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This paper discusses and demonstrates the construction of a quantum modular exponentiation circuit in the Qiskit simulator for use in Shor's Algorithm for integer factorization problem (IFP), which is deemed to be able to crack RSA cryptosystems when a large-qubit quantum computer exists. We base our implementation on Vedral, Barenco, and Ekert (VBE) proposal of quantum modular exponentiation, one of the firsts to explicitly provide the aforementioned circuit. Furthermore, we present an example simulation of how to construct a 7xmod 15 circuit in a step-by-step manner, giving clear and detailed information and consideration that currently not provided in the existing literature, and present the whole circuit for use in Shor's Algorithm. Our present simulation shows that the 4-bit VBE quantum modular exponentiation circuit can be constructed, simulated, and measured in Qiskit, while the Shor's Algorithm incorporating this VBE approach itself can be constructed but not yet simulated due to an overly large number of QASM instructions.

Adverse effects of lightning strike are studied through the modeling of the lightning-induced over-voltage (LIOV) using the channel base current (CBC) functions. A lightning current is characterized by the parameters like current peak value (Im), time-taken by the current to reach Im (tm), maximum rise rate of the lightning current (di/dt)max (steepness), and charge transferred at the point of contact of the lightning strike (Q). Using the CBC functions, the lightning electromagnetic fields (LEMFs) are calculated to compute the LIOV using a coupling model. Since the choice of CBC function plays an important role in LIOV computation, the present work studies its effect on the computed LIOV. As a preliminary study two functions: Heidler’s and NCBC functions were examined. It was shown that the a-sort-of delay characteristic from the NCBC function is reflected in the computed LIOV and also the tripolar nature of the LIOV for the case imperfect ground.

This work proposes to optimize iterative-based dividers for a natural logarithm operator design. The logarithm operator approximates the function at the base e. Such an operator is implemented using Taylor Series approximation. In this approximation, the division is a costly operation. In this work, we explore two iterative-based divider circuits for logarithm operator. We also offer an algorithm responsible for allowing input values different from the ones in the convergence region of the Taylor Series, with a reduced number of iterations. Through co-simulation using both the Matlab® and ModelSim® softwares, it was possible to determine the approximation quality of the implemented circuits, with a curve response very close to the Matlab one. Moreover, the Goldschmidt divider presents a slightly fewer relative error, mainly for higher input values comparing with Newton-Raphson. Synthesis results show that although the logarithm circuit with Newton-Raphson divider has marginally more area, it is more power-efficient than the one using Goldschmidt divider.

We present measurement results of commercially-available 90-nm SiGe HBTs at 300 K, 78 K, and 7 K. The data reveal increased variability of SiGe HBTs at 78 K and 7 K compared to that at 300 K. The variation of collector current, base current, and DC current gain (β) increase from 5% at 300 K to 50% at 7 K around the average measured values. Transconductance (g m ) variation increases from 0.6% at 300 K to 5% at 7 K. Peak f T variation increases from 2.6% to 7.1%, while the f T at low injection increases from 1.8% at 300 K to 24.9% at 7 K. Increased variability is observed at lower injection levels at 78 K and 7 K and DC parameters tend to have more variation than RF parameters. The implications of increased variability for circuit designs supporting emerging cryogenic applications such as quantum computing are discussed.

A novel 4H-SiC MOSFET (PM-MOSFET) for rated 3.3 kV applications is proposed, which features the protruded P-base and the mesa above JFET. Numerical simulation based on Silvaco is carried out to investigate the benefits of the proposed structure. The on-state resistance of PM-MOSFET is 11.9 mΩ·cm2, which is dramatically lower compared to on-resistance of 18.2 mΩ·cm2 of the traditional split-gate MOSFET (SG-MOSFET). The C rss of SG-MOSFET extracted at V d = 1800 V is 17.5 pF/cm2, while the C rss of PM-MOS extracted is 6.5 pF/cm2, which is three times lower than that of the SG-MOSFET. It is demonstrated that the PM-MOSFET structure is superior to the SG-MOSFET. More importantly, the benefits above are achieved without degradation of other performances of MOSFET. As a result, the PM-MOSFET presents superior figure of merit ( HF-FOM) (R on × C rss ) than that of the SG-MOSFET. The PM-MOSFET achieves much faster switching speed than the SG-MOSFET.

Most of Power semiconductor devices contain back-to-back PN junctions which consist the open-base transistor whose breakdown voltage will be limited by the gain of the transistor Compared to the parallel-plane junction, the width of the base region is an important factor for reaching the ideal breakdown voltages. The simulation in this paper is the result of how does the width of base region influences the breakdown voltages.

The logarithm function is employed in several areas of knowledge because its curve approximates various physical and chemical phenomena. In this work, we propose an operator which can approximate the logarithm function at the base e. Such an operator is implemented using Taylor Series approximation with five terms. We also offer an algorithm responsible for allowing input values different from the ones that are included in the convergence region of the Taylor Series. Through co-simulations using both the Madab® and ModelSim® simulators, it was possible to determine that the approximation error remains less than 0.6% for the entire input range. The input range used in this paper is in integer format with a one-byte length, and the system output has 19 bits with 4.15 form.

This paper presents a low noise LDO with pre-amplified stage and base current compensation with low noise and high transient response. In this proposed LDO, a pre-amplification structure, where a BJT pre-amplified stage is added before the conventional error amplifier (EA), is employed to reduce the 1/f noise of the EA to improve the LDO noise performance. Owing to the existence of the BJT base current, the base current compensation is added before the pre-amplified stage to ensure the output voltage accuracy. In this paper, a charge release path is added to the output to improve the LDO transient response. The chip was implemented in 0.18μm CMOS process. The integrated noise is approximately 50μV in the range of 10 Hz to 100 kHz at the input voltage of 1.4 V and the load current of 50 mA. The output noise is 0.8μV at a frequency of 10 Hz. The LDO output voltage stabilizes within 6.8μs as the load current is abrupt from 50 mA to 1 mA.

The SiC BJT offers an attractive alternative to the more popular SiC MOSFETs. However, large power consumption of its base driver hampers its widespread in the market. In this paper, we propose a new proportional base driver to minimize its base driver's power consumption in the conduction state. It uses Si BJT to provide adaptive base current for the SiC BJT when the collector current varies with the load. Theoretical formulation predicts that it can provide an ideal base current for the SiC BJT with minimum base driver loss by means of optimum selection of the Si BJT. The proportional base drive method is validated in a boost converter where varying duty cycles are used to emulate the variation of load. The experimental results show that the power consumption of the proposed proportional base driver is reduced by 90.1% compared to the conventional dual source base driver in conduction state when collector current is 1.72A.

Qualitative change of performance of texture images generated on the base of a binary Gibbs model with normalized potentials in a case of a phase transition is investigated. Occurrence of a phase transition is determined by analysis of estimates of potentials and conditional probabilities calculated on the base of the former.

This paper demonstrates a push-pull traveling-wave Mach-Zehnder modulator on InP which operates up to 50Gb/s in C band optical transmission system. This MZM could potentially be integrated to form the IQ modulators, Dual IQ modulators and PM-IQ modulators to achieve higher operating speed.

The operation of SiGe HBTs at cryogenic temperatures is investigated experimentally and theoretically. It is demonstrated that the collector current at cryogenic temperatures is caused by electron tunneling through the base. The temperature dependence of the transistor characteristics reveals a transition from conventional thermally activated transport at room temperature to tunneling dominated transport at cryogenic temperatures. Experimental results are presented for HBTs with a peak current gain of 8000 at 300 K and 45000 at 10 K.

Modular exponentiations are very important in many fields of computer science, including network security protocols. Modular exponentiations of polynomials are a type of modular exponentiations, where the base and modulus are polynomials. In this paper, a parallel modular exponentiation algorithm, which was proposed by Lara et al., is extended to solve modular exponentiations of polynomials in parallel, and further compared to two other proposed parallel algorithms. Essentially those algorithms differ only in their load-balancing methods. The result is, for exponents of length up to 2048 bits, the implementation of Lara et al.'s algorithm results in 28.01% faster running time compared to the implementation of the sequential algorithm. The result also shows that this algorithm is more efficient than the two other proposed algorithms.

In this paper we mainly describe the research progress in a kind of Re doped Y2O3-Gd2O3-HfO2 W base direct-heated cathode, which includes the emission current and the lifetime testing of the cathode. The test results show that the DC emission is beyond 3.23A/cm2 at 1500 °Cbr. The lifetime is reached 4000h with a DC load 1.5A/cm2 at 1600 °Cbr. And the anti-electron-bombing characteristic of the cathode is also studied. Experimental results show that the cathode has good anti-electron-bombing capability.

A real-time and area-efficient hardware implementation of base-2 logarithm (log 2 ) finds many applications. In this paper, we analyze previous shift and add-based approximations of logarithm. Based on the analysis we present a new two region add and shift-based method to approximate log 2 in hardware. The proposed approach results in 81.55% less percentage error and 42.85% less average error compared to previously reported best two region based approximation approaches with comparable area cost and latency. The proposed method uses most significant four bits of fractional part of shift and add-based method with different weights to approximate fractional part of log 2 . Weights to these bits are assigned by simple addition, logical OR and logical AND operation to make hardware implementation more efficient.

The miraculous powers of modern day calculations rests on three important discoveries namely Arabic notation, decimal fractions and logarithm. The concept of logarithm has been used for more than three hundred years and it has simplified lot of calculations but in today's modern systems such as FPGAs which are employed in Software Defined Radios there is a need to efficiently implement logarithm on these programmable devices. But logarithms are implemented either with a look-up table or CORDIC processing system where each has their own drawbacks. In this paper logarithm to the base of any number has been implemented using simple operations such as addition and shift operations with high degree of accuracy. The implementation is done by writing a HDL code for a Artix-7 series FPGA device.

The aim of this study was to develop an off-line, fast, efficient and reliable analytical methodology, capable to determine, both qualitatively and quantitatively, the content of a common oil base mud filtrate in contaminated formation fluids samples. We demonstrate the performance of a methodology based on Gel-Permeation Chromatographic (GPC) analytical signals, combined with a modified factorization algorithm to estimate the oil fractions and an optimization procedure to calculate their concentrations within the mixtures. The proposed scheme is innovatively applied for the determination of the mud filtrate in contaminated oil samples and self-adapted to data without any former information. The results of this work indicate the efficiency of the algorithmic framework to reveal the content of a complex petroleum mixture analyzing the chromatograms of a limited number of samples. The presented technique has a great potential in upstream oil industry, enabling the un-mixing of analytical signals from mixtures of oil samples contaminated with specific petroleum fractions.

The way to predict the high quality time series of soil moisture has important significance for scientific research and production practice. In this paper, a new method based on BP neural network and particle swarm algorithm (PSO) is established to predict the time series of soil moisture data obtained from wireless sensor networks. Experiment results show that our method has higher predicting accuracy and convergence speed.

This article presents a simple, less computational complexity method for constructing exponent matrix (3, K) of girth 8, 10 and 12 of quasi-cyclic low-density parity-check codes (QC-LDPC) based on generation of base matrix. The construction of code deals with generation of base matrix by a simple algorithm and element wise element method for girth 8, while only element wise element method for girth 10 and 12. These methods are flexible for block-column length K. The simulations are shown in comparison with some existing appreciable work.

Elliptic curve discrete logarithm problem (ECDLP) is the base of the security of elliptic curve cryptography (ECC). The verification of the security of ECC has been studied by solving an ECDLP. However, we need a large amount of computational resources for the verification. Then, this paper proposes a method gathering computational resources with Web-based Volunteer Computing (Web-based VC). This paper solves 70-bit ECDLP, and evaluates the computational performance of 2 types of the execution clients: Native Client (NaCl) and Portable NaCl (PNaCl). In the case of NaCl, 70-bit ECDLP was solved in 3086 seconds. On the other hand, in the case of PNaCl, 70-bit ECDLP was solved in 6583 seconds.

In many power converter applications, minority carrier lifetime assessment in the carrier storage region of IGBT is considered desirable. This paper presents a minority carrier lifetime estimation technique through investigation into transient base charge modeling of Non-punch Through (NPT) Insulated Gate Bipolar Transistor (IGBT). Parabolic approximation has been used for derivation of minority carrier concentration within the base. With the help of derived expression, an analytical model has been developed for transient base charge decay of IGBT in all minority carrier lifetime conditions. Better agreements with the experimental results have been found compared to the previously used linear model. Finally, the implications of carrier lifetime dependence on the charge decay rate are discussed, including implementation of such a carrier lifetime measurement technique.

This work develops an analytical model of the base transit time for the SiGe-heterojunction bipolar transistors (HBT) having non-uniformly and heavily doped base considering the field-dependence of the carrier mobility under moderate-level injection. The proposed model considers all the non-ideal effects found in the literature owing to the non-uniformity and the heavy levels of the base doping. The evolving mathematical intractability has been resolved by applying an exponential approximation technique and the concept of the perturbation theory. Simulation results of the proposed model for the exponentially doped base with three types of Ge-dosing profile (box, trapezoidal and triangular) show that the effects of the field-dependent carrier mobility on the base transit time is significant.

In many power converter applications, study of doping concentration in the carrier storage region of IGBT is considered desirable. This paper introduces an estimation technique for base doping concentration through investigation into transient anode voltage modeling of Non-punch through (NPT) Insulated Gate Bipolar Transistor (IGBT). Parabolic profile has been used for derivation of minority carrier concentration within the base. With the derived expression, an analytical model has been developed for turn-off anode voltage of IGBT in all doping profile conditions. Better agreements with the experimental results have been found compared to the previously used linear model. Finally, the implications of base doping dependence on the anode voltage are discussed, including implementation of such a doping concentration estimation technique.

MDS (Maximum Distance Separable) code has been studied for a long time in the theory of error-correcting code and has been applied widely in cryptography. Some authors studied and proposed some methods for constructing MDS matrices which do not base on MDS codes. Some MDS matrix transformations have been studied and direct exponent is such a transformation. In this paper, we present some new results on the preservation of the number of fixed points of an MDS matrix under direct exponent transformation. In addition, the important applications of these results will be shown in block ciphers.

A common base four-finger InGaAs/InP DHBT with 535 GHz fmax using 0.5μm emitter technology is fabricated. Multi-finger design was used to increase input current. Common base configuration was compared with common emitter configuration, and demonstrated a smaller K factor at high frequency span, indicating a larger MSG/MAG breakpoint frequency and thus a higher gain when frequency reaches MAG region of common emitter devices.

It is found that ionizing-radiation can lead to 1/f noise degradations in PNP bipolar junction transistors. In this paper, it is suggested that the surface of the space charge region is the main source of the base surface 1/f noise. A model is developed which identifies the parameters and describes their interactive contribution to the base surface recombination current at the surface of the space charge region. Based on the theory of carrier number fluctuation and the model of base recombination surface current, a 1/f noise model is developed. This model suggests that the 1/f noise degradations are the result of accumulation of oxide-trapped charges and interface states. The radiations were performed in a Co60 source at a dose rate of 0.1Gy(Si)/s up to a total dose of 700Gy(Si). The model can explain well the experimental results.

For a Gaussian doped graded base AlGaAs Hetero-junction Bipolar Transistor (HBT), base transit time (BTT) has been determined using a suitable analytical model. Here the authors have investigated the dependency of base transit time on different physical and input parameters such as the collector current density, base emitter voltage etc. Electric field dependent carrier mobility also has been included into the analytic model and found that the base transit time worsens compared to the value found without taken the field dependent mobility into account.

An accurate and efficient base resistance (R B ) extraction methodology for SiGe HBT HICUM model is developed in this paper. Differing from previous methods, the proposed technique is based on the rational function fitting. Two formulas are used to determine the lower and upper limits of R B , and then R B is confined to a very narrow range and can be estimated analytically only from S-parameter data, without any special structures or numerical optimization. The proposed method is successfully applied to SiGe HBTs with different device geometries. Results demonstrate that the average error for extracted R B is less than 2.5% over a wide range of bias points. Therefore, we believe that the proposed technique is a reliable routine applicable to estimation of the base resistance for SiGe HBT HICUM model.

Nanoparticles mixed with transformer oil can potentially increase the breakdown strength of the base liquid. Unfortunately, the basic physical mechanisms leading to such improvement are still not c ...

Base width variation effects on resonance frequency and resonance peak of Double-Hetero structure Long Wavelength Transistor Laser (DH-LWTL) is investigated. Resonance behavior has significant effects on optoelectronic performance of LWTL that calculated through its frequency response. In our structure, resonance peak maximized to 16.23 dB in 135 nm base width. Also, in 305 nm base width, resonance frequency saturated around 24 GHz.

The problem of finding an analytical closed form solution of the solar cell junction ideality factor n is studied in some detail, by the Special Trans Functions Theory (STFT). The novel mathematical method just as the structure of the theoretical derivation is presented, while proofs and numerical results confirm the validity and base principle of the STFT. In addition, the obtained results are compared with the calculated values of other methods for alternative proving its significance. Undoubtedly, the proposed novel STFT analytical approach implies qualitative improvement of the conventional analytical and numerical methods.

Lasing characteristics of 1.3-μm npn-AlGaInAs/InP transistor laser (TL) depend on base layer structure were investigated through simulation and fabrication. As a result, while the TL has the same current gain, better lasing characteristics were observed for thinner thickness and wider bandgap.

This article presents 3 axis magnetotransistor based on the carrier recombination and deflection effect for detecting the magnetic field in B X , B Y and B Z direction. The structure composes of four magnetotransistors along with x-axis and y-axis that has a common emitter while all collectors and bases are independent. The output is in the form of difference current of collector and base ΔI CB . For vertical field detection, the magnetotransistor uses the carrier deflection of the deviation collector current and recombination base current as ΔI CB . For lateral field detection B X and B Y it uses a pair of transistors that emitter biased current perpendicular to magnetic field. The output response is the difference current between collector of one and the base current of the another of a pair transistors as ΔI C(1)B(3) and ΔI C(2)B(4) for B X and B y , respectively. The sensitivity at I E 5 mA, 0-1 T of B X , B Y and B Z direction are -0.0248 mA/T, -0.0248 mA/T and 0.0092 mA/T, respectively by TCAD Sentaurus simulation.

A novel two-stage reaction-control scheme with a background-cancelling circuit - for reducing data volume and analysis time of an ion-sensitive-FET (ISFET) - based DNA sequencer-is proposed. The scheme successfully reduces the background noise and renders time-consuming background analysis unnecessary. It also reduces sample-to-data time by 72% (3.6 times faster) and data volume by two orders of magnitude.

Influence of gamma radiation on sensors based on GaAs is considered. The volt-ampere characteristics and the noise spectral density of magnetic field sensors before and after irradiations were investigated. It was found stabilizing effect of gamma radiation on sensors with the dose (8-10) ·103 Gy and destroying effect at the greater doses.

InxGa1-xSb-based double heterojunction bipolar transistor (DHBT) with compositional graded base and collector is presented. A numerical device simulator Silvaco's ATLAS is used to analyze the performance of the device. The Gummel plots and simulation analysis demonstrate extremely high DC current gain with uniform characteristic for the wide range of collector current. The magnitude of the current gain is found to about 1300 and it is the highest gain for HBTs/DHBTs as reported so far. Preliminarily we achieved this extremely high gain may be due to energy band engineering using compositional gradient technique in the device structure.

We have developed by solving continuity equation the expressions for the terminal currents of Transistor Lasers that incorporate Multiple Quantum Wells in the base. The bulk carrier density in base is related with the two-dimensional carrier density in QWs via virtual states. Strain, 2D density-of-states, polarization dependent momentum matrix element, Fermi statistics and Lorentzian broadening are considered to estimate the QW gain. Comparison between the calculated and experiment values indicates substantial reduction in threshold base current for symmetric MQW-TL having equal QW and barrier widths. Calculations are also made for three QWs of different widths having variable barrier widths (Asymmetric MQW-TL). Reduction of threshold base current by different amounts is observed in all cases.

In this paper the author propose a fast and efficient algorithm for multilook K-distribution parameter estimation. It is base on the approximate inverse function of log(ν) − ψ(ν), which is calculated by the least squares nonlinear curve fitting technique. Numerical experiments demonstrate the efficiency and accuracy of this new algorithm.

When the gyro-harmonic heating and some other instability happen at the same time, several instabilities interact with each other, which is easier for them to ionize neural gas. It is represented as the huge enhancement of the electron density amplitude, and the scale of enhancement will extend to several hundreds kilometers. Base on the observation results of the heating experiment in polar region, the super thermal electron induced by nth gyro-harmonic frequency heating is validated and the relevant physical process is explained.

This paper discusses the nonlinear third interpolating polynomials on tree growth data based on volumetric equations used in Forestry Science. Data variables used are diameter of stem at breast height (D bh ), base (D b ), middle (D m ) and top (D t ), just before the crown, with their corresponding stem height of tree or bole (S T ). There are 130 mensuration data samples, and the cubic interpolating polynomials are interpolated using Maple. To obtain a robust model for biomass estimation, comparisons are simulated and the best model is selected, based on the sum of square error (SSE). Results obtained indicate the range of the constants and β-coefficients of the polynomials. The models are statistically significant based on the variance analysis. The best cubic interpolating model, however, is found to be an asymptotic curve with the parameters from mensuration data. This is with respect to the different tree volumetric equations for biomass estimation.

A simulation study of (p+) a-Si/ (i) a-Si/ (n) c-Si/ (i) a-Si/ (n+) a-Si solar cell is carried out to identify the carrier loss mechanisms, which are a-Si/c-Si interface and base recombination. Improvements in open circuit voltage (V OC ) and thus the efficiency can be achieved through better a-Si/c-Si interface passivation. In devices with excellent a-Si/c-Si interface passivation, base recombination is the dominant process. In such cases, reducing the base thickness (L Base ) increases the carrier concentration in the base. The L Base can be reduced without significant loss in short circuit current (J SC ) through effective light trapping techniques. Next, the relative contributions of the emitter/base ((i) a-Si/ (n) c-Si) and base/Back Surface Field ((n) c-Si/ (i) a-Si) interfaces to the overall carrier recombination loss are discussed. It is found that both interfaces have similar contributions to total carrier loss in long as well as short base devices.