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Postharvest assessment of 'Hass' avocado fruit ripening is frequently monitored by the fruit texture as it changes from hard to soft and 'buttery'. This large change in texture is easily measured, commonly by a penetrometer after removal of a small area of skin or by a whole-fruit compression measurement. The penetrometer is slow and destructive whereas the compression measurement is rapid and may be considered as non-destructive depending on the method. Investigation of the two methods on the same batch of fruit reveals information pertinent to the understanding of fruit ripening — beyond the simple provision of a numerical assessment of the progress of ripening. Monitoring of fruit under drying conditions revealed the role that fruit turgor plays in the compression measurement, and how it contributes to our understanding of the numerical values. Likewise, the observed variation among individual fruit ripening times may mean that averaged values are misleading, suggesting that fruit ripening takes longer than it actually does. The key element in the fruit-to-fruit variability was the pre-climacteric period before the fruit ripened. Additional penetrometer measurements of five regions of the fruit flesh for each fruit assessed quantified differences in mesocarp softening within the fruit. [ABSTRACT FROM AUTHOR]

Kiwifruit (Actinidia chinensis var. chinensis) firmness is routinely measured in a destructive manner for decision-making purposes. Thus, a population's quality is inferred by measuring a sample from that population. Consequently, studies have investigated non-destructive techniques for measuring fruit firmness. However, most of these studies have been restricted to a single season or focused on performance over long-term storage. This work compared non-destructive compression (1 mm deformation) and acoustic stiffness with flesh firmness measured with a penetrometer across three seasons. 'SunGold' kiwifruit were harvested from 11, 9 and 3 orchards on multiple occasions in 2020, 2021 and 2022, respectively. Kiwifruit was freighted to Palmerston North and assessed on arrival. Thirty fruit per orchard were measured on lab arrival, whilst 24 fruit per orchard were stored for two weeks at 0°C prior to assessment. The non-destructive methods had a strong (r2 > 0.89–0.92) segmented correlation with flesh firmness (0.52–10 kgf). Flesh firmness could be adequately estimated with the non-destructive methods within a season. However, segmented regression performance was reduced when predicting for a season outside of the training population. Nonetheless, these non-destructive methods may be useful for estimating flesh firmness at harvest and after short-term storage (2 weeks at 0 °C). [ABSTRACT FROM AUTHOR]

Elastic contact deformation of gear teeth is investigated. A formula is derived for the elastic tooth deformation in the contact zone. This deformation does not depend on the radius of curvature of the teeth in the contact zone; it is about 42% of the total contact deformation. Analysis of the results indicates that they are in good agreement with literature data. [ABSTRACT FROM AUTHOR]

The exponential growth in internet data usage has created a pressing demand for highly efficient Network Intrusion Detection Systems (NIDS) capable of scaling with ever-increasing bandwidths to safeguard sensitive information. A cornerstone of NIDS, packet inspection, hinges on the ability to rapidly identify and analyze patterns within incoming data streams. The more diverse and extensive the pattern database, the more robust and effective the NIDS becomes. While the parallel failure-less version of the Aho-Corasick (AC) algorithm provides maximum parallelism, it faces significant memory constraints due to the large transition tables generated when dealing with a vast number of patterns. To mitigate this limitation and enhance the scalability of NIDS, we introduce a novel parallel failure-less compressed hashed variation of the Aho-Corasick algorithm. Our proposed approach leverages the power of compression and hashing techniques to significantly reduce memory consumption without compromising performance. Empirical evaluations demonstrate that our algorithm requires only a fraction (approximately the square root) of the memory footprint compared to the original parallel failure-less Aho-Corasick algorithm, making it a more practical and scalable solution for modern NIDS architectures. [ABSTRACT FROM AUTHOR]

Approximating a series of timestamped data points through a sequence of line segments with a maximum error guarantee is a fundamental data compression problem, termed as Piecewise Linear Approximation (PLA). As the demand for analyzing large volumes of time-series data across various domains continues to grow, the significance of this problem has recently received considerable attention. Recent PLA algorithms have emerged to help us handle the overwhelming amount of information, albeit at the expense of some precision loss. More precisely, these algorithms involve a delicate balance between the maximum acceptable precision loss and the space savings that can be achieved. In our recent work we proposed Sim-Piece, offering a fresh perspective on the long-standing challenge of PLO approximation. Sim-Piece identifies similarities among line segments in a PLA representation enabling their grouping and joint representation. This way, Sim-Piece delivers space-saving advantages that outperform even the optimal PLA approximation. In this work, we present Mix-Piece, an improved PLA compression algorithm that builds upon the core idea of Sim-Piece (i.e., exploiting similar PLA segments) but improves further its performance by (1) considering multiple candidate PLA segments when ingesting a time series, (2) enabling grouping of additional segments not utilized by Sim-Piece, and, (3) making use of a versatile output format that exploits all segment similarities. Our experimental evaluation demonstrates that Mix-Piece outperforms Sim-Piece and previous competing techniques, attaining compression ratios with more than twofold improvement on average over what PLA algorithms can offer. This allows for providing significantly higher accuracy with equivalent space requirements. [ABSTRACT FROM AUTHOR]

In this investigation, Cu-TiO2-Graphite hybrid composites were fabricated with variations in wt.% of TiO2 and fixed wt.% of Graphite contents through stir casting technique. The size of the grains measured after casting were 83 ± 04, 64 ± 10, 41 ± 10 and 29 ± 04 μm for 0, 3, 6, and 9 wt% hybrid composites, respectively. The addition of 1 wt.% graphite (Gr) was not only to enhance the mechanical and tribological properties but also to improve the wettability during casting. The influence of TiO2 and Gr in Cu-hybrid composite on compression test was investigated followed by characterisation studies involving XRD, EDS, TEM, EBSD. The results reveal that 9 wt% reinforced composite exhibits more strain hardening. Further, composite exhibits higher strength due to the presence of combined strengthening mechanisms such as grain boundary, Orowan and thermal expansion coefficient mismatch in commensurate with ceramic particle addition. Out of these, it is found that Orowan strengthening contributes significantly to the compression strength of the hybrid system investigated. [ABSTRACT FROM AUTHOR]

A significant agricultural biomass with the intrinsic potential for lingo-cellulosic fiber is eliminated as garbage after harvesting in underdeveloped countries. The effective use of these natural fibers is one strategy to ensure a sustainable economy and reduce environmental pollution caused by synthetic fibers. The present work focuses on fabricating a core with uniformly dispersed Habeshian short banana fiber sandwiched between woven banana fiber composites. Epoxy core were fabricated by varying amount of short banana fiber (0, 2.5, 5, 7.5, and 10 wt.%) and fixed woven banana fiber content (40 wt.%). Composites were prepared by hand layup technique. The work aims to enhance the overall performance of composites by leveraging the specific properties of Habeshian short banana fibers, to tailor the properties of the composite material to suit specific application requirements. The tensile and compressive properties enhance with increase in the short banana fiber content in core indicating beneficial advantages of reinforcing banana fibers to improve the compressive properties. Fracture toughness of composite also increase with increase in the chopped banana fiber content. The increase in the core wt.% has conveyed an enhancement in properties of composites till 10 wt.%. The structure and attributes of test specimens were correlated using scanning electron micrographs. The work can be extended for higher percentages of core, thus realizing enhancement in properties related to mechanical and chemical. [ABSTRACT FROM AUTHOR]

In this paper, new epoxy resin/rubber powder/hollow beads three-phase composites were prepared by designing the incorporation of fly ash hollow beads with different mass fractions (5%, 10%, 15%, and 20%) as new reinforcing phases into epoxy resin/rubber powder two-phase composites with 5% mass fraction of carbon black rubber powder. Quasi-static compression tests were conducted at room temperature to test the compressive properties of the oxygen resin/rubber powder/hollow beads composites. Calculate the energy absorption properties and energy absorption efficiency of the composites from the compression curves. Fracture characteristics of compressed material specimens with microscopic morphology were observed by scanning electron microscopy. By systematically analyzing the effect of fly ash hollow beads content on the mechanical properties of epoxy resin/rubber powder/hollow beads three-phase composites, it was found that fly ash hollow beads as reinforcing materials can effectively improve the brittleness and yield strength of epoxy resin/rubber powder as well as the energy-absorbing properties and efficiency of the composites. The energy absorption properties of the epoxy resin/rubber powder/hollow beads composites increased and then decreased with the increase in the mass fraction of fly ash hollow beads. In the epoxy resin/rubber powder/hollow beads composites, the most significant performance was observed when the mass fraction of fly ash was 10%. [ABSTRACT FROM AUTHOR]

Piezoelectric energy generation is relevant for developing advanced electronics. However, the poor understanding of the influence of triboelectricity as an alternate charge generation mechanism has, in many cases, resulted in the reporting of exaggerated piezoelectric outputs. Herein, the signal output is systematically investigated from a range of organic piezoelectric materials (poled polyvinylidene fluoride (PVDF)), moderately piezoelectric (heat‐treated PVDF), and non‐piezoelectric (non‐poled PVDF), polytetrafluoroelthylene (Teflon) and nylon) under tapping and compression (33 direction) and stretching (31 direction) in both encapsulated and non‐encapsulated forms. This findings reveal that regardless of their piezoelectric properties, all tested materials exhibit substantial voltage outputs (4.2–4.6 V) during tapping, primarily attributed to the triboelectric effect at the contact interface. The triboelectric contribution to the signal is reduced by 99% in compression mode for non‐piezoelectric materials and the piezoelectric signal is the primary contributor in the stretching mode with a high signal output of 7.71 V N−1 for poled PVDF and a negligible signal (0.01–0.12 V N−1) for non‐piezoelectric materials. Moreover, elastomeric encapsulation is demonstrated to markedly increase triboelectric signals in tapping mode. These results have important implications for the future design of piezoelectric‐triboelectric devices and the accurate interpretation of the data obtained from such devices. [ABSTRACT FROM AUTHOR]

The treatment and care of patients suffering from Venous Leg Ulceration (VLU) constitutes a significant portion of wound care delivered in the UK. Despite the abundance of empirical evidence in this field, across the UK there is considerable variation in care. There is an underuse of evidence-based practice and overuse of ineffective practices. The accessibility of evidence-based care is key to enhancing healing rates. Service leaders are urged to promptly assess their existing clinical pathways and service provision to ensure that patient groups are able to access care that is supported by empirical data. Only through facilitating such access can unwarranted variations in care be reduced, resulting in enhanced healing rates, decreased risk of recurrence and, ultimately, an improved quality of life for patients [ABSTRACT FROM AUTHOR]

Drying shrinkage during ambient pressure drying of silica gels is made reversible by preventing condensation reactions of surface silanol groups via surface modification. This partial recovery of the gel volume and structure is referred to as the spring-back effect (SBE) and enables the production of monolithic silica aerogels by evaporative drying. The SBE is sometimes completed by annealing at mild temperatures. Similarities between drying-related deformations and deformations induced by mechanical stimuli suggest analogous underlying mechanisms. While the causes of drying shrinkage are relatively well-known, it remains unclear how the relaxation of the structure by drying and annealing occurs across the different length scales. Here we show a complete structural recovery of silica aerogels at the macro- and nano-scale enabled by annealing. We propose that residual deformations after drying and mechanical compression are caused by the entanglement of silica clusters that can be unraveled by annealing at 230 °C. The deformation under loading is interpreted as two different re-arrangement mechanisms for dry and annealed gels, by the sliding of the silica clusters along the loading direction and by the compression of large pores beyond the fractal structure, respectively. Our results demonstrate how the shape and structure of silica aerogels can be restored and controlled by thermal activation, broadening the various applications of these materials. We also emphasize how tuning silica gels to promote a two-step SBE by annealing can pave the way toward the production of larger monolithic aerogels by APD. Highlights: Two-step spring-back of silica aerogels upon annealing at 230 °C. Residual solvent and silica cluster entanglement hinder full re-expansion. Annealed aerogels show a near-zero Poisson's ratio during compression. Interpretation of fractal dimension evolution during deformation of mesoporous materials. Annealing allows full recovery of macro- and nano-structure, highlighting programmable nature. [ABSTRACT FROM AUTHOR]

Machine learning (ML) models have demonstrated discriminative and representative learning capabilities over a wide range of applications, even at the cost of high-computational complexity. Due to their parallel processing capabilities, reconfigurability, and low-power consumption, systems on chip based on a field programmable gate array (SoC/FPGA) have been used to face this challenge. Nevertheless, SoC/FPGA devices are resource-constrained, which implies the need for optimal use of technology for the computation and storage operations involved in ML-based inference. Consequently, mapping a deep neural network (DNN) architecture to a SoC/FPGA requires compression strategies to obtain a hardware design with a good compromise between effectiveness, memory footprint, and inference time. This letter presents an efficient end-to-end workflow for deploying DNNs on an SoC/FPGA by integrating hyperparameter tuning through Bayesian optimization (BO) with an ensemble of compression techniques. [ABSTRACT FROM AUTHOR]

Laser shock peening (LSP) is a novel non-contact surface modification technique to enhance the corrosion and compression behavior of stainless steel 308L (SS308L) material for a cryogenic application. SS308L is commonly used as a weld filler, weld electrode and cryogenic environment due to its low carbon content and good mechanical and high corrosion resistance properties. In this present study, wire-arc additive manufacturing (WAAM) has been utilized to manufactured SS308L material and studied the compression, corrosion, wettability and surface properties of the material. Further, the nanosecond laser shock peening has been utilized to modify the additive-manufactured SS308L surface and mechanical properties. From the experimental results, it has been observed that the uni-directional flow path (UDFP) deposition has better corrosion resistance wettability and surface finish than the bi-directional flow path (BDFP) deposition on wire-arc additive-manufactured SS308L material due to its more uniform microstructure and smoother surface finish. In addition, the post-processing treatment (LSP) of SS308L materials has improved the compressive strength of additive-manufactured SS308L material with 20.6 and 15.9% as compared to UDFP and BDFP due to grain surface refinement and increases in dislocation density. The corrosion rate of LSP-treated materials was reduced by 20.7% compared to the UDFP materials due to the higher corrosion potential and lower corrosion current density. The higher surface roughness has produced better passive film formation to enhanced corrosion resistance in the UDFP with LSP. Finally, the microstructure and chemical composition have been analyzed using scanning electron microscope and energy-dispersive x-ray spectroscopy. [ABSTRACT FROM AUTHOR]

Aims To compare the efficacy, cost effectiveness and user satisfaction achieved when 4-layer compression bandages (4LCB) and adjustable VelcroR compression devices (AVCD) are used in the treatment of venous leg ulcers (VLU), in community dwelling adults. Methods A prospective cross-over study was conducted. A convenience sample of 50 patients with VLUs were recruited. Patients were randomised to receive either 4LCB or AVCD for a period of 6 weeks, then crossed to the alternative treatment for an additional 6 weeks. Baseline and weekly wound assessments were recorded. Patients and nurses completed satisfaction surveys at the end of each arm. A cost analysis was completed. Results Patients experienced a comparable reduction in ulcer size with both compression modalities. Nurses and patients reported higher satisfaction with AVCD. The costs associated with a reusable AVCD as compared to single use 4LCB was dependent on the duration of treatment and frequency of changes. Cost benefits were associated with AVCD after 17 episodes of care where a single set of bandages was required and sooner in larger legs. Conclusions The use of AVCD proved cost-effective and produced comparable healing rates in the community setting. Both nurses and patients expressed higher satisfaction scores when using AVCD. [ABSTRACT FROM AUTHOR]

Abstract Background To what degree a string of symbols can be compressed reveals important details about its complexity. For instance, strings that are not compressible are random and carry a low information potential while the opposite is true for highly compressible strings. We explore to what extent microbial genomes are amenable to compression as they vary considerably both with respect to size and base composition. For instance, microbial genome sizes vary from less than 100,000 base pairs in symbionts to more than 10 million in soil-dwellers. Genomic base composition, often summarized as genomic AT or GC content due to the similar frequencies of adenine and thymine on one hand and cytosine and guanine on the other, also vary substantially; the most extreme microbes can have genomes with AT content below 25% or above 85% AT. Base composition determines the frequency of DNA words, consisting of multiple nucleotides or oligonucleotides, and may therefore also influence compressibility. Using 4,713 RefSeq genomes, we examined the association between compressibility, using both a DNA based- (MBGC) and a general purpose (ZPAQ) compression algorithm, and genome size, AT content as well as genomic oligonucleotide usage variance (OUV) using generalized additive models. Results We find that genome size (p

Abstract Background Hydatid disease is a zoonotic infection caused by the species Echinococcus that typically affects the liver. Most liver hydatid cysts are asymptomatic at first, but as the cyst grows larger, symptoms, such as compression effects, start to appear. Ultrasonography and computed tomography scans are the widely used diagnostic tools, and surgery is considered the mainstay of treatment. Case presentation We present an unusual case of a giant pedunculated hydatid cyst causing inferior vena cava syndrome in a 20-year-old male patient from the Oromo ethnic group from a rural area of the country. Abdominal ultrasound and computed tomography scan confirmed the diagnosis. Our patient underwent radical surgical resection of the cyst and had a good outcome. Conclusion Hydatid liver cyst diagnosis needs a high index of suspicion for echinococcal etiology when dealing with a giant liver cyst as it results in grave complications without any manifestations.

Researchers are increasingly becoming fascinated by the possibilities of utilizing natural fibre, which is a byproduct of production processes, as an addition in concrete. This fibre exhibits a low density and is amenable to chemical changes. The primary aim of this research study is to examine the influence of agave cantula roxb. fibre (ACRF) in low-density foamed concrete (FC) after being subjected to different doses of alkali treatment using sodium hydroxide (NaOH). Various weight fractions of treated ACRF were employed in the FC mix, namely 0% (as the control), 1%, 2%, 3%, 4%, and 5%. FC with a density of 1060 kg/m3 was produced and subsequently tested. The three types of strength properties that have been evaluated and analysed included flexural, tensile, and compressive strengths. The findings from this study have revealed that the inclusion of 3% of treated ACRF in FC yields highly favourable results in relation to strength properties. The use of treated ACRF improves the FC’s strength characteristics, particularly its bending and tensile strength, by bridging microscopic cracks and filling up gaps. It is noteworthy to emphasize that accumulation and unequal dispersion of ACRF are possible if the weight fraction of ACRF applied above the optimal value of 3% which led to decrease in FC’s strength properties. This exploratory work will lead to a better understanding of the potential applications of treated ACRF in FC. It is critical to encourage the long-term development and implementation of FC products and technology.

The consumption of foamed concrete (FC) in conjunction with the incorporation of natural fibre is recognized as an outstanding effort in promoting sustainable practices. This effort is aimed at reducing greenhouse gas emissions and the impact it leaves behind on the environment. The goal of this experiment is to discover the viability of incorporating raw bamboo fibre (BF) into the fabrication of 1000 kg/m3density FC. The shrinkage, flexural, compressive, and tensile strengths of the material were the four characteristics that were considered throughout the analysis. The weight fractions of BF that were utilized were 0.0%, 0.1%, 0.2%, 0.3%, and 0.4% respectively. According to the results, the FC-BF composites’ drying shrinkage, compressive, flexural, and tensile strengths were best achieved when 0.3% BF was present. This was caused by the BF’s adhesion to the cementitious matrix of the FC. Additionally, BF functioned as an anti-micro crack that prevented FC from developing internally induced microcracks and cracks.

Abstract Background Currently, low‐level evidence suggests loss of ambulation associated with acute thoracolumbar disk extrusion is best treated by decompressive spinal surgery. Conservative management can be successful, but the proportion of dogs that recover and the fate of herniated material are uncertain. Objectives Determine the proportion of nonambulatory dogs with conservatively treated acute thoracolumbar disk extrusion that recover ambulation and measure the change in spinal cord compression during the first 12 weeks after presentation. Animals Seventy‐two client‐owned nonambulatory dogs with acute thoracolumbar intervertebral disk extrusion. Methods This is a prospective cohort study. Enrolled dogs underwent magnetic resonance imaging at presentation and owners were provided with conservative management recommendations. Imaging was repeated after 12 weeks. Recovery of ambulation was defined as 10 consecutive steps without falling. Spinal cord compression was determined from the cross‐sectional area of the vertebral canal and extradural compressive material at the lesion epicenter. The association between recovery and change in compression over the 12‐week observational period was examined. Results Forty‐nine of fifty‐one (96%; 95% confidence interval [CI], 87%‐99%) of deep pain‐positive and 10/21 (48%; 95% CI, 28%‐68%) of deep pain‐negative dogs recovered ambulation within the 12‐week period. The median time to ambulation was 11 and 25 days for deep pain‐positive and ‐negative dogs, respectively. Reduction in spinal cord compression varied among individuals from minimal to complete and apparently was unrelated to the recovery of ambulation. Conclusions and Clinical Importance A high proportion of conservatively treated dogs recovered ambulation after conservative management of acute thoracolumbar disk herniation. Recovery was not dependent on the resolution of compression.

Abstract Background Chromosome organization plays an important role in biological processes such as replication, regulation, and transcription. One way to study the relationship between chromosome structure and its biological functions is through Hi-C studies, a genome-wide method for capturing chromosome conformation. Such studies generate vast amounts of data. The problem is exacerbated by the fact that chromosome organization is dynamic, requiring snapshots at different points in time, further increasing the amount of data to be stored. We present a novel approach called the High-Efficiency Contact Matrix Compressor (HiCMC) for efficient compression of Hi-C data. Results By modeling the underlying structures found in the contact matrix, such as compartments and domains, HiCMC outperforms the state-of-the-art method CMC by approximately 8% and the other state-of-the-art methods cooler, LZMA, and bzip2 by over 50% across multiple cell lines and contact matrix resolutions. In addition, HiCMC integrates domain-specific information into the compressed bitstreams that it generates, and this information can be used to speed up downstream analyses. Conclusion HiCMC is a novel compression approach that utilizes intrinsic properties of contact matrix, such as compartments and domains. It allows for a better compression in comparison to the state-of-the-art methods. HiCMC is available at https://github.com/sXperfect/hicmc .

AbstractIn this study, the synthesis-structure-property relationship of graphene-reinforced Al matrix nanocomposites was investigated. The Al-Li-GNPs nanocomposite was synthesized to attain both high strength and good ductility. The incorporation of GNPs as a reinforcement in the Al-based matrix provided a nanocomposite structure for an integrated strengthening effect. To promote plasticity and maintain good ductility, the nanocrystalline Al matrix was alloyed with Li to reduce its stacking fault energy and promote additional deformation mechanisms. The compressive yield strength (CYS) increased from 88 MPa for the starting Al to 403 MPa for the Al-Li-GNPs nanocomposites with 1.0 wt% GNPs. Fracture analysis indicated that the synthesized nanocomposite exhibited a ductile nature and significant plastic deformation. Based on microscopic analysis, the enhanced strength of the Al-Li-GNPs nanocomposite was attributed to grain refinement, load transfer, and strain hardening. The good ductility, on the other hand, was attributed to dislocation slipping, the formation of stacking faults, and twinning.

The purpose of this study was to compare average rate of oxygen consumption (VO2), slow component of oxygen consumption (VO2 drift), heart rate (HR) and rating of perceived exertion (RPE) while wearing compression pants vs. a control garment during long-distance running. Methods: Nine injury-free and recreationally active participants (32 ± 11 years) were recruited for this study. Participants ran in full-leg compression pants (COMP) and a loose-fitting control garment (CON). Participants ran in each condition for 40 min at a preferred submaximal speed. The rate of oxygen consumption (VO2) was measured continuously via a metabolic cart throughout each condition. Both HR and RPE were recorded every 5 min during each condition. Oxygen consumption was averaged across the entirety of the steady state during the 40 min conditions for analysis. Additionally, the average from the first five minutes of the steady state was subtracted from the average of the last five minutes to assess VO2. A paired t-test was used to assess for differences for both variables. Both HR and RPE were each compared between conditions using 2 (garment) × 8 (time) repeated measure ANOVAs (α = 0.05). Results: There were no differences between VO2 or VO2 drift while running with full-leg compression pants vs. the control garment (p > 0.05). Neither RPE nor HR were influenced by the garments (p > 0.05) or time (p > 0.05) during each condition. Conclusion: Wearing compression pants did not result in reduced VO2, VO2 drift, HR or RPE during a long-distance run. Although measured performance variables were not aided using compression pants, there were no negative effects to the use of compression pants.

ObjectivesIn this paper, an orthogonal braided glass fiber composite sandwich panel with a PVC foam core and dimensions of 150 mm×100 mm×26 mm is selected as the research object in order to study the impact mechanical properties of composite sandwich panels. The dynamic response and residual compressive strength of the panel under single-point low-velocity impact are then analyzed.MethodsFirst, a series of drop hammer impact tests are conducted to study the failure mode, impact force-displacement response and energy absorption characteristics of the panel under different impact energies. Next, quasi-static compression experiments are conducted to investigate the maximum compression load capacity and residual compressive strength under impact damage.ResultsThere are significant differences in the failure modes and impact force-displacement characteristics of the sandwich panel under different impact energies. The core mainly absorbs impact energy through compression deformation. As the impact energy increases, the maximal impact force, dent depth and absorbed energy of panel gradually increase, while the maximum compression load capacity and residual strength decrease after impact. The damage degree of the impacted composite sandwich panel determines its residual compressive strength. ConclusionThe findings of this study can provide valuable references for the impact resistance design of naval ship structures.

Abstract Diverse applications and tremendous usefulness of siliciclastic sedimentary sands make investigation into their mechanics of behaviour very essential globally. This study examines the convergence or otherwise of the specimens in compression; physical, fabric, chemical and mineralogical characteristics and their relationships with compression behaviour; shape characteristics, possible particle breakage and their overall effect on the behaviour of siliciclastic sedimentary sands obtained from two locations. The findings are as follows; (a) Siliciclastic sedimentary sands are poorly graded and coarse in nature. (b) The fabrics are characterized by aggregation of sub rounded particles and smaller particles tend to combine with fines to form coatings around bigger particles. (c) Chemical compositions are predominantly silica and alumina and heamatite are significant. (d) Quartz dominates the mineralogy and the other minerals are muscovite, albite, orthoclase and chlorite. (e) The samples have convergent behaviour and the compressibility is not significantly different but lower than the related materials. (f) The original particle is sub round in shape and the particles become sub angular after the test with no relationship between particle shape and compression behaviour. (g) The particle breakage is linked to coarser nature of the specimens and the overall effect of particle breakage on the compression behaviour of siliciclastic sedimentary sand is small.

The problem of stability of a cylindrical shell with various modules on a viscoelastic base is investigated. It is assumed that the shell of a circular cross section is subjected to force and loses stability in an axisymmetric form. It is believed that one end of the shell remains motionless, while the other changes its location (moves) at a certain speed. It is assumed that the transverse displacement is greater than the longitudinal one. When solving the problem, the resistance of the external environment was taken into account, and it was also read that the cylindrical shell was made of a material of different modularity. Relationship equations are obtained between the critical force and the characteristic parameters for a cylindrical shell located on a base, characterized, in turn, as a viscoelastic base and the Pasternak model. From the equations obtained and the results presented, it can be seen that serious errors are allowed if, when solving stability issues, the resistance of the external environment and different modularity are not taken into account. The calculation results show that the value of the critical force in the case under consideration differs significantly from the values corresponding to classical problems, and depends on the parameters characterizing the base resistance. The results obtained can be used in calculations of multi-modulus cylindrical shells for strength, stability, and frequency-amplitude characteristics, taking into account the resistance of the external environment.

The use of video streaming is constantly increasing. High-resolution video requires resources on both the sender and the receiver side. Many compression techniques can be utilized to compress the video and simultaneously maintain quality. The main goal of this paper is to provide an overview of video streaming and QoE. This paper describes the basic concepts and discusses existing methodologies to measure QoE. Subjective, objective, and video compression technologies are discussed. This review paper gathers the codec implementation developed by MPEG, Google, and Apple. This paper outlines the challenges and future research directions that should be considered in the measurement and assessment of the quality of experience for video services.

Copper (Cu) is highly sought for its excellent electrical and thermal conductivity. However, its limited mechanical strength hinders its wider application in demanding fields. This work explores the potential of graphene nanoplatelets (GNPs) as a strengthening agent for Cu. Cu-GNP composites with varying GNP content (0.1–1.5 wt%) were fabricated using a combined ball milling and powder metallurgy approach. The microstructure and mechanical properties of the composites were comprehensively analyzed using field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Raman spectroscopy. Compared to pure Cu, the Cu-GNP composites showcased significantly improved mechanical performance. Notably, the Cu-1.0 wt% GNP composite exhibited a remarkable ∼27% and ∼53% enhancement in compressive strength and micro-hardness, respectively. This improvement is attributed to the effective load transfer between Cu and well-dispersed GNPs, which act as reinforcement elements and inhibit dislocation movement. These findings demonstrate the promising potential of Cu-GNP composites for applications requiring high strength.

The research focuses on examining the impact of technological defects, specifically "dry-spot" and "wrinkles," on the mechanical behavior and buckling resistance of structural composites. The investigation of the buckling phenomenon was carried out through a compression test on a thin plate fabricated from carbon-fiber-reinforced polymer (CFRP) laminate. This test was performed using a specialized fixture designed in accordance with ASTM 3410 standard. For the analysis, the study employed a three-dimensional digital optical system, Vic-3D, in conjunction with the AMSY-6 acoustic emission system. The research showcases findings from acoustic emission signals that verify the shear-based mechanism of buckling in plates constructed from CFRP featuring "dry-spot" type defects. In the case of "wrinkles" defects, it was observed that transverse shear transpires at the stress concentration points created by the "excess" layers.

Background & Aim: Hypotension is a common complication associated with plasmapheresis. Elevating the legs and using elastic stockings are nursing interventions aimed at preventing hypotension. The objective of this study was to compare the effects of elastic stockings and leg elevation on the prevention of hypotension during plasmapheresis. Methods & Materials: This randomized crossover clinical trial was conducted on 35 patients undergoing plasmapheresis at Beheshti Hospital in Hamadan from 2020 to 2021. Patients were selected based on convenience sampling and then allocated to four different methods in four sessions using random permuted block designs: elastic stockings (A), leg elevation (B), a combination of elastic stockings and leg elevation (C), and a control group (D). Blood pressure was monitored before, during (every half hour), and half an hour after the completion of plasmapheresis. Data analysis was performed using SPSS version 24, applying repeated measures ANOVA with a significance level of 0.05. Results: During plasmapheresis, systolic blood pressure decreased over time in all four methods (P

Managing venous ulcers poses significant challenges for nursing personnel. This article outlines the current strategies employed in addressing venous ulcers, with particular emphasis on the updated T.I.M.E.R.S. wound assessment tool and compression therapy. Diagnosis should consider risk factors associated with chronic venous disease as well as other conditions such arterial ischaemia, ulcers related to diabetic neuropathy, or cancer. Doppler duplex ultrasound is typically conducted to validate the diagnosis. In the treatment of chronic wounds, implementing the updated wound assessment strategy T.I.M.E.R.S. is recommended. Optimal wound management requires tailored dressings and usage of antimicrobial agents. Application of local antibiotics on wounds should be avoided, with the exception of gentamicin embedded in a collagen matrix presented in the form of a sponge. Correctly adjusted com-pression therapy is a gold standard of treatment. Pentoxifylline is advised as an oral treatment to expedite the rate of ulcer healing.

The utilization of readily accessible natural fibres in lightweight foamed concrete (LWFC), which is already a widely used building material, can have a substantial positive impact on the environment. Therefore, the mechanical characteristics might be increased by using a correct mix proportion of fibre-reinforced LWFC. Innovative LWFC-agave fibre (AF) composites were created in this experiment. In order to get the best mechanical qualities, this investigation set out to establish the correct weight fraction of AF to be added to LWFC. Two LWFC densities of 750 and 1500 kg/m3 were produced with the addition of several weight fractions of AF, precisely 0.0%, 1.5%, 3.0%, 4.5%, 6.0%, and 7.5%, were used. To establish the mechanical characteristics of LWFCAF composites, flexural tests, tensile strength tests, axial compression tests, and ultrasonic pulse velocity tests were carried out. Test results revealed that the combination of LWFC together with a weight fraction of 4.5% of AF exhibited superior mechanical properties. Beyond 4.5% of AF’s weight fraction, the mechanical properties started to deteriorate. This study gives insight and crucial data on the mechanical characteristics of LWFC-AF composites therefore it will enable future researchers to explore other properties of LWFC reinforced with AF.

Abstract The rapid growth on the amount of generated 3D data, particularly in the form of Light Detection And Ranging (LiDAR) point clouds (PCs), poses very significant challenges in terms of data storage, transmission, and processing. Point cloud (PC) representation of 3D visual information has shown to be a very flexible format with many applications ranging from multimedia immersive communication to machine vision tasks in the robotics and autonomous driving domains. In this paper, we investigate the performance of four reference 3D object detection techniques, when the input PCs are compressed with varying levels of degradation. Compression is performed using two MPEG standard coders based on 2D projections and octree decomposition, as well as two coding methods based on Deep Learning (DL). For the DL coding methods, we used a Joint Photographic Experts Group (JPEG) reference PC coder, that we adapted to accept LiDAR PCs in both Cartesian and cylindrical coordinate systems. The detection performance of the four reference 3D object detection methods was evaluated using both pre-trained models and models specifically trained using degraded PCs reconstructed from compressed representations. It is shown that LiDAR PCs can be compressed down to 6 bits per point with no significant degradation on the object detection precision. Furthermore, employing specifically trained detection models improves the detection capabilities even at compression rates as low as 2 bits per point. These results show that LiDAR PCs can be coded to enable efficient storage and transmission, without significant object detection performance loss.

To efficiently yet reliably represent and process information, our brains need to produce information-rich signals that differentiate between moments or cognitive states, while also being robust to noise or corruption. For many, though not all, natural systems, these two properties are often inversely related: More information-rich signals are less robust, and vice versa. Here, we examined how these properties change with ongoing cognitive demands. To this end, we applied dimensionality reduction algorithms and pattern classifiers to functional neuroimaging data collected as participants listened to a story, temporally scrambled versions of the story, or underwent a resting state scanning session. We considered two primary aspects of the neural data recorded in these different experimental conditions. First, we treated the maximum achievable decoding accuracy across participants as an indicator of the "informativeness" of the recorded patterns. Second, we treated the number of features (components) required to achieve a threshold decoding accuracy as a proxy for the "compressibility" of the neural patterns (where fewer components indicate greater compression). Overall, we found that the peak decoding accuracy (achievable without restricting the numbers of features) was highest in the intact (unscrambled) story listening condition. However, the number of features required to achieve comparable classification accuracy was also lowest in the intact story listening condition. Taken together, our work suggests that our brain networks flexibly reconfigure according to ongoing task demands and that the activity patterns associated with higher-order cognition and high engagement are both more informative and more compressible than the activity patterns associated with lower-order tasks and lower engagement. [ABSTRACT FROM AUTHOR]

The problem of submerged body motion in a frozen channel is considered. The fluid in the channel is assumed to be inviscid and incompressible. Fluid flow is the potential. The ice cover has non-uniform compression along the principal coordinates. The damping of hydroelastic waves generated by the motion of submerged body is modeled by taking into account porosity of ice. The submerged body is modeled as a dipole, the potential of which is determined using mirror images from the channel walls. The main problem of the submerged body motion at constant speed along the central line of the channel is considered. Two subproblems are addressed: comparison of damping effects of the porosity and viscosity of ice and investigation of effects of symmetrically variable ice thickness relative to the central line of the channel. It was found that the most important compressive stress is the stress in the direction of the motion of the submerged body. The speed of the body, which was subcritical for uncompressed ice, may become critical or supercritical. Compressive stresses perpendicular to the direction of motion do not qualitatively change the character of the ice response. These stresses, in combination with compressive stresses along the direction of motion, strengthen the effect of the latter, making the transition from subcritical to supercritical regime faster. [ABSTRACT FROM AUTHOR]

The effect of marforming (low-temperature compression deformation of В19ꞌ-martensite at 203 K and subsequent annealing at 713 K for 0.5 h) on superelasticity (SE), temperature range of SE, and cyclic stability of superelastic behavior at 323 K are studied on [001]В2 and В2 single crystals of the Ti50.2Ni49.8 (at %) alloy under compression. It is shown that marforming leads to an increase in the offset yield strength σ0.1 of the high-temperature В2-phase and to the development of SE, which was not observed in quenched crystals. The orientation dependence of the SE temperature range and the cyclic stability of superelastic behavior, which is determined by the orientation dependence of the σ0.1 stresses of the В2-phase, is established. The maximum SE temperature range is 87 K, and the cyclic stability of superelastic behavior at a temperature of 323 K is found in the [001]В2 orientation with a high σ0.1 stress level of the В2-phase. [ABSTRACT FROM AUTHOR]

This investigation deals with the problem of identifying the mechanical behaviour of rubbers from compression tests, performed on specimens having unfavorable geometry. A typical situation is that of flat specimens obtained from high-friction sports surfaces. To this purpose, experimental tests were conducted, aimed at measuring friction under various conditions and evaluating its effect on the compressive behavior of different rubber samples. The experimental results have been interpreted in view of an existing analytical model proposed by Gent and coworkers. The method was shown to be valid within a relatively broad range of conditions (in terms of materials, lubrication and aspect ratio). Its application allowed the creation of virtual "frictionless" curves, by rescaling experimental data for the stiffening factor predicted by Gent model. These curves represent more closely the intrinsic material behaviour, removing the large frictional contribution present in the experimental tests, and can be used as a more reliable input for numerical simulations. [ABSTRACT FROM AUTHOR]

Collecting data such vibration signal or others from elevators is crucial for a regular maintenance or emergency repair in industry. However, traditional methods for data transmission through compression and decompression process usually require large input data arrays to be assigned. Therefore, a long computational time is unavoidable so that it may affect system performance efficiency significantly. Therefore, an elevator vibration and loading data collection system was developed using simple compression encoding mechanism. First, in Data Acquisition Unit, the signal-acquiring microprocessor is used for data acquisition through Inter-Integrated Circuit (I2C) bus. Second, in Data Storage Unit, the collected data from the signal-acquiring microprocessor is compressed and transmitted to the signal-processing microprocessor. Third, in Monitor Unit, the elevator analysis tool is developed to analyze the vibration data, which can be viewed directly from APP. Experimental results demonstrated that the restored data are consistent with the results measured from the standard instrument. The proposed hexadecimal compression process can make the data transmission mechanism simple, but two times faster than that using traditional way without compression. Consequently, the demanded memory capacity for signal transmission can be therefore reduced considerably. [ABSTRACT FROM AUTHOR]

The effect of biaxial compressive loading on hollow steel box column (HSBC) and concrete-filled steel box column (CFSBC) sections wrapped with low-modulus carbon-fibre-reinforced polymer (CFRP) was studied. The CFSBC and HSBC sections were simulated using Abaqus finite-element software and validated using available experimental data. Biaxial compressive loading was considered for different eccentricities (i.e. eccentricity to depth ratio (e/D) ratio of zero to 0.32). The results indicated that, for CFRP-wrapped HSBCs at low eccentricity (e/D = 0.08), compact and non-compact sections were effective at carrying higher load, while a slender section was effective for concentric loads. For the CFRP-wrapped CFSBCs, compact and non-compact sections were effective for all the eccentric loads (e/D = 0–0.32). It was also found that the low-modulus CFRP layer wrapping the CFSBC sections had no significant effect on strength. An empirical relationship was developed based on trend analysis, which gives the load-carrying capacity of any section. For the CFSBC sections, axial compression–uniaxial moment (P–M) interaction curves are presented to validate the simulation results under biaxial loading. [ABSTRACT FROM AUTHOR]

Aerodynamic instability plays an important role in compressor design and may cause performance degradation and fatigue damage. In this paper, an experimental study on the evolution of aerodynamic instability is carried out on a compressor that combines the performance benefits of an axial stage and centrifugal stage. The spatiotemporal characteristics of unsteady wall pressure were obtained using fast-responding pressure transducers over a range of operating conditions. The results show that the axial stage works on the positive slope of the performance characteristic curve from choke to stall at low-speed operating conditions, and mainly features rotating instability. Rotating stall is also observed in the impeller (IMP) and diffuser passages. At medium-speed operating conditions, the centrifugal stage suffers a high-frequency mild surge, alternating with rotating stall. With the increase in back pressure, the mild surge diminishes, and rotating stall persists. This behavior is similar to a two-regime-surge, which has been reported for centrifugal compressors. At high-speed operating conditions, the compressor directly reaches surge without other instabilities. Further analysis of the spatial pattern of the rotating stall revealed the existence of a high-pressure region near the volute tongue, resulting in obvious pressure distortion along the circumferential direction at the volute inlet. This induced the amplitude difference of stall cells in corresponding diffuser passages. The disturbance caused by stall cells propagates upstream through the blade passage, and the largest pressure disturbance induced by the stall cell propagation appears in a circumferential position 45 deg downstream of the volute tongue at the impeller inlet and the axial stage inlet. [ABSTRACT FROM AUTHOR]

Gallium oxide (Ga2O3) usually fractures in the brittle form, and achieving large plastic deformability to avoid catastrophic failure is in high demand. Here, ε‐Ga2O3 thin films with columnar crystals and partial unoccupied Ga sites are synthesized, and it is demonstrated that the ε‐Ga2O3 at the submicron scale can be compressed to an ultra‐large plastic strain of 48.5% without cracking. The compressive behavior and related mechanisms are investigated by in situ transmission electron microscope nanomechanical testing combined with atomic‐resolution characterizations. The serrated plastic flow and large strain burst are two major deformation forms of ε‐Ga2O3 during compression, which are attributed to the dislocation nucleation and avalanches, formation of new grains, and amorphization. The ultra‐large compressive plasticity of ε‐Ga2O3 thin films at the submicron scale can inspire new applications of Ga2O3 in micro‐ or nano‐ electronic and optoelectronic devices, especially those that require impact resistance during processing or service. [ABSTRACT FROM AUTHOR]

Role-based access control (RBAC) is a widely adopted access control model in various domains for defining security management. Role mining is closely related to role-based access control, as the latter employs role assignments to offer a flexible and scalable approach to managing permissions within an organization. The edge role mining problem (Edge RMP), a variant of the role mining problem (RMP), has long been recognized as an effective strategy for role assignment. Role mining, which groups users with similar access permissions into the same role, bears some resemblance to symmetry. Symmetry categorizes objects or graphics with identical characteristics into one group. Both involve a certain form of "classification" or "induction". Edge-RMP reduces the associations between users and permissions, thereby lowering the security risks faced by the system. While an algorithm based on Boolean matrix factorization exists for this problem, it fails to further refine the resulting user–role assignment (UA) and role–permission assignment (PA) relationships. Additionally, this algorithm does not address constraint-related issues, such as cardinality constraints, user exclusion constraints, and user capabilities. Furthermore, it demonstrates significant redundancy of roles when handling large datasets, leaving room for further optimization of Edge-RMP results. To address these concerns, this paper proposes the MFC-RMA algorithm based on Boolean matrix factorization. The method achieves significant optimization of Edge-RMP results by handling relationships between roles possessing various permissions. Furthermore, this paper clusters, compresses, modifies, and optimizes the original data based on the similarity between users, ensuring its usability for role mining. Both theoretical and practical considerations are taken into account for different types of constraints, and algorithms are devised to reallocate roles incorporating these constraints, thereby generating UA and PA matrices. The proposed approach yields optimal numbers of generated roles and the sum of the minimum number of generated edges to address the aforementioned issues. Experimental results demonstrate that the algorithm reduces management overhead, provides efficient execution results, and ensures the accuracy of generated roles. [ABSTRACT FROM AUTHOR]

Lattice structures are widely employed in bone scaffolds to obtain high porosity with interconnected pores and high surface area-to-volume and strength-to-weight ratios. Here, 21 lattice-based scaffold architectures were modeled using implicit functions and additively manufactured using epoxidized soybean oil-based resin. The porosity of the scaffolds ranged from 53.42% ± 1.16% to 98.28% ± 0.75%. Scaffolds with the lowest overall porosity (Group 1) exhibited the highest compressive strength. The compressive strength of eighteen different three-dimensional scaffold designs was compatible with that of human trabecular bone. The results and methodology presented here can facilitate the mathematical design of complex porous scaffolds for bone tissue engineering. [ABSTRACT FROM AUTHOR]

Bone scaffolds serve a crucial role in tissue engineering, particularly in facilitating bone regeneration where natural repair is insufficient. Despite advancements in the fabrication of polymeric bone scaffolds, the challenge remains to optimize their mechanical resilience. Specifically, research on the fatigue behaviour of polymeric bone scaffolds is scarce. This study investigates the influence of pore architecture on the mechanical performance of poly-lactic-acid (PLA) scaffolds under quasi-static and cyclic compression. PLA scaffolds with a 60% porosity were fabricated using extrusion-based 3D printing in various designs: Gyroid, Lidinoid, Fischer–Koch, IWP, and Voronoi. Results demonstrated that Gyroid scaffolds had the highest compressive strength (6.6 MPa), followed by Lidinoid, Fischer–Koch, IWP, and Voronoi designs. Increased strut thickness was linked to higher compressive strength. However, normalized fatigue resistance showed a different pattern. While scaffolds resisted fatigue cycles at low strain amplitudes, fatigue damage was observed at higher strains. Voronoi structures exhibited the highest normalized fatigue performance, enduring around 58,000 cycles at 85% strain amplitude, followed by Gyroid, Fischer–Koch, Lidinoid, and IWP structures. Enhanced fatigue performance in different topologies correlated with the minimum cross-sectional area of scaffolds. Given the importance of both static and fatigue strength, the Gyroid topology emerges as the superior choice overall. [ABSTRACT FROM AUTHOR]

The joint video experts team (JVET) has recently finalized a next-generation open-source video codec, called versatile video coding (VVC). The new standard presents a higher gain in the run time and rate compressions. Based on the reference software (VTM, VVC Test Model) of VVC, an optimized encoder was developed these last years resulting in a fast and efficient encoder, called Fraunhofer versatile video encoder (VVenC). Based on the Bjontegaard methodology and the GPROF profiling tool, this paper presents a technical complexity analysis and comparison of both VVC and VVenC. The appropriate comparisons cover the percentage taken by each block in terms of processing time and the resulting whole encoding time. The peak signal-to-noise ratio (PSNR) and bit rate between VVC and VVenC encoders based on the common test conditions manual are also analyzed and compared. The profiling results show that the VVenC encoder presents a maximum gain of runtime and bit rate of 90% and 20% respectively in classes A and D test sequences, compared to the VVC encoder. [ABSTRACT FROM AUTHOR]

Sensors commonly used to record sub-bandage pressures may be less reliable than is commonly believed. The techniques employed for the calibration or validation of these devices can sometimes produce a highly inaccurate prediction of their performance in vivo. In this review, the various calibration methods referenced in the literature are briefly described and the limitations of each discussed. The significance of these limitations is illustrated by reference to the results of published studies cited in a systematic review which report widely different values for the accuracy of one particular device, the Kikuhime pressure measuring system (ZiboCare, Denmark). The use of inappropriate calibration techniques therefore casts serious doubt upon the pressure values quoted historically in many published scientific and clinical studies in which these particular instruments have been employed. It is proposed that an international standard method be developed to ensure that all sensors intended for the measurement of sub-bandage pressure are characterised using a validated, clinically relevant technique. A programme of education is also required to correct some of the widely held misconceptions often expressed in the literature concerning the use of the Laplace equation to calculate sub-bandage pressure. [ABSTRACT FROM AUTHOR]

A fabric touch tester is a novel instrument with fabric handling properties. Its principal advantage is that the device has integrated modules for compression, surface friction, and thermal and bending properties. This module integration simplifies the testing process, and provides an efficient measurement method, and a comprehensive physical index. This study focused on woven fabrics for dress shirts. The fabric samples comprised three groups with various yarn compositions – that is, cotton, polyester, and wool. Sample group 1 was composed of cotton, polyester, and blended yarns; sample group 2 mainly compared the effect of twist yarns on the fabric touch; and sample group 3 was composed of wool and blended yarns with polyester. The handling properties were assessed by compression work and the compression recovery rate for the compression attributes. The results revealed that fabric (T100p1) with high twist-level yarns had a higher value of compression work (242.56 gf*mm2), and the texture type may affect the compression characteristics more significantly than the blending ratio. The fabric touch tester can also distinguish small changes in the compression properties of samples (0.43–0.71), the maximum heat flux and surface roughness amplitude for the thermal and surface roughness properties. The results revealed that the maximum heat flux value of all the samples in this study was 1109 Wm−2, the sample C100 using pure cotton yarn had the highest maximum heat flux value (1270 Wm−2). Moreover, the sample W100 with 100% wool fiber yarn had the highest surface roughness amplitude in the warp direction (81 μm) and surface roughness amplitude in the weft direction (67 μm). Finally, the bending average rigidity was used to assess the bending performance of the fabric samples. These fabric touch tester indicators were applied to analyze the fabric handling characteristics of woven shirting fabrics, and perform cross-analysis among samples. [ABSTRACT FROM AUTHOR]

As we move into the digital era, the pace of technological advancement is accelerating rapidly. Network traffic often becomes congested during the transmission of large data volumes. To mitigate this, data compression plays a crucial role in minimizing transmitted data. Vector quantization (VQ) stands out as a potent compression technique where each image block is encoded independently as an index linked to a codebook, effectively reducing the bit rate. In this paper, we introduce a novel scheme for recompressing VQ indices, enabling lossless restoration of the original indices during decoding without compromising visual quality. Our method not only considers pixel correlations within each image block but also leverages correlations between neighboring blocks, further optimizing the bit rate. The experimental results demonstrated the superior performance of our approach over existing methods. [ABSTRACT FROM AUTHOR]

The durability of sandstones of historical building materials and geoheritage landforms is a major issue that requires an assessment methodology to follow salt weathering evolution. The building blocks of monuments support decorative carvings and reliefs that are outstanding testimonies of human activity. An evaluation based on quasi- and non-destructive testing is a reliable and generally accepted way of testing and inspecting historical building materials. Compression tests were performed on specimens of similar building sandstones extracted close to those of from St. Leonard's Middle Ages Church, and microdrilling tests were carried out on adequate blocks of this monument. The locations of the latter tests were determined using the results of low-pressure water absorption tests, which contributed to finding a link between the sandstone specimens and the building blocks of the monument. This innovative methodology was used to generate simulated stress–strain diagrams of the building blocks of this church based on drilling strength results, avoiding the cutting of specimens from the façades with the sizes needed to ensure the mechanical validity of the results. A good agreement between the predicted and experimental stress–strain curves was achieved. The stress–strain curves of sound stones from historical building blocks and of their weathered envelopes are shown. The evolution of weathering profiles can be followed through the analysis of stress–strain diagrams, allowing an assessment of structural stability, which is essential to the study of the durability of historical building sandstones. This innovative methodology allows the adequate conservation of monuments and is a contribution to the knowledge of sustainable cultural tourism. [ABSTRACT FROM AUTHOR]

The problem of layout segmentation is still very challenging in document images like newspapers, magazines, and research articles, that have both text and non-text components arranged in an artistic way to attract various types of readers. Traditionally, layout segmentation has been carried out in the pixel domain, with an assumption that images are always available in the uncompressed pixel form. However, in reality, the images are acquired and rendered in the compressed form, and therefore the traditional techniques require additional stage of decompression to get back the images in the pixel form for further processing. Therefore, in this research paper, the idea of direct layout segmentation in compressed document images is proposed, to bypass the decompression stage and at the same time provide good performance with reduced computation time. This paper proposes to explore a novel deep learning architecture called as DCT-CompSegNet, that learns features straight from the DCT compressed streams of JPEG documents to accomplish layout segmentation directly in the JPEG compressed domain. Unlike the existing layout segmentation methods that work in pixel domain, the novelty here is that a compressed stream of DCT coefficients extracted from the JPEG documents is used to train the deep learning network. The feature learning in the model is so efficient that it is capable of accomplishing layout segmentation in both printed as well as handwritten document images with state-of-the-art performance. Experiments have been carried out using two benchmark datasets - Publay and Prima consisting of complex machine-printed document images, and the robustness of the model is also demonstrated with the self-created Handwritten dataset. [ABSTRACT FROM AUTHOR]