scholarly journals Speed-Up of the Excited-State Benchmarking: Double-Hybrid Density Functionals as Test Cases

2017 ◽  
Vol 13 (11) ◽  
pp. 5539-5551 ◽  
Author(s):  
Éric Brémond ◽  
Marika Savarese ◽  
Ángel José Pérez-Jiménez ◽  
Juan Carlos Sancho-García ◽  
Carlo Adamo
Keyword(s):  
Excited State ◽  
Test Cases ◽  
Density Functionals ◽  
Speed Up

scholarly journals Speeding-up mutation testing via data compression and state infection

2016 ◽  
Author(s):  
Qianqian Zhu ◽  
Annibale Panichella ◽  
Andy Zaidman
Keyword(s):  
Data Compression ◽  
Formal Concept Analysis ◽  
Computational Cost ◽  
Mutation Testing ◽  
Formal Concept ◽  
Test Cases ◽  
Vast Number ◽  
Speed Up ◽  
Novel Method ◽  
Initial Results

Mutation testing is widely considered as a high-end test criterion due to the vast number of mutants it generates. Although many efforts have been made to reduce the computational cost of mutation testing, its scalability issue remains in practice. In this paper, we introduce a novel method to speed up mutation testing based on state infection information. In addition to filtering out uninfected test executions, we further select a subset of mutants and a subset of test cases to run leveraging data-compression techniques. In particular, we adopt Formal Concept Analysis (FCA) to group similar mutants together and then select test cases to cover these mutants. To evaluate our method, we conducted an experimental study on six open source Java projects. We used EvoSuite to automatically generate test cases and to collect mutation data. The initial results show that our method can reduce the execution time by 83.93% with only 0.257% loss in precision.

Comparative assessment of density functionals for excited-state dipole moments

2013 ◽  
Vol 584 ◽  
pp. 58-62 ◽  
Author(s):  
Joanna Bednarska ◽  
Agnieszka Roztoczyńska ◽  
Wojciech Bartkowiak ◽  
Robert Zaleśny
Keyword(s):  
Excited State ◽  
Dipole Moments ◽  
Comparative Assessment ◽  
Density Functionals ◽  
Excited State Dipole Moments

scholarly journals Conflict Generalisation in ASP: Learning Correct and Effective Non-Ground Constraints

2020 ◽  
Vol 20 (5) ◽  
pp. 799-814
Author(s):  
RICHARD TAUPE ◽  
ANTONIUS WEINZIERL ◽  
GERHARD FRIEDRICH
Keyword(s):  
Computational Cost ◽  
Problem Instance ◽  
Test Cases ◽  
New Approach ◽  
Deductive Logic ◽  
Significant Performance ◽  
Speed Up ◽  
Problem Instances ◽  
Low Computational Cost ◽  
Additional Constraints

AbstractGeneralising and re-using knowledge learned while solving one problem instance has been neglected by state-of-the-art answer set solvers. We suggest a new approach that generalises learned nogoods for re-use to speed-up the solving of future problem instances. Our solution combines well-known ASP solving techniques with deductive logic-based machine learning. Solving performance can be improved by adding learned non-ground constraints to the original program. We demonstrate the effects of our method by means of realistic examples, showing that our approach requires low computational cost to learn constraints that yield significant performance benefits in our test cases. These benefits can be seen with ground-and-solve systems as well as lazy-grounding systems. However, ground-and-solve systems suffer from additional grounding overheads, induced by the additional constraints in some cases. By means of conflict minimization, non-minimal learned constraints can be reduced. This can result in significant reductions of grounding and solving efforts, as our experiments show.

scholarly journals Speeding-up mutation testing via data compression and state infection

2016 ◽  
Author(s):  
Qianqian Zhu ◽  
Annibale Panichella ◽  
Andy Zaidman
Keyword(s):  
Data Compression ◽  
Formal Concept Analysis ◽  
Computational Cost ◽  
Mutation Testing ◽  
Formal Concept ◽  
Test Cases ◽  
Vast Number ◽  
Speed Up ◽  
Novel Method ◽  
Initial Results

Mutation testing is widely considered as a high-end test criterion due to the vast number of mutants it generates. Although many efforts have been made to reduce the computational cost of mutation testing, its scalability issue remains in practice. In this paper, we introduce a novel method to speed up mutation testing based on state infection information. In addition to filtering out uninfected test executions, we further select a subset of mutants and a subset of test cases to run leveraging data-compression techniques. In particular, we adopt Formal Concept Analysis (FCA) to group similar mutants together and then select test cases to cover these mutants. To evaluate our method, we conducted an experimental study on six open source Java projects. We used EvoSuite to automatically generate test cases and to collect mutation data. The initial results show that our method can reduce the execution time by 83.93% with only 0.257% loss in precision.

scholarly journals INTEGRATED IMAGING APPROACHES SUPPORTING THE EXCAVATION ACTIVITIES. MULTI-SCALE GEOSPATIAL DOCUMENTATION IN HIERAPOLIS (TK)

2018 ◽  
Vol XLII-2 ◽  
pp. 1075-1082
Author(s):  
A. Spanò ◽  
F. Chiabrando ◽  
G. Sammartano ◽  
L. Teppati Losè
Keyword(s):  
Laser Scanning ◽  
Archaeological Sites ◽  
Test Cases ◽  
Terrestrial Lidar ◽  
Multi Scale ◽  
3D Data ◽  
Ancient City ◽  
Surface Models ◽  
Continuous Surface ◽  
Speed Up

The paper focuses on the exploration of the suitability and the discretization of applicability issues about advanced surveying integrated techniques, mainly based on image-based approaches compared and integrated to range-based ones that have been developed with the use of the cutting-edge solutions tested on field. The investigated techniques integrate both technological devices for 3D data acquisition and thus editing and management systems to handle metric models and multi-dimensional data in a geospatial perspective, in order to innovate and speed up the extraction of information during the archaeological excavation activities. These factors, have been experienced in the outstanding site of the Hierapolis of Phrygia ancient city (Turkey), downstream the 2017 surveying missions, in order to produce high-scale metric deliverables in terms of high-detailed Digital Surface Models (DSM), 3D continuous surface models and high-resolution orthoimages products. In particular, the potentialities in the use of UAV platforms for low altitude acquisitions in aerial photogrammetric approach, together with terrestrial panoramic acquisitions (Trimble V10 imaging rover), have been investigated with a comparison toward consolidated Terrestrial Laser Scanning (TLS) measurements.<br> One of the main purposes of the paper is to evaluate the results offered by the technologies used independently and using integrated approaches. A section of the study in fact, is specifically dedicated to experimenting the union of different sensor dense clouds: both dense clouds derived from UAV have been integrated with terrestrial Lidar clouds, to evaluate their fusion. Different test cases have been considered, representing typical situations that can be encountered in archaeological sites.

Porting NEMO diagnostics to GPU accelerators

2021 ◽  
Author(s):  
Maicon Faria ◽  
Mario Acosta ◽  
Miguel Castrillo ◽  
Stella V. Paronuzzi Ticco ◽  
Sergi Palomas ◽  
...  
Keyword(s):  
Data Management ◽  
Data Communication ◽  
Main Memory ◽  
Test Cases ◽  
Time Step ◽  
Main Hypothesis ◽  
Speed Up ◽  
Code Maintenance ◽  
Study Case ◽  
Computational Resources

&lt;p&gt;This work makes part of an effort to make NEMO capable of taking advantage of modern accelerators. To achieve this objective we focus on port routines in NEMO that have a small impact on code maintenance and the higher possible overall time footprint reductions. Our candidates to port were the diagnostic routines, specifically &lt;em&gt;diahsb&lt;/em&gt; (heat, salt, volume budgets) and &lt;em&gt;diawri&lt;/em&gt; (Ocean variables) diagnostics. These two diagnostics correspond to 5% of the NEMO's runtime each on our test cases. Both can be executed in an asynchronous fashion allowing overlap between diagnostic GPU and other NEMO routines CPU computations. &lt;br&gt;We report a methodology to port runtime diagnostics execution on NEMO to GPU using CUDA Fortran and OpenACC. Both synchronous and asynchronous are implemented on &lt;em&gt;diahsb&lt;/em&gt; and &lt;em&gt;diawri&lt;/em&gt; diagnostics. Associated time step and stream interleave are proposed to allow the overlap of CPU execution of NEMO and data communication between CPU, and GPU.&lt;br&gt;&lt;br&gt;In the case of constraint computational resources and high-resolution grids, synchronous implementation of &lt;em&gt;diahsb&lt;/em&gt; and &lt;em&gt;diawri&lt;/em&gt; show up to 3.5x speed-up. With asynchronous implementation we achieve a higher speed-up from 2.7x to 5x with &lt;em&gt;diahsb&lt;/em&gt; in the study cases. The results for this diagnostic optimization point out that the asynchronous approach is profitable even in the case where plenty of computational resources are available and the number of MPI ranks is in the threshold of parallel effectiveness for a given computational workload. For &lt;em&gt;diawri&lt;/em&gt; on the other hand, the results of the asynchronous implementation depart from the &lt;em&gt;diahsb&lt;/em&gt;. In the &lt;em&gt;diawri&lt;/em&gt; diagnostic module there are 30 times more datasets demanding pinned memory to overlap communication between CPU and GPU with CPU execution. Pinned memory attribute limits data management of datasets allocated on main memory, therefore makes possible to the GPU access to main memory, overlapping CPU computation. The result is a scenario where the improvement from offloading the diagnostic computation impacts on NEMO CPU general execution. Our main hypothesis is that the amount of pinned memory used decreases the performance on runtime data management, this is confirmed by the 7% increase of the L3 data cache misses in the study case. Although the necessity of evaluating the amount of datasets needed for asynchronous communication on a diagnostic port, the payout of asynchronous diagnostic may be worth given the higher speed-up values that we can achieve with this technique. This work proves that models such as NEMO, developed only for CPU architectures, can port some of their computation to accelerators. Additionally, this work explains a successful and simple way to implement an asynchronous approach, where CPU and GPU are working in parallel, but without modifying the CPU code itself, since the diagnostics are extracted as kernels for the GPU and the CPU is yet working in the simulation.&lt;/p&gt;

scholarly journals Numerical simulation of shock wave propagation in 2-D channels with obstacles filled with chemically reacting gas suspensions

2019 ◽  
Vol 23 (Suppl. 2) ◽  
pp. 623-630 ◽  
Author(s):  
Yulia Kratova ◽  
Alexander Kashkovsky ◽  
Anton Shershnev
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Wave Propagation ◽  
Shock Wave Propagation ◽  
Test Case ◽  
Test Cases ◽  
Fortran Code ◽  
Speed Up ◽  
Chemically Reacting ◽  
Good Agreement

Modification of the serial Fortran code for solving unsteady 2-D Euler equations for the mixture of compressible gas and polydisperse particles was carried out using OpenMP technology. Modified code was verified and parallel speed-up was measured. Analysis showed that the data on parallel efficiency is in a good agreement with the Amdahls law, which gives the estimate for serial code fraction about 30%. Parallel code was used for the numerical simulation of two test-cases, namely shock wave propagation in 2-D channel with obstacles filled with reactive Al-O2 gas particle mixture and heterogeneous detonation propagation in polydisperse suspensions. For the first test-case the data on particles distribution in the flow was obtained, the existense of particle free zones inside the vortices was demonstrated and the attenuation of a shock wave was studied. In the second test, numerical simulation of detonation shock wave propagation in plain 2-D channel for the three polydisperse mixtures was carried out and data on detonation regimes was also obtained.

scholarly journals Effects of the locality of a potential derived from hybrid density functionals on Kohn–Sham orbitals and excited states

2017 ◽  
Vol 19 (15) ◽  
pp. 10177-10186 ◽  
Author(s):  
Jaewook Kim ◽  
Kwangwoo Hong ◽  
Sang-Yeon Hwang ◽  
Seongok Ryu ◽  
Sunghwan Choi ◽  
...  
Keyword(s):  
Excited State ◽  
Excited States ◽  
Density Functionals ◽  
Virtual Orbitals

The locality of the Kohn–Sham potential in hybrid DFT results in physically meaningful virtual orbitals more suitable to excited state calculations.

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