Miracle-dz/UniFAR-FTUs huggingface dataset:
Electrical Field Change of an XLPE Bounded Air-filled Spherical Cavity during DC Voltage Decreasing and Voltage Polarity Reversal

Partial discharge testing under DC voltage can be used to detect possible insulation defect of extruded HVDC cable system. And electric field distribution and field change at the defect is a decisive factor of partial discharge. An XLPE bounded spherical air cavity model was established in this paper, and electrical field change during applied DC voltage decreasing and polarity reversal were studied. The influence of field coefficient of XLPE conductivity was considered during the simulation. The obtained results predicted partial discharge with polarity opposite to the initial applied DC voltage. And this deduction accords with reported experimental results.
The Performance and Energy Efficiency Potential of FPGAs in Scientific Computing

Hardware specialization is a promising direction for the future of digital computing. Reconfigurable technologies enable hardware specialization with modest non-recurring engineering cost. In this paper, we use FPGAs to evaluate the benefits of building specialized hardware for numerical kernels found in scientific applications. In order to properly evaluate performance, we not only compare Intel Arria 10 and Xilinx U280 performance against Intel Xeon, Intel Xeon Phi, and NVIDIA V100 GPUs, but we also extend the Empirical Roofline Toolkit (ERT) to FPGAs in order to assess our results in terms of the Roofline Model. Although FPGA performance is known to be far less than that of a GPU, we also benchmark the energy efficiency of each platform for the scientific kernels comparing to microbenchmark and technological limits. Results show that while FPGAs struggle to compete in absolute terms with GPUs on memory- and compute-intensive kernels, they require far less power and can deliver nearly the same energy efficiency.
A Hybrid Algorithm for Recognition of Power Quality Disturbances

An algorithm making use of hybrid features of Hilbert transform (HT) and Stockwell transform (ST) to identify the single-stage and multiple (multi-stage) power quality disturbances (PQDs) is introduced in this manuscript. A power quality index (PI) and time location index (TLI), based on the features computed from the voltage signal by the use of HT and ST are proposed for recognition of the PQDs. Four features extracted from the PI and TLI are considered for classification of the PQDs achieved using decision tree driven by rules. The algorithm is tested on the PQDs generated with the help of mathematical models (in conformity with standard IEEE-1159). Performance is evaluated on 100 data set of every disturbance computed by varying various parameters, and efficiency is found to be greater than 99%. It is established that an algorithm is effective for recognition of PQ events with an efficiency greater than 98% even in the presence of high-level noise. Algorithm is faster compared to many reported techniques and scalable for application to voltages of all range. Results are validated through comparison with the results of the algorithms reported in the literature. Performance of the algorithm is effectively validated on the practical utility network. This algorithm can be effectively implemented for designing the power quality (PQ) monitoring devices for the utility grids.
OpenCL-enabled Parallel Raytracing for Astrophysical Application on Multiple FPGAs with Optical Links

In an earlier study, we optimized the Authentic Radiative Transfer (ART) method to solve the space radiative transfer problems in early universe astrophysical simulations using an Intel Arria 10 Field Programmable Gate Array (FPGA). In this paper, we optimize this method for use on the latest FPGA, an Intel Stratix 10, and evaluate its performance by comparing the GPU implementation on multiple nodes. For the multi-FPGA computing and communication framework, we apply our original system, called as Communication Integrated Reconfigurable CompUting System (CIRCUS), to realize OpenCL based programming and utilize multiple optical links on an FPGA for parallel FPGA processing, and this study is the first implementation of a real application applied using CIRCUS. The FPGA implementation is 4.54-, 8.41-, and 10.64-times faster than that of a GPU on one, two, and four nodes, respectively, for multi-GPU cases using an InfiniBand HDR100 network. It also achieves 94.2 % parallel efficiency running on four FPGAs. We believe this efficiency is brought about from the low-latency and high-efficiency pipelined communication of CIRCUS, which provide easy programming on multi-FPGAs using OpenCL for high-performance computing applications.
The Bearing Capacity of Compacted Clay Reinforced by Geotextile and Sand Cushion

The paper presents a series of laboratory tests for the California Bearing Ratio (CBR) for investigating the bearing capacity of soft clay reinforced by nonwoven geotextile and sand cushion. The variation of test conditions included levels of compaction energy and the thickness of sand layers. The result reveals that a thin sand cushion layer and reinforcement inclusion improved the CBR value of the reinforced riverbed clay significantly. The optimum thickness of sand cushion was 1.5 cm, which equivalent to the ratio between the depth of the first reinforcement layer and the diameter of the penetrated piston is equal unity. The CBR of the reinforced specimens could be increased as high as 25.5-34.8% at this optimum reinforcement ratio.
Study of Harmonic Mitigation Techniques Based on Ranges Level Voltage Refer to IEEE 519-2014

The use of semiconductor-based electrical and electronic devices has been known to be widespread and applied in all fields due to increased efficiency and energy saving. But on the other side, the use of non-linear loads, causing power quality problems in the electric power system so that it becomes an important issue and must be overcome, one of which is Harmonic. Harmonics is a disturbance that occurs in an electric power distribution system due to the distortion of current and voltage waves. In this paper discusses the harmonic phenomenon, harmonic standards and harmonic mitigation technology. The discussed harmonic standards refer to IEEE 519-2014 and IEC 6100-3-2. Due to the large number and variety of methods available, the harmonic mitigation techniques are grouped into 3 categories, including passive harmonic filters, active harmonic filters and hybrid harmonic filters. The use of harmonic filters, among others, is adjusted to the voltage level and conditions of the electric power system. From the study results it is known that to suppress harmonic distortion for levels voltage of V ≤ 1.0 kV using passive harmonic filters and DC chokes, at a distribution level voltage of 1.0 kV < V ≤ 69 kV using a zigzag transformer mounted on the load side of the distribution transformer, at level voltage of 69 kV ≤ 161 kV using a hybrid filter technique. Meanwhile, to reduce harmonics at a level voltage of V> 161 kV by keeping the voltage level of the transformer operating at its nominal voltage.
An On-Chip Self-Powered Non-Volatile One-Time-Programmable Memory System in Standard CMOS Technology

An on-chip self-powered memory system fully realizable in standard CMOS technology is presented. The memory cells consist of a MOS capacitor operated as an antifuse, which is written by applying high voltage between its terminals during tens of milliseconds. The full system comprises an on-chip solar cell, a cross coupled charge pump DC-DC converter, stacked MOSFET high voltage drivers and CMOS anti-fuse one-time programmable memory cells. The writing of each memory cell can be commanded through a digital signal provided by an on-chip control circuit or other on-chip sensors. The proposed memory system is intended to be integrated in small autonomous on-chip devices. This paper describes each of the components that build up the proposed system and demonstrates its feasibility through results of its implementation in 0.18 um CMOS technology.
Vision-based People Counting for Attendance Monitoring System

In this paper, an automatic people detection and counting system using data collected from an over-head camera is proposed. The purpose of this research is to develop a fast and accurate intelligent people counting technique for attendance monitoring systems in offices and lecture rooms. The proposed method includes two stages working sequentially. First, the detection task is executed to find any person presented in the current frame. A deep learning architecture, MobileNetv2-SSD, was used to carry out the detecting phase. If there is any detected person, the tracking phase, which based on visual-tracking techniques, will be initialized, and keeps track of the people’s position. Based on the tracked motion path of the detected people, we can determine if there is any person who has entered or exited the room. Therefore, we can monitor the number of attending people. The testing hardware was a Raspberry Pi computer and a camera. This work has been tested on different stages of a day and achieved real-time performance with sufficient accuracy.
Energy-Efficient Design of Approximated Full Adders

This work analyses a set of approximate full adder circuits in 7nm FinFET device technology in order to identify how energy-efficient these designs are for different voltage operation points. The behavior in a specific environment with voltage scaling is compared to conventional exact adders. The results allow designers access to the pros and cons of each design in error-tolerant applications. Considering the impact on delay and power consumption, approximate XNOR and PTL based FAs showed increase in PDP for all voltages applied. However, Mirror Adder inspired approximate designs showed a reduction in PDP at 0.4V. The PDP for buffer approximated FAs remained constant throughout voltage scaling.
DEN: Disentanglement and Enhancement Networks for Low Illumination Images

Though learning-based low-light enhancement methods have achieved significant success, existing methods are still sensitive to noise and unnatural appearance. The problems may come from the lack of structural awareness and the confusion between noise and texture. Thus, we present a lowlight image enhancement method that consists of an image disentanglement network and an illumination boosting network. The disentanglement network is first used to decompose the input image into image details and image illumination. The extracted illumination part then goes through a multi-branch enhancement network designed to improve the dynamic range of the image. The multi-branch network extracts multi-level image features and enhances them via numerous subnets. These enhanced features are then fused to generate the enhanced illumination part. Finally, the denoised image details and the enhanced illumination are entangled to produce the normallight image. Experimental results show that our method can produce visually pleasing images in many public datasets.
Performance Comparison of Proportional-Integral and Fuzzy-PI for a Droop Control of DC Microgrid

This work presents the droop control performance for sharing loads on the DC microgrid network. The traditional droop control consists of voltage control and current control where the PI controller is used as compensation for the error. The droop control performance can be seen from the fast response of the system when load power sharing between two DC generating sources is enabled. The Fuzzy-PI controller as an intelligent control functions to improve the performance of droop control on the DC microgrid. The Fuzzy PI controller suggested is built with the aid of a closed loop control based on the power of each unit DCG (DC Generator), and accurate power distribution has been realized proportionally to the power ratings of each DCG taking into account load changes. The use of Fuzzy-PI in droop control makes the dynamic reaction quicker (0. 06s rise time) and microgrid system stability better compared with PI controllers. The proposed control strategy is completely tested with a Mathlab/Simulink simulation.
Enhancement of COD-Nutrients Removals and Filterability of Secondary Clarifier Municipal Wastewater Influent Using Electrocoagulation Technique

The present work studied experimentally the variations of some characteristics of the mixed liquor solution in wastewater treatment plants (WWTPs) under the effect of electrocoagulation (EC) technique. Unlike conventional methods, electrocoagulation was performed using cylindrical perforated iron electrodes to achieve a good distribution of the applied DC field onto the municipal wastewater. Effects of electrocoagulation time, applied voltage gradient, and aeration on the mixed liquor characteristics were considered. The study figured out the dependency of the local pH and oxidation potential reduction (OPR) values, near anode and cathode on these operational conditions. It was found that electrocoagulation process reached steady state conditions in no more than 60 minutes. At high voltage gradient (6 V/cm), the steady removal efficiencies of COD and nutrients exceeded 89%. While aeration showed moderate influence on removal efficiencies and wastewater sludge filterability, it significantly affected the pH and ORP near the electrodes especially at the low voltage gradient. Results also indicated that the sludge filterability was improved notably by increasing the voltage gradient to have minimal levels of specific-resistance to filtration (SRF).
The Effect Of Capital Structure On Profitability: An Empirical Analysis Of Vietnamese Listed Banks

This paper aims at investigate the impact of capital structure on profitability of seventeen listed banks in Vietnam over a period from 2015 to 2018. The profitability is measured by Return on Total Assets (ROA) while capital structure is measured by Debt to Total Assets (DA), firm’s size, growth opportunity, and tangibility. The data has been analyzed by using descriptive statistics, correlation, and panel data regression models. The findings show that there is a strong negative impact of capital structure on firm’s profitability. These findings offer useful insights for the banks and lending institutions based on empirical evidence.
Converter Topologies for MVDC Traction Transformers

The paper compares the conventional railway traction systems with new traction systems proposed and developed in the last decade that are also suitable for the medium voltage DC (MVDC) railway electrification concept presented in this project. Differences and requirements of the MVDC traction system will be considered while investigating converter topologies for MVDC transformers (Power Electronic Traction Transformers - PETTs or Solid State Transformers $SSTs$). Then, the paper will focus on presenting the most suitable DC-DC converters for this application, defining an example of optimal configuration and requirements of control, which in the future can be further developed for a novel MVDC railway electrification's traction systems on-board.
Determination of Ochratoxin A in Food by High Performance Liquid Chromatography

Ochratoxin A (OTA) is an important mycotoxin that is produced by Aspergillus and Penicillium species. Ochratoxin A is a common contaminant of various foods including cereals, spices, coffee, cacao, beer, wine, raisins, pulses, meat, meat products, or edible offal. Due to a wide range of its toxic effects in humans and animals, ochratoxin A needs to be monitored. With regard to this necessity, a sensitive HPLC-FD method for purposes of the quantification of trace amounts of ochratoxin A in foods of plant and animal origin was developed, validated and applied for analysis. Food samples were cleaned using commercial immunoaffinity columns and analyzed by means of a high performance liquid chromatography method with fluorescence detection. Limit of quantification of the method ranged between 0.01–0.30 µg/kg depending on the sample matrix. Recoveries were 80–88% in the concentration range of 0.01–0.30 µg/kg, depending upon sample type. The quality of laboratory results was confirmed by successful participation in international inter-laboratory proficiency testing. This laboratory was accredited accordance to CSN ISO/EN 17025. The developed method was applied to the determination of ochratoxin A in samples from 61 types of foodstuffs of plant and animal origin, that were collected in 4 sampling terms at 12 regions of the Czech Republic in years 2011–2012. In total, 732 food samples were gathered and analyzed.
Automatic processing of rotation diffraction data from crystals of initially unknown symmetry and cell constants

An algorithm has been developed for the automatic interpretation of a given set of observed reciprocal-lattice points. It extracts a reduced cell and assigns indices to each reflection by a graph-theoretical implementation of the local indexing method. All possible symmetries of the observed lattice compatible with the metric of the reduced cell are recognized and reported, together with the unit-cell constants and the linear index transformation relating the conventional to the reduced cell. This algorithm has been incorporated into the program XDS [Kabsch (1988). J. Appl. Cryst. 21, 916–924], which is now able to process single-crystal area-detector data without prior knowledge of the symmetry and the unit-cell constants.
Predicting Polymer Flow during High-Temperature Atomic Force Microscope Nanoindentation

This paper reports predictions of nanometer-scale polymer deformation during nanoprobe indentation at elevated temperature. The simulations assume continuum polymer properties with modified boundary conditions to model subcontinuum polymer mechanical deformation. The indenter is a heated atomic force microscope (AFM) tip, and the media is a high molecular weight polymer film where tip radius, film thickness, and polymer coil radius are of similar size, in the range 20−50 nm. The simulations model isothermal conditions, where the tip and polymer are at the same temperature, or nonisothermal conditions, where the tip is hot while the polymer is cool. Isothermal simulations with shear-thinning bulk material behavior and full-slip polymer−tip interface predict force, displacement, and displacement rate. Nonisothermal simulations show that the polymer−tip interface temperature governs the indentation process. The temperature-dependent polymer viscosity varies by several orders of magnitude within 50 nm of the .
Origin of kinetic isotope effects during the oxidative coupling of methane over a lithium(1+)/magnesia catalyst

Kinetic isotope effects (KIEs) during the oxidative coupling of methane over a Li + /MgO catalyst at 700 o C have been determined using several different experimental methods and by a reaction model that includes both heterogeneous and homogeneous reactions. By maintaining a constant partial pressure of methane of 190 Torr and changing the partial pressure of oxygen, a variation in the H/D KIE, based on differing rates of CH 4 and CD 4 conversion, was observed
Thermodynamic properties and phase equilibria in the Fe–P system

Differential scanning calorimetry (DSC) has been used to measure the heat capacities of iron phosphides Fe3P, Fe2P and FeP in the temperature range 113–873 K. Simultaneously a Knudsen effusion method with mass-spectrometric analysis of the gaseous phase has been applied to investigate the thermodynamic properties of iron phosphides (1041–1549 K), bcc solid solutions Fe–P (1384–1619 K) and Fe–P liquid alloys (1349–1811 K). ΔfS of the iron phosphides calculated according to the second and third laws of thermodynamics agree within the limits of experimental error. ΔfG of the phosphides produced from γ-Fe and P2 gas have been approximated with the following equations (in J mol–1): ΔfGFe3 P=–(239 076 ± 2269)+(80.44 ± 1.70)T, ΔfGFe2 P=–(231 728 ± 1110)+(79.95 ± 0.81)T, ΔfGFeP=–(193 892 ± 2700)+(82.10 ± 2.30)T. The thermodynamic behaviour of P diluted in α-Fe obeys Henry's law, the non-magnetic part of the excess Gibbs energy of mixing of the bcc solid solution being equal to (standard states: α-Fe and white P)ΔfGex(nm)=(–280.4T+ 0.195T2–3.70 × 10–5T3)XPXFe J mol–1. The thermodynamic properties of liquid solutions have been described with the ideal associated-solution model assuming that Fe3P, Fe2P and FeP complexes exist in the melt. The phase diagram computed with the help of the thermodynamic data agrees with the published information.
Investigation of the Carbon K and Metal Emission Bands and Bonding for Stoichiometric and Nonstoichiometric Carbides

The carbon K and metal LII,III emission bands from stoichiometric and nonstoichiometric transition metal carbides were measured with a high resolving power grating spectrometer. It was possible to relate the intensity distribution of the C K band to bonding. Groups IV and V transition metal carbides, which are strongly bonded carbides, have narrow C K bands. For the weakly bonded carbides, group VI and higher, the C K bands are broad and have an intensity distribution close to that of the C K band from graphite. The intensity distribution of the carbide and graphite C K bands was compared to Coulson and Taylor's π, σ subbands. The metal LII,III bands from the first series transition metal carbides showed a change in band characteristics relative to the LII,III band from the metal at group VI carbides. From shifts in wavelength of the metal emission in the carbide it is found that the vanadium and titanium atom is more negative in the carbide than in the metal.
Determination of impurity–point defect binding energies in alloys

AbstractModelling of radiation induced or thermal non-equilibrium segregation needs data on impurity–point defect binding energies. These data are generally unavailable although some attempts have been made to calculate them. In the present paper an approach to calculating impurity–interstitial (mixed dumbbell) binding energies is established on the basis of strain field arguments. Earlier work is slightly modified for more accurate calculation of oversized impurity–vacancy binding energies. The method is applied to predictions of various impurity–point defect binding energies in several transition metal matrixes. With the aid of these predictions, other experimental and theoretical results on impurity–point defect binding energies and radiation induced segregation are reasonably explained.MST/3512
Annealing effects on the properties of copper oxide thin films prepared by chemical deposition

We have investigated the annealing effect on the structural, optical and electrical properties of copper oxide films prepared on glass substrates by chemical deposition. The films were annealed in air for different temperatures ranging from 200 to 350 °C. X-ray diffraction patterns showed that the films as-deposited and annealed at 200 and 250 °C are of cuprite structure with composition Cu2O. Annealing at 300 °C converts these films to CuO. This conversion is accompanied by a shift in the optical band gap from 2.20 eV to 1.35 eV. Also this conversion was obtained by the dc electrical conductivity and FTIR spectroscopy measurements.