The detector control system for the HMPID in the ALICE experiment at LHC

The DCS (Detector Control System) of the ALICE experiment at LHC aims to integrate, configure, and monitor all the participating sub-detectors. The HMPID (High Momentum Particle Identification Detector), based on a Ring Imaging Cherenkov, is one of the ALICE sub-detectors. Its control system (CS) has to ensure the detector configuration, standalone running mode for test and maintenance, and integration in the ALICE DCS. In order to design the HMPID CS, we present in this paper an approach based on the GRAFCET Model. First results from the application of the GRAFCET to the liquid circulation apparatus, an HMPID subsystem, are reported. The impact of the solutions for the HV-LV sub-systems on the CS is also presented

Practical implementation of diffused sensing elements for TDR-based monitoring of rising damp in building structures

This paper describes the operating and technical details of the practical implementation of an innovative time domain reflectometry (TDR)-system for monitoring rising damp in building structures. The proposed system employs wire-like, passive, diffused sensing elements (SE's) that are embedded, at the time of construction or renovation, inside the walls of the building to be monitored. The SE's remain permanently inside the wall, ready to be interrogated when necessary

Accuracy improvement in the TDR-based localization of water leaks

A time domain reflectometry (TDR)-based system for the localization of water leaks has been recently developed by the authors. This system, which employs wire-like sensing elements to be installed along the underground pipes, has proven immune to the limitations that affect the traditional, acoustic leak-detection systems. Starting from the positive results obtained thus far, in this work, an improvement of this TDR-based system is proposed. More specifically, the possibility of employing a low-cost, water-absorbing sponge to be placed around the sensing element for enhancing the accuracy in the localization of the leak is addressed. To this purpose, laboratory experiments were carried out mimicking a water leakage condition, and two sensing elements (one embedded in a sponge and one without sponge) were comparatively used to identify the position of the leak through TDR measurements. Results showed that, thanks to the water retention capability of the sponge (which maintains the leaked water more localized), the sensing element embedded in the sponge leads to a higher accuracy in the evaluation of the position of the leak

The Hodge numbers of O'Grady 10 via Ngô strings

We determine the Hodge numbers of the hyper-Kähler manifold known as O'Grady 10 by studying some related modular Lagrangian fibrations by means of Nĝo strings, which we introduce via a refinement of the Ngô Support Theorem

Towards a social robot as interface for tourism recommendations

The popularity of social robots is steadily increasing, mainly due to the interesting impact they have in several application domains. In this paper, we propose the use of Pepper Robot as an interface of a recommender system for tourism. In particular, we used the robot to interact with the users and to provide them with personalized recommendations about hotels, restaurants, and points of interest in the area. The personalization mechanism encoded in the social robot relies on soft biometrics traits automatically recognized by the robot, as age and gender, user interests and personal facets. All these data are used to feed a neural network that returns as output the most suitable recommendations for the target user. To evaluate the effectiveness of the interaction driven by a social robot, we carried out a user study whose goal was to evaluate: (1) how the robot affects the perceived accuracy of the recommendations; (2) how the user experience and the engagement vary by interacting with a social robot instead of a classic web application. Even if there is a large room for improvement, mainly due to the poor speech recognizer integrated in the Pepper, the results showed that the robot can strongly attract people, thanks to its presence and interaction capabilities. These findings encouraged us in performing a larger field study to test the approach in the wild and to understand whether it can increase the acceptance of recommendations in real environments

Single neuron activity-dependent signal processing

Activity in a neural network can affect both the synaptic strengths and the intrinsic electrical properties of neurons within the network. Changes of the intrinsic properties can enhance, reduce or stabilize the neural excitability. One of the activity-dependent regulatory mechanisms is the afterhyperpolarization, generally due to the activation of K+ conductances and to a Na+/K+ pump. In many neurons, the afterhyperpolarization is modified after a period of spike activity. In the mechanosensory T neurons of the leech, a prolonged electrical activity produces an increase of the afterhyperpolarization. This is believed to induce conduction block of spikes in several regions of the neuron, which in turn may decrease presynaptic invasion of spikes and thereby decrease transmitter release. To explore this possibility, we developed a multicompartment model of a T neuron [1]. The model incorporated empirical data describing the geometry of the cell and activity-dependent changes of the afterhyperpolarization. Simulations indicated that at some branching points activity-dependent increases of the afterhyperpolarization reduced the number of spikes transmitted from the receptive fields to the soma and beyond. Simulations also showed that the afterhyperpolarization could modulate transmission from the soma to the synaptic terminals, suggesting that it can regulate spike conduction within the presynaptic arborizations of the neuron, contributing to the synaptic depression correlated with increases in the afterhyperpolarization. In order to investigate how the afterhyperpolarization modulatory capabilities on transmission were dependent on the axonal geometry as well as on membrane properties, we developed [2] another multicompartment model of the mechanosensory cell, representing the reduced version of the model developed in [1]. The simulations suggested that channel kinetics influence the afterhyperpolarization-dependent modulation of spike conduction through points of impedance mismatch. The processing or conductive features of neurons seems to be determined in the first instance by the channel kinetics of the membrane and secondarily by the axonal geometry and activity-dependent processes and noise. We have also showed [3] that the role of the afterhyperpolarization induced by Na+/K+ pump-activity, which consists in a slow reduction in excitability, is also involved in neuronal coding. We showed that the regulation of excitability by Na+/K+ pump-activity is necessary for the neuron to make different responses depending on the statistical context of the stimuli. We investigate the role of membrane kinetics and input conductance mismatch in the adaptation of spike bursting to stimulus statistics

The current progress of the ALICE Ring Imaging Cherenkov Detector

Recently, the last two modules (out of seven) of the ALICE High Momentum Particle Identification detector (HMPID) were assembled and tested. The full detector, after a pre-commissioning phase, has been installed in the experimental area, inside the ALICE solenoid, at the end of September 2006. In this paper we review the status of the ALICE/HMPID project and we present a summary of the series production of the CsI photo-cathodes. We describe the key features of the production procedure which ensures high quality photo-cathodes as well as the results of the quality assessment performed by means of a specially developed 2D scanner system able to produce a detailed map of the CsI photo-current over the entire photo-cathode surface. Finally we present our recent R&D efforts toward the development of a novel generation of imaging Cherenkov detectors with the aim to identify, in heavy ions collisions, hadrons up to 30 GeV/c.Comment: Presented at the Imaging-2006 Conference, Stockholm, Sweden, June 200

An inverse validation for detecting pipe leaks with a TDR-based method

Recently, an innovative system based on time domain reflectometry (TDR) for the individuation of leaks in underground pipes has been proposed and validated. Starting from the results obtained so far, the present works aims at further investigating the practical applicability of the aforementioned system. In particular, the goal of this work is to assess the system in the detection of two close leaks (i.e. leakages that may occur on the same length of pipe). To this purpose, an experimental setup was arranged: two "leakage conditions" were imposed, and the position of the leaks were considered as unknown and calculated through the dedicated developed algorithm. Results show that, differently from traditional leak detection methods (in which the presence of a leak may "mask" the presence of other leaks), the TDR-based system successfully individuates and correctly localizes the presence of two leaks

Moisture content measurements through TDR: A metrological assessment for industrial applications

In this paper a metrological assessment on the accuracy provided by a Time Domain Reflectometry (TDR)-based method for the estimation of moisture content of granular materials is proposed. In particular, comparative moisture content measurements are carried out through two different TDR instruments: an inexpensive portable unit and a high-performance unit. The main goals are first to assess a robust procedure for TDR moisture monitoring (in particular for sand-like materials), and second to provide a deep metrological analysis for minimizing and characterizing error contributions. This feature is particularly important when considering the proposed measurement procedures for industrial applications, where both accuracy and low cost must be guaranteed