Open Access

Flying in virtual reality (VR) using standard handheld controllers can be cumbersome and contribute to unwanted side effects such as motion sickness and disorientation. This paper investigates a novel hands-free flying interface - HeadJoystick, where the user moves their head similar to a joystick handle toward the target direction to control virtual translation velocity. The user sits on a regular office swivel chair and rotates it physically to control virtual rotation using 1:1 mapping. We evaluated short-term (Study 1) and extended usage effects through repeated usage (Study 2) of the HeadJoystick versus handheld interfaces in two within-subject studies, where participants flew through a sequence of increasingly difficult tunnels in the sky. Using the HeadJoystick instead of handheld interfaces improved both user experience and performance, in terms of accuracy, precision, ease of learning, ease of use, usability, long-term use, presence, immersion, sensation of self-motion, workload, and enjoyment in both studies. These findings demonstrate the benefits of using leaning-based interfaces for VR flying and potentially similar telepresence applications such as remote flight with quadcopter drones. From a theoretical perspective, we also show how leaning-based motion cueing interacts with full physical rotation to improve user experience and performance compared to the gamepad.

Telepresence robots allow people to participate in remote spaces, yet they can be difficult to manoeuvre with people and obstacles around. We designed a haptic-feedback system called “FeetBack," which users place their feet in when driving a telepresence robot. When the robot approaches people or obstacles, haptic proximity and collision feedback are provided on the respective sides of the feet, helping inform users about events that are hard to notice through the robot’s camera views. We conducted two studies: one to explore the usage of FeetBack in virtual environments, another focused on real environments.We found that FeetBack can increase spatial presence in simple virtual environments. Users valued the feedback to adjust their behaviour in both types of environments, though it was sometimes too frequent or unneeded for certain situations after a period of time. These results point to the value of foot-based haptic feedback for telepresence robot systems, while also the need to design context-sensitive haptic feedback.

Damage to grasslands is mainly caused by wild boar during foraging. Farmers in Germany thereby register yield losses and expenses for damage repair. This contribution analyzes the acquisition and processing of aerial images to orthomosaics and image segmentation to perform spatial measurements of damaged patches in grasslands. A sample set of manually annotated orthomosaics is analyzed. Preliminary classification results applying a convolutional neural network approach to segment damaged patches are presented. First results show the applicability of the applied methods in the detection of damage caused by wild boar and suggest that other damage causes (e.g., mole damage) should be considered to improve results.

This paper utilizes machine learning to investigate the classification of encryption applied to network traffic and the underlying activities. It is firstly motivated by the difficulty of traditional traffic classification caused by additional encryption as ports and headers are hidden. Secondly, the results also present the effectiveness of currently available privacy-enhancing technologies. A new dataset is created, containing Pure (without additional encryption), Tor, Tor with obfuscation, VPN and VPN+Tor network traffic. Additionally, there are five different activities performed during each kind of traffic recording, namely audio streaming, browsing, P2P/SFTP file transfers and video conferencing. The traffic is classified by extracting features based on flows calculated by ARGUS and CICFlowMeter, combining three classifiers with seven feature selection algorithms. The results for the classification of the encryption clearly indicate the possibility of using this detection system in a modified fashion within a practical application. For the detection of activities inside encrypted network traffic, the results show that the disguise is ineffective. Overall, this reveals the need to improve the resistance of commonly used techniques for the protection of network traffic against machine learning.

Deep learning models produce overconfident predictions even for misclassified data. This work aims to improve the safety guarantees of software-intensive systems that use deep learning based classification models for decision making by performing comparative evaluation of different uncertainty estimation methods to identify possible misclassifications. In this work, uncertainty estimation methods applicable to deep learning models are reviewed and those which can be seamlessly integrated to existing deployed deep learning architectures are selected for evaluation. The different uncertainty estimation methods, deep ensembles, test-time data augmentation and Monte Carlo dropout with its variants, are empirically evaluated on two standard datasets (CIFAR-10 and CIFAR-100) and two custom classification datasets (optical inspection and RoboCup@Work dataset). A relative ranking between the methods is provided by evaluating the deep learning classifiers on various aspects such as uncertainty quality, classifier performance and calibration. Standard metrics like entropy, cross-entropy, mutual information, and variance, combined with a rank histogram based method to identify uncertain predictions by thresholding on these metrics, are used to evaluate uncertainty quality. The results indicate that Monte Carlo dropout combined with test-time data augmentation outperforms all other methods by identifying more than 95% of the misclassifications and representing uncertainty in the highest number of samples in the test set. It also yields a better classifier performance and calibration in terms of higher accuracy and lower Expected Calibration Error (ECE), respectively. A python based uncertainty estimation library for training and real-time uncertainty estimation of deep learning based classification models is also developed.

We have designed an inexpensive intelligent pedestrian counting system. The pedestrian counting system consists of several counters that can be connected together in a distributed fashion and communicate over the wireless channel. The motion pattern is recorded using a set of passive infrared (PIR) sensors. Each counter has one wireless sensor node that processes the PIR sensor data and transmits it to a base station. Then echo state network, a special kind of recurrent neural network, is used to predict the pedestrian count from the input pattern. The evaluation of the performance of such networks in a novel kind of application is one focus of this work. The counter gave a performance of 80.4% which is better than the commercially available low-priced pedestrian counters. The article reports the experiments we did for analyzing the counterperformance and lists the strengths and limitations of the current implementation. It will also report the preliminary test results obtained by substituting the PIR sensors with low-cost active IR distance sensors which can improve the counter performance further.

Usability und User Experience (UX) haben als Design-Aspekte in der Produktentwicklung zunehmend an Bedeutung gewonnen. Daher ist es sinnvoll, die organisationale Kompetenz zur Ent-wicklung von Produkten mit einer positiven UX zu stärken. Ver-änderungen in Organisationen sind jedoch mit großem Aufwand verbunden. Deshalb müssen Organisationen entscheiden, welche Aktivitäten zur Veränderung der eigenen Kompetenz durchge-führt werden sollen und welche nicht. Die bisherige Forschung hat sich weitgehend auf die Anwendbarkeit bestimmter Metho-den im Projekt- und Produktkontext konzentriert. Um geeignete Aktivitäten zur Verbesserung der organisationalen UX-Kompetenz zu identifizieren, wurden 17 UX-Professionals be-fragt. Diese UX-Professionals haben mindestens zehn Jahre Er-fahrung durch die Arbeit in mehreren Unternehmen und durch die Übernahme einer Führungsrolle im Bereich UX gesammelt. Aus diesen Interviews wurden 13 mögliche Maßnahmen zur Steigerung der UX-Kompetenz von Organisationen abgeleitet. Dazu gehören beispielsweise die Erhöhung der Kompetenz ein-zelner Mitarbeiter, das Teilen von UX-Erfolgsgeschichten oder das Ermöglichen von User Research.

Human and robot tasks in household environments include actions such as carrying an object, cleaning a surface, etc. These tasks are performed by means of dexterous manipulation, and for humans, they are straightforward to accomplish. Moreover, humans perform these actions with reasonable accuracy and precision but with much less energy and stress on the actuators (muscles) than the robots do. The high agility in controlling their forces and motions is actually due to "laziness", i.e. humans exploit the existing natural forces and constraints to execute the tasks. The above-mentioned properties of the human lazy strategy motivate us to relax the problem of controlling robot motions and forces, and solve it with the help of the environment. Therefore, in this work, we developed a lazy control strategy, i.e. task specification models and control architectures that relax several aspects of robot control by exploiting prior knowledge about the task and environment. The developed control strategy is realized in four different robotics use cases. In this work, the Popov-Vereshchagin hybrid dynamics solver is used as one of the building blocks in the proposed control architectures. An extension of the solver’s interface with the artificial Cartesian force and feed-forward joint torque task-drivers is proposed in this thesis. To validate the proposed lazy control approach, an experimental evaluation was performed in a simulation environment and on a real robot platform.

Automatic Short Answer Grading (ASAG) is the process of grading the student answers by computational approaches given a question and the desired answer. Previous works implemented the methods of concept mapping, facet mapping, and some used the conventional word embeddings for extracting semantic features. They extracted multiple features manually to train on the corresponding datasets. We use pretrained embeddings of the transfer learning models, ELMo, BERT, GPT, and GPT-2 to assess their efficiency on this task. We train with a single feature, cosine similarity, extracted from the embeddings of these models. We compare the RMSE scores and correlation measurements of the four models with previous works on Mohler dataset. Our work demonstrates that ELMo outperformed the other three models. We also, briefly describe the four transfer learning models and conclude with the possible causes of poor results of transfer learning models.

Neben der notwendigen Handlungstendenz der Versicherten „ist nicht zusätzlich … einschränkend zu fordern, dass der Weg zum Ort der Tätigkeit, den der Versicherte nicht von seinem Lebensmittelpunkt … aus angetreten hat, unter Berücksichtigung aller Umstände des jeweiligen Einzelfalles in einem angemessenen Verhältnis zu dem üblichen Weg zwischen dem häuslichen Bereich und dem Ort der Tätigkeit steht“.