We consider cache replacement algorithms at a shared cache in a multicore system which receives an arbitrary interleaving of requests from processes that have full knowledge about their individual request sequences. We establish tight bounds on the competitive ratio of deterministic and randomized cache replacement strategies when processes share memory blocks. Our main result for this case is a deterministic algorithm called GLOBAL-MAXIMA which is optimum up to a constant factor when processes share memory blocks. Our framework is a generalization of the application controlled caching framework in which processes access disjoint sets of memory blocks. We also present a deterministic algorithm called RR-PROC-MARK which exactly matches the lower bound on the competitive ratio of deterministic cache replacement algorithms when processes access disjoint sets of memory blocks. We extend our results to multiple levels of caches and prove that an exclusive cache is better than both inclusive and non-inclusive caches; this validates the experimental findings in the literature. Our results could be applied to shared caches in multicore systems in which processes work together on multithreaded computations like Gaussian elimination paradigm, fast Fourier transform, matrix multiplication, etc. In these computations, processes have full knowledge about their individual request sequences and can share memory blocks. / text

<p>This research explores the impact of road infrastructure on deforestation, the role of forest governance and a carbon tax/credit mechanism in mitigating the effect on land use change and subsequent GHG emissions, with application to the states of Pará and Mato Grosso in Brazil. Few studies have addressed how policies to protect forested land affect the rate of deforestation associated with road and infrastructure improvement. This research makes three main contributions to the literature of roads and deforestation: 1) the concept of cost of access to the “closest” market in terms of time (expressed in person hours per ten ton load) is introduced to reflect variations in the road network infrastructure; 2) development of empirical evidence of the role of forest governance in diminishing the rate of deforestation linked to roads, using data from Brazil; and 3) and assessment of the efficacy of a carbon tax/credit scheme for mitigating the impact of infrastructure investment on land use and resultant changes in GHG emissions. Access cost ranged between 0.01 and 3084 person hours per load, however 80 percent of the pixels measured less than 784 person hours across the three years analyzed (2003, 2013, and 2018). This measure facilitated a contrast in spatial accessibility due to road infrastructure across pixels within the same year and across years on a same pixel. The use of a fractional logit model allowed the incorporation of proportions of different land uses within a same pixel at the same resolution of other <a></a>variables not available at the same fine scale. Strong forest governance reduced up to 25% the elasticities on forest lands with respect to access cost; in other words, the impact of roads on deforestation is reduced by one fourth when forest governance is strengthened. These larger impacts occur at the frontier where most of the efforts need to be addressed. Finally, provided a shock in road infrastructure, a carbon tax/credit level of $82/tCO2e permitted to abate an additional amount of GHG emissions estimated in 244 million tons of CO2e released due to changes in carbon stocks and flow emissions from agricultural activities induced from changes in road infrastructure. More importantly, this research provided insights of a proportion of GHG emissions that could be abated at different levels of a carbon tax/credit.</p>