FPU

Se realiza una propuesta metodológica para la medición del rendimiento de un ASP con una unidad de coma flotante con énfasis en la potencia.

Adicionalmente, se realiza la síntesis de una unidad de sumado, multiplicación, coseno y seno parametrizable, y verificados para una precisión simple y doble.

Se encuentra que el sumador segmentado se puede operar a una velocidad máxima de 350MHz, el multiplicador (con multiplicación a los significandos de Karatsuba) a una velocidad de 243MHz y el operador CORDIC a una velocidad de 537MHz, sin el operador de sumado.

Thermalization in nonlinear systems is a central concept in statistical mechanics and has been extensively studied theoretically since the seminal work of Fermi, Pasta, and Ulam. Using molecular dynamics and continuum modeling of a ring-down setup, we show that thermalization due to nonlinear mode coupling intrinsically limits the quality factor of nanomechanical graphene drums and turns them into potential test beds for Fermi-Pasta-Ulam physics. We find the thermalization rate Γ to be independent of radius and scaling as Γ∼T∗/ε2pre, where T∗ and εpre are effective resonator temperature and prestrain.

A busca crescente por alternativas para aumentar o desempenho de operadores aritméticos implementados em hardware  torna cada vez mais importante a análise dos custos destas implementações em termos de desempenho e consumo de recursos físicos. Este artigo apresenta os resultados do desenvolvimento dos somadores Ripple Carry, Carry Select, Carry Look-ahead e o Macro Function. Essa análise foi realizada com base no projeto de uma unidade de ponto flutuante sintetizada em uma FPGA, de acordo com o padrão IEEE 754-2008, para precisão simples e meia precisão simples.

The influence of cellulose accessibility and protein loading on the efficiency of enzymatic hydrolysis of steam pretreated Douglas-fir was assessed. It was apparent that the lignin component significantly influences the swelling/accessibility of cellulose as at low protein loadings (5 FPU/g cellulose), only 16% of the cellulose present in the steam pretreated softwood was hydrolyzed while almost complete hydrolysis was achieved with the delignified substrate. When lignin (isolated from steam pretreated Douglas-fir) was added back in the same proportions it was originally found to the highly accessible and swollen, delignified steam pretreated softwood and to a cellulose control such as Avicel, the hydrolysis yields decreased by 9 and 46%, respectively. However, when higher enzyme loadings were employed, the greater availability of the enzyme could overcome the limitations imposed by both the lignin’s restrictions on cellulose accessibility and direct binding of the enzymes, resulting in a near complete hydrolysis of the cellulose.► The work compared two major influences of lignin during the enzymatic hydrolysis of steam pretreated Douglas-fir. ► The overall inhibitory effect of lignin is dependent on enzyme loading and cellulose accessibility. ► At low enzyme loading, lignin’s influence on both limited cellulose accessibility and unproductive binding were at play. ► The impact of lignin’s enzyme binding was also dependent on how accessible the cellulose was. ► The cumulative effect of lignin is thus, ultimately dependent on overall cellulose accessibility.