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A promising next step to improve silicone composite insulators is to add cost-efficient, light-weight filling materials to the cost-intensive silicone. Therefore, in our research, hollow micro spheres (HMS) are used to create syntactic foam (Figure 1). Syntactic foam has already been investigated for high voltage indoor applications, based on epoxy resin and silicone gel [1-3]. Hence, the knowledge...
One of the most important objectives of anesthesiologists is to ensure an adequate depth of anesthesia for patients during surgeries. The adequate depth of anesthesia does not mean patient's sleeping as deep as possible but it means as deep as necessary to prevent awareness without unintentional overloading the patient with high doses of the anesthesia's drug. Overloading patients that already have...
We present terahertz lenses made of polymeric compounds which provide a better focusing capability and an increased functionality than state of the art lenses made of pure base polymers. This is achieved by employing mixtures between polypropylene and alumina as well as polypropylene and zinc sulfide which allows for a significant increase of the refractive index of the lens base material.
An overview about research activities in the field of high frequency integrated circuits and communication systems performed within the German cluster project Cool Silicon is given. Cool Silicon is located around Dresden/Silicon Saxony/Germany and features around 50 projects and 100 partners from industry and research institutions, and aims at significantly increasing the energy efficiency of information...
In this paper, a 60 GHz system demonstrator for multi-Gb/s, short-range, line-of-sight communications is presented. The system utilizes a highly efficient receiver architecture with phase noise suppression capability, which performs carrier synchronization in the analog domain, eliminating the need for high speed, high precision analog-to-digital converters. In the presented demonstrator, with only...
Recently, we have shown that a considerable increase in image acquisition speed can be achieved by employing a dedicated grating/lens system, converting spectral into spatial resolution. Here, we present first results of spectrum to space computed THz tomography, using this novel imaging approach.
We present first results of pulsed THz emission from low temperature (LT) MBE grown Be-doped InGaAs/InAlAs multi-nanolayer structures at an excitation wavelength of 1030 nm. The spectra obtained reach 3 THz. We further investigate the material's relaxation time constants by differential transmission experiments.
This paper proposes an alternative to expensive means for VoIP speech quality measurement. While current applications and measurement devices on the market are very expensive, the authors propose a solution based on open-source components that allows the determination of the Mean Opinion Score (MOS) value according the Perceptual Evaluation of Speech Quality (PESQ) test methodology.
Visually impaired or blind people have a reduced ability to perceive their environment. The accessible environment is drastically constrained by the length of canes. Numerous approaches e.g. ultrasound enhanced canes did not solve the problem. Most of them use the auditory system for information transfer, which is not appreciated by the blind because acoustics are already involved in the spatial orientation...
This paper describes the integration of the presence management service into existing IP Multimedia Subsystem (IMS) laboratory infrastructures. Both laboratories - NGNlab in Bratislava and the laboratory in Leipzig - use the Fraunhofer OpenIMS as core components for their testing IMS environment (i.e. Call Session Control Functions (CSCF), Home Subscriber Server (HSS)). The virtualization of these...
This paper describes the general concept of combinational/blended services for IP-based Television (IPTV) services in next generation networks towards its service oriented architecture concept (SOA). Besides introducing general approaches of service reusability (SOA concepts), the service enables (e.g. presence, notification, messaging) as application service function in next generation networks will...
Over recent years, the explosion of radio access technologies and wireless networking devices has triggered the intensive use of nomadic computing. Mobile devices receive intermittent network access, and alternate between connected and disconnected states. However, today's personal gadgets have more networking capabilities, wireless network coverage is becoming ubiquitous, and always-on IP-based services...
The paper summarizes and proofs that existing VoIP programs are powerful and flexible enough to build complex applications. The applications are independent and can be used either stand-alone or within carrier-grade Telco environments. The described example of building a call center application (outbound calling) shows the power that lies not only in existing open-source Session Initiation Protocol...
This article focuses on the interconnection border control function (IBCF) entity in the current IP multimedia subsystem (IMS) architecture. Based on the analysis of various types of IMS interconnection scenarios, we describe our proof-of concept solution. We evaluate the signaling in several interconnected IMS domains using open sip express router (OpenSER) based prototype of IBCF.
Respiratory system mechanics are nonlinear, i.e. may depend on volume, pressure and flow [1, 2]. A new multipoint method is presented for simultaneously determining dynamic compliance and resistance based on the equation of motion. The adaptive slice method (ASM) is derived from the slice method [4], which divides a breathing cycle into several fixed volume slices. For each slice, one compliance value...
Alveolar microscopy allows in vivo inspection of changes in alveolar geometry during mechanical ventilation in animal models. It is currently an open question how the size of alveoli relates to cyclic mechano-stimulation during ventilation. Determining the changes in alveolar geometry from recorded videos would provide new insights into alveolar dynamics. But the evaluation of thousands of video frames...
Annually 133.000 people world-wide get sick on malign melanoma, tendency increasing. The purpose of this study is the early diagnosis of malignant skin cancer. At the moment the dermatologists are screening for anomalies at the relevant lesion by examining the skin area with a microscope. To determine changes, another scan has to be taken in a follow-up session after a time period of about 15-20 weeks...
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