Swarm Coordination Under Conflict and Use of Enhanced Lyapunov Control

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Daniel A. Sierra ◽  
Paul McCullough ◽  
Nejat Olgac ◽  
Eldridge Adams
Keyword(s):  
Stability Analysis ◽  
Time Window ◽  
Single Step ◽  
Complex Nature ◽  
Control Logic ◽  
Wide Range ◽  
New Strategy ◽  
Dissipative Control ◽  
Parametric Effects ◽  
Multi Agent

We consider hostile conflicts between two multi-agent swarms. First, we investigate the complex nature of a single pursuer attempting to intercept a single evader (1P-1E), and establish some rudimentary rules of engagement. The stability repercussions of these rules are investigated using a Lyapunov-based stability analysis. Second, we extend the modeling and stability analysis to interactions between multi-agent swarms of pursuers and evaders. The present document considers only swarms with equal membership strengths for simplicity. This effort is based on a set of suggested momenta deployed on individual agents. The control of group pursuit is divided into two phases: the approach phase during which the two swarms act like individuals in the 1P-1E interaction, and the assigned pursuit phase, where each pursuer follows an assigned evader. A simple, single-step dissipative control strategy, which results in undesirable control chatter, is considered first. A distributed control logic is then introduced, in order to ameliorate the chatter problems. In this new logic, the dissipative control action is spread out over a time window. A wide range of case studies is tested in order to quantify the parametric effects of the new strategy.

Swarm Coordination Under Conflict and Use of Enhanced Lyapunov Based Controller

2009 ◽  
Author(s):  
Daniel A. Sierra ◽  
Paul McCullough ◽  
Nejat Olgac ◽  
Eldridge Adams
Keyword(s):  
Stability Analysis ◽  
Distributed Control ◽  
Complex Nature ◽  
Control Logic ◽  
Group Pursuit ◽  
Dissipative Control ◽  
Multi Agent ◽  
Two Phases ◽  
The Stability ◽  
Approach Phase

We consider hostile conflicts between two multi-agent swarms. First, we investigate the complex nature of a single pursuer attempting to intercept a single evader (1P-1E), and establish some rudimentary rules of engagement. We elaborate on the stability repercussions of these rules. Second, we extend the modelling and stability analysis between multi-agent swarms of pursuers and evaders. The present document considers only swarms with equal membership strengths for simplicity. This effort is based on a set of suggested momenta deployed on individual agents. Due to the strong nonlinearities, Lyapunov-based stability analysis is used. The control of a group pursuit is divided into two phases: the approach phase during which the two swarms act like individuals in the 1P-1E interaction; and the assigned pursuit phase where each pursuer is assigned to an evader. A dissipative control momentum was suggested in an earlier publication, which caused undesirable control chatter. This study introduces a distributed control logic which ameliorates the chatter problems considerably.

COVID-19 Outbreak Prediction with Machine Learning

2020 ◽  
Author(s):  
Sina Faizollahzadeh Ardabili ◽  
Amir Mosavi ◽  
Pedram Ghamisi ◽  
Filip Ferdinand ◽  
Annamaria R. Varkonyi-Koczy ◽  
...  
Keyword(s):  
Machine Learning ◽  
Prediction Models ◽  
Fuzzy Inference ◽  
Control Measures ◽  
Future Research ◽  
Complex Nature ◽  
Inference System ◽  
Wide Range ◽  
Standard Models ◽  
High Level

Several outbreak prediction models for COVID-19 are being used by officials around the world to make informed-decisions and enforce relevant control measures. Among the standard models for COVID-19 global pandemic prediction, simple epidemiological and statistical models have received more attention by authorities, and they are popular in the media. Due to a high level of uncertainty and lack of essential data, standard models have shown low accuracy for long-term prediction. Although the literature includes several attempts to address this issue, the essential generalization and robustness abilities of existing models needs to be improved. This paper presents a comparative analysis of machine learning and soft computing models to predict the COVID-19 outbreak as an alternative to SIR and SEIR models. Among a wide range of machine learning models investigated, two models showed promising results (i.e., multi-layered perceptron, MLP, and adaptive network-based fuzzy inference system, ANFIS). Based on the results reported here, and due to the highly complex nature of the COVID-19 outbreak and variation in its behavior from nation-to-nation, this study suggests machine learning as an effective tool to model the outbreak. This paper provides an initial benchmarking to demonstrate the potential of machine learning for future research. Paper further suggests that real novelty in outbreak prediction can be realized through integrating machine learning and SEIR models.

The use of intelligent agents in modeling an integrated information system of transport logistics

2020 ◽  
Vol 5 ◽  
pp. 59-66
Author(s):  
Y.M. Iskanderov ◽  
Keyword(s):  
Information System ◽  
Supply Chains ◽  
Intelligent Agents ◽  
Technological Processes ◽  
Transport Services ◽  
Wide Range ◽  
Integrated Information System ◽  
Multi Agent ◽  
Transport Logistics ◽  
Integrated Information

Aim. The use of intelligent agents in modeling an integrated information system of transport logistics makes it possible to achieve a qualitatively new level of design of control systems in supply chains. Materials and methods. The article presents an original approach that implements the possibilities of using multi-agent technologies in the interests of modeling the processes of functioning of an integrated information system of transport logistics. It is shown that the multi-agent infrastructure is actually a semantic shell of the information system, refl ecting the rules of doing business and the interaction of its participants in the supply chains. The characteristic of the model of the class of an intelligent agent, which is basic for solving problems of management of transport and technological processes, is given. Results. The procedures of functioning of the model of integration of information resources of the participants of the transport services market on the basis of intelligent agents are considered. The presented procedures provide a wide range of network interaction operations in supply chains, including traffi c and network structure “fl exible” control, mutual exchange of content and service information, as well as their distributed processing, and information security. Conclusions. The proposed approach showed that the use of intelligent agents in modeling the functioning of an integrated information system makes it possible to take into account the peculiarities of transport and technological processes in supply chains, such as the integration of heterogeneous enterprises, their distributed organization, an open dynamic structure, standardization of products, interfaces and protocols.

scholarly journals Consumer Neuroscience Techniques in Advertising Research: A Bibliometric Citation Analysis

2021 ◽  
Vol 13 (3) ◽  
pp. 1589
Author(s):  
Juan Sánchez-Fernández ◽  
Luis-Alberto Casado-Aranda ◽  
Ana-Belén Bastidas-Manzano
Keyword(s):  
Self Report ◽  
Future Research ◽  
Complex Nature ◽  
Clear Understanding ◽  
Continuous Growth ◽  
Main Research ◽  
Consumer Neuroscience ◽  
Starting Point ◽  
Wide Range ◽  
Performance Analysis Tools

The limitations of self-report techniques (i.e., questionnaires or surveys) in measuring consumer response to advertising stimuli have necessitated more objective and accurate tools from the fields of neuroscience and psychology for the study of consumer behavior, resulting in the creation of consumer neuroscience. This recent marketing sub-field stems from a wide range of disciplines and applies multiple types of techniques to diverse advertising subdomains (e.g., advertising constructs, media elements, or prediction strategies). Due to its complex nature and continuous growth, this area of research calls for a clear understanding of its evolution, current scope, and potential domains in the field of advertising. Thus, this current research is among the first to apply a bibliometric approach to clarify the main research streams analyzing advertising persuasion using neuroimaging. Particularly, this paper combines a comprehensive review with performance analysis tools of 203 papers published between 1986 and 2019 in outlets indexed by the ISI Web of Science database. Our findings describe the research tools, journals, and themes that are worth considering in future research. The current study also provides an agenda for future research and therefore constitutes a starting point for advertising academics and professionals intending to use neuroimaging techniques.

scholarly journals The Supportive Care Needs of Cancer Patients: a Systematic Review

2021 ◽  
Author(s):  
Madeleine Evans Webb ◽  
Elizabeth Murray ◽  
Zane William Younger ◽  
Henry Goodfellow ◽  
Jamie Ross
Keyword(s):  
Cancer Patients ◽  
Healthcare Professionals ◽  
Treatment Options ◽  
Complex Nature ◽  
Narrative Synthesis ◽  
Care Needs ◽  
Wide Range ◽  
Need Support ◽  
Lack Of Control ◽  
Everyday Work

AbstractCancer, and the complex nature of treatment, has a profound impact on lives of patients and their families. Subsequently, cancer patients have a wide range of needs. This study aims to identify and synthesise cancer patients’ views about areas where they need support throughout their care. A systematic  search of the literature from PsycInfo, Embase and Medline databases was conducted, and a narrative. Synthesis of results was carried out using the Corbin & Strauss “3 lines of work” framework. For each line of work, a group of key common needs were identified. For illness-work, the key needs idenitified were; understanding their illness and treatment options, knowing what to expect, communication with healthcare professionals, and staying well. In regards to everyday work, patients wanted to maintain a sense of normalcy and look after their loved ones. For biographical work, patients commonly struggled with the emotion impact of illness and a lack of control over their lives. Spiritual, sexual and financial problems were less universal. For some types of support, demographic factors influenced the level of need reported. While all patients are unique, there are a clear set of issues that are common to a majority of cancer journeys. To improve care, these needs should be prioritised by healthcare practitioners.

scholarly journals Femtosecond Laser Fabrication of Hybrid Metal-Dielectric Structures with Nonlinear Photoluminescence

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 121
Author(s):  
Ekaterina Ponkratova ◽  
Eduard Ageev ◽  
Filipp Komissarenko ◽  
Sergei Koromyslov ◽  
Dmitry Kudryashov ◽  
...  
Keyword(s):  
Visible Spectral Region ◽  
Single Step ◽  
Hybrid Nanostructures ◽  
Nonlinear Properties ◽  
Nanophotonic Devices ◽  
Sensing Applications ◽  
Structure Morphology ◽  
Wide Range ◽  
Nonlinear Signal ◽  
Dielectric Structures

Fabrication of hybrid micro- and nanostructures with a strong nonlinear response is challenging and represents a great interest due to a wide range of photonic applications. Usually, such structures are produced by quite complicated and time-consuming techniques. This work demonstrates laser-induced hybrid metal-dielectric structures with strong nonlinear properties obtained by a single-step fabrication process. We determine the influence of several incident femtosecond pulses on the Au/Si bi-layer film on produced structure morphology. The created hybrid systems represent isolated nanoparticles with a height of 250–500 nm exceeding the total thickness of the Au-Si bi-layer. It is shown that fabricated hybrid nanostructures demonstrate enhancement of the SHG signal (up to two orders of magnitude) compared to the initial planar sample and a broadband photoluminescence signal (more than 200 nm in width) in the visible spectral region. We establish the correlation between nonlinear signal and phase composition provided by Raman scattering measurements. Such laser-induced structures have significant potential in optical sensing applications and can be used as components for different nanophotonic devices.

scholarly journals Deeply Learned Pose Invariant Image Analysis with Applications in 3D Face Recognition

2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Naeem Ratyal ◽  
Imtiaz Ahmad Taj ◽  
Muhammad Sajid ◽  
Anzar Mahmood ◽  
Sohail Razzaq ◽  
...  
Keyword(s):  
Face Recognition ◽  
Superior Performance ◽  
Support Vector ◽  
Complex Nature ◽  
Alignment Algorithm ◽  
3D Face Recognition ◽  
3D Face ◽  
Norm Minimization ◽  
Wide Range ◽  
The Face

Face recognition aims to establish the identity of a person based on facial characteristics and is a challenging problem due to complex nature of the facial manifold. A wide range of face recognition applications are based on classification techniques and a class label is assigned to the test image that belongs to the unknown class. In this paper, a pose invariant deeply learned multiview 3D face recognition approach is proposed and aims to address two problems: face alignment and face recognition through identification and verification setups. The proposed alignment algorithm is capable of handling frontal as well as profile face images. It employs a nose tip heuristic based pose learning approach to estimate acquisition pose of the face followed by coarse to fine nose tip alignment using L2 norm minimization. The whole face is then aligned through transformation using knowledge learned from nose tip alignment. Inspired by the intrinsic facial symmetry of the Left Half Face (LHF) and Right Half Face (RHF), Deeply learned (d) Multi-View Average Half Face (d-MVAHF) features are employed for face identification using deep convolutional neural network (dCNN). For face verification d-MVAHF-Support Vector Machine (d-MVAHF-SVM) approach is employed. The performance of the proposed methodology is demonstrated through extensive experiments performed on four databases: GavabDB, Bosphorus, UMB-DB, and FRGC v2.0. The results show that the proposed approach yields superior performance as compared to existing state-of-the-art methods.

Experimental Investigation of Subsonic Turbulent Flow Over Single and Double Backward Facing Steps

1962 ◽  
Vol 84 (3) ◽  
pp. 317-325 ◽  
Author(s):  
D. E. Abbott ◽  
S. J. Kline
Keyword(s):  
Experimental Investigation ◽  
Velocity Profile ◽  
Flow Pattern ◽  
Reynolds Numbers ◽  
Area Ratio ◽  
Single Step ◽  
Reattachment Length ◽  
Double Step ◽  
Wide Range ◽  
Geometric Variables

Results are presented for flow patterns over backward facing steps covering a wide range of geometric variables. Velocity profile measurements are given for both single and double steps. The stall region is shown to consist of a complex pattern involving three distinct regions. The double step contains an assymmetry for large expansions, but approaches the single-step configuration with symmetric stall regions for small values of area ratio. No effect on flow pattern or reattachment length is found for a wide range of Reynolds numbers and turbulence intensities, provided the flow is fully turbulent before the step.

Application of LWD Multipole Sonic for Quantitative Cement Evaluation – Well Integrity in the Norwegian Continental Shelf

2021 ◽  
Author(s):  
Subhadeep Sarkar ◽  
Mathias Horstmann ◽  
Tore Oian ◽  
Piotr Byrski ◽  
George Lawrence ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Time Window ◽  
Full Range ◽  
Hybrid Approach ◽  
Bond Quality ◽  
Bond Index ◽  
Early Evaluation ◽  
Well Integrity ◽  
Wide Range ◽  
Norwegian Continental Shelf

Abstract One of the crucial components of well integrity evaluation in offshore drilling is to determine the cement bond quality assuring proper hydraulic sealing. On the Norwegian Continental Shelf (NCS) an industry standard as informative reference imposes verification of cement length and potential barriers using bonding logs. Traditionally, for the last 50 years, wireline (WL) sonic tools have been extensively used for this purpose. However, the applicability of logging-while-drilling (LWD) sonic tools for quantitative cement evaluation was explored in the recent development drilling campaign on the Dvalin Field in the Norwegian Sea, owing to significant advantages on operational efficiency and tool conveyance in any well trajectory. Cement bond evaluation from conventional peak-to-peak amplitude method has shown robust results up to bond indexes of 0.6 for LWD sonic tools. Above this limit, the casing signal is smaller than the collar signal and the amplitude method loses sensitivity to bonding. This practical challenge in the LWD realm was overcome through the inclusion of attenuation rate measurements, which responds accordingly in higher bonding environments. The two methods are used in a hybrid approach providing a full range quantitative bond index (QBI) introduced by Izuhara et al. (2017). In order to conform with local requirements related to well integrity and to ascertain the QBI potential from LWD monopole sonic, a wireline cement bond log (CBL) was acquired in the first well of the campaign for comparison. This enabled the strategic deployment of LWD QBI service in subsequent wells. LWD sonic monopole data was acquired at a controlled speed of 900ft/h. The high-fidelity waveforms were analyzed in a suitable time window and both amplitude- and attenuation-based bond indexes were derived. The combined hybrid bond index showed an excellent match with the wireline reference CBL, both in zones of high as well as lower cement bonding. The presence of formation arrivals was also in good correlation with zones of proper bonding distinguishable on the QBI results. This established the robustness of the LWD cement logging and ensured its applicability in the rest of the campaign which was carried out successfully. While the results from LWD cement evaluation service are omnidirectional, it comes with a wide range of benefits related to rig cost or conveyance in tough borehole trajectories. Early evaluation of cement quality by LWD sonic tools helps to provide adequate time for taking remedial actions if necessary. The LWD sonic as part of the drilling BHA enables this acquisition and service in non-dedicated runs, with the possibility of multiple passes for observing time-lapse effects. Also, the large sizes of LWD tools relative to the wellbore ensures a lower signal attenuation in the annulus and more effective stabilization, thereby providing a reliable bond index.

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