeneous memory architecture in many/multi core heterogeneous system. This makes it often impossible to determine for the same instruction if a high frequency core has low or high memory latency in comparison to the low frequency core and vice-versa. The work proposes an improved scheduler for such systems in which both core and memory are heterogeneous. It defines average effective time ( $$\hbox {AE}_\mathrm{t}$$ AE t ) as the base parameter for this purpose. Priorities of each thread (workload) and the core are dynamically generated using $$\hbox {AE}_\mathrm{t}$$ AE t for effective mapping. Experimental results, on the benchmark data, reveal that the proposed scheduler performs much better in terms of cores utilization, speedup and efficiency in comparison to other similar models.

Liquid-phase oxidation of tetralin in the presence of heterogeneous catalysts

A STUDY Of heterogeneous catalysts in liquid-phase oxidation of hydrocarbons has recently at tracted increasing attention [1-3]. This interest is due to special features of the effect of the heterogeneous surface on the process as a whole and to a somewhat (in many cases) different distribution of reaction products. Typical heterogeneous catalysts of gaseous oxidation of hydrocarbons--transition metal oxides (IV and V periods) [4, 5]--were examined in most detail. Two points of view are now dealt with in the literature which are based on these investigations and concern the role of heterogeneous catalysts in liquidphase oxidation. According to the first, heterogeneous catalysts only initiate the process [2, 6]. Oi1 the other hand, it was found in many studies that in addition to the initiating effect, heterogeneous catalysts have a considerable influence on the distribution of reaction products [1, 7, 8]. This study deals with liquid-phase oxidation of tetralin in the presence of heterogeneous systems representing bivalent cobalt ions applied on zeolites, activated charcoal and silica gel. Cobalt oxide Co304 was also examined. Results obtained by oxidation of tetralin in heterogeneous catalysts were compared with results of non-catalytic oxidation and oxidation in the presence of cobalt stearate, a homogeneous catalyst.