Optimal Compression Research Articles

Optimal edge thinning compression and similarity based data hiding for 5G empowered architecture

Optimal edge thinning compression and similarity based data hiding for 5G empowered architecture

Scaling Data Infrastructure for High-Volume Manufacturing: Challenges and Solutions in Big Data Engineering

Abstract—Scaling data infrastructure for high- volume manufacturing presents significant challenges owing to the rapid growth, diversity, and complexity of the data generated by modern production processes. This review explores the key challenges and solutions in big-data engineering to enable efficient, scalable, and reliable data management in manufacturing environments. The primary challenges include handling the volume, velocity, and variety of data; ensuring real-time processing and analysis; managing data storage and retrieval at scale; and maintaining data quality and consistency. To address these challenges, various big data engineering solutions have been discussed, including distributed computing frameworks, cloud-based storage and computing resources, data lakes, data governance and metadata management, stream processing technologies, machine learning, and AI for predictive analytics. This review also examines the role of data architecture and infrastructure in building scalable systems, highlighting the importance of microservices, containerization, orchestration, NoSQL databases, and data security and privacy. Performance optimization techniques, such as query optimization, data partitioning, sharding, caching, and data compression, have been explored to ensure efficient operation of large-scale data systems. The review includes case studies of successful implementations and discusses emerging trends, such as edge computing, and the growing importance of data interoperability and standardization. Future research directions were identified, emphasizing the need for ongoing development in this field to meet the ever- growing demand for high-volume manufacturing. Keywords—high-volume manufacturing, big data, data infrastructure, distributed computing frameworks, cloud computing, data lakes, microservices, containerization, orchestration, query optimization, data partitioning, sharding, caching, data compression

Convolutional auto-encoder and discrete wavelet transform for lossy region-based medical image compression

Medical imaging is a vital and ever-evolving discipline that plays a critical role in detecting, diagnosing, and planning surgeries for diseases. In medical imaging, image compression systems are employed to reduce storage and bandwidth requirements. This paper presents a region of interest (ROI) based image compression method for brain MRI images by employing a convolutional auto-encoder (CAE) and discrete wavelet transform (DWT) to achieve both efficient compression and high-quality reconstruction in terms of lossy compression. Our compression approach involves separating image regions, employing a lossy compression technique based on CAE and DWT, with a lossless compression technique based arithmetic encoding. To achieve optimal compression of non-ROI regions, the encoding network of the CAE generates a compacted feature map that preserves structural information, which aids the DWT based codec and the decoding network of the CAE in reconstructing the output. To maintain diagnostically significant information, the ROI portion of the image is losslessly compressed using arithmetic encoding technique. To assess the effectiveness of our proposed method, we compared our results to standard lossy compression algorithms and recent approaches. Our method achieved a peak signal-to-noise ratio (PSNR) of 37.91 dB and a mean structural similarity index measure (MS-SSIM) of 98.62% at a high compression ratio of 30.

An efficient optimized encryption and compression techniques to improve medical image security and transmission in the cloud

As digital technology for illness diagnosis and analysis has advanced, medical images are sent over the Internet. Cloud computing plays a major role for low-cost data storage and data sharing. In the healthcare industry, data security and privacy are key issues with cloud computing. It is imperative that healthcare professionals make sure that patient data is safe against hackers, unauthorized access, and thrift. To secure the confidential data and store the huge amount of data, encryption and compression techniques are used. This paper provides an enhanced optimized encryption and efficient hybrid compression strategies based on cloud environment. The proposed model involves various operations such as generate optimal key, encryption, compression, decompression and decryption. In order to transfer the data using high speed cloud data retrieval, we initially propose the Huffman Fano Hybrid Entropy approach. In the next step, the proposed model performs Elliptic Curve Coding based encryption technique to secure compressed medical image transmission. Here the shared secret keys are generated optimally by dynamic group based cooperative optimization algorithm, which makes use of the encryption quality measures and is called DGBCO–ECC model. On the receiving end, the image is decrypted and decompressed. The proposed model performance is validated by exploiting various parameters namely Mean Square Error, Standard Deviation of the Mean Error, Universal image quality index, Structural Similarity Index, Entropy, Peak Signal to Noise Ratio, Compression Ratio, Data Rate Saving and compression time. When the experimental outcome is contrasted with existing methods, it is found to perform better.

Massive Compression for High Data Rate Macromolecular Crystallography (HDRMX): Impact on Diffraction Data and Subsequent Structural Analysis.

New higher-count-rate, integrating, large area X-ray detectors with framing rates as high as 17,400 images per second are beginning to be available. These will soon be used for specialized MX experiments but will require optimal lossy compression algorithms to enable systems to keep up with data throughput. Some information may be lost. Can we minimize this loss with acceptable impact on structural information?

The impact of lossy data compression on the power spectrum of the high-redshift 21 cm signal with LOFAR

Current radio interferometers output multi-petabyte-scale volumes of data per year, making the storage, transfer, and processing of these data a sizeable challenge. This challenge is expected to grow with next-generation telescopes such as the Square Kilometre Array (SKA), which will produce a considerably larger data volume than current instruments. Lossy compression of interferometric data post-correlation can abate this challenge, but any drawbacks from the compression should be well understood in advance. Lossy data compression reduces the precision of data, introducing additional noise. Since high-redshift (e.g., cosmic dawn or epoch of reionization) 21 cm studies impose strict precision requirements, the impact of this effect on the 21 cm signal power spectrum statistic is investigated in a bid to rule out unwanted systematics. We applied dysco visibility compression, a technique for normalizing and quantizing specifically designed for radio interferometric data, to observed visibilities datasets from the LOFAR telescope as well as simulated ones. The power spectrum of these data was analyzed, and we establish the level of the compression noise in the power spectrum in comparison to the thermal noise. We also examined its coherency behavior by employing the cross-coherence metric. Finally, for optimal compression results, we compared the compression noise obtained from different compression settings to a nominal 21 cm signal power. From a single night of observation, we find that the noise introduced due to the compression is more than five orders of magnitude lower than the thermal noise level in the power spectrum. The noise does not affect calibration. Furthermore, the noise remains subdominant to the noise introduced by the nonlinear calibration algorithm used following random parameter initialization across different runs. The compression noise shows no correlation with the sky signal and has no measurable coherent component, therefore averaging down optimally with the integration of more data. The level of compression error in the power spectrum ultimately depends on the compression settings. dysco visibility compression is found to be an insignificant concern for 21 cm power spectrum studies. Hence, data volumes can be safely reduced by factors of $ 4$ with insignificant bias to the final power spectrum. Data from SKA-Low will likely be compressible by the same factor as data from LOFAR owing to the similarities of the two instruments. The same technique can be used to compress data from other telescopes, but a small adjustment of the compression parameters might be required.

Compression of Porous Transport Layers Enhanced Bubble Transport in Polymer Electrolyte Membrane Water Electrolyzers

At high current densities, oxygen bubble formation limits the performance of polymer electrolyte membrane (PEM) water electrolyzers, particularly due to bubble accumulation at the porous transport layer (PTL)/catalyst layer (CL) interface. Efficient bubble removal from the PTL/CL interface is therefore crucial for PEM water electrolyzers1,2. Bubble transport at the PTL/CL interface is dominated by mechanical compression 3,4. However, it is still unclear how mechanical compression impacts bubble transport at the PTL/CL interface, due to difficulties in capturing the multiphase flow and differentiating liquid/gas in the pores of the titanium PTL. Thanks to its spatial resolution and high transmissivity for titanium, neutron imaging enables visualization of the bubble distribution in the PTL hence allowing for the identification of the role of compression in the bubble transport.We conducted operando neutron imaging for PEM water electrolyzers and examined the relationship between compression ratio and electrochemical performance. Neutron imaging results showed that the through-plane bubble distributions became more homogeneous as compression increased. Additionally, pore network modelling simulations indicated that compression-induced catalyst coated membrane intrusion homogenized the bubble distribution in the PTL. We identified an optimal compression condition for enhanced interfacial bubble transport that can contribute to the next-generation material development to improve the efficiency of PEM water electrolyzers at high current densities with low mass transport losses. References J. K. Lee and A. Bazylak, Joule, 5, 19–21 (2021).S. Yuan et al., Prog. Energy Combust. Sci., 96, 101075 (2023).T. Schuler, T. J. Schmidt, and F. N. Büchi, J. Electrochem. Soc., 166, F555–F565 (2019).A. Martin et al., J. Electrochem. Soc., 169, 014502 (2022).

In Situ Crosslinked Biodegradable Hydrogels Based on Poly(Ethylene Glycol) and Poly(ε-Lysine) for Medical Application.

Hydrogels have emerged as promising biomaterials due to their excellent performance; however, their biocompatibility, biodegradability, and absorbability still require improvement to support a broader range of medical applications. This paper presents a new biofunctionalized hydrogel based on in situ crosslinking between maleimide-terminated four-arm-poly(ethylene glycol) (4-arm-PEG-Mal) and poly(ε-lysine) (ε-PL). The PEG/ε-PL hydrogels, named LG-n, were rapidly formed via amine/maleimide reaction by mixing 4-arm-PEG-Mal and ε-PL under physiological conditions. The corresponding dry gels (DLG-n) were obtained through a freeze-drying technique. 1H NMR, FT-IR, and SEM were utilized to confirm the structures of 4-arm-PEG-Mal and LG-n (or DLG-n), and the effects of solid content on the physicochemical properties of the hydrogels were investigated. Although high solid content could increase the swelling ratio, all LG-n samples exhibited a low equilibrium swelling ratio of less than 30%. LG-7, which contained moderate solid content, exhibited optimal compression properties characterized by a compressive fracture strength of 45.2 kPa and a deformation of 69.5%. Compression cycle tests revealed that LG-n demonstrated good anti-fatigue performance. In vitro degradation studies confirmed the biodegradability of LG-n, with the degradation rate primarily governing the drug (ceftibuten) release efficiency, leading to a sustained release duration of four weeks. Cytotoxicity tests, cell survival morphology observation, live/dead assays, and hemolysis tests indicated that LG-n exhibited excellent cytocompatibility and low hemolysis rates (<5%). Furthermore, the broad-spectrum antibacterial activity of LG-n was verified by an inhibition zone method. In conclusion, the developed LG-n hydrogels hold promising applications in the medical field, particularly as drug sustained-release carriers and wound dressings.

Optimal Intermediate Pressure Investigation in a CO₂ Transcritical Distributed Compression Refrigeration Cycle

The CO2 transcritical distributed compression cycle proposal provides a novel approach for refrigerant cooling in traditional transcritical cycles. This paper employed an exhaustive search method to derive the correlation formula for the optimal intermediate pressure. From the perspectives of thermodynamic performance and economics, a comparative analysis was conducted between the cycle established under the optimal intermediate pressure obtained in this study, the cycle based on equal compression ratios in traditional two-stage compression cycles, and the cycle established using the optimal secondary compression ratio method based on low-pressure stage discharge pressure mentioned in previous literature study. The research results indicate that the system's COP calculated using the obtained optimal intermediate pressure correlation method can be improved by up to 7.26% and 5.32%, respectively, compared to the traditional and literature-based methods. The exergy loss with the optimal intermediate pressure method is less than with the other two methods. The entransy dissipation rate of the system obtained using the optimal intermediate pressure correlation method is 24.61% and 50.14% lower than that of the traditional and literature-based methods, respectively. The investment cost of the main components using the optimal intermediate pressure correlation method is about 5% higher than that of the traditional method and about 1% higher than that of the optimal pressure ratio method. However, the total annual cost rate of the system is the lowest. The research enriches and improves the theory of the CO₂ transcritical distributed compression cycle, thereby facilitating the advancement of practical applications based on this cycle theory.

Adaptive Prediction Structure for Learned Video Compression

Learned video compression has developed rapidly and shown competitive rate-distortion performance compared with the latest traditional video coding standard H.266 (VVC). However, existing works were restricted to fixed prediction direction and GoP size. The inflexibility on prediction structure hinders learned video compression towards optimal compression efficiency in diverse motion scenarios. In this paper, we propose to advance learned video compression with adaptive prediction structure decision. Specifically, we propose a unified compression framework that supports both forward prediction and bi-directional prediction. The framework can flexibly switch to different prediction direction to achieve better prediction performance. Meanwhile, we propose a low-complexity prediction structure decision algorithm, where prediction direction and GoP size are adaptively determined based on motion complexity to achieve optimal compression efficiency. Experimental results demonstrate that the proposed unified framework with adaptive decision algorithm improves compression efficiency of pure forward prediction-based or bi-directional prediction-based framework with neglectable ( \(0.9\%\) ) encoding time increment. Meanwhile, it achieves comparable compression performance with VVC and recent learned video coding methods.

Gender-Based Differences in the Biomechanical Behavior of the Thorax During CPR Maneuvers.

In this study, 18 rib cages (8 males and 10 females) were segmented from computer tomography (CT) images. In order to analyze the potential differences in thoracic biomechanics during cardiopulmonary resuscitation (CPR), a set of numerical experiments was conducted using finite elements (FE). Compression forces were applied at different points on the rib cage. Results indicated that the optimal compression area for both sexes is the sternum at the 5th rib level, requiring the least force to achieve the desired compression depth. Males required greater force than females. Among females, those with lower width/depth ratios (more rounded thoracic shape) required less force compared to those with higher ratios (more oval-shaped thorax).

Investigating experimentally the performances of a natural gas reciprocating compressor adapted to pure hydrogen up to 30 MPa

Abstract Hydrogen as an energy carrier can be integrated into various value chains, enabling the decarbonization of hard-to-abate processes. Hydrogen storage is necessary to handle the intermittency of renewables. Moreover, it allows hydrogen to be deployed in sectors such as mobility and backup power. Currently, high-pressure vessels are typically used for hydrogen storage. The compression process is required since hydrogen production occurs at lower pressure than storage. This study examines a three-stage reciprocating compressor for natural gas, which is operated with pure hydrogen. The compressor, driven by a 3-kW electric motor, can deliver 30 MPa starting from pressures between 0.3 and 0.8 MPa. The aim is to assess the energy impact of compression on hydrogen production and analyze potential issues such as leakages or contamination that can arise after changing the Gluid. The study involves measuring hydrogen Glow rates, inlet and outlet pressures, and electric power consumption during the Gilling of a vessel. The experiment shows a specific power input of 1.2 kW/(Nm3/h), more than 1/3 of the lower heating value, maximum isothermal efficiency of 21% and maximum isentropic efficiency of 34%. The optimal compression ratio is found to be between 25 and 30. Based on the few data available in literature, the performances do not reach state-of-art levels of 55-80% isentropic efficiency. However, the device was optimized for the compression of natural gas, and the scope of this study was to use it with fewer possible modifications.

Analysis of behavior and uniaxial compression failure modes in ungrouted hollow concrete block masonry and their implication in design expressions

In this study, new analytical expressions for the design and revision of ungrouted masonry of hollow concrete blocks under gravitational effects were developed. These expressions can predict the compressive strength and modulus of elasticity for full and face-shell mortar beddings. A trend chart was generated, considering various modes of failure for different strength relationships between blocks and mortar. The study revealed that the main international masonry design codes underestimate the compression resistance of masonry when using weak mortar in combination with full mortar bedding. Results obtained using the Finite Element Method indicated that the optimal compression strength ranges were: 62–70 % for weaker mortar than the block with full mortar bedding; 152 % for block weaker than the mortar with full mortar bedding; and close to 67 % with face-shell bedding mortar.

Non-collinear bipulse reconstruction via dispersion scan.

Light pulses in the femtosecond range require sophisticated methods for their precise temporal characterization. Several techniques have been developed over the past decades that deliver the temporal structure of ultrashort light pulses. Still, there are special cases left that cannot be treated directly by established methods. Here we expand the applicability of existing tools to the case of non-collinear propagation of a pair of identical pulses with an unknown, but fixed temporal spacing. By applying the successful dispersion scan (d-scan) technique to a setup known from the established frequency-resolved optical gating (FROG) technique, we record a rather peculiar measurement trace. A nonlinear signal is only generated outside optimal temporal compression, in contrast to previously used techniques. This feature enables an improved dynamic range for the measurement of the temporal wings of a pulse. We expand a well-established retrieval algorithm to reconstruct the pulse structure from the measurement data. Our results are confirmed by comparison to d-scan and FROG measurements.

Widely wavelength-tunable high-repetition-rate femtosecond pulse source with highest average power up to 28 W

We have proposed and demonstrated a high-repetition-rate ultrashort pulse fiber amplification system based on a wavelength-tunable oscillator. This fiber amplification system produces an average power exceeding 20 W in bursts of 200 pulses with a 578 MHz intra-burst pulse repetition rate and a 1 MHz burst repetition rate. The center wavelength of the amplified pulses can be tuned from 1030 to 1080 nm. By utilizing pre-chirp management nonlinear amplification technique, the achieved shortest pulse duration is 27 fs with an average power of 25 W at 1032 nm. For all the amplified pulses with different wavelengths, the pulse duration after optimal compression is below 60 fs. To the best of our knowledge, this is the first time that a widely wavelength-tunable high-power laser with a repetition rate exceeding 100 MHz and a pulse duration of several tens of femtoseconds has been realized. Additionally, using only common double-cladding Yb-doped fiber as the gain fiber, without any large-mode-area Yb-doped photonic crystal fiber or rod-type Yb-doped fiber, makes the system compact and reliable due to the simple fusion operation.

Structural optimization design and compression performance of porous titanium prepared by laser powder bed fusion

Porous implants composed of periodically-repeating porous units have been applied in orthopedic surgeries to replace damaged bones. An important requirement for bone implants is to find a balance between biological and mechanical properties, that is, to ensure high pore connectivity and a certain strength. In this work, center-supported and perimeter-supported porous optimization models were established by a swarm intelligence optimization algorithm, and the corresponding titanium porous samples were fabricated by laser powder bed fusion (L-PBF). The effects of cell topology and porosity on the compressive behavior of L-PBF titanium porous structures were systematically investigated by a combination of compression simulation and experiments. Compression simulation shows that the deformation failure behavior of center-supported and perimeter-supported porous structures consists of three stages: elastic deformation, plastic deformation and compression collapse, showing the characteristics of elastic-plastic porous materials. According to the compression test results, the compressive strength of center-supported and perimeter-supported structure samples are 151–188 MPa and 178–196 MPa, respectively, and the compressive stability of the perimeter-supported structure is better than that of the center-supported structure. The porosity error of center-supported structure is 1.6%–2.9%, and the porosity error of perimeter-supported structure is 3.1%–4.5%. The compressive strength of the same type of structure decreases with the increase of the porosity of the porous structure. The simulation/experimental compressive strength errors of center-supported and perimeter-supported structures are less than 6% and 5.9%, respectively. The constructed quasi-static compression model has certain guiding significance for the study of the fracture of the titanium implants under external force.

Continuous muscle pump activation by neuromuscular electrical stimulation of the common peroneal nerve in the treatment of patients with venous leg ulcers: A position paper.

The standard treatment for patients with confirmed Venous Leg Ulcers (VLUs) is compression therapy to improve the function of the calf muscle pump. There is a significant cohort of patients who are unable to tolerate optimal compression therapy or indeed any level of compression therapy. In addition, there is a cohort of patients who can tolerate compression whose ulcers show little or no evidence of healing. There is a need for ways to further improve calf muscle pump function and to improve venous ulcer healing in these patients. Published data were reviewed on the use of Muscle Pump Activation (MPA) using common peroneal nerve neuromuscular electrical stimulation (NMES) to improve calf muscle pump function. There is physiological evidence that MPA can improve calf muscle pump function and venous return in both control subjects and in patients with venous disease. The use of MPA has also been shown to improve venous flow volume and venous flow velocity on ultrasound scanning in patients with venous disease. MPA has been shown to improve microcirculation in the skin using Laser Doppler and laser Doppler Speckle Contrast Imaging, in both normal subjects as well as in patients with venous disease and VLU. A recent randomized controlled trial of MPA plus compression therapy compared with compression therapy alone, found significantly faster rates of healing with the use of MPA in addition to compression therapy. There are indications for the use of MPA as an adjunctive treatment to enhance calf muscle pump function in patients with VLU: who cannot tolerate compression therapy who can only tolerate suboptimal, low-level compression whose ulcer healing remains slow or stalled with optimal compression.

Optimal Positioning of Load-Distributing Band CPR Device by Body Mass Index.

Background: Research investigating the optimal compression position for load-distributing bands (LDBs) in treating cardiac arrest is limited This study aimed to determine the optimal LDB position based on body mass index (BMI). Methods: A simulation study was conducted using chest and abdominal computed tomography imaging data collected with patients in the arms-down position. Participants were categorized into three BMI groups: low (<18.5 kg/m2), normal (18.5-25 kg/m2), and high (≥25 kg/m2). The assumed compression area was 20 cm below the axilla. The optimal compression position was identified by adjusting the axilla to maximize the thorax-to-abdomen volume ratio (TAR) and the covered heart volume ratio (CHR), defined as the ratio of heart volume compressed by the LDB to total heart volume. Optimal compression positions were compared across BMI groups. Results: Among 117 patients, TAR was significantly lower in the low BMI group compared to the normal and high BMI groups (p < 0.001), while CHR differences were not significant (p = 0.011). The distance between the optimal position and axilla height was significantly greater in the normal and high BMI groups than in the low BMI group (46.5 cm vs. 66.0 cm vs. 72 cm, respectively; p < 0.001). For each unit increase in BMI, the optimal position shifted significantly cephalad relative to axilla height (β coefficient 2.39, adjusted p < 0.001). Conclusions: Significant differences in TAR were observed among BMI groups. As BMI increased, the optimal LDB position shifted progressively cephalad.

2D Discrete Element Simulation of Electrode Structural Evolutions in Li‐Ion Battery During Drying and Calendering

Drying and calendering are critical steps in the manufacture of electrodes for lithium‐ion battery that affect their mechanical and electrochemical properties. A 2D representative volume element (RVE) model, including active material and carbon binder domain particles of different shapes and sizes, is developed. The evolution of the RVE structure is simulated using the discrete element method, providing insight into changes in velocity, coordination number, porosity, pore size distribution, tortuosity, and stress. Based on this analysis, a three‐step drying scheme is proposed in accordance with the experimental drying results. In addition, the calendering process significantly improves the mechanical integrity and electronic conductivity of the electrode. Through simulations and experimental observations of changes in surface morphology and porosity, an optimal compression ratio of about 20% is determined for the electrode.

Effects of stiffness-altered sport compression garments on lower-limb biomechanics in cutting maneuvers

Athletes commonly use compression garments (CGs) for perceived effectiveness in preventing injury occurrence. However, limited evidence is available on whether lower-limb CGs reduce the risk of injury. This study aimed at (1) evaluating the effects of CGs on mitigating the risk factors of cutting-related knee injuries; (2) identifying undesirable side-effects of CGs on other joints and cutting performance; and (3) identifying possible interactions between sex and condition. 62 healthy adults performed pre-planned 90˚ cutting tasks under four conditions: control, knee sleeves, placebo leggings and stiffness-altered leggings. Joint angle at initial contact, range of motion, moments, and ground reaction force were measured. A mixed two-way (sex*condition) ANOVA was performed, followed by post-hoc comparisons and subset analyses for sexes. Results showed that the leggings restricted hip sagittal (45.4 ± 1.3 vs. control 50.0 ± 1.3˚, p = 0.001) and rotational (16.8 ± 0.8 vs. control 22.5 ± 1.1˚, p < 0.001) motion. At initial contact, the stiffness-altered leggings reduced knee valgus (0.4 ± 0.8 vs. control −2.1 ± 0.8˚, p = 0.031). However, the altered alignment of lower-limb joints did not reduce multiplanar knee joint moments (p > 0.05). CGs were not effective protective equipment yet. There was no significant difference between knee sleeves and control, nor between leggings conditions (p > 0.05). Force plate measurements, such as increased rate of force development (stiffness-altered 42.6 ± 1.1 & placebo 42.9 ± 1.1 vs. control 39.9 ± 1.0 BW/s, p < 0.028), implied the possibility of performance enhancement through CGs. While further investigations on the optimal compression and stiffness alterations are warranted, athletes are recommended to be aware of the discrepancies between the claimed and actual biomechanical effects of CGs.