Available Thesis Topics

Depending on your preference, theses may be written in English or German.

Designing EMS Control Loops using Reinforcement Learning and Neural Networks
Master Thesis, Supervisor: Tim Dünte

Electrical Muscle Stimulation (EMS) is being researched in many different applications in the field of human-computer interaction. Current limitations of using EMS refer to an only rough control of the muscles and the need for an individual calibration for each subject. The combination of Reinforcement Learning with Neural Networks showed in a previous thesis promising results to overcome these limitations.

Individual Topics
Bachelor/Master Thesis, Supervisor: Maximilian Schrapel

I'm looking for passionate students that would like to work on future research projects. Depending on your skills and plans for the future, we will look together for a topic in my research areas that suits you best. In your thesis you will enjoy a high level of support and get in touch with emerging topics like IoT, AI and big data. At the beginning I would like to encourage you to contact me. We will then talk about future opportunities via video chat.

Assigned Thesis Topics

Augmentation of Headphones by Wearable Displays -- Design and Usage Scenarios
Bachelor Thesis, Student: Pia Brandt, Supervisor: Dennis Stanke , Start: April 2021

Headphones allow defining your own soundscape and privately listening to audio sources in public. Active noise-cancelling headphones can even reduce external sounds that intrude into this soundscape. However, to others, the state of a person wearing headphones is unclear (is s/he listening to music? may s/he be spoken to?), which is socially problematic. The goal of this thesis is to explore whether displays integrated in headphones may help to communicate the state of the user to other people. What should be depicted on the display to indicate the state? What about privacy concerns? How should the headphones sense the state of the user? How could the user explicitly provide the content to be shown? This thesis comprises brainstorming about scenarios, sketching and designing potential visualizations on earpieces, asking potential users about the prospect of such display-enhanced headphones, and (if done as a Master's thesis) implementing a prototype.

An Interface for Interactive Exploration of Communities on Social Media
Bachelor Thesis, Student: Maximilian Spiekermann, Supervisor: Jan Wolff , Start: April 2021

The role social platforms play when it comes to radicalization on the internet is a hot topic. Increasingly segregated sub-communities ("filter bubbles") serve to reinforce fringe opinions and don't allow for healthy exposure to sentiments expressed elsewhere. Existing work has already been done to identify such bubbles within the social graph of Twitter. The goal of this thesis is to design an interface that enables an interactive exploration of this graph, with a focus on social bubbles and their interconnections. This includes researching methods to map and present the data and to consider which additional information could be displayed. Furthermore, a user study will have to be conducted to evaluate the design's expressiveness and intelligibility.

Preventing Selective Exposure on Twitter via Nudging
Bachelor Thesis, Student: Kerim Balci, Supervisor: Jan Wolff , Start: April 2021

The content provided to users of social platforms is pre-filtered based on past behaviour on the platform. It is subject to selection biases of individual users, thus preventing any confrontation with divergent opinions. This thesis concerns with the design of an interface that makes users aware of overly selective exposure in their social feeds. The aim of this interface is to subtly steer users towards a broader exposure via nudging. Said design nudge should incentivize users to counteract increasing disconnection of sub-communities on social platforms. Furthermore, a user study is to provide insight into the acceptance of such a feature and the agreement with its feedback.

Design and Evaluation of a Trackball as an Input Device for Smartwatches
Bachelor Thesis, Student: Peer Schroth, Supervisor: Dennis Stanke , Start: April 2021

The fact that the finger covers the screen during touch input and the user can no longer see the screen content is still a problem when using smartwatches. Many smartwatches have alternative input possibilities to the touchscreen to prevent this problem. These include the rotation of the crown or bezel to interact without covering the screen with the users finger. This thesis will analyze already implemented interaction techniques and extend them by using a trackball as input device. Therefore, a trackball crown should be created for an Android smartwatch. Focus of this thesis is also the evaluation of a trackball as input device for smartwatches and the analysis of the user acceptance in user studies.

Comparison and Evaluation of Public and Private Output Modalities on the Earlobe
Master Thesis, Student: Kerem Can Demir, Supervisors: Dennis Stanke , Tim Dünte , Start: March 2021

This thesis should investigate the earlobe as a location to provide feedback to a user, e.g. when a notification arrives. Designing different earclip prototypes to provide different feedback modalities is a part of the thesis as well as the evaluation if the provided feedback is suitable for earclips. As an additional feedback technology besides standard technologies, like e.g. vibration, electrotactile feedback should be presented on the earlobe. A user study should evaluate the feedback methods in direct comparison and should analyze the acceptance of the user. Further usage scenarios or application demos have to be developed and evaluated. The thesis should try to answer the following questions: Which criteria are important for users if feedback ist presented at the earlobe? Which feedback technology do user prefer? Is there a significant difference in reaction time in a distraction task?

Design and Evaluation of a Wrist-Band Prototype for Hand Gesture Recognition via Electromyography
Master Thesis, Student: Miena Basta Badres, Supervisor: Tim Dünte , Start: December 2020

This thesis is about the evaluation and the refinement of a prototype for the measurement of EMG signals on the forearm. The prototype differs from commercially available devices like the MYO armband in the fact, that it has only one EMG sensor instead of eight sensors but also eight electrode pairs. This setup brings therefore some limitations, e.g. measuring all eight electrodes with one sensor needs 40ms resulting in a frequency of 20Hz. The question is, if these limitations result in a lower recognition accuracy of gestures. By further improving the prototype, it should be able to use 16 electrode pairs. The amount of needed EMG sensors for the future prototype should be evaluated in this work to guarantee a good hand gesture recognition.

Completed Theses

Design and Implementation of mobile Application Scenarios for Electrotactile Feedback on a Smartwatch
Bachelor Thesis, Student: Niklas Herkenhoff, Supervisor: Tim Dünte , Submitted: March 2021

The output capabilities of smartwatches are limited by the design and the used technologies, e.g. vibration and displays. We envision the use of electrotactile feedback to expand the output space of smartwatches. A working prototype that can present various sensations via electrotactile feedback is available and should be used to design and implement mobile scenarios that benefit from the enhanced output capabilities. Scenarios could be in the context of notifications, navigation, mobile gaming or etc. The thesis should start with a focus on literature to discover potential application scenarios. Then the thesis should create concepts for the discovered scenarios and after that at least one scenario should be implemented and evaluated with a few participants.

Development and Exploration of the Extension of the Smartwatch Display to the Watch Band
Bachelor Thesis, Student: Daniel Wittenburg, Supervisor: Dennis Stanke , Submitted: September 2020

Smartwatches are becoming more and more popular. But so far the screen size is limited to the watchface. In this work, a smartwatch watch strap has to be developed to extend the smartwatch display from the watchface to the watch strap. For this purpose, flexible displays will be used which can display additional information or notifications. The analysis of the design space on the watch strap, as well as the possible areas of application are to be identified and implemented. In addition, haptic feedback along the watch strap should be provided to inform the user about specific information (and their position) on the watch strap display.

Development and Exploration of Feedback Methods for Ear Clips
Bachelor Thesis, Student: Elias Moualem, Supervisor: Dennis Stanke , Submitted: September 2020

This thesis will deal with ear clips as output devices for notifications. Therefore an ear clip prototype will be created and evaluated with different feedback modalities (e.g. vibration, sound, LED, ...). The focus is on the evaluation of these modalities and their comparison. The ear clip should be able to connect to any Android device via Bluetooth and inform the user about notifications received on the Android device. Knowledge in Android programming is recommended.

Exploration of Control Loop Strategies for EMS Applications using Neural Networks
Master Thesis, Student: Stefan Schmidt, Supervisor: Tim Dünte , Submitted: July 2020

Electrical Muscle Stimulation (EMS) is being researched in many different applications in the field of human-computer interaction, such as learning to play an instrument. Current problems refer to a only rough control of the muscles. Therefore, a solution strategy using neural networks is examined here. The research question is: How well are neural networks suitable for controlling an EMS application? To answer this question, the basic problems of EMS are first analyzed. Thereby an approach is presented which is based on the combination of Reinforcement Learning with neural networks. Experiments show that Recurrent Neural Networks (RNNs) are superior to feedforward networks. Analyses show significant differences in controlling of different angles. Therefore, comparisons between controllers for individual angles must be made. A comparison of PID controller and RNN shows an average increase in precision of 4.17°, in favor of the RNN. A comparison between PID controller and Bidirectional Recurrent Neural Network (BiRNN) shows an average increase of 7.63°. A comparison between RNN and BiRNN shows an increase of 3.46° by the BiRNN.

Evaluation of Eletrotactile Feedback for Everyday Usage Scenarios
Master Thesis, Student: Justin Schulte, Supervisor: Tim Dünte , Submitted: June 2020

Nowadays, most people own at least one smartphone and at the same time smartwatches and other wearables are becoming more and more popular. These devices send a variety of notifications to the wearer, usually in the form of vibration, sound or a status LED. Further, many users prefer invisible feedback, so that only the attention of the addressee and no third party is attracted. Accordingly, vibration feedback is used to a large extent, but this feedback is not sufficiently distinguishable. In this thesis, a wristwatch for mobile use is designed to evaluate an alternative invisible notification method using electrotactile feedback. By adjusting the parameters of the electro-tactile feedback the creation of different sensations is investigated. Potentially distinguishable natural notifications such as vibrating, itching or prodding are generated. A wristwatch prototype with corrosion-resistant gold-plated electrodes was designed, which were produced in a new electrode manufacturing process. Furthermore, a calibration procedure is presented to determine the individual strengths of the different electro-tactile stimulations. The time required for this process could be reduced to about one third of the time needed for a previous work. When calibrating a certain stimulation, it had to be played 3.2 times on average instead of 11.1 times. In the first study, the 17 participants were asked to assign terms, which correspond to one sensation each, to different stimulations. The stimulation associated with Prodding was best recognized (87 %). Furthermore, the majority of the participants would also use the stimulations Vibrating, Jabbing, Prodding and Pulsating in everyday life. In total, 76 % of the participants would use the designed system in everyday life. The second study, which included a distraction task, was planned but only conducted on one expert user. An average detection rate of 88 % was achieved. This result cannot be generalized, but shows the potential of the feedback method.

Implementation and Usability Evaluation of a Real-Time Insect Monitoring System
Bachelor Thesis, Student: Jakob Hederich, Supervisor: Kin-Woon Yeow , Submitted: May 2020

In this project a pest monitoring system will be implemented using a Raspberry Pi, some LEDs and an IDS camera. The monitoring device is used to attract insects using light frequency of the LEDs and to monitor them using a camera. The insects will be detected using the You Only Look Once (YOLO) algorithm and further classified using Support Vector Machine(SVM). Two insect species (Aphids and Thrips) are identified with the method mentioned and the classification is done into three classes (Class 1: Aphids, Class 2: Thrips, Class 3: Others). The system will provide feedback to the user via an Android application. The real-time insect population will be recorded and displayed in a graphical form in the Android application. Furthermore, in the Android application, the user is able to set the type and frequency of the notification, either notifications in regular interval (daily or weekly basis) or warnings when a certain threshold is reached. The threshold mentioned is a population value that is either predetermined via experimental executions (eg. 80% of the maximum population) or inserted the threshold manually from the user. The setup feasibility of the monitoring system and the procedural execution in Android application are investigated in the user study. A simulated garden environment is conducted to ensure the users are able to use the system in a correct manner. Before the execution of the user study, a user manual for the monitoring system will be written for the user understanding. In the end of this thesis, an analysis/ a data tabulation that consists of usability and user-friendliness will be included from the survey conducted.

A Mobile Vision-Based Recognition System
Master Thesis, Student: Zhengyuan Miao, Supervisor: Kin-Woon Yeow , Submitted: May 2020

An Android application will be developed for amount-counting task of the pests in green house for this project. The whole system consists of two parts - mobile device with application and the server. User can use the application to take photos for the leaves of the vegetables and then these photos will be sent to the server for image recognition and object detection so that the number of pests will be automatically counted. By the server side, an image recognition algorithm will be run to calculate the number of the pests (and also with classifications of the pest types), after calculating server will send the results back to the user side and user can easily get the total quantities of different pests. Based on the result numbers user can take actions if the value of the pests’ quantity is beyond the threshold to protect the crops. Furthermore, we can see the data in server via ssh in the computer to analyze the data for experiment or somewhat. At the end of the project, a user study will be conducted, before the user study one user manual is required to be written and then user can read the manual to understand how to use the application.

Combining a Neural Network with Scene Recognition to Provide Mobile Audio Guidance for the Blind
Master Thesis, Student: Kersten Behrens, Supervisor: Oliver Beren Kaul , Submitted: May 2020

Compared to people with healthy vision, individuals with visual impairments have major disadvantages in scene and object recognition, especially in unknown environments. The purpose of this thesis is to combine the object detection capabilities of modern neural networks (NNs), e.g. YOLO with mobile scene generation frameworks (e.g. Apple ARKit or Google ARCode) in a mobile application. Using the generated mobile scene annotated with object names, the user should be provided with auditory guidance (names of the detected objects all around him or her, ideally using a personalized HRTF). Using a voice activated search function, the user can be guided to a desired object. Furthermore, the user will also hear auditory warnings for possible future collisions with objects or surroundings. The implemented app has to be validated in two consecutive user studies in order to test usability and fix design flaws.

For more information, consult the thesis proposal (PDF)

Digitizing Notes with Eye Tracking and World Cameras
Master Thesis, Student: Jiang Xuan, Supervisor: Maximilian Schrapel , Submitted: May 2020

Notes are an integral part of everyday life. They often contain important information, which, however, is only available analogously. Subsequent digitalisation is time-consuming and rarely done. In this thesis it will be investigated whether world cameras of eye trackers together with gaze points are able to digitize the written information on the basis of pre-trained neural networks of the image sections.

Easy Walking: Pedestrian Navigation Depending on Weather Conditions
Master Thesis, Student: Markus Krömker, Supervisor: Maximilian Schrapel , Submitted: May 2020

Paths can become muddy or slippery, depending on the weather conditions. Until now, such conditions are not available or only by manual input in map data. This results in safety risks that have not yet been taken into account in navigation systems for pedestrians. In this thesis, information about routes is to be recorded with our sernsor system and automatically inserted into map data. Based on this data, routes will be redesigned and evaluated according to weather conditions. The aim of this work is to design routes in such a way that even in bad weather conditions the car can be avoided. Adequate knowledge of artificial intelligence and deep learning should be available. The whole System will be set up on Android. Feel free to contact me.

Measuring Bicycle Lanes
Master Thesis, Student: Timon Breßgott, Supervisor: Maximilian Schrapel , Submitted: April 2020

Mobility is an important part of our daily lives. Above all, however, the bicycle is becoming increasingly important because it can cover moderate distances CO2-neutrally in a short period of time. The associated physical activity also contributes to improving health. However, depending on the weather or other circumstances, not every route is suitable for daily journeys. For this work, we have developed a mobile sensor platform to determine characteristics of the routes, which are then automatically entered into maps. The aim is to redesign the routes so that cyclists reach their destinations as safely and untroubled as possible. In order to complete the task successfully, knowledge of Android programming is required. Ideally, you should have knowledge of artificial intelligence with Python/Keras. If you have any questions, please do not hesitate to contact me.

Interaction Techniques for Magnetic Pointing Devices on Smartwatches
Bachelor Thesis, Student: Steffen Ryll, Supervisor: Maximilian Schrapel , Submitted: March 2020

Smartwatches are not yet able to completely replace the smartphone. In addition to the not yet available computing power and battery life, which may be solved in the future, the small display size is a big challenge. When the device is used, the finger covers a large interaction area and hides the interaction elements. This physical condition is called fat finger problem and can hardly be reduced on especially small displays like from Smartwatches. For this purpose, we created an interactive pointing device used on the back of the hand that solves efficiently these challenges. So far the technical evaluation has been completed but no useful application has been implemented and tested. Therefore, this thesis will investigate how users can interact with such a technique.

A Survey of Context Awareness for Wearables
Bachelor Thesis, Student: Daniela Wilhelm, Supervisor: Dennis Stanke , Submitted: March 2020

The aim of this thesis is to provide an overview of recent research on Context-Awareness. Therefore, previous research dealing with conceptual modelling and practical implementation should be elaborated. In addition, the limits of context awareness in current applications should be shown. This work is suited for students who are interested in current research and not in a technical implementation. Good English skills and a high degree of self-motivation are highly recommended to explore the original English articles in detail.

The Influence of Notifications on Activities
Master Thesis, Student: Miguel Escobar Rojas, Supervisor: Maximilian Schrapel , Submitted: November 2019

Smart watches or smartphones can help to motivate sporting activities. However, notifications are very obtrusive and not always appropriate. Therefore, this thesis will examine to what degree notifications can be adapted to the user and whether this can have a positive effect. General knowledge in machine learning and Android should be present. I can give you further information on this thesis by e-mail and in person. Feel free to contact me.

A Survey of Recent Advances in Tactile Feedback
Bachelor Thesis, Student: Moritz Hasemann, Supervisor: Oliver Beren Kaul , Submitted: September 2019

The purpose of this thesis is a literature review of current research and recent advances in tactile feedback, its biological background, sensations, actuators, and use cases. The review should provide a broad background of related work and is suited for students who wish to work on a bachelor thesis which is more research-oriented and less technical. This thesis is primarily suitable for students with strong English skills and a high degree of self-motivation to explore the subject in detail, because it involves reading and reporting about original articles written in English.

For more information, consult the thesis proposal (PDF)

A Survey of Recent Advances in Audio Classification
Bachelor Thesis, Student: Tim-Marek Thomas, Supervisor: Oliver Beren Kaul , Submitted: September 2019

A literature review of current research and recent advances in audio event (speech sounds and natural sounds) classification using a variety of different artificial intelligence approaches and their use cases is the purpose of this thesis. The review should provide a broad background of related work and is suited for students who wish to work on a bachelor thesis which is more research-oriented and less technical. This thesis is primarily suitable for students with strong English skills and a high degree of self-motivation to explore the subject in detail, because it involves reading and reporting about original articles written in English.

For more information, consult the thesis proposal (PDF)

Development of a Virtual Reality User Interface supporting the Drafting of Vibrotactile Patterns for a Head-worn Output Device
Bachelor Thesis, Student: Andreas Domin, Supervisor: Oliver Beren Kaul , Submitted: August 2019

In earlier work, we developed a vibrotactile guidance and immersion display called “HapticHead”, a system utilizing 24 vibration actuators distributed in three concentric ellipses around the head to give intuitive haptic guidance hints and to increase immersion for VR and AR applications (see Publications). The purpose of this Bachelor’s thesis will be an in-depth evaluation of the possibilities arising from this device by taking an existing example of a 2D vibrotactile pattern design user interface (UI) in Unity and extending it by a fully functional VR UI. This VR UI shall then be evaluated and further improved by conducting consecutive user studies, iteratively improving the design and functionality.

For more information, consult the thesis proposal (PDF)

Electrotactile Feedback as a Notification Method for interactive Wearables
Master Thesis, Student: Dennis Stanke, Supervisor: Tim Dünte , Submitted: June 2019

This thesis presents the development and evaluation of multiple wearable prototypes. The suitability of electro-tactile feedback on wearables was evaluated. Vibrotactile feedback is used for comparison. Wristband and ring prototypes were created which can generate these two types of feedback. Depending on the wearable, up to four electrodes or vibration motors can be activated to initiate the corresponding feedback. A display that can be attached to the wearable shows information like received messages. The wearable prototypes were evaluated in two studies. The forearm and finger positions as well as the electro- and vibrotactile feedback were compared. In the first study 12 participants marked in two graphics where they felt a sensation on the skin caused by the prototypes. A significantly larger area was marked for the electro-tactile wristband compared to the vibro-tactile wristband. In the comparison of the electro- and vibrotactile ring a significantly larger area was marked for the vibrotactile feedback. The localization of the vibrotactile feedback on the finger shows extensive scattering. A second study with 18 participants focuses on the recognition of notification patterns. For this purpose nine notification patterns were created. The participants achieved a recognition rate of 35.8% with the vibrotactile ring. The recognition with electrotactile feedback on the finger was 53.3%. On the forearm the participants were able to identify the patterns more accurately than on the finger. With vibrotactile feedback on the forearm the participants achieved a recognition rate of 67.7%. With electrotactile feedback they reached a recognition rate of 68.5%. Although the participants described electrotactile feedback as localized and vibrotactile feedback as diffuse. The participants described vibration feedback as comfortable and less stressful than electrotactile feedback.

AR Search for bookshelves
Master Thesis, Student: Thilo Schulz, Supervisor: Maximilian Schrapel , Submitted: June 2019

Have you ever looked for a book in a library, but it wasn't in the right place? The visual search may take a long time, but it may not be successful. In this thesis you will use image processing on Smartphones to find book covers in bookshelves. Algorithms have to be invented, implemented and tested. Furthermore, a user study will compare your implementation to visual search. Knowledge in Android is recommended.

Comparison of External and Internal Sensor Data of Digital Pens for Gesture Input
Bachelor Thesis, Student: Polina Geisler, Supervisor: Maximilian Schrapel , Submitted: April 2019

Digital Pens detect handwriting by different sensors. Most known are cameras or inertial measurement units (IMU). We have shown that high accuracies can be achieved when audio signals from inside of the pen are added to the motion signals. This principle also works for signatures but the question remains if the signals from outside can replicate the inner signals? In this thesis those questions will be answered by using external audio signals in combination with motion signals from an optitrack system.

Effects of the Phantom Sensation on 3D Tactile Guidance around the Head
Bachelor Thesis, Student: Kerem Can Demir, Supervisor: Oliver Beren Kaul , Submitted: March 2019

In earlier work, we developed a vibrotactile guidance and immersion display called “HapticHead”, a system utilizing 24 vibration motors distributed in three concentric ellipses around the head to give intuitive haptic guidance hints and to increase immersion for VR and AR applications (see Publications). The purpose of this thesis will be an in-depth evaluation of the possibilities arising from this device by taking an existing prototype for 3D guidance and evaluating whether the Phantom Sensation occurs on different head regions with the current configuration. Furthermore, the maximum possible distance for the Phantom Sensation to arise shall be evaluated on different sites around the head by reconstructing a prototype from related work (Kerdegari et al.). Lastly, this thesis should investigate whether the Phantom Sensation has an effect on guidance performance of HapticHead and how a possible positive effect can be tuned to further increase the guidance performance.

For more information, consult the thesis proposal (PDF)

Extraction of Immersive Tactile Effects from the Sound of Movies for a Head-Based Output Interface
Bachelor Thesis, Student: Jonas Fabiasik, Supervisor: Oliver Beren Kaul , Submitted: March 2019

In earlier work, we developed a vibrotactile guidance and immersion display called “HapticHead”, a system utilizing 24 vibration motors distributed in three concentric ellipses around the head to give intuitive haptic guidance hints and to increase immersion for VR and AR applications (see Publications). The purpose of this Bachelor’s thesis will be an in-depth evaluation of the possibilities arising from this device by implementing a framework to automatically extract sound from movies and turning this extracted sound into tactile effects for HapticHead. Furthermore, a user study shall prove the viability of the concept and test whether users experience an increased feeling of immersion in movies by adding these tactile effects.

For more information, consult the thesis proposal (PDF)

Evaluation of the Expressivity of EMS Patterns
Bachelor Thesis, Student: Kendall Ly, Supervisor: Tim Dünte , Submitted: March 2019

This thesis deals with the examination of electrical muscle stimulation as method for notifications. It goes more into detail at what kind of information EMS patterns can convey and which factors are crucial for the perception of the importance and expressiveness of EMS patterns. An existing prototype was used for this, which together with the Let-Your-Body-Move-Toolkit enables the generation of manipulated EMS signals. The corresponding Android application was extended by further evaluation criteria for the purpose of evaluating the EMS patterns. In addition, a total of nine different EMS patterns were evaluated in the course of this work in a user study with 13 participants. The EMS patterns were evaluated both in their detection rates and times, as well as in their properties. In addition, the interpretability to seven different notifications have been investigated. It turned out that all EMS patterns have recognition rates of over 80% and were therefore well recognized. For three of the nine EMS patterns it has been shown that they are particularly suitable as notification patterns due to their expressiveness. These showed clear interpretability as well as clearly defined characteristics. According to this, there were three factors on which the perceived importance of the EMS patterns depend. These factors include the length of the pulses, the number of long pulses and the position of the long pulses in the EMS patterns.

Design of Multi Channel EMS Notifications and their Effects on the User Experience
Bachelor Thesis, Student: Mu'aid Mughrabi, Supervisor: Tim Dünte , Submitted: January 2019

This thesis investigates the use of electrical muscle stimulation on multiple muscles for notifications. The main focus is on the quantity of recognisable notification patterns and their possible notification uses. For this purpose, a software prototype was created which can simplify creating multi channelled patterns. The software generates the notification patterns to be played in conjunction with (multiple) Let Your Body Move Toolkit(s), a device for manipulating an electrical signal that is used for muscle stimulation. The designed notification patterns were evaluated in two user studies with (n=5,12) participants respectively. In the first study, five patterns that uses only one stimulation channel were evaluated with regard to their recognition rates. Except for one pattern with a recognition rat of 100%, the studied patterns had low recognition rates(mean=44.8%). Because of the high confusion between those patterns, they could not be used for notification purposes. The second study concentrated on 15 patterns that uses multiple communication channels (up to four muscles were used). Those patterns were evaluated mainly with regard to their recognition rate, perceived properties, and possible device’s informational states that they can convey. The results show that the patterns were easily recognisable, 13 of them had recognition rate over 85%. This and the fact that the feedback of the participants about using such EMS patterns for device notifications was slightly positive indicates that EMS notifications with multiple channels can be used an alternative to the traditional notification methods such as sound, vibration and LED. The reported pattern properties and their suitable device’s informational states were individually different between the study’s participants.

Measuring the world: Make electronic devices smart!
Bachelor Thesis, Student: Laurent Skiba, Supervisor: Maximilian Schrapel , Submitted: January 2019

Nowadays, many devices are integrated into the Smart Home network. Even simple devices such as electric water boilers can be switched on and off automatically. However, these devices have very special characteristics in the current consumption that reflect the current state. So far such features are unexplored. This thesis will use a given prototype to develop a smart home application that classifies the current status of multiple devices and uses it for human-computer interaction.

Implementation and Evaluation of a Silent Head-Mounted Tactile Interface
Master Thesis, Student: Jonas Bock, Supervisor: Oliver Beren Kaul , Submitted: December 2018

Current generation virtual reality (VR) and augmented reality (AR) head-mounted displays (HMDs) usually include no or only a single vibration motor for haptic feedback and do not use it for guidance. We developed a vibrotactile guidance and immersion display called “HapticHead”, a system utilizing 24 vibration motors distributed in three concentric ellipses around the head to give intuitive haptic guidance hints and to increase immersion for VR and AR applications. The purpose of this Master’s thesis will be to replace the standard vibration motors with sophisticated actuators (under NDA) which feature independent amplitude and frequency control and the ability to still provide a high amplitude at a frequency as low as 20 Hz. A user study is to be conducted on the question of how well users can perceive low-frequency vibration feedback on different sites around the head and which amplitude factors need to be applied on different sites around the head so that the vibration amplitude feels the same on all sites. The modified prototype shall then be compared to the old prototype in a second, comparison user study versus related work.

For more information, consult the thesis proposal (PDF)

Development of a User Interface for Designing Vibrotactile Patterns for a Head-Mounted Output Device
Bachelor Thesis, Student: Leonard Hansing, Supervisor: Oliver Beren Kaul , Submitted: November 2018

Current generation virtual reality (VR) and augmented reality (AR) head-mounted displays (HMDs) usually include no or only a single vibration motor for haptic feedback and do not use it for guidance. We developed a vibrotactile guidance and immersion display called “HapticHead”, a system utilizing 24 vibration motors distributed in three concentric ellipses around the head to give intuitive haptic guidance hints and to increase immersion for VR and AR applications. The purpose of this Bachelor's thesis will be an in-depth evaluation of the possibilities arising from this device by developing a vibrotactile pattern design application in Unity. This includes finding and cataloging promising vibrotactile patterns, disseminating them into parts and developing a visual interface to design such patterns in a convenient way.

For more information, consult the thesis proposal (PDF)

Active Navigation
Master Thesis, Student: Peter Brandes, Supervisor: Maximilian Schrapel , Submitted: November 2018

Future mobility will introduce more flexible use of different means of transportation. It is important to stay healthy especially when you can travel from door to door without walking long distances. This thesis will give you the possibility to investigate on how you can combine autonomous cars, walking and/or cycling with health recommendations in urban environments. Your task is to implement a navigation system for android under usage of smart watches, health and contextual data (e.g. Weather, Calendar,...). Knowledge in android programming is recommended, feel free to contact me.

Visualization Framework for Motion Sensors
Master Thesis, Student: Ferdinand Lange, Supervisor: Maximilian Schrapel , Submitted: October 2018

Motion sensors are widely used in human-computer interaction. Their precise measurement data provide information about the current position of the hardware. This is important, for instance, to prevent drones from falling or to determine the current position of a smartphone. Even in automotive navigation systems IMU’s are applied to provide accurate data about the vehicle's current speed. For testing such sensors in new techniques it is often important to visualize the data first. In this thesis a framework will be created which animates 3D models based on the filtered raw data of such sensors. Basic knowledge in C++ is required. Feel free to contact be for more details.

Spectrophone: A novel apporach for surface classification with smartphones
Master Thesis, Student: Philipp Etgeton, Supervisor: Maximilian Schrapel , Submitted: October 2018

"Is it genuine leather or imitation leather?" - You may have asked or heard this question before in a shopping mall. What if you could classify surfaces such as leather or any others with your smartphone? This thesis will give you the opportunity to discover a novel approach for surface classification with today's smartphone sensors. Experiences in Android and image processing is recommended.

Design of a natural leve-based Interaction Method for EMG and EMS based Notifications
Bachelor Thesis, Student: Niklas Rosenbusch, Supervisor: Tim Dünte , Submitted: September 2018

Smartphones have become an integral part of everyday life in this day and age. The various programs and applications that are used create notifications that draw the user’s attention to an event that has occurred. The widespread notification modalities such as sound, vibration and visualization of the notifications require that visual contact to the smartphone or smartwatch must be established in order to find out exactly what it is about. For this reason, this paper examines whether electrical muscle stimulation (EMS) and different intensity patterns can be used to detect the respective incoming notifications, which are displayed at different levels. In addition, it will be tested how reliably the reaction of the user can be detected by electromyography (EMG). It is possible for the user to control by a hand movement whether he wants to receive detailed information about the notification or not. To test this a software was programmed which can measure the reactions of the muscles and a study (N=12) was carried out. This leads to the conclusion that the different patterns could be recognized with a recognition rate of 94.2% and that the response via EMG was also 91.4% largely reliable. However, the majority of the subjects could not imagine such a control of their smartphones. This work thus extends the existing literature to include knowledge of the reliability of EMG detection in responding to notification. However, the conduct of the study is limited by a laboratory study, which requires further research.

Designing and Implementing an Augmented Reality Application for a Shape-Changing Display
Bachelor Thesis, Student: Mateusz Ryzewski, Supervisor: Tim Dünte , Submitted: August 2018

The goal of this thesis is to design, implement and evaluate an augmented reality application for a Shape-Changing Display. This display can fetch information from the internet and visualize them through the LEDs on each from the four sides of the display. Moreover the display uses the change of the high for the information visualization. For example the display could map the current temperature. The augmented reality app shall get the information from the shape-changing display and visualize them as virtual content on the phone screen. Additionally the app shall be evaluated in a user study. The developed app can recognize each side of the shape-changing display by a marker and show the information as virtual content in a correct perspective and position. The scenarios can be changed with touch gestures in the way of direct manipulation. The user study provided improvement suggestions for the information visualization. Furthermore ideas for other interaction techniques were collected. The usability of the app was rated as good.

Position Detection of an Electrode Grid via EMG Raw Data
Bachelor Thesis, Student: Patrick Sachmann, Supervisor: Tim Dünte , Submitted: June 2018

In the field of man-machine communication, the use of EMG and EMS is becoming increasingly popular. A special problem was the fast and correct calibration of such systems. In this paper an approach for position detection of an electrode field with EMG raw data is presented. The prototype developed here at the institute consists of 2 electrode wristbands containing 18 and 22 electrodes. In the course of this work, a method for position detection was evaluated and the software of the prototype was rewritten. Eight subjects took part in the study, which was carried out to evaluate the position recognition and the prototype. Each subject made 54 gestures while the prototype was positioned at 3 different positions, one third of the circumference of the forearm being moved to each other. With the data collected from the study, the position sensing procedure was tested. The average displacement was 9 electrodes for rotation by a third. A shift of 14 electrodes was assumed for the two-thirds rotation, but the mean was 7 electrodes. Finally, reasons for the high discrepancy are discussed and proposals are made which could lead to more positive results in a new investigation.

EMG-Based Hand and Finger Gesture Recognition with a Multi Electrode Grid
Master Thesis, Student: Christian Dirkes, Supervisor: Tim Dünte , Submitted: May 2018

This master thesis deals with the question whether a 2D-electrode field is necessary to recognize hand and finger gestures. One focus here is the acquisition of EMG raw data using an existing prototype, which consists of two wristbands with 18 and 22 electrodes. Furthermore, it is examined how many gestures can be recognized with the existing prototype.For this purpose, a user study was conducted with twelve participants who performed 46 different hand and finger gestures in one session. The data obtained from this were evaluated with different machine learning classification methods against each other, using different gesture sets from the literature, depending on the user as well as independently of the user. Detection rates of up to 57% were achieved in the user-dependent procedure and up to 13% in the user-independent procedure with 46 different gestures. Furthermore, the recognition rates obtained here are compared with similar works.

Design and Evaluation of a wearable Device for the visual Representation of physical Exertion in Sport Groups
Bachelor Thesis, Student: Felix Trommer, Supervisor: Tim Dünte , Submitted: April 2018

In this work a portable prototype is developed, which visualizes the physical effort of the wearer for others. This wearable is evaluated with a view to its use in sports groups in which a trainer could better adapt the training to the individual participants by using the wearable. The pulse of the carrier is measured and visualized by an LED. To measure the pulse, two different algorithms for heart rate detection are presented and discussed, three different types of visualization are proposed. Those visualizations are an LED pulsating parallel to the heartbeat, a coloured representation with three levels and a combination of the above representations. In a user study, these representations are evaluated with six participants with regard to acceptance, correctness of displayed excertion and simplicity of interpretation. In addition, different locations are discussed where the wearable can be worn on the body during sport without restricting the user.

Extending and Testing the PostFix IDE
Bachelor Thesis, Student: Marcel Budoj, Supervisor: Michael Rohs , Submitted: March 2018

PostFix is a programming language and IDE for beginners. PostFix is a stack-based language. Its only data structure is the array. All objects are immutable. The language is inspired by stack-based languages such as PostScript and Forth, but also by Lisps such as Racket and NewLisp. An integrated development environment (IDE) has been designed in a prior Master’s Thesis. The IDE is currently being used in an introductory programming course. The aim of this Bachelor’s Thesis is to use the experience from the course to improve the IDE and to add novel features. In particular the following aspects should be addressed: Improvement of the interactive graphics capabilities of PostFix, improved error messages, a testing framework for PostFix and the IDE, and tail-call optimization.

Design of a Casual Interaction Method for Notifications using EMS and EMG
Bachelor Thesis, Student: Gerrit Rode, Supervisor: Tim Dünte , Submitted: March 2018

This bachelor thesis examines the use of electrical muscle stimulation for notifications. The focus is on the quantity of recognizable notification patterns. For this purpose, an existing prototype for mobile application scenarios was enhanced and twelve different notification patterns were designed. An Android app was developed, which can serve as a basis for future mobile applications of the prototype. The app generates the notification patterns in conjunction with the Let-Your-Body-Move-Toolkit, a device for manipulating an electrical signal that is used for muscle stimulation.The designed notification patterns were evaluated in a user study with 15 participants. The patterns were evaluated with regard to their recognition rates, the decision times required for recognition and feedback from participants. The average pattern recognition rate is 69.58%. Of the twelve notification patterns three patterns performed especially well in all these points. These patterns achieved detection rates of over 93% with short decision times of less than ten seconds and positive feedback from study participants. The positive feedback from the participants indicates that the use of EMS notifications can be an alternative to the traditional notification methods of a smartphone - sound, vibration and LED.

Design and Evaluation of various EMG Sensors for Electrode Grids
Bachelor Thesis, Student: Hendrik Frei, Supervisor: Tim Dünte , Submitted: March 2018

This thesis focuses on the development of an EMG -sensor especially for use in electrode fields such as wristbands. Different variants of this sensor were evaluated in a technical study with commercial EMG -sensors for the application of the electrode field. Downtimes of these sensors were investigated in a serial measurement setup. Differences between different high-pass filters for eliminating a DC offset voltage could be worked out. It was proven that the downtime of the sensors is dependent on the previous resistance state of the signal electrodes.

Ambient Notifications for a Shape-Changing Display
Bachelor Thesis, Student: Christian Althaus, Supervisor: Tim Dünte , Submitted: February 2018

This thesis is about a shape-changing display, which can display information through height adjustment and led lights. An existing system was used to control the shape-changing display. This system will be examined and then redesigned with the objective to make it simpler and more compact, so that a user can take it with home. The developed system should allow visualization of real-time information from web sources. Furthermore, it should display information in an unobtrusive manner.The displayed scenarios, for example the current or predicted temperature, can be configured in a graphical user interface. It can be specified, how the information will be displayed. This, among others, includes specification of the led colors or different visualization modes. Therefore, a concept for displaying quantitative values is developed. Different animations were implemented to provide better feed-back of the developed system and scenarios.

Curved Treemaps
Master Thesis, Student: Christian Brosy, Supervisor: Michael Rohs , Submitted: November 2017

A Treemap is a space-filling visualization that shows an overview of the relative sizes of a large number of items. There has been a lot of research on Treemaps since their invention in the early 1990s. A challenge still is to adequately show the different nesting levels of a hierarchical structure. Typical approaches use labeled frames and borders whose width decreases with nesting level. This thesis investigates the idea of curved treemaps, i.e., treemaps with slightly bent borders. The main question to explore is whether curved treemaps are effective in conveying the hierarchical structure of the data. One justification for investigating curved boundaries are the Gestalt laws, in particular the laws of continuity and good form: We perceive continuous smooth curves (without sharp directional changes) as belonging together. In curved treemaps continuous curves are meant to be subdivide data on the same level.

Spatial Patterns for a Head-Worn Vibrotactile Display
Master Thesis, Student: Marc Mogalle, Supervisor: Oliver Beren Kaul , Submitted: November 2017

Haptic feedback can replace auditory or visual feedback in case the other senses are already engaged or may not be disturbed. The HapticHead is a 3D vibrotactile around the head display able to play back a variety of tactile effects and patterns. This thesis explores different use cases of such a display, like as a notification display or navigational aid. For this purpose three experiments were conducted. Firstly, the appeal and distinguishability of vibrotactile patterns around the head were evaluated. As a result, ten patterns with above average recognition rate and rating were found. In the follow-up experiment, these top ten patterns were compared against single vibration motor patterns found in related work in terms of type, priority and location. The goal was to determine their eligibility of transmitting different kinds of phone notifications. The patterns’ types were recognized correctly at over 90 %, while the patterns’ recognition rate for location was even higher than 98 %. In the the third and final experiment, blindfolded participants were successfully guided through an obstacle course by static and dynamic patterns.

Design, Implementation, and Analysis of an IDE for a Beginner's Programming Language
Master Thesis, Student: Björn Fiedler, Supervisor: Michael Rohs , Submitted: November 2017

The goal of this thesis is to develop an IDE that supports beginning programmers in writing simple programs and in understanding fundamental programming concepts. There is evidence that good error messages, syntax highlighting, short editing cycles, immediate feedback, stepwise execution, visualization of the execution state, and last but not least simple language semantics are important aspects of an IDE that aims to support programmers in their initial steps. The IDE is used in conjunction with a simple programming language, provisionally called PostFix, which is based on PostScript and Forth and which provides explicit access to the runtime stack. The explicit stack simplifies parameter passing and return semantics. The language is well suited for visualizing the execution state at each point. The IDE should support incremental interactive development using read-eval-print loops (REPLs) as in LISP-like languages. Programmers should be able to step through the execution of a program and see the evolution of the program stack and the dictionary stack of variables. This thesis should take into account existing approaches from practice as well as principles from the programming language usability community, such as the Cognitive Dimensions Framework. As part of the thesis selected aspects of the developed IDE should be evaluated.

Deep learning for handwriting recognition based on multi sensor data from pens
Master Thesis, Student: Max-Ludwig Stadler, Supervisor: Maximilian Schrapel , Submitted: October 2017

Remembering handwritten Notes like dates or shopping list is a challenging task in a digitalized world. People may forget their important handwritten notes when they need them. Digital writing can build a bridge between handwritten papers and digital informations. There are several approaches to digitalize handwritten letters. This work focuses on movement sensors combined with audio data collected from the pen and involves research questions like how can simple letters be classified with neural networks?

Improving VR Presence using Head-Based Vibrotactile Feedback and Hand Tracking
Master Thesis, Student: Bastian Krefeld, Supervisor: Oliver Beren Kaul , Submitted: October 2017

The feeling of being in a virtual environment, so-called presence, is important for experiencing these environments. In this thesis, the improvement of presence through the use of vibration feedback around the head in combination with interaction through hands is explored. The feedback at the head is given through a hat with built-in vibration motors, the so-called HapticHead. Interactions with the virtual world are done through the HTC Vive and its handtrackers. Interactions between the virtual objects held in the hand and the virtual head are simulated and analyzed. To analyze the feeling of presence, questionnaires are used. Additionally, data that is collected while users interact with the system is evaluated in regards to improvements of the feeling of presence through vibration feedback.

Application Scenarios for Smartwatch Interactions with Distance Sensors
Bachelor Thesis, Student: Lars Hamann, Supervisor: Michael Rohs , Submitted: October 2017

Touch screen interaction on smartwatches is problematic because of the small size of the screen and the occlusion caused by the finger. An alternative approach is around-device interaction in which the interaction happens in the space around the smartwatch. An object, the user's finger, or the user's body is tracked to trigger actions on the smartwatch. The objective of this thesis is to develop application scenarios for around-device interaction with smartwatches. The tracking is realized with an existing prototype that has a small number of time-of-flight distance sensors, which are attached to the watchstrap.

Using pen movement and audio data to verify signatures
Bachelor Thesis, Student: Lukas Nagel, Supervisor: Maximilian Schrapel , Submitted: August 2017

Forging of a signature is a serious problem in everyday business. A lot of transactions like cash transfer have to trust signatures. Your task will be to implement an additional acoustic mechanism which can differentiate between fake and original signatures. This will lead to basic research questions: How to detect signatures on different surfaces? or the quality of the classification? A small user study will evaluate the system. Knowledge in C, C++ or Java and Python is recommended. For more details please contact me.

Usage of eye tracking depth information for interaction with objects in virtual reality
Bachelor Thesis, Student: Jannik Dahlke, Supervisor: Maximilian Schrapel , Submitted: August 2017

Eye trackers can be used for gaze prioritized graphics or games and other tasks in VR. By collecting deph information from pupil positions the possibilities of VR human computer interactions can be increased rapidly. For example think about multiple overlayed VR-desktops you can select with your eyes or a CT scan you can look though. Even deph interactions in VR games are possible. In this thesis you implement and evaluate an interactive VR user Interface with deph informations given by an VR eye tracker. Knowledge in Unity and python is recommended. For further informations feel free to contact me.

Implicit calibration of three dimensional eyetracking gaze points based on moving objects in virtual reality
Bachelor Thesis, Student: Tim Cofala, Supervisor: Maximilian Schrapel , Submitted: August 2017

A serious problem with eye trackers is the so called calibration drift. After a while with your eye tracking VR headset the gaze point will contain an offset error. In this this thesis you will implement an technique which follows your eye movements to determine what youre looking at. With that information you will correct a given 3D gaze point. Thus you will evaluate the research question can we increase the accuracy of eyetrackers for virtual reality? and What objects can be used for VR smooth pursuit? Knowledge in Unity and python is recommended. For further informations feel free to contact me.

Electromyography-Based Acknowledgement of Haptic Notifications
Bachelor Thesis, Student: Justin Schulte, Supervisor: Tim Dünte , Submitted: August 2017

In this thesis, three acknowledgment methods for haptic notifications are compared. To this end, a system has been developed that can be used to receive notifications by muscular stimulation and send acknowledgments by electromyography on the same muscle. The three methods differ by the property that the acknowledgment is spatially or temporally encoded by electromyography or as a comparison a Smartwatch application is used. In a study of 12 participants, these different acknowledgment methods were compared. For this purpose, the data were evaluated quantitatively for response time and error rate as well as qualitatively with regard to the user acceptance. As a result, the electromyography-based method Direction achieved the best performance with a very positive user rating and a detection rate of 96%.

Position Detection of an Electrode Grids on the Forearm via EMG
Bachelor Thesis, Student: Malte Lucius, Supervisor: Tim Dünte , Submitted: August 2017

Haptic input and output methods are becoming more and more popular in HCI. These require a good calibration in order to make the best use of these methods possible. This work is devoted to the problem of calibration of electrode grids on the forearm. For this purpose, an approach for displacement detection is presented. A prototype consisting of two separate bracelets with 18 or 22 electrodes was used to capture data. In the course of this thesis the prototype was reproduced and revised from the point of view of mobility. The changes made are presented during the course of the work. Subsequently, a study was conducted with twelve participants. These had to perform 135 repetitive gestures under various constraints such as rotation of the prototype to investigate whether different gestures can be used for displacement detection. Furthermore, qualitative information on the prototype was collected and evaluated. An attempt was made to apply a simple displacement detection method to the data collected in the study. This procedure led to an unsatisfactory result. The reasons for the failure of the procedure are discussed, evaluated and approaches for further investigations derived.

Real-Time Navigation of Visually Impaired Users via a Self-Positioning Device and Vibrotactile Feedback
Master Thesis, Student: Guido Gardlo, Supervisor: Oliver Beren Kaul , Submitted: August 2017

Currently blind people rely on a stick to navigate through their surroundings. This thesis proposes a solution that could replace that method in the future. It combines a Google Tango smartphone, which is capable of self localization and object detection with HapticHead, a vibrotactile head worn device that is built for intuitive three-dimensional guidance. Together these tools form a navigation system for the blind. Two experiments are conducted where the first one indicates that vibrotactile patterns, when learned, could be used to transport navigational information. The second experiment shows a 75% success rate in waypoint navigation without crashing into unknown obstacles and a complete success in finding the direction of unknown objects with a mean error of 7 degrees.

EMG-Based Hand Gesture Recognition with a Multi Electrode Grid
Bachelor Thesis, Student: Josef Kriegel, Supervisor: Tim Dünte , Submitted: August 2017

This bachelor thesis covers the measurement of muscle activity in the forearm using electromyography, an electrode sleeve and the evaluation of the values arising from the measurement with a machine-learning algorithm to distinguish different hand gestures. The prototype was evaluated in an additional study in which 5 gestures were successfully detected. The maximum detection accuracy fluctuated around 55 % using a Support Vector Machine and between 80 and 100 % using a randomForest algorithm.

Indoor Navigation with Smartwatches
Master Thesis, Student: Linh Phan, Supervisor: Michael Rohs , Submitted: May 2017

ScrollingHome is an interesting concept of indoor navigation using a smartwatch: A navigation path is broken up into a 1D stripe, shown visually on a smartwatch, and the user scrolls the photo stream to move towards the target. The goal of this thesis is to replace manual scrolling by the use of the sensors of the smartwatch and the mobile phone of the user and to develop a framework that allows selecting targets in a larger building. The main university building should serve as a testbed for this goal. Questions concern the achievable reliability of an automatic approach using only the built-in sensors of the smartwatch and the mobile phone.

Smartwatch Posture Tracking
Master Thesis, Student: Christian Domin, Supervisor: Michael Rohs , Submitted: May 2017

Navigating through large information spaces on smartwatches is hard. A significant amount of touch screen interaction is necessary. If the absolute position and orientation of a smartwatch with respect to the body position of the user could be determined, then information navigation could presumably be performed more efficiently. It is difficult to determine absolute smartwatch position from acceleration data alone. Hence this thesis investigates which additional sensors can support smartwatch posture tracking to make it simpler and more reliable. Initial ideas include using trajectories (history information) instead of just end positions, using absolute distance sensors (time-of-flight sensors), and taking advantage of smartwatch interactions for calibration. The goal of this thesis is to develop a solution involving a small set of sensors (to be added to the smartwatch and/or strap) for smartwatch posture tracking and to develop an example application.

Rapid Serial Visual Presentation on the Go
Bachelor Thesis, Student: Tim Rouven Hamp, Supervisor: Michael Rohs , Submitted: March 2017

Smartwatches have extremely small display areas. Information presentation and selection could potentially be made more effective by transferring these tasks from the spatial to the temporal domain. This includes the presentation of text but also the selection from menus. The goal of this thesis is to explore how to realize the transformation from the spatial to the temporal domain, what parameters to consider and what sensor data, interaction possibilities, and contextual information are required give the user a sense of control. One specific aspect is how to deal with task interruptions and how to resume tasks.

Analysis and Modeling of Interactive Devices
Bachelor Thesis, Student: Daphne Schössow, Supervisor: Michael Rohs , Submitted: March 2017

The goal of this thesis is to develop a platform that allows to easily analyze the user interface of existing interactive devices and to represent them as a virtual model. The virtual model can then be used in an interactive Web page or as a standalone app, and be modified for user testing. The virtual model may also serve to compute certain usability characteristics, given device states and display contents. The platform is supposed to include an interactive tabletop and camera-based capturing system. You should be familiar with Java and ideally have some experience with human-computer interaction.

Compression Feedback for Notifications
Master Thesis, Student: Hung Ngo Quang, Supervisor: Henning Pohl , Submitted: October 2016

While we have explored general parameters of compression feedback, this thesis is supposed to evaluate concrete performance of compression feedback for notifications in an actual working scenario. Thus, you will need to hook into the Android notification mechanism and map incoming notifications or derived state from several notifications to some form of compression output.

Evaluation of a Vibrotactile Guidance and Immersion Display on the Head
Bachelor Thesis, Student: Kevin Meier, Supervisor: Oliver Beren Kaul , Submitted: October 2016

Current generation virtual reality (VR) and augmented reality (AR) head-mounted displays (HMDs) usually include no or only a single vibration motor for haptic feedback and do not use it for guidance. We developed a vibrotactile guidance and immersion display called “HapticHead”, a system utilizing 20 vibration motors distributed in three concentric ellipses around the head to give intuitive haptic guidance hints and to increase immersion for VR and AR applications. The purpose of this Bachelor’s thesis will be an in-depth evaluation of the possibilities arising from this device. This includes conducting a user study with multiple participants on a target-finding task and the implementation and evaluation of immersive VR scenes with haptic feedback.

Competitive Emoji Response Game
Bachelor Thesis, Student: Marco Deneke, Supervisor: Henning Pohl , Submitted: August 2016

In this thesis your job would be to implement a fun game for either Android or the web where players compete against each other in a contest to pick the best emoji. We envision this to be in an Apples to Apples like format where players respond to animated gifs showing an emotion.

Reactive Compression Feedback
Bachelor Thesis, Student: Peter Brandes, Supervisor: Henning Pohl , Submitted: August 2016

With our existing compression feedback prototype, we would like to explore reactive interactions. Here users press on the pressure cuff, which reacts by letting out some of the pressure. By varying the release pattern, users can perceive several different stimuli. The feedback here is reactive in that it only occurs once users specifically query state.

An Ambient Multi-Scale Information Object
Bachelor Thesis, Student: Sezer Dursun, Supervisor: Henning Pohl , Submitted: August 2016

Ambient devices provide glanceable information in the periphery. One example of such a device would be a sphere glowing red when a stock is falling and green when it is rising. Such objects can nicely blend into the background, yet can provide useful information for the knowledgeable user. However, such objects usually fall short once more detailed information is desired - instead of just red or green, a user might want to see the actual percentage change in stock price. In this thesis, you will build an ambient device that helps people catch their next bus or tram. It will subtly change color as a new connection is approaching. However, your object shall actually include more information as the user approaches it (which bus, how many minutes, ...). For this, we will embed a proximity sensor into the object. Building such an object is fairly straightforward. An equally important part of this project shall be the evaluation. You'll give your device to several users who will keep it in their homes or offices for at least a couple of weeks. We'll use diary methods and interviews to find out more on how users perceived such objects and how their interaction with them changed over time.

Casual Interaction with a Smartwatch
Master Thesis, Student: Sven Röttering, Supervisor: Henning Pohl , Submitted: July 2016

We have an existing prototype for a bracelet that acts as a wearable smart-home lighting controller. We would like to build on this and extend the available interaction space. We would also like to transition the prototype to a smartwatch in order to further integrate the system.

Conception and Implementation of a System for Obstacle Avoidance in Pedestrian Navigation with Electrical Muscle Stimulation
Master Thesis, Student: Sven Lilge, Supervisors: Max Pfeiffer , Steffen Busch , Submitted: July 2016

This work focuses on the exploration of electrical muscle stimulation (EMS) applications in the context of navigation tasks for pedestrians and visually impaired persons. The combination of localization, environment perception and EMS allows to navigate the user without the usual high cognitive load. In order to achieve this goal, a navigation system which uses EMS to steer its users around obstacles in their surroundings is designed and implemented. The system makes particulary use of a color and depth imaging system to perceive the environment and localize the user in it. The functionality and reliability of the system is evaluated in a user study, planned and carried out within this research work. Considering the achieved results of the study it is discussed whether an EMS based navigation can be used in every day life.

A Self-Calibrating Wearable Electrode Grid for Controlling Hand Gestures via EMS
Master Thesis, Student: Tim Dünte, Supervisor: Max Pfeiffer , Submitted: July 2016

In this thesis the development and use of a prototype is presented, which allows the generation of hand gestures via electrical muscle stimulation (EMS). The prototype consists of two parts: a stimulation and control unit and an electrode grid. The stimulation unit can be used to control up to 20 different muscles with freely selectable parameters. The electrode grid consists of two silicone bracelets with 22 and 18 encapsulated electrodes. The prototype was self-constructed. Therefore, relevant components of the hardware as well as the software are presented. Since the prototype is self-made, the safety of the prototype is also discussed. The aim of the development was to enable a fine-granular control of the muscles in the forearm. With this fine-granular control hand gestures can be produced as a combination of several individual movements. Before the user can use the prototype, it must be calibrated to the user. For this reason, different calibration approaches for the calibration of the prototype are presented and a self-calibration approach is developed, which does not require any sensors at hand. Finally, a conclusion is drawn on the work and further research is presented, which is made possible by the prototype or its components.

A Shape-Changing Display for Ambient Notifications
Master Thesis, Student: Andre Lehnert, Supervisor: Max Pfeiffer , Submitted: July 2016

The objective of this work is to provide a development environment for the design of an ambient multi-purpose shape-changing display which is controllable via a RESTful Web Service. The shape-changing display provides visual and physical representation of digital information in a comprehensible manner. In order to explain this closer a description of theoretical basis of the perception and the psychology of perception is given, which is set in relation to the development of physical data visualizations and tangible user interfaces (TUI). The token-based interaction is considered in more detail as part of TUIs. The findings are included in a concept that is evaluated with paper prototypes. The development of the prototype is done in an iterative design process. The resulting increments are presented. The qualitative assessment and the identification of additional applications completed a design workshop.

Design of a Tool for Analyzing and Modeling Interactive Devices
Bachelor Thesis, Student: André Kamrad, Supervisor: Michael Rohs , Submitted: May 2016

The goal of this bachelor thesis is to design and develop a program capable of constructing a Finite State Machine graph out of a recorded video. The idea was to simplify the process of analyzing and optimizing the usability of interactive devices, by providing a low-effort tool to construct a FSM for further simulations.

A Zooming Emoji Keyboard
Bachelor Thesis, Student: Dennis Stanke, Supervisor: Henning Pohl , Submitted: March 2016

This thesis implemented a zooming UI for a novel emoji keyboard on Android. Enabled by current high resolution phone displays, this allows showing all emoji at once and quick selection with as few as two taps.

Haptic Feedback in 3D Interaction – Simulating Object Properties Using EMS
Bachelor Thesis, Student: Wei Chen, Supervisor: Max Pfeiffer , Submitted: January 2016

In 3D interaction haptic feedback is facing challenges to increase realism. In previous projects we investigated a novel approach to simulate haptic object properties such as size with electrical muscle stimulation. In this project we would like to use 3D projection or head amounted displays to investigate novel interaction methods for our haptic feedback approach. If you are interested in new haptic feedback methods, 3D programming, prototyping, and user study design, contact me.

Categorical Emoji Keyboard
Bachelor Thesis, Student: Philipp Seelig, Supervisor: Henning Pohl , Submitted: October 2015

Instead of presenting emoji in a list, this thesis explores how category labels, such as positive and negative can help in emoji text entry.

Pedestrian Navigation – Controlling Walking Direction using EMS
Bachelor Thesis, Student: Peter Denis, Supervisor: Max Pfeiffer , Submitted: October 2015

In previous projects we investigated a novel approach to control pedestrians’ walking direction for navigation. We showed that controlling the direction with electrical muscle stimulation works in outdoor navigation scenarios. As a follow-up project we will use our prototype to investigate the precision of that approach. In this thesis a differential GPS-based navigation prototype should be designed and developed for a mobile phone and tested in outdoor user studies. You will get a deeper understanding of novel haptic feedback methods, differential GPS, mobile development, prototyping, and user study design.

Universal Haptic Touch – Simulating Haptic Touch Feedback on Large, Small, and Mobile Touch Devices
Bachelor Thesis, Student: Eike Schlicht, Supervisor: Max Pfeiffer , Submitted: October 2015

Nowadays haptic feedback is located in the device itself. In a new approach we investigate haptic feedback for touch input that is located on the user. In our current work we are using electrical muscle stimulation for haptic feedback on multi-touch surfaces and investigate different feedback patterns. In a follow-up project we would like to extend this approach to multiple devices and add new patterns. In this thesis you will get a deeper understanding of haptic feedback with electrical muscle stimulation, multiple devices development, and user study design.

Biofeedback for User Evaluation – Collecting and Analyzing Data of an Arduino-Based Low-Cost Biofeedack System
Bachelor Thesis, Student: Björn Fiedler, Supervisor: Max Pfeiffer , Submitted: October 2015

In user studies it is often hard to measure continuous user feelings such as stress, frustration, or satisfaction. In addition to the traditional evaluation methods Biofeedback can be used to get a broad understanding of the user. Biofeedback are processed data of physical functions of the user such as blood pressure, heart rate, galvanic skin response (GSR), electrocardiography (EKG), electroencephalography (EEG), or electromyography (EMG) data. In this thesis, first, a literature review should be done; second, an Arduino-based Biofeedback evaluation tool should be implemented; and third, the prototype should be tested in a user study. If you are interested in Arduino programming, user evaluation, and prototyping, then contact me.

Compression Feedback Gaming
Bachelor Thesis, Student: Franziska Hoheisel, Supervisor: Henning Pohl , Submitted: October 2015

We are going to design a pervasive game where interacting with virtual objects can result in real-life encumberance.

Eye-Tracking for Casual Interaction with a Phone
Bachelor Thesis, Student: Christoph Lenz, Supervisor: Henning Pohl , Submitted: September 2015

Your phone is lying on a table and you want to check who sent you that text without picking it up. Write some code to combine our eye-tracker with our motion tracker to implement a way to interact with the phone just with gaze.

Casual Output for Smartwatches
Bachelor Thesis, Student: Justyna Medrek, Supervisor: Henning Pohl , Submitted: September 2015

Smartwatches are hogging our attention with a constant buzzing of notifications. We want to explore scattering light in the arm for a lower intensity kind of feedback that only grabs attention mildly.

A Context-Based Approach to a Proactive Launcher for Mobile Devices
Master Thesis, Student: Andreas Möhring, Supervisor: Michael Rohs , Submitted: July 2015

Due to the growing number of applications being installed on smartphones it is becoming harder for users to manage all of those applications and to find the right one at the right time. Context-aware proactive app launchers that utilize machine learning to predict the applications that are most likely to be opened next are one solution to this problem. However, it is still not clear how exactly to design these best and especially how to visualize the predictions to achieve the best user experience, i.e. in a way that helps users without confusing them and taking away control. In this thesis I report about SmartLauncher, a prototype of such a system, and a field study I conducted, utilizing visual salience to guide users in an unobtrusive way. The study shows that a combination of good predictions and this subtle way of assistance can improve the mean speed of finding apps by up to 8% while being superior in terms of user acceptance to other approaches utilizing e.g. rearrangement. Part of this thesis has also been submitted as a scientific paper to the 17 th International Conference on Human-Computer Interaction with Mobile Devices and Services (MobileHCI 2015). Thus some parts can be found in both documents and are not explicitly cited.

A Mobile Feedback and Microlearning System for University courses
Master Thesis, Student: Marcus Wobig, Supervisor: Michael Rohs , Submitted: July 2015

Diese Arbeit untersucht, wie mithilfe eines crowdbasierten Ansatzes das Problem der geringen Beteiligung von Studenten in Universitätsvorlesungen vermindert werden kann. Studenten haben nur wenige Möglichkeiten, dem Dozenten direktes Feedback zu geben, während einer Vorlesung meist ausschließlich verbal. Viele Studenten trauen sich nicht eine Frage zu stellen, beispielsweise aus Angst von den Kommilitonen als “dumm“ wahrgenommen zu werden, den Fluss der Vorlesung zu unterbrechen, oder weil sie mehr Zeit benötigen, um über die Inhalte nachzudenken und eine Frage zu formulieren. So bleiben viele Fragen der Studenten ungestellt, die Frontalvorlesung wird im Sinne des Wortes genutzt: Der Dozent trägt vor und die Studenten schreiben den Tafelinhalt mit. In dieser Arbeit wird ein System entwickelt, das Fragen und Antworten der Studenten erfasst und automatisiert in ein Quiz umgewandelt. Das Quiz gibt den Studenten Feedback über ihren aktuellen Lernstand und ihre Fortschritte in der Auseinandersetzung mit den Vorlesungsinhalten. Studenten können die Lerninhalte auch mobil bearbeiten (Microlearning) und sich somit aktiver damit auseinandersetzen. Der Dozent erhält Feedback, zu welchen Vorlesungsinhalten es viele Fragen gibt. In einer Evaluation wird das entwickelte System getestet, durch die Funde kann es dann noch weiter verbessert werden. Damit ergibt sich ein System, welches in Vorlesungen oder ähnlichen Kursen zur Unterstützung des Lern- / Lehrprozesses eingesetzt werden kann. Durch die Automatisierung wird dabei dem Dozenten ein großer Teil an Arbeit abgenommen, wodurch mehr Zeit für die inhaltliche Vermittlung von Ideen und Konzepten bleibt.

Haptic Feedback for Mobile Augmented Reality Interactions with Physical Objects
Master Thesis, Student: Oliver Beren Kaul, Supervisor: Max Pfeiffer , Submitted: May 2015

Augmented reality (AR) aims at providing additional information about physical objects. This information is primarily displayed as graphical overlays that are aligned with these objects. Currently, it is difficult to generate haptic output in augmented reality interactions. Vibrotactile output is common, for example with mobile phones, but is limited in the kind of output it can generate. Mechanical haptic output devices, such as the Phantom device, generate high-fidelity haptic output, but are expensive, bulky, and not mobile. This work aims at improving this situation by exploring electrical muscle stimulation (EMS) as novel kind of lightweight haptic output mechanism. A concrete task is to use virtual haptic feedback for guiding users relative to a physical object in augmented reality situations. Potential scenarios are educational (e.g., exploring cables and functional units in a motor), maintenancerelated (e.g., showing how to twist and turn a replacement part such that it fits into a target position), or related to exhibitions (e.g. guiding the user towards a building in a city model).

Plagiarism Detection in Student Programming Assignments
Bachelor Thesis, Student: Christian Domin, Supervisor: Markus Krause , Submitted: May 2015

In this thesis we design a plagiarism detection tool, which detects plagiarism in student programming assignments. This system increases the prediction accuracy with dynamic removal of parts in assignments, which are part in almost every assignment. We call this common ground. This approach enables the system to distinguish between normal similarities and plagiarism in relation to the course. The technique used by the system is language independent. However we can achieve a similar detection accuracy like the plagiarism detection tool Moss.

Motivationsverstärkung bei Studenten in Onlinekursen durch Gamification
Bachelor Thesis, Student: Marc Mogalle, Supervisor: Markus Krause , Submitted: May 2015

Gamification wird häufig verwendet, um die Bearbeitung von Aufgaben für die Teilnehmer angenehmer zu gestalten. Auf dieser Grundlage wollen wir unsere Hypothese, dass Gamification auch die Motivation der Bearbeitenden verstärkt, überprüfen. Dazu gestalten wir die Plattform eines Onlinekurses um und führen damit zwei Experimente durch, in denen die Teilnehmer in drei Gruppen (Standard, Gamified und Social-Gamified) Teile eines Onlinekurses bearbeiten. In der Benutzerstudie hat sich herausgestellt, dass ein signifikanter Unterschied zwischen der Standard und der Gamified-Gruppe, sowie von der Standard- und der Social-Gamified-Gruppe in der Bewertung der Nutzer vorliegt. Die Gamified und Social-Gamified-Varianten wurden in den Punkten Spaß an der Nutzung der Plattform und Design signifikant besser bewertet. Zusätzlich haben die Social-Gamified-Nutzer angegeben, den Kurs weiterempfehlen zu wollen, sowie mehr Spaß am Kurs selber gehabt zu haben, als die Vergleichsgruppen. Dies kann man auf die intrinsische Motivation durch Freude an der Nutzung der Plattform zurückführen.

Simulation von Texturen mit EMS-basiertem haptischem Feedback für interaktive Oberflächen
Bachelor Thesis, Student: Le Duy Linh Phan, Supervisor: Max Pfeiffer , Submitted: May 2015

In this bachelor thesis a possibility for simulating textures with haptic feedback on interactive surfaces using eletric muscle stimulation (EMS) is introduced. With EMS a user can be controlled using the force of their own muscles and they perfom movements according to prefabricated patters on the surface to simulate textures. A prototype with an Arduino Nano as base unit has been designed which can communicate with a surface using WLAN and which will trigger a user’s hand movement on touching a texture on the surface. A user case study is used to evaluate if texture simulation with EMS is possible using the prototype.

Supporting audiometric testing for children through a computer game
Bachelor Thesis, Student: Marco Herbst, Supervisor: , Submitted: May 2015

Cortical evoked response audiometry (CERA) is an objective audiometric test to determine hearing loss. In order to capture good measurements, participants needs to remain calm and listen carefully to the played sounds. Children tend not to stay calm and listen carefully. Thus, the test is only administered to adults at the Medical School Hanover (MHH). The interactive computer game CERAtronis developed to support testing children. The aim of this thesis is to use a serious game in order to increase the attention level and obtain valid measurement data from children during audiometric testing. The CERA was given to 4 children and 5 adults with the game. The generated average curves for the different dB-values are analyzed and observed for the N1-P2 complex. The results indicate that the average curves of adults with the CERAtron game provide a N1-P2 complex, but the data from children does not. Nevertheless, the children manage to finish the test with the CERAtron game which confirmed that the attention level was raised. However, future research could improve the test by conducting more measurements during the game. This might allow to receive improved average curves and detect the N1-P2 complex in children data as well.

Digital Games for Voice Taining
Bachelor Thesis, Student: Kevin Raetz, Supervisor: Markus Krause , Submitted: May 2015

The process of learning can be repetitive and boring. An approach to counteract this is using digital games to complement the learning task or to develop games that teach the required skill and knowledge. A problem regarding this approach is that only certain people enjoy certain games and it is not given that all participants in a class are appealed by the chosen game. There is work that investigates how to make applications and especially games more accessible by using pitch and even using games played by singing in an educational context. This thesis builds upon these works in that it develops a functional prototype which helps the user to learn to sing in tune by providing an interface that maps pitches onto key input which is used to play a game that is not build to be played by vocal input. For the thesis the game Tekken 3 was chosen and a mapping for the character Hwoarang was created. Tekken 3 is chosen because of its action-heavy and fast-paced concept what should provide good insight about the possibility to conserve the fun of playing the game even though the game concept is violated by making it turn-based. It is expected that the learner finds this more engaging and enjoyable than a regular „sing in tune“ application or the gamification of such application, since he is playing a game with all its features.

Entwurf und Analyse einer interaktiven Visualisierung für planare Graphen höherer Ordnung
Bachelor Thesis, Student: Thiemo Fischer, Supervisor: Michael Rohs , Submitted: May 2015

Many different disciplines use node-link diagrams as a preferred metod of visualization for relational data. Over the years various aesthetic criteria for these visualizations emerged. Most important is the demand to draw graphs crossing-free. No edges are supposed to cross each other. In this bachelor thesis a universal data model for node-link diagrams is developed. It harmonizes the concepts of similar models and adds the ability for representing faces and three dimensional domains as well. Subsequently an algorithm is engineered. It produces a mouse-controllable, crossing free node-link diagram of the named data model. The technique is based on using planar embeddings of graphs into higher genus surfaces. Finally the utility, aesthetics and limits of the procedure are discussed.

Haptisches Feedback in 3D Interaktionen- Simulation von Objekteigenschaften mittels EMS
Bachelor Thesis, Student: Martin Buntrock, Supervisor: Max Pfeiffer , Submitted: May 2015

In this bachelor thesis the use of haptic feedback using electrical muscle stimulation (EMS) for simulating object properties is considered. A prototype capable of stimulating up to two muscles is used to simulate object sizes by contracting forearm muscles. The system setup and prototype are described and the precision of the simulation of object sizes is evaluated using a user study. The user study is described in detail and the results are discussed. Problems concerning the implementation of a weight simulation are presented and the limits of the achievable feedback using this prototype are discussed. Finally an outlook based on the findings is given.

Multi-Scale Around-Device Output
Bachelor Thesis, Student: Bastian Krefeld, Supervisor: Henning Pohl , Submitted: March 2015

Previously, embedding LEDs in device bezels has been explored at coarse and static resolutions. We would like to investigate more fine-grained around-device output. Thus, we'll use conventional displays and route those to the edge using fibre optics to simulate full-output bezels. Possible use-cases include offscreen-visualization and casual interactions.

Casual Interaction with a Bracelet
Master Thesis, Student: Karoline Busse, Supervisor: Henning Pohl , Submitted: December 2014

Interaction with wearables nicely affords switching between focused and casual interactions. A bracelet, for example, is mostly in the periphery of our attention. However, a simple arm movement can bring it into focus. Here we would like to explore how to build a prototype bracelet device that can support different interactions at each of those attention levels. In a smart-home scenario, we furthermore will investigate specific ways to control lighting with varying levels of engagement.

Thumb Input for Tablet Computers
Bachelor Thesis, Student: Tim Dannhauer, Supervisor: Michael Rohs , Submitted: October 2014

When holding a tablet computer the thumbs typically just hold the device. This thesis investigates how the thumbs can be involved in the interaction when navigating through content or playing games. Various sensors will be used to measure thumb movement. The ergonomic possibilities and limitations will be evaluated. Based on these results, new interaction techniques will be developed.

Comparison of Object-Oriented and Functional Programming for GUI Development
Master Thesis, Student: Eugen Kiss, Supervisor: Michael Rohs , Submitted: August 2014

Traditionally, the object-oriented paradigm has been considered a good fit for designing and developing graphical user interfaces (GUIs). A large number of GUI frameworks are based on object orientation (OO). Recently, functional programming (FP) has become more popular for mainstream development. This thesis is concerned with a comparison of the object-oriented approach and the functional approach applied to the development of graphical user interfaces. To limit the scope, the thesis focuses on languages that are available on the Java Virtual Machine. In particular, the main candidates are Java/Swing on the object-oriented side, and Clojure/Swing and Clojure/Seesaw on the functional side. If time allows, Scala/Swing might be considered as a hybrid object-oriented and functional language.

Multi-Touch Text Entry for Mobile Devices
Master Thesis, Student: Minh Anh Truong, Supervisor: Michael Rohs , Submitted: July 2014

Text entry on mobile devices with capacitive touch screens is in widespread use. However, limited display sizes and lack of tactile feedback make mobile text entry challenging for users. A number of research efforts have tried to improve mobile text entry by, e.g., using language models to allow for imprecise typing, using different keyboards for specific tasks, finding optimized keyboard layouts, and developing gesture-based text entry systems. Less emphasis has been put on using the capabilities of multi-touch screens for text input in the sense that disambiguation between characters can be achieved by touching a key with different numbers of fingers. This thesis is going to explore the possibilities of multi-touch text input on mobile devices. This includes investigating the accuracy and speed of rapid changes between single- and multiple-finger touches. It also requires optimizing keyboard layouts. The final variant should be implemented on Android devices as a replacement of the standard keyboard.

Design and Implementation of a Wearable Prototype for EMS-Based Pedestrian Navigation
Bachelor Thesis, Student: Tim Dünte, Supervisor: Max Pfeiffer , Submitted: May 2014

In this work, two options are presented how pedestrian navigation can take place with electrical muscle stimulation (EMS). The first approach involves the stimulation of forearm muscles with EMS, while the second approach involves the stimulation of a thigh muscle per leg. These two possibilities will be presented for each a corresponding concept, in which the used muscles and a possible encoding of the information for the navigation will be discussed. For the generation and control of the EMS-signals, the implementation of a wearable prototype is presented. This was created based on an Arduino Uno, a self-made circuit and a commercially available EMS unit. This EMS-system will allow controlling the intensity of the EMS-signal and a communication with a mobile device, for example a smartphone. The created EMS-system and the second approach will be evaluated in a laboratory study. The study is intended to make quantitative and qualitative statements, whether navigation of the user over the thigh muscle is possible and whether navigation could take place in everyday life in this way.

Semantic Similarity - Comparing Crowdworkers with Experts
Bachelor Thesis, Student: Nils Batram, Supervisor: Markus Krause , Submitted: May 2014

Humans have a natural ability for language processing which computer algorithms lack. However, for some areas of natural language processing, computer algorithms can provide a fast and cheap alternative to manpower. Instead of conducting a conventional survey, distribution of the workload over the internet to a large group of independent workers (crowdworkers) can increase flexibility and reduce costs. This thesis analyzes the performance of crowdworkers on semantic similarity tasks. To this end, a crowdworker study is conducted and the results are compared to offline contributors and computer algorithms. The effects of quality control are investigated by repeating the experiment under various quality control conditions. This thesis will show that, with quality control mechanisms in place, crowdworkers can provide results close in quality to offline contributors. It will also provide evidence that current algorithms outperform single human contributors, but still cannot compete with aggregated results gathered from groups of contributors.

Simulation von haptischem Feedback in 3D Interaktionen: Unterscheidung von Objektgrössen durch EMS
Bachelor Thesis, Student: Gil Engel, Supervisor: Max Pfeiffer , Submitted: May 2014

In this bachelor thesis a system to simulate haptical feedback by electric muscle stimulation will be described. With this system it is possible to make virtual objects perceptible. A approach will be introduced that uses two muscles on the lower arm. The EMS Signals gets controlled by a self designed prototyp which will be decribed in detail. Portability of the prototyp gets reached by designing it small and with the use of portable technics like WiFi. With a case study the efficiency of the approach will be measured. The study will be decribed more in detail. Furthermore the results get presented precisely. Finally a discussion of the results will be made and an outlook be given.

Around-Device In-Air Gestural Interactions
Bachelor Thesis, Student: Sven Greiner, Supervisor: Henning Pohl , Submitted: March 2014

For a direct interaction with around-device targets it is neccessary to know the minimal size of a target a user can interact with. In a study the size is determined under the assumption of a good visualization supporting the user in finding the correct location. Measurements result in a sphere of around 40 mm in diameter.