linear measurements
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2022 ◽  
Vol 43 (1) ◽  
pp. 449-458
Author(s):  
Danilo Conrado Silva ◽  
◽  
Maria Clorinda Soares Fioravanti ◽  
Paulo José Bastos Queiroz ◽  
Marcelo Corrêa da Silva ◽  
...  

This study aimed to carry out the morphological characterization of the remaining specimens of the Curraleiro horse in municipalities of the state of Goiás, Brazil. Forty male horses were evaluated using the age of five years as a criterion. Sixteen linear measurements and 13 zootechnical indices were obtained. Subsequently, the mean, standard deviation, minimum, maximum, and covariances of these measures and indices were obtained using the software IBM SPSS Statistics for Windows. The measures withers height (WH), croup height (CH), midback height (MH), sternum-to-ground height (SH), chest index (CI), and estimated weight (W) allowed characterizing Curraleiro horses as small-sized, light, and fast, with proportional measures. The dactyl-thoracic index (DTI), body index (BI), conformation index (CFI), load index 1 and 2 (LOI1 and LOI2), and compactness index 1 and 2 (COI1 and COI2) showed that the Curraleiro horse has an intermediate capacity for speed and strength, bearing considerable weight on the back, with saddling aptitude and fast work. These results represent the beginning of the formation of a database that may contribute to future studies and the conservation of the Curraleiro horse in the state of Goiás.


2021 ◽  
Author(s):  
Pia Mandahus ◽  
Lukas Eberhardsteiner ◽  
Bernhard Pichler ◽  
Mehdi Aminbaghai ◽  
Ronald Blab

About a half of the Austrian highways are rigid pavement constructions, and increasingly more money has to be invested in their renovation and redevelopment. However, there are different approaches for the evaluation of the condition assessment of concrete pavements. The aim of the research presented in this paper is a concept for assessing the condition of a road section in rigid pavement. This consists of a structural and a visual assessment scheme for selecting appropriate maintenance actions. For the verification of this new method of assessment of the structural condition of concrete pavements, several field tests were examined. Furthermore, a case study was carried out to examine the level of influence of several input parameter. This analysis shows that the influence of the layer thickness is very high, while the influence of the modulus of elasticity of the existing concrete is significant lower. The FWD measurements were carried out radial (instead of linear) for the first time. The results show possible inhomogeneities in the subgrade or in the bedding, which would not be recognized by the standard linear measurements. With the results from the already mentioned measurements, the remaining service life of the test tracks could be calculated.


2021 ◽  
Author(s):  
Hang Xu ◽  
Song Li ◽  
Junhong Lin

Abstract Many problems in data science can be treated as recovering a low-rank matrix from a small number of random linear measurements, possibly corrupted with adversarial noise and dense noise. Recently, a bunch of theories on variants of models have been developed for different noises, but with fewer theories on the adversarial noise. In this paper, we study low-rank matrix recovery problem from linear measurements perturbed by $\ell_1$-bounded noise and sparse noise that can arbitrarily change an adversarially chosen $\omega$-fraction of the measurement vector. For Gaussian measurements with nearly optimal number of measurements, we show that the nuclear-norm constrained least absolute deviation (LAD) can successfully estimate the ground-truth matrix for any $\omega<0.239$. Similar robust recovery results are also established for an iterative hard thresholding algorithm applied to the rank-constrained LAD considering geometrically decaying step-sizes, and the unconstrained LAD based on matrix factorization as well as its subgradient descent solver.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Carol Moussa ◽  
Louis Hardan ◽  
Cynthia Kassis ◽  
Rim Bourgi ◽  
Walter Devoto ◽  
...  

There is a scant literature on the accuracy of dental photographs captured by Digital Single-Lens Reflex (DSLR) and smartphone cameras. The aim was to compare linear measurements of plaster models photographed with DSLR and smartphone’s camera with digital models. Thirty maxillary casts were prepared. Vertical and horizontal reference lines were marked on each tooth, with exception to molars. Then, models were scanned with the TRIOS 3 Basic intraoral dental scanner (control). Six photographs were captured for each model: one using DSLR camera (Canon EOS 700D) and five with smartphone (iPhone X) (distance range 16-32 cm). Teeth heights and widths were measured on scans and photographs. The following conclusions could be drawn: (1) the measurements of teeth by means of DSLR and smartphone cameras (at distances of at least 24 cm) and scan did not differ. (2) The measurements of anterior teeth by means of DSLR and smartphone cameras (at all distances tested) and scan exhibited no difference. For documentational purposes, the distortion is negligeable, and both camera devices can be applied. Dentists can rely on DSLR and smartphone cameras (at distances of at least 24 cm) for smile designs providing comparable and reliable linear measurements.


2021 ◽  
Vol 21 ◽  
pp. e227903
Author(s):  
Hany Salah Eldin Eid ◽  
Omnia A. Elhiny

Aim: To evaluate the accuracy and the validity of orthodontic diagnostic measurements, as well as virtual tooth transformations using a generic open access 3D software compared to OrthoAnalyzer (3Shape) software; which was previously tested and proven for accuracy. Methods: 40 maxillary and mandibular single arch study models were duplicated and scanned using 3Shape laser scanner. The files were imported into the generic and OrthoAnalyzer software programs; where linear measurements were taken twice to investigate the accuracy of the program. To test the accuracy of the program format, they were printed, rescanned and imported into OrthAnalyzer. Finally, to investigate the accuracy of editing capabilities, linear and angular transformation procedures were performed, superimposed and printed to be rescanned and imported to OrthoAnalyzer for comparison. Results: There was no statistically significant difference between the two groups using the two software programs regarding the accuracy of the linear measurements (p>0.05). There was no statistically significant difference between the different formats among all the measurements, (p>0.05). The editing capabilities also showed no statistically significant difference (p>0.05). Conclusion: The generic 3D software (Meshmixer) was valid and accurate in cast measurements and linear and angular editing procedures. It can be used for orthodontic diagnosis and treatment planning without added costs.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Aditya Phadnis ◽  
Monica Forbes-Amrhein

Swallowing of amniotic fluid alters the volume of the fetal stomach; therefore an abnormal fetal stomach size can be indicative of pathology. Previous studies have used linear measurements on ultrasound to approximate stomach sizes. Fetal magnetic resonance imaging (MRI) allows for volumetric measurement of the stomach. The objective of this study was to develop a library of normal fetal stomach volumes on MRI at each gestational age. We also sought to measure stomach volumes of fetuses with esophageal atresia and compare to normal volumes at similar gestation ages (GA).  A retrospective review of fetal MRIs from patients 20-38 weeks GA was conducted.  Exclusion criteria for the controls included any impairment that would impede swallowing or alter stomach sizes.  Patients with esophageal atresia were identified and postnatal records were reviewed to confirm the diagnosis. The stomach volume was measured on T2-weighted imaging using Phillips Intellispace software. The stomach volumes of the controls at each GA were compared using one-way ANOVA with Games-Howell Post-Hoc (p<0.05).  The stomach volume in esophageal atresia was compared to controls using a T-test (p<0.001).    185 control studies, 10 at each week of gestation, and 8 patients with esophageal atresia were included. For normal fetuses, there was a trend of increased stomach size and broadened standard deviation with increasing GA.  No significant difference was found between any two sequential weeks, however the difference in second and third trimester volumes was significant (p<0.001).   The patients with esophageal atresia had significantly smaller stomach volumes compared to control patients of the same GA range (p<0.001).   This pilot study established reference values for fetal stomach volume, which was found to increase with GA. The stomach volume is significantly smaller in patients with esophageal atresia.  Thus, esophageal atresia can be identified prenatally, allowing for delivery at an appropriate acuity NICU and early intervention.   


2021 ◽  
pp. 5-10
Author(s):  
A.M. Hohol ◽  
A.I. Pankevych ◽  
I.A. Kolisnyk ◽  
D.S. Machulenko ◽  
Ya.A. Hohol

Topic relevance. The dental surgeon often is left alone with the dilemma: to save or remove the third lower molars. The justification of indications for tooth extraction must have objective criteria. It should be noted that a patient with this problem does not always have the opportunity to receive comprehensive advice from an orthodontist. In view of this, the solution to this problem requires the search for radiological data, which are the most available today and would help to justify treatment tactics for preservation or removal of the tooth. The conditions of tooth preservation in the dentition are most favorable with a slight medio-distal inclination and a vertical position of the third lower molars. However, this does not exclude the possibility of tooth impaction, which is often accompanied by periodic inflammatory phenomena in the tissues adjacent to the tooth and motivates both the patient and the dental surgeon to solve this problem. The aim of our study was to research of radiographic indicators of orthopantomography of the mandible to predict the vertical retention of the third lower molars. Material and methods of research. The platforms of Google Scholar, Research Gate and PubMed are used for research and analysis of the scientific literature on the application of objective criteria of mandibular orthopantomography data in the prediction of vertical impaction of the third lower molars. Impaction of mandibular molars is the result of a number of factors, including heredity, racial characteristics, muscle function, the nature of the food consumed, insufficient growth of the mandible, the size of the retromolar space. The accurately determination the positions of the molars and the size of the retromolar space of the mandible by available methods of X-ray diagnosis (the most common of which is the method of orthopantomography of the jaws) are necessary to prediction of tooth retention. The accuracy of imaging and measurements on orthopantomograms of the jaws was studied by both domestic and foreign authors. The angle of inclination of lower wisdom tooth, the size of the retromolar space of the mandible and the mesiodistal size of the teeth are determined on OPTG of jaws in the vast majority of publications. The age aspect of patients is also important for prediction of tooth impaction. In particular, most researchers state the fact that up to 20 years of life there is a significant probability of changing the position of the teeth during their eruption and therefore it is quite appropriate to wait. To predict the nature of the impaction of the third lower molars, the authors provide indicators of the angle of the tooth, the structure of their roots, the degree of impact and age of the patient. The publication of Maria Mersedes Gallas-Torreira and co-authors, which compared two methods of linear measurements on OPTG – Olive-Basford’s and Olmos ’methods have greatest interest. Both methods can be used to predict of impaction of lower wisdom tooth. However, if the prognostic estimate is based on orthopantomogram data rather than cone-beam computed tomography, the Olmos` method demonstrates a lower error rate and a more plausible prediction. To substantiate the algorithm for predicting the vertical retention of third lower molar in order to improve treatment tactics for the preservation or removal of the tooth which based on the obtained search data and the results of our own clinical observations and it is planned in the future.


Author(s):  
Yoon Hak Kim

AbstractWe address the problem of selecting a given number of sensor nodes in wireless sensor networks where noise-corrupted linear measurements are collected at the selected nodes to estimate the unknown parameter. Noting that this problem is combinatorial in nature and selection of sensor nodes from a large number of nodes would require unfeasible computational cost, we propose a greedy sensor selection method that seeks to choose one node at each iteration until the desired number of sensor nodes are selected. We first apply the QR factorization to make the mean squared error (MSE) of estimation a simplified metric which is iteratively minimized. We present a simple criterion which enables selection of the next sensor node minimizing the MSE at iterations. We discuss that a near-optimality of the proposed method is guaranteed by using the approximate supermodularity and also make a complexity analysis for the proposed algorithm in comparison with different greedy selection methods, showing a reasonable complexity of the proposed method. We finally run extensive experiments to investigate the estimation performance of the different selection methods in various situations and demonstrate that the proposed algorithm provides a good estimation accuracy with a competitive complexity when compared with the other novel greedy methods.


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