Search results for "EXPLORATION"

A stigmergic approach for social interaction design in collaboration engineering

2014

The increasing number of available collaborative tools and their extensive use in many organizational activities has constantly raised the complexity of collaboration engineering. It presumes the design of group decision processes, supported by a wide-range of groupware tools, in an ill-structured, dynamic, and open environment. As many of these processes are recurring by nature, the development of a shared repository to store the collective knowledge and experiences of group decision process designs became a core research topic of collaboration engineering in last few years. The paper presents a human-computer interaction engineering approach to design a software prototype that provides pe…

Shaping the firm's external search strategy

2014

This paper explores the determinants of external knowledge search strategies, specifically, exploitative and exploratory search. The literature emphasizes environmental context and technological resources, especially R&D, as important determinants of the search strategy. In this paper we focus on two types of the firm's formal structure: formalized and decentralized structures. The study uses survey data from the ceramic tile industry in Spain. The results show that a competitive environment and a decentralized organizational structure play a role in shaping the firm's external search strategy, but that R&D has no effect. We find that competition inhibits exploratory search, while a decentr…

Power Bus Management Techniques for Space Missions in Low Earth Orbit

2021

In space vehicles, the typical configurations for the Solar Array Power Regulators in charge of managing power transfer from the solar array to the power bus are quite different from the corresponding devices in use for terrestrial applications. A thorough analysis is reported for the most popular approaches, namely Sequential Switching Shunt Regulation and parallel-input Pulse Width Modulated converters with Maximum Power Point Tracking. Their performance is compared with reference to a typical mission in low Earth orbit, highlighting the respective strengths and weaknesses. A novel solar array managing technique, the Sequential Maximum Power Tracking, is also introduced in the trade-off a…

Weights Space Exploration Using Genetic Algorithms for Meta-classifier in Text Document Classification

2012

La stereotomia nella cattedra di Architettura statica di Carlo Giachery

2014

La scuola di architettura di Palermo, sin dalla sua fondazione nel 1779, con la creazione della cattedra di Architettura civile affidata a Giuseppe Venanzio Marvuglia, era divenuta inevitabilmente il luogo di verifica e talvolta di esplorazione dei temi legati alla pratica professionale e, quindi, all’arte del costruire. Giachery, Professore di Architettura statica e civile dal 1837 al 1865, è il primo ad avvertire, da docente, la crisi profonda del sistema didattico della scuola di architettura di Palermo isterilita dalla ricerca di astratte idealità neoclassiche e straniatasi dal processo evolutivo della cultura architettonica europea dopo la morte dei “maestri” Marviglia e Gentile. Secon…

Predicting gully occurrence at watershed scale: Comparing topographic indices and multivariate statistical models

2020

In this study, the ability of five topographic indices to predict the gully trajectories observed in two adjacent watersheds located in Sicily (Italy) was evaluated. Two of these indices, named MSPI and MTWI, as far as we know, have never been employed to this aim. They were obtained by multiplying the stream power index (SPI) and the topographic wetness index (TWI), respectively, by the convergence index (CI). The predictive ability of the topographic indices was measured by using both cut-off independent (AUC: area under the receiver operating characteristic curve) and dependent statistics (Cohen's kappa index κ, sensitivity, specificity). These statistics were calculated also for 100 MAR…

Soil fungal community composition does not alter along a latitudinal gradient through the maritime and sub-Antarctic

2012

We investigated the relationships between fungal community composition, latitude and a range of physicochemical parameters in 58 soils sampled from a 2370 km latitudinal gradient between South Georgia (54 S, 38 W) in the sub-Antarctic and Mars Oasis (72 S, 68 W) on Alexander Island in the southern maritime Antarctic. Our study, which is based on approximately ten times the number of samples used in previous similar studies, indicates that latitude and its associated environmental parameters are not related to fungal community composition. Significant changes in the composition of soil fungal communities were observed in relation to gradients of the ratio of total organic carbon to nitrogen,…

Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater

2005

The cover shows part of the Larry's Lookout panorama, seen from the Mars Exploration Rover (MER) Spirit during its drive up Husband Hill: the summit is about 200 metres from the rover. Six papers this week report in detail on the MER mission. An Analysis compares predictions used to select a landing site with the conditions actually encountered. This ‘ground truth’ will be invaluable for interpreting future remote-sensing data. Surface chemistry suggests that the upper layer of soil may contain 1% meteoritic material. MER provides a unique glimpse of solar transits of the moons Phobos and Deimos. Rover Opportunity examined wind-related processes, and spectroscopy indicates a dry origin for …

Attraversare l’inatteso selvatico urbano. Un’esperienza di cammino con Stalker a Roma est

2021

Italian cities have undergone in the past century a rapid development which has generated abandoned areas within its limits. Many of these places are now uncultivated and rich in spontaneous vegetation. The article reports the relationship between a wild area in eastern Rome, the ex-SNIA-Viscosa Lake, from which the artistic group Stalker has started some walking experiences. During the crossing of the wild spaces that characterize this part of the city, questions emerged related to the link between a community and unpredictable nature, the search for new approaches to conservation and the planning of natural spaces in the city.

Gully Erosion Susceptibility Mapping Using Multivariate Adaptive Regression Splines—Replications and Sample Size Scenarios

2019

Soil erosion is a serious problem affecting numerous countries, especially, gully erosion. In the current research, GIS techniques and MARS (Multivariate Adaptive Regression Splines) algorithm were considered to evaluate gully erosion susceptibility mapping among others. The study was conducted in a specific section of the Gorganroud Watershed in Golestan Province (Northern Iran), covering 2142.64 km2 which is intensely influenced by gully erosion. First, Google Earth images, field surveys, and national reports were used to provide a gully-hedcut evaluation map consisting of 307 gully-hedcut points. Eighteen gully erosion conditioning factors including significant geoenvironmental and morph…