An advanced virtual dance performance evaluator

The ever increasing availability of high speed Internet access has led to a leap in technologies that support real-time realistic interaction between humans in online virtual environments. In the context of this work, we wish to realise the vision of an online dance studio where a dance class is to be provided by an expert dance teacher and to be delivered to online students via the web. In this paper we study some of the technical issues that need to be addressed in this challenging scenario. In particular, we describe an automatic dance analysis tool that would be used to evaluate a student's performance and provide him/her with meaningful feedback to aid improvement

Persistent homology for 3D reconstruction evaluation

Space or voxel carving is a non-invasive technique that is used to produce a 3D volume and can be used in particular for the reconstruction of a 3D human model from images captured from a set of cameras placed around the subject. In [1], the authors present a technique to quantitatively evaluate spatially carved volumetric representations of humans using a synthetic dataset of typical sports motion in a tennis court scenario, with regard to the number of cameras used. In this paper, we compute persistent homology over the sequence of chain complexes obtained from the 3D outcomes with increasing number of cameras. This allows us to analyze the topological evolution of the reconstruction process, something which as far as we are aware has not been investigated to date

EvoL: The new Padova T-SPH parallel code for cosmological simulations - I. Basic code: gravity and hydrodynamics

We present EvoL, the new release of the Padova N-body code for cosmological simulations of galaxy formation and evolution. In this paper, the basic Tree + SPH code is presented and analysed, together with an overview on the software architectures. EvoL is a flexible parallel Fortran95 code, specifically designed for simulations of cosmological structure formation on cluster, galactic and sub-galactic scales. EvoL is a fully Lagrangian self-adaptive code, based on the classical Oct-tree and on the Smoothed Particle Hydrodynamics algorithm. It includes special features such as adaptive softening lengths with correcting extra-terms, and modern formulations of SPH and artificial viscosity. It is designed to be run in parallel on multiple CPUs to optimize the performance and save computational time. We describe the code in detail, and present the results of a number of standard hydrodynamical tests.Comment: 33 pages, 49 figures, accepted on A&

Inflatable device for installing strain gage bridges

Methods and devices for installing in a tubular shaft multiple strain gages are disclosed with focus on a method and a device for pneumatically forcing strain gages into seated engagement with the internal surfaces of a tubular shaft in an installation of multiple strain gages in a tubular shaft. The strain gages or other electron devices are seated in a template-like component which is wrapped about a pneumatically expansible body. The component is inserted into a shaft and the body is pneumatically expanded after a suitable adhesive was applied to the surfaces

Climate change, the green economy and reimagining the city: the case of structurally disadvantaged European maritime port cities

The concept of the New Environmental Politics of Urban Development (NEPUD) examines the impact of international and national environmental regulation on the politics of urban development. The NEPUD concept emerged from case studies of environmental governance in entrepreneurial cities. However, little is known about the concept’s relevance for less competitive cities, especially urban centres facing profound problems associated with economic decline, social deprivation and negative external images or ‘structurally disadvantaged cities.’ This paper examines how the NEPUD has played out within two structurally disadvantaged maritime port cities in Northern Europe, Hull (UK) and Bremerhaven (Germany). Both cities face serious social and economic challenges associated with long-term industrial decline, such as high unemployment rates, low skill levels, economic peripherality, and poor external images. Nevertheless, new opportunities opened up by climate change and the green economy have prompted political actors in Hull and Bremerhaven to build new alliances between local government, business and civil society and enhance governance capacities on climate change and green urban development. Highlighting similarities and differences between these two places, the paper reveals how climate change regulations provide opportunities for certain structurally disadvantaged cities to attract ‘green jobs’ and transform their external image

Classification of sporting activities using smartphone accelerometers

In this paper we present a framework that allows for the automatic identification of sporting activities using commonly available smartphones. We extract discriminative informational features from smartphone accelerometers using the Discrete Wavelet Transform (DWT). Despite the poor quality of their accelerometers, smartphones were used as capture devices due to their prevalence in today’s society. Successful classification on this basis potentially makes the technology accessible to both elite and non-elite athletes. Extracted features are used to train different categories of classifiers. No one classifier family has a reportable direct advantage in activity classification problems to date; thus we examine classifiers from each of the most widely used classifier families. We investigate three classification approaches; a commonly used SVM-based approach, an optimized classification model and a fusion of classifiers. We also investigate the effect of changing several of the DWT input parameters, including mother wavelets, window lengths and DWT decomposition levels. During the course of this work we created a challenging sports activity analysis dataset, comprised of soccer and field-hockey activities. The average maximum F-measure accuracy of 87% was achieved using a fusion of classifiers, which was 6% better than a single classifier model and 23% better than a standard SVM approach

Mass transfer in eccentric binaries: the new Oil-on-Water SPH technique

To measure the onset of mass transfer in eccentric binaries we have developed a two-phase SPH technique. Mass transfer is important in the evolution of close binaries, and a key issue is to determine the separation at which mass transfer begins. The circular case is well understood and can be treated through the use of the Roche formalism. To treat the eccentric case we use a newly-developed two phase system. The body of the donor star is made up from high-mass "water" particles, whilst the atmosphere is modelled with low-mass "oil" particles. Both sets of particles take part fully in SPH interactions. To test the technique we model circular mass-transfer binaries containing a 0.6 Msun donor star and a 1 Msun white dwarf; such binaries are thought to form cataclysmic variable (CV) systems. We find that we can reproduce a reasonable CV mass-transfer rate, and that our extended atmosphere gives a separation that is too large by aproximately 16%, although its pressure scale height is considerably exaggerated. We use the technique to measure the semi-major axis required for the onset of mass transfer in binaries with a mass ratio of q=0.6 and a range of eccentricities. Comparing to the value obtained by considering the instantaneous Roche lobe at pericentre we find that the radius of the star required for mass transfer to begin decreases systematically with increasing eccentricity.Comment: 9 pages, 8 figures, accepted by MNRA

SCReen Adjusted Panoramic Effect - SCRAPE

A Cave Automatic Virtual Environment (CAVE) is an enclosed virtual reality room that uses multiple projectors to display images across its surfaces. It uses one or more computers to synchronise and combine the images and allows users to control virtual worlds using a host of interaction devices. Traditionally, a CAVE is used by a single user at any one time and by utilising some form of motion sensing, the user's head position can be tracked to allow for first virtual perception. The images are then displayed in stereographic 3D in order to complete the virtual reality effect. Professional CAVE installations are expensive and can cost upwards of several hundred thousand euros. This tends to act as a significant barrier to their propagation, however, as the reduction in cost of high specification computers, projectors and graphics cards continues apace, it has sparked a renewed interest in CAVE environments and given rise to the realistic possibility of setting up low cost, amateur CAVEs. Unfortunately, one of the greatest disadvantages of CAVE systems is the lack of inexpensive, easy to use, specialised software. In this paper we present an open source and easy to use CAVE software toolkit called SCReen Adjusted Panoramic Effect or SCRAPE for short. We believe that SCRAPE is the first major piece in a longer-term vision that aims to bring easy to setup, easy to use, portable CAVE systems to all types of non-expert users

Dynamic voxel carving in tennis based on player localisation using a low cost camera network

In this paper, we address the problem of reconstructing 3D volumetric models, illustrating human sporting performance for use in coaching scenarios. We advocate the use of low cost camera networks for acquiring such data, allowing the approach to be feasibly adopted by both amateur and elite level sports athletes. A dynamic voxel carving approach is described, coupled with over-head player tracking and autonomous background subtraction, to automatically produce a 3D reconstruction technique that intelligently uses memory resources. We demonstrate the efficacy of our approach in the context of tennis as a challenging application scenario