Search results for "Curve"
showing 10 items of 1693 documents
Validation procedures in radiological diagnostic models. Neural network and logistic regression
1999
The objective of this paper is to compare the performance of two predictive radiological models, logistic regression (LR) and neural network (NN), with five different resampling methods. One hundred and sixty-seven patients with proven calvarial lesions as the only known disease were enrolled. Clinical and CT data were used for LR and NN models. Both models were developed with cross validation, leave-one-out and three different bootstrap algorithms. The final results of each model were compared with error rate and the area under receiver operating characteristic curves (Az). The neural network obtained statistically higher Az than LR with cross validation. The remaining resampling validatio…
The dynamic interactive pattern of assimilation and contrast: Accounting for standard extremity in comparative evaluations
2021
Abstract Social judgments are often influenced by comparison to some standard in the environment, either moving the judgment closer (assimilating) to or away (contrasting) from this standard. Which direction this effect will take depends heavily on the relative standing of these standards on the judgment dimension compared to the target of the judgment. In previous research, items and comparison standards were often selected arbitrarily, ignoring or simplifying their influence substantially. The current work takes a fine-grained holistic curve fitting approach to measure response patterns across a wide range of standard extremities, showing that a narrower approach can pose limits to the ge…
THE CARMA INTEREST RATE MODEL
2014
In this paper, we present a multi-factor continuous-time autoregressive moving-average (CARMA) model for the short and forward interest rates. This model is able to present an adequate statistical description of the short and forward rate dynamics. We show that this is a tractable term structure model and provides closed-form solutions to bond prices, yields, bond option prices, and the term structure of forward rate volatility. We demonstrate the capabilities of our model by calibrating it to a panel of spot rates and the empirical volatility of forward rates simultaneously, making the model consistent with both the spot rate dynamics and forward rate volatility structure.
SVILUPPO DI METODOLOGIE DI PROGETTAZIONE INTEGRATA PER BARCHE A VELA DA COMPETIZIONE
2021
In questo lavoro di tesi sono presi in esame i metodi di progettazione integrata con riferimento al disegno nautico delle piccole imbarcazioni a vela da competizione. La progettazione di una barca a vela, in tutte le sue parti, è un processo molto complesso in quanto richiede una profonda esperienza in questo campo ed inoltre necessita di diverse competenze dal punto di vista tecnico in aree anche molto distanti tra loro. Nella vita di tutti i giorni spesso risolviamo problemi relativamente semplici e quindi troviamo la soluzione anche in modo intuitivo, in ingegneria solitamente si affrontano problemi un po’ più complessi e seguire una procedura strutturata aiuta molto per trovare soluzion…
Light Curves of Radio Supernovae
2007
We present the results from the on-going radio monitoring of recent type II supernovae (SNe), including SNe 2004et, 2004dj, 2002hh, 2001em, and 2001gd. Using the Very Large Array to monitor these supernovae, we present their radio light-curves. From these data we are able to discuss parameterizations and modeling and make predictions of the nature of the progenitors based on previous research. Derived mass loss rates assume wind-established circumstellar medium, shock velocity ~10,000 km/s, wind velocity ~10 km/s, and CSM Temperature ~10,000 K.
A Molecular Dynamics-Shared Pharmacophore Approach to Boost Early-Enrichment Virtual Screening: A Case Study on Peroxisome Proliferator-Activated Rec…
2016
Molecular dynamics (MD) simulations can be used, prior to virtual screening, to add flexibility to proteins and study them in a dynamic way. Furthermore, the use of multiple crystal structures of the same protein containing different co-crystallized ligands can help elucidate the role of the ligand on a protein's active conformation, and then explore the most common interactions between small molecules and the receptor. In this work, we evaluated the contribution of the combined use of MD on crystal structures containing the same protein but different ligands to examine the crucial ligand-protein interactions within the complexes. The study was carried out on peroxisome proliferator-activat…
A Visual Introduction to Cubic Surfaces Using the Computer Software Spicy
2003
At the end of the 19th century geometers like Clebsch, Klein and Rodenberg constructed plaster models in order to get a visual impression of their surfaces, which are so beautiful from an abstract point of view. But these were static visualizations. Using the computer program Spicy 1, which was written by the second author, one can now draw algebraic curves and surfaces depending on parameters interactively.
Classification of diabetes-related retinal diseases using a deep learning approach in optical coherence tomography
2019
Background and objectives: Spectral Domain Optical Coherence Tomography (SD-OCT) is a volumetric imaging technique that allows measuring patterns between layers such as small amounts of fluid. Since 2012, automatic medical image analysis performance has steadily increased through the use of deep learning models that automatically learn relevant features for specific tasks, instead of designing visual features manually. Nevertheless, providing insights and interpretation of the predictions made by the model is still a challenge. This paper describes a deep learning model able to detect medically interpretable information in relevant images from a volume to classify diabetes-related retinal d…
Symplectic analysis of thin-walled curved box girders with torsion, distortion and shear lag warping effects
2022
Shear lag effect and torsional and distortional warping can significantly affect the performance of thin-walled curved box girders used in modern bridge engineering. The structural behaviour of these bridges exhibits complexity due to coupled bending and torsion together with warping effects of non-uniform torsion, distortion and shear lag. A practical method of analysis, based on the symplectic approach, with the same perspective as the Higher Order Beam Theories, is presented for overcoming the difficulties of numerical approaches via the Finite Element Method. In this paper, the Hamiltonian Structural Analysis method implements the analysis of the shear lag effect together with non-unifo…
HIGH-RESOLUTION PALAEONVIRONMENTAL RECONSTRUCTION OF ODP HOLE 963D (SICILY CHANNEL) DURING THE LAST DEGLACIATION BASED ON CALCAREOUS NANNOFOSSILS
2004
Abstract A palaeoenvironmental reconstruction of Ocean Drilling Program (ODP) Hole 963D (Sicily Channel) has been obtained on the basis of quantitative abundance fluctuations in the calcareous nannofossil assemblages. The studied hole is characterized by a very high sedimentary resolution and covers the last ca. 20 kyr. A new palaeoclimatic curve, based on the Gephyrocapsa muellerae/Upper Photic Zone (UPZ) group ratio, permitted the detection of the rapid climatic fluctuations that characterized the last deglaciation. Cold water masses occupied the Sicily Channel during the glacial period and the Younger Dryas, whereas they were generally warm during the Bolling–Allerod and the Holocene. An…