Experiment selection for the discrimination of semi-quantitative models of dynamical systems

AbstractModeling an experimental system often results in a number of alternative models that are all justified by the available experimental data. To discriminate among these models, additional experiments are needed. Existing methods for the selection of discriminatory experiments in statistics and in artificial intelligence are often based on an entropy criterion, the so-called information increment. A limitation of these methods is that they are not well-adapted to discriminating models of dynamical systems under conditions of limited measurability. Moreover, there are no generic procedures for computing the information increment of an experiment when the models are qualitative or semi-quantitative. This has motivated the development of a method for the selection of experiments to discriminate among semi-quantitative models of dynamical systems. The method has been implemented on top of existing implementations of the qualitative and semi-quantitative simulation techniques QSIM, Q2, and Q3. The applicability of the method to real-world problems is illustrated by means of an example in population biology: the discrimination of four competing models of the growth of phytoplankton in a bioreactor. The models have traditionally been considered equivalent for all practical purposes. Using our model discrimination approach and experimental data we show, however, that two of them are superior for describing phytoplankton growth under a wide range of experimental conditions

Analysis and Design of High Speed Serial Interfaces for Automotive Applications

The demand for an enriched end-user experience and increased performance in next generation electronic applications is never ending, and it is a common trend for a wide spectrum of applications owing to different markets, like computing, mobile communication and automotive. For this reason High Speed Serial Interface have become widespread components for nowadays electronics with a constant demand for power reduction and data rate increase. In the frame of gigabit serial systems, the work discussed in this thesis develops in two directions: on one hand, the aim is to support the continuous data rate increase with the development of novel link modeling approaches that will be employed for system level evaluation and as support in the design and characterization phases. On the other hand, the design considerations and challenges in the implementation of the transmitter, one of the most delicate blocks for the signal integrity performance of the link, are central. The first part of the activity regarding link performance predictions lead to the development of an enhanced statistical simulation approach, capable to account for the transmitter waveform shape in the ISI analysis, a characteristic that is missed by the available state-ofthe- art simulation approaches. The proposed approach has been extensively tested by comparison with traditional simulation approaches (Spice-like simulators) and validated against experimental characterization of a test system, with satisfactory results. The second part of the activity consists in the design of a high speed transmitter in a deeply scaled CMOS technology, spanning from the concept of the circuit, its implementation and characterization. Targets of the design are to achieve a data rate of 5 Gb/s with a minimum voltage swing of 800 mV, thus doubling the data rate of the current transmitter implementation, and reduce the power dissipation adopting a voltage mode architecture. The experimental characterization of the fabricated lot draws a twofold picture, with some of the performance figures showing a very good qualitative and quantitative agreement with pre-silicon simulations, and others revealing a poor performance level, especially for the eye diagram. Investigation of the root causes by the analysis of the physical silicon design, of the bonding scheme of the prototypes and of the pre-silicon simulations is reported. Guidelines for the redesign of the circuit are also given.Nel panorama delle applicazioni elettroniche il miglioramento delle performance di un prodotto da una generazione alla successiva ha lo scopo di offrire all\u2019utilizzatore finale nuove funzioni e migliorare quelle esistenti. Negli ultimi anni grazie al costante avanzamento della tecnologia integrata, si \ue8 assistito ad un enorme sviluppo della capacit\ue0 computazionale dei dispositivi in tutti i segmenti di mercato, quali ad esempio l\u2019information technology, la comunicazione mobile e l\u2019automotive. La conseguente necessit\ue0 di mettere in comunicazione dispostivi diversi all\u2019interno della stessa applicazione e di traferire grosse quantit\ue0 di dati ha provocato una capillare diffusione delle interfacce seriali ad alta velocit\ue0, o High Speed Serial Interfaces (HSSIs). La necessit\ue0 di ridurre il consumo di potenza e aumentare il bit rate per questo tipo di applicazioni \ue8 diventata dunque un ambito di ricerca di estremo interesse. Il lavoro discusso in questa tesi si colloca nell\u2019ambito della trasmissione di dati seriali a bit rate superiori ad 1Gb/s e si sviluppa in due direzioni: da un lato, a sostegno del continuo aumento del bit rate nelle nuove generazioni di interfacce, \ue8 stato affrontato lo sviluppo di nuovi approcci di modellazione del sistema, che possano essere impiegati nella valutazione delle prestazioni dell\u2019interfaccia e a supporto delle fasi di progettazione e di caratterizzazione. Dall\u2019altro lato, si \ue8 focalizzata l\u2019attenzione sulle sfide e sulle problematiche inerenti il progetto di uno dei blocchi pi\uf9 delicati per le prestazioni del sistema, il trasmettitore. La prima parte della tesi ha come oggetto lo sviluppo di un approccio di simulazione statistico innovativo, in grado di includere nell\u2019analisi degli effetti dell\u2019interferenza di intersimbolo anche la forma d\u2019onda prodotta all\u2019uscita del trasmettitore, una caratteristica che non \ue8 presente in altri approcci di simulazione proposti in letteratura. La tecnica proposta \ue8 ampiamente testata mediante il confronto con approcci di simulazione tradizionali (di tipo Spice) e mediante il confronto con la caratterizzazione sperimentale di un sistema di test, con risultati pienamente soddisfacenti. La seconda parte dell\u2019attivit\ue0 riguarda il progetto di un trasmettitore integrato high speed in tecnologia CMOS a 40nm e si estende dallo studio di fattibilit\ue0 del circuito fino alla sua realizzazione e caratterizzazione. Gli obiettivi riguardano il raggiungimento di un bit rate pari a 5 Gb/s, raddoppiando cos\uec il bit rate dell\u2019attuale implementazione, e di una tensione differenziale di uscita minima di 800mV (picco-picco) riducendo allo stesso tempo la potenza dissipata mediante l\u2019adozione di una architettura Voltage Mode. I risultati sperimentali ottenuti dal primo lotto fabbricato non delineano un quadro univoco: alcune performance mostrano un ottimo accordo qualitativo e quantitativo con le simulazioni pre-fabbricazione, mentre prestazioni non soddisfacenti sono state ottenute in particolare per il diagramma ad occhio. Grazie all\u2019analisi del layout del prototipo, del bonding tra silicio e package e delle simulazioni pre-fabbricazione \ue8 stato possibile risalire ai fattori responsabili del degrado delle prestazioni rispetto alla previsioni pre-fabbricazione, permettendo inoltre di delineare le linee guida da seguire nella futura progettazione di un nuovo prototipo

ECLSS advanced automation preliminary requirements

A description of the total Environmental Control and Life Support System (ECLSS) is presented. The description of the hardware is given in a top down format, the lowest level of which is a functional description of each candidate implementation. For each candidate implementation, both its advantages and disadvantages are presented. From this knowledge, it was suggested where expert systems could be used in the diagnosis and control of specific portions of the ECLSS. A process to determine if expert systems are applicable and how to select the expert system is also presented. The consideration of possible problems or inconsistencies in the knowledge or workings in the subsystems is described

Biomedical applications of belief networks

Biomedicine is an area in which computers have long been expected to play a significant role. Although many of the early claims have proved unrealistic, computers are gradually becoming accepted in the biomedical, clinical and research environment. Within these application areas, expert systems appear to have met with the most resistance, especially when applied to image interpretation.In order to improve the acceptance of computerised decision support systems it is necessary to provide the information needed to make rational judgements concerning the inferences the system has made. This entails an explanation of what inferences were made, how the inferences were made and how the results of the inference are to be interpreted. Furthermore there must be a consistent approach to the combining of information from low level computational processes through to high level expert analyses.nformation from low level computational processes through to high level expert analyses. Until recently ad hoc formalisms were seen as the only tractable approach to reasoning under uncertainty. A review of some of these formalisms suggests that they are less than ideal for the purposes of decision making. Belief networks provide a tractable way of utilising probability theory as an inference formalism by combining the theoretical consistency of probability for inference and decision making, with the ability to use the knowledge of domain experts.nowledge of domain experts. The potential of belief networks in biomedical applications has already been recog¬ nised and there has been substantial research into the use of belief networks for medical diagnosis and methods for handling large, interconnected networks. In this thesis the use of belief networks is extended to include detailed image model matching to show how, in principle, feature measurement can be undertaken in a fully probabilistic way. The belief networks employed are usually cyclic and have strong influences between adjacent nodes, so new techniques for probabilistic updating based on a model of the matching process have been developed.An object-orientated inference shell called FLAPNet has been implemented and used to apply the belief network formalism to two application domains. The first application is model-based matching in fetal ultrasound images. The imaging modality and biological variation in the subject make model matching a highly uncertain process. A dynamic, deformable model, similar to active contour models, is used. A belief network combines constraints derived from local evidence in the image, with global constraints derived from trained models, to control the iterative refinement of an initial model cue.In the second application a belief network is used for the incremental aggregation of evidence occurring during the classification of objects on a cervical smear slide as part of an automated pre-screening system. A belief network provides both an explicit domain model and a mechanism for the incremental aggregation of evidence, two attributes important in pre-screening systems.Overall it is argued that belief networks combine the necessary quantitative features required of a decision support system with desirable qualitative features that will lead to improved acceptability of expert systems in the biomedical domain

Variability in Resistive Memories

This research was supported by project B-TIC-624-UGR20 funded by the Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía (Spain) and the FEDER program. F.J.A. acknowledges grant PGC2018-098860-B-I00 and PID2021-128077NB-I00 financed by MCIN/ AEI/10.13039/501100011033/FEDER and A-FQM-66-UGR20 financed by the Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía (Spain) and the FEDER program. M.B.G. acknowledges the Ramón y Cajal Grant No. RYC2020-030150-I. M.L. and M.A.V. acknowl- edge generous support from the King Abdullah University of Science and Technology. A.N.M., N.V.A., A.A.D., M.N.K. and B.S. acknowledge the Government of the Russian Federation under Megagrant Program (agreement no. 074-02-2018-330 (2)) and the Ministry of Science and Higher Education of the Russian Federation under “Priority-2030” Academic Excellence Program of the Lobachevsky State University of Nizhny Novgorod (N-466-99_2021-2023). The authors thank D.O. Filatov, A.S. Novikov, and V.A. Shishmakova for their help in studying the dependence of MFPT on external voltage (Section 4). The devices in Section 4 were designed in the frame of the scientific program of the National Center for Physics and Mathematics (project “Artificial intel- ligence and big data in technical, industrial, natural and social systems”) and fabricated at the facilities of Laboratory of memristor nanoelectronics (state assignment for the creation of new laboratories for electronics industry). E.M. acknowledges the support provided by the European proj- ect MEMQuD, code 20FUN06, which has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.Resistive memories are outstanding electron devices that have displayed a large potential in a plethora of applications such as nonvolatile data storage, neuro- morphic computing, hardware cryptography, etc. Their fabrication control and performance have been notably improved in the last few years to cope with the requirements of massive industrial production. However, the most important hurdle to progress in their development is the so-called cycle-to-cycle variability, which is inherently rooted in the resistive switching mechanism behind the operational principle of these devices. In order to achieve the whole picture, variability must be assessed from different viewpoints going from the experi- mental characterization to the adequation of modeling and simulation techni- ques. Herein, special emphasis is put on the modeling part because the accurate representation of the phenomenon is critical for circuit designers. In this respect, a number of approaches are used to the date: stochastic, behavioral, meso- scopic..., each of them covering particular aspects of the electron and ion transport mechanisms occurring within the switching material. These subjects are dealt with in this review, with the aim of presenting the most recent advancements in the treatment of variability in resistive memories.Junta de Andalucía B-TIC-624-UGR20 PID2021-128077NB-I00European CommissionMCIN/AEI/FEDER A-FQM-66-UGR20 PGC2018-098860-B-I00Spanish Government RYC2020-030150-IKing Abdullah University of Science & TechnologyGovernment of the Russian Federation under Megagrant Program 074-02-2018-330 (2)Ministry of Science and Higher Education of the Russian Federation under "Priority-2030" Academic Excellence Program of the Lobachevsky State University of Nizhny Novgorod N-466-99_2021-2023European project MEMQuD 20FUN06EMPIR programmeEuropean Union's Horizon 2020 research and innovation programm

A personalised and adaptive insulin dosing decision support system for type 1 diabetes

People with type 1 diabetes (T1D) rely on exogenous insulin to maintain stable glucose levels. Despite the advent of diabetes technologies such as continuous glucose monitors and insulin infusion pumps, the majority of people with T1D do not manage to bring back glucose levels into a healthy target after meals. In addition to patient compliance, this is due to the complexity of the decision-making on how much insulin is required. Commercial insulin bolus calculators exist that help with the calculation of insulin for meals but these lack fine-tuning and adaptability. This thesis presents a novel insulin dosing decision support system for people with T1D that is able to provide individualised insulin dosing advice. The proposed research utilises Case-Based Reasoning (CBR), an artificial intelligence methodology, that is able to learn over time based on the behaviour of the patient and optimises the insulin therapy for various diabetes scenarios. The decision support system has been implemented into a user-friendly smartphone-based patient platform and communicates with a clinical platform for remote supervision. In-silico studies are presented demonstrating the overall performance of CBR as well as metrics used to adapt the insulin therapy. Safety and feasibility of the developed system have been assessed incrementally in clinical trials; initially during an eight-hour study in hospital settings followed by a six-week study in the home environment of the user. Human factors play an important role in the clinical adoption of technologies such as the one proposed. System usability and acceptability were evaluated during the second study phase based on feedback obtained from study participants. Results from in-silico tests show the potential of the proposed research to safely automate the process of optimising the insulin therapy for people with T1D. In the six-week study, the system demonstrated safety in maintaining glycemic control with a trend suggesting improvement in postprandial glucose outcomes. Feedback from participants showed favourable outcomes when assessing device satisfaction and usability. A six-month large-scale randomised controlled study to evaluate the efficacy of the system is currently ongoing.Open Acces

Small Business Innovation Research. Program solicitation. Closing date: July 21, 1992

The National Aeronautics and Space Administration (NASA) invites small businesses to submit Phase 1 proposals in response to its Small Business Innovation Research (SBIR) Program Solicitation 92-1. Firms with research or research and development capabilities (R/R&D) in science or engineering in any of the areas listed are encouraged to participate. This, the tenth annual SBIR solicitation by NASA, describes the program, identifies eligibility requirements, describes the proposal evaluation and award selection process, and provides other information to assist those interested in participating in NASA's SBIR program. It also identifies, in Section 8.0, the technical topics and subtopics in which SBIR Phase 1 proposals are solicited in 1992. These topics and subtopics cover a broad range of current NASA interests but do not necessarily include all areas in which NASA plans or currently conducts research. The NASA SBIR program seeks innovative approaches that respond to the needs, technical requirements, and new opportunities described in the subtopics. The focus is on innovation through the use of emerging technologies, novel applications of existing technologies, exploitation of scientific breakthroughs, or new capabilities or major improvements to existing technologies. NASA plans to select about 320 high-quality research or research and development proposals for Phase 1 contract awards on the basis of this Solicitation. Phase 1 contracts are normally six months in duration and funded up to $50,000, including profit. Selections will be based on the competitive merits of the offers and on NASA needs and priorities

Feasibility study of scanning celestial attitude determination system SCADS for small scientific spacecraft S sup 3 Final report

Scanning celestial attitude determination system for small scientific satellite

Model-based diagnosis of electric cooling fan drive systems

This work is a contribution to the field of fault detection and diagnosis for electrically driven engine cooling fans. Its main focus is on the online gathering and determination of important parameters and internal states. The algorithms are specifically designed in a resource and computing efficient manner to allow for series implementation on microcontrollers usually employed in small electrical drives. Furthermore, the developed methods for fault detection and diagnosis are characterized by a low application effort, drastically reducing the costs for transferring them to other applications. Novel algorithms are presented for determination of the winding resistance, the flux linkage over angle and the equivalent series resistance. Furthermore, a novel approach for determination of the magnet temperature is proposed, utilizing the winding temperature, which is derived from the winding resistance without requiring an additional temperature sensor. A method is presented for detection of a demagnetization event based on the flux linkage over angle. Besides that, detection of an aged DC-link capacitor and of winding faults is demonstrated. Furthermore, a novel approach is presented for detection and diagnosis of unusual load conditions, caused for example, by a blockage or dirt on the fan blade