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Systems development for diagnostics and dexterity rehabilitation by means of touchscreen technology
No full textThis thesis stems from the need to implement the existing technology in the rehabilitation. Smartphones, touch screen technology, apps, which are a common part of our daily life don’t find an application in clinical practice. The aim of this work is to verify the effectiveness of using this technology both in the hospital and outside. The exergames we developed can be played on usual touchscreen devices, on personal computers and on the custom device built in our laboratory. The device used during our experimentation is now installed in a medical facility with other latest generation medical devices like the Armeo and two different types of exoskeletons. In the first part of this project we focused on developing some exergames oriented to the rehabilitation of persons affected by strokes and in the characterization of people affected by Parkinson.
In the second part, because of the strong correlation between physical activity and neurocognitive functions we decided to use the device since the very beginning of the rehabilitation process, developing some kind of exergames used also to monitor patients during this phase.
Thanks to the collaboration with the medical staff we analysed and summarized the macro areas and the neurocognitive functions involved during the rehabilitation process. After that, we analysed some of the usual exercises given to the patients highlighting the neurocognitive functions involved, and for each exercise we defined some indicators, like touch precision and its standard deviation, mean of force and its standard deviation, total time to execute the test, number of errors, etc... To develop the exergames based on what we decided with the medical staff we used the game engine called Unity3D and we wrote the code of the exergames in C#. After a first test phase in which the medical staff tried the exergames and gave us a feedback, we fixed the bugs and decided to integrate all the exergames in a common platform. Then, we defined an official procedure for the rehabilitation program based on this new method in order to submit it to the ethics committee. In a second phase, the medical staff selected the group of patients to be assigned to the test program, and defined some useful indicators about the neurocognitive functions involved. Finally, to validate the efficiency of this protocol, patients need to executed the exergames for a certain time, after which the medical staff measured the indicators.
In this way we were able to validate the efficiency of the exergames and of the device installed. By working in the European project NoTremor we developed two different type of test with the aim of characterize a model of people affected by Parkinson
Linking Carbon Dynamics in Stream Ecosystems to Dissolved Organic Matter Quality
No full textStream ecosystems form an active component of the carbon (C) cycle, and are identified as “hotspots” for carbon dioxide (CO2) emissions. However, the mechanisms driving CO2 emissions from streams are not completely understood. Beside the input of C in the form of CO2 from groundwater, streams receive organic matter from aquatic and terrestrial origins which is partly mineralized to inorganic nutrients and CO2. Future predictions suggest enhanced input of terrestrial organic matter into streams. As such, surrounding land use may highly influence dissolved organic matter (DOM) composition and turnover in streams. The quality, i.e. bioavailability or lability, of aquatic and terrestrial organic matter, as well as which quality feature provides which bioavailability, is controversially discussed and the research is still in its infancy. Thus, the main goal of my thesis is to enhance the understanding of the role of organic matter quality as a potential driver for organic matter turnover in stream ecosystems. A further goal is to shed light on C dynamics with main focus on CO2 of streams surrounded by different land use. The presented work is based on an experimental approach in the laboratory, supported by seasonal field studies and a developed model in order to explore C dynamics and the corresponding drivers in stream ecosystems. The underlying mechanisms and the importance of DOM quality as a main driver was assessed on the small scale in laboratory experiments. The C emissions from streams were quantified and the influence of DOM quality was examined on a stream reach scale by investigating two stream types with different organic matter quality inputs. By developing a process-based model, the understanding of the daily and seasonal scale of C turnover in stream ecosystems was amplified. The results from the experiment under controlled conditions demonstrate that DOM quality governs microbial metabolism (i.e. respiration and bacterial protein production). Moreover, I revealed significant quality differences between two terrestrial DOM sources, while respiration and bacterial protein production increased with the available proportion of the labile DOM source. The molecular weight of DOM was the strongest predictor of bacterial protein production and respiration, while among others, the concentration of low molecular weight substances was another highly influential predictor. The importance of molecular size/weight and DOM quality for microbial metabolism was further confirmed on the stream reach scale where we demonstrated among others a significant linkage between molecular size of DOM and pCO2 across agricultural and forest streams. Moreover, agricultural streams contained significantly higher pCO2 compared to forest streams during all seasons. However, CO2 emissions measured with the powerful drifting chamber method were not significantly different between the stream types. Modeled dissolved oxygen (O2) and CO2 dynamics calibrated with field data resulted in respiratory quotients (RQ = mole of CO2 produced per mole of O2 consumed), which are intimately linked to the elemental composition of the respired compounds across four seasons and two stream types. RQ values were not related to adjacent land use or season. Nevertheless, I found significant relationships between RQ values and DOM quality indicators, such as fluorescing component characteristic for higher plant material and molecule size of DOM in agricultural streams.
In conclusion, this thesis demonstrates that DOM quality is an important driver for organic matter turnover in streams. Consequently, my results indicate that ongoing and future land use change and enhanced terrestrial DOM input into streams may influence CO2 emissions, and underline the status of streams as C turnover “hotspots”. Thus, my thesis contributes to the mechanistic understanding of organic matter cycling in stream ecosystems and their role in the regional and global C cycle. Therefore, organic matter quality should be considered in future models and studies with respect to C cycling
Silicon-based photonic integrated circuit for label-free biosensing
No full textSilicon-based Photonic Integrated Circuit (PIC) is a device that integrates several optical components using the mature semiconductor technology platform, developed through years for the needs of electronic integrated circuits. In recent years, silicon PICs have been demonstrated as a powerful platform for biosensing systems - devices which play an omnipresent role in such essential life aspects as health care, environmental monitoring, food safety, etc. The growing importance of silicon photonics technologies for biosensor development consists in the possibility of realization compact and simple-to-use instruments, socalled
Lab-On-a-Chip (LOC), enabling rapid point-of-care analysis. This dissertation was carried out within the European project Symphony (grant number 610580), dedicated to the development of a portable sensor instrument for timely detection of highly carcinogenic compound Aflatoxin M1 in milk. The main objective of this Thesis is a development of one of the key element of such system - a photonic chip for label-free biosensing. The PIC operates at the short-wave near-infrared wavelength range (at 850 nm) and integrates an array of silicon oxynitride microring resonators for multiplexed analysis of the samples in aqueous ambient. An innovative technology is developed for monolithic
on-chip integration of a low-cost silicon photodetector, used to monitor the sensor response. The theoretical background includes the basics of microring resonators, the optical label-free biosensing principles and the fundamentals of photodetectors. The design of photonic circuit elements and different numerical models, used for the device simulations, are discussed in details. A great part of the work is dedicated to the optimization of the fabrication process, which is comprehensively explained and illustrated in the thesis. A complete characterization of the realized optical components is presented, including the study of typical performance parameters of waveguides, splitters and microring resonators. To evaluate the sensors functionality, the volumetric sensing experiments are performed using the home-made microfluidic module. The results reveal a high sensor performance, comparable with the state-of-the-art: the devices are able to sense the changes in the refractive index of solution with the limit of detection down to 2*10^-6 refractive index units.
Finally, the characterization of the on-chip integrated PIN photodiodes is presented. The detectors demonstrate the very encouraging results, showing a good responsivity at 850 nm and a capability to efficiently monitor the response of the biosensor array. The successful integration of silicon photodetectors on the highly-sensitive sensor chip can permit the realization of tiny, robust and cost-effective optical biosensors, which gives an important contribution towards the simplification of development of LOC devices
Combined experimental and numerical Approaches to the Assessment of historical Masonry Structures
Get PDFThe assessment and the conservation of historical masonry structures are very challenging issues. According to the actual methodology, all the phases of the entire process of assessment require efforts and reciprocal comparison in order to understand reliably the structural behaviour and to design effective interventions. This thesis goes through such phases (anamnesis, diagnosis and treatment), introducing some innovations in each step and connecting the experimental experiences to models with the support of some real cases. Three techniques are developed about the knowledge phase, namely sonic test, flat jacks and dynamic identification. Deeper studies have been dedicated to vault systems by means of an extended experimental campaign with five full scale vaults tests and a reverse analysis to better understand the behaviour of structures and, at the same time, the limits of models. Sometime this comparison suggests a lack between model parameters and physical meaning due to modelling approaches (mesh, element type) and parameters (material properties and constitutive laws) and this gap may be fulfil by both local and global tests.
From the experimental point of view this work presents a wide range of tests from the local to the global behaviour and varying among non-destructive, minor destructive and destructive tests. On the other hand for models, both linear and non-linear approaches have been adopted looking as well to local and global phenomena. Finally, about the deepest analysis on vaults even the scale of modelling was evaluated with the comparison between macro and meso-scale modelling. In this framework some proposal in kinematic analysis of strengthened vaults were provided. The work carried out allows therefore to compare traditional and more used tools for structural assessment purposes with real and measured experiences helping to validate the current methodology in the safety evaluation of existing buildings
The influences of preparation and brain states on the time-course of oculomotor control in visual selection
No full textWhen in time a response is made seems critically important in defining whether visual selection is driven by physical stimulus-salience or goal-driven control. In study 1 we investigated whether observers are able to control the timing of selection and regulate the trade-off between stimulus- and goal-driven influences. Participants were instructed to make a saccade to an orientation target while a cue instructed them to do so either ‘fast’ or ‘accurate’. Relative salience of the target and an irrelevant distractor was manipulated. Performance in the fast-cue condition appeared to be driven by stimulus salience, while in the accurate-cue condition saccades were guided by the search template. A main effect of cue suggests that preparation can bias mechanisms of selection prior to saccadic execution. In study 2, using spontaneous response time variability, we tested the hypothesis that alpha-oscillations (8-12 Hz) occurring in the prestimulus period may influence performance and saccadic reaction times in a visual search task. Using a similar design, MEG and eye movements were measured concurrently. Results revealed that slow oculomotor reaction times in the non-salient target condition were predicted by an overall increase of power in the alpha range. Additionally, higher alpha pre-stimulus activity seems to predict erroneous response similarly for fast and slow saccadic reaction times. When further decomposing the source of the difference between correct and incorrect responses for fast and slow saccadic reaction times, analyses revealed two main sources of activity. Wrong responses for fast saccadic reaction times were anticipated by higher alpha activity occurring in the parietal regions, with sources located in the lateral intraparietal area. The source of alpha activity for the errors occurring in the slow responses was instead located more in the frontal lobes and specifically around the dorsolateral prefrontal cortex
Progetti didattici ed educativi sull'energetica - Analisi di situazioni per la proposta di un incontro rinnovato con la fisica.
No full textSi presenta in questa tesi una serie di progetti didattici e divulgativi a tema energetica svolti nel corso del dottorato dal candidato. Trova spazio la presentazione di un'indagine originale che ha coinvolto 730 cittadini e volta alla comprensione di quale sia la percezione comune circa alcune tematiche di carattere energetico di estrema attualità. Sono, in seguito, presentati dei progetti didattici che hanno coinvolto scolaresche di scuole primarie e secondarie di primo e secondo grado. Lo scritto, infine, termina con la presentazione di un progetto di start Up accedemica volto alla divulgazione scientifica
Arbitrary high order discontinuous Galerkin methods for the shallow water and incompressible Navier-Stokes equations on unstructured staggered meshes
No full textIn this work we present a new class of well-balanced, arbitrary high order accurate semi-implicit discontinuous Galerkin methods for the solution of the shallow water and incompressible Navier-Stokes equations on staggered unstructured curved meshes. Isoparametric finite elements are used to take into account curved domain boundaries.
Regarding two-dimensional shallow water equations, the discrete free surface elevation is defined on a primal triangular grid, while the discrete total height and the discrete velocity field are defined on an edge-based staggered dual grid. Similarly, for the two-dimensional incompressible Navier-Stokes case, the discrete pressure is defined on the main triangular grid and the velocity field is defined on the edge-based staggered grid. While staggered meshes are state of the art in classical finite difference approximations of the incompressible Navier-Stokes equations, their use in the context of high order DG schemes is novel and still quite rare. High order (better than second order) in time can be achieved by using a space-time finite element framework, where the basis and test functions are piecewise polynomials in both space and time.
Formal substitution of the discrete momentum equation on the dual grid into the discrete continuity equation on the primary grid yields a very sparse system for the scalar pressure involving only the direct neighbor elements, so that it becomes a block four-point system in 2D and a block five-point system for 3D tetrahedral meshes. The resulting linear system is conveniently solved with a matrix-free GMRES algorithm. Note that the same space-time DG scheme on a collocated grid would lead to ten non-zero blocks per element in 2D and seventeen non-zero blocks in 3D, since substituting the discrete velocity into the discrete continuity equation on a collocated mesh would involve also neighbors of neighbors. From numerical experiments we find that our linear system is well-behaved and that the GMRES method converges quickly even without the use of any preconditioner, which is a unique feature in the context of high order implicit DG schemes. A very simple and efficient Picard iteration is then used in order to derive a space-time pressure correction algorithm that achieves also high order of accuracy in time, which is in general a non-trivial task in the context of high order discretizations for the incompressible Navier-Stokes equations.
The special case of high order in space low order in time allows us to recover further regularity about the main linear system for the pressure, such as the symmetry and the positive semi-definiteness in the general case. This allows us to use a very fast linear solver such as the conjugate gradient (CG) method. The flexibility and accuracy of high order space-time DG methods on curved unstructured meshes allows to discretize even complex physical domains with very coarse grids in both space and time.
We will further extend the previous method to three-dimensional incompressible Navier-Stokes system using a tetrahedral main grid and a corresponding face-based hexaxedral dual grid. The resulting dual mesh consists in non-standard 5-vertex hexahedral elements that cannot be represented using tensor products of one dimensional basis functions. Indeed a modal polynomial basis will be used for the dual mesh. This new family of numerical schemes is verified by solving a series of typical numerical test problems and by comparing the obtained numerical
results with available exact analytical solutions or other numerical reference data. Furthermore, the comparison with available experimental results will be presented for incompressible Navier-Stokes equations
Innovation Patterns in the Design-Driven Industries. Opening Up the 'Made in Italy'
No full textThe main argument of the dissertation is structured around the relationship of innovation and modularity with a special focus on innovation openness. This research took a grasp in understanding the context, the classics, story of Italian design, and Made in Italy at the same time exploring design today: based on a field work in Milan, Lombardy. Case study method proved to be as most suitable for answering the explorative nature of this research. The approach was thus relying on secondary data, desk research and observation for understanding the context both from the angle of tradition and current discourse, as for reaching the next level: collecting cases worth to pursue. The cases presented were chosen to elucidate the targeted questions, and to open the path for further research. However, obstacles faced on the field narrowed the cases covered, and the breadth of the investigation of each case study. Limitations in data access did not allow going beyond the story, I had to rely on what was constructed by the company itself. Despite these obstacles the analysis benefited from the perspective of communication and branding: it made possible to investigate a complex innovation effort. This proved to be a valuable insight, since design-driven industries are driven by producing meanings, forming the discourse where communication plays a key role. This work explores what modularity means in production opening up the perspective toward the aesthetic and semantic realm of production of goods. Furthermore in search for the locus of innovation it examines the relationship of modularity, innovation and openness. By exploring architectural innovation [Henderson and Clark 1990] I found that core design concepts that define the direction of technological improvements enter the conceptual frame of innovation:
• What was interpreted as ‘values’ by the company defining the design are proven to be core design concepts in the conceptual frame, as they define here a technological and conceptual [stylistic] frame.
• Thus, architecture draws here a semantic and aesthetic frame of conveying meanings. [Not just merely defining the technological construction of the artifact described by the interaction of the elements].
• Procedural innovation [coined by me]: the effort that evolves around the main objective to most efficiently elaborate on the core design concepts in technological, and semantic realms.
Further findings of the case studies suggest that open methodology of design and innovation is prone to come from third parties to established firms:
• open design methodology as a communication strategy that contributes to innovation practices of the company, and not as a conscious strategy coming from the other way round. Here technological and communication tools are intertwined, as they are conveying meanings defined by the core design concepts
• Firms in need for raising their capacities and reshaping organizational routines to innovate turn to third parties in the Knowledge-Intensive Business Services
• elucidate hybrid forms of innovation
Adding to theory
The above-mentioned empirical findings were backed by a concise summary on:
• open/ user/ collaborative innovation scholarship
• links between modularity and innovation
• and understanding the relationship of modular design in the history of design and architecture;
also elaborating the:
• Semantic frame of innovation: where the product is an architecture of meanings
• Framework for understanding stylistic realm of conveying meanings and innovation
• Linking modular design of products as a conceptual approach [aesthetics] and linking it to production from an evolutionary perspective
Adding empirical insights to be considered for
• Organizational theory: namely redefining the boundaries of the firm
• Innovation openness: based on the locus of innovation
• Modularity: apart from focusing on production, organization and that modular construction of goods has also a conceptual meaning (conceptually exploring the relationship of modular design and integrality with examples from architecture and classics of Italian design). Considering goods as an architecture of meanings and firms producing brands rather than goods, it draws on the implications of arrangement of production
Quality Assurance Strategies in Microtask Crowdsourcing
No full textCrowdsourcing is the outsourcing of a unit of work to a crowd of people via an open call for contributions. While there are various forms of crowdsourcing, such as open innovation, civic engagement and crowdfunding in this work we specifically focus on microtasking. Microtasking is a branch of crowdsourcing, where a work is presented as a set of identical microtasks, each requiring contributors only several minutes to complete usually in exchange for a reward of less than 1 USD. Labeling images, transcribing documents, analyzing sentiments of short sentences and cleaning datasets are popular examples of work which could be solved as microtasks. Available up to date microtask crowdsourcing platforms, such as CrowdFlower and Amazon Mechanical Turk, allow thousands of microtasks to be solved in parallel by hundreds of contributors available online. To tackle the problem of quality in microtask crowdsourcing, it is necessary to study different quality attributes, to investigate what causes low quality of results and slow task execution in microtask crowdsourcing, to identify effective methods to both assess and assure that these quality attributes are of high level. We conducted the most extensive literature review analysis of quality attributes, assessment and assurance techniques ever done in the area of microtasking and crowdsourcing in general. We further advanced the state of the art in three research tracks: i) Improving accuracy and execution speed (the major track), where we monitor in-page user activity of each individual worker, automatically predict abandoned assignments causing delays and assignments with low quality of results, and relaunch them to other workers using our tool ReLauncher; ii) Crowdsourcing complex processes, where we introduce BPMN-extensions to design business processes of both crowd and machine tasks, and the crowdsourcing platform Crowd Computer to deploy these tasks; and iii) Improving workers user experience, where we identify problems workers face searching for tasks to work on, address these problems in our prototype of the task listing interface and introduce a new mobile crowdsourcing platform, CrowdCafe, designed in a way to optimize task searching time and to motivate workers with tangible rewards, such as a coffee
Energy Adaptive Infrastructure for Sustainable Cloud Data Centres
No full textWith the raising concerns about the environment, the ICT equipments have been pointed out as a major and ever rising source of energy consumption and pollution. Among those ICT equipments, data centres play obviously a major role with the rise of the Cloud computing paradigm. In the recent years, researchers have focused on reducing the energy consumption of data centres. Furthermore, future environmentally friendly data centres are also expected to prioritize the usage of renewable energies over brown energies. However, managing the energy consumption within a data centre is challenging because data centres are complex facilities which supports a huge variety of hardware, computing styles and SLAs. Those may evolve through time as user requirements can change rapidly. Furthermore, differently from non-renewable energy sources, the availability of renewable energies is very volatile and time dependent: e.g. solar power is obtainable only during the day, and is subject to variations due to the meteorological conditions. The goal in this case is to shift the workload of running applications, according to the forecasted availability of the renewable energy. In this thesis we propose a flexible framework called Plug4Green able to reduce the energy consumption of a Cloud data centre. Plug4Green is based on the Constraint Programming paradigm, allowing it to take into account a great number of constraints regarding energy, hardware and SLAs in data centres. We also propose the concept of an energy adaptive software controller (EASC), able to augment the usage of renewable energies in data centres. The EASC supports two kind of applications: service-oriented and task-oriented applications; and two kind of computing environments: Infrastructure as a Service and Platform as a Service. We evaluated our solutions in several trials executed in the testbeds of Milan and Trento, Italy. Results show that Plug4Green was able to reduce the power consumption by 27% in the Milan trial, while the EASC was able to augment the renewable energy percentage by 7.07pp in the Trento trial