Gating Technique Research Articles

The application of temporal gating in the measurement of response amplitude operators

Scale model testing of wave energy converters (WEC) in wave flumes and basins is essential for full scale development. One of the parameters commonly measured is the response amplitude operator (RAO), which represents the response of the WEC to wave excitation. These are typically measured at discrete frequencies using regular waves. This approach can be slow, depending on the fidelity and frequency resolution. An alternative is to use a broadband wave source, however reflections from walls can significantly contaminate the frequency response measurement. In this paper, a rapid method for measuring the RAO is presented using a chirp signal to generate waves in the frequency range of interest to measure the transfer function, and a temporal gating technique (commonly used in experimental acoustics and RF engineering) to remove reflections. The technique will be demonstrated on numerical data, as well as two scale experiments.

Low-threshold supercontinuum generation in a homogeneous bulk material at 76 MHz pulse repetition rate.

We report on high average power, low threshold supercontinuum generation in a homogeneous bulk material at 76 MHz pulse repetition rate with amplified as well as unamplified pulses from a Yb:KGW oscillator. An octave-spanning supercontinuum was produced in undoped potassium gadolinium tungstate (KGW), which demonstrated robust, damage-free long-term performance with a total average pump power of 6.4 W. The supercontinuum generation was unambiguously attested by the distinctive features of the phenomenon: beam filamentation visualized via filament-induced luminescence; conical emission and its characteristic angular distribution captured by angle-resolved spectral measurements; and pulse splitting that produced the sub-pulses with well-behaved phases, as retrieved from the measurements employing a second harmonic frequency-resolved optical gating technique.

ADS-B data gating technique and its probabilistic models

The article developed a gating technique that allows us to validate ADS-B data without the necessity to verify using the secondary surveillance radar or multilateration. Probabilistic models of the ADS-B data gating technique, as well as the algorithm for applying these models were proposed. Benchmark cases that occur when aircraft (A/C) positioning by ADS-B systems, determined by threshold values of navigation and pilot’s errors, were analyzed. The first benchmark case assumes not exceeding of navigation and pilot’s errors the bounds of the tolerance limits, which allows us to draw up a conclusion concerning the ADS-B data validation. The second one assumes exceeding of a pilot’s error the bounds of the tolerance limits under an allowable navigational error. Herewith, the air traffic controller (ATC) obtains a message about the proper ADS-B operation and the necessity to issue instructions to the pilot to correct a flight. The third benchmark case assumes exceeding of a navigation error the bounds of the tolerance limits under an allowable or not allowable pilot’s error. In this case, the ATC obtains a message about not valid ADS-B data and the incapability to use these systems. The simulation of the given benchmark cases was performed. In addition, the Rayleigh and Rice distributions were applied to implement the ADS-B data gating technique. The simulation results allow us to assess the required amount of accumulated ADS-B data for the evaluation. Thus, it was found that during the estimate based on the Rayleigh distribution, it is sufficient to accumulate 15–20 measurements, which, when transmitting 2 messages per second and under the condition of the normal ADS-B equipment operation, will take 8–10 s. During the estimate, using the Rice distribution, an accumulation of 25–30 measurements is sufficient, which will take 13–20 s. The developed method will allow the use of ADS-B systems at regional aerodromes with the low intensity of air traffic as the primary or sole surveillance means.

Cross-Mesh Clock Network Synthesis

In the clock network design, the trade-off between power consumption and timing closure is an important and difficult issue. The clock tree architecture has a shorter wire length and better power consumption, but it is more difficult to achieve timing closure with it. On the other hand, clock mesh architecture is easier to satisfy the clock skew constraint, but it usually has much more power consumption. Therefore, a hybrid clock network architecture that combines both the clock tree and clock mesh seems to be a promising solution. In a normal hybrid mesh/tree structure, a driving buffer is placed in the intersection of mesh lines. In this paper, we propose a novel cross-mesh architecture, and we distribute the buffers to balance the overall switching capacitance, reducing the number of registers connected to a subtree, and the load capacitance of a buffer. With the average dispersion of the overall driving force, our methodology creates small non-zero skew clock trees. In addition, we integrate clock gating, register clustering, and load balancing techniques to optimize clock skew and load capacitance simultaneously. The proposed methodology has four stages: cross-mesh planning, register clustering, mesh line connecting, and load balancing. Experimental results show that our cross-mesh architecture has high tolerance for process variation, and is robust in all the operation modes. Comparing it to the uniform mesh architecture, our methodology and algorithms reduce 28.9% of load capacitance and 80.4% of clock skew on average. Compared to the non-uniform mesh architecture, we also reduce capacitance by 22.4% and skew by 76.7% on average. This illustrates that we can obtain a feasible solution effectively and improve both power consumption and clock skew simultaneously.

Temperature Analysis of DMGC CGAA FET for Future Deep Space and Military Applications: An Insight into Analog/RF/Self-Heating/Linearity

This manuscript introduces a pioneering investigation on the temperature effects of Dual Material Graded Channel (DMGC) Cylindrical Gate All Around (CGAA) FET by outlining its significance in various aspects such as analog/RF, self-heating, and linearity performance metrics. For this analysis, we have proposed a DMGC CGAA FET by amalgamating the gate and channel engineering techniques and the temperature is varied from 250 K to 450 K. A significant improvement in Ion/Ioff, SS, and DIBL by an amount of 96.98%, 19.49%, and 51.26% is obtained respectively for the proposed DMGC CGAA FET as compared to the single material graded channel (SMGC) CGAA FET. As the temperature is reduced from 450 K to 250 K, a noticeable improvement in analog/RF figure of merits and delay is obtained. Further, the self-heating effect (SHE) analysis revealed that the utilization of lower Rth is preferrable to minimize SHE in the device. Moreover, linearity parameters like gm2, gm3, VIP2, VIP3, IIP3 and IMD3 are noticed to be better for lower temperatures at higher VGS indicating good linearity. The obtained results make proposed device an ideal choice for various applications especially that operate in low temperature environments such as deep space, military, and RF applications.

Gated Dynamic Neural Network Model for Digital Predistortion of RF Power Amplifiers With Varying Transmission Configurations

The future intelligent transmitter will dynamically adjust the transmission configuration on demand, which will bring new challenges to digital predistortion (DPD). In this article, we present a gated dynamic neural network (GDNN) DPD model to linearize the power amplifier (PA) with varying transmission configurations. The proposed GDNN model is composed of a gating network and a backbone network that can be any NN-based DPD model designed for a fixed configuration. The core idea of the GDNN model is that the backbone model can be dynamically adjusted using the configuration-dependent weights generated by the gating network to achieve transmission configuration-adaptive DPD. To further reduce the running complexity of the GDNN DPD, a sparse GDNN (SGDNN) DPD model is also proposed, which selectively activates the neurons of the backbone network according to the transmission configuration. Experiments are performed with a Doherty PA to validate the proposed method, where the varying transmission configuration includes power level, signal bandwidth (BW), and peak-to-average power ratio. The test results demonstrate that the proposed method can effectively linearize the PA with dynamic transmission configuration and has excellent configuration generalization capability. Moreover, the sparse gating technique can reduce the running complexity of the GDNN DPD by more than 50 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\%$</tex-math> </inline-formula> with only a slight performance loss.

Analysis of Performance and Failure Modes of the IROC Proton Liver Phantom.

To analyze trends in institutional performance and failure modes for the Imaging and Radiation Oncology Core's (IROC's) proton liver phantom. Results of 66 phantom irradiations from 28 institutions between 2015 and 2020 were retrospectively analyzed. Univariate analysis and random forest models were used to associate irradiation conditions with phantom results. Phantom results included pass/fail classification, average thermoluminescent dosimeter (TLD) ratio of both targets, and percentage of pixels passing gamma of both targets. The following categories were evaluated in terms of how they predicted these outcomes: irradiation year, treatment planning system (TPS), TPS algorithm, treatment machine, number of irradiations, treatment technique, motion management technique, number of isocenters, and superior-inferior extent (in cm) of the 90% TPS isodose line for primary target 1 (PTV1) and primary target 2 (PTV2). In addition, failures were categorized by failure mode. Average pass rate was approximately 52% and average TLD ratio for both targets had slightly improved. As the treatment field increased to cover the target, the pass rate statistically significantly fell. Lower pass rates were observed for Mevion machines, scattered irradiation techniques, and gating and internal target volume (ITV) motion management techniques. Overall, the accuracy of the random forest modeling of the phantom results was approximately 73% ± 14%. The most important predictor was the superior-inferior extent for both targets and irradiation year. Three failure modes dominated the failures of the phantom: (1) systematic underdosing, (2) poor localization in the superior-inferior direction, and (3) range error. Only 44% of failures have similar failure modes between the 2 targets. Improvement of the proton liver phantom has been observed; however, the pass rate remains the lowest among all IROC phantoms. Through various analysis techniques, range uncertainty, motion management, and underdosing are the main culprits of failures of the proton liver phantom. Clinically, careful consideration of the influences of liver proton therapy is needed to improve phantom performance and patient outcome.

Environmental life cycle assessment and economic comparison of different roof systems

Recently, the negative environmental impacts of the construction industry have been of great concern. Since roofs are a major part of the building components, they may play a significant role in generating environmental pollution. One of the solutions to improve the environment in the construction industry is to attempt to achieve a roof system with minimal environmental impact. In the present work, the life cycle assessment (LCA) of one square meter of concrete joists and chromite joists roofs with various types of concrete, clay and polystyrene blocks, concrete slab, and Uboot concrete slab from cradle to the gate and processing technique using Simapro 9.1.1.7 software with the CML-IA baseline)2001) was studied. Also, the results of LCA obtained from the CML-IA baseline method were compared with the results achieved from GaBi software. The sensitivity analysis was performed to find materials with the greatest role in pollution generation. Furthermore, the economic evaluation of the roofs according to the price list for the building on Iran's Plan and Budget Organization (PBO) was carried out. The roof of the Concrete joist and polystyrene block has performed the most suitable on the roofs due to global warming, acidification, and eutrophication. The global warming, acidification, and eutrophication results using the CML-IA baseline (World 2000) method were slightly different from the BEES+ and the IPCC techniques results. Concrete joist with concrete block roof is the most economical roof among the different roofs. The comparison of LCA of eight roof systems with Simapro 9.1.1.7 and Gabi software is the first-time study, which may indicate one of the originalities of the work.

Performance Analysis of an Efficient Router using X Y Algorithm

As more and more functions are expected to be performed by a single electronic device (such as a smartphone, smart television, etc.), the need to have more and more components on SoC is increasing, posing new difficulties for NoC. The majority of NoC designs utilise mesh, torus, or other topologies to ensure a robust router. Most solutions, however, fall short when it comes to addressing key issues like throughput, area overhead, and latency, as well as QoS and congestion. The current paper proposes a concept for a reconfigurable router that can be used in No C settings. For the suggested router's design, we use Verilog, formal language for describing hardware (Verilog HDL). The four-channel router presented here has an east-west-north-south orientation and a crossbar switch connecting the two pairs of channels. Each channel consists of a multiplexer and a FIFO buffer. The input and output are handled by multiplexers, and the data is stored in FIFO buffers. The FIFO and multiplexer architectures for the south channel are developed initially. Afterwards the remaining three channels and the crossbar switch are made. Routers use channels, FIFO buffers, multiplexers, and crossbar switches in their overall design. Simulating the proposed design in Modelsim and obtaining the RTL view in Xilinx ISE 14.0 are the two primary methods of approaching this problem. The suggested reconfigurable router's power consumption is greatly reduced by employing the Power gating technique.. The XPower Analyzer application is used to determine the total power. As demonstrated by the findings obtained, the proposed design uses less energy than conventional reconfigurable routers.

Effects of logic glitch and (area-power dissipation) leakage on cryptosystems using clock gating technique to enhance web etiquette

The last century has seen an evolution in technology that has improved communication systems and, in general, made life easier for people. Our communication systems have become faster and more dependable as a result of the explosion of gadgets and services. But, these upgrades come at a price. The power consumption is one of the most worrying costs. In recent years, the solution involved installing larger, more powerful batteries—so long as doing so did not limit mobility. Today's economic and environmental problems compel us to consider alternative solutions, like methods for lowering the power consumption of digital devices. This study focuses on using digital circuits, which promise to deliver good energy efficiency and desirable performance at very low voltage savings. Certain digital switches are allegedly redundant and not required for the circuit to function properly, yet they continue to use energy. So, one of the primary issues for low power design is reducing such redundant switches. Subthreshold conduction in digital circuits is typically seen as a “parasitic” leakage in a condition where there should ideally be no conduction. Sub-threshold activities thereby reduce the problem of lowering power consumption, but do so at the expense of system throughput deterioration, fluctuations in system stability and functionality, temperature variations, and most critically, design space utilization. In order to minimize some of these redundant switches and to make circuits more energy-efficient while maintaining functionality, this study suggests two novel techniques. It uses an optimization method based on threshold voltage change to reduce glitch power. A glitch-free circuit netlist is created using an algorithm, while still maintaining the requisite delay performance. Using this approach results in a 6.14% overall reduction in energy consumption.

Control of the electron dynamics in solid-state high harmonic generation on ultrafast time scales by a polarization-skewed laser pulse.

Since high-order harmonic generation (HHG) from atoms depends sensitively on the polarization of the driving laser field, the polarization gating (PG) technique was developed and applied successfully to generate isolated attosecond pulses from atomic gases. The situation is, however, different in solid-state systems as it has been demonstrated that due to collisions with neighboring atomic cores of the crystal lattice strong HHG can be generated even by elliptically- and circularly-polarized laser fields. Here we apply PG to solid-state systems and find that the conventional PG technique is inefficient for the generation of isolated ultrashort harmonic pulse bursts. In contrast, we demonstrate that a polarization-skewed laser pulse is able to confine the harmonic emission to a time window of less than one-tenth of the laser cycle. This method provides a novel way to control HHG and to generate isolated attosecond pulses in solids.

Generation of the isolated highly elliptically polarized attosecond pulse using the polarization gating technique: TDDFT approach.

This paper theoretically investigates the generation of isolated elliptically polarized attosecond pulses with a tunable ellipticity from the interaction of Cl2 molecule and a polarization-gating laser pulse. A three-dimensional calculation based on the time-dependent density functional theory is done. Two different methods are proposed for generating elliptically polarized single attosecond pulses. The first method is based on applying a single-color polarization gating laser and controlling the orientation angle of the Cl2 molecule with respect to the polarization direction of the laser at the gate window. An attosecond pulse with an ellipticity of 0.66 and a pulse duration of 275 as is achieved by tuning the molecule orientation angle to 40° in this method and superposing harmonics around the harmonic cutoff. The second method is based on irradiating an aligned Cl2 molecule with a two-color polarization gating laser. The ellipticity of the attosecond pulses obtained by this method can be controlled by adjusting the intensity ratio of the two colors. Employing an optimized intensity ratio and superposing harmonics around the harmonic cutoff would lead to the generation of an isolated, highly elliptically polarized attosecond pulse with an ellipticity of 0.92 and a pulse duration of 648 as.

Research on Calibration Sources for a 35–40 GHz Millimeter-Wave Solar Radio Observation System

The microwave spectra in the optically thin regime provides unique information about the solar corona magnetic field; thus, a millimetre-wave solar radio observation system (35-40 GHz) in the Chashan Observatory is newly established to obtain relevant data. Herein, we design and develop a blackbody calibration source employing a metal cone array and absorbing patch to calibrate the system and obtain accurate solar observation data for analysis and decision-making. The reflectivity of the calibration source is simulated and measured to characterize its emissivity. The reflectivity is obtained by the finite-integration (FIT) method under various fitting conditions, i.e., the thickness of the absorbent patches and aspect ratios of the cone. The temperature gradient of cones is determined by the finite-element method (FEM). A 5×5 array microwave blackbody was developed based on a cone with a low scattering coefficient and excellent temperature uniformity. To reduce the influence of spurious signals, the time-domain gate technique is used to test the reflectivity of the target. The results demonstrate that the emissivity of the blackbody is higher than 0.9995 in the 35-40 GHz band. The temperature difference between the cone top and the cone bottom is 0.20 °C.

Multilevel Data and Decision Fusion Using Heterogeneous Sensory Data for Autonomous Vehicles

Autonomous vehicles (AVs) are predicted to change transportation; however, it is still difficult to maintain robust situation awareness in a variety of driving situations. To enhance AV perception, methods to integrate sensor data from the camera, radar, and LiDAR sensors have been proposed. However, due to rigidity in their fusion implementations, current techniques are not sufficiently robust in challenging driving scenarios (such as inclement weather, poor light, and sensor obstruction). These techniques can be divided into two main groups: (i) early fusion, which is ineffective when sensor data are distorted or noisy, and (ii) late fusion, which is unable to take advantage of characteristics from numerous sensors and hence yields sub-optimal estimates. In this paper, we suggest a flexible selective sensor fusion framework that learns to recognize the present driving environment and fuses the optimum sensor combinations to enhance robustness without sacrificing efficiency to overcome the above-mentioned limitations. The proposed framework dynamically simulates early fusion, late fusion, and mixtures of both, allowing for a quick decision on the best fusion approach. The framework includes versatile modules for pre-processing heterogeneous data such as numeric, alphanumeric, image, and audio data, selecting appropriate features, and efficiently fusing the selected features. Further, versatile object detection and classification models are proposed to detect and categorize objects accurately. Advanced ensembling, gating, and filtering techniques are introduced to select the optimal object detection and classification model. Further, innovative methodologies are proposed to create an accurate context and decision rules. Widely used datasets like KITTI, nuScenes, and RADIATE are used in experimental analysis to evaluate the proposed models. The proposed model performed well in both data-level and decision-level fusion activities and also outperformed other fusion models in terms of accuracy and efficiency.

Near-infrared ultrafast third-order nonlinear optical response of 2D NbS2, NbSe2, ZrTe2, and MoS2.

By employing the optical Kerr gate technique at 800 nm with 180 fs pulses at 76 MHz, we evaluated the third-order nonlinear optical response of two-dimensional (2D) semiconducting MoS2, semimetallic ZrTe2, and metallic NbS2 and NbSe2. The modulus of the nonlinear refractive index was measured to range from 8.6 × 10-19 m2/W to 5.3 × 10-18 m2/W, with all materials' response time limited by the pulse duration. The physical mechanism to explain the ultrafast response time's origin considers the nature of the 2D material, as will be discussed.

A triple-node-upset self-recoverable design based on Schmitt-triggers and C-elements

As the semiconductor process development, it is shrinking rapidly for the distance of adjacent transistors in integrated circuits (ICs). Hence, latches are increasingly vulnerable to multiple-node-upset (MNU). To effectively mitigate MNU while keeping lower power consumption and delay, this paper proposed a latch design (namely CS-TNURL). The latch consists of four C-elements (CEs), four Schmitt-triggers (STs), seven transmission gates (TGs), and is capable of triple-node-upset (TNU) self-recovery. Besides, this latch uses fewer transistors and clock gating technique, which results in lower power consumption and D-Q delay. Compared with existing latches with TNU self-recoverability, the simulation has shown the proposed latch reduces power consumption by 70 %, delay by 10.62 %, area overhead by 29.71 %, and the power-delay-product (PDP) by 70.34 % on average, respectively. Additionally, the estimation of process, voltage, and temperature (PVT) variation indicated CS-TNURL has a moderate sensitivity towards the PVT variation.

Design of High Performance and Power Efficient Flash ADC

In this paper, Flash Analog to digital converter is implemented. The designed Flash ADC consists of a resistive ladder network, comparators, the thermometer to a binary encoder and the entire design is carried out using Tanner tools employing 180nm technology. The reference voltage applied to the resistive ladder network is 1.8V. A two-stage operational amplifier is used as a comparator in the flash ADC. Here, we are modifying the structure of operational Amplifier using Power Gating Technique. Binary code is obtained from the thermometer code by utilizing a Mux based encoder by designing the MUX in domino Logic. The major problem that usually appears in flash ADC is as the number of resolution bits increases, the Area, as well as the power consumption of the circuit, also increases. In this paper, we principally concentrated to lessen the propagation delay of the ADC by optimizing encoder circuitry. With the purpose of reducing latency, Encoder is implemented using 2:1 mux based on Pseudo NMOS Logic. Performance parameters of Flash ADC such as delay as well as average power are calculated and compared.

In situ electrical and thermal transport properties of FeySe1−xTex films with ionic liquid gating

We combine in-situ electrical transport and Seebeck coefficient measurements with the ionic liquid gating technique to investigate superconductivity and the normal state of FeySe1-xTex (FST) films. We find that the pristine FST films feature a non-Fermi liquid temperature dependence of the Seebeck coefficient, i.e., S/T ~ AS lnT, and AS is strongly correlated with the superconducting transition temperature (Tc). Ionic liquid gating significantly raises Tc of FST films, for which the Seebeck coefficient displays a novel scaling behavior and retains the logarithmic temperature dependence. Moreover, a quantitative relationship between the slope of T-linear resistivity (A\r{ho}) and Tc for gated films is observed, i.e., (A\r{ho})1/2 ~ Tc, consistent with previous reports on cuprates and FeSe. The scaling behaviors of AS and A\r{ho} point to a spin-fluctuation-associated transport mechanism in gated FeySe1-xTex superconductors.

Accurate bundle matching and generation via multitask learning with partially shared parameters.

How can we recommend existing bundles to users accurately? How can we generate new tailored bundles for users? Recommending a bundle, or a group of various items, has attracted widespread attention in e-commerce owing to the increased satisfaction of both users and providers. Bundle matching and bundle generation are two representative tasks in bundle recommendation. The bundle matching task is to correctly match existing bundles to users while the bundle generation is to generate new bundles that users would prefer. Although many recent works have developed bundle recommendation models, they fail to achieve high accuracy since they do not handle heterogeneous data effectively and do not learn a method for customized bundle generation. In this paper, we propose BundleMage, an accurate approach for bundle matching and generation. BundleMage effectively mixes user preferences of items and bundles using an adaptive gate technique to achieve high accuracy for the bundle matching. BundleMage also generates a personalized bundle by learning a generation module that exploits a user preference and the characteristic of a given incomplete bundle to be completed. BundleMage further improves its performance using multi-task learning with partially shared parameters. Through extensive experiments, we show that BundleMage achieves up to 6.6% higher nDCG in bundle matching and 6.3× higher nDCG in bundle generation than the best competitors. We also provide qualitative analysis that BundleMage effectively generates bundles considering both the tastes of users and the characteristics of target bundles.

Revealing the nature of the graphene on-off control of the electrolyte gating effect in WO3 film phase transition

Electrolyte gating-induced metallization has been broadly observed in various transition metal oxides for decades, while the gating mechanism is still under debate. In this work, we realize the Insulator-Metal Transition (IMT) control of WO3 film by inserting a few-layer graphene. It's found that a sharp IMT process in WO3 film emerges if applying an electrolyte gating treatment, while this IMT behavior will be strikingly suppressed if inserting a graphene layer between the WO3 film and ionic liquid. Interestingly, the pronounced IMT behavior can be always observed if substituting the ionic liquid by acid solution, regardless of graphene layer insertion or not. According to the first-principles calculations, the diffusion energy barriers for the hydrogen or oxygen propagating graphene layer are extracted, and then the mechanism of electrolyte gating in WO3 films is proposed. Moreover, the roles of hydrogen and oxygen vacancy on the WO3 IMT process are further discussed based on the band structure calculations. Our current study will boost the development of electrolyte gating technique and bring deeper understanding of the electrolyte gating treatment for other transition metal oxides.