Cross-correlation Factor Research Articles

Stability Analysis of Partially Saturated Soil Slope by Random Limit Equilibrium Method

Disregarding soil suction in computing the shear strength of unsaturated soils is widely used practice above the water table where the pore pressure is negative. Stability analysis was conducted using Rocscience Slide 2 software to evaluate matric suction contribution to the shear strength of the unsaturated soil in a slope in Hong Kong. The stability analysis resulted in a critical deterministic factor of safety for fully saturated soil and 1.2 when the matric suction is considered. Uncertainty in shear strength properties is considered by conducting multi scenarios probabilistic analysis. Lognormal distribution was assigned to the soil properties. The distribution was sampled 1000 times using Latin Hypercube method. A new sample was used to determine the safety factor in each simulation. Probability of failure (PF), mean safety factor (FSmean) and reliability index (RI) were determined in each scenario. It was shown that the most realistic results are obtained when cross correlation factors and correlation length (θ) are involved in the scenario. The study indicates that PF and RI are sensitive to a change in the correlation length less than 25 and less significant change beyond 25 m. The FSmean did not show noticeable fluctuation with the variation of correlation lengths.

Impact of temperature variation on noise parameters and HCI degradation of Recessed Source/Drain Junctionless Gate All Around MOSFETs

With the continuous scaling for MOS device, the noise parameters has becoming a critical parameter. The noise performance of an electronic device can be measured with the help of Minimum Noise Figure (MNF), Auto-Correlation Factor (ACF), Cross-Correlation Factor (CCF), and Output Impedance (Real Z0). In this article, we have investigated the effects of temperature fluctuation on the noise parameter performance, and the Hot-Carrier Injection (HCI) degradation of the device Recessed Source/Drain Junctionless Gate All Around (Re-S/D-JL-GAA) and Junctionless Gate All Around (JL-GAA) MOSFETs. The comparative analysis presents that the temperature difference has the minimum impact on all noise characteristics. In this paper, the temperature variations from 200 K to 500 K have been studied to study the noise performance of the device at both low and high temperature applications. The simulation results confirm that all noise parameters are minimum in Re-S/D-JL-GAA compared to JL-GAA MOSFET. As a result, the Re-S/D-JL-GAA MOSFET is better alternative for analog circuits with low noise applications over a wider temperature range.

On the Scalability of Duty-Cycled LoRa Networks With Imperfect SF Orthogonality

This letter uses stochastic geometry and queuing theory to study the scalability of long-range (LoRa) networks, accounting for duty cycling restrictions and imperfect spreading factor (SFs) orthogonality. The scalability is characterised by the joint boundaries of device density and traffic intensity per device. Novel cross-correlation factors are used to quantify imperfect SF-orthogonality. Our results show that a proper characterisation of LoRa orthogonality extends the scalability of the network. They also highlight that for low/medium densities decreasing the SF extends the spanned spectrum of sensing applications characterised by their traffic requirements (i.e., sensing rate). However, for high density <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$(&gt;10^{4}$ </tex-math></inline-formula> nodes/Km <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{2}$ </tex-math></inline-formula> ), the Pareto frontiers converge to a stability limit governed by the SF allocation scheme and the predefined capture thresholds. The results further evince the importance of capturing threshold distribution among the SFs to mitigate the unfair latency.

Entangled microwave photons generation using cryogenic low noise amplifier (transistor nonlinearity effects)

This article mainly focuses on important quantum phenomenon called entanglement arising the nonlinearity property. This study uses a unique approach in which transistor nonlinearity effect (third-order nonlinearity) entangled microwave photons are created in a cryogenic low-noise amplifier (LNA). For entanglement analysis, the Hamiltonian of the designed cryogenic LNA (containing two coupled oscillators) is derived, and then, using the dynamic equation of motion, the oscillator’s number of photons and the phase-sensitive cross-correlation factor are calculated in the Fourier domain to calculate the entanglement metric. The oscillators are coupled to each other through the gate–drain capacitor, and nonlinear transconductance is as an important factor strongly manipulating the entanglement. As a main conclusion, the study shows that the designed circuit using transistor third-order nonlinearity has the ability to generate the entangled microwave photons at very low intrinsic transconductance and more importantly when the noise figure (NF) is strongly minimized. As a complementary task, the printed circuit board of the cryogenic LNA is designed and simulated to verify the ability of the circuit to achieve an ultralow NF, by which the probability of the generation of entangled microwave photons is increased.

The relationship between inter-diffusion and self-diffusion of different liquid metals studied by molecular dynamics simulations

Long-capillary simulation method was used to calculate the inter-diffusion coefficient using nonequilibrium molecular dynamics simulations. The inter-diffusion coefficient of the binary Al80Ni20, Al80Cu20, La80Ni20 and La80Al20 melts were calculated over a wide temperature range. We found that the relationship between inter- and self-diffusion coefficients of Al80Cu20 melts can be well expressed by Darken equation, which agreed with the previous results. For Al80Ni20, La80Ni20 and La80Al20 melts, dynamic cross correlation factor S was needed to correlate the Darken equation. S of Al80Ni20 and La80Ni20 ranged from 0.68 to 0.92, while that of La80Al20 was larger than 1. The effect of pressure on S was further investigated. We found that S of Al80Ni20 under 30 GPa was about 0.46 at 2000K and it was much lower than that of zero pressure, which means that the pressure had a great influence on S. Our investigations provided an improved understanding of cross correlation factor S.

Generalized regression neural network application for fault type detection in distribution transformer windings considering statistical indices

PurposeThis study aims to use frequency response analysis, a powerful tool to detect the location and types of transformer winding faults. Proposing an effective intelligent approach for interpreting the frequency responses is the most crucial problem of this method and has created many challenges.Design/methodology/approachHeat maps based on appropriate statistical indices have been supplied to depict the variations in the frequency responses associated with each fault type, fault location and fault extent along the windings. Also, after analyzing the results of artificial neural network (ANN) techniques, the generalized regression neural network method is introduced as the most effective solution for the classification of transformer winding faults.FindingsUsing a comparative approach, the performance of the used indices and ANN techniques are evaluated. The results showed the proper performance of Lin’s concordance coefficient (LCC) index and the amplitude (Amp) part of the frequency response. The proposed fitting percentage (FP) index can assist the intelligent classifiers in diagnosing the radial deformation (RD) fault with the highest accuracy considering all frequency response components in the classification procedure of winding faults.Practical implicationsVarious ANN techniques are used to detect and determine the type of four important faults of transformer winding, i.e. axial displacement, RD, disc space variation and short circuit. Various statistical indices, such as cross-correlation factor, LCC, standard difference area, sum of errors, normalized root-mean-square deviation and FP, are used to extract the features of the frequency responses to consider as the ANN inputs. In addition, different components of the frequency response, such as Amp, argument, real and imaginary parts are examined in this paper. To implement the proposed procedure, step by step, various types of winding faults with different locations and extents are applied on the 20 kV winding of a 1.6 MVA distribution transformer.Originality/valueContributions have been made in identifying and diagnosing transformer winding defects through the use of appropriate algorithms for future research.

Low-frequency noise measurements as an analysis and prediction tool for the reliability evaluation of 808 nm laser diodes.

We investigated the low-frequency optical and electrical noise characteristics and their cross-correlation factor of the 808 nm laser diodes (LDs) samples, whose performances were degraded and stabilized after operating a period of time or during ex-factory reliability lifetime tests. It was shown that the optical noise in unreliable samples exhibited white components in the frequency range from 1 kHz to 10 kHz, while a Lorentzian-type component was superimposed on 1/f electrical noise. Meanwhile, the optical and electrical noise correlation exhibited positive result. In contrast, both low-frequency optical and electrical noise presented pure 1/f-type fluctuations in stable samples. These presented results suggest that it is feasible to employ low-frequency noise measurements as a tool for predicting and diagnosing the reliability of LDs.

Design and optimization of junctionless-based devices with noise reduction for ultra-high frequency applications

This paper offers the study of the noise performance of four devices namely junctionless dual-gate FET (JL-DGFET), junctionless nanowire FET (JL-NWFET), charge-plasma based dopingless dual-gate FET (DL-DGFET) and dopingless nanowire FET (DL-NWFET). This work examines the maximum Noise-Figure (NFmax.), Auto-correlation factor ( )/( ), cross-correlation factor ( ), and output impedance (real Zo). To understand the performance of devices, analog characteristics of all four devices and effect on these characteristics with the variations of different device structure parameters are analyzed and compared. Internal physics of device is understood by device design parameters such as electric field, channel potential, carrier mobility and carrier concentration. It is observed from the simulated results that JL-DGFET has better noise performance, highest ION/IOFF current ratio than other devices.

Authenticate audio video-crypto invisible watermarking approach for enhancing hidden information security and robustness

For any type of watermarking techniques imperceptibility, robustness, embedding capacity, security of hidden watermark data and good visual recovery of both cover, as well as watermark secret data, are the major issues. To solve these issues the selected frames of video and the secret data is divided into the equal number of parts and every part is mapped using adaptive pixel location mapping (APLM) algorithm to get watermarked video, hence the embedding capacity and security of hidden watermark data are increased. Furthermore, the proposed system also calculates the key security parameters like peak signal to noise ratio (PSNR), mean square error (MSE), histogram, structural similarity index module (SSIM) and cross-correlation factor (CCF) before watermarking, after watermarking and after recovering the secret data from watermarked video which are found to be identical, hence the proposed system is more insusceptible to any type of attack as compared to existing watermarking approaches.

A female perspective: testing the effects of noise masking on signal transmission patterns inside the nest box

Abstract During the breeding season, avian pairs coordinate interactions with songs and calls. For cavity nesting birds, females inside nest boxes may rely on male vocalizations for information. Anthropogenic noise masks male songs, which could affect information gained by females. We explored song transmission from a female house wren (Troglodytes aedon) perspective, testing the hypothesis that noise masking alters songs that reach females inside nest boxes. We broadcast songs at three distances up to 25 m from nest boxes and re-recorded songs using two microphones, positioned inside and outside nest boxes. We measured signal-to-noise ratios and cross-correlation factors to estimate the effects of masking on transmission. In noise, songs received inside nest boxes had lower signal-to-noise ratios and cross-correlation factors than songs recorded outside of boxes, and these effects decreased with distance. For females, noise may reduce information conveyed through male songs and in response pairs may need to adjust their interactions.

Authenticate audio video-crypto invisible watermarking approach for enhancing hidden information security and robustness

For any type of watermarking techniques imperceptibility, robustness, embedding capacity, security of hidden watermark data and good visual recovery of both cover, as well as watermark secret data, are the major issues. To solve these issues the selected frames of video and the secret data is divided into the equal number of parts and every part is mapped using adaptive pixel location mapping (APLM) algorithm to get watermarked video, hence the embedding capacity and security of hidden watermark data are increased. Furthermore, the proposed system also calculates the key security parameters like peak signal to noise ratio (PSNR), mean square error (MSE), histogram, structural similarity index module (SSIM) and cross-correlation factor (CCF) before watermarking, after watermarking and after recovering the secret data from watermarked video which are found to be identical, hence the proposed system is more insusceptible to any type of attack as compared to existing watermarking approaches.

Anthropogenic noise masking diminishes house wren (Troglodytes aedon) song transmission in urban natural areas

ABSTRACT Anthropogenic noise changes the acoustic environment in which avian signals have evolved, possibly decreasing active space or the area over which signals may be detected and discriminated by receivers. Linking signal transmission patterns to signal function and species’ spatial ecology is important for understanding behavioural changes of receivers in noise. We tested whether varying levels of ambient noise affects transmission of two structurally distinct sections of male house wren (Troglodytes aedon) song used for short- and long-distance communication. We placed our experiment in an ecological context by measuring signal degradation and attenuation in relation to species-typical spacing patterns to investigate whether song structure is maintained within (short-distance within-pair communication) and between territories (long-distance male-male and extra-pair communication) depending on noise levels. Songs experienced more masking and fell below thresholds for detection and discrimination at shorter distances under noisier conditions. Decay of signal-to-noise ratios and cross-correlation factors in noise were so pronounced that song components used for both short- and long-distance communication did not transmit beyond average territory boundaries. Noise masking could affect species ecology: if signals are not detected by intended receivers in noisier habitats, settlement, space use and social interactions may be fundamentally altered compared to those in quieter environments.

Geometry-independent attenuation and randomness of ultrasound wave propagation in concrete measured by embedded PZT transducers

Ultrasound is widely used in nondestructive testing (NDT). It is the basis of many NDT techniques, such as acoustic emission, phased array and synthetic aperture focusing technique. The attenuation of ultrasound is a key factor that ensures the feasibility of these techniques. Conventional studies of attenuation are mostly conducted in specimens that have dimensions smaller than ultrasound wavelengths. In this type of study, reflections from media boundaries interfere with the wave, resulting in a geometry-dependent attenuation that cannot be applied in another specimen with a different geometry, even if the material is identical. Another factor that impacts on the viability of ultrasound NDT techniques is the spatial uniformity of waves in the concrete sample. To serve as a reference in testing defects, the degree of randomness caused by the material’s heterogeneity should be estimated in conditions free of defects. In this study, a large concrete specimen was fabricated to suppress boundary reflections of the wave, creating an environment less dependent on geometry. Twenty-two PZT (lead zirconate-titanate ceramics) transducers were arranged in a three-by-seven array to transmit and receive ultrasound waves. This experiment sought to measure attenuation over distance and by frequency, as well as analyzing attenuation factors such as geometrical spreading and material absorption. A quadratic trend with good consistency between attenuation and frequency was found, indicating minimal local attenuation. The degree of randomness in the wave was measured by three indices: amplitude, group velocity and the frequency spectrum cross-correlation factor. Frequency dispersion was also described using group velocity. The findings of this study can serve as a reference for other NDT research, disclosing geometry-independent attenuation and the variability of wave characteristics in concrete.

Linearity Distortion Assessment and Small-Signal Behavior of Nano-Scaled SOI MOSFET for Terahertz Applications

Fully-Depleted Silicon-on-Insulator (FD SOI) MOS technology has already been reported as a strong contender in nanoscale CMOS designs. This work presents the linearity-distortion assessment, small-signal and radio-frequency noise-behavior of dual-metal-insulated-gate (DMIG) source-engineered (SE) FD SOI MOSFET for terahertz (THz) applications. Here, linearity-distortion performance has been monitored on the basis of numerical calculations of transconductance and its higher-order derivatives along with the voltage-intercept points, and various parameters of intermodulation-distortion. This analysis also practices the guidelines of device design with least linearity-distortion in radio-frequency integrated-circuits based communication systems at 50 nm technology node. Further, the small-signal and RF noise-behavior have been examined on the basis of high-frequency scattering-parameters for the analysis of input/output reflection-coefficients (S11/S22), reverse/forward transmission-coefficients (S12/S21), Stern's-stability-factor (K), minimum noise-figure, noise-conductance and cross-correlation factor (<VN-in.VN-out*>). The analysed results affirm the ultimate reduction in reflection-coefficients and a significant increase in transmission-coefficients in case of DMIG FD SOI MOSFET at THz range as compared to existing MOS structures. Also, the analysis reveals the considerable reduction in various radio-frequency noise FOMs and thus represents the device efficacy in low-noise-amplifiers. All these studies have been carried out by performing numerical simulations over TCAD-ATLAS simulator from Silvaco along with quantum-mechanical-effect (QME) and Bohm-quantum-potential (BQP) models.

DENOISING OF MULTICHANNEL IMAGES WITH NONLINEAR TRANSFORMATION OF REFERENCE IMAGE

It has been demonstrated recently that efficiency of filtering a noisy component image of a multichannel image can be sufficiently improved under condition that the multichannel image has almost noise-free component image(s) that possess high correlated with the noisy component image used as reference. High correlation and practical absence of the noise are only pre-requisites for efficient filtering of the noisy image using reference. Other criteria of similarity than cross-correlation factor are important. In this paper we show how it is possible to make the reference image very "close" to the noisy one by exploiting nonlinear transformation. Moreover, it is demonstrated that the proposed approach can be useful for denoising images corrupted by signal-dependent noise which is often the case for multichannel remote sensing data.

Preventing damage and redeposition during focused ion beam milling: The “umbrella” method

Focused ion beam (FIB) milling has enabled the development of key microstructure characterization techniques (e.g. 3D electron backscatter diffraction (EBSD), 3D scanning electron microscopy imaging, site-specific sample preparation for transmission electron microscopy, site-specific atom probe tomography), and micro-mechanical testing techniques (e.g. micro-pillar compression, micro-beam bending, in-situ TEM nanoindentation). Yet, in most milling conditions, some degree of FIB damage is introduced via material redeposition, Ga+ ion implantation or another mechanism. The level of damage and its influence vary strongly with milling conditions and materials characteristics, and cannot always be minimized. Here, a masking technique is introduced, that employs standard FIB-SEM equipment to protect specific surfaces from redeposition and ion implantation. To investigate the efficiency of this technique, high angular resolution EBSD (HR-EBSD) has been used to monitor the quality of the top surface of several micro-pillars, as they were created by milling a ringcore hole in a stress-free silicon wafer, with or without protection due to an “umbrella”. HR-EBSD provides a high-sensitivity estimation of the amount of FIB damage on the surface. Without the umbrella, EBSD patterns are severely influenced, especially within 5 µm of the milled region. With an optimized umbrella, sharp diffraction patterns are obtained near the hole, as revealed by average cross correlation factors greater than 0.9 and equivalent phantom strains of the order 2 × 10−4. Thus, the umbrella method is an efficient and versatile tool to support a variety of FIB based techniques.

INNOVATIVE DATA HIDING SECURITY MODEL USING FORENSIC AUDIO VIDEO CRYPTO-STEGANOGRAPHY

Secret information concealing using steganography is simple but to maintain its security, perceptibility, robustness, embedding capacity and good recovery of both cover as well as secret information are the major issues. In this paper we have applied Block Plane Coding Technique (BPCT) for concealing the secret data into the randomly obtained frames of video and Least Significant Bit (LSB) algorithm for audio of same video. We have obtained the key security parameters like Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE), Normalize Cross Correlation Factor (NCCF), Bit Error Rate (BER), histogram and spectrograph before embedding and after recovering the protected data from stego video using forensic technique to increase the data security. Moreover, the proposed scheme provides a large hiding capacity, more security for secret data and good visual recovery of both secret data and original video than any other existing methods. Through many attack during transmission on stego video, it is found that the suggested approach is more robust than any other existing methods.

Inter-diffusion and its correlation with dynamical cross correlation in liquid Ce80Ni20

We reported the inter-diffusion coefficients in liquid Ce $$_{80}$$ Ni $$_{20}$$ measured by the sliding cell technique. Combined with the self-diffusion data of Ni measured by quasi-elastic neutron scattering in the literature, it was found that the relationship between inter-diffusion and self-diffusion in liquid Ce $$_{80}$$ Ni $$_{20}$$ was strongly deviated from the standard Darken equation with an abnormally small dynamical cross correlation factor S (the so called Manning factor) in a range of 0.6–0.8, less than unity in standard systems. Through the calculated distinct diffusion coefficient and its deviation from the standard one, it was discovered that the small S value was directly originated from enhanced distinct diffusion between Ce and Ni atoms and reduced distinct diffusion between Ni and Ni atoms. Because the inter-atomic interaction was not considered in the standard liquids, the present small S factor and intrinsic distinct diffusion coefficients were believed to be resulted from the chemical interaction between Ce and Ni in the liquid. The results provide new evidence of the dynamic cross correlation in liquid diffusion, and thus shed light on the understanding of the correlation between dynamics and structure in liquid alloys.

Determination of water-soluble and fat-soluble vitamins in tears and blood serum of infants and parents by liquid chromatography/mass spectrometry

Tears serve as a viable diagnostic fluid with advantages including less invasive sample to collect and less complex to prepare for analysis. Several water-soluble and fat-soluble vitamins were detected and quantified in human tears and compared with blood serum levels. Samples from 15 family pairs, each pair consisting of a four-month-old infant and one parent were analyzed; vitamin concentrations were compared between tears and blood serum for individual subjects, between infants and parents, and against self-reported dietary intakes. Water-soluble vitamins B1, B2, B3 (nicotinamide), B5, B9 and fat-soluble vitamin E (α-tocopherol) were routinely detected in tears and blood serum while fat-soluble vitamin A (retinol) was detected only in blood serum. Water-soluble vitamin concentrations measured in tears and blood serum of single subjects were comparable, while higher concentrations were measured in infants compared to their parents. Fat-soluble vitamin E concentrations were lower in tears than blood serum with no significant difference between infants and parents. Serum vitamin A concentrations were higher in parents than infants. Population trends were compiled and quantified using a cross correlation factor. Strong positive correlations were found between tear and blood serum concentrations of vitamin E from infants and parents and vitamin B3 concentrations from parents, while slight positive correlations were detected for infants B3 and parents B1 and B2 concentrations. Correlations between infants and parents were found for the concentrations of B1, B2, B3, and E in tears, and the concentrations of B2, A, and E in blood serum. Stronger vitamin concentration correlations were found between infants and parents for the breast-fed infants, while no significant difference was observed between breast-fed and bottle-fed infants. This work is the first to demonstrate simultaneous vitamin A, B, and E detection and to quantify correlations between vitamin concentrations in tears and blood serum. Our results suggest that tears are a viable biofluid to monitor nutritional health because they sufficiently mirror blood serum data and may enhance the speed of deficiency diagnoses.

Influence of gate metal engineering on small-signal and noise behaviour of silicon nanowire MOSFET for low-noise amplifiers

In this paper, we have investigated the small-signal behaviour and RF noise performance of gate electrode workfunction engineered (GEWE) silicon nanowire (SiNW) MOSFET, and the results so obtained are simultaneously compared with SiNW and conventional MOSFET at THz frequency range. This work examines reflection and transmission coefficients, noise conductance, minimum noise figure and cross-correlation factor. Results reveal significant reduction in input/output reflection coefficient and an increase in forward/reverse transmission coefficient owing to improved transconductance in GEWE-SiNW in comparison with conventional counterparts. It is also observed that minimum noise figure and noise conductance of GEWE-SiNW is reduced by 17.4 and 31.2 %, respectively, in comparison with SiNW, thus fortifying its potential application for low-noise amplifiers (LNAs) at radio frequencies. Moreover, the efficacy of gate metal workfunction engineering is also studied and the results validate that tuning of workfunction difference results further improvement in device small-signal behaviour and noise performance.