Deutsche Telekom

About: Deutsche Telekom is a company organization based out in Welwyn Garden City, United Kingdom. It is known for research contribution in the topics: Telecommunications network & Signal. The organization has 3473 authors who have published 5208 publications receiving 65429 citations. The organization is also known as: DTAG & German Telecom.

Detecting real life anger

Abstract: Acoustic anger detection in voice portals can help to enhance human computer interaction. A comprehensive voice portal data collection has been carried out and gives new insight on the nature of real life data. Manual labeling revealed a high percentage of non-classifiable data. Experiments with a statistical classifier indicate that, in contrast to pitch and energy related features, duration measures do not play an important role for this data while cepstral information does. Also in a direct comparison between Gaussian Mixture Models and Support Vector Machines the latter gave better results.

The complexity of obstruction-free implementations

Abstract: Obstruction-free implementations of concurrent objects are optimized for the common case where there is no step contention, and were recently advocated as a solution to the costs associated with synchronization without locks. In this article, we study this claim and this goes through precisely defining the notions of obstruction-freedom and step contention. We consider several classes of obstruction-free implementations, present corresponding generic object implementations, and prove lower bounds on their complexity. Viewed collectively, our results establish that the worst-case operation time complexity of obstruction-free implementations is high, even in the absence of step contention. We also show that lock-based implementations are not subject to some of the time-complexity lower bounds we present.

Web search clickstreams

Abstract: Search engines are a vital part of the Web and thus the Internet infrastructure. Therefore understanding the behavior of users searching the Web gives insights into trends, and enables enhancements of future search capabilities. Possible data sources for studying Web search behavior are either server-side logs or client-side logs. Unfortunately, current server-side logs are hard to obtain as they are considered proprietary by the search engine operators. Therefore we in this paper present a methodology for extracting client-side logs from the traffic exchanged between a large user group and the Internet. The added benefit of our methodology is that we do not only extract the search terms, the query sequences, and search results of each individual user but also the full clickstream, i.e., the result pages users view and the subsequently visited hyperlinked pages. We propose a finite-state Markov model that captures the user web searching and browsing behavior and allows us to deduce users' prevalent search patterns. To our knowledge, this is the first such detailed client-side analysis of clickstreams.

Power efficiency of optical versus electronic access networks

Abstract: Based on a model of a typical operator network we have compared the power consumption of different broadband access technologies and architectures especially DSL, FTTN + VDSL and FTTH. Even though power management improves the performance there is still clear advantage of FTTH with respect to energy efficiency.

Proceedings of the 9th ACM SIGCOMM conference on Internet measurement conference

Abstract: It is our great pleasure to welcome you to the 9th ACM Internet Measurement Conference -- IMC 2009. This year's conference continues its tradition of being the premier forum for the dissemination of research results on furthering our understanding of how to collect or analyze Internet measurements, to give insight into how the Internet behaves. We paid particular attention to uphold IMC's salient features: the explicit encouragement of publications re-appraising previous findings on new data sets (something traditionally relegated to journal publications), and the co-existence, in the program, of both full-length and short papers. Short papers are intended to convey exciting work in progress with potentially less mature results. This year, we raised the short paper size by one page to 7 pages (as opposed to 14 pages for full papers), in an attempt to relieve the difficulty authors usually face in fitting a full set of references in their short submissions. IMC is a very selective conference. This year, however, in response to the will of the IMC steering committee and without compromising on quality, a record number of 41 papers were accepted out of 183 submissions. More precisely, 27 full papers were accepted out of 115 submissions, and 14 short papers were accepted out of 68 submissions. As a consequence, the conference has now grown, for the first time, to a full 3-day, more inclusive program. In selecting the final program, we were assisted by 22 highly skilled technical program committee members, who put an incredible amount of time, effort and professionalism into the selection process. We are indebted to them, as well as to our external reviewers, for their help and thank them all for their dedication. The paper selection process was carried out as 4 successive phases: in phase 1, all submitted papers received 2 reviews; this phase identified 123 papers for further consideration and that received at least an additional review during the second reviewing phase. This was followed by a phase of intensive on-line discussions which resulted in 80 papers being selected for final consideration and thorough discussions during the TPC meeting that was held in Berlin, Germany in July, and which was attended by the vast majority of the program committee members.