13 resultados para custom

em AMS Tesi di Dottorato - Alm@DL - Università di Bologna


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Specific aims The aim is to improve the treatment of the bone losses at the metacarpal bones level (both diaphysis and epiphysis) combining microsurgery, tissue engineering and biomaterials, so to minimize the donor side morbidity and optimize healing and outcomes. Methods Pre-operative controlateral X-ray or 3-D CT to allow custom-made HA scaffolds. Cement as temporary spacer in acute lesion and monitoring of infective risks. Treatment of the bone loss recurring to pre-fabricated or custom-made HA scaffolds, adding platelet gel or growth factor OP1. Stable synthesis. Control group with auto/omografts. Outcome indices: % of bone-union; finger TAM, Kapandji, DASH score; NMR and Scintigraphy at 180 days for revascularisation and bio-substitution of the scaffold. Preliminary results The authors just treated 6 patients, 4 males and 2 females, with an average age of 38.5 yrs, affected by segmental bone losses at the hand and wrist, recurring to pre-fabricated not vascularised scaffolds. In all cases the synthesis was performed with angular stability plates and a stable synthesis achieved. All patients have been controlled at a mean follow-up of 10.5 months (from 2 to 16 ). In all case but one the bone-scaffold osteo-integration was achieved at an average of 38 days at the hand, and 46 days at the wrist. The outcome studies, according to the DASH score, finger TAM, and Kapandji, were good and excellent in 5 cases, poor in one.

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Today, third generation networks are consolidated realities, and user expectations on new applications and services are becoming higher and higher. Therefore, new systems and technologies are necessary to move towards the market needs and the user requirements. This has driven the development of fourth generation networks. ”Wireless network for the fourth generation” is the expression used to describe the next step in wireless communications. There is no formal definition for what these fourth generation networks are; however, we can say that the next generation networks will be based on the coexistence of heterogeneous networks, on the integration with the existing radio access network (e.g. GPRS, UMTS, WIFI, ...) and, in particular, on new emerging architectures that are obtaining more and more relevance, as Wireless Ad Hoc and Sensor Networks (WASN). Thanks to their characteristics, fourth generation wireless systems will be able to offer custom-made solutions and applications personalized according to the user requirements; they will offer all types of services at an affordable cost, and solutions characterized by flexibility, scalability and reconfigurability. This PhD’s work has been focused on WASNs, autoconfiguring networks which are not based on a fixed infrastructure, but are characterized by being infrastructure less, where devices have to automatically generate the network in the initial phase, and maintain it through reconfiguration procedures (if nodes’ mobility, or energy drain, etc..., cause disconnections). The main part of the PhD activity has been focused on an analytical study on connectivity models for wireless ad hoc and sensor networks, nevertheless a small part of my work was experimental. Anyway, both the theoretical and experimental activities have had a common aim, related to the performance evaluation of WASNs. Concerning the theoretical analysis, the objective of the connectivity studies has been the evaluation of models for the interference estimation. This is due to the fact that interference is the most important performance degradation cause in WASNs. As a consequence, is very important to find an accurate model that allows its investigation, and I’ve tried to obtain a model the most realistic and general as possible, in particular for the evaluation of the interference coming from bounded interfering areas (i.e. a WiFi hot spot, a wireless covered research laboratory, ...). On the other hand, the experimental activity has led to Throughput and Packet Error Rare measurements on a real IEEE802.15.4 Wireless Sensor Network.

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Several activities were conducted during my PhD activity. For the NEMO experiment a collaboration between the INFN/University groups of Catania and Bologna led to the development and production of a mixed signal acquisition board for the Nemo Km3 telescope. The research concerned the feasibility study for a different acquisition technique quite far from that adopted in the NEMO Phase 1 telescope. The DAQ board that we realized exploits the LIRA06 front-end chip for the analog acquisition of anodic an dynodic sources of a PMT (Photo-Multiplier Tube). The low-power analog acquisition allows to sample contemporaneously multiple channels of the PMT at different gain factors in order to increase the signal response linearity over a wider dynamic range. Also the auto triggering and self-event-classification features help to improve the acquisition performance and the knowledge on the neutrino event. A fully functional interface towards the first level data concentrator, the Floor Control Module, has been integrated as well on the board, and a specific firmware has been realized to comply with the present communication protocols. This stage of the project foresees the use of an FPGA, a high speed configurable device, to provide the board with a flexible digital logic control core. After the validation of the whole front-end architecture this feature would be probably integrated in a common mixed-signal ASIC (Application Specific Integrated Circuit). The volatile nature of the configuration memory of the FPGA implied the integration of a flash ISP (In System Programming) memory and a smart architecture for a safe remote reconfiguration of it. All the integrated features of the board have been tested. At the Catania laboratory the behavior of the LIRA chip has been investigated in the digital environment of the DAQ board and we succeeded in driving the acquisition with the FPGA. The PMT pulses generated with an arbitrary waveform generator were correctly triggered and acquired by the analog chip, and successively they were digitized by the on board ADC under the supervision of the FPGA. For the communication towards the data concentrator a test bench has been realized in Bologna where, thanks to a lending of the Roma University and INFN, a full readout chain equivalent to that present in the NEMO phase-1 was installed. These tests showed a good behavior of the digital electronic that was able to receive and to execute command imparted by the PC console and to answer back with a reply. The remotely configurable logic behaved well too and demonstrated, at least in principle, the validity of this technique. A new prototype board is now under development at the Catania laboratory as an evolution of the one described above. This board is going to be deployed within the NEMO Phase-2 tower in one of its floors dedicated to new front-end proposals. This board will integrate a new analog acquisition chip called SAS (Smart Auto-triggering Sampler) introducing thus a new analog front-end but inheriting most of the digital logic present in the current DAQ board discussed in this thesis. For what concern the activity on high-resolution vertex detectors, I worked within the SLIM5 collaboration for the characterization of a MAPS (Monolithic Active Pixel Sensor) device called APSEL-4D. The mentioned chip is a matrix of 4096 active pixel sensors with deep N-well implantations meant for charge collection and to shield the analog electronics from digital noise. The chip integrates the full-custom sensors matrix and the sparsifification/readout logic realized with standard-cells in STM CMOS technology 130 nm. For the chip characterization a test-beam has been set up on the 12 GeV PS (Proton Synchrotron) line facility at CERN of Geneva (CH). The collaboration prepared a silicon strip telescope and a DAQ system (hardware and software) for data acquisition and control of the telescope that allowed to store about 90 million events in 7 equivalent days of live-time of the beam. My activities concerned basically the realization of a firmware interface towards and from the MAPS chip in order to integrate it on the general DAQ system. Thereafter I worked on the DAQ software to implement on it a proper Slow Control interface of the APSEL4D. Several APSEL4D chips with different thinning have been tested during the test beam. Those with 100 and 300 um presented an overall efficiency of about 90% imparting a threshold of 450 electrons. The test-beam allowed to estimate also the resolution of the pixel sensor providing good results consistent with the pitch/sqrt(12) formula. The MAPS intrinsic resolution has been extracted from the width of the residual plot taking into account the multiple scattering effect.

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I continui sviluppi nel campo della fabbricazione dei circuiti integrati hanno comportato frequenti travolgimenti nel design, nell’implementazione e nella scalabilità dei device elettronici, così come nel modo di utilizzarli. Anche se la legge di Moore ha anticipato e caratterizzato questo trend nelle ultime decadi, essa stessa si trova a fronteggiare attualmente enormi limitazioni, superabili solo attraverso un diverso approccio nella produzione di chip, consistente in pratica nella sovrapposizione verticale di diversi strati collegati elettricamente attraverso speciali vias. Sul singolo strato, le network on chip sono state suggerite per ovviare le profonde limitazioni dovute allo scaling di strutture di comunicazione condivise. Questa tesi si colloca principalmente nel contesto delle nascenti piattaforme multicore ad alte prestazioni basate sulle 3D NoC, in cui la network on chip viene estesa nelle 3 direzioni. L’obiettivo di questo lavoro è quello di fornire una serie di strumenti e tecniche per poter costruire e aratterizzare una piattaforma tridimensionale, cosi come dimostrato nella realizzazione del testchip 3D NOC fabbricato presso la fonderia IMEC. Il primo contributo è costituito sia una accurata caratterizzazione delle interconnessioni verticali (TSVs) (ovvero delle speciali vias che attraversano l’intero substrato del die), sia dalla caratterizzazione dei router 3D (in cui una o più porte sono estese nella direzione verticale) ed infine dal setup di un design flow 3D utilizzando interamente CAD 2D. Questo primo step ci ha permesso di effettuare delle analisi dettagliate sia sul costo sia sulle varie implicazioni. Il secondo contributo è costituito dallo sviluppo di alcuni blocchi funzionali necessari per garantire il corretto funziomento della 3D NoC, in presenza sia di guasti nelle TSVs (fault tolerant links) che di deriva termica nei vari clock tree dei vari die (alberi di clock indipendenti). Questo secondo contributo è costituito dallo sviluppo delle seguenti soluzioni circuitali: 3D fault tolerant link, Look Up Table riconfigurabili e un sicnronizzatore mesocrono. Il primo è costituito fondamentalmente un bus verticale equipaggiato con delle TSV di riserva da utilizzare per rimpiazzare le vias guaste, più la logica di controllo per effettuare il test e la riconfigurazione. Il secondo è rappresentato da una Look Up Table riconfigurabile, ad alte prestazioni e dal costo contenuto, necesaria per bilanciare sia il traffico nella NoC che per bypassare link non riparabili. Infine la terza soluzione circuitale è rappresentata da un sincronizzatore mesocrono necessario per garantire la sincronizzazione nel trasferimento dati da un layer and un altro nelle 3D Noc. Il terzo contributo di questa tesi è dato dalla realizzazione di un interfaccia multicore per memorie 3D (stacked 3D DRAM) ad alte prestazioni, e dall’esplorazione architetturale dei benefici e del costo di questo nuovo sistema in cui il la memoria principale non è piu il collo di bottiglia dell’intero sistema. Il quarto ed ultimo contributo è rappresentato dalla realizzazione di un 3D NoC test chip presso la fonderia IMEC, e di un circuito full custom per la caratterizzazione della variability dei parametri RC delle interconnessioni verticali.

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This thesis deals with the studies on the Cooperative Teleoperation Systems. The literature on cooperative teleoperation did not take into account control architectures composed of pairs of wave-based bilateral teleoperators operating in a shared environment. In this work The author two cooperative control schemes based on wave variables by considering two pairs of single-master/single-slave devices collaborating to carry out operations in a shared remote environment are proposed. Such architectures have been validated both with simulations and experimental tests. Ch. 2 introduces a description of the two control architectures proposed and presents some simulation results where the cooperative teleoperation systems evolve in free space and in contact with a stiff wall. In the Ch. 3 some experimental results which confirm the positive results of the control schemes are illustred. Such results have been achieved by using a prototype custom built at Laboratory of Automaiton and Robotics of University of Bologna, which is also illustrated in this chapter. In Ch. 4 the problem of defining proper tools and procedures for an analysis, and possibly a comparison, of the performances of cooperative teleoperation systems is addressed. In particular, a novel generalization of criteria adopted for classical (i.e. one master-one slave) teleoperators is presented and illustrated on the basis of the force-position and the position-position cooperative control schemes proposed in Ch. 2, both from a transparency and stability point of view, and by assuming a null time delay in the communication channel.

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This thesis proposes design methods and test tools, for optical systems, which may be used in an industrial environment, where not only precision and reliability but also ease of use is important. The approach to the problem has been conceived to be as general as possible, although in the present work, the design of a portable device for automatic identification applications has been studied, because this doctorate has been funded by Datalogic Scanning Group s.r.l., a world-class producer of barcode readers. The main functional components of the complete device are: electro-optical imaging, illumination and pattern generator systems. For what concerns the electro-optical imaging system, a characterization tool and an analysis one has been developed to check if the desired performance of the system has been achieved. Moreover, two design tools for optimizing the imaging system have been implemented. The first optimizes just the core of the system, the optical part, improving its performance ignoring all other contributions and generating a good starting point for the optimization of the whole complex system. The second tool optimizes the system taking into account its behavior with a model as near as possible to reality including optics, electronics and detection. For what concerns the illumination and the pattern generator systems, two tools have been implemented. The first allows the design of free-form lenses described by an arbitrary analytical function exited by an incoherent source and is able to provide custom illumination conditions for all kind of applications. The second tool consists of a new method to design Diffractive Optical Elements excited by a coherent source for large pattern angles using the Iterative Fourier Transform Algorithm. Validation of the design tools has been obtained, whenever possible, comparing the performance of the designed systems with those of fabricated prototypes. In other cases simulations have been used.

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Biomedical analyses are becoming increasingly complex, with respect to both the type of the data to be produced and the procedures to be executed. This trend is expected to continue in the future. The development of information and protocol management systems that can sustain this challenge is therefore becoming an essential enabling factor for all actors in the field. The use of custom-built solutions that require the biology domain expert to acquire or procure software engineering expertise in the development of the laboratory infrastructure is not fully satisfactory because it incurs undesirable mutual knowledge dependencies between the two camps. We propose instead an infrastructure concept that enables the domain experts to express laboratory protocols using proper domain knowledge, free from the incidence and mediation of the software implementation artefacts. In the system that we propose this is made possible by basing the modelling language on an authoritative domain specific ontology and then using modern model-driven architecture technology to transform the user models in software artefacts ready for execution in a multi-agent based execution platform specialized for biomedical laboratories.

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L’obbiettivo di una ricostruzione micro vascolare di mandibola è quello di assicurare al paziente il miglior risultato estetico e funzionale auspicabile. Ciò può essere conseguito utilizzando il lembo microvascolare di perone/cresta iliaca e una placca ricostruttiva in titanio che funga da guida nella fase di modellamento del lembo per ricreare un contorno parabolico il più possibile simile al profilo mandibolare originario del paziente. Il modellamento manuale ed artigianale intraoperatorio di una placca ricostruttiva è operatore dipendente ed anche in mani molto abili o ricorrendo a modelli anatomici stereolitografici non sempre risulta preciso quanto voluto e spesso non porta ai risultati postoperatori attesi e desiderati. Obbiettivo del nostro studio è stato pertanto, sfruttando le moderne tecnologie CAD-CAM, la produzione di placche ricostruttive “custom -made” progettate direttamente al computer ricreanti il profilo osseo originale del paziente.

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The promising development in the routine nanofabrication and the increasing knowledge of the working principles of new classes of highly sensitive, label-free and possibly cost-effective bio-nanosensors for the detection of molecules in liquid environment, has rapidly increased the possibility to develop portable sensor devices that could have a great impact on many application fields, such as health-care, environment and food production, thanks to the intrinsic ability of these biosensors to detect, monitor and study events at the nanoscale. Moreover, there is a growing demand for low-cost, compact readout structures able to perform accurate preliminary tests on biosensors and/or to perform routine tests with respect to experimental conditions avoiding skilled personnel and bulky laboratory instruments. This thesis focuses on analysing, designing and testing novel implementation of bio-nanosensors in layered hybrid systems where microfluidic devices and microelectronic systems are fused in compact printed circuit board (PCB) technology. In particular the manuscript presents hybrid systems in two validating cases using nanopore and nanowire technology, demonstrating new features not covered by state of the art technologies and based on the use of two custom integrated circuits (ICs). As far as the nanopores interface system is concerned, an automatic setup has been developed for the concurrent formation of bilayer lipid membranes combined with a custom parallel readout electronic system creating a complete portable platform for nanopores or ion channels studies. On the other hand, referring to the nanowire readout hybrid interface, two systems enabling to perform parallel, real-time, complex impedance measurements based on lock-in technique, as well as impedance spectroscopy measurements have been developed. This feature enable to experimentally investigate the possibility to enrich informations on the bio-nanosensors concurrently acquiring impedance magnitude and phase thus investigating capacitive contributions of bioanalytical interactions on biosensor surface.

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An extensive study of the morphology and the dynamics of the equatorial ionosphere over South America is presented here. A multi parametric approach is used to describe the physical characteristics of the ionosphere in the regions where the combination of the thermospheric electric field and the horizontal geomagnetic field creates the so-called Equatorial Ionization Anomalies. Ground based measurements from GNSS receivers are used to link the Total Electron Content (TEC), its spatial gradients and the phenomenon known as scintillation that can lead to a GNSS signal degradation or even to a GNSS signal ‘loss of lock’. A new algorithm to highlight the features characterizing the TEC distribution is developed in the framework of this thesis and the results obtained are validated and used to improve the performance of a GNSS positioning technique (long baseline RTK). In addition, the correlation between scintillation and dynamics of the ionospheric irregularities is investigated. By means of a software, here implemented, the velocity of the ionospheric irregularities is evaluated using high sampling rate GNSS measurements. The results highlight the parallel behaviour of the amplitude scintillation index (S4) occurrence and the zonal velocity of the ionospheric irregularities at least during severe scintillations conditions (post-sunset hours). This suggests that scintillations are driven by TEC gradients as well as by the dynamics of the ionospheric plasma. Finally, given the importance of such studies for technological applications (e.g. GNSS high-precision applications), a validation of the NeQuick model (i.e. the model used in the new GALILEO satellites for TEC modelling) is performed. The NeQuick performance dramatically improves when data from HF radar sounding (ionograms) are ingested. A custom designed algorithm, based on the image recognition technique, is developed to properly select the ingested data, leading to further improvement of the NeQuick performance.

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Nowadays the rise of non-recurring engineering (NRE) costs associated with complexity is becoming a major factor in SoC design, limiting both scaling opportunities and the flexibility advantages offered by the integration of complex computational units. The introduction of embedded programmable elements can represent an appealing solution, able both to guarantee the desired flexibility and upgradabilty and to widen the SoC market. In particular embedded FPGA (eFPGA) cores can provide bit-level optimization for those applications which benefits from synthesis, paying on the other side in terms of performance penalties and area overhead with respect to standard cell ASIC implementations. In this scenario this thesis proposes a design methodology for a synthesizable programmable device designed to be embedded in a SoC. A soft-core embedded FPGA (eFPGA) is hence presented and analyzed in terms of the opportunities given by a fully synthesizable approach, following an implementation flow based on Standard-Cell methodology. A key point of the proposed eFPGA template is that it adopts a Multi-Stage Switching Network (MSSN) as the foundation of the programmable interconnects, since it can be efficiently synthesized and optimized through a standard cell based implementation flow, ensuring at the same time an intrinsic congestion-free network topology. The evaluation of the flexibility potentialities of the eFPGA has been performed using different technology libraries (STMicroelectronics CMOS 65nm and BCD9s 0.11μm) through a design space exploration in terms of area-speed-leakage tradeoffs, enabled by the full synthesizability of the template. Since the most relevant disadvantage of the adopted soft approach, compared to a hardcore, is represented by a performance overhead increase, the eFPGA analysis has been made targeting small area budgets. The generation of the configuration bitstream has been obtained thanks to the implementation of a custom CAD flow environment, and has allowed functional verification and performance evaluation through an application-aware analysis.

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Questo studio ha valutato l'efficacia di un approccio rigenerativo utilizzando cellule staminali mesenchimali (MSC) e uno scaffold di idrossiapatite pura e porosa (HA) progettata con tecnologia CAD-CAM per sostituire il condilo dell'articolazione temporomandibolare (ATM). Metodi.Uno scaffolds di HA con porosità totale del 70% è stato prototipato per sostituire i due condili temporomandibolari (sinistro e destro) dello stesso animale. MSC sono state ottenute dalla cresta iliaca ed espanse in coltura. Guide chirurgiche su misura sono state create e utilizzate per esportare la pianificazione virtuale delle linee di taglio dell'osso nell'ambiente chirurgico. Sei pecore sono state sacrificate a 4 mesi dopo l'intervento.Gli scaffold sono stati espiantati, campioni istologici sono stati preparati, ed è stata eseguota l'analisi istomorfometrica. Risultati.L'analisi della riduzione di porosità per apposizione di osso neoformato mostrata una differenza statisticamente significativa tra la formazione ossea nei condili carichi di MSC rispetto ai condili senza (

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Background: Piezoelectric instrumentation seems to offer 3 important advantages for cutting bone structures. Be more precise because it is produced by micro-vibrations from the cutting insert. Be safer because the ultrasonic frequency used does not affect soft tissue. Thirdly, the less invasive cutting action produces minor tissue damage and consequently probably a better healing Aim of the Study: The aim of this study is to evaluate the effectiveness of piezoelectric device capability in maxillo-facial surgery, in order to take advantage of these favourable capacity. Material and Methods: Considering the several potential application of the piezoelectric technology in Orthognathic, Oncologic and Extractive surgery, we would like to design protocols in order to verify how this new device can modify the surgical technique, the surgical time, the patients healing and its quality of life. Results: Due to the precise Piezosurgery cut, we can manage the Cad-Cam-Custom Made plates protocol in Oncologic Surgery and in Orthognatic Surgery increasing our percentage of comparison between the 3D preoperative plan and the surgical execution. We also found a better quality of life impaction in Patient who underwent and extractive surgery Conclusion: Piezosurgery device seems to be a strong surgical aid were safe and precise cut are needed and its capability to reduce the discomfort Patients need to be study in deep also in major surgery like Orthognatic and Oncologic surgery.