Fak. 4 Elektrotechnik und Informatik

1052 Items

Recent Submissions
Machine learning of accurate energy-conserving molecular force fields

Chmiela, Stefan ; Tkatchenko, Alexandre ; Sauceda, Huziel E. ; Poltavsky, Igor ; Schütt, Kristof T. ; Müller, Klaus-Robert (2017)

Using conservation of energy - a fundamental property of closed classical and quantum mechanical systems - we develop an efficient gradient-domain machine learning (GDML) approach to construct accurate molecular force fields using a restricted number of samples from ab initio molecular dynamics (AIMD) trajectories. The GDML implementation is able to reproduce global potential energy surfaces of...

Quasi one dimensional transport in individual electrospun composite nanofibers

Avnon, A. ; Wang, B. ; Zhou, S. ; Datsyuk, V. ; Trotsenko, S. ; Grabbert, N. ; Ngo, H.-D. (2014)

We present results of transport measurements of individual suspended electrospun nanofibers Poly(methyl methacrylate)-multiwalled carbon nanotubes. The nanofiber is comprised of highly aligned consecutive multiwalled carbon nanotubes. We have confirmed that at the range temperature from room temperature down to ∼60 K, the conductance behaves as power-law of temperature with an exponent of α ∼ 2...

Insights into the reversibility of aluminum graphite batteries

Elia, Giuseppe Antonio ; Hasa, Ivana ; Greco, Giorgia ; Diemant, Thomas ; Marquardt, Krystan ; Hoeppner, Katrin ; Behm, R. Jürgen ; Hoell, Armin ; Passerini, Stefano ; Hahn, Robert (2017)

Herein we report a novel study on the reaction mechanism of non-aqueous aluminum/graphite cell chemistry employing 1-ethyl-3-methylimidazolium chloride:aluminum trichloride (EMIMCl:AlCl3) as the electrolyte. This work highlights new insights into the reversibility of the anion intercalation chemistry besides confirming its outstanding cycle life exceeding 2000 cycles, corresponding to more than...

MAC Based Dynamic VLAN Tagging with OpenFlow for WLAN Access Networks

Koerner, Marc ; Kao, Odej (2016)

Many network device vendors are providing a vendor specific VLAN based access solutions for WLAN clients. This applications allows network operators to specify WLAN devices which automatically fall into their department specific networks ans allows them to access their local resources like e.g. printers. The configuration of these VLAN mappings is usually manufacturer specific and depends also ...

A System Architecture for Real-time Anomaly Detection in Large-scale NFV Systems

Gulenko, Anton ; Wallschläger, Marcel ; Schmidt, Florian ; Kao, Odej ; Liu, Feng (2016)

Virtualization as a key IT technology has developed to a predominant model in data centers in recent years. The flexibility regarding scaling-out and migration of virtual machines for seamless maintenance has enabled a new level of continuous operation and changed service provisioning significantly. Meanwhile, services from domains striving for highest possible availability – e.g. from the tele...

A Framework for Handling Heterogeneous M2M Traffic

Elmangoush, Asma ; Corici, Andreea Ancuta ; Steinke, Ronald ; Corici, Marius ; Magedanz, Thomas (2015)

Sensors, actuators and devices that compose the Internet of Things (IoT) world are becoming more diverse every day in terms of capabilities and amount of generated traffic. Current Machine-to-Machine (M2 M) communication standardization efforts try to formalize the interfaces between M2 M nodes based on the perspective of exchanging uniform small data size with low sampling rate only. However, ...

The Influence of ITO Dopant Density on J-V Characteristics of Silicon Heterojunction Solar Cells: Experiments and Simulations

Kirner, Simon ; Hartig, Manuel ; Mazzarella, Luana ; Korte, Lars ; Frijnts, Tim ; Scherg-Kurmes, Harald ; Ring, Sven ; Stannowski, Bernd ; Rech, Bernd ; Schlatmann, Rutger (2015)

The TCO/a-Si:H(p) contact is a critical part of the silicon heterojunction solar cell. At this point, holes from the emitter have to recombine loss free with electrons from the TCO. Since tunneling is believed to be the dominant transport mechanism, a high dopant density in both adjacent layers is critical. In contrast to this, it has been reported that high TCO dopant density can reduce field ...

An intelligent health assistant for migrants

Plumbaum, Till ; Narr, Sascha ; Schwartze, Veit ; Hopfgartner, Frank ; Albayrak, Sahin (2013)

Preventive health is becoming an increasingly important part of our society. In addition to improving people’s personal well being, another positive effect is the reduction of costs for medical treatments that put a high burden on individuals and health care providers. Despite these advantages, preventive health services are still not used at a desired level. This is especially true for people ...

Workshop on benchmarking adaptive retrieval and recommender systems - BARS 2013

Castells, Pablo ; Hopfgartner, Frank ; Said, Alan ; Lalmas, Mounia (2013)

Evaluating adaptive and personalized information retrieval techniques is known to be a difficult endeavor. The rapid evolution of novel technologies in this scope raises additional challenges that further stress the need for new evaluation approaches and methodologies. The BARS 2013 workshop seeks to provide a specific venue for work on novel, personalization-centric benchmarking approaches to ...

Detecting violent content in Hollywood movies by mid-level audio representations

Acar, Esra ; Hopfgartner, Frank ; Alyabrak, Sahin (2013)

Movie violent content detection e.g., for providing automated youth protection services is a valuable video content analysis functionality. Choosing discriminative features for the representation of video segments is a key issue in designing violence detection algorithms. In this paper, we employ mid-level audio features which are based on a Bag-of-Audio Words (BoAW) method using Mel-Frequency ...

Violence detection in Hollywood movies by the fusion of visual and mid-level audio cues

Acar, Esra ; Hopfgartner, Frank ; Albayrak, Sahin (2013)

Detecting violent scenes in movies is an important video content understanding functionality e.g., for providing automated youth pro- tection services. One key issue in designing algorithms for violence detection is the choice of discriminative features. In this paper, we employ mid-level audio features and compare their discriminative power against low-level audio and visual features. We fuse ...

Activating the Crowd: Exploiting User-Item Reciprocity for Recommendation

Larson, Martha ; Said, Alan ; Shi, Yue ; Cremonesi, Paolo ; Tikk, Domonkos ; Karatzoglou, Alexandros ; Baltrunas, Linas ; Geurts, Jozef ; Anguera, Xavi ; Hopfgartner, Frank (2013-10-12)

Recommender systems have always faced the problem of sparse data. In the current era, however, with its demand for highly personalized, real-time, context-aware recommendation, the sparse data problem only threatens to grow worse. Crowd-sourcing, specifically, outsourcing micro-requests for information to the crowd, opens new possibilities to fight the sparse data challenge. In this paper, we l...

Workshop and Challenge on News Recommender Systems

Tavakolifard, Mozhgan ; Atle Gulla, Jon ; Almeroth, Kevin C. ; Hopfgartner, Frank ; Kille, Benjamin ; Plumbaum, Till ; Lommatzsch, Andreas ; Brodt, Torben ; Bucko, Arthur ; Heintz, Tobias (2013-10-12)

Recommending news articles entails additional requirements to recommender systems. Such requirements include special con- sumption patterns, fluctuating item collections, and highly sparse user profiles. This workshop (NRS’13@RecSys) brought together researchers and practitioners around the topics of designing and evaluating novel news recommender systems. Additionally, we offered a challenge a...

The plista dataset

Kille, Benjamin ; Hopfgartner, Frank ; Brodt, Torben ; Heintz, Tobias (2013)

Releasing datasets has fostered research in fields such as information retrieval and recommender systems. Datasets are typically tailored for specific scenarios. In this work, we present the plista dataset. The dataset contains a collection of news articles published on 13 news portals. Additionally, the dataset comprises user interactions with those articles. We inctroduce the dataset’s main c...

Perceived and Actual Role of Gamification Principles

Meder, Michael ; Plumbaum, Till ; Hopfgartner, Frank (2013-12-09)

Although gamification has successfully been applied in office scenarios, it remains unclear how employees really feel about the introduction of a gamified system at their workplace. In this paper, we address this issue from two directions. First, we present the outcome of an online survey where we analyze users’ opinion about gamification in a workplace environment. Then, we analyze the interac...

TACO: A scheduling scheme for parallel applications on multicore architectures

Schönherr, Jan H. ; Juurlink, Ben ; Richling, Jan (2014)

While multicore architectures are used in the whole product range from server systems to handheld computers, the deployed software still undergoes the slow transition from sequential to parallel. This transition, however, is gaining more and more momentum due to the increased availability of more sophisticated parallel programming environments. Combined with the ever increasing complexity of mu...

Reducing HEVC encoding complexity using two-stage motion estimation

Cebrián-Márquez, Gabriel ; Chi, Ching Chi ; Martínez, José Luis ; Cuenca, Pedro ; Sanz-Rodríguez, Sergio ; Álvarez Mesa, Mauricio ; Juurlink, Ben (2015)

We propose a technique for optimizing the High Efficiency Video Coding (HEVC) encoder by reducing the number of operations performed in the motion estimation stage. The technique is based on the fact that a significant number of motion estimation operations are performed repetitively for the same image samples, but for different block partition sizes. By decoupling the initial motion estimation...

Front-side interface engineering for liquid-phase crystallized silicon solar cells on glass

Preissler, Natalie (2018)

Liquid-phase crystallization (LPC) is a process technology to fabricate thin (< 30 μm) crystalline silicon layers on glass substrates. To this end, as-deposited amorphous or nano-crystalline silicon layers on glass are molten locally with a high energy density source (laser or electron beam). Subsequently, the silicon cools down and crystallizes. Resulting layers exhibit grains with a length of...

Protective redundancy overhead reduction using instruction vulnerability factor

Borodin, Demid ; Juurlink, Ben (2010)

Due to modern technology trends, fault tolerance (FT) is acquiring an ever increasing research attention. To reduce the overhead introduced by the FT features, several techniques have been proposed. One of these techniques is Instruction-Level Fault Tolerance Configurability (ILCOFT). ILCOFT enables application developers to protect different instructions at varying degrees, devoting more resou...

Parallel scalability and efficiency of HEVC parallelization approaches

Chi, Ching Chi ; Álvarez-Mesa, Mauricio ; Juurlink, Ben ; Clare, Gordon ; Henry, Félix ; Pateux, Stéphane ; Thomas, Schierl (2012)

Unlike H.264/advanced video coding, where parallelism was an afterthought, High Efficiency Video Coding currently contains several proposals aimed at making it more parallel-friendly. A performance comparison of the different proposals, however, has not yet been performed. In this paper, we will fill this gap by presenting efficient implementations of the most promising parallelization proposal...