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At present, dampers are widely used in the field of energy dissipation in engineering structures. However, when the displacement and velocity output of dampers are not significant under small and medium-sized earthquakes, it is difficult for a damper to fully exert its energy dissipation capacity. The use of toggle-brace mechanisms in the structure is an effective method to solve the above problems, and the effect of toggle-brace-viscous dampers (referred to as TBVDs) in the structure can be reflected by a magnification factor (referred to as Mf). Therefore, it is particularly important to study the calculation method for the Mf of TBVD. Domestic and foreign scholars have achieved certain results in the study of the calculation method for the Mf of TBVD, and the corresponding calculation formula for the Mf has been proposed. Given the existing research results, this article conducts the following work: analyzing the shortcomings of existing methods for calculating the Mf of TBVD, proposing an improved method for calculating the Mf of viscous dampers, comparing the accuracy of existing and improved algorithms, and analyzing the calculation results to provide practical suggestions for engineering applications. [ABSTRACT FROM AUTHOR]

The composite materials Si/AlC, crystal quartz, and ceramic glass are becoming an important part of the present society in many engineering and non-engineering fields. Conventional methods available for machining these materials have many flaws due to which their application on large scale is restricted. A non-conventional process known as ultrasonic machining (USM), can be implemented for machining of these materials effectively. Anyhow machining efficiency of USM greatly depends upon its horn design and therefore in the present study a horn based on a catenoidal profile with aluminum and titanium material for USM was designed and developed by using solid works and ANSYS. Modal and harmonic analysis was done on the horn for computation of various parameters of interest such as resonant frequency, amplitude vibration and equivalent stresses. After the computation of the results, they were analyzed and compared with those available in the literature in terms of stresses and magnification factor for their validation comparison with literature, it was found that an aluminum catenoidal horn shows higher magnification with the least stress magnitude as compared to horns avail-able in the literature and hence can be used in USM as a replacement for existing horns.

In order to analyze the impact of seismic waves on the venue earthquake, based on the display finite element method, the viscoelastic artificial boundary is used to analyze the variation of the ground motion amplification coefficient and the Fourier spectrum of the raised terrain under different incident angles with SV wave oblique incidence on different slopes. This verification model analysis solution and numerical solution are better. The numerical simulation results show that as the degree of the slope increases, the seismic amplification coefficient increases, and its slope amplification coefficient changes significantly. The X direction coefficient is greater than Y's magnification coefficient. The Fourier curve with a frequency of 0.2~1 Hz increases with the slope of the raised terrain; when the El Centro is incorporated at 30°, the Fourier spectrum amplitude decreases as the incident angle increases in the low-frequency band. The amplitude of the Fourier spectrum at the high-frequency band monitoring point changes with the incident angle. In the high-frequency band from 1 to 10 Hz, the rate of amplitude change is the largest. When the incident angle is at 0°, the amplification coefficient in the Y direction is basically symmetric. [ABSTRACT FROM AUTHOR]

At present, dampers are widely used in the field of energy dissipation in engineering structures. However, when the displacement and velocity output of dampers are not significant under small and medium-sized earthquakes, it is difficult for a damper to fully exert its energy dissipation capacity. The use of toggle-brace mechanisms in the structure is an effective method to solve the above problems, and the effect of toggle-brace-viscous dampers (referred to as TBVDs) in the structure can be reflected by a magnification factor (referred to as Mf). Therefore, it is particularly important to study the calculation method for the Mf of TBVD. Domestic and foreign scholars have achieved certain results in the study of the calculation method for the Mf of TBVD, and the corresponding calculation formula for the Mf has been proposed. Given the existing research results, this article conducts the following work: analyzing the shortcomings of existing methods for calculating the Mf of TBVD, proposing an improved method for calculating the Mf of viscous dampers, comparing the accuracy of existing and improved algorithms, and analyzing the calculation results to provide practical suggestions for engineering applications.

For decades, optical fiber interferometers have been extensively studied and applied for their inherent advantages. With the rapid development of science and technology, fiber sensors with higher detection sensitivity are needed on many occasions. As an effective way to improve measurement sensitivity, Vernier effect fiber sensors have drawn great attention during the last decade. Similar to the Vernier caliper, the optical Vernier effect uses one interferometer as a fixed part of the Vernier scale and the other as a sliding part of the Vernier scale. This paper first illustrates the principle of the optical Vernier effect, then different configurations used to produce the Vernier effect are classified and discussed. Finally, the outlook for Vernier effect fiber sensors is presented. [ABSTRACT FROM AUTHOR]

This paper proposes a fiber-optic sensor based on the virtual harmonic Vernier effect (VHVE). The VHVE is obtained by processing the spectrum of the traditional Vernier effect (TVE). We demonstrate that the periodic outer envelope and the high-frequency fringes in the TVE can be used as the spectra of the virtual interferometer and sensing interferometer of the VHVE, respectively. Thus, the VHVE-based spectrum will be viewed as a "superposition" of the spectra of the virtual interferometer and sensing interferometer. The optical path length of the virtual interferometer is multiple times different from that of the sensing interferometer, they meet the excitation condition of the HVE, and they can use the same spectral demodulation method. Thus, this is called the "VHVE." A novel parallel-structured dual Fabry–Perot interferometer fiber-optic sensor is employed to detect gas refractive index. The spectral demodulation methods of the VHVE and TVE are used to track the same set of spectral data, and the obtained sensitivities are 1,158,000 nm/RIU and 39,000 nm/RIU, respectively. Experimental results show that through the VHVE, the sensitivity of the sensor is increased to 106 orders of magnitude. Compared with the HVE, the VHVE can easily increase the harmonic order. In this experiment, the harmonic order reaches 28. Meanwhile, based on the proposed VHVE principle, any sensor based on the TVE can be converted into a VHVE-based sensor to significantly enhance the sensitivity without changing the existing sensor structure. This new sensing mechanism has significant potential in improving sensor sensitivity. [ABSTRACT FROM AUTHOR]

Microsphere-assisted nanoscopy has shown great potential in recent developments in the field of super-resolution imaging. The precise control of microspheres is leading to new discoveries that can help verify the theories behind the super-resolution imaging mechanism. However, microsphere imaging involves multiple planes that have different magnification factors, which affect the determination of the overall resolution of the image. In this study, we present a flexible probe-lens assembly scheme that uses a barium titanate glass microsphere, as well as various scanning stages that can be used to freely investigate the sample surface and perform large-area super-resolution imaging (80 μm × 60 μm). The obtained resolution using this assembly under water immersion condition is 130 nm. By investigating the relationship between the magnification factors and the corresponding focus position of the different feature patterns, a remarkable difference in the focusing characteristics between arbitrary and periodic patterns was revealed. Results demonstrate the universality of the proposed method for the quantitative selection of the best focused plane and determination of the corresponding magnification factor and resolution of a microsphere virtual image for any feature pattern. The findings provide additional insights into the interpretation of arbitrary nanostructures through 3D optical imaging.

In order to analyze the impact of seismic waves on the venue earthquake, based on the display finite element method, the viscoelastic artificial boundary is used to analyze the variation of the ground motion amplification coefficient and the Fourier spectrum of the raised terrain under different incident angles with SV wave oblique incidence on different slopes. This verification model analysis solution and numerical solution are better. The numerical simulation results show that as the degree of the slope increases, the seismic amplification coefficient increases, and its slope amplification coefficient changes significantly. The X direction coefficient is greater than Y’s magnification coefficient. The Fourier curve with a frequency of 0.2~1 Hz increases with the slope of the raised terrain; when the El Centro is incorporated at 30°, the Fourier spectrum amplitude decreases as the incident angle increases in the low-frequency band. The amplitude of the Fourier spectrum at the high-frequency band monitoring point changes with the incident angle. In the high-frequency band from 1 to 10 Hz, the rate of amplitude change is the largest. When the incident angle is at 0°, the amplification coefficient in the Y direction is basically symmetric.

This study extends the seismic dynamics of two-phase/three-phase poroelastic sediments in coupled ocean-sediment-substrate systems to gas hydrate-bearing sediments. The ocean sediment floor is described as a finite-thickness porous medium with two solids and a compressible viscous fluid (porous skeleton, gas hydrate, and fluid), which sits on an elastic seabed. In the coupled system of seawater, gas hydrate-bearing sediment layer and seabed, analytical solutions for the P wave reflection and transmission coefficients are derived. Two key factors are derived: displacement amplitude and magnification factor. The relationship among two key factors with incident angle, frequency, sediment thickness, cementation parameter, contact parameter, temperature and saturation in the sedimentary layer containing gas hydrate is analyzed. The research shows that when the P wave is vertically incident (θ ip = 0°), the incident frequency has a greater influence on the vertical displacement amplitude, and when the P wave is grazing incident (θ ip = 90°), the influence is not observed. The displacement of the sedimentary layer fluctuates in different degrees with the increase of the layer thickness. When the temperature increases, the saturation is higher, that is, the hydrate content is lower, and the influence of the contact parameters gradually disappears. [ABSTRACT FROM AUTHOR]

Automated segmentation of histopathological images is a challenging task to detect cancerous cells in breast tissue. Recent reviews state high accuracy to segment image, but depends on user input, say window area size, time steps, level set, magnification factor and so on. To extract the region of interest effectively, the subject expert performs post-processing operations several times on the segmentation results with different input values for different parameters say, area opening, fill holes and selects most appropriate enhanced image required for further analysis. The authors proposed an automated segmentation technique followed by self-driven post-processing operations to detect cancerous cells effectively. The post-processing method itself determines the value of different parameters for different operations based on segmented results obtained. The proposed technique has the following features: (i) technique is context sensitive; (ii) no prior setting of time step, weighted area coefficient parameters is required; (iii) magnification independent; (iv) post-processing operations are self-driven which enhance segmentation results adaptively. The experimental results are compared with four state-of-the-art techniques: fuzzy C-means, spatial fuzzy C-means, spatial neutrosophic distance regularised level set and convolutional neural network-based PangNet. Experimental results obtained on two publicly available data sets show that the proposed technique outperforms effectively.

For decades, optical fiber interferometers have been extensively studied and applied for their inherent advantages. With the rapid development of science and technology, fiber sensors with higher detection sensitivity are needed on many occasions. As an effective way to improve measurement sensitivity, Vernier effect fiber sensors have drawn great attention during the last decade. Similar to the Vernier caliper, the optical Vernier effect uses one interferometer as a fixed part of the Vernier scale and the other as a sliding part of the Vernier scale. This paper first illustrates the principle of the optical Vernier effect, then different configurations used to produce the Vernier effect are classified and discussed. Finally, the outlook for Vernier effect fiber sensors is presented.

Automated segmentation of histopathological images is a challenging task to detect cancerous cells in breast tissue. Recent reviews state high accuracy to segment image, but depends on user input, say window area size, time steps, level set, magnification factor and so on. To extract the region of interest effectively, the subject expert performs post‐processing operations several times on the segmentation results with different input values for different parameters say, area opening, fill holes and selects most appropriate enhanced image required for further analysis. The authors proposed an automated segmentation technique followed by self‐driven post‐processing operations to detect cancerous cells effectively. The post‐processing method itself determines the value of different parameters for different operations based on segmented results obtained. The proposed technique has the following features: (i) technique is context sensitive; (ii) no prior setting of time step, weighted area coefficient parameters is required; (iii) magnification independent; (iv) post‐processing operations are self‐driven which enhance segmentation results adaptively. The experimental results are compared with four state‐of‐the‐art techniques: fuzzy C‐means, spatial fuzzy C‐means, spatial neutrosophic distance regularised level set and convolutional neural network‐based PangNet. Experimental results obtained on two publicly available data sets show that the proposed technique outperforms effectively. [ABSTRACT FROM AUTHOR]

The problem of the clutch operation accuracy increase without introducing material changes into its construction is solved on the ground of N.D. Verner's construction of the adaptive lamellar clutch which friction group consists of disks made from the materials with different friction values.

A large and balanced training data are the foremost requirement in proper convergence of a deep convolutional neural network (CNN). Medical data always suffer from the problem of unbalancing and inadequacy that makes it difficult to train CNN from scratch. It is known that the transfer learning approach provides great potential to deal with inadequate dataset besides the benefit of faster training. The efficient transfer of knowledge from natural images to histopathological images has yet to be achieved. In view of the foregoing, an attempt has been made toward the classification of BreakHis dataset using pre-trained 'AlexNet' model with a suitable fine-tuning approach. The effective depth of fine-tuning is also determined at different levels of magnification (40×, 100×, 200× and 400 ×). The experimental trials conform that the moderate level of fine-tuning is an optimum choice for the classification of magnification-dependent histology images in contrast to the shallow and deep tuning of the pre-trained network which in turn depends on the size and relative distribution of a dataset. Additionally, the layer-wise fine-tuning approach provides a neck-to-neck performance with the latest state-of-the-art developments. [ABSTRACT FROM AUTHOR]

The Elements by a System of Transfer (EST) method offers exact solutions for various vibration problems of trusses, beams and frames. The method can be regarded as an improved or modified transfer matrix method where the roundoff errors generated by multiplying transfer arrays are avoided. It is assumed that in a steady state a bar/beam will vibrate with the circular frequency of a harmonic excitation force. The universal equation of elastic displacement (2nd/4th order differential equation) is described as a system of first order differential equations in matrix form. For the differential equations the compatibility conditions of a bar/beam element displacements at joint serve as essential boundary conditions. As the natural boundary conditions at joints, the equilibrium equations of elastic forces of bar/beam elements are considered. At the supports, restrictions to displacements (support conditions) have been applied. For steady-state forced vibration the phenomena of dynamic vibration absorption near the saddle points are observed and the response curves for displacement amplitude and elastic energy are calculated. The magnification factor at the excitation frequency is determined. [ABSTRACT FROM AUTHOR]

A theoretical and experimental investigation of an eccentric rotational channel-type damping system is presented. The proposed damping system can incorporate any type of existing passive dampers and provide a wider field of view to residents compared with existing damping systems. Furthermore, the efficiency of the proposed damping system can be magnified by modifying the geometry of the channel-type secondary system. Cyclic loading and free vibration tests of a full-scale test model with steel dampers were conducted to investigate the validity of the suggested simple behavior prediction model and the vibration characteristics of the proposed damping system. The experimental results were in good agreement with the numerical analysis. The results of numerical prediction studies on a single degree of freedom system with the proposed damping system also showed the effect of the eccentric rotational channel-type damping system on seismic response reduction. [ABSTRACT FROM AUTHOR]

Theoretical analyses of the dynamic properties of a 2-2 multi-layered cement-based piezoelectric composite are presented based on the theory of piezoelasticity and D'Alembert's principle. An arbitrary mechanical load acts on the free end of the composite in the form of pressure. The Taylor series expansion method is introduced for the arbitrary mechanical load, and the theoretical solutions of the composite are obtained mainly based on the eigenfunction expansion method, Duhamel integral, and Laplace transform. Comparisons between the theoretical results, numerical results, and four related theoretical studies are presented, and good agreements are found. Furthermore, the theoretical expression of magnification factors of the composite under the harmonic load are obtained and analyzed. In addition to providing a theoretical basis for the design and experimentation of 2-2 cement-based piezoelectric composites under the arbitrary loading, the theoretical methods presented in the article could be extended to analyze the dynamic characteristics of any multilayered composite structure. [ABSTRACT FROM AUTHOR]

Shadows cast by retinal blood vessels are represented in striate cortex of the squirrel monkey. Their pattern was exploited to generate a true retinotopic map of VI. For calibration, retinal landmarks were projected onto a tangent screen to measure their visual field location. Next, the retina was warped onto striate cortex, distorting it as necessary to match each retinal vessel to its cortical representation. Maps from four hemispheres of two normal adult squirrel monkeys were created and used to derive expressions for cortical magnification factor (M). A mean map was produced by averaging the individual maps. To address the controversial issue of whether the ratio of retinal ganglion cell (RGC) density to M is constant at all eccentricities, we stained a retinal whole mount from one of the two monkeys for Nissl substance. A ganglion cell density map was compiled by sampling the concentration of cells at 171 retinal points. Allowance was made for displaced amacrine cells and for the centripetal displacement of RGCs from central photoreceptors. After these corrections the VI surface area and RGC density were compared at each eccentricity. The cortical representation of the macula was found to be amplified, even beyond the magnification expected from its high density of RGCs. For example, the central 4degrees of visual field were allotted 27% of the surface area of VI but were supplied by only 12% of RGCs. We conclude that, in monkey striate cortex, more tissue is allocated per ganglion cell for the analysis of information emanating from the macula as compared with the peripheral retina.

Electrocorticogram (ECoG), obtained by low-pass filtering the brain signal recorded from a macroelectrode placed on the cortex, is extensively used to find the seizure focus in drug-resistant epilepsy and is of growing importance in cognitive and brain-machine- interfacing studies. To accurately estimate the epileptogenic cortex or to make inferences about cognitive processes, it is important to determine the "spatial spread" of ECoG (i.e., the extent of cortical tissue that contributes to its activity). However, the ECoG spread is currently unknown; even the spread of local field potential (LFP) obtained from microelectrodes is debated, with estimates ranging from a few hundred micrometers to several millimeters. Spatial spread can be estimated by measuring the receptive field (RF) and multiplying by the cortical magnification factor, but this method overestimates the spread because RF size gets inflated due to several factors. This issue can be partially addressed using a model that compares the RFs of two measures, such as LFP and multi-unit activity (MUA). To use this approach for ECoG, we designed a customized array containing both microelectrodes and ECoG electrodes to simultaneously map MUA, LFP, and ECoG RFs from the primary visual cortex of awake monkeys (three female Macaca radiata). The spatial spread of ECoG was surprisingly local (diameter ~3 mm), only 3 times that of the LFP. Similar results were obtained using a model to simulate ECoG as a sum of LFPs of varying electrode sizes. Our results further validate the use of ECoG in clinical and basic cognitive research. [ABSTRACT FROM AUTHOR]

Reinforced concrete structure with infill wall provides better strength, stiffness and energy dissipation capacity compared to bare frame while analyzing the models. Strength and stiffness of the structure decrease when percentage of openings in a wall increases. Open Ground Storey Structure (OGSS) shows very poor performance in earthquakeprone areas as discussed in past researches. Literature shows that damages in members of soft storey structures are dependent upon their relative stiffness with respect to adjacent storeys. When the effect of Soil Structure Interaction (SSI) is included, displacement demand and natural period will be high, and also decrease in base shear occurs which is not beneficial (Goud and Ramancharla, 2017). The paper studies the seismic response of fully infilled and OGSS models with different percentages of wall openings for both with and without SSI effect. The analysis of different models is carried out in software ETABS-2009. The main parameters investigated are natural period, base shear, displacement and storey drift. Also, magnification factors for soft storey members with different percentages of openings in upper storeys are found. It is found that magnification factor decreases as the percentage of openings in wall infill increases. [ABSTRACT FROM AUTHOR]

Numerous difficult to perceive minor signals, such as minute color variations and modest movements, carry crucial information. The ability to see small signals in video has been demonstrated to be greatly aided by video magnification techniques. The Eulerian video magnification (EVM) method produces excellent results when magnifying minute colors and motions; but, it is susceptible to artifacts and outcomes that are blurry, especially when bigger magnifications are used. In this research, we propose a novel video magnification method based on adaptive Laplacian pyramid to achieve non-contact optical measurements. Experiments were conducted on real video sequences containing biological or mechanical motion signals, the results demonstrated that our approach achieves video amplification and extraction of subtle signals, supports larger amplification factors, and obtains sharper video quality with reduced artifacts and blurring. • A novel adaptive Laplacian pyramid image decomposition method is proposed. • A mathematical model for video spatio-temporal processing is developed. • We achieve the measurement of tiny biological and mechanical motion signals. • Our method shows excellent objective evaluation results. [ABSTRACT FROM AUTHOR]

Electrically stimulating early visual cortex results in a visual percept known as a phosphene. Although phosphenes can be evoked by a wide range of electrode sizes and current amplitudes, they are invariably described as small. To better understand this observation, we electrically stimulated 93 electrodes implanted in the visual cortex of 13 human subjects who reported phosphene size while stimulation current was varied. Phosphene size increased as the stimulation current was initially raised above threshold, but then rapidly reached saturation. Phosphene size also depended on the location of the stimulated site, with size increasing with distance from the foveal representation. We developed a model relating phosphene size to the amount of activated cortex and its location within the retinotopic map. First, a sigmoidal curve was used to predict the amount of activated cortex at a given current. Second, the amount of active cortex was converted to degrees of visual angle by multiplying by the inverse cortical magnification factor for that retinotopic location. This simple model accurately predicted phosphene size for a broad range of stimulation currents and cortical locations. The unexpected saturation in phosphene sizes suggests that the functional architecture of cerebral cortex may impose fundamental restrictions on the spread of artificially evoked activity and this may be an important consideration in the design of cortical prosthetic devices. [ABSTRACT FROM AUTHOR]

• A novel method using deep learning-based amplification and tracking is proposed to measure the micro-vibration. • This method can be used under complex light fields with different illumination and backgrounds. • The target object is first magnified and tracked, and then converted into actual displacement values. A new deep learning-based vision measurement method is proposed to accurately measure the micro-vibration displacements of objects in different illuminations and backgrounds. The measurement method pre-process the video, then the deep learning correlation methods are used to zoom in the target object and track the vibration trajectory, and the pixel displacement is converted to actual displacement by pixel equivalents. By comparing the three sets of experiments, the proposed method has exceptional accuracy. When measuring vibration displacement of 0.1 mm, the Root Mean Square Error (RMSE) and Normalized Root Mean Square Error (NRMSE) are 0.0234 mm and 11.8601 %. By comparing with the Rectangle Detection Algorithm and the Template Matching Algorithm, the proposed algorithm outperforms these two traditional methods, especially for the complex environments. It can be concluded that this method, as a new visual measurement method, can be adapted to a variety of complex environments and can accurately measure micro-amplitude vibrations. [ABSTRACT FROM AUTHOR]

Exploring the factors that simultaneously increase the accumulation of various pollutants in cells of organisms to restrict the toxic effects of pollutants on organisms has become a focus of research aimed at protecting ecosystems. Here, we found that the accumulation of organic [e.g., benzo(a)pyrene (BaP)], inorganic [e.g., cadmium (Cd)] and emerging [e.g., rare earth elements (REEs)] pollutants in leaf cells of different plants grown in Nanjing was 567–1022%, 547–922% and 972–1392% of those grown in Haikou, respectively, when the concentration of REEs in rainwater of Nanjing and Haikou was 4.31 × 10−3 μg/L and 3.04 × 10−6 μg/L. Unprecedentedly, endocytosis in leaf cells of different plants grown in Nanjing was activated by REEs, and then extracellular BaP, Cd and REEs (e.g. terbium) were transported into these leaf cells together via endocytic vesicles. Particularly, the co-accumulation of those pollutants in these leaf cells was sharply increased, thus magnifying their toxic effects on these plants. Furthermore, the co-accumulation of those pollutants in human cells was also significantly increased by REEs, in a similar way to these leaf cells. Therefore, REEs in environments are key factors that greatly increase the co-accumulation of various pollutants in cells of organisms. These results provide new insights into how pollutants are accumulated in cells of organisms in ecosystems, informing a reference for making policy to ensure the safety of ecosystems. [Display omitted] • REEs activated endocytosis in leaf cells of various plants in ecological environment. • Pollutants were simultaneously transported into leaf cells via endocytic vesicles. • REEs increased pollutant accumulations in leaf cells in ecological environment. • Toxic effects of pollutants on plants were magnified at different levels. • REEs also sharply and simultaneously increased pollutant accumulations in human cells. [ABSTRACT FROM AUTHOR]