scholarly journals Beyond the lognormal approximation: a general simulation scheme

2020 ◽  
Vol 498 (2) ◽  
pp. 2663-2675
Author(s):  
Federico Tosone ◽  
Mark C Neyrinck ◽  
Benjamin R Granett ◽  
Luigi Guzzo ◽  
Nicola Vittorio
Keyword(s):  
Correlation Function ◽  
Random Fields ◽  
Three Dimensional ◽  
Analytical Techniques ◽  
Proof Of Concept ◽  
Matter Distribution ◽  
Modest Improvement ◽  
Local Properties ◽  
Non Local ◽  
Simulation Scheme

ABSTRACT We present a public code to generate random fields with an arbitrary probability distribution function (PDF) and an arbitrary correlation function. The algorithm is cosmology independent and applicable to any stationary stochastic process over a three-dimensional grid. We implement it in the case of the matter density field, showing its benefits over the lognormal approximation, which is often used in cosmology for the generation of mock catalogues. We find that the covariance of the power spectrum from the new fast realizations is more accurate than that from a lognormal model. As a proof of concept, we also apply the new simulation scheme to the divergence of the Lagrangian displacement field. We find that information from the correlation function and the PDF of the displacement–divergence provides modest improvement over other standard analytical techniques to describe the particle field in the simulation. This suggests that further progress in this direction should come from multiscale or non-local properties of the initial matter distribution.

Criticism of D.B Volkov’s Teleofunctional Solution to the Problem of Mental Causation

2020 ◽  
Vol 63 (1) ◽  
pp. 116-135
Author(s):  
Anton V. Kuznetsov
Keyword(s):  
Free Will ◽  
Mental Causation ◽  
Physical Factors ◽  
Multiple Realizability ◽  
Causal Relevance ◽  
Relational Properties ◽  
Local Properties ◽  
Non Local ◽  
Mental Properties ◽  
First Editions

The articles examines the teleofunctional solution to the problem of mental causation, presented by Dmitry Volkov in his recently published book Free Will. An Illusion or an Opportunity. D.B. Volkov proposes solutions to three big metaphysical problems – mental causation, personal identity, and free will. Solving the first problem, Volkov creatively combines the advantages of Dennett’s teleofunctional model and Vasilyev’s local interactionism. Volkov’s teleofunctional model of mental causation seeks to prove the causal relevance of mental properties as non-local higher order properties. In my view, its substantiation is based on three points: (a) critics of the exclusion problem and Kim’s model of mental causation, (b) “Library of first editions” argument, (c) reduction of the causal trajectories argument (CTA 1) by Vasilyev to the counterpart argument (CTA 2) by Volkov. Each of these points faces objections. Kim’s criticism is based on an implicit confusion of two types of reduction – reduction from supervenience and from multiple realizability. The latter type does not threaten Kim’s ideas, but Volkov uses this very type in his criticism. The “Library of first editions” argument does not achieve its goal due to compositional features and because non-local relational properties are a type of external properties that cannot be causally relevant. The reduction of CTA 1 to CTA 2 is unsuccessful since, in the case of this reduction, important features of CTA 1 are lost – these are local mental properties, due to which the influence of non-local physical factors occurs. My main objection is that the concept of causally relevant non-local properties is incompatible with the very concept of cause. The set of causally relevant properties of cause can only be local.

scholarly journals A 3D hydrodynamic flow-focusing device for cell sorting

2021 ◽  
Vol 25 (3) ◽  
Author(s):  
Xiaofei Yuan ◽  
Andrew Glidle ◽  
Hitoshi Furusho ◽  
Huabing Yin
Keyword(s):  
Cell Sorting ◽  
Control Strategies ◽  
Three Dimensional ◽  
Hydrodynamic Flow ◽  
Proof Of Concept ◽  
Flow Focusing ◽  
Hydrodynamic Focusing ◽  
Cell Handling ◽  
Fluid Flow Control ◽  
High Degree

AbstractOptical-based microfluidic cell sorting has become increasingly attractive for applications in life and environmental sciences due to its ability of sophisticated cell handling in flow. The majority of these microfluidic cell sorting devices employ two-dimensional fluid flow control strategies, which lack the ability to manipulate the position of cells arbitrarily for precise optical detection, therefore resulting in reduced sorting accuracy and purity. Although three-dimensional (3D) hydrodynamic devices have better flow-focusing characteristics, most lack the flexibility to arbitrarily position the sample flow in each direction. Thus, there have been very few studies using 3D hydrodynamic flow focusing for sorting. Herein, we designed a 3D hydrodynamic focusing sorting platform based on independent sheath flow-focusing and pressure-actuated switching. This design offers many advantages in terms of reliable acquisition of weak Raman signals due to the ability to precisely control the speed and position of samples in 3D. With a proof-of-concept demonstration, we show this 3D hydrodynamic focusing-based sorting device has the potential to reach a high degree of accuracy for Raman activated sorting.

scholarly journals A Proof-of-Concept Algorithm for the Retrieval of Total Column Amount of Trace Gases in a Multi-Dimensional Atmosphere

2021 ◽  
Vol 13 (2) ◽  
pp. 270
Author(s):  
Adrian Doicu ◽  
Dmitry S. Efremenko ◽  
Thomas Trautmann
Keyword(s):  
Trace Gases ◽  
Three Dimensional ◽  
Principal Component ◽  
Radiative Transfer Model ◽  
Computational Time ◽  
Transfer Model ◽  
Proof Of Concept ◽  
Discrete Ordinate ◽  
Distribution Method ◽  
Total Column

An algorithm for the retrieval of total column amount of trace gases in a multi-dimensional atmosphere is designed. The algorithm uses (i) certain differential radiance models with internal and external closures as inversion models, (ii) the iteratively regularized Gauss–Newton method as a regularization tool, and (iii) the spherical harmonics discrete ordinate method (SHDOM) as linearized radiative transfer model. For efficiency reasons, SHDOM is equipped with a spectral acceleration approach that combines the correlated k-distribution method with the principal component analysis. The algorithm is used to retrieve the total column amount of nitrogen for two- and three-dimensional cloudy scenes. Although for three-dimensional geometries, the computational time is high, the main concepts of the algorithm are correct and the retrieval results are accurate.

scholarly journals From correlation functions to event shapes in QCD

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
D. Chicherin ◽  
J. M. Henn ◽  
E. Sokatchev ◽  
K. Yan
Keyword(s):  
Correlation Function ◽  
Correlation Functions ◽  
Event Shape ◽  
Proof Of Concept ◽  
Yang Mills ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Event Shapes ◽  
A Charge ◽  
Conserved Currents

Abstract We present a method for calculating event shapes in QCD based on correlation functions of conserved currents. The method has been previously applied to the maximally supersymmetric Yang-Mills theory, but we demonstrate that supersymmetry is not essential. As a proof of concept, we consider the simplest example of a charge-charge correlation at one loop (leading order). We compute the correlation function of four electromagnetic currents and explain in detail the steps needed to extract the event shape from it. The result is compared to the standard amplitude calculation. The explicit four-point correlation function may also be of interest for the CFT community.

Poly-(lactic acid) and fibrin bioactive cellularized scaffold for use in bone regenerative medicine: Proof of concept

2021 ◽  
pp. 088391152199640
Author(s):  
Renata Aquino de Carvalho ◽  
Valmir Vieira Rocha Júnior ◽  
Antonio José Felix Carvalho ◽  
Heloisa Sobreiro Selistre de Araújo ◽  
Mônica Rosas Costa Iemma ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Regenerative Medicine ◽  
Platelet Rich Plasma ◽  
Three Dimensional ◽  
Culture Conditions ◽  
Infrapatellar Fat Pad ◽  
Dimensional Structure ◽  
Poly Lactic Acid ◽  
Proof Of Concept ◽  
Critical Bone Defects

Bone regenerative medicine (BRM) aims to overcome the limitations of conventional treatments for critical bone defects by developing therapeutic strategies, based on temporary bioactive substitutes, capable of stimulating, sustaining, and guiding tissue regeneration. The aim of this study was to validate the “proof of concept” of a cellularized bioactive scaffold and establish its potential for use in BRM. For this purpose, three-dimensional scaffolds of poly-(lactic acid) (PLA), produced by the additive manufacturing technique, were incorporated into a human platelet-rich plasma (PRP-h) fibrin matrix containing human infrapatellar fat pad mesenchymal stem cells (hIFPMSC). The scaffolds (PLA/finbrin-bioactive) were kept under ideal culture conditions in a medium free from fetal bovine serum and analyzed at 5 and 10 days by Scanning Electron Microscopy (SEM), Fourrier Transform Infrared (FTIR), Circular Dichroism and fluorescence microscopy. The results demonstrated the feasibility of obtaining a rigid, cytocompatible, and cellularized three-dimensional structure. In addition, PRP platelets and leukocytes were able to provide a bioactive environment capable of maintaining the viability of hIFPMSC into scaffolds. The results validate the concept of a customizable, bioactive, cellularized, and non-immunogenic strategy for application in BRM.

scholarly journals A Low-Complexity Region-Based Authentication Algorithm for 3D Polygonal Models

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yuan-Yu Tsai ◽  
Tsung-Chieh Cheng ◽  
Yao-Hsien Huang
Keyword(s):  
Three Dimensional ◽  
Low Complexity ◽  
Secret Key ◽  
Authentication Code ◽  
Geometrical Properties ◽  
Property Evaluation ◽  
Adaptive Embedding ◽  
Local Properties ◽  
Embedding Rate ◽  
Polygonal Models

This study proposes a low-complexity region-based authentication algorithm for three-dimensional (3D) polygonal models, based on local geometrical property evaluation. A vertex traversal scheme with a secret key is adopted to classify each vertex into one of two categories: embeddable vertices and reference vertices. An embeddable vertex is one with an authentication code embedded. The algorithm then uses reference vertices to calculate local geometrical properties for the corresponding embeddable vertices. For each embeddable vertex, we feed the number of reference vertices and local properties into a hash function to generate the authentication code. The embeddable vertex is then embedded with the authentication code, which is based on a simple message-digit substitution scheme. The proposed algorithm is of low complexity and distortion-controllable and possesses a higher and more adaptive embedding capacity and a higher embedding rate than most existing region-based authentication algorithms for 3D polygonal models. The experimental results demonstrate the feasibility of the proposed algorithm.

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