Compression Type Research Articles

Validation of Relative Motion Measurement Method of Lateral Compression Pelvic Fractures During Examination Under Anesthesia.

To determine if the relative distance between the acetabular teardrops on unstressed and lateral compressive stress examination under anesthesia (EUA) pelvic fluoroscopic images is reproducible between independent reviewers. Retrospective database review. Level 1 trauma center. Fifty-eight patients with a lateral compression type 1 pelvic ring injury who underwent EUA. Validation of EUA objective measurements between blinded, independent reviewers using interclass and intraclass correlation coefficients. There was excellent interobserver and intraobserver reliability between all reviewers. Values for each intraclass correlation coefficients (including 95% confidence intervals) were between 0.96 (0.95-0.098) and 0.99 (0.99-0.99) for all measurements. P values were <0.0001 for all measured parameters. The relative change in distance between the acetabular tear drops during lateral compressive EUA of lateral compression type 1 pelvic injuries is reliable between independent reviewers. This allows for accurate, objective measurement of pelvic motion independent of patient size or body habitus. Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Musically-acoustic Thesaurus as Spatial Dimension of Cognitive Process

The article considers musically-acoustic thesaurus of collective and individual, a complex structure, which composition of multiple parts is effectuated by multiple channels of receiving information from the outside and ways of manipulation with it, that is turning of separate facts into systematic knowledge stored in memory. This structure consists of two groups with duplex connection. The first one is the knowledge of the world as a sonic phenomenon and of human auditory activity, as well as of the experience of absorbing the information received, principles of manipulation with it, overall – fulfills inherent inclination of individual towards usage of auditory images as a requirement for appearance of musical ones. All the sonorities are bracketed in two groups: extra-musical and musical itself. The latter group consists of musical units of acoustically-sonic environment, having utility, practical significance for a person, allowing orientation in given spacetime. At the same time, they are potentially opened to emotional experiences and aesthetic approach towards them. Acoustically-sonic environment possesses basic traits of organization, being reflected in mind by such characteristics as cyclicity, variability, combinationalism, montage structure, simultaneity, interdependency of “shape” and “background”. In a thesaurus of a collective and individual external environment is imprinted in two ways: as undifferentiated background noise and as separate units, creating relief. The memory contains them both, creating thus sonic image of the world. The knowledge, appearing thus, is stored in thesaurus in compressed type, acquiring its full and kinetic form in cases of contact with reality.

Pruning and quantization for deep neural network acceleration: A survey

Deep neural networks have been applied in many applications exhibiting extraordinary abilities in the field of computer vision. However, complex network architectures challenge efficient real-time deployment and require significant computation resources and energy costs. These challenges can be overcome through optimizations such as network compression. Network compression can often be realized with little loss of accuracy. In some cases accuracy may even improve. This paper provides a survey on two types of network compression: pruning and quantization. Pruning can be categorized as static if it is performed offline or dynamic if it is performed at run-time. We compare pruning techniques and describe criteria used to remove redundant computations. We discuss trade-offs in element-wise, channel-wise, shape-wise, filter-wise, layer-wise and even network-wise pruning. Quantization reduces computations by reducing the precision of the datatype. Weights, biases, and activations may be quantized typically to 8-bit integers although lower bit width implementations are also discussed including binary neural networks. Both pruning and quantization can be used independently or combined. We compare current techniques, analyze their strengths and weaknesses, present compressed network accuracy results on a number of frameworks, and provide practical guidance for compressing networks.

Effect of tensile and compressive nonlinear edge loads on the buckling performance of hybrid metal composite laminates with cutouts

In the current study, the finite element approach has been used to investigate the effect of compression and tension types of nonlinear edge loads on the vibration and buckling performance of interlaminar hybrid fiber metal laminates (HFMLs) with and without cutouts. The effect of various hybridizations in cross ply, angle ply and quasi isotropic laminate schemes is studied extensively. Toward this a 9-noded heterosis plate element has been used to discretize the plate by taking into account the effect of shear deformation and rotary inertia. Since the stress distribution within the plate is highly non-uniform in nature, the dynamic approach has been used to solve the buckling problems. The present study consists of aluminum metal face sheets bounded with four layered hybrid laminate schemes, which includes glass and carbon layers. In which, six different hybrid configurations have been considered. The performance of each hybrid configuration along with different sized and positioned cutouts is well investigated under various nonlinear loading conditions, which are compressive and tensile in nature.

DOUBLE COMPRESSION BASED LOW BANDWIDTH VIDEO TRANSMITTER

It is very difficult to imagine our modern life without data. As new technologies and data volume increase, sending them quickly is becoming one of the most important issues. Compression methods are commonly used to transfer data faster when transmitting data. Image compression is one of the data compression types used to compress digital images, to reduce their cost for storage or transmission. In this paper, we propose double compression based low bandwidth video transmitter. The device is capable of transmitting data two-stage compression. The first stage is compression based on the existing interpolation method. In the second stage, it is compressed based on the JPEG method. The relationship between bandwidth and quality in image transmission is also analyzed.

Lossless Image Compression Schemes: A Review

Data compression refers to the process of representation of data using fewer number of bits. Data compression can be lossless or lossy. There are many schemes developed and used to perform either lossless or lossy compression. Lossless data compression allows the original data be conveniently reconstructed from the compressed data while lossy compression allow only an approximate of the original data to be constructed. The type of data to compressed can be classified as image data, textual data, audio data or even video content. Various researches are being carried out in the area of image compression. This paper presents various literatures in field of data compression and the techniques used to compress image using lossless type of compression. In conclusion, the paper reviewed some schemes used to compress an image using a single schemes or combination of two or more schemes methods.

Examination Under Anesthesia Improves Agreement on Mechanical Stability: A Survey of Experienced Pelvic Surgeons

To assess agreement among experts in pelvic fracture management regarding stability and need for operative repair of lateral compression-type pelvic fractures with static radiographs compared to static radiographs and examination under anesthesia (EUA). Online survey. Ten patients who presented to our level-1 trauma center with a pelvic ring injury were selected. Vignettes were distributed to 11 experienced pelvic surgeons. Examination under anesthesia. Agreement regarding pelvic fracture stability and need for surgical fixation. Agreement on stability was achieved in 4 (40%) cases without EUA compared to 8 (80%) cases with EUA. Interreviewer reliability was poor without EUA and moderate with EUA (0.207 vs. 0.592). Agreement on need to perform surgery was achieved in 5 (50%) cases compared to 6 (60%) cases with EUA. Interreviewer reliability was poor without EUA and moderate with EUA (0.250 vs. 0.432). For reference cases with agreement, surgeons were able to predict stability or instability using standard imaging in 57 of a possible 88 reviewer choices (64.8%) compared to 82 of 88 choices (93.2%) with the addition of EUA (P < 0.0001). EUA increased agreement among experienced pelvic surgeons regarding the assessment of pelvic ring stability and the need for operative intervention. Further research is necessary to define specific indications for which patients may benefit from EUA.

Effect of compression and tension types of concentrated edge loads on buckling and vibration behavior of interlaminar hybrid fibre metal laminates

The present study deals with the numerical investigation on the buckling and vibration behaviour of interlayer hybrid fibre metal laminates (HFMLs) subjected to different types of concentrated edge compression and tension loads. The term interlayer hybrid represents carbon and glass fibre laminates are sandwiched in between aluminum face sheets. Totally six different hybrid configurations are taken into consideration separately for cross-ply and angle-ply layup schemes. To serve this purpose a finite element code using MATLAB is developed to examine the effects of hybrid configuration, aspect ratio, fiber orientation, type of loading and boundary conditions have been considered to study the buckling responses of HFMLs. The plate is modelled by using 9-noded heterosis elements by considering the effect of shear deformation and rotary inertia. It is revealed from the investigation that the hybrid configurations and loading conditions significantly affect the buckling and vibration characteristics of HFMLs.

Nodule Deformation on Cleaning of PVA Roller Brushes and its Relation to Cross-contamination

This study investigates nodule deformation and contact area during PVA roller-type brush scrubbing to clarify their relationship with cross-contamination. Two high-speed video cameras with collimating LED light sources and an evanescent field on a prism enabled us to observe brush nodule deformation and contact area. Deformation analysis showed that the volume of a roller-type brush changes gradually at the beginning of compression, deforms more when vertically pushed at maximum compression, and then recovers rapidly at the end of compression. The brush contact area changes according to the brush and wafer rotation speed. The contact area can be categorized into three: the front, rear side face in the brush traveling direction, and vertically pushed bottom face on the surface. We analyzed the three types of brush contacts on a 100 mm type wafer and observed that the vertical compression type significantly affected the cross-contamination region.

Image Reconstruction in Surgical Field Using Deep Learning

The field of medical image reconstruction helps to improve image quality by manipulating image features and artefact with Filtered-Back Propagation for X-ray Computer Tomography (CT), Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET). This project focuses on detection of tumour cells using Radiomics application that aims to extract extensive quantitative features from magnetic resonance images. In this paper image discretization models and image interpolation techniques are used to segment the MR images and train them for Image Reconstruction. The image based gray level segmentation is carried out for required feature extraction to improve the clustering analysis for segmentation. Convolution Neural Network is used for image classification and recognition because of its high accuracy. The CNN follows a hierarchical model which works on building a network and finally gives out a fully-connected layer where all the neurons are connected to each other and the output is processed. The JPEG approach is a commonly used type of compression of lossy images that centres on the Discrete Cosine Transform. By splitting images into components of varying frequencies, the DCT functions. Finally the output from the Radiomics application is compared with the existing methodology for determining the Mean Squared Error - Loss Function to ensure the image compression quality.

Nonlinear plane waves in saturated porous media with incompressible constituents

We consider the propagation of nonlinear plane waves in porous media within the framework of the Biot–Coussy biphasic mixture theory. The tortuosity effect is included in the model, and both constituents are assumed incompressible (Yeoh-type elastic skeleton, and saturating fluid). In this case, the linear dispersive waves governed by Biot’s theory are either of compression or shear-wave type, and nonlinear waves can be classified in a similar way. In the special case of a neo-Hookean skeleton, we derive the explicit expressions for the characteristic wave speeds, leading to the hyperbolicity condition. The sound speeds for a Yeoh skeleton are estimated using a perturbation approach. Then we arrive at the evolution equation for the amplitude of acceleration waves. In general, it is governed by a Bernoulli equation. With the present constitutive assumptions, we find that longitudinal jump amplitudes follow a nonlinear evolution, while transverse jump amplitudes evolve in an almost linearly degenerate fashion.

CLINICAL PROFILE AND ETIOLOGICAL EVALUATION OF NON-TRAUMATIC MYELOPATHIES USING MAGNETIC RESONANCE IMAGING

Objective: The present study was conducted with an objective to identify the etiology of non-traumatic myelopathies of both compressive and non-compressive types with the aid of magnetic resonance imaging (MRI).&#x0D; Methods: This retrospective observational cross-sectional study was conducted on 100 patients with a clinical diagnosis of non-traumatic myelopathy belonging to the age group of 15–75 years from August 2018 to July 2020 in the Departments of General Medicine and Radiodiagnosis of MKCG Medical College and Hospital, Berhampur, Odisha. Detailed history, clinical evaluation, laboratory investigations, and findings of MRI spine and brain were compiled. Results were analyzed using descriptive statistics.&#x0D; Results: Among 100 patients of non-traumatic myelopathy, 65 patients presented with compressive myelopathy and 35 patients with non-compressive myelopathy where 56 patients presented with paraparesis and 44 with quadriparesis. Pott’s spine (n=25, 38.46%) and acute transverse myelitis (ATM) (n=24, 68.57%) were the most common etiologies found in compressive and non-compressive groups, respectively.&#x0D; Conclusion: Pott’s Spine, spondylotic myelopathy, and ATM were the most common etiologies of non-traumatic myelopathy. MRI has proven to be the ultimate imaging modality for their etiological evaluation.

“Outcome of thoracolumbar compression fractures following non-operative treatment”

Axial compressive/flexion moderate forces on the anterior spinal elements may cause vertebral compression fractures (VCF), compromising the anterior column of the spine, reducing vertebral body height and leading to characteristic wedge-shaped deformity. 60% to 75% of VCFs are located in the thoracolumbar junction (T12 – L2) due to mechanical forces upon the transition from the relatively fixed thoracic to the relatively mobile lumbar spine. Compression force spinal fractures vary in literature according to the classification system in use, resulting in controversial treatment options. Type A fracture patterns of AO classification are eligible for non-operative treatment provided the posterior complex is intact and there are no neurologic complications. That includes both simple compressive and burst fractures. The aim of this study is to investigate the long-term consequences of non-operative treated compressive thoracolumbar fractures regarding posttraumatic deformity, chronic back pain, and functional status. A retrospective study of 75 patients with stable (compressive and burst type A AO) spinal fractures of the thoracolumbar spine (T12-L2) without neurological symptoms and treated non-operatively was conducted. Post traumatic regional kyphosis, Visual Analogue Scale (VAS) and the Oswestry Disability Index (ODI) were used to evaluate deformity progression, pain and alteration of the quality of life during follow up. There was no significant correlation between magnitude of posttraumatic regional kyphosis, sex, pain score and disability index. Statistically significant correlation between patients age and disability index was revealed.

Residual ultimate strength of ship cracked plates considering fatigue crack propagation under cyclic loads

ABSTRACT The main objective of this paper is to investigate the bearing capacity behaviour of cracked plates considering low-cycle fatigue (LCF) propagation under cyclic loads. The accumulative plastic damage after crack growth is treated as the residual stress and deformation of the plate. In this study, a cracked plate model is proposed to investigate the difference of its residual ultimate strength with preset crack and LCF crack. The present study has analysed the relationship between accumulated lateral deflection and residual stress of cracked plates in different cases. Its effect on the collapse behaviour of the cracked plate is also discussed. The influence factors such as crack length, tensile /compressive cyclic loads, maximum load, minimum load and crack location type are considered in the ultimate strength study of cracked plates. The numerical results clearly reveal the accumulative plastic damage and the bearing capacity behaviour of cracked plates under different cyclic loads.

Dynamic instability of trapezoidal composite plates under non-uniform compression using moving kriging based meshfree method

Meshfree formulation based on the element free Galerkin method (EFGM) in conjunction with moving kriging (MK) shape function is employed to investigate buckling and parametric instability behaviour of shear deformable isotropic and laminated composite trapezoidal plates subjected to different types of non-uniform periodic edge compressive loads. Hamilton’s principle is used to derive the governing equations, which are transformed into the discretized form using the EFG method. The actual pre-buckling stresses are determined from static analysis to evaluate the accurate buckling loads of isotropic and laminated composite trapezoidal plates under non-uniform edge compression. The ordinary differential equations of Mathieu–Hill type are solved using Bolotin’s method to determine regions of dynamic instability. The accuracy of the present formulation is examined first by comparing results with those available in the literature. Thereafter, the influence of geometric parameters, lamination scheme, boundary conditions, static pre-load, and various types of non-uniform edge compression on the critical buckling loads and dynamic instability behaviour of both isotropic and laminated composite trapezoidal plate is investigated. The new results on dynamic stability behaviour of trapezoidal plates under non-uniform edge loads are presented for the first time, which may serve as benchmark results for future research. Furthermore, the time history response and corresponding phase plots are also presented for a better understanding of the dynamic behaviour of the trapezoidal plates.

Metallurgical characterization of laser hardened, mechanically textured 2.5 Ni-Cr-Mo low alloy steel and optimization using RSM

Surface modification of 2.5 Nickel-Chromium-Molybdenum low alloy steel is carried through laser transformation hardening technique under different laser parameters. A 4 kW high power diode laser with a flat top-hat beam of dimension 10x1mm is employed in this study. In this investigation, substrate surface was roughened with abrasive paper to minimize the specular reflection and to increase the absorption rate of laser beam. Microstructure analysis, corrosion analysis, residual stress distribution and the percentage of austenite retained in the hardened region were done. Response Surface Methodology (RSM), a statistical method used for analyzing input variables (Laser power (LP), scan speed (SS) and focal plane distance (FPP)) that influences the hardening process and response optimization, is employed in this study. Characterization analysis of specimen reveals the presence of lath type martensite microstructure in the hardened region with nearly 2.5 times increase in hardness (700 ± 10HV0.5) is achieved with a combination of 1000 W laser power, 240 mm/min scanning speed and 290 mm laser head distance (optimal solution) obtained from the RSM. By performing residual stress analysis, compressive type residual stress at the laser hardened region's cross-section is confirmed. With the optimum laser parameters, a peak residual stress value of −211 MPa is achieved. Retained austenite percentage analysis and corrosion analysis were carried out at the hardened region of RSM's optimal solution. It is observed that 5.76% of retained austenite is obtained in the hardened region using laser hardening. In corrosion, the hardened track obtained using the optimal solution showed a significant improvement in corrosion resistance than that of the base metal due to microstructural homogenization.

Determining design criteria to reduce power and cost in filling high-pressure oxygen cylinders directly from cryogenic air separation plants

Cryogenic air separation plants produce pressurized oxygen gas at 150 bar and 99.8% purity to fill oxygen cylinders directly. It is either produced by compression in oxygen compressor (external compression) or pumping and vaporizing liquid oxygen in main heat exchanger by incoming air (internal compression). Small and medium-scale plants differ in the types of main heat exchanger, compression and expansion devices owing to limitations of market availability. Levelized cost of production of oxygen gas is about 9% less in external compression, though internal compression process is far more fire-safe. Design and operating parameters applicable for internal compression plants supplying oxygen at 40 bar cannot be extended to 150 bar plants due to the differences of fluid properties between super-critical and sub-critical oxygen. UA (surface area times overall heat transfer coefficient) of main heat exchangers, flow and pressure of incoming air are optimized for minimum capital and operating costs. If the chosen flow and pressures deviate substantially from the optimum points, size of main heat exchanger may even increase five-fold. Ideally, 27–29% of total air intake should be compressed between 110 and 100 bar in a medium-scale internal compression plant to keep levelized cost of production at the minimum.

Wave propagation with degenerate electron–positron in magnetically quantised ion beam plasma

In an ion beam plasma system, the effect of magnetically quantised degenerate trapped electron and positron, on small-amplitude ion-acoustic solitary waves are studied with the help of Korteweg–de Vries (KdV) equation. Here the magnetised positive ions and beam ions are considered as non-degenerate. The effect of magnetic quantisation, degenerate temperature, normalised positron concentration, normalised ion beam concentration along with other relevant physical plasma parameters of the origin of astrophysical plasma environment, on solitary wave propagation is studied especially in the nonlinear regime. On the other hand, in the linear regime, the dependency of frequency and wavenumber on the aforementioned plasma parameters are discussed. It is found that both compressive and rarefactive type solitary waves can exist in such a plasma environment. Three different modes of propagation, the fast beam and slow beam modes and the inherent ion-acoustic mode coexist in such plasma systems and the role of different degenerate plasma parameters on these wave modes are also discussed in detail. The normalised positron concentration and velocity, as well as the normalised ion beam concentration along with different degenerate plasma parameters, has an astounding control on the amount of compression and rarefaction, a typical plasma wave mode is supposed to undergo. Within the chosen degenerate and non-degenerate plasma parameters, for a compressive (rarefactive) fast beam mode, the slow mode appears as rarefactive (compressive). For some typical combinations of degenerate parameters, the fast mode can propagate with a hypersonic phase velocity which shows distinctive characteristics with positron density.

Lateral compression type 1 (LC1) pelvic ring injuries: a spectrum of fracture types and treatment algorithms.

Lateral compression type 1 (LC1) fractures are the commonest pelvic ring injury. However, they represent a heterogenous spectrum of injury mechanisms and fracture patterns, resulting in a lack of strong evidence for a universally agreed treatment algorithm. Although consensus exists that LC1 fractures have a preserved posterior ligamentous complex and are vertically stable, controversy persists around defining internal rotational instability. As such, treatment strategies extend from routine non-operative management through to dynamic imaging such as examination under anaesthetic (EUA) or stress radiographs to guide fixation algorithm. Multiple protocols sit between these two, all with slightly different thresholds for advocating surgery or otherwise, exemplifying a broad lack of consensus that is not seen for other, more severe, grades of pelvic ring injury. In the following review we discuss the evolving concepts of pelvic ring instability and management, starting from a historical perspective, through to current trends and controversies in LC1 fracture treatment. Emerging directions for research and emerging pharmacological and surgical treatments/technologies are also considered and expert commentary from 3 leading centres provided. The distinction is made between LC1 fracture arising from high-energy trauma and those following low-energy falls from standing height (so-called fragility fractures of the pelvis-FFP), since these two patient groups have different functional requirements and medical vulnerabilities. Issues pertaining to FFP are considered separately.

Prevalence and severity of neurovascular compression in hemifacial spasm patients.

Hemifacial spasm is typically caused by vascular compression of the proximal intracranial facial nerve. Although the prevalence of neurovascular compression has been investigated in a cohort of patients with classical trigeminal neuralgia, the prevalence and severity of neurovascular compression has not been well characterized in patients with hemifacial spasm. We aimed to investigate whether presence and severity of neurovascular compression are correlated to the symptomatic side in patients with hemifacial spasm. All patients in our study were evaluated by a physician who specializes in the management of cranial nerve disorders. Once hemifacial spasm was diagnosed on physical exam, the patient underwent a dedicated cranial nerve protocol magnetic resonance imaging study on a 3 T scanner. Exams were retrospectively reviewed by a neuroradiologist blinded to the symptomatic side. The presence, severity, vessel type, and location of neurovascular compression along the facial nerve was recorded. Neurovascular compression was graded as contact alone (vessel touching the facial nerve) versus deformity (indentation or deviation of the nerve by the culprit vessel). A total of 330 patients with hemifacial spasm were included. The majority (232) were female while the minority (98) were male. The average age was 55.7 years. Neurovascular compression (arterial) was identified on both the symptomatic (97.88%) and asymptomatic sides (38.79%) frequently. Neurovascular compression from an artery along the susceptible/proximal portion of the nerve was much more common on the symptomatic side (96.36%) than on the asymptomatic side (12.73%), odds ratio = 93.00, P < 0.0001. When we assessed severity of arterial compression, the more severe form of neurovascular compression, deformity, was noted on the symptomatic side (70.3%) much more frequently than on the asymptomatic side (1.82%) (odds ratio = 114.00 P < 0.0001). We conclude that neurovascular compression that results in deformity of the susceptible portion of the facial nerve is highly associated with the symptomatic side in hemifacial spasm.