Artigos de revistas: "Force histogram"

1

Xue, Hao, e Hong Jun Fu. "Characterization of the Interphase in Carbon Fiber/Epoxy Composites Using Force Modulation Atomic Force Microscope". Advanced Materials Research 602-604 (dezembro de 2012): 53–56. http://dx.doi.org/10.4028/www.scientific.net/amr.602-604.53.

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In order to describe directly interphase properties of composite, force modulation of atomic force microscopy is adopted to study the cross-section of unidirectional carbon fiber/epoxy composites systematically. Research results indicate that in force modulation mode of AFM, relative stiffness of various phases distinct in distribution, which is described by probability histogram of relative stiffness. By comparison of probability histogram of relative stiffness nearby interphase of untreated and oxidation treated by ozone composites, the relative stiffness change oxidation treated one was more obviously to be found than the one untreated. Indirect show that obvious interphase formed by oxidation treatment. This method plays a valuable role in assessment of interphase strength of carbon fiber/epoxy, as well as in instruction composite production technology.

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Lelièvre, Tony, Lise Maurin e Pierre Monmarché. "The adaptive biasing force algorithm with non-conservative forces and related topics". ESAIM: Mathematical Modelling and Numerical Analysis 56, n.º 2 (28 de fevereiro de 2022): 529–64. http://dx.doi.org/10.1051/m2an/2022010.

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We propose a study of the Adaptive Biasing Force method’s robustness under generic (possibly non-conservative) forces. We first ensure the flat histogram property is satisfied in all cases. We then introduce a fixed point problem yielding the existence of a stationary state for both the Adaptive Biasing Force and Projected Adapted Biasing Force algorithms, relying on generic bounds on the invariant probability measures of homogeneous diffusions. Using classical entropy techniques, we prove the exponential convergence of both biasing force and law as time goes to infinity, for both the Adaptive Biasing Force and the Projected Adaptive Biasing Force methods.

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Yang, Guifeng, Jiulun Fan e Dong Wang. "Recursive Algorithms of Maximum Entropy Thresholding on Circular Histogram". Mathematical Problems in Engineering 2021 (24 de março de 2021): 1–13. http://dx.doi.org/10.1155/2021/6653031.

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Circular histogram thresholding is a novel color image segmentation method, which makes full use of the hue component color information of the image, so that the desired target can be better separated from the background. Maximum entropy thresholding on circular histogram is one of the exist circular histogram thresholding methods. However, this method needs to search for a pair of optimal thresholds on the circular histogram of two-class thresholding in an exhaustive way, and its running time is even longer than that of the existing circular histogram thresholding based on the Otsu criteria, so the segmentation efficiency is extremely low, and the real-time application cannot be realized. In order to solve this problem, a recursive algorithm of maximum entropy thresholding on circular histogram is proposed. Moreover, the recursive algorithm is extended to the case of multiclass thresholding. A large number of experimental results show that the proposed recursive algorithms are more efficient than brute force and the existing circular histogram thresholding based on the Otsu criteria.

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Chapple, William D. "Regulation of Muscle Stiffness During Periodic Length Changes in the Isolated Abdomen of the Hermit Crab". Journal of Neurophysiology 78, n.º 3 (1 de setembro de 1997): 1491–503. http://dx.doi.org/10.1152/jn.1997.78.3.1491.

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Chapple, William. Regulation of muscle stiffness during periodic length changes in the isolated abdomen of the hermit crab. J. Neurophysiol. 78: 1491–1503, 1997. Reflex activation of the ventral superficial muscles (VSM) in the abdomen of the hermit crab, Pagurus pollicarus, was studied using sinusoidal and stochastic longitudinal vibration of the muscle while recording the length and force of the muscle and the spike times of three exciter motoneurons. In the absence of vibration, the interspike interval histograms of the two larger motoneurons were bimodal; cutting sensory nerves containing most of the mechanoreceptor input removed the short interval peak in the histogram, indicating that the receptors are important in maintaining tonic firing. Vibration of the muscle evoked a reflex increase in motoneuron frequency that habituated after an initial peak but remained above control levels for the duration of stimulation. Motoneuron frequency increased with root mean square (rms) stimulus amplitude. Average stiffness during stimulation was about two times the stiffness of passive muscle. The reflex did not alter muscle dynamics. Estimated transfer functions were calculated from the fast Fourier transform of length and force signals. Coherence was >0.9 for the frequency range of 3–35 Hz. Stiffness magnitude gradually increased over this range in both reflex activated and passive muscle; phase was between 10 and 20°. Reflex stiffness decreased with increasing stimulus amplitudes, but at larger amplitudes, this decrease was much less pronounced; in this range stiffness was regulated by the reflex. The sinusoidal frequency at which reflex bursts were elicited was ∼6 Hz, consistent with previous measurements using ramp stretch. During reflex excitation, there was an increase in amplitude of the short interval peak in the interspike interval histogram; this was reduced when the majority of afferent pathways was removed. A phase histogram of motoneuron firing during sinusoidal vibration had a peak at ∼110 ms, also suggesting that an important component of the reflex is via direct projections from the mechanoreceptors. These results are consistent with the hypothesis that a robust feedforward regulation of abdominal stiffness during continuous disturbances is achieved by mechanoreceptors signalling the absolute value of changing forces; habituation of the reflex, its high-threshold for low frequency disturbances and the activation kinetics of the muscle further modify reflex dynamics.

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Janosi, Lorant, e Manolis Doxastakis. "Accelerating flat-histogram methods for potential of mean force calculations". Journal of Chemical Physics 131, n.º 5 (2009): 054105. http://dx.doi.org/10.1063/1.3183165.

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Chirico, Giuseppe. "Effect of a trapping force on a photon-counting histogram". Applied Optics 41, n.º 4 (1 de fevereiro de 2002): 593. http://dx.doi.org/10.1364/ao.41.000593.

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Stevens, Forrest, Yu-Shiu Lo, Joel M. Harris e Thomas P. Beebe. "Computer Modeling of Atomic Force Microscopy Force Measurements: Comparisons of Poisson, Histogram, and Continuum Methods". Langmuir 15, n.º 1 (janeiro de 1999): 207–13. http://dx.doi.org/10.1021/la980683k.

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Jun, Zhang, Chang Qingbing e Ren Zongjin. "Research on a non-linear calibration method for dynamometer". Sensor Review 40, n.º 2 (9 de março de 2020): 167–73. http://dx.doi.org/10.1108/sr-07-2019-0181.

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Purpose The purpose of this paper is to solve the problem that the relationship between loading forces, which were applied at different positions on a plane, and output values of load-sharing dynamometer is non-linear. Design/methodology/approach First, the analytical model of ISPM (isodynamic surface proportional mapping method) method, which is used to calibrate dynamometer, was established. Then, a series of axial force calibration tests were performed on a load-sharing dynamometer at different loading positions. Finally, according to output values, calibration forces at different loading positions were calculated by ISPM method, and corresponding distribution histogram of calibration force error was generated. Findings The largest error between calculated force and standard force is 2.92 per cent, and the probability of calculated force error within 1 per cent is 91.03 per cent, which verify that the ISPM method is reliable for non-linear calibration of dynamometers. Originality/value The proposed ISPM method can achieve non-linear calibration between measured force and output signal of load-sharing dynamometer at different positions. In addition, ISPM method can also solve some complex non-linear problems, such as prediction of plane cutting force under the influence of multiple parameters, the force measurement of multi-degree-of-freedom platform and so on.

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9

Songneam, Nattapong. "Thai Sign Language Image Recognition for the Hearing-Impaired using Radial Inverse Force Histogram combined with Max-Min Boundary". International Journal of Engineering and Advanced Technology 10, n.º 5 (30 de junho de 2021): 422–33. http://dx.doi.org/10.35940/ijeat.e2868.0610521.

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Sign language image recognition is also a very interesting research topic. Because it can be applied to help normal people understand and use it as a communication tool for the hearing impaired. The objectives of this research were to: 1) study and analyze Thai Sign Language image recognition image data for hearing impaired, 2) develop Thai Sign Language image recognition system for hearing impaired by using new techniques, and 3) measure the efficiency of Thai sign language image recognition for hearing impaired using Radial Inverse Force Histogram and the Maximum and Minimum boundary values. The results of the research were as follows: 1) The study and analysis of image data of Thai Sign Language Image Recognition In this research, 62,694 sign language images were used, divided into 2 parts: 1) American Sign Language images, which consisted of 36 groups of images, namely 26 groups of letters (AZ) and 10 groups of numbers (0-9), and Part 2) Picture of Thai Sign Language consisting of 61 groups of images, including 44 groups of letters (ก-ฮ), 7 groups of vowels and 10 groups of numbers (0-9). Each group of pictures is rotated, enlarged, and Image promotion There were 6 sub-groups of images in various forms, divided into 2 parts: 70% of the images for training and 30% of the images for testing. 3) The results of measuring the efficiency of image recognition. It is divided into two parts: American Sign Language Image Recognition and Thai Sign Language Image Recognition. Compared with the Angular histogram method, the mean image accuracy was 0.86, the recall of the mean American sign language was 0.91, and the accuracy of the Thai Sign Language was 0.78. The recognition performance for Thai Sign Language images averaged 0.89, while the recognition efficiency was achieved when using radial inverse force histograms in combination with image similarity measurements with maximum-minimum boundary values. Accuracy for Mean American Sign Language was 0.99 and Remembrance for Mean American Sign was 1.00, while Accuracy for Mean Thai Sign Language was 0.89. Mean Remembrance for Thai Sign Language was 0.96. The results of the visual recognition performance measurement of both the American Sign Language and the Thai Sign Language images were very good compared to the Angular Histogram method.

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Tabbone, Salvatore, e Laurent Wendling. "Color and grey level object retrieval using a 3D representation of force histogram". Image and Vision Computing 21, n.º 6 (junho de 2003): 483–95. http://dx.doi.org/10.1016/s0262-8856(03)00016-7.

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Wendling, L., I. Debled-Rennesson e H. Nasser. "Multilevel polygonal descriptor matching defined by combining discrete lines and force histogram concepts". Multimedia Tools and Applications 79, n.º 47-48 (27 de abril de 2019): 34701–15. http://dx.doi.org/10.1007/s11042-019-7531-6.

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12

Cukier, Robert I. "Variance of a Potential of Mean Force Obtained Using the Weighted Histogram Analysis Method". Journal of Physical Chemistry B 117, n.º 47 (18 de novembro de 2013): 14785–96. http://dx.doi.org/10.1021/jp407956c.

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Yao, Yaxuan, Lingling Ren, Sitian Gao e Shi Li. "Histogram method for reliable thickness measurements of graphene films using atomic force microscopy (AFM)". Journal of Materials Science & Technology 33, n.º 8 (agosto de 2017): 815–20. http://dx.doi.org/10.1016/j.jmst.2016.07.020.

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14

Fang, Shu, De Liang Li, Li Tao Liu e Zhen Wei Zhang. "Pitting Corrosion Diagnosis of Bearing Based on Power Cepstrum and Histogram". Advanced Materials Research 512-515 (maio de 2012): 1672–76. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.1672.

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The axle assembly of fire robot need endure both heavy load and high impact force, and the pitting corrosion in the bearing race become a commom fault. In this paper, the vibration of bearing both in the inner ring and outer ring was analyzed, the characteristics of bearing with pitting corrosion were also analyzed, and based on those characteristics a new method for pitting corrosion diagnosis were proposed, in this method the power cepstrum in the axial direction and histogram of the vibration amplitude in the radial direction were used for detecting the pitting corrosion of bearing, and experiments results proved the practicability and effectiveness of this method.

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Wheeler, John, Zhenting Jiang, David J. Prior e Jan Tullis. "Dynamic Recrystallisation of Quartz". Materials Science Forum 467-470 (outubro de 2004): 1243–50. http://dx.doi.org/10.4028/www.scientific.net/msf.467-470.1243.

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It is generally agreed that the driving force (plastic strain energy) is much too small to allow "classical" nucleation during static and dynamic recrystallisation, and that rotation/growth of subgrains is an alternative. The latter explanation predicts that new grains should begin at low angles to old grains. We have used electron backscatter diffraction on an experimentally deformed quartz polycrystal that has deformed by dislocation creep and partially recrystallised. In a region shortened by about 30% new grains are at high angles (much greater than 15º) to adjacent parent grains. A histogram of misorientation versus number of boundaries shows a gap at 15-20º. In its simple form we expect the subgrain rotation model to predict a spectrum of misorientations but with most of them being low angle. Instead, the histogram suggests that new boundaries began life as high-angle structures, so current models for deformation-induced nucleation require refinement.

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Uyeda, Chiaki, Keiji Hisayoshi e Kentaro Terada. "Separation of Particles Composed of a Solid Solution [Mg₂SiO₄ -Fe₂SiO₄] in the Sequence of Fe²⁺ Concentration Using a Pocketsize Magnetic-Circuit". Key Engineering Materials 843 (maio de 2020): 105–9. http://dx.doi.org/10.4028/www.scientific.net/kem.843.105.

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Magentic separation generally required strong magnetic forces induced in ferromagnetic or strong paramagnetic particles; in order to realize the separation in diamagnetic or weak paramagnetic particles, it was necessary to attach magnetic beads or magnetic ions to induce the strong magnetic force. A method to separate mixture of weak magnetic particles by its concentration of paramagnetic ferrous ion is newly proposed, which does not require the abovementioned magnetic attachments. The efficiently of the new method is experimentally examined using a pocketsize magnetic circuit (4.5 cm x2.0 cm x 1.0 cm) and a piece of cross sectional paper (5.0 cm x1.0cm). The separation is based on a principle that velocity of a translating particle, induced by a magnetic volume force in an area of monotonically decreasing field, is uniquely determined only by its magnetic susceptibility (per unit mass) of the particle; the velocity is independent to mass of particle. By examining the spectra of the separated particles recovered on the cross sectional paper, a histogram on Fe concentration is easily obtained for the particles without the need of consuming them.

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Femi, D., G. Veera Babu e B. V Sumanth Kumar Reddy. "A New Method for Forensic Detection of Image Manipulation". International Journal of Engineering & Technology 7, n.º 2.19 (17 de abril de 2018): 61. http://dx.doi.org/10.14419/ijet.v7i2.19.15048.

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As the use of digital images has expanded, so has the methods and the motivating force to make advanced picture frauds. As needs be, there is an incredible requirement for advanced image legal sciences methods equipped for identifying image changes and manufactured images. We demonstrate that pixel value mappings desert factual follows which we might allude to as a mappings inherent unique finger impression in an image pixel value histogram. We at that point propose scientific techniques for recognizing general structures all around and privately connected complexity upgrade and in addition a strategy for distinguishing the utilization of histogram leveling via hunting down the recognizing highlights of every task intrinsic fingerprint. Also we propose a technique to identify the worldwide expansion of noise to a formerly JPEG - compacted image by watching that the key fingerprint of a particular planning will be adjusted on the off chance that it is connected to a image’s pixel value after the noise addition.

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Qiu, Hanshuo, Xiangzi Zhang, Huaixiao Yue e Jizhao Liu. "A Novel Eighth-Order Hyperchaotic System and Its Application in Image Encryption". Mathematics 11, n.º 19 (28 de setembro de 2023): 4099. http://dx.doi.org/10.3390/math11194099.

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With the advancement in information and communication technologies (ICTs), the widespread dissemination and sharing of digital images has raised concerns regarding privacy and security. Traditional methods of encrypting images often suffer from limitations such as a small key space and vulnerability to brute-force attacks. To address these issues, this paper proposes a novel eighth-order hyperchaotic system. This hyperchaotic system exhibits various dynamic behaviors, including hyperchaos, sub-hyperchaos, and chaos. The encryption scheme based on this system offers a key space larger than 22338. Through a comprehensive analysis involving histogram analysis, key space analysis, correlation analysis, entropy analysis, key sensitivity analysis, differential attack analysis, and cropping attack analysis, it is demonstrated that the proposed system is capable of resisting statistical attacks, brute force attacks, differential attacks, and cropping attacks, thereby providing excellent security performance.

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Butt, Khushbu Khalid, Guohui Li, Sajid Khan e Sohaib Manzoor. "Fast and Efficient Image Encryption Algorithm Based on Modular Addition and SPD". Entropy 22, n.º 1 (16 de janeiro de 2020): 112. http://dx.doi.org/10.3390/e22010112.

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Bit-level and pixel-level methods are two classifications for image encryption, which describe the smallest processing elements manipulated in diffusion and permutation respectively. Most pixel-level permutation methods merely alter the positions of pixels, resulting in similar histograms for the original and permuted images. Bit-level permutation methods, however, have the ability to change the histogram of the image, but are usually not preferred due to their time-consuming nature, which is owed to bit-level computation, unlike that of other permutation techniques. In this paper, we introduce a new image encryption algorithm which uses binary bit-plane scrambling and an SPD diffusion technique for the bit-planes of a plain image, based on a card game trick. Integer values of the hexadecimal key SHA-512 are also used, along with the adaptive block-based modular addition of pixels to encrypt the images. To prove the first-rate encryption performance of our proposed algorithm, security analyses are provided in this paper. Simulations and other results confirmed the robustness of the proposed image encryption algorithm against many well-known attacks; in particular, brute-force attacks, known/chosen plain text attacks, occlusion attacks, differential attacks, and gray value difference attacks, among others.

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Blaszczyk, Janusz W., Bogdan Bacik e Grzegorz Juras. "Clinical Assessment of Postural Stability". Journal of Mechanics in Medicine and Biology 03, n.º 02 (junho de 2003): 135–44. http://dx.doi.org/10.1142/s0219519403000715.

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One of the most important applications of postural sway analysis is the detection of such impairments to the motor system that would allow us to predict risk of falling. Force plate posturography is a commonly used clinical method for the evaluation of postural instability. The diagnostic value of postural sway represented here by oscillations of the center-of-foot pressure (COFP) is being questioned very often. These diagnostic problems result from the lack of an adequate and reliable method of sway analysis — a method that would present a clear connection between stability and quality of postural control. To gain better insight into this problem, the following experiments were done and some effective methods of sway analysis typically applied in conventional mechanics and electrical engineering are presented here. Quality of the postural stability was assessed using, in addition to standard parameters, spatial histograms, body transfer function, contour plots as well as the COFP fractal dimension. Such complex analysis allowed us to extract significant sway parameters that are relevant to postural instability. Analysis of the data revealed that spatial histogram has clear peak which maximum was sensitive to sensory conditions. Changes in the postural sway distributions have been confirmed by the increase of the COFP fractal dimension.

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F. Abbas, Safa, e Lahieb M. Jawad. "PASS POINT SELECTION OF AUTOMATIC GRAPHICAL PASSWORD AUTHENTICATION TECHNIQUE BASED ON HISTOGRAM METHOD". Iraqi Journal of Information and Communication Technology 6, n.º 1 (30 de abril de 2023): 28–39. http://dx.doi.org/10.31987/ijict.6.1.212.

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Graphical passwords, as opposed to textual passwords, require the user to pick pictures or draw symbols rather than input written letters. They are an option that may be explored in order to get over the issues that are caused by the system of passwords that are based on text. It has been hypothesized that graphical passwords are more difficult to crack using a brute force technique or to figure out through guessing. This paper proposes an authentication system based on a graphical password method. The proposed system computes the password points using histogram arithmetic and encrypts the chosen password points using SHA512. The envisioned system has been realized as an android application and evaluated with existing research considering multiple measurements such as required login time, password space, and entropy. The findings reveal that the new suggested system outperforms the reference work by more than 85% in terms of login latency and more than 72% in terms of entropy results.

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El-Hoseny, Heba M., Wael Abd El-Rahman, El-Sayed M. El-Rabaie, Fathi E. Abd El-Samie e Osama S. Faragallah. "An efficient DT-CWT medical image fusion system based on modified central force optimization and histogram matching". Infrared Physics & Technology 94 (novembro de 2018): 223–31. http://dx.doi.org/10.1016/j.infrared.2018.09.003.

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Mohammed, Imran, Iain B. Collings e Stephen V. Hanly. "A Gravity Inspired Approach to Multiple Target Localization Through-the-Wall Using Non-Coherent Bi-Static Radar". Electronics 10, n.º 13 (23 de junho de 2021): 1524. http://dx.doi.org/10.3390/electronics10131524.

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This paper considers multiple target localization using a non-coherent bi-static radar with multiple receivers, where the targets are located behind a wall. This paper presents a new clustering algorithm inspired by Newtonian gravity that iteratively groups particles at target locations and eliminates particles at non-target locations. We first propose a histogram based pre-processing algorithm that imposes a grid over the region of interest and defines a particle with measurement-dependent mass for each grid square. We then calculate a Newtonian inspired force on each of the particles and move them in the direction of the force. We repeat the process until there is no further movement. The proposed algorithm works even when some of the measurements are unavailable or missing and when some of the measurements are false measurements. Location accuracy is shown to be in the order of 8 cm.

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Zhang, Tong, Baoying Shen e Xinghua Shi. "“Crawling” on the self-assembly system: A molecular simulation of peptide position adjusting over self-assembly block". MATEC Web of Conferences 189 (2018): 02002. http://dx.doi.org/10.1051/matecconf/201818902002.

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By combining non-equilibrium molecular dynamics(NEMD), umbrella sampling, and weighted histogram analysis method(WHAM), we calculated the potential of mean force of histidine peptide moving over a self-assembly structure. The reaction coordinate is along the main chain direction of the histidine peptide in the self-assembly structure. It is found that the energy needed for the histidine peptide with 3 and 5 residues while moving along the reaction coordinate is around -2.2 kCal/mol and -7.4 kCal/mol, respectively. And the histidine peptide crawls along the reaction coordinate, performing a snake-like movement. This result could illustrate how histidine peptide adjusts its position during self-assembly process.

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Rashid Shakir, Huda, Sadiq Abdul Aziz Mehdi e Anwar Abbas Hattab. "Chaotic-DNA system for efficient image encryption". Bulletin of Electrical Engineering and Informatics 11, n.º 5 (1 de outubro de 2022): 2645–56. http://dx.doi.org/10.11591/eei.v11i5.3886.

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In order to prevent unwanted access to sensitive data by unauthorized individuals, color images are encoded. Because chaotic-deoxyribonucleic acid (chaotic-DNA) encoding can make information highly secure, it is often employed in image encryption. In this study, a new image encryption technique has been proposed based on a new 4D-chaotic system and DNA computing. The algorithm consists of two phases: in the first phase, the pixel positions are permuted by chaotic sequences. In the second phase, according to the concept of DNA cryptography, a set of operations (like DNA addition, DNA XOR, DNA subtraction, shift right, and shift left) are performed on the DNA encoding sequence. The performance of the suggested algorithm is evaluated through analyses like correlation coefficient, entropy, histogram, and key space. The results show that the encryption method that was exhibited has good encryption performance and high security. For encrypted images, the histogram is fairly uniform, the correlation values between adjacent pixels are very small and close to zero, and the entropy is near to the ideal value of eight. In addition, the proposed system has a very large key space that is equal to 2627 keys, which makes it resistant to brute-force, differential, and statistical attacks.

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Revelly, JP, F. Feihl, T. Liebling e C. Perret. "Time constant histograms from the forced expired volume signal: a clinical evaluation". European Respiratory Journal 2, n.º 6 (1 de junho de 1989): 536–42. http://dx.doi.org/10.1183/09031936.93.02060536.

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We evaluated a multicompartment analysis of forced expiration, based on modelling the lung as a set of twenty parallel compartments emptying exponentially with time constants ranging from 0.1-10 s; the forced expired volume signal was represented by a histogram showing the fraction of forced vital capacity as a function of compartmental time constants. We applied this technique to 80 healthy and 12 asthmatic subjects. The histograms computed from three consecutive forced expirations were poorly reproducible in 18 of the 80 healthy and 2 of the 12 asthmatic subjects. In the asthmatics, the time constant histograms conveyed no additional information on bronchial obstruction, beyond that already present in standard spirometric indices. A simulation study showed a high sensitivity of the histograms to the truncation of the terminal part of forced expiration. We conclude that the usefulness of the time constant histogram technique appears doubtful.

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Debenedetti, Pablo G., Francesco Sciortino e Gül H. Zerze. "Second critical point in two realistic models of water". Science 369, n.º 6501 (16 de julho de 2020): 289–92. http://dx.doi.org/10.1126/science.abb9796.

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The hypothesis that water has a second critical point at deeply supercooled conditions was formulated to provide a thermodynamically consistent interpretation of numerous experimental observations. A large body of work has been devoted to verifying or falsifying this hypothesis, but no unambiguous experimental proof has yet been found. Here, we use histogram reweighting and large-system scattering calculations to investigate computationally two molecular models of water, TIP4P/2005 and TIP4P/Ice, widely regarded to be among the most accurate classical force fields for this substance. We show that both models have a metastable liquid-liquid critical point at deeply supercooled conditions and that this critical point is consistent with the three-dimensional Ising universality class.

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Nowak, Andrzej S., e Hid N. Grouni. "Serviceability considerations for guideways and bridges". Canadian Journal of Civil Engineering 15, n.º 4 (1 de agosto de 1988): 534–38. http://dx.doi.org/10.1139/l88-073.

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Serviceability limit states such as fatigue, cracking, corrosion, permanent deformations (kinking), deflection, and vibration are considered. A probability-based approach to develop design criteria is proposed. Load history is represented by load histogram and ADTT (average daily truck traffic) volume. Criteria for the selection of acceptable serviceability levels can be derived from the available test data, bridge surveys, and theoretical studies. Simple format is suggested for the code, with a characteristic value representing load effect and an allowable stress or force representing the structural ability to absorb damage. In the case of deflection and vibration, human perception threshold levels are used as the acceptance criteria. Key words: bridges, damage accumulation, design criteria, limite states, serviceability.

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Moreno, Plinio, Dario Figueira, Alexandre Bernardino e José Santos-Victor. "People and Mobile Robot Classification Through Spatio-Temporal Analysis of Optical Flow". International Journal of Pattern Recognition and Artificial Intelligence 29, n.º 06 (12 de agosto de 2015): 1550021. http://dx.doi.org/10.1142/s0218001415500214.

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The goal of this work is to distinguish between humans and robots in a mixed human-robot environment. We analyze the spatio-temporal patterns of optical flow-based features along several frames. We consider the Histogram of Optical Flow (HOF) and the Motion Boundary Histogram (MBH) features, which have shown good results on people detection. The spatio-temporal patterns are composed of groups of feature components that have similar values on previous frames. The groups of features are fed into the FuzzyBoost algorithm, which at each round selects the spatio-temporal pattern (i.e. feature set) having the lowest classification error. The search for patterns is guided by grouping feature dimensions, considering three algorithms: (a) similarity of weights from dimensionality reduction matrices, (b) Boost Feature Subset Selection (BFSS) and (c) Sequential Floating Feature Selection (SFSS), which avoid the brute force approach. The similarity weights are computed by the Multiple Metric Learning for large Margin Nearest Neighbor (MMLMNN), a linear dimensionality algorithm that provides a type of Mahalanobis metric Weinberger and Saul, J. MaCh. Learn. Res.10 (2009) 207–244. The experiments show that FuzzyBoost brings good generalization properties, better than the GentleBoost, the Support Vector Machines (SVM) with linear kernels and SVM with Radial Basis Function (RBF) kernels. The classifier was implemented and tested in a real-time, multi-camera dynamic setting.

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Jirjees, Seerwan Waleed, e Farah Flayyeh Alkhalid. "IMGTXT: Image to Text Encryption Based on Encoding Pixel Contrasts". Mathematical Modelling of Engineering Problems 9, n.º 2 (28 de abril de 2022): 539–44. http://dx.doi.org/10.18280/mmep.090233.

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Nowadays, when data is exchanged over the internet, the security of data is critical in every element of life. Unauthorized network access is possible due to information transmission. As image usage increased in most communications, image privacy became an issue. Image encryption is one of the methods used to protect images online. In this paper, we proposed a new approach called IMGTXT that converts the image to text by coding the pixel values depending on locations then encrypts them by any trust encryption text algorithm, so that this method provides resistance to a variety of attacks such as histogram attacks and brute force attack. The state of the art of this research is the image is represented as a text and there is no relationship between the cipher-image and the plain image. Although this results in a large data volume. The proposed technique builds and testes on various images with different sizes, the recorded results demonstrate the technique’s efficacy and robustness to resist the brute force attack and statistical cryptanalysis of original and encrypted images.

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El-Hoseny, Heba M., Zeinab Z. El Kareh, Wael A. Mohamed, Ghada M. El Banby, Korany R. Mahmoud, Osama S. Faragallah, S. El-Rabaie, Essam El-Madbouly e Fathi E. Abd El-Samie. "An optimal wavelet-based multi-modality medical image fusion approach based on modified central force optimization and histogram matching". Multimedia Tools and Applications 78, n.º 18 (10 de junho de 2019): 26373–97. http://dx.doi.org/10.1007/s11042-019-7552-1.

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32

Ramasamy, Priya, Vidhyapriya Ranganathan, Seifedine Kadry, Robertas Damaševičius e Tomas Blažauskas. "An Image Encryption Scheme Based on Block Scrambling, Modified Zigzag Transformation and Key Generation Using Enhanced Logistic—Tent Map". Entropy 21, n.º 7 (3 de julho de 2019): 656. http://dx.doi.org/10.3390/e21070656.

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Nowadays, the images are transferred through open channels that are subject to potential attacks, so the exchange of image data requires additional security in many fields, such as medical, military, banking, etc. The security factors are essential in preventing the system from brute force and differential attacks. We propose an Enhanced Logistic Map (ELM) while using chaotic maps and simple encryption techniques, such as block scrambling, modified zigzag transformation for encryption phases, including permutation, diffusion, and key stream generation to withstand the attacks. The results of encryption are evaluated while using the histogram, correlation analysis, Number of Pixel Change Rate (NPCR), Unified Average Change Intensity (UACI), Peak-Signal-to-Noise Ratio (PSNR), and entropy. Our results demonstrate the security, reliability, efficiency, and flexibility of the proposed method.

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Panthi, Bikash, e Nurapati Pantha. "Hydrophobicity of small alkane molecules (propane dimer) in solvents: a classical molecular dynamics study". BIBECHANA 17 (1 de janeiro de 2020): 1–12. http://dx.doi.org/10.3126/bibechana.v17i0.25504.

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Molecular Dynamics (MD) simulations of propane dimer in different solvents (water, acetonitrile and methanol) were performed by using CHARMM platform for modeling the solute and solvents. A series of Umbrella sampling MD simulations were carried out in each solvent separately and potential of mean force (PMFs) were calculated by using Weighted Histogram Analysis Method. Results show that two minima (contact minima and solvent separated minima) characterize the PMF of propane dimer in all three solvent environments. The contact minima are deeper and less sensitive to solvent environment for its position. However, significant effect in the position of second minima, solvent separated minima, was observed. Our study reveals that the interaction between propane dimer is softer in methanol and acetonitrile than in water. BIBECHANA 17 (2020) 1-12

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Ngo, Van A., Ilsoo Kim, Toby W. Allen e Sergei Y. Noskov. "Estimation of Potentials of Mean Force from Nonequilibrium Pulling Simulations Using Both Minh-Adib Estimator and Weighted Histogram Analysis Method". Journal of Chemical Theory and Computation 12, n.º 3 (10 de fevereiro de 2016): 1000–1010. http://dx.doi.org/10.1021/acs.jctc.5b01050.

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Czaplewski, Cezary, Sebastian Kalinowski, Adam Liwo e Harold A. Scheraga *. "Comparison of two approaches to potential of mean force calculations of hydrophobic association: particle insertion and weighted histogram analysis methods". Molecular Physics 103, n.º 21-23 (10 de novembro de 2005): 3153–67. http://dx.doi.org/10.1080/00268970500233797.

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Litvinov, Rustem I., Henry Shuman, David H. Farrell, Joel S. Bennett e John W. Weisel. "Interaction of the Integrin αIIbβ3 with Monomeric Fibrin at the Single-Molecule Level." Blood 114, n.º 22 (20 de novembro de 2009): 4018. http://dx.doi.org/10.1182/blood.v114.22.4018.4018.

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Abstract Abstract 4018 Poster Board III-954 Although platelets aggregated with fibrin constitute major components of in vivo blood clots and thrombi, heretofore most research has focused on fibrinogen's role in platelet aggregation. The integrin αIIbβ3 has been shown to primarily mediate platelet-fibrin interactions, but the mechanism of αIIbβ3 binding to fibrin is largely unknown and may be significantly different from binding to fibrinogen. To elucidate mechanisms of platelet interactions with fibrin, we have compared the overall reactivity, binding strength, and specificity towards αIIbβ3 of human fibrinogen vs. monomeric fibrin, using single-molecule optical trap-based rupture force spectroscopy of the surface-bound proteins. In this system, a ligand-coated bead is trapped by the laser and repeatedly brought into contact with a receptor-coated surface so that the forces required to separate the two can be measured and displayed as rupture force histograms. We have applied this technique to the interaction of fibrin(ogen) and αIIbβ3 by measuring the force required to separate a laser-trapped bead coated with either fibrinogen or monomeric fibrin from an immobilized pedestal coated with purified αIIbβ3. Experiments were performed with plasma-purified or recombinant homodimeric γA/γA and γ′/γ′ fibrin(ogen)s. The latter protein represents a splicing variant in which the γ chain has a substitution in the C-terminal four amino acids in 400-411 dodecapeptide, the major αIIbβ3-binding site in fibrinogen. Surface-bound monomeric fibrin was obtained by treating fibrinogen-coated surfaces with thrombin. Control integrin-fibrinogen interactions manifested as a characteristic bimodal rupture force histogram with rupture forces ranging from 20 pN to 140 pN, similar to what we had observed previously (PNAS, 2002, 99, 7426). The interactions were highly sensitive to inhibitory effects of abciximab and eptifibatide, specific αIIbβ3 antagonists, and to Mn2+-induced activation, indicating that they were mediated by the functional integrin. Monomeric fibrin γA/γA was at least as reactive towards αIIbβ3 as the parental fibrinogen γA/γA, sometimes exhibiting even higher binding probabilities and slightly stronger rupture forces. Fibrin-integrin interactions were less sensitive to the inhibitory effect of abciximab compared to fibrinogen, suggesting that some additional structures in αIIbβ3, not completely blocked by this Fab fragment, might be involved in binding to fibrin. Similar to fibrinogen, fibrin-integrin interactions were partially sensitive to eptifibatide, cRGD peptide and γC-dodecapeptide, indicating that their specificity is akin to fibrinogen but may not be identical. Fibrinogen γ′/γ′, lacking the established binding site for the integrin, was reactive with αIIbβ3, but the binding strength was somewhat smaller. The effect of replacing the γA with the γ′ chains in fibrinogen was qualitatively similar to competitive inhibition by the γC-dodecapeptide and resulted in complete cutoff of the larger force peak as well as in partial reduction of weaker interactions. That fibrinogen γ′/γ′ maintained its ability to bind αIIbβ3 suggests that the γ400-411 motif is not the only structure involved in the binding of immobilized fibrinogen to the integrin. Fibrin γ′/γ′ was as reactive with αIIbβ3 as fibrinogen γ′/γ′. Both of them interacted with αIIbβ3 in an RGD-sensitive manner. The data show that both surface-bound fibrinogen and monomeric fibrin are highly reactive with the integrin αIIbβ3. Fibrin is somewhat more reactive than fibrinogen in terms of binding probability and strength and is less sensitive to a specific inhibitor, abciximab, suggesting that αIIbβ3-fibrin interactions have distinct specificity. Susceptibility to competitive inhibitors, such as cRGD and γC-dodecapeptide, along with maintenance of integrin-binding activity of fibrinogen γ′/γ′ suggest that the αIIbβ3-binding sites in fibrin(ogen) are complex and include, but are not confined to, the γC-terminal 400-411 motif. Disclosures: No relevant conflicts of interest to declare.

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Matsui, Atsuya, Jean-Pierre Bellier, Takeshi Kanai, Hiroki Satooka, Akio Nakanishi, Tsukasa Terada, Takafumi Ishibe et al. "The Effect of Ethanol on Disassembly of Amyloid-β1-42 Pentamer Revealed by Atomic Force Microscopy and Gel Electrophoresis". International Journal of Molecular Sciences 23, n.º 2 (14 de janeiro de 2022): 889. http://dx.doi.org/10.3390/ijms23020889.

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The most common type of dementia, Alzheimer’s disease, is associated with senile plaques formed by the filamentous aggregation of hydrophobic amyloid-β (Aβ) in the brains of patients. Small oligomeric assemblies also occur and drugs and chemical compounds that can interact with such assemblies have attracted much attention. However, these compounds need to be solubilized in appropriate solvents, such as ethanol, which may also destabilize their protein structures. As the impact of ethanol on oligomeric Aβ assembly is unknown, we investigated the effect of various concentrations of ethanol (0 to 7.2 M) on Aβ pentameric assemblies (Aβp) by combining blue native-PAGE (BN-PAGE) and ambient air atomic force microscopy (AFM). This approach was proven to be very convenient and reliable for the quantitative analysis of Aβ assembly. The Gaussian analysis of the height histogram obtained from the AFM images was correlated with band intensity on BN-PAGE for the quantitative estimation of Aβp. Our observations indicated up to 1.4 M (8.3%) of added ethanol can be used as a solvent/vehicle without quantitatively affecting Aβ pentamer stability. Higher concentration induced significant destabilization of Aβp and eventually resulted in the complete disassembly of Aβp.

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Rahmawati, Weny Mistarika, e Febri Liantoni. "Penggunaan Arnold Cat Map Dan Beta Chaotic Map Pada Enkripsi Data Citra". Jurnal ELTIKOM 2, n.º 2 (22 de dezembro de 2018): 50–57. http://dx.doi.org/10.31961/eltikom.v2i2.85.

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Penggunaan citra dalam kehidupan sehari-hari mengalami peningkatan seiring berkembangnya teknologi informasi. Untuk itu diperlukan sebuah cara agar data citra dapat ditransmisikan dengan aman. Salah satunya adalah dengan melakukan enkripsi pada citra. Citra terenkripsi akan membuat citra hanya dapat dibaca oleh pihak yang berwenang saja. Skema yang digunakan pada proses enkripsi dapat berupa permutasi. Pada penelitian ini menggunakan Arnold cat map untuk melakukan permutasi pada enkripsi citra. Namun permutasi saja tidak cukup aman untuk mengenkripsi citra. Citra yang telah dipermutasi selanjutnya ditambah dengan algoritma lain berbasis chaos. Beta chaotic map digunakan dalam penelitian ini karena memiliki parameter yang lebih banyak dibandingkan dengan map jenis lain. Dengan parameter yang lebih besar maka akan memperkuat hasil enkripsi. Hasil pengujian yang dilakukan pada penelitian ini menunjukkan bahwa skema enkripsi memiliki ketahanan terhadap serangan brute force dan serangan analisis histogram. Citra asli akan memiliki bentuk yang sangat berbeda dengan citra hasil enkripsi yang dibuktikan dengan perhitungan nilai NPCR.

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Akiwate, Bahubali, e Latha Parthiban. "Efficient DNA Cryptographic Framework for Secured Data Encryption Based on Chaotic Sequences". International Journal of Information Security and Privacy 16, n.º 1 (janeiro de 2022): 1–18. http://dx.doi.org/10.4018/ijisp.2022010114.

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Data is big, data is diverse, data comes in zillion formats, it is important to ensure the safety and security of the shared data. With existing systems limited and evolving, the objective of the current research work is to develop a robust Image Encryption technique that is adept and effective at handling heterogeneous data and can withstand state-of-the-art hacking efforts such as brute force attacks, cropping attacks, mathematical attacks, and differential attacks. The proposed Efficient DNA Cryptographic System (EDCS) model presents a pseudorandom substitution method using logistic sine cosine chaotic maps, wherein there is very little correlation between adjacent pixels, and it can decode the image with or without noise, thereby making the proposed system noise-agnostic. The proposed EDCS-based Image model using Chaotic Maps showed enhancements in parameters such as Unified Average Changing Intensity (UACI), Number of Pixels Change Rate (NPCR), Histogram, and Entropy when compared with existing image security methods.

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Cao, Pengxin, Xiaoqing Li e Mingyue Ding. "A Fusion Method for Atomic Force Acoustic Microscopy Cell Imaging Based on Local Variance in Non-Subsampled Shearlet Transform Domain". Applied Sciences 10, n.º 21 (22 de outubro de 2020): 7424. http://dx.doi.org/10.3390/app10217424.

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Atomic force acoustic microscopy (AFAM) is a measurement method that uses the probe and acoustic wave to image the surface and internal structures of different materials. For cellular material, the morphology and phase images of AFAM reflect the outer surface and internal structures of the cell, respectively. This paper proposes an AFAM cell image fusion method in the Non-Subsampled Shearlet Transform (NSST) domain, based on local variance. First, NSST is used to decompose the source images into low-frequency and high-frequency sub-bands. Then, the low-frequency sub-band is fused by the weight of local variance, while a contrast limited adaptive histogram equalization is used to improve the source image contrast to better express the details in the fused image. The high-frequency sub-bands are fused using the maximum rule. Since the AFAM image background contains a lot of noise, and improved segmentation algorithm based on the Otsu algorithm is proposed to segment the cell region, and the image quality metrics based on the segmented region will make the evaluation more accurate. Experiments with different groups of AFAM cell images demonstrated that the proposed method can clearly show the internal structures and the contours of the cells, compared with traditional methods.

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Bawa, Parveen, e Blair Calancie. "Rate-coding of spinal motoneurons with high-frequency magnetic stimulation of human motor cortex". Canadian Journal of Physiology and Pharmacology 82, n.º 8-9 (1 de julho de 2004): 740–48. http://dx.doi.org/10.1139/y04-069.

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Rate-coding in spinal motoneurons was studied using high-frequency magnetic stimulation of the human motor cortex. The subject made a weak contraction to cause rhythmic (i.e., tonic) discharge of a single motor unit in flexor (or extensor) carpi radialis or tibialis anterior, while the motor cortical representation of that muscle was stimulated with brief trains of pulses from a Pyramid stimulator (4 Magstim units connected by 3 BiStim modules). An "m@n" stimulus train consisted of m number of pulses (1–4), with an interpulse interval (IPI) of n ms (1–6). Peristimulus time histograms were constructed for each stimulus condition of a given motor unit, and related to the average rectified surface electromyography (EMG) from that muscle. Surface EMG responses showed markedly more facilitation than single-pulse stimulation, with increasing numbers of pulses in the train; responses also tended to increase in magnitude for the longer IPI values (4 and 6 ms) tested. Motor-unit response probability increased in a manner comparable to that of surface EMG. In particular, motoneurons frequently responded twice to a given stimulus train. In addition to recruitment of new motor units, the increased surface EMG responses were, in part, a direct consequence of short-term rate-coding within the tonically discharging motoneuron. Our results suggest that human corticomotoneurons are capable of reliably following high-frequency magnetic stimulation rates, and that this activity pattern is carried over to the spinal motoneuron, enabling it to discharge at extremely high rates for brief periods of time, a pattern known to be optimal for force generation at the onset of a muscle contraction.Key words: Human, single motor unit, repetitive transcranial magnetic stimulation, rate-coding, high-frequency stimulation, corticomotoneuron, peri-stimulus time histogram.

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Prenga, Dode, Elmira Kushta e Fatjon Musli. "Enhancing Concept Inventory Analysis by Using Indexes, Optimal Histogram Idea, and the Likert Analysis". Journal of Human, Earth, and Future 4, n.º 1 (1 de março de 2023): 103–20. http://dx.doi.org/10.28991/hef-2023-04-01-08.

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Since the introduction of the Force Concept Inventory (FCI) in 1992, the CI tests have been widely used for measuring conceptual knowledge and for studying teaching issues in almost all disciplines and levels of study. A standard concept inventory analysis includes the design of a qualitative test, adequate realization of testing, calibration procedure, and comprehensive analysis of its findings. Usually, the CI test calibration is carried out through the Rasch sociometric technique, which is also used for calculating crucial indicators of knowledge such as item difficulties, students’ abilities, and many more. Whereas the quality of the tests’ design can be guaranteed by using certified and professional CI tests, the statistical adequacy of the testing merits critical attention before going on to the final step of the analysis. Also, the analysis of CI outcomes can be advanced by contemplating auxiliary tools and complementary techniques. In this framework, we propose to enforce the test index validity requirement for qualifying the CI outcomes as local or global. Specifically, the conclusions of CI analysis are acceptable for the whole population from which the sample has been extracted if the test's indexes comply with the validity requirements provided by the index theory. In the case when test indexes are out of validity range and re-conducting them is impractical for some objective circumstances or research specifics, we suggest injecting some new records into the existing one or mixing the data gathered from different samples until the new indexes are in the desired range. Using this methodology, we have reviewed our previous FCI tests, which were initially intended to demonstrate the impairment of learning in the physics discipline triggered by online learning during the pandemic closure. Through this renormalization procedure, we obtained a credible assessment of the understanding of mechanics and electromagnetism in high school students who followed online lectures during the pandemic closure. Also, by using indexes’ validity as an auxiliary tool, we identified that for measuring the knowledge of electromagnetism in students enrolled in branches where physics is a basic discipline, a shortened version of the BEMA test was a better instrument than the corresponding shortened EMCI test. Next, we used the optimal histogram idea borrowed from distribution fitting procedures to identify the natural levels of students’ abilities for solving a certain CI test. Another intriguing proposal presented in this work consists of combining an ad-hoc Likert scale assignment for usual errors in physics exams with the FCI designation of the basic commonsense confusion in mechanics for identifying their pairing features in common exams. We believe that the methods proposed herein can improve CI analysis in more general senses. Doi: 10.28991/HEF-2023-04-01-08 Full Text: PDF

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Shamsa Kanwal, Saba Inam, Fahima Hajjej, Omar Cheikhrouhou, Zainab Nawaz, Ayesha Waqar e Majid Khan. "A New Image Encryption Technique Based on Sine Map, Chaotic Tent Map, and Circulant Matrices". Security and Communication Networks 2022 (30 de outubro de 2022): 1–17. http://dx.doi.org/10.1155/2022/4152683.

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Image encryption is one of the sensitive areas used recently to save information over the Internet and confirms the security on a higher level. A new cryptosystem has been proposed for the encoding and decoding of images using sine map, chaotic tent map, and circulant matrices. The process involves three stages. The sine map is used for the permutation phase. In the substitution phase, the Hill cipher method together with prime circulant matrix are used and a chaotic tent map is used in the diffusion phase. The algorithm becomes impenetrable to resist differential- and statistical-type attacks. The algorithm's key space is sufficient in size to withstand brute-force attacks. This symmetric image encryption algorithm indicates good results for correlation analysis, key space analysis, entropy analysis, key sensitivity analysis, histogram analysis, number of pixel change rate (NPCR), unified average changing intensity (UACI), and peak signal-to-noise ratio (PSNR). From all these simulation results, we come to know that the constructed image encryption cryptosystem is systematic and vigorous, supplying better protection for image encryption.

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Ray, Sudip, Anil K. Bhowmick e S. Bandyopadhyay. "Atomic Force Microscopy Studies on Morphology and Distribution of Surface Modified Silica and Clay Fillers in an Ethylene-Octene Copolymer Rubber". Rubber Chemistry and Technology 76, n.º 5 (1 de novembro de 2003): 1091–105. http://dx.doi.org/10.5254/1.3547789.

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Abstract Topographic and phase imaging in tapping mode atomic force microscopy (TMAFM) has been performed to investigate the effect of surface modification of silica and clay fillers on the morphology and the microdispersion of the filler particles in the rubber matrix. The above fillers have been modified by using surface coating agents like an acrylate monomer (trimethylolpropane triacrylate, TMPTA) or a silane coupling agent (triethoxy vinylsilane, TEVS) followed by electron beam modification at room temperature. Both unmodified and surface modified fillers have been incorporated in an ethylene-octene copolymer rubber. The phase images of the above composites elucidate the reduction in aggregate size due to the filler surface modification, which is more pronounced in the case of silane modification. The results obtained from the section analysis and the histogram of the filler distribution further corroborate the above findings. The corresponding topographic images are characterized by various statistical quantities like roughness parameters and two-dimensional power spectral density (2-D PSD). As compared to the control silica and clay filled rubbers, a noticeable reduction in the surface roughness is observed in the case of modified filled composites. Thus, the whole study based on AFM suggests that the surface modification of the above fillers significantly reduces the filler-filler interaction, which in turn reduces the filler aggregate size and helps in improving the filler dispersion.

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Rodriguez-Falces, Javier, Francesco Negro e Dario Farina. "Correlation between discharge timings of pairs of motor units reveals the presence but not the proportion of common synaptic input to motor neurons". Journal of Neurophysiology 117, n.º 4 (1 de abril de 2017): 1749–60. http://dx.doi.org/10.1152/jn.00497.2016.

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We investigated whether correlation measures derived from pairs of motor unit (MU) spike trains are reliable indicators of the degree of common synaptic input to motor neurons. Several 50-s isometric contractions of the biceps brachii muscle were performed at different target forces ranging from 10 to 30% of the maximal voluntary contraction relying on force feedback. Forty-eight pairs of MUs were examined at various force levels. Motor unit synchrony was assessed by cross-correlation analysis using three indexes: the output correlation as the peak of the cross-histogram (ρ) and the number of synchronous spikes per second (CIS) and per trigger (E). Individual analysis of MU pairs revealed that ρ, CIS, and E were most often positively associated with discharge rate (87, 85, and 76% of the MU pairs, respectively) and negatively with interspike interval variability (69, 65, and 62% of the MU pairs, respectively). Moreover, the behavior of synchronization indexes with discharge rate (and interspike interval variability) varied greatly among the MU pairs. These results were consistent with theoretical predictions, which showed that the output correlation between pairs of spike trains depends on the statistics of the input current and motor neuron intrinsic properties that differ for different motor neuron pairs. In conclusion, the synchronization between MU firing trains is necessarily caused by the (functional) common input to motor neurons, but it is not possible to infer the degree of shared common input to a pair of motor neurons on the basis of correlation measures of their output spike trains. NEW & NOTEWORTHY The strength of correlation between output spike trains is only poorly associated with the degree of common input to the population of motor neurons. The synchronization between motor unit firing trains is necessarily caused by the (functional) common input to motor neurons, but it is not possible to infer the degree of shared common input to a pair of motor neurons on the basis of correlation measures of their output spike trains.

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Elshoush, Huwaida T., Banan M. Al-Tayeb e Khalil T. Obeid. "Enhanced Serpent algorithm using Lorenz 96 Chaos-based block key generation and parallel computing for RGB image encryption". PeerJ Computer Science 7 (17 de dezembro de 2021): e812. http://dx.doi.org/10.7717/peerj-cs.812.

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This paper presents a new approach to enhance the security and performance of the Serpent algorithm. The main concepts of this approach is to generate a sub key for each block using Lorenz 96 chaos and then run the process of encryption and decryption in ECB parallel mode. The proposed method has been implemented in Java, openjdk version “11.0.11”; and for the analysis of the tested RGB images, Python 3.6 was used. Comprehensive experiments on widely used metrics demonstrate the effectiveness of the proposed method against differential attacks, brute force attacks and statistical attacks, while achieving superb results compared to related schemes. Moreover, the encryption quality, Shannon entropy, correlation coefficients, histogram analysis and differential analysis all accomplished affirmative results. Furthermore, the reduction in encryption/decryption time was over 61%. Moreover, the proposed method cipher was tested using the Statistical Test Suite (STS) recommended by the NIST and passed them all ensuring the randomness of the cipher output. Thus, the approach demonstrated the potential of the improved Serpent-ECB algorithm with Lorenz 96 chaos-based block key generation (BKG) and gave favorable results. Specifically, compared to existing encryption schemes, it proclaimed its effectiveness.

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Huang, Huiqing, e Dongsheng Cheng. "3-Image Bit-Level Encryption Algorithm Based on 3D Nonequilateral Arnold Transformation and Hyperchaotic System". Security and Communication Networks 2020 (26 de novembro de 2020): 1–13. http://dx.doi.org/10.1155/2020/8841302.

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In this paper, we propose a novel 3-image bit-level encryption algorithm based on 3D nonequilateral Arnold transformation and hyperchaotic system. Firstly, the three plain images with N × M are decomposed into 8-bit planes and then they overlap into a 3D bit matrix with size N × M × 24 . Then, the 3D bit matrix is scrambled by 3D nonequilateral Arnold transformation and the scrambled 3D bit matrix is integrated and transformed into three 2D pixel-level images. Finally, the hyperchaotic system is used to diffuse the three 2D pixel-level images; then three diffused images are rearranged to be one color image, resulting in the encrypted image. Numerical simulations and analyses of the proposed encryption scheme are given to validate the feasibility and safety of the method. The statistical analyses like histogram, correlation, and entropy confirm that the proposed method can effectively resist statistical attacks and security key analysis shows that the key space is large enough to render the brute-force attack ineffective in proposed method. The differential analysis confirms that the proposed method is effective against differential attacks and the results of the experiment confirmed that the method can resist occlusion attack.

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Jayadi, H., N. R. Janat, B. J. Santosa, D. D. Warnana, A. D. Nugraha, H. Leopatty, I. F. Asyhar, I. U. Meidji, T. Fitriana e Ninasafitri. "Hypocenter Relocation of Local Earthquake using Double Difference Method in Central Sulawesi from BMKG Network Data: Time Periods of July 26 - August 18, 2021". IOP Conference Series: Earth and Environmental Science 1157, n.º 1 (1 de abril de 2023): 012023. http://dx.doi.org/10.1088/1755-1315/1157/1/012023.

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Abstract Last July 2021, a destructive earthquake occurred in the northern Ampana area, Central Sulawesi, with the epicenter at sea. We investigated the earthquake and found 101 hypocenter points with a magnitude of 2-6 Mw from 26 July to 18 August 2021 using the BMKG network. Of the 101 earthquakes, we relocated the hypocenter using the multiple difference method and obtained 75 earthquake events resulting from the relocation. The results obtained from the relocation are that several earthquake events with a fixed depth of 10 km have been updated. To validate the results, we used a histogram of travel time results, which depict the relocation results as good, and some close to zero. The results of the hypocenter relocation have a depth of 5 to 30 km and are collected in one location. The shift’s direction and angle from the relocation results show that most of them are in a dominant direction to the north. It is interpreted that the earthquake was caused by force activity caused by the Balantak thrust, which is in the east and has a north direction towards the study site.

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Wu, Lewen, Keping Zhou, Feng Gao, Zhongyuan Gu e Chun Yang. "Research on the Mechanical Characteristics of Cyclic Loading and Unloading of Rock Based on Infrared Thermal Image Analysis". Mathematical Problems in Engineering 2021 (10 de abril de 2021): 1–16. http://dx.doi.org/10.1155/2021/5578629.

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In the operations of underground rock engineering, such as mining, the formation of goafs is often accompanied by unloading and energy effects. In this study, a cyclic loading and unloading stress test is carried out to analyze the strength characteristics of the loaded samples under different loading and unloading ranges as well as different numbers of cycles. The rock force is accompanied by substantial energy changes. To better fit the energy analysis under cyclic loading and unloading conditions, thermal infrared radiation characteristic analysis is performed during rock loading and unloading. An infrared radiation camera is adopted to detect the infrared characteristics of the rock force process after cyclic loading and unloading. Multiangle detection is implemented on the temperature, temperature field, and frequency histogram. The analysis shows that cyclic loading and unloading first strengthen and then weaken the rock. Moreover, the failure caused by the local stress concentration leads to a sharp increase in the temperature. There are significant temperature fluctuations before and after failure, and the temperature field after failure can be divided into three zones, namely, the normal temperature zone, heating zone, and mutational temperature zone, to comprehensively reflect that rock compression failure which is accompanied by the process of energy accumulation and release. On the basis of infrared energy analysis, the index of the energy release rate is introduced, and the loading and unloading analysis model is constructed. The research results reveal that rock failure is accompanied by the process of energy accumulation and release, which provides evidence for the analysis of the spatial stability of the rock mass under cyclic loading and unloading conditions and engineering excavation.

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Ali, Hussam J., Talib M. Jawad e Hiba Zuhair. "Data security using random dynamic salting and AES based on master-slave keys for Iraqi dam management system". Indonesian Journal of Electrical Engineering and Computer Science 23, n.º 2 (1 de agosto de 2021): 1018. http://dx.doi.org/10.11591/ijeecs.v23.i2.pp1018-1029.

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In the present time, dam management is considered one of the important challenges for e-government in Iraq, becuase it needs information technology infrastructure, data integrity and protection of user privacy against Internet threats that render such vital infrastructure ineffective. This struggle between the proposed dam management system (DMS) and a multi-tier secure model specifically for the Fallujah dam (and generally for all dams) which is addressed in this paper as a case study. To do this, a relational database design will discuss the development of a multi-tier secure model for integration of the dam management framework with its functions. This paper will discusse encryption and decryption of the dam data using the advanced encryption standard (AES) algorithm with derived keys via PBKDF2 and RNG sequences generator and Slave key for salting protection. The experimental results and analysis on the speed of encryption/decryption process, entropy value, plain text sensitivity, key sensitivity, keyspaceanalysis and histogram analysis will prove the the proposed scheme can impede the known attacks like brute force attacks, statistical and differential.Thus, the encryption scheme can be implemented on the proposed DMS and any other information system, as the implementation which will be presented in the results.

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