Towards Multi-robot Exploration: A Decentralized Strategy for UAV Forest Exploration

Efficient exploration strategies are vital in tasks such as search-and-rescue missions and disaster surveying. Unmanned Aerial Vehicles (UAVs) have become particularly popular in such applications, promising to cover large areas at high speeds. Moreover, with the increasing maturity of onboard UAV perception, research focus has been shifting toward higher-level reasoning for single- and multi-robot missions. However, autonomous navigation and exploration of previously unknown large spaces still constitutes an open challenge, especially when the environment is cluttered and exhibits large and frequent occlusions due to high obstacle density, as is the case of forests. Moreover, the problem of long-distance wireless communication in such scenes can become a limiting factor, especially when automating the navigation of a UAV swarm. In this spirit, this work proposes an exploration strategy that enables UAVs, both individually and in small swarms, to quickly explore complex scenes in a decentralized fashion. By providing the decision-making capabilities to each UAV to switch between different execution modes, the proposed strategy strikes a great balance between cautious exploration of yet completely unknown regions and more aggressive exploration of smaller areas of unknown space. This results in full coverage of forest areas of variable density, consistently faster than the state of the art. Demonstrating successful deployment with a single UAV as well as a swarm of up to three UAVs, this work sets out the basic principles for multi-root exploration of cluttered scenes, with up to 65% speed up in the single UAV case and 40% increase in explored area for the same mission time in multi-UAV setups

A bio-inspired reinterpretation of symbiotic human-robot collaboration in assembly processes

The emergence of collaborative robotics allowed humans and robots to work closely together to perform manufacturing activities. By combining their distinctive strengths and abilities, humans and robots can support each other in completing complex tasks. The relationship between humans and robots is frequently described in the literature as symbiotic. However, the concept of symbiosis, originally conceived in natural science, is often oversimplified as the mere exchange of mutual benefits. In practice, the term ‘symbiosis’ encompasses a wide range of nteractions, ranging from relationships with positive impacts to relationships with negative impacts. Understanding the foundation of Human-Robot Symbiosis is crucial for its management. Two are the primary aims of this paper: (i) reinterpreting the collaborative tasks in assembly processes according to the properties of symbiotic elationships; (ii) proposing a novel approach for evaluating assembly tasks based on the bio-inspired features of symbiotic Human-Robot collaborative systems

Climate Aridity under Changing Conditions and Implications for the Agricultural Sector: Italy as a Case Study

A comprehensive diachronic analysis (1951–2010) of precipitation and temperature regimes has been carried out at the national and regional scale in Italy to investigate the impact of climate aridity on the agricultural system. Trends in climate aridity have been also analysed using UNEP aridity index which is the ratio between rainfall and potential evapotranspiration on a yearly basis. During the examined time period, and particularly in the most recent years, a gradual reduction in rainfall and growing temperatures have been observed which have further widened the gap between precipitation amounts and water demand in agriculture

Real-time single image depth perception in the wild with handheld devices

Depth perception is paramount to tackle real-world problems, ranging from autonomous driving to consumer applications. For the latter, depth estimation from a single image represents the most versatile solution, since a standard camera is available on almost any handheld device. Nonetheless, two main issues limit its practical deployment: i) the low reliability when deployed in-the-wild and ii) the demanding resource requirements to achieve real-time performance, often not compatible with such devices. Therefore, in this paper, we deeply investigate these issues showing how they are both addressable adopting appropriate network design and training strategies -- also outlining how to map the resulting networks on handheld devices to achieve real-time performance. Our thorough evaluation highlights the ability of such fast networks to generalize well to new environments, a crucial feature required to tackle the extremely varied contexts faced in real applications. Indeed, to further support this evidence, we report experimental results concerning real-time depth-aware augmented reality and image blurring with smartphones in-the-wild.Comment: 11 pages, 9 figure

Land evaluation and agri-environmental indicators : exploring spatial trends of nitrogen balance in Greece

The development and application of a suitable methodology for establishing agro-environmental indicators was the aim of this study, according to the new approaches of environmental dimension of the Common Agricultural Policy (CAP) of the European Union. Agro-environmental indicator development is illustrated by a concrete case study of Nitrogen balance at detailed spatial scale (NUTS IV or LAU1) administrative level in Greece. The nitrogen balance is an indicator of the risk posed to the environment from the excess of nitrogen due to the agriculture. The LAU1 analysis of the Nitrogen balance was carried-out in order to identify vulnerable areas in terms of soil and water resources. To this end an original methodology has been developed, using information from statistical databases and from Geographical Information System (GIS) in an attempt to answer this question. Vulnerable areas, due to high nitrogen surplus, are identified using this methodology achieving that specific policy measures for environmental protection at the national level can be applied. This study can be considered as a scale tool informing the reorientation of the CAP, which is directed to transfer support from agricultural products to local incomes and encourage environmentally friendly agricultural activities.peer-reviewe

Identifying rural areas using entrepreneurship indicators : a case study in Greece

The need for a more comprehensive, multidimensional tool for policy formulation and evaluation became evident when the negative repercussions of the EU Common Agricultural Policy (CAP) had to be faced by policy makers in the early 1990s, especially in response to rural depopulation, increasing income inequalities, and environmental degradation problems. Over the last thirty years, agricultural regions in Greece have undergone dramatic structural changes, which in turn have altered their rural identity. Changes in employment composition is an indicator of the transformations taking place in the agricultural sector, and claim for more comprehensive methodologies for rural areas for profiles. The emerging need for developing new methodologies for traditionally rural and rapidly changing regions in Europe, is pertinent to rural policies. This paper comments on the possible use of an original classification criterion based on the entrepreneurial trajectory of rural areas. Aiming at the requirements set by the new EU Rural Development Regulation EC 1698/2005, the existing methodologies are also reviewed, their strengths and weaknesses are presented, and the emerging need for an enhanced tool for rural classification is finally discussed. The classificationtypology is best derived when accounting for variables describing the entrepreneurial activity in rural areas using a flexible and effective response to policy needs (policy targeting and monitoring of rural development).peer-reviewe

Influence of Storage Temperature on Radiochemical Purity of 99mTc-Radiopharmaceuticals

The influence of effective room temperature on the radiochemical purity of 99mTc-radiopharmaceuticals was reported. This study was born from the observation that in the isolators used for the preparation of the 99mTc-radiopharmaceuticals the temperatures can be higher than those reported in the commercial illustrative leaflets of the kits. This is due, in particular, to the small size of the work area, the presence of instruments for heating, the continuous activation of air filtration, in addition to the fact that the environment of the isolator used for the 99mTc-radiopharmaceuticals preparation and storage is completely isolated and not conditioned. A total of 244 99mTc-radiopharmaceutical preparations (seven different types) have been tested and the radiochemical purity was checked at the end of preparation and until the expiry time. Moreover, we found that the mean temperature into the isolator was significantly higher than 25 C, the temperature, in general, required for the preparation and storage of 99mTc-radiopharmaceuticals. Results confirmed the radiochemical stability of radiopharmaceutical products. However, as required in the field of quality assurance, the impact that different conditions than those required by the manufacturer on the radiopharmaceuticals quality have to be verified before human administration

Crime and the (Mediterranean) city : exploring the geography of (in) security in Rome, Italy

The spatial distribution of a selection of crime and demographic indicators in urban and suburban Rome, Italy, was explored in this paper to correlate socioeconomic conditions with urban deviance at local scale. An index of crime concentration was derived at district scale by composing all crime indicators. A principal components analysis was undertaken to correlate crime indicators with the socioeconomic context described through economic and demographic variables, living conditions, and the environmental quality. The geographical distribution of crime in Rome showed a pattern mainly associated to variables including population density, settlement form (compact vs dispersed), income, and unemployment. The spatial distribution of some crime indicators was finally compared with the citizens’ perception of security as it was measured by a specific field survey carried out at the same spatial scale. The paper illustrates that the integration between statistical data and qualitative information collected through field observation is an effective tool to inform policies contrasting criminality at local scale.peer-reviewe