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Journal articles on the topic 'Edge layer'
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1
Li, Zhijun, Haiping Gao, Zhiyong Shang, and Wenming Zhang. "Robustness of Consensus of Two-Layer Ring Networks." Symmetry 15, no. 5 (May 15, 2023): 1085. http://dx.doi.org/10.3390/sym15051085.
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The topology structure of multi-layer networks is highly correlated with the robustness of consensus. This paper investigates the influence of different interlayer edge connection patterns on the consensus of the two-layer ring networks. Two types of two-layer ring network models are first considered: one is a kind of two-layer ring network with two linked edges between layers (Networks-a), and the other is a kind of two-layer ring network with three linked edges between layers (Networks-b). Using the Laplacian spectrum, the consensus of the network model is derived. The simulation experiments are used to demonstrate the influence of different interlayer edge connection patterns on the consensus of networks. To determine the best edge connection pattern for Networks-a and Networks-b, the number of nodes in a single-layer ring network is denoted by n. The best edge connection pattern for Networks-a is 1 & [(n+2)/2]. Furthermore, n is subdivided into 3k,3k+1,3k+2, and the best edge connection patterns of Networks-b are near 1 & k+1 & 2k+1.
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Sommer, Oliver, and Günter Wozniak. "Investigation of Coating Liquid Layer Behaviour at Curved Solid Edges." Applied Mechanics and Materials 831 (April 2016): 126–43. http://dx.doi.org/10.4028/www.scientific.net/amm.831.126.
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In our study we examined the behaviour of thin liquid layers at curved solid edges experimentally and numerically by coating investigations based on the laser-induced fluorescence technique (LIF) and by numerical film simulations based on the Volume-of-Fluid multiphase flow model (VOF), respectively. The main motivation was to find optimal combinations of influencing quantities to reduce the so-called Fat-Edge effect. Therefore, we performed a study of these influencing quantities, in which application parameters like edge curvature radii of the solid substrates and application layer thicknesses as well as determining liquid properties like viscosity and surface tension have been varied. Results are described qualitatively at corresponding Fat-Edge shapes and quantified by suitable Fat-Edge parameters, which had to be identified and selected.We can show that adverse and appropriate influencing parameter combinations exist, which generate conspicuous and less distinctive Fat-Edges, respectively. The experimental findings and proportionalities regarding Fat-Edge shapes and dimensions are found to be physically plausible. Furthermore, an order of significance of the influencing quantities has been established.Eventually, we could derive a dimensionless quantity by dimensional analysis, which describes the Fat-Edge effect. Thus, the Fat-Edge effect may also be described by the application of similarity theory and a corresponding dimensionless number.
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SUDERMAN, MATTHEW. "PATHWIDTH AND LAYERED DRAWINGS OF TREES." International Journal of Computational Geometry & Applications 14, no. 03 (June 2004): 203–25. http://dx.doi.org/10.1142/s0218195904001433.
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An h-layer drawing of a graph G is a planar drawing of G in which each vertex is placed on one of h parallel lines and each edge is drawn as a straight line between its end-vertices. In such a drawing, we say that an edge is proper if its endpoints lie on adjacent layers, flat if they lie on the same layer and long otherwise. Thus, a proper h-layer drawing contains only proper edges, a short h-layer drawing contains no long edges, an upright h-layer drawing contains no flat edges, and an unconstrained h-layer drawing contains any type of edge. In this paper, we derive upper and lower bounds on the number of layers required by proper, short, upright, and unconstrained layered drawings of trees. We prove that these bounds are optimal with respect to the pathwidth of the tree being drawn. Finally, we give linear-time algorithms for obtaining layered drawings that match these upper bounds.
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Sakamoto, Haruhisa, Hitoshi Tsubakiyama, Shinji Shimizu, and Shinichi Kashiwabara. "Quantification Method of Cutting-Edge Density Considering Grain Distribution and Grinding Mechanism." Advanced Materials Research 76-78 (June 2009): 149–54. http://dx.doi.org/10.4028/www.scientific.net/amr.76-78.149.
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In this study, the quantification method of the cutting-edge density is proposed because of its close relation to the grinding mechanism. The cutting-edge density depends upon not only the grain distribution but also the thickness of effective cutting-edge layer. Therefore, the quantification of the cutting-edge density requires measuring not only the profile but also the grinding force. The thickness of effective cutting-edge layer can be determined based on the grain distribution, the grinding force and the stiffness of a grinding wheel. From applied result of the proposed method for the actual grinding process, the cutting-edge density and the effective cutting-edges layer is determined appropriately corresponding to the change in the working surface condition.
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Erlebach, Thomas, and Jakob T. Spooner. "Exploration of k-edge-deficient temporal graphs." Acta Informatica 59, no. 4 (August 2022): 387–407. http://dx.doi.org/10.1007/s00236-022-00421-5.
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AbstractA temporal graph with lifetime L is a sequence of L graphs $$G_1, \ldots ,G_L$$ G 1 , … , G L , called layers, all of which have the same vertex set V but can have different edge sets. The underlying graph is the graph with vertex set V that contains all the edges that appear in at least one layer. The temporal graph is always connected if each layer is a connected graph, and it is k-edge-deficient if each layer contains all except at most k edges of the underlying graph. For a given start vertex s, a temporal exploration is a temporal walk that starts at s, traverses at most one edge in each layer, and visits all vertices of the temporal graph. We show that always-connected, k-edge-deficient temporal graphs with sufficient lifetime can always be explored in $$O(kn \log n)$$ O ( k n log n ) time steps. We also construct always-connected, k-edge-deficient temporal graphs for which any exploration requires $$\varOmega (n \log k)$$ Ω ( n log k ) time steps. For always-connected, 1-edge-deficient temporal graphs, we show that O(n) time steps suffice for temporal exploration.
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Li, Tao, Xin Tian, and Jin Wen Tian. "A Layer Segmentation Based Compression Algorithm." Applied Mechanics and Materials 602-605 (August 2014): 3635–38. http://dx.doi.org/10.4028/www.scientific.net/amm.602-605.3635.
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In this paper, we proposed a layer segmentation based compression algorithm for gray images. Image textures and some high frequency noise are described in a high frequency layer while the coarse part of the image is included in the low frequency layer. A mixed dictionary and sparse coding is applied for high frequency layer coding and the low frequency layer is coded using the traditional wavelets based coding system. The results show that the proposed scheme achieves better rate-distortion performance compared with several competing compression system. Furthermore, in the sparse coding part, some edge-related atoms are added in the dictionary and a high sparseness factor is set for the edge blocks, making more accurate approximations for edges. We avoid further degradation of edges caused by compression.
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Dong, Xia Bin, Xin Sheng Huang, Wan Ying Xu, and Lu Rong Shen. "Multi-Layer and Adaptive Edge Detection Method Based on Multi-Scale Gabor Wavelets." Applied Mechanics and Materials 380-384 (August 2013): 3890–94. http://dx.doi.org/10.4028/www.scientific.net/amm.380-384.3890.
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Recent years, the common adaptive edge detection algorithms use merely the global character of images, and the local character is ignored. The lack of image information always leads these algorithms are difficult to detect the low contrast edges and sensitive to asymmetric illumination. A novel adaptive edge detection algorithm is proposed to improve the edge detection performance. First, the original image is filtered to obtain the edge response image by introducing multi-scale Gabor filters. Second, non-maxima suppression technique is used on the edge response image to get the coarse edge points. Then, the edge response image is delaminated to adaptively select different thresholds towards different pixels of different layers according to pixels local mean and variance values. The fine edge points are got after filtering the edge response image with these thresholds. Finally, combine the coarse edge points and fine edge points together and get the final edge. Experimental results show that the proposed algorithm achieves lower contrast edge detection and robustness to asymmetric illumination, has better edge detection performance.
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Liepa, Līga, Zigmārs Rendenieks, Āris Jansons, Inga Straupe, Edgars Dubrovskis, and Olga Miezīte. "The Persisting Influence of Edge on Vegetation in Hemiboreal Alnus Glutinosa (L.) Gaertn. Swamp Forest Set-Asides Adjacent to Recently Disturbed Stands." Forests 11, no. 10 (October 12, 2020): 1084. http://dx.doi.org/10.3390/f11101084.
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To increase set-aside areas and protect biodiversity values in managed hemiboreal forest landscapes, small forest parcels called Woodland Key Habitats have been designated in Baltic and Nordic countries. The aim of this study was to investigate the persisting influence of the edge on vegetation dynamics for young, medium-old and old edges in Alnus glutinosa (L.) Gaertn. Woodland Key Habitats. All of these edges are adjacent to recently disturbed (clear-cut) stands. We surveyed edge influence on vegetation in bryophyte, herbaceous, shrub and tree layers in 90 plots in 30 set-aside forest stands in Southern Latvia. We tested the differences in the number of species and projective coverage in all vegetation layers, but plant functional types were examined—separately in the herbaceous layer. We found that edge influence in protected forest stands of A. glutinosa swamp forests reflects strong changes in vegetation and plant functional types in the herbaceous layer mostly up to 20 years after clear-cut disturbance in adjacent stands. The greatest differences were between young edges (≤20 years) and old edges (≥41 years), but there were very few significant differences between medium-old (21–40 years) and old edges which signifies more rapid changes in the early stages of edge influence and gradual stabilization of vegetation later on. We found that in edges adjacent to recently disturbed stands (up to 20 years), significantly less rare and indicator epiphytic lichen species occur, but this occurrence increases over time and edge influence is no longer present beyond 20 years after disturbance. Changes in vegetation and species occurrence found in our study indicated the need to plan the allocation of set-aside patches in production forest landscapes to ensure connectivity over longer period of time. Careful planning of clear-cuts in neighboring areas over time can significantly reduce the impact of edge effect on these set-asides.
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Wang, Kai, Congcong Wu, Yuanyuan Jiang, Dong Yang, Ke Wang, and Shashank Priya. "Distinct conducting layer edge states in two-dimensional (2D) halide perovskite." Science Advances 5, no. 7 (July 2019): eaau3241. http://dx.doi.org/10.1126/sciadv.aau3241.
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Two-dimensional (2D) lead halide perovskite with a natural “multiple quantum well” (MQW) structure has shown great potential for optoelectronic applications. Continuing advancement requires a fundamental understanding of the charge and energy flow in these 2D heterolayers, particularly at the layer edges. Here, we report the distinct conducting feature at the layer edges between the insulating bulk terrace regions in the (C4H9NH3)2PbI4 2D perovskite single crystal. The edges of the 2D exhibit an extraordinarily large carrier density of ~1021 cm−3. By using various mapping techniques, we found the layer edge electrons are not related to the surface charging effect; rather, they are associated with the local nontrivial energy states of the electronic structure at the edges. This observation of the metal-like conducting feature at the layer edge of the 2D perovskite provides a different dimension for enhancing the performance of the next-generation optoelectronics and developing innovative nanoelectronics.
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Corso, Alessandra, Lucia Valentina Gambuzza, Pietro De Lellis, and Mattia Frasca. "Synchronizing network systems in the presence of limited resources via edge snapping." Chaos: An Interdisciplinary Journal of Nonlinear Science 33, no. 1 (January 2023): 013123. http://dx.doi.org/10.1063/5.0093560.
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In this work, we propose a multilayer control protocol for the synchronization of network dynamical systems under limited resources. In addition to the layer where the interactions of the system take place, i.e., the backbone network, we propose a second, adaptive layer, where the edges are added or removed according to the edge snapping mechanism. Different from classic edge snapping, the inputs to the edge dynamics are modified to cap the number of edges that can be activated. After studying the local stability of the overall network dynamics, we illustrate the effectiveness of the approach on a network of Rössler oscillators and then show its robustness in a more general setting, exemplified with a model of the Italian high-voltage power grid.
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WYGNANSKI, ISRAEL, PHILIPP TEWES, HOLGER KURZ, LUTZ TAUBERT, and CHUNMEI CHEN. "The application of boundary layer independence principle to three-dimensional turbulent mixing layers." Journal of Fluid Mechanics 675 (May 11, 2011): 336–46. http://dx.doi.org/10.1017/jfm.2011.95.
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Turbulent mixing layers emanating from slanted trailing edges or nozzles evolve in a manner that is explainable by applying the independence principle to boundary layer flows. Although measurements downstream of a planar chevron splitter plate validate the concept, the intent of this short article is to re-examine the broader ramifications of this observation. Turbulent boundary layer growth on a yawed flat plate is re-examined as is the attached flow direction near the trailing edge of a highly swept-back wing.
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NAGARAJAN, S., S. K. LELE, and J. H. FERZIGER. "Leading-edge effects in bypass transition." Journal of Fluid Mechanics 572 (January 23, 2007): 471–504. http://dx.doi.org/10.1017/s0022112006001893.
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The effect of a blunt leading edge on bypass transition is studied by numerical simulation. A mixed direct and large-eddy simulation of a flat plate with a super-ellipse leading edge is carried out at various conditions. Onset and completion of transition is seen to move upstream with increasing bluntness. For sharper leading edges, at lower levels of turbulence, transition usually occurs through instabilities on low-speed streaks as observed by Jacobs & Durbin (2001) and Brandt et al. (2004) whereas increasing either the turbulence intensity or the leading-edge bluntness brings into play another mechanism. Free-stream vortices are amplified at the leading edge because of stretching. In the case of particularly strong vortices, this interaction induces a localized streamwise vortical disturbance in the boundary layer which then grows as it convects downstream and eventually breaks down to form a turbulent spot. These disturbances, which are localized and hence wavepacket-like, move at speeds in the range 0.55 U∞–0.65 U∞ and occur in the lower portion of the boundary layer. Simulations conducted with isolated vortices confirm such a response of the boundary layer.
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Cherubini, S., P. De Palma, J. Ch Robinet, and A. Bottaro. "Edge states in a boundary layer." Physics of Fluids 23, no. 5 (May 2011): 051705. http://dx.doi.org/10.1063/1.3589842.
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Sundaram, Ganesh, Douwe Monsma, and Jill Becker. "Leading Edge Atomic Layer Deposition Applications." ECS Transactions 16, no. 4 (December 18, 2019): 19–27. http://dx.doi.org/10.1149/1.2979977.
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Searl, Alison. "Saddle dolomite: a new view of its nature and origin." Mineralogical Magazine 53, no. 373 (December 1989): 547–55. http://dx.doi.org/10.1180/minmag.1989.053.373.05.
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AbstractSaddle dolomite is a common product of late-stage diagenesis and hydrothermal activity. It has been suggested that during growth Ca enrichment occurs towards crystal edges leading to a lattice expansion relative to face centres. However, backscatter scanning electron microscopy of eight samples has revealed that, instead of edge associated Ca enrichment, saddle dolomites have a series of edge associated Mg enriched wedges, between 5 and 20 µm thick and 300 µm long. Wedge geometry implies development of extra lattice layers at edges relative to face centres. It is suggested that the wedges develop during rapid, transport-controlled, crystal growth. The wedges possibly reflect a switching from continuous growth across the face to edge-nucleated growth as the boundary layer solution becomes progressively depleted. Continuous growth might be reinstigated through convective turnover of the boundary layer presenting fresh solution to the growing crystal.
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Aizawa, Tatsuhiko, Tomomi Shiratori, Yoshihiro Kira, Tomoaki Yoshino, and Yohei Suzuki. "Femtosecond Laser Trimming with Simultaneous Nanostructuring to Fine Piercing Punch to Electrical Amorphous Steel Sheets." Micromachines 12, no. 5 (May 17, 2021): 568. http://dx.doi.org/10.3390/mi12050568.
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A CVD (Chemical Vapor Deposition) diamond coated tungsten carbide (WC) and cobalt (Co) sintered alloy punch was trimmed by the femtosecond laser machining to sharpen its edge with about 2 μm and to simultaneously make nanostructuring to its side surface. In addition to the sharpened edge, its edge profile was formed to be homogeneous enough to reduce the damage layer width by piercing the electrical amorphous steel sheet stack. Each brittle sheet in the stacked work was damaged to have three kinds of defects by piercing; e.g., the droop-like cracking in the thickness and at the vicinity of hole, the wrinkling in peak-to-valley with partial cracking on the peaks, and the circumferential cracking. When using the WC (Co) punch with the inhomogeneous edge profile in the sharpened edge width, these three damages were induced into each sheet and the maximum damage width exceeded 80 μm. When using the punch with the sharpened edge and homogeneous edge profile, the wrinkling mode was saved and the total affected layer width was significantly reduced to less than 20 μm. Through the precise embossing experiments, this effect of punch edge profile condition to the induced damages was discussed with a statement on the nanostructuring effect on the reduction of damaged width in electrical amorphous steel sheets. The developed tool with the sharpened edge and homogenous edge condition contributes to the realization of a low iron loss motor with a reduced affected layer width.
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Rabiu, M., S. Y. Mensah, I. Y. Seini, and S. S. Abukari. "Magnetoplasmon Excitations at Graphene Vortex Hall Fluid Edge." Physics Research International 2016 (February 23, 2016): 1–5. http://dx.doi.org/10.1155/2016/8971759.
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We investigate magnetoplasmon dynamics localized on the edges of graphene vortex Hall fluid. The vortex matter captures an anomalous term that causes vortex localization near fluid boundary and creates a double boundary layer, Δ0∝(β-1)lB with β being filling factor. The term also has qualitative effect on resonant excitations of edge magnetoplasmons. We found that, for sharp edges under experimental conditions, graphene edge magnetoplasmon (EMP) resonances have similar behavior as in recent experiments. Gradual distinctions arise for smooth edges in the presence of the anomalous term, where a weak EMP peak appears. The second peak becomes well noticed as the smoothness is increased. We identified the resonant mode as an Inter-EMP. It originates from the oscillations of charges in the inner boundary of the double layer. The present observation brings to light the direct cause of Inter-EMP which remained to be detected in graphene experiments.
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Paraschiv, Alexandru, Gheorghe Matache, Nicolae Constantin, and Mihai Vladut. "Investigation of Scanning Strategies and Laser Remelting Effects on Top Surface Deformation of Additively Manufactured IN 625." Materials 15, no. 9 (April 28, 2022): 3198. http://dx.doi.org/10.3390/ma15093198.
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The main drawbacks of the Laser Powder Bed Fusion (LPBF) process are the surface quality and dimensional accuracy of manufactured parts due to the edge and corner effects. These effects can be diminished by using an appropriate balance of the process parameters and scanning strategies. This paper focuses on the assessment of reducing the edge and corner effects that occur in additively manufactured IN 625 alloy via the LPBF technique by varying the hatch angle rotation (by 45°, 67°, and 90°) and volumetric energy density (VED), and using the laser top surface remelting technique (LSR). The edge and corner effects of the cubic samples were quantitatively evaluated on the top surface by 3D laser surface scanning. It was found that the edge and corner effects became more pronounced in the cases of samples built with no contour and hatch angles of 45° and 67°, while the smallest deformations were obtained when the hatch angle was rotated by 90°. Moreover, the heights of both the edge and corner ridges increase as the number of remeltings passing the top layer increases. Conversely, when a lower VED was used for melting the top layer(s) of the samples, the edge and corner ridges were slightly reduced.
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Kumstel, Judith, and Sven Lüken. "Deburring and rounding of sheet metals and functionally relevant edges of parts using laser radiation." MATEC Web of Conferences 190 (2018): 02003. http://dx.doi.org/10.1051/matecconf/201819002003.
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The manufacturing of sheet metal parts or component edges often leads to burrs. Due to different requirements regarding the appearance, haptics, tribology et cetera the edges have to be deburred or rounded in a subsequent process. Especially for complex geometries, automated post-processing has been difficult up to now. Laser remelting is one possible solution. It is fully automated and suitable for most 3D geometries. During laser remelting the laser beam is focused on the surface, thus a thin surface layer up to 100 μm is melted. The surface tension in the liquid state is smoothing out the surface and the edge resolidifies rounded. The radius of the rounding is adjustable by the chosen process parameters, especially laser power PL and feed speed vfeed. Furthermore the resulting roughness and the gloss level are controllable via the process parameters. Typical processing speeds are 100 mm edge length per second. First studies with industry partners showed promising results. Laser remelting of push belts for the torque transmission in CVTs lead to an increase of fatigue strength by up to 200% which enables a higher torque.
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SCHRADER, L. U., L. BRANDT, C. MAVRIPLIS, and D. S. HENNINGSON. "Receptivity to free-stream vorticity of flow past a flat plate with elliptic leading edge." Journal of Fluid Mechanics 653 (April 27, 2010): 245–71. http://dx.doi.org/10.1017/s0022112010000376.
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Receptivity of the two-dimensional boundary layer on a flat plate with elliptic leading edge is studied by numerical simulation. Vortical perturbations in the oncoming free stream are considered, impinging on two leading edges with different aspect ratio to identify the effect of bluntness. The relevance of the three vorticity components of natural free-stream turbulence is illuminated by considering axial, vertical and spanwise vorticity separately at different angular frequencies. The boundary layer is most receptive to zero-frequency axial vorticity, triggering a streaky pattern of alternating positive and negative streamwise disturbance velocity. This is in line with earlier numerical studies on non-modal growth of elongated structures in the Blasius boundary layer. We find that the effect of leading-edge bluntness is insignificant for axial free-stream vortices alone. On the other hand, vertical free-stream vorticity is also able to excite non-modal instability in particular at zero and low frequencies. This mechanism relies on the generation of streamwise vorticity through stretching and tilting of the vertical vortex columns at the leading edge and is significantly stronger when the leading edge is blunt. It can thus be concluded that the non-modal boundary-layer response to a free-stream turbulence field with three-dimensional vorticity is enhanced in the presence of a blunt leading edge. At high frequencies of the disturbances the boundary layer becomes receptive to spanwise free-stream vorticity, triggering Tollmien–Schlichting (T-S) modes and receptivity increases with leading-edge bluntness. The receptivity coefficients to free-stream vortices are found to be about 15% of those to sound waves reported in the literature. For the boundary layers and free-stream perturbations considered, the amplitude of the T-S waves remains small compared with the low-frequency streak amplitudes.
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Sriram, R., L. Srinath, Manoj Kumar K. Devaraj, and G. Jagadeesh. "On the length scales of hypersonic shock-induced large separation bubbles near leading edges." Journal of Fluid Mechanics 806 (September 30, 2016): 304–55. http://dx.doi.org/10.1017/jfm.2016.591.
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The interaction of a hypersonic boundary layer on a flat plate with an impinging shock – an order of magnitude stronger than that required for incipient separation of the boundary layer – near sharp and blunt leading edges (with different bluntness radii from 2 to 6 mm) is investigated experimentally, complemented by numerical computations. The resultant separation bubble is of length comparable to the distance of shock impingement from the leading edge, rather than the boundary layer thickness at separation; it is termed large separation bubble. Experiments are performed in the IISc hypersonic shock tunnel HST-2 at nominal Mach numbers 5.88 and 8.54, with total enthalpies 1.26 and $1.85~\text{MJ}~\text{kg}^{-1}$ respectively. Schlieren flow visualization using a high-speed camera and surface pressure measurements using fast response sensors are the diagnostics. For the sharp leading edge case, the separation length was found to follow an inviscid scaling law according to which the scaled separation length $(L_{sep}/x_{r})M_{er}^{3}$ is found to be linearly related to the reattachment pressure ratio $p_{r}/p_{er}$; where $L_{sep}$ is the measured separation length, $x_{r}$ the distance of reattachment from the leading edge, $M$ the Mach number, $p$ the static pressure and the subscripts $r$ and $e$ denote the conditions at the reattachment location and at the edge of the boundary layer at the shock impingement location respectively. However, for all the blunt leading edges $(L_{sep}/x_{r})M_{er}^{3}$ was found to be a constant irrespective of Mach number and much smaller than the sharp leading edge cases. The possible contributions of viscous and non-viscous mechanisms towards the observed phenomena are explored.
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WANDERLEY, JUAN B. V., and THOMAS C. CORKE. "Boundary layer receptivity to free-stream sound on elliptic leading edges of flat plates." Journal of Fluid Mechanics 429 (February 25, 2001): 1–21. http://dx.doi.org/10.1017/s0022112000002548.
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The leading-edge receptivity to acoustic waves of two-dimensional bodies is investigated using a spatial solution of the Navier–Stokes equations in vorticity/stream function form in general curvilinear coordinates. The free stream is composed of a uniform flow with a superposed periodic velocity fluctuation of small amplitude. The method follows that of Haddad & Corke (1998), in which the solution for the basic flow and the linearized perturbation flow are solved separately. The initial motivation for the work comes from past physical experiments for flat plates with elliptic leading edges, which indicated narrow frequency bands of higher neutral-curve Branch I receptivity. We investigate the same conditions in our simulations, as well as on a parabolic leading edge. The results document the importance of the leading edge, junction between the ellipse and flat plate, and pressure gradient to the receptivity coefficient at Branch I. Comparisons to the past experiments and other numerical simulations showed the influence of the elliptic leading-edge/flat-plate joint as an additional site of receptivity which, along with the leading edge, provides a wavelength selection mechanism which favours certain frequencies through linear superposition.
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Tanaka, Ryutaro, Takashi Kito, Akira Hosokawa, Takashi Ueda, and Tatsuaki Furumoto. "Machined Workpiece Edge Shape Control by Laser Hardening —Optimizing Laser Scan Conditions and Cutter Paths—." International Journal of Automation Technology 4, no. 1 (January 5, 2010): 21–25. http://dx.doi.org/10.20965/ijat.2010.p0021.
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Burring is a vital factor in metal cutting processes, since it may cause production-line problems that add unwanted time and cost required for deburring. We found that laser hardening of workpieces before face milling efficiently prevents burr formation. Our purpose here is to study optimum laser hardening conditions and cutter paths. Where no burring occurs, minimal chipping such as in chamfering is seen at the martensite layer on the workpiece exit face. The martensite layer thickens with laser power density, increasing chamfer height. The larger the exit angle, the more difficult it is to form a chamfer-like edge. Even for relatively small exit angles, the lower the feed rate, the more difficult it becomes to form a chamfer-like edge.
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Hsu, R. K. C., and S. M. Copley. "Producing Three-Dimensional Shapes by Laser Milling." Journal of Engineering for Industry 112, no. 4 (November 1, 1990): 375–79. http://dx.doi.org/10.1115/1.2899602.
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A laser milling process employing a pulsed, carbon dioxide laser has been investigated using graphite as a model material. Material is removed by scanning the focused beam across the surface of the workpiece leaving behind a series of narrow, parallel, overlapping grooves. These grooves, together, constitute the removal of a thin layer of uniform thickness lying parallel to a layer plane. In order to remove layers bounded at the edge by upright walls perpendicular to the layer plane, the laser beam must be tilted with respect to the layer plane. Using this approach, it is possible to produce perpendicular steps and cylindrical surfaces.
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Zhang, Heng, Gang Liu, Wenchong Wang, Lifeng Chi, and Shiling Yuan. "Step-edge induced area selective growth: a kinetic Monte Carlo study." RSC Adv. 4, no. 48 (2014): 25005–10. http://dx.doi.org/10.1039/c4ra01756k.
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Murtha-Smith, Erling, and Thuyen P. Nguyen. "Buckling of Double Layer Grid Edge Members." International Journal of Space Structures 12, no. 2 (June 1997): 81–87. http://dx.doi.org/10.1177/026635119701200203.
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Stability equations are developed for edge joints for Double Layer Grids. Translations are neglected and rotations at each joint are related. Hence, the stiffness matrix reduces to a diagonal matrix of unit bandwidth so each joint becomes an independent substructure. Instability of an edge joint occurs when the minimum principal stiffness coefficient of the joint goes to zero. Using stability functions and the regular geometric relationships of DLG topology, the buckling forces in the members and hence the external load on the system are determined. A simple example in which the members were all of the same length, material and moment of inertia, gives effective length factors for the edge members of between 0.77 to 0.81.
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Scott, B. "Gyrokinetic study of the edge shear layer." Plasma Physics and Controlled Fusion 48, no. 5A (April 21, 2006): A387—A392. http://dx.doi.org/10.1088/0741-3335/48/5a/s39.
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Mohammadi, B., H. Hosseini-Toudeshky, and M.-H. Sadr-Lahidjani. "Free-edge effects analysis of angle-ply laminates under transverse loading using layer-wise finite-element method with semi-analytical shear stress calculation." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 223, no. 2 (December 1, 2008): 293–306. http://dx.doi.org/10.1243/09544062jmes1063.
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Free-edge stress fields are of an utmost localized nature exhibiting steep stress gradients and they rapidly decay with increasing distance from the laminates’ edges. Layer-wise theory has already been used to analyse the stress field at the free edges of the laminates. In this investigation, the layer-wise theory in finite-element method (FEM) is used to analyse the stress field of the laminates’ free edges. In this study, apart from the conventional FEM in which the stresses are calculated from the constitutive laws, the shear stress components along the thickness are calculated from the equilibrium equations by employing a semi-analytical approach. It is shown that the obtained stresses from the current investigation are very close to those available from the three-dimensional elasticity solution for a square laminate under transversely double sinusoidal pressure distribution. To investigate the free edge influence on shear stress distribution of laminates under transverse loading, the analyses are performed for three angle-ply lay-ups with clustered and alternating sequences. It is shown that the free edge effects of angle-ply laminates with different stacking sequences under transverse pressure loading could be considerably different from laminates with in-plane loading conditions.
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Zhi-Bo Wang, Zhi-Bo Wang. "Node Resource Management Model of Hierarchical Edge Computing." 電腦學刊 32, no. 5 (October 2021): 233–44. http://dx.doi.org/10.53106/199115992021103205020.
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This article focuses on hierarchical edge computing in the industrial Internet of Things scenario, and studies the static resource deployment of hierarchical edge computing networks. When deploying a hierarchical edge computing network with new equipment, the allocation of computing capacity between layers is one of the hot is-sues. This paper proposes a method for the allocation of edge computing node capacity between layers based on the M/M/1/c queue model, delay and call loss are performance indicators, and the optimal inter-layer capacity allocation algorithm is designed and implemented. This algorithm can reduce the global average delay of the sys-tem under the premise of meeting the requirement of call loss rate. Simulation verification shows that the optimal inter-layer capacity allocation algorithm can effectively reduce the system’s global average delay and call loss rate under the condition of a certain total system cost.
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Li, Houyin, Zhenyu Wang, Zhennan Wang, Chengxin Deng, Jinlong Luo, Jian Huang, Xiaoyan Wang, and Hai Yang. "Acoustic multichannel transports of valley edge states in bilayer sonic crystals." Applied Physics Letters 121, no. 24 (December 12, 2022): 243101. http://dx.doi.org/10.1063/5.0127559.
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Backscattering immunity of valley edge states for a monolayer sonic crystal provides a basis for designing devices with unconventional functions. Recently, the valley edge state of a bilayer sonic crystal, regarded as a new degree of freedom, gives a powerful platform for manipulating acoustic waves. In this Letter, we realize valley spin insulators in a bilayer sonic crystal and find that the layer-mixed, layer-polarized, and layer-locked edge states exist on both zigzag and armchair interfaces. There are significant differences between the armchair edge states and the zigzag edge states at the interfaces formed by two domains of distinct acoustic layer-valley Hall phases. Based on the projected dispersion relations for a bilayer sonic crystal, we achieve theoretically and experimentally bilayer multichannel transmission with different layers locking. This paper provides a design approach for applications of bilayer acoustic multichannel communication devices.
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Hrabčáková, Lucia, and Alicia Mašlejová. "Metallographic Analysis of Filiform Corrosion." Solid State Phenomena 270 (November 2017): 142–46. http://dx.doi.org/10.4028/www.scientific.net/ssp.270.142.
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The surface line type defects on the can twist-off lids from lacquered tinplate material have been analyzed. The analyzed defects manifested themselves like the lines bulged above the surrounding surface. They were aligned roughly perpendicular to the lid circumference; they were mostly arranged on the lower part of lid circumference edge. The defects surface was fully covered by lacquer layer. After lacquer layer removal it was visible in the defective area that tin layer was damaged on some defect areas. The defect presented itself like filiform corrosion which occurred in conditions slightly above room temperature and high humidity under the originally continuous covering layer. According to the findings, corrosion occurred on the hidden sheet cut edges and then propagated first perpendicular to the circumference into the sheet. Then sometimes its direction changed into the sheet rolling direction along the lines with less but still suitable tin layer thickness. This defect can be controlled by special protecting of lid cut edge against corrosion or decreasing of the temperature and the humidity conditions in the stores.
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SAATHOFF, P. J., and W. H. MELBOURNE. "Effects of free-stream turbulence on surface pressure fluctuations in a separation bubble." Journal of Fluid Mechanics 337 (April 25, 1997): 1–24. http://dx.doi.org/10.1017/s0022112096004594.
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Wind-tunnel experiments were conducted to investigate the cause of large pressure fluctuations near leading edges of sharp-edged bluff bodies. Measurements obtained with a blunt flat plate showed that very low pressures occur in a narrow region located approximately 0.25XR from the leading edge, where XR defines the distance from the leading edge to the mean reattachment location. This phenomenon occurs in the undisturbed flow as well as turbulent flow, although the magnitude of peak pressure fluctuations increases with both turbulence intensity, σu/u, and turbulence scale, LX.Flow visualization experiments conducted with a high-speed cine-camera reveal the process that causes large pressure fluctuations in separation bubbles. This process is initiated when a perturbation in the approaching flow causes a roll-up of the separated shear layer, producing a strong vortex near the surface. Conditional sampling of pressure data was used to determine the spanwise length of the vortex. A significant increase in the spanwise correlation of pressure fluctuations occurs when the shear layer rolls up. Coherence measurements indicate that the spanwise length of vortices in the separation bubble is not directly related to longitudinal velocity fluctuations in the free-stream.
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Dohan, Mohammed Iqbal, Nora Ahmed Mohammed, and Mohammed Rajeh Mohammed. "Optimized Content Adaptive Approach for Image Detailed Enhancement to Reduce Color Distortion." Webology 18, Special Issue 04 (September 30, 2021): 1056–69. http://dx.doi.org/10.14704/web/v18si04/web18181.
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Digital imaging has significantly influenced the outcome of research in various disciplines. For example, artificial intelligence and robotics, biometric security, multimedia and image processing, etc. Technically, image processing and the Human Visual System (HVS) relies heavily on image enhancement to improve the content of the image. One of the biggest challenges in image processing is detail enhancement due to halo artefacts and gradient inversion artefacts at edges. It has been used to enhance the visual quality of an image. Most algorithms that used to enhance the detail of an image essentially depend on edge-preserving decomposition techniques. in general, the image consist of two major elements are a base layer and a detail layer, which extracted by edge-preserving decomposition algorithms. The detail layer is enhanced to improve the details of the generated image. we propose in this paper, a new model to preserve the sharp edges and achieve better visual quality than the existing norm-based algorithm to enhance the details of the image. Experiments show that the proposed method reduces the distortion at the edges. It improves the details of the generated image significantly.
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Li, Yaofang, and Bin Wu. "Software-Defined Heterogeneous Edge Computing Network Resource Scheduling Based on Reinforcement Learning." Applied Sciences 13, no. 1 (December 29, 2022): 426. http://dx.doi.org/10.3390/app13010426.
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With the rapid development of wireless networks, wireless edge computing networks have been widely considered. The heterogeneous characteristics of the 6G edge computing network bring new challenges to network resource scheduling. In this work, we consider a heterogeneous edge computing network with heterogeneous edge computing nodes and task requirements. We design a software-defined heterogeneous edge computing network architecture to separate the control layer and the data layer. According to different requirements, the tasks in heterogeneous edge computing networks are decomposed into multiple subtasks at the control layer, and the edge computing node alliance responding to the tasks is established to perform the decomposed subtasks. In order to optimize both network energy consumption and network load balancing, we model the resource scheduling problem as a Markov Decision Process (MDP), and design a Proximal Policy Optimization (PPO) resource scheduling algorithm based on deep reinforcement learning. Simulation analysis shows that the proposed PPO resource scheduling can achieve low energy consumption and ideal load balancing.
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Altman, Donald B. "Critical layers in accelerating two-layer flows." Journal of Fluid Mechanics 197 (December 1988): 429–51. http://dx.doi.org/10.1017/s0022112088003313.
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A series of laboratory experiments on accelerating two-layer shear flows over topography is described. The mean flow reverses at the interface of the layers, forcing a critical layer to occur there. It is found that for a sufficiently thin interface, a slowly growing recirculating region, the ‘acceleration rotor’, develops on the interfacial wave at mean-flow Richardson numbers of O(0.5). This, in turn, can induce a secondary dynamical shear instability on the trailing edge of the wave. A single-mode, linear, two-layer numerical model reproduces many features of the acceleration rotor if mean-flow acceleration and bottom forcing are included. Velocity measurements are obtained from photographs using image processing software developed for the automated reading of particle-streak photographs. Typical results are shown.
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Wakabayashi, Katsunori. "Electronic transport properties of graphene nanostructures." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C197. http://dx.doi.org/10.1107/s2053273314098027.
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The electronic states of graphene near the Fermi energy are well described by massless Dirac Fermion. The presence of edges, however, makes strong implications for the spectrum of the electrons. In graphene nanoribbons with zigzag edges, localized states appear at the edge with energies close to the Fermi level. In contrast, edge states are absent for ribbons with armchair edges. In my talk, we focus on edge and nanoscale effect on the electronic properties of graphene nanoribbons. We discuss the following aspects of graphene nanostructured systems. (1) In zigzag nanoribbons, for nonmagnetic long-ranged disorder, a single perfectly conducting channel emerges associated with a chiral mode due to the edge state, i.e., the absence of the localization in this class. (2) We show the electronic transport properties of graphene nanojunctions crucially depend on the peripheral lattice structures. The condition for electron confinement is discussed. (3) We will discuss the effect of edge chemical modification on magnetic properties of nanographene systems. Also, we discuss the hole doping effect on the spin-polarized states appearing along the graphene zigzag edges. Our studies reveal that the peculiar electronic, magnetic and transport properties of graphene nanostructured systems. In addition, we present our recent work on graphene double layer structure (GDLS), where two graphene layers are separated by a thin dielectric. We will discuss the dielectric environment effect on the charged-impurity-limited carrier mobility of the GDLS on the basis of the Boltzmann transport theory. It is found that carrier mobility strongly depends on the dielectric constant of the barrier layer if the interlayer distance becomes larger than the inverse of the Fermi wave vector. Our results suggest effective use of ultra-thin dielectric barriers and a practical design strategy to improve the charged-impurity-limited mobility of the GDLS.
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Prakash, R., L. M. Le Page, L. P. McQuellin, S. L. Gai, and S. O’Byrne. "Direct simulation Monte Carlo computations and experiments on leading-edge separation in rarefied hypersonic flow." Journal of Fluid Mechanics 879 (October 2, 2019): 633–81. http://dx.doi.org/10.1017/jfm.2019.692.
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A comprehensive study of the fundamental characteristics of leading-edge separation in rarefied hypersonic flows is undertaken and its salient features are elucidated. Separation of a boundary layer undergoing strong expansion is typical in many practical hypersonic applications such as base flows of re-entry vehicles and flows over deflected control surfaces. Boundary layer growth under such conditions is influenced by effects of rarefaction and thermal non-equilibrium, thereby differing significantly from the conventional no-slip Blasius type. A leading-edge separation configuration presents a fundamental case for studying the characteristics of such a flow separation but with minimal influence from a pre-existing boundary layer. In this work, direct simulation Monte Carlo computations have been performed to investigate flow separation and reattachment in a low-density hypersonic flow over such a configuration. Distinct features of leading-edge flow, limited boundary layer growth, separation, shear layer, flow structure in the recirculation region and reattachment are all explained in detail. The fully numerical shear layer profile after separation is compared against a semi-theoretical profile, which is obtained using the numerical separation profile as the initial condition on existing theoretical concepts of shear layer analysis based on continuum flow separation. Experimental studies have been carried out to determine the surface heat flux using thin-film gauges and computations showed good agreement with the experimental data. Flow visualisation experiments using the non-intrusive planar laser-induced fluorescence technique have been performed to image the fluorescence of nitric oxide, from which velocity and rotational temperature distributions of the separated flow region are determined.
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Bechert, D. W. "Excitation of instability waves in free shear layers. Part 1. Theory." Journal of Fluid Mechanics 186 (January 1988): 47–62. http://dx.doi.org/10.1017/s0022112088000035.
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The generation of instability waves in free shear layers is investigated theoretically. The model assumes an infinitesimally thin shear layer shed from a semi-infinite plate which is exposed to sound excitation. For this model the forced instability waves are calculated. The shear-layer excitation by a source farther away from the plate edge in the downstream direction is very weak while upstream from the plate edge the excitation is relatively efficient. A special solution is given for the source at the plate edge. Any type of source farther away from the plate edge produces a parabolic pressure field near the edge. For this latter, fairly general case, a reference quantity is found for the magnitude of the excited instability waves. The theory is then extended to two streams, one on each side of the shear layer, having different velocities and densities. Furthermore, the excitation of a shear layer in a channel is calculated. The limitations to the theory and some aspects related to experiments are discussed. In particular, for a comparison with measurements, numerical computations of the velocity field outside the shear layer have been carried out.
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Dr. Pasumponpandian. "Analysis of Data Stream Processing At Edge Layer for Internet of Things." Journal of ISMAC 2, no. 1 (March 15, 2020): 26–37. http://dx.doi.org/10.36548/jismac.2020.1.003.
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The progress of internet of things at a rapid pace and simultaneous development of the technologies and the processing capabilities has paved way for the development of decentralized systems that are relying on cloud services. Though the decentralized systems are founded on cloud complexities still prevail in transferring all the information’s that are been sensed through the IOT devices to the cloud. This because of the huge streams of information’s gathered by certain applications and the expectation to have a timely response, incurring minimized delay, computing energy and enhanced reliability. So this kind of decentralization has led to the development of middle layer between the cloud and the IOT, and was termed as the Edge layer, meaning bringing down the service of the cloud to the user edge. The paper puts forth the analysis of the data stream processing in the edge layer taking in the complexities involved in the computing the data streams of IOT in an edge layer and puts forth the real time analytics in the edge layer to examine the data streams of the internet of things offering a data- driven insight for parking system in the smart cities.
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Beneitez, Miguel, Yohann Duguet, Philipp Schlatter, and Dan S. Henningson. "Edge tracking in spatially developing boundary layer flows." Journal of Fluid Mechanics 881 (October 24, 2019): 164–81. http://dx.doi.org/10.1017/jfm.2019.763.
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Recent progress in understanding subcritical transition to turbulence is based on the concept of the edge, the manifold separating the basins of attraction of the laminar and the turbulent state. Originally developed in numerical studies of parallel shear flows with a linearly stable base flow, this concept is adapted here to the case of a spatially developing Blasius boundary layer. Longer time horizons fundamentally change the nature of the problem due to the loss of stability of the base flow due to Tollmien–Schlichting (TS) waves. We demonstrate, using a moving box technique, that efficient long-time tracking of edge trajectories is possible for the parameter range relevant to bypass transition, even if the asymptotic state itself remains out of reach. The flow along the edge trajectory features streak switching observed for the first time in the Blasius boundary layer. At long enough times, TS waves co-exist with the coherent structure characteristic of edge trajectories. In this situation we suggest a reinterpretation of the edge as a manifold dividing the state space between the two main types of boundary layer transition, i.e. bypass transition and classical transition.
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Ivanov, Sergei Yu, Artur Vildanov, Pavel A. Golovin, Antoni Artinov, and Ivan Karpov. "Effect of Inter-Layer Dwell Time on Distortion and Residual Stresses of Laser Metal Deposited Wall." Key Engineering Materials 822 (September 2019): 445–51. http://dx.doi.org/10.4028/www.scientific.net/kem.822.445.
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The laser metal deposition is an advanced manufacturing technology enabling the production of large-sized parts and partially or completely elimination of machining and welding. The process is characterised by a non-uniform local heating of the buildup leading to a stress distribution, which may exceed the yield strength of the material and leads to loss of dimensional accuracy. The interlayer dwell time has a strong influence on the temperature field. The effect of the interlayer dwell time on the distortion and the stress distribution during laser metal deposition of a single-pass wall on the edge of 2 mm thick plate was studied experimentally and numerically. The deposited material was IN625 and the substrate material was AISI 316. A decrease of the residual displacement, due to a uniform shrinkage after the deposition of the last layer and a lower level of the residual compressive longitudinal plastic strain, has been observed in the studies without a dwell time. The peak increment of the free edge displacement corresponds to the first layer and hence the subsequent layers will be deposited on the already plastically deformed buildup. The tensile residual longitudinal stress near the top of the buildup and transverse stress near the edges of the buildup is higher than yield strength in the studies with dwell time.
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Li, Guangshun, Jiping Wang, Junhua Wu, and Jianrong Song. "Data Processing Delay Optimization in Mobile Edge Computing." Wireless Communications and Mobile Computing 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/6897523.
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With the development of Internet of Things (IoT), the number of mobile terminal devices is increasing rapidly. Because of high transmission delay and limited bandwidth, in this paper, we propose a novel three-layer network architecture model which combines cloud computing and edge computing (abbreviated as CENAM). In edge computing layer, we propose a computational scheme of mutual cooperation between the edge devices and use the Kruskal algorithm to compute the minimum spanning tree of weighted undirected graph consisting of edge nodes, so as to reduce the communication delay between them. Then we divide and assign the tasks based on the constrained optimization problem and solve the computation delay of edge nodes by using the Lagrange multiplier method. In cloud computing layer, we focus on the balanced transmission method to solve the data transmission delay from edge devices to cloud servers and obtain an optimal allocation matrix, which reduces the data communication delay. Finally, according to the characteristics of cloud servers, we solve the computation delay of cloud computing layer. Simulation shows that the CENAM has better performance in data processing delay than traditional cloud computing.
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Terada, Shohei, Kyoichiro Asayama, Masahiko Tsujimoto, Hiroki Kurata, and Seiji Isoda. "Chemical Shift of Electron Energy-Loss Near-Edge Structure on the Nitrogen K-Edge and Titanium L3-Edge at TiN/Ti Interface." Microscopy and Microanalysis 15, no. 2 (March 16, 2009): 106–13. http://dx.doi.org/10.1017/s1431927609090175.
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AbstractWe investigated the chemical shift of the electron energy-loss near-edge structure (ELNES) for the nitrogen K-edge and titanium L3-edge measured from the interface region between a titanium nitride layer and a titanium layer. Both the titanium nitride and titanium layers were prepared by a sputtering method. Elemental analysis for nitride and titanium in the vicinity of the interface region was performed using a standard technique in electron energy-loss spectroscopy. It was demonstrated that both the ELNES of nitrogen K-edge and titanium L3-edge presented the chemical shift, more or less, depending on the composition of TiNx. The experimental findings were interpreted using a first-principles band structure calculation. The chemical shifts of nitrogen K-edge and titanium L3-edge can be used as fingerprinting for readily distinguishing the composition of TiNx.
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Xu, Jixi, Weichang Li, Xin Wang, Jingping Tang, Wei Chen, Shubin Chen, and Lili Hu. "Numerical Simulations of the Influence on the Temperature Fields of Large-Sized Nd-Glass Slab with Designed Edge-Cladding Materials, Methods, and Structures." Photonics 9, no. 12 (December 2, 2022): 931. http://dx.doi.org/10.3390/photonics9120931.
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The good cladding of a large-sized Nd-doped phosphate glass slab as a laser amplifier requires not only the amplified spontaneous emission and parasitic oscillation to be fully absorbed, to hold up the small signal gain coefficient of the Nd ions, but also the absorbed heat energy to be appropriately dissipated to extend a uniform temperature field for the larger laser beam aperture of the edge-cladded Nd–glass slab. In the present work, numerical simulations were performed based on the developed feasible edge-cladding designs for a 786 × 436 × 40 mm3 Nd–glass slab, including the following alterations: optical absorptivity, quantum-dot absorption centers, ceramics with higher thermal diffusivity, glasses with lower and higher specific heat values, 3D printing edge-cladding methods, double-deck edge-cladding structure with transparent strips as a buffer layer, and thickening of the edge-cladding. All of these designed edge-cladding materials, methods, and structures satisfy both requirements of sufficiently absorbing and precisely matching with the refractive index, as emphasized by the edge-cladding for the Nd–glass. Some of the designed edge-claddings resulted in a much more uniform temperature field than the composite polymer–glass edge-cladding as the standard for comparison, which could be utilized to extend the effective laser aperture of the Nd–glass slab, thus being beneficial to the laser beam size and laser energy in the optics recycle loop strategy.
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Tanaka, Ryutaro, Hiroki Morishita, Yong Chuan Lin, Akira Hosokawa, Takashi Ueda, and Tatsuaki Furumoto. "Cutting Tool Edge Temperature in Finish Hard Turning of Case Hardened Steel." Key Engineering Materials 407-408 (February 2009): 538–41. http://dx.doi.org/10.4028/www.scientific.net/kem.407-408.538.
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This study deals with the influence of tool characteristics on the cutting edge temperature in turning case hardened steel. The cutting test is undertaken with the inserts which have different thermal conductivity and coating layer. The tool edge temperature is measured with a two-color pyrometer. The tool edge temperature increases with the increase in cutting speed. The higher thermal conductivity cutting insert causes lower tool edge temperature. The coating hardly affects the tool edge temperature. The white layer thickness increases with increasing cutting speed reaching a maximum at certain cutting speed and decreases with cutting speed.
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Kocharin, Vasilii L., Nikolai V. Semionov, Alexander D. Kosinov, Aleksey A. Yatskikh, Sofia A. Shipul, and Yury G. Yermolaev. "Experimental Study of the Influence of Unit Reynolds Number on the Laminar-Turbulent Transition on the Model Swept Wing with a Subsonic Leading Edge at M = 2." Siberian Journal of Physics 16, no. 1 (2021): 44–52. http://dx.doi.org/10.25205/2541-9447-2021-16-1-44-52.
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Experimental studies of the influence of unit Reynolds number on the laminar-turbulent transition in a supersonic boundary layer of a swept wing with a subsonic leading edge at Mach number 2 are performed. The experiments were performed on a model of a swept wing with a swept angle of the leading edge of 72 degrees and with a 3% profile with a variable chord length in span. The hot-wire measurements showed that a laminar-turbulent transition in a supersonic boundary layer of a swept wing with a subsonic leading edge occurs earlier (~25-30%) than on a model with a supersonic leading edge with the same oncoming flow parameters. It is shown that a change unit Reynolds number insignificant influence the laminar-turbulent transition in the boundary layer of a swept wing with a subsonic leading edge.
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Sun, Zitan, Xin Huang, Qing Liu, and Jianliang Xu. "Efficient Star-based Truss Maintenance on Dynamic Graphs." Proceedings of the ACM on Management of Data 1, no. 2 (June 13, 2023): 1–26. http://dx.doi.org/10.1145/3589278.
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K-truss is a useful notion of dense subgraphs, which can represent cohesive parts of a graph in a hierarchical way. In practice, in order to enable various truss-based applications to answer queries faster, the edge trussnesses are computed in advance. However, real-world graphs may not always be static and often have edges inserted or removed, leading to costly truss maintenance of recomputing all edge trussnesses. In this paper, we focus on dynamic graphs with star insertions/deletions, where a star insertion can represent a newly joined user with friend connections in social networks or a recently published paper with cited references in citation networks. To tackle such star-based truss maintenance, we propose a new structure of AffBall based on the local structure of an inserted/deleted star motif. With AffBall, we make use of the correlation of inserted edges to compute the trussnesses of the inner edges surrounding the star. Then, we analyze the onion layer of k-truss and conduct truss maintenance for the edges beyond the star, which can be efficiently achieved with a time complexity related to the number of the edges that change the onion layer. Moreover, we extend star-based truss maintenance to handle general updates and single-edge insertions/deletions. Extensive experiments on real-world dynamic graphs verify the effectiveness and efficiency of proposed algorithms against state-of-the-art truss maintenance algorithms.
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Zhang, Xin Lin, Jun Yan Zhao, Shi Yong Luo, and Wen Cai Xu. "A Novel Method to Seal the Edge of the Vacuum Glazing." Applied Mechanics and Materials 193-194 (August 2012): 1397–400. http://dx.doi.org/10.4028/www.scientific.net/amm.193-194.1397.
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Vacuum glazing is a new building material with excellent energy conservation and sound insulation properties. Usually, the edge sealing layer between two sheets of glass substrates are prepared by spraying the seal glass paste and then sintering. In the present research, a more effective preparation method is reported. The edge sealing layer is prepared with a glass paste by screen printing, and then sintering. The glass paste for the preparation of edge sealing layer of vacuum glazing was prepared by using low melting glass powder, ZrW2O8 powder with negative coefficient of thermal expansion and ethyl cellulose terpineol solution. The test result of the shear strength of the sealing layer indicated that the sealing is reliable.
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Matuszak, Jakub, and Kazimierz Zaleski. "Analysis of deburring effectiveness and surface layer properties around edges of workpieces made of 7075 aluminium alloy." Aircraft Engineering and Aerospace Technology 90, no. 3 (April 9, 2018): 515–23. http://dx.doi.org/10.1108/aeat-05-2016-0074.
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Purpose This paper aims to present a comprehensive analysis of deburring effectiveness and surface layer properties after deburring process by wire brushing from milled 7075 aluminium alloys objects. Edge states (rounding, chamfering), surface roughness around the edge, microhardness and residual stress distribution were analyzed. Design/methodology/approach During the machining process, undesirable phenomenon occurs, which is the formation of burrs at the edges of workpieces. They occur in most elements formed by machining. There are many methods that can be used for deburring, but in the case of large components, typical of aerospace industry, using certain methods becomes difficult or uneconomic. Taking advantage of the fact that a part is mounted on the machine, it is advisable to make deburring operation the last action. This operation can be carried out by wire brushing. Findings On the basis of conducted studies, it was demonstrated that it was possible to choose such technological brushing conditions as to ensure an effective process of deburring, form appropriate edge state and generate the desired surface layer properties. Practical implications The method presented in the article allows for efficient, automatic deburring, especially for large components made of 7075 aluminium alloy. This eliminates manual, time-consuming methods of removing burrs by locksmiths. Moreover, the results allow to evaluate changes occurring in the surface layer after brushing process. Originality/value Results of brushing experiment provide full information on selection of technological parameters to obtain the required surface roughness and edge state. Moreover, analysis of surface layer properties (microhardness, residual stress) allows to assess the degree of impact hitting fibre on the workpiece.
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Zess, G. A., and K. A. Thole. "Computational Design and Experimental Evaluation of Using a Leading Edge Fillet on a Gas Turbine Vane." Journal of Turbomachinery 124, no. 2 (April 1, 2002): 167–75. http://dx.doi.org/10.1115/1.1460914.
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With the desire for increased power output for a gas turbine engine comes the continual push to achieve higher turbine inlet temperatures. Higher temperatures result in large thermal and mechanical stresses particularly along the nozzle guide vane. One critical region along a vane is the leading edge-endwall juncture. Based on the assumption that the approaching flow to this juncture is similar to a two-dimensional boundary layer, previous studies have shown that a horseshoe vortex forms. This vortex forms because of a radial total pressure gradient from the approaching boundary layer. This paper documents the computational design and experimental validation of a fillet placed at the leading edge-endwall juncture of a guide vane to eliminate the horseshoe vortex. The fillet design effectively accelerated the incoming boundary layer thereby mitigating the effect of the total pressure gradient. To verify the CFD studies used to design the leading edge fillet, flowfield measurements were performed in a large-scale, linear, vane cascade. The flowfield measurements were performed with a laser Doppler velocimeter in four planes orientated orthogonal to the vane. Good agreement between the CFD predictions and the experimental measurements verified the effectiveness of the leading edge fillet at eliminating the horseshoe vortex. The flow-field results showed that the turbulent kinetic energy levels were significantly reduced in the endwall region because of the absence of the unsteady horseshoe vortex.