High Fidelity Computational Approach to Validate Spine Biomechanics Measurements: A Case Study to Correct Scoliosis

Author(s):  
B. Addison ◽  
N. Sarigul-Klijn ◽  
R. Roberto ◽  
A. Jamali ◽  
M. Thompson

This paper presents a high fidelity computational approach to be used in validation of biomechanics experimental measurements. As a demonstration, a case study involving a spinous process implant to correct scoliosis is presented. The biomechanical behavior of the spinous process and implant under tensile loading is investigated using experiments and computations. The experimental study examined the ultimate strength of calf thoracic and lumbar spinous processes in three pullout directions. A statistical analysis was performed on the experimental results to reveal relationships and variations between pullout direction and vertebral type. The finite element high fidelity computational analysis was performed to validate the experimental results. In the process, the material properties of cortical and trabecular bone were elucidated for calf spinous processes. Good comparisons are obtained. The high fidelity computational approach detailed here should serve useful in validation of experimental values from spine biomechanics experimental.

2015 ◽  
Vol 2015 (1-2) ◽  
pp. 107-120
Author(s):  
Uwe C. Steiner

Simmel’s Sociology explores elementary processes of socialization or collectivization. Thus, the sociology of the senses examines how sight, hearing, feeling, smelling and tasting contributes to constituting societies. Though Simmel observes that modern refined civilization diminishes the depths of the senses but increases its emphasis or enhancement with lust or aversion, the conclusion cannot be avoided that the artifacts and technologies of hearing have to be examined. Accordingly, this article can be regarded as a case study in the wake of Simmel: How do modern aural technologies at the threshold between high fidelity and postfidelity inform contemporary hearing?


2008 ◽  
Vol 59 (10) ◽  
Author(s):  
Delia Perju ◽  
Harieta Pirlea ◽  
Gabriela-Alina Brusturean ◽  
Dana Silaghi-Perju ◽  
Sorin Marinescu

The European laws and recently the Romanian ones impose more and more strict norms to the large nitrogen dioxide polluters. They are obligated to continuously improve the installations and products so that they limit and reduce the nitrogen dioxide pollution, because it has negative effects on the human health and environment. In this paper are presented these researches made within a case study for the Timi�oara municipality, regarding the modeling and simulation of the nitrogen dioxide dispersion phenomenon coming from various sources in atmosphere with the help of analytical-experimental methods. The mathematical model resulting from these researches is accurately enough to describe the real situation. This was confirmed by comparing the results obtained based on the model with real experimental values.


2020 ◽  
Vol 39 (3) ◽  
pp. 407-437
Author(s):  
Markus Bader

Abstract In German, a verb selected by another verb normally precedes the selecting verb. Modal verbs in the perfect tense provide an exception to this generalization because they require the perfective auxiliary to occur in cluster-initial position according to prescriptive grammars. Bader and Schmid (2009b) have shown, however, that native speakers accept the auxiliary in all positions except the cluster-final one. Experimental results as well as corpus data indicate that verb cluster serialization is a case of free variation. I discuss how this variation can be accounted for, focusing on two mismatches between acceptability and frequency: First, slight acceptability advantages can turn into strong frequency advantages. Second, syntactic variants with basically zero frequency can still vary substantially in acceptability. These mismatches remain unaccounted for if acceptability is related to frequency on the level of whole sentence structures, as in Stochastic OT (Boersma and Hayes2001). However, when the acceptability-frequency relationship is modeled on the level of individual weighted constraints, using harmony as link (see Pater2009, for different harmony based frameworks), the two mismatches follow given appropriate linking assumptions.


2021 ◽  
Vol 11 (15) ◽  
pp. 7169
Author(s):  
Mohamed Allouche ◽  
Tarek Frikha ◽  
Mihai Mitrea ◽  
Gérard Memmi ◽  
Faten Chaabane

To bridge the current gap between the Blockchain expectancies and their intensive computation constraints, the present paper advances a lightweight processing solution, based on a load-balancing architecture, compatible with the lightweight/embedding processing paradigms. In this way, the execution of complex operations is securely delegated to an off-chain general-purpose computing machine while the intimate Blockchain operations are kept on-chain. The illustrations correspond to an on-chain Tezos configuration and to a multiprocessor ARM embedded platform (integrated into a Raspberry Pi). The performances are assessed in terms of security, execution time, and CPU consumption when achieving a visual document fingerprint task. It is thus demonstrated that the advanced solution makes it possible for a computing intensive application to be deployed under severely constrained computation and memory resources, as set by a Raspberry Pi 3. The experimental results show that up to nine Tezos nodes can be deployed on a single Raspberry Pi 3 and that the limitation is not derived from the memory but from the computation resources. The execution time with a limited number of fingerprints is 40% higher than using a classical PC solution (value computed with 95% relative error lower than 5%).


2020 ◽  
Vol 11 (1) ◽  
pp. 301
Author(s):  
Sławomir Paśko ◽  
Wojciech Glinkowski

Scoliosis is a three-dimensional trunk and spinal deformity. Patient evaluation is essential for the decision-making process and determines the selection of specific and adequate treatment. The diagnosis requires a radiological evaluation that exposes patients to radiation. This exposure reaches hazardous levels when numerous, repetitive radiographic studies are required for diagnostics, monitoring, and treatment. Technological improvements in radiographic devices have significantly reduced radiation exposure, but the risk for patients remains. Optical three-dimensional surface topography (3D ST) measurement systems that use surface topography (ST) to screen, diagnose, and monitor scoliosis are safer alternatives to radiography. The study aimed to show that the combination of plain X-ray and 3D ST scans allows for an approximate presentation of the vertebral column spinous processes line in space to determine the shape of the spine’s deformity in scoliosis patients. Twelve patients diagnosed with scoliosis, aged 13.1 ± 4.5 years (range: 9 to 20 years) (mean: Cobb angle 17.8°, SD: ±9.5°) were enrolled in the study. Patients were diagnosed using full-spine X-ray and whole torso 3D ST. The novel three-dimensional assessment of the spinous process lines by merging 3D ST and X-ray data in patients with scoliosis was implemented. The method’s expected uncertainty is less than 5 mm, which is better than the norm for a standard measurement tool. The presented accuracy level is considered adequate; the proposed solution is accurate enough to monitor the changes in the shape of scoliosis’s spinous processes line. The proposed method allows for a relatively precise calculation of the spinous process lines based on a three-dimensional point cloud obtained with a four-directional, three-dimensional structured light diagnostic system and a single X-ray image. The method may help reduce patients’ total radiation exposure and avoid one X-ray in the sagittal projection if biplanar radiograms are required for reconstructing the three-dimensional line of the spinous processes line.


Author(s):  
Ian Rouse ◽  
David Power ◽  
Erik G. Brandt ◽  
Matthew Schneemilch ◽  
Konstantinos Kotsis ◽  
...  

We present a multiscale computational approach for the first-principles study of bio-nano interactions. Using titanium dioxide as a case study, we evaluate the affinity of titania nanoparticles to water and biomolecules through atomistic and coarse-grained techniques.


2019 ◽  
Vol 5 (1) ◽  
pp. 444-467
Author(s):  
Katherine A. Crawford

AbstractOstia, the ancient port of Rome, had a rich religious landscape. How processional rituals further contributed to this landscape, however, has seen little consideration. This is largely due to a lack of evidence that attests to the routes taken by processional rituals. The present study aims to address existing problems in studying processions by questioning what factors motivated processional movement routes. A novel computational approach that integrates GIS, urban network analysis, and agent-based modelling is introduced. This multi-layered approach is used to question how spectators served as attractors in the creation of a processional landscape using Ostia’s Campo della Magna Mater as a case study. The analysis of these results is subsequently used to gain new insight into how a greater processional landscape was created surrounding the sanctuary of the Magna Mater.


Author(s):  
Mohammad Hemmat Esfe

In the present article, the effects of temperature and nanoparticles volume fraction on the viscosity of copper oxide-ethylene glycol nanofluid have been investigated experimentally. The experiments have been conducted in volume fractions of 0 to 1.5 % and temperatures from 27.5 to 50 °C. The shear stress computed by experimental values of viscosity and shear rate for volume fraction of 1% and in different temperatures show that this nanofluid has Newtonian behaviour. The experimental results reveal that in a given volume fraction when temperature increases, viscosity decreases, but relative viscosity varies. Also, in a specific temperature, nanofluid viscosity and relative viscosity increase when volume fraction increases. The maximum amount of increase in relative viscosity is 82.46% that occurs in volume fraction of 1.5% and temperature of 50 °C. Some models of computing nanofluid viscosity have been suggested. The greatest difference between the results obtained from these models and experimental results was down of 4 percent that shows that there is a very good agreement between experimental results and the results obtained from these models.


Author(s):  
Xiangxue Zhao ◽  
Shapour Azarm ◽  
Balakumar Balachandran

Online prediction of dynamical system behavior based on a combination of simulation data and sensor measurement data has numerous applications. Examples include predicting safe flight configurations, forecasting storms and wildfire spread, estimating railway track and pipeline health conditions. In such applications, high-fidelity simulations may be used to accurately predict a system’s dynamical behavior offline (“non-real time”). However, due to the computational expense, these simulations have limited usage for online (“real-time”) prediction of a system’s behavior. To remedy this, one possible approach is to allocate a significant portion of the computational effort to obtain data through offline simulations. The obtained offline data can then be combined with online sensor measurements for online estimation of the system’s behavior with comparable accuracy as the off-line, high-fidelity simulation. The main contribution of this paper is in the construction of a fast data-driven spatiotemporal prediction framework that can be used to estimate general parametric dynamical system behavior. This is achieved through three steps. First, high-order singular value decomposition is applied to map high-dimensional offline simulation datasets into a subspace. Second, Gaussian processes are constructed to approximate model parameters in the subspace. Finally, reduced-order particle filtering is used to assimilate sparsely located sensor data to further improve the prediction. The effectiveness of the proposed approach is demonstrated through a case study. In this case study, aeroelastic response data obtained for an aircraft through simulations is integrated with measurement data obtained from a few sparsely located sensors. Through this case study, the authors show that along with dynamic enhancement of the state estimates, one can also realize a reduction in uncertainty of the estimates.


2009 ◽  
Vol 289-292 ◽  
pp. 385-395 ◽  
Author(s):  
Jerzy Jedlinski

This paper reviews briefly the relationship between the growth mechanism and matter transport using as an example the best currently applied metallic materials being alumina formers. The attention is paid to the experimental approach as well as to the interpretation procedure of experimental results. The scale structure, microstructure, morphology and phase composition are indicated as factors strongly affecting its growth mechanism. The attempt is made to elucidate the possible relationships between the obtained experimental results and actual scale growth mechanisms operating during oxidation exposures.


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