bluuebunny/crossref_metadata_2025 huggingface dataset:
Modalidades veridictorias en el discurso operístico
Authors: González Martínez Juan Miguel
Published: March 2024

En la ópera, una parte fundamental del sentido textual deriva del concepto de verdad, considerado tanto en el nivel del enunciado como en el de la enunciación. Este concepto es importante en la definición del proyecto narrativo que fundamenta la composición y en el proceso hermenéutico que guía la percepción, el cual culmina con un juicio epistémico. Tomando como apoyo los conceptos básicos de la semiótica greimasiana se considera verdad, falsedad, mentira y secreto como términos que resultan de proyectar la verdad como categoría semántica en el cuadrado semiótico. De la apariencia (manifestación) se infiere la verdad (inmanencia) a través de unos mecanismos propios de la ópera que consisten básicamente en la interacción entre música y palabras de acuerdo con los principios de la focalización y la convergencia dentro del ámbito general de la heterosemiosis.
El rito de la Misa como práctica significante
Authors: Blanco Desiderio
Published: March 2024

El rito de la Misa se desarrolla como una práctica significante. Toda práctica significante requiere la presencia y participación de un cuerpo sensible junto a otros cuerpos igualmente sensibles. El rito de la Misa, como práctica, se inicia con el rito de la fracción del pan por Jesucristo en la Última Cena. Los testimonios más cercanos dan cuenta de la repetición asidua de esa práctica entre los primeros cristianos. La tradición de una práctica conlleva la repetición de enunciaciones sucesivas, las cuales van dejando su impronta en los cuerpos que participan en ella. El rito de la Misa se inscribe en el espacio de lo sagrado. Habitualmente, ese rito se cumple en el templo. El desarrollo del rito alcanza determinados picos de intensidad, el más alto y asombroso de los cuales se da en el momento de la consagración. La moderada lentitud del rito expresa el sentido de solemnidad que adquiere la práctica. Al paso de los siglos, el rito se transforma en mito (en “dogma”) por arte de las sutilezas teológicas de los pensadores cristianos, comenzando por el “apóstol” Pablo.
La construcción mítica del discurso nacionalista vasco
Authors: Alonso Aldama Juan
Published: March 2024

En la perspectiva de una semiótica de la cultura, este artículo busca poner de relieve las estrategias que el nacionalismo vasco efectúa para la construcción de un discurso que legitimiza una visión de la historia, así como una justificación de su proyecto político. Este discurso, gracias a una serie de operaciones semióticas (selección paradigmática y organización sintagmática por bricolaje) de la reelaboración de la cultura, logra elaborar un corpus mítico que escapa a la refutación fundada sobre las modalidades de lo verdadero y de lo falso, pues tiene una mirada exclusivamente pragmática de la perpetuación.
Lingüística interpretativa y fundamentos semióticos de la traducción
Authors: Rastier François
Published: March 2024

En este estudio, anterior a las propuestas descriptivas que hemos formulado en Rastier (2006), nos proponemos identificar los problemas creados por las concepciones semióticas que rigen las teorías cognitivas y comunicativas de la traducción. Puesto que éstas se basan en la división tripartita sintaxis/ semántica/ pragmática, definida por el positivismo lógico, no son capaces de captar la especificidad de los signos lingüísticos ni la semiosis textual, evidenciadas por la lingüística histórica y comparada, especialmente con Saussure. La problemática del texto supera a la del signo, ya que permite reintroducir la actividad interpretativa de la lingüística y concebirla como una interacción entre pasajes en el interior del texto y en el intertexto. Así, la lingüística de textos, sobre todo en su dimensión interpretativa, asume la responsabilidad de describir con una metodología unificada las relaciones dentro del texto y entre textos, sea que pertenezcan a una misma lengua o que provengan de lenguas diferentes.
El arte de la lentitud. Precipitado de la historia
Authors: Ouellet Pierre
Published: March 2024

En este trabajo se plantea que, debido a la rapidez con que se suscitan los acontecimientos, el tiempo de la Historia se ha precipitado y caído, de modo tal que sus sedimentos lentifican o inmovilizan lo que se ha denominado progreso. Sobre este orden de cosas, la literatura y el arte dan testimonio de acontecimientos que precisan ser descritos en términos sociopolíticos, etnofenomenológicos y semioestéticos que a la vez representan su propio “fuera de tiempo” y, al hacerlo, saca al tiempo de la Historia de su curso acelerado. Este planteamiento se ilustra mediante el análisis de la novela Éden, Éden, Éden de Pierre Guyotat, la cual contradice toda lógica causal y disuelve toda jerarquía a través de ciertos recursos discursivos.
Del tempo en pintura
Authors: Zilberberg Claude
Published: March 2024

En este estudio el autor se propone denunciar la idea según la cual la pintura concierne el espacio y la música el tiempo. Pero precisamente el futuro de la pintura ha agregado a la línea y al color una tercera capa: el toque que proporciona el plano de la expresión de una semiosis inédita que tiene como plano del contenido las modalidades de la velocidad pictórica. Estas modalidades proporcionan un paradigma que puede ser reconocido como una aceleración o bien como una desaceleración. En este caso, Francis Bacon sería el héroe de la aceleración y Rothko el héroe de la desaceleración.
Presentación
Authors: Ruiz Moreno Luisa , Rodríguez Blanca Alberta
Published: March 2024

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المفهوم الاجتماعي والاقتصادي للعمل من المنظور الإسلامي والرأسمالي
Authors: العوران أحمد فرّاس
Published: March 2024

تتناول هذه الدراسة المفهوم الاجتماعي والاقتصادي للعمل من المنظور الرأسمالي السائد في الدراسات الاقتصادية، والمنظور الإسلامي في ضوء مقاصد القرآن الكريم لبناء الحضارة والعُمران، من خلال تدبُّر خطاب الوحي المرتبط بالموضوع. ويأتي هذا الطرح -في جانبه المقارن- للتأكيد على قضايا قد تفوت على بعض الباحثين وعلى رأسها الأساس الثقافي الاجتماعي للمفهوم وما يترتب عليه، وعلى أهمية تحديد المعنى الاصطلاحي للمفاهيم عموماً؛ للفت الانتباه إلى التفاوت الطبيعي في تحديد المعاني الاصطلاحية للمفاهيم الثقافية وما يترتب على ذلك من فهم للقضايا الاجتماعية، ومن ثم كيفية التعامل معها ما بين الثقافات المتعددة. وتتجلى أهمية تناول مفهوم العمل من المنظور الإسلامي من خلال الارتباط الوثيق بين المعنى الاصطلاحي الإسلامي للعمل، وتحديد الموقف الإسلامي من بعض القضايا الاقتصادية التي ينعكس فهمها، وتحديد سياسات التعامل معها على المستوى الاقتصادي عند تحديد المعنى الاصطلاحي لمفهوم العمل؛ ومنها: تحديد حجم اليد العاملة، وحساب معدل البطالة، والربط ما بين البطالة والفقر، وربط محاربة الفقر بالنمو الاقتصادي، ومشاركة الجنسين في سوق العمل، ومدى الارتباط الحقيقي لذلك بحقوق الإنسان وبالتقدم العلمي، وبتحقيق معنى التنمية البشرية.
Análisis histopatológico en apendicectomía profiláctica
Authors: Vallejo Parada Diego , Orellana Tapia Marcela , Celedón Porzio Felipe , Uribe Araya Sebastián
Published: March 2024

Objetivo: Reportar los hallazgos anatomopatológicos de las apendicectomías profilácticas en el Hospital Clínico de la Fuerza Aérea de Chile (FACh) y compararlos con los estudios reportados en la literatura.Material y método: Análisis retrospectivo, descriptivo de los pacientes sometidos a apendicectomía laparoscópica profiláctica entre los años 2013 y 2017 en el Hospital FACh, y sus resultados anatomopatológicos de la pieza operatoria, según registro clínico y reportes de laboratorio patológico.Resultados: Se rescataron un total de 200 muestras de pacientes sometidos a apendicectomía. El 80% resultó sin hallazgos patológicos, mientras que 13,5% obliteración fibrosa, y 2,5% en apendicitis aguda en distinta etapa. Se evidenció una muestra de 0,5% de neoplasia maligna.Discusión: El porcentaje de apéndices no patológicos obtenidos se correlaciona con resultados expuestos en la literatura sobre apendicectomías incidentales. Por su parte, los hallazgos de malignidad están presentes en todos los reportes revisados, con una tasa relativa baja variable. Existe el debate si todos los apéndices deben ser estudiados.Conclusiones: No existen estudios similares al presente, sin embargo, es comparable a los reportes de apendicectomía incidental. Pareciera ser indispensable el estudio histopatológico por el riesgo de prevalencia de malignidad.
Stock exchange in the development of the country's financial sector: theoretical-example aspects
Authors: Krupka Andrii , Pyrih Halyna
Published: March 2024

Introduction. Stock exchanges are an indispensable component of the country's financial system, playing an important role in stimulating economic development. They provide a flexible mechanism for attracting capital, facilitating business development, financing new projects and expanding companies.
Attracting capital through stock exchanges allows companies to grow, create new jobs and make a significant contribution to the development of the national economy.
Goal. The purpose of the article is to analyze the essence of stock exchanges, determine their main functions taking into account theoretical aspects, as well as modelling and providing practical recommendations for improving the activity of stock exchanges in Ukraine.
The results. The main functions and significance of stock exchanges as an integral component of the stock market are defined. The main problems that limit the development of stock trading in Ukraine have been studied. Ways of development of stock exchanges in Ukraine in the post-war period are proposed, with arguments for the importance of this segment of the financial market for the development of the economy of the entire country.
Tax discount in Ukraine: importance, features and impact on budgets
Authors: Marshalok Taras , Rudan Vitaly
Published: March 2024

Introduction. The article is devoted to the analysis of the features and impact of tax rebates on budgets in Ukraine, with a special emphasis on the conditions of the modern economic situation and the challenges associated with martial law.
Goal. The purpose of the study is to analyze the impact of the personal income tax and the mechanism of tax discounts on the economic stability and development of Ukraine, with an emphasis on the optimization of tax policy in wartime conditions.
Method (methodology). A comprehensive approach was used for the analysis, which includes a review of legal acts, analysis of statistical data, and comparative analysis. The basis of the research is the methods of critical analysis, synthesis, as well as the methods of economic analysis for assessing the impact of tax reductions on budget indicators.
The results. The study confirms the significant role of the personal income tax in filling the state and local budgets of Ukraine, as well as the effectiveness of the tax rebate mechanism as a tool for reducing the tax burden for citizens. Administration problems and insufficient use of tax discounts have been identified, which requires optimization of tax policy and raising public awareness. A number of proposals have been developed, including the introduction of digital technologies to simplify the procedure for obtaining tax rebates, conducting information campaigns to raise public awareness of the mechanisms and advantages of tax rebates, as well as the revision of existing regulations to expand the list of expenses that give the right to a tax rebate.
Management of the efficiency of use of material and technical resources at the enterprise
Authors: Mykytyuk Petro , Flys Viktor
Published: March 2024

Introduction. The article focuses on the analysis of strategies for managing the efficiency of the use of material and technical resources at enterprises, with an emphasis on the need to adapt to changing economic conditions. The main challenges and prospects facing companies in the context of globalization and innovative technologies are outlined.
Goal. The main goal of the article is the development and implementation of a comprehensive resource management methodology, which includes evaluating the effectiveness of resource use, planning material needs, and cost optimization.
Method (methodology). The study is based on the application of analytical methods, statistical analysis, as well as mathematical modelling methods for evaluating and forecasting the efficiency of resource use.
The results. As a result, methodical recommendations were developed, which allow to increase the efficiency of management of material and technical resources, ensuring cost savings and increasing the competitiveness of enterprises. Cases of implementation of the proposed solutions in practice are presented.
Low-carbon development as a strategic approach to positioning an enterprise in the market
Authors: Vovchuk Dmytro
Published: March 2024

The integration of carbon neutrality into the enterprise's strategic management system is a topical issue.
Purpose. The article is devoted to the study of a strategic approach to positioning an enterprise in the market in the context of its low-carbon development.
Method (methodology). The following methods were used to conduct the study: analysis and synthesis to consider regulatory measures for the transition to carbon neutrality in Ukraine and the European Union; deduction and induction to identify market mechanisms for reducing greenhouse gas emissions; epistemological approach to determine the structure of low-carbon markets; method of dialectical cognition to build a chain of conscious consumption.
Results. The article examines regulatory measures for the transition to carbon neutrality in Ukraine and the European Union. The market mechanisms for reducing greenhouse gas emissions are identified. The necessity of applying a strategic approach to the positioning of an enterprise on the basis of low-carbon development in the context of developing voluntary carbon markets is established. The structure of formation of low-carbon markets is presented, which provides for the transition to low-carbon development of enterprise as a strategic approach to its positioning in the market. It is determined that ensuring the low-carbon development of enterprises involves the interaction of all market participants in the development, production and consumption of low-carbon goods and services. A chain of formation of conscious consumption is built, the springboard of which is the formation of common values between consumers and enterprises, consisting in the production and consumption of environmentally friendly and carbon-neutral products and services. Prospects for the study are to identify the components of the enterprise's transition to low-carbon development.
Economic security and business process management in IT enterprises
Authors: Papinko Andriy
Published: March 2024

Introduction. In the context of modern challenges and needs of the global business environment, effective management of business processes and ensuring economic security are extremely important for the success of IT enterprises. This article examines the key aspects of economic security and business process management in the context of information technology, enabling analysis, evaluation, and optimization of enterprise activities in this sector.
Research Objective. Studying key aspects of economic security and business process management in the context of their optimization in the IT sector, as well as researching methods of business process management and providing practical recommendations that can be useful for IT enterprises to improve their efficiency and competitiveness.
Method (methodology). The research methodology involves literature analysis, empirical studies, and the use of analytical, synthesis, modeling, and forecasting methods to gain a deeper understanding of economic security and business process management in the IT sector. General scientific techniques have been utilized, including the analysis of scientific literature addressing issues of economic security and business process management. Empirical studies include the analysis of practical situations in the IT sector, allowing for the examination of specific cases of success or challenges in the field of economic security and business process management. This combination of methods will enable a comprehensive analysis and provide recommendations for improving practices in the IT sector.
The results. The research methodology encompasses literature analysis, empirical studies, and the utilization of analysis, synthesis, modeling, and forecasting methods to gain a deeper understanding of economic security and business process management in the IT sector. Empirical research involves analyzing practical situations in the IT sector, allowing for the examination of specific cases of success or challenges in the realm of economic security and business process management. This combination of methodologies enables a comprehensive analysis and provides recommendations for improving business process management practices within the context of economic security in the IT sector
Conclusions. The issues of achieving economic security status by IT businesses have been studied and summarized, taking into account their specificities. Methods for assessing the effectiveness of business process management through the use of indicator systems adapted to the IT industry have been generalized. Suggestions have been made for developing performance indicators for IT enterprise business processes to enhance management practices and ensure stability and competitiveness of IT companies within the context of economic security.
Resource determinants of economic development in Middle East countries and prospects for renewable energy
Authors: Zastavnyy Andriy , Okonskyi Mykhailo , Demkura Ivan
Published: March 2024

Introduction. Global transformations and regional characteristics of countries’ development bring the issue of resource provision for economic growth, social progress, and environmental efficiency to the fore. This article focuses on the energy resources supply issue in Middle Eastern countries and identifies the prospects for the region’s transition to renewable energy sources.
Purpose. The aim of this article is to analyze the resource impact on the economic development of Middle Eastern countries and to identify prospects and opportunities for implementing renewable energy projects.
Method (Methodology). The study applies various methods, including theoretical generalization, abstract-logical methods, analysis and synthesis, comparative analysis and generalization, and the graphical method.
Results. This article reveals the main trends in the development of the global energy system. It substantiates the specificity of Middle East countries’ development and argues for the significant role of resources – oil and gas – in their economic development. It confirms significant asymmetries in their socio-economic development and identifies countries for which resources such as oil and gas are strategically important. The impact of changes in the world oil and gas markets’ situation on the economies of the Middle East countries is clarified. The importance of transitioning to renewable energy sources is confirmed, and the main opportunities are highlighted. The strengths and weaknesses, as well as the opportunities and threats, of the Middle East’s energy transition to renewable sources are analyzed. Opportunities identified include economic growth, creation of new jobs, export of technologies and innovations, sustainable energy supply, reduction of environmental load, improved access to energy in remote areas and for vulnerable populations, international partnership, and involvement in international organizations’ projects. Proposals are made for the Middle Eastern countries for their gradual transition to renewable sources and ensuring energy security.
Modeling SiO2 Ion Impurities Aging in Insulated Gate Power Devices Under Temperature and Voltage Stress
Authors: E. Ginart Antonio , N. Ali Irfan , R. Celaya José , W. Kalgren Patrick , D. Poll Scott , J. Roemer Michael
Published: March 2024

This paper presents a formal computational methodology to explain how the oxide in semiconductors degrades over time and the dependence of oxide degradation on voltage and temperature stresses. The effects of aging are modeled and quantified by modification of the gate-source capacitance value. The model output is validated using experimental results of a thermally aged power semiconductor device.
Towards Prognostics of Power MOSFETs: Accelerated Aging and Precursors of Failure
Authors: R. Celaya Jose , Saxena Abhinav , Wysocki Philip , Saha Sankalita , Goebel Kai
Published: March 2024

This paper presents research results dealing with power MOSFETs (metal oxide semiconductor field effect transistor) within the prognostics and health management of electronics. Experimental results are presented for the identification of the on-resistance as a precursor to failure of devices with die-attach degradation as a failure mechanism. Devices are aged under power cycling in order to trigger die-attach damage. In situ measurements of key electrical and thermal parameters are collected throughout the aging process and further used for analysis and computation of the on-resistance parameter. Experimental results show that the devices experience die-attach damage and that the on-resistance captures the degradation process in such a way that it could be used for the development of prognostics algorithms (data-driven or physics-based).
Towards Defining and Allocating PHM Requirements for Military Systems
Authors: J. Luna Joel
Published: March 2024

Issues and methods of relating program requirements to PHM requirements and allocation of PHM requirements to lower system levels are discussed as alternatives to technology-driven approaches. This paper focuses on evaluating program requirements for improving reliability for military systems with a required maintenance free operating period. Reliability improvements are related to PHM attributes, which are condensed to two primary attributes: coverage and inefficiency. Methods of allocation of higher level PHM requirements to lower level requirements are examined, focusing on a normalized weighting approach. An alternative approach beginning with coverage estimates is also examined. A discrete-event simulation model is developed and exercised to confirm analytical results.
A Probabilistic Detectability-Based Structural Sensor Network Design Methodology for Prognostics and Health Management
Authors: Wang Pingfeng , D. Youn Byeng , Hu Chao
Published: March 2024

Significant technological advances in sensing and communication promote the use of large sensor networks to monitor structural systems, identify damages, and quantify damage levels. Prognostics and health management (PHM) technique has been developed and applied for a variety of safety-critical engineering structures, given the critical needs of the structure health state awareness. The PHM performance highly relies on real-time sensory signals which convey the structural health relevant information. Designing an optimal structural sensor network (SN) with high detectability is thus of great importance to the PHM performance. This paper proposes a generic SN design framework using a detectability measure while accounting for uncertainties in material properties and geometric tolerances. Detectability is defined to quantify the performance of a given SN. Then, detectability analysis will be developed based on structural simulations and health state classification. Finally, the generic SN design framework can be formulated as a mixed integer nonlinear programming (MINLP) using the detectability measure and genetic algorithms (GAs) will be employed to solve the SN design optimization problem. A power transformer study will be used to demonstrate the feasibility of the proposed generic SN design methodology.
Data-Driven Anomaly Detection Performance for the Ares I-X Ground Diagnostic Prototype
Authors: A. Martin Rodney , A. Schwabacher Mark , L. Matthews Bryan
Published: March 2024

In this paper, we will assess the performance of a data-driven anomaly detection algorithm, the In- ductive Monitoring System (IMS), which can be used to detect simulated Thrust Vector Control (TVC) system failures. However, the ability of IMS to detect these failures in a true operational setting may be related to the realistic nature of how they are simulated. As such, we will investi- gate both a low fidelity and high fidelity approach to simulating such failures, with the latter based upon the underlying physics. Furthermore, the ability of IMS to detect anomalies that were pre- viously unknown and not previously simulated will be studied in earnest, as well as apparent de- ficiencies or misapplications that result from us- ing the data-driven paradigm. Our conclusions indicate that robust detection performance of sim- ulated failures using IMS is not appreciably af- fected by the use of a high fidelity simulation. However, we have found that the inclusion of a data-driven algorithm such as IMS into a suite of deployable health management technologies does add significant value.
Emerging Challenges and Technologies in Signal Processing for Prognostics and Health Management in Wind Energy
Authors: Johnson Preston
Published: March 2024

The use of condition monitoring (CM) in wind energy machines continues to evolve as wind energy machines grow in size and move offshore. Early and smaller wind generation machines offered little financial incentives for condition monitoring, justifying only simple and inexpensive health monitoring technologies. Today, multi-megawatt wind machines are more complex, more difficult to physically reach, and generate more revenue than previous models. This paper reviews challenges and candidate technologies for next generation condition monitoring in Wind Energy.

Larger wind turbines typically employ Doubly-Fed induction generators with gearbox based drive trains or direct drive generators with multi pole rotors and fixed stators. Both configurations employ variable speed wind driven rotors, variable due to wind speed. Fixed rotor speed signal processing techniques no longer work in a variable speed environment. Synchronous sampling, order analysis, wavelet filters, Cepstrum and related frequency analysis of sensor waveforms are examples of advanced feature extraction tools now available for up-tower condition monitoring systems to address the variable speed nature of modern wind turbines. These signal processing tools operate to reduce and preprocess sensory data producing and extracting signal features. With extracted features, performance prediction and health diagnostics are then able to produce machine degradation rate and degradation levels.

This paper provides a tutorial of signal processing techniques for analysis of sensory information from variable speed rotary machines. The paper concludes with a discussion of prediction and diagnostics techniques which consume the analysis results of previously mentioned signal processing techniques.
Probabilistic Latent Component Analysis for Gearbox Vibration Source Separation
Authors: Isom Joshua , Shashanka Madhusudana , Tewari Ashutosh , Lazarevic Aleksandar
Published: March 2024

Probabilistic latent component analysis (PLCA) is applied to the problem of gearbox vibration source separation. A model for the probability distribution of gearbox vibration employs a latent variable intended to correspond to a particular vibration source, with the measured vibration at a particular sensor for each source the product of a marginal distribution of vibration by frequency, a marginal distribution of vibration by shaft rotation, and a sensor weight distribution. An expectation-maximization algorithm is used to approximate a maximum-likelihood parameterization for the model. In contrast to other unsupervised source-separation methods, PLCA allows for separation of vibration sources when there are fewer vibration sensors than vibration sources. Once the vibration components of a healthy gearbox have been identified, the vibration characteristics of damaged gearbox elements can be determined. The efficacy of the technique is demonstrated with an application on a gearbox vibration data set.
Confidence Assessment in Fatigue Damage Prognosis
Authors: Sankararaman Shankar , Ling You , Mahadevan Sankaran
Published: March 2024

This paper presents a methodology for assessing the confidence and the predictive capability of prognosis models, using the application of fatigue crack growth analysis. Structures with complicated geometry and multi-axial variable amplitude loading conditions are considered. Several models –finite element model, crack growth model, retardation model, surrogate model, etc. – are efficiently connected through a Bayes network and the parameters of these models are calibrated after collecting inspection data. The results of the calibration are then used to develop a Bayesian confidence metric to assess the confidence of the models used in fatigue crack growth analysis. Three types of uncertainty are included in analysis: (1) natural variability in loading and material properties; (2) data uncertainty, due to crack detection uncertainty, measurement errors, and sparse data; (3) modeling uncertainty and errors in crack growth analysis, and finite element analysis. The proposed methodology is illustrated using a numerical example of surface cracking in a cylindrical structure.
Efficient probabilistic methods for real-time fatigue damage prognosis
Authors: Xiang Yibing , Liu Yongming
Published: March 2024

A general probabilistic fatigue crack growth prediction methodology for accurate and efficient damage prognosis is proposed in this paper. This methodology consists two major parts. First, the realistic random loading is transformed to an equivalent constant amplitude loading process based on a recently developed mechanism model. This transformation avoids the cycle-by-cycle calculation of fatigue crack growth under variable amplitude loading. Following this, an inverse first-order reliability method (IFORM) is used to evaluate the fatigue crack growth at an arbitrary reliability level. Inverse FORM method does not require a large number of function evaluations compared to the direct Monte Carlo simulation. Computational cost is significantly reduced and the proposed method is very suitable for real-time damage prognosis. Numerical examples are used to demonstrate the proposed method. Various experimental data under variable amplitude loading are collected and model predictions are compared with experimental data for model validation.
Stage Separation Failure: Model Based Diagnostics and Prognostics
Authors: Luchinsky Dmitry , Hafiychuk Vasyl , Kulikov Igor , Smelyanskiy Vadim , Patterson-Hine Ann , Hanson John , Hill Ashley
Published: March 2024

Safety of the next-generation space flight vehicles requires development of an in-flight Failure Detection and Prognostic (FD&P) system. Development of such system is challenging task that involves analysis of many hard hitting engineering problems across the board. In this paper we report progress in the development of FD&P for the re-contact fault between upper stage nozzle and the inter-stage caused by the first stage and upper stage separation failure. A high-fidelity models and analytical estimations are applied to analyze the following sequence of events: (i) structural dynamics of the nozzle extension during the impact; (ii) structural stability of the deformed nozzle in the presence of the pressure and temperature loads induced by the hot gas flow during engine start up; and (iii) the fault induced thrust changes in the steady burning regime. The diagnostic is based on the measurements of the impact torque. The prognostic is based on the analysis of the correlation between the actuator signal and fault-induced changes in the nozzle structural stability and thrust.
A Design for Availability Approach for Use with PHM
Authors: Jazouli Taoufik , Sandborn Peter
Published: March 2024

Prognostics and Health Management (PHM) methods are incorporated into systems for the purpose of avoiding unanticipated failures that can impact system safety, result in additional life cycle cost, and/or adversely affect the availability of the system. Availability is the probability that a system will be able to function when called upon to do so. A vailability depends on the system’ s reliability (how often it fails) and its maintainability (how efficiently and frequently it is pro-actively maintained, and how quickly it can be repaired and restored to operation when it does fail). Availability is directly impacted by the success of PHM. Increasingly, customers of critical systems are entering into “availability contracts” in which the customer either buys the availability of the system (rather than actually purchasing the system itself) or the amount that the system developer/manufacturer/supplier is paid for the system is a function of the availability achieved by the customer. Predicting availability based on known or predicted system reliability, operational parameters, logistics, etc., is relatively straightforward and can be accomplished using existing methods. However, while determining the availability that results from a set of events is straightforward, determining the events that result in a desired availability is not, and prediction of a system’s attributes to meet an availability requirement can only be accomplished using “brute force” search-based methods that are not general and become quickly impractical for real systems and when uncertainties are introduced. This paper presents a “design for availability” approach that starts with an availability requirement and uses it to predict the required logistics, design and operation parameters. The method is general and can be applied when the inputs to the problem are uncertain (even the availability requirement can be a probability distribution). The method is demonstrated on several examples with and without PHM.
Model-Based Assurance of Diagnostic Procedures for Complex Systems
Authors: Kurtoglu Tolga , Lutz Robyn , S. Feather Martin
Published: March 2024

Verifying diagnostic procedures for complex systems is hard and labor-intensive. Usually this verification is accomplished primarily through extensive review of the procedures by experts. We aim to augment this review process by using insights from comparing the diagnostic steps described in the procedural definitions with diagnostics information derived from existing models of the system. These comparisons offer various conformance checks between the manually developed diagnostic procedures and the diagnostic trees auto- generated from the diagnostic system models. We previously described our DTV (Diagnostic Tree for Verification) technique based on these comparisons. This paper describes an extension to DTV, and reports results of an application of DTV to a representative system’s diagnostic procedures. Specifically, it outlines four analyses (branch analysis, root cause coverage, path verification, and efficiency) that can be performed using DTV; illustrates the process for applying DTV; and reports results from our application of DTV to assure fifteen of the procedures developed for diagnosing problems in an electrical power system testbed for spacecraft.
Markov Modeling of Component Fault Growth Over A Derived Domain of Feasible Output Control Effort Modifications
Authors: Bole Brian , Goebel Kai , Vachtsevanos George
Published: March 2024

This paper introduces a novel Markov process formulation of stochastic fault growth modeling, in order to facilitate the development and analysis of prognostics-based control adaptation. A metric representing the relative deviation between the nominal output of a system and the net output that is actually enacted by an implemented prognostics-based control routine, will be used to define the action space of the formulated Markov process. The state space of the Markov process will be defined in terms of an abstracted metric representing the relative health remaining in each of the system’s components. The proposed formulation of component fault dynamics will conveniently relate feasible system output performance modifications to predictions of future component health deterioration.
Reliability Growth Analysis of Satellite Systems
Authors: W.Evans Dr.John , P.Kaminskiy Dr.Mark , D.GalloJr. Mr.Luis
Published: March 2024

A reliability trend/growth analysis methodology for satellite systems is suggested. A satellite system usually consists of many satellites successively launched over many years, and its satellites typically belong to different satellite generations. This paper suggests an approach to reliability trend/growth data analysis for the satellite systems based on grouped data and the Power Law (Crow-AMSAA) Non- Homogeneous Poisson process model, for both one (time) and two (time and generation) variables. Based on the data specifics, the maximum likelihood estimates for the Power Law model parameters are obtained. In addition, the Cumulative Intensity Function (CIF) of a family of satellite systems was analyzed to assess its similarity to that of a repairable system. The suggested approaches are illustrated by a case study based on Tracking and Data Relay Satellite System (TDRSS) and Geostationary Operational Environmental Satellite (GOES) data.
Experimental Tests of Wind Turbine Main Shaft Motion on a Laboratory Test Rig
Authors: Lutschinger Dirk , Howard Ian
Published: March 2024

This paper introduces research and discusses findings dealing with failure modes of gearboxes in wind turbines. These gearboxes fail in general after five years which is far below the expected design life of twenty years of a wind turbine. The research is taking a more holistic approach towards finding typical behaviour of the main shaft taking the transient nature of the wind into consideration. In this research, a small scale wind turbine test rig has been designed and manufactured with displacement sensors installed to observe the displacement of the main shaft at specific points, namely the main bearing locations of the forward framework of a wind turbine nacelle, where the main shaft is installed. The experimental data measured from the test rig is being analysed with common beam bending, statistical and fatigue theories to draw conclusions for long term loading in service. Aspects of the turbulent nature of the wind driving the wind turbine have been taken into consideration as being part of the aerodynamic loading onto the rotor and eventually the gearbox, transmitted through the main shaft. The purpose of the test rig at this stage is to obtain a quantitative insight into the motion of the main shaft. The deliberately chosen softer aluminum material and the more slender geometry for the components should provide exaggerated displacements which help to make motion and deformations more obvious. At this point, no resemblance to real size wind turbines has been established.
Fault Detection and Isolation for Autonomous Parafoils
Authors: R. Stoeckle Matthew , Fejzic Amer , S. Breger Louis , P. How Jonathan
Published: March 2024

Autonomous precision airdrop systems are widely used to de- liver supplies to remote locations. Payloads that are delivered far from their intended targets or with high impact velocity may be rendered unusable. Faults occurring during flight can severely degrade vehicle performance, effectively nullifying the value of the guided system, or worse. Quickly detecting and identifying faults enables the choice of an appropriate recovery strategy, potentially mitigating the consequences of an out-of-control vehicle and recovering performance. This paper presents a multi-observer, multi-residual fault detection and isolation (FDI) method for an autonomous parafoil system. The detection and isolation processes use residual signals generated from observers and other system models. statistical methods are applied to evaluate these residuals and determine whether a fault has occurred, given a priori knowledge of system uncertainty characteristics. Several examples are used to illustrate the detection and isolation algorithm on- line using available navigation and telemetry outputs. Tests of this FDI method on a large number of high-fidelity simulations indicate that it is possible to detect and isolate some common faults with a high percentage of success and a very small chance of raising a false alarm.
SIL/HIL Replication of Electric Aircraft Powertrain Dynamics and Inner-Loop Control for V&V of System Health Management Routines
Authors: Bole Brian , Teubert Christopher , Chi Quach Cuong , Hogge Edward , Vazquez Sixto , Goebel Kai , Vachtsevanos George
Published: March 2024

Software-in-the-loop and hardware-in-the-loop testing of failure prognostics and decision making tools for aircraft systems will facilitate more comprehensive and cost-effective testing than what is practical to conduct with flight tests. A framework is described for the offline recreation of dynamic loads on simulated or physical aircraft powertrain components based on a real-time simulation of airframe dynamics running on a flight simulator, an inner-loop flight control policy executed by either an autopilot routine or a human pilot, and a supervisory fault management control policy. The offline testing framework is described for the example of battery charge depletion failure scenarios onboard a prototype electric unmanned aerial vehicle.
State of Charge Estimation of Lithium-ion Batteries Considering Model and Parameter Uncertainties
Authors: Xi Zhimin , Jing Rong , Guang Yang Xiao , Decker Ed
Published: March 2024

Up to date, model and parameter uncertainties are generally overlooked by majority of researchers in the field of battery study. As a consequence, accuracy of the SOC estimation is dominated by the model fidelity and may vary from cell-to- cell. This paper proposes a systematic framework with associated methodologies to quantify the battery model and parameter uncertainties for more effective battery SOC estimation. Such a framework is also generally applicable for estimating other battery performances of interest (e.g. capacity and power capability). There are two major benefits using the proposed framework: i) consideration of the cell-to-cell variability, and ii) accuracy improvement of the low fidelity model comparable to the high fidelity without scarifying computational efficiency. One case study is used to demonstrate the effectiveness of the proposed framework.
Simple Metrics for Evaluating and Conveying Prognostic Model Performance To Users With Varied Backgrounds
Authors: E. Sharp Michael
Published: March 2024

The need for standardized methods for comparison and evaluation of new models and algorithms has been known for nearly as long as there has been models and algorithms to evaluate. Conveying the results of these comparative algorithms to people not intimately familiar with the methods and systems can also present many challenges as nomenclature and relative representative values may vary from case to case. Many predictive models rely primarily on the minimization of simplistic error calculation techniques such as the Mean Squared Error (MSE) for their performance evaluation. This, however, may not provide the total necessary information when the criticality, or importance of a model’s predictions changes over time. Such is the case with prognostic models; predictions early in life can have relatively larger errors with lower impact on the operations of a system than a similar error near the end of life. For example, an error of 10 hours in the prediction of Remaining Useful Life (RUL) when the predicted value is 1000 hours is far less significant than when the predicted value is 25 hours. This temporality of prognostic predictions in relation to the query unit’s lifetime means that any evaluation metrics should capture and reflect this evolution of importance. This work briefly explores some of the existing metrics and algorithms for evaluation of prognostic models, and then offers a series of alternative metrics that provide clear and intuitive measures that fully represent the quality of the model performance on a scale that is independent of the application. This provides a method for relating performance to users and evaluators with a wide range of backgrounds and expertise without the need for specific knowledge of the system in question, helping to aid in collaboration and cross-field use of prognostic methodologies. Four primary evaluation metrics can be used to capture information regarding both timely precision and accuracy for any series or set of prognostic predictions of RUL. These metrics, the Weighted Error Bias, the Weighted Prediction Spread, the Confidence Interval Coverage, and the Confidence Convergence Horizon are all detailed in this work and are designed such that they can easily be combined into a single representative “score” of the overall performance of a prediction set and by extension, the prognostic model that produced it. Designed to be separately informative or used as a group, this set of performance evaluation metrics can be used to quickly compare different prognostic prediction sets not only for the same corresponding query set, but just as simply from differing query data sets by scaling all predictions and metrics to relative values based on the individual query cases.
Ensemble classifiers for drift detection and monitoring in dynamical environments
Authors: Khamassi Imen , Sayed-Mouchaweh Moamar , Hammami Moez , Ghédira Khaled
Published: March 2024

Detecting and monitoring changes during the learning process are important areas of research in many industrial applications. The challenging issue is how to diagnose and analyze these changes so that the accuracy of the learning model can be preserved. Recently, ensemble classifiers have achieved good results when dealing with concept drifts. This paper presents two ensembles learning algorithms BagEDIST and BoostEDIST, which respectively combine the Online Bagging and the Online Boosting with the drift detection method EDIST. EDIST is a new drift detection method which monitors the distance between two consecutive errors of classification. The idea behind this combination is to develop an ensemble learning algorithm which explicitly handles concept drifts by providing useful descriptions about location, speed and severity of drifts. Moreover, this paper presents a new drift diversity measure in order to study the diversity of base classifiers and see how they cope with concept drifts. From various experiments, this new measure has provided a clearer vision about the ensemble’s behavior when dealing with concept drifts.