120 research outputs found

    Diagnosis of Pregnancy Disease in Sheep

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    Field practitioners are frequently confronted with the problem of diagnosis of disease of pregnant ewes that show weakness, depression, anorexia and a variety of central nervous disturbances as incoordination, circling, convulsions or coma. The frequent diagnosis of pregnancy disease in these cases may be misleading as to the prevalence of this condition. This syndrome may be confused with listeriosis, brain abscesses, enterotoxemia, hemorrhagic septicemia, plant and chemical poisons and rickettsial conjunctivitis

    More is Less, Less is More: Molecular-Scale Photonic NoC Power Topologies

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    Abstract Molecular-scale Network-on-Chip (mNoC) crossbars use quantum dot LEDs as an on-chip light source, and chromophores to provide optical signal filtering for receivers. An mNoC reduces power consumption or enables scaling to larger crossbars for a reduced energy budget compared to current nanophotonic NoC crossbars. Since communication latency is reduced by using a high-radix crossbar, minimizing power consumption becomes a primary design target. Conventional Single Writer Multiple Reader (SWMR) photonic crossbar designs broadcast all packets, and incur the commensurate required power, even if only two nodes are communicating. This paper introduces power topologies, enabled by unique capabilities of mNoC technology, to reduce overall interconnect power consumption. A power topology corresponds to the logical connectivity provided by a given power mode. Broadcast is one power mode and it consumes the maximum power. Additional power modes consume less power but allow a source to communicate with only a statically defined, potentially non-contiguous, subset of nodes. Overall interconnect power is reduced if the more frequently communicating nodes use modes that consume less power, while less frequently communicating nodes use modes that consume more power. We also investigate thread mapping techniques to fully exploit power topologies. We explore various mNoC power topologies with one, two and four power modes for a radix-256 SWMR mNoC crossbar. Our results show that the combination of power topologies and intelligent thread mapping can reduce total mNoC power by up Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from [email protected]. to 51% on average for a set of 12 SPLASH benchmarks. Furthermore performance is 10% better than conventional resonator-based photonic NoCs and energy is reduced by 72%

    The Combinatorics of Cache Misses during Matrix Multiplication

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    In this paper we construct an analytic model of cache misses during matrix multiplication. The analysis in this paper applies to square matrices of size 2m where the array layout function is given in terms of a function Θ that interleaves the bits in the binary expansions of the row and column indices. We first analyze the number of cache misses for direct-mapped caches and then indicate how to extend this analysis to -way associative caches. The work in this paper accomplishes two things. First, we construct fast algorithms to estimate the number of cache misses. Second, we develop a theoretical understanding of cache misses that will allow us, in subsequent work, to approach the problem of minimizing cache misses by appropriately choosing the bit interleaving function that goes into the array layout function

    Mechanisms for cooperative shared memory

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    This paper explores the complexity of implementing directory protocols by examining their mechanisms - primitive operations on directories, caches, and network interfaces. We compare the following protocols: Dir1B, Dir4B, Dir4NB, DirnNB, Dir1SW and an improved version of Dir1SW (Dir1SW+). The comparison shows that the mechanisms and mechanism sequencing of Dir1SW and Dir1SW+ are simpler than those for other protocols. We also compare protocol performance by running eight benchmarks on 32 processor systems. Simulations show that Dir1SW+'s performance is comparable to more complex directory protocols. The significant disparity in hardware complexity and the small difference in performance argue that Dir1SW+ may be a more effective use of resources. The small performance difference is attributable to two factors: the low degree of sharing in the benchmarks and Check-In/Check-Out (CICO) directives
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