Performance of a Method for Formulating Geometrically Exact Complementarity Constraints in Multibody Dynamic Simulation

2014 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Montrallo Flickinger ◽  
Jedediyah Williams ◽  
Jeffrey C. Trinkle
Keyword(s):  
Dynamic Simulation ◽  
Collision Detection ◽  
High Performance ◽  
Parameter Tuning ◽  
Problem Formulation ◽  
Rigid Bodies ◽  
Detection Scheme ◽  
Practical Applications ◽  
System States ◽  
And Performance

Contemporary problem formulation methods used in the dynamic simulation of rigid bodies suffer from problems in accuracy, performance, and robustness. Significant allowances for parameter tuning, coupled with careful implementation of a broad-phase collision detection scheme are required to make dynamic simulation useful for practical applications. A constraint formulation method is presented herein that is more robust, and not dependent on broad-phase collision detection or system tuning for its behavior. Several uncomplicated benchmark examples are presented to give an analysis and make a comparison of the new polyhedral exact geometry (PEG) method with the well-known Stewart–Trinkle method. The behavior and performance for the two methods are discussed. This includes specific cases where contemporary methods fail to match theorized and observed system states in simulation, and how they are ameliorated by the new method presented here. The goal of this work is to complete the groundwork for further research into high performance simulation.

Evaluating the Performance of Constraint Formulations for Multibody Dynamics Simulation

2013 ◽  
Author(s):  
Daniel Montrallo Flickinger ◽  
Jedediyah Williams ◽  
Jeffrey C. Trinkle
Keyword(s):  
Dynamic Simulation ◽  
Collision Detection ◽  
Parameter Tuning ◽  
Rigid Bodies ◽  
Dynamics Simulation ◽  
Software Systems ◽  
Unilateral Constraints ◽  
Detection Scheme ◽  
Practical Applications ◽  
Exact Geometry

Contemporary software systems used in the dynamic simulation of rigid bodies suffer from problems in accuracy, performance, and robustness. Significant allowances for parameter tuning, coupled with the careful implementation of a broad phase collision detection scheme is required to make dynamic simulation useful for practical applications. A geometrically accurate constraint formulation, the Polyhedral Exact Geometry method, is presented. The Polyhedral Exact Geometry formulation is similar to the well-known Stewart-Trinkle formulation, but extended to produce unilateral constraints that are geometrically correct in cases where polyhedral bodies have a locally non-convex free space. The PEG method is less dependent on broad-phase collision detection or system tuning than similar methods, demonstrated by several examples. Uncomplicated benchmark examples are presented to analyze and compare the new Polyhedral Exact Geometry formulation with the well-known Stewart-Trinkle and Anitescu-Potra methods. The behavior and performance for the methods are discussed. This includes specific cases where contemporary methods fail to match theorized and observed system states in simulation, and how they are ameliorated by PEG.

scholarly journals A High-Performance Elliptic Curve Cryptographic Processor of SM2 over GF(p)

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 431 ◽  
Author(s):  
Xianghong Hu ◽  
Xin Zheng ◽  
Shengshi Zhang ◽  
Weijun Li ◽  
Shuting Cai ◽  
...  
Keyword(s):  
Elliptic Curve ◽  
High Performance ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Prime Field ◽  
Practical Applications ◽  
Public Key Cryptosystems ◽  
Cell Library ◽  
Multiplication Operation ◽  
And Performance

Elliptic curve cryptography (ECC) is widely used in practical applications because ECC has far fewer bits for operands at the same level of security than other public-key cryptosystems such as RSA. The performance of an ECC processor is usually determined by modular multiplication (MM) and point multiplication (PM) operations. For recommended prime field, MM operation can consist of multiplication and fast reduction operations. In this paper, a 256-bit multiplication operation is implemented by a 129-bit (half-word) multiplier using Karatsuba–Ofman multiplication algorithm. The fast reduction is a modulo operation, which gets 512-bit input data from multiplication and outputs a 256-bit result ( 0 ≤ Z < p ) . We propose a two-stage fast reduction algorithm (TSFR) over SCA-256 prime field, which can obtain an intermediate result of 0 ≤ Z < 2 p instead of 0 ≤ Z < 14 p in traditional algorithm, avoiding a lot of repetitive subtraction operations. The PM operation is implemented in width nonadjacent form (NAF) algorithm and its operational schedules are improved to increase the parallelism of multiplication and fast reduction operations. Synthesized with a 0.13 μ m complementary metal oxide semiconductor (CMOS) standard cell library, the proposed processor costs an area of 280 k gates and PM operation takes 0.057 ms at the frequency of 250 MHz. The design is also implemented on Xilinx Virtex-6 platform, which consumes 27.655 k LUTs and takes 0.37 ms to perform one 256-bit PM operation, attaining six times speed-up over the state-of-the-art. The processor makes a tradeoff between area and performance, thus it is better than other methods.

scholarly journals Pitfalls and Best Practices in Algorithm Configuration

2019 ◽  
Vol 64 ◽  
pp. 861-893 ◽  
Author(s):  
Katharina Eggensperger ◽  
Marius Lindauer ◽  
Frank Hutter
Keyword(s):  
Best Practices ◽  
High Performance ◽  
State Of The Art ◽  
Parameter Tuning ◽  
Propositional Satisfiability ◽  
Ai Planning ◽  
Practical Applications ◽  
Automated Algorithm ◽  
Algorithm Configuration ◽  
Satisfiability Solving

Good parameter settings are crucial to achieve high performance in many areas of artificial intelligence (AI), such as propositional satisfiability solving, AI planning, scheduling, and machine learning (in particular deep learning). Automated algorithm configuration methods have recently received much attention in the AI community since they replace tedious, irreproducible and error-prone manual parameter tuning and can lead to new state-of-the-art performance. However, practical applications of algorithm configuration are prone to several (often subtle) pitfalls in the experimental design that can render the procedure ineffective. We identify several common issues and propose best practices for avoiding them. As one possibility for automatically handling as many of these as possible, we also propose a tool called GenericWrapper4AC.

A GPU Optimized Technique for Scalable Spiking Neural Network Simulation

2019 ◽  
Vol 8 (3) ◽  
pp. 4612-4616
Keyword(s):  
Neural Networks ◽  
High Performance ◽  
Parameter Tuning ◽  
Spiking Neural Networks ◽  
Internal Variables ◽  
Time Step ◽  
Simulation Speed ◽  
Active Synapse ◽  
And Performance ◽  
System Variables

Simulation studies, in general, heavily rely upon the internal variables of the system / entity in the studies. In case of simulation study of the Spiking Neural Networks (SNNs), the major internal system variables are membrane potentials of the neurons and their respective synaptic inputs which demand to be updated at a sub-millisecond resolution. It would be very apt here to note that this requires thousands of updates to simulate one second of an activity per neuron and this factor makes it imperative to have a highly scalable model to derive some inferences from the simulation. Conventionally, high performance CPUs with high degree of multi-threading were leveraged to conduct simulations and derive inferences. With the advances in the hardware, the degree of parallelism has also increased, especially the GPUs have opened a multitude of avenues to perform SNN simulations at scale. In our pervious works [1, 2, 3], we have demonstrated how GPUs can be leveraged to achieve scalability and performance by using hybrid CPU-GPU approach which have improved the performance as compared to multi-threading on high performance CPUs. In this work, we have focused on hyper parameter tuning of some of the key parameters such as delay insensitivity, time step grouping and the active synapse grouping to achieve greater simulation speed of scalable spiking neural networks

scholarly journals Optimisation of soil conservation systems within integrated territorial protection

2009 ◽  
Vol 4 (No. 2) ◽  
pp. 57-65 ◽  
Author(s):  
M. Dumbrovský ◽  
S. Korsuň
Keyword(s):  
Soil Erosion ◽  
Soil Conservation ◽  
High Performance ◽  
Flood Control ◽  
Prevention Measures ◽  
Practical Applications ◽  
Discrete Programming ◽  
And Performance ◽  
Universal Applicability ◽  
Optimisation Procedure

The objective of this contribution is to provide information on a generally applicable optimisation procedure intended for designing a system of terraces and retention reservoirs within integrated territory protection from the harmful effects of soil erosion. The formulated procedure is a universal tool which can be used for any territory. An optimisation mathematical model was used to find the most suitable combination of various elaborated pre-optimisation variants of the soil conservation and flood prevention measures under the given conditions of each particular habitat. This model was created on the basis of a mixed discrete programming. The model compilation and its analysis on a high performance computer was performed using the model and calculation system GAMS. The model solution was controlled by one or more simultaneously operating optimisation criteria. A system of terraces as an important part of the soil erosion and flood control was chosen to verify the possibilities of the described optimisation procedure utilisation. The system was proposed within the land consolidation in the case study areas of Hustopeče and Starovice cadastral areas. First, the model function and performance were verified. Then the possibilities of experimentation on the model of the solved system of complex conservation measures were tested. The main results of the real and some experimental solutions are summarised. The results of practical applications of the integrated territory protection model validate its functionality and universal applicability.

Trace nanoanalysis

1994 ◽  
Vol 52 ◽  
pp. 940-941
Author(s):  
D. E. Newbury ◽  
R. D. Leapman
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Detection Efficiency ◽  
Volume Element ◽  
And Performance ◽  
Trace Constituents ◽  
Secondary Ion ◽  
Concentration Levels ◽  
Structure Properties

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).

https://imsciences.edu.pk/files/journals/vol12_2/New%201%20MA.864.pdf

2020 ◽  
Vol 12 (2) ◽  
pp. 19-50 ◽  
Author(s):  
Muhammad Siddique ◽  
Shandana Shoaib ◽  
Zahoor Jan
Keyword(s):  
Organizational Performance ◽  
Structural Equation ◽  
High Performance ◽  
Service Sector ◽  
Performance Outcomes ◽  
Theory And Practice ◽  
Relational Coordination ◽  
Multiple Sources ◽  
And Performance ◽  
High Level

A key aspect of work processes in service sector firms is the interconnection between tasks and performance. Relational coordination can play an important role in addressing the issues of coordinating organizational activities due to high level of interdependence complexity in service sector firms. Research has primarily supported the aspect that well devised high performance work systems (HPWS) can intensify organizational performance. There is a growing debate, however, with regard to understanding the “mechanism” linking HPWS and performance outcomes. Using relational coordination theory, this study examines a model that examine the effects of subsets of HPWS, such as motivation, skills and opportunity enhancing HR practices on relational coordination among employees working in reciprocal interdependent job settings. Data were gathered from multiple sources including managers and employees at individual, functional and unit levels to know their understanding in relation to HPWS and relational coordination (RC) in 218 bank branches in Pakistan. Data analysis via structural equation modelling, results suggest that HPWS predicted RC among officers at the unit level. The findings of the study have contributions to both, theory and practice.

scholarly journals Study on strong spinning preparation method and mechanism of the industrial pure titanium ultrafine crystallization

2019 ◽  
Vol 14 ◽  
pp. 155892501989525
Author(s):  
Yu Yang ◽  
Yanyan Jia
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
Pure Titanium ◽  
Grain Structure ◽  
Theoretical Research ◽  
Ultrafine Grain ◽  
Forming Process ◽  
Spinning Process ◽  
And Performance ◽  
Material Utilization

Ultrafine crystallization of industrial pure titanium allowed for higher tensile strength, corrosion resistance, and thermal stability and is therefore widely used in medical instrumentation, aerospace, and passenger vehicle manufacturing. However, the ultrafine crystallizing batch preparation of tubular industrial pure titanium is limited by the development of the spinning process and has remained at the theoretical research stage. In this article, the tubular TA2 industrial pure titanium was taken as the research object, and the ultrafine crystal forming process based on “5-pass strong spin-heat treatment-3 pass-spreading-heat treatment” was proposed. Based on the spinning process test, the ultimate thinning rate of the method is explored and the evolution of the surface microstructure was analyzed by metallographic microscope. The research suggests that the multi-pass, medium–small, and thinning amount of spinning causes the grain structure to be elongated in the axial and tangential directions, and then refined, and the axial fiber uniformity is improved. The research results have certain scientific significance for reducing the consumption of high-performance metals improving material utilization and performance, which also promote the development of ultrafine-grain metals’ preparation technology.

scholarly journals Flux Method Growth of Large Size Group IV–V 2D GeP Single Crystals and Photoresponse Application

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 235
Author(s):  
Shuqi Zhao ◽  
Tongtong Yu ◽  
Ziming Wang ◽  
Shilei Wang ◽  
Limei Wei ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystals ◽  
High Performance ◽  
Group Iv ◽  
X Ray Diffraction ◽  
High Quality ◽  
Practical Applications ◽  
Large Size ◽  
Growth Method ◽  
Polarized Raman

Two-dimensional (2D) materials driven by their unique electronic and optoelectronic properties have opened up possibilities for their various applications. The large and high-quality single crystals are essential to fabricate high-performance 2D devices for practical applications. Herein, IV-V 2D GeP single crystals with high-quality and large size of 20 × 15 × 5 mm3 were successfully grown by the Bi flux growth method. The crystalline quality of GeP was confirmed by high-resolution X-ray diffraction (HRXRD), Laue diffraction, electron probe microanalysis (EPMA) and Raman spectroscopy. Additionally, intrinsic anisotropic optical properties were investigated by angle-resolved polarized Raman spectroscopy (ARPRS) and transmission spectra in detail. Furthermore, we fabricated high-performance photodetectors based on GeP, presenting a relatively large photocurrent over 3 mA. More generally, our results will significantly contribute the GeP crystal to the wide optoelectronic applications.

High-Performance Image Filters via Sparse Approximations

2020 ◽  
Vol 3 (2) ◽  
pp. 1-19
Author(s):  
Kersten Schuster ◽  
Philip Trettner ◽  
Leif Kobbelt
Keyword(s):  
High Performance ◽  
Hardware Acceleration ◽  
Optimization Method ◽  
Translation Invariant ◽  
Approximation Quality ◽  
Trade Offs ◽  
Sparse Approximations ◽  
Image Filters ◽  
Good Trade ◽  
And Performance

We present a numerical optimization method to find highly efficient (sparse) approximations for convolutional image filters. Using a modified parallel tempering approach, we solve a constrained optimization that maximizes approximation quality while strictly staying within a user-prescribed performance budget. The results are multi-pass filters where each pass computes a weighted sum of bilinearly interpolated sparse image samples, exploiting hardware acceleration on the GPU. We systematically decompose the target filter into a series of sparse convolutions, trying to find good trade-offs between approximation quality and performance. Since our sparse filters are linear and translation-invariant, they do not exhibit the aliasing and temporal coherence issues that often appear in filters working on image pyramids. We show several applications, ranging from simple Gaussian or box blurs to the emulation of sophisticated Bokeh effects with user-provided masks. Our filters achieve high performance as well as high quality, often providing significant speed-up at acceptable quality even for separable filters. The optimized filters can be baked into shaders and used as a drop-in replacement for filtering tasks in image processing or rendering pipelines.

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