scholarly journals Generic characterization of diagnosis and prognosis for complex heterogeneous systems

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Pauline Ribot ◽  
Yannick Pencol´ ◽  
Michel Combacau
Keyword(s):  
Complex System ◽  
Monitoring System ◽  
Heterogeneous Systems ◽  
Modeling Framework ◽  
Global System ◽  
System Failures ◽  
Diagnosis And Prognosis ◽  
Generic Modeling ◽  
Prognostic Functions

Maintenance efficiency of complex industrial systems is an important economical and business issue. Main difficulties come from the choice of maintenance actions. A wrong choice can lead to maintenance costs that are not acceptable. In this paper, we propose a generic health monitoring system that integrates some diagnostic and prognostic capabilities to determine the current and future state of a large and complex system such as an aircraft. The diagnostic function aims at identifying faulty components that may cause global system failures. The prognostic function estimates the remaining time until the next global system failure. A formal and generic modeling framework for a complex system encapsulating the knowledge required to get the consistent coordination of the diagnostic and prognostic functions is presented. We propose in this framework to take into account component redundancies which is common in systems like aircrafts. Moreover, an original coupling of diagnosis and prognosis is established based on the characterization of the system operational modes and on a decentralized architecture of the monitoring system.

scholarly journals Complexity Analysis of Escher’s Art

Entropy ◽  
2019 ◽  
Vol 21 (6) ◽  
pp. 553 ◽  
Author(s):  
António M. Lopes ◽  
J. A. Tenreiro Machado
Keyword(s):  
Complex System ◽  
Quantitative Analysis ◽  
Complexity Analysis ◽  
Quantitative Characterization ◽  
Cultural Economic ◽  
Scaling Technique ◽  
Artistic Production ◽  
Formidable Challenge ◽  
Visualization Techniques

Art is the output of a complex system based on the human spirit and driven by several inputs that embed social, cultural, economic and technological aspects of a given epoch. A solid quantitative analysis of art poses considerable difficulties and reaching assertive conclusions is a formidable challenge. In this paper, we adopt complexity indices, dimensionality-reduction and visualization techniques for studying the evolution of Escher’s art. Grayscale versions of 457 artworks are analyzed by means of complexity indices and represented using the multidimensional scaling technique. The results are correlated with the distinct periods of Escher’s artistic production. The time evolution of the complexity and the emergent patterns demonstrate the effectiveness of the approach for a quantitative characterization of art.

Electrical Characterization of Inhomogeneous and Heterogeneous Systems with Microstuctural Periodicity

2001 ◽  
Vol 699 ◽  
Author(s):  
Joachim Maier
Keyword(s):  
Heterogeneous Systems ◽  
Electrical Characterization

AbstractThis paper discusses how inhomogeneities and heterogeneities enter impedance and conductivity analyses in the case of microstructural periodicity. The specific considerations of various examples of ionically and ionically/electronically conductiong materials systems (bicrystals, microcrystalline and nanocrystalline samples) show how a reliable and thorough characterization is possible.

Combined AFM/Raman Studies of Heterogeneous Polymer Materials

MRS Advances ◽  
2016 ◽  
Vol 1 (25) ◽  
pp. 1859-1864 ◽  
Author(s):  
Marko Surtchev ◽  
Mark Wall ◽  
Sergei Magonov
Keyword(s):  
Surface Morphology ◽  
Polymer Blends ◽  
Heterogeneous Systems ◽  
Polymer Materials ◽  
Raman Mapping ◽  
Immiscible Polymer Blends ◽  
Immiscible Polymer ◽  
Heterogeneous Polymer ◽  
Comprehensive Characterization

ABSTRACTCompositional imaging of several immiscible polymer blends was examined with the combination of AFM-based mechanical and electric modes with chemically-specific Raman mapping. Results showed that these methods substantially complement each other in comprehensive characterization of surface morphology by helping to identify a composition of top surface and sub-surface materials in polymer heterogeneous systems.

scholarly journals A RFID-Based Monitoring System for Characterization of Perching Behaviors of Individual Poultry

2018 ◽  
Author(s):  
Kailao Wang ◽  
Kai Liu ◽  
Hongwei Xin ◽  
Lilong Chai ◽  
Yu Wang ◽  
...  
Keyword(s):  
Monitoring System

Bayesian Spectroscopic Characterization of Directly Imaged Planets and Brown Dwarfs and Implications for Ultracool Model Atmospheres

2021 ◽  
Author(s):  
Zhoujian Zhang ◽  
Michael Liu ◽  
Mark Marley ◽  
Michael Line ◽  
William Best
Keyword(s):  
Physical Properties ◽  
Near Infrared ◽  
Brown Dwarfs ◽  
Spectroscopic Characterization ◽  
Cool Temperature ◽  
Brown Dwarf ◽  
Modeling Framework ◽  
High Quality ◽  
Model Predictions

<p>Spectroscopic characterization of imaged exoplanets and brown dwarfs is essential for understanding their atmospheres, formation, and evolution, but such work is challenged by the unavoidably simplified model atmospheres needed to interpret spectra. While most previous work has focused on single or at most a few objects, comparing a large collection of spectra to models can uncover trends in data-model inconsistencies needed to improve model predictions, thereby leading to robust properties from exoplanet and brown dwarf spectra. Therefore, we are conducting a systematic analysis of a valuable but underutilized resource: the numerous high-quality spectra of (directly imaged and free-floating) exoplanets and brown dwarfs already accumulated by the community.<span class="Apple-converted-space"> </span></p> <p>Focusing on the cool-temperature end, we have constructed a Bayesian modeling framework using the new Sonora-Bobcat model atmospheres and have applied it to study near-infrared low-resolution spectra of >50 late-T imaged planets and brown dwarfs (≈600-1200K, ≈10-70 M<sub>Jup</sub>) and infer their physical properties (effective temperature, surface gravity, metallicity, radii, mass). By virtue of having such a large sample of high-quality spectra, our analysis identifies the systematic offsets between observed and model spectra as a function of wavelength and physical properties to pinpoint specific shortcomings in model predictions. We have also found that the spectroscopically inferred metallicities, ages, and masses of our sample all considerably deviate from expectations, suggesting the physical and chemical assumptions made within these models need to be improved to fully interpret data. Our work has established a systematic validation of cloudless model atmospheres to date and we discuss extending such analysis to wider temperature and wavelength (e.g., JWST) ranges, as well as finding new planetary-mass and brown dwarf benchmarks, in order to validate ultracool model atmospheres over larger parameter space.</p>

Material Characterization of Additively Manufactured Part via Multi-Level Stochastic Upscaling Method

2015 ◽  
Author(s):  
Recep M. Gorguluarslan ◽  
Sang-In Park ◽  
David W. Rosen ◽  
Seung-Kyum Choi
Keyword(s):  
Material Characterization ◽  
Modeling Framework ◽  
Upscaling Technique ◽  
Simulation Based ◽  
Scale Models ◽  
Multiple Levels ◽  
Multiscale Modeling Framework ◽  
Input Uncertainties

An integrated multiscale modeling framework that incorporates a simulation-based upscaling technique is developed and implemented for the material characterization of additively manufactured cellular structures in this paper. The proposed upscaling procedure enables the determination of homogenized parameters at multiple levels by matching the probabilistic performances between fine and coarse scale models. Polynomial chaos expansion is employed in upscaling procedure to handle the computational burden caused by the input uncertainties. Efficient uncertainty quantification is achieved at the mesocale level by utilizing the developed upscaling technique. The homogenized parameters of mesostructures are utilized again at the macroscale level in the upscaling procedure to accurately obtain the overall material properties of the target cellular structure. Actual experimental results of additively manufactured parts are integrated into the developed procedure to demonstrate the efficacy of the method.

Performability Modeling of Distributed Systems and Its Formal Methods Representation

2020 ◽  
pp. 203-233
Author(s):  
Razib Hayat Khan
Keyword(s):  
Complex System ◽  
Quantitative Analysis ◽  
Functional Properties ◽  
Distributed System ◽  
System Performance ◽  
Early Stage ◽  
Behavioral Changes ◽  
Design Development ◽  
Modeling Framework ◽  
System Components

A distributed system is a complex system. Developing complex systems is a demanding task when attempting to achieve functional and non-functional properties such as synchronization, communication, fault tolerance. These properties impose immense complexities on the design, development, and implementation of the system that incur massive effort and cost. Therefore, it is vital to ensure that the system must satisfy the functional and non-functional properties. Once a distributed system is developed, it is very difficult and demanding to conduct any modification in its architecture. As a result, the quantitative analysis of a complex distributed system at the early stage of the development process is always an essential and intricate endeavor. To meet the above challenge, this chapter introduces an extensive framework for performability evaluation of a distributed system. The goal of the performability modeling framework is to consider the behavioral change of the system components due to failures. This reveals how such behavioral changes affect the system performance.

scholarly journals Effect of Ionic Compounds of Different Valences on the Stability of Titanium Oxide Colloids

2018 ◽  
Vol 2 (3) ◽  
pp. 32 ◽  
Author(s):  
Szabolcs Muráth ◽  
Szilárd Sáringer ◽  
Zoltán Somosi ◽  
István Szilágyi
Keyword(s):  
Titanium Oxide ◽  
Colloidal Stability ◽  
Heterogeneous Systems ◽  
Multivalent Ions ◽  
Aggregation Behaviour ◽  
Ionic Compounds ◽  
Oxide Particles ◽  
Synthetic Routes ◽  
The Stability

Titanium oxide particles of various morphologies have been prepared for applications of scientific or industrial interest in recent decades. Besides development of novel synthetic routes and solid-state characterization of the obtained particles, colloidal stability of titanium oxide dispersions was the focus of numerous research groups due to the high importance of this topic in applications in heterogeneous systems. The influence of dissolved ionic compounds, including monovalent salts, multivalent ions and polyelectrolytes, on the charging and aggregation behaviour of titanium oxide materials of spherical and elongated structures will be discussed in the present review.

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