1,721,979 research outputs found
psort
Full text linkpsort è stato il più veloce software di ordinamento per macchine di classe PC dal 2008 al 2011 (benchmark Pennysort, http://sortbenchmark.org) e un suo adattamento per cluster ha migliorato il record per il benchmark datamation di quasi un ordine di grandezza nel 2011. Il rapporto tecnico ufficiale si trova sul sito sortbenchmark.org (che cataloga i più efficienti software di ordinamento per varie categorie di task/hardware - originariamente mantenuto dal premio Turing Jim Gray) all'URL http://sortbenchmark.org/psort_2011.pdf -- Ulteriori dettagli si possono trovare nelle pubblicazioni:
P. Bertasi, M. Bressan, E. Peserico. psort, yet another fast stable sorting software, ACM Journal of Experimental Algorithmics, vol. 16, 2011 --
P. Bertasi, M. Bonazza, M. Bressan, E. Peserico. Datamation: a quarter of a century and four orders of magnitude later. Proc. of IEEE CLUSTER 201
Paging with Dynamic Memory Capacity
Full text linkWe study a generalization of the classic paging problem that allows the amount of available memory to vary over time - capturing a fundamental property of many modern computing realities, from cloud computing to multi-core and energy-optimized processors.
It turns out that good performance in the "classic" case provides no performance guarantees when memory capacity fluctuates: roughly speaking, moving from static to dynamic capacity can mean the difference between optimality within a factor 2 in space and time, and suboptimality by an arbitrarily large factor. More precisely, adopting the competitive analysis framework, we show that some online paging algorithms, despite having an optimal (h,k)-competitive ratio when capacity remains constant, are not (3,k)-competitive for any arbitrarily large k in the presence of minimal capacity fluctuations.
In this light it is surprising that several classic paging algorithms perform remarkably well even if memory capacity changes adversarially - in fact, even without taking those changes into explicit account! In particular, we prove that LFD still achieves the minimum number of faults, and that several classic online algorithms such as LRU have a "dynamic" (h,k)-competitive ratio that is the best one can achieve without knowledge of future page requests, even if one had perfect knowledge of future capacity fluctuations. Thus, with careful management, knowing/predicting future memory resources appears far less crucial to performance than knowing/predicting future data accesses.
We characterize the optimal "dynamic" (h,k)-competitive ratio exactly, and show it has a somewhat complex expression that is almost but not quite equal to the "classic" ratio k/(k-h+1), thus proving a strict if minuscule separation between online paging performance achievable in the presence or absence of capacity fluctuations
Content attribution ignoring content
No full textCan we tell the author of a message, without reading the message? This work tackles authorship analysis through features that ignore the explicit content of a contribution - informally, those that can be computed even if every character in the body of a message (but not metadata such as timing or \likes") is replaced by an X. Focusing on forum posts, we distil a case-study set of these content-agnostic features, and prove its viability for authorship verification and attribution, using data from four online forums (of different size, language, and topic). A simple classification testbed, relying exclusively on content-agnostic features, confirms the author of a message with 76% accuracy, and discriminates between two candidate authors with 94% accuracy. Being able to re-identify a user without looking at the content of her contributions poses a serious threat to common data anonymization practices
Peserico (Anna). Le brocche « a fungo » fenicie nel Mediterraneo. Tipologia e cronologia.
No full textDebergh Jacques. Peserico (Anna). Le brocche « a fungo » fenicie nel Mediterraneo. Tipologia e cronologia.. In: Revue belge de philologie et d'histoire, tome 80, fasc. 1, 2002. Antiquite - Oudheid. pp. 336-337
Peserico (Anna). Le brocche « a fungo » fenicie nel Mediterraneo. Tipologia e cronologia.
No full textDebergh Jacques. Peserico (Anna). Le brocche « a fungo » fenicie nel Mediterraneo. Tipologia e cronologia.. In: Revue belge de philologie et d'histoire, tome 80, fasc. 1, 2002. Antiquite - Oudheid. pp. 336-337
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