��Remain Faithful to the Earth!��*: Reporting Experiences of Artifact-Centered Design in Healthcare

In this paper we report about two design experiences in the domain of healthcare information technology that shed light on the advantages of getting rid of complex and abstract representations of hospital work and of concentrating on the artifacts that practitioners habitually use in their daily practice. We ground our approach in the recent literature on the often unintended shortcomings exhibited by healthcare information systems and propose a lightweight method to support the phases of requirement elicitation and functional design. We then discuss the main requirements expressed in our recent research activity and provide examples of how to address them in terms of modular and reusable design solutions.     

Average TimeSynch: A consensus-based protocol for clock synchronization in wireless sensor networks

This paper describes a new consensus-based protocol, referred to as Average TimeSync (ATS), for synchronizing the clocks of a wireless sensor network. This algorithm is based on a cascade of two consensus algorithms, whose main task is to average local information. The proposed algorithm has the advantage of being totally distributed, asynchronous, robust to packet drop and sensor node failure, and it is adaptive to time-varying clock drifts and changes of the communication topology. In particular, a rigorous proof of convergence to global synchronization is provided in the absence of process and measurement noise and of communication delay. Moreover, its effectiveness is shown through a number of experiments performed on a real wireless sensor network.     

Indexing quantized ensembles of exemplar-SVMs with rejecting taxonomies

Multimedia Tools and Applications - Ensembles of Exemplar-SVMs have been introduced as a framework for Object Detection but have rapidly found a large interest in a wide variety of computer vision...     

Adaptive Robust Three‐dimensional Trajectory Tracking for Actively Articulated Tracked Vehicles*

A new approach is proposed for an adaptive robust three‐dimensional (3D) trajectory‐tracking controller design. The controller is modeled for actively articulated tracked vehicles (AATVs). These vehicles have active sub‐tracks, called flippers, linked to the ends of the main tracks, to extend the locomotion capabilities in hazardous environments, such as rescue scenarios. The proposed controller adapts the flippers configuration and simultaneously generates the track velocities, to allow the vehicle to autonomously follow a given feasible 3D path. The approach develops both a direct and differential kinematic model of the AATV for traversal task execution correlating the robot body motion to the flippers motion. The benefit of this approach is to allow the controller to flexibly manage all the degrees of freedom of the AATV as well as the steering. The differential kinematic model integrates a differential drive robot model, compensating the slippage between the vehicle tracks and the traversed terrain. The underlying feedback control law dynamically accounts for the kinematic singularities of the mechanical vehicle structure. The designed controller integrates a strategy selector too, which has the role of locally modifying the rail path of the flipper end points. This serves to reduce both the effort of the flipper servo motors and the traction force on the robot body, recognizing when the robot is moving on a horizontal plane surface. Several experiments have been performed, in both virtual and real scenarios, to validate the designed trajectory‐tracking controller, while the AATV negotiates rubble, stairs, and complex terrain surfaces. Results are compared with both the performance of an alternative control strategy and the ability of skilled human operators, manually controlling the actively articulated components of the robot.     

Continuous localization and mapping of a pan–tilt–zoom camera for wide area tracking

Pan–tilt–zoom (PTZ) cameras are well suited for object identification and recognition in far-field scenes. However, the effective use of PTZ cameras is complicated by the fact that a continuous online camera calibration is needed and the absolute pan, tilt and zoom values provided by the camera actuators cannot be used because they are not synchronized with the video stream. So, accurate calibration must be directly extracted from the visual content of the frames. Moreover, the large and abrupt scale changes, the scene background changes due to the camera operation and the need of camera motion compensation make target tracking with these cameras extremely challenging. In this paper, we present a solution that provides continuous online calibration of PTZ cameras which is robust to rapid camera motion, changes of the environment due to varying illumination or moving objects. The approach also scales beyond thousands of scene landmarks extracted with the SURF keypoint detector. The method directly derives the relationship between the position of a target in the ground plane and the corresponding scale and position in the image and allows real-time tracking of multiple targets with high and stable degree of accuracy even at far distances and any zoom level.     

A two-step optimization procedure for assessing water constituent concentrations by hyperspectral remote sensing techniques: An application to the highly turbid Venice lagoon waters

Over the past few years, the increased spectral and spatial resolution of remote sensing equipment has promoted the investigation of new techniques for inland and coastal water monitoring. The availability of new high-resolution data has allowed improvements in models based on the radiative transfer theory for assessing optical water quality parameters. In this study, we fine-tuned a physical model for the highly turbid Venice lagoon waters and developed an inversion technique based on a two-step optimization procedure appropriate for hyperspectral data processing to retrieve water constituent concentrations from remote data. In the first step, the solution of a linearized analytical formulation of the radiative transfer equations was found. In the second step, this solution was used to provide the initial values in a non-linear least squares-based method. This effort represents a first step in the construction of a feasible and timely methodology for Venice lagoon water quality monitoring by remote sensing, especially in view of the existing experimental hyperspectral satellite (Hyperion) and the future missions such as PRISMA, EnMap and HyspIRI. The optical properties of the water constituents were assessed on the basis of sea/lagoon campaigns and data from the literature. The water light field was shaped by an analytical formulation of radiative transfer equations and the application of numerical simulations (Hydrolight software). Once the optical properties of the Venice lagoon bio-optical model were validated, the inverse procedure was applied to local radiometric spectra to retrieve concentrations of chlorophyll, colored dissolved organic matter and tripton. The inverse procedure was validated by comparing these concentrations with those measured in the laboratory from in situ water samples, then it was applied to airborne (CASI and MIVIS) and satellite (Hyperion) sensors to derive water constituent concentration maps. The consistent results encourage the use of this procedure using future missions satellite (PRISMA, EnMap and HyspIRI).     

Trading off between control and autonomy: a narrative review around de-design

ABSTRACT

In this work, we provide an overview of contemporary perspectives of design that may challenge the traditional design of IT and socio-technical systems. Our starting metaphor is that of ‘wicked problems’, where the singularity, incompleteness and intrinsic uncertainty of real world settings foregrounds how the worldview that designers offer to practitioners may be optimal in theory but useless in practice. To go beyond traditional notions of design and designer, we intercepted insights coming from minoritarian voices in both theoretic and practice-based design fields. ‘De-design’ is a term we coined to encompass this wide spectrum of approaches that make more resilient and sustainable information artifact, de-emphasize design as a theoretical construct, and reconsider practice as the leading principle of digital innovation. This paper is a narrative review of voices in an extensive array of fields: from Information Systems to Human-Computer Interaction, from End-User Development to Critical Design, from Software Design to Design Studies. Our contribution retraces the motivational roots of de-design and tries to characterise de-design by filling relational gaps between disparate approaches and by bringing them back to IT and socio-technical design, to make digital artifacts sustainable in all of the new environmental, organisational and cultural spaces near to come.     

Energy cost and mechanical efficiency of riding a human-powered recumbent bicycle

When dealing with human-powered vehicles, it is important to quantify the capability of converting metabolic energy in useful mechanical work by measuring mechanical efficiency. In this study, net mechanical efficiency (eta) of riding a recumbent bicycle on flat terrain and at constant speeds (v, 5.1-10.0 m/s) was calculated dividing mechanical work (w, J/m) by the corresponding energy cost (C(c), J/m). w and C(c) increased linearly with the speed squared: w = 9.41 + 0.156 . v(2); C(c) = 39.40 + 0.563 . v(2). eta was equal to 0.257 +/- 0.0245, i.e. identical to that of concentric muscular contraction. Hence, i) eta seems unaffected by the biomechanical arrangement of the human-vehicle system; ii) the efficiency of transmission seems to be close to 100%, suggesting that the particular biomechanical arrangement does not impair the transformation of metabolic energy in mechanical work. When dealing with human-powered vehicles, it is important to quantify mechanical efficiency (eta) of locomotion. eta of riding a recumbent bicycle was calculated dividing the mechanical work to the corresponding energy cost of locomotion; it was practically identical to that of concentric muscular contraction (0.257 +/- 0.0245), suggesting that the power transmission from muscles to pedals is unaffected by the biomechanical arrangement of the vehicle.     

Why zombies cannot write significant source code: The Knowledge Game and the art of computer programming

This article analyses the knowledge needed to understand a computer program within the philosophy of information. L. Floridi's method of levels of abstraction is applied to the relation between an ideal programmer and a modern computer seen together as an informational organism. The results obtained by the mental experiment known as the Knowledge Game are applied to this relation, so to explain what a programmer should know in order to program a modern computer. In particular, this analysis clearly shows why non-conscious agents have no hopes to write significant programs. Two main objections are then presented and attacked by corresponding counterobjections.