Roadheaders offer a unique capability and flexibility for the excavation of soft to medium strength rock formations, therefore, are widely used in underground mining and tunneling operations. A critical issue in successful roadheader application is the ability to develop accurate and reliable estimates of machine production capacity and the associated bit costs. This paper presents and discusse...

Branch prediction reversal has been proved to be an effective alternative approach to dropping misprediction rates by means of adding a Confidence Estimator to a correlating branch predictor. This paper presents a Branch Prediction Reversal Unit (BPRU) especially oriented to enhance correlating branch predictors, such as the gshare and the Alpha 21264 metapredictor. The novelty of this proposal...

Among the hardware techniques, two-level adaptive branch predictors with two-bit saturating counters are acknowledged as best branch predictors. They accomplish very competitive performance at low hardware cost. However, with the rapid of evolution of superscalar processors, the more accurate predictors are desired for more correct branch prediction as one of speculation method. They will lead ...

We describe a rigorous ATPG-like methodology for validating the branch prediction mechanism of the Pow-erPC604 which can be easily generalized and made applicable to other processors. Test sequences based on nite state machine (FSM) testing are derived from small FSM-like models of the branch prediction mechanism. These sequences are translated into PowerPC instruction sequences. Simulation res...

This paper announces a new software side-channel attack — enabled by the branch prediction capability common to all modern highperformance CPUs. The penalty paid (extra clock cycles) for a mispredicted branch can be used for cryptanalysis of cryptographic primitives that employ a data-dependent program flow. Analogous to the recently described cache-based side-channel attacks our attacks also a...

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If you believe this document infringes copyright then please contact the KAR admin team with the take-down information provided at http://kar.kent.ac.uk/contact.html Citation for published version Otero, Fernando E.B. and Segond, Marc and Freitas, Alex A. and Johnson, Colin G. and Robilliard, Denis and Fonlupt, Cyril (2009) An empirical evaluation of the effectiveness of different types of pred...

Query performance predictors are commonly evaluated by reporting correlation coefficients to denote how well the methods perform at predicting the retrieval performance of a set of queries. Despite the amount of research dedicated to this area, one aspect remains neglected: how strong does the correlation need to be in order to realize an improvement in retrieval effectiveness in an operational...

We approach the problem of computational crystal structure prediction, implementing an evolutionary algorithm—USPEX (Universal Structure Predictor: Evolutionary Xtallography). Starting from chemical composition we have tested USPEX on numerous systems (with up to 80 atoms in the unit cell) for which the stable structure is known and have observed a success rate of nearly 100%, simultaneously fi...