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Journal articles on the topic 'Data compression (Computer science) – Testing'

Author: Grafiati

Published: 4 June 2021

Last updated: 7 February 2022

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1

Permuter, Haim H., Young-Han Kim, and Tsachy Weissman. "Interpretations of Directed Information in Portfolio Theory, Data Compression, and Hypothesis Testing." IEEE Transactions on Information Theory 57, no. 6 (June 2011): 3248–59. http://dx.doi.org/10.1109/tit.2011.2136270.

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2

Jung, Jun-Mo, and Jong-Wha Chong. "Efficient Test Data Compression and Low Power Scan Testing in SoCs." ETRI Journal 25, no. 5 (October 14, 2003): 321–27. http://dx.doi.org/10.4218/etrij.03.0303.0017.

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3

Ruan, Xiaoyu, and Rajendra S. Katti. "Data-Independent Pattern Run-Length Compression for Testing Embedded Cores in SoCs." IEEE Transactions on Computers 56, no. 4 (April 2007): 545–56. http://dx.doi.org/10.1109/tc.2007.1007.

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4

Minkin, A. S., O. V. Nikolaeva, and A. A. Russkov. "Hyperspectral data compression based upon the principal component analysis." Computer Optics 45, no. 2 (April 2021): 235–44. http://dx.doi.org/10.18287/2412-6179-co-806.

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The paper is aimed at developing an algorithm of hyperspectral data compression that combines small losses with high compression rate. The algorithm relies on a principal component analysis and a method of exhaustion. The principal components are singular vectors of an initial signal matrix, which are found by the method of exhaustion. A retrieved signal matrix is formed in parallel. The process continues until a required retrieval error is attained. The algorithm is described in detail and input and output parameters are specified. Testing is performed using AVIRIS data (Airborne Visible-Infrared Imaging Spectrometer). Three images of differently looking sky (clear sky, partly clouded sky, and overcast skies) are analyzed. For each image, testing is performed for all spectral bands and for a set of bands from which high water-vapour absorption bands are excluded. Retrieval errors versus compression rates are presented. The error formulas include the root mean square deviation, the noise-to-signal ratio, the mean structural similarity index, and the mean relative deviation. It is shown that the retrieval errors decrease by more than an order of magnitude if spectral bands with high gas absorption are disregarded. It is shown that the reason is that weak signals in the absorption bands are measured with great errors, leading to a weak dependence between the spectra in different spatial pixels. A mean cosine distance between the spectra in different spatial pixels is suggested to be used to assess the image compressibility.

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5

Li, L., K. Chakrabarty, S. Kajihara, and S. Swaminathan. "Three-stage compression approach to reduce test data volume and testing time for IP cores in SOCs." IEE Proceedings - Computers and Digital Techniques 152, no. 6 (2005): 704. http://dx.doi.org/10.1049/ip-cdt:20045150.

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6

Zhang, He, Fatick Nath, Prathmesh Naik Parrikar, and Mehdi Mokhtari. "Analyzing the Validity of Brazilian Testing Using Digital Image Correlation and Numerical Simulation Techniques." Energies 13, no. 6 (March 19, 2020): 1441. http://dx.doi.org/10.3390/en13061441.

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Characterizing the mechanical behavior of rocks plays a crucial role to optimize the fracturing process in unconventional reservoirs. However, due to the intrinsic anisotropy and heterogeneity in unconventional resources, fracture process prediction remains the most significant challenge for sustainable and economic hydrocarbon production. During the deformation tracking under compression, deploying conventional methods (strain gauge, extensometer, etc.) is insufficient to measure the deformation since the physical attachment of the device is restricted to the size of the sample, monitoring limited point-wise deformation, producing difficulties in data retrieval, and a tendency to lose track in failure points, etc. Where conventional methods are limited, the application of digital image correlation (DIC) provides detailed and additional information of strain evolution and fracture patterns under loading. DIC is an image-based optical method that records an object with a camera and monitors the random contrast speckle pattern painted on the facing surface of the specimen. To overcome the existing limitations, this paper presents numerical modeling of Brazilian disc tests under quasi-static conditions to understand the full-field deformation behaviors and finally, it is validated by DIC. As the direct tensile test has limitations in sample preparation and test execution, the Brazilian testing principle is commonly used to evaluate indirectly the tensile strength of rocks. The two-dimensional numerical model was built to predict the stress distribution and full-field deformation on Brazilian disc under compression based on the assumptions of a homogenous, isotropic and linear elastic material. The uniaxial compression test was conducted using the DIC technique to determine the elastic properties of Spider Berea sandstone, which were used as inputs for the simulation model. The model was verified by the analytical solution and compared with the digital image correlation. The numerical simulation results showed that the solutions matched reasonably with the analytical solutions where the maximum deviation of stress distribution was obtained as 14.59%. The strain evolution (normal and shear strains) and displacements along the central horizontal and vertical planes were investigated in three distinguishable percentages of peak loads (20%, 40%, and 90%) to understand the deformation behaviors in rock. The simulation results demonstrated that the strain evolution contours consistently matched with DIC generated contours with a reasonable agreement. The changes in displacement along the central horizontal and vertical planes showed that numerical simulation and DIC generated experimental results were repeatable and matched closely. In terms of validation, Brazilian testing to measure the indirect tensile strength of rocks is still an issue of debate. The numerical model of fracture propagation supported by digital image correlation from this study can be used to explain the fracturing process in the homogeneous material and can be extended to non-homogeneous cases by incorporating heterogeneity, which is essential for rock mechanics field applications.

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7

Meng, Qingbin, Yanlong Chen, Mingwei Zhang, Lijun Han, Hai Pu, and Jiangfeng Liu. "On the Kaiser Effect of Rock under Cyclic Loading and Unloading Conditions: Insights from Acoustic Emission Monitoring." Energies 12, no. 17 (August 23, 2019): 3255. http://dx.doi.org/10.3390/en12173255.

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The Kaiser effect reflects the memory of the loaded rock to the irreversible damage and deformation. The stress level, loading rate and lithology are the main factors affecting the Kaiser effect of the rock. To identify the accurate stress point of the Kaiser effect, the MTS 816 rock mechanics testing system and the DS5-A acoustic emission testing and analysis system were adopted. The uniaxial cyclic loading–unloading and acoustic emission characteristic test of 90 rock specimens from three types of rocks under different stress level and loading rate was carried out. The evolution of acoustic emission under uniaxial compression of the rock corresponds to the compaction stage, elastic stage, yield stage and post-peak stress drop stage of the rock deformation and failure process and is divided into the quiet period, transition period, active period and decay period of the acoustic emission. The larger the hardness of rock is, the earlier the stress point of the Kaiser effect appears. The loading stress level (σA) has appreciable influence on the Kaiser effect of the rock. When σA ≥ 0.7σc, the Kaiser effect disappears. Usually, the dilatancy stress (crack initiation stress) does not exceed 70% of the uniaxial compressive strength (σc) of the rock, and the stress point can be the threshold to determine whether the Kaiser effect occurs. The influence of loading rate (lr) on Felicity rate (FR) is relatively large when lr < 0.01 mm/s, and FR rapidly grows with increase of the loading rate. When lr ≥ 0.01 mm/s, the influence of the loading rate on FR is relatively small. The findings facilitate the future application of the Kaiser effect and improvement of the accuracy of the acoustic emission data interpretation.

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8

Cican, Grigore, Marius Deaconu, and Daniel-Eugeniu Crunteanu. "Impact of Using Chevrons Nozzle on the Acoustics and Performances of a Micro Turbojet Engine." Applied Sciences 11, no. 11 (June 2, 2021): 5158. http://dx.doi.org/10.3390/app11115158.

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This paper presents a study regarding the noise reduction of the turbojet engine, in particular the jet noise of a micro turbojet engine. The results of the measurement campaign are presented followed by a performances analysis which is based on the measured data by the test bench. Within the tests, beside the baseline nozzle other two nozzles with chevrons were tested and evaluated. First type of nozzle is foreseen with eight triangular chevrons, the length of the chevrons being L = 10 percentages from the equivalent diameter and an immersion angle of I = 0 deg. For the second nozzle the length and the immersion angle were maintained, only the chevrons number were increased at 16. The micro turbojet engine has been tested at four different regimes of speed. The engine performances were monitored by measuring the fuel flow, the temperature in front of the turbine, the intake air flow, the compression ratio, the propulsion force and the temperature before the compressor. In addition, during the testing, the vibrations were measured on axial and radial direction which indicate a normal functioning of the engine during the chevron nozzles testing. Regarding the noise, it was concluded that at low regimes the noise doesn’t presents any reduction when using the chevron nozzles, while at high regimes an overall noise reduction of 2–3 dB(A) was achieved. Regarding the engine performances, a decrease in the temperature in front of the turbine, compression ratio and the intake air and fuel flow was achieved and also a drop of few percent of the propulsion force.

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9

Santana, Teresa, João Gonçalves, Fernando Pinho, and Rui Micaelo. "Effects of the Ratio of Porosity to Volumetric Cement Content on the Unconfined Compressive Strength of Cement Bound Fine Grained Soils." Infrastructures 6, no. 7 (June 26, 2021): 96. http://dx.doi.org/10.3390/infrastructures6070096.

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This paper presents an experimental investigation into the effects of porosity, dry density and cement content on the unconfined compressive strength and modulus of elasticity of cement-bound soil mixtures. A clayey sand was used with two different proportions of type IV Portland cement, 10% and 14% of the dry mass of the soil. Specimens were moulded with the same water content but using four different compaction efforts, corresponding to four different dry densities. Unconfined compression testing was conducted at seven days of curing time on unsoaked samples. The results showed that the compressive strength increased with the increase in cement content and with the decrease in porosity. From the experimental data, a unique relationship was found between the unconfined compressive strength and the ratio of porosity to volumetric cement content for all the mixtures and compaction efforts tested. The equation developed demonstrates that it is possible to estimate the amount of cement and the dry density to achieve a certain level of unconfined compressive strength. A normalized general equation was also found to fit other authors’ results for similar soils mixed with cement. From this, a cement-bound soil model was proposed for the development of a mixing design procedure for different soils.

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10

Galajda, Pavol, Alena Galajdova, Stanislav Slovak, Martin Pecovsky, Milos Drutarovsky, Marek Sukop, and Ihab BA Samaneh. "Robot vision ultra-wideband wireless sensor in non-cooperative industrial environments." International Journal of Advanced Robotic Systems 15, no. 4 (July 1, 2018): 172988141879576. http://dx.doi.org/10.1177/1729881418795767.

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In this article, the ultra-wideband technology for localization and tracking of the robot gripper (behind the obstacles) in industrial environments is presented. We explore the possibilities of ultra-wideband radar sensor network employing the centralized data fusion method that can significantly improve tracking capabilities in a complex environment. In this article, we present ultra-wideband radar sensor network hardware demonstrator that uses a new wireless ultra-wideband sensor with an embedded controller to detect and track online or off-line movement of the robot gripper. This sensor uses M-sequence ultra-wideband radars front-end and low-cost powerful processors on a system on chip with the advanced RISC machines (ARM) architecture as a main signal processing block. The ARM-based single board computer ODROID-XU4 platform used in our ultra-wideband sensor can provide processing power for the preprocessing of received raw radar signals, algorithms for detection and estimation of target’s coordinates, and finally, compression of data sent to the data fusion center. Data streams of compressed target coordinates are sent from each sensor node to the data fusion center in the central node using standard the wireless local area network (WLAN) interface that is the feature of the ODROID-XU4 platform. The article contains experimental results from measurements where sensors and antennas are located behind the wall or opaque material. Experimental testing confirmed capability of real-time performance of developed ultra-wideband radar sensor network hardware and acceptable precision of software. The introduced modular architecture of ultra-wideband radar sensor network can be used for fast development and testing of new real-time localization and tracking applications in industrial environments.

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11

Iskhakov, Iakov, Ilya Frolov, and Yuri Ribakov. "Experimental Investigation of Concrete Transverse Deformations at Relatively High Loading Rates for Interpretation of High Strength Concrete Behavior." Applied Sciences 11, no. 18 (September 12, 2021): 8460. http://dx.doi.org/10.3390/app11188460.

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Loading rates affect the behavior of concrete specimens from the beginning of the loading process until failure. At rather high loading rates, longitudinal deformations in concrete specimens under a compressive load are practically elastic up until the ultimate limit state. It has been previously demonstrated that transverse deformations effectively indicate high-strength concrete behavior in the entire static loading process range. A theoretical model for cylindrical concrete specimen failure under compressive load, based on a structural phenomenon, has also been proposed. The aim of the present research is experimental verification of using transverse deformations in addition to longitudinal ones for investigating high-strength concrete behavior at the non-elastic stage. This research is based on testing normal-strength concrete cylindrical specimens under compression at relatively high loading rates. The theoretical model of the cracking and failure scheme of the cylindrical specimens are experimentally confirmed. The obtained results demonstrate that it is possible to use transverse deformations for the interpretation of initiation and development of inelastic deformations in high-strength concrete up to class C90 based on the data for normal-strength concrete specimens of class C30 subjected to relatively high loading rates.

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12

Ga, H., and W. Zeng. "Image compression and encryption based on wavelet transform and chaos." Computer Optics 43, no. 2 (April 2019): 258–63. http://dx.doi.org/10.18287/2412-6179-2019-43-2-258-263.

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With the rapid development of network technology, more and more digital images are transmitted on the network, and gradually become one important means for people to access the information. The security problem of the image information data increasingly highlights and has become one problem to be attended. The current image encryption algorithm basically focuses on the simple encryption in the frequency domain or airspace domain, and related methods also have some shortcomings. Based on the characteristics of wavelet transform, this paper puts forward the image compression and encryption based on the wavelet transform and chaos by combining the advantages of chaotic mapping. This method introduces the chaos and wavelet transform into the digital image encryption algorithm, and transforms the image from the spatial domain to the frequency domain of wavelet transform, and adds the hybrid noise to the high frequency part of the wavelet transform, thus achieving the purpose of the image degradation and improving the encryption security by combining the encryption approaches in the spatial domain and frequency domain based on the chaotic sequence and the excellent characteristics of wavelet transform. Testing experiments show that such algorithm reduces the memory consumption and implements the complexity, not only can decrease the key spending and compress the time spending, but also can improve the quality of decoded and reconstructed image, thus showing good encryption features with better encryption effect.

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13

Palkowski, Carsten, Andreas Zottl, Ivan Malenkovic, and Anne Simo. "Fixing Efficiency Values by Unfixing Compressor Speed: Dynamic Test Method for Heat Pumps." Energies 12, no. 6 (March 18, 2019): 1045. http://dx.doi.org/10.3390/en12061045.

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The growing market penetration of heat pumps indicates the need for a performance test method that better reflects the dynamic behavior of heat pumps. In this contribution, we developed and implemented a dynamic test method for the evaluation of the seasonal performance of heat pumps by means of laboratory testing. Current standards force the heat pump control inactive by fixing the compressor speed. In contrast, during dynamic testing, the compressor runs unfixed while the heat pump is subjected to a temperature profile. The profile consists of the different outdoor temperatures of a typical heating season based on the average European climate and also includes temperature changes to reflect the dynamic behavior of the heat pump. The seasonal performance can be directly obtained from the measured heating energy and electricity consumption making subsequent data interpolation and recalculation with correction factors obsolete. The method delivers results with high precision and high reproducibility and could be an appropriate method for a fair rating of heat pumps.

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14

Olliff, D., J. Qu, M. Gaynes, R. Kodnani, and A. Zubelewicz. "Characterizing the Failure Envelope of a Conductive Adhesive." Journal of Electronic Packaging 121, no. 1 (March 1, 1999): 23–30. http://dx.doi.org/10.1115/1.2792657.

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This paper focuses on mechanical testing designed to determine the static failure envelope for a conductive adhesive. Samples were made by bonding copper pegs together with the conductive adhesive. The samples were then tested at various loading conditions including tension, tension shear, and compression shear. Results were analyzed in order to check for correlations between the data and the testing procedures. The statistical distribution of the data was also analyzed. Furthermore, a finite element model of the test sample was constructed and used to verify the assumptions made with respect to the interpretation of the data. The data from various loading conditions was then used to construct the static failure envelope of the material. A modified Coulomb–Mohr failure criterion was used to model the failure envelope of the conductive adhesive. This criterion contains four material constants to be determined experimentally. Once these parameters are determined, a failure envelope can be easily constructed. The envelope can then be used to predict failure at any combination of shear and normal stresses. The test results showed that the empirical data are well characterized by the modified Coulomb–Mohr failure envelope.

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15

Małkowski, Piotr, Łukasz Ostrowski, and Łukasz Bednarek. "The Effect of Selected Factors on Floor Upheaval in Roadways—In Situ Testing." Energies 13, no. 21 (October 30, 2020): 5686. http://dx.doi.org/10.3390/en13215686.

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The phenomenon of the floor upheaval occurs in virtually every type of rock mass and at every depth, accompanying the process of excavation of tunnels and headings. Despite its inconvenience, it is rarely studied because of the complexity of the process and the multiplicity of the factors causing deformations in floor rocks. To quantify the effect of the selected factors on floor upheaval, this article presents an analysis of results of in situ measurements carried out in three coal mine roadways at 15 measuring stations. These measurements were taken over varying periods of time, between 129 and 758 days. Groundwater and fault zones intersecting the excavations were considered as the key factors that affect floor upheavals. Therefore, the measurement bases were located at local faults and sites of water inflow. To compare the results, the stations were also located where the rock mass was not exposed to any factors other than stresses resulting from the depth of the excavation. The excavations were driven in various rocks and were located at different depths from 750 to 1010 m. The analyses of the study results show that the floor upheaval always depends on time and can be described in polynomial form: ufl = a·t2 + b·t + c or by a power function: ufl = a·tb. However, the further regression analyses show that roadway’s floor upheaval can be expressed by a complex form using the key parameters determining the phenomena. In the absence of an impact of geological factors on the stability of the excavation, the floor upheaval depends on floor rocks compressive strength σc and Young’s modulus E: ln(ufl)=a·ln(tσc)−bE−c; in the case of rock mass condition affected by water depends on the rock compressive strength reduction after submerging rock in water σcs 6h: ufl=a·t0.5−bσcs 6hσc+c and in the case of fault depends on the fault’s throw f: ufl=a·t0.8+b·f1.2−c. Statistical analysis has shown that the matching of the models to the measurement data is high and amounts to r = 0.841–0.895. Hence, in general, the analysis shows that the floor upheaval in underground excavation in any geological conditions may grow indefinitely.

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16

Warguła, Łukasz, Dominik Wojtkowiak, Mateusz Kukla, and Krzysztof Talaśka. "Symmetric Nature of Stress Distribution in the Elastic-Plastic Range of Pinus L. Pine Wood Samples Determined Experimentally and Using the Finite Element Method (FEM)." Symmetry 13, no. 1 (December 29, 2020): 39. http://dx.doi.org/10.3390/sym13010039.

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This article presents the results of experimental research on the mechanical properties of pine wood (Pinus L. Sp. Pl. 1000. 1753). In the course of the research process, stress-strain curves were determined for cases of tensile, compression and shear of standardized shapes samples. The collected data set was used to determine several material constants such as: modulus of elasticity, shear modulus or yield point. The aim of the research was to determine the material properties necessary to develop the model used in the finite element analysis (FEM), which demonstrates the symmetrical nature of the stress distribution in the sample. This model will be used to analyze the process of grinding wood base materials in terms of the peak cutting force estimation and the tool geometry influence determination. The main purpose of the developed model will be to determine the maximum stress value necessary to estimate the destructive force for the tested wood sample. The tests were carried out for timber of around 8.74% and 19.9% moisture content (MC). Significant differences were found between the mechanical properties of wood depending on moisture content and the direction of the applied force depending on the arrangement of wood fibers. Unlike other studies in the literature, this one relates to all three stress states (tensile, compression and shear) in all significant directions (anatomical). To verify the usability of the determined mechanical parameters of wood, all three strength tests (tensile, compression and shear) were mapped in the FEM analysis. The accuracy of the model in determining the maximum destructive force of the material is equal to the average 8% (for tensile testing 14%, compression 2.5%, shear 6.5%), while the average coverage of the FEM characteristic with the results of the strength test in the field of elastic-plastic deformations with the adopted ±15% error overlap on average by about 77%. The analyses were performed in the ABAQUS/Standard 2020 program in the field of elastic-plastic deformations. Research with the use of numerical models after extension with a damage model will enable the design of energy-saving and durable grinding machines.

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17

Chan, Septriandi A., Paul Edigbue, Sikandar Khan, Abdul L. Ashadi, and Abdullatif A. Al-Shuhail. "Viscoelastic Model and Synthetic Seismic Data of Eastern Rub’Al-Khali." Applied Sciences 11, no. 4 (February 4, 2021): 1401. http://dx.doi.org/10.3390/app11041401.

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The Rub’ Al-Khali basin in Saudi Arabia remains unexplored and lacks data availability due to its remoteness and the challenging nature of its terrain. Thus far, there are neither digital geologic models nor synthetic seismic data from this specific area accessible for testing research techniques and analysis. In this study, we build a 2D viscoelastic model of the eastern part of the Rub’ Al-Khali basin and generate a corresponding dual-component seismic data set. We compile high-resolution depth models of compressional- and shear-wave velocities, density, as well as compressional- and shear-wave quality factors from published data. The compiled models span Neoproterozoic basement up to Quaternary sand dunes. We then use the finite-difference technique to model the propagation of seismic waves in the compiled viscoelastic medium of eastern Rub’ Al-Khali desert. In particular, we generate vertical and horizontal components of the shot gathers with accuracy to the fourth and second orders in space and time, respectively. The viscoelastic models and synthetic seismic datasets are made available in an open-source site for prospective re-searchers who desire to use them for their research. Users of these datasets are urged to make their findings also accessible to the geoscience community as a way of keeping track of developments related to the Rub’ Al-Khali desert.

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18

DeVasConCellos, P., V. K. Balla, S. Bose, R. Fugazzi, W. S. Dernell, and A. Bandyopadhyay. "Patient specific implants for amputation prostheses: Design, manufacture and analysis." Veterinary and Comparative Orthopaedics and Traumatology 25, no. 04 (2012): 286–96. http://dx.doi.org/10.3415/vcot-11-03-0043.

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SummaryObjectives: To design, manufacture and analyze custom implants with functional gradation in macrostructure for attachment of amputation prostheses.Methods: The external shape of the implant was designed by extracting geometrical data of canine cadavers from computed tomography (CT) scans to suit the bone cavity. Three generations of implant designs were developed and were optimized with the help of fit/fill and mechanical performance of implant-cadaver bone assembly using CT analysis and compression testing, respectively. A final optimized, custom Ti6Al4V alloy amputation implant, with approximately 25% porosity in the proximal region and approximaltely zero percent porosity in the distal region, was fabricated using Laser Engineered Net Shaping (LENS™) – a laser based additive manufacturing technology.Results: The proposed design changes in the second generation designs, in terms of refining thresholds, increased the average fill of the bone cavity from 58% to 83%. Addition of a flange between the stem and the head in the second generation designs resulted in more than a seven-fold increase in the compressive load carrying capacity of the assembly. Application of LENS™ in the fabrication of present custom fit Ti6Al4V alloy implants enabled incorporation of 20 to 30% porosity in the proximal region and one to two percent residual porosity in the distal portion of the implant.Clinical significance: Patient specific prostheses having direct connection to the skeletal structure can potentially aid in problems related to load transfer and proprioception in amputees. Furthermore, application of LENS™ in the fabrication of custom implants can be faster to incorporate site specific porosity and gradients for improving long-term stability.

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Caiazzo, Fabrizia, Vittorio Alfieri, and Brahim David Bujazha. "Additive manufacturing of biomorphic scaffolds for bone tissue engineering." International Journal of Advanced Manufacturing Technology 113, no. 9-10 (February 26, 2021): 2909–23. http://dx.doi.org/10.1007/s00170-021-06773-5.

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AbstractBone tissue engineering has evolved owing to new opportunities of deep customisation offered by additive manufacturing technologies. Gyroid structures, which have been widely used for energy absorption or chemical catalysis, are now being employed as biomorphic structures as well to provide customer-oriented scaffolds for missing or injured bones. Unfortunately, limited data in terms of manufacturability and mechanical properties are available in the literature to support a wide application scope, because the bone to match is strongly dependent on the individual. Therefore, the study aimed at addressing this lack of knowledge, assessing the manufacturability of metal gyroids and further developing the correlation of the structural response with the designed geometry, so to allow the designer to provide the proper biomorphic structure on a case-by-case basis. Biocompatible steel was used to manufacture samples via laser powder-bed fusion; their elastic moduli and yield strengths were evaluated as a function of the orientation of the elementary cells, the symmetry and the wall thickness based on compression testing. Grounds have been given to support potential applications for tibias and vertebras.

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Park, Jun-Ryeol, Hye-Jin Lee, Keun-Hyeok Yang, Jung-Keun Kook, and Sanghee Kim. "Study on Influence of Range of Data in Concrete Compressive Strength with Respect to the Accuracy of Machine Learning with Linear Regression." Applied Sciences 11, no. 9 (April 24, 2021): 3866. http://dx.doi.org/10.3390/app11093866.

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This study aims to predict the compressive strength of concrete using a machine-learning algorithm with linear regression analysis and to evaluate its accuracy. The open-source software library TensorFlow was used to develop the machine-learning algorithm. In the machine-earning algorithm, a total of seven variables were set: water, cement, fly ash, blast furnace slag, sand, coarse aggregate, and coarse aggregate size. A total of 4297 concrete mixtures with measured compressive strengths were employed to train and testing the machine-learning algorithm. Of these, 70% were used for training, and 30% were utilized for verification. For verification, the research was conducted by classifying the mixtures into three cases: the case where the machine-learning algorithm was trained using all the data (Case-1), the case where the machine-learning algorithm was trained while maintaining the same number of training dataset for each strength range (Case-2), and the case where the machine-learning algorithm was trained after making the subcase of each strength range (Case-3). The results indicated that the error percentages of Case-1 and Case-2 did not differ significantly. The error percentage of Case-3 was far smaller than those of Case-1 and Case-2. Therefore, it was concluded that the range of training dataset of the concrete compressive strength is as important as the amount of training dataset for accurately predicting the concrete compressive strength using the machine-learning algorithm.

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21

Ngo, Huong Thi Thanh, Tuan Anh Pham, Huong Lan Thi Vu, and Loi Van Giap. "Application of Artificial Intelligence to Determined Unconfined Compressive Strength of Cement-Stabilized Soil in Vietnam." Applied Sciences 11, no. 4 (February 23, 2021): 1949. http://dx.doi.org/10.3390/app11041949.

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Cement stabilized soil is one of the commonly used as ground reinforcement solutions in geotechnical engineering. In this study, the main object was to apply three machine learning (ML) methods namely gradient boosting (GB), artificial neural network (ANN) and support vector machine (SVM) to predict unconfined compressive strength (UCS) of cement stabilized soil. Soil samples were collected at Hai Duong city, Vietnam. A total of 216 soil–cement samples were mixed in the laboratory and compressed to determine the UCS. This data set is divided into two parts of the training data set (80%) and testing set (20%) to build and test the model, respectively. To verify the performance of ML model, various criteria named correlation coefficient (R), mean absolute error (MAE) and root mean square error (RMSE) were used. The results show that all three ML models were effective methods to predict the UCS of cement-stabilized soil. Amongst three model used in this study, optimized ANN model provided superior performance compare to two others models with performance indicator R = 0.925, RMSE = 419.82 and MAE = 292.2 for testing part. This study can provide an effective tool to quickly predict the UCS of cement stabilized soil with high accuracy.

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Tomczak, Kamil, Jacek Jakubowski, and Łukasz Kotwica. "Self-Sealing Process Evaluation Method Using Ultrasound Technique in Cement Composites with Mineral Additives." Materials 13, no. 15 (July 27, 2020): 3336. http://dx.doi.org/10.3390/ma13153336.

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The self-sealing process, associated with chemical and microstructural changes inside damaged cement-based composites, leads to the recovery of the original material integrity. Assessing the magnitude of internal changes in samples using non-destructive techniques to capture only the self-sealing effects is difficult. The challenge is evaluating the differences between subsequent observations in time and between samples with different properties. This paper proposes a new approach to the use of an ultrasonic technique for self-sealing investigation. The method allows the quantification of material changes strictly related to self-sealing processes, excluding changes caused by the naturally progressing hydration of binders. The applied ultrasonic pulse velocity (UPV) data processing procedure allows the investigation of material changes inside and near the cracks, the effects of stimulating the self-sealing of cement composites with mineral additives, and the assessment of changes over time. An important aspect of the method is the sample preparation procedure and testing conditions that reduce the impact of moisture content on the UPV measurements. New parameters allowing the quantitative characterization of the self-sealing process are proposed. The method was evaluated using cement mortars modified with siliceous fly ash with induced cracks 0 to 750 µm wide, which were then cured in water for 152 days. The maximum degree of effective crack filling as a result of autogenous self-sealing in the tested mortars was determined to range from 33% to 57%. Observations of the microstructure of the crack surface confirmed that apart from the volume of the newly formed products, the density of these products may have a key impact on the ultrasonic measurements of the self-sealing performance. The studies were supplemented by the examination of the compression strength of mortars, mortar sample scanning and computer image processing, and observations using an optical microscope and scanning electron microscope with energy dispersive spectroscopy.

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Rodríguez, Verónica, Celia Tobar, Carlos López-Suárez, Jesús Peláez, and María J. Suárez. "Fracture Load of Metal, Zirconia and Polyetheretherketone Posterior CAD-CAM Milled Fixed Partial Denture Frameworks." Materials 14, no. 4 (February 18, 2021): 959. http://dx.doi.org/10.3390/ma14040959.

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The aim of this study was to investigate the load to fracture and fracture pattern of prosthetic frameworks for tooth-supported fixed partial dentures (FPDs) fabricated with different subtractive computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: Thirty standardized specimens with two abutments were fabricated to receive three-unit posterior FDP frameworks with an intermediate pontic. Specimens were randomly divided into three groups (n = 10 each) according to the material: group 1 (MM)—milled metal; group 2 (L)—zirconia; and group 3 (P)—Polyetheretherketone (PEEK). The specimens were thermo-cycled and subjected to a three-point bending test until fracture using a universal testing machine (cross-head speed: 1 mm/min). Axial compressive loads were applied at the central fossa of the pontics. Data analysis was made using one-way analysis of variance, Tamhane post hoc test, and Weibull statistics (α = 0.05). Results: Significant differences were observed among the groups for the fracture load (p < 0.0001). MM frameworks showed the highest fracture load values. The PEEK group registered higher fracture load values than zirconia samples. The Weibull statistics corroborated these results. The fracture pattern was different among the groups. Conclusions: Milled metal provided the highest fracture load values, followed by PEEK, and zirconia. However, all tested groups demonstrated clinically acceptable fracture load values higher than 1000 N. PEEK might be considered a promising alternative for posterior FPDs.

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Lin, Chia-Ju, and Nan-Jing Wu. "An ANN Model for Predicting the Compressive Strength of Concrete." Applied Sciences 11, no. 9 (April 22, 2021): 3798. http://dx.doi.org/10.3390/app11093798.

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An artificial neural network (ANN) model for predicting the compressive strength of concrete is established in this study. The Back Propagation (BP) network with one hidden layer is chosen as the structure of the ANN. The database of real concrete mix proportioning listed in earlier research by another author is used for training and testing the ANN. The proper number of neurons in the hidden layer is determined by checking the features of over-fitting while the synaptic weights and the thresholds are finalized by checking the features of over-training. After that, we use experimental data from other papers to verify and validate our ANN model. The final result of the synaptic weights and the thresholds in the ANN are all listed. Therefore, with them, and using the formulae expressed in this article, anyone can predict the compressive strength of concrete according to the mix proportioning on his/her own.

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25

Denisiewicz, Arkadiusz, Mieczysław Kuczma, Krzysztof Kula, and Tomasz Socha. "Influence of Boundary Conditions on Numerical Homogenization of High Performance Concrete." Materials 14, no. 4 (February 20, 2021): 1009. http://dx.doi.org/10.3390/ma14041009.

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Concrete is the most widely used construction material nowadays. We are concerned with the computational modelling and laboratory testing of high-performance concrete (HPC). The idea of HPC is to enhance the functionality and sustainability of normal concrete, especially by its greater ductility as well as higher compressive, tensile, and flexural strengths. In this paper, the influence of three types (linear displacement, uniform traction, and periodic) of boundary conditions used in numerical homogenization on the calculated values of HPC properties is determined and compared with experimental data. We take into account the softening behavior of HPC due to the development of damage (micro-cracks), which finally leads to failure. The results of numerical simulations of the HPC samples were obtained by using the Abaqus package that we supplemented with our in-house finite element method (FEM) computer programs written in Python and the homogenization toolbox Homtools. This has allowed us to better account for the nonlinear response of concrete. In studying the microstructure of HPC, we considered a two-dimensional representative volume element using the finite element method. Because of the random character of the arrangement of concrete’s components, we utilized a stochastic method to generate the representative volume element (RVE) structure. Different constitutive models were used for the components of HPC: quartz sand—linear elastic, steel fibers—ideal elastic-plastic, and cement matrix—concrete damage plasticity. The numerical results obtained are compared with our own experimental data and those from the literature, and a good agreement can be observed.

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26

Saxena and Robinson. "Accumulator Compression Testing." IEEE Transactions on Computers C-35, no. 4 (April 1986): 317–21. http://dx.doi.org/10.1109/tc.1986.1676764.

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Son, Michelle M., and L. Daniel Latt. "Hindfoot Bone Viscoelasticity and Stress Relaxation." Foot & Ankle Orthopaedics 4, no. 4 (October 1, 2019): 2473011419S0040. http://dx.doi.org/10.1177/2473011419s00403.

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Category: Ankle, Ankle Arthritis, Basic Sciences/Biologics, Hindfoot Introduction/Purpose: Hindfoot arthrodeses have a non-union rate as high as 40%. Compression at the arthrodesis site plays a key role in stimulating bone growth leading to successful fusion. The ability to obtain and maintain compression depends not only on the surgical technique and the hardware which develop the compressive force but also on the response of the bone to compression. Bone, like other musculoskeletal tissues, is viscoelastic meaning that it has properties of both fluids and solids. Because bone is viscoelastic, it experiences stress relaxation (decrease in compressive force over time). The rate and magnitude of such stress relaxation is unknown. Our primary objective was to quantify stress relaxation of the hindfoot bones when subjected to a fixed compression displacement as would be done during arthrodesis. Methods: 10 human cadaveric bone cylinders measuring 10 mm in both diameter and height were cut from the articular surfaces of the talus, calcaneus, and distal tibia using a disposable cylindrical osteochondral harvester (OATS, Arthrex inc, Naples, FL). Each bone cylinder sample included subchondral and trabecular bone, and articular cartilage was removed during preparation. Each sample was scanned with a micro-computed tomography (uCT) scanner (Biomedical Micro CT Scanner, Scanco Medical, Switzerland) to quantify bone volume/total volume ratio (BV/TV), trabecular thickness, trabecular separation, trabecular number, and connectivity density. Each specimen was submerged in a saline bath and compressed by 1 mm at a strain rate of 1mm/sec using a material testing machine (System 810, MTS Systems, Eden Prairie, MN), and load data was gathered by an Interface load cell. Displacement was held constant for 3 hours, after which each sample was removed from the test machine and immediately rescanned with the uCT scanner. Results: The ensemble load curve of the ten samples displayed uniform exponential decay. After the initial load was placed on the bone, a steep, negative load velocity was apparent. Rapid decay occurred within the first 3 minutes, after which the load plateaued, holding constant over the subsequent 3 hours of compression. The average peak load was 515.53 N (SD: 254.58 N). The average percent load loss was 65.77% over 30 minutes (SD: 20.95%). Discrete time periods (B1, B2, B3, B4) were established corresponding to 0-3 min, 3-10 min, 10-20 min, and 20-30 min, respectively. Time periods B1, B2, B3, and B4 demonstrated an average percent load loss per time period of 43.35% (SD: 10.09%), 13.80% (SD: 14.77%), 18.65% (SD: 24.97%) and 7.95% (SD: 13.37%), respectively. Conclusion: Our data suggest that a significant percentage of compressive load placed across a bone is lost within the first 3 minutes as compared to any subsequent time period. Moreover, approximately 65.77% of the compressive load is lost over the first 30 minutes. These data suggest that when performing arthrodesis with compressive hardware, the majority of the initially applied compressive load may dissipate over the first 3-30 minutes, which may contribute to nonunion. Thus, a re-tightening of screws after 5-30 minutes or the use of a continuous compressive device may help to maintain compression at the arthrodesis site throughout healing.

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Lee, Hang-Lo, Jin-Seop Kim, Chang-Ho Hong, and Dong-Keun Cho. "Ensemble Learning Approach for the Prediction of Quantitative Rock Damage Using Various Acoustic Emission Parameters." Applied Sciences 11, no. 9 (April 28, 2021): 4008. http://dx.doi.org/10.3390/app11094008.

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Monitoring rock damage subjected to cracks is an important stage in underground spaces such as radioactive waste disposal repository, civil tunnel, and mining industries. Acoustic emission (AE) technique is one of the methods for monitoring rock damage and has been used by many researchers. To increase the accuracy of the evaluation and prediction of rock damage, it is required to consider various AE parameters, but this work is a difficult problem due to the complexity of the relationship between several AE parameters and rock damage. The purpose of this study is to propose a machine learning (ML)-based prediction model of the quantitative rock damage taking into account of combined features between several AE parameters. To achieve the goal, 10 granite samples from KAERI (Korea Atomic Energy Research Institute) in Daejeon were prepared, and a uniaxial compression test was conducted. To construct a model, random forest (RF) was employed and compared with support vector regression (SVR). The result showed that the generalization performance of RF is higher than that of SVRRBF. The R2, RMSE, and MAPE of the RF for testing data are 0.989, 0.032, and 0.014, respectively, which are acceptable results for application in laboratory scale. As a complementary work, parameter analysis was conducted by means of the Shapley additive explanations (SHAP) for model interpretability. It was confirmed that the cumulative absolute energy and initiation frequency were selected as the main parameter in both high and low-level degrees of the damage. This study suggests the possibility of extension to in-situ application, as subsequent research. Additionally, it provides information that the RF algorithm is a suitable technique and which parameters should be considered for predicting the degree of damage. In future work, we will extend the research to the engineering scale and consider the attenuation characteristics of rocks for practical application.

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Zirkind, Givon. "AFIS data compression." ACM SIGGRAPH Computer Graphics 41, no. 4 (November 2007): 1–36. http://dx.doi.org/10.1145/1331098.1331103.

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30

Bailey, R. L. "Pipelining Data Compression Algorithms." Computer Journal 33, no. 4 (April 1, 1990): 308–13. http://dx.doi.org/10.1093/comjnl/33.4.308.

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31

Farruggia, Andrea, Paolo Ferragina, Antonio Frangioni, and Rossano Venturini. "Bicriteria Data Compression." SIAM Journal on Computing 48, no. 5 (January 2019): 1603–42. http://dx.doi.org/10.1137/17m1121457.

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32

Fiala, E. R., and D. H. Greene. "Data compression with finite windows." Communications of the ACM 32, no. 4 (April 1989): 490–505. http://dx.doi.org/10.1145/63334.63341.

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33

Witten, Ian H., Radford M. Neal, and John G. Cleary. "Arithmetic coding for data compression." Communications of the ACM 30, no. 6 (June 1987): 520–40. http://dx.doi.org/10.1145/214762.214771.

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34

Ma, Z. M., W. J. Zhang, and F. Mili. "Fuzzy data compression based on data dependencies." International Journal of Intelligent Systems 17, no. 4 (February 26, 2002): 409–26. http://dx.doi.org/10.1002/int.10029.

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35

Keogh, Eamonn, Stefano Lonardi, Chotirat Ann Ratanamahatana, Li Wei, Sang-Hee Lee, and John Handley. "Compression-based data mining of sequential data." Data Mining and Knowledge Discovery 14, no. 1 (January 26, 2007): 99–129. http://dx.doi.org/10.1007/s10618-006-0049-3.

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Robert, L., and R. Nadarajan. "Fault-Tolerant Text Data Compression Algorithms." International Journal of Information Technology and Web Engineering 4, no. 2 (April 2009): 1–19. http://dx.doi.org/10.4018/jitwe.2009040101.

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37

Bentley, Jon Louis, Daniel D. Sleator, Robert E. Tarjan, and Victor K. Wei. "A locally adaptive data compression scheme." Communications of the ACM 29, no. 4 (April 1986): 320–30. http://dx.doi.org/10.1145/5684.5688.

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38

Cormack, Gordon V. "Data compression on a database system." Communications of the ACM 28, no. 12 (December 1985): 1336–42. http://dx.doi.org/10.1145/214956.214963.

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39

Burroughs, S. H., and T. R. Lattrell. "Data compression technology in ASIC cores." IBM Journal of Research and Development 42, no. 6 (November 1998): 725–32. http://dx.doi.org/10.1147/rd.426.0725.

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40

Yacobi, Yacov. "Fast Exponentiation Using Data Compression." SIAM Journal on Computing 28, no. 2 (January 1998): 700–703. http://dx.doi.org/10.1137/s0097539792234974.

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Huyn, Dung T. "Effective entropies and data compression." Information and Computation 90, no. 1 (January 1991): 67–85. http://dx.doi.org/10.1016/0890-5401(91)90060-f.

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42

Goldberg, Mark A. "Image data compression." Journal of Digital Imaging 11, S1 (August 1998): 230–32. http://dx.doi.org/10.1007/bf03168323.

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Goldberg, Mark A. "Image data compression." Journal of Digital Imaging 10, S1 (August 1997): 9–11. http://dx.doi.org/10.1007/bf03168640.

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44

Richards, Dana. "Data compression and gray-code sorting." Information Processing Letters 22, no. 4 (April 1986): 201–5. http://dx.doi.org/10.1016/0020-0190(86)90029-3.

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Joseph, V. Roshan, and Simon Mak. "Supervised compression of big data." Statistical Analysis and Data Mining: The ASA Data Science Journal 14, no. 3 (April 8, 2021): 217–29. http://dx.doi.org/10.1002/sam.11508.

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46

Samet, Hanan. "Data structures for quadtree approximation and compression." Communications of the ACM 28, no. 9 (September 1985): 973–93. http://dx.doi.org/10.1145/4284.4290.

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47

Makinen, E. "On Implementing two Adaptive Data-compression Schemes." Computer Journal 32, no. 3 (March 1, 1989): 238–40. http://dx.doi.org/10.1093/comjnl/32.3.238.

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Jones, D. W. "Application of splay trees to data compression." Communications of the ACM 31, no. 8 (August 1988): 996–1007. http://dx.doi.org/10.1145/63030.63036.

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Shang, Jin, and Liyong Zhang. "Test Data Compression Scheme Based on Compatible Data Block Coding." Information Technology Journal 12, no. 1 (December 15, 2012): 204–8. http://dx.doi.org/10.3923/itj.2013.204.208.

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Murtagh, F., M. Louys, J. L. Starck, and F. Bonnarel. "Compression of grayscale scientific and medical image data." Data Science Journal 1 (2002): 111–27. http://dx.doi.org/10.2481/dsj.1.111.

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