5,061 research outputs found

    Preparation For Independence

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    A Note on Fractional KdV Hierarchies

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    We introduce a hierarchy of mutually commuting dynamical systems on a finite number of Laurent series. This hierarchy can be seen as a prolongation of the KP hierarchy, or a ``reduction'' in which the space coordinate is identified with an arbitrarily chosen time of a bigger dynamical system. Fractional KdV hierarchies are gotten by means of further reductions, obtained by constraining the Laurent series. The case of sl(3)^2 and its bihamiltonian structure are discussed in detail.Comment: Final version to appear in J. Math. Phys. Some changes in the order of presentation, with more emphasis on the geometrical picture. One figure added (using epsf.sty). 30 pages, Late

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    Debris-flow susceptibility assessment through cellular automata modeling: an example from 15?16 December 1999 disaster at Cervinara and San Martino Valle Caudina (Campania, southern Italy)

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    International audienceOn 15?16 December 1999, heavy rainfall severely stroke Campania region (southern Italy), triggering numerous debris flows on the slopes of the San Martino Valle Caudina-Cervinara area. Soil slips originated within the weathered volcaniclastic mantle of soil cover overlying the carbonate skeleton of the massif. Debris slides turned into fast flowing mixtures of matrix and large blocks, downslope eroding the soil cover and increasing their original volume. At the base of the slopes, debris flows impacted on the urban areas, causing victims and severe destruction (Vittori et al., 2000). Starting from a recent study on landslide risk conditions in Campania, carried out by the Regional Authority (PAI ?Hydrogeological setting plan, in press), an evaluation of the debris-flow susceptibility has been performed for selected areas of the above mentioned villages. According to that study, such zones would be in fact characterised by the highest risk levels within the administrative boundaries of the same villages ("HR-zones"). Our susceptibility analysis has been performed by applying SCIDDICA S3?hex ? a hexagonal Cellular Automata model (von Neumann, 1966), specifically developed for simulating the spatial evolution of debris flows (Iovine et al., 2002). In order to apply the model to a given study area, detailed topographic data and a map of the erodable soil cover overlying the bedrock of the massif must be provided (as input matrices); moreover, extent and location of landslide source must also be given. Real landslides, selected among those triggered on winter 1999, have first been utilised for calibrating SCIDDICA S3?hex and for defining "optimal" values for parameters. Calibration has been carried out with a GIS tool, by quantitatively comparing simulations with actual cases: optimal values correspond to best simulations. Through geological evaluations, source locations of new phenomena have then been hypothesised within the HR-zones. Initial volume for these new cases has been estimated by considering the actual statistics of the 1999 landslides. Finally, by merging the results of simulations, a deterministic susceptibility zonation of the considered area has been obtained. In this paper, aiming at illustrating the potential for debris-flow hazard analyses of the model SCIDDICA S3?hex, a methodological example of susceptibility zonation of the Vallicelle HR-zone is presented

    Corridor MPC for Multi-Agent Inspection of Orbiting Structures

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    In this work, we propose an extension of the previously introduced Corridor Model Predictive Control scheme for high-order and distributed systems, with an application for on-orbit inspection. To this end, we leverage high order control barrier function (HOCBF) constraints as a suitable control approach to maintain each agent in the formation within a safe corridor from its reference trajectory. The recursive feasibility of the designed MPC scheme is tested numerically, while suitable modifications of the classical HOCBF constraint definition are introduced such that safety is guaranteed both in sampled and continuous time. The designed controller is validated through computer simulation in a realistic inspection scenario of the International Space Station.Comment: Paper accepted at Conference on Decision and Control 2023 (CDC

    Occupational Safety and Health Program: Foundation of Technology Management in SUCs

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    Ergonomics and other technology to reduce risk or prevent accidents must be effectively used and managed for SUC to become competitive locally and in the region. The research evaluated the association of Occupational Safety, Health and Social Environment to the health condition of teachers of State Colleges and Universities (SUCs) in the Philippines as the basis for crafting the Occupation Safety and Health Program for SUCs. The descriptive-quantitative- correlational method was used in this study using survey questionnaires that were administered to 84 teachers across the three identified SUCs. Findings revealed a relationship between Occupational safety, level of occupational health, and social environment to the teachers' health status. Health and safety conditions included work environment, housekeeping, and health and medical services provided by the concerned institutions to their faculty. On the other hand, productivity consisted of outputs in instructions, research, community and extension services, and creative productions. The different occupational and non-occupational illnesses were taken into consideration. Afterward, provisions on occupational safety and health for faculty productivity were proposed by the researchers to help school administrators maintain a safe and healthful atmosphere in the academe, thereby increasing the productivity of the faculty

    Three Li-rich K giants: IRAS 12327-6523, IRAS 13539-4153, and IRAS 17596-3952

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    We report on spectroscopic analyses of three K giants previously suggested to be Li-rich: IRAS 12327-6523, IRAS 13539-4153, and IRAS 17596-3952. High-resolution optical spectra and the LTE model atmospheres are used to derive the stellar parameters: (TeffT_{\rm eff}, log gg, [Fe/H]), elemental abundances, and the isotopic ratio 12^{12}C/13^{13}C. IRAS 13539-4153 shows an extremely high Li abundance of logϵ\log\epsilon(Li) \approx 4.2, a value ten times more than the present Li abundance in the local interstellar medium. This is the third highest Li abundance yet reported for a K giant. IRAS 12327-6523 shows a Li abundances of logϵ\log\epsilon(Li)\approx 1.4. IRAS 17596-3952 is a rapidly rotating (VsiniV{\sin i} \approx 35 km s1^{-1}) K giant with logϵ\log\epsilon(Li) \approx 2.2. Infrared photometry which shows the presence of an IR excess suggesting mass-loss. A comparison is made between these three stars and previously recognized Li-rich giants.Comment: 17 pages, 6 figures, accepted for A

    Thaumetopoea Pinivora Treitschke, 1834, Thaumetopoidae nou per a la fauna de Catalunya (Lepidoptera)

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    Se da cuenta del hallazgo en Cataluña (Els Coms de Das, Baixa Cerdanya, Pirineo oriental) de Thaumetopoea pinivora Treitschke, 1834, Thaumetopoeidae nuevo para la región. Se exponent los aspectos más interesantes de su bionomía y se pone al día la distribución de esta especie en la Península Ibérica.Thaumetopoea pinivora Treitschke, 1834, Thaumetopoidae new for Catalonia (Lepidoptera). In this paper the authors report the found in Catalonia (Els Coms de Das, Baixa Cerdanya, Pirineu oriental) of Thaumetopoea pinivora Treitschke, 1834, Thaumetopoeidae new for the area. We expose the more interesting aspects of its bionomy and actualize its distribution in the lberian fauna
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