GEARS: A General and Efficient Algorithm for Rendering Shadows

We present a soft shadow rendering algorithm that is general, efficient and accurate. The algorithm supports fully dynamic scenes, with moving and deforming blockers and receivers, and with changing area light source parameters. For each output image pixel, the algorithm computes a tight but conservative approximation of the set of triangles that block the light source as seen from the pixel sample. The set of potentially blocking triangles allows estimating visibility between light points and pixel samples accurately and efficiently. As the light source size decreases to a point, our algorithm converges to rendering pixel accurate hard shadows.     

eWALL: An Open-Source Cloud-Based eHealth Platform for Creating Home Caring Environments for Older Adults Living with Chronic Diseases or Frailty

Independent living of older adults is one of the main challenges linked to the ageing population. Especially those living with diseases like COPD, MCI or frailty, need more support in everyday life and this is by itself a big societal challenge with impact in multiple sectors. In this paper we present eWALL, an innovative open-source eHealth platform that aims to address these challenges by means of an advanced cloud-based infrastructure. eWALL is designed in an innovative manner and achieved technical breakthroughs in eHealth platforms, while prioritizing user and market needs that are often abandoned and are the major reason for technically sound solutions that fail. We consider this as an opportunity and we aim to change the eHealth systems’ experience for older adults and break the barriers for the penetration of ICT solutions.     

1001 Acquisition viewpoints: efficient and versatile view-dependent modeling of real-world scenes

Modeling is a severe bottleneck for computer graphics applications. Manual modeling is time consuming and fails to capture the complexity of real-world scenes. Automated modeling based on acquiring color and depth data is a promising alternative. However, the usual approach of densely sampling the scene from a few viewpoints suffers from long acquisition times, high data redundancy, and lack of robustness, leading to incomplete models. We propose automated modeling based on sampling the scene sparsely from a dense set of viewpoints. We show that the sparse data quickly accumulates to generate models with good scene coverage. The sparse depth is acquired efficiently and robustly, which enables an interactive, operator-in-the-loop acquisition pipeline. We describe a modeling system that implements this approach. The system acquires scenes with complex geometry and complex reflective properties from thousands of viewpoints in minutes. The resulting models are compact and support photorealistic rendering at interactive rates.     

Polyester/lignosulfonate blends, 2. Accelerated aging behavior

The behavior of the poly[(ethylene terephthalate)‐co‐(ethylene isophthalate)] copolymer/epoxy‐modified lignosulfonate (LER) blends has been studied during aging, in the conditions of sewage sludge test. The bulk and surface properties of the aged blends have been followed by electron microscopy, DSC, TG/DTG, IR spectroscopy and contact angle measurements, and compared with undegraded samples. It has been established that the UV‐irradiated blends undergo more important changes in their properties after aging than the unirradiated samples. The physical treatment and increase of LER content in the blend could be a way to obtain materials with a good balance of properties and environmental degradation.     

New cellulose-lignin hydrogels and their application in controlled release of polyphenols

Novel superabsorbant cellulose-lignin hydrogels (CL) were prepared by a new two-step procedure consisting in dissolving cellulose in an alkaline solution with further mixing with lignin, followed by the chemical crosslinking with epichlorohydrin. The crosslinking occurrence was verified by Fourier Transform Infrared spectroscopy (FT-IR). The effect of the structure features of cellulose-lignin hydrogels on their dehydration heat was evaluated by Differential Scanning Calorimetry (DSC). The Scanning Electron Microscopy (SEM) images reveal some morphological aspects of the hydrogels. The degree as well as the rate of swelling in a mixture of water:ethanol = 19:1 were estimated. The possible application of these hydrogels as controlled release systems was tested. Polyphenols known as having a wide range of biological effects were selected to be incorporated in such hydrogels by an optimal procedure. The extract of grapes seeds from the Chambourcin type was used as a source of polyphenols (PF). The amount of the incorporated polyphenols was estimated by UV-VIS measurements. Characterization of the hydrogels containing polyphenols was performed by FTIR spectroscopy. Some parameters were estimated based on the registered spectra, as H-bond energy (E_H), the asymmetric index (a/b) and the enthalpy of H-bond formation (ΔH). The modifications of the thermal behavior and morphology induced by the presence of the polyphenols in hydrogels were highlighted by DSC and SEM, respectively. The release of polyphenols from CL hydrogels depended on the lignin content from matrices, as assessed by spectral studies. Both loading with polyphenols and their release can be controlled by the composition of the hydrogels. The kinetic of polyphenols release was studied.     

An evaluation of 3-D scene exploration using a multiperspective image framework

Multiperspective images (MPIs) show more than what is visible from a single viewpoint and are a promising approach for alleviating the problem of occlusions. We present a comprehensive user study that investigates the effectiveness of MPIs for 3-D scene exploration. A total of 47 subjects performed searching, counting, and spatial orientation tasks using both conventional and multiperspective images. We use a flexible MPI framework that allows trading off disocclusion power for image simplicity. The framework also allows rendering MPI images at interactive rates, which enables investigating interactive navigation and dynamic 3-D scenes. The results of our experiments show that MPIs can greatly outperform conventional images. For searching, subjects performed on average 28% faster using an MPI. For counting, accuracy was on average 91% using MPIs as compared to 42% for conventional images.     

Nanoalumina obtained by pyrosol method

Ceramic materials are interesting due to their properties such as chemical and thermal stability, corrosion resistance, biocompatibility, piezoelectricity, high dielectricity. Also, nano-sized materials may have properties different from the micro scale materials. Pyrosol method is an alternative method to obtain nanoscale particles. In this study alumina particles were prepared by pyrosol method using AlCl₃ (0.1 M and 0.05 M) as precursor solutions. The particles were obtained by maintaining the temperature of 400 °C in the pyrolysis furnace. Then, the powders were heat treated at 1000 °C for 2 hours. The X-ray diffraction analyses indicated that the obtained nanoparticles were identified as a mixture of a and g crystalline alumina. Scanning electron microscopy images showed that the prepared Al₂O₃ nanoparticles obtained from the concentration of 0.05 M had smaller dimensions than those obtained from the concentration of 0.1 M. Images of transmission electron microscopy showed spherical particles with the median diameter approximately of 150 nm, using as precursor AlCl₃ solution (0.05 M).     

Synthesis and characterisation of Al2O3/Ni-type composites obtained by spark plasma sintering

This paper presents the influence of sintering on the structure, morphology and compressing strength of alumina/nickel composite compacts obtained by spark plasma sintering (SPS). Al₂O₃/Ni composites were prepared by SPS in argon atmosphere at temperatures in the range of 1000–1200 –C with a holding time of 2, 5 and 10?minutes. The heating rate was 200 C?min^?1. These composites have been characterised by X-ray diffraction, SEM and EDX. The relative density and compressive strength of the as-obtained compacts were determined. The results showed that the alumina particles are uniformly dispersed in a quasi-continuous Ni network, and there was no sign of phase changes during sintering. The maximum strength of the alumina/nickel composite with a content of 75 vol. ? Al₂O₃ and 25 vol. ? Ni was about 240?MPa for the samples sintered at 1200?C for 10?minutes.

Special block from the conference RoPM2017 guest edited by Ionel Chicinas, Technical University, Cluj-Napoca.