Edge Face Research Articles

An integrated approach of topological optimization with parametric validation and response surfaces, using ANSYS®

In industrial engineering practice, the use of cutting tools, or those of plastic deformation (dies), is known, involves high costs of materials, and requires, at the same time, conditions of high resistance to deformation. The reduction of the mass of the parts, ie the reduction of the costs with the materials, from the composition of the tools, at the same time with the constant maintenance, or, if possible, with the increase of the rigidity, which, in turn, is identical with the decrease of the metallic materials. when trying to optimize the shape of mechanical parts. To evaluate and to study the behavior of a plate material, also, elastic deformation of a tool component part, a specialized Computer Aided Engineering (CAE) software, Ansys Academic R22, was used. The load was applied to the holes contour of the plate to simulate “action” which determines the generation of permanent plate deformation.The boundary conditions, i.e. the fixed supports, are materialized in the lateral face of the piece and the upper edge of the opposite face. Both the applied load and the limit conditions simulate real situations from industrial practice.

AI BASED REALTIME FACE MASK DETECTION

The world has not yet fully Recover from this pandemic and the vaccine that can effectively treat Covid-19 is yet to be discovered. Wearing a face mask will help prevent the spread of infection and prevent the individual from contracting any airborne infectious germs. Done by evaluation of the classification results by analysing real-time streaming from the Camera. Using Face Mask Detection System, one can monitor if the people are wearing masks or not. Here HAARCASACADE algorithm is used for image detection. Collating with other existing algorithms, this classifier produces a high recognition rate even with varying expressions, efficient feature selection and low assortment of false positive features. HAAR feature-based cascade classifier system utilizes only 200 features out of 6000 features to yield a recognition rate of 98-100%. According to this motivation we demand mask detection as a unique and public health service system during the global pandemic COVID-19 epidemic. The model is trained by face mask image and non-face mask image. KEYWORDS Face mask detection Face edges (FMD) CNN- Convolutional Neural Network

LES study on variation of flow pattern around a 4:1 rectangular cylinder and corresponding wind load during VIV

Vortex-induced vibration (VIV) is one of the typical flow-induced large amplitude vibrations. In this study, large eddy simulation (LES) is carried out to investigate the whole VIV process of a rectangular cylinder with aspect ratio 4. The flow fields and wind loads for rigid and elastic models are examined and compared to clarify the crucial flow characteristics during VIV. Results show that the time-averaged reattachment point of separated shear layer moves towards upstream direction with the increase of response amplitude. The mean negative pressure is consequently increased near leading edge of side face. For dynamic flow and wind load, in initial branch, the reattachment point of the separated shear layer, corresponding to the instant of largest side face wind load, gradually moves towards downstream with the increase of response amplitude. Meanwhile, the fluctuating lift coefficient and span-wise wind load correlation increase accordingly. In upper branch, the separated shear layer temporally separates from the side face, which leads to a sharp reduction of fluctuating lift coefficient and span-wise wind load correlation. The response amplitude, however, does not change apparently. In desynchronization, the response amplitude starts to decrease, as the vibration can no longer capture the shedding frequency of shape-induced vortex. The characteristics of the motion-induced wind loads corresponding to different wind speeds are also discussed in this study.

Double Duplication of Special Classes of Cycle Related Graphs

Let <img src=image/13427481_01.gif> be a simple, finite, connected, plane graph with the vertex set <img src=image/13427481_02.gif>, the edge set <img src=image/13427481_03.gif> and the face set <img src=image/13427481_04.gif>). Martin Baca [1] defined, a connected plane graph <img src=image/13427481_01.gif> with vertex set <img src=image/13427481_02.gif>, edge set <img src=image/13427481_03.gif> and face set <img src=image/13427481_04.gif> to be <img src=image/13427481_05.gif> face antimagic if there exists positive integers <img src=image/13427481_06.gif> and <img src=image/13427481_07.gif> and a bijection <img src=image/13427481_08.gif>: <img src=image/13427481_09.gif> such that the induced mapping <img src=image/13427481_10.gif>: <img src=image/13427481_11.gif>, where for a face <img src=image/13427481_12.gif>, <img src=image/13427481_13.gif> is the sum of all <img src=image/13427481_14.gif> for all edges <img src=image/13427481_15.gif> surrounding <img src=image/13427481_12.gif> is also a bijection. This paper proves the existence of face antimagic labeling for the double duplication of all vertices by edges of gear graph <img src=image/13427481_16.gif> for <img src=image/13427481_17.gif>, grid graph <img src=image/13427481_18.gif> for <img src=image/13427481_19.gif>, where <img src=image/13427481_20.gif> even, prism graph <img src=image/13427481_21.gif> for <img src=image/13427481_22.gif> and the double duplication of all vertices by edges of strong face of triangular snake graph <img src=image/13427481_23.gif> for <img src=image/13427481_17.gif>. The <img src=image/13427481_05.gif> face antimagic labeling for double duplication of special graphs can be used to encrypt and decrypt the messages, which is used as a real time application. In [3], we used <img src=image/13427481_05.gif> face antimagic labeling of strong face of duplication of all vertices by edges of a tree <img src=image/13427481_23.gif> for <img src=image/13427481_24.gif> to encrypt and decrypt thirteen secret numbers which can be extended to double duplication of graphs to encode and decode the numbers, which in turn can be used in military base, ATM and so on.

Numerical Simulation and Experimental Validation of Squeeze Casting of AlSi9Mg Aluminum Alloy Component with a Large Size.

The squeeze casting process for an AlSi9Mg aluminum alloy flywheel housing component was numerically simulated using the ProCAST software, and orthogonal simulation tests were designed according to the L16 (4) 5 orthogonal test table to investigate the alloy melt flow rule under four factors and four levels each of the pouring temperature, mold temperature, pressure holding time and specific pressure, as well as the distributions of the temperature fields, stress fields and defects. The results showed that the flywheel housing castings in all 16 test groups were fully filled, and the thinner regions solidified more quickly than the thicker regions. Hot spots were predicted at the mounting ports and the convex platform, which could be relieved by adding a local loading device. Due to the different constraints on the cylinder surface and the lower end surface, the solidification was inconsistent, the equivalent stress at the corner junction was larger, and the castings with longer pressure holding time and lower mold temperature had larger average equivalent stress. Shrinkage cavities were mainly predicted at mounting ports, the cylindrical convex platform, the peripheral overflow groove and the corner junctions, and there was also a small defect region at the edge of the upper end face in some test groups.

20‐2: Integration of Through Glass Via Interconnects within Thin Film Transistor Active Matrix Backplanes

There is increasing interest in minimizing display bezels or creating truly borderless displays for liquid crystal, organic light emitting diode, and emerging microLED technologies. The current approach is integration of side‐bonded electrodes or wrap‐around electrodes to enable flex connector attachment on the backplane edge face or backs surface. These approaches utilize the backplane perimeter to achieve the required electrical interconnection. In contrast, metallized through glass via interconnects can be distributed across the backplane surface. This provides a more localized connection for backplane signal and power. This paper summarizes successful integration of metallized via interconnects with thin film transistors.

Influence of Wear Profile Geometry on Critical Plane Fatigue Crack Initiation Criteria in Plane and Axisymmetric Elastic Fretting Contacts

The subsurface elastic stress fields in plane and axisymmetric contacts with friction under oscillating tangential loading are calculated via a very robust, high-precision method, which operates with appropriate superpositions of analytic solutions for the respective Hertzian contact problems. Based on the stress fields, two critical plane fatigue crack initiation criteria—the Smith-Watson-Topper (SWT) parameter and the Findley parameter—are evaluated for three types of contact profile geometries: (unworn) parabolic contact, the partial slip limiting wear profile of an initially parabolic contact, and truncated parabolic contact. Appropriate scaling laws are introduced to formulate a general solution in terms of non-dimensional variables. The crack initiation criteria are determined in the full subsurface loading plane. It is found that the truncated profile—which may originate from sliding wear—has practically the same local distribution of crack initiation criteria as the unworn profile, despite the (weak) stress singularity at the edge of the flat face. The partial slip limiting wear profile, on the other hand, exhibits a strong edge stress singularity at the boundary of the permanent stick zone, the crack initiation criteria are drastically increased (and theoretically infinite). Also, while for the unworn and truncated profiles high values of the crack initiation criteria are extremely localized around “hotspots” at the surface, for the partial slip limiting wear profile they reach much deeper into the subsurface material. This offers a new explanation for the dominance of fatigue failure in the partial slip regime of fretting. The differences between plane and axisymmetric cases are generally small. The SWT parameter is generally more localized than the Findley parameter.

Development of Tool Wear Standards and Wear Mechanism for Micro Milling Ti-6Al-4V Alloy

With the rapid development of high-precision-device technology, new demands are put forward for micro milling. The size effect and low cutting energy of micro milling make the process expensive and difficult, especially for Ti-6Al-4V alloys. The wear of the micro-milling cutter lacks corresponding international standards and its cutting mechanism is complex. In this paper, four kinds of micro-milling cutters with different wear states were obtained by designing micro-milling experiments, and the wear process and wear mechanism were observed and analyzed. The cutter diameter reduction, end face wear, flank wear and edge radius are comprehensively analyzed. It is considered that the formulation of a micro-milling-cutter wear standard needs comprehensive consideration, and the wear of end face 30 μm, wear of flank 35 μm and tool diameter reduction 55 μm can be used as the failure criteria of the micro-milling cutter. The wear forms mainly include abrasion marks, material adhesion, built-up edges and micro-collapse blades. Adhesive wear exists in the whole cutting process and plays a major role. Abrasive wear, diffusion wear and oxidation wear will occur when the cutting temperature reaches the melting point of Co. The wear of the micro-milling cutter is analyzed more comprehensively, a new wear-failure standard is formulated and the complex wear mechanism is revealed.

Stochastic parameterized modeling for aerodynamic design of wind turbine airfoil

Aerodynamic optimization of the airfoil is of great significance to the shape design for wind turbine blade. However, it is tough to calculate the aerodynamic forces of airfoil with random shape variations. In response to this challenge, a stochastic parameterized model based on uncertainty quantification method is proposed. And the influence of non-deterministic airfoil geometry caused by designed parameters on the aerodynamic characteristics is evaluated through the combination of sparse grid-based polynomial chaos (SGPC) and computational fluid dynamic (CFD) taking two airfoils at different Reynolds numbers as examples. OpenFOAM is employed as CFD solver and connected with the in-house stochastic parametric analysis code in a non-intrusive way. Finally, the aerodynamic responses of lift, drag, as well as the surface pressure coefficients are obtained, and the sensitivity of the lift and drag coefficients to the stochastic designed parameters are evaluated. It can be concluded that for the same type airfoil, the sensitive parameters after stall behavior are effected to some extent by increasing Reynolds number, that is, the impact of the maximum curvature index on pressure surface is weakened. As for two kinds of airfoils, S809 is sensitive to parameters near the maximum curvature of the airfoil and the trailing edge of the suction surface under attached flow, while convert to those near the leading edge and maximum curvature of suction face once stalled. FFA-W3-241 airfoil has no sensitivity factors in attached flow and features the same sensitive indicators after stall. These results will provide a reference for coarse-to-fine strategy in optimizing the sample library which is generally the first step of airfoil design process.

An edge center-based strain-smoothing triangular and tetrahedral element for analysis of elasticity

A novel edge center-based strain-smoothing method is put forward and applied to triangular and tetrahedral finite elements for linear and geometric nonlinear analysis of elastic mechanics. In the proposed edge center-based strain-smoothing element (EC-SSE), the linear strain field is constructed accordingly to the smoothed strain at element edge centers or face centers. The smoothed strain at both triangular and tetrahedral element edge centers is obtained directly utilizing elements adjacent to the edge, without requiring smooth domain. Besides, the smoothed strain at edge centers is averaged and assigned to the face center for tetrahedral elements. Compared with other methods, EC-SSE not only constructs a linear strain field within elements without introducing extra DOFs, but also ensures the strain consistency at the centers of intersecting edges or interfaces, which help to tremendously improve the smoothness of strain/stress distribution in the whole field. The EC-SEE passes basic element tests, including standard patch test, zero energy mode and linear independent tests. Subsequently, some attractive performances of EC-SSE, such as high accuracy and convergence rates for both displacement and strain energy, smoother stress field and the absence of temporal instability problems, are demonstrated through a variety of practical numerical examples.

Tribological aspects of tool wear during turning Ti-15Mo alloy with cemented tungsten carbide cutting inserts prepared with different surface finishes

Due to the low machinability of titanium alloys, which have been increasingly applied in medical and aerospace industries, several studies have been carried out focusing on the improvement of tool life in machining processes that involve such class of material. Aiming at contributing to the technological investigations and at expanding the knowledge on the phenomena involved in the tool-workpiece contact, this work presents tool wear results and a tribological analysis of the application of cemented tungsten carbide cutting inserts with different roughness characteristics in the edge and flank face as well as grinding marks (grooves) in the rake face in distinct directions. The inserts were prepared by plunge-face grinding and used in turning of a beta-titanium alloy (Ti-15Mo). Results showed that the insert with lower surface and edge roughness and with grooves in the rake face perpendicular to chip flow direction led to the lowest final flank wear value when the tool life criterion was achieved. Higher flank wear values were obtained for the rougher inserts, due to the greater edge chipping produced in grinding.

Effect of aging temperature on ordered structure of Ni-Cr-Al-Fe precision resistance alloy

The electrical resistivity of Ni-Cr-Al-Fe precision resistance alloy is quite sensitive to aging temperature, due to the resulting evolution of ordered structures. For the first time, the dependence of the electrical resistivity and microstructure on aging temperature has been investigated via an isochronal aging procedure at different temperature. Electrical resistivities of the as-quenched and -aged samples were measured in order to identify the typical samples that were used to reveal the effect of aging temperature on the microstructure. Transmission electron microscopy (TEM) and atom probe tomography (APT) were used to study the microstructure. The L12 ordered structure formed during aging process was identified by selective area electron diffraction (SAED). Based on the results of APT, composition distributions in the samples were analyzed and compared with each other. It was found that the L12 long range order (LRO) was formed during aging at 460 °C, and grew up with the increase of aging temperature. In the superlattice, Ni atoms occupy primarily the face center sites, while Al atoms take the face edge sites more than Cr and Fe atoms do. No compositional difference was found between the LRO clusters and the matrix in the sample aged at 460 °C. With the increase of aging temperature, Cr and Fe atoms tend to be excluded from the ordered clusters and reside in the disordered matrix. Therefore, the composition of the ordered clusters is different than the matrix in the samples aged at 595 °C and 670 °C.

Light Extraction and Brightness Enhancement of Luminescent Rectangular Slabs

The extraction efficiency and the brightness are critical parameters to increase the performance of luminescent rectangular slabs such as scintillators, luminescent concentrators, or diamonds with NV centers. This work explains how an additional face breaking the rectangular symmetry can improve the extraction efficiency and brightness. The study is based on a fully analytical approach corroborated experimentally with cerium‐doped yttrium aluminum garnet (Ce:YAG) slabs. The model gives an analytical expression of the extraction efficiency and the brightness of the additional face as a function of the slab parameters (dimensions, refractive index, losses). Results highlight that the extraction efficiency by an additional face can be improved even if the area of the additional face is lower than the area of the smallest face of the slab, generally chosen as the output face in a standard configuration. Therefore, the output brightness can be easily improved and controlled by the dimension of the additional face. Balancing the extraction efficiency and the brightness, a 1 × 3 × 22 mm3 Ce:YAG slab with an optimized edge face and with mirrors on the lateral faces exhibits an efficiency 1.9 times better and a brightness 5.6 higher than a Ce:YAG in a standard configuration.

Research on Identification Method for Interface Flange in Automatic Docking System of Fluid Loading and Unloading Arm for Bottom Loading

The automatic docking system of the loading and offloading arm of a tank car is the key link to realizing the unmanned operation of tank car loading and unloading. The spatial position detection of the flange port of a tank car can guide the automatic docking of the fluid loading and offloading arm and flange port of the tank car. In this paper, a flange position detection method based on image recognition was proposed. Firstly, the end state of the loading arm was analyzed to determine the expression mode of the loading arm’s spatial pose so as to form a unified expression with the flange position and docked pose on the tank car. Then, for the image processing of the flange port of the tank car, this paper binarized the edge of the flange end face based on the Otsu algorithm, used the Canny algorithm for edge detection, used the least squares method to fit the image edge coordinates into a spatial circle, calculated the center coordinates and normal vector of the flange end face, and used these parameters to guide the end of the loading arm to adjust the position and attitude so that it was consistent with the position and pose of the flange port to realize docking. Then, a circular object center detection and calibration experiment, a flange end face image experiment, and an automobile tank car flange port physical detection experiment were carried out. The test results show that the spatial coordinate accuracy of the flange port diameter and center detected by this method meets the requirements of the loading arm automatic docking system, providing a research idea for the design of an automatic docking system for the loading and unloading arm of a tank car.

Development of a Method for Quantitative Evaluation of Facial Swelling in a Rat Model of Cerebral Ischemia by Facial Image Processing.

A quantitative method for the evaluation of facial swelling in rats with middle cerebral artery occlusion (MCAO) was established using a mathematical method for the first time. The rat model of MCAO was established via bilateral common carotid artery ligation. Three groups of rats with the same baseline were selected (model group, positive drug group, and control group) according to their behavioral score and body weight 24 h after surgery. Drug administration was initiated on post-MCAO day 8 and was continued for 28 days. Mobile phones were used to collect facial images at different time points after surgery. In facial image analysis, the outer canthi of both eyes were used as the facial dividing line, and the outer edge of the rat's face was framed using the marking method, and the framed part was regarded as the facial area (S) of the rats. The histogram created with Photoshop CS5 was used to measure the face area in pixels. The distance between the outer canthi of both eyes (Le) and vertical line from the tip of the nose to the line joining the eyes was recorded as H1, and the line from the tip of the nose to the midpoint of the line joining the eyes was recorded as H2. The facial area was calibrated based on the relationship between H1 and H2. The distance between the eyes was inversely proportional to the distance between the rats and mobile phone such that the face area was calibrated by unifying Le. The size of Le between the eyes was inversely proportional to the distance between the rats and mobile phone. This was used to calibrate the face area. When compared with the control group, the facial area of the model group gradually increased from postoperative day 1 to day 7, and there was a significant difference in the facial area of the model group on postoperative day 7. Hence, positive drugs exhibited the effect of improving facial swelling. H1 and H2 can reflect the state of turning the head and raising the head of the rats, respectively. Facial area was calibrated according to the relationship between H1 and H2, which had no obvious effect on the overall conclusion. Furthermore, mobile phone lens was used to capture the picture of rat face, and the distance between the eyes and H1 and H2 was used to calibrate the facial area. Hence, this method is convenient and can be used to evaluate subjective judgment of the human eyes via a quantitative method.

Galaxy classification: a deep learning approach for classifying Sloan Digital Sky Survey images

ABSTRACTIn recent decades, large-scale sky surveys such as Sloan Digital Sky Survey (SDSS) have resulted in generation of tremendous amount of data. The classification of this enormous amount of data by astronomers is time consuming. To simplify this process, in 2007 a volunteer-based citizen science project called ‘Galaxy Zoo’ was introduced, which has reduced the time for classification by a good extent. However, in this modern era of deep learning, automating this classification task is highly beneficial as it reduces the time for classification. For the last few years, many algorithms have been proposed which happen to do a phenomenal job in classifying galaxies into multiple classes. But all these algorithms tend to classify galaxies into less than six classes. However, after considering the minute information which we know about galaxies, it is necessary to classify galaxies into more than eight classes. In this study, a neural network model is proposed so as to classify SDSS data into 10 classes from an extended Hubble Tuning Fork. Great care is given to disc edge and disc face galaxies, distinguishing between a variety of substructures and minute features which are associated with each class. The proposed model consists of convolution layers to extract features making this method fully automatic. The achieved test accuracy is 84.73 per cent which happens to be promising after considering such minute details in classes. Along with convolution layers, the proposed model has three more layers responsible for classification, which makes the algorithm consume less time.

An improved posture evaluation method for cylindrical intersecting holes on large aerospace components based on monocular vision

Cylindrical intersecting holes (CIHs) are common connection and location reference features in the assembly of large aerospace structures such as missiles and rocket cabins. The posture accuracy of assembly holes significantly impacts the relative position accuracy of joined parts and the fatigue strength of the finished product. At present, monocular vision measurement is widely used in the automatic drilling of assembly holes due to its integration simplicity and lower cost, but in most research, only the front face edge of the hole is used in the measurement model, and the hole end surface is usually assumed to be plane, which inevitably leads to precision loss. In this research, a novel posture measurement method for CIHs is proposed. Firstly, by introducing an ambiguity removal strategy, a coarse posture estimation method based on the plane hypothesis of the two end surfaces of CIHs is suggested. Secondly, considering that there is no simple explicit expression for a CIH’s edge, it is difficult to adopt the conventional model projection-based pose optimization method. In view of this, the 3D points corresponding to the edge pixels of the CIHs’ image are derived, and the pose optimization model is established by minimizing the deviations between the distance from the points to the CIHs’ axis and the hole radius. Moreover, to better control the direction parameters of CIHs during the global optimization process, the approximately perpendicular and intersection constraints between the CIHs’ axis and cylindrical component axis are involved in the solution. The effectiveness of the posture measurement method is verified by comparative experiments with current methods and coordinate measuring machine, which demonstrates improvements in both measurement accuracy and robustness.

Evaluation of Leg Injury to Rail Passenger Occupying Walkover Seat in a Train Accident

It is important to enhance the safety to passenger even in a train accident. In order to grasp secondary impact risk to walkover seat occupant, the sled tests that assumed a level crossing accident were carried out. The results of the test made it clear that the severity of the leg injury to the passenger was higher than any other parts of body since the passenger's legs collided with the edge of a seating face of the front seat. To reduce such type of injury risk, the seating face which supported both ends of the aluminum pipe with the urethane elastomer was developed based on the impact test results. The sled tests were carried out to identify the injury risk reduction effect of the seating face with buffer. It was found that the leg injury risk of the seating face with buffer reduced for the conventional seating face more than 60%.

Bottom-Pressure Development Due to an Abrupt Slope Reduction at Stepped Spillways

Fluctuating bottom-pressures on stepped chutes are relevant for the spillway design. An abrupt slope reduction causes a local alteration of the bottom-pressure development. Little information is available regarding the air–water flow properties near an abrupt slope reduction on stepped chutes, particularly on the local pressure evolution. Nevertheless, the option of providing a chute slope reduction may be of interest in spillway layout. The experiments presented herein include pressure distributions on both vertical and horizontal step faces, subsequent to an abrupt slope reduction on stepped chutes. A relatively large-scale physical model including abrupt slope reductions from 50° to 18.6° and from 50° to 30° was used, operated with skimming flow. The data indicate a substantial influence of the tested slope reductions on the bottom-pressure development. In the vicinity of the slope reduction, the mean pressure head near the edge of the horizontal step face reached 0.4 to 0.6 times the velocity head upstream of the slope reduction, for critical flow depths normalized by the step height ranging between 2.6 and 4.6.

Spectrum of Thermal Radiation of Surface Plasmon-Polaritons Diffracted at the Edge of a Plane Metal Face

Spectrum of Thermal Radiation of Surface Plasmon-Polaritons Diffracted at the Edge of a Plane Metal Face