Institut für Softwaretechnik und Theoretische Informatik

216 Items

Recent Submissions
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...

On the use of MLDS in the study of depth and lightness perception

Aguilar Cornejo, Guillermo Andres (2017)

An open question in vision research is how to measure the perceptual dimension evoked by the stimulus in a reliable way. Although a variety of psychophysical procedures are available, it is still a challenge to find methods that are efficient and avoid critical confounds, such as strategies triggered by difficult and unnatural tasks used by discrimination methods. In this doctoral thesis I prop...

Quality-influencing factors in mobile gaming

Beyer, Justus Philipp (2017)

In the wake of the smartphone revolution, mobile games have not only become a spare time activity for the majority of phone owners, they have also created a prospering new industry. To thrive in an increasingly stiff competition, both game developers and service providers are seeking to improve their customers’ gaming experience and understand how it is affected by external influences in order ...

Linking appearance to neural activity through the study of the perception of lightness in naturalistic contexts

Maertens, Marianne ; Shapley, Robert (2013)

The present paper deals with the classical question how a psychological experience, in this case apparent lightness, is linked by intervening neural processing to physical variables. We address two methodological issues: (a) how does one know the appropriate physical variable (what is the right x ?) to look at, and (b) how can behavioral measurements be used to probe the internal transformation...

A critical assessment of the importance of seedling age in the system of rice intensification (sri) in Eastern India

Deb, Debal ; Lässig, Jörg ; Kloft, Marius (2012)

A survey of the system of rice intensification (SRI)-related literature indicates that different authors have drawn conflicting inferences about rice yield performances under the SRI, chiefly because the SRI methodology has been variously advocated, interpreted and implemented in the field using different rice varieties, seedling ages at transplantation, cultivation seasons and nutrient managem...

Low-dimensional spike rate models derived from networks of adaptive integrate-and-fire neurons

Augustin, Moritz ; Ladenbauer, Josef ; Baumann, Fabian ; Obermayer, Klaus (2017)

The spiking activity of single neurons can be well described by a nonlinear integrate-and-fire model that includes somatic adaptation. When exposed to fluctuating inputs sparsely coupled populations of these model neurons exhibit stochastic collective dynamics that can be effectively characterized using the Fokker-Planck equation. This approach, however, leads to a model with an infinite-dimens...

How adaptation currents change threshold, gain, and variability of neuronal spiking

Ladenbauer, Josef ; Augustin, Moritz ; Obermayer, Klaus (2014)

Many types of neurons exhibit spike rate adaptation, mediated by intrinsic slow K+ currents, which effectively inhibit neuronal responses. How these adaptation currents change the relationship between in vivo like fluctuating synaptic input, spike rate output, and the spike train statistics, however, is not well understood. In this computational study we show that an adaptation current that pri...

How adaptation shapes spike rate oscillations in recurrent neuronal networks

Augustin, Moritz ; Ladenbauer, Josef ; Obermayer, Klaus (2013)

Neural mass signals from in-vivo recordings often show oscillations with frequencies ranging from <1 to 100 Hz. Fast rhythmic activity in the beta and gamma range can be generated by network-based mechanisms such as recurrent synaptic excitation-inhibition loops. Slower oscillations might instead depend on neuronal adaptation currents whose timescales range from tens of milliseconds to seconds....

Transfer learning of gaits on a quadrupedal robot

Degrave, Jonas ; Burm, Michael ; Kindermans, Pieter-Jan ; Dambre, Joni ; Wyffels, Francis (2015)

Learning new gaits for compliant robots is a challenging multi-dimensional optimization task. Furthermore, to ensure optimal performance, the optimization process must be repeated for every variation in the environment, for example for every change in inclination of the terrain. This is unfortunately not possible using current approaches, since the time required for the optimization is simply t...

Exploitation of environmental constraints in human and robotic grasping

Eppner, Clemens ; Deimel, Raphael ; Álvarez-Ruiz, José ; Maertens, Marianne ; Brock, Oliver (2015)

We investigate the premise that robust grasping performance is enabled by exploiting constraints present in the environment. These constraints, leveraged through motion in contact, counteract uncertainty in state variables relevant to grasp success. Given this premise, grasping becomes a process of successive exploitation of environmental constraints, until a successful grasp has been establish...

Network dynamics of adaptive spiking neurons: model reduction and numerical analysis

Moritz, Augustin (2017)

The brain is a complex dynamical system. It can operate in many different states of neuronal network activity and switch between them, depending on cognitive demands. To better understand functionally relevant network states and pathological activity it is beneficial to employ computational models for predictions and mechanistic analyses. In this thesis, I consider a biophysical neuronal netwo...

On the physical security of physically unclonable functions

Tajik, Shahin (2017)

Reconfigurable hardware is the primary component of electronic embedded devices employed in several applications ranging from wireless communication to cloud computing. Due to their significant role these modern platforms are targets of intellectual property (IP) piracy and tampering. Cloning of a design or manipulation of its content is carried out by conducting physical attacks (e.g., side-ch...

On the learnability of physically unclonable functions

Ganji, Fatemeh (2017)

Along with the expansion of the application of integrated circuits (ICs), the risk of security vulnerabilities of them has been rising dramatically. Diverse type of successful attacks against ICs have been launched by adversaries taking advantage of those vulnerabilities to expose confidential information, e.g., intellectual property (IP), and customer data. As a remedy for the shortcomings of ...

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

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

EEG and behavioral data of seventeen participants recorded by members of the Neurotechnology Group at Technische Universität Berlin. Details of the study are published in "Nicolae I-E, Acqualagna L and Blankertz B. (2017). Assessing the Depth of Cognitive Processing as the Basis for Potential User-State Adaptation. Front. Neurosci. 11:548, 2017a. doi: https://doi.org/10.3389/fnins.2017.00548

Learning representations with neuromodulators

Holca-Lamarre, Raphael (2017)

Neurons in the cortex and in multi-layer perceptrons (MLPs) represent inputs as patterns of activity. In both systems, the nature of a neural representation carries important consequences and, accordingly, the mechanisms guiding representation learning are of great relevance. In MLPs, the most widespread learning method is the error-backpropagation algorithm. Although functionally effective, th...

Improving and interpreting machine learning algorithms with applications

Vidovic, Marina Marie-Claire (2017)

Advancing understanding and interpretation of machine learning algorithms has recently been receiving much attention. Although classification systems achieve high prediction accuracies and are used across a wide spectrum of academic fields, they act like a black-box and provide little or no reasoning information about their decisions. However, several applications in science and technology requ...

Evaluating embodied conversational agents in multimodal interfaces

Weiss, Benjamin ; Wechsung, Ina ; Kühnel, Christine ; Möller, Sebastian (2015)

Based on cross-disciplinary approaches to Embodied Conversational Agents, evaluation methods for such human-computer interfaces are structured and presented. An introductory systematisation of evaluation topics from a conversational perspective is followed by an explanation of social-psychological phenomena studied in interaction with Embodied Conversational Agents, and how these can be used fo...

Prediction of difficulty levels in video games from ongoing EEG

Neumann, Laura ; Schultze-Kraft, Matthias ; Dähne, Sven ; Blankertz, Benjamin (2017)

Real-time assessment of mental workload from EEG plays an important role in enhancing symbiotic interaction of human operators in immersive environments. In this study we thus aimed at predicting the difficulty level of a video game a person is playing at a particular moment from the ongoing EEG activity. Therefore, we made use of power modulations in the theta (4–7 Hz) and alpha (8–13 Hz) freq...

Maritime cognitive workload assessment

Miklody, Daniel ; Uitterhoeve, Wendie M. ; van Heel, Dimitri ; Klinkenberg, Kerstin ; Blankertz, Benjamin (2017)

The human factor plays the key role for safety in many industrial and civil every-day operations in our technologized world. Human failure is more likely to cause accidents than technical failure, e.g. in the challenging job of tugboat captains. Here, cognitive workload is crucial, as its excess is a main cause of dangerous situations and accidents while being highly participant and situation d...

Accelerated secure GUI for virtualized mobile handsets

Danisevskis, Janis (2017)

Mobile handsets, especially so-called smartphones, have become an indispensable commodity in day-to-day life. However, their growing versatility came at the cost of ever-increasing complexity, and this raises severe security concerns. This has come to be especially problematic for corporate IT infrastructures, because it is increasingly hard to reconcile personal user expectations with corporat...