7 resultados para Placement trajectory
em AMS Tesi di Dottorato - Alm@DL - Università di Bologna
Resumo:
Motion control is a sub-field of automation, in which the position and/or velocity of machines are controlled using some type of device. In motion control the position, velocity, force, pressure, etc., profiles are designed in such a way that the different mechanical parts work as an harmonious whole in which a perfect synchronization must be achieved. The real-time exchange of information in the distributed system that is nowadays an industrial plant plays an important role in order to achieve always better performance, better effectiveness and better safety. The network for connecting field devices such as sensors, actuators, field controllers such as PLCs, regulators, drive controller etc., and man-machine interfaces is commonly called fieldbus. Since the motion transmission is now task of the communication system, and not more of kinematic chains as in the past, the communication protocol must assure that the desired profiles, and their properties, are correctly transmitted to the axes then reproduced or else the synchronization among the different parts is lost with all the resulting consequences. In this thesis, the problem of trajectory reconstruction in the case of an event-triggered communication system is faced. The most important feature that a real-time communication system must have is the preservation of the following temporal and spatial properties: absolute temporal consistency, relative temporal consistency, spatial consistency. Starting from the basic system composed by one master and one slave and passing through systems made up by many slaves and one master or many masters and one slave, the problems in the profile reconstruction and temporal properties preservation, and subsequently the synchronization of different profiles in network adopting an event-triggered communication system, have been shown. These networks are characterized by the fact that a common knowledge of the global time is not available. Therefore they are non-deterministic networks. Each topology is analyzed and the proposed solution based on phase-locked loops adopted for the basic master-slave case has been improved to face with the other configurations.
Resumo:
Object of the search is the advertising phenomenon of the "product placement", with reference to that it has been investigated legality’s limits, as well as the relationship with the constitutionally protected liberty of expression. Particularly, it has been analyzed, in first place, the problem of the relationship between the freedom of expression and the liberty of economic initiative, with particular reference to the different circles of guardianship to these prepared: or, larger, the one provided for the first from the 21th article of Costitution, more circumscribed, instead, the one established in the 41th article of Costitution, with reference to the second. This analysis has been made with the purpose to investigate the coordination among such liberties in those forms of communications that, for the proper peculiarities that characterize them, can be qualified, according to the concrete circumstances in which they are spread, so much forms of liberty of expression, how much exercise of an activity of enterprise. Under this last profile, it has been taken attention on the advertising activity and, specially, on the non transparent publicities, or not immediately perceivable as such from their receivers, and, therefore, in contrast with the advertising trasparence’s principle: or, the so-called cases of hidden publicity, what the editorial publicity, both "in narrow sense" both "in general sense", as well as the phenomenon of the product placement (or positioning of product), by now diffused in the commercial routine. Therefore, it has been proceeded to a complete and exhaustive examination of innovations introduced by the recent legislative discipline in subject of “planned placement of marks and products” in the cinema works, appraising, in the specific one, the effects, juridical and no juridical, consequential from the introduction of a first form of regulation of the phenomenon of the product placement and, particularly, from the express provision about the legality of the use to such advertising, if it has realized according to specific requirements or condition. In relationship to such profile, it has been also investigate limits (sub kind of normative gaps) from which the recently introduced discipline in subject would seem characterized. Finally, a further circle of investigation has concerned the possible organization of the phenomenon under a negotiate aspect, as particular contract of advertising, in which the object consists in an promotional activity. Concerning this, the experience of foreign countries (above all the Anglo-Saxon one) has been very important, because of the absence, in our arrangement, of a general normative discipline about advertising contracts. Consequently, I’ve investigated principal characteristics of similar contracts, in first place the atypicalness, because of the lack, in Italy, of a legislative discipline of this contract. Such investigation has also been developed through a comparation between the positioning of product and the other advertising contracts, among which, particularly, the sponsorship, as well as the contracts for the advertising exploitation of the name and other people's image, and, specially, the contract of testimonial and the contract of endorsement.
Resumo:
Through this research I have tried to demonstrate how the evolution of the newest marketing strategies - that work towards engaging relationships with consumers, thus building an emotional connection between the brand and the user- can be considered as a response to the evolution of young audiences and consumers. More specifically, I have analized product placement as a cultural and social phenomena above all, and not only as an economical one, thus demonstrating all the social and cultural practices that this tool implies. The approach I have chosen to do so, is historical-analytical, particularly focusing on the evolution of the society and of the consumer, especially for what teenagers (both as audiences and as consumers) are concerned.
Resumo:
The subject of the present thesis is about the enhancement of orbiter spacecraft navigation capabilities obtained by the standard radiometric link, taking advantage of an imaging payload and making use of a novel definition of optical measurements. An ESA Mission to Mercury called BepiColombo, was selected as a reference case for this study, and in particular its Mercury Planetary Orbiter (MPO), because of the presence of SIMBIO-SYS, an instrument suite part of the MPO payload, capable of acquiring high resolution images of the surface of Mercury. The use of optical measurements for navigation, can provide complementary informations with respect to Doppler, for enhanced performances or a relaxation of the radio tracking requisites in term of ground station schedule. Classical optical techniques based on centroids, limbs or landmarks, were the base to a novel idea for optical navigation, inspired by concepts of stereoscopic vision. In brief, the relation between two overlapped images acquired by a nadir pointed orbiter spacecraft at different times, was defined, and this information was then formulated into an optical measurement, to be processed by a navigation filter. The formulation of this novel optical observable is presented, moreover the analysis of the possible impact on the mission budget and images scheduling is addressed. Simulations are conducted using an orbit determination software already in use for spacecraft navigation in which the proposed optical measurements were implemented and the final results are given.
Resumo:
Co-evolving with the human host, gut microbiota establishes configurations, which vary under the pressure of inflammation, disease, ageing, diet and lifestyle. In order to describe the multi-stability of the microbiome-host relationship, we studied specific tracts of the bacterial trajectory during the human lifespan and we characterized peculiar deviations from the hypothetical development, caused by disease, using molecular techniques, such as phylogenetic microarray and next-generation sequencing. Firstly, we characterized the enterocyte-associated microbiota in breast-fed infants and adults, describing remarkable differences between the two groups of subjects. Successively, we investigated the impact of atopy on the development of the microbiome in Italian childrens, highlithing conspicuous deviations from the child-type microbiota of the Italian controls. To explore variation in the gut microbiota depending on geographical origins, which reflect different lifestyles, we compared the phylogenetic diversity of the intestinal microbiota of the Hadza hunter-gatherers of Tanzania and Italian adults. Additionally, we characterized the aged-type microbiome, describing the changes occurred in the metabolic potential of the gut microbiota of centenarians with respect to younger individuals, as a part of the pathophysiolology of the ageing process. Finally, we evaluated the impact of a probiotics intervention on the intestinal microbiota of elderly people, showing the repair of some age-related dysbioses. These studies contribute to elucidate several aspects of the intestinal microbiome development during the human lifespan, depicting the microbiota as an extremely plastic entity, capable of being reconfigured in response to different environmental factors and/or stressors of endogenous origin.
Resumo:
China is a large country characterized by remarkable growth and distinct regional diversity. Spatial disparity has always been a hot issue since China has been struggling to follow a balanced growth path but still confronting with unprecedented pressures and challenges. To better understand the inequality level benchmarking spatial distributions of Chinese provinces and municipalities and estimate dynamic trajectory of sustainable development in China, I constructed the Composite Index of Regional Development (CIRD) with five sub pillars/dimensions involving Macroeconomic Index (MEI), Science and Innovation Index (SCI), Environmental Sustainability Index (ESI), Human Capital Index (HCI) and Public Facilities Index (PFI), endeavoring to cover various fields of regional socioeconomic development. Ranking reports on the five sub dimensions and aggregated CIRD were provided in order to better measure the developmental degrees of 31 or 30 Chinese provinces and municipalities over 13 years from 1998 to 2010 as the time interval of three “Five-year Plans”. Further empirical applications of this CIRD focused on clustering and convergence estimation, attempting to fill up the gap in quantifying the developmental levels of regional comprehensive socioeconomics and estimating the dynamic convergence trajectory of regional sustainable development in a long run. Four clusters were benchmarked geographically-oriented in the map on the basis of cluster analysis, and club-convergence was observed in the Chinese provinces and municipalities based on stochastic kernel density estimation.
Resumo:
This Thesis studies the optimal control problem of single-arm and dual-arm serial robots to achieve the time-optimal handling of liquids and objects. The first topic deals with the planning of time-optimal anti-sloshing trajectories of an industrial robot carrying a cylindrical container filled with a liquid, considering 1-dimensional and 2-dimensional planar motions. A technique for the estimation of the sloshing height is presented, together with its extension to 3-dimensional motions. An experimental validation campaign is provided and discussed to assess the thoroughness of such a technique. As far as anti-sloshing trajectories are concerned, 2-dimensional paths are considered and, for each one of them, three constrained optimizations with different values of the sloshing-height thresholds are solved. Experimental results are presented to compare optimized and non-optimized motions. The second part focuses on the time-optimal trajectory planning for dual-arm object handling, employing two collaborative robots (cobots) and adopting an admittance-control strategy. The chosen manipulation approach, known as cooperative grasping, is based on unilateral contact between the cobots and the object, and it may lead to slipping during motion if an internal prestress along the contact-normal direction is not prescribed. Thus, a virtual penetration is considered, aimed at generating the necessary internal prestress. The stability of cooperative grasping is ensured as long as the exerted forces on the object remain inside the static-friction cone. Constrained-optimization problems are solved for 3-dimensional paths: the virtual penetration is chosen among the control inputs of the problem and friction-cone conditions are treated as inequality constraints. Also in this case experiments are presented in order to prove evidence of the firm handling of the object, even for fast motions.