Desired Pattern Research Articles

Peridynamic modeling of early-age cracking behaviour in continuously reinforced concrete pavement

ABSTRACT Continuously reinforced concrete pavement (CRCP) is frequently used for heavy traffic. In CRCP, early-age cracking can be caused by environmental loading freely and randomly, but only certain crack patterns can affect its long-term performance and induce distress such as punchouts. In this work, we introduce a peridynamic model that includes the time dependency of the environmental loading and material properties to investigate the early-age behaviour of CRCP and predict its cracking. The simulation results match those from field observations in terms of crack patterns, average transverse crack spacing, and crack width. We conduct parametric analyses and find the effects changing environmental conditions and design parameters have on crack patterns. An investigation of active crack control demonstrates that the model can be used to determine optimal pre-notch spacing, for specific environmental conditions, that leads to desirable crack patterns.

PH-responsive wormlike micelles for acid stimulation in carbonate reservoirs

Stimulation is a technique used for damage removal and to increase the reservoir permeability. For carbonate reservoirs, this process is benefited by the reaction of the fluid with the matrix. However, generally the process is restricted to occurs only in regions of high permeability. In order, to solve this problem, acid diverting fluids based on viscoelastic surfactants (VES) are commonly used. The divergence in this case is caused by viscosity changes of VES triggered by chemical stimulus, such as pH variations. Formulations based in VES can be prepared to respond to [H+] and [Ca2+], tuning the rheological properties of the surfactant solution and producing polymer-like aggregates named as wormlike micelles. When increasing the viscosity due to these responses, the divergence phenomenon occurs, and the fluid changes its direction heading regions of low permeability. As consequence, desirable corrosion patterns known as wormholes are formed. A laboratory scale investigation might be required to properly adopt such special fluids, so a protocol for neutralization of acid fluids was stablished and tested by using two commercial fluids. The rheology of the fluids upon different neutralizing degrees were studied and simulates the rheological behavior when they are flowing and reacting into the carbonate matrix. Additionally, several generations of a new responsive diverting fluid based on VES, named as QuoVadis (from the Latin “Whither goest thou”), were developed and their rheological characteristics, in linear and non-linear regimes, were obtained in different H+ and Ca2+ concentrations. Such formulations are subject of a patent application filed in the National Institute of Industrial Property of Brazil (INPI patent application number BR102020006183-6). The QuoVadis samples were submitted to the neutralizing protocol and their rheological behaviors were considered to evaluate their performance in several core-flooding experiments. The statistical results demonstrate that the desirable dominant wormhole is formed, which was visualized in one of the outcrops through NMR images.

Functional control of oscillator networks

Oscillatory activity is ubiquitous in natural and engineered network systems. The interaction scheme underlying interdependent oscillatory components governs the emergence of network-wide patterns of synchrony that regulate and enable complex functions. Yet, understanding, and ultimately harnessing, the structure-function relationship in oscillator networks remains an outstanding challenge of modern science. Here, we address this challenge by presenting a principled method to prescribe exact and robust functional configurations from local network interactions through optimal tuning of the oscillators’ parameters. To quantify the behavioral synchrony between coupled oscillators, we introduce the notion of functional pattern, which encodes the pairwise relationships between the oscillators’ phases. Our procedure is computationally efficient and provably correct, accounts for constrained interaction types, and allows to concurrently assign multiple desired functional patterns. Further, we derive algebraic and graph-theoretic conditions to guarantee the feasibility and stability of target functional patterns. These conditions provide an interpretable mapping between the structural constraints and their functional implications in oscillator networks. As a proof of concept, we apply the proposed method to replicate empirically recorded functional relationships from cortical oscillations in a human brain, and to redistribute the active power flow in different models of electrical grids.

Perceived occupational engagement and gaps among community-dwelling older adults in Malaysia

Introduction: Engagement in occupations is an essential aspect of daily life among older people. Changes in age are often associated with changes in the pattern of engagement in occupations. However, the relationship between the actual and desired activities pattern of occupational engagement remains unclear among community-dwelling older adults in Malaysia. This study aimed to determine occupational engagement for each activity and occupational gaps related to domains among the older adults. Method A cross-sectional study was conducted among 335 community-dwelling older people, using the Malay version of the Occupational Gaps Questionnaire (OGQ-M). Findings: The findings indicate that there are significant differences in occupational engagement across domains: leisure ( p < 0.001), social ( p = 0.04) and total occupational domains ( p < 0.001). There is a significant difference between actual and desired performed activities in doing laundry ( p = 0.031), outdoor activities ( p < 0.001), listening to the radio and watching television/video ( p = 0.003), helping and supporting others ( p = 0.019), travelling for pleasure ( p < 0.001) and performing voluntary work ( p = 0.025). Conclusion: In conclusion, OGQ is a useful tool in screening the occupational gaps among community-dwelling older adults. Age, health and continuity of roles and responsibility as caretakers of the family are several factors that lead to higher occupational gaps among the older people in the community. With the emergence of occupational engagement and gaps, advancements in health care delivery are necessary for retirement planning among community-dwelling older adults in enhancing active participation towards better retirement life.

Sleep Patterns and School Readiness of Pre-Kindergarteners from Racially and Ethnically Diverse, Low-Income Backgrounds

To explore patterns in parent-reported child sleep health and to investigate connections between such patterns and school readiness for newly enrolled prekindergarten (PreK) attendees from racially and ethnically diverse, low-income backgrounds. In a secondary analysis from a larger multiple-cohort longitudinal observational study of prekindergartners in low-income families, parental reports of sleep health for 351 children (mean age, 52.8±3.5months) during the first month of PreK were analyzed. Children also had completed direct assessments measuring language, literacy, mathematics, and executive functioning, and teachers rated children's social-emotional-behavioral competencies and approaches to learning at PreK entry. We performed latent class analyses to identify patterns in sleep health and used regression models to examine concurrent associations between child sleep health patterns and school readiness competencies across 6 domains: language, literacy, mathematics, executive functioning, social-emotional-behavioral, and approaches to learning. Two classes emerged reflecting more and less desirable patterns of sleep health. Children classified in the earlier, longer, consistent sleep health class (87% of children) experienced earlier bedtimes, longer night-time sleep durations, more consistent sleep routines, less caffeine consumption ≤3hours before bedtime, and scored higher on a direct assessment of expressive vocabulary and on teacher-reported measures of social-emotional-behavioral competencies and learning approaches than their peers in the later, shorter, inconsistent sleep health class (13% of children). Consistent sleep routines and more optimal sleep health may serve as a protective mechanism for the language development, social-emotional-behavioral regulation, and approaches to learning of PreK from racially and ethnically diverse, low-income backgrounds. Clinician-parent discussions regarding optimal sleep health may provide key opportunities for targeted education that promotes school readiness skill development.

Using Airborne LiDAR to Monitor Spatial Patterns in South Central Oregon Dry Mixed-Conifer Forest

Abstract A common forest restoration goal is to achieve a spatial distribution of trees consistent with historical forest structure, which can be characterized by the distribution of individuals, clumps, and openings (ICO). With the stated goal of restoring historical spatial patterns comes a need for effectiveness monitoring at appropriate spatial scales. Airborne light detection and ranging (LiDAR) can be used to identify individual tree locations and collect data at landscape scales, offering a method of analyzing tree spatial distributions over the scales at which forest restoration is conducted. In this study, we investigated whether tree locations identified by airborne LiDAR data can be used with existing spatial analysis methods to quantify ICO distributions for use in restoration effectiveness monitoring. Results showed fewer large clumps and large openings, and more small clumps and small openings relative to historical spatial patterns, suggesting that the methods investigated in this study can be used to monitor whether restoration efforts are successful at achieving desired tree spatial patterns. Study Implications: Achieving a desired spatial pattern is often a goal of forest restoration. Monitoring for spatial pattern, however, can be complex and time-consuming in the field. LiDAR technology offers the ability to analyze spatial pattern at landscape scales. Preexisting methods for evaluation of the distribution of individuals, clumps, and openings were used in this study along with LiDAR individual tree detection methodology to assess whether a forest restoration project implemented in a Southern Oregon landscape achieved desired spatial patterns.

Proactive Conformal Waveguide Slot Array Antenna to Synthesize Cosecant Squared Pattern Based on 3-D Printing Manufacturing Process

It is difficult for a standing-wave waveguide slot array antenna to generate a complex beam shape in H-plane, such as the cosecant squared pattern. The reason is that a conventional standing-wave waveguide slot array antenna cannot flexibly and independently adjust the amplitude and phase of radiating elements. In this article, a proactive conformal waveguide slot array antenna is designed with the cosecant squared pattern in its H-plane. It is able to control the element phase by proactively curving the array shape. That means the antenna shape is employed as a new parameter to break the limitation in the phase control. Based on this, the proactive conformal waveguide slot array antenna can modulate the element amplitude and phase independently to form the desired complex far-field pattern. The commercial selective laser melting (SLM) technology is applied to print the curved antenna after carefully considering the printing direction and slot shape. A 35 GHz prototype antenna is fabricated and measured. Good performance can be observed in the measured results.

Efficient and Accurate Synthesis for Array Pattern Shaping.

Array pattern synthesis (APS) aims to create the desired array pattern as closely as possible to the prescribed mask template by varying the element excitations of the array. Herein, an efficient approach for the APS to control the sidelobe level is proposed. After designing the mask template to meet the prescribed sidelobe requirements and the waveform pattern, a set of element excitations is calculated through the Fourier transform performed on the projection the waveform pattern onto the mask template. Then, a desired array pattern can be synthesized from this updated set of excitation coefficients. The proposed APS approach directly presents a mathematical formulation of the exact set of excitations without any iterative optimization process. The proposed method is particularly suited for many array elements in linear antenna array. Thus, the proposed APS achieves substantial improvements in terms of computation complexity, performance, and ease of implementation in the algorithm when compared with conventional methods. Several simulation results are provided to verify the efficacy and effectiveness of the proposed method.

Fabrication and performance evaluation of full-inkjet-printed dielectric-barrier-discharge plasma actuators

Toward the establishment of the manufacturing process of a novel active airflow control device using atmospheric pressure discharge referred as to dielectric-barrier-discharge (DBD) plasma actuator, a full-inkjet-printed DBD plasma actuator is fabricated for the first time. Printed electronics are superior in view of low-cost process and large area printing compared to photolithography process. Electrodes and dielectric layers are formed by silver nanoparticles-based inks and ultraviolet-curable inks, respectively. Surface observation using a digital microscope reveals the significant improvement of the printing accuracy with an inkjet experimental equipment used in this study compared to that fabricated with a commercially supplied inkjet printer. Electrical and mechanical characteristics of the full-inkjet-printed DBD plasma actuator are evaluated through measurements of discharge current, light emission from surface DBD, and induced flow visualization with particle image velocimetry technique. The results obtained in this study indicate that the fabricated actuator works properly as the active airflow control device using surface DBDs. The full-inkjet-printing process allows the fabrication of a flexible DBD plasma actuator that has an arbitrary electrode shape to induce desirable flow patterns and can be installed on a complex curved surface.

Pattern Reconstruction for Antennas with Characteristic Mode Analysis and Surrogate Model

A novel approach is applied to obtain a desired pattern for a perfect electric plate with two ports. The location of ports is decided with the help of characteristic mode analysis. Two capacitive coupling elements are chosen to be used as excitation. The magnitude and phase of each excitation are obtained by the Bayesian inference method. In order to avoid complexity of computational design, a surrogate model, which is based on polynomial chaos expansion, is built. The surrogate model is ensured to mimic the computational model over 90%. Then, the desired pattern is compared with the synthesized one, and it is seen that the two patterns fit very well to each other and the correlation between the two patterns is above 0.9.

Relationship desire and life satisfaction among never-married and divorced men and women

Very little attention has been paid to relationship desire and its consequences. The existing literature on relationship desire and life satisfaction among singles provides mixed findings from a limited range of datasets. To address this significant gap in the literature, this study uses the Panel Analysis of Intimate Relationships and Family Dynamics (Pairfam) dataset to investigate patterns of relationship desire and life satisfaction among divorced and never-married adults. The results of cross-sectional analyses showed that never-married men and women, as well as divorced women, depicted a negative correlation between relationship desire and life satisfaction. In addition, the perceived benefits of singlehood are a stronger correlate of relationship desire than life satisfaction, thus reducing the likelihood of a halo effect argument. The implications of the negative association of relationship desire with life satisfaction are discussed.

Potential of graded doses of neem (Azadirachta indica) seed oil on ruminal fermentation characteristics, degradability, and methane formation in vitro

Abstract Neem (Azadirachta indica) belongs to Meliaceae family, represented mainly by trees, and widely cultivated and adapted in many tropical regions. The objective of this study was to evaluate the effect of increasing doses of neem seed oil (NSO) on ruminal methane (CH4) formation, diet degradability, and fermentation characteristics after 24 h of in vitro incubation. Treatments were randomly designed to four doses of NSO supplemented to the basal diet (0, 20, 40, or 60 ml/kg DM). Increasing NSO dose resulted in a quadratic decrease (P < 0.05) in net gas (expressed as ml/g DM and ml/g TDOM) and CH4 (expressed as ml/g TDNDF) production, while CH4 (expressed as ml/g TDOM), acetate and propionate proportions decreased linearly confirming a dose-related effect. A quadratic increase in TDOM and linear increase (P = 0.023) in DNDF, NH3-N concentrations, and total protozoal counts were observed. However, a linear increase (P = 0.009) was found in the ruminal butyrate proportion and partitioning factor as dietary NSO supplementation increased. In conclusion, dietary NSO supplementation mediated some desirable fermentation patterns, reducing ruminal NH3-N concentration and CH4 production with some adverse effects on fiber degradability. However, practical research under long-term conditions is required for further investigation.

Design of Conformal Array of Rectangular Waveguide-Fed Metasurfaces

We present a systematic design method for a cylindrical conformal array of rectangular waveguide-fed metasurfaces. The conformal metasurface consists of multiple curved rectangular waveguides loaded with metamaterial elements—electrically small apertures—inserted into the upper conducting walls of the waveguides. Each element radiates energy into free space to contribute to an overall radiation pattern. Thus, the geometry or electrical configuration of each of the elements needs to be tailored to generate a desired pattern. Generally, due to difficulties in modeling the effect of curvature, the design of conformal metasurface arrays has relied on full-wave simulations or experiments. In this study, we propose a design method utilizing the semianalytical model of a planar metasurface accounting for metamaterial elements’ locations and orientations over a curved surface. Although approximate, we demonstrate that the alteration along with the framework of dipolar modeling of planar elements can be used for the analysis of conformal arrays with small curvature. We then design a conformal array metasurface using the method combined with the covariance matrix adaptation evolution strategy (CMA-ES) optimizer. Through numerical simulations, we confirm the validity of the proposed design method. Applications include the design of metasurfaces for radar, communications, and imaging systems for mobile platforms.

Ameliorative Effects of Grewia asiatica Leaves in Animal Models of Pain and Inflammation

ABSTRACT The analgesic and anti-inflammatory effects of Grewia asiatica leaf solvent extracts were evaluated in animal models. The methanol and ethyl acetate fractions prepared from the leaves showed potent analgesic and anti-inflammatory effects at 400 mg kg−1 and 100 mg kg−1, respectively. Myricetin was isolated from the ethyl acetate fraction by column chromatography. Molecular docking studies with myricetin showed a desirable binding pattern of myricetin with both COX-1 and COX-2, supporting its anti-inflammatory potential. Results showed that the anti-inflammatory and analgesic effect of methanol extract of G. asiatica leaves may be due to COX-1 and COX-2 inhibition by myricetin.

Reversible and Irreversible Laser Interference Patterning of MOF Thin Films

Laser interference patterning on top of a thin film and inside a crystal is a powerful tool today to create the desired patterns for optical data processing. Here, we demonstrate reversible and irreversible laser interference patterning on a metal-organic framework (MOF) thin film through the water desorption and thermal decomposition processes, respectively. The irreversible interference pattern with a period of the strips of up to 5 µm has been realized, and its morphology has been characterized using confocal Raman and reflection spectroscopy as well as atomic force microscopy. We revealed that reducing the distance between the interference maxima from 10.5 to a record of 5 µm for MOFs yields a 10-fold increase in the surface roughness of the irreversible pattern; on the other hand, the reversible laser pattern provides a completely non-destructive effect of variable optical contrast. The experimental results obtained open up prospects for the use of MOF crystals as photosensitive materials in the template drawing of the desired patterns for different application scopes.

A mixed-modeling framework for whole-brain dynamic network analysis.

The emerging area of dynamic brain network analysis has gained considerable attention in recent years. However, development of multivariate statistical frameworks that allow for examining the associations between phenotypic traits and dynamic patterns of system-level properties of the brain, and drawing statistical inference about such associations, has largely lagged behind. To address this need we developed a mixed-modeling framework that allows for assessing the relationship between any desired phenotype and dynamic patterns of whole-brain connectivity and topology. This novel framework also allows for simulating dynamic brain networks with respect to desired covariates. Unlike current tools, which largely use data-driven methods, our model-based method enables aligning neuroscientific hypotheses with the analytic approach. We demonstrate the utility of this model in identifying the relationship between fluid intelligence and dynamic brain networks by using resting-state fMRI (rfMRI) data from 200 participants in the Human Connectome Project (HCP) study. We also demonstrate the utility of this model to simulate dynamic brain networks at both group and individual levels. To our knowledge, this approach provides the first model-based statistical method for examining dynamic patterns of system-level properties of the brain and their relationships to phenotypic traits as well as simulating dynamic brain networks.

Support quadric method in non-imaging optics problems that can be reformulated as a mass transfer problem

The article deals with problems of generating desired illumination patterns, formulated in a special way. More precisely, we consider problems that can be reformulated as a Monge–Kantorovich mass transfer problem with some cost function. For all problems of this type, we uniformly formulate the support quadric method and show that it coincides with the gradient method for finding the maximum of a certain concave function.

Synthesizing Circularly Polarized Multi-Beam Planar Dipole Arrays With Sidelobe and Cross-Polarization Control by Two-Step Element Rotation and Phase Optimization

In this article, a novel method is presented to synthesize multi-beam circularly polarized (CP) patterns with sidelobe level (SLL) and cross-polarization level (XPL) suppression for planar dipole arrays by optimizing both element rotations and excitation phases. Multiple sets of excitation phases are adopted as optimization variables other than the determined values according to the rotation angles in the conventional sequentially rotated technique (SRT) and the random sequentially rotated technique (RSRT), so as to improve the performance of the obtained CP multi-beam patterns. This releases many more degrees of synthesis freedom but leads to a new problem of demanding excessive computation resources for a planar rotated dipole array with multiple CP patterns. Then, a two-step rotation and phase optimization strategy is proposed to effectively solve this optimization problem. In the initial step, the common element rotations and approximated excitation phases composed of the common phase parts plus the beam focusing phase parts are found for multiple desired CP patterns with different beam directions. And then, a refining step is performed to refine the excitation phases individually for each CP beam for improved pattern performance. Four representative examples of synthesizing multi-beam patterns with both SLL and XPL suppression are provided to verify the effectiveness of the proposed method. Comparisons with the conventional SRT and RSRT are also provided to show the superiority of the proposed method.

CREATING AND USING MASK IMAGES FOR SEGMENTATION IN POINT CLOUD DATA

Abstract. The task of preparing the training data for machine learning is tedious but crucial for accurate results. Aiming at labelling meaningful features semi-automatically rather than manually in order to reduce time, we hereby present initial results for two cases of 13th century Seljuk brick-ornamentation. As our broader research involves machine learning methods for the segmentation of digital survey data for creating meaningful three-dimensional models, the primary goal here is to determine the parts of the patterns from the whole composition and to use this data for different buildings of the genre. Prior to any machine learning, labelling the data of either a whole pattern or pieces of a pattern is a time-consuming task prone to errors. We propose a semi-automated mask generating model for labelling. In order to create the black and white mask images of the original photographs, we utilise the colour difference between the pattern parts. Examined samples have at least three visually distinguishable colours that are turquoise, black and natural. We use photogrammetry-based survey data and image processing to create attributed point clouds and eventually 3D digital models. Using the ready batch processing of a commercial software, we create a distinct mask and apply it to all images of the photogrammetry process. Point cloud data is then created with RAW images, and the generated masks are used to filter desired patterns. As such, we are able to easily label the bricks in the point cloud towards a machine learning training set.

Cilia metasurfaces for electronically programmable microfluidic manipulation.

Cilial pumping is a powerful strategy used by biological organisms to control and manipulate fluids at the microscale. However, despite numerous recent advances in optically, magnetically and electrically driven actuation, development of an engineered cilial platform with the potential for applications has remained difficult to realize1-6. Here we report on active metasurfaces of electronically actuated artificial cilia that can create arbitrary flow patterns in liquids near a surface. We first create voltage-actuated cilia that generate non-reciprocal motions to drive surface flows at tens of microns per second at actuation voltages of 1 volt. We then show that a cilia unit cell can locally create a range of elemental flow geometries. By combining these unit cells, we create an active cilia metasurface that can generate and switch between any desired surface flow pattern. Finally, we integrate the cilia with a light-powered complementary metal-oxide-semiconductor (CMOS) clock circuit to demonstrate wireless operation. As a proof of concept, we use this circuit to output voltage pulses with various phase delays to demonstrate improved pumping efficiency using metachronal waves. These powerful results, demonstrated experimentally and confirmed using theoretical computations, illustrate a pathway towards fine-scale microfluidic manipulation, with applications from microfluidic pumping to microrobotic locomotion.