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Hydrocarbon production in the reservoir depends on fluid flow through its porous media, such as fractures and their physical parameters, which affect the analysis of the reservoir's physical properties. The fracture's physical parameters can be measured conventionally by laboratory analysis or using numerical approaches such as simulations with the Lattice Boltzmann method. However, these methods are time-consuming and resource-intensive; therefore, this research explores the application of machine learning as an alternative method to predict the physical parameters of fractures such as permeability, surface roughness, and mean aperture. Synthetic three-dimensional digital fracture data that resemble real rock fractures were used to train the machine learning models. These included two convolutional neural networks (CNNs) designed and implemented in this research—which are referred to as CNN-1 and CNN-2—as well as three pre-trained models—including DenseNet201, VGG16, and Xception. The models were then evaluated using the R 2 and mean absolute percentage error (MAPE). CNN-2 was the best model for accurately predicting the three fracture physical parameters but experienced a drop in performance when tested on real rock fractures. [ABSTRACT FROM AUTHOR]

In many disciplines, the growth of online courses was propelled by the COVID-19 pandemic, but this trend moderated as health concerns receded. Before the pandemic, computer science-related disciplines were less keen on online labs because of their inherently hands-on nature. This study presents a comparative analysis of student and faculty perceptions towards online labs in three computing-related disciplines a year after the pandemic. Through a survey with 242 students and 20 faculty responses, we found students were, overall, positive about their online lab experience—as were faculty. Students and instructors both agree that (1) where provided, online lab courses are being taught effectively, and (2) it is crucial to continue investing in technology infrastructure to enhance the quality and accessibility of both online and in-person labs. However, students and instructors disagree on two issues: (1) teamwork for lab activities and assignments (i.e., faculty tended to have a more optimistic view of online collaborative activities); and (2) modality for lab sessions (i.e., student preferences were evenly split between synchronous and asynchronous labs while faculty mostly preferred synchronous online labs). Faculty appear more optimistic about the effectiveness of online labs but show heightened concern regarding technological disruptions. Notably, all comments from students asserted the importance of having recorded demonstrations, even when a live synchronous demonstration may have been provided. Utilizing recordings and making them available is an example of a best practice worth promoting despite the added effort for faculty. [ABSTRACT FROM AUTHOR]

The mixed signal of respiratory waveform and heartbeat waveform detected by the Laser-Doppler system is processed with an intermediate-frequency (IF) interference filtering method, an enhanced extraction method and a waveform-fixing method. To filter the IF interference signals and the noise scatters in the time-frequency graph, the filtering method based on coefficient of variation (CoV) values and the enhanced curve extraction method based on noise-scatter theory are utilized in vital signal analysis. To decouple the respiratory signal and the heartbeat signal in time domain, the waveform-fixing method based on second-order difference theory is utilized in signal decoupling. This method as an algorithm is applied in the computer simulation and laboratory environments. The results show that the above methods can extract the mixed waveforms and identify the respiratory rates and heart rates in real experimental data. The IF interference signal can be filtered adaptively, and the accuracy of the analyzed rates can be improved to about 95%. [ABSTRACT FROM AUTHOR]

Previous studies have explored using scrap rubber in constructing the ballasted track and showed tremendous potential to mitigate noise and vibration. However, its application for slab tracks has not been extensively investigated. This study intends to utilise scrap rubber in the base layer of the slab track; however, the high stress below base layer of the slab track may render its use unsuitable. The addition of scrap rubber would improve the damping performance but reduce the elastic modulus and cause excessive settlement of the track. This paper utilises an experimental programme comprising static and cyclic triaxial testing and numerical analyses to assess the suitability of four mixes, e.g., mix-A (soil), mix-B (soil mixed with rubber), mix-C (polyurethane-treated soil), and mix-D (polyurethane-treated soil mixed with rubber), as a base layer in slab tracks. The laboratory investigations reveal that the best performance in terms of improved damping ratio and resilient modulus, and lowered excess pore water pressure and vertical strains are shown by mix-D. These experimental test findings were supplemented with the results from three-dimensional full-scale finite element analyses, which showed a drastic reduction in the vibration levels of the track with mix-D as a base layer instead of conventional lean-mix concrete. [ABSTRACT FROM AUTHOR]

Since 2008, all members of the University of Vienna have been able to archive digital scholarly materials in the PHAIDRA repository. What was conceived as a single repository with a long-term archiving function has, after many years of cooperation between the University Library and the Vienna University Computer Center, developed into a repository landscape that provides a comprehensive infrastructure for research data management for the entire University with all its different disciplines. This article describes the key milestones in the development from the PHAIDRA repository to today’s diverse offering with national and international networks. [ABSTRACT FROM AUTHOR]

The present article deals with the application of the Data Envelopment Analysis (DEA) methodology to identify the most weighty factors that are associated with student performance on large-scale assessments, amongst them, the permanent assessment system for basic education "SPAECE" test. The DEA Slacks-Based-Measure (SBM) model was used to estimate the relative efficiency of school units in the city of Sobral (CE), one of the most prominent Brazilian counties in the educational scenario. It was evident that the presence of libraries, computer labs, sports courts and rooms for special care in school units constitutes a significant factor associated with the high performance of students, impacting, therefore, school efficiency. [ABSTRACT FROM AUTHOR]

Nowadays, with the widespread supply of very powerful laboratory and computer equipment, it is expected that the analyses conducted for geotechnical problems are carried out with very high precision. Precise analyses lead to better knowledge of structures' behavior, which, in turn, reduces the costs related to uncertainty of materials' behavior. A precise analysis necessitates a precise knowledge and definition of the behavior of the constituent materials, which itself requires applying an appropriate constitutive model to show the behavior of materials. Constitutive models used in the generalized plasticity framework are very powerful constitutive models for the simulation of sand behavior. However, the simulation of a cyclic behavior in these models, especially the simulation of the undrained cyclic behavior, is not well-recognized. In this study, in order to eliminate the weakness of generalized constitutive models under cyclic loading, a new equation is presented to substitute the so-called coefficient of the discrete memory factor to consider the loading history in such a way that the plastic modulus is modified during reloading and, as a result, more appropriate predictions of sand behavior are obtained. The performance accuracy of the proposed coefficient was evaluated in accordance with the experimental data. Finally, the results show that after using the modification of the loading history coefficient, predictions of the constitutive model are significantly improved. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) is gradually changing the way teaching and learning take place in on-campus programs. In particular, face capture services improve student concentration to create an efficient classroom atmosphere by using face recognition algorithms that support end devices. However, reducing response latency and executing face analysis services effectively in real-time is still challenging. For this reason, this paper proposed a pedagogical model of face recognition for IoT devices based on edge computing (TFREC). Specifically, this research first proposed an IoT service-based face capture algorithm to optimize the accuracy of face recognition. In addition, the service deployment method based on edge computing is proposed in this paper to obtain the best deployment strategy and reduce the latency of the algorithm. Finally, the comparative experimental results demonstrate that TFREC has 98.3% accuracy in face recognition and 72 milliseconds in terms of service response time. This research is significant for advancing the optimization of teaching methods in school-based courses, meanwhile, providing beneficial insights for the application of face recognition and edge computing in the field of education. [ABSTRACT FROM AUTHOR]

Safe autonomous vehicle (AV) operations depend on an accurate perception of the driving environment, which necessitates the use of a variety of sensors. Computational algorithms must then process all of this sensor data, which typically results in a high on-vehicle computational load. For example, existing lane markings are designed for human drivers, can fade over time, and can be contradictory in construction zones, which require specialized sensing and computational processing in an AV. But, this standard process can be avoided if the lane information is simply transmitted directly to the AV. High definition maps and road side units (RSUs) can be used for direct data transmission to the AV, but can be prohibitively expensive to establish and maintain. Additionally, to ensure robust and safe AV operations, more redundancy is beneficial. A cost-effective and passive solution is essential to address this need effectively. In this research, we propose a new infrastructure information source (IIS), chip-enabled raised pavement markers (CERPMs), which provide environmental data to the AV while also decreasing the AV compute load and the associated increase in vehicle energy use. CERPMs are installed in place of traditional ubiquitous raised pavement markers along road lane lines to transmit geospatial information along with the speed limit using long range wide area network (LoRaWAN) protocol directly to nearby vehicles. This information is then compared to the Mobileye commercial off-the-shelf traditional system that uses computer vision processing of lane markings. Our perception subsystem processes the raw data from both CEPRMs and Mobileye to generate a viable path required for a lane centering (LC) application. To evaluate the detection performance of both systems, we consider three test routes with varying conditions. Our results show that the Mobileye system failed to detect lane markings when the road curvature exceeded ± 0.016 m−1. For the steep curvature test scenario, it could only detect lane markings on both sides of the road for just 6.7% of the given test route. On the other hand, the CERPMs transmit the programmed geospatial information to the perception subsystem on the vehicle to generate a reference trajectory required for vehicle control. The CERPMs successfully generated the reference trajectory for vehicle control in all test scenarios. Moreover, the CERPMs can be detected up to 340 m from the vehicle's position. Our overall conclusion is that CERPM technology is viable and that it has the potential to address the operational robustness and energy efficiency concerns plaguing the current generation of AVs. [ABSTRACT FROM AUTHOR]

Expansive unsaturated soils present challenges in construction due to their moisture-induced behavior. This study proposes empirical equations to estimate the maximum wetting depth over time. Laboratory experiments and numerical analyses using SEEP/W software investigate wetting depth considering time and sand content in coastal and inland regions. Results reveal the significant influence of sand content on maximum soil moisture depth, emphasizing a recommended content above 30% to mitigate heave. The equations offer practical tools for assessing wetting depth, accounting for temporal and spatial variations. This research highlights the importance of wetting depth in addressing soil-related concerns and provides a foundation for further exploration of related factors. [ABSTRACT FROM AUTHOR]

The Quasi-Impedance-Source Inverter (Quasi-Z inverter) is an interesting DC-AC converter topology that can be used in applications such as fuel cells and photovoltaic generators. This topology allows for both boost capability and DC-side continuous input current. Another very interesting feature is its reliability, as it limits the current when two switches on one leg are conducting simultaneously. This is due to an extra conduction state, specifically the shoot-through state. However, the shoot-through state also causes a loss of performance, increasing electromagnetic interference and harmonic distortion. To address these issues, this work proposes a modified carrier-based control method for the T-Type single-phase quasi-Z inverter. The modified carrier-based method introduces the use of two additional states to replace the standard shoot-through state. The additional states are called the upper shoot-through and the lower shoot-through. An approach to minimize the number of switches that change state during transitions will also be considered to reduce switching losses, improving the converter efficiency. The proposed modified carrier-based control strategy will be tested using computer simulations and laboratory experiments. From the obtained results, the theoretical considerations are confirmed. In fact, through the presented results, it is possible to understand important improvements that can be obtained in the THD of the output voltage and load current. In addition, it is also possible to verify that the modified carrier method also reduces the input current ripple. [ABSTRACT FROM AUTHOR]

Wireless monitoring systems for the marine environment are important for rapidly growing subsea developments. The power supply of wireless sensor nodes within the monitoring systems, however, is a major challenge. This study proposes a novel piezoelectric wave energy converter (pWEC) device to power the wireless sensing nodes. Unlike previous studies, the proposed device utilizes contactless pWEC technology in which a spring pendulum provides a two-stage frequency amplification of 3.8 times for low-frequency wave environments. The pWEC device consists of a floating body, inner pendulum, spring pendulum, magnets and piezoelectric sheets. In order to harvest the energy from relatively low frequency ocean waves, the pWEC device is designed to have an enhanced energy-capturing frequency. The effects of internal pendulum mass, spring pendulum weight, pendulum length and spring stiffness on wave energy absorption are investigated using theoretical and numerical analysis combined with laboratory experiments. The slider that drives the motion of the piezoelectric sheet vibrates at up to 3.8 times the wave frequency. To test the piezoelectric generators in the laboratory environment, a mechanical structure is set up to simulate the motion of the external floating body and the internal wave energy converter under the action of waves. When the four piezoelectric plates are arranged horizontally, the average output power per plate is increased by 2.4 times, and a single piezoelectric plate can generate an average of 10 mW of power. The proposed piezoelectric wave energy converter device has the potential to provide long-term energy supply for small ocean monitoring platforms at remote locations with reasonable wave energy resources. [ABSTRACT FROM AUTHOR]

The Covid-19 pandemic accelerated the development of electronic (e-learning) assessment methods and forced their use worldwide. Many instructors and students had to familiarize themselves with the form of distance education. During and since Covid-19 in Hungary, at the Faculty of Engineering of the University of Debrecen, the written part of the Comprehensive Exam in Mathematics is organized in a computer lab of the university using an online test. Our goal is that the results of the tests may be as reliable as possible in terms of measuring the students' knowledge, and thus the grades given based on the test results would be realistic. In this paper, we show the analysis of a sample written exam and compare the real exam results of students who were prepared for the comprehensive exam during Covid-19 and who have participated in face-to-face education since then. The tools provided by the Moodle system necessary for comparison are also presented. [ABSTRACT FROM AUTHOR]

This paper presents the results of laboratory tests of CFRP (carbon fiber-reinforced polymer) laminates, which allowed the development of numerical material models. The obtained data were used in a further stage to perform numerical simulations of four variants of medical tabletops, differing, among other features, in the shape of the cross-section. Maximum deflections and effort in the composite material were analyzed. The final step was to perform a laboratory test for one of the tabletop versions, the results of which confirmed the correctness of the numerical calculations. This work is aimed at both researchers and designers involved in the practical application of fiber-reinforced polymer matrix composites. [ABSTRACT FROM AUTHOR]

Would another origin of life resemble Earth's biochemical use of amino acids? Here, we review current knowledge at three levels: (1) Could other classes of chemical structure serve as building blocks for biopolymer structure and catalysis? Amino acids now seem both readily available to, and a plausible chemical attractor for, life as we do not know it. Amino acids thus remain important and tractable targets for astrobiological research. (2) If amino acids are used, would we expect the same L-alpha-structural subclass used by life? Despite numerous ideas, it is not clear why life favors L-enantiomers. It seems clearer, however, why life on Earth uses the shortest possible (alpha-) amino acid backbone, and why each carries only one side chain. However, assertions that other backbones are physicochemically impossible have relaxed into arguments that they are disadvantageous. (3) Would we expect a similar set of side chains to those within the genetic code? Many plausible alternatives exist. Furthermore, evidence exists for both evolutionary advantage and physicochemical constraint as explanatory factors for those encoded by life. Overall, as focus shifts from amino acids as a chemical class to specific side chains used by post-LUCA biology, the probable role of physicochemical constraint diminishes relative to that of biological evolution. Exciting opportunities now present themselves for laboratory work and computing to explore how changing the amino acid alphabet alters the universe of protein folds. Near-term milestones include: (a) expanding evidence about amino acids as attractors within chemical evolution; (b) extending characterization of other backbones relative to biological proteins; and (c) merging computing and laboratory explorations of structures and functions unlocked by xeno peptides. [ABSTRACT FROM AUTHOR]

This paper investigated the awareness and use of Web 2.0 tools by students at BA ISAGO University, Botswana. Structured questionnaires were used to collect data from the targeted respondents. The results revealed that students are quite familiar with most Web 2.0 tools, such as Facebook, Twitter, media sharing tools, Google Drive, and instant messaging. Even though students are very familiar with and aware of the identified tools, the study found that most students hardly used them. Some of the reasons given by the students include inadequate numbers of computers available to be used by the students in the computer laboratories and limited access to Internet services as well as power failures. Based on these findings, the study recommended integrating a large part of using Web 2.0 tools in the curricula and improving the university infrastructures to facilitate higher uptake and improvement in student skills and the drive to use the tools. [ABSTRACT FROM AUTHOR]

Computer laboratories are learning environments where students learn programming languages by practicing under teaching assistants' supervision. This paper presents the outcomes of a real case study carried out in our university in the context of a database course, where learning SQL is one of the main topics. The aim of the study is to analyze the level of engagement of the laboratory participants by tracing and correlating the accesses of the students to each laboratory exercise, the successful/failed attempts to solve the exercises, the students' requests for help, and the interventions of teaching assistants. The acquired data are analyzed by means of a sequence pattern mining approach, which automatically discovers recurrent temporal patterns. The mined patterns are mapped to behavioral, cognitive engagement, and affective key indicators, thus allowing students to be profiled according to their level of engagement in all the identified dimensions. To efficiently extract the desired indicators, the mining algorithm enforces ad hoc constraints on the pattern categories of interest. The student profiles and the correlations among different engagement dimensions extracted from the experimental data have been shown to be helpful for the planning of future learning experiences. [ABSTRACT FROM AUTHOR]

This paper is concerned with the calibration and validation of a numerical procedure for the analysis of pile performance in soft clays during seismic soil–pile–superstructure interaction (SSPSI) scenarios. Currently, there are no widely accepted methods or guidelines. Centrifuge and shaking table model tests are often used to supplement the available field case histories with the data obtained under controlled conditions. This paper presents a new calibration method for establishing a reliable and accurate relationship between full-scale numerical analysis and scaled laboratory tests in a 1g environment. A sophisticated approach to scaling and validating full-scale seismic soil–structure interaction problems is proposed that considers the scaling concept of implied prototypes as well as "modelling of models" techniques that can ensure an excellent level of accuracy. In this study, a new methodology was developed that can provide an accurate, practical, and scientific calibration for the relationship between full-scale numerical analysis and scaled laboratory tests in the 1g environment. The framework can be followed by researchers who intend to validate their seismic soil–structure interaction findings. [ABSTRACT FROM AUTHOR]

Pancreatic fibrosis (PF) is a part of the pathogenesis in most pancreatic disorders and plays a crucial role in chronic pancreatitis development. The aim of our study was to investigate a relationship between PF grade and signs in resected pancreatic specimens, and the results of both multidetector computed tomography (MDCT) post-processing parameters and fibronectin (FN), hyaluronic acid (HA), matrix metalloproteinase (MMP)-1, and MMP-9 serum levels. The examination results of 74 patients were analyzed. The unenhanced pancreas density (UPD) value and contrast enhancement ratio (CER) showed statistically significant differences in groups with peri- and intralobular fibrosis grades, an integrative index of fibrosis, inflammation in pancreatic tissue, and pancreatic duct epithelium metaplasia, while the normalized contrast enhancement ratio in the venous phase (NCER VP) significantly differed with the perilobular fibrosis grade, integrative fibrosis index, and inflammation (p < 0.05). The blood FN level showed a weak positive correlation with the intralobular fibrosis grade (rho = 0.32, p = 0.008). The blood level of HA positively correlated with the presence of prominent and enlarged peripheral nerves (rho = 0.28, p = 0.02) and negatively correlated with the unenhanced pancreas density value (rho = −0.42, p = 0.0001). MMP-1 and MMP-9 values' intergroup analysis and correlation did not show any statistical significance. The UPD value, NCER VP, and CER, as well as blood levels of FN and HA, could be used in non-invasive PF diagnosis. [ABSTRACT FROM AUTHOR]

Experimental teaching is an important component of computer practical teaching, and students can better absorb the knowledge learned in class by conducting experiments in computer laboratories. However, there are still some deficiencies in current computer laboratories that need to be supplemented with new technologies. Therefore, this article studied the innovative model of computer laboratories based on cloud computing, aiming to upgrade computer laboratories through cloud computing technology. This article experimentally tested the utilization rate of computer laboratory rooms before and after using cloud computing. Through data analysis, it was found that the utilization rate of computer laboratory rooms after using cloud computing could reach a maximum of 92% and a minimum of 79%. The utilization rate of traditional computer rooms was highest at 68% and lowest at 50%. From this experimental data, it could be seen that cloud computing showed good performance in computer laboratories. [ABSTRACT FROM AUTHOR]

This article was written to present a new solution for a phase-shifting transformer and to show that, in many aspects, the proposed device is more functional and improved when compared to the other currently available phase-shifting structures. The article shows the construction of the new phase-shifting transformer, with longitudinal and transverse voltage regulation. The proposed device's functionality and available operation states are compared to other existing solutions. Selected steady-state variants of the operation of the proposed transformer were checked based on computer simulations and the laboratory model presented in detail in the article. Convergence between measurements and simulations was achieved. Power flow calculations were also performed in the five-node electrical power system model. In these calculations, two variants of the proposed device's work were considered and compared with the asymmetric phase shifter. The tests confirmed in the proposed structure, both angle and voltage regulation, enabled maintaining a constant active power flow. The authors show that the proposed solution combines the advantages and functionality of various types of phase shifters while, at the same time, being characterized by a much simpler structure, which results in a two-times-lower cost of the device. [ABSTRACT FROM AUTHOR]

Introduction: orthopedic residency training was established in the West African sub-region a few decades ago, but sub-specialty in arthroscopy has only become established in the last decade. This study was aimed at evaluating available arthroscopy training resources and their impact on skill acquisition by orthopedic residents. Methods: this was a cross-sectional study involving the use of a structured online survey of consultant orthopedic surgeons and orthopedic resident doctors. Details relating to the structure of training and challenges with training and recommendations for improved training were enquired. Results: one hundred and two responses were received. There were 95% males (73) and 5% (4) females among the residents and 92% (23) males and 8% (2) females among the responding consultants. Of the residents, 47% (36) were registrars while 53% (41) were senior registrars. Seventy-six percent (77) were residents and twenty-five (24%) were consultants. Didactic lectures were the most impactful available training adjunct. Only 3% (2) of the residents had access to dry laboratory sessions with no specified number of practice hours attached. There was no computer simulation laboratory or cadaveric laboratory training facility for arthroscopy training in any of the training centres. Ninety-two percent (23) of the responding consultants would prefer a 6 - 12-month rotation in arthroscopy for residents. Fiftythree percent (41) of the residents had regular opportunities to participate in arthroscopic surgeries. Conclusion: orthopedic residency in arthroscopy in Nigeria is emerging and can be improved upon by increasing the available training resources and trained personnel. [ABSTRACT FROM AUTHOR]

New diamond chip resistors have been used in high-power devices widely due to excellent heat dissipation and high-frequency performance. However, systematic research about their solder joint reliability is rare. In this paper, a related study was conducted by combining methods between numerical analysis and laboratory reliability tests. In detail, the shape simulation and thermal cycling finite element simulation for solder joints with different volumes were carried out. The optimized solder volume was 0.05 mm3, and the maximum thermal cycling stress under the optimized shape was 38.9 MPa. In addition, the thermal cycling tests with current and high temperature storage tests were carried out for the optimized solder joint, which showed good agreement with the simulation results, clarified the growth and evolution law of intermetallic compound at the interconnection interface, and proved the optimized solder joint had great anti-electromigration, temperature cycling and high temperature storage reliability. In this work, an optimized solder joint structure of a diamond chip resistor with high reliability was finally obtained, as well as providing considerable reliability data for the new type of diamond chip resistors, which would boost the development of power devices. [ABSTRACT FROM AUTHOR]

Monitoring the health of short-span and medium-span bridges in urban transportation systems is a crucially important issue in civil engineering, as is locating damage. Earlier studies have attempted to use bridge deflection or acceleration to locate damage. However, the deflection is not so sensitive to enable damage location. Few studies have investigated low-frequency acceleration responses. For this study, a proposed model-free method is evaluated for damage localization using low-frequency bridge acceleration under a moving vehicle. First, the bridge dynamic responses in a vehicle–bridge interaction (VBI) system are derived theoretically, where the bridge is modeled as a simply supported beam, the vehicle as a moving sprung mass, and damage as a reduction of the beam's bending stiffness. A partially moving loading model is proposed to explain the influence of the structural damage on the dynamic behavior of the beam. A simple relation was found between low-frequency bridge acceleration and the damage location. Specifically, an abnormal "bump" occurred on the low-frequency bridge acceleration when a vehicle passes over the damaged area. Using this relation, one can directly locate potential damage from the low-pass filtered acceleration time history of the beam. A series of numerical analyses and laboratory and field experiments were conducted to validate the proposed damage localization method. • Low-frequency bridge acceleration by moving vehicles at a point can detect damage. • Stiffness-reduction models can show bridge damage from vehicle–bridge interaction. • Bridge damage appears as a partially moving load on a corresponding intact bridge. • Low-frequency acceleration histories of intact bridges are piecewise linear. • "Bumps" would occur on a damaged beam's low-frequency acceleration time history. [ABSTRACT FROM AUTHOR]

Biodiversity decline and climate change are among the most important environmental issues society faces. Information to address these issues has benefited from increasing big data, advances in cloud computing, and subsequent new tools for analytics. Accessing such tools is streamlined by virtual laboratories for ecological analysis, like the 'Biodiversity and Climate Change Virtual Laboratory' (BCCVL) and 'ecocloud'. These platforms help reduce time and effort spent on developing programming skills, data acquisition and curation, plus model building. Recently this functionality was extended, producing EcoCommons Australia—a web-based ecological modeling platform for environmental problem-solving—with upgraded infrastructure and improved ensemble modeling, post-model analysis, workflow transparency and reproducibility. We outline our user-centered approach to systems design, from initial surveys of stakeholder needs to user involvement in testing, and collaboration with specialists. We illustrate EcoCommons and compare model evaluation statistics through four case studies, highlighting how the modular platform meets users' needs. [ABSTRACT FROM AUTHOR]

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The thermal properties of pavement layers made of concrete with varying bulk densities are a particularly interesting topic in the context of development road technologies. If a hybrid layer system is used as a starting point, with thin asphalt layers (from 1 cm to 4 cm) laid on top of a foam concrete layer, thermal properties begin to play a crucial role. The main research problem was to create a test method enabling the assessment of the influence of solar heating on the thermal parameters of the building material, especially cement concrete. For this reason, this paper is concerned specifically with the assessment of a new methodology for testing and calculating the value of the thermal diffusivity coefficient of samples made of concrete varying bulk densities. In this case, using the proprietary concept the authors built a solar simulator using a multi-source lighting system. The analysis of the results of laboratory tests and numerical analyses allowed the authors to observe that there is a strong correlation between the bulk density of samples heated and the thermal diffusivity parameter, which appears in the unidirectional heat transfer equation. The strength of this relationship has been expressed with the coefficient of determination and amounts to 99%. The calculated values of the coefficient of thermal diffusivity for samples made of foam concrete range from 0.16 × 10 − 6 m 2 s to 0.52 × 10 − 6 m 2 s and are lower (from 2.5 to 8 times) than the value determined for samples made of typical cement concrete. [ABSTRACT FROM AUTHOR]

This paper reports an algorithm for quick and precise estimation of the single‐phase grid frequency under DC offset and both odd and even harmonics. The proposed single‐phase grid frequency estimation method is derived from a three‐phase relation. It relies on a recursive discrete Fourier transform‐based orthogonal signal generator and a two samples‐based algorithm. The proposed approach is simple, demands low computational effort and generates the single‐phase grid frequency at a cost of only one fundamental period as the transient response time under the DC offset and both odd and even harmonics condition. It also produces enhanced performance when compared to several single‐phase grid frequency estimation methods documented in the technical literature. Computer simulations and laboratory experiments are conducted to demonstrate the usefulness of the proposed single‐phase grid frequency estimation method. This paper reports an algorithm for quick and precise estimation of the single‐phase grid frequency. The proposed approach is simple, demands low computational effort and generates the single‐phase grid frequency at a cost of only one fundamental period as the transient response time under the DC offset and both odd and even harmonics condition. It also produces enhanced performance when compared to several existing single‐phase grid frequency estimation methods. [ABSTRACT FROM AUTHOR]

In this paper, we build upon Bruno Latour's political writings to address the current impasse regarding algorithms in public life. We assert that the increasing difficulties at governing algorithms—be they qualified as "machine learning," "big data," or "artificial intelligence"—can be related to their current ontological thinness: deriving from constricted views on theoretical practices, algorithms' standard definition as problem-solving computerized methods provides poor grips for affective dissensions. We then emphasize on the role historical and ethnographic studies of algorithms can potentially play in the politicization of algorithms. By both digging into the genealogy of algorithms' constricted definition and by making their contemporary constitutive relationships more visible, both historical and ethnographic studies can contribute to vascularizing algorithms and making them objects of enlarged disputes. We conclude by giving a flavor of the political potential of the vascularization efforts we call for, using materials from an ethnographic study conducted in a computer science laboratory. [ABSTRACT FROM AUTHOR]

This article presents the main results of a study on the strategies and experiences of environmental education carried out by the network of Computer Reconditioning Centers (CRC) of the Computers for Inclusion Program, focusing on their relationship with space. The study, with a qualitative approach and exploratory-descriptive design, used documentary research as its main methodological procedure research. The analysis was carried out in two stages. The first, to get closer to the research object, was carried out by adapting the cartography of environmental education currents proposed by Lucie Sauvé. The second took as its categories of analysis references from Miltonian geography and the bibliography on Educating Cities, in which we sought to compose a theoretical-methodological framework to understand the relationship that this CRC network establishes with the different territories where it operates. From the systematization exercises carried out, it was possible to identify and describe the different approaches to environmental education carried out in this network. The intentions and actions expressed articulate two major challenges: the CRCs' action on socio-spatial inequalities and their confrontation with the logic of sociodigital exclusion. Environmental education, as a field of knowledge and a field of educational action in contemporary Brazil, needs to deal with processes of exclusion engendered in the technical-scientificinformational environment by a logic of production that is not at the service of life. Through different strategies, environmental education actions in CRCs invite young people and adults to take ownership of learning, knowledge and spaces, giving new meanings to their territories. [ABSTRACT FROM AUTHOR]

Building physical simulation software rely on assumptions regarding the local equilibria in materials' pore systems, which may be unjustified for certain materials. While local hygrothermal non-equilibrium has still been in focus in some previous studies, it has been unclear how significant factor it may be when modeling real structures. In case of wood, the non-equilibrium is related to the slowness of intrusion of water molecules into the hygroscopic cell walls. Including local non-equilibrium in macroscopic model requires separate variables for pore air vapor and adsorbed moisture, and modeling the local mass transfer between pore air and adsorbed moisture requires effective material parameters, whose experimental determination is not straightforward. Commercially available sorption balances can be used to record data, which can be used in the parameter estimation. In this type of problem of parameter estimation from time-dependent data the mathematical challenge is to find global optimum from different solutions, which yield similar values for objective function. This difficulty can be overcome by using statistical inversion approach, which we applied in studying low-density woodfibre material (LDF). Dynamic sorption parameters were finally applied in numerical analysis of a laboratory test assembly. Based on the results, our conclusion is that the slowness of sorption is obvious in small LDF sample, which is exposed to changing humidity, but with the studied material the sorption seem to happen fast enough so that local non-equilibrium may have only slight effects in modeling of real structures. [ABSTRACT FROM AUTHOR]

Distributed Denial of Service (DDoS) attack is one of the most destructive internet network attacks, denying legitimate users access to resources and networks by maliciously blocking available computing resources. Intruders send a large number of packets to the network in order to create a crowding effect. Unlike a Denial of Service (DoS) attack, where a single compromised source generates all of the traffic, a Distributed Denial of Service (DDoS) attack generates traffic from multiple compromised nodes spread across multiple geographies. To address the challenges posed by the Distributed Denial of Service (DDoS) attack, several researchers proposed a variety of solutions for early detection and prevention of the attack. Effective solutions for the prevention and early detection of Distributed Denial of Service (DDoS) attacks, on the other hand, have yet to be developed, and the problem remains a prominent research focus area. This paper tries to present a novel and optimal solution for detecting Distributed Denial of Service (DDoS) attacks on internet networks more quickly and accurately. The proposed model is an anomaly-based real-time prevention model for web networks. The model is based on machine learning principles and can effectively counter new types of Distributed Denial of Service (DDoS) attacks. To demonstrate the efficiency, accuracy, model robustness, and relative of the proposed model, a simulation study was run on an LLDOS session log, and the results indicated that the model performed better than benchmark models found in the literature. [ABSTRACT FROM AUTHOR]

Most real-time speech signals are frequently disrupted by noise such as traffic, babbling, and background noises, among other things. The goal of speech denoising is to extract the clean speech signal from as many distorted components as possible. For speech denoising, many researchers worked on sparse representation and dictionary learning algorithms. These algorithms, however, have many disadvantages, including being overcomplete, computationally expensive, and susceptible to orthogonality restrictions, as well as a lack of arithmetic precision due to the usage of double-precision. We propose a greedy technique for dictionary learning with sparse representation to overcome these concerns. In this technique, the input signal's singular value decomposition is used to exploit orthogonality, and here the ℓ1-ℓ2 norm is employed to obtain sparsity to learn the dictionary. It improves dictionary learning by overcoming the orthogonality constraint, the three-sigma rule-based number of iterations, and the overcomplete nature. And this technique has resulted in improved performance as well as reduced computing complexity. With a bit-precision of Q7 fixed-point arithmetic, this approach is also used in resource-constrained embedded systems, and the performance is considerably better than other algorithms. The greedy approach outperforms the other two in terms of SNR, Short-Time Objective Intelligibility, and computing time. [ABSTRACT FROM AUTHOR]

To probe into the performance of concrete-filled double-skin elliptical steel tubular (CFDEST) members, this paper designs and conducts an experiment on CFDEST short columns imposed with axial pressure, and finite element (FE) models of the axially compressed CFDEST stub columns are established and verified by the test outcomes, taking the influences of elliptical cross-section and hollow ratio into account. The impressions of various parameters, such as hollow ratio, diameter-to-thickness ratio, aspect ratio and so on, on the load-bearing capacity, initial rigidity and ductility property were investigated systematically. Moreover, the typical failure modes, contact pressure and concrete longitudinal stress of the axially compressed CFDEST short column are revealed. In light of the findings acquired by the laboratory tests and numerical analyses, the calculation formulae for evaluating the axial compress capacity of the CFDEST short column are proposed by taking the impact of the sectional aspect ratio and hollow ratio into account. The results indicate that the failure morphologies of axially compressed CFDEST short columns mainly include outward local bulges of the outside EST, the inward bulges of the inside EST and the crushing of core concrete. The axial compress capacity of the CFDEST short column would increase with the decrease in the sectional hollow ratio and aspect ratio. The calculation method is proved to be an accurate and reliable approach to evaluate the axial compress capacity of the CFDEST short column. [ABSTRACT FROM AUTHOR]

Cloud computing supports the fast expansion of data and computer centers; therefore, energy and load balancing are vital concerns. The growing popularity of cloud computing has raised power usage and network costs. Frequent calls for computational resources may cause system instability; further, load balancing in the host requires migrating virtual machines (VM) from overloaded to underloaded hosts, which affects energy usage. The proposed cost-efficient whale optimization algorithm for virtual machine (CEWOAVM) technique helps to more effectively place migrating virtual machines. CEWOAVM optimizes system resources such as CPU, storage, and memory. This study proposes energy-aware virtual machine migration with the use of the WOA algorithm for dynamic, cost-effective cloud data centers in order to solve this problem. The experimental results showed that the proposed algorithm saved 18.6%, 27.08%, and 36.3% energy when compared with the PSOCM, RAPSO-VMP, and DTH-MF algorithms, respectively. It also showed 12.68%, 18.7%, and 27.9% improvements for the number of virtual machine migrations and 14.4%, 17.8%, and 23.8% reduction in SLA violation, respectively. [ABSTRACT FROM AUTHOR]

The major challenge faced by electronic device designers is to defend the system from attackers and malicious modules called Hardware Trojans and to deliver a secured design. Although there are many cryptographic preventive measures in place adversaries find different ways to attack the device. Differential Power Analysis (DPA) attack is a type of Side Channel Attacks, used by an attacker to analyze the power leakage in the circuit, through which the functionality of the circuit is extracted. To overcome this, a lightweight approach is proposed in this paper using, Wave Dynamic Differential Logic (WDDL) technique, without incurring any additional resource cost and power. The primary objective of WDDL is to make the power consumption constant of an entire circuit by restricting the leakage power. The alternate strategy used by an adversary is to leak the information through reverse engineering. The proposed work avoids this by using a bit sequencer and a modified butterfly PUF based randomizing architecture. A modified version of butterfly PUF is also proposed in this paper, and from various qualitative tests performed it is evident that this PUF can prevent information leakage. This work is validated on ISCAS 85, ISCAS 89 benchmark circuits and the results obtained indicate that the difference in leakage power is found to be very marginal. [ABSTRACT FROM AUTHOR]

This paper aims to provide a high-level overview of practical approaches to machine-learning respecting the privacy and confidentiality of customer information, which is called Privacy-Preserving Machine Learning. First, the security approaches in offline-learning privacy methods are assessed. Those focused on modern cryptographic methods, such as Homomorphic Encryption and Secure Multi-Party Computation, as well as on dedicated combined hardware and software platforms like Trusted Execution Environment - Intel® Software Guard Extensions (Intel® SGX). Combining the security approaches with different machine learning architectures leads to our Proof of Concept in which the accuracy and speed of the security solutions will be examined. The next step was exploring and comparing the Open-Source Python-based solutions for PPML. Four solutions were selected from almost 40 separate, state-of-the-art systems: SyMPC, TF-Encrypted, TenSEAL, and Gramine. Three different Neural Network architectures were designed to show different libraries' capabilities. The POC solves the image classification problem based on the MNIST dataset. As the computational results show, the accuracy of all considered secure approaches is similar. The maximum difference between non-secure and secure flow does not exceed 1.2%. In terms of secure computations, the most effective Privacy-Preserving Machine Learning library is based on Trusted Execution Environment, followed by Secure Multi-Party Computation and Homomorphic Encryption. However, most of those are at least 1000 times slower than the nonsecure evaluation. Unfortunately, it is not acceptable for a realworld scenario. Future work could combine different security approaches, explore other new and existing state-of-the-art libraries or implement support for hardware-accelerated secure computation. [ABSTRACT FROM AUTHOR]

Epidemiological studies investigating transmission chains of tuberculosis are undertaken worldwide to tackle its spread. CRISPR locus diversity, called spoligotyping, is a widely used genotyping assay for Mycobacterium tuberculosis complex (MTBC) characterization. Herein, we developed a house-made targeted next-generation sequencing (tNGS) spoligotyping, and compared its outputs with those of membrane-based spoligotyping. A total of 144 clinical MTBC strains were retrospectively selected to be representative of the local epidemiology. Data analysis of a training set allowed for the setting of "presence"/"absence" thresholds for each spacer to maximize the sensibility and specificity related to the membrane-based spoligotyping. The thresholds above, in which the spacer was considered present, were 50 read per millions for spacers 10 and 14, 20,000 for spacers 20, 21, and 31, and 1000 for the other spacers. The confirmation of these thresholds was performed using a validation set. The overall agreement on the training and validation sets was 97.5% and 93.8%, respectively. The discrepancies concerned six strains: Two for spacer 14, two for spacer 31, and two for spacer 32. The tNGS spoligotyping, whose thresholds were finely-tuned during a careful bioinformatics pipeline development process, appears be a technique that is reliable, inexpensive, free of handling errors, and automatable through automatic transfer into the laboratory computer system. [ABSTRACT FROM AUTHOR]

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This document is a correction notice for an article titled "Platform pricing and blockchain adoption for capacity sharing with cross-network externality and supply risk" published in the Annals of Operations Research. The correction addresses an error in the author's affiliation, specifically the omission of the sub-school. The correct affiliation should be read as the College of Management and Economics & The Laboratory of Computation and Analytics of Complex Management Systems (CACMS), Tianjin University, Tianjin 300072, China. The original article has been corrected. The publisher, Springer Nature, remains neutral regarding jurisdictional claims and institutional affiliations. The authors of the article are Longfei He, Xiao Zhang, Baofeng Huo, and Yang Zhang. [Extracted from the article]

During the sixties, a most curious symbiosis took hold between Heinz von Foerster (1911–2002) then the Director of a top-notch and lavishly funded US laboratory [Biological Computer Laboratory (BCL), 1958–1975] and the Chilean neuroscientist Humberto R. Maturana (1928–2021) professor at the Universidad de Chile. The chance encounter between them triggered a long-lasting friendship and a fundamental change in our understanding of Systems Science. In particular the contributions of Biology of Cognition and Autopoiesis are important to understand this change and the years 1968–1973 are particularly relevant. In this period, Maturana published, as a Technical Report of BCL, the foundational document The Neurophysiology of Cognition. Later, in 1973, the book De Maquinas y Seres Vivos put forward the notion of Autopoietic Systems. Also, between 1971 and 1973, the Allende government tried to cybernitize the Chilean economy with the SYNCO project. In that project, Maturana and von Foerster played a role by teaching Cybernetics to the engineers and administrators of this technological dream. During this same time, Cybernetics was important in Chile and Professors Maturana and von Foerster although not directly involved in the day-to-day running of SYNCO were important in that unique effort. When a military coup deposed Allende and sent Chile into a tailspin of right-wing retribution (9-11-1973), von Foerster, a foreigner who loved Chile and its people, did his outmost to assure the safety of many people involved in this unique Latin American Cybernetics dream. [ABSTRACT FROM AUTHOR]

Mine waste dump material has no economic value to the industry. Therefore, the mine waste is dumped, forming slopes. Mine waste dump slopes obtain 30% to 50% of the mining area. To reduce the land occupancy of these slopes, they are created with high altitudes. Hence, they are susceptible to failure. Slope stability analysis is a major aspect of geotechnical engineering. Slope stability analyses are mostly done with assumptions on the geometry. This is avoided in this paper with the usage of UAVs. The 3D model is created from UAV imagery of a coal mine in Raniganj coalfield, India. The model is fine-tuned with the DGPS survey. Geotechnical data were collected and tested in the laboratory for various numerical analyses. An active mine waste dump slope is analyzed for slope failure. Earthquakes and rainfall cannot be controlled, and their effects on the stability of the mine waste dump slope were examined. The study extracted various factor of safety (FOS) analyses on static, seismic, and rainfall conditions. The seismic condition simulates a condition of the slope to be failed with low (0.948) FOS. However, rainfall condition predicts the slope to be more stable. The deformation pattern and magnitude of the slope failure are also discussed. [ABSTRACT FROM AUTHOR]

Due to the nonlinear nature of photovoltaic (PV) cells and the dependence of the maximum achievable power on environmental conditions, a robust nonlinear controller is essential to warrant maximum power point tracking (MPPT) by managing the nonlinearities of the system and making it robust against varying environmental conditions. Most methods used to obtain MPPT have some disadvantages; one of them is the oscillation around the operating point. In this paper, to minimize these problems, a robust nonlinear sliding mode controller based on the power curve of a PV (SMC-PCPV) was proposed to determine the maximum power point (MPP) of a PV panel, for a quasi Z-source inverter (qZSI) as a single-stage inverter. Single-stage inverters have lower components and prices, smaller sizes, more simplicity, and higher efficiency than two-stage inverters. One of the important features of this controller is its ease of implementation compared to other methods presented in the articles. To show the effectiveness and robustness of the proposed scheme, the SMC-PCPV was carried out on computer simulations and laboratory prototypes. The simulation and experimental results showed that the proposed controller was properly resistant to changes in input parameters, such as temperature and radiation, and controlled the converter at the best point to obtain the most power from the PV panel, and it had good speed in response to the changing environmental condition. [ABSTRACT FROM AUTHOR]