Search results for " Computer"
showing 10 items of 6910 documents
Spatiocolorimetric neighborhood hypergraph and Image Processing Applications : Noise Removal and Edge Detection.
2004
In this document, we are interested in image modeling by the means of the hypergraph theory. Our contribution is essentially centered on the determination of the properties resulting from this theory and on the analysis from their adequacy with image problems, particularly edge and noise detection.First, we study the image spatiocolorimetric neighborhood hypergraph representation. Three representations are respectively presented incorporating global properties, local properties and similarity functions. Then, we use the hypergraph properties generated by the representation in order to define the structural models of noise and edge. This enables us to deduce the algorithms of noise suppressi…
Variables cognitives i factors de personalitat dels subjectes amb millor control d’una Interfície Cervell Computadora
2022
Objectiu :La interrelació entre l’humà i la màquina en una tasca amb una Interficie Cervell-Computadora ( BCI de les sigles en anglès) es especialment transcendental. Hi ha subjectes incapaços d’aprendre a manipular-la( Illiteracy). El present treball analitza la influència del tipus de paradigma de control , les habilitats atencionals , els trets de personalitat i la resposta d’afrontament de la resposta davant el fracàs a l'hora d’utilitzar-la. Mètode: Hem emprat dues mostres de 89 i 191 estudiants de 1er i 2n curs de la Universitat de València en dos estudis consecutius els anys 2016 i 2017. S’han aplicat test de personalitat i qüestionaris sobre activitats rutinàries, avaluació atencion…
Restoration and Enhancement of Historical Stereo Photos
2021
Restoration of digital visual media acquired from repositories of historical photographic and cinematographic material is of key importance for the preservation, study and transmission of the legacy of past cultures to the coming generations. In this paper, a fully automatic approach to the digital restoration of historical stereo photographs is proposed, referred to as Stacked Median Restoration plus (SMR+). The approach exploits the content redundancy in stereo pairs for detecting and fixing scratches, dust, dirt spots and many other defects in the original images, as well as improving contrast and illumination. This is done by estimating the optical flow between the images, and using it …
Space-Frequency Quantization for Image Compression With Directionlets
2007
The standard separable 2-D wavelet transform (WT) has recently achieved a great success in image processing because it provides a sparse representation of smooth images. However, it fails to efficiently capture 1-D discontinuities, like edges or contours. These features, being elongated and characterized by geometrical regularity along different directions, intersect and generate many large magnitude wavelet coefficients. Since contours are very important elements in the visual perception of images, to provide a good visual quality of compressed images, it is fundamental to preserve good reconstruction of these directional features. In our previous work, we proposed a construction of critic…
Humanoid Cognitive Robots That Learn by Imitating: Implications for Consciousness Studies.
2018
While the concept of a conscious machine is intriguing, producing such a machine remains controversial and challenging. Here we describe how our work on creating a humanoid cognitive robot that learns to perform tasks via imitation learning relates to this issue. Our discussion is divided into three parts. First, we summarize our previously-detailed framework for advancing the understanding of the nature of phenomenal consciousness. This framework is based on identifying computational correlates of consciousness. Second, we describe a cognitive robotic system that we recently developed that learns to perform tasks by imitating human-provided demonstrations. This humanoid robot uses cause-ef…
Evaluating the Authenticity of Virtual Environments: Comparison of Three Devices
2016
Immersive virtual environments (VEs) have the potential to provide novel cost effective ways for evaluating not only new environments and usability scenarios, but also potential user experiences. To achieve this, VEs must be adequately realistic. The level of perceived authenticity can be ascertained by measuring the levels of immersion people experience in their VE interactions. In this paper the degree of authenticity is measured via anauthenticity indexin relation to three different immersive virtual environment devices. These devices include (1) a headband, (2) 3D glasses, and (3) a head-mounted display (HMD). A quick scale for measuring immersion, feeling of control, and simulator sick…
Immersive Virtual Reality Education Application : Four Development Iterations along Design Science Research Methodology
2022
This study introduces a research and development process of an immersive Virtual Reality (VR) education application. Altogether four application development iterations are showcased along the Design Science Research methodology. The results show how initial problems change and new problems occur during the course of a long-term DSR project with multiple iterations. Moreover, the study results confirm various previous findings, for example, that VR works better on higher learning levels such as application -level and personalization is a way to achieve this. In addition, 360 photos and videos were found to be easy and cost-efficient ways to increase personalization of VR applications. The re…
Combined TL and 10B-alanine ESR dosimetry for BNCT
2004
The dosimetric technique described in this paper is based on electron spin resonance (ESR) detectors using an alanine-boric compound acid enriched with 1 0 B, and beryllium oxide thermoluminescent (TL) detectors; with this combined dosimetry, it is possible to discriminate the doses due to thermal neutrons and gamma radiation in a mixed field. Irradiations were carried out inside the thermal column of a TRIGA MARK II water-pool-type research nuclear reactor, also used for Boron Neutron Capture therapy (BNCT) applications, with thermal neutron fluence from 10 9 to 10 1 4 n t h cm - 2 . The ESR dosemeters using the alanine-boron compound indicated ESR signals about 30-fold stronger than those…
Dose calculation in biological samples in a mixed neutron-gamma field at the TRIGA reactor of the University of Mainz
2010
To establish Boron Neutron Capture Therapy (BNCT) for non-resectable liver metastases and for in vitro experiments at the TRIGA Mark II reactor at the University of Mainz, Germany, it is necessary to have a reliable dose monitoring system. The in vitro experiments are used to determine the relative biological effectiveness (RBE) of liver and cancer cells in our mixed neutron and gamma fi eld. We work with alanine detectors in combination with Monte Carlo simulations, where we can measure and characterize the dose. To verify our calculations we perform neutron fl ux measurements using gold foil activation and pin-diodes . Material and methods . When L- α -alanine is irradiated with ionizing …
Prediction of properties of chiral compounds by molecular topology
1998
Abstract A common assumption in chemistry is that chiral behavior is associated with 3-D geometry. However, chiral information is related to symmetry, which allows the topological handling of chiral atoms by weighted graphs and the calculation of new descriptors that give a weight to the corresponding entry in the main diagonal of the topological matrix. In this study, it is demonstrated that, operating in this way, chiral topological indices are obtained that can differentiate the pharmacological activity between pairs of enantiomers. The 50% inhibitory concentration (IC50) values of the D2 dopamine receptor and the σ receptor for a group of 3-hydroxy phenyl piperidines are specifically pr…