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Virtual-reality (VR) is an immersive technology with a growing market and many applications for gesture recognition. This thesis presents a VR gesture recognition method using signal processing techniques. The core concept is based on the comparison of motion features in the form of signals between a runtime recording of users and a possible gesture set. This comparison yields a similarity score through which the most similar gesture can be recognized by a continuous recognition system. Some selected comparison methods are presented, evaluated and discussed. An example implementation is demonstrated. However, due to an introduced layer model parts of the method and its implementation are interchangeable.
Similar or even better performance is achieved compared to other related work. The comparison method Dynamic Time Warping (DTW) reaches an average positive recognitions rate of 98.18% with acceptable real-time application performance. Additionally, the method comes with some benefits: position and direction of users is irrelevant, body proportions have no significant negative impact on recognition rates, faster and slower gesture executions are possible, no user inputs are needed to communicate gesture start and end (continuous recognition), also continuous gestures can be recognized, and the recognition is fast enough to trigger gesture specific events already during the execution.
Secure Search
(2011)
Nowadays it is easy to track web users among websites: cookies, web bugs or browser fingerprints are very useful techniques to achieve this. The data collected can be used to derive a specific user profile. This information can be used by third parties to present personalized advertisements while surfing the web. In addition a potential attacker could monitor all web traffic of an user e.g. its search queries. As a conclusion the attacker knows the intentions of the web user and of the company he is working for. As competitors maybe very interested in such information, this could lead to a new form of industrial espionage. In this paper I present some of the techniques commonly used. I illustrate some problems caused by the usage of insecure transmission lines and compromised search engines. Some camouflage techniques presented may help to protect the web users identity. This paper is a based on the lecture "Secure Systems" teached by Professor Walter Kriha at the Media University (HdM) Stuttgart.
This bachelor thesis wants to describe a prototypical implementation of a 3D user interface for intuitive real-time set editing in virtual production. Furthermore this approach is evaluated qualitatively through a user group, testing the device and fill in a questionnaire. The dimension of virtual elements created with computer graphics technology in all areas of entertainment industry is steadily growing since the past years. Nevertheless can the editing process of virtual elements still require a costly process in terms of time and money. With the appearance of new input devices and improved tracking technologies it is interesting to evaluate if a real-time editing process could improve this situation. Being currently bound to experts on special workstations, this could lead to a more intuitive and real-time workflow, enabling everybody on a film set to influence the digital editing process and work collaboratively on the scene consisting of virtual and real elements.
Websites or web applications, whether they represent shopping systems, on demand services or a social networks, have something in common: data must be stored somewhere and somehow. This job can be achieved by various solutions with very different performance characteristics, e.g. based on simple data files, databases or high performance RAM storage solutions. For todays popular web applications it is important to handle database operations in a minimum amount of time, because they are struggling with a vast increase in visitors and user generated data. Therefore, a major requirement for modern database application is to handle huge data (also called big data) in a short amount of time and to provide high availability for that data. A very popular database application in the open source community is MySQL, which was originally developed by a swedisch company called MySQL AB and is now maintenanced by Oracle. MySQL is shipped in a bundle with the Apache web server and therefore has a large distribution. This database is easily installed, maintained and administrated. By default MySQL is shipped with the MyISAM storage engine, which has good performance on read requests, but a poor one on massive parallel write requests. With appropriate tuning of various database settings, special architecture setups (replication, partitioning, etc.) or other storage engines, MySQL can be turned into a fast database application. For example Wikipedia uses MySQL for their backend data storage. In the lecture Ultra Large Scale Systems and System Engineering teached by Walter Kriha at Media University Stuttgart, the question Can a MySQL database application handle more then 3000 database requests per second? came up some time. Inspired by this issue, I got myself going to find out, if MySQL is able to handle such a amount of requests per second. At that time I also read something about the high availability and scalability solution MySQL Cluster and it was the right time to test the performance of that solution. In this paper I describe how to set up a MySQL database server with the additional MySQL Cluster storage engine ndbcluster and how to configure a database cluster. In addition I execute some database tests on that cluster to proof that its possible the get a throughput of >= 3000 read requests per second with a MySQL database.
Head Mounted Displays (HMD) are increasingly used in various industries. But apart from the industry environment, the potentials of HMDs in a private environment like at home has been rel- atively unexplored so far. What daily tasks can these help with, in the home kitchen for example?
The aim of this thesis is to obtain knowledge about the usefulness of such an HMD, the HoloLens, in combination with an application, while following a new recipe. Therefore a prototype applica- tion for the HoloLens got developed which guides a user through the cooking of a sushi burger by using multimedia content.
With a mixed method design, consisting of quantitative and qualitative methods, the HoloLens in combination with an application was evaluated by 14 participants.
Not only the weight of the device was a problem for users. The test also revealed that the display is darkening the view and participants tend to look below the glasses. An advantage is indeed to reach the next cooking step without the need of using hands and always having in sight what needs to be done next. Positive feedback was given as well for the application. Through voice control the user communicates to a character which will guide through the recipe by videos and text.
If in future the technical characteristics of HMD devices will improve, an application in this con- text will be of advantage in order to simplify learning a new recipe. This device, in combination with an application, could help early-middle stage cognitive impaired people and blind people to cook.
Password-based authentication is widely used online, despite its numerous shortcomings, enabling attackers to take over users’ accounts. Phishing-resistant Fast IDentity Online (FIDO) credentials have therefore been proposed to improve account security and authentication user experience. With the recent introduction of FIDO-based passkeys, industry-leading corporations aim to drive widespread adoption of passwordless authentication to eliminate some of the most common account takeover attacks their users are exposed to. This thesis presents the first iteration of a distributed web crawler measuring the adoption of FIDO-based authentication methods on the web to observe ongoing developments and assess the viability of the promised passwordless future. The feasibility of automatically detecting authentication methods is investigated by analyzing crawled web content. Because today’s web is increasingly client-side rendered, capturing relevant data with traditional scraping methods is challenging. Thus, the traditional approach is compared to the browser-based crawling of dynamic content to optimize the detection rate. The results show that authentication method detection is possible, although there are some limitations regarding accuracy and coverage. Moreover, browser-based crawling is found to significantly increase detection rate.
Today’s digital cameras use a mosaic of red, green, and blue color filters to capture images in three color channels on a single sensor plane. This thesis investigates the use of convolutional neural networks (CNNs) for demosaicing – the process of reconstructing full-color images from raw mosaic sensor data. While there are existing CNNs for demosaicing raw images from the well-established regular Bayer color filter array (CFA), this thesis focuses on how they perform on alternative non-regular sampling patterns that produce less aliasing artifacts, namely the stochastic Gaussian- and the RandomQuarter sampling pattern (Backes and Fröhlich, 2020).
A basic UNet (Ronneberger et al., 2015) and the spatially adaptive SANet (T. Zhang et al., 2022) are implemented in a supervised training pipeline based on the PixelShift200 image dataset (Qian et al., 2021) to investigate their suitability for the irregular demosaicing task. The experiments indicate that the basic UNet encounters difficulties in restoring the missing color values, whereas the spatially adaptive convolutional layers help in processing the irregularly sampled raw images.
In addition, this thesis enhances SANet effectiveness by employing an alternative residual branch based on a CFA-normalized Gaussian filter, as well as a tileable modification to the Gaussian CFA pattern. The modified SANet is shown to outperform the conventional dFSR algorithm (Backes & Fröhlich, 2020) in terms of peak signal to noise ratio (PSNR) and structural similarity index measure (SSIM).
Large-scale computing platforms, like the IBM System z mainframe, are often administrated in an out-of-band manner, with a large portion of the systems management software running on dedicated servers which cause extra hardware costs. Splitting up systems management applications into smaller services and spreading them over the platform itself likewise is an approach that potentially helps with increasing the utilization of platform-internal resources, while at the same time lowering the need for external server hardware, which would reduce the extra costs significantly. However, with regard to IBM System z, this raises the general question how a great number of critical services can be run and managed reliably on a heterogeneous computing landscape, as out-of-band servers and internal processor modules do not share the same processor architecture.
In this thesis, we introduce our prototypical design of a microservice infrastructure for multi-architecture environments, which we completely built upon preexisting open source projects and features they already bring along. We present how scheduling of services according to application-specific requirements and particularities can be achieved in a way that offers maximum transparency and comfort for platform operators and users.
By now GPUs have become powerful general purpose processors that found their way not only into desktop systems but also supercomputers. To use GPUs efficiently one needs to understand their basic architecture and their limitations. We take a look at how GPUs evolved and how they differ from CPUs to gain a deeper understanding of the workloads well suited for GPUs.
The Eclipse rich client platform as container for componentoriented plugins provides a framework to host plugins, which concerning its look and feelembed well in a client workstation. J2EE client container provide a runtime environment for applications, integrated in a multitier architecture and therefore have to access services Java 2 Enterprise Edition (J2EE). Combining the two container approaches will create a new runtime environment for application clients, which appear in the user interface style of Eclipse and are able to take up the J2EE services. This diploma thesis discusses concepts of combining Eclipse and the client container.