Articles de revues : « Reflection pattern »

1

Halliwell, Lesley. « Pattern : Entry and reflection ». Drawing : Research, Theory, Practice 4, n^o 1 (1 avril 2019) : 97–102. http://dx.doi.org/10.1386/drtp.4.1.97_7.

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Hussein, Bilal, Aref Mehanna et Yahia Rabih. « Visitor Design Pattern Using Reflection Mechanism ». International Journal of Software Innovation 8, n^o 1 (janvier 2020) : 92–107. http://dx.doi.org/10.4018/ijsi.2020010106.

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Design patterns of today play a fundamental role in software development and implementation and provide a wide range of design solutions for recurring problems. Most research in this area focus on the creation and update of design patterns in order to fill all the gaps produced by their original structures. The purpose of this article is to present the visitor design pattern, to show its advantages in the software development process, and to provide it in a new version that allows the software to be easily upgraded without making complex modifications. This contribution consists in updating the structure and implementation of the Visitor design pattern using the reflection mechanism.

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Du, Zhou, Ville Viikari, Juha Ala-Laurinaho, Aleksi Tamminen et Antti V. Raisanen. « ANTENNA PATTERN RETRIEVAL FROM REFLECTION COEFFICIENT MEASUREMENTS WITH REFLECTIVE LOADS ». Progress In Electromagnetics Research 148 (2014) : 15–22. http://dx.doi.org/10.2528/pier14050902.

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Vanden Eynden, Frederic, Bachar El-Oumeiri, Thierry Bové, Guido Van Nooten et Patrick Segers. « Proximal pressure reducing effect of wave reflection in the pulmonary circulation disappear in obstructive disease : insight from a rabbit model ». American Journal of Physiology-Heart and Circulatory Physiology 316, n^o 5 (1 mai 2019) : H992—H1004. http://dx.doi.org/10.1152/ajpheart.00635.2018.

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Locating the site of increased resistance within the vascular tree in pulmonary arterial hypertension could assist in both patient diagnosis and tailoring treatment. Wave intensity analysis (WIA) is a wave analysis method that may be capable of localizing the major site of reflection within a vascular system. We investigated the contribution of WIA to the analysis of the pulmonary circulation in a rabbit model with animals subjected to variable occlusive pulmonary disease. Animals were embolized with different sized microspheres for 6 wk ( n = 10) or underwent pulmonary artery (PA) ligation for 6 wk ( n = 3). These animals were compared with a control group ( n = 6) and acutely embolized animals ( n = 4). WIA was performed and compared with impedance-based methods to analyze wave reflections. The control group showed a relatively high extent of reflected waves (15.7 ± 10.6%); reflections had a net effect of pressure reduction during systole, suggesting an open-end reflector. The pattern of wave reflection was not different in the group with partial PA ligation (12.4 ± 4.1%). In the chronically embolized group, wave reflection was not observed (3.6 ± 1.5%). In the acute embolization group, wave reflection was more prominent (37.3 ± 12.6%), with the appearance of a novel wave increasing pressure, suggesting the appearance of a closed-end reflector. Wave reflections of an open-end type are present in the normal rabbit pulmonary circulation. However, the pattern and nature of reflections vary according to the extent of pulmonary vascular occlusion. NEW & NOTEWORTHY The study proposes an original framework of a complementary analysis of wave reflections in the time domain and in the frequency domain. The methodology was used in the pulmonary circulation with different forms of chronic obstructions. The results suggest that the pulmonary vascular tree generates a reflection pattern that could actually assist the heart during ejection, and chronic obstruction significantly modifies the pattern.

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Wang, Su Ling, Xiao Bang Yang et Ya Ning Liu. « Reflection Property of the Two-Dimensional High Impedance Surface ». Applied Mechanics and Materials 312 (février 2013) : 635–38. http://dx.doi.org/10.4028/www.scientific.net/amm.312.635.

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One of the properties of high impedance surface is that the phase of the reflection wave by the surface is zero.A high impedance surface was used as antenna reflecting surface. A dipole antenna was designed as radiation source. Simulation demonstrated that when the patches number of surface changed the radiation pattern changed and the gain varied also. The distance between antenna and the reflection face varied the radiation pattern also changed. Controlling the number of cells or distance between antennas from reflection plane the gain of antenna can be improved.

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Geerts, Walter M., Henderien W. Steenbeek et Van Geert Paul L. C. « Visualising the Development of a Teacher-In-Training into a Beginning Expert ». International Education Studies 10, n^o 12 (28 novembre 2017) : 1. http://dx.doi.org/10.5539/ies.v10n12p1.

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Teachers use situated knowledge to deal with the complex and diffuse educational contexts they operate in. To be able to take deliberated action, based on the situated knowledge, reflection is necessary during the teacher training. Video cases with common, real world situations are suitable for reflection because of their holistic and diffuse character. Reflection concerns learning experiences with increasing complexity: single-loop (reflecting on a current action), double-loop (reflecting to gain new insights) and triple-loop (reflecting in order to adjust individual identity) learning. The knowledge gained from loop learning is of a situated nature. The current article operationalizes situated knowledge as educational purposes and design patterns; educational purposes determine which course of action (design pattern), is the best option. Using this distinction, we investigate whether the reflection done by fourth-year teachers in training corresponds to what can be expected of a starting expert, namely, reflection on all three levels. The results indicate that three out of four teachers in training can be characterized as starting experts, based on their responses to a video case. They experience learning on all three loop levels, and these experiences contribute to a variety of educational purposes and design patterns. It is the teacher trainers’ challenge to have their students reflects using video cases, so they can use loop-learning to build their situated knowledge. This knowledge will allow them to adequately respond to the complex and diffuse situations in their educational practice.

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HAGEDOORN, MICHIEL, et REMCO C. VELTKAMP. « A ROBUST AFFINE INVARIANT METRIC ON BOUNDARY PATTERNS ». International Journal of Pattern Recognition and Artificial Intelligence 13, n^o 08 (décembre 1999) : 1151–63. http://dx.doi.org/10.1142/s0218001499000653.

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Affine invariant pattern metrics are useful for shape recognition. It is important that such a metric is robust for various defects. We formalize these types of robustness using four axioms. Then, we present the reflection metric. This is an affine invariant metric defined for the large family of "boundary patterns". A boundary pattern is a finite union of n-1 dimensional algebraic surface patches in ℝn. Such a pattern may have multiple connected components. We prove that the reflection metric satisfies the four robustness axioms.

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Suzuki, Yoshikazu, Peter E. D. Morgan et Koichi Niihara. « Use of a high X-ray flux instrument for a mineral : X-ray powder diffraction pattern of CaMg(CO3)2 ». Powder Diffraction 13, n^o 4 (décembre 1998) : 216–21. http://dx.doi.org/10.1017/s0885715600010137.

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The usefulness of a high X-ray flux instrument to improve the accuracy of a powder diffraction pattern is demonstrated. In this case, very weak reflections of a well-characterized and well-known natural mineral can be detected by an often-used X-ray rotating anode diffractometer. High purity natural dolomite, CaMg(CO3)2, for example, was used to produce a slightly more comprehensive indexed X-ray powder diffraction. The powder pattern obtained in this study was compared with that of the reported high quality PDF pattern (36-426, with “*” mark) and that of a calculated pattern derived from single crystal structure data. A very weak 003 reflection at low angle and many weak reflections at high angles, not reported in the PDF pattern, were successfully identified using this high-power X-ray instrument. Unit cell parameters were determined to be a=4.8090±0.0001 Å and c=16.0182±0.0003 Å, which were in good agreement with the extant PDF pattern. Accuracy of the relative intensities between the measured and calculated patterns was apparently somewhat improved in this study, probably also attained through less preferred orientation and the higher purity of the sample used.

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Sugino, Tadanori, Yumi Satozono et Yasuo Yamane. « Gloss Evaluation Method for Metal Surface with Hairline Using Patterned Area Illumination ». Key Engineering Materials 407-408 (février 2009) : 723–26. http://dx.doi.org/10.4028/www.scientific.net/kem.407-408.723.

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Gloss evaluation of a metal surface is important for the quality as the product. In general, gloss of a metal surface is influenced by specular reflection of light on the surface. Therefore to evaluate the specular reflection is almost the same as the evaluation of the gloss. We propose the method to evaluate the specular reflection using patterned area illumination. In the specular reflection, the angle of incidence is equal to the angle of reflection. Consequently when lights (rays) of the area illumination which has a stripe pattern are projected to a glossy metal surface, the stripe pattern occurs on the reflection image by the mirror-like reflection and the sharpness of the stripe pattern of the image has information of the specular reflection on the surface. This character is applied for the metal surface with hairline. The metal surface with hairline has different gloss feeling at different point of view. When the direction of the stripe pattern of the illumination is changed, the sharpness of stripe pattern on the reflection image varies owing to the surface roughness of hairline. Therefore we can evaluate the glossiness for various directions by rotating the stripe pattern. This paper shows the availability of the proposed method through the experiment.

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Suncov, O., et L. Zhikharev. « Investigation of Reflection from Curved Mirrors on a Plane in the Wolfram Mathematica ». Geometry & ; Graphics 9, n^o 2 (11 novembre 2021) : 29–45. http://dx.doi.org/10.12737/2308-4898-2021-9-2-29-45.

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In this article, the study of the geometry of the flat shapes reflection from curved lines located in the plane of these shapes continues. The paper is devoted to a more detailed description of reflection from the analytical geometry point of view. In addition, the range of proposed tasks has been significantly expanded. An algorithm for reflecting zero-dimensional and one-dimensional objects from plane curves is compiled, and corresponding illustrations are given. For the first time, the authors have obtained equations that allow us to construct reflections of a point from second-order curves: a circle, an ellipse, a parabola and a hyperbola, as well as from high-order curves: Bernoulli lemniscates and cardioids [17], [24], [13], [25], [23], [22]. In addition, equations for the reflection results of one-dimensional objects: a segment and a circle, from the same plane curves were obtained. Similar studies are being conducted in the works [2], [1], [32], [28], [3], [4]. All equations are accompanied by blueprints of special cases of reflections obtained using the Wolfram Mathematica mathematical package [18], [19]. In addition, the application contains the source codes, which gives the reader to configure the reflection parameters themselves on condition having access this program, as well as visually assess the change in the reflection pattern when changing these parameters for various types of flat mirrors. This article demonstrates the possibilities that the obtained equations provide, and the prospects for further work, which consist in obtaining new equations of objects reflected from other flat mirrors.

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Sadowiak, P., et T. Wever. « Reflection-diffraction seismic pattern at crustal suture zones ». Tectonics 9, n^o 6 (décembre 1990) : 1495–513. http://dx.doi.org/10.1029/tc009i006p01495.

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Cai Hongji, 蔡宏吉, 姚治海 Yao Zhihai, 高超 Gao Chao, 任捷 Ren Jie, 刘籍元 Liu Jiyuan et 王晓茜 Wang Xiaoqian. « Reflection Ghost Imaging Based on Superimposed Speckle-Pattern ». Laser & ; Optoelectronics Progress 56, n^o 7 (2019) : 071101. http://dx.doi.org/10.3788/lop56.071101.

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Nishino, J., M. Morigami, M. Harada, S. Terakado, S. Kobayashi, S. Fujiwara, K. Kaneda et al. « Attempt at LSI pattern demagnification by Bragg reflection ». Review of Scientific Instruments 60, n^o 7 (juillet 1989) : 2153–56. http://dx.doi.org/10.1063/1.1140806.

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Scheffer, Hans-Joachim, et Soren Kohlhase. « REFLECTION OF IRREGULAR WAVES AT PARTIALLY REFLECTING STRUCTURES INCLUDING OBLIQUE WAVE APPROACH ». Coastal Engineering Proceedings 1, n^o 20 (29 janvier 1986) : 162. http://dx.doi.org/10.9753/icce.v20.162.

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The reflection of irregular seas is increasingly considered in coastal engineering and harbour design as well with respect to wave pattern at the structure and energy dissipation as regarding the dimensioning of structures exposed to waves. It becomes evident that the three-dimensional sea state (oblique wave approach, irregularity of the waves) at partially-reflecting structures of a complex design cannot be described by means of a constant reflection coefficient alone, as is common practice. This is due to the fact that the coefficient is largely frequency-dependent and the physically effective reflection point of the structure cannot be clearly specified. In the light of this, basic investigations on wave reflection have been performed with different partially-reflecting structures, wave spectra and wave approach angles. In addition to laboratory experiments using both a wave flume and a wave basin, a theoretical solution based on diffraction theory was determined to describe the wave field in the reflection area of various structures. The investigations were restricted to non-breaking wave conditions. The reflection behaviour of structures is expressed by a complex reflection coefficient, containing two parameters, which have to be determined by model tests.

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Ling, P., H. A. Kawayoshi, L. Martinez et T. Tien. « The Effect of Large-Angle Tilting on the Electron Diffraction Pattern of Chrysotile Asbestos ». Proceedings, annual meeting, Electron Microscopy Society of America 49 (août 1991) : 976–77. http://dx.doi.org/10.1017/s0424820100089196.

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The structure of chrysotile asbestos is very unique. Morphologically, individual filaments can be thought of as thin sheets which have been rolled into cylinders or scrolls. Because of this structure, the electron diffraction pattern is very unusual and contains (OkO) and (001) reflections along the zero layer line and characteristic flared reflections of the type (hkO) , where h and k are odd. In practice, chrysotile asbestos is commonly identified by 7.3 Å (002) reflection, a 4.6 Å (020) spacing, and a repeat layer spacing of 5.3 Å.

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Liu, Yi, et David J. Sellmyer. « Selected Reflection Imaging of Nanostructured Materials ». Microscopy and Microanalysis 4, S2 (juillet 1998) : 752–53. http://dx.doi.org/10.1017/s1431927600023886.

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Nanostructured materials are finding increasing applications. In characterizing the nanostructured materials, we have developed a technique using a conventional TEM to characterize the nanostructure. The technique is named selected reflection imaging and could be used for measuring the grain size, measuring the volume fraction of a second phase in a dual phase material, measuring the texture and identifying the crystal structure in multiphase materials.The technique is evolved from dark field imaging which is known to generate strong contrast. In conventional materials with a grain size larger than 1 μm, selected area diffraction pattern is from a single crystal. Dark field image could be formed by allowing one of the diffracted beam to go through the objective aperture. In nanostructured materials, however, the diffraction pattern becomes a ring pattern. Ordinary dark field image could be formed by allowing one of the spot in the ring to go through the aperture. However, only a limited number of grains are differentiated from the rest.

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Sugino, Tadanori, et Yasuo Yamane. « Gloss Evaluation of Hairline-Finished Metal Surface Using Patterned Area Illumination Method : Reproduction of Gloss Evaluation by Ray Tracing ». Key Engineering Materials 656-657 (juillet 2015) : 468–72. http://dx.doi.org/10.4028/www.scientific.net/kem.656-657.468.

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Gloss of a metal surface is an important aspect for product quality evaluation. Evaluating the specular reflection is almost the same as evaluating the gloss. We propose a method that uses patterned area illumination to evaluate specular reflection. In specular reflection, the angle of incidence equals the angle of reflection. Consequently, when light (ray) of the area illumination, which has a striped pattern, are projected on a glossy metal surface, a striped pattern forms on the reflected image as a mirror-like reflection, and the sharpness of the striped pattern of the image provides information about the specular reflection on the surface. This characteristic is applied to a metal with a hairline surface finish. A hairline surface presents different glossiness at different viewpoints. When the direction of the striped pattern of illumination is changed, the sharpness of striped pattern on the reflected image varies owing to the surface roughness of the hairline finish. Therefore, we can evaluate the glossiness in various directions by rotating the pattern. The relationships between gloss evaluation value and surface roughness were indicated in our study. We tried the reproduction of the gloss evaluation by ray tracing to obtain the more detailed relationships between them. Ray tracing is a technique to generate an image in computer graphics. The approximate reproduction of gloss evaluation was obtained by the simulation.

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Sugino, Tadanori, Yuki Tashiro et Yasuo Yamane. « Gloss Evaluation of Hairline-Finished Metal Surface Using Patterned Area Illumination Method : Relationship between Gloss Evaluation and Surface Roughness for the Estimation of Surface Roughness ». Key Engineering Materials 749 (août 2017) : 251–56. http://dx.doi.org/10.4028/www.scientific.net/kem.749.251.

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The gloss of a metal surface is an important aspect for product quality evaluation. In general, gloss is influenced by specular reflection of light on a metal surface. Therefore, evaluating the specular reflection is almost the same as evaluating the gloss. We propose a method that uses patterned area illumination to evaluate specular reflection. In specular reflection, the angle of incidence equals the angle of reflection. Consequently, when light (ray) of the area illumination, which has a striped pattern, are projected on a glossy metal surface, a striped pattern forms on the reflected image as a mirror-like reflection, and the sharpness of the striped pattern of the image provides information about the specular reflection on the surface. This characteristic is applied to a metal with a hairline surface finish. A hairline surface presents different glossiness at different viewpoints. When the direction of the striped pattern of illumination is changed, the sharpness of striped pattern on the reflected image varies owing to the surface roughness of the hairline finish. Therefore, we can evaluate the glossiness in various directions by rotating the pattern. The rough relationships between gloss evaluation value and surface roughness were indicated in our study. In order to make the relationship between gloss evaluation and surface roughness for the estimation of surface roughness, we had tried the comparison for the gloss evaluation value and the surface roughness. The more precise relationship for seven directions on hairline-finished metal surface was measured. This report describes the results and considers the possibility of estimation of surface roughness by the gloss evaluation value.

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Su, Qian, Jie Li et Zhenxing Liu. « Flow Pattern Identification of Oil–Water Two-Phase Flow Based on SVM Using Ultrasonic Testing Method ». Sensors 22, n^o 16 (16 août 2022) : 6128. http://dx.doi.org/10.3390/s22166128.

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A flow pattern identification method combining ultrasonic transmission attenuation with an ultrasonic reflection echo is proposed for oil–water two-phase flow in horizontal pipelines. Based on the finite element method, two-dimensional geometric simulation models of typical oil–water two-phase flow patterns are established, using multiphysics coupling simulation technology. An ultrasonic transducer test system of a horizontal pipeline with an inner 50 mm diameter was built, and flow pattern simulation experiments of oil–water two-phase flow were carried out in the tested field area. The simulation results show that the ultrasonic attenuation coefficient is extracted to identify the W/O&O/W dispersion flow using the ultrasonic transmission attenuation method, and the identification accuracy is 100%. By comparison, using the ultrasonic reflection echo method, the echo duration is extracted as an input feature vector of support vector machine (SVM), and the identification accuracy of the stratified flow and dispersed flow is 95.45%. It was proven that the method of the ultrasonic transmission attenuation principle combined with the ultrasonic reflection echo principle can identify oil–water two-phase flow patterns accurately and effectively, which provides a theoretical basis for the flow pattern identification of liquid–liquid multiphase flow.

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Copland, Luke, et Martin Sharp. « Mapping thermal and hydrological conditions beneath a polythermal glacier with radio-echo sounding ». Journal of Glaciology 47, n^o 157 (2001) : 232–42. http://dx.doi.org/10.3189/172756501781832377.

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AbstractSpatial patterns in residual bed reflection power (BRPr), derived from ground-based radio-echo sounding, were mapped and interpreted in terms of the thermal and hydrological conditions at the base of a high-Arctic polythermal glacier (John Evans Glacier, Ellesmere Island, Canada). BRPr is the residual from a statistical relationship between measured bed reflection power and ice thickness that describes the rate of dielectric loss with depth in the glacier. We identified three types of thermal structure: (a) Positive BRPr and an internal reflecting horizon occur over the glacier terminus. The reflecting horizon is interpreted as the boundary between warm and cold ice, and suggests the presence of a warm basal layer. (b) Positive BRPr occurs without an internal reflector in the upper part of the ablation zone. This suggests that ice is at the pressure-melting point only at the bed. (c) Negative BRPr without an internal reflector occurs in all other regions, suggesting cold ice at the bed. Where BRPr is positive, its pattern is similar to the pattern of subglacial water flow predicted from the form of the subglacial hydraulic equipotential surface. This suggests that hydrological conditions at the glacier bed are a major control on BRPr, probably because the dielectric contrast between ice and water is higher than that between ice and other subglacial materials.

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Manjit, Yongyut, Saksit Sukprasong, Apichart Limpichaipanit et Athipong Ngamjarurojana. « Investigation of Fringe Pattern Distribution in Circular Disk by Reflection Polariscope Technique ». Applied Mechanics and Materials 848 (juillet 2016) : 68–71. http://dx.doi.org/10.4028/www.scientific.net/amm.848.68.

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In this study, the fringe pattern distribution of various loads on circular disk of homogeneous acrylic in different thicknesses by using reflection polariscope technique was carried out. The load was pressed at the top and the bottom to produce the fringe patterns, which were recorded by digital camera. Then the results were analyzed. The number of isochromatic fringe pattern depends on the magnitude of force acting on the circular disk and these relation is linearly. The application of these research is used to predict stress distribution on the transparent material in the case of different dimension of the circular disk shape.

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Liu, J., et J. M. Cowley. « Scanning reflection electron imaging of crystal surfaces ». Proceedings, annual meeting, Electron Microscopy Society of America 47 (6 août 1989) : 538–39. http://dx.doi.org/10.1017/s0424820100154664.

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Scanning reflection electron imaging has been developed in recent years as a potential surface probing technique. The small beam size (0.5 nm) used in the SREM work make it possible to perform nano-scale analysis of crystal surfaces. Microdiffraction RHEED patterns can be obtained to identify surface reaction products. The problems of reductions on metal oxide crystal surfaces, metal surface oxidation processes and metal-substrate interactions have been investigated by SREM technique. Surface channelling effect have also been studied in SREM mode by taking advantage of the small incident beam size. In principle SREM images are analogous to, due to the reciprocity theorem, the REM images. In practice, in order to get reasonable signal large objective apertures are generally used whereas small detector apertures have to be used to obtain adequate image contrast. The main contrast mechanism in SREM images of atomic steps and surface defects may be due to phase contrast since most of the diffraction contrast will be washed out because of the large beam convergence. For example the RHEED pattern in figure 1 is effectively a convergent beam pattern and was obtained from a cleaved MgO (001) surface. These patterns are useful for determining the crystal orientation and for the inspection of diffraction conditions such as surface resonance condition. By employing small detector apertures and moderate objective apertures single atomic steps can be imaged with high contrast as shown in figure 2 which is a SREM image of platinum (111) surface obtained with (555) specular beam excited. The characteristic black and white contrast of the down and up steps is revealed clearly (arrowed in fig. 2). The similarity between the SREM image and the corresponding REM images suggests that the two imaging modes are equivalent.

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LIU, JINGYUE. « Energy-filtered reflection electron microscopy and reflection high-energy electron diffraction on Zeiss 912 TEM ». Proceedings, annual meeting, Electron Microscopy Society of America 51 (1 août 1993) : 580–81. http://dx.doi.org/10.1017/s0424820100148733.

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In reflection electron microscopy (REM) and reflection high energy electron diffraction (RHEED) the average path length of the elastically scattered electrons in the crystal ranges from 10 -100 nm and a significant portion of the electrons in the RHEED pattern spots used for imaging is inelastically scattered. The excitations of surface plasmons, bulk plasmons and valence electrons involves energy losses of 10 ∽30 eV. Thus the image contrast and resolution in REM are degraded due to chromatic aberration of the objective lens. The use of energy filters in a TEM should offer significant improvement in resolution and contrast of REM images. We present here some new results on the investigation of resolution limit and contrast mechanisms in energy filtered REM images.The experiments were performed on a Zeiss 912 TEM fitted with an Omega magnetic imaging energy filter. Digital RHEED patterns and REM images were acquired into 1024 pixels by 1024 pixels via a Gatan 679 CCD camera fitted to the microscope.

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Wendt, Florian, et Robert Höldrich. « Precedence effect for specular and diffuse reflections ». Acta Acustica 5 (16 décembre 2020) : 1. http://dx.doi.org/10.1051/aacus/2020027.

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Studies on the precedence effect are typically conducted by presenting two identical sounds simulating direct sound and specular reflection. However, when a sound is reflected from irregular surface, it is redirect into many directions resulting in directional and temporal diffusion. This contribution introduces a simulation of Lambertian diffusing reflections. The perceptual influences of diffusion are studied in a listening experiment; echo thresholds and masked thresholds of specular and diffuse reflections are measured. Results show that diffusion makes the reflections more easily detectable than specular reflections of the same total energy. Indications are found that this mainly due to temporal diffusion, while the directional diffusion has little effect. Accordingly, the modeling of the echo thresholds is achieved by a temporal alignment of the experimental data based on the energy centroid of reflection responses. For the modeling of masked threshold the temporal masking pattern for forward masking is taken into account.

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Herranz, A., J. J. Moreno et N. Maya. « Declarative Reflection and its Application as a Pattern Language ». Electronic Notes in Theoretical Computer Science 76 (novembre 2002) : 197–215. http://dx.doi.org/10.1016/s1571-0661(04)80794-1.

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Mohamad, Siti Khadijah, Zaidatun Tasir, Jamalludin Harun et Nurbiha A. Shukor. « Pattern of reflection in learning Authoring System through blogging ». Computers & ; Education 69 (novembre 2013) : 356–68. http://dx.doi.org/10.1016/j.compedu.2013.07.031.

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Olafiranye, Oladipupo, Ghazanfar Qureshi, Haroon Kamran, Lee Gao, Louis Salciccioli et Jason Lazar. « RELATIONSHIP OF AORTIC WAVE REFLECTION TO TRANSMITRAL FILLING PATTERN ». Chest 134, n^o 4 (octobre 2008) : 39P. http://dx.doi.org/10.1378/chest.134.4_meetingabstracts.p39003.

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Liu, Qiulan, Youhua Chen, Wenjie Liu, Yubing Han, Ruizhi Cao, Zhimin Zhang, Cuifang Kuang et Xu Liu. « Total internal reflection fluorescence pattern-illuminated Fourier ptychographic microscopy ». Optics and Lasers in Engineering 123 (décembre 2019) : 45–52. http://dx.doi.org/10.1016/j.optlaseng.2019.06.023.

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Nespolo, Massimo, Giovanni Ferraris et Bernd Souvignier. « Effects of merohedric twinning on the diffraction pattern ». Acta Crystallographica Section A Foundations and Advances 70, n^o 2 (12 février 2014) : 106–25. http://dx.doi.org/10.1107/s2053273313029082.

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In merohedric twinning, the lattices of the individuals are perfectly overlapped and the presence of twinning is not easily detected from the diffraction pattern, especially in the case of inversion twinning (class I). In general, the investigator has to consider three possible structural models: a crystal with space-group typeHand point groupP, either untwinned (H model) or twinned through an operationtin vector space (t-H model), and an untwinned crystal with space groupGwhose point groupP′ is obtained as an extension ofPthrough the twin operationt(G model). In 71 cases, consideration of the reflection conditions may directly rule out theGmodel; in seven other cases the reflection conditions suggest a space group which does not correspond to the extension ofHby the twin operation and the structure solution or at least the refinement will fail. When the twin operation belongs to a different crystal family (class IIBtwinning: the crystal has a specialized metric), thepresenceof twinning can often be recognized by the peculiar effect it has on the reflection conditions.

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Salem Hesari, Sara, et Jens Bornemann. « Design of a SIW Variable Phase Shifter for Beam Steering Antenna Systems ». Electronics 8, n^o 9 (11 septembre 2019) : 1013. http://dx.doi.org/10.3390/electronics8091013.

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This paper proposes a new beam steering antenna system consisting of two variable reflection-type phase shifters, a 3 dB coupler, and a 90° phase transition. The entire structure is designed and fabricated on a single layer of substrate integrated waveguide (SIW), which makes it a low loss and low-profile antenna system. Surface mount tuning varactor diodes are chosen as electrical phase control elements. By changing the biasing voltage of the varactor diodes in the phase shifter circuits, the far-field radiation pattern of the antenna steers from −25° to 25°. The system has a reflection coefficient better than −10 dB for a 2 GHz bandwidth centered at 17 GHz, a directive radiation pattern with a maximum of 10.7 dB gain at the mid-band frequency, and cross polarization better than 20 dB. A prototype is fabricated and measured for design verification. The measured far-field radiation patterns, co and cross polarization, and the reflection coefficient of the antenna system agree with simulated results.

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Xin, Chen, Tan Wenhui et Wang Peng. « Effects of Geometrical Parameters on Stress Wave Propagation across the Rough Joint ». Advances in Civil Engineering 2018 (27 août 2018) : 1–7. http://dx.doi.org/10.1155/2018/1364839.

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The contact surface of the rough joint has geometrical parameters as the joint matching coefficient (JMC) and the distribution pattern of the contact segments. The specimen used in the modified SHPB test got the artificial joint by sawing some notches on the surface contacted to the output bar. Different assemblies of the notches formed various contact areas and distribution patterns. Using the modified SHPB tests data, the altered thin-layer interface model was used to analyze the effects of geometrical parameters on one-dimensional stress wave transmission and energy dissipation across a single rough joint. It revealed that the transmission coefficient decreased with the diminution of JMC, and it increased with the scattered distribution pattern as the similar trend for each JMC set. As for the energy coefficients, with the decrease of JMC, the transmission energy coefficient reduced sharply, but it increased very slowly with the reflection energy coefficient and irreversible energy coefficient. It revealed that the JMC of 0.5 was the critical point of the energy dissipation. More energy transmitted across the joint rather than reflecting back and dissipating, when JMC > 0.5. Nevertheless, the irreversible energy coefficient was much larger than the transmission and reflection coefficients, when JMC < 0.5.

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Igra, O., G. Hu, J. Falcovitz et W. Heilig. « Blast Wave Reflection From Wedges ». Journal of Fluids Engineering 125, n^o 3 (1 mai 2003) : 510–19. http://dx.doi.org/10.1115/1.1567310.

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While a lot of attention was given to shock wave reflections from wedges during the past four decades, only little work was published regarding the similar case of blast wave reflection from wedges. In the present paper this subject is studied experimentally and theoretically/numerically. The obtained results show that the geometry of the reflected wave pattern is similar in the two cases when both incident waves have the same initial pressure jump across their fronts. However, different reflected pressure signatures (history) are observed in these two cases. The pressures obtained behind a reflected shock wave are always higher than those obtained behind the corresponding similar blast wave. In the present case differences as high as 17% were observed.

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TROSHIN, S. M., et N. E. TYURIN. « REFLECTION AND DIPS IN ELASTIC SCATTERING ». Modern Physics Letters A 24, n^o 14 (10 mai 2009) : 1103–8. http://dx.doi.org/10.1142/s0217732309030588.

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We discuss how the reflective scattering would affect elastic scattering in the region of small and moderate values of -t, in particular, we demonstrate that diffractive pattern in the angular distribution will be kept in a modified form.

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Hsu, Tung. « Reflection electron microscopy (REM) of NaCl crystals ». Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994) : 808–9. http://dx.doi.org/10.1017/s0424820100171778.

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NaCl and other alkaline halide crystals are unstable under the electron beam and therefore have seldom been examined with the various electron beam techniques. Surfaces of these crystals, however, are of fundamental and application interests. There has been a considerable effort in studying these surfaces using the replica methods.Reflection high energy electron diffraction (RHEED) and reflection electron microscopy (REM) have been successfully applied to the study of stable insulators. Since direct observation on an uncoated surface is always desirable, we tried RHEED and REM on cleaved NaCl(100) surfaces.The experiment was carried out on a JEOL JEM-200CX electron microscope with a high tilt side-entrystage. The accelerating voltage of lOOkV was used throughout the experiment. There is no special protection to the specimen except the standard anti-contamination cold finger. The initial effort of doing ordinary REM on NaCl was a failure: When the electron beam and the specimen were properly tilted toget a good RHEED pattern, the bright pattern remained for only a couple of seconds and then turned into a pattern of weak spots and high diffuse background. The bright REM image also lost its contrast in a few seconds.

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Rotshild, David, Daniel Rozban, Efi Rahamim, Asaf Barom, Rotem Yosef, Liel Bhanam et Amir Abramovich. « Steer by Image Technology for Intelligent Reflecting Surface Based on Reconfigurable Metasurface with Photodiodes as Tunable Elements ». Crystals 12, n^o 7 (7 juillet 2022) : 951. http://dx.doi.org/10.3390/cryst12070951.

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Lately, metasurface has become an essential and promising component in implementing Intelligent Reflecting Surface (IRS) for 5G and 6G. A novel method that simplifies the ability to reconfigure the metasurface is presented in this paper. The suggested technology uses a PIN photodiode as a tuning element. The desired image is projected on the metasurface’s backside, where the PIN photodiodes are placed and reconfigures the metasurface. The projected image’s color and intensity pattern influence the PIN photodiode’s junction capacitance, which leads to local reflection phase control. This enables the required pattern reflection phase distribution to manipulate the reflection beam, for example, 2D beam steering or focusing, and any other beam forming combination, instead of wiring many digital-to-analog converters (DACs) or FPGA outputs, which bias the standard tuning element such as PIN diode or varactor using a complex RF circuit. Using a PIN photodiode as a tunable element instead of a varactor diode, PIN diode, Liquid Crystal and MEMS allows the changing of the internal junction capacitance without direct contact and thus continuously controlling the reflection phase. In addition, an open circuit work mode with negligible energy consumption can be obtained. This technology can be used to implement metasurface based on discrete or continuous phases and is called Steer by Image (SBI). A full description of the SBI technology using PIN photodiode is presented in this paper.

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Choi, Jihyun, Luiggi Cantos, Jinho Choi et Yun Hee Kim. « Sum Rate Optimization of IRS-Aided Uplink Muliantenna NOMA with Practical Reflection ». Sensors 22, n^o 12 (12 juin 2022) : 4449. http://dx.doi.org/10.3390/s22124449.

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Recently, intelligent reflecting surfaces (IRSs) have drawn huge attention as a promising solution for 6G networks to enhance diverse performance metrics in a cost-effective way. For massive connectivity toward a higher spectral efficiency, we address an intelligent reflecting surface (IRS) to an uplink nonorthogonal multiple access (NOMA) network supported by a multiantenna receiver. We maximize the sum rate of the IRS-aided NOMA network by optimizing the IRS reflection pattern under unit modulus and practical reflection. For a moderate-sized IRS, we obtain an upper bound on the optimal sum rate by solving a determinant maximization (max-det) problem after rank relaxation, which also leads to a feasible solution through Gaussian randomization. For a large number of IRS elements, we apply the iterative algorithms relying on the gradient, such as Broyden–Fletcher–Goldfarb–Shanno (BFGS) and limited-memory BFGS algorithms for which the gradient of the sum rate is derived in a computationally efficient form. The results show that the max-det approach provides a near-optimal performance under unit modulus reflection, while the gradient-based iterative algorithms exhibit merits in performance and complexity for a large-sized IRS with practical reflection.

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Paul Morniroli, Jean, et Michel Gantois. « Simultaneous Identification of the Bravais Lattice and Glide Planes From Microdiffraction Patterns : Deduction of the Possible Space Groups ». Proceedings, annual meeting, Electron Microscopy Society of America 48, n^o 2 (12 août 1990) : 478–79. http://dx.doi.org/10.1017/s042482010013599x.

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Microdiffraction experiments obtained with a small spot size and a nearly parallel electron beam are well-adapted to most specimens and especially to small particles. They are particularly useful when Convergent Beam Electron Diffraction (CBED) patterns do not give the 2D and 3D information required to identify the point and the space groups. They can also be used to start the identification or the determination of a crystal structure. Specific and simplest CBED experiments are later realized to remove left ambiguities.The microdiffraction Zone Axis Patterns (ZAP) are composed of sharp reflections whose high angular resolution helps to appreciate the shifts and the periodicity differences between the Zero (ZOLZ) and First (FOLZ) Order Laue Zones reflection nets. Observations of thin areas at low temperature are recommended in order to produce many well visible FOLZ reflections.It was already indicated that the crystal system and the Laue class are deduced from observation of the whole pattern symmetry of the reflections.

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Tyler, Jeramey, Mei Si et Jonas Braasch. « Predicting reflection patterns from binaural activity maps using deep neural networks ». Journal of the Acoustical Society of America 151, n^o 4 (avril 2022) : A222. http://dx.doi.org/10.1121/10.0011124.

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A new model architecture is presented to predict room acoustical parameters from a running binaural signal. For this purpose, a deep neural network architecture is combined with a precedence effect model to extract the spatial and temporal locations of the direct signal and early reflections. The precedence effect model builds on the modified BICAM algorithm [Braasch, J. Acoust. Soc. Am. 140, EL143], for which the 1st layer auto-/cross correlation functions are replaced with a Cepstrum method. The latter allows a better separation of features relating to the source signal's early reflections and harmonic structure. The precedence effect model is used to create binaural activity maps that are analyzed by the neural network for pattern recognition. Anechoic orchestral recordings were reverberated by adding four early reflections and late reverberation to test the model. Head-related transfer functions were used to spatialize direct sound and early reflections. The model can identify the main reflection characteristics of a room, offering applications in numerous fields, including room acoustical assessment, acoustical analysis for virtual-reality applications, and modeling of human perception. [Work supported by the National Science Foundation under Grant No. IIS-1909229.]

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Chen, Mingfang, Xiang Mo, Yongxia Zhang et Seng Wang. « Research on fusion control of sensor information and biological reflection based on CPG ». Advances in Mechanical Engineering 15, n^o 1 (janvier 2023) : 168781322211495. http://dx.doi.org/10.1177/16878132221149560.

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To enhance the environmental adaptability of the quadruped robot and realize its stability in terrain with obstacles, this paper studies the fusion of sensor information feedback and bio-reflection control algorithm. First, a central pattern generator (CPG) that generates basal rhythmic movements is constructed. Secondly, a simplified foot end that can be used to identify the touchdown and obstacle information is designed. To enhance the stability of the quadruped robot during the flexor reflex process and avoid the problem of solidification in the reflex process, the foot touch signal was introduced into the flexor reflex algorithm, which enhanced the flexibility of the reflex process. To avoid secondary collisions with obstacles, the postswing reflection process is optimized, and active obstacle avoidance is realized after the obstacle is touched. Finally, the organic fusion of sensor information feedback, CPG control network, and bio-reflection control algorithm is realized. The simulation results show that the robot’s ability to overcome obstacles is improved, the number of reflections is less, and the reflection process is more stable.

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ICHIKAWA, TOSHIHIRO. « Characterization of surface structure. Reflection electron diffraction (Diffraction pattern evaluation). » Nihon Kessho Gakkaishi 29, n^o 2 (1987) : 107–9. http://dx.doi.org/10.5940/jcrsj.29.107.

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Wang, Ruiyang, Dahai Li, Kaiyuan Xu, Xinwei Zhang et Peng Luo. « Parasitic reflection elimination using binary pattern in phase measuring deflectometry ». Optics Communications 451 (novembre 2019) : 67–73. http://dx.doi.org/10.1016/j.optcom.2019.06.009.

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ADAMATZKY, ANDREW. « CHOOSEY HOT SAND : REFLECTION OF GRAIN SENSITIVITY ON PATTERN MORPHOLOGY ». International Journal of Modern Physics C 11, n^o 01 (février 2000) : 47–68. http://dx.doi.org/10.1142/s0129183100000067.

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We build and investigate a nonstandard model of pattern formation in a system of discrete entities evolving in discrete space and time. We chose a sandpile paradigm to fit our ideas in the frame of current research. In our model sand is hot because a grain can topple against gradient, i.e., the grain can walk to another node even when a number of grains in its current node is less than a number of neighboring nodes. Sand is choosey because behavior of the grains is not determined by any global parameter or any threshold of a number of neighboring grains (called here a grain sensitivity) but depends on the exact number of grains in the neighboring nodes. Namely, we assume that a grain being at a node x goes to one of the eight neighboring nodes, chosen at random, if there is another grain at the node x or if the number of grains in eight neighboring nodes lies in some set of 2{1,…,8}. These 256 rules of sensitivity are investigated. The classification of the rules if offered, based on the morphology of the patterns generated by each rule. Eight morphological classes are found. Fine structure of every class is investigated and transient phenomena are analyzed. Three kinds of description of class rules by Boolean expressions are offered. Evolution of the classes governed by several one-dimensional parameters is considered.

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Yao, Nan, et J. M. Cowley. « Convergence of the incident beam in reflection Electron Microscopy ». Proceedings, annual meeting, Electron Microscopy Society of America 47 (6 août 1989) : 532–33. http://dx.doi.org/10.1017/s0424820100154639.

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The RHEED (Reflection High Energy Electron Diffraction) patterns as essential indications of the diffraction conditions in relation to REM (Reflection Electron Microscopy) imaging provide a wealth of information about the surfaces. They contain extensive patterns of Kikuchi lines, bands and envelopes resulting from diffuse inelastic scattering processes. They also contain arrays of diffuse spots forbidden by the boundary conditions for elastic scattering but generated by multiple diffuse scattering processes.However, a word of caution has to be sounded. Strictly speaking, the normal RHEED pattern does not exactly present the diffraction condition for REM imaging in a commercial transmission electron microscope. Practical and theoretical studies of the electron optics of the illuminating system on a Philip-400T transmission electron microscope, in which the specimen is immersed in the magnetic field of the twin objective lens, indicate that the convergent angle of the incident electron beam can be adjusted precisely, in a range from about 0.1 mrad to 5 mrad, with a selection of the second condenser aperture size, by adjusting the excitation current in the second condenser lens. For the best contrast and illumination, the RHEED pattern is generally obtained by focusing the electron beam on the surface with the maximum convergence angle, and the REM image is obtained with an almost parallel illumination with the minimum convergence angle. A typical example obtained from a fresh cleavage (110) surface of InP single crystal is demonstrated in figure 1, in which (a) and (b) are RHEED patterns with the (10,10,0) specular Bragg-reflection condition fulfilled and correspond to the incident electron beam with 2 mrad and 0.2 mrad convergence angles, respectively; (c) is a REM image obtained under exactly the same operation condition as (b) except for changing from diffraction mode to image mode, which indeed has nothing to do with the illumination condition above the specimen position; and (c) is taken from an area consisting of many steps of atomic height. Comparison of (a) and (b) shows that, for the parallel electron illumination, only those diffraction spots are dominant which represent the possible diffracted directions and mark the intersections of Ewald sphere with reciprocal lattice rods of the crystal surface. The extensive Kikuchi lines, bands and envelopes, and even the parabolas appearing in (a), are scarcely visible in (b). This suggests that the channeling effects characterized as the appearance of surface diffraction parabolas showing in RHEED pattern are mainly caused by the portion of electrons with incident direction slightly deviated from the rows of atoms; that is, the inelastically scattered electrons propagating in the directions of rows of atoms only occur when the initial incident electrons interact with the lattice in a direction slightly different from that of the rows of atoms. Following this argument, we may propose that the contrasts observed in REM image are mostly contributed from the diffraction and phase contrasts.

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Spitzer, Roman, Alan G. Green et Frank O. Nitsche. « Minimizing field operations in shallow 3‐D seismic reflection surveying ». GEOPHYSICS 66, n^o 6 (novembre 2001) : 1761–73. http://dx.doi.org/10.1190/1.1487118.

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By appropriately decimating a comprehensive shallow 3‐D seismic reflection data set recorded across unconsolidated sediments in northern Switzerland, we have investigated the potential and limitations of four different source‐receiver acquisition patterns. For the original survey, more than 12 000 shots and 18 000 receivers deployed on a [Formula: see text] grid resulted in common midpoint (CMP) data with an average fold of ∼40 across a [Formula: see text] area. A principal goal of our investigation was to determine an acquisition strategy capable of producing reliable subsurface images in a more efficient and cost‐effective manner. Field efforts for the four tested acquisition strategies were approximately 50%, 50%, 25%, and 20% of the original effort. All four data subsets were subjected to a common processing sequence. Static corrections, top‐mute functions, and stacking velocities were estimated individually for each subset. Because shallow reflections were difficult to discern on shot and CMP gathers generated with the lowest density acquisition pattern (20% field effort) such that dependable top‐mute functions could not be estimated, data resulting from this acquisition pattern were not processed to completion. Of the three fully processed data subsets, two (50% field effort and 25% field effort) yielded 3‐D migrated images comparable to that derived from the entire data set, whereas the third (50% field effort) resulted in good‐quality images only in the shallow subsurface because of a lack of far‐offset data. On the basis of these results, we concluded that all geological objectives associated with our particular study site, which included mapping complex lithological units and their intervening shallow dipping boundaries, would have been achieved by conducting a 3‐D seismic reflection survey that was 75% less expensive than the original one.

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Ray, Steven, et Yessica Nataliani. « Pengolahan Citra Digital pada Pembuatan Motif Keramik Menggunakan Grup Simetri ». Jurnal Buana Informatika 13, n^o 1 (1 avril 2022) : 11–22. http://dx.doi.org/10.24002/jbi.v13i1.5499.

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Abstract. Digital Image Processing in Making Ceramic Patterns Using Symmetry Groups. The large number of requests for ceramic motifs makes ceramic craftsmen have to create a new and fast ceramic motif design idea. The generation of patterns on ceramic motifs digitally can be used by ceramic craftsmen. This study discusses the pattern of ceramic patterns using digital image processing with digital applications. The ceramic pattern design is made with a symmetrical pattern by the process of translation, rotation, reflection, and sliding reflection. The purpose of this research is to develop various ceramic patterns by applying symmetrical groups as motif designs on ceramics. The application is expected to make it easier for designers to find or create new designs from a basic pattern or what is commonly called a unit pattern or unit grid. The results obtained from this study are 17 patterns from 17 symmetric groups originating from one basic pattern. The combination of several patterns is also formed from the symmetry group into a new, more varied pattern.Keywords: Symmetric Group, Ceramic, Crystallography, Transformation. Abstrak. Banyaknya permintaan motif keramik membuat pengrajin keramik harus menciptakan sebuah ide desain motif keramik yang baru dan cepat. Pembangkitan pola pada motif keramik secara digital dapat digunakan oleh para pengrajin keramik. Penelitian ini membahas pola motif keramik menggunakan pengolahan citra digital dengan aplikasi digital. Desain motif keramik tersebut dibuat dengan pola simetris dari proses translasi, rotasi, refleksi, dan refleksi luncur. Tujuan penelitian ini adalah mengembangkan berbagai macam pola keramik dengan menerapkan grup simetris sebagai desain motif pada keramik. Aplikasi diharapkan dapat memudahkan para desainer untuk menemukan atau menciptakan desain-desain baru dari sebuah pola dasar atau yang biasa disebut pola satuan atau kisi satuan. Hasil yang didapat dari penelitian ini berupa 17 pola dari 17 grup simetri yang berasal dari satu pola dasar. Gabungan beberapa pola juga dibentuk dari grup simetri menjadi pola baru yang lebih bervariasi. Kata Kunci: Grup Simetris, Keramik, Kristalografi, Transformasi.

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M., Suma, Goutham M.A et Paramesha . « Moment method approach to analyze waveguide array radiator with crossed dipole as a near field sensor ». International Journal of Engineering & ; Technology 8, n^o 4 (19 octobre 2019) : 417. http://dx.doi.org/10.14419/ijet.v8i4.29646.

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Moment method approach is used to estimate the error encountered by the sensor in the near field and probe measures co-pole and cross-pole voltages at the same time. Conversely, due to several reflections between the waveguide and dipole sensor, near field values are changed. Calculations are done to analyze the absolute sampled co-pole voltage pattern and relative sampled electric field (without probe) pattern in the scan plane, and inaccuracy induced by the sensor is determined. The waveguide reflection coefficient, radiation admittance and susceptance with measuring sensor are reformed with respect to the equivalent values in the absence of the sensor in the near field.

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Eades, J. A., A. E. Smith et D. F. Lynch. « convergent-beam diffraction from surfaces ». Proceedings, annual meeting, Electron Microscopy Society of America 45 (août 1987) : 30–33. http://dx.doi.org/10.1017/s0424820100125208.

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It is quite simple (in the transmission electron microscope) to obtain convergent-beam patterns from the surface of a bulk crystal. The beam is focussed onto the surface at near grazing incidence (figure 1) and if the surface is flat the appropriate pattern is obtained in the diffraction plane (figure 2). Such patterns are potentially valuable for the characterization of surfaces just as normal convergent-beam patterns are valuable for the characterization of crystals.There are, however, several important ways in which reflection diffraction from surfaces differs from the more familiar electron diffraction in transmission.GeometryIn reflection diffraction, because of the surface, it is not possible to describe the specimen as periodic in three dimensions, nor is it possible to associate diffraction with a conventional three-dimensional reciprocal lattice.

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Khlopov, Maxim Yu. « Dark matter reflection of particle symmetry ». Modern Physics Letters A 32, n^o 15 (27 avril 2017) : 1740001. http://dx.doi.org/10.1142/s0217732317400016.

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In the context of the relationship between physics of cosmological dark matter and symmetry of elementary particles, a wide list of dark matter candidates is possible. New symmetries provide stability of different new particles and their combination can lead to a multicomponent dark matter. The pattern of symmetry breaking involves phase transitions in the very early Universe, extending the list of candidates by topological defects and even primordial nonlinear structures.

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Wang, Su. « TEM observation of cylindrite ». Proceedings, annual meeting, Electron Microscopy Society of America 47 (6 août 1989) : 420–21. http://dx.doi.org/10.1017/s042482010015407x.

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Cylindrite, approximately FePb3Sn4Sb2S14, contains two different types of layers, pseudo-tetragonal(t-lattice) with PbS structure and pseudo-hexagonal (h-lattice) with SnS2 structure. The two kinds of layers are superimposed in the order of htht.., and the repeat periodicity is a. In the past only the composite SAED pattern corresponding to the b*c* plane of the two lattices was obtained as shown in Fig. 1a. Now we have succeeded, by careful tilting, in taking separate SAED patterns and HREM images of these two lattices(Figs. 2 and 3). The CBED pattern containing two [100] zone axes indicates: , as shown in Fig. lb.In the SAED patterns shown in Figs. 2, 3 and 4, each main reflection is accompanied by a row of satellite spots caused by the common structural modulation of the two lattices shown by the dark bands inthe HREM images. The rows of satellites, defined by q, in general donot parallel to any axes defined by the main reflections. In the q direction, the additional long-range periodicity corresponding to the satellites and the basic periodicity of both lattices are incommensurate.

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Kaufmann, Mareile, Simon Egbert et Matthias Leese. « Predictive Policing and the Politics of Patterns ». British Journal of Criminology 59, n^o 3 (7 décembre 2018) : 674–92. http://dx.doi.org/10.1093/bjc/azy060.

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AbstractPatterns are the epistemological core of predictive policing. With the move towards digital prediction tools, the authority of the pattern is rearticulated and reinforced in police work. Based on empirical research about predictive policing software and practices, this article puts the authority of patterns into perspective. Introducing four ideal-typical styles of pattern identification, we illustrate that patterns are not based on a singular logic, but on varying rationalities that give form to and formalize different understandings about crime. Yet, patterns render such different modes of reasoning about crime, and the way in which they feed back into policing cultures, opaque. Ultimately, this invites a stronger reflection about the political nature of patterns.

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