Fak. 4 Elektrotechnik und Informatik

1160 Items

Recent Submissions
Automated Analysis of Eye Tracking Movements

Ruetsche, Adrian ; Baumann, Ann ; Jiang, Xiaoyi ; Mojon, Daniel (2003)

Objective: To present a quick algorithm to automatically analyze the raw data acquired by a photo-oculography (POG) system. Methods: We developed a simple algorithm for POG data analysis based on an extrapolation of missing values due to blinking and on exclusion of outliers using the robust mean and standard deviation. Results: POG curves of 4 children aged between 1.5 and 7 years are shown be...

Alternating current loss measurement of power cable conductors with large cross sections using electrical methods

Suchantke, René (2018)

High voltage power cables for bulk AC power transport use the Milliken conductor design from a certain cross section up to decrease transmission losses. It is not possible to reliably assess their AC losses by simulation or other calculation methods in advance, as the performance of this complex design strongly depends on manufacturing processes and quality. The exact knowledge of the AC resist...

Wideband GaN microwave power amplifiers with class-G supply modulation

Wolff, Nikolai (2018)

The continuous and rapidly growing demand for mobile communication access led worldwide to a major increase in the number of base stations to provide the sufficient coverage and quality of service. As a consequence, mobile communication networks have become a significant contributor to the worldwide energy consumption. The necessity to save operational cost and the increased energy awareness fu...

Managing cloud ecosystems

Slawik, Mathias (2018)

In recent years, the ever-growing proliferation of cloud services led to the creation of large cloud ecosystems. The most prominent example is the cloud ecosystem of Amazon Web Services (AWS), which now has over 8,000 partners and more than $ 18 billion in revenue in 2017. In addition to these "giants", many smaller ecosystems address more specific challenges. An example is the TRESOR cloud eco...

Enhancing the smoothness of joint motion induced by functional electrical stimulation using co-activation strategies

Ruppel, Mirjana ; Klauer, Christian ; Schauer, Thomas (2017-09-07)

The motor precision of today’s neuroprosthetic devices that use artificial generation of limb motion using Functional Electrical Stimulation (FES) is generally low. We investigate the adoption of natural co-activation strategies as present in antagonistic muscle pairs aiming to improve motor precision produced by FES. In a test in which artificial knee-joint movements were generated, we could i...

Modeling and characterization of PCB coils for inductive wireless charging

Curran, Brian ; Maaß, Uwe ; Fotheringham, Gerhard ; Stevens, Nobby ; Ndip, Ivan ; Lang, Klaus-Dieter (2015)

Wireless charging is emerging as a viable technology in many industries, including consumer, medical, and sensor electronics. An investigation of design principles is conducted for a wireless charging platform that is designed to charge devices of different sizes and technologies, using only through vias. It is shown that at a 5 mm separation distance, a coupling coefficient can be achieved whi...

In-ear photoplethysmography for central pulse waveform analysis in non-invasive hemodynamic monitoring

Tigges, Timo ; Rockstroh, Jonas ; Pielmuş, Alexandru-Gabriel ; Klum, Michael ; Feldheiser, Aarne ; Hunsicker, Oliver ; Orglmeister, Reinhold (2017)

In recent years, the analysis of the photoplethys-mographic (PPG) pulse waveforms has attracted much research focus. However, the considered signals are primarily recorded at the fingertips, which suffer from reduced peripheral perfusion in situations like hypovolemia or sepsis, rendering waveform analysis infeasible. The ear canal is not affected by cardiovascular centralization and could thus...

Correlation of arterial blood pressure to synchronous piezo, impedance and photoplethysmographic signal features

Pielmuş, Alexandru-Gabriel ; Osterland, Dennis ; Klum, Michael ; Tigges, Timo ; Feldheiser, Aarne ; Hunsicker, Oliver ; Orglmeister, Reinhold (2017)

In this paper we investigate which pulse wave pick-up technologies are well suited for blood pressure trend estimation. We use custom built hardware to acquire electrocardiographic, applanation-tonometric, photo- and impedance-plethysmographic signals during low intensity workouts. Beat-to-beat features and pulse wave runtimes are correlated to the reference arterial blood pressure. Temporal la...

Blockchain-based Supply Chain Traceability: Token Recipes model Manufacturing Processes

Westerkamp, Martin ; Victor, Friedhelm ; Küpper, Axel (2018)

Growing consumer awareness as well as manufacturers’ internal quality requirements lead to novel demands on supply chain traceability. Existing centralized solutions suffer from isolated data storage and lacking trust when multiple parties are involved. Decentralized blockchain-based approaches attempt to overcome these shortcomings by creating digital representations of physical goods to facil...

Spatial sampling of a driver’s visual field: characterising peripheral adaptation

Winter, Jan-Christoph (2018)

For the application of the recommended system of mesopic photometry of the Commission Internationale d'Eclairage (CIE) in road lighting design it is necessary to estimate the peripheral state of adaptation of a driver in an urban environment after dark. Estimating the state of adaptation of a driver in the natural setting is not straightforward, because the visual scene is likely complex and i...

Stability, voltage performance and power sharing issues of inverter-based microgrids via LMI optimization

Truong, Duc Trung (2018)

Numerous small distributed energy resources (DERs) form a new generation of power systems - the microgrid. In general, a microgrid stands for a cluster of DERs, which can collectively operate as an individual low-voltage power system during islanded mode. A microgrid can also be operated in connected mode with a large power system. DERs are often interfaced to a microgrid through power electron...

Adhesion mechanism between laser sputtered materials, Copper and Aluminum on Silicon substrate

Azhdast, Mohammad Hossein (2018)

The present study aims to the novel technique by laser deposition of Aluminum and Copper nano particles on silicon wafer substrate. Thin µm films have been deposited from one-side coated glass to Silicon wafers by sputtering nano particles using laser radiation. The Distance between donor film and substrate was up to several 100 µm, and it has been optimized as 300 µm. As soon as the laser en...

Entwicklung einer Hybridsolarzelle mit CuInSe2 und den kleinen organischen Molekülen ZnPc und C60

Morzé, Natascha von (2018)

Bei der vorliegenden Arbeit handelt es sich um eine Machbarkeitsstudie einer Hybridsolarzelle mit dem anorganischen Absorber CuInSe2 und den kleinen organischen Molekülen ZnPc und C60. Ähnlich wie bei einer Tandemsolarzelle soll bei diesem Konzept der Absorber CuInSe2 die Sonnenenergie im Infrarotbereich in Strom umwandeln und das Farbstoffmolekül ZnPc im sichtbaren Bereich. Das Fulleren C60 di...

Tentative designs for X- and W-band klystrons with corkscrew-modulated hollow electron beam

Nie, Jiwei (2018)

Klystrons employing a hollow beam provides much higher RF power, compared to solid state amplifiers and compared to klystrons employing a pencil beam. This is the most important reason for the development of klystrons employing a hollow beam. This paper presents tentative designs for X-band and W-band klystrons with corkscrew-modulated hollow electron beam. The X-band TM110-mode klystron opera...

Application-Specific Cache and Prefetching for HEVC CABAC Decoding

Habermann, Philipp ; Chi, Chi Ching ; Álvarez-Mesa, Mauricio ; Juurlink, Ben (2017)

Context-based Adaptive Binary Arithmetic Coding (CABAC) is the entropy coding module in the HEVC/H.265 video coding standard. As in its predecessor, H.264/AVC, CABAC is a well-known throughput bottleneck due to its strong data dependencies. Besides other optimizations, the replacement of the context model memory by a smaller cache has been proposed for hardware decoders, resulting in an improve...

Dynamic resource allocation for distributed dataflows

Thamsen, Lauritz (2018)

Distributed dataflow systems enable users to process large datasets in parallel on clusters of commodity nodes. Users temporarily reserve resources for their batch processing jobs in shared clusters through containers. A container in this context is an abstraction of a specific amount of resources, typically a number of virtual cores and an amount of memory. For their production batch jobs, use...

Distortion in microwave class-S power amplifiers

AL-Mozani, Dhamia (2018)

To tackle the critical challenge in microwave transmitters of achieving high efficiency at higher power back-offs, class-S power amplifier, as promising class of operation, attracts the attention since some time ago. It provides a theoretical efficiency of 100% regardless of power back-off which is required nowadays in wireless communication infrastructure. The current work focused on the class...

E²MC: Entropy Encoding Based Memory Compression for GPUs

Lal, Sohan ; Lucas, Jan ; Juurlink, Ben (2017)

Modern Graphics Processing Units (GPUs) provide much higher off-chip memory bandwidth than CPUs, but many GPU applications are still limited by memory bandwidth. Unfortunately, off-chip memory bandwidth is growing slower than the number of cores and has become a performance bottleneck. Thus, optimizations of effective memory bandwidth play a significant role for scaling the performance of GPUs....

Functional regression of densities with application to the simulation of molecular dynamics

Brockherde, Felix (2018)

Applications of machine learning have shown promising results modeling the non-interacting kinetic energy functional in 1-D. This holds the promise of enabling orbital-free density functional theory calculations, by-passing the computationally expensive Kohn-Sham equations. This would yield substantial savings in computer-time so that larger systems or longer time scales can be simulated. ...

Investigation of hybrid organic-inorganic lead halide perovskites by modulated surface photovoltage spectroscopy

Omondi, Celline Awino (2018)

Hybrid organic-inorganic metal halide perovskites (called here perovskites) have emerged as a new group of materials for highly efficient solar cells (SCs) based on earth abundant elements which can be processed from solutions at low temperature. CH3NH3Pb(I1-xBrx)3 perovskite films were studied in the thesis since it belongs to the materials which are of great interest for top SCs in tandem SCs...