3,442 research outputs found
Utilising Deep Learning Models for the Surface Registration Problem in HoloNav
No full textSurface Registration is a registration problem that handles the registration of two similar surfaces. In most research that utilises Deep Learning (DL) models to handle surface registration two theories are investigated; the first being whether surfaces sampled from the same origin can be registered together, and the second theory being whether the models can register Point Clouds with low overlapping data for utilisation in Simultaneous Localisation and Mapping (SLAM) applications. However, the surface registration to be utilised in the HoloNav Augmented Reality (AR) navigation system will utilise Point Clouds sampled from different origins with a high overlap ratio. This research, therefore, aims to determine the viability of DL methods for surface registration in HoloNav data. To determine the viability, rotation and translation errors in the match were used, with the aforementioned metrics later being evaluated manually with the utilisation of a visualiser. The results indicate that the models can generalise on the navigator data for an initial Euler angle difference of 45 degrees, but due to the difference in sampling density on the utilised point clouds can not provide accurate matches. Therefore, the utilisation of DL models can be considered to be viable if the navigator data has a sampling density similar to the pre-operative model.https://github.com/alpcicimen/holonav-dl-registration The link to the github repository containing the utilised dataset, scripts, as well as the modified DL models RPMNet and PREDATOR.CSE3000 Research ProjectComputer Science and Engineerin
The Scent of a Smell: An Extensive Comparison between Textual and Structural Smells
No full textCode smells are symptoms of poor design or implementation choices that have a negative effect on several aspects of software maintenance and evolution, such as program comprehension or change- and fault-proneness. This is why researchers have spent a lot of effort on devising methods that help developers to automatically detect them in source code. Almost all the techniques presented in literature are based on the analysis of structural properties extracted from source code, although alternative sources of information (e.g., textual analysis) for code smell detection have also been recently investigated. Nevertheless, some studies have indicated that code smells detected by existing tools based on the analysis of structural properties are generally ignored (and thus not refactored) by the developers. In this paper, we aim at understanding whether code smells detected using textual analysis are perceived and refactored by developers in the same or different way than code smells detected through structural analysis. To this aim, we set up two different experiments. We have first carried out a software repository mining study to analyze how developers act on textually or structurally detected code smells. Subsequently, we have conducted a user study with industrial developers and quality experts in order to qualitatively analyze how they perceive code smells identified using the two different sources of information. Results indicate that textually detected code smells are easier to identify and for this reason they are considered easier to refactor with respect to code smells detected using structural properties. On the other hand, the latter are often perceived as more severe, but more difficult to exactly identify and remove.Accepted Author ManuscriptSoftware Engineerin
Evaluation of a point-of-care test for quantitative determination of total thyroxine in feline serum
No full textObjectives: Total thyroxine (TT4) evaluation is the most commonly used first-line test for the diagnosis and monitoring of cats with hyperthyroidism. Vcheck T4 is a point-of-care immunoassay that measures TT4 using a Vcheck V200 analyser. This study aimed to evaluate the analytic performance of the Vcheck T4 assay in feline sera and the agreement in the classification of normal, high and low TT4 concentrations of Vcheck T4 with those measured by an enzyme immunoassay (EIA). Methods: Assay precision, reproducibility and linearity were evaluated for the Vcheck T4. For method comparison, TT4 concentrations in 73 serum samples were analysed by both methods. Results: Vcheck T4 demonstrated good precision, reproducibility (intra- and inter-assay coefficients of variation between 3% and 13.5%) and linearity in the diagnostic range of <0.5 and >8 μg/dl. The correlation coefficient was 0.87, Passing-Bablok regression showed a proportional, but not constant bias, Bland-Altman plots revealed a mean difference of +0.5 μg/dl. The overall inter-rater agreement (K) between TT4 EIA and Vcheck results was substantial (K = 0.69), with 82.2% of concordant results. As a diagnostic test for hyperthyroidism, Vcheck T4 showed a sensitivity and specificity of 88.9% and 84.4%, and a positive predictive value (PPV) and negative predictive value (NPV) of 44.5% and 98.2%, respectively. Conclusions and relevance: Vcheck T4 assay provided precise and reproducible results in substantial agreement with the EIA. Given the high NPV, Vcheck T4 is useful in ruling out hyperthyroidism when screening cats, but, based on low PPV, samples with results with high TT4 need to be analysed by another reference method. Further analysis with haemolytic, icteric and lipaemic samples is needed to assess the test performance. Finally, the reference intervals provided by the manufacturer require verification, and TT4 intervals specific to this method must be established in future studies
March dl: Adding Adaptive Heuristics and a New Branching Strategy
No full textWe introduce the march dl satisability (SAT) solver, a successor of march eq. The latter was awarded state-of-the-art in two categories during the Sat 2004 competition. The focus lies on presenting those features that are new in march dl. Besides a description, each of these features is illustrated with some experimental results. By extending the pre-processor, using adaptive heuristics, and by using a new branching strategy, march dl is able to solve nearly all benchmarks faster than its predecessor. Moreover, various instances which were beyond the reach of march eq, can now be solved - relatively easily - due to these new features.Software TechnologyElectrical Engineering, Mathematics and Computer Scienc
Crash Reproduction Using Helper Objectives
No full textEvolutionary-based crash reproduction techniques aid developers in their debugging practices by generating a test case that reproduces a crash given its stack trace. In these techniques, the search process is typically guided by a single search objective called Crash Distance. Previous studies have shown that current approaches could only reproduce a limited number of crashes due to a lack of diversity in the population during the search. In this study, we address this issue by applying Multi-Objectivization using Helper-Objectives (MO-HO) on crash reproduction. In particular, we add two helper-objectives to the Crash Distance to improve the diversity of the generated test cases and consequently enhance the guidance of the search process. We assessed MO-HO against the single-objective crash reproduction. Our results show that MO-HO can reproduce two additional crashes that were not previously reproducible by the single-objective approach.Virtual/online event due to COVID-19 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Software EngineeringSoftware Technolog
A General Formulation to Describe Empirical Rainfall Thresholds for Landslides
No full textAbstractIn this paper, a brief description of the Generalized FLaIR Model (GFM, De Luca and Versace, 2016) is provided, that is able to reproduce all the empirical thresholds proposed in literature, aimed to forecast landslides triggered by rainfall. In particular, this paper focuses on Antecedent Precipitation (AP) schemes. The paper demonstrates that these are particular solutions of the GFM and will exemplify this using AP schemes for NE Italy1, Seattle2 and Nicaragua - El Salvador3
Releasing Fast and Slow: An Exploratory Case Study at ING
No full textThe appeal of delivering new features faster has led many software projects to adopt rapid releases. However, it is not well understood what the effects of this practice are. This paper presents an exploratory case study of rapid releases at ING, a large banking company that develops software solutions in-house, to characterize rapid releases. Since 2011, ING has shifted to a rapid release model. This switch has resulted in a mixed environment of 611 teams releasing relatively fast and slow. We followed a mixed-methods approach in which we conducted a survey with 461 participants and corroborated their perceptions with 2 years of code quality data and 1 year of release delay data. Our research shows that: rapid releases are more commonly delayed than their non-rapid counterparts, however, rapid releases have shorter delays; rapid releases can be beneficial in terms of reviewing and user-perceived quality; rapidly released software tends to have a higher code churn, a higher test coverage and a lower average complexity; challenges in rapid releases are related to managing dependencies and certain code aspects, e.g. design debt.Software EngineeringSoftware Technolog
Ammonia concentration and bacterial evaluation of feline whole blood and packed red blood cell units stored for transfusion
No full textAmmonia concentrations increase in human, canine and equine WB and PRBC units during storage. The aim of this study was to determine the effect of storage on ammonia concentration in feline WB and PRBC units stored in a veterinary blood bank and to evaluate possible correlations with bacterial contamination. Ammonia concentration was evaluated in 15 WB units and 2 PRBC units on day 1 and at the end of storage after 35 and 42 days, respectively. In an additional 5 WB units and 4 PRBC units ammonia concentrations were determined daily until the day the normal reference range was exceeded and then weekly to the end of storage. All units were evaluated for bacterial contamination. Ammonia increased markedly during storage as a linear function over time. On the 35th and 42th day of storage at 4±2°C mean±SD ammonia concentration reached 909±158 μg/dl and 1058±212 μg/dl in WB and PRBC units, respectively. Bacterial culture was negative in all units. High ammonia concentrations in stored WB and PRBC units could result in toxicity, particularly in feline recipients with liver failure, portosystemic shunts or those receiving large transfusion volumes. Clinical in vivo studies evaluating the effects on recipients should be performed
Hematological reference values for stray colony cats of northern Italy : hematological references intervals for stray cats
No full textIn additional to significant dietary, lifestyle and hormonal differences, stray cats may have different hematological parameters from pet cats. The objectives of this study are to determine hematological reference intervals (RIs) from a large population of stray cats in northern Italy, to establish whether published RIs for the general pet feline population are valid in stray cats and to evaluate the effects of age and sex on hematological parameters. Hematological data were analyzed retrospectively from the database of a trap-neuter-release program (performed in 2008–2010 in northern Italy) to generate normal RIs. RIs were determined and compared with established pet cat RIs according to the National Committee for Clinical Laboratory Standard guidelines and the American Society of Veterinary Clinical Pathology guidelines. Data from 90 healthy stray cats from 17 colonies were available for determination of hematological RIs. Based on the results of comparison with published feline RIs, new RIs were proposed for RBC count, Hct, MCV, MCHC, and WBC count in stray cats. Male cats had a statistically significant higher value than did females for RBC count (mean RBC count in females 6.5 × 1012 versus 7.4 × 1012/L in males, P = 0.001), Hb (mean Hb concentration in females 9.9 versus 10.9 g/dL in males, P = 0.004), and Hct (mean Hct in females 24.8 versus 28.2 % in males, P = 0.001). Significant differences in five hematological parameters were found between stray and pet cats, for most of which the most plausible explanation is probably anesthetic effect and infections or parasitism. It can therefore be assumed that there is no need to establish a specific RI for most of the CBC variables in stray cats
Rimodellamento dell'isola pancreatica nel diabete di tipo 2 : studio in primati non-umani
No full textRIMODELLAMENTO DELL’ISOLA PANCREATICA NEL DIABETE DI TIPO 2: STUDIO IN PRIMATI NON-UMANI
F.Folli1 C.Perego2 R.Guardado-Mendoza1 S.Moretti2 S.Larosa3, G.Finzi3 A. Davalli4 1Dept of Medicine, UTHSCSA, San Antonio, Texas USA; 2Dip Sc. Farmacologiche e Biomolecolari, Università di Milano; 3Dip di Patologia, Ospedale di Circolo, Varese; 4Ospedale San Raffaele, Milano.
La progressiva disfunzione dell’isola del Langerhans è uno dei principali fattori alla base della patogenesi del diabete di tipo 2. Alterazioni morfologiche e funzionale a carico dell’isola (diminuzione della massa beta cellulare e aumento di quella alfa cellulare) sono state riscontrate durante la progressione del diabete, in soggetti umani e primati non-umani. Scarse sono le informazioni relative alla massa delta-cellulare e all’impatto che queste variazioni possano avere sulla progressione del diabete. Scopo del lavoro è stato quello di valutare quantitativamente le variazioni delle diverse popolazioni endocrine dell’isola (con particolare attenzione alle cellule delta) e di correlare i dati a parametri metabolici e clinici utilizzando come modello sperimentali primati non-umani che spontanemanete sviluppano diabete.
Risultati: sulla base dei valori di glicemia, i babbuini sono stati stratificati in 4 gruppi: (G1: FPG<80mg/dl n=10; G2: FPG=80-94mg/dl n=9, G3: FPG=95-125mg/dl n=9,G4 FPG≥126mg/dl n=12). Come atteso, all’aumentare di FPG, diminuisce il volume relativo beta-cellulare/isola (17% e 60% nei gruppi G3 e G4), in modo proporzionale a FPG (R2 =0.5428, p<0.001) e alla deposizione di amiloide (R2 =0.7679, p<0.001). Il volume relativo delle cellule alfa aumenta del 50% (nel gruppo G3 e G4), mentre il volume delle cellule delta diminuisce (del 39% e 31% in G3 e G4, rispetto G1, p<0.05). Analisi di immunofluorescenza e microscopia elettronica hanno rilevato segni di sofferenza e apoptosi a carico di cellule delta e beta nel pancreas di babbuini del gruppo G4. I livelli di glucagone aumentano proporzionalmente alla FPG (r =0.2821, p<0.05) ma l’analisi multivariabile evidenzia una correlazione negativa solo tra livelli di glucagone e volume relativo delle cellule delta/isola (partial r=-0.45, p=0.01).
Conclusioni. Questa è la prima evidenza sperimentale, di apotosi in cellule delta nel diabete di tipo 2, in primati non-umani
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