Miracle-dz/UniFAR-FTUs huggingface dataset:
Optimal Demand Response Bidding and Pricing Mechanism With Fuzzy Optimization: Application for a Virtual Power Plant

In this paper, a virtual power plant (VPP) that consists of generation, both renewable and conventional, and controllable demand is enabled to participate in the wholesale markets. The VPP makes renewable energy sources (RES) and distributed generations controllable and observable to the system operator. The main objective is to introduce a framework that optimizes the bidding strategies and maximizes the VPP's profit on day-ahead and real-time bases. To achieve this goal, the VPP trades energy externally with a wholesale market, and trades energy and demand response (DR) internally with the consumers in its territory. That is, when generation exceeds demand, the VPP sells the excess energy to the market, and it buys energy from the market when the generation and reduction in demand due to DR scheme are less than the required demand in its territory. Both load curtailment and load shift are modeled. For the day-ahead internal VPP market, fuzzy optimization is proposed to consider the uncertainty in the RES. Comparison results with deterministic and probabilistic optimizations demonstrate the effectiveness of the fuzzy approach in terms of achieving higher realized profits with reasonable computation effort. It is also shown that considering uncertainties in the optimization can result in reduced dependence on the conventional generator.
Non-invasive spinal vibration testing using ultrafast ultrasound imaging: A new way to measure spine function

Ultrafast ultrasound imaging provides investigators with the possibility of imaging events using thousands of frames/sec. With the success of ultrafast ultrasound imaging across a wide variety of disciplines, we now explore the ability of ultrafast imaging to capture spinal vibrations for non-invasive spinal testing in living subjects. Previous work has shown that invasive accelerometer-based methods can detect and classify spinal pathologies. Here we show that non-invasive ultrasound imaging is successfully able to replicate the uni-axial performance of invasive accelerometers across a broad range of frequencies (10–100 Hz), with correlations in both time- and frequency-domain between 0.90 and 0.99.
A ZVS-PWM Full-Bridge Converter With Reduced Conduction Losses

A new soft-switching pulse-width-modulated (PWM) full-bridge converter is proposed in this paper. The proposed converter has zero voltage switching (ZVS) in all its switches with fewer conduction losses than other ZVS-PWM full-bridge converters, due to a novel auxiliary circuit scheme. In this paper, the operation of the new converter is explained and analyzed, a design procedure is presented and demonstrated with an example, and experimental results that confirm the feasibility of the converter are also presented.
Substrate controllable transverse magnetic surface waves onto a graphene layer at far-infrared frequencies

The propagation properties of transverse magnetic surface waves onto an infinite graphene layer and the influence of the surrounding media are thoroughly examined in the present paper. After developing a realistic model of graphene, located in a homogeneous medium, its conductivity and the main characteristics of the resulting surface waves are extracted and compared in terms of the medium's dielectric permittivity. Finally, a similar comparison is conducted, where graphene's substrate is altered, while maintaining the vacuum superstrate, thus illustrating the importance of the appropriate media environment selection.
Design and Analysis of an Interior Permanent Magnet (IPM) Machine With Very Wide Constant Power Operation Range

This paper evaluates the design of a new segmented interior permanent magnet (SIPM) machine with very wide constant power operation range. The machine uses segmentation of the rotor magnets with the help of iron bridges between magnet segments. This provides for an inherent flux-weakening capability to the interior permanent magnet (IPM) machine. A very wide flux-weakening range has been achieved by using a standard distributed stator winding only. The flux-weakening capability of the proposed SIPM motor was compared to a conventional IPM machine. The same stator was used in both machines for direct comparison. The paper also presents the design optimization process and experimental verification of the performance of the proposed machine as a case study of a 42 V alternator operation in which the speed range is from 600 to 6000 r/min.
Non-linear dynamics of positional parameters of the collimated coherent beam at the end of the long atmospheric path

The non-linear dynamics methods were applied to the analysis of the time series of the collimated beam positional characteristics at the output of the long atmospheric path. The results are presented. The space of embedding dimension values for components of the first and second spatial moments and the structure of phase portraits, were obtained as well as Poincar recurrence time. Those allow to classify quantitatively the structure of turbulent distortions in a beam intensity distribution profile.
Influence of transmit beamforming parameters on image quality in quantitative elastography

High levels of noise in shear wave elastography can lead to inaccurate shear wave velocity estimates or false negatives in the detection of masses such as tumors. Recent work has shown that ultrasound speckle can be a significant source of noise in conventional, multiple tracking location (MTL) shear wave elasticity imaging, particularly when small beam spacings are employed to achieve a high spatial resolution. An alternative approach, termed single tracking location (STL), appears to produce images that are immune to speckle noise but subject to errors from push beam variance. The objective of this study is to quantify the effects of transmit beamforming parameters on STL and MTL image noise. These data will provide guidance for the selection of STL or MTL methods, and the optimal beamforming parameters in a particular imaging situation.
Controlling the Fermi Level in a Single-Layer Graphene QHE Device for Resistance Standard

The National Metrology Institute of Japan/ National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) and the National Institute of Standards and Technology (NIST) are collaborating on the development of graphene-based quantized Hall resistance devices. We formed graphene films on silicon carbide (0001) substrates and processed the samples into Hall bar devices using the NIST clean room facility. The electronic transport properties have been observed at the NIST and NMIJ/AIST. Hydrogen intercalation and photochemical gating were employed to control the Fermi level in the samples. For the first method, the Fermi level was observed to move across the Dirac point. For the latter technique, it moved closer to the Dirac point.
Condition Monitoring of Electrical Equipment in Nuclear Power Plants

This paper presents the results of a review of maintenance methods that may be considered for condition monitoring of equipment in a nuclear power plant. Some of these methods are presently being used on instruments and equipment whose performance is governed by the plant technical specifications. Other methods are being used to monitor the condition of heavy power production equipment in the plant. From a survey of eight utilities which have or will soon have operating generating stations it was found that eM was not being used on light equipment or environmentally qualified equipment. An exception is the monitoring of drift in pressure transmitters by some utilities. An explanation for the lack of widespread use of condition monitoring (CM) is the uncertainty over the cost effectiveness and reliability of the test methods to yield unambiguous information. A purpose of CM is to optimize the preventive maintenance program by adjusting the tests performed and the schedule to the unique requirements of the equipment. By showing the changing condition of the equipment with time, CM may also be able to predict when certain criteria will be reached in the future. CM programs to demonstrate the ability of certain tests to show a correlation between degradation and the measured parameter and to establish criteria for judging the condition of the equipment could help remove some of the ambiguity that now exists.
Finite Arithmetic Considerations for the FFT Implemented in FPGA-Based Embedded Processors in Synthetic Instruments

An important trend in the synthetic instrument community is the development of products around the capabilities of field programmable gate array (FPGA) based embedded processors. It is assumed here that signals arrive at the FPGA input at high data rates, low to medium data bit width, and low to medium signal-to-noise ratio. As a consequence of the processing that reduces signal bandwidth, the data bit width is increased in concert with the increased signal-to-noise ratio resulting from the reduced bandwidth. The FPGA has the unique capability to allocate its internal resources in an optimal way to best match the dynamic range of the sampled data signal at various points in the signal flow path. Since the fast Fourier transform (FFT) is primarily a tool in the synthetic instrument, the effect of fixed point arithmetic on its performance is reviewed, and suggested bit width assignments for FFT algorithms are presented. Computational noise in the FFT is due to finite bit width input data, finite bit width sine-cosine tables, finite bit width multipliers and accumulators, and distributed scaling between data passes. The noise generated by these contributors is not uniform over the frequency band and a number of mechanisms to minimize the noise contribution to the measurement process performed by the synthetic instrument are presented.
An Improved Zero-Voltage-Switching Inverter Using Two Coupled Magnetics In One Resonant Pole

A novel soft switching inverter using two small coupled magnetics in one resonant pole is proposed to guarantee the main switches operating at zero-voltage-switching (ZVS) from zero load to full load and the auxiliary switches at zero-current-switching (ZCS) with load adaptability and small current stress. Since independent magnetics structure avoids the unwanted magnetizing current freewheeling loop, the size of the coupled magnetics can be minimized with low magnetizing inductance and the saturable inductor is eliminated. Detailed circuit operation is described and voltage-second balance condition of the magnetics is expressed mathematically. A 4-kW hardware prototype has been designed, fabricated and tested to verify the validity of the novel circuit and the improved performs of the proposed soft switching inverter. Experimental results show excellent agreement with analytical results.
Blind separation of mixed images using multiscale transforms

It was previously shown that sparse representations can improve and simplify the estimation of an unknown mixing matrix of a set of images and thereby improve the quality of separation of source images. Here we propose a multiscale approach to the problem of blind separation of images from a set of their mixtures. We take advantage of the properties of multiscale transforms such as wavelet packets and decompose signals and images according to sets of local features. The resulting partial representations on a tree of data structure depict various degrees of sparsity. We show how the separation error is affected by the sparsity of the decomposition coefficients, and by the misfit between the prior, formulated in accordance with the probabilistic model of the coefficients distribution, and the actual distribution of the coefficients. Our error estimator, based on the Taylor expansion of the quasi log-likelihood function, is used in selection of the best subsets of coefficients, utilized in turn for further separation. The performance of the proposed method is assessed by separation of noise-free and noisy data. Experiments with simulated and real signals and images demonstrate significant improvement of separation quality over previously reported results.
A very low power CMOS mixed-signal IC for implantable pacemaker applications

A single-chip, very-low-power interface IC used in implantable pacemaker systems is presented. It contains LNAs, filters, ADCs, a battery management system, voltage multipliers, high voltage pulse generators, programmable logic and timing control. The 200k transistor IC occupies 49mm/sup 2/, is fabricated in a 0.5/spl mu/m 2P3M multi-V, CMOS process and consumes 8/spl mu/W from a 2.8V supply.
Condition monitoring and diagnosis of power transformers

Power transformers are important components of all electric networks. They are usually very expensive and therefore diagnosis and monitoring systems will be valuable for preventing damages. A continuous control of the status of the transformer condition is worthwhile and will support the appropriate decision in case of a problem. The transformers are geographically spread and with the aid of Internet, it is possible to collect appropriate information from these transformers to a central node for diagnostic purposes under the supervision of high voltage engineering experts. The aim of this paper is to show the main problems related to power transformers and to review mitigation methods for the monitoring and diagnosis of power transformers.
Low-THD, Fast-Transient, and Cost-Effective Synchronous-Frame Repetitive Controller for Three-Phase UPS Inverters

This paper presents a novel synchronous-frame repetitive controller for three-phase UPS inverters. Distinguished from conventional repetitive control techniques, the proposed synchronous-frame approach minimizes the repetitive control time delay to one-sixth of the fundamental period such that the dynamic response is significantly improved. In order to overcome the harmonic distortions under severe load conditions (e.g., unbalanced and nonlinear), in this paper, three synchronous rotating frames are deliberately selected, in each of which the repetitive controller is incorporated. Resultantly, the (6n ±1)th harmonics as well as the triplen harmonics are compensated. Moreover, a high-performance fourth-order linear phase infinite-impulse-response filter is applied to further enhance the accuracy of steady-state tracking. The proposed controller is programmed on the 16-bit fixed-point digital signal processor (TI TMS320LF2407) and eliminates high-resolution current sensors for cost effectiveness. Simulations and experimental tests have been carried out based on an 18-kW three-phase UPS system. Low total harmonic distortion (<;0025;) has been achieved under heavily distorted nonlinear load and unbalanced load. Fast dynamic response has been demonstrated during step load transients.
Hybridization and karyotype variability of three endemic Fritillaria L. (Liliaceae) in Argolis Peninsula (Greece)

Abstract The Argolis Peninsula covers the north-eastern part of Peloponnisos and is surrounded by the Gulf of Argosaronic. The area hosts three species of the genus Fritillaria: F. graeca, F. rhodocanakis and F. spetsiotica. Fritillaria graeca is a Greek endemic taxon and its distribution includes Peloponnisos, C & E Sterea Ellas, C Evia and in proximity to Sterea Ellas, Salamis and Kea islands, while the stenoendemic F. rhodocanakis and F. spetsiotica are mainly found on Idra and Spetses islands respectively. The last two taxa are included in the Red Data Book of Rare and Threatened Plants of Greece, while F. rhodocanakis is also included in the IUCN Red List. Hybridization among them is a common phenomenon in the areas where they coexist, leading to an array of morphologically and karyologically intermediate forms. The current study presents the taxa’s karyomorphometric analysis for the first time and reveals hybrids’ cytological variety, including differences in marker chromosomes, polyploidy and the number of B-chromosomes.
Nitrogen vs. Phophorus as Implant Species for High-Voltage Lateral RESURF MOSFETs on 4H-SiC

High-voltage lateral RESURF MOSFETs have been fabricated on 4H-SiC with both nitrogen and phosphorus as source/drain and RESURF region implants. Blocking voltages as high as 1200 V and specific on-resistances of 4 /spl Omega/ cm/sup 2/ have been obtained, with the high on-resistance attributed to poor inversion layer mobility. Phosphorus is most appropriate for the source/drain implants due to low sheet resistance and contact resistance with low temperature anneals. However, poor activation of low dose phosphorus implants at 1200/spl deg/C makes nitrogen the preferred choice for the RESURF region.
Novel phase reconfigurable synthesized transmission line and its application to reconfigurable hybrid coupler

A novel phase reconfigurable synthesized transmission line is proposed in this paper. By utilizing quasilumped elements and varactor diodes, the synthesized line functions as a 1-bit phase shifter by switching its electrical length between two states; the characteristic impedance, meanwhile, is kept unaltered. The design concept, circuit model, and performance are carefully investigated and discussed. Based on newly developed synthesized line, a reconfigurable hybrid coupler, which can be electrically switched between a rat-race or branch-line coupler at the same frequency, is designed as a demonstration. The measured results showed acceptable insertion loss level and good output phase response.
Relationship between Serum Stress Hormone Profile and Breast Cancer in Saudi Patients

Breast cancer, which is the most common type of cancer, is influenced by endogenous hormones. When women suffer from depression some hormone levels increase leading to cell proliferation and abnormal cell growth. Relative alteration in the hormone profile may however associate with mood and stress factors. In the current work stress hormones such as prolactin and cortisol as well as female hormones such as estradiol and progesterone and the male hormone androgen(androstenedione) as well as superoxide dismutase enzyme were investigated in the blood serum of some Saudi female breast cancer patients to confirm if there is a relationship between these hormones and breast cancer. Twenty seven breast cancer females as well as thirty two control subjects were investigated. Their age ranged between 30-70 years. According to the clinical investigation on the patients, there was a high risk of breast cancer in relation to early menarche, age at first birth, obesity, drug medication and hormone replacement therapy (HRT). The highest significant difference was observed between control subjects and patients in relation to estradiol, progesterone and androstenedione levels while there was no significant difference between control subjects and patients in relation to prolactin, cortisol and SOD. A positive result was obtained with women who received HRT and fertility drug who had a chance of 19.5 times and 11.5 times to get breast cancer than those who did not receive the treatment.
Analysis of the power delivery path from the 12 V VR to the microprocessor

This paper offers a thorough analysis of the power delivery path. Based on the power delivery path model, the current slew rate of each loop is derived. The relationship between the slew rate of the inductor current of the voltage regulator (VR) and the bandwidth is also derived. Then, the level of the voltage spike across the capacitors of each loop is determined, after which the relationship between the bandwidth and the capacitance can be plotted. We find that for today's power delivery structure, the bulk capacitors can be eliminated as long as the bandwidth is pushed beyond 350 kHz. The experimental results of a 2 MHz two-stage 12 V VR verify this analysis.
Corona Modelling for the Calculation of Transients on Transmission Lines

The paper presents a mathematical corona model and its use for transmission line modelling with corona and, if desired, with frequency dependence of its parameters. The corona model has been developed from macroscopical physical laws, reflecting relations between charge, electric field intensity and voltage. Space charges, their development and their displacement are taken into account. The parameters of the model are determined so that the simulated qv curves closely fit those available from measurements. The corona model is then used as an element of the discretized transmission line model. This consists either of longitudinal inductances or of travel delay modules. Modelling of frequency dependence is optional. The line equations are integrated using the trapezoidal rule, so that Norton equivalents are obtained for the two line ends for the purpose of interfacing with the external system. Thus the model is fully compatible with an Electro-Magnetic Transients Program (EMTP).
Investigation of amplification characteristic for DPSK signal in SOA

The amplification characteristics of DPSK signal in semiconductor optical amplifier (SOA) is numerically simulated and experimentally demonstrated for the first time. The results show that the bit pattern effect (BPE) of the DPSK signal is induced by SOA. According to the results, when pulsewidth of the signal is comparable to the gain recovery time of SOA, the BPE is severe. And when the pulsewidth of the signal becomes much larger or shorter than the gain recovery time of SOA, the BPE is alleviated. In addition, the experiment results show that by adjusting the injection current of SOA, the BPE can be alleviated effectively.
Rotor Design on Torque Ripple Reduction for a Synchronous Reluctance Motor with Concentrated Winding using Response Surface Methodology

This paper deals with the optimum rotor design solution on torque ripple reduction for a SynRM with concentrated winding using response surface methodology (RSM). The RSM has been achieved to use the experimental design method in combination with finite element method and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. Comparisons are given with characteristics of a SynRM according to flux barrier number, Kw variation, respectively
Efficient Modeling of an MMC-Based Multiterminal DC System Employing Hybrid HVDC Breakers

The feasibility of future multiterminal dc (MTDC) systems depends largely on the capability to withstand dc-side faults. Simulation models of MTDC systems play a very important role in investigating these faults. For such studies, the test system needs to be accurate and computationally efficient. This paper proposes a detailed equivalent model of the modular multilevel converter (MMC), which is used to develop the MTDC test system. The proposed model is capable of representing the blocked-mode operation of the MMC, and can be used to study the balancing control of the capacitor voltages. In addition, the operation of the MMC when redundant submodules are included in the arms can also be studied. A simplified model of a hybrid high-voltage dc breaker is also developed. Hence, the developed test system is capable of accurately describing the behavior of the MMC-based MTDC system employing hybrid HVDC breakers, during fault conditions. Using time-domain simulations, permanent dc-side faults are studied in the MTDC system. In addition, a scheme to control the fault current through the MMC using thyristors on the ac side of the converter is proposed.
Energy Prices-Inflation Nexus: A Historical Analysis for the Case of Ottoman Empire

In this paper, the link between energy prices and price level is investigated from a historical perspective for the case of Ottoman Empire during the period 1885-1914. Although the unit root test results revealed that none of the variables are integrated of second or higher order, the findings of the unit root tests were conflicting. Therefore, to investigate the dynamic relations between energy prices and inflation, ARDL approach to cointegration is employed. The results of the bounds tests showed that energy prices and CPI were cointegrated. Furthermore, ARDL long-run results showed that a 1% change in inflation causes a 0.85% change in energy prices in same direction.