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—Research to date has analyzed the Internet AS-level topology at a worldwide level of detail. Every inference found for an AS is extrapolated from the global set of AS paths gathered from public monitors, independently of the geographic location of the ASes. This approach is useful when the Internet is analyzed at a very coarse level. However, it may be(More)
In the last decade many studies have used the Internet AS-level topology to perform several analyses, from discovering its graph properties to assessing its impact on the effectiveness of worm-containment strategies. Yet, the BGP data typically used to reveal the topologies are far from being complete. Our contribution is three-fold. Firstly, we analyse BGP(More)
The structure of the Internet is still unknown even though it provides services for most of the world. Its current configuration is the result of complex economic interactions developed in the last 20 years among important carriers and ISPs. Although with only some success, in the last few years some research has tried to shed light on the economic(More)
The pantograph-overhead contact wire system is investigated by using an infrared camera. As the pantograph has a vertical motion because of the non-uniform elasticity of the catenary, in order to detect the temperature along the strip from a sequence of infrared images, a segment-tracking algorithm, based on the Hough transformation, has been employed. An(More)
Several works over the past few years have shown that the Internet AS-level topology is partially hidden from the current Internet measurement infrastructures. Most have focused on the incompleteness of the connectivity extracted from BGP data. A few have analysed the connectivity collected by traceroute measurement infrastructures showing the amount of(More)
—An experimental method is proposed to estimate all design specifications represented by circles in the Nyquist plane (e.g., phase margin, sensitivity, and closed-loop bandwidth) in case of closed-loop dc/dc switching converters. The method is based on the complete root contour (CRC) analysis in the root locus plane. All typical specifications for(More)
International interest is growing for improving performance of the rail transport system. A crucial problem for railway companies is to prevent damages to the overhead line equipment and to pantographs. A brief overview of our research activities is addressed , in the fields of active pantographs and advanced methods for measuring the quality of the current(More)
In this paper a new performance index, based on a periodic evaluation of the integral of the absolute error, is proposed for monitoring switching DC-DC converters. Parameter variations or operating condition modifications can be easily estimated using a relay closed loop tests without stopping the process. An interesting practical application of such method(More)