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11.
We present a novel approach for extreme simplification of point set models, in the context of real-time rendering. Point sets
are often rendered using simple point primitives, such as oriented discs. However, this requires using many primitives to
render even moderately simple shapes. Often, one wishes to render a simplified model using only a few primitives, thus trading
accuracy for simplicity. For this goal, we propose a more complex primitive, called a splat, that is able to approximate larger and more complex surface areas than oriented discs. We construct our primitive by decomposing
the model into quasi-flat regions, using an efficient algebraic multigrid algorithm. Next, we encode these regions into splats
implemented as planar support polygons textured with color and transparency information and render the splats using a special
blending algorithm. Our approach combines the advantages of mesh-less point-based techniques with traditional polygon-based
techniques. We demonstrate our method on various models. 相似文献
12.
Daniela PatrascuAuthor VitaeIulia DavidAuthor Vitae Vasile DavidAuthor VitaeConstantin MihailciucAuthor Vitae Ioan StamatinAuthor VitaeJean CiureaAuthor Vitae Livia NagyAuthor VitaeGéza NagyAuthor Vitae Anton Alexandru CiucuAuthor Vitae 《Sensors and actuators. B, Chemical》2011,156(2):731-736
Iron(II) phthalocyanine (FePc) modified multi-wall carbon nanotubes paste electrodes (MWCNTPEs) were used as voltammetric sensors to selectively detect dopamine (DA) in the presence of serotonin (5-HT). The electrochemical behavior of DA at the new modified electrode was investigated using CV. The enhanced current response of DA indicates that FePc modification of the MWCNTPE surface results in a high catalytic activity for the redox reaction of DA. Differential pulse voltammetry was applied in detection of DA and 5-HT at FePc-MWCNTPE. The method parameters were optimized. Detection limit of 2.05 × 10−7 M was obtained for DA by using the electrocatalytic oxidation signal corresponding to the FeII/FeIII redox process. The separation between the peak potentials of DA and 5-HT is 170 mV which is large enough for the simultaneously, selective determination of the two chemical species in their mixtures. There was no electrochemical response for ascorbic acid (AA) added in the sample. The monoamine neurotransmitter measuring method has been tested in analyzing deproteinized serum samples. 相似文献
13.
Muhammad F. Mysorewala Dan O. Popa Frank L. Lewis 《Journal of Intelligent and Robotic Systems》2009,54(4):535-565
The use of robotics in distributed monitoring applications requires wireless sensors that are deployed efficiently. A very
important aspect of sensor deployment includes positioning them for sampling at locations most likely to yield information
about the spatio-temporal field of interest, for instance, the spread of a forest fire. In this paper, we use mobile robots
(agents) that estimate the time-varying spread of wildfires using a distributed multi-scale adaptive sampling strategy. The
proposed parametric sampling algorithm, “EKF-NN-GAS” is based on neural networks, the extended Kalman filter (EKF), and greedy heuristics. It combines measurements arriving
at different times, taken at different scale lengths, such as from ground, airborne, and spaceborne observation platforms.
One of the advantages of our algorithm is the ability to incorporate robot localization uncertainty in addition to sensor
measurement and field parameter uncertainty into the same EKF model. We employ potential fields, generated naturally from
the estimated fire field distribution, in order to generate fire-safe trajectories that could be used to rescue vehicles and
personnel. The covariance of the EKF is used as a quantitative information measure for sampling locations most likely to yield
optimal information about the sampled field distribution. Neural net training is used infrequently to generate initial low
resolution estimates of the fire spread parameters. We present simulation and experimental results for reconstructing complex
spatio-temporal forest fire fields “truth models”, approximated by radial basis function (RBF) parameterizations. When compared
to a conventional raster scan approach, our algorithm shows a significant reduction in the time necessary to map the fire
field. 相似文献
14.
Iuliana Armaş Mihaela Gheorghe Ana Maria Lendvai Paul Daniel Dumitru Octavian Bădescu Alexandru Călin 《International journal of remote sensing》2016,37(23):5565-5580
This research aims to complex validate radar displacement products over Bucharest based on Global Navigation Satellite System or GNSS. Validation was represented by the comparison of the recent TerraSAR-X (TSX) displacement results with field GNSS data. For this purpose, 24 and 27 high-resolution images acquired from the TSX satellite between 2011 and 2014 were processed by Permanent Scatterer Inteferometry (PSI) and Small BASeline Subset (SBAS) – interferometric techniques using synthetic aperture radar (SAR) images. The images were selected from a larger pool of SAR images, after consulting weather databases, which helped eliminate the images acquired under adverse weather conditions. GNSS locations were cross-checked on high-resolution optical images and 21 ground points (including three permanent stations) were selected. All these points were (1) characterized by high coherence on radar images; (2) were on the ground; (3) were situated in large vacant spaces; and (4) far away from radar obstacles such as trees. A major challenge in achieving the research goal was to overcome the lack of permanent stations at the ground level within the area of Bucharest. Instead of permanent stations, our team designed and installed forced centring systems that remained stable over time, eliminating the instalment errors of GNSS receivers. The line-of-site (LOS) components derived from GNSS data have been compared with those of the SAR scatterers closest to the GNSS markers (never coinciding). For each location, the vertical reading was projected in the LOS of the SAR sensor. These readings were compared with the displacement values determined at the locations of permanent scatterers (PSs) within 100 m from the GNSS nodes, by eliminating all scatterers on buildings. The comparison has shown a good agreement. 相似文献
15.
In this paper, the discrete-time exponential forgetting factor observer is specialised for the joint estimation of state and parameters, leading to an adaptive observer in which the decay rates of the estimation errors for the two distinct objects can be quasi-separated. The effectiveness of the observer is demonstrated through numerical simulation. 相似文献
16.
Adelina-Gabriela Niculescu Dan Eduard Mihaiescu Alexandru Mihai Grumezescu 《International journal of molecular sciences》2022,23(15)
Microfluidics is defined as emerging science and technology based on precisely manipulating fluids through miniaturized devices with micro-scale channels and chambers. Such microfluidic systems can be used for numerous applications, including reactions, separations, or detection of various compounds. Therefore, due to their potential as microreactors, a particular research focus was noted in exploring various microchannel configurations for on-chip chemical syntheses of materials with tailored properties. Given the significant number of studies in the field, this paper aims to review the recently developed microfluidic devices based on their geometry particularities, starting from a brief presentation of nanoparticle synthesis and mixing within microchannels, further moving to a more detailed discussion of different chip configurations with potential use in nanomaterial fabrication. 相似文献
17.
Liliana Marinescu Denisa Ficai Anton Ficai Ovidiu Oprea Adrian Ionut Nicoara Bogdan Stefan Vasile Laura Boanta Alexandru Marin Ecaterina Andronescu Alina-Maria Holban 《International journal of molecular sciences》2022,23(11)
The synthesis of nanoparticles from noble metals has received high attention from researchers due to their unique properties and their wide range of applications. Silver nanoparticles (AgNPs), in particular, show a remarkable inhibitory effect against microorganisms and viruses. Various methods have been developed to obtain AgNPs, however the stability of such nanostructures over time is still challenging. Researchers attempt to obtain particular shapes and sizes in order to tailor AgNPs properties for specific areas, such as biochemistry, biology, agriculture, electronics, medicine, and industry. The aim of this study was to design AgNPs with improved antimicrobial characteristics and stability. Two different wet chemical routes were considered: synthesis being performed (i) reduction method at room temperatures and (ii) solvothermal method at high temperature. Here, we show that the antimicrobial properties of the obtained AgNPs, are influenced by their synthesis route, which impact on the size and shape of the structures. This work analyses and compares the antimicrobial properties of the obtained AgNPs, based on their structure, sizes and morphologies which are influenced, in turn, not only by the type or quantities of precursors used but also by the temperature of the reaction. Generally, AgNPs obtained by solvothermal, at raised temperature, registered better antimicrobial activity as compared to NPs obtained by reduction method at room temperature. 相似文献
18.
Adelina-Gabriela Niculescu Alexandru Mihai Grumezescu 《International journal of molecular sciences》2022,23(9)
Being one of the leading causes of death and disability worldwide, cancer represents an ongoing interdisciplinary challenge for the scientific community. As currently used treatments may face limitations in terms of both efficiency and adverse effects, continuous research has been directed towards overcoming existing challenges and finding safer specific alternatives. In particular, increasing interest has been gathered around integrating nanotechnology in cancer management and subsequentially developing various tumor-targeting nanoparticles for cancer applications. In this respect, the present paper briefly describes the most used cancer treatments in clinical practice to set a reference framework for recent research findings, further focusing on the novel developments in the field. More specifically, this review elaborates on the top recent studies concerning various nanomaterials (i.e., carbon-based, metal-based, liposomes, cubosomes, lipid-based, polymer-based, micelles, virus-based, exosomes, and cell membrane-coated nanomaterials) that show promising potential in different cancer applications. 相似文献
19.
Claudia Terezia Socol Alexandra Chira Maria Antonia Martinez-Sanchez Maria Angeles Nuez-Sanchez Cristina Maria Maerescu Daniel Mierlita Alexandru Vasile Rusu Antonio Jose Ruiz-Alcaraz Monica Trif Bruno Ramos-Molina 《International journal of molecular sciences》2022,23(9)
Obesity and colorectal cancer (CRC) are among the leading diseases causing deaths in the world, showing a complex multifactorial pathology. Obesity is considered a risk factor in CRC development through inflammation, metabolic, and signaling processes. Leptin is one of the most important adipokines related to obesity and an important proinflammatory marker, mainly expressed in adipose tissue, with many genetic variation profiles, many related influencing factors, and various functions that have been ascribed but not yet fully understood and elucidated, the most important ones being related to energy metabolism, as well as endocrine and immune systems. Aberrant signaling and genetic variations of leptin are correlated with obesity and CRC, with the genetic causality showing both inherited and acquired events, in addition to lifestyle and environmental risk factors; these might also be related to specific pathogenic pathways at different time points. Moreover, mutation gain is a crucial factor enabling the genetic process of CRC. Currently, the inconsistent and insufficient data related to leptin’s relationship with obesity and CRC indicate the necessity of further related studies. This review summarizes the current knowledge on leptin genetics and its potential relationship with the main pathogenic pathways of obesity and CRC, in an attempt to understand the molecular mechanisms of these associations, in the context of inconsistent and contradictory data. The understanding of these mechanisms linking obesity and CRC could help to develop novel therapeutic targets and prevention strategies, resulting in a better prognosis and management of these diseases. 相似文献
20.
Maria Cazacu Carmen Racles Mihaela Alexandru Aurelia Ioanid Angelica Vlad 《Polymer International》2009,58(6):697-702
BACKGROUND: It is well known that, due to their extremely low polarity, polysiloxanes are incompatible with almost any organic system. This incompatibility leads to phase separation in mixed siloxane–organic systems. RESULTS: Three siloxane–organic copolymers, poly[(5,5′‐methylene‐bis‐salicylaldehyde)‐imine‐(1,3‐bis(propylene)tetramethyldisiloxane)] (Paz1), poly[(2,5‐dihydroxy‐1,4‐benzoquinone)‐imine‐(1,3‐bis(propylene)tetramethyldisiloxane)] (Paz2) and poly[1,3‐bis(propylene)tetramethyldisiloxane diamide] (Pam), were prepared by the reaction of 1,3‐bis(3‐aminopropyl)tetramethyldisiloxane with appropriate organic partners (5,5′‐methylene‐bis‐salicylaldehyde, 2,5‐dihydroxy‐1,4‐benzoquinone and oxalyl chloride, respectively). The morphologies dictated by the incompatibility between siloxane and polar organic moieties were investigated using differential scanning calorimetry and scanning electron microscopy. The surface activity of the copolymers and water vapour sorption capacity were also measured. CONCLUSION: Even though the polar sequences are very short ones, the highly flexible siloxane‐containing sequence permits the self‐assembly of these into more or less polar domains. Such an organization influences the properties of the resulting materials, an important place being occupied by the surface properties. Copyright © 2009 Society of Chemical Industry 相似文献