825 resultados para performance assessment


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In the last years the attentions on the energy efficiency on historical buildings grows, as different research project took place across Europe. The attention on combining, the need of the preservation of the buildings, their value and their characteristic, with the need of the reduction of energy consumption and the improvements of indoor comfort condition, stimulate the discussion of two points of view that are usually in contradiction, buildings engineer and Conservation Institution. The results are surprising because a common field is growing while remains the need of balancing the respective exigencies. From these experience results clear that many questions should be answered also from the building physicist regarding the correct assessment: on the energy consumption of this class of buildings, on the effectiveness of the measures that could be adopted, and much more. This thesis gives a contribution to answer to these questions developing a procedure to analyse the historic building. The procedure gives a guideline of the energy audit for the historical building considering the experimental activities to dial with the uncertainty of the estimation of the energy balance. It offers a procedure to simulate the energy balance of building with a validated dynamic model considering also a calibration procedure to increase the accuracy of the model. An approach of design of energy efficiency measures through an optimization that consider different aspect is also presented. All the process is applied to a real case study to give to the reader a practical understanding.

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This thesis regards the study and the development of new cognitive assessment and rehabilitation techniques of subjects with traumatic brain injury (TBI). In particular, this thesis i) provides an overview about the state of art of this new assessment and rehabilitation technologies, ii) suggests new methods for the assessment and rehabilitation and iii) contributes to the explanation of the neurophysiological mechanism that is involved in a rehabilitation treatment. Some chapters provide useful information to contextualize TBI and its outcome; they describe the methods used for its assessment/rehabilitation. The other chapters illustrate a series of experimental studies conducted in healthy subjects and TBI patients that suggest new approaches to assessment and rehabilitation. The new proposed approaches have in common the use of electroencefalografy (EEG). EEG was used in all the experimental studies with a different purpose, such as diagnostic tool, signal to command a BCI-system, outcome measure to evaluate the effects of a treatment, etc. The main achieved results are about: i) the study and the development of a system for the communication with patients with disorders of consciousness. It was possible to identify a paradigm of reliable activation during two imagery task using EEG signal or EEG and NIRS signal; ii) the study of the effects of a neuromodulation technique (tDCS) on EEG pattern. This topic is of great importance and interest. The emerged founding showed that the tDCS can manipulate the cortical network activity and through the research of optimal stimulation parameters, it is possible move the working point of a neural network and bring it in a condition of maximum learning. In this way could be possible improved the performance of a BCI system or to improve the efficacy of a rehabilitation treatment, like neurofeedback.

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Movement analysis carried out in laboratory settings is a powerful, but costly solution since it requires dedicated instrumentation, space and personnel. Recently, new technologies such as the magnetic and inertial measurement units (MIMU) are becoming widely accepted as tools for the assessment of human motion in clinical and research settings. They are relatively easy-to-use and potentially suitable for estimating gait kinematic features, including spatio-temporal parameters. The objective of this thesis regards the development and testing in clinical contexts of robust MIMUs based methods for assessing gait spatio-temporal parameters applicable across a number of different pathological gait patterns. First, considering the need of a solution the least obtrusive as possible, the validity of the single unit based approach was explored. A comparative evaluation of the performance of various methods reported in the literature for estimating gait temporal parameters using a single unit attached to the trunk first in normal gait and then in different pathological gait conditions was performed. Then, the second part of the research headed towards the development of new methods for estimating gait spatio-temporal parameters using shank worn MIMUs on different pathological subjects groups. In addition to the conventional gait parameters, new methods for estimating the changes of the direction of progression were explored. Finally, a new hardware solution and relevant methodology for estimating inter-feet distance during walking was proposed. Results of the technical validation of the proposed methods at different walking speeds and along different paths against a gold standard were reported and showed that the use of two MIMUs attached to the lower limbs associated with a robust method guarantee a much higher accuracy in determining gait spatio-temporal parameters. In conclusion, the proposed methods could be reliably applied to various abnormal gaits obtaining in some cases a comparable level of accuracy with respect to normal gait.

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Il presente studio si colloca all’interno di una ricerca più ampia volta alla definizione di criteri progettuali finalizzati all’ottimizzazione delle prestazioni energetiche delle cantine di aziende vitivinicole, di dimensioni produttive medio - piccole. Nello specifico la ricerca riguarda la riqualificazione di fabbricati rurali esistenti di modeste dimensioni, da convertire a magazzini per la conservazione del vino in bottiglia. Lo studio si pone come obiettivo la definizione di criteri di analisi per la valutazione di interventi di retrofit di tali fabbricati, volto sia al miglioramento delle prestazioni energetiche dell’involucro edilizio, sia alla riduzione del fabbisogno energetico legato al funzionamento di eventuali impianti di controllo termico. La ricerca è stata condotta mediante l’utilizzo del software di simulazione termica Energy Plus, per ottenere i valori simulati di temperatura interna relativi ai diversi scenari migliorativi ipotizzati, e mediante la successiva definizione di indicatori che esplicitino l’influenza delle principali variabili progettuali sull’andamento delle temperature interne dei locali di conservazione e sul fabbisogno energetico del fabbricato necessario a garantire l’intervallo di temperatura di comfort del vino. Tra tutti gli interventi possibili per il miglioramento della prestazione energetica degli edifici, quelli analizzati in questo studio prevedono l’aggiunta di un isolamento a cappotto delle pareti esterne, l’isolamento della copertura e l’aggiunta di una struttura ombreggiante vegetale esterna. I risultati ottenuti danno una prima indicazione sugli interventi più efficaci in termini di miglioramento energetico e mettono in luce l’utilità del criterio proposto nell’evidenziare le criticità degli interventi migliorativi ipotizzati. Il metodo definito nella presente ricerca risulta quindi un valido strumento di valutazione a supporto della progettazione degli interventi di retrofit dei fabbricati rurali da convertire a magazzini per la conservazione del vino.

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Il progetto di tesi riguarda principalmente la progettazione di moderni sistemi wireless, come 5G o WiGig, operanti a onde millimetriche, attraverso lo studio di una tecnica avanzata detta Beamforming, che, grazie all'utilizzo di antenne direttive e compatte, permette di superare limiti di link budget dovuti alle alte frequenze e introdurre inoltre diversità spaziale alla comunicazione. L'obiettivo principale del lavoro è stato quello di valutare, tramite simulazioni numeriche, le prestazioni di alcuni diversi schemi di Beamforming integrando come tool di supporto un programma di Ray Tracing capace di fornire le principali informazioni riguardo al canale radio. Con esso infatti è possibile sia effettuare un assessment generale del Beamforming stesso, ma anche formulare i presupposti per innovative soluzioni, chiamate RayTracing-assisted- Beamforming, decisamente promettenti per futuri sviluppi così come confermato dai risultati.

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Nell'ambito della Fisica Medica, le simulazioni Monte Carlo sono uno strumento sempre più diffuso grazie alla potenza di calcolo dei moderni calcolatori, sia nell'ambito diagnostico sia in terapia. Attualmente sono disponibili numerosi pacchetti di simulazione Monte Carlo di carattere "general purpose", tra cui Geant4. Questo lavoro di tesi, svolto presso il Servizio di Fisica Sanitaria del Policlinico "S.Orsola-Malpighi", è basato sulla realizzazione, utilizzando Geant4, di un modello Monte Carlo del target del ciclotrone GE-PETtrace per la produzione di C-11. Nel modello sono stati simulati i principali elementi caratterizzanti il target ed il fascio di protoni accelerato dal ciclotrone. Per la validazione del modello sono stati valutati diversi parametri fisici, tra i quali il range medio dei protoni nell'azoto ad alta pressione e la posizione del picco di Bragg, confrontando i risultati con quelli forniti da SRIM. La resa a saturazione relativa alla produzione di C-11 è stata confrontata sia con i valori forniti dal database della IAEA sia con i dati sperimentali a nostra disposizione. Il modello è stato anche utilizzato per la stima di alcuni parametri di interesse, legati, in particolare, al deterioramento dell'efficienza del target nel corso del tempo. L'inclinazione del target, rispetto alla direzione del fascio di protoni accelerati, è influenzata dal peso del corpo del target stesso e dalla posizione in cui questo é fissato al ciclotrone. Per questo sono stati misurati sia il calo della resa della produzione di C-11, sia la percentuale di energia depositata dal fascio sulla superficie interna del target durante l'irraggiamento, al variare dell'angolo di inclinazione del target. Il modello che abbiamo sviluppato rappresenta, dunque, un importante strumento per la valutazione dei processi che avvengono durante l'irraggiamento, per la stima delle performance del target nel corso del tempo e per lo sviluppo di nuovi modelli di target.

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Nowadays the environmental issues and the climatic change play fundamental roles in the design of urban spaces. Our cities are growing in size, many times only following immediate needs without a long-term vision. Consequently, the sustainable development has become not only an ethical but also a strategic need: we can no longer afford an uncontrolled urban expansion. One serious effect of the territory industrialisation process is the increase of urban air and surfaces temperatures compared to the outlying rural surroundings. This difference in temperature is what constitutes an urban heat island (UHI). The purpose of this study is to provide a clarification on the role of urban surfacing materials in the thermal dynamics of an urban space, resulting in useful indications and advices in mitigating UHI. With this aim, 4 coloured concrete bricks were tested, measuring their emissivity and building up their heat release curves using infrared thermography. Two emissivity evaluation procedures were carried out and subsequently put in comparison. Samples performances were assessed, and the influence of the colour on the thermal behaviour was investigated. In addition, some external pavements were analysed. Albedo and emissivity parameters were evaluated in order to understand their thermal behaviour in different conditions. Surfaces temperatures were recorded in a one-day measurements campaign. ENVI-met software was used to simulate how the tested materials would behave in two typical urban scenarios: a urban canyon and a urban heat basin. Improvements they can carry to the urban microclimate were investigated. Emissivities obtained for the bricks ranged between 0.92 and 0.97, suggesting a limited influence of the colour on this parameter. Nonetheless, white concrete brick showed the best thermal performance, whilst the black one the worst; red and yellow ones performed pretty identical intermediate trends. De facto, colours affected the overall thermal behaviour. Emissivity parameter was measured in the outdoor work, getting (as expected) high values for the asphalts. Albedo measurements, conducted with a sunshine pyranometer, proved the improving effect given by the yellow paint in terms of solar reflection, and the bad influence of haze on the measurement accuracy. ENVI-met simulations gave a demonstration on the effectiveness in thermal improving of some tested materials. In particular, results showed good performances for white bricks and granite in the heat basin scenario, and painted concrete and macadam in the urban canyon scenario. These materials can be considered valuable solutions in UHI mitigation.

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PURPOSE: Assessment of language dominance with functional magnetic resonance imaging (fMRI) and neuropsychological evaluation is often used prior to epilepsy surgery. This study explores whether language lateralization and cognitive performance are systematically related in young patients with focal epilepsy. METHODS: Language fMRI and neuropsychological data (language, visuospatial functions, and memory) of 40 patients (7-18 years of age) with unilateral, refractory focal epilepsy in temporal and/or frontal areas of the left (n = 23) or right hemisphere (n = 17) were analyzed. fMRI data of 18 healthy controls (7-18 years) served as a normative sample. A laterality index was computed to determine the lateralization of activation in three regions of interest (frontal, parietal, and temporal). RESULTS: Atypical language lateralization was demonstrated in 12 (30%) of 40 patients. A correlation between language lateralization and verbal memory performance occurred in patients with left-sided epilepsy over all three regions of interest, with bilateral or right-sided language lateralization being correlated with better verbal memory performance (Word Pairs Recall: frontal r = -0.4, p = 0.016; parietal r = -0.4, p = 0.043; temporal r = -0.4, p = 0.041). Verbal memory performance made the largest contribution to language lateralization, whereas handedness and side of seizures did not contribute to the variance in language lateralization. DISCUSSION: This finding reflects the association between neocortical language and hippocampal memory regions in patients with left-sided epilepsy. Atypical language lateralization is advantageous for verbal memory performance, presumably a result of transfer of verbal memory function. In children with focal epilepsy, verbal memory performance provides a better idea of language lateralization than handedness and side of epilepsy and lesion.

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BACKGROUND: Only few standardized apraxia scales are available and they do not cover all domains and semantic features of gesture production. Therefore, the objective of the present study was to evaluate the reliability and validity of a newly developed test of upper limb apraxia (TULIA), which is comprehensive and still short to administer. METHODS: The TULIA consists of 48 items including imitation and pantomime domain of non-symbolic (meaningless), intransitive (communicative) and transitive (tool related) gestures corresponding to 6 subtests. A 6-point scoring method (0-5) was used (score range 0-240). Performance was assessed by blinded raters based on videos in 133 stroke patients, 84 with left hemisphere damage (LHD) and 49 with right hemisphere damage (RHD), as well as 50 healthy subjects (HS). RESULTS: The clinimetric findings demonstrated mostly good to excellent internal consistency, inter- and intra-rater (test-retest) reliability, both at the level of the six subtests and at individual item level. Criterion validity was evaluated by confirming hypotheses based on the literature. Construct validity was demonstrated by a high correlation (r = 0.82) with the De Renzi-test. CONCLUSION: These results show that the TULIA is both a reliable and valid test to systematically assess gesture production. The test can be easily applied and is therefore useful for both research purposes and clinical practice.

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Induced mild hypothermia after cardiac arrest interferes with clinical assessment of the cardiovascular status of patients. In this situation, non-invasive cardiac output measurement could be useful. Unfortunately, arterial pulse contour is altered by temperature, and the performance of devices using arterial blood pressure contour analysis to derive cardiac output may be insufficient.

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The original and modified Wells score are widely used prediction rules for pre-test probability assessment of deep vein thrombosis (DVT). The objective of this study was to compare the predictive performance of both Wells scores in unselected patients with clinical suspicion of DVT.

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The aim of the study was to examine the economic performance as well as perceived social and environmental impacts of organic cotton in Southern Kyrgyzstan on the basis of a comparative field study (44 certified organic farmers and 33 conventional farmers) carried out in 2009. It also investigated farmers’ motivation for and assessment of conversion to organic farming. Cotton yields on organic farms were found to be 10% lower whereby input costs per unit were 42% lower, which resulted in organic farmers having a 20% higher revenue from cotton. Due to lower input costs and organic and fair trade price premiums the average gross margin from organic cotton was 27%. In addition to direct economic benefits organic farmers enjoy a number of additional benefits such as easy access to credits on favourable terms, provision with uncontaminated cotton cooking oil and seed cake as animal feed, marketing support as well as extension and training, services provided by the newly established organic service provider. A big majority of organic farmers perceives an improvement of soil qualities, improved health conditions, and positively assesses their previous decision to convert to organic farming. The major disadvantage of organic farming is the high manual labour input required. In the study area, where manual farm work is mainly women’s work and male labour migration widespread, women are most affected by this negative aspect of organic farming. Altogether, the results suggest that despite the inconvenience of higher work load the advantages of organic farming outweigh the disadvantages and that conversion to organic farming can improve the livelihoods of small-scale farmers.

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The PediaFlow pediatric ventricular assist device is a miniature magnetically levitated mixed flow pump under development for circulatory support of newborns and infants (3-15 kg) with a targeted flow range of 0.3-1.5 L/min. The first generation design of the PediaFlow (PF1) was manufactured with a weight of approximately 100 g, priming volume less than 2 mL, length of 51 mm, outer diameter of 28 mm, and with 5-mm blood ports. PF1 was evaluated in an in vitro flow loop for 6 h and implanted in ovines for three chronic experiments of 6, 17, and 10 days. In the in vitro test, normalized index of hemolysis was 0.0087 ± 0.0024 g/100L. Hemodynamic performance and blood biocompatibility of PF1 were characterized in vivo by measurements of plasma free hemoglobin, plasma fibrinogen, total plasma protein, and with novel flow cytometric assays to quantify circulating activated ovine platelets. The mean plasma free hemoglobin values for the three chronic studies were 4.6 ± 2.7, 13.3 ± 7.9, and 8.8 ± 3.3 mg/dL, respectively. Platelet activation was low for portions of several studies but consistently rose along with observed animal and pump complications. The PF1 prototype generated promising results in terms of low hemolysis and platelet activation in the absence of complications. Hemodynamic results validated the magnetic bearing design and provided the platform for design iterations to meet the objective of providing circulatory support for young children with exceptional biocompatibility.

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To check the effectiveness of campaigns preventing drug abuse or indicating local effects of efforts against drug trafficking, it is beneficial to know consumed amounts of substances in a high spatial and temporal resolution. The analysis of drugs of abuse in wastewater (WW) has the potential to provide this information. In this study, the reliability of WW drug consumption estimates is assessed and a novel method presented to calculate the total uncertainty in observed WW cocaine (COC) and benzoylecgonine (BE) loads. Specifically, uncertainties resulting from discharge measurements, chemical analysis and the applied sampling scheme were addressed and three approaches presented. These consist of (i) a generic model-based procedure to investigate the influence of the sampling scheme on the uncertainty of observed or expected drug loads, (ii) a comparative analysis of two analytical methods (high performance liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry), including an extended cross-validation by influent profiling over several days, and (iii) monitoring COC and BE concentrations in WW of the largest Swiss sewage treatment plants. In addition, the COC and BE loads observed in the sewage treatment plant of the city of Berne were used to back-calculate the COC consumption. The estimated mean daily consumed amount was 107 ± 21 g of pure COC, corresponding to 321 g of street-grade COC.

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In-stream structures including cross-vanes, J-hooks, rock vanes, and W-weirs are widely used in river restoration to limit bank erosion, prevent changes in channel gradient, and improve aquatic habitat. During this investigation, a rapid assessment protocol was combined with post-project monitoring data to assess factors influencing the performance of more than 558 in-stream structures and rootwads in North Carolina. Cross-sectional survey data examined for 221 cross sections from 26 sites showed that channel adjustments were highly variable from site to site, but approximately 60 % of the sites underwent at least a 20 % net change in channel capacity. Evaluation of in-stream structures ranging from 1 to 8 years in age showed that about half of the structures were impaired at 10 of the 26 sites. Major structural damage was often associated with floods of low to moderate frequency and magnitude. Failure mechanisms varied between sites and structure types, but included: (1) erosion of the channel bed and banks (outflanking); (2) movement of rock materials during floods; and (3) burial of the structures in the channel bed. Sites with reconstructed channels that exhibited large changes in channel capacity possessed the highest rates of structural impairment, suggesting that channel adjustments between structures led to their degradation of function. The data question whether currently used in-stream structures are capable of stabilizing reconfigured channels for even short periods when applied to dynamic rivers.