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Guidelines for the good practice of surface wave analysis: a product of the InterPACIFIC project
No full textSurface wave methods gained in the past decades a primary role in many seismic projects. Specifically they are often used to retrieve a 1D shear wave velocity model or to estimate the VS,30 at a site. The complexity of the interpretation process and the variety of possible approaches to surface wave analysis make it very hard to set a fixed standard to assure quality and reliability of the results. The present guidelines provide practical information on the acquisition and analysis of surface wave data by giving some basic principles and specific suggestions related to the most common situations. They are primarily targeted to non-expert users approaching surface wave testing, but can be useful to specialists in the field as a general reference. The guidelines are based on the experience gained within the InterPACIFIC project and on the expertise of the participants in acquisition and analysis of surface wave data
Polynomial classification model for real-time fall prediction system
No full textHuman gait is a dynamic biometrical feature that describes the kinematics of human walking. Gait modeling is studied in order to find a pattern of walking that can be used for diagnosis of walking disorder or abnormal walk detection. Difficulty in walking progressively increases with aging and causes unintentional falls, which is a common incident among elderly people. Fall prediction systems can help to prevent unintentional falls that could cause serious injuries, therefore they can reduce the health service costs. This paper presents an algorithm with polynomial classification model of human gait for real-time fall prediction. This approach enables the user to detect the transition from a normal to an abnormal walking pattern. A dataset based on the state-of-the-art techniques in simulating abnormal walks was created by using an accelerometer embedded in a smartphone, which is recognized to be precise enough for fall avoidance systems. The proposed approach improves state-of-the-art fall prediction approaches, by achieving 99.2% of accuracy in abnormal walk detection
Use of biological mesh in trans-anal treatment for recurrent recto-urethral fistula
No full textDear Author, I read with interest the letter by Deepak Batura about our paper entitled Use of biological mesh in trans-anal treatment for recurrent recto-urethral fistula. I thank the colleague for his accurate comments. I take this opportunity to clarify the following points: 1.All 7 patients reported in the original article underwent double diversion at least 2 months before the author's procedure. In this situation, no enteric preparation is necessary with a surgical field clean and ideal to use a mesh in a potential infected site. The biological mesh has a great capacity to progressively integrate itself; 2.All 7 patients we described underwent extensive clinical investigations during serial follow-up visits that excluded urethral stricture, signs of infections or urethral sequelae. That's way the patients did not undergo extra exams (endoscopic or bacteriological) once the stoma was closed; I hope this additional information will help to clarify up your querie
Classification algorithms for landmine detection using hyperspectral imaging
No full textIn this paper we show some preliminary results obtained when applying various supervised classification algorithms for the detection of landmines in hyperspectral images. These classification algorithms already exist in the literature and are usually used for the general purpose of target detection using hyperspectral imaging. Landmines constitute a special case of targets because they are usually rare in the scene, may be covered by other materials (vegetation, sand, etc.) and they are made of different components so they have different reflectance spectra. In this study, we present the most suitable supervised classification techniques for the detection of landmines, their theoretical background and propose possible ways to improve their performance. The comparison between the classification techniques is based on three criteria: Probability of detection, False Alarm Rate and computation time
Thermal-hydraulics of passive safety systems for advanced Nuclear Reactors
No full textThe present thesis addresses several topics of thermal-hydraulics applied to the heat transfer in the nuclear field, both in normal operating and accidental conditions. The problem is to demonstrate that innovative heat exchanger geometries and safety systems are able to effectively remove thermal power from a primary system of a nuclear reactor. Normal operating condition was addressed by looking at several heat exchanger and steam generator geometries for heat removal in advanced nuclear reactors, such as Small Modular Reactors and generation IV reactors. Helical coil, microchannel and bayonet tube geometries have been studied. Concerning helical coil heat exchangers, a numerical model has been developed to study the thermal performance of a unit on Matlab Environment. The model requires input data such as the geometry, the type of fluids and boundary conditions, and is able to compute the spatial behaviour of the most important thermal-hydraulic parameters of the flow such as temperature, pressure, void fraction, quality, heat transfer coefficients, etc. The model adopts an iterative solving scheme of solution for the different control volumes of the component and semi-empirical correlations to compute heat transfer coefficients and pressure drops. The model has been validated against reference data of the steam generator of IRIS reactor and BREST fast reactor, and demonstrated to be able to reproduce the reference data with a very high accuracy. The microchannel configuration has been studied for the large modular reactor I2S by means of the system code RELAP5-3D. The bayonet configuration has been widely studied for ALFRED reactor in LEADER configuration by means of the system code RELAP5-3D. Sensitivity studies have revealed the impact of some important geometrical parameters and the role of regenerative heat transfer on heat exchanger performance. Results obtained during the PhD period have been used for optimization purposes of ALFRED steam generator. Some heat transfer devices connecting safety systems to the environment have been studied in the light of accidental sequences. In particular, air heat exchangers and pool heat exchangers have been investigated through several RELAP5-3D simulations in the light of a Station Black Out (SBO) event for the large integral reactor I2S. The most important topic of the thesis is the decay heat removal system of ALFRED reactor. The safety system is both able to remove power due to decay heat and to delay primary coolant freezing in the long term of operation by means of noncondensable gases. Both safety functions are performed in a passive manner. The safety system makes use of the bayonet steam generator for normal operation and connects it to a ultimate heat sink, which is an isolation condenser. A tank is connected to the bottom of the isolation condenser and allows the housing of noncondensable gases. Following an accident, noncondensable gases are firstly collected in the tank and then released during time to reduce the heat transfer in the isolation condenser, so to avoid primary system overcooling. In this framework, the present PhD thesis presents a set of sensitivity studies performed on the safety system by means of the system code RELAP5-3D. Initial gas pressure and tank volume have been addressed. The study have highlighted the most important parameters for design optimization and revealed some important physical phenomena. In a second part, the safety system has been used as reference to design an experimental facility able to reproduce the most important physical phenomena on which the safety system relies. The scaled facility will be built in SIET laboratories in Piacenza thanks to the SIRIO project, partially funded by the Italian Ministry of Economic Development. The present thesis reports the development of the conceptual design of the facility and some preliminary simulations to ensure that the facility can reproduce the most important phenomena of the safety system
Design for Children's Playful Learning with Robots
No full textThis article presents an investigation of the implications of designing for children's playful learning with robots. This study was carried out by adopting a Research through Design approach that resulted in the development of a novel low-anthropomorphic robot called Shybo. The article reports the main phases of the project: the preliminary and exploratory research that was carried out to define a list of design requirements; the design of the robot and its supplementary materials for carrying out playful learning experiences; and the evaluation of the project that involved both parents and children. The robot, in fact, was finally tested as part of a two-hour experience that engaged children in activities related to the associations between sounds and colours. The article presents and discusses the results of this evaluation to point out positive aspects of the experience, emerging issues and hints for future works. These are documented to share lessons learned that might be supportive of the general development of children's playful learning and cognitive experiences with robots
A Novel Methodology to Integrate Manufacturing Execution Systems with the Lean Manufacturing Approach
No full textIn order to deal with global competition, industries have undertaken many efforts directed to improve manufacturing efficiency. From a broad perspective, two possible approaches are the adoption of lean manufacturing methodologies or the implementation of information tools: for several years, these two approaches have been assumed to be mutually exclusive. The present work aims to define a methodology to support developers and practitioners in the integration of Manufacturing Execution Systems with the lean manufacturing approach. A case-study in the field of aeronautics is presented to validate the method
Cepstral and entropy analyses in vowels excerpted from continuous speech of dysphonic and control speakers
No full textThere is a growing interest in Cepstral and Entropy analyses of voice samples for defining a vocal health indicator, due to their reliability in investigating both regular and irregular voice signals. The purpose of this study is to determine whether the Cepstral Peak Prominence Smoothed (CPPS) and Sample Entropy (SampEn) could differentiate dysphonic speakers from normal speakers in vowels excerpted from readings and to compare their discrimination power. Results are reported for 33 patients and 31 controls, who read a standardized phonetically balanced passage while wearing a head mounted microphone. Vowels were excerpted from recordings using Automatic Speech Recognition and, after obtaining a measure for each vowel, individual distributions and their descriptive statistics were considered for CPPS and SampEn. The Receiver Operating Curve analysis revealed that the mean of the distributions was the parameter with the highest discrimination power for both CPPS and SampEn. CPPS showed a higher diagnostic precision than SampEn, exhibiting an Area Under Curve (AUC) of 0.85 compared to 0.72. A negative correlation between the parameters was found (Spearman; = −0.61), with higher SampEn corresponding to lower CPPS. The automatic method used in this study could provide support to voice monitorings in clinic and during individual's daily activities
Adaptive longitudinal control of an autonomous vehicle with an approximate knowledge of its parameters
No full textThis paper explores the longitudinal control problem of an autonomous car in legal speed range. The goal is to develop a longitudinal controller that does not rely on vehicle identification parameters, while being capable of tracking the speed profile with comfort acceleration. A modification of a Model Reference Adaptive Control (MRAC) technique found in literature has been deeply studied and implemented, by setting the proper initial conditions for the target application. The proposed architecture is capable of controlling a vehicle whose parameters are known approximately. A CarSim-Simulink joint simulation verifies the feasibility of the proposed strategy and evaluates performances of vehicles at low and high dynamics conditions