Diagonal Pattern Research Articles

An Experimental Study of Dynamic Compression Performance of Self-Compacting Concrete.

To investigate the dynamic performance of self-compacting concrete (SCC), the dynamic uniaxial compression tests at eight different loading strain rates were performed on the ordinary concrete and SCC cubic specimens. Based on the tests, the compression failure patterns and stress–strain curves of both kinds of concrete were obtained. The results show that SCC performs more brittle than ordinary concrete by showing the diagonal crack failure pattern of SCC at a high strain rate. Besides, with the increase of loading strain rate, the peak compressive stress of SCC is slightly lower than that of ordinary concrete, but the increase of elastic modulus is slightly higher than that of ordinary concrete. The peak compressive strains of the two kinds of concrete are discrete under the influence of loading strain rate, thus putting forward the relation equation for the loading strain rate and peak compressive stress increase coefficient of the two kinds of concrete. Besides, based on the theory of elastic–plastic damage and considering the dynamic extension of damage, the dynamic constitutive relation with good applicability between ordinary concrete and SCC was established.

Modelling the viscoelastic compaction behavior of 3D stitched carbon fabric with different stitching parameters

The viscoelastic behavior of fabric under compaction is of crucial importance to the preforming process of fabric reinforced composites. Here, a viscoelastic model was originally proposed to characterize the compression and relaxation behavior for the 3D stitched carbon fabric with different stitching parameters. The compaction experiments were conducted to validate the proposed model. The established viscoelastic model agrees well with the experimental results and effectively captures the stress evolution. In the compression stage, the elastic modulus of the spring element is confirmed to play a dominating role in the rapid growth of compressive stress. The reduction of stitching space leads to the enhancement of the fiber volume fraction. Correspondingly, the elastic modulus of the spring element is remarkably enlarged. In the relaxation stage, the decreasing stitching space and the diagonal stitching pattern reduce the viscous stress in the fabric, resulting in the reduction the stress relaxation ratio of the first and second Maxwell elements. The enhanced elastic stress relaxation ratio indicates the weakened relaxation ability. As the restriction effect of the stitching thread primarily acts on the parallel fibers, the delay time of the second Maxwell element is much smaller than the delay time of the first Maxwell element. The viscoelastic model provides a significant insight into the viscoelastic behavior, especially the mechanism and influence of the stitching parameters on the 3D stitched carbon fabric.

Effects of In-Utero Zika Virus Transmission on the Development of Gait in Infant Rhesus Macaques

Abstract Date Presented 03/26/20 Transmission of Zika virus from a mother to an infant results in a spectrum of mild to severe deficits. Using a rhesus macaque model, the impact of Zika on gait development was examined using the Noldus Catwalk XT. Infants exposed to the Zika virus in utero, compared to control animals, used a less mature gait over the first month of life, specifically related to their use of diagonal walking patterns. Primary Author and Speaker: Sabrina Kabakov Additional Authors and Speakers: Sarah Navin, Natalie Dulaney, Kathryn Bach, Karla Ausderau

Effect of mesoscopic magnetomechanical hysteresis on magnetization curves and first-order reversal curve diagrams of magnetoactive elastomers

Magnetoactive elastomers may display magnetic hysteresis, even if they are filled only with magnetically soft particles. In this work we discuss application of the first-order reversal curve (FORC) analysis to identify and study hysteresis of that kind. To obtain theoretical magnetization curves and FORC diagrams for the composites in question, a simple model comprising two magnetically soft particles embedded in an elastic environment is proposed. Elucidation of the features present in FORC diagrams is conducted using computer simulation. Despite the simplicity of the model, it allows one to explain the origin of diagonal ridge patterns, which turn up in the FORC diagrams of elastomer composites with magnetically soft filler, and to quantify the experimental results. As the ridge pattern of the diagrams is inherently exclusive to such types of materials, it could be useful for their diagnostics.

External surface cracked offshore steel pipes reinforced with composite repair system subjected to cyclic bending: An experimental investigation

In this paper, we experimentally studied the external surface crack growth in steel pipes reinforced with Composite System Repaired (CRS). CRS reinforced surface cracked API 5L X65 pipes were tested, containing three initial notch sizes and four reinforcement schemes. During the tests, the crack growth results, as well as the strain on the external mid-bottom composite laminate around the cracked area, and the vertical deflection of the specimens were recorded. The results showed that within the surface crack growth stage, the composite laminates were adequately bonded on the steel substrate, which significantly decreased the crack growth rate and prolonged the residual fatigue life. In addition, CRS reinforcement has increased the stiffness of the surface cracked pipes. Through the analysis on applying different reinforcement schemes, we indicated that increasing the amount of composite layers evidently facilitated the reinforcement effectiveness, while increasing the bond length did not; and the inversely diagonal wrapping pattern performance less effective.

Effect of Diagonal Pattern Training on Trunk Function, Balance, and Gait in Stroke Patients

Introduction: Trunk control disability commonly occurs after stroke. This study investigated the effect of diagonal pattern training in the sitting position to improve trunk control ability and gait performance. Method: 46 stroke patients were enrolled in this study. We used single plane training and diagonal pattern training. Additionally, the subjects were randomly assigned to the experiment group (diagonal pattern training) and the control group (single plane training). Diagonal pattern training was modified with proprioceptive neuromuscular facilitation technique’s chopping and lifting pattern to create 10 movements. Results: the trunk impairment scale score, Berg balance scale score, 10 m walking test result, and gait significantly increased in the experiment group compared to the control group. Conclusions: diagonal pattern training can be regarded as a promising method to improve postural control and increase balance and gait in stroke patients

Effects of Diagonal Pattern Self-Exercise on Trunk Control, Balance, and Gait Ability in Chronic Stroke Patients

Background: Weakness of the trunk muscles decreases the trunk control ability of stroke patients, which is significantly related to balance and gait. Objectives: To compare the impact of diagonal pattern self-exercise on an unstable surface and a stable surface for trunk rehabilitation on trunk control, balance, and gait ability in stroke patients. Design: Nonequivalent control group design. Methods: Twenty four participants were randomized into the experimental group (diagonal pattern self-exercise while sitting on an unstable surface, n=12) and the control group (diagonal pattern self-exercise while sitting on a stable surface, n=12). All interventions were conducted for 30 minutes, three times a week for four weeks, and the trunk impairment scale (TIS), berg balance scale (BBS), functional gait assessment (FGA), and G-walk were measured. Results: All groups indicated significant increases in all variables (TIS, BBS, FGA, cadence, speed, stride length) after four weeks. The TIS, BBS, FGA, cadence, gait speed, and stride length group-by-time were significantly different between the two groups. Conclusion: We found that, in stroke patients, diagonal pattern self-exercise on an unstable surface is a more effective method for improving trunk control, balance, and gait ability than diagonal pattern self-exercise on a stable surface.

Analysis of Scapular Muscle EMG Activity During Elastic Resistance Oscillation Exercises From the Perspective of Different Arm Positions.

Little is known about the optimal exercise intensity and the effects of arm position on elastic resistance exercise. The purpose of this study was to investigate scapular muscle activity in different arm positions utilized during standing elastic resistance exercise. Lower trapezius (LT), serratus anterior (SA), and infraspinatus (IS) muscle activity will vary across arm positions above shoulder level. Also, oscillation resistance exercise will result in increased muscle activity compared with isometric contraction. Controlled laboratory study. Level 4. A total of 19 uninjured male collegiate baseball players volunteered to participate in this study. The electromyography (EMG) activity of the LT, upper trapezius (UT), middle deltoid (MD), SA, and IS muscles was determined using surface EMG in 3 arm positions: diagonal pattern 1 (D1), 120° of shoulder abduction (120), and 90° shoulder abduction with external rotation and elbow flexion (90/90) during both isometric contraction and oscillation resistance exercise. No difference in EMG activity of the LT muscle was found between the 120 and 90/90 position. However, the 120 position increased UT and MD muscle activity significantly more than those of the 90/90 position. The D1 arm position significantly increased SA muscle activity more than the 120 and 90/90 positions while the LT muscle activity was nearly silent. The standing 90/90 position effectively generated both LT and IS muscle EMG activity while minimizing both UT and MD muscle activity. The use of oscillation movements under elastic loading can create high muscle activation in the LT muscle without an adverse effect of the humeral head position and scapular rotation.

Active controllable dual broadband terahertz absorber based on hybrid metamaterials with vanadium dioxide.

In this paper, we present an active controllable terahertz absorber with dual broadband characteristics, comprised by two diagonal identical patterns of vanadium dioxide in the top layer of the classical three-layer structure of metamaterial perfect absorbers. Simulation results show that two bandwidths of 80% absorption are 0.88 THz and 0.77 THz from 0.56 to 1.44 THz and 2.88 to 3.65 THz, respectively. By using thermal control to change the conductivity of the vanadium dioxide, absorptance can be continuously adjusted from 20% to 90%. The impedance matching theory is introduced to analyze and elucidate the physical mechanism of the perfect absorption. Field analyses are further investigated to get more insight into the physical origin of the dual broadband absorption. In addition, incident polarization insensitivity and wide-angle absorption are also demonstrated. The proposed absorber promises diverse applications in terahertz regime, such as imaging, modulating, sensing and cloaking.

The Communication Patterns of Leadership in Improving Work Ethic of Lecturer and Staff in Asahan University (Islamic Communication Perspective)

This study aims to analyze the communication patterns of leadership in improving work ethic of lecturer and staff, the implementation of leadership communication patterns to the principles of Islamic communication and to identify various barriers occurring at Asahan University. The research method used in this study is a descriptive method through a qualitative approach, by observing the state of the subject or object of research at the time of the study based on the events that are seen. The results of research carried out show the communication patterns of leadership in improving work ethic of lecturer and staff through vertical patterns, horizontal patterns and diagonal patterns. Whereas the implementation of Islamic communication Principles at Asahan University are Qaulan Sadīdā, Maīysūrā Qaulan, Ma'rūfā Qaulan, Layyinā Qaulan, Karīma Qaulan and Balighā Qaulan. Barriers in improving work ethic of lecturer and staff include mental attitude, primordial relation, welfare levels and improper placement of work fields.

Diagonal Symmetric Pattern-Based Illumination Invariant Measure for Severe Illumination Variation Face Recognition

The center symmetric pattern (CSP) was widely used in the local binary pattern based facial feature, whereas never used to develop the illumination invariant measure in the literature. This paper proposes a novel diagonal symmetric pattern (DSP) to develop the illumination invariant measure for severe illumination variation face recognition. Firstly, the subtraction of two diagonal symmetric pixels is defined as the DSP unit in the face local region, which may be positive or negative. The DSP model is obtained by combining the positive and negative DSP units in the even $\times $ even block region. Then, the DSP model can be used to generate several DSP images based on the $2\times 2$ block or the $4\times 4$ block by controlling the proportions of positive and negative DSP units, which results in the DSP2 image or the DSP4 image. The single DSP2 or DSP4 image with the arctangent function can develop the DSP2-face or the DSP4-face. Multi DSP2 or DSP4 images employ the extended sparse representation classification (ESRC) as the classifier that can form the DSP2 images based classification (DSP2C) or the DSP4 images based classification (DSP4C). Further, the DSP model is integrated with the pre-trained deep learning (PDL) model to construct the DSP-PDL model. Finally, the experimental results on the Extended Yale B, CMU PIE, AR, and VGGFace2 face databases indicate that the proposed methods are efficient to tackle severe illumination variations.

An Efficient Retrieval System for Biomedical Images Based on Radial Associated Laguerre Moments

The ability of any retrieval system to extract features by using its feature descriptor is the primary criterion to measure its efficiency. In this paper a novel technique for feature extraction of biomedical images is presented. The mooted system uses the Radial Associated Laguerre Moments (RALMs) as a feature descriptor to obtain features from two types of medical images: computer tomography (CT) and magnetic resonance images (MRI). RALMs represent one sort of discrete orthogonal moments. RALMs extract the features from images using orthogonal moments to retrieve images from a database. Our approach is extensively assessed with noise-free and noisy images from three different benchmark databases: Emphysema-CT, NEMA CT, and NEMA MRI. The first two databases are used for CT image retrieval, while the third is for MR image retrieval. The proposed approach was tested against the state-of-the art local feature descriptors: Local Binary Pattern (LBP), and local diagonal extrema pattern (LDEP). It was also evaluated against orthogonal Fourier-Mellin moments (OFMMs) as a global descriptor. The comparison shows a significant improvement in favor of the proposed approach in terms of three different performance metrics: ARP, ARR, and F_score. The proposed approach was also compared against the convolutional neural network (CNN) as a deep learning based method over the NEMA-MRI dataset. The RALMs based approach showed a significant improvement when compared against two state-of-the-art medical image retrieval approaches: Histogram of Compressed Scattering Coefficients (HCSCs) and a local bit-plane decoding-based AlexNet descriptor (LBpDAD), the study has done over the TCIA-CT dataset. The proposed approach was also tested with big well-known dataset from the international skin imaging collaboration (ISIC) 2018.

Features of schemes of the explosive loosening, with big slowdowns

The task of the article is to determine the influence of the blasting charge power on the intensity of preliminary destruction of the blasting block mass at long delays. Increase of the destruction radius r from the blasthole charges action at diagonal pattern of hole-by-hole blasting, caused by change of explosive charge energy or rock properties, decreases the number of stress waves passing in the vicinity of specific blast holes. They cause the rock disturbance in the pre-destruction area due to increasing of explosion energy absorption in the area of blasthole charges destruction. However, at the same time, the value of the predestruction factor increases. The calculation shows that 3.5 times increase of the blasthole charge destruction radius, reduces in 1.36 times the number of stress waves passing through the vicinity of specific blasthole charges, but the factor of pre-destruction intensity increases tenfold and the total impact of these factors – by a factor of 8.

Use of bamboo mat as a potential soil reinforcement material – An experimental study

This paper discusses the results of laboratory model tests on cohesionless soils reinforced with different weaving patterns of bamboo mat. Bamboo mat with diagonal weaving and rectangular weaving patterns was used for the present study. The optimum placement depth and with of reinforcement layer were fixed based on the previous studies carried in the bamboo mat reinforced soil. The amount of material used for the production of two different types of mat kept almost equal and compared their performance as a soil reinforcement material. An improvement factor of 2.47 was obtained for the diagonal pattern for a settlement ratio of 30% whereas, in the rectangular pattern, it was 2.17. The test results indicate that the inclusion of the bamboo mat improves the bearing capacity of soil and the weaving patterns have some influence on the performance of reinforced soil bed. The heave formations on the soil bed during the test for both unreinforced and reinforced conditions were also reported here.

Microstructure pattern extraction based image retrieval

Computer vision techniques enhanced by the advent of deep learning has become a quintessential part of our day-to-day life. The application of such computer vision techniques in image retrieval can be termed as query based image retrieval process. Conventional methods have limitations such as increased dimensionality, reduced accuracy, high time consumption, and dependence on indexing for retrieval. In order to overcome these limitations, this research work aims to develop a new image retrieval system by developing an image preprocessing mechanism via target prediction technique, which isolates object from the background. Further, a Micro-structure based Pattern Extraction (MPE) technique is implemented to extract the patterns from the preprocessed image, where the diagonal patterns are generated for increasing the accuracy of the retrieval process. Consequently, the Convolutional Neural Network (CNN) is utilized to reduce the dimensionality of the features, and the similarity learning approach is utilized to map the selected features with trained features based on the distance metric. The performance of the proposed system is evaluated by using various measures. Thereby, the efficiency of the proposed technique is ascertained by comparing it with the existing techniques.

Spatiotemporal quantification of gait in common marmosets

BackgroundObjective gait evaluation in humans is used as a predictive disability outcome measure as well as an indicator for intervention effectiveness. Parallel methods of gait analysis in nonhuman primate models are essential for clinical translation. The goal of this study was to first assess whether marmosets’ gait data could be reliably collected in a Noldus CatWalk XT10.6 and second, establish a testing protocol to assess gait and the intraindividual variability during repeated testing. New methodThe CatWalk, originally developed for rodents, was modified and used to assess gait in eight adult common marmoset monkeys across multiple days and trials. Data was first analyzed to identify valid runs. Repeated measures ANOVA was completed for the following gait measures: mean base of support, average stride length, average swing time, and average stance time. ResultsRaters had a high level of concurrence of usable data across all trials with successful trials including four consecutive hindfoot footfalls, during a continuous, uninterrupted segment of walking. A significant main effect of time (p < 0.000) but not rater (p = 0.98) was present with significant interactions for time by subject (p < 0.000), but not rater per subject (p = 0.538), time (p = 0.186), or three-way interaction (p = 0.297). Comparison with existing method(s)Gait has been assessed using force-plate and video data. The CatWalk allowed reproducible, automated and translational locomotor data to be collected at multiple time points with detailed analyses that identified a diagonal gait pattern. ConclusionsThe CatWalk system, similar to those used in humans, can be effectively used to quantify spatiotemporal characteristics of gait in the common marmoset.

Proprioceptive Neuromuscular Facilitation in Shoulder Rehabilitation of Women Submitted to Surgical Treatment for Breast Cancer

Background: Survivors of breast cancer show loss of function of the homolateral limb after treatment, which involves reduction of the functional range of the shoulder, as well as impairment of the involved musculature. The aim of this study was to evaluate the electromyographic activity and the strength of the muscles in the shoulder complex of women who have been subjected to mastectomies, after an intervention using Proprioceptive Neuromuscular Facilitation (PNF) exercises. Methods: This study included 18 women submitted to modified radical mastectomy, with a mean age of 52.55±8.42 years. The training exercises with Proprioceptive Neuromuscular Facilitation occurred two times per week for eight weeks, the standards used were the diagonal pattern, with flexion-abductionexternal rotation and extension-adduction-internal rotation. For the evaluation of the electromyographic activity, electrodes were positioned in the muscles of the upper trapezius and deltoid (anterior, middle and posterior muscle fibers). Results: The electromyographic analysis demonstrated a 32% elevation in the Standard Envelope (SE) of the middle fiber of the deltoid muscle (DM), 15% in the SE of the upper trapezius (UT), an increase in muscle strength of 15% in the DM and 15% in the UT, also raising the strength of these muscles by 36%. Conclusion: The results of the proposed intervention allow us to conclude that, for the sample evaluated, there was an increase in the recruitment of motor units and of muscle strength of the shoulder affected by the surgery to treat breast cancer.

Collisional mechanics of the diagonal gaits of horses over a range of speeds.

One of the goals of the neuromotor control system is to minimize the cost of locomotion by reducing mechanical energy losses. Collisional mechanics, which studies the redirection of the downwards motion of the center of mass (COM) by ground reaction forces (GRF) generated by the limbs, represents an important source of energy loss. The primary objective of this study was to compare collisional mechanics and the associated mechanical energy losses in horses performing diagonally-synchronized gaits over a range of speeds. It is to be expected that collisional energy losses will be high when the COM velocity vector is closely aligned with the GRF vector. This condition is achieved in piaffe, an artificial gait performed in dressage competitions that has a diagonal limb coordination pattern similar to trot but performed with little or no forward velocity. Therefore, we hypothesized that collisional energy losses would be higher in piaffe than in trot. Synchronized kinematic and GRF data were collected from three highly-trained horses performing piaffe, passage and trot at a range of speeds. Derived variables were vertical excursion and velocity of the trunk COM, fore and hind limb compression expressed as percentage reduction of standing limb lengths, range of limb pro-retraction, GRF vector magnitude and vector angle, collision angle (Φ), and mechanical cost of motion (CoMotmech). Linear regression was used to investigate the relationship between CoMotmech and speed for each gait. Partial correlation was used to seek relationships between COM excursion and limb mechanics for each gait. Piaffe, passage and trot were clearly separated on the basis of speed. In all gaits the trunk was high at contact and lift off and descended to its lowest point in midstance following the pattern typical of spring mass mechanics. Mechanical cost was significantly (p < .05) and inversely related to speed in trot and piaffe with the value increasing steeply as speed approached zero due to a near vertical orientation of both the COM velocity vector and the GRF vector. Limb compression during stance was significantly (p < .05) linked to trunk COM vertical excursion in all gaits, with a stronger relationship in the forelimb. Hindlimb compression was, however, large in piaffe where the force magnitudes are notably smaller. The study illustrates the potential value of studying artificial gaits to provide data encompassing the entire range of locomotor capabilities. The results supported the experimental hypothesis by showing a threefold increase in collisional energy losses in piaffe compared with trot. In all gaits, dissociation between diagonal limb contacts and lift offs was thought to be an important strategy in reducing in collisional losses. Piaffe, the most costly gait, has similar characteristics to hopping on the spot. It appears that greater hindlimb compliance and a lower step frequency are important energy conservation strategies for piaffe.

Numerical study on the shear failure behavior of RC beams subjected to drying

To improve the aging management of nuclear power plants (NPPs) and to extend the plant life by allowing long-term operation, a numerical model, which can evaluate the changes in the structural performance due to drying (i.e., drying shrinkage, resultant shrinkage-induced cracks, and property changes due to desiccation), is proposed. For the numerical model, a 3D rigid-body-spring-network model (RBSM) combined with a truss network model was adopted, and moisture transport, subsequent drying shrinkage, and changes in physical properties were implemented. In this study, four beams were analyzed, with two beam sizes without stirrups being subjected and not subjected to desiccation, respectively. All beams considered for the numerical investigation are shear critical. The numerical model produced reasonable results for the following points: 1) a strain distribution of rebar after drying, 2) changes in diagonal cracking patterns, and 3) trends in the load–deformation relationship, especially with the diagonal-cracking strength showing agreement with the experimental result. However, the ultimate shear strengths did not correspond with the experimental results. Based on previous research, this discrepancy can be improved by considering the “dowel effect” at the shear failure.

A Novel Monitoring Approach for Train Tracking and Incursion Detection in Underground Structures Based on Ultra-Weak FBG Sensing Array.

Tracking operating trains and identifying illegal intruders are two important and critical issues in subway safety management. One challenge is to find a reliable methodology that would enable these two needs to be addressed with high sensitivity and spatial resolution over a long-distance range. This paper proposes a novel monitoring approach based on distributed vibration, which is suitable for both train tracking and incursion detection. For an actual subway system, ultra-weak fiber Bragg grating (FBG) sensing technology was applied to collect the distributed vibration responses from moving trains and intruders. The monitoring data from the subway operation stage were directly utilized to evaluate the feasibility of the proposed method for tracking trains. Moreover, a field simulation experiment was performed to validate the possibility of detecting human intrusion. The results showed that the diagonal signal pattern in the distributed vibration response can be used to reveal the location and speed of the moving loads (e.g., train and intruders). Other train parameters, such as length and the number of compartments, can also be obtained from the vibration responses through cross-correlation and envelope processing. Experimental results in the time and frequency domains within the selected intrusion range indicated that the proposed method can distinguish designed intrusion cases in terms of strength and mode.