Search results for "RECONSTRUCTION"
showing 10 items of 784 documents
Frames and weak frames for unbounded operators
2020
In 2012 G\u{a}vru\c{t}a introduced the notions of $K$-frame and of atomic system for a linear bounded operator $K$ in a Hilbert space $\mathcal{H}$, in order to decompose its range $\mathcal{R}(K)$ with a frame-like expansion. In this article we revisit these concepts for an unbounded and densely defined operator $A:\mathcal{D}(A)\to\mathcal{H}$ in two different ways. In one case we consider a non-Bessel sequence where the coefficient sequence depends continuously on $f\in\mathcal{D}(A)$ with respect to the norm of $\mathcal{H}$. In the other case we consider a Bessel sequence and the coefficient sequence depends continuously on $f\in\mathcal{D}(A)$ with respect to the graph norm of $A$.
Persistent link between Caribbean precipitation and Atlantic Ocean circulation during the Last Glacial revealed by a speleothem record from Puerto Ri…
2020
The sensitivity of tropical Atlantic precipitation patterns to the mean position of the Intertropical Convergence Zone (ITCZ) at different time scales is well‐known. However, recent research suggests a more complex behavior of the northern hemispheric tropical rain belt related to the ITCZ in the western tropical Atlantic. Here we present a precisely dated speleothem multi‐proxy record from a well‐monitored cave in Puerto Rico, covering the period between 46.2 and 15.3 ka. The stable isotope and trace element records document a pronounced response of regional rainfall to abrupt climatic excursions in the North Atlantic across the Last Glacial such as Heinrich stadials and Dansgaard/Oeschger…
Distributed Clustering Algorithm for Spatial Field Reconstruction in Wireless Sensor Networks
2015
En este trabajo, consideramos el problema de la estimación espacial distribuida para la reconstrucción del campo radio en redes de sensores inalámbricos. Para estimar el campo, se utiliza una técnica geoestadística llamada kriging. La estimación espacial centralizada con un gran número de sensores conllevan un elevado coste computacional y gasto de energía. Presentamos un novedoso algoritmo de clustering distribuido para estimar mapas de interferencia espacial, que son esenciales para las operaciones y la gestión de las futuras redes inalámbricas. En este algoritmo, los clústeres de sensores se forman de forma adaptativa mediante la minimización de la varianza de kriging. El cálculo del sem…
A naive approach to compose aerial images in a mosaic fashion
2002
There is growing interest in multiple sequence image analysis to represent those data in a new landscape, for instance reconstruction of old films, mosaicing of images. This paper focuses attention on the mosaic problem; it introduces a naive method to link together images where a common part of the scene is present among two images. An application has been developed to test the method on aerial sequences of images. Given the long distance of aircraft from the scene, the method assumes images without distortions and without problems of prospective. Moreover, the application does not need any additional parameters coming from human experience and for this reason it can be thought of as a ful…
Software zur automatischen Quantifizierung von Belüftungszuständen bei akutem Lungenversagen in dynamischen CT-Aufnahmen der Lunge1
2001
Purpose: Density measurements in dynamic CT image series of the lungs allow one to quantify ventilated, hyperinflated, and atelectatic pulmonary compartments with high temporal resolution. Fast automatic segmentation of lung parenchyma and a subsequent evaluation of it's respective density values are a prerequisite for any clinical application of this technique. Material and Methods: For automatic lung segmentation in thoracic CT scans, an algorithm was developed which uses (a) different density masks, and (b) anatomic knowledge to differentiate heart, diaphragm and chest wall from ventilated and atelectatic lung parenchyma. With Animal Care Committee approval, the automated technique was t…
Abdominal wall reconstruction by a regionally distinct biocomposite of extracellular matrix digest and a biodegradable elastomer.
2013
Current extracellular matrix (ECM) derived scaffolds offer promising regenerative responses in many settings, however in some applications there may be a desire for more robust and long lasting mechanical properties. A biohybrid composite material that offers both strength and bioactivity for optimal healing towards native tissue behavior may offer a solution to this problem. A regionally distinct biocomposite scaffold composed of a biodegradable elastomer (poly(ester urethane)urea) and porcine dermal ECM gel was generated to meet this need by a concurrent polymer electrospinning/ECM gel electrospraying technique where the electrosprayed component was varied temporally during the processing…
Data-based modeling of vehicle crash using adaptive neural-fuzzy inference system
2014
Vehicle crashes are considered to be events that are extremely complex to be analyzed from the mathematical point of view. In order to establish a mathematical model of a vehicle crash, one needs to consider various areas of research. For this reason, to simplify the analysis and improve the modeling process, in this paper, a novel adaptive neurofuzzy inference system (ANFIS-based) approach to reconstruct kinematics of colliding vehicles is presented. A typical five-layered ANFIS structure is trained to reproduce kinematics (acceleration, velocity, and displacement) of a vehicle involved in an oblique barrier collision. Subsequently, the same ANFIS structure is applied to simulate different…
An algorithm for oncologic scalp reconstruction.
2010
Background: Modern reconstructive surgery allows for radical resection and reconstruction of any scalp tumor. However, a significant number of patients are still not treated optimally because of incomplete reconstructive guidelines. Methods: The treatment of scalp tumors was documented in 60 patients over a 10-year period. Data regarding tumor type, size, and localization; reconstructive procedure; oncologic, functional, and aesthetic outcome; and complications were collected and analyzed retrospectively. These data were correlated to recurrence and survival rates. The findings extracted from the data were amalgamated to produce the proposed reconstructive algorithm. Results: Five reconstru…
Virtual Planning and 3D printing modeling for mandibular reconstruction with fibula free flap
2017
Background This study was to evaluate the use of virtual planning and 3D printing modeling in mandibular reconstruction and compare the operation time and surgical outcome of this technique with conventional method. Material and Methods Between 2014 and 2017, 15 patients underwent vascularized fibula flap mandibular reconstruction using virtual planning and 3D printing modeling. Titanium plates were pre-bent using the models and cutting guides were used for osteotomies. 15 patients who underwent mandibular reconstruction using fibula flap without aid of virtual planning and 3D printing models were selected as control group. The operation time was recorded and compared in two groups. Accurac…
Maxillary reconstruction using rectus femoris muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle
2018
Background Maxillary reconstruction using various pedicled and free-tissue transfer techniques with bone graft or without bone graft has some drawbacks. In this study, we demonstrate maxillary reconstruction using femoris rectus muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle through the modified lateral lip-submandibular approach. Material and Methods Nine patients suffering from maxillary defects secondary to maxillary cancer ablation, who underwent maxillary reconstruction using rectus femoris muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle, were enrolled into this study between November 201…