TY - CHAP A1 - Sanusi, Khaleel Asyraaf Mat A1 - Klemke, Roland T1 - Immersive Multimodal Environments for Psychomotor Skills Training T2 - Proceedings of the 1st Games Technology Summit N2 - Modern immersive multimodal technologies enable the learners to completely get immersed in various learning situations in a way that feels like experiencing an authentic learning environment. These environments also allow the collection of multimodal data, which can be used with artificial intelligence to further improve the immersion and learning outcomes. The use of artificial intelligence has been widely explored for the interpretation of multimodal data collected from multiple sensors, thus giving insights to support learners’ performance by providing personalised feedback. In this paper, we present a conceptual approach for creating immersive learning environments, integrated with multi-sensor setup to help learners improve their psychomotor skills in a remote setting. KW - immersive learning technologies KW - multimodal learning KW - sensor devices KW - artificial intelligence KW - psychomotor training Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246016 ER - TY - THES A1 - Nogatz, Falco T1 - Defining and Implementing Domain-Specific Languages with Prolog T1 - Definition und Implementierung domänenspezifischer Sprachen mit Prolog N2 - The landscape of today’s programming languages is manifold. With the diversity of applications, the difficulty of adequately addressing and specifying the used programs increases. This often leads to newly designed and implemented domain-specific languages. They enable domain experts to express knowledge in their preferred format, resulting in more readable and concise programs. Due to its flexible and declarative syntax without reserved keywords, the logic programming language Prolog is particularly suitable for defining and embedding domain-specific languages. This thesis addresses the questions and challenges that arise when integrating domain-specific languages into Prolog. We compare the two approaches to define them either externally or internally, and provide assisting tools for each. The grammar of a formal language is usually defined in the extended Backus–Naur form. In this work, we handle this formalism as a domain-specific language in Prolog, and define term expansions that allow to translate it into equivalent definite clause grammars. We present the package library(dcg4pt) for SWI-Prolog, which enriches them by an additional argument to automatically process the term’s corresponding parse tree. To simplify the work with definite clause grammars, we visualise their application by a web-based tracer. The external integration of domain-specific languages requires the programmer to keep the grammar, parser, and interpreter in sync. In many cases, domain-specific languages can instead be directly embedded into Prolog by providing appropriate operator definitions. In addition, we propose syntactic extensions for Prolog to expand its expressiveness, for instance to state logic formulas with their connectives verbatim. This allows to use all tools that were originally written for Prolog, for instance code linters and editors with syntax highlighting. We present the package library(plammar), a standard-compliant parser for Prolog source code, written in Prolog. It is able to automatically infer from example sentences the required operator definitions with their classes and precedences as well as the required Prolog language extensions. As a result, we can automatically answer the question: Is it possible to model these example sentences as valid Prolog clauses, and how? We discuss and apply the two approaches to internal and external integrations for several domain-specific languages, namely the extended Backus–Naur form, GraphQL, XPath, and a controlled natural language to represent expert rules in if-then form. The created toolchain with library(dcg4pt) and library(plammar) yields new application opportunities for static Prolog source code analysis, which we also present. N2 - Die Landschaft der heutigen Programmiersprachen ist vielfältig. Mit ihren unterschiedlichen Anwendungsbereichen steigt zugleich die Schwierigkeit, die eingesetzten Programme adäquat anzusprechen und zu spezifizieren. Immer häufiger werden hierfür domänenspezifische Sprachen entworfen und implementiert. Sie ermöglichen Domänenexperten, Wissen in ihrem bevorzugten Format auszudrücken, was zu lesbareren Programmen führt. Durch ihre flexible und deklarative Syntax ohne vorbelegte Schlüsselwörter ist die logische Programmsprache Prolog besonders geeignet, um domänenspezifische Sprachen zu definieren und einzubetten. Diese Arbeit befasst sich mit den Fragen und Herausforderungen, die sich bei der Integration von domänenspezifischen Sprachen in Prolog ergeben. Wir vergleichen die zwei Ansätze, sie entweder extern oder intern zu definieren, und stellen jeweils Hilfsmittel zur Verfügung. Die Grammatik einer formalen Sprache wird häufig in der erweiterten Backus–Naur–Form definiert. Diesen Formalismus behandeln wir in dieser Arbeit als eine domänenspezifische Sprache in Prolog und definieren Termexpansionen, die es erlauben, ihn in äquivalente Definite Clause Grammars für Prolog zu übersetzen. Durch das Modul library(dcg4pt) werden sie um ein zusätzliches Argument erweitert, das den Syntaxbaum eines Terms automatisch erzeugt. Um die Arbeit mit Definite Clause Grammars zu erleichtern, visualisieren wir ihre Anwendung in einem webbasierten Tracer. Meist können domänenspezifische Sprachen jedoch auch mittels passender Operatordefinitionen direkt in Prolog eingebettet werden. Dies ermöglicht die Verwendung aller Werkzeuge, die ursprünglich für Prolog geschrieben wurden, z.B. zum Code-Linting und Syntax-Highlighting. In dieser Arbeit stellen wir den standardkonformen Prolog-Parser library(plammar) vor. Er ist in Prolog geschrieben und in der Lage, aus Beispielsätzen automatisch die erforderlichen Operatoren mit ihren Klassen und Präzedenzen abzuleiten. Um die Ausdruckskraft von Prolog noch zu erweitern, schlagen wir Ergänzungen zum ISO Standard vor. Sie erlauben es, weitere Sprachen direkt einzubinden, und werden ebenfalls von library(plammar) identifiziert. So ist es bspw. möglich, logische Formeln direkt mit den bekannten Symbolen für Konjunktion, Disjunktion, usw. als Prolog-Programme anzugeben. Beide Ansätze der internen und externen Integration werden für mehrere domänen-spezifische Sprachen diskutiert und beispielhaft für GraphQL, XPath, die erweiterte Backus–Naur–Form sowie Expertenregeln in Wenn–Dann–Form umgesetzt. Die vorgestellten Werkzeuge um library(dcg4pt) und library(plammar) ergeben zudem neue Anwendungsmöglichkeiten auch für die statische Quellcodeanalyse von Prolog-Programmen. KW - PROLOG KW - Domänenspezifische Sprache KW - logic programming KW - knowledge representation KW - definite clause grammars Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-301872 ER - TY - RPRT A1 - Loh, Frank A1 - Geißler, Stefan A1 - Hoßfeld, Tobias T1 - LoRaWAN Network Planning in Smart Environments: Towards Reliability, Scalability, and Cost Reduction T2 - Würzburg Workshop on Next-Generation Communication Networks (WueWoWas'22) N2 - The goal in this work is to present a guidance for LoRaWAN planning to improve overall reliability for message transmissions and scalability. At the end, the cost component is discussed. Therefore, a five step approach is presented that helps to plan a LoRaWAN deployment step by step: Based on the device locations, an initial gateway placement is suggested followed by in-depth frequency and channel access planning. After an initial planning phase, updates for channel access and the initial gateway planning is suggested that should also be done periodically during network operation. Since current gateway placement approaches are only studied with random channel access, there is a lot of potential in the cell planning phase. Furthermore, the performance of different channel access approaches is highly related on network load, and thus cell size and sensor density. Last, the influence of different cell planning ideas on expected costs are discussed. KW - Datennetz KW - LoRaWan Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-280829 ER - TY - JOUR A1 - Loh, Frank A1 - Mehling, Noah A1 - Hoßfeld, Tobias T1 - Towards LoRaWAN without data loss: studying the performance of different channel access approaches JF - Sensors N2 - The Long Range Wide Area Network (LoRaWAN) is one of the fastest growing Internet of Things (IoT) access protocols. It operates in the license free 868 MHz band and gives everyone the possibility to create their own small sensor networks. The drawback of this technology is often unscheduled or random channel access, which leads to message collisions and potential data loss. For that reason, recent literature studies alternative approaches for LoRaWAN channel access. In this work, state-of-the-art random channel access is compared with alternative approaches from the literature by means of collision probability. Furthermore, a time scheduled channel access methodology is presented to completely avoid collisions in LoRaWAN. For this approach, an exhaustive simulation study was conducted and the performance was evaluated with random access cross-traffic. In a general theoretical analysis the limits of the time scheduled approach are discussed to comply with duty cycle regulations in LoRaWAN. KW - LoRaWAN KW - IoT KW - channel management KW - scheduling KW - collision Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-302418 SN - 1424-8220 VL - 22 IS - 2 ER - TY - JOUR A1 - Kern, Florian A1 - Kullmann, Peter A1 - Ganal, Elisabeth A1 - Korwisi, Kristof A1 - Stingl, René A1 - Niebling, Florian A1 - Latoschik, Marc Erich T1 - Off-The-Shelf Stylus: Using XR Devices for Handwriting and Sketching on Physically Aligned Virtual Surfaces JF - Frontiers in Virtual Reality N2 - This article introduces the Off-The-Shelf Stylus (OTSS), a framework for 2D interaction (in 3D) as well as for handwriting and sketching with digital pen, ink, and paper on physically aligned virtual surfaces in Virtual, Augmented, and Mixed Reality (VR, AR, MR: XR for short). OTSS supports self-made XR styluses based on consumer-grade six-degrees-of-freedom XR controllers and commercially available styluses. The framework provides separate modules for three basic but vital features: 1) The stylus module provides stylus construction and calibration features. 2) The surface module provides surface calibration and visual feedback features for virtual-physical 2D surface alignment using our so-called 3ViSuAl procedure, and surface interaction features. 3) The evaluation suite provides a comprehensive test bed combining technical measurements for precision, accuracy, and latency with extensive usability evaluations including handwriting and sketching tasks based on established visuomotor, graphomotor, and handwriting research. The framework’s development is accompanied by an extensive open source reference implementation targeting the Unity game engine using an Oculus Rift S headset and Oculus Touch controllers. The development compares three low-cost and low-tech options to equip controllers with a tip and includes a web browser-based surface providing support for interacting, handwriting, and sketching. The evaluation of the reference implementation based on the OTSS framework identified an average stylus precision of 0.98 mm (SD = 0.54 mm) and an average surface accuracy of 0.60 mm (SD = 0.32 mm) in a seated VR environment. The time for displaying the stylus movement as digital ink on the web browser surface in VR was 79.40 ms on average (SD = 23.26 ms), including the physical controller’s motion-to-photon latency visualized by its virtual representation (M = 42.57 ms, SD = 15.70 ms). The usability evaluation (N = 10) revealed a low task load, high usability, and high user experience. Participants successfully reproduced given shapes and created legible handwriting, indicating that the OTSS and it’s reference implementation is ready for everyday use. We provide source code access to our implementation, including stylus and surface calibration and surface interaction features, making it easy to reuse, extend, adapt and/or replicate previous results (https://go.uniwue.de/hci-otss). KW - virtual reality KW - augmented reality KW - handwriting KW - sketching KW - stylus KW - user interaction KW - usability evaluation KW - passive haptic feedback Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260219 VL - 2 ER - TY - JOUR A1 - Bartl, Andrea A1 - Wenninger, Stephan A1 - Wolf, Erik A1 - Botsch, Mario A1 - Latoschik, Marc Erich T1 - Affordable but not cheap: a case study of the effects of two 3D-reconstruction methods of virtual humans JF - Frontiers in Virtual Reality N2 - Realistic and lifelike 3D-reconstruction of virtual humans has various exciting and important use cases. Our and others’ appearances have notable effects on ourselves and our interaction partners in virtual environments, e.g., on acceptance, preference, trust, believability, behavior (the Proteus effect), and more. Today, multiple approaches for the 3D-reconstruction of virtual humans exist. They significantly vary in terms of the degree of achievable realism, the technical complexities, and finally, the overall reconstruction costs involved. This article compares two 3D-reconstruction approaches with very different hardware requirements. The high-cost solution uses a typical complex and elaborated camera rig consisting of 94 digital single-lens reflex (DSLR) cameras. The recently developed low-cost solution uses a smartphone camera to create videos that capture multiple views of a person. Both methods use photogrammetric reconstruction and template fitting with the same template model and differ in their adaptation to the method-specific input material. Each method generates high-quality virtual humans ready to be processed, animated, and rendered by standard XR simulation and game engines such as Unreal or Unity. We compare the results of the two 3D-reconstruction methods in an immersive virtual environment against each other in a user study. Our results indicate that the virtual humans from the low-cost approach are perceived similarly to those from the high-cost approach regarding the perceived similarity to the original, human-likeness, beauty, and uncanniness, despite significant differences in the objectively measured quality. The perceived feeling of change of the own body was higher for the low-cost virtual humans. Quality differences were perceived more strongly for one’s own body than for other virtual humans. KW - virtual humans KW - 3D-reconstruction methods KW - avatars KW - agents KW - user study Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260492 VL - 2 ER - TY - JOUR A1 - Wienrich, Carolin A1 - Latoschik, Marc Erich T1 - eXtended Artificial Intelligence: New Prospects of Human-AI Interaction Research JF - Frontiers in Virtual Reality N2 - Artificial Intelligence (AI) covers a broad spectrum of computational problems and use cases. Many of those implicate profound and sometimes intricate questions of how humans interact or should interact with AIs. Moreover, many users or future users do have abstract ideas of what AI is, significantly depending on the specific embodiment of AI applications. Human-centered-design approaches would suggest evaluating the impact of different embodiments on human perception of and interaction with AI. An approach that is difficult to realize due to the sheer complexity of application fields and embodiments in reality. However, here XR opens new possibilities to research human-AI interactions. The article’s contribution is twofold: First, it provides a theoretical treatment and model of human-AI interaction based on an XR-AI continuum as a framework for and a perspective of different approaches of XR-AI combinations. It motivates XR-AI combinations as a method to learn about the effects of prospective human-AI interfaces and shows why the combination of XR and AI fruitfully contributes to a valid and systematic investigation of human-AI interactions and interfaces. Second, the article provides two exemplary experiments investigating the aforementioned approach for two distinct AI-systems. The first experiment reveals an interesting gender effect in human-robot interaction, while the second experiment reveals an Eliza effect of a recommender system. Here the article introduces two paradigmatic implementations of the proposed XR testbed for human-AI interactions and interfaces and shows how a valid and systematic investigation can be conducted. In sum, the article opens new perspectives on how XR benefits human-centered AI design and development. KW - human-artificial intelligence interface KW - human-artificial intelligence interaction KW - XR-artificial intelligence continuum KW - XR-artificial intelligence combination KW - research methods KW - human-centered, human-robot KW - recommender system Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260296 VL - 2 ER - TY - JOUR A1 - Wienrich, Carolin A1 - Carolus, Astrid T1 - Development of an Instrument to Measure Conceptualizations and Competencies About Conversational Agents on the Example of Smart Speakers JF - Frontiers in Computer Science N2 - The concept of digital literacy has been introduced as a new cultural technique, which is regarded as essential for successful participation in a (future) digitized world. Regarding the increasing importance of AI, literacy concepts need to be extended to account for AI-related specifics. The easy handling of the systems results in increased usage, contrasting limited conceptualizations (e.g., imagination of future importance) and competencies (e.g., knowledge about functional principles). In reference to voice-based conversational agents as a concrete application of AI, the present paper aims for the development of a measurement to assess the conceptualizations and competencies about conversational agents. In a first step, a theoretical framework of “AI literacy” is transferred to the context of conversational agent literacy. Second, the “conversational agent literacy scale” (short CALS) is developed, constituting the first attempt to measure interindividual differences in the “(il) literate” usage of conversational agents. 29 items were derived, of which 170 participants answered. An explanatory factor analysis identified five factors leading to five subscales to assess CAL: storage and transfer of the smart speaker’s data input; smart speaker’s functional principles; smart speaker’s intelligent functions, learning abilities; smart speaker’s reach and potential; smart speaker’s technological (surrounding) infrastructure. Preliminary insights into construct validity and reliability of CALS showed satisfying results. Third, using the newly developed instrument, a student sample’s CAL was assessed, revealing intermediated values. Remarkably, owning a smart speaker did not lead to higher CAL scores, confirming our basic assumption that usage of systems does not guarantee enlightened conceptualizations and competencies. In sum, the paper contributes to the first insights into the operationalization and understanding of CAL as a specific subdomain of AI-related competencies. KW - artificial intelligence literacy KW - artificial intelligence education KW - voice-based artificial intelligence KW - conversational agents KW - measurement Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260198 VL - 3 ER - TY - JOUR A1 - Wienrich, Carolin A1 - Reitelbach, Clemens A1 - Carolus, Astrid T1 - The Trustworthiness of Voice Assistants in the Context of Healthcare Investigating the Effect of Perceived Expertise on the Trustworthiness of Voice Assistants, Providers, Data Receivers, and Automatic Speech Recognition JF - Frontiers in Computer Science N2 - As an emerging market for voice assistants (VA), the healthcare sector imposes increasing requirements on the users’ trust in the technological system. To encourage patients to reveal sensitive data requires patients to trust in the technological counterpart. In an experimental laboratory study, participants were presented a VA, which was introduced as either a “specialist” or a “generalist” tool for sexual health. In both conditions, the VA asked the exact same health-related questions. Afterwards, participants assessed the trustworthiness of the tool and further source layers (provider, platform provider, automatic speech recognition in general, data receiver) and reported individual characteristics (disposition to trust and disclose sexual information). Results revealed that perceiving the VA as a specialist resulted in higher trustworthiness of the VA and of the provider, the platform provider and automatic speech recognition in general. Furthermore, the provider’s trustworthiness affected the perceived trustworthiness of the VA. Presenting both a theoretical line of reasoning and empirical data, the study points out the importance of the users’ perspective on the assistant. In sum, this paper argues for further analyses of trustworthiness in voice-based systems and its effects on the usage behavior as well as the impact on responsible design of future technology. KW - voice assistant KW - trustworthiness KW - trust KW - anamnesis tool KW - expertise framing (Min5-Max 8) Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260209 VL - 3 ER - TY - JOUR A1 - Wienrich, Carolin A1 - Komma, Philipp A1 - Vogt, Stephanie A1 - Latoschik, Marc E. T1 - Spatial Presence in Mixed Realities – Considerations About the Concept, Measures, Design, and Experiments JF - Frontiers in Virtual Reality N2 - Plenty of theories, models, measures, and investigations target the understanding of virtual presence, i.e., the sense of presence in immersive Virtual Reality (VR). Other varieties of the so-called eXtended Realities (XR), e.g., Augmented and Mixed Reality (AR and MR) incorporate immersive features to a lesser degree and continuously combine spatial cues from the real physical space and the simulated virtual space. This blurred separation questions the applicability of the accumulated knowledge about the similarities of virtual presence and presence occurring in other varieties of XR, and corresponding outcomes. The present work bridges this gap by analyzing the construct of presence in mixed realities (MR). To achieve this, the following presents (1) a short review of definitions, dimensions, and measurements of presence in VR, and (2) the state of the art views on MR. Additionally, we (3) derived a working definition of MR, extending the Milgram continuum. This definition is based on entities reaching from real to virtual manifestations at one time point. Entities possess different degrees of referential power, determining the selection of the frame of reference. Furthermore, we (4) identified three research desiderata, including research questions about the frame of reference, the corresponding dimension of transportation, and the dimension of realism in MR. Mainly the relationship between the main aspects of virtual presence of immersive VR, i.e., the place-illusion, and the plausibility-illusion, and of the referential power of MR entities are discussed regarding the concept, measures, and design of presence in MR. Finally, (5) we suggested an experimental setup to reveal the research heuristic behind experiments investigating presence in MR. The present work contributes to the theories and the meaning of and approaches to simulate and measure presence in MR. We hypothesize that research about essential underlying factors determining user experience (UX) in MR simulations and experiences is still in its infancy and hopes this article provides an encouraging starting point to tackle related questions. KW - mixed reality KW - virtual-reality-continuum KW - spatial presence KW - place-illusion KW - plausibility-illusion KW - transportation KW - realism Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260328 VL - 2 ER -