Partial differential equations for function based geometry modelling within visual cyberworlds

We propose the use of Partial Differential Equations (PDEs) for shape modelling within visual cyberworlds. PDEs, especially those that are elliptic in nature, enable surface modelling to be defined as boundary-value problems. Here we show how the PDE based on the Biharmonic equation subject to suitable boundary conditions can be used for shape modelling within visual cyberworlds. We discuss an analytic solution formulation for the Biharmonic equation which allows us to define a function based geometry whereby the resulting geometry can be visualised efficiently at arbitrary levels of shape resolutions. In particular, we discuss how function based PDE surfaces can be readily integrated within VRML and X3D environment

The “Ontological Fibrillation” of Transmedia Storyworlds. Paratexts, Cyberworlds and Augmented Reality

In this study we shall be trying to examine in more depth the relationships between the processes of trans-medial world-building and their “ontological fibrillation” via the affordances of recent digital technology. The analysis will be concentrating on the contribution from Augmented Reality in the ontological materialization of The Walking Dead transmedia storyworld. To this end, the dual configuration of a narrative continuum and an attractive-interactive materialization of the make-believe will be taken into consideration. This assumption will be backed up by our endeavouring to update the conceptual contributions of narratological categories, such as para-textuality, and medial categories, such as cyberworlds and the social media; the trend towards materialization of storyworlds, following in the tracks of a historical-archaeological perspective of pre-digital transmediality will be traced with reference to several scholars within transmedia studies

A conceptual framework for interactive virtual storytelling

This paper presents a framework of an interactive storytelling system. It can integrate five components: management centre, evaluation centre, intelligent virtual agent, intelligent virtual environment, and users, making possible interactive solutions where the communication among these components is conducted in a rational and intelligent way. Environment plays an important role in providing heuristic information for agents through communicating with the management centre. The main idea is based on the principle of heuristic guiding of the behaviour of intelligent agents for guaranteeing the unexpectedness and consistent themes

A Hardware/Software Platform to Acquire Bioelectrical Signals. A Case Study: Characterizing Computer Access through Attention

This paper describes a hardware/software platform to acquire human body signals. In the field of physiological computing it is desirable to have a system that allows the synchronized acquisition of signals coming from different sources. Here is described how to unify the whole process of acquiring signals from both customized hardware and low cost commercial devices such as Neurosky’s mindwave. A case study using this platform is also shown: studying the feasibility of using sustained attention to access a computer. In order to do that brain activity was measured using Neurosky’s mindwave. The participants in this study were asked to keep their attention high/low for as long as possible during several trials. Experimentation was performed by 7 normally developed subjects and 3 people with cerebral palsy (CP). Our preliminary work shows that 60% of participants might be potential users of this technology. Eventually, modulating the attention to access a communication board needs a scanning period greater than 5.76s

A real-time proximity querying algorithm for haptic-based molecular docking

Intermolecular binding underlies every metabolic and regulatory processes of the cell, and the therapeutic and pharmacological properties of drugs. Molecular docking systems model and simulate these interactions in silico and allow us to study the binding process. Haptic-based docking provides an immersive virtual docking environment where the user can interact with and guide the molecules to their binding pose. Moreover, it allows human perception, intuition and knowledge to assist and accelerate the docking process, and reduces incorrect binding poses. Crucial for interactive docking is the real-time calculation of interaction forces. For smooth and accurate haptic exploration and manipulation, force-feedback cues have to be updated at a rate of 1 kHz. Hence, force calculations must be performed within 1ms. To achieve this, modern haptic-based docking approaches often utilize pre-computed force grids and linear interpolation. However, such grids are time-consuming to pre-compute (especially for large molecules), memory hungry, can induce rough force transitions at cell boundaries and cannot be applied to flexible docking. Here we propose an efficient proximity querying method for computing intermolecular forces in real time. Our motivation is the eventual development of a haptic-based docking solution that can model molecular flexibility. Uniquely in a haptics application we use octrees to decompose the 3D search space in order to identify the set of interacting atoms within a cut-off distance. Force calculations are then performed on this set in real time. The implementation constructs the trees dynamically, and computes the interaction forces of large molecular structures (i.e. consisting of thousands of atoms) within haptic refresh rates. We have implemented this method in an immersive, haptic-based, rigid-body, molecular docking application called Haptimol_RD. The user can use the haptic device to orientate the molecules in space, sense the interaction forces on the device, and guide the molecules to their binding pose. Haptimol_RD is designed to run on consumer level hardware, i.e. there is no need for specialized/proprietary hardware

Using 2D photography as a 3D constructional tool within the metaverse

Photography is a powerful two dimensional representation tool to document three dimensional volumes like architecture. It is possible to manipulate photos with two dimensional tools like Photoshop in order to suggest new three dimensional re/formations and re/interpret architecture. One can alternatively use two dimensional textures as mappings to create realistic three dimensional model renderings. This project is a combination of these two approaches: photographing architecture, turning the resulting photos into transparent image files, and then mapping these photos onto three dimensional volumes in order to create a ‘new’ architecture from an ‘existing’ architecture. One of the advantages of using photographs to create architecture is that the photo pool can easily be composed of visuals from various cultures and you may end up using an amalgam of visuals from, say, so-called opposite cultures. This possibility reminds the peaceful collaboration of musicians from different cultures to create a unique music. In addition, this act can also be taken as a migration of media through appropriation of photography for three dimensional volume creation and re/presentation. At this point, we are talking about a double representation, since photography is a representation tool already and it gains another representational dimension when it is remapped onto three dimensional volumes for the construction of an alternative reality. This article concentrates on using a representation tool (photography) to construct a three dimensional space (architecture) within a virtual three dimensional environment (Second Life®). During the process the concepts of perception, reality, cultural context, re/presentation and appropriation will be examined

GPU-based ultra-fast direct aperture optimization for online adaptive radiation therapy

Online adaptive radiation therapy (ART) has great promise to significantly reduce normal tissue toxicity and/or improve tumor control through real-time treatment adaptations based on the current patient anatomy. However, the major technical obstacle for clinical realization of online ART, namely the inability to achieve real-time efficiency in treatment re-planning, has yet to be solved. To overcome this challenge, this paper presents our work on the implementation of an intensity modulated radiation therapy (IMRT) direct aperture optimization (DAO) algorithm on graphics processing unit (GPU) based on our previous work on CPU. We formulate the DAO problem as a large-scale convex programming problem, and use an exact method called column generation approach to deal with its extremely large dimensionality on GPU. Five 9-field prostate and five 5-field head-and-neck IMRT clinical cases with 5\times5 mm2 beamlet size and 2.5\times2.5\times2.5 mm3 voxel size were used to evaluate our algorithm on GPU. It takes only 0.7~2.5 seconds for our implementation to generate optimal treatment plans using 50 MLC apertures on an NVIDIA Tesla C1060 GPU card. Our work has therefore solved a major problem in developing ultra-fast (re-)planning technologies for online ART

Anthropology of virtual worlds : history, current debates and future possibilities

La importancia de la investigación de los mundos virtuales ha ido incrementando y poco a poco se ha convertido en una parte importante de la antropología digital en los últimos años. Ofrece así posibilidades prometedoras para la ciencia social, como la realización de experimentos en los mundos virtuales. Sin embargo, el campo está lejos de estar unificado en muchos aspectos, y el debate sobre las definiciones, los usos y los términos importantes no está aún concluído. Este artículo ofrece una introducción a los mundos virtuales, la participación antropológica en este tema y los actuales discursos antropológicos, terminando con el debate de las perspectivas de la investigación de percepciones y las prácticas de violencia dentro de los mundos virtuales.The research of virtual worlds has become an increasingly important part of digital anthropology in recent years and offers promising possibilities for social science, such as conducting experiments in virtual worlds. However, the field is far from being unified on a lot of topics and the discussion about definitions, uses and important terms is not yet finished. This article provides an introduction to virtual worlds, anthropological involvement with that topic and current anthropological discourses, finishing with a discussion of the prospects of researching perceptions and practices of violence within virtual worlds