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Although deep learning has received extensive attention and achieved excellent performance in various scenarios, it suffers from adversarial examples to some extent. In particular, physical attack poses a greater threat than digital attack. However, existing research has paid less attention to the physical attack of object detection in UAV remote sensing images (RSIs). In this work, we carefully analyze the universal adversarial patch attack for multi-scale objects in the field of remote sensing. There are two challenges faced by an adversarial attack in RSIs. On one hand, the number of objects in remote sensing images is more than that of natural images. Therefore, it is difficult for an adversarial patch to show an adversarial effect on all objects when attacking a detector of RSIs. On the other hand, the wide height range of the photography platform causes the size of objects to vary a great deal, which presents challenges for the generation of universal adversarial perturbation for multi-scale objects. To this end, we propose an adversarial attack method of object detection for remote sensing data. One of the key ideas of the proposed method is the novel optimization of the adversarial patch. We aim to attack as many objects as possible by formulating a joint optimization problem. Furthermore, we raise the scale factor to generate a universal adversarial patch that adapts to multi-scale objects, which ensures that the adversarial patch is valid for multi-scale objects in the real world. Extensive experiments demonstrate the superiority of our method against state-of-the-art methods on YOLO-v3 and YOLO-v5. In addition, we also validate the effectiveness of our method in real-world applications.

In order to investigate the pullout resistance of the Horizontal-Vertical reinforcement, a “denti-geogrid” was assembled by bonding a “denti-strip” with the geogrid and the pullout tests were carried out. Subsequently, the analytical approaches were investigated to calculate the pullout resistance on the basis of the surface sliding model, Perterson and Anderson’s model, Jewell’s model, Chai’s model, and the proposed stress summation model. Moreover, a new index named “scale factor” was suggested to reflect the proportion of bearing resistance provided by transversal members. The research showed that: 1) under the same test conditions, the pullout resistance of denti-geogrid was much higher than that of a common geogrid. All common geogrids showed linear strain softening in the later stage of pullout tests. Given the same normal stresses, due to the expansion of effective areas suffering lateral earth pressure, more denti-strips meant more significant resistance; 2) Among five theoretical approaches, the solutions of the proposed stress summation model made the best agreement with lab test results, with an average relative error of 2.82%. On the other hand, the stress summation model also showed a simplicity in calculation; and 3) Due to higher gradient of the fitting curve of scale factors under lower load, the bearing resistance would be more and more dominant, which means that the lateral resistance of denti-strips could play a decisive role in cases of low stress level.

The main motivation of our study is to explore Rényi holographic dark energy, Sharma–Mittal holographic dark energy, Rényi new agegraphic dark energy, and Sharma–Mittal new agegraphic dark energy in the context of generalized Rastall gravity with the two-fluid system, dark energy, and dark matter. In this regard, we have considered the scale factors into two distinct categories, one of which corresponds to the future singularity, whereas the other represents initial singularity. By employing future event horizon as infrared (IR)-cutoff, different cosmological quantities like deceleration parameter, equation of state (EoS) parameter are evaluated, and their ramifications have been described graphically. Analyzing the squared speed of sound, we have seen classically stable and unstable behavior for each of the considered models. Finally, we study ω D – ω D ′ plane and find the thawing/freezing regions. [ABSTRACT FROM AUTHOR]

In this work, we have studied various cosmological parameters in the presence of viscous new Tsallis holographic dark energies for interacting scenarios in the framework of Chern–Simons modified gravity. The bulk viscosity has been considered with the bulk viscous pressure chosen in the form Π = − 3 H ξ 0 + ξ 1 H + ξ 2 (Ḣ + H 2) . Hubble parameter H has been obtained from the above choice of scale factor and in this viscous scenario, the effective pressure has been obtained in Chern–Simons framework whose field equation, cosmological consequences have been investigated. It has been observed that for the interaction scenario in the presence of bulk viscosity the EoS parameter is staying above − 1 , which indicates quintessence behavior. Hence, for the universe filled with a bulk viscous fluid can have the possibility of avoidance of big-rip, although the earlier transition from quintessence to phantom is not avoidable. [ABSTRACT FROM AUTHOR]

Copyright of Electronics & Control Systems is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Multi-fidelity (MF) surrogate models are increasingly utilized in engineering design due to their capability to achieve desired accuracy at a reduced cost. However, many existing MF modeling methods presuppose a hierarchical relationship between different fidelity models, which may not be applicable when multiple low-fidelity (LF) models exhibit varying fidelity levels across the design space due to different simplification methods. To tackle this issue, a multi-fidelity surrogate modeling method based on local correlation-weighted fusion (LCWF-MFS) is developed. In this proposed approach, each LF model is assigned variable weights depending on its local correlation with the high-fidelity (HF) model, thereby maximizing the utilization of information from these LF data sources. Furthermore, an innovative parameter tuning technique rooted in penalty error optimization is introduced, aiming to establish a more reliable scale factor between HF and LF models. Several numerical examples as well as a maximum deformation prediction problem pertaining to the micro aerial vehicle (MAV) fuselage during landing or impact are used to illustrate the effectiveness of the proposed method. Results demonstrate the superior accuracy and robustness of the proposed LCWF-MFS method in comparison to alternative methods. [ABSTRACT FROM AUTHOR]

A surveyor deals with cartographic projections, equations, properties, and deformation characteristics, within the scope of Geodetic Cartography. Application of the cartographic projections assumes an overview of a user of surveying data and cadastral maps, through numerical determination of deformation distribution for the whole state territory. During introduction of new geodetic datums and cartographic projections, it is necessary to respect experiences of other European countries, with maximal treatment of national interests and capabilities. The paper presents chronology of establishment of the state coordinate system of the Republic of Serbia (Bessel ellipsoid and GaussKrűger projection) and the state reference system for horizontal and vertical positioning over GRS80 ellipsoid and UTM projection. Particularly, the paper presents values of lengths deformation for the whole area of the Republic of Serbia in the existing projections. Also, the optimal scale factor is calculated.

The research is devoted to steel structure diagnostics by the acoustic emission (AE) method. The existing regulatory documents for AE diagnostics of metals and alloys do not take into account some critical factors, among which one is the scale factor should be highlighted. As a result, this can lead to an unreliable assessment of the danger degree of defects in structures when using standard AE diagnostic criteria. This paper presents a quantitative assessment of the scale factor impact on the AE data during the static tension test of steel specimens to failure. Experimental studies were carried out on flat specimens of various thicknesses with a side notch made of high-quality alloyed steel 30 KhGSA. It was established that AE data changed (rise in the AE signals amplitudes and AE activity) within the increase of specimen thickness. Growth in the recorded AE signals cumulative energy was registered with a greater specimen thickness. Partial correlation dependences of the mean count frequency and cumulative energy of AE signals on the specimen thickness were obtained. It was shown that such an effect occurred due to both a general increase in the deformed metal volume and greater strain intensity during the tension of thick specimens. The obtained dependences may contribute to the development of AE diagnostics of metallic materials which is invariant to the scale factor impact.

We present a 27-day-long common view measurement of an absolute cold atom gravimeter (CAG) and a relative iGrav superconducting gravimeter, which we use to calibrate the iGrav scale factor. This allowed us to push the CAG long-term stability down to the level of 0.5 nm s - 2 . We investigate the impact of the duration of the measurement on the uncertainty in the determination of the correlation factor and show that it is limited to about 3‰ by the coloured noise of our cold atom gravimeter. A 3-day-long measurement session with an additional FG5X absolute gravimeter allows us to directly compare the calibration results obtained with two different absolute meters. Based on our analysis, we expect that with an improvement of its long-term stability, the CAG will allow to calibrate the iGrav scale factor to better than the per mille level (1 σ level of confidence) after only 1 day of concurrent measurements for maximum tidal amplitudes. [ABSTRACT FROM AUTHOR]

Facing the dual pressure of economic development and ecological environmental protection, it is undoubtedly a good strategy to strengthen energy conservation and emission reduction while further increasing carbon sink. The contribution of forest carbon sink is well-known, but the carbon sink function of mariculture is rarely known. Based on the statistics of China's fishery department and the quality assessment method, this paper constructed a preliminary accounting system for the removable carbon sink of mariculture shellfish and algae, and estimated its capacity in China from 2005 to 2017. On this basis, the logarithmic mean Divisia index was used to analyze the effects of structure and scale factors on the removable carbon sink of mariculture shellfish and algae. The results showed that the annual average removable carbon sink of shellfish and algae in China's mariculture reached 92.7 ten thousand tons, and the overall trend was upward. The total removable carbon sink of shellfish was greater than that of algae. Among them, Grassastrea gigas was the main source of removable carbon sink in China's mariculture, followed by Ruditapes philippinarum. The economic value of annual removable carbon sink of mariculture shellfish and algae in China was equivalent to 139–556 million dollars. Furthermore, the scale factor plays a leading role in the removable carbon sink capacity of mariculture in China, while the structure factor plays a minor role. [ABSTRACT FROM AUTHOR]

Two rolling bearing life models based on the concept of dynamic stress capacity are considered. They are the modified Lundberg–Palmgren model and the Gupta–Zaretsky model. Consistency of these models with patterns of dependences of the bearing life from temperature and scale factor is analyzed. Stability of the model parameters to the conditions of the experiments used to determine them is analyzed as well. A significant dependence of the material's contact durability on its elastic properties is a negative characteristic of the Gupta–Zaretsky model, since in studies of the temperature dependence of fatigue properties, changes in elastic properties are not explicitly taken into account. The scale factor adopted in the modified Lundberg–Palmgren model is in good agreement with the experimental data for ball bearings with balls up to 25.4 mm, and in the Gupta–Zaretsky model, for bearings with balls larger than 25.4 mm. The results of the stability analysis of the experimental parameters of the considered models to the shear stress life exponent in the life equation without a scale factor, considered in the example of a 32 220 bearing, indicate the preference of the modified Lundberg–Palmgren model. The modified Lundberg–Palmgren model has good validity characteristics. It requires further improvements aimed at taking into account the residual and operating stresses, as well as adequately taking into account the scale factor in calculating ball bearings with a ball diameter over 25.4 mm. [ABSTRACT FROM AUTHOR]

This paper presents an in-run scale factor error compensation for the micro-electro-mechanical system (MEMS) gyroscope without system calibration and data fitting. The causes of three scale factor errors (instability, nonlinearity, and asymmetry) are analyzed. Next, the instability and nonlinearity by open-loop detection (Mode I), and closed-loop detection (Mode II) are discussed according to the specific comb capacitance and the front-end detection circuit. The closed-loop detection transfer function is studied, and a series of equivalent conversions are performed to obtain a method (Mode III) for improving the temperature stability of scale factor. The results of the experiment indicated that the nonlinearity and asymmetry of the Mode II and Mode III are increased by 1.8 times and 3.5 times than that of Mode I. Furthermore, the instability of Mode II and Mode III is reduced by 10 times and 19 times over -20°C to 40°C. Besides, the mode III does not affect the static and dynamic performance of gyroscope according to the test results of bias and bandwidth. [ABSTRACT FROM AUTHOR]

In this contribution, we propose a novel neuromuscular disease detection framework employing weighted visibility graph (WVG) aided analysis of electromyography signals. WVG converts a time series into an undirected graph, while preserving the signal properties. However, conventional WVG is sensitive to noise and has high computational complexity which is problematic for lengthy and noisy time series analysis. To address this issue in this article, we investigate the performance of WVG by varying two important parameters, namely penetrable distance and scale factor, both of which have shown promising results by eliminating the problem of signal adulteration and decreasing the computational complexity, respectively. We also aim to unfold the combined effect of these two aforesaid parameters on the WVG performance to discriminate between myopathy, amyotrophic lateral sclerosis (ALS) and healthy EMG signals. Using graph theory based features we demonstrated that the discriminating capability between the three classes increased significantly with the increase in both penetrable distance and scale factor values. Three binary (healthy vs. myopathy, myopathy vs. ALS and healthy vs. ALS) and one multiclass problems (healthy vs. myopathy vs. ALS) have been addressed in this study and for each problem, we obtained optimum parameter values determined on the basis of F-value computed using one way analysis of variance (ANOVA) test. Using optimal parameter values, we obtained mean accuracy of 98.57%, 98.09% and 99.45%, respectively for three binary and 99.05% for the multi-class classification problem. Additionally, the computational time was reduced by 96% with optimally selected WVG parameters compared to traditional WVG. [ABSTRACT FROM AUTHOR]

Ground-based time-variable gravimetry with high accuracy is an important approach in monitoring geodynamic processes. The uncertainty of instruments including scale factor (SF) and drift rate are the primary factors affect the quality of observation data. Differing from the conventional gravity adjustment procedure, this study adopted the modified Bayesian gravity adjustment (MBGA) method, which accounts for the nonlinear drift rate, and where the SF is considered as one of the hyperparameters estimated using Akaike’s Bayesian information criterion. Based on the terrestrial time-variable gravity datasets (2018–2020) from the southeastern Tibetan Plateau, errors caused by nonlinear drift rate and SF were processed quantitatively through analysis of the gravity difference (GD) residuals and the mutual difference of the GD. Additionally, cross validation from absolute gravity (AG) values was also applied. Results suggest that: (1) the drift rate of relavive instruments show nonlinear characteristics, and owing to their different spring features, the drift rate of CG-5 is much larger than that of LCR-G gravimeters; (2) the average bias between the original and optimized SF of the CG-5 gravimeters is approximately 169 ppm, while that of the LCR-G is no more than 63 ppm; (3) comparison of the differences in gravity values (GV) suggests that the uncertainty caused by the nonlinear drift rate is smaller than that attributable to SF. Overall, the novel approach adopted in this study was found effective in removing errors, and shown to be adaptive and robust for large-scale hybrid surface gravity campaign which providing high accuracy gravity data for the geoscience research.

Einstein equations give minimum and maximum limits of cosmic scale factor by considering pressure. In our suggested model the contraction before expansion of cosmos is like the birth of a star. As in nuclear fusion stage, the temperature and pressure of the star depends on its mass, in the order of magnitude of universe mass fusion after gravitational contraction brings about explosion. This does not require to accept the big bang singularity. Explosions have thrown external layers and formed parts of the expanding cosmos in several stages. We dealt with the problem of horizon by considering the idea of step- by step explosions. In observable part of the universe high percentage of dark energy and dark matter confirms that these are the remains of other parts of the cosmos. Neutrinos being highly energetic and without any interaction are the most suitable candidates for dark energy and massive black holes being found at the central part of galaxies and in stellar clusters are the most suitable candidates for dark matter. [ABSTRACT FROM AUTHOR]

We considered cosmological model within the framework of the generalized F(R,T) gravity in flat FLRW metric. Earlier, an exponential solution was shown for the generalized case, which describes the inflationary stage of the evolution of the Universe. In this paper, it is shown that for the particular case of the Starobinsky model, the generalized model has, among other things, a power-law solution that describes the dust-like stage and the stage of radiation dominance. It should be noted that this solution was obtained by the analytical method as a solution to the Euler-Lagrange equation for this model, taking into account the functions u, v -- describing the relationship between the curvature scalar and the torsion scalar, and depending not only on the first, but also on the second time derivative of the scale factor. This solution is of interest, since it shows not only that this model has a solution, but also that this solution can describe the modern observable Universe for more complex forms u, v than described earlier. This solution allows other related cosmological parameters to be obtained accordingly. The paper presents the parameter ω for the equation of state, which describes the stage of the evolution of the Universe. [ABSTRACT FROM AUTHOR]

The article describes the proposition for developing the similar dynamically downscaled model of a medium range passenger aircraft and its application for researches in area of aerodynamics and flight dynamics. Computer simulations of aerodynamic flows are commonly used in advanced aircraft designing. Numerous data on the characteristics of an airplane can be obtained from tunnel tests of geometrically scaled models. To get complete characteristics from both stable and unstable flight conditions, dynamically scaled models are constructed and applied in static or dynamic tests. The dynamically similar scaled model is, in fact, a reduced model of the real airplane which has specific qualities similar to qualities of a real aircraft and these relations are strictly defined with specific similarity numbers (factors). The article presents methodology for determining scale factors in relation to geometric, aerodynamic, and structural properties (mass, stiffness) of the aircraft. The methodology will be presented on the example of Tu-154 aircraft that crashed in April 2010 with the President of the Republic of Poland and many military and government officials on board. Dynamically similar downscaled model was designed in Faculty of Mechatronics and Aerospace of the Military University of Technology (FMA MUT, Warsaw, Poland) and is still being developed in the framework of ongoing research project. This paper presents only general assumptions taken for the process and the current stage of successively developed model. [ABSTRACT FROM AUTHOR]

In geoinformatics, there is a considerable demand for dealing with different layers given in different geodetic datums and map projections within the same project. In the majority of the software, the computations are completed on-the-fly using the open-source program PROJ. In recent years, the definition of national reference systems for a wide range of countries has already been developed and published; therefore, users have the opportunity to set them in GIS applications. Another significant challenge is to set local reference systems in individual mapping products, developed and maintained for a limited area, typically for industrial zones. These local reference systems may have special requirements as regards avoiding length distortions caused by map projections. This paper presents a solution for defining such kinds of local coordinate systems and implementing it in any mapping system using the PROJ library. The applied method can also be imported into different GNSS units at the same time. [ABSTRACT FROM AUTHOR]

The latest gravity survey of the gravity base network in Qinghai Province, China, was conducted with six Scintrex CG gravimeters and this gravity survey was tied to existed gravity reference stations. In this gravity network with long segments and very rugged topography, the calibration of scale factors is a time-consuming progress and its accuracy may be affected by many uncertainties, and the change in drift rates of the relative gravimeters are complex over time in this long-term survey. The reasonable calculation of scale factors and drift rates plays an important role in improving the gravity estimation accuracy. In this paper, based on the least squares, robust least squares, and Bayesian methods, various parameter calculation methods were employed to process this gravity network. The performance and practicality of each method were analyzed in terms of internal and external accuracy. The results indicated that the scale factors calibrated in the baseline field had poor applicability due to insufficient gravity difference, in this case, the scale factors estimated by the adjustment models were more accurate, which weakened the correlation between gravity differences and mutual differences. The drift rates estimated by the Bayesian method were relatively smooth over time, while drift rates estimated using symmetric observations were more practical for the gravimeter with highly variable drift. The weight constraints of observations can be optimized by the robust least squares method, the gravity values obtained by it were more consistent with absolute gravity values than those obtained by the least squares method, and the robust least squares method was recommended to process gravity data in plateau areas.

The on-site measurement of transient voltages is of great significance in analyzing the fault cause of power systems and optimizing the insulation coordination of power equipment. Conventional voltage transformers normally have a narrow bandwidth and are unable to accurately measure various transient voltages in power systems. In this paper, a wideband parallel resistive–capacitive voltage divider is developed, which can be used for online monitoring of transient voltages in a 220 kV power grid. The structures of the high-voltage and low-voltage arms were designed. The internal electric field distribution of the high-voltage arm was analyzed. The influence factors and improvement techniques of the upper frequency limit were studied. The parameters of the elements of the divider were determined. The voltage withstand performances and scale factors under lightning impulses and AC and DC voltages, the temperature stabilities of scale factors and the step response and bandwidth of the developed voltage divider were tested. The results show that the deviations of the scale factors under various voltage waveforms and different temperatures ranging from −20 to 40 °C are within 3%. The withstand voltage meets the relevant requirements specified in IEC60071-1-2011. The step response 10~90% rise time is approximately 29 ns, and the 3 dB bandwidth covers the range of DC to 10 MHz.

The Maxwell field equations (MFEs), as ecumenical model of electromagnetic phenomena, are scale-invariant under Lorentz Transformation (LT). To apply LT, some considerations are required which are not all practically available or technologically attainable; hence, the scale-invariant feature may not be reached effectively. Paving the way to focus on this issue, the effect of substrate thickness scaling as an uncontrollable parameter, is explored on eight identical patch antennas with different substrate thicknesses. In this way, the resonant frequency and complex value of return loss are measured. The effect of manufacturing tolerances of dielectric thickness on resonant frequency deviation and return loss magnitude are carefully studied, too. Also the unwanted distortive effect of selected electrical connection, say as a female SMA connector, is investigated at higher frequencies. The obtained results are comparatively analyzed which confirm the practical bottlenecks in meeting the antenna parameters scaling.

The construction of large scale harbor structures at Maengbang beach, which is located on the eastern coast of Korea, is of great concern because it may cause disastrous beach erosion in the vicinity. Therefore, a hydraulic model experiment was conducted to examine the morphological changes after such construction. The water depth was scaled using the method of Van Rijn (2010), which is a well-known scale law, but the results appeared to be overestimated. The present study developed a new scale law that applies an equilibrium beach profile formula to scale the model evolution to the prototype scale. When compared with survey data observed at Maengbang beach, the proposed method showed better agreement than the method of Van Rijn (2010).

Dean's equilibrium beach profile formula was used to investigate the correlation between the static shoreline position and the incident wave energy. The effect of the longshore sediment transport was neglected, and the results showed the reasonable agreement compared with the field observations of Yates et al.(2009), which were conducted for almost 5 years on southern California beaches, USA. The shoreline response varies with the scale factor of Dean's equilibrium beach profile. This implies that the shoreline response could be simply estimated using the sampled grain size without laborious long-term field work. Therefore, the present study results are expected to be practically used for the layout design of submerged or exposed detached breakwaters although the further work is required for performance verification. In addition, after laborous mathematical reviews, the linear relation between incident energy and shoreline response, which was obtained from Yates’s field study, yielded a clear mathematical equation showing how the beach slope is related to the grain size.

This paper aims to present a case study where a scaling factor was used to design a series of toggle style injection molding machines for the plastics industry. The series ranged from 100 to 1000 US tons of clamping capacity. Every machine in the series was scaled down or up from a prototype that had undergone extensive fatigue testing before the decision to design an entire range of machines. In this study, a comparison is made between a prototype machine with 250 US tons of clamping force and a scaled-up machine with 1000 US tons of clamping force. Finding dimensionless scaling factors when designing a series of machines requires machines that have dynamic similitude. To qualify, there must be geometric similarity, dynamic similarity, and kinematic similarity. In the case study presented below, the geometric (static) similarity will be forced to exist, and the dynamic similarity and kinematic similarity will be shown to result from this. A dimensionless scale factor (square root rule) was derived by scaling dimensions based on the square root of the clamping force ratio. As each size machine was built, measurements showed that stresses in all critical points were the same as at corresponding points on the prototype. Also, deflections in each direction followed the scale factor. Static relationships in the toggle systems followed the scale factor, and critical positions of the linkage system all occurred at the same link angles. By using this scale factor, the company saves thousands of man-hours in design effort, completes the design for the entire line and gets to the market in less than half the weeks normally required for such an effort. Additional benefits are: (i) very high confidence level in resistance to failure by metal fatigue, (ii) very accurate advanced information on tooling requirements for manufacturing, and (iii) very accurate advanced marketing and sales information on performance specifications, floor space requirements, and energy requirements for the entire range. [ABSTRACT FROM AUTHOR]

Summary: There is a growing tendency toward the performance‐based design of tall buildings, where any assessment using response history analysis requires a set of ground motion (GM) records. This paper considering a tall building as a case study investigates how judgment on the seismic safety of the structure is affected by the use of recorded or spectrally matched GMs. Three model structures are developed: (a) using conventional design procedure of Chapter 12 of ASCE 7‐16; (b) adopting linear analysis requirements of Chapter 16 of ASCE 7‐16; (c) designing for service‐level design earthquake of Los Angles Tall Building Structural Design Council (LATBSDC) procedure. It is shown that all of the structures give acceptable performance when subjected to simulated GMs, although this is not the case for amplitude‐scaled GMs based on ASCE 7‐16 and LATBSDC. Finally, to have an objective assessment of performance, independent of GM types, incremental dynamic analysis is employed to derive fragility and mean annual rate of exceeding (MAR). Results show that for anticipated drifts at Maximum Considered Earthquake (MCE) level, the structures provide acceptable MAR at the fundamental period. However, for the higher modes including the second and third periods, MAR values become acceptable only at drifts as large as 0.085. [ABSTRACT FROM AUTHOR]

Most research about using piezoelectric stacks to suppress vibration of mechanical structures didn't involve the similarity problem for the piezoelectric stacks. The goal of this paper is to investigate the dynamic similarity between a prototype piezo stack and a scaled up or down piezo stack, whilst discussing the feasibility of predicting the vibration of prototype structure which use the piezoelectric stacks for vibration control. To illustrate this problem concisely, a single-DOF system consists of a proof mass and a piezo stack shunted with a series RL circuit is considered. Firstly, the governing equation of such piezo-electromechanical system in frequency domain is derived. Next the dynamic similarity of prototype and model stack is analyzed by similitude theory. After that the scaling laws are derived. Finally, a numerical simulation and relative error analysis are given to demonstrate the scaling laws. [ABSTRACT FROM AUTHOR]

Here, we have investigated the interaction of Bianchi type-I anisotropic cloud string cosmological model universe with electromagnetic field in the context of general relativity. In this paper, the energy-momentum tensor is assumed to be the sum of the rest energy density and string tension density with an electromagnetic field. To obtain exact solution of Einstein's field equations, we take the average scale factor as an integrating function of time. Also, the dynamics and significance of various physical parameters of model are discussed. [ABSTRACT FROM AUTHOR]

The fiber optic gyroscope (FOG) has a broad application prospect in the field of dynamic angle measurement. The scale factor, which is an important indicator of the FOG, directly determines the angle measurement precision. In this paper, the principles of angular velocity method and angular increment method, which have been commonly used in obtaining the scale factor, are introduced, and the error sources that affect the scale factor in both methods are analyzed in detail. The theoretical analysis results show that the main error sources of the scale factor are the relative error of the angular velocity benchmark generated by the rotary table and the value of the selected angular velocity benchmark in the angular velocity method. Other error sources need to be considered only at small angular velocity benchmark. Instead, the main error of the scale factor comes from the position precision of the rotary table in the angular increment method. Finally, the experiments on the scale factors of the FOG in both methods are carried out, and they are applied to the angle measurement experiments, respectively. The angle measurement results show that the deviation of the angle can be limited in 0.002° when the scale factor obtained by the angular increment method is adopted in angle measurement. It is an order of magnitude smaller than the angular velocity method. We can get the conclusion that the scale factor obtained by the angular increment method is more suitable for angle measurement than the angular velocity method. [ABSTRACT FROM AUTHOR]

Classical time series modeling is often used by practitioners for prediction purposes. Many researchers were already developed a way to predict time series using new methods, one of which is a method of fuzzy method. Fuzzy models were constructed based on the data, commonly not yet have an optimal value of Mean Absolute Error (MAE), which mean MAE on the model can still be reduced. This paper describes how the reduction of MAE on fuzzy model using of giving the amplitude scale factor. Impairment of MAE mathematically demonstrated in the evidence. [ABSTRACT FROM AUTHOR]

In this paper, we obtain the effect of backreaction on the scale factor of the Friedmann–Lemaître–Robertson–Walker (FLRW) and de Sitter spaces. We consider a non-minimally coupled massive scalar field to the curvature scalar. For our purpose, we use the results of vacuum expectation values of energy–momentum tensor, which have been obtained previously. By substituting the quantum energy density into the Friedmann equation, we obtain the linear order perturbation of the scale factor. So, the effect of backreaction leads to the new scale factor. [ABSTRACT FROM AUTHOR]

Copyright of Inzynieria Mineralna is the property of Polskie Towarzystwo Przerobki Kopalin and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An angle sensor can be used to evaluate profiles without any shape references. We regard it suitable for evaluating a large profile and consider a gyro as an angle sensor for evaluating a profile larger than 100 m with an accuracy of better than 1 mm. A gyro can evaluate profiles without restrictions in span or direction; however, angles detected by a gyro typically fluctuate unacceptably for our purpose. We demonstrate that periodical reversal measurement by flipping a gyro is effective in reducing the effect of the fluctuation. Then, we rotate the gyro for continuously realizing the reversal, where the angles of the gyro's rotating axis against the earth's rotating axis can be derived without being affected by the fluctuation, and can be used as an angle sensor. Here, we consider a new method using gyro signals rotating around four orthogonally aligned axes. This can improve the accuracy of the derived angles by eliminating the effects of the gyro's scale factor as well as the fluctuations. [ABSTRACT FROM AUTHOR]

Background and Objectives: Using field calibration methods without precision laboratory equipment, systematic faults of inertial sensors can be reduced and measurement accuracy can be increased. Methods: In this paper, a simple and fast method called improved least squares is used to find calibration coefficients of an accelerometer including bias, scale factor and non-orthogonality. In this method, this principal is used that the magnitude of acceleration measured by accelerometer in static condition is equal to the magnitude of gravity vector and a cost function is then defined. Also, in gyroscope field calibration, sensor is rotated manually around all three axes separately and then it is put in the static mode. Changes in the angle obtained from gyroscope at each movement are compared with the ones obtained from the calibrated accelerometer. Calibration coefficients including bias and scale factor are obtained using least squares method. Results: Simulation results in MATLAB show that the measurement accuracy of accelerometer after calibration has improved by about 60% and the accuracy of the gyroscope has increased by about 40%. Also, comparison with the other methods proves that the proposed method performs well in the accuracy, speed, time required, and the effect of noise changes. Conclusion: This paper by finding a fast, simple, and low-cost field calibration method to calibrate MEMS accelerometer and gyroscope without using accurate laboratory equipment can help a wide range of industries that use advanced and expensive sensors or use expensive laboratory equipment to calibrate their sensors, to decrease their costs.======================================================================================================Copyrights©2018 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.======================================================================================================

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The research presented in the current article explores the potential for inflation realization in a cosmic environment with bulk viscosity using a tachyon scalar field. The present study rewrites the entropy conservation equation to take bulk viscosity into account. The work's initial phase examined the behaviour of the equation of state parameter for logamediate, intermediate, and emergent scenarios within a framework of viscous cosmology having the viscosity coefficient in linear and polynomial forms. The study then focused on the relative dominance of the scalar field and potential for the tachyon scalar field in the presence of bulk viscosity for the different choices of scale factor and came to the conclusion that the prerequisite for the realization of inflation is met in the framework of bulk viscosity. • The study investigates the likelihood of inflation. • A cosmological background with bulk viscosity is taken into account. • The EoS parameter is investigated for various scale factor options. • Entropy conservation is rephrased with tachyon. • The inflation realization for viscous tachyon scalar field is examined. [ABSTRACT FROM AUTHOR]

Magnetic field gradients interfere with the coherence of the atomic ensemble and degrade the performance of the spin-exchange relaxation-free (SERF) atomic magnetometer. In this paper, the influence of magnetic field gradients is incorporated into the response model of single-beam atomic magnetometer, and the theoretical models of transverse relaxation rate, spin polarization and scale factor are established. Based on this model, we find that magnetic field gradients in different directions can cause varying degrees of degradation in the performance parameters of the magnetometer. The magnetic linewidths under different light power and magnetic field gradients are measured using the designed dedicated magnetic field gradients coils, and the spin polarization and magnetic field gradients relaxation rate are obtained through fitting. An unevenness and deviation of the curve are also observed in the experiments, indicating the presence of the magnetic field gradient of approximately 2 nT/cm in the magnetic shields. Furthermore, in a magnetic field gradient environment of 20 nT/cm, the mean of the long-term sensitivity decreased by 3.5 times and the standard deviation increased by 11 times. It shows that the magnetic field gradients will not only affect the signal-to-noise ratio, but also make the magnetometer more vulnerable to external interference when working. The sensitivity and stability of magnetometer will be greatly reduced. The research in this article provides a theoretical and experimental basis for eliminating the influence of magnetic field gradients and improving the accuracy of magnetic field measurements. • The models of the influence of MFGs on the parameters of the OPMs are established. • The experimental results are in good agreement with the proposed equations. • The asymmetry of the curve indicates the presence of residual MFGs. • The MFGs make the OPM more vulnerable to interference from the external environment. [ABSTRACT FROM AUTHOR]

Audio compression history detection is an important part of audio forensics,which is important to detect whether audio has been tampered or forged.An algorithm of AAC audio compression history detection was presented by using the transition probability differences of scale factors as the discriminative feature.Experimental results demonstrate that the proposed method can distinguish the single,double and triple compressed AAC audios effectively,and from the low-bite-rate to high-bit-rate,the average classification accuracy achieves 99.75%,the same-bit-rate detection accuracy achieves 97.28%.In addition,the results of comparison experiments show that the proposed algorithm outperforms the state-of-the-art algorithm.

In order to describe the nature of image space of the wavelet transform and a limited spectrum and decay faster wavelet，this paper uses Shannon scaling function to construct a wavelet function，take advantage of wavelet analysis theory to give the nature of image space of the wavelet transform and the wavelet transform. Fixing the scale factor，we get this wavelet transform as the space of two specific expressions of reproducing kernel function，take advantage of the reproducing kernel space theory to describe the wavelet transform of image space and provide the theoretical basis for numerical calculation of the wavelet.