Search results for "Climb"
showing 10 items of 57 documents
Probabilistic description of traffic breakdowns
2001
We analyze the characteristic features of traffic breakdown. To describe this phenomenon we apply to the probabilistic model regarding the jam emergence as the formation of a large car cluster on highway. In these terms the breakdown occurs through the formation of a certain critical nucleus in the metastable vehicle flow, which enables us to confine ourselves to one cluster model. We assume that, first, the growth of the car cluster is governed by attachment of cars to the cluster whose rate is mainly determined by the mean headway distance between the car in the vehicle flow and, may be, also by the headway distance in the cluster. Second, the cluster dissolution is determined by the car …
Video-Analysis of the flight of a model aircraft
2011
A video-analysis software tool has been employed in order to measure the steady-state values of the kinematics variables describing the longitudinal behaviour of a radio-controlled model aircraft during take-off, climbing and gliding. These experimental results have been compared with the theoretical steady-state configurations predicted by the phugoid model for longitudinal flight. A comparison with the parameters and performance of the full-size aircraft has also been outlined.
Parallel Random Search and Tabu Search for the Minimal Consistent Subset Selection Problem
1998
The Minimal Consistent Subset Selection (MCSS) problem is a discrete optimization problem whose resolution for large scale instances requires a prohibitive processing time. Prior algorithms addressing this problem are presented. Randomization and approximation techniques are suitable to face the problem, then random search and meta-heuristics are proposed and consequently Tabu Search strategies are applied and evaluated. Parallel computing helps to reduce processing time and/or produce better results; different approaches for designing parallel tabu search are analyzed.
Stable Automatic Unsupervised Segmentation of Retinal Vessels Using Self-Organizing Maps and a Modified Fuzzy C-Means Clustering
2011
In this paper an automatic unsupervised method for the segmentation of retinal vessels is proposed. Three features are extracted from the tested image. The features are scaled down by a factor of 2 and mapped into a Self-Organizing Map. A modified Fuzzy C-Means clustering algorithm is used to divide the neuron units of the map in 2 classes. The entire image is again input for the Self-Organizing Map and the class of each pixel will be the class of its best matching unit in the Self-Organizing Map. Finally, the vessel network is post-processed using a hill climbing strategy on the connected components of the segmented image. The experimental evaluation on the DRIVE database shows accurate ex…
Automatic Unsupervised Segmentation of Retinal Vessels Using Self-Organizing Maps and K-Means Clustering
2011
In this paper an automatic unsupervised method for the segmentation of retinal vessels is proposed. A Self-Organizing Map is trained on a portion of the same image that is tested and K-means clustering algorithm is used to divide the map units in 2 classes. The entire image is again input for the Self-Organizing Map, and the class of each pixel will be the class of the best matching unit on the Self-Organizing Map. Finally, the vessel network is post-processed using a hill climbing strategy on the connected components of the segmented image. The experimental evaluation on the publicly available DRIVE database shows accurate extraction of vessels network and a good agreement between our segm…
An Updated Checklist of the Genus Capparis L. (Capparaceae) in Vietnam, including a New Species from Hon Tre Island
2022
The Indochinese Peninsula is a main center of speciation of Capparis, but the taxonomic treatment of the genus is still critical in this area. With regard to Vietnam, a discordant number of species was recorded by different authors during the last century, whereas various new species have been recently described. An updated checklist of the intrageneric taxa occurring in the country is here presented, including a new species from the island of Hon Tre, Khanh Hoa Province. The genus comprises in Vietnam 37 species, 9 subspecies and 3 varieties, all belonging to Capparis sect. Monostichocalyx. The study area, with 10 endemic species, is confirmed as one of the hotspots of the genus. Three lec…
Motorcycle Hill Climbing. Sport e social media in prospettiva globale
2021
Motorcycle Hill Climbing. Sport and social media in a global perspective. The contribution aims to reconstruct the history, rules and diffusion of the Motorcycle hill climbing (MHC) sport; inserted among the categories of Enduro competitions, the MHC represents an extreme discipline divided into championships organized all over the world. The article, starting from a descriptive approach, will try to give a picture of the spatial diffusion of the main MHC events and the public flows generated, focusing in particular on the main European competitions. The article will then explore the relational and community dynamics that develop in some of the social networking platforms dedicated to the d…
Higher Brain Centers for Intelligent Motor Control in Insects
2011
The higher control of orientation, walking and gap climbing behavior in the fruit fly Drosophila is studied by neurogenetic means. An insect brain model is presented for the control of object approaches. The model comprises learning abilities of flies at two different time scales. A short-term orientation memory allows for the continued approach of objects that disappeared from sight. Flies can come back to the still invisible object even after a detour to a distracter object. A long-term memory allows for the storage of experience with particular types of objects in order to trigger avoidance behavior in the future instead of the default approach behavior. Moreover, we provide evidence tha…
Evolution of growth form in epiphytic Dissochaeteae (Melastomataceae)
2001
Abstract We trace the evolution of root climbing and scrambling in Dissochaeteae and Sonerileae, two closely related groups that comprise the majority of Old World climbing Melastomataceae. The morphological and anatomical adaptations of the different climbers are interpreted in the context of a phylogeny based on chloroplast (cp) DNA sequences of the ndhF gene, generated for 31 representatives of Dissochaeteae and Sonerileae/Oxysporeae plus nine outgroups. For 20 of these taxa, the ndhF sequences were combined with cpDNA rpl16 intron sequences to obtain higher statistical support. Parsimony, minimum evolution, and maximum likelihood approaches yield congruent topologies that imply that scr…
La posició dels clítics i de les marques de negació pressuposicional en els contextos de reestructuració
2021
En aquest article presentem l'estudi de la variació microsintàctica en els parlars catalans com a estratègia per a una comprensió millor i més aprofundida dels contextos de reestructuració i de les dependències a llarga distància. Proposem que la reestructuració implica l'existència d'una estructura biclausal amb un domini subordinat defectiu. Aportem proves a favor d'aquesta anàlisi tot explorant les posicions dels clítics i de les marques de negació pressuposicional en contextos de reestructuració en les varietats del català. D'una banda, les dades recollides demostren que, tot i que l'ascens del clític i l'ús de les marques pressuposicionals al domini subordinat són fenòmens independents…