A multimodal smartphone interface for active perception by visually impaired

The diffuse availability of mobile devices, such as smartphones and tablets, has the potential to bring substantial benefits to the people with sensory impairments. The solution proposed in this paper is part of an ongoing effort to create an accurate obstacle and hazard detector for the visually impaired, which is embedded in a hand-held device. In particular, it presents a proof of concept for a multimodal interface to control the orientation of a smartphone's camera, while being held by a person, using a combination of vocal messages, 3D sounds and vibrations. The solution, which is to be evaluated experimentally by users, will enable further research in the area of active vision with human-in-the-loop, with potential application to mobile assistive devices for indoor navigation of visually impaired people

Robot control based on qualitative representation of human trajectories

A major challenge for future social robots is the high-level interpretation of human motion, and the consequent generation of appropriate robot actions. This paper describes some fundamental steps towards the real-time implementation of a system that allows a mobile robot to transform quantitative information about human trajectories (i.e. coordinates and speed) into qualitative concepts, and from these to generate appropriate control commands. The problem is formulated using a simple version of qualitative trajectory calculus, then solved using an inference engine based on fuzzy temporal logic and situation graph trees. Preliminary results are discussed and future directions of the current research are drawn

Multisensor-based human detection and tracking for mobile service robots

The one of fundamental issues for service robots is human-robot interaction. In order to perform such a task and provide the desired services, these robots need to detect and track people in the surroundings. In the present paper, we propose a solution for human tracking with a mobile robot that implements multisensor data fusion techniques. The system utilizes a new algorithm for laser-based legs detection using the on-board LRF. The approach is based on the recognition of typical leg patterns extracted from laser scans, which are shown to be very discriminative also in cluttered environments. These patterns can be used to localize both static and walking persons, even when the robot moves. Furthermore, faces are detected using the robot's camera and the information is fused to the legs position using a sequential implementation of Unscented Kalman Filter. The proposed solution is feasible for service robots with a similar device configuration and has been successfully implemented on two different mobile platforms. Several experiments illustrate the effectiveness of our approach, showing that robust human tracking can be performed within complex indoor environments

Multisensor data fusion for joint people tracking and identification with a service robot

Tracking and recognizing people are essential skills modern service robots have to be provided with. The two tasks are generally performed independently, using ad-hoc solutions that first estimate the location of humans and then proceed with their identification. The solution presented in this paper, instead, is a general framework for tracking and recognizing people simultaneously with a mobile robot, where the estimates of the human location and identity are fused using probabilistic techniques. Our approach takes inspiration from recent implementations of joint tracking and classification, where the considered targets are mainly vehicles and aircrafts in military and civilian applications. We illustrate how people can be robustly tracked and recognized with a service robot using an improved histogram-based detection and multisensor data fusion. Some experiments in real challenging scenarios show the good performance of our solution

Integrating mobile robotics and vision with undergraduate computer science

This paper describes the integration of robotics education into an undergraduate Computer Science curriculum. The proposed approach delivers mobile robotics as well as covering the closely related field of Computer Vision, and is directly linked to the research conducted at the authors’ institution. The paper describes the most relevant details of the module content and assessment strategy, paying particular attention to the practical sessions using Rovio mobile robots. The specific choices are discussed that were made with regard to the mobile platform, software libraries and lab environment. The paper also presents a detailed qualitative and quantitative analysis of student results, including the correlation between student engagement and performance, and discusses the outcomes of this experience

On the origin of cement setting, and how to control the properties of the fresh and hardened material

Cement paste forms an elastic gel immediately after mixing cement and water. The gel’s strength rapidly increases during the dormant period. The cohesion of the gel originates from attractive forces among the hydrating surfaces and a network of nanoparticles of calcium-silicate-hydrate (C-S-H). These attractive forces do not vary throughout the dormant period, and cement paste stiffening can be interpreted as the result of an aging process occurring when cement paste is at rest. This aging process goes along with a refinement of the paste microstructure, with the large pores decreasing in volume. Shear interrupts the aging and brings back the system to its initial state, until the massive Portlandite precipitation occurring at the beginning of the acceleratory period initiates setting. The microstructure of cement paste, which is at the core of both concrete strength and durability, is determined by the mechanisms of gel formation and by the coalescence of the cement and hydrates’ particles into flocs which span the entire space. This comes to say that the porosity, strength and toughness of the hardened paste result from the intensity of inter-particle forces and from the kinetics of particle aggregation. It is widely accepted, even if not completely understood, that chemical admixtures modify these forces. It is thus possible to control the properties of cement paste, both in its fresh and hardened state, by using chemical admixtures which interact with the hydrating surfaces and modify their interaction potential. Most of such applications are already in use and have been developed with a trial and error approach, however the understanding of the forces at the origin of cement cohesion, and the knowledge of how to modify them may lead to the development of new, more sustainable binders

Sagging Support Statute: A Critical Analysis of the District of Columbia Uniform Reciprocal Enforcement of Support Act

These comments are part of Developments of the Law in the District of Columbia

Sagging Support Statute: A Critical Analysis of the District of Columbia Uniform Reciprocal Enforcement of Support Act

These comments are part of Developments of the Law in the District of Columbia

Resistencia al neoliberalismo urbano a través de la innovación social: el caso del Centri Sociali italiano

Centri sociali have been a common social, political, and spatial phenomenon in Italian cities since the 1970s. Since then, they emerged as active, youth-oriented places of left-wing and radical activism often operating at the margins of the urban fabric and in conflict with local institutions. In addition to political action, Centri Sociali play a social and cultural role in cities as spaces of leisure, social aggregation, and mutual support. This paper investigates how these groups locate themselves in an increasingly neoliberal urban environment by exploring their goals, the role they play in the wider communities, the issues they wish to address, and the strategies they mobilise. After presenting an overview of the concept and history of Italian Centri Sociali, the theoretical concept of urban neoliberalism is used to set the scene in which such groups are currently active and to explain the nature of the issues and challenges they aim to tackle. Further, the actions and strategies used by Centri Sociali are analysed through the lenses of Social Innovation Theory. This paper aims to understand how social innovation is used by Centri Sociali to create alternative urban spaces outside of neoliberal and capitalistic dynamics. It does so by using secondary data retrieved through literature review and through primary data collected via semi-structured interviews with 15 representatives from various Centri Sociali around Italy.Centri Sociali (Centros Sociales) han sido un fenómeno social, político, y espacial común en ciudades italianas desde los años 70s. Desde sus inicios, surgieron como lugares activos con inclinación de izquierda, orientados a las y los jóvenes, a través de una propuesta de activismo radical, a menudo operando en los márgenes de la fábrica urbana y en conflicto con instituciones locales. Además de su acción política, Los Centri Sociali juegan un rol social y cultural en ciudades como espacios de ocio, agregación social, y apoyo mutuo. Este artículo investiga cómo estos grupos se localizan en un ambiente urbano crecientemente neoliberal explorando sus objetivos, el rol que juegan en la comunidad ampliada, los temas que buscan abordar, y las estrategias que movilizan para estos fines. Después de presentar una visión general del concepto y la historia de los Centri Sociali italianos, el concepto teórico de neoliberalismo urbano es utilizado para delinear el contexto en el cual estos grupos se desarrollan actualmente y para explicar la naturaleza de los temas y desafíos que enfrentan. Luego, las acciones y estrategias de los Centri Sociali son analizadas desde la propuesta teórica de la innovación social. Este artículo intenta comprehender cómo la innovación social es utilizada por los Centri Sociali para crear espacios urbanos alternativos fuera de las dinámicas capitalista-neoliberales. Todo esto basado en datos secundarios provenientes de una revisión bibliográfica sobre el fenómeno y datos primarios recolectados en 15 entrevistas semiestructuradas con representantes de varios Cenri Sociales a lo largo de Italia