nils-herrmann/clean_scirepeval huggingface dataset:
A high performance Full Adder based on Ballistic Deflection Transistor technology

In this paper, we propose a 1-bit Full Adder circuit built with Ballistic Deflection Transistors (BDT). BDT is a disruptive technology based on AlGaAs/InGaAs heterostructure. Different combinational circuits were successfully realized using BDT NAND gate and General  Gate (GPG) structures. The developed circuit is an extension of BDT GPG and different from that of the previously implemented adder circuit. The proposed Adder consists of Sum and Carryout structures, comprising seven and five BDTs, respectively. Monte Carlo modeling of a BDT NAND Gate, which consists of associating two BDTs, has been performed and the obtained I-V characteristics were integrated with Verilog AMS to investigate the feasibility of the proposed circuit. Simulation results performed on Cadence Spectre simulator indicate the correct functionality of the proposed full adder.
Local Bayesian image restoration using variational methods and Gamma-Normal distributions

In this paper we present a new Bayesian methodology for the restoration of blurred and noisy images. Bayesian methods rely on image priors that encapsulate prior image knowledge and avoid the ill-posedness of image restoration problems. We use a spatially varying image prior utilizing a Gamma-Normal hyperprior distribution on the local precision parameters. This kind of hyperprior distribution, which to our knowledge has not been used before in image restoration, allows for the incorporation of information on local as well as global image variability, models correlation of the local precision parameters and is a conjugate hyperprior to the image model used in the paper. The proposed restoration technique is compared with other image restoration approaches, demonstrating its improved performance.
Super Resolution of Images and Video

This book focuses on the super resolution of images and video. The authors’ use of the term super resolution (SR) is used to describe the process of obtaining a high resolution (HR) image, or a sequence of HR images, from a set of low resolution (LR) observations. This process has also been referred to in the literature as resolution enhancement (RE). SR has been applied primarily to spatial and temporal RE, but also to hyperspectral image enhancement. This book concentrates on motion based spatial RE, although the authors also describe motion free and hyperspectral image SR problems. Also examined is the very recent research area of SR for compression, which consists of the intentional downsampling, during pre-processing, of a video sequence to be compressed and the application of SR techniques, during post-processing, on the compressed sequence.It is clear that there is a strong interplay between the tools and techniques developed for SR and a number of other inverse problems encountered in sig...
Plasma-resonant THz detection with HEMTs

In this work, by means of Monte Carlo simulations we analyze the dependence of the DC drain current value in a 80nm-gate InAlAs/InGaAs HEMTs on the frequency of a sinusoidal signal superimposed to the DC gate bias. Interestingly, a resonant peak appears in the drain current response, which lies in the THz frequency range, in good agreement with recent experiments made on similar devices. Moreover, the frequency of the resonant peak is dependent on the length of the source-gate region, but independent of the length of the drain-gate region, thus indicating that the source-gate region acts as the plasma wave cavity leading to the resonant detection of THz radiation in HEMTs.
Bayesian multichannel image restoration using compound Gauss-Markov random fields

In this paper, we develop a multichannel image restoration algorithm using compound Gauss-Markov random fields (CGMRF) models. The line process in the CGMRF allows the channels to share important information regarding the objects present in the scene. In order to estimate the underlying multichannel image, two new iterative algorithms are presented and their convergence is established. They can be considered as extensions of the classical simulated annealing and iterative conditional methods. Experimental results with color images demonstrate the effectiveness of the proposed approaches.
Improvement of the high frequency performance of HEMTs by bufferless technology

By means of a 2D Monte Carlo simulation of 50-nm-gate lattice matched AlInAs/InGaAs HEMTs, we show the benefits of using bufferless technology in terms of improvement of the cutoff frequency and noise characteristics. We have found an increase of approximately a 15% in f/sub c/, f/sub t/ and f/sub max/. Moreover, though only a slight reduction of 0.2 dB in the minimum noise figure is obtained, the bufferless HEMT shows an important decrease of the noise resistance (almost 5 /spl Omega/) and a 2.3 dB increase of the associated gain at 94 GHz.
Comparison of noise characteristics of GaAs and GaN Schottky diodes for millimeter and submillimeter applications

A Monte Carlo (MC) analysis of the noise spectra of GaAs and GaN Schottky barrier diodes (SBDs) operating under static and time varying conditions is carry out in this paper. Especial attention is payed to the dependence of the noise spectra with the structure of the diode, temperature and working conditions. Published noise analytical models of SBDs are employed to verify the results obtained from MC simulations.
Noise and Terahertz rectification in semiconductor diodes and transistors

In this work we explore high frequency collective phenomena present in classic HEMTs and in asymmetric nanodiodes, so called self-switching diodes (SSDs), that leads to a peak in the current noise spectrum which enhances the DC response of the devices, thus originating a THz resonance in the rectification of AC signals. These mechanisms have been evidenced in recent experiments made with HEMTs, in which THz detection as a result of plasma wave resonances has been demonstrated. In this paper, the noise spectra of the devices have been obtained by means of Monte Carlo simulations self-consistently coupled to a Poisson solver, able to provide not only static results but also the effect of collective phenomena such as plasma oscillations.
Exploration of digital latch design using ballistic deflection transistors — Modeling and simulation

In this paper, we explore the feasibility of a digital latch design using ballistic deflection transistors (BDTs). An analytical model, based on Monte Carlo simulations for different sizes of BDTs, has been integrated into a behavioral Verilog A module to facilitate the investigation of digital latch design. The simulation results indicate interesting capability of latch operation by holding data in a stable operating state.
Exploring Digital Logic Design Using Ballistic Deflection Transistors Through Monte Carlo Simulations

We present exploratory studies of digital circuit design using the recently proposed ballistic deflection transistor (BDT) devices. We demonstrate a variety of possible logic functions through simple reconfiguration of two drain-connected BDTs. We further propose the creation of a three-BDT logic cell to yield differential versions of each logic function, improving overall flexibility of BDT circuit design. Each of the proposed gate configurations has been verified through extensive numerical calculations using an in-house Monte Carlo simulator. Simulation results show that the proposed gate arrangements are capable of achieving 400-GHz operating frequencies at room temperature. A compact fit-based analytical model to aid circuit design using BDTs is also introduced.
A Bayesian approach to blind deconvolution based on Dirichlet distributions

This paper deals with the simultaneous identification of the blur and the restoration of a noisy and blurred image. We propose the use of Dirichlet distributions to model our prior knowledge about the blurring function together with smoothness constraints on the restored image to solve the blind deconvolution problem. We show that the use of Dirichlet distributions offers a lot of flexibility in incorporating vague or very precise knowledge about the blurring process into the blind deconvolution process. The proposed MAP estimator offers additional flexibility in modeling the original image. Experimental results demonstrate the performance of the proposed algorithm.
Comparison Between the Dynamic Performance of Double- and Single-Gate AlInAs/InGaAs HEMTs

The static and dynamic behavior of InAlAs/InGaAs double-gate high-electron mobility transistors (DG-HEMTs) is studied by means of an ensemble 2-D Monte Carlo simulator. The model allows us to satisfactorily reproduce the experimental performance of this novel device and to go deeply into its physical behavior. A complete comparison between DG and similar standard HEMTs has been performed, and devices with different gate lengths have been analyzed in order to check the attenuation of short-channel effects expected in the DG-structures. We have confirmed that, for very small gate lengths, short-channel effects are less significant in the DG-HEMTs, leading to a better intrinsic dynamic performance. Moreover, the higher values of the transconductance over drain conductance ratio gm /gd, and, especially, the lower gate resistance Rg also provide a significant improvement of the extrinsic fmax.
Langevin forces and generalized transfer fields for noise modelling in deep submicron devices

One of the most suitable techniques to compute noise in electronic devices is the standard impedance field method, a deterministic approach able to provide analytical and numerical solutions for the noise spectra of electronic devices at a hydrodynamic (HD) level. The starting point of our investigation consists in showing that this method is not appropriate for the calculation of noise spectra in deep submicron devices where spatial correlations between noise sources are of relevant importance. To overcome the difficulties which are intrinsic to the standard impedance field method we have developed a new scheme based on Langevin forces and generalized transfer fields.
100nm InAlAs/InGaAs double-gate HEMT using transferred substrate

100nm T-gates InP double-gate HEMTs (DG-HEMT) have been fabricated by use of transferred substrate technique. Theses devices are compared with standard single 100nm T-gate HEMT. The maximum extrinsic transconductance gm of DG-HEMT is two times higher than the HEMT one, and the extrinsic output conductance gd is significantly reduced with DG-HEMT. The combined high gm and low gd induced an extremely high intrinsic unloaded voltage gain gm/gd of 100. So, theses results allowed an improvement of the maximum oscillation frequency (f/sub max/) of 30% compared with standard single 100nm T-gate HEMT. These results are attributed to reduction of short channel effects, related to higher charge control efficiency and suppression of buffer effect.
Comparison Between the Noise Performance of Double- and Single-Gate InP-Based HEMTs

The noise performance of InAlAs/InGaAs double-gate (DG) and standard high-electron-mobility transistors (HEMTs) is analyzed by means of an ensemble 2-D Monte Carlo simulator. The DG-HEMT is found to have a better noise behavior than the single-gate (SG) device. The results show a moderate decrease of the and noise parameters for the DG HEMT with respect to that of the SG device, since current fluctuations due to electrons injected into the buffer are eliminated. Moreover, the DG HEMT reveals a significantly lower extrinsic minimum noise figure and a higher associated gain , not only due to the better intrinsic performance but also to the lower contact resistances.
DC and RF cryogenic behaviour of InAs/AlSb HEMTs

DC and RF properties are reported for InAs/AlSb HEMTs operating under cryogenic conditions (6 K) for a drain source bias up to 0.3 V. Compared to room temperature (300 K), a large improvement in device properties was observed: lower Ron, lower gds, a more distinct knee in the Ids (Vds) characteristics, increased fT and a reduction of the gate leakage current of more than two orders of magnitude. This makes InAs/AlSb HEMT technology of large interest in cryogenic low-noise amplifier designs with high constraints on power dissipation.
Nonlinear effects in T-branch junctions

The negative potential appearing at the central branch of T-branch junctions (TBJs) when biasing left and right contacts in push-pull fashion has been found to appear under high biasing not only for short (ballistic) TBJs but also for long (diffusive) ones. By means of a microscopic Monte Carlo simulation we are able to explain this nonlinear effect as a consequence of intervalley scattering mechanisms leading to the emergence of an accumulation domain that modifies the electronic potential profile within the devices.
Bayesian resolution enhancement of compressed video

Super-resolution algorithms recover high-frequency information from a sequence of low-resolution observations. In this paper, we consider the impact of video compression on the super-resolution task. Hybrid motion-compensation and transform coding schemes are the focus, as these methods provide observations of the underlying displacement values as well as a variable noise process. We utilize the Bayesian framework to incorporate this information and fuse the super-resolution and post-processing problems. A tractable solution is defined, and relationships between algorithm parameters and information in the compressed bitstream are established. The association between resolution recovery and compression ratio is also explored. Simulations illustrate the performance of the procedure with both synthetic and nonsynthetic sequences.
A general multichannel image restoration method using compound models

In this paper we present a multichannel image restoration method using compound Gauss Markov random field (CGMRF) models. Information regarding the objects present in the scene is shared via the line process in the CGMRF. Two new iterative algorithms to estimate the underlying multichannel image are presented, which can be considered as extensions of the classical simulated annealing and ICM methods. Experimental results demonstrate the effectiveness of the proposed approach.
Frequency response of T-shaped Three Branch Junctions as Mixers and Detectors

Nonlinear electrical characteristics of three-branch junction (TBJ) devices are investigated experimentally and numerically as a function of frequency. Based on the bell-shaped output voltage obtained under push-pull input we analyze the low frequency performance (≪1 MHz) of TBJs operating as mixers. Concerning high frequency, by means of Monte Carlo simulations we illustrate the functionality of the device as a frequency doubler or rectifier up to 1 THz.
Noise and transit time in ungated FET structures

Using a classical Monte-Carlo simulation, tested by means of the comparison with experimental measurements of I-V characteristics and noise temperature, we compare the frequency and noise behavior of GaAs/Al/sub 0.2/Ga/sub 0.8/As ungated HEMT (called u-HEMT) with respect to GaAs ungated MESFET (u-MESFET). The small fraction of Al in the AlGaAs makes the real-space transfer between the GaAs and AlGaAs layers become important; its effects will be analyzed. As main tool for the comparison we employ the transit time of the electrons through the devices. This magnitude can give exact information not only about the speed but also about the noise behavior of the devices. We have observed an important reduction of the switch-on time which passes from 14 ps in the u-MESFET to 10 ps in the u-HEMT (at a biasing of 2.0 V). The transit-time distribution shows that the current in the u-HEMT comes from electrons whose velocities do not spread as much as in the u-MESFET, where the distribution Is wider. This leads to a lower value of the current variance, which is related to the total noise spectrum of the devices.
Operation of GaN Planar Nanodiodes as THz Detectors and Mixers

In this paper, we perform, by means of Monte Carlo simulations and experimental measurements, a geometry optimization of GaN-based nano-diodes for broadband Terahertz direct detection (in terms of responsivity) and mixing (in terms of output power). The capabilities of the so-called self-switching diode (SSD) are analyzed for different dimensions of the channel at room temperature. Signal detection up to the 690 GHz limit of the experimental set-up has been achieved at zero bias. The reduction of the channel width increases the detection responsivity, while the reduction in length reduces the responsivity but increases the cut-off frequency. In the case of heterodyne detection an intrinsic bandwidth of at least 100 GHz has been found. The intermediate frequency (IF) power increases for short SSDs, while the optimization in terms of the channel width is a trade-off between a higher non-linearity (obtained for narrow SSDs) and a large current level (obtained for wide SSDs). Moreover, the RF performance can be improved by biasing, with optimum performances reached, as expected, when the DC non-linearity is maximum.
Monte Carlo calculation of In0.53Ga0.47As and InAs noise parameters

The increase of modern electronics performances depends on the ability to grow high-frequency, low-noise and low-power devices. Nowadays, InP technology is mature and In0.53Ga0.47As is clearly a material of interest. Moreover, Sb-based devices constitute the next step , which makes InAs transport and noise parameters analysis a relevant topic. The difficulties to obtain these quantities through experiments can be overcome by the onset of an appropriate numerical protocol. In this framework, we propose a Monte Carlo calculation of both diffusion coefficient and noise temperature of bulk In0.53Ga0.47As and InAs within a correlation functions formalism.
Monte Carlo study of the dynamic performance of isolated-gate InAs/AlSb HEMTs

In this work, by means of Monte Carlo simulations, the static and dynamic performance of InAs/AlSb HEMTs at low drain voltages is analyzed. A very good agreement between experimental and simulation results has been obtained not only for the static behavior, but also for small signal equivalent circuit parameters like C<inf>gs</inf>, C<inf>gd</inf>, f<inf>t</inf> and f<inf>c</inf>. Problems arise when trying to reproduce the values of g<inf>d</inf> and C<inf>ds</inf> due to the experimental frequency dispersion, leading also to discrepancies in the values obtained for the intrinsic g<inf>m</inf> and also f<inf>max</inf>.
Design optimization of AlInAs-GaInAs HEMTs for high-frequency applications

By using a Monte Carlo simulator, the static and dynamic characteristics of 50-nm-gate AlInAs-GaInAs /spl delta/-doped high-electron mobility transistors (HEMTs) are investigated. The Monte Carlo model includes some important effects that are indispensable when trying to reproduce the real behavior of the devices, such as degeneracy, presence of surface charges, T-shape of the gate, presence of dielectrics, and contact resistances. Among the large quantity of design parameters that enter the fabrication of the devices, we have studied the influence on their performance of two important factors: the doping level of the /spl delta/-doped layer, and the width of the devices. We have confirmed that the value of the /spl delta/-doping must be increased to avoid the reduction of the drain current due to the depletion of the channel by the surface potential. However, a higher /spl delta/-doping has the drawback that the frequency performance of the HEMTs is deteriorated, and its value must be carefully chosen depending on the system requirements in terms of delivered power and frequency of operation. The reduction of the device width has been also checked to improve the cutoff frequencies of the HEMTs, with a lower limit imposed by the degradation provoked by the offset extrinsic capacitances.
Monte Carlo modeling of ultra-fast operating Ballistic Deflection Transistor

This paper presents Monte Carlo simulations of a unique non-linear device called Ballistic Deflection Transistor. A self-consistent model for surface charges has been used and has shown a remarkable efficiency to reproduce the non-linearity. A dynamic analysis is completing the transistor study. Results are showing very good response to an ultra-fast excitation. These are confirming Terahertz performances of our device, leading to the development of more efficient logical computing circuits.
Stochastic model for ion shot noise in Hodgkin and Huxley neurons

A stochastic model based on the Monte Carlo technique able to reproduce the steady state and the action potential in neurons in terms of the probabilities for different ions to cross the cell membrane is presented. Gating channels for sodium and potassium cations and leakage channels are considered following the Hodgkin-Huxley equations. Ion shot noise, this is, the noise associated to the random passage of ions across the cell membrane, is naturally accounted for in the model. Shot noise by itself can lead to the excitation and inhibition of action potentials, being of increasing influence the smaller is the area of the membrane patch.
Monte Carlo Comparison Between InAlAs/InGaAS Double-Gate and Standard HEMTs

An ensemble 2D Monte Carlo simulator is employed to analyze the static and dynamic performance of InAlAs/ InGaAs double-gate high electron mobility transistors (DG-HEMTs) by comparing them with standard single-gate (SG) ones. Different gate length devices are analyzed in order to check the attenuation of short-channel effects expected in the DG-structures. The transconductance g<sub>m</sub> and the output conductance g<sub>d</sub> are confirmed to be improved by the DG-geometry. As well, the higher values of the figure of merit g<sub>m</sub> / g<sub>d</sub> jointly with the lower value of the gate resistance R<sub>g</sub> lead to an improvement of the extrinsic frequency performance (f<sub>max</sub> and f<sub>t</sub>).
Super resolution of multispectral images using ℓ1 image models and interband correlations

In this paper we propose a novel super-resolution based algorithm for the pansharpening of multispectral images. Within the Bayesian formulation, the proposed methodology incorporates prior knowledge on the expected characteristics of multispectral images; that is, imposes smoothness within each band by means of the energy associated to the l1 norm of vertical and horizontal first order differences of image pixel values and also takes into account the correlation between the bands of the multispectral image. The observation process is modeled using the sensor characteristics of both panchromatic and multispectral images. The method is tested on real and synthetic images, compared with other pan-sharpening methods, and its quality is assessed both qualitatively and quantitatively.
Operation of a novel nanoscale unipolar rectifying diode

Recently, a nanoscale unipolar rectifying diode, so called self-switching diode (SSD), based on electrostatic effects, was presented in Ref. (1). This device provides a rectifying behavior without the use of any doping junction or barrier structure (like in p-n or Schottky barrier diodes) and can be fabricated with a simple single-step lithographic process. The downscaling of the SSDs is therefore so simple that, together with the intrinsically high electron velocity of InGaAs channels, the fabrication of devices working in the THz range can be envisaged. In this work we will exploit the microscopic description of transport given by a semiclassical 2D Monte Carlo (MC) simulation to provide an in depth explanation of the self-switching operation of the SSD. Moreover, the high frequency performance of the SSDs will be optimized by means of an optimally designed downscaling process.