Nonlinear Engine Component Fault Diagnosis From a Limited Number of Measurements Using a Combinatorial Approach

2003 ◽  
Vol 125 (3) ◽  
pp. 642-650 ◽  
Author(s):  
N. Aretakis ◽  
K. Mathioudakis ◽  
A. Stamatis
Keyword(s):  
Selection Procedure ◽  
Combinatorial Approach ◽  
Jet Engines ◽  
Turbofan Engine ◽  
Analysis Techniques ◽  
Engine Simulation ◽  
Health Indices ◽  
Faulty Component ◽  
Component Faults

A method for diagnosing component faults of jet engines is presented. It uses nonlinear gas path analysis techniques to determine the values of health parameters, with the help of a suitably formulated engine simulation model. The incentive of the method is to achieve the determination of the values of component health indices when a limited number of measured quantities is available, which do not allow the determination of all the fault indices simultaneously. A combinatorial approach is introduced, in order to circumvent the problem of the insufficient information for determining a full set of indices. After obtaining a set of possible solutions, a selection procedure is applied to isolate the ones that can give the actual fault identity. Quantification of the fault comes at a final step, when the faulty component has been identified. Different scenarios of faults on a twin spool partially mixed turbofan engine are considered in order to demonstrate the effectiveness of the method. The limitations of the method are also discussed.

Non-Linear Engine Component Fault Diagnosis From a Limited Number of Measurements Using a Combinatorial Approach

2002 ◽  
Author(s):  
N. Aretakis ◽  
K. Mathioudakis ◽  
A. Stamatis
Keyword(s):  
Selection Procedure ◽  
Combinatorial Approach ◽  
Jet Engines ◽  
Turbofan Engine ◽  
Engine Simulation ◽  
Health Indices ◽  
Non Linear ◽  
Faulty Component ◽  
Component Faults

A method for diagnosing component faults of jet engines is presented. It uses non-linear gas path analysis techniques to determine the values of health parameters, with the help of a suitably formulated engine simulation model. The incentive of the method is to achieve the determination of the values of component health indices when a limited number of measured quantities is available, which do not allow the determination of all the fault indices simultaneously. A combinatorial approach is introduced, in order to circumvent the problem of the insufficient information for determining a full set of indices. After obtaining a set of possible solutions, a selection procedure is applied to isolate the ones that can give the actual fault identity. Quantification of the fault comes at a final step, when the faulty component has been identified. Different scenarios of faults on a twin spool partially mixed turbofan engine are considered in order to demonstrate the effectiveness of the method. The limitations of the method are also discussed.

scholarly journals Benchmarking Gas Path Diagnostic Methods: A Public Approach

2008 ◽  
Author(s):  
Donald L. Simon ◽  
Jeff Bird ◽  
Craig Davison ◽  
Al Volponi ◽  
R. Eugene Iverson
Keyword(s):  
Power Systems ◽  
Health Management ◽  
Diagnostic Methods ◽  
Fault Detection And Isolation ◽  
Benchmark Problem ◽  
Noise Levels ◽  
Turbofan Engine ◽  
Engine Simulation ◽  
Component Faults ◽  
New Algorithms

Recent technology reviews have identified the need for objective assessments of engine health management (EHM) technology. The need is two-fold: technology developers require relevant data and problems to design and validate new algorithms and techniques while engine system integrators and operators need practical tools to direct development and then evaluate the effectiveness of proposed solutions. This paper presents a publicly available gas path diagnostic benchmark problem that has been developed by the Propulsion and Power Systems Panel of The Technical Cooperation Program (TTCP) to help address these needs. The problem is coded in Matlab™ and coupled with a non-linear turbofan engine simulation to produce “snap-shot” measurements, with relevant noise levels, as if collected from a fleet of engines over their lifetime of use. Each engine within the fleet will experience unique operating and deterioration profiles, and may encounter randomly occurring relevant gas path faults including sensor, actuator and component faults. The challenge to the EHM community is to develop gas path diagnostic algorithms to reliably perform fault detection and isolation. An example solution to the benchmark problem is provided along with associated evaluation metrics. A plan is presented to disseminate this benchmark problem to the engine health management technical community and invite technology solutions.

DINAMIKA POLITIK PERSETUJUAN BERSAMA TENTANG PENETAPAN DESA ADAT DI KABUPATEN ROKAN HULU TAHUN 2014

2017 ◽  
Vol 15 (1) ◽  
pp. 21
Author(s):  
Haryo Suganda ◽  
Raja Muhammad Amin
Keyword(s):  
Regulatory Region ◽  
Field Research ◽  
Analysis Techniques ◽  
Political Dynamics ◽  
Political Interests ◽  
Wide Range ◽  
Information Method ◽  
Qualitative Descriptive ◽  
The Village

This study is motivated the identification of policies issued by the regional Governmentof Rokan Hulu in the form of Regulatory region number 1 by 2015 on the determination of thevillage and Indigenous Village. Political dynamics based on various interests against themanufacture of, and decision-making in the process of formation of the corresponding localregulations determination of Indigenous Villages in the Rokan Hulu is impacted to a verysignificantamount of changes from the initial draft of the number i.e. 21 (twenty one) the villagebecame Customary 89 (eighty-nine) the Indigenous Villages who have passed. Type of thisresearch is a qualitative descriptive data analysis techniques. The research aims to describe theState of the real situation in a systematic and accurate fact analysis unit or related research, aswell as observations of the field based on the data (information). Method of data collectionwas done with interviews, documentation, and observations through fieldwork (field research).The results of the research on the process of discussion of the draft local regulations andmutual agreement about Designation of Indigenous Villages in the Rokan Hulu is, showed thatthe political dynamics that occur due to the presence of various political interests, rejectionorally by Villagers who were judged to have met the requirements of Draft Regulations to beformulated and the area for the set to be Indigenous Villages, and also there is a desire fromsome villages in the yet to Draft local regulations in order to set the Indigenous village , there isa wide range of interests of these aspects influenced the agreement to assign the entire localVillage which is in the Rokan Hulu become Indigenous village, and the village of Transmigrationinto administrative Villages where the initiator of the changes in the number of IndigenousVillages in the Rokan Hulu it is the desire of the local Government of its own.

scholarly journals Full spectrum and genetic algorithm-selected spectrum-based chemometric methods for simultaneous determination of azilsartan medoxomil, chlorthalidone, and azilsartan: Development, validation, and application on commercial dosage form

2021 ◽  
Vol 19 (1) ◽  
pp. 205-213
Author(s):  
Hany W. Darwish ◽  
Abdulrahman A. Al Majed ◽  
Ibrahim A. Al-Suwaidan ◽  
Ibrahim A. Darwish ◽  
Ahmed H. Bakheit ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Simultaneous Determination ◽  
Predictive Power ◽  
Principal Component Regression ◽  
Selection Procedure ◽  
Principal Component ◽  
Chemometric Methods ◽  
Full Spectrum ◽  
Azilsartan Medoxomil

Abstract Five various chemometric methods were established for the simultaneous determination of azilsartan medoxomil (AZM) and chlorthalidone in the presence of azilsartan which is the core impurity of AZM. The full spectrum-based chemometric techniques, namely partial least squares (PLS), principal component regression, and artificial neural networks (ANN), were among the applied methods. Besides, the ANN and PLS were the other two methods that were extended by genetic algorithm procedure (GA-PLS and GA-ANN) as a wavelength selection procedure. The models were developed by applying a multilevel multifactor experimental design. The predictive power of the suggested models was evaluated through a validation set containing nine mixtures with different ratios of the three analytes. For the analysis of Edarbyclor® tablets, all the proposed procedures were applied and the best results were achieved in the case of ANN, GA-ANN, and GA-PLS methods. The findings of the three methods were revealed as the quantitative tool for the analysis of the three components without any intrusion from the co-formulated excipient and without prior separation procedures. Moreover, the GA impact on strengthening the predictive power of ANN- and PLS-based models was also highlighted.

scholarly journals Efficiency of Machine Learning Algorithms for the Determination of Macrovesicular Steatosis in Frozen Sections Stained with Sudan to Evaluate the Quality of the Graft in Liver Transplantation

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1993
Author(s):  
Fernando Pérez-Sanz ◽  
Miriam Riquelme-Pérez ◽  
Enrique Martínez-Barba ◽  
Jesús de la Peña-Moral ◽  
Alejandro Salazar Nicolás ◽  
...  
Keyword(s):  
Machine Learning ◽  
Liver Transplantation ◽  
Learning Algorithms ◽  
Selection Procedure ◽  
Machine Learning Algorithms ◽  
Liver Biopsies ◽  
Convenient Technique ◽  
End Stage ◽  
Macrovesicular Steatosis

Liver transplantation is the only curative treatment option in patients diagnosed with end-stage liver disease. The low availability of organs demands an accurate selection procedure based on histological analysis, in order to evaluate the allograft. This assessment, traditionally carried out by a pathologist, is not exempt from subjectivity. In this sense, new tools based on machine learning and artificial vision are continuously being developed for the analysis of medical images of different typologies. Accordingly, in this work, we develop a computer vision-based application for the fast and automatic objective quantification of macrovesicular steatosis in histopathological liver section slides stained with Sudan stain. For this purpose, digital microscopy images were used to obtain thousands of feature vectors based on the RGB and CIE L*a*b* pixel values. These vectors, under a supervised process, were labelled as fat vacuole or non-fat vacuole, and a set of classifiers based on different algorithms were trained, accordingly. The results obtained showed an overall high accuracy for all classifiers (>0.99) with a sensitivity between 0.844 and 1, together with a specificity >0.99. In relation to their speed when classifying images, KNN and Naïve Bayes were substantially faster than other classification algorithms. Sudan stain is a convenient technique for evaluating ME in pre-transplant liver biopsies, providing reliable contrast and facilitating fast and accurate quantification through the machine learning algorithms tested.

Turbofan Engine Robust H-∞ Dynamical Output Feedback Control Design Based on LMI Method

2005 ◽  
Author(s):  
Xi Wang ◽  
Daoliang Tan ◽  
Tiejun Zheng
Keyword(s):  
Output Feedback ◽  
Linear Models ◽  
Nonlinear Models ◽  
Design Method ◽  
State Space Model ◽  
Output Feedback Control ◽  
Linear Matrix ◽  
Turbofan Engine ◽  
Engine Simulation ◽  
Linear State

This paper presents an approach to turbofan engine dynamical output feedback controller (DOFC) design in the framework of LMI (Linear Matrix Inequality)-based H∞ control. In combination with loop shaping and internal model principle, the linear state space model of a turbofan engine is converted into that of some augmented plant, which is used to establish the LMI formulations of the standard H∞ control problem with respect to this augmented plant. Furthermore, by solving optimal H∞ controller for the augmented plant, we indirectly obtain the H∞ DOFC of turbofan engine which successfully achieves the tracking of reference instructions and effective constraints on control inputs. This design method is applied to the H∞ DOFC design for the linear models of an advanced multivariate turbofan engine. The obtained H∞ DOFC is only in control of the steady state of this turbofan engine. Simulation results from the linear and nonlinear models of this turbofan engine show that the resulting controller has such properties as good tracking performance, strong disturbance rejection, and satisfying robustness.

scholarly journals A Multi-criteria Approach in the Project Selection Process in Multi-Project Context

2021 ◽  
Vol 14 (6) ◽  
pp. 125
Author(s):  
Charles Éric Manyombé ◽  
Sébastien H. Azondékon
Keyword(s):  
Selection Process ◽  
Selection Procedure ◽  
Project Selection ◽  
Project Portfolio ◽  
Organizational Complexity ◽  
Scarce Resources ◽  
Project Environment ◽  
Effective Decision ◽  
Effective Decision Making

In a multi-project environment, organizational complexity refers to the difficulties that organizations often face in choosing projects to build their portfolios, since they do not aim to achieve the same strategic business objectives. It is for this reason that the project selection process requires the implementation of an effective decision-making tool when composing a project portfolio. The objective of this paper is to propose an adapted framework for a better project selection procedure inspired by the approaches of strategic relevance, profitability criteria, uncertainty, and risk analysis, the ability to dispose of scarce resources, and the determination of interdependencies between different projects. 

scholarly journals Reputasi Auditor sebagai Pemoderasi Pengaruh Opini Audit dan Pergantian Manajemen pada Auditor Switching

2020 ◽  
Vol 30 (10) ◽  
pp. 2456
Author(s):  
Nyoman Ratna Candradewi ◽  
Gayatri Gayatri
Keyword(s):  
Regression Analysis ◽  
Sampling Method ◽  
Significant Positive Effect ◽  
Audit Opinion ◽  
Management Change ◽  
Analysis Techniques ◽  
Opinion Change ◽  
Auditor Switching ◽  
Positive Effect

Auditor turnover is a behavior that the client company does to transfer the auditor. This reaserch aims to obtain empirical evidence of the effect of audit opinion and management change on auditor switching and how the auditor's reputation is able to moderate the influence of audit opinion and management change on auditor switching. Determination of the research sample using purposive sampling method with a sample of 145 companies. Data analysis techniques used are logistic regression analysis and Moderated Regression Analysis (MRA). Based on the results of this study indicate that audit opinion and management change have a significant positive effect on auditor switching. However, the auditor's reputation is unable to moderate the effect of audit opinion and management change on auditor switching. Keywords: Audit Opinion; Change of Management; Auditor Switching; Auditor’s Reputation.

scholarly journals PELAKSANAAN HUMAS DALAM SOSIALISASI PROGRAM JAMINAN SOSIAL KETENAGAKERJAAN DI KANTOR BPJS KETENAGAKERJAAN PADANG

Jurnal Ecogen ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 308
Author(s):  
Sharly Yoenaz
Keyword(s):  
Social Security ◽  
Public Relations ◽  
Snowball Sampling ◽  
Model Data ◽  
Social Security Program ◽  
Analysis Techniques ◽  
Descriptive Research ◽  
Qualitative Descriptive ◽  
The Media

The implementation of public relations in the socialization of the labor social security program at the BPJS Ketenagakerjaan Padang has not been carried out optimally because the socialization carried out does not cover all BPJS Employment stakeholders and socialization media that are underutilized optimally. The purpose of this study was to determine the implementation of public relations in the socialization of the labor social security program at the BPJS Ketenagakerjaan Padang. The method used is Qualitative Descriptive Research. Determination of Informants in this study was carried out with Snowball Sampling Techniques. Data collection is done through Observation, Interview and Documentation, with Model Data Analysis Techniques of Miles and Huberman. The findings in this study indicate that (1) the socialization of the labor social security program is not carried out directly to workers; (2) the lack of awareness of employers registering workers in the BPJS Ketenagakerjaan Padang program; (3) the media for socialization of the labor social security program has not been used optimally.Keyword: Public Relations, Socialization, Employment Social Security

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