Static Write Buffer Cache Modeling to Increase Host-Compiled Simulation Accuracy

2017 ◽  
Author(s):  
Hector Posadas ◽  
Luis Diaz ◽  
Eugenio Villar
Keyword(s):  
Simulation Accuracy ◽  
Buffer Cache ◽  
Cache Modeling ◽  
Write Buffer

A Unified Write Buffer Cache Management Scheme for Flash Memory

2014 ◽  
Vol 22 (12) ◽  
pp. 2779-2792 ◽  
Author(s):  
Liang Shi ◽  
Jianhua Li ◽  
Qingan Li ◽  
Chun Jason Xue ◽  
Chengmo Yang ◽  
...  
Keyword(s):  
Flash Memory ◽  
Cache Management ◽  
Management Scheme ◽  
Buffer Cache ◽  
Write Buffer

Predictive Cache Modeling and Analysis

2011 ◽  
Author(s):  
Russell Kegley ◽  
Jonathan Preston ◽  
Brian Dougherty ◽  
Jules White ◽  
Anirudda Gokhale
Keyword(s):  
Modeling And Analysis ◽  
Cache Modeling

scholarly journals AOIO: Application Oriented I/O Optimization for Buffer Management

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 573
Author(s):  
Xiaochang Li ◽  
Zhengjun Zhai ◽  
Xin Ye
Keyword(s):  
System Performance ◽  
Simulation Experiment ◽  
Buffer Management ◽  
Input Output ◽  
Output Data ◽  
Program Counter ◽  
Efficient Management ◽  
Management Scheme ◽  
Buffer Cache ◽  
Management Schemes

Emerging scale-out I/O intensive applications are broadly used now, which process a large amount of data in buffer/cache for reorganization or analysis and their performances are greatly affected by the speed of the I/O system. Efficient management scheme of the limited kernel buffer plays a key role in improving I/O system performance, such as caching hinted data for reuse in future, prefetching hinted data, and expelling data not to be accessed again from a buffer, which are called proactive mechanisms in buffer management. However, most of the existing buffer management schemes cannot identify data reference regularities (i.e., sequential or looping patterns) that can benefit proactive mechanisms, and they also cannot perform in the application level for managing specified applications. In this paper, we present an A pplication Oriented I/O Optimization (AOIO) technique automatically benefiting the kernel buffer/cache by exploring the I/O regularities of applications based on program counter technique. In our design, the input/output data and the looping pattern are in strict symmetry. According to AOIO, each application can provide more appropriate predictions to operating system which achieve significantly better accuracy than other buffer management schemes. The trace-driven simulation experiment results show that the hit ratios are improved by an average of 25.9% and the execution times are reduced by as much as 20.2% compared to other schemes for the workloads we used.

scholarly journals Application of Dynamically Constrained Interpolation Methodology in Simulating National-Scale Spatial Distribution of PM2.5 Concentrations in China

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 272
Author(s):  
Ning Li ◽  
Junli Xu ◽  
Xianqing Lv
Keyword(s):  
Transport Model ◽  
Ground Level ◽  
Kriging Interpolation ◽  
Model Parameters ◽  
National Scale ◽  
Constrained Interpolation ◽  
Simulation Accuracy ◽  
Interpolation Accuracy ◽  
Geographical Regions ◽  
The Right

Numerous studies have revealed that the sparse spatiotemporal distributions of ground-level PM2.5 measurements affect the accuracy of PM2.5 simulation, especially in large geographical regions. However, the high precision and stability of ground-level PM2.5 measurements make their role irreplaceable in PM2.5 simulations. This article applies a dynamically constrained interpolation methodology (DCIM) to evaluate sparse PM2.5 measurements captured at scattered monitoring sites for national-scale PM2.5 simulations and spatial distributions. The DCIM takes a PM2.5 transport model as a dynamic constraint and provides the characteristics of the spatiotemporal variations of key model parameters using the adjoint method to improve the accuracy of PM2.5 simulations. From the perspective of interpolation accuracy and effect, kriging interpolation and orthogonal polynomial fitting using Chebyshev basis functions (COPF), which have been proved to have high PM2.5 simulation accuracy, were adopted to make a comparative assessment of DCIM performance and accuracy. Results of the cross validation confirm the feasibility of the DCIM. A comparison between the final interpolated values and observations show that the DCIM is better for national-scale simulations than kriging or COPF. Furthermore, the DCIM presents smoother spatially interpolated distributions of the PM2.5 simulations with smaller simulation errors than the other two methods. Admittedly, the sparse PM2.5 measurements in a highly polluted region have a certain degree of influence on the interpolated distribution accuracy and rationality. To some extent, adding the right amount of observations can improve the effectiveness of the DCIM around existing monitoring sites. Compared with the kriging interpolation and COPF, the results show that the DCIM used in this study would be more helpful for providing reasonable information for monitoring PM2.5 pollution in China.

Modelling and Analysis of Integrated Hotforming and Quenching Processes

2005 ◽  
Vol 6-8 ◽  
pp. 787-794 ◽  
Author(s):  
D. Lorenz ◽  
Karl Roll
Keyword(s):  
Lightweight Design ◽  
Experimental Investigations ◽  
Boron Steel ◽  
General Tendency ◽  
The Finite Element Method ◽  
Contact Heat ◽  
Simulation Accuracy ◽  
Structural Part ◽  
Component Strength ◽  
Structural Parts

In the automotive industry a general tendency to choose steels with enhanced strength for structural parts can be observed. This trend results from the increased lightweight design efforts to satisfy the fleet consumption restrictions. Hot forming and quenching of boron steel offers the possibility to improve the component strength and reduce the weight of structural parts. The main influences on the process are described and a method to model and simulate this process using the finite element method using LS-DYNA is presented. Experimental investigations of the contact heat transfer have been carried out to enhance the simulation accuracy. A prototyping tool of a structural part is used to examine the process under production conditions. Temperatures of the tool and the part are measured during the process. These temperatures are compared with the simulation results in order to reevaluate the results of the process simulation.

scholarly journals Effect of the Intra-Abdominal Pressure and the Center of Segmental Body Mass on the Lumbar Spine Mechanics – A Computational Parametric Study

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
W. M. Park ◽  
S. Wang ◽  
Y. H. Kim ◽  
K. B. Wood ◽  
J. A. Sim ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Computational Models ◽  
Muscle Force ◽  
Weight Bearing ◽  
Upper Body ◽  
Abdominal Pressure ◽  
Lumbosacral Spine ◽  
Simulation Accuracy ◽  
Joint Force ◽  
Geometric Center

Determination of physiological loads in human lumbar spine is critical for understanding the mechanisms of lumbar diseases and for designing surgical treatments. Computational models have been used widely to estimate the physiological loads of the spine during simulated functional activities. However, various assumptions on physiological factors such as the intra-abdominal pressure (IAP), centers of mass (COMs) of the upper body and lumbar segments, and vertebral centers of rotation (CORs) have been made in modeling techniques. Systematic knowledge of how these assumptions will affect the predicted spinal biomechanics is important for improving the simulation accuracy. In this paper, we developed a 3D subject-specific numerical model of the lumbosacral spine including T12 and 90 muscles. The effects of the IAP magnitude and COMs locations on the COR of each motion segment and on the joint/muscle forces were investigated using a global convergence optimization procedure when the subject was in a weight bearing standing position. The data indicated that the line connecting the CORs showed a smaller curvature than the lordosis of the lumbar spine in standing posture when the IAP was 0 kPa and the COMs were 10 mm anterior to the geometric center of the T12 vertebra. Increasing the IAP from 0 kPa to 10 kPa shifted the location of CORs toward the posterior direction (from 1.4 ± 8.9 mm anterior to intervertebral disc (IVD) centers to 40.5 ± 3.1 mm posterior to the IVD centers) and reduced the average joint force (from 0.78 ± 0.11 Body weight (BW) to 0.31 ± 0.07 BW) and overall muscle force (from 349.3 ± 57.7 N to 221.5 ± 84.2 N). Anterior movement of the COMs from −30 mm to 70 mm relative to the geometric center of T12 vertebra caused an anterior shift of the CORs (from 25.1 ± 8.3 mm posterior to IVD centers to 7.8 ± 6.2 mm anterior to IVD centers) and increases of average joint forces (from 0.78 ± 0.1 BW to 0.93 ± 0.1 BW) and muscle force (from 348.9 ± 47.7 N to 452.9 ± 58.6 N). Therefore, it is important to consider the IAP and correct COMs in order to accurately simulate human spine biomechanics. The method and results of this study could be useful for designing prevention strategies of spinal injuries and recurrences, and for enhancing rehabilitation efficiency.

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