scholarly journals Global Directed Dynamic Behaviors of a Lotka-Volterra Competition-Diffusion-Advection System

Axioms ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 195
Author(s):  
Lili Chen ◽  
Shilei Lin ◽  
Yanfeng Zhao
Keyword(s):  
Dynamical System ◽  
Principal Eigenvalue ◽  
Dynamical System Theory ◽  
Heterogeneous Environments ◽  
Dynamic Behaviors ◽  
Dynamical Behaviors ◽  
Further Development ◽  
And Diffusion ◽  
Competition Diffusion

This paper investigates the problem of the global directed dynamic behaviors of a Lotka-Volterra competition-diffusion-advection system between two organisms in heterogeneous environments. The two organisms not only compete for different basic resources, but also the advection and diffusion strategies follow the dispersal towards a positive distribution. By virtue of the principal eigenvalue theory, the linear stability of the co-existing steady state is established. Furthermore, the classification of dynamical behaviors is shown by utilizing the monotone dynamical system theory. This work can be seen as a further development of a competition-diffusion system.

scholarly journals Global Stability of a Lotka-Volterra Competition-Diffusion-Advection System with Different Positive Diffusion Distributions

Axioms ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 166
Author(s):  
Lili Chen ◽  
Shilei Lin ◽  
Yanfeng Zhao
Keyword(s):  
Global Stability ◽  
Stability Result ◽  
Functional Method ◽  
Heterogeneous Environments ◽  
Homogeneous Steady State ◽  
Competition Ability ◽  
Lyapunov Functional Method ◽  
And Diffusion ◽  
Biological Organisms ◽  
Competition Diffusion

In this paper, the problem of a Lotka–Volterra competition–diffusion–advection system between two competing biological organisms in a spatially heterogeneous environments is investigated. When two biological organisms are competing for different fundamental resources, and their advection and diffusion strategies follow different positive diffusion distributions, the functions of specific competition ability are variable. By virtue of the Lyapunov functional method, we discuss the global stability of a non-homogeneous steady-state. Furthermore, the global stability result is also obtained when one of the two organisms has no diffusion ability and is not affected by advection.

A Taxonomy for Psycho-Oncological Intervention Techniques in an Acute Care Hospital in Germany

2021 ◽  
pp. 1-7
Author(s):  
Martina Madl ◽  
Marietta Lieb ◽  
Katharina Schieber ◽  
Tobias Hepp ◽  
Yesim Erim
Keyword(s):  
Acute Care ◽  
Interrater Reliability ◽  
Acute Care Hospital ◽  
Future Research ◽  
Systematic Research ◽  
Care Hospital ◽  
Certification System ◽  
Stepwise Procedure ◽  
Further Development

<b><i>Background:</i></b> Due to the establishment of a nationwide certification system for cancer centers in Germany, the availability of psycho-oncological services for cancer patients has increased substantially. However, little is known about the specific intervention techniques that are applied during sessions in an acute care hospital, since a standardized taxonomy is lacking. With this study, we aimed at the investigation of psycho-oncological intervention techniques and the development of a comprehensive and structured taxonomy thereof. <b><i>Methods:</i></b> In a stepwise procedure, a team of psycho-oncologists generated a data pool of interventions and definitions that were tested in clinical practice during a pilot phase. After an adaptation of intervention techniques, interrater reliability (IRR) was attained by rating 10 previously recorded psycho-oncological sessions. A classification of interventions into superordinate categories was performed, supported by cluster analysis. <b><i>Results:</i></b> Between April and June 2017, 980 psycho-oncological sessions took place. The experts agreed on a total number of 22 intervention techniques. An IRR of 89% for 2 independent psycho-oncological raters was reached. The 22 techniques were classified into 5 superordinate categories. <b><i>Discussion/Conclusion:</i></b> We developed a comprehensive and structured taxonomy of psycho-oncological intervention techniques in an acute care hospital that provides a standardized basis for systematic research and applied care. We expect our work to be continuously subjected to further development: future research should evaluate and expand our taxonomy to other contexts and care settings.

Towards a More Holistic Approach to Quality Improvements in Aluminium Die Casting

2009 ◽  
Vol 618-619 ◽  
pp. 341-344
Author(s):  
Sandrine Zanna ◽  
Yakov Frayman ◽  
Bruce Gunn ◽  
Saeid Nahavandi
Keyword(s):  
Dynamical System ◽  
System Theory ◽  
Die Casting ◽  
Holistic Approach ◽  
Natural Process ◽  
Dynamical System Theory ◽  
Quality Improvements ◽  
System Perspective ◽  
Porosity Defects ◽  
Natural Equilibrium

This work evaluates the feasibility of using a holistic approach, based on dynamical system theory, to reduce porosity defects in high pressure aluminum die casting. Quality improvements, from a dynamical system perspective mean the ability to move the die casting process out of its natural equilibrium to a more beneficial state and the ability to maintain this new process state. This more beneficial state may be achieved in several ways. One way is to increase the amount of forcing to overcome natural process resistance. This forcing approach is represented by typical continuous intervention policy, with modifications in die/part design and/or process parameters. An alternative approach is to reduce the amount of natural process resistance, in particular the amount of process disturbance, allowing the process to move out of its natural equilibrium with much less forcing. This alternative uses the self-regulating ability of dynamical systems thus decreasing the amount of human intervention required. In this respect, the influence of vacuum on time on chattering at the first stage of the casting shot was identified as a good process candidate for testing using dynamical system theory. A significant reduction in porosity defects was achieved, which also set the process on a path of slow but consistent self-improvement.

scholarly journals A Novel Chaotic Neural Network Using Memristive Synapse with Applications in Associative Memory

2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
Xiaofang Hu ◽  
Shukai Duan ◽  
Lidan Wang
Keyword(s):  
Neural Network ◽  
Associative Memory ◽  
Large Scale ◽  
Cmos Technology ◽  
Chaotic Neural Network ◽  
Circuit Element ◽  
Nanoscale Cmos ◽  
Dynamical Behaviors ◽  
Implementation Scheme ◽  
Further Development

Chaotic Neural Network, also denoted by the acronym CNN, has rich dynamical behaviors that can be harnessed in promising engineering applications. However, due to its complex synapse learning rules and network structure, it is difficult to update its synaptic weights quickly and implement its large scale physical circuit. This paper addresses an implementation scheme of a novel CNN with memristive neural synapses that may provide a feasible solution for further development of CNN. Memristor, widely known as the fourth fundamental circuit element, was theoretically predicted by Chua in 1971 and has been developed in 2008 by the researchers in Hewlett-Packard Laboratory. Memristor based hybrid nanoscale CMOS technology is expected to revolutionize the digital and neuromorphic computation. The proposed memristive CNN has four significant features: (1) nanoscale memristors can simplify the synaptic circuit greatly and enable the synaptic weights update easily; (2) it can separate stored patterns from superimposed input; (3) it can deal with one-to-many associative memory; (4) it can deal with many-to-many associative memory. Simulation results are provided to illustrate the effectiveness of the proposed scheme.

Classification of first-episode psychosis: a multi-modal multi-feature approach integrating structural and diffusion imaging

2014 ◽  
Vol 122 (6) ◽  
pp. 897-905 ◽  
Author(s):  
Denis Peruzzo ◽  
◽  
Umberto Castellani ◽  
Cinzia Perlini ◽  
Marcella Bellani ◽  
...  
Keyword(s):  
Diffusion Imaging ◽  
First Episode Psychosis ◽  
First Episode ◽  
Episode Psychosis ◽  
And Diffusion

scholarly journals System development for its disclosure of Portuguese digital type design

2016 ◽  
Author(s):  
Vítor Quelhas ◽  
Vasco Branco ◽  
Rui Mendonça
Keyword(s):  
Early Stage ◽  
System Development ◽  
Complete Agreement ◽  
Collaborative System ◽  
Test And Evaluation ◽  
Usability Tests ◽  
Type Design ◽  
Third Stage ◽  
Further Development

This study aims to cover the current development of a platform for the disclosure of the Portuguese type design community, since the beginning of the desktop revolution, until today. 
To deepen our understanding, interviews were made to a selected and representative group of type designers from our sample based on several criteria. The interview tested six dimensions: people, processes, products, uses, identity and platform. The results analyzed in the last dimension, through content analysis and quantitative data, lead to the development of an online digital collaborative system – one of our specific objectives. 
Our hypothesis – that the development of a online digital collaborative system would allow further development of knowledge between products, users and authors, as well as, processes and uses – was also corroborated by the interviewers. 
Reviews have been made to reference international online projects to identify their purposes, areas of activity, objectives, mechanisms of interaction, usability and accessibility. This previous research brought together a set of notes that would become essential in the definition and development of our concept. 

The classification of typefaces is a subject of study by researchers and designers, but it is certainly not a topic for complete agreement. Organizing and balancing the content for the database was our first challenge since we were expecting users with good knowledge on the field, but also beginners. Several diagrams were put into test during the early stage of information architecture to better define categories, filters, and sorting methods, as well as users role in the system. The items and categories chosen were redefined in a second stage, and in the third stage hi-fidelity wireframes were produced, to concentrate on design aspects and decisions, and put the system into test and evaluation. 

The current results on the platform development, with the improvements made through several user tests, evaluations and refinements undertaken in all phases of the project have been crucial. We are expecting to run some pilot tests, as well as usability tests prior to the full implementation to further improve the system and meet the expectations.DOI: http://dx.doi.org/10.4995/IFDP.2016.3351

scholarly journals Application of neuron networks of deep learning for exposures editing of digital phonograms

2020 ◽  
Vol 65 (4) ◽  
pp. 506-512
Author(s):  
V. I. Solovyov ◽  
O. V. Rybalskiy ◽  
V. V. Zhuravel ◽  
V. K. Zheleznyak
Keyword(s):  
Deep Learning ◽  
Binary Classification ◽  
Maximum Size ◽  
Maximum Efficiency ◽  
Correct Classification ◽  
Digital Audio ◽  
Neuron Networks ◽  
Effective System ◽  
Further Development

Possibility of creation of effective system, which is intended for exposure of tracks of editing in digital phonograms and is built on the basis of neuron networks of the deep learning, is experimentally proven. Sense of experiment consisted in research of ability of the systems on the basis of such networks to expose pauses with tracks of editing. The experimental array of data is created in a voice editor from phonograms written on the different apparatus of the digital audio recording (at frequency of discretisation 44,1 kHz). A preselection of pauses was produced from it, having duration from 100 мs to a few seconds. From 1000 selected pauses the array of fragments of pauses is formed in the automatic (computer) mode, from which the arrays of fragments of pauses of different duration are generated by a dimension about 100 000. For forming of array of fragments of pauses with editing, the chosen pauses were divided into casual character parts in arbitrary correlation. Afterwards, the new pauses were created from it with the fixed place of editing. The general array of all fragments of pauses was broken into training and test arrays. The maximum efficiency, achieved on a test array in the process of educating, was determined. In general case this efficiency is determined by the maximum size of probability of correct classification of fragments with editing and fragments without editing. Scientifically reasonable methodology of exposure of signs of editing in digital phonograms is offered on the basis of neuron networks of the deep learning. The conducted experiments showed that the construction of the effective system is possible for the exposure of such tracks. Further development of methodology must be directed to find the ways to increase the probability of correct binary classification of investigated pauses.

scholarly journals Advances in application of nanomaterials in remediation of heavy metal contaminated soil

2021 ◽  
Vol 261 ◽  
pp. 04027
Author(s):  
Na Ding ◽  
Mengxuan Han ◽  
Yao He ◽  
Xinshuai Wang ◽  
Yuxuan Pan ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Contaminated Soil ◽  
Environmental Problem ◽  
High Reactivity ◽  
Large Specific Surface Area ◽  
Remediation Technology ◽  
Strong Adsorption ◽  
Combination Technology ◽  
Further Development

Soil heavy metal pollution has become an environmental problem that has attracted worldwide attention. Nanomaterials have the advantages of large specific surface area, strong adsorption capacity and high reactivity, making nanomaterials remediation technology an excellent application prospect in contaminated soil remediation. This article introduces the main classification of nanomaterials, summarizes the mechanism of nanomaterials to remove heavy metals, and the combination technology of nanomaterials. It provides a scientific reference for the further development of this field.

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