Tecnologia da Informática Márcio Francisco Dutra e Campos

Archive for October, 2012

Caching in theory and practice

10.17.2012 · Posted in Eng. Computação

“The Dropbox mobile client caches frequently-accessed files, so that viewing them doesn’t require a network call. Both our Android and iOS clients use the LRU caching algorithm, which often selects good files to cache. But while this is the usual algorithm for caching, I wondered: are there better algorithms, and if not, why is LRU ...

How your phone knows where it is

10.17.2012 · Posted in Eng. Computação

“Assisted GPS is used by millions of smartphone users every day to get driving directions, find places, and find themselves. As it turns out, the good old GPS satellite system, by itself, works very slowly and often not at all when you”re indoors or walking beneath tall buildings. That”s why the GPS software in your ...

An Empirical Study of Zero-Day Attacks

10.17.2012 · Posted in Direito Geral, Eng. Computação

“Little is known about the duration and prevalence of zero-day attacks, which exploit vulnerabilities that have not been disclosed publicly. Knowledge of new vulnerabilities gives cyber criminals a free pass to attack any target of their choosing, while remaining undetected. Unfortunately, these serious threats are dicult to analyze, because, in general, data is not available until after an attack is ...

What is static program analysis?

10.08.2012 · Posted in Eng. Computação

The halting problem asks whether the execution of a specific program for a given input will terminate. The halting problem is famous for being undecidable. This article illustrates some basic principles behind static analysis, and then builds an analyzer for a register-based machine language in Racket. Leia mais em: http://matt.might.net/articles/intro-static-analysis/ ...

Utility for Measuring Network Performance

10.08.2012 · Posted in Eng. Computação

PsPing is a command-line utility for measuring network performance. In addition to standard ICMP ping functionality, it can report the latency of connecting to TCP ports, the latency of TCP round-trip communication between systems, and the TCP bandwidth available to a connection between systems. Leia mais em: http://technet.microsoft.com/en-us/sysinternals/jj729731 ...