scholarly journals Generating Multibillion Element Unstructured Meshes on Distributed Memory Parallel Machines

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Seren Soner ◽  
Can Ozturan
Keyword(s):  
Parallel Machines ◽  
Test Results ◽  
Surface Mesh ◽  
Mesh Generator ◽  
Fine Mesh ◽  
Matching Test ◽  
Fine Surface ◽  
Coarse Surface ◽  
Volume Mesh ◽  
Partition Boundary

We present a parallel mesh generator called PMSH that is developed as a wrapper code around the open source sequential Netgen mesh generator. Parallelization of the mesh generator is carried out in five stages: (i) generation of a coarse volume mesh; (ii) partitioning of the coarse mesh; (iii) refinement of coarse surface mesh to produce fine surface submeshes; (iv) remeshing of each fine surface submesh to get a final fine mesh; (v) matching of partition boundary vertices followed by global vertex numbering. A new integer based barycentric coordinate method is developed for matching distributed partition boundary vertices. This method does not have precision related problems of floating point coordinate based vertex matching. Test results obtained on an SGI Altix ICE X system with 8192 cores confirm that our approach does indeed enable us to generate multibillion element meshes in a scalable way.

scholarly journals A Hybrid Model Method for Accurate Surface Deformation and Incision Based on FEM and PBD

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Shijie Tan ◽  
Hongjun Zhou ◽  
Jinjin Zheng
Keyword(s):  
Real Time ◽  
Surface Deformation ◽  
Virtual Surgery ◽  
Surface Mesh ◽  
Deformation Method ◽  
Hybrid Mesh ◽  
Time Performance ◽  
Small Incision ◽  
Fine Surface ◽  
Volume Mesh

In some simulations like virtual surgery, an accurate surface deformation method is needed. Many deformation methods focus on the whole model swing and twist. Few methods focus on surface deformation. For the surface deformation method, two necessary characteristics are needed: the accuracy and real-time performance. Some traditional methods, such as position-based dynamics (PBD) and mass-spring method (MSM), focus more on the real-time performance. Others like the finite element method (FEM) focus more on the accuracy. To balance these two characteristics, we propose a hybrid mesh deformation method for accurate surface deformation based on FEM and PBD. Firstly, we construct a hybrid mesh, which is composed of a coarse volume mesh and a fine surface mesh. Secondly, we implement FEM on coarse volume mesh and PBD on fine surface mesh, and the deformation of fine surface mesh is constrained by the displacement of the coarse volume mesh. Thirdly, we introduced a small incision process for our proposed method. Finally, we implemented our method on a simple deformation simulation and a small incision simulation. The result shows an accurate surface deformation performance by implementing our method. The incision effect shows the compatibility of our proposed method. In conclusion, our proposed method acquires a better trade-off between accuracy and real-time performance.

Vehicle Thermal Management Simulation Using a Rapid Omni-Tree Based Adaptive Cartesian Mesh Generation Methodology

2004 ◽  
Author(s):  
Kumar Srinivasan ◽  
Z. J. Wang ◽  
Wei Yuan ◽  
Richard Sun
Keyword(s):  
Thermal Management ◽  
Mesh Generation ◽  
Development Process ◽  
Cfd Simulation ◽  
New Method ◽  
Surface Mesh ◽  
Passenger Vehicle ◽  
Traditional Approaches ◽  
Volume Mesh ◽  
Vehicle Development Process

CFD simulation of vehicle under-hood and under-body poses several challenges. Specifically, the complexity of the geometry involved makes the use of traditional mesh generation approaches, based on the boundary-to-interior methodology, impractical and time consuming. The current work presents the use of an interior-to-boundary method wherein the need for creating a ‘water-tight’ surface mesh is not a pre-requisite for volume mesh generation. The application of the new method is demonstrated for an actual passenger vehicle under-hood model with nearly a hundred components. Coupled radiation/convection simulations are performed to obtain the complete airflow and thermal map of the engine compartment. Results are validated with test data. The new method results in significant gains in efficiency over traditional approaches allowing the simulation tool to be used effectively in the vehicle development process.

Use of Matching Method in Measuring Reliability of Individual Clinician's Diagnostic Judgment

1965 ◽  
Vol 16 (2) ◽  
pp. 491-496
Author(s):  
Joseph G. Phelan
Keyword(s):  
Clinical Diagnosis ◽  
Test Data ◽  
Chance Level ◽  
Sentence Completion ◽  
Test Results ◽  
Matching Method ◽  
Promising Tool ◽  
Matching Test ◽  
Completion Test ◽  
Better Than

This study aimed at exploring reliability differences in clinical diagnostic judgments. Twenty clinical psychologists volunteered for an examination of the consistency of their judgmental performance in matching test results and projective protocols against autobiographies. Psychologist-judges matched, at a better than chance level, Rorschach, TAT, and Sentence Completion Test protocols and objective, paper-and-pencil test data for 6 Ss against their complete autobiographies. Judges differed among themselves but individually were consistent. Judges who were superior in matching one kind of test against autobiography were superior in matching all other tests against autobiography. The matching test is a promising tool for measuring the reliability of diagnostic judgment of test analyzers and interpreters. Further research is needed in the use of matching methods in the study of clinical diagnosis.

A robust and coarse surface mesh modified by interpenetrating polymer network hydrogel for oil-water separation

2015 ◽  
Vol 132 (19) ◽  
pp. n/a-n/a ◽  
Author(s):  
Jinlong Zhu ◽  
Huili Li ◽  
Juan Du ◽  
Wenchen Ren ◽  
Pingping Guo ◽  
...  
Keyword(s):  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Surface Mesh ◽  
Water Separation ◽  
Coarse Surface ◽  
Oil Water Separation ◽  
Oil Water

scholarly journals Seleksi Wajah Digital Menggunakan Algoritma Camshift

2020 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Anita Sindar R M Sinaga
Keyword(s):  
Physical Development ◽  
Video Data ◽  
Position Tracking ◽  
Test Results ◽  
Face Database ◽  
Face Matching ◽  
Matching Test ◽  
Camshift Algorithm ◽  
Digital File ◽  
The Face

Real time for digital face database selection using camshift algorithm] Education taken 4-5 years affects physical development. This study uses student digital video data. The recording results are used to identify certain characteristics possessed by a student later stored in the digital file database catalog. The stages of the study consisted of identification, recognition and matching of faces. It starts from converting .mp4 videos to .AVI format. The CAMShift algorithm uses basic HSV colors for tracking face position (tracking) and faces recognition. 1-2 seconds video produces 45-200 frames PNG file. The face matching test results were carried out on several video play, the success of detection: 100% selected, 45%-60%, 80-90%, concluded around 50%-100% successful. Face movements will be caught by the centroid bounding box, if the color of the face is dominant in Hue.  

Verifikasi Telapak Tangan dengan Multimodal Biometrik Fermat’s Spiral

2019 ◽  
Vol 3 (3) ◽  
pp. 408-413
Author(s):  
Agus Anwar Eka Wahyudi ◽  
I Made Oka Widyantara ◽  
Komang Oka Saputra
Keyword(s):  
High Performance ◽  
Threshold Value ◽  
Reference Image ◽  
Test Results ◽  
Test Image ◽  
Matching Test ◽  
Self Recognition ◽  
Geometrical Features ◽  
Reference Images ◽  
Length Width

The use of biometrics in various issues of data security, transactions, privacy has been widely used. Regarding security, surely the level of accuracy in one's self-recognition must be accurate. The palmprint is one of biometrics which has various unique characteristics. These characteristics include geometrical features such as length, width, and area of the palmprint, characteristics of main lines such as heart lines, headlines, and lifelines, tangled or weak lines, delta dot characteristics, and minus characteristics. Main lines and tangled lines, which are often referred to as line features, have several advantages over other biometric features, such as they can be obtained from low-resolution images, are difficult to duplicate, and are stable because they have experienced slight changes over a long period of time. This research introduces the method of Fermat's Spirals in the extraction of the features of the palmprint which are represented in the time series curve. Testing uses 450 palm images sourced from 50 people, each person taken 9 palmprint images where 5 images as a test image and 4 images as a reference image. The test is carried out based on the threshold value determined from the simulation results based on matching test images with reference images on the ROC graph. Based on the test results it can be concluded that the system shows high performance at a threshold value of 0.036 to get an FNMR value of 2.80%, FMR of 0.88% with an accuracy of 96.31% where the number of reference images to the test image affects the level of accuracy.  

A Fast Grid Deformation Algorithm for Aerodynamic Shape Optimization

2010 ◽  
Author(s):  
Kaveh Mohamed ◽  
Kurt Sermeus ◽  
Eric Laurendeau
Keyword(s):  
Optimization Problems ◽  
Flow Simulation ◽  
Surface Model ◽  
Initial Surface ◽  
Surface Mesh ◽  
B Spline ◽  
Mesh Movement ◽  
Spline Surface ◽  
The Difference ◽  
Volume Mesh

A mesh movement algorithm suitable for aerodynamic design optimization problems is presented. It involves B-spline surface construction, projection and evaluation on B-spline faces for the surface mesh movement, as well as inverse-distance and 2D/3D TFI interpolations for the volume mesh deformation. The algorithm is fast and exhibits an excellent parallel efficiency. It is used to deform the surface and volume mesh of an ONERA-M6 wing undergoing several planform changes. The quality of the deformed mesh is preserved as long as the difference between the initial surface mesh and the B-spline surface model is small. A good agreement reported between the flow simulation results on the deformed mesh and those obtained on initial fixed mesh.

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