Institut für Softwaretechnik und Theoretische Informatik

234 Items

Recent Submissions
Real-time robustness evaluation of regression based myoelectric control against arm position change and donning/doffing

Hwang, Han-Jeong ; Hahne, Janne Mathias ; Müller, Klaus-Robert (2017)

There are some practical factors, such as arm position change and donning/doffing, which prevent robust myoelectric control. The objective of this study is to precisely characterize the impacts of the two representative factors on myoelectric controllability in practical control situations, thereby providing useful references that can be potentially used to find better solutions for clinically ...

Learning from label proportions in brain-computer interfaces

Hübner, David ; Verhoeven, Thibault ; Schmid, Konstantin ; Müller, Klaus-Robert ; Tangermann, Michael ; Kindermans, Pieter-Jan (2017)

Objective Using traditional approaches, a brain-computer interface (BCI) requires the collection of calibration data for new subjects prior to online use. Calibration time can be reduced or eliminated e.g., by subject-to-subject transfer of a pre-trained classifier or unsupervised adaptive classification methods which learn from scratch and adapt over time. While such heuristics work well in p...

Universal exact algorithm for globally augmented MAP inference in structured prediction

Bauer, Alexander (2017)

The ultimate goal of discriminative learning is to train a prediction system by optimizing a desired measure of performance. Unlike in the standard learning scenario with univariate real-valued outputs, in structured prediction we aim at predicting a structured label corresponding to complex objects such as sequences, alignments, sets, or graphs. Here, structural support vector machine (SSVM) e...

Visualization-driven data aggregation

Jugel, Uwe (2017)

Visual analysis of high-volume numerical data is traditionally required for understanding sensor data in manufacturing and engineering scenarios. Today, the visual analysis of any kind of big data has become ubiquitous and is a most-wanted feature for data analysis tools. It is vital for commerce, finance, sales, and an ever-growing number of industries, whose data are traditionally stored in r...

Secure remote service execution for web media streaming

Mikityuk, Alexandra (2017)

Through continuous advancements in streaming and Web technologies over the past decade, the Web has become a platform for media delivery. Web standards like HTML5 have been designed accordingly, allowing for the delivery of applications, high-quality streaming video, and hooks for interoperable content protection. Efficient video encoding algorithms such as AVC/HEVC and streaming protocols ...

Structural graph theory meets algorithms: covering and connectivity problems in graphs

Akhoondian Amiri, Saeed (2017)

Structural graph theory proved itself a valuable tool for designing efficient algorithms for hard problems over recent decades. We exploit structural graph theory to provide novel techniques and algorithms for covering and connectivity problems. First, we focus on the Local model of distributed computing. In the Local model, minimizing the number of communication rounds is the main goal. We ex...

Zero training for BCI – Reality for BCI systems based on event-related potentials

Tangermann, Michael ; Kindermans, Pieter-Jan ; Schreuder, Martijn ; Schrauwen, Benjamin ; Müller, Klaus-Robert (2013)

This contribution reviews how usability in Brain- Computer Interfaces (BCI) can be enhanced. As an example, an unsupervised signal processing approach is presented, which tackles usability by an algorithmic improvement from the field of machine learning. The approach completely omits the necessity of a calibration recording for BCIs based on event-related potential (ERP) paradigms. The positive...

The hybrid brain-computer interface: a bridge to assistive technology?

Müller-Putz, Gernot R. ; Schreuder, Martijn ; Tangermann, Michael ; Leeb, R. ; Millán del, R. J. (2013)

Brain-Computer Interfaces (BCIs) can be extended by other input signals to form a so-called hybrid BCI (hBCI). Such an hBCI allows the processing of several input signals with at least one brain signal for control purposes, i.e. communication and environmental control. This work shows the principle, technology and application of hBCIs and discusses future objectives.

Identifying causal networks of neuronal sources from EEG/MEG data with the phase slope index: a simulation study

Ewald, Arne ; Avarvand, Forooz Shahbazi ; Nolte, Guido (2013)

The investigation of functional neuronal synchronization has recently become a growing field of research. With high temporal resolution, electroencephalography and magnetoencephalography are well-suited measurement techniques to identify networks of interacting sources underlying the recorded data. The analysis of the data in terms of effective connectivity, nevertheless, contains intrinsic iss...

Object-based audio reproduction and the audio scene description format

Geier, Matthias ; Ahrens, Jens ; Spors, Sascha (2010)

The introduction of new techniques for audio reproduction such as HRTF-based technology, wave field synthesis and higher-order Ambisonics is accompanied by a paradigm shift from channel-based to object-based transmission and storage of spatial audio. Not only is the separate coding of source signal and source location more efficient considering the number of channels used for reproduction by la...

Synchrony versus causality in distributed systems

Peters, Kirstin ; Schicke-Uffmann, Jens-Wolfhard ; Goltz, Ursula ; Nestmann, Uwe (2014)

Given a synchronous system, we study the question whether – or, under which conditions – the behaviour of that system can be realized by a (non-trivially) distributed and hence asynchronous implementation. In this paper, we partially answer this question by examining the role of causality for the implementation of synchrony in two fundamental different formalisms of concurrency, Petri nets and ...

Breaking symmetries

Peters, Kirstin ; Nestmann, Uwe (2014)

A well-known result by Palamidessi tells us that πmix (the π-calculus with mixed choice) is more expressive than πsep (its subset with only separate choice). The proof of this result analyses their different expressive power concerning leader election in symmetric networks. Later on, Gorla offered an arguably simpler proof that, instead of leader election in symmetric networks, employed the red...

Full abstraction for expressiveness: history, myths and facts

Gorla, Daniele ; Nestmann, Uwe (2014)

What does it mean that an encoding is fully abstract? What does it not mean? In this position paper, we want to help the reader to evaluate the real benefits of using such a notion when studying the expressiveness of programming languages. Several examples and counterexamples are given. In some cases, we work at a very abstract level; in other cases, we give concrete samples taken from the fiel...

Analysis of permutation equivalence in M-adhesive transformation systems with negative application conditions

Hermann, Frank ; Corradini, Andrea ; Ehrig, Hartmut (2014)

M-adhesive categories provide an abstract framework for a large variety of specification frameworks for modelling distributed and concurrent systems. They extend the well-known frameworks of adhesive and weak adhesive HLR categories and integrate high-level constructs such as attribution as in the case of typed attributed graphs. In the current paper, we investigate M-adhesive transformation sy...

Formal analysis of model transformations based on triple graph grammars

Hermann, Frank ; Ehrig, Hartmut ; Golas, Ulrike ; Orejas, Fernando (2014)

Triple graph grammars (TGGs) are a well-established concept for the specification and execution of bidirectional model transformations within model driven software engineering. Their main advantage is an automatic generation of operational rules for forward and backward model transformations, which simplifies specification and enhances usability as well as consistency. In this paper we present ...

M-adhesive transformation systems with nested application conditions. Part 1: parallelism, concurrency and amalgamation

Ehrig, Hartmut ; Golas, Ulrike ; Habel, Annegret ; Lambers, Leen ; Orejas, Fernando (2014)

Nested application conditions generalise the well-known negative application conditions and are important for several application domains. In this paper, we present Local Church–Rosser, Parallelism, Concurrency and Amalgamation Theorems for rules with nested application conditions in the framework of M-adhesive categories, where M-adhesive categories are slightly more general than weak adhesive...

Multi-amalgamation of rules with application conditions in M-adhesive categories

Golas, Ulrike ; Habel, Annegret ; Ehrig, Hartmut (2014)

Amalgamation is a well-known concept for graph transformations that is used to model synchronised parallelism of rules with shared subrules and corresponding transformations. This concept is especially important for an adequate formalisation of the operational semantics of statecharts and other visual modelling languages, where typed attributed graphs are used for multiple rules with nested app...

Finitary M-adhesive categories

Gabriel, Karsten ; Braatz, Benjamin ; Ehrig, Hartmut ; Golas, Ulrike (2014)

Finitary M-adhesive categories are M-adhesive categories with finite objects only, where M-adhesive categories are a slight generalisation of weak adhesive high-level replacement (HLR) categories. We say an object is finite if it has a finite number of M-subobjects. In this paper, we show that in finitary M-adhesive categories we not only have all the well-known HLR properties of weak adhesive ...

Simultaneous Acquisition of EEG and NIRS during Cognitive Tasks for an Open Access Dataset

Shin, Jaeyoung ; von Lühmann, Alexander ; Kim, Do-won ; Mehnert, Jan ; Hwang, Han-Jeong ; Müller, Klaus-Robert (2017)

We provide an open access multimodal brain-imaging dataset of simultaneous electroencephalography (EEG) and near-infrared spectroscopy (NIRS) recordings. Twenty-six healthy participants performed three cognitive tasks: 1) n-back (0-, 2- and 3-back), 2) discrimination/selection response task (DSR) and 3) word generation (WG) tasks. The data provided includes: 1) measured data, 2) demographic dat...

Assessing the depth of cognitive processing as the basis for potential user-state adaptation

Nicolae, Irina-Emilia ; Acqualagna, Laura ; Blankertz, Benjamin (2017)

Objective: Decoding neurocognitive processes on a single-trial basis with Brain-Computer Interface (BCI) techniques can reveal the user's internal interpretation of the current situation. Such information can potentially be exploited to make devices and interfaces more user aware. In this line of research, we took a further step by studying neural correlates of different levels of cognitive pro...