scholarly journals Extending the Fully Bayesian Unfolding with Regularization Using a Combined Sampling Method

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2100
Author(s):  
Petr Baroň ◽  
Jiří Kvita
Keyword(s):  
Sampling Method ◽  
High Energy ◽  
Computational Time ◽  
Strength Parameter ◽  
Pp Collisions ◽  
Quark Pairs ◽  
Optimal Value ◽  
Particle Level ◽  
Fully Bayesian

Regularization extensions to the Fully Bayesian Unfolding are implemented and studied with an algorithm of combined sampling to find, in a reasonable computational time, an optimal value of the regularization strength parameter in order to obtain an unfolded result of a desired property, like smoothness. Three regularization conditions using the curvature, entropy and derivatives are applied, as a model example, to several simulated spectra of top-pair quark pairs that are produced in high energy pp collisions. The existence of a minimum of a χ2 between the unfolded and particle-level spectra is discussed, with recommendations on the checks and validity of the usage of the regularization feature in Fully Bayesian Unfolding (FBU).

scholarly journals Correlation between heavy flavour production and multiplicity in pp and p-Pb collisions at high energy in the multi-pomeron exchange model

2018 ◽  
Vol 171 ◽  
pp. 18003 ◽  
Author(s):  
Grigory Feofilov ◽  
Vladimir Kovalenko ◽  
Andrei Puchkov
Keyword(s):  
String Tension ◽  
High Energy ◽  
Exchange Model ◽  
Pomeron Exchange ◽  
Strength Parameter ◽  
Wide Energy Range ◽  
Particle Multiplicity ◽  
Charged Particle Multiplicity ◽  
Pp Collisions ◽  
Wide Energy

The multiplicity dependence of heavy flavour production in pp-collisions at LHC energies is studied in the framework of the multi-pomeron exchange model. The model is introducing the string-string interaction collectivity effects in pp collisions, which modifies multiplicity and transverse momenta, leading to the non-trivial mean pt vs. multiplicity (〈pt〉Nch − Nch). correlation. The string collectivity strength parameter is fixed by experimental data on multiplicity and transverse momentum correlation in a wide energy range (from ISR to LHC). The particles discrimination is implemented according to Schwinger mechanism taking into account the strong decays of hadron resonances. We demonstrate, that the faster-than-linear growth of the open charm production with the event charged particle multiplicity, observed in experimental pp high energy collisions, can be explained by the modification of the string tension due to the increasing overlap and interaction of quark-gluon strings. The model is extended for p-A interactions and the calculations for p-Pb collisions are performed.

A New Sampling Approach for the Multi-Scale Design of Metallic Materials

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Pinar Acar
Keyword(s):  
Material Properties ◽  
Sampling Method ◽  
Solution Space ◽  
Computational Time ◽  
Polycrystalline Materials ◽  
Microstructure Design ◽  
Multi Scale ◽  
Generate Property ◽  
Scale Design ◽  
Sampling Approach

Abstract We present a new sampling method for the multi-scale design of polycrystalline materials, which improves the computational time efficiency compared to the existing computational approaches. The solution strategy aims to find microstructure designs that optimize component-scale mechanical properties. The microstructure is represented with a probabilistic texture descriptor that quantifies the volume fractions of different crystallographic orientations. However, the original microstructure design space is high-dimensional and thus optimization in this domain is not favorable. Instead, we generate property closures, which are the reduced spaces of volume-averaged material properties that are computed in terms of the microstructural texture descriptors. We observe that the traditional design approaches which are based on sampling in the original microstructure space and sampling on the property closure are inefficient as they lead to highly concentrated design samples in the solution space. Therefore, we introduce a new sampling method in the property closure, which creates simplexes using the triangulation of the property hull and then generating samples for each simplex. Example problems include the optimization of Galfenol and α-titanium microstructures to improve non-linear material properties. The new sampling approach is shown to obtain better solutions while decreasing the required computational time compared to the previous microstructure design methods.

Multiscale Modeling of Electro-Chemo-Mechanical Degradation in Si/C Core–Shell Anode for the Lithium-Ion Battery of High Energy Density

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Xiang Gao ◽  
Jun Xu
Keyword(s):  
Energy Density ◽  
Lithium Ion Battery ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Mechanical Degradation ◽  
Core Shell ◽  
Capacity Fade ◽  
Charging Rate ◽  
Particle Level

Abstract The capacity fade in lithium-ion battery (LIB) of high energy density using Si/C core–shell particle anode is one of the major barriers blocking its wide application. However, the underlying mechanism of electro-chemo-mechanical degradation remains unclear. In this study, we propose and validate a multiscale model (electrode level and particle level), considering electrochemical–mechanical coupling and cohesive zone method at the particle level. The effects of charging rate, core/shell ratio, and mechanical properties of the shell on the separation and capacity fade are discussed. We discover that larger charging rate, smaller core/shell ratio, and stiffer shell can mitigate the core–shell separation gap, leading to higher capacity retention. Results shed light on the degradation mechanism of Si/C core–shell anode and provide design guidance for Si/C anode materials in minimizing the capacity fade and safe battery charging/discharging strategy.

scholarly journals Measurement of the W boson helicity fractions in the decays of top quark pairs to lepton + jets final states produced in pp collisions at s=8TeV

2016 ◽  
Vol 762 ◽  
pp. 512-534 ◽  
Author(s):  
V. Khachatryan ◽  
A.M. Sirunyan ◽  
A. Tumasyan ◽  
W. Adam ◽  
E. Asilar ◽  
...  
Keyword(s):  
Top Quark ◽  
W Boson ◽  
Final States ◽  
Pp Collisions ◽  
Quark Pairs ◽  
Lepton Jets ◽  
Top Quark Pairs

A two-component model for hadron production in high-energy pp collisions

1985 ◽  
Vol 89 (4) ◽  
pp. 353-380 ◽  
Author(s):  
H. Banerjee ◽  
T. De ◽  
D. Syam
Keyword(s):  
High Energy ◽  
Hadron Production ◽  
Component Model ◽  
Pp Collisions ◽  
Two Component

A novel concatenation method for generating optimal robotic assembly sequences

2015 ◽  
Vol 231 (10) ◽  
pp. 1966-1977 ◽  
Author(s):  
MVA Raju Bahubalendruni ◽  
Bibhuti Bhusan Biswal
Keyword(s):  
Computer Aided Design ◽  
Cost Effective ◽  
High Energy ◽  
Robotic Assembly ◽  
Computational Time ◽  
Assembly Sequence ◽  
Design Environment ◽  
Assembly Sequences ◽  
Computer Aided ◽  
Assembly Sequence Generation

Selection of optimized assembly sequence is significantly essential to achieve cost-effective manufacturing process. This paper presents a novel efficient methodology to generate cost-effective feasible robotic assembly sequences though concatenation of parts. Part concatenation process will be followed with liaison predicate test and feasibility predicate test. A unique method called bounding box method is described to test the feasibility predicate efficiently in the computer-aided design environment. Assembly indexing technique is proposed to filter the redundant assembly subsets with high energy in order to minimize the computational time. The cost of collision free assembling operation is considered by the weight and distance traveled by the part in the assembly environment to join with the mating part. The method is successful in finding feasible optimal assembly sequence without ignoring any possible assembly sequence and found to be efficient in solving computer-aided assembly sequence generation. The correctness of the methodology is illustrated with an example.

scholarly journals Class imbalance techniques for high energy physics

2019 ◽  
Vol 7 (6) ◽  
Author(s):  
Christopher W. Murphy
Keyword(s):  
High Energy Physics ◽  
Charm Quark ◽  
Class Imbalance ◽  
High Energy ◽  
Longitudinal Polarization ◽  
Class Versus ◽  
Quark Pairs ◽  
Physics Experiment ◽  
Polarization Fraction ◽  
Energy Physics

A common problem in a high energy physics experiment is extracting a signal from a much larger background. Posed as a classification task, there is said to be an imbalance in the number of samples belonging to the signal class versus the number of samples from the background class. In this work we provide a brief overview of class imbalance techniques in a high energy physics setting. Two case studies are presented: (1) the measurement of the longitudinal polarization fraction in same-sign WW scattering, and (2) the decay of the Higgs boson to charm-quark pairs.

scholarly journals Bait-ER: a Bayesian method to detect targets of selection in Evolve-and-Resequence experiments

2020 ◽  
Author(s):  
Carolina Barata ◽  
Rui Borges ◽  
Carolin Kosiol
Keyword(s):  
High Throughput Sequencing ◽  
Null Distribution ◽  
Computational Time ◽  
Experimental Conditions ◽  
Moran Model ◽  
Genome Wide ◽  
Open Source Software Package ◽  
Genome Wide Data ◽  
Specific Allele ◽  
Fully Bayesian

For over a decade, experimental evolution has been combined with high-throughput sequencing techniques in so-called Evolve-and-Resequence (E&R) experiments. This allows testing for selection in populations kept in the laboratory under given experimental conditions. However, identifying signatures of adaptation in E&R datasets is far from trivial, and it is still necessary to develop more efficient and statistically sound methods for detecting selection in genome-wide data. Here, we present Bait-ER - a fully Bayesian approach based on the Moran model of allele evolution to estimate selection coefficients from E&R experiments. The model has overlapping generations, a feature that describes several experimental designs found in the literature. We tested our method under several different demographic and experimental conditions to assess its accuracy and precision, and it performs well in most scenarios. However, some care must be taken when analysing specific allele trajectories, particularly those where drift largely dominates and starting frequencies are low. We compare our method with other available software and report that ours has generally high accuracy even for very difficult trajectories. Furthermore, our approach avoids the computational burden of simulating an empirical null distribution, outperforming available software in terms of computational time and facilitating its use on genome-wide data. We implemented and released our method in a new open-source software package that can be accessed at https://github.com/mrborges23/Bait-ER.

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