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We present what we believe to be the first thorough characterization of <i>live</i> streaming media content delivered over the Internet. Our characterization of over 3.5 million requests spanning a 28-day period is done at three increasingly granular levels, corresponding to clients, sessions, and transfers. Our findings support two important conclusions.(More)
The previous research on cluster-based servers has focused on homogeneous systems. However, real-life clusters are almost invariably heterogeneous in terms of the performance, capacity, and power consumption of their hardware components. In this paper, we argue that designing efficient servers for heterogeneous clusters requires defining an efficiency(More)
Understanding the nature and characteristics of e-business workloads is a crucial step to improve the quality of service offered to customers in electronic business environments. However, the variety and complexity of the interactions between customers and sites make the characterization of e-business workloads a challenging problem. Using a multi-layer(More)
The rapid increase in the volume of unsolicited commercial e-mails, also known as spam, is beginning to take its toll in system administrators, business corporations and end-users. Widely varying estimates of the cost associated with spam are available in the literature. However, a quantitative analysis of the determinant characteristics of spam traffic is(More)
Due to the increasing amount of information present on the Web, Automatic Document Classification (ADC) has become an important research topic. ADC usually follows a standard supervised learning strategy, where we first build a model using preclassified documents and then use it to classify new unseen documents. One major challenge for ADC in many scenarios(More)
— Predicting trends in the stock market is a subject of major interest for both scholars and financial analysts. The main difficulties of this problem are related to the dynamic, complex, evolutive and chaotic nature of the markets. In order to tackle these problems, this work proposes a day-trading system that " translates " the outputs of an artificial(More)
The peak power consumption of hardware components affects their powersupply, packaging, and cooling requirements. When the peak power consumption is high, the hardware components or the systems that use them can become expensive and bulky. Given that components and systems rarely (if ever) actually require peak power, it is highly desirable to limit power(More)