Virtual reality (VR) is increasingly recognized as a powerful tool for science education, offering interactive environments to explore intangible concepts. Traditional teaching methods often struggle to convey abstract concepts in science, where many phenomena are not directly observable. VR can address this issue by modeling and visualizing complex and unobservable entities and processes, allowing learners to dynamically interact with what would otherwise not be directly perceptible. However, relatively few controlled studies have compared immersive VR learning with equivalent hands-on laboratory learning in physics education, particularly for more abstract topics. In this work, we designed a VR-based physics lab that is capable of visualizing electrons and electromagnetic fields to teach fundamental concepts of electronics and magnetism, closely replicating a traditional electronics learning kit used as a baseline for comparison. We evaluated the impact of the two conditions (VR versus traditional) on students' learning outcomes, motivation, engagement, and cognitive load. Our results show significantly higher knowledge retention in the VR group compared to the traditional group. Also, while there were no significant differences in immediate comprehension between the two groups, participants in the VR group spent substantially more time engaged with the learning content. These findings highlight the potential of visually enriched virtual environments to enhance the learning experience and improve knowledge retention of intangible scientific concepts.

Block-based programming has been used as an introductory gateway to programming thanks to its simpler, visual approach for composing code. This work re-imagines this style of coding through the mobile-first framework DartBlock, which is intended to be integrated in a quiz application. It targets an older audience aiming to more quickly transition to the conventional programming language Java, by adopting a syntax visualization and interaction design inspired by integrated development environments. DartBlock focuses on teaching debugging through its included runtime which allows the execution of faulty code with descriptive exception throwing, as well as supporting automatic evaluation of programs given a sample solution to serve as feedback. To suit the smaller screen of mobile devices, the library relies on calculator-like visual editors for each primitive data type to facilitate the composition of complex boolean and numeric expressions without the need for textual input. Finally, we present preliminary student impressions of DartBlock from an initial use case study in a university class and provide organizational recommendations for introducing new frameworks to students.

Tablet computers are gaining in presence in modern-day classrooms, enabling the use of a variety of apps for purposes such as note-taking or assessment. Augmented Reality (AR) experiences in the classroom, made possible by current hardware, permit new ways of interaction and visualization, as well as increase student motivation and engagement. They also overcome the need for potentially expensive hardware required for experiments in certain scientific domains. The movement of Open Educational Resources (OER) has enabled the sharing of heterogeneous learning resources. Their retrieval can be improved by enriching their metadata using Semantic Web technologies. In this paper, we present AR4OER, a semantic platform for heterogeneous AR experiences provided as OER. We showcase four AR scenarios from different school subjects. These scenarios can be integrated through a lose coupling in third-party apps. Apart from describing how this integration works, we demonstrate how a note-taking app can benefit from these scenarios.

Domain ontologies about one or several programming languages have been created in various occasions, mostly in the context of Technology Enhanced Learning (TEL). Their benefits range from modeling learning outcomes, over organization and annotation of learning material, to providing scaffolding support in programming labs by integrating relevant learning resources. The Swift programming language, introduced in 2014, is currently gaining momentum in different fields of application. Both its powerful syntax as well as the provided type safety make it a good language for first-year computer science students. However, it has not yet been the subject of a domain ontology. In this paper, we present an SKOS-based vocabulary on the Swift programming language, aiming at enabling the benefits of previous research for this particular language. After reviewing existing ontologies on other programming languages, we present the modeling process of the Swift vocabulary, its integration into the LOD Cloud and list all of its resources available to the research community. Finally, we showcase how it is being used in different TEL tools.

The collaborative authoring of complex document structures by geographically distributed users is no longer a special case in today's global economy or people's personal lives. However, integrating single-user application responsiveness and feature sets with the additional demands and expectations presented towards distributed multi-user environments remains a challenge. Current solutions approaching this challenge almost exclusively rely on traditional, file-based data structures. This often introduces arbitrary workflow restrictions to the user and reduces the potential to benefit from an otherwise inherently concurrent system. Our distributed compound document authoring environment aims at addressing these challenges while providing system-level collaboration support to the user. We attain this through the close integration of a fine-grained data structure with a highly scalable, priority-based concurrency model for command distribution and application. This paper discusses our enhanced data representation and concurrency model together with the evaluation of their prototypical implementation.

Computer-supported collaborative learning scenarios provide an opportunity for the participants to develop their conceptual understanding of a topic in a shared e-learning environment. This requires the integration of collaborative and cooperative authoring functionality for a wide range of distinct types of data, including multimedia. However, restricting access to currently manipulated elements by the means of locks and requiring the user to manually initiate and manage the synchronization process are still common side-effects to this support. Allowing for predominantly unrestricted, interruption-free and non-destructive multimedia editing in a distributed collaborative learning environment thus still presents a challenge. We propose to address these issues by integrating a fine-grained data model, concurrency-based command processing, and a primarily autonomous consistency management approach. Distinct editing operations by individual participants define manipulations on data type-specific attributes, which form the basis for an up-to-date representation of the targeted multimedia assets. We utilize an advanced Compound Document System and accompanying data models to allow for a feature rich, yet responsive and unobtrusive collaboration environment.

Today social networks and microblogging services attract much attention and their importance and pervasion is constantly increasing. This trend is fostered by the increasing prevalence of mobile internet devices, which enable users to be online every time and everywhere. A popular kind of applicatio

The prevalence of the small-world phenomenon in numerous efficient networks, such as social networks, Internet, nervous systems, implies that small-worlds are an evolutionary solution for locally growing networks. These networks require short communication distances between their nodes in spite of their potentially large network diameter but at the same time are robust against randomly occurring failures. Integrating these properties into human-made communication networks drastically increases their efficiency and performance but represents an enormous challenge in the case of mobile ad hoc networks since their communication graphs rely on local construction principles. In this paper, the focus is on backbone-assisted ad hoc networks. In such networks devices connect arbitrarily to other devices within their transmission range, and dedicated devices are able to connect to a backbone network. This construction principle leads to a geometric graph that has a small average path length, but that is sensitive to random attacks or failures. The challenge in evoking small-world properties in backbone-assisted mobile ad hoc networks is to build a topology control algorithm that works with localized data (i.e. using neighboring information) despite knowledge of average path length and clustering coefficient requiring global information. Such a topology control algorithm is described here. Empirical results show that depending on network density, small-world properties can be efficiently evoked.

Mobile devices, such as laptops, smartphones, and PDAs are nowadays widely used. One essential daily task, among others, is the sharing of files, e.g. podcasts, pictures, or learning material, with others. The dynamic nature of mobile networks, together with the limited bandwidth, make common file sharing protocols unsuitable for such dynamic environments. In this paper two different strategies for the dissemination of files in mobile networks are introduced. Both approaches are evaluated based on different criteria, such as the file size and the level of interest. The first strategy is based on the en-passant communication pattern, which is a peer-to-peer approach between local one-hop neighbors. The second approach employs a clustering algorithm for mobile networks.

Ad hoc networks, sensor network, vehicular networks, delay tolerant networks, etc. are instances of dynamic communication networks. These networks are in particular characterized by spontaneous link failures caused by node mobility or connection problems in the wireless medium. It is a challenging task to manage networking in a dynamic environment. Ideally, important tasks and processes have to be assigned to nodes that suffer less dynamic influences. Recent results show that the lifetime of links is not uniformly distributed. This means that there are links that last longer than others in a mobile environment. This paper reports on heuristics in order to classify nodes whose links are more stable than others. The heuristics described rely solely on local topological information and are fully distributed.

In this paper, we introduce HyLearn, a cooperative learning system for mobile devices running on a hybrid wireless network. HyLearn deploys information to interested nodes through both fixed as well as mobile networks. Due to the mobility of nodes, an efficient approach for self-organization the ad hoc network is required. For that, we apply a multi-hop clustering technique that forms hierarchical structures of an otherwise flat network in order to match HyLearn's expected communication pattern. This clustering algorithm is parameterized in terms of cluster size and can therefore adapt the size according to the mobility degree of nodes. Local information only is required to establish and maintain clusters.

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