Artigos de revistas sobre o tema "Soft transforms"
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AlZubi, Shadi, Naveed Islam e Maysam Abbod. "Multiresolution Analysis Using Wavelet, Ridgelet, and Curvelet Transforms for Medical Image Segmentation". International Journal of Biomedical Imaging 2011 (2011): 1–18. http://dx.doi.org/10.1155/2011/136034.
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The experimental study presented in this paper is aimed at the development of an automatic image segmentation system for classifying region of interest (ROI) in medical images which are obtained from different medical scanners such as PET, CT, or MRI. Multiresolution analysis (MRA) using wavelet, ridgelet, and curvelet transforms has been used in the proposed segmentation system. It is particularly a challenging task to classify cancers in human organs in scanners output using shape or gray-level information; organs shape changes throw different slices in medical stack and the gray-level intensity overlap in soft tissues. Curvelet transform is a new extension of wavelet and ridgelet transforms which aims to deal with interesting phenomena occurring along curves. Curvelet transforms has been tested on medical data sets, and results are compared with those obtained from the other transforms. Tests indicate that using curvelet significantly improves the classification of abnormal tissues in the scans and reduce the surrounding noise.
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Wang, Hongzhang, Bo Yuan, Shuting Liang, Rui Guo, Wei Rao, Xuelin Wang, Hao Chang, Yujie Ding, Jing Liu e Lei Wang. "PLUS-M: a Porous Liquid-metal enabled Ubiquitous Soft Material". Materials Horizons 5, n.º 2 (2018): 222–29. http://dx.doi.org/10.1039/c7mh00989e.
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Hui, Chung-Yuen, Zezhou Liu, Nicolas Bain, Anand Jagota, Eric R. Dufresne, Robert W. Style, Ryuji Kiyama e Jian Ping Gong. "How surface stress transforms surface profiles and adhesion of rough elastic bodies". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 476, n.º 2243 (novembro de 2020): 20200477. http://dx.doi.org/10.1098/rspa.2020.0477.
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The surface of soft solids carries a surface stress that tends to flatten surface profiles. For example, surface features on a soft solid, fabricated by moulding against a stiff-patterned substrate, tend to flatten upon removal from the mould. In this work, we derive a transfer function in an explicit form that, given any initial surface profile, shows how to compute the shape of the corresponding flattened profile. We provide analytical results for several applications including flattening of one-dimensional and two-dimensional periodic structures, qualitative changes to the surface roughness spectrum, and how that strongly influences adhesion.
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Berkner, Kathrin, e Raymond O. Wells. "Smoothness Estimates for Soft-Threshold Denoising via Translation-Invariant Wavelet Transforms". Applied and Computational Harmonic Analysis 12, n.º 1 (janeiro de 2002): 1–24. http://dx.doi.org/10.1006/acha.2001.0366.
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Jameel, Jaleel Sadoon. "Medical Image Denoising Using Mixed Transforms". Journal of University of Babylon for Engineering Sciences 26, n.º 4 (20 de fevereiro de 2018): 272–81. http://dx.doi.org/10.29196/jub.v26i4.804.
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In this paper, a mixed transform method is proposed based on a combination of wavelet transform (WT) and multiwavelet transform (MWT) in order to denoise medical images. The proposed method consists of WT and MWT in cascade form to enhance the denoising performance of image processing. Practically, the first step is to add a noise to Magnetic Resonance Image (MRI) or Computed Tomography (CT) images for the sake of testing. The noisy image is processed by WT to achieve four sub-bands and each sub-band is treated individually using MWT before the soft/hard denoising stage. Simulation results show that a high peak signal to noise ratio (PSNR) is improved significantly and the characteristic features are well preserved by employing mixed transform of WT and MWT due to their capability of separating noise signals from image signals. Moreover, the corresponding mean square error (MSE) is decreased accordingly compared to other available methods.
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McLarney, Ellen. "Beyoncé’s Soft Power". Camera Obscura: Feminism, Culture, and Media Studies 34, n.º 2 (1 de setembro de 2019): 1–39. http://dx.doi.org/10.1215/02705346-7584892.
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This article charts Beyoncé’s multimedia intervention into the politics of the Trump presidency as she draws on the work of black Muslim and Latinx artists to challenge white monopolies on representation in the Breitbart era. It specifically looks at the political interventions Beyoncé staged through collaborations with Warsan Shire, a British poet born in Kenya to Somali parents; Awol Erizku, an Ethiopian-born American artist raised in the Bronx; and Daniela Vesco, a Costa Rican photographer. This collective of artists forge a black aesthetics at a heightened level of visibility, using new performative technologies to intervene in the politics of #BlackLivesMatter, crackdowns on Muslim and Latinx refugees and immigrants, the proposed wall with Mexico, and neo-Nazi mobilization. Focusing on Beyoncé’s pregnancy announcement, the article explores the politics of representation of black bodies and black lives, as she transforms the trope of suffering black mothers and their martyred black youth into a celebration of black motherhood and the pregnant body. These images are consciously rooted in a genealogy of black women’s representations of black women’s bodies. Despite the political power of these interventions, accusations were leveled at Beyoncé of cultural appropriation and exploitation of suffering by the neoliberal entertainment machine. By mentoring these artists, Beyoncé sought to convey the fertility of creative foment across borders and power hierarchies, even if her star power ultimately eclipsed the message as well as the marginalized artist that she sought to highlight.
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Močkoř, Jiří. "Semiring-Valued Fuzzy Sets and F-Transform". Mathematics 9, n.º 23 (2 de dezembro de 2021): 3107. http://dx.doi.org/10.3390/math9233107.
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The notion of a semiring-valued fuzzy set is introduced for special commutative partially pre-ordered semirings, including basic operations with these fuzzy structures. It is showed that many standard MV-algebra-valued fuzzy type structures with standard operations, such as hesitant, intuitionistic, neutrosophic or fuzzy soft sets are, for appropriate semirings, isomorphic to semiring-valued fuzzy sets with operations defined. F-transform and inverse F-transform are introduced for semiring-valued fuzzy sets and properties of these transformations are investigated. Using the transformation of MV-algebra-valued fuzzy type structures to semiring-valued fuzzy sets, the F-transforms for these fuzzy type structures is introduced. The advantage of this procedure is, among other things, that the properties of this F-transform are analogous to the properties of the classical F-transform and because these properties are proven for any semiring-valued fuzzy sets, it is not necessary to prove them for individual fuzzy type structures.
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Liu, Chuyang, Yujing Zhang, Yu Tang, Zongrong Wang, Ning Ma e Piyi Du. "The tunable magnetic and microwave absorption properties of the Nb5+–Ni2+ co-doped M-type barium ferrite". Journal of Materials Chemistry C 5, n.º 14 (2017): 3461–72. http://dx.doi.org/10.1039/c7tc00393e.
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BaFe12−2xNbxNixO19 transforms into a potential soft magnetic material and its excellent absorption properties with a broad bandwidth cover a wide range of <18 to >40 GHz with x varying from 0 to 0.8.
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Niño-Adan, Iratxe, Itziar Landa-Torres, Diana Manjarres, Eva Portillo e Lucía Orbe. "Soft-Sensor for Class Prediction of the Percentage of Pentanes in Butane at a Debutanizer Column". Sensors 21, n.º 12 (9 de junho de 2021): 3991. http://dx.doi.org/10.3390/s21123991.
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Refineries are complex industrial systems that transform crude oil into more valuable subproducts. Due to the advances in sensors, easily measurable variables are continuously monitored and several data-driven soft-sensors are proposed to control the distillation process and the quality of the resultant subproducts. However, data preprocessing and soft-sensor modelling are still complex and time-consuming tasks that are expected to be automatised in the context of Industry 4.0. Although recently several automated learning (autoML) approaches have been proposed, these rely on model configuration and hyper-parameters optimisation. This paper advances the state-of-the-art by proposing an autoML approach that selects, among different normalisation and feature weighting preprocessing techniques and various well-known Machine Learning (ML) algorithms, the best configuration to create a reliable soft-sensor for the problem at hand. As proven in this research, each normalisation method transforms a given dataset differently, which ultimately affects the ML algorithm performance. The presented autoML approach considers the features preprocessing importance, including it, and the algorithm selection and configuration, as a fundamental stage of the methodology. The proposed autoML approach is applied to real data from a refinery in the Basque Country to create a soft-sensor in order to complement the operators’ decision-making that, based on the operational variables of a distillation process, detects 400 min in advance with 98.925% precision if the resultant product does not reach the quality standards.
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Thaj Mary Delsy, T., N. M. Nandhitha e B. Sheela Rani. "Feasibility of spectral analysis techniques for disruption analysis in Aditya tokamak". International Journal of Engineering & Technology 7, n.º 4 (5 de dezembro de 2018): 3843–46. http://dx.doi.org/10.14419/ijet.v7i4.19396.
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Aditya Tokamak is a medium size fusion reactor that uses plasma for the generation of power. Magnetic fields are used to confine plasma inside the torus. Release of plasma from its confinement is called plasma disruption. Plasma disruption is a dangerous event, which damages the in – vessel components of the Tokamak. So the early stage prediction of plasma disruption is quite important. Wavelet transform is a powerful tool for the analysis of the non - stationary signals. In this paper, analysis of plasma disruption signals using Biorthogonal wavelet transforms is perform to identify disruption. Plasma current, Vloop, Halpha, Hard X ray, Mirnov coil signal, Soft X-ray are diagnostic signals. Performance is measured in terms of sensitivity and specificity. Â
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GAVRYSH, IRYNA, ALLA YAROSHENKO, OLEKSANDRA KHLTOBINA, NATALIIA KUZEMKO, ANZHELIKA SEMENENKO e ZORIANA GONTAR. "TRANSFORMATION OF HIGHER EDUCATION IN UKRAINE IN THE CONTEXT OF GLOBALIZATION". AD ALTA: 14/01-XLI. 14, n.º 1 (30 de abril de 2024): 146–51. http://dx.doi.org/10.33543/j.140141.146151.
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In the article, globalization landscape of today higher education development is considered, and the place of Ukraine in it. It is shown that globalization transforms higher education in multifold ways, at the same time, however, evoking a vector towards glocalization. The large part of research is devoted to national security aspects of higher education within the soft power paradigm.
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Scholle, Frank, Katharine M. Bendt e Nancy Raab-Traub. "Epstein-Barr Virus LMP2A Transforms Epithelial Cells, Inhibits Cell Differentiation, and Activates Akt". Journal of Virology 74, n.º 22 (15 de novembro de 2000): 10681–89. http://dx.doi.org/10.1128/jvi.74.22.10681-10689.2000.
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ABSTRACT The Epstein-Barr virus LMP2A protein was expressed in a human keratinocyte cell line, HaCaT, and effects on epithelial cell growth were detected in organotypic raft cultures and in vivo in nude mice. Raft cultures derived from LMP2A-expressing cells were hyperproliferative, and epithelial differentiation was inhibited. The LMP2A-expressing HaCaT cells were able to grow anchorage independently and formed colonies in soft agar. HaCaT cells expressing LMP2A were highly tumorigenic and formed aggressive tumors in nude mice. The LMP2A tumors were poorly differentiated and highly proliferative, in contrast to occasional tumors that arose from parental HaCaT cells and vector control cells, which grew slowly and remained highly differentiated. Animals injected with LMP2A-expressing cells developed frequent metastases, which predominantly involved lymphoid organs. Involucrin, a marker of epithelial differentiation, and E-cadherin, involved in the maintenance of intercellular contact, were downregulated in LMP2A tumors. Whereas activation of the mitogen-activated protein kinase pathway was not observed, phosphatidylinositol-3-kinase (PI3-kinase)-dependent activation of the serine-threonine kinase Akt was detected in LMP2A-expressing cells and LMP2A tumors. Inhibition of this pathway blocked growth in soft agar. These data indicate that LMP2A greatly affects cell growth and differentiation pathways in epithelial cells, in part through activation of the PI3-kinase–Akt pathway.
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Tang, Jian, Zhuo Liu, Yong Jian Wu e Li Jie Zhao. "Modeling Difficult-to-Measure Process Parameters Based on Intrinsic Mode Functions Frequency Spectral Features of Mechanical Vibration and Acoustical Signals". Advanced Materials Research 989-994 (julho de 2014): 3671–74. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.3671.
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Heavy mechanical devices of complex industrial process produce soundly mechanical vibration and acoustical signals. Some difficult-to-measure key process parameters have direct relationship with these signals. A newly ensemble empirical mode decomposition (EEMD), Fast Fourier Transform (FFT), Mutual information (MI), and Kernel partial least squares (KPLS) based modeling approach is proposed to measure these process parameters. At first, different scale intrinsic mode functions (IMFs) of mechanical vibration and acoustical signals are obtained using EEMD technology. Then, FFT transforms these multi-scale IMFs into frequency domain, and MI based feature selection method selects interesting frequency spectral features. Finally, KPLS constructs the final soft sensor models using the selected features. Experimental results based on vibration and acoustical signals of ball mill demonstrate this approach is more effective than other exist multi-scale decomposition based methods.
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Bülow, Heiko, e Andreas Birk. "Scale-Free Registrations in 3D: 7 Degrees of Freedom with Fourier Mellin SOFT Transforms". International Journal of Computer Vision 126, n.º 7 (23 de fevereiro de 2018): 731–50. http://dx.doi.org/10.1007/s11263-018-1067-5.
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Qu, Jin, e David Du. "Mechanics Research on the Vertical Bearing Characteristics of Suction Pile Cluster in Soft Ground". Advanced Materials Research 788 (setembro de 2013): 582–85. http://dx.doi.org/10.4028/www.scientific.net/amr.788.582.
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For a suction pile, drainage condition influences the magnitude of under-pressure ('suction'). As the growth of suction, the break-out resistance transforms from local shear failure, local tensile failure to general shear failure. This paper will discuss the failure mechanism of suction pile cluster under vertical load with different drainage conditions. The finite element method and software ABAQUS are employed to analysis these problems.
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Besser, Daniel, Jacqueline F. Bromberg, James E. Darnell e Hidesaburo Hanafusa. "A Single Amino Acid Substitution in the v-Eyk Intracellular Domain Results in Activation of Stat3 and Enhances Cellular Transformation". Molecular and Cellular Biology 19, n.º 2 (1 de fevereiro de 1999): 1401–9. http://dx.doi.org/10.1128/mcb.19.2.1401.
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ABSTRACT The receptor tyrosine kinase Eyk, a member of the Axl/Tyro3 subfamily, activates the STAT pathway and transforms cells when constitutively activated. Here, we compared the potentials of the intracellular domains of Eyk molecules derived from c-Eyk and v-Eyk to transform rat 3Y1 fibroblasts. The v-Eyk molecule induced higher numbers of transformants in soft agar and stronger activation of Stat3; levels of Stat1 activation by the two Eyk molecules were similar. A mutation in the sequence Y933VPL, present in c-Eyk, to the v-Eyk sequence Y933VPQ led to increased activation of Stat3 and increased transformation efficiency. However, altering another sequence, Y862VNT, present in both Eyk molecules to F862VNT markedly decreased transformation without impairing Stat3 activation. These results indicate that activation of Stat3 enhances transformation efficiency and cooperates with another pathway to induce transformation.
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Wang, Hai Xia, Ping Zhan Si, Wei Jiang, Jin Jun Liu, Jung Goo Lee, C. J. Choi e Hong Liang Ge. "Structure and Magnetic Properties of MnAl/α-Fe Nano-Composite Powders Prepared by High-Energy Ball Milling". Advanced Materials Research 287-290 (julho de 2011): 1492–95. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.1492.
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Novel nano-composite powders composed of hard-magnetic Mn54Al46 and soft-magnetic α-Fe were prepared by high-energy ball milling. The effect of α-Fe and preparation conditions on the structure and magnetic properties of the composite powders has been investigated. The ε-MnAl transforms to γ-MnAl, τ-MnAl, and β-phase under ball milling and annealing. The saturation magnetization and coercivity of the two-phase samples decrease with increasing temperature for the τ-phase decomposes at elevated temperatures. With increasing iron content, the coercivity decrease first and then increase up to 0.33 T when the Fe content is 10 wt%. Further addition of the magnetically soft iron phase would result in a decrease of the coercivity.
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Kharitonova, E. "Soft Power Effectiveness: Problem of Evaluation". World Economy and International Relations, n.º 6 (2015): 48–58. http://dx.doi.org/10.20542/0131-2227-2015-6-48-58.
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The article focuses on the task of measuring and evaluating a state's soft power. While the soft power concept developed by Joseph Nye is currently widely accepted and used, its theoretical understanding and practical application remains challenging. Both international relations scholars and those responsible for soft power in governmental and non-state agencies are looking for the tools to assess their work and the country's standing in the world in terms of soft power. As the author of the concept and other researchers noted, evaluation and measurement may be difficult due to the number of influencing factors including the use of hard power that can overshadow soft power efforts, and also because soft power efforts can bring results only in a distant period of time. However, in response to the researchers' and policy makers' need to evaluate, measure and compare soft power related parameters, a number of international ratings evolved during the past several years, such as various ratings of soft power, nation brands, countries' reputation and presence. At the same time, such rankings have several weaknesses. First of all, they present mainly the western point of view which focuses on the parameters important for western audiences and may overlook characteristics important for other, non-western cultures. They also may be subjective due to financial reasons. Besides that, while some of the ratings aim to evaluate resources or assets of nations' soft power, other focus on results like influence or reputation. Evaluation of instruments used to enhance a country's soft power and their effectiveness is also important. In many cases, even significant resources of soft power do not guarantee strong positions in this context. Comparing certain countries' positions in different ratings helps to understand a country's standing in terms of soft power, identify strong sides and analyze whether a state's soft power potential transforms into the desired outcomes.
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Su, Chao, Heng Zhang, Shaopei Hu, Jiawei Bai e Jianjian Dai. "Combining Finite Element and Analytical methods to Contact Problems of 3D Structure on Soft Foundation". Mathematical Problems in Engineering 2020 (30 de outubro de 2020): 1–18. http://dx.doi.org/10.1155/2020/8827681.
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The computational efficiency and nonconvergence of the iteration are two main difficulties in contact problems, especially in the creep of the foundation. This paper proposes a method to analyze the structural soft foundation system affected by time. The methodology is an explicit method, combining the finite element method with the analytical method. The creep deformation of soft foundation is obtained based on Laplace transforms. The structural deformation contains the statically determinate structural deformation and rigid body displacement, solved by the finite method. The contact forces are calculated by the deformation coordination equations and equilibrium equations. The methodology is validated through augmented Lagrangian (AL) method. The results can clearly illustrate the local disengagement phenome, greatly overcome the nonconvergence of the iteration, and significantly improve computing efficiency.
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Habib, Shaista, e Muhammad Akram. "Diagnostic methods and risk analysis based on fuzzy soft information". International Journal of Biomathematics 11, n.º 08 (novembro de 2018): 1850096. http://dx.doi.org/10.1142/s1793524518500961.
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In our daily life problem we face uncertainties in making right decisions. In this study, we propose two different decision-making problems in medical field. The first problem is fever diagnosing and second problem is mouth cancer risk analysis. In the first problem, we use fuzzy soft similarity measures and fuzzy soft matrix operations to diagnose the type of fever. We consider a hypothetical case study and manipulate similarity measures on it. Our work diagnoses different patients having similar symptoms. We also develop a small application using JAVA. In the second problem, we perform risk analysis of mouth cancer. The proposed fuzzy soft expert system takes two biochemical parameters as inputs that is, serum total malondialdehyde (MDA), and serum proton donors capacity (donors_protons) and determines the risk of mouth cancer. Our study facilitates doctors by diagnosing mouth cancer at its earlier stages. There are four main components of our fuzzy soft expert system. The first component is named as fuzzification which converts crisp input into linguistic variables and formulates fuzzy sets. The second component transforms fuzzy sets into their respective fuzzy soft sets. The third component determines indispensable parameters and performs parameter reduction. The fourth component performs risk analysis by using algorithm. We use exemplary dataset and run all the components of fuzzy soft expert system to compute cancer risk.
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Chala, Gemechu, R. Karthikeyan e Tamrat Tesfaye. "Optimizing Soft Leather Production from Back Cut Skins". Journal of the American Leather Chemists Association 119, n.º 8 (1 de agosto de 2024): 331–38. http://dx.doi.org/10.34314/bg0z6y08.
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This research addresses the significant challenges in converting back cut skins of Nile crocodiles (Crocodylus niloticus) into soft leather. The process is complicated by the skins’ inherent hardness and distinct texture. Sourced from the Arba Minch Crocodile Farm, these skins are aesthetically pleasing due to their unique scale patterns. However, they are often overlooked by leather manufacturers because of their rigidity and the complexities involved in processing. Our study proposes a critical modification in the pickling and chrome tanning process, specifically designed to improve fiber opening and separation. This method effectively transforms the durable back cut skins into flexible, soft leather, enhancing their applicability in various leather goods. Furthermore, the research encompasses an extensive evaluation of the raw materials, focusing on their fat and nitrogen composition. Advanced techniques, such as scanning electron microscopy analysis, along with visual examinations and physical tests, affirm the modified tanning process’s efficacy in producing soft leather from crocodile back cut skins. These findings underscore the potential of this refined approach not only to overcome processing challenges but also to expand the use of back cut skins in the leather industry. This research not only offers new opportunities for product diversification but also promotes sustainable practices at Ethiopian Nile Crocodile Farms, contributing to innovative and environmentally responsible leather production methods.
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Baughman, David C., e Peter A. Becker. "An Analytical Fourier Transformation Model for the Production of Hard and Soft X-Ray Time Lags in Active Galactic Nuclei: Application to 1H 0707-495". Astrophysical Journal 932, n.º 2 (1 de junho de 2022): 113. http://dx.doi.org/10.3847/1538-4357/ac6e67.
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Abstract The variability of the X-ray emission from active galactic nuclei is often characterized using time lags observed between soft and hard energy bands in the detector. The time lags are usually computed using the complex cross-spectrum, which is based on the Fourier transforms of the hard and soft time series data. It has been noted that some active galactic nuclei display soft X-ray time lags, in addition to the more ubiquitous hard lags. Hard time lags are thought to be produced via propagating fluctuations, spatial reverberation, or via the thermal Comptonization of soft seed photons injected into a hot electron cloud. The physical origin of the soft lags has been a subject of debate over the last decade. Currently, the reverberation interpretation is recognized as a leading theory. In this paper, we explore the alternative possibility that the soft X-ray time lags result partially from the thermal and bulk Comptonization of monochromatic seed photons which, in the case of the narrow-line Seyfert 1 galaxy 1H 0707-495, may correlate with fluorescence of iron L-line emission. In our model, the seed photons are injected into a hot, quasi-spherical corona in the inner region of the accretion flow. We develop an exact, time-dependent analytical model for the thermal and bulk Comptonization of the seed photons based on a Fourier-transformed radiation transport equation, and we demonstrate that the model successfully reproduces both the hard and soft time lags observed from 1H 0707-495.
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GNANADURAI, D., e V. SADASIVAM. "IMAGE DE-NOISING USING DOUBLE DENSITY WAVELET TRANSFORM BASED ADAPTIVE THRESHOLDING TECHNIQUE". International Journal of Wavelets, Multiresolution and Information Processing 03, n.º 01 (março de 2005): 141–52. http://dx.doi.org/10.1142/s0219691305000701.
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This paper describes an efficient and adaptive method of threshold estimation for removing impulse noise from images, based on Double Density Wavelet Transform (DDWT). The performance of image de-noising algorithms using wavelet transforms can be improved significantly by fixing an optimum threshold value, based on the analysis of the statistical parameters of subband coefficients. In this proposed method, the choice of the threshold estimation is carried out by analyzing the statistical parameters of the wavelet subband coefficients like standard deviation, arithmetic mean and geometrical mean. Here the noisy image is first decomposed into many levels to obtain different frequency bands using DDWT. Then soft thresholding method is used to remove the noisy coefficients, by fixing the optimum threshold value by the proposed method. Experimental results on several test images by using the proposed method show that, the proposed method yields significantly superior image quality and better Peak Signal-to-Noise Ratio (PSNR). Some comparisons with the best available results will be given in order to illustrate the effectiveness of the proposed algorithm.
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Wang, Zhen, Dongni Shi, Xiaowen Wang, Yibao Chen, Zheng Yuan, Yan Li, Zhixing Ge e Wenguang Yang. "A Multifunctional Light-Driven Swimming Soft Robot for Various Application Scenarios". International Journal of Molecular Sciences 23, n.º 17 (25 de agosto de 2022): 9609. http://dx.doi.org/10.3390/ijms23179609.
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The locomotor behavior of creatures in nature can bring a lot of inspiration for the fabrication of soft actuators. In this paper, we fabricated a bionic light-driven swimming soft robot that can perform grasping of tiny objects and achieve the task of object transfer. By adding carbon nanotubes (CNTs), the temperature-sensitive hydrogels can be endowed with light-responsive properties. The fabricated composite hydrogel structure can control the contraction and expansion of volume by light, which is similar to the contraction and diastole behavior of muscles. The oscillation of the fish tail and the grasping action of the normally closed micromanipulator can be achieved by the control of the irradiation of the xenon light source. The bending of the bionic arm can be controlled by the irradiation of a near-infrared (NIR) laser, which transforms the spatial position and posture of the micromanipulator. The proposed scheme is feasible for miniaturized fabrication and application of flexible actuators. This work provides some important insights for the study of light-driven microrobots and light-driven flexible actuators.
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Alkinidri, Mohammed, Sajjad Hussain e Rab Nawaz. "Analysis of noise attenuation through soft vibrating barriers: an analytical investigation". AIMS Mathematics 8, n.º 8 (2023): 18066–87. http://dx.doi.org/10.3934/math.2023918.
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<abstract><p>In this article, the impact of fluid flow and vibration on the acoustics of a subsonic flow is examined. Specifically, it focuses on the noise generated by a convective gust in uniform flow that is scattered by a vibrating plate of limited size. The study analyzes the interaction between acoustics and structures by considering the scattering of sound waves by a soft finite barrier. To achieve this, the Wiener-Hopf technique is utilized for the analytical treatment of the acoustic model. The approach involves performing temporal and spatial Fourier transforms on the governing convective boundary value problem, then formulating the resulting Wiener-Hopf equations. The product decomposition theorem, an extended version of Liouville's theorem, and analytic continuation are employed to solve these equations. Finally, the scattered potential integral equations are computed asymptotically. This study can be significant for understanding the acoustic properties of structures and how they interact with fluid flow in subsonic environments, which could have applications in fields such as aerospace engineering, noise reduction, and structural acoustics.</p></abstract>
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Rosen, Meghan. "Math & Technology: Wax transforms soft to strong: Stiffness of plastics, foam can be tuned with temperature". Science News 186, n.º 4 (11 de agosto de 2014): 18. http://dx.doi.org/10.1002/scin.2014.5591860419.
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Chang, Chia L., e Huan J. Keh. "Slow Rotation of a Soft Colloidal Sphere Normal to Two Plane Walls". Colloids and Interfaces 7, n.º 1 (23 de fevereiro de 2023): 18. http://dx.doi.org/10.3390/colloids7010018.
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The creeping flow of a viscous fluid around a soft colloidal sphere rotating about a diameter normal to two planar walls at an arbitrary position between them is theoretically investigated in the steady limit of small Reynolds numbers. The fluid velocity outside the particle consists of the general solutions of the Stokes equation in circular cylindrical and spherical coordinates, while the fluid velocity inside the porous surface layer of the particle is expressed by the general solution of the Brinkman equation in spherical coordinates. The boundary conditions are implemented first on the planar walls by means of the Hankel transforms and then at the particle and hard-core surfaces by a collocation technique. The torque exerted on the particle by the fluid is calculated as a function of the ratio of the core-to-particle radii, ratio of the particle radius to the flow penetration length of the porous layer, and relative particle-to-wall spacings over the entire range. The wall effect on the rotating soft particle can be significant. The hydrodynamic torque exerted on the confined soft sphere increases as the relative particle-to-wall spacings decrease and stays finite even when the soft sphere contacts the plane walls. It is smaller than the torque on a hard sphere (or soft one with a reduced thickness or penetration length of the porous layer), holding the other parameters constant. For a given relative wall-to-wall spacing, this torque is minimal when the particle is situated midway between the walls and rises as it locates closer to either wall.
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Prestipino, Santi, Alessandro Sergi, Ezio Bruno e Paolo V. Giaquinta. "A variational mean-field study of clusterization in a zero-temperature system of soft-core bosons". EPJ Web of Conferences 230 (2020): 00008. http://dx.doi.org/10.1051/epjconf/202023000008.
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We work out the ground-state diagram of weakly-repulsive penetrable bosons, using mean-field theory with a Gaussian ansatz on the single-particle wave function. Upon compression, the fluid transforms into a cluster supersolid, whose structure is characterized for various choices of the embedding space. In Euclidean space, the stable crystals are those with the most compact structure, i.e., triangular and fcc in two and three dimensions, respectively. For particles confined in a spherical surface, as the sphere radius increases we observe a sequence of transitions between different cluster phases, all having a regular or semiregular polyhedron as supporting frame for the clusters. The present results are relevant for the behavior of ultracold bosons weakly coupled to a Rydberg state.
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Suhail, Sameera, Kayla Harris, Gaurav Sinha, Maayan Schmidt, Sujala Durgekar, Shivam Mehta e Madhur Upadhyay. "Learning Cephalometric Landmarks for Diagnostic Features Using Regression Trees". Bioengineering 9, n.º 11 (27 de outubro de 2022): 617. http://dx.doi.org/10.3390/bioengineering9110617.
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Lateral cephalograms provide important information regarding dental, skeletal, and soft-tissue parameters that are critical for orthodontic diagnosis and treatment planning. Several machine learning methods have previously been used for the automated localization of diagnostically relevant landmarks on lateral cephalograms. In this study, we applied an ensemble of regression trees to solve this problem. We found that despite the limited size of manually labeled images, we can improve the performance of landmark detection by augmenting the training set using a battery of simple image transforms. We further demonstrated the calculation of second-order features encoding the relative locations of landmarks, which are diagnostically more important than individual landmarks.
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Zhao, Kang, Ling Xing e Honghai Wu. "S3UCA: Soft-Margin Support Vector Machine-Based Social Network User Credibility Assessment Method". Mobile Information Systems 2021 (25 de novembro de 2021): 1–10. http://dx.doi.org/10.1155/2021/7993144.
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Among the algorithms used to assess user credibility in social networks, most of them quantify user information and then calculate the user credibility measure by linear summation. The algorithm above, however, ignores the aliasing of user credibility results under the linear summation dimension, resulting in a low evaluation accuracy. To solve this problem, we propose a user credibility evaluation method based on a soft-margin support-vector machine (SVM). This method transforms the user credibility evaluation dimension from a linear summation dimension to a plane coordinate dimension, which reduces the evaluation errors caused by user aliasing in the classification threshold interval. In the quantization of user information, the ladder assignment method is used to process the user text information and numeric information, and the weight assignment method of information entropy is used to calculate the weight assignment among different feature items, which reduces the errors caused by the inconsistency of the order of magnitude among different types of user information. Simulation results demonstrate the superiority of the proposed method in the user’s credibility evaluation results.
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GARCÍA, SILVIA, PAULINA TREJO GARCIA, JOEL MERLOS ESPERICUETA e ILCE CASTILLO GALVAN. "NANOSILICA TO MODIFY THE CONSISTENCY OF HIGH COMPRESSIBLE LACUSTRINE CLAYS". DYNA 97, n.º 2 (1 de março de 2022): 145–49. http://dx.doi.org/10.6036/10358.
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Despite the incredible advances in the most innovative branch of materials science, the nanotechnology research on its application in the geotechnical field is still very limited. Since many minerals in soil and rocks are nanomaterials and their chemical reactions are at the nanoscale, there is a great potential for the use of this important technology in different geotechnical problems. In this study, the stabilization of a soft lacustrine clay using nano-SiO2 is investigated. Through the examination of the Atterberg Limits, as the simplest and most affordable indicators of the consistency of these highly compressible and plastic materials, it is shown that the addition of nanosilica to clay masses substantially modifies their compressibility and resistance as well as their drainage and absorption capacities. When nano-SiO2 is mixed these very plastic and high-water content clays, it transforms them into consistent masses (from very soft to firm). The results presented contribute to widen the knowledge about nano-substances and plastic soils revealing the effects on exceptional lacustrine clays.
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Pascu, Nicoleta Elisabeta, e Tiberiu Dobrescu. "Modeling, Texturing and Lighting in CAD Applications". Advanced Materials Research 423 (dezembro de 2011): 116–27. http://dx.doi.org/10.4028/www.scientific.net/amr.423.116.
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Numerous modeling techniques exist, as well as many modeling formats. Point modeling, edge loop modeling, box modeling and paint modeling are a few of the polygon modeling techniques. Polygon proxy modeling is a variation of subdivision modeling. NURBS surfaces are used extensively in industrial design, manufacturing, and the automotive industry. Texturing and lighting transforms the dull-gray denizens of the modeling world into lifelike objects. Although texturing is nothing without good lighting, good lighting is nothing without good texturing. This article presents the process of modeling, texturing, lighting and rendering a scene in 3D. It also shows how create realistic fur, and implement studio lighting to create nice and soft shadows and highlights.
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Rajaguru, Harikumar, e Vijayakumar Thangavel. "Wavelets and Morphological Operators Based Classification of Epilepsy Risk Levels". Mathematical Problems in Engineering 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/813197.
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The objective of this paper is to compare the performance of Singular Value Decomposition (SVD), Expectation Maximization (EM), and Modified Expectation Maximization (MEM) as the postclassifiers for classifications of the epilepsy risk levels obtained from extracted features through wavelet transforms and morphological filters from EEG signals. The code converter acts as a level one classifier. The seven features such as energy, variance, positive and negative peaks, spike and sharp waves, events, average duration, and covariance are extracted from EEG signals, out of which four parameters like positive and negative peaks, spike and sharp waves, events, and average duration are extracted using Haar, dB2, dB4, and Sym8 wavelet transforms with hard and soft thresholding methods. The above said four features are also extracted through morphological filters. The performance of the code converter and classifiers are compared based on the parameters such as Performance Index (PI) and Quality Value (QV). The Performance Index and Quality Value of code converters are at low value of 33.26% and 12.74, respectively. The highest PI of 98.03% and QV of 23.82 are attained at dB2 wavelet with hard thresholding method for SVD classifier. All the postclassifiers are settled at PI value of more than 90% at QV of 20.
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Mizoue, Yumi, Tomomi Ikeda, Takako Ikegami, Oleksandra Riabets, Yoshie Oishi, Morikuni Tobita, Hidenori Akutsu, Koichi Hattori, Beate Heissig e Hiroshi Koide. "The stem cell transcription factor ZFP296 transforms NIH3T3 cells and promotes anchorage-independent growth of cancer cells". International Journal of Developmental Biology 67, n.º 4 (2023): 147–53. http://dx.doi.org/10.1387/ijdb.230143hk.
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Cancer cells and embryonic stem (ES) cells share several biological properties, suggesting that some genes expressed in ES cells may play an important role in cancer cell growth. In this study, we investigated the possible role of zinc finger protein 296 (ZFP296), a transcription factor expressed in ES cells, in cancer development. First, we found that overexpression of Zfp296 in NIH3T3 mouse fibroblasts induced two phenomena indicative of cell transformation: enhanced proliferation under low-serum conditions and anchorage-independent growth. We also found that Zfp296 expression was upregulated in the tumor area of a mouse model of colon carcinogenesis. In addition, the expression levels of ZFP296 in various human cell lines were generally low in normal cells and relatively high in cancer cells. Finally, using a soft agar assay, we found that overexpression of ZFP296 promoted the anchorage-independent growth of cancer cells, while its knockdown had the opposite effect. Overall, these results suggest a possible role of the ES-specific transcription factor ZFP296 in cancer.
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Sun, Minna, Wenyu Chen, Lei Qin e Xu-Ming Xie. "The Effect of Colloidal Nanoparticles on Phase Separation of Block and Heteroarm Star Copolymers Confined between Polymer Brushes". Materials 17, n.º 4 (7 de fevereiro de 2024): 804. http://dx.doi.org/10.3390/ma17040804.
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The effect of colloidal nanoparticles on the phase changes of the amphiphilic AB linear diblock, A1A2B, and A2B heteroarm star copolymers confined between two polymer brush substrates was investigated by using a real-space self-consistent field theory. By changing the concentrations of nanoparticles and polymer brushes, the phase structure of the amphiphilic AB copolymer transforms from lamellar to core-shell hexagonal phase to cylinder phase. The pattern of A2B heteroarm star copolymer changes from core-shell hexagonal phases to lamellar phases and the layer decreases when increasing the density of the polymer brushes. The results showed that the phase behavior of the system is strongly influenced by the polymer brush architecture and the colloidal nanoparticle numbers. The colloidal nanoparticles and the soft confined surface of polymer brushes make amphiphilic AB copolymers easier to form ordered structures. The dispersion of the nanoparticles was also investigated in detail. The soft surfaces of polymer brushes and the conformation of the block copolymers work together to force the nanoparticles to disperse evenly. It will give helpful guidance for making some new functional materials by nano etching technology, nano photoresist, and nanoprinting.
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Eid, Alexandre, Guy Clerc, Badr Mansouri e Stella Roux. "A Novel Deep Clustering Method and Indicator for Time Series Soft Partitioning". Energies 14, n.º 17 (4 de setembro de 2021): 5530. http://dx.doi.org/10.3390/en14175530.
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The aerospace industry develops prognosis and health management algorithms to ensure better safety on board, particularly for in-flight controls where jamming is dreaded. For that, vibration signals are monitored to predict future defect occurrences. However, time series are not labeled according to severity level, and the user can only assess the system health from the data mining procedure. To that extent, a clustering algorithm using a deep neural network core is developed. Time series are encoded into pictures to be fed into an artificially trained neural network: U-NET. From the segmented output, one-dimensional information on cluster frontiers is extracted and filtered without any parameter selection. Then, a kernel density estimation finally transforms the signal into an empirical density. Ultimately, a Gaussian mixture model extracts the latter independent components. The method empowered us to reveal different degrees of severity faults in the studied data, with their respective likelihoods, without prior knowledge. It was then compared to state-of-the-art machine learning algorithms. However, internal clustering results evaluation for time series is an open question. As the state-of-the-art indexes were not producing relevant results, a new indicator was built to fulfill this task. We applied the whole method to an actuator consisting of an induction machine linked to a ball screw. This study lays the groundwork for future training of diagnosis and prognosis structures in the health management framework.
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Zhang, Min, Jiaming Guo, Chengying Ma, Guangjun Qiu, Junjie Ren, Fanguo Zeng e Enli Lü. "An Effective Prediction Approach for Moisture Content of Tea Leaves Based on Discrete Wavelet Transforms and Bootstrap Soft Shrinkage Algorithm". Applied Sciences 10, n.º 14 (14 de julho de 2020): 4839. http://dx.doi.org/10.3390/app10144839.
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The traditional method used to determine the moisture content of tea leaves is time consuming and destructive. To address this problem, an effective and non-destructive prediction method based on near-infrared spectroscopy (NIRS) is proposed in this paper. This new method combines discrete wavelet transforms (DWT) with the bootstrap soft shrinkage algorithm (BOSS). To eliminate uninformative or interfering variables, DWT is applied to remove the noise in the spectral data by decomposing the origin spectrum into six layers. BOSS is used to select informative variables by reducing the dimensions of the sub-layers’ reconstruction spectrum. After selecting the effective variables using DWT and BOSS, a prediction model based on partial least squares (PLS) is built. To validate effectiveness and stability of the prediction model, full-spectrum PLS, genetic algorithm PLS (GA-PLS), and interval PLS (iPLS) were compared with the proposed method. The experiment results illustrate that the proposed prediction model outperforms the other classical models considered in this study and shows promise for the prediction of the moisture content in Yinghong No. 9 tea leaves.
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Buttersack, Tillmann, Philip E. Mason, Ryan S. McMullen, H. Christian Schewe, Tomas Martinek, Krystof Brezina, Martin Crhan et al. "Photoelectron spectra of alkali metal–ammonia microjets: From blue electrolyte to bronze metal". Science 368, n.º 6495 (4 de junho de 2020): 1086–91. http://dx.doi.org/10.1126/science.aaz7607.
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Experimental studies of the electronic structure of excess electrons in liquids—archetypal quantum solutes—have been largely restricted to very dilute electron concentrations. We overcame this limitation by applying soft x-ray photoelectron spectroscopy to characterize excess electrons originating from steadily increasing amounts of alkali metals dissolved in refrigerated liquid ammonia microjets. As concentration rises, a narrow peak at ~2 electron volts, corresponding to vertical photodetachment of localized solvated electrons and dielectrons, transforms continuously into a band with a sharp Fermi edge accompanied by a plasmon peak, characteristic of delocalized metallic electrons. Through our experimental approach combined with ab initio calculations of localized electrons and dielectrons, we obtain a clear picture of the energetics and density of states of the ammoniated electrons over the gradual transition from dilute blue electrolytes to concentrated bronze metallic solutions.
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Mikami, Tsuyoshi, Hirotaka Takahashi e Kazuya Yonezawa. "DETECTING NONLINEAR AND NONSTATIONARY PROPERTIES OF POST-APNEIC SNORING SOUNDS USING HILBERT–HUANG TRANSFORM". Biomedical Engineering: Applications, Basis and Communications 31, n.º 03 (27 de maio de 2019): 1950017. http://dx.doi.org/10.4015/s1016237219500170.
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This study focuses on patients with severe obstructive sleep apnea syndrome (OSAS), and clarifies the existence of nonlinear and nonstationary properties in post-apneic snoring sounds. Many researchers have tried to discover intrinsic properties of the snoring sounds in OSAS patients for the past decades using linear frequency analysis, but no one has shown any evidence of the existence of nonlinearity and nonstationarity based on the quantitative evaluation of the post-apneic snoring sounds. In this study, Hilbert–Huang transform (HHT), which is designed for analyzing nonlinear and nonstationary signals, is adopted to generate a time-frequency map and the temporal variation in the spectral density is quantitatively evaluated using the averaged Kullback–Leibler divergence (AKL). As a result, for six OSAS patients, there is a tendency that most of AKL calculated from post-apneic snores are higher than those from non-apneic snores, which indicates that post-apneic snores are more nonstationary. In addition, we also evaluated the difference between the HHT time-frequency maps and spectrograms using short-time fourier transforms (STFT). Such analyses revealed that frequency fluctuations inherent to snoring can be adequately represented through HHT, but not with STFT. These nonlinear and nonstationary properties seem to be highly related to the physiological phenomena of OSAS, two of which are the explosive airflow after reopening of the closed airway and the collision vibration of the soft tissues.
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Mohankumar, M., S. Akilan, B. Hariprasath, R. Ariprasath e S. Dhanu Dharsan. "A Novel Undistorted Image Fusion and DWT Based Compression Model with FPGA Implementation for Medical Applications". Middle East Journal of Applied Science & Technology 05, n.º 02 (2022): 09–16. http://dx.doi.org/10.46431/mejast.2022.5202.
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The usage of a fused image and compressed model in a VLSI implementation is demonstrated. In this study, distortion correction is also considered. In distortion correction models, least-squares estimate is utilized. The technique of picture fusion is widely employed in medical imaging. Many pictures are obtained from various sensors (or) multiple images are captured at different times by one sensor in the image fusion approach. CT scans give useful information on denser tissue with the least amount of distortion. The information obtained from a magnetic resonance imaging (MRI) of soft tissue with significant distortion is useful. The DWT-based image fusion approach employs discrete wavelet transforms, a novel multi-resolution analytic tool. Back mapping expansion polynomial is used to reduce computer complexity. Using 0.18um technology, the suggested VLSI design achieves 218MHz with 1480 logical components.
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Yan, Jie, e Cong Wang. "Receding Contact Problem of Multi-Layered Elastic Structures Involving Functionally Graded Materials". Crystals 12, n.º 3 (6 de março de 2022): 354. http://dx.doi.org/10.3390/cryst12030354.
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This paper studies a receding contact problem of a functionally graded layer laminate pressed against a functionally graded coated homogeneous half-plane substrate by a rigid flat indenter. The shear modulus of the functionally graded materials with a constant Poisson’s ratio is modeled by an exponential function which varies along the thickness direction. Both the governing equations and the boundary conditions of the receding contact problem are converted into a pair of singular integral equations using the Fourier integral transforms, which are numerically integrated by the Chebyshev–Gauss quadrature. The contact pressure and the contact size at both contact interfaces are eventually obtained iteratively, as developed from the steepest descent algorithm. Extensive parametric studies suggest that it is possible to regulate the contact pressure and contact size by constructing the top layer from a soft functionally graded material.
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Yang, Jianlin, Xinxin Li, Mark Runciman, James Avery, Zhangxi Zhou, Zhijun Sun e George Mylonas. "A Novel, Soft, Cable-Driven Parallel Robot for Minimally Invasive Surgeries Based on Folded Pouch Actuators". Applied Sciences 14, n.º 10 (11 de maio de 2024): 4095. http://dx.doi.org/10.3390/app14104095.
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This paper introduces a soft, cable-driven parallel robot for minimally invasive surgeries. The robot comprises a pneumatic inflatable scaffold, six hydraulic, folded pouch actuators, and a hollow, cylindrical end-effector offering five degrees of freedom. A key development is the design of the pouch actuators, which are small, low-profile, simple structures, capable of a high stroke of 180° angular displacement. The scaffold, actuators, and plastic cables are economically and rapidly fabricated using laser cutting and welding techniques. Constructed primarily from soft plastic materials, the robot can be compactly folded into a cylinder measuring 110 mm in length and 14 mm in diameter. Upon inflation, the scaffold transforms into a hexagonal prism structure with side lengths of 34 mm and edge lengths of 100 mm. The kinematic model of the robot has been developed for workspace calculation and control purposes. A series of tests have been conducted to evaluate the performance of the actuator and the robot. Repeatability tests demonstrate the robot’s high repeatability, with mean and root mean square errors of 0.3645 mm and 0.4186 mm, respectively. The direct connection between the end-effector and the actuators theoretically eliminates cable friction, resulting in a hysteresis angle of less than 2°, as confirmed by the tracking results. In addition, simulated surgical tasks have been performed to further demonstrate the robot’s performance.
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Valentinis, B., A. Morrione, S. J. Taylor e R. Baserga. "Insulin-like growth factor I receptor signaling in transformation by src oncogenes." Molecular and Cellular Biology 17, n.º 7 (julho de 1997): 3744–54. http://dx.doi.org/10.1128/mcb.17.7.3744.
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R- cells, a line of mouse embryo fibroblasts with a targeted disruption of the insulin-like growth factor I (IGF-I) receptor genes, are refractory to transformation by several viral and cellular oncogenes. Using colony formation in soft agar as a measure of full transformation, we report here that R- cells can be transformed by v-src, although they still cannot be transformed by the activated c-src527 (mutation at tyrosine 527 to phenylalanine), which readily transforms mouse embryo cells with a wild-type number of IGF-I receptors (W cells). Although v-src is a more potent inducer of tyrosine phosphorylation than c-src527, the extent of phosphorylation of either insulin receptor substrate 1 or Shc, two of the major substrates of the IGF-I receptor, does not seem sufficiently different to explain the qualitative difference in soft agar growth. v-src, however, is considerably more efficient than c-src527 in its ability to tyrosyl phosphorylate, in R- cells, the focal adhesion kinase, Stat1, and p130cas. These results indicate that v-src, but not c-src527, can bypass the requirement for a functional IGF-I receptor in the full transformation of mouse embryo fibroblasts and suggest that qualitative and quantitative differences between the two oncogenes can be used to identify some of the signals relevant to the mechanism(s) of transformation.
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Zeng, Ming, Yu-Jia Li, Tao Ren e Qing Tu. "Material stiffness control of compliant tools by using electromagnetic suction". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, n.º 13 (28 de fevereiro de 2019): 4719–28. http://dx.doi.org/10.1177/0954406219834059.
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Variable rigidity materials that are safe, controllable, reversible, and repeatable have potentially widespread implications in robotic technologies. This paper presents a method for controlling the stiffness of materials for compliant tools, such as grippers, soft robots, and endoscopes. The force of electromagnetic suction transforms two structures from their relaxed-state into a more rigid state. The system presented here has the ability of quickly increasing the stiffness with increased current in the coils that create electromagnetic suction, wherein the stiffness can be controlled by the variation of supply current. The process of controlling stiffness variation is reversible and repeatable under the safe voltage of human body. The system can lead to the production of tools that are small, flexible, dexterous, and safe. Suction force, friction force, and rotational stiffness were calculated to evaluate the performance of the system. Experiments were carried out to verify the proposed concept and the calculations.
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Mustafa, Firas Mahmood. "Image Enhancement based on the Histogram Equalization and Multiresolution Discrete Stationary Wavelet Transforms". Academic Journal of Nawroz University 11, n.º 2 (23 de abril de 2022): 50–59. http://dx.doi.org/10.25007/ajnu.v11n2a1323.
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In recent years, due to the tremendous development that took place on the Internet and its applications in the aspects of human life, the demands of using digital images have also increased dramatically, and that opens up horizons for scientific research in the field of improving the quality of the digital images by removing the noise that caused by to processes that are applied within network transmissions like performing storage, retrieval, and encryption to preserve privacy. All these effects are yielded to reduce image quality and loss of visual information. To surmount this problem, image enhancement methods are used to eliminate the noise while preserving supreme exact details and essential characteristics as much as possible in the digital image. The wavelet image enhancement technique played a critical role in this field by attempts to reduce noise in the image while retaining the vital features of the image due to the capability to separate the image into sub-bands (sub-images) and influence the frequencies of each sub-band separately, where acquiring the original image content is essential to obtaining reliable performance.
Different enhancement techniques have been realized by many researchers so far. Each technique has its own privileges and shortcomings. In this work, a proposed procedure is presented and effectuated to the image modified by Additive White Gaussian Noise (AWGN). The proposed enhancement operation was achieved using the combination of Histogram Equalization with a two-dimensional stationary discrete wavelet transform (2D-SWT) as a multi-resolution analysis technique in image processing at three levels of decomposition to obtain revised results of the method of noise removing. To distinguish and eliminate noise from affected pixel points in the wavelet domain the 2D-SWT is used based on the hard and soft threshold systems on both high and low frequencies to decrease noise from the noisy image. Then, the multi-level 2D inverse wavelet transform (2D-IWT) is applied to eliminate noise and complete the synthesis of the image by the proposed image enhancement techniques.
In the end, the performance of the proposed methods has been evaluated by using the Peak Signal to Noise Ratio (PSNR). Experimental measurements determine that the results of the proposed techniques enhanced the PSNR by about (16.16%) with respect to the results of the related works, and the structure of the image quality has also been improved in terms of edges retaining and greater noise elimination.
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Chou, M. M., J. E. Fajardo e H. Hanafusa. "The SH2- and SH3-containing Nck protein transforms mammalian fibroblasts in the absence of elevated phosphotyrosine levels". Molecular and Cellular Biology 12, n.º 12 (dezembro de 1992): 5834–42. http://dx.doi.org/10.1128/mcb.12.12.5834-5842.1992.
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We have established the human nck sequence as a new oncogene. Nck encodes one SH2 and three SH3 domains, the Src homology motifs found in nonreceptor tyrosine kinases, Ras GTPase-activating protein, phosphatidylinositol 3-kinase, and phospholipase C-gamma. Overexpression of human nck in 3Y1 rat fibroblasts results in transformation as judged by alteration of cell morphology, colony formation in soft agar, and tumor formation in nude BALB/c mice. However, overexpression of nck does not induce detectable elevation of the phosphotyrosine content of specific proteins, as is observed for v-crk, another SH2/SH3-containing oncogene. Despite this fact, we demonstrate that Nck retains the ability to bind tyrosine phosphorylated proteins in vitro, using a fusion protein of Nck with glutathione-S-transferase (GST). Moreover, when incubated with lysates prepared from v-src-transformed 3Y1 cells or the nck-overexpressing cell lines, GST-Nck binds to both p60v-src and serine/threonine kinases, respectively. Although phosphotyrosine levels are not elevated in the nck-expressing fibroblasts, vanadate treatment of these cells results in a phosphotyrosine pattern that is altered from the parental 3Y1 pattern, suggestive of a perturbation of indigenous tyrosine kinase pathways. These results suggest the possibility that human nck induces transformation in 3Y1 fibroblasts by virtue of its altered affinity or specificity for the normal substrates of its rat homolog and that Nck may play a role in linking tyrosine and serine/threonine kinase pathways within the cell.
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Chou, M. M., J. E. Fajardo e H. Hanafusa. "The SH2- and SH3-containing Nck protein transforms mammalian fibroblasts in the absence of elevated phosphotyrosine levels." Molecular and Cellular Biology 12, n.º 12 (dezembro de 1992): 5834–42. http://dx.doi.org/10.1128/mcb.12.12.5834.
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We have established the human nck sequence as a new oncogene. Nck encodes one SH2 and three SH3 domains, the Src homology motifs found in nonreceptor tyrosine kinases, Ras GTPase-activating protein, phosphatidylinositol 3-kinase, and phospholipase C-gamma. Overexpression of human nck in 3Y1 rat fibroblasts results in transformation as judged by alteration of cell morphology, colony formation in soft agar, and tumor formation in nude BALB/c mice. However, overexpression of nck does not induce detectable elevation of the phosphotyrosine content of specific proteins, as is observed for v-crk, another SH2/SH3-containing oncogene. Despite this fact, we demonstrate that Nck retains the ability to bind tyrosine phosphorylated proteins in vitro, using a fusion protein of Nck with glutathione-S-transferase (GST). Moreover, when incubated with lysates prepared from v-src-transformed 3Y1 cells or the nck-overexpressing cell lines, GST-Nck binds to both p60v-src and serine/threonine kinases, respectively. Although phosphotyrosine levels are not elevated in the nck-expressing fibroblasts, vanadate treatment of these cells results in a phosphotyrosine pattern that is altered from the parental 3Y1 pattern, suggestive of a perturbation of indigenous tyrosine kinase pathways. These results suggest the possibility that human nck induces transformation in 3Y1 fibroblasts by virtue of its altered affinity or specificity for the normal substrates of its rat homolog and that Nck may play a role in linking tyrosine and serine/threonine kinase pathways within the cell.
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Jain, Nishant, Arvind Yadav, Yogesh Kumar Sariya e Arun Balodi. "Analysis of Discrete Wavelet Transforms Variants for the Fusion of CT and MRI Images". Open Biomedical Engineering Journal 15, n.º 1 (31 de dezembro de 2021): 204–12. http://dx.doi.org/10.2174/1874120702115010204.
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Background: Medical image fusion methods are applied to a wide assortment of medical fields, for example, computer-assisted diagnosis, telemedicine, radiation treatment, preoperative planning, and so forth. Computed Tomography (CT) is utilized to scan the bone structure, while Magnetic Resonance Imaging (MRI) is utilized to examine the soft tissues of the cerebrum. The fusion of the images obtained from the two modalities helps radiologists diagnose the abnormalities in the brain and localize the position of the abnormality concerning the bone. Methods: Multimodal medical image fusion procedure contributes to the decrease of information vulnerability and improves the clinical diagnosis exactness. The motive is to protect salient features from multiple source images to produce an upgraded fused image. The CT-MRI image fusion study made it conceivable to analyze the two modalities straightforwardly. Several states of the art techniques are available for the fusion of CT & MRI images. The discrete wavelet transform (DWT) is one of the widely used transformation techniques for the fusion of images. However, the efficacy of utilization of the variants of wavelet filters for the decomposition of the images, which may improve the image fusion quality, has not been studied in detail. Therefore the objective of this study is to assess the utility of wavelet families for the fusion of CT and MRI images. In this paper investigation on the efficacy of 8 wavelet families (120 family members) on the visual quality of the fused CT & MRI image has been performed. Further, to strengthen the quality of the fused image, two quantitative performance evaluation parameters, namely classical and gradient information, have been calculated. Results: Experimental results demonstrate that amongst the 120 wavelet family members (8 wavelet families), db1, rbio1.1, and Haar wavelets have outperformed other wavelet family members in both qualitative and quantitative analysis. Conclusion: Quantitative and qualitative analysis shows that the fused image may help radiologists diagnose the abnormalities in the brain and localize the position of the abnormality concerning the bone more easily. For further improvement in the fused results, methods based on deep learning may be tested in the future.
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Zhu, Chuanqi, Hao Fan, Wanrong Liu e Shaobo Li. "Mechanical Mechanism of Water Injection to Enhance the Stability of Soft Coal". Advances in Materials Science and Engineering 2021 (14 de setembro de 2021): 1–10. http://dx.doi.org/10.1155/2021/9374217.
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The physical and mechanical properties of soft coal body constitute one of the most important factors inducing coal wall spalling. In order to explore the mechanical essence of coal instability disaster and stability enhancement of water injection, the 7# coal in Huainan mining area is taken as the research object. Firstly, the distribution characteristics of coal particle size, point-load strength, original water content, microstructure characteristics, and shear strength of coal under different water contents are measured by laboratory tests. Then, based on the test results, the cementation morphology and force evolution law of granular coal water in coal body are analyzed using liquid bridge theory. The results show the following: (1) With the increase of particle size, the mass ratio of granular coal increases gradually. The percentage of particle coal with particle size less than 2.5 mm accounts for 47.157%, fractal dimension is 2.172, and uniaxial compressive strength and tensile strength are 3.822 MPa and 0.165 MPa, respectively. (2) The coal body is dry (the original moisture content is 1.336%), containing a large number of loose particles, pores, fissures, and other microfabrics. This “low water content and multiporosity” feature is the essential reason for its low strength, fragmentation, and instability and disaster. (3) In the process of water content increasing from 0.966% to 26.580%, the shear stress-displacement curve of coal body gradually changes from softening type to hardening type, and the failure type transitions from brittleness to ductility. The cohesive force increases first and then decreases, while the angle of internal friction almost has no change. (4) After reasonable water injection, the shape of liquid bridge in coal body changes into capillary tube, and the liquid bridge force reaches the maximum value, which transforms from a highly unstable bulk to a stable continuum. The research results have important theoretical significance and practical value for the safe and efficient mining of soft coal seams.
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Talarico, D., M. M. Ittmann, R. Bronson e C. Basilico. "A retrovirus carrying the K-fgf oncogene induces diffuse meningeal tumors and soft-tissue fibrosarcomas". Molecular and Cellular Biology 13, n.º 4 (abril de 1993): 1998–2010. http://dx.doi.org/10.1128/mcb.13.4.1998-2010.1993.
Texto completo da fonteResumo:
The K-fgf/hst oncogene encodes a growth factor of the fibroblast growth factor (FGF) family and transforms cells through an autocrine mechanism which requires extracellular activation of its receptor(s). To identify the cell and tissue targets of K-fgf oncogenic potential in vivo, we constructed a recombinant retrovirus carrying the human K-fgf cDNA and injected it, together with helper Moloney murine leukemia virus, into immunocompetent as well as nude mice. The original construct was highly transforming in tissue culture but produced no detectable pathologies in vivo with the exception of a single fibrosarcoma which arose after a long latency. The virus produced by this tumor appears to have undergone a complex series of recombination events involving the helper Moloney murine leukemia virus. It encodes an Env/K-FGF fusion protein whose expression is under the control of a hybrid long terminal repeat. This virus (designated MFS, for meningeal fibrosarcoma) induces tumors in mice with high frequency and short latency. These neoplasms consist of aggressive fibrosarcomas of soft tissue as well as diffuse meningeal tumors originating from the dura mater that surround the whole central nervous system and cause severe hydrocephalus. The Env/K-FGF fusion protein expressed by the MFS virus has retained all of the biological properties of native K-FGF, including secretion, mitogenic activity, heparin binding, and neutralization by anti-K-FGF antibodies. These and other results indicate that the tumors induced by the MFS virus result from the oncogenic potential of K-FGF.