Miracle-dz/UniFAR-FTUs huggingface dataset:
Analysis of a Fast Acting Circuit Breaker Mechanism Part I: Electrical Aspects

Fast operation of high voltage circuit breakers has been achieved in recent years by electromagnetically driven mechanisms. Technical design and operational data must be available with manufacturers acturers of such circuit breakers. However, a detailed analysis of such a mechanism has not been published so far. In this paper the authors analyse the electromechanical behaviour of a model fast-acting circuit breaker mechanism. Numerical design techniques are also developed. Part I deals with the electrical aspects, while mechanical and thermal aspects are discussed in an accompanying paper (Part II).
Simulation of flow over double-element airfoil and wind tunnel test for use in vertical axis wind turbine

Nowadays, small vertical axis wind turbines are receiving more attention due to their suitability in micro-electricity generation. There are few vertical axis wind turbine designs with good power curve. However, the efficiency of power extraction has not been improved. Therefore, an attempt has been made to utilize high lift technology for vertical axis wind turbines in order to improve power efficiency. High lift is obtained by double-element airfoil mainly used in aeroplane wing design. In this current work a low Reynolds number airfoil is selected to design a double-element airfoil blade for use in vertical axis wind turbine to improve the power efficiency. Double-element airfoil blade design consists of a main airfoil and a slat airfoil. Orientation of slat airfoil is a parameter of investigation in this paper and air flow simulation over double-element airfoil. With primary wind tunnel test an orientation parameter for the slat airfoil is initially obtained. Further a computational fluid dynamics (CFD) has been used to obtain the aerodynamic characteristics of double-element airfoil. The CFD simulations were carried out using ANSYS CFX software. It is observed that there is an increase in the lift coefficient by 26% for single-element airfoil at analysed conditions. The CFD simulation results were validated with wind tunnel tests. It is also observe that by selecting proper airfoil configuration and blade sizes an increase in lift coefficient can further be achieved.
Identifying preventative measures against frailty, locomotive syndrome, and sarcopenia in young adults: a pilot study

[Purpose] The purpose of this study was to propose potential preventive measures against future mobility impairments and muscle loss in healthy young adults by comprehensively evaluating their status of frailty, locomotive syndrome, and sarcopenia. [Participants and Methods] A total of 83 Japanese young adults were enrolled in this study and evaluated using the diagnostic criteria for frailty (Japanese version of the Cardiovascular Health Study), locomotive syndrome (calculated as scores of the LOCOMO-25, the stand-up test, and two-step test), and sarcopenia (handgrip strength, usual gait test, skeletal muscle index). [Results] The prevalence of frailty-prefrailty (45.9%) was higher than that of presarcopenia (22.3%) and locomotive syndrome (14.1%). The prevalence of combinations of frailty-prefrailty and presarcopenia; frailty-prefrailty and locomotive syndrome; and frailty-prefrailty, locomotive syndrome, and pre-sarcopenia was 9.4%, 4.7%, and 3.5%, respectively. [Conclusion] Only 40% of the participants did not meet the three diagnostic criteria. On the other hand, there were not many participants with sarcopenia and/or locomotive syndrome diagnoses, suggesting that the improvement in intrinsic skeletal muscle mass rather than physical function is important for healthy Japanese young adults and could possibly be protective against future mobility or muscle-loss disorders.
85--115-GHz Receivers for Radio Astronomy

Low-noise receivers for radio astronomy have been built using Pb alloy superconducting tunnel junction mixers operating at 4.5 K. They have been used for 85-115-GHz astronomy with double-sideband receiver noise temperature between 70 and 200 K. Junction fabrication and receiver construction, operation, and performance are described herein.
Selecting maintenance strategy in mining industry by analytic network process and TOPSIS

Which maintenance strategy is the most suitable one to maintain equipments? This is one of the questions which the majority of maintenance managers face it. The main aim of this study is to recommend an efficient method to determine the most suitable maintenance strategy. The main purpose of this study is to develop an analytic network process (ANP) method and the technique for order preference by similarity to an ideal solution (TOPSIS) for selecting suitable maintenance strategy. First of all, the priority of criteria is identified by ANP method. Then, paired comparing maintenance strategies related to criteria, table of importance of criteria is arranged. Considering the table and weights of criteria which is evaluated by ANP method, a decision-making matrix is arranged. Finally, employing TOPSIS method, maintenance strategies are ranked. The proposed method in this study has been employed for a category of equipment in Chadormalu Mining Industrial Company. Five maintenance strategies called DOM, TPM, CBM, TBM, EM according to four criteria called cost, maintainability, availability, reliability for a category of equipment in this plant were compared in which, CBM and TPM strategies ranked first and second among others.
A Monopole Antenna with Dual-Band Reconfigurable Circular Polarization

This paper describes a monopole antenna with dual-band switchable circular polarization (CP) sense in WLAN and WiMAX bands. The proposed antenna consists of a rectangular patch fed by a microstrip line and a ground plane embedded with a T-shaped slot integrated with PIN diodes. The slotted ground is capable of exciting CP sense around 2.45 GHz for WLAN and around 3.4 GHz for WiMAX, respectively. Two triangular strips are added to improve impedance matching. The CP sense of the proposed antenna can be reconfigured between the right-handed circular polarization (RHCP) and left-handed circular polarization (LHCP) by switching the states of PIN diodes in the slot. The lower band 3-dB axial ratio (AR) bandwidth is 8.6%, and the upper band 3-dB AR bandwidth is 20.8%, in which the return loss is less than −10-dB. Simulated analysis and measured results are carried out and good agreement is achieved.
Direct Integration of Optimized Phase-Change Heat Spreaders Into SiC Power Module for Thermal Performance Improvements Under High Heat Flux

Silicon carbide (SiC) power modules are attractive in many applications due to the superiority of their semiconductor characteristics. However, power modules are subjected to repetitive thermo-mechanical stress caused by the mismatch of the coefficient of thermal expansion between different layers of materials. Moreover, the relatively smaller die size of SiC chips makes the heat flux increase significantly, which brings new challenges to the thermal management and reliability of SiC power modules. To tackle these challenges, this article proposes a new thermal enhanced packaging method based on vapor chamber (VC) phase change heat spreader (PCHS) for SiC power modules, achieving the advantages of high thermal conductivity, low weight, low cost, and low thermal stress. In this new design, SiC mosfet bare dies are directly soldered on the top of VC-PCHS, which not only act as heat spreaders but also conduct the drain current of mosfets. The integrated VC-PCHS is optimized based on thermal and thermomechanical performance. An SiC power module prototype directly integrated with VC-PCHS is built using a new fabrication process. Both the simulations and experiments demonstrate significant improvements in thermal and thermomechanical performance. The modules integrated with VC-PCHS can operate under 200 W of power dissipation per die (632 W/cm2) without exceeding the maximum rated junction temperature. This article reveals the potential of directly integrating phase change cooling components inside power modules, providing a new solution to improve the thermal performance and reliability of SiC power modules without adding complexity and energy consumptions to external cooling systems.
ERA5 derived precipitation: Insights from historical rainfall networks in southern Africa

Patterns of freshwater availability — its variability and distribution — are already shifting as a function of global climate change and climate variability. High resolution global gridded reanalyses products present an important tool to understand the already observed changes, and thereby improve future scenarios as the climate evolves. A historical 100-year long district rainfall dataset and a unique set of highly detailed rainfall data from the highveld of South Africa spanning a 10-year period provides an opportunity to independently evaluate the European Centre for Medium Range Weather Forecasting ERA5 reanalysis product. Evaluation is challenged by the episodic nature of significant rainfall events of southern Africa as well as differences in spatial and temporal resolution between model output and surface precipitation data. Here we present a convergent methodology spanning annual to event timescales and regional to gauge-level spatial scales in order to identify the characteristics of systematic biases in variability and amount of rain as well as timing of events. We find that ERA5 is consistently wetter than observed in ways that affect the timing of individual events, while performing well on metrics associated with large scale trends and seasonal variability. Errors are associated with both stratiform and convective rainfall types, but the timing of onset of convective rainfall is a challenge that is critical in this summer rainfall dominated region.
Investigation of modified WPM medium for the best meristem proliferation of Corylus avellana L.

Cultivation of Corylus avellana L. in Turkey is performed generally in the northern regions where it is an important source of livelihood for the local farmers. More than 70% of world hazelnut production is supplied by Turkey, but compared with other countries, Turkey’s hazelnut production area is quite narrow. In this study was aimed to develop an effective in vitro production for seven local cultivars of C. avellana. Therefore, WPM medium supplemented with 6-Benzylaminopurine (BAP) was modified by using single or in combination of Fe-EDDHA, AgNO3, H3BO3, charcoal and gibberellic acid. In all varieties, the best regeneration rates varying between 68% and 94% were obtained from WPM medium supplemented with 4.4 µM BAP, 27.8 µM Fe-EDDHA and 10g/L Charcoal. Genetic stability of shoots derived from meristem culture using the best medium was analysed using ISSR primers, when the gel images of the PCR products were examined, no polymorphic band was observed in samples collected from seven provinces, and the genetic stability was determined as 100%.
Development of a Predictive Optimal Controller for Thermal Energy Storage Systems

This paper describes the development and simulation of a predictive optimal controller for thermal energy storage systems. The “optimal” strategy minimizes the cost of operating the cooling plant over the simulation horizon. The particular case of a popular ice storage system (ice-on-coil with internal melt) was investigated in a simulation environment. Various predictor models were analyzed with respect to their performance in forecasting cooling load data and information on ambient conditions (dry-bulb and wet-bulb temperatures). The predictor model provides load and weather information to the optimal controller in discrete time steps. An optimal storage charging and discharging strategy was planned at every time step over a fixed look-ahead time window utilizing newly available information. The first action of the optimal sequence of actions was executed over the next time step and the planning process was repeated at every following time step. The effect of the length of the planning horizon was inves.
VEHICLE TYPE RECOGNITION BASED ON HARRIS CORNER DETECTOR

With the development of computer technology in recent years, video-based detection technology in the intelligent transportation system has been widely used, this article uses a identification method based on the Harris corner detection for rapid and accurate identification. First of all, extract moving goal vehicles of the video, and then extract its Harris corners in gray image, and select the Harris corner of cars, buses and lorries as standard samples. Then the Hausdorff distance are calculated of Harris corner between the standard types and the swatches which need to be recognized. The two whose Hausdorff distance is smallest can be judged as the same type. Experiment results show that the method is accurate, effective and better real-time.
Size-dependent pull-in instability of electrostatically actuated microbeam-based MEMS

We present a size-dependent model for electrostatically actuated microbeam-based MEMS using strain gradient elasticity theory. The normalized pull-in voltage is shown to increase nonlinearly with the decrease of the beam height, and the size effect becomes prominent if the beam thickness is on the order of microns or smaller (i.e. when the beam dimension is comparable to the material length scale parameter). Very good agreement is found between the present model and available experimental data. The study may be helpful to characterize the mechanical properties of small size MEMS, or guide the design of microbeam-based devices for a wide range of potential applications.
A structured model for evaluating information systems effectiveness

Research in information systems (IS) indicates an absence of clear-cut models to assess IS effectiveness. While the costs are easily identifiable it is the benefits which are most difficult to assess due to the scope of impact of information systems. In order to provide structure to the problem this paper presents a hierarchical approach to develop an IS effectiveness model using structured modelling techniques. This study uses the prior research work and a survey to identify and relate factors of IS effectiveness. The results of the model show that ‘improving systems integration’ has the highest influence on information systems effectiveness, followed by ‘facilitating information retrieval’. We were able to validate our results by showing that they are consistent with the widely accepted ‘stages model’ of IS development. Of particular interest is the finding that significantly high levels of IS effectiveness are experienced by organizations in the penultimate or final stage of IS development. The most significant contribution of this study is the development of a comprehensive IS effectiveness evaluation framework that resolves many subjective dilemmas of traditional user-centred evaluation approaches. Copyright © 1999 John Wiley & Sons, Ltd.
Effect of Physical Exercise Program Based on Active Breaks on Physical Fitness and Vigilance Performance

Simple Summary Our study aimed to analyze the effects of 8 weeks physical training on vigilance performance in high school students. Forty-two healthy students were assigned for convenience and matched into two groups, a Control Group (CG) and an Active-Break Group (ABG). The participants were assessed before the training program using the Alpha-Fitness test battery and Psychomotor Vigilance Task (PVT) to observe their physical fitness and vigilance performance. Compared with the pre-test, significant different were observed in the post-test PVT. Results showed a main effect of ABG responding faster than students in the CG group. This demonstrated that 8 weeks physical training have an effect on vigilance performance and improve the efficiency of vigilance in high school students. Abstract The scientific literature has shown the beneficial effects of chronic Physical Exercise (PE) on a wide range of tasks that involve high-order functioning. For this reason, the present study aimed to investigate the effects of active breaks on physical fitness and vigilance performance in high school students through eight weeks of physical training. A total of 42 healthy students (age = 16.50 ± 0.59 years; height = 171.08 ± 8.07 cm; weight = 67.10 ± 13.76 kg) from one Andalusian high school (Spain) were assigned for convenience and matched into two groups, a Control Group (CG) and an Active-Break Group (ABG). The ABG performed two active breaks (based on strength and self-loading exercises) during the school day, first at 10:00 a.m. and second at 12:30 p.m. The participants were assessed before and after the training program using the Alpha-Fitness test battery and the Psychomotor Vigilance Task (PVT). Significant differences were observed in the post-training PVT results, compared with the pretraining PVT, showing ABG responding faster than CG. Thus, the presents study demonstrated that eight weeks of physical training affects vigilance performance (compared to CG) and improves the efficiency of vigilance in high school students, contributing to enhancement of quality of education.
Analysis and Performance Comparison of Competing Desktop Cooling Technologies

The present work compares the performance of various competing thermal management technologies for the desktop sector. An air-cooled heat sink used for the Intel Pentium 4 Processor is used as the baseline for comparison. Heat sinks based on metal foams, microchannels (with single-phase liquid) and jet impingement (with air and single-phase liquid) are compared based on total heat sink system thermal resistance and heat dissipation capacity. The analysis is carried out under the constraints of a fixed heat sink volume available in a typical desktop, and a fixed ambient air temperature. The comparison of thermal resistances is made under the constraint of the same pumping power as in the baseline heat sink. The maximum heat dissipation possible using a particular heat sink technology is estimated and this can be used to select technologies to meet future thermal challenges as outlined in the International Technology Roadmap for Semiconductors (ITRS). The results show that microchannel and liquid jet impingement cooling provide the greatest heat removal rates under the given constraints. The maximum power dissipation for these cases is almost double that of the baseline air-cooled heat sink. Under the chosen constant value of the junction to heat sink resistance, only modest improvements in heat removal rate are obtained with the microchannel and jet impingement technologies even if the pumping power constraint is relaxed, and a specific pump curve is used instead. The junction to heat sink resistance is significantly higher than the heat sink to ambient resistance, and is the key determinant in the comparisons.Copyright © 2007 by ASME
Compliant Mechanisms for Robotic Ankles

We have developed a compliant robotic tendon mechanism for a robotic ankle. In this paper, we analyze the differences between a stiff and compliant robotic tendon versus a stiff and compliant slider crank mechanism. The compliant, slider-crank mechanism reduces peak forces and speed required by an actuator at the ankle.Copyright © 2013 by ASME
HingePlace: Focused transcranial electrical current stimulation that allows subthreshold fields outside the stimulation target

Transcranial Electrical Stimulation (TES) is a promising tool for treating many neurological disorders, but it classically results in diffused stimulation. Many optimization algorithms have been proposed for focusing TES, commonly by creating multi-electrode arrangements and choosing current amplitudes such that the resulting current fields in the brain are focused in the target region, and are as small as possible outside the target region. Consequently, it is likely that such optimization does not harness the non-linear nature of neural dynamics, particularly their thresholding phenomenon, i.e., the observation that neurons fire only when the stimulating currents are above a certain threshold. In this work, we propose HingePlace which explicitly harnesses this thresholding phenomenon by designing multi-electrode arrangements which allow the electric fields outside the target region to be non-zero but still below the stimulation threshold. In idealized simulated models, we compare HingePlace with existing algorithms and find that HingePlace performs strictly better, in some cases providing ~20% reduction in stimulated area for a specified limit on maximum injected current.
Modeling Radio Recombination in MWC 349A. I. Saturation Properties

Strong nonlocal thermodynamic equilibrium recombination line emission from the envelope of MWC 349A has been studied observationally and theoretically and has been used to derive information about the physical and kinematic properties of the circumstellar environment around this object. In this paper, we construct a detailed model of radiative transfer of the commonly observed maser lines H26α and H30α in MWC 349A, specifically taking into account the effect of maser saturation. The envelope is modeled as a combination of an ionized Keplerian rotating disk and a disk wind expanding at a velocity of 60 km s−1. Our modeling results show that millimeter-line H26α is significantly affected by the saturation effect. The line intensity is predicted to be greatly reduced in comparison with previous models which ignore the saturation effect. The H30α maser is predicted to be unsaturated. Our model shows that the predicted intensity and line shape are in agreement with observations. The predicted position–velocity diagrams are also consistent with observations and the interpretation that the H26α maser appears at smaller radii in comparison to the H30α maser. We also emphasize that the wind component is important in shaping the line profiles of the recombination masers.
Neural Network‐Based Long‐Term Hydropower Forecasting System

Artificial neural networks are alternatives to stochastic models even if the optimization of their architectures remains a tricky problem. Two different approaches in long‐term forecasting of potential energy inflows using a feedforward neural network (FNN) and a recurrent neural network (RNN) are proposed. The problem of overfitting, particularly critical for limited hydrologic data records, is addressed using a new approach entitled optimal weight estimate procedure (OWEP). The efficiency of the two models using OWEP is assessed through multistep forecasts. The experiment results show that, in general, OWEP improves the models' performance and significantly reduces the training time on the order of 60 percent. The RNN outperforms the FNN but costs about a factor of 2 longer in training time. Furthermore, the neural network‐based models provide more accurate forecasts than traditional stochastic models. Overall, the RNN appears to be the best suited for potential energy inflows forecasting and therefore for hydropower systems management and planning.
A Classification Algorithm: Data Mining and Mathematical Model

In this paper, we propose a classification algorithm based on Recency-Frequency-Monetary (RFM) model and K-means data mining method. In addition, the designed algorithm is verified by the experiments on the member data in a large shopping mall. The experiments results show that the proposed algorithm can provide an accurate classification of the members. Finally, some marketing strategies for different classes of members are given according to the classification results.