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.

Method and device for reducing the formation of speckle on a projection screen

Abstract: The invention relates to a method and a device for reducing the speckle that is formed on a projection display when a coherent light source (1) is used. Before being projected, the light coming from the light source strikes an electrically controllable optical element (4) with a spatially inhomogeneous index of refraction and penetrates said optical element, whereby the index of refraction within the period of projection is temporally altered. This leads to the averaging out of the speckle pattern on the projection screen (6). A multimode light source is preferably used for illumination and/or the light coming from the light source is split into several spatial modes in order to increase the effect. The light from the light source is preferably split by being coupled into a multimode light-conducting fibre. Said optical element is advantageously a liquid crystal element consisting of at least two liquid crystal layers, to which a position-dependent voltage is applied in order to produce a position-dependent index of refraction and whose birefringence is compensated by the appropriate alignment of the layers in relation to each other.

A device for inputting data

Abstract: The device comprises a grid of photodetectors which is coordinated with a grid of light-emitting picture elements. The light emitted by at least one of the picture elements is reflected to at least one of the photodetectors when an object approaches the device. The output signals produced by the photodetectors indicate which of the photodetectors have received reflected light.

Groupthink and Peer Pressure: Social Influence in Online Social Network Groups

Abstract: In this paper, we present a horizontal view of social influence, more specifically a quantitative study of the influence of neighbours on the probability of a particular node to join a group, on four popular Online Social Networks (OSNs), namely Orkut, YouTube, LiveJournal, and Flickr. Neighbours in OSNs have a mutually acknowledged relation, most often defined as friendship, and they are directly connected on a graph of a social network. Users in OSNs can also join groups of users. These groups represent common areas of interest.We present a simple social influence model to describe and explain the group joining process of users on OSNs. To this end, we extract the social influence from data sets of OSNs of a million sample nodes. One of our findings is that a set of neighbours in the OSN is about $100$ times more powerful in influencing a user to join a group than the same number of strangers.

All Users Are (Not) Equal - The Influence of User Characteristics on Perceived Quality, Modality Choice and Performance

Abstract: This study investigated if cognitive skills, mood, attitudes and personality traits influence quality perceptions, modality choice (speech vs. touch), and performance. It was shown that attitudes and mood are related to quality perceptions while performance is linked to personality traits. Modality choice is influenced by attitudes and personality. Cognitive abilities had no effect.

Comparison of approaches for instrumentally predicting the quality of text-to-speech systems.

Abstract: In this paper, we compare and combine different approaches for instrumentally predicting the perceived quality of Text-to-Speech systems First, a log-likelihood is determined by comparing features extracted from the synthesized speech signal with features trained on natural speech Second, parameters are extracted which capture quality-relevant degradations of the synthesized speech signal Both approaches are combined and evaluated on three auditory test databases The results show that auditory quality judgments can in many cases be predicted with a sufficiently high accuracy and reliability, but that there are considerable differences, mainly between male and female speech samples