bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of work motivation on the performance of employees in a public company
Authors: Buelna-Peñuñuri Ramiro Arnoldo , Castro-Espino Ana Paz , Valdez-Pineda Dina Ivonne , Ortega-Arriola Jorge
Published: March 2024

The objective of this research is to know if there is an influence of work motivation on the performance of its workers. An investigation was carried out on the concepts related to the subject of study, in which indications are reported that there is no motivation towards employees, which generates low performance. The importance of carrying out the study, the beneficiaries and the impact it could have for future research are mentioned. The research presented is of a quantitative type with a cross-sectional design and an instrument was applied through a non-probabilistic sampling for convenience to the company. The procedure that was carried out to obtain results was to request permission and authorization from the organization. Subsequently, a survey was applied in Google Forms to 100 collaborators, sent by WhatsApp. With SPSS, α and graphs of results were obtained; the most significant questions were: Do you instruct the trained personnel in the new processes? (70% agree), (23% disagree) and (7% indifferent); Does the pension they receive grant security in the future (60% agree), (23% disagree) and (17% indifferent). In conclusion, the company under study shows favorable results and can improve its organizational culture.
Degree of application of social responsibility by gender and age and educational level of the owners of the Mypes in Chihuahua City
Authors: Anchondo-Chavarría Guadalupe , Prieto-García Brenda , Gonzalez-Valverde Vivian Gabriela , Tintori-Lara Manuel
Published: March 2024

The present research has the objective to determine the degree of application of social responsibility in Micro and Small Enterprises (Mypes) in the city of Chihuahua, considering the variables of gender, age and academic level of the owners. For this investigation a quantitative method with a descriptive scope is employed, as this research seeks to specify the profiles (by gender and age) of Mypes owners in the city of Chihuahua and the degree of application of social responsibility in their companies. The design is cross-sectional. A random sample of 450 micro and small companies in the city is examined. The results allow gender and age to determine the degree of application of social responsibility in local businesses. This research has allowed us to determine the degree of social responsibility implemented in the companies of this city in relation to age, gender, and educational level. Among the findings, it was found that companies led by men and with a higher educational level are the ones where more social responsibility actions are implemented.
Comparative study of the effects caused by polymers, bubbles and surfactants in a turbulent flow
Authors: López Aguado-Montes José Luis , Rivera-López Jesús Eduardo , Arciniega-Martínez José Luis , Juarez-Navarro Carlos Alfonso
Published: March 2024

In the present work, the particle image velocimetry (PIV) technique was used to measure the velocity components in the direction normal and tangent to the wall to obtain average velocity fields, wall shear stresses, friction velocity, drag reduction and average deformation fields were obtained by adding bubbles (injected by electrolysis), polymer (WSR-301 polyox) and surfactant (cationic) and their bubble-polymer, bubble-surfactant and polymer-surfactant combinations at concentrations of 164 and 272 ppm in a water flow in a channel (2cm x 10cm x 160cm) with a Reynolds number of 5200. Increased levels of drag reduction were obtained when combining the techniques, for example in the bubbles with polymers (WSR - 301 polyox) combinations, drag reduction results of 82 and 93 % were obtained for the concentrations of 164 and 272 ppm respectively, While when the combinations of bubbles with surfactants were used, the results were 37 % for 164 ppm and only 16 % for 272 ppm, and for the combination of polymer with surfactant for 164 ppm the results were 47 % and for 272 ppm the drag increased by 25 %, possibly due to an incorrect preparation of the polymer or surfactant, which leads to the conclusion that the greatest synergistic benefit is presented when combining the drag reducing techniques of bubbles and polymers.
Comparison and interpretation of solarimetric station data (diffuse solar radiation, UVB radiation, temperature, and relative humidity) from January 2017 to November 2018 in Zacatecas
Authors: Berlanga-Moreno Edgar Dario , García-González Juan Manuel , González-Cabrera Adriana Elizabeth , Villegas-Martínez Rodrigo Cervando
Published: March 2024

In this research work, the data from the solarimetric station in Zacatecas during the period from January 2017 to November 2018 are compared and interpreted. The main objective is to analyze the climate and solar radiation characteristics in the region and identify possible correlations between variables. The methodology involved data collection using the solarimetric station and data processing in Excel. Hourly, daily, and monthly averages were calculated for diffuse solar radiation, UVB radiation, temperature, and relative humidity. In addition, graphs were generated using Excel, and two R codes were developed: one to obtain correlations among the analyzed variables and another to visualize the UVB index. This study provides a detailed analysis of climate data and solar radiation patterns in Zacatecas. The obtained results are relevant for the design and implementation of solar energy systems in the region and in areas with similar climatic conditions. In summary, this study compares and interprets the data from the solarimetric station in Zacatecas, aiming to understand the climate and solar radiation characteristics. The conducted analyses contribute to the development of solar energy strategies in Zacatecas and similar regions. solar radiation, climate analysis, Zacatecas.
Total harmonic distortion optimization in a seven level multilevel inverter by the random search heuristic algorithm
Authors: Gómez-Rosas Ana María , Torres-Cruz Nicolas , Joers-Delgado Carlos Alberto , Peña-Delgado Adrián Fermín
Published: March 2024

In this article, the random search heuristic optimization algorithm is proposed to guarantee that the voltage synthesized by a seven-level multilevel inverter contains the lowest possible total harmonic distortion. The algorithm in this work is presented as an alternative, simple, and easy-to-implement method for solving a set of transcendental mathematical equations of multilevel inverters. The obtained results demonstrate the algorithm's capability to solve the mathematical formulation that minimizes the total harmonic distortion. It is important to highlight that the algorithm was implemented in Matlab®, and the obtained results were validated in a simulation conducted in Simulink®. Equally and not less important, the results were physically implemented in a laboratory prototype of three integrated circuits with H-bridges containing insulated gate bipolar transistors.
Prediction of thermal infrared radiation using an artificial neural network applied to the projection and design of processes in renewable energies
Authors: Valencia-Tobías Francia Paulette , Merino Treviño Marco Antonio , García-Pérez Fatima Fernanda , Centeno-Sierra Mariana Soledad
Published: March 2024

This work aims to predict thermal infrared radiation in geographical areas where the necessary measurement devices are not available, through the design of an artificial neural network (RNA). The RNA uses the following variables as input data: specific humidity, relative humidity, ambient temperature, wind speed, and atmospheric pressure, it is important to mention that the sample of space of time is from, (1990 - 2019), they are data from Mexico City, as it is a metropolis with an extensive air quality database, which are obtained from two online tools developed by the National Aeronautics and Space Administration (NASA). In addition, thermal infrared radiation data from NASA are included, to validate the prediction made by the algorithm. Matlab was used to implement RNA, a multiplatform software that offers an integrated development environment with its own programming language. It is recognized for its computational ability and is considered a suitable tool for this purpose.
JURIDICAL REVIEW RESOLUTION OF TORT DISPUTES IN ARISAN ACTIVITIES
Authors: Khoirala Rossyita , Mahanani Anajeng Esri Edhi
Published: March 2024

Gathering activities are often carried out by the surrounding community which are unknowingly recognized as a form of agreement. Such as the gathering activity in Margomulyo Village, Tuban Regency, where the practice of the gathering agreement is carried out verbally based on a mutual agreement which gives birth to rights and obligations to be fulfilled. Wanprestasi, namely when the rights and obligations are not fulfilled properly which results in losses for other parties. This research method, namely empirical law, is the law of reviewing or looking at itself from outside elements (law) based on social phenomena in the real world (empirical) that influence legal behavior both personally and institutionally in society and institutions. law. The approach used in this study is a qualitative approach. Legal materials in research are primary legal materials, secondary legal materials, and tertiary legal materials. The results of the study can be concluded that the arisan agreement is verbalhas the legal force to bind the parties who make it, so that if a default occurs it can be used as a basis for declaring someone to have committed a wanprestasi. Meanwhile, settlement of default disputes can be resolved either through litigation or non-litigation.
JURIDICAL STUDY OF CHILDREN WHO WORK AS INFLUENCERS IN RECEIVING ENDORSEMENTS IN SOCIAL MEDIA
Authors: Nasanta Ester , Wahyudi Eko
Published: March 2024

Child influencers are a profession that can channel the talents and interests of the child in positive terms, one of which is by receiving endorsements. Endorsement is a support in the form of cooperation between companies and celebrities/influencers by promoting a product produced by the company and bound by a valid agreement. As in Indonesia, many public figures raise their children to become influencers from an early age. In this case, what is the view of the child influencer profession according to positive law in Indonesia, bearing in mind that there are frequent reports of public figures suspected of exploiting children and their legal protection for child influencers in receiving endorsements on social media in the event of data leakage and default, both from the company or from the endorser himself.

This study uses normative legal research methods, namely discussing the doctrine of legal facts, principles, norms, and principles in the science of law, which focuses on laws and regulations related to working children, electronic transaction systems, and child protection using a statutory approach. invitation or statue approach..

The results of this study explain the legal views regarding the child influencer profession according to positive law in Indonesia, which begins with the position of child influencers as endorsers, forms of legal violations that can occur when receiving endorsements on social media and legal protection efforts for child influencers as a whole. preventive and repressive.
IMPLEMENTATION OF PERMA NUMBER 1 OF 2016 CONCERNING MEDIATION IN SETTLEMENT OF INHERITANCE CASES IN SURABAYA RELIGIOUS COURT
Authors: Setiawan Baharudin , Waluyo
Published: March 2024

In this study, the authors used an empirical juridical method, namely research that aims to find out and analyze the implementation of Supreme Court Regulation Number 1 of 2016 concerning Mediation in the settlement of inheritance cases at the Surabaya Religious Court (Case Study: Application for Inheritance at the Surabaya Religious Court), and data sources were obtained from interviews with various parties related to the implementation of mediation at the Surabaya Religious Court, data obtained from the Surabaya Religious Court, legislation, and various literature.

The results of this study can be concluded that many inheritance cases in the Surabaya Religious Court have not succeeded in obtaining a peace certificate in the mediation process. Mediation has not been carried out optimally because there are still obstacles both from the Surabaya Religious Court and from external parties. These obstacles include mediators, parties, and attorneys. Based on the results of research conducted by the authors of the various inhibiting factors that arise in the mediation implementation process, there are still efforts that can be made. Efforts made include the parties and attorneys must have good faith in carrying out the mediation.
ANALYSIS OF FACTORS CONTRIBUTING TO WORK STRESS AMONG EXPATRIATE AIRLINES CREW IN SAUDI ARABIA
Authors: Molina Prima , Teresa  , V.V Satvika Maharani , E. Gunawan Fergyanto
Published: March 2024

Work stress can significantly impact the performance of cabin crew in the airline industry, potentially leading to job errors with critical implications for safety, a paramount concern in the industry. The research focuses on factors influencing work stress among cabin crew, providing a valuable reference for improving both service quality and safety in the industry. The potential key factors that affect work stress, including workload, cross-cultural adjustment, rotating work schedules, interpersonal relationships, organizational relationships, and physical demands, are established through extensive literature reviews. The relevant data were collected from a sample of cabin crews in Saudi Arabia representing various nationalities. The most pertinent factors for the problem setting are determined by applying a multivariate regression analysis, where the theoretical understanding is statistically verified. The analysis suggests that the theory is supported by the sample data with a fitness level of 0.85 in terms of the determination coefficient, implying strong materialization of the theory. Furthermore, the agreement between theory and reality is supported by the ANOVA and t-tests. The study concludes that workload is the most dominant factor affecting work stress, followed by organizational relationships and rotating work schedules. Statistically less significant factors include cross-cultural adjustment, interpersonal relationships, and physical demands.
Efektivitas Waktu Perubahan Perilaku Lanjut Usia Pengguna Gigi Tiruan Lengkap dengan Menggunakan Video Pembersihan Gigi Tiruan Lengkap
Authors: Falatehan Niko , Johannis Stefano D.
Published: March 2024

Abstract: Aging process brings about several problems, particularly in the realm of oral health inter alia tooth loss in elderly. Dental prosthetic treatments, such as complete denture treatment can be employed to restore aesthetic, masticatory, and phonetic functions. The timing of follow-up appointments significantly influences the success of complete denture treatments. This study aimed to determine the effectiveness of using educational videos of cleaning complete dentures on time of behavior change among the elderly residents at Panti Jompo Pusaka 41 Yayasan Al-Madiniyah. This was an experimental study with a cross-sectional design using a questionnaire consisting of 15 questions. The results obtained 22 elderlies as subjects. Data collection was performed four times: before the video intervention; control I (one day after the video intervention); control II (one week after control I); and control III (two weeks after control II). Changes in elderly behavior were tested using the Friedman test. The results showed that the most significant change of behavior was during control I, which was one day after receiving instructions in the form of a video. The Friedman test resulted in a p-value of 0.001. In conclusion, the best follow-up time that resulted in the most significant improvement in behavior is control I, which is one day after the administration of instructional videos.
Keywords: elderly; complete denture; control time; educational videos; behaviour
 
Abstrak: Bertambahnya usia akan menimbulkan beberapa permasalahan, khususnya di bidang kesehatan gigi dan mulut; salah satunya ialah kehilangan gigi pada kelompok lanjut usia (lansia). Pada kehilangan gigi dapat dilakukan perawatan gigi tiruan lengkap (GTL) untuk mengembalikan fungsi estetik, mastikasi, dan fonetik. Waktu kontrol memiliki pengaruh besar dalam keberhasilan perawatan GTL. Penelitian ini bertujuan untuk mengetahui efektivitas penggunaan video edukasi pembersihan GTL terhadap waktu perubahan perilaku lansia pengguna GTL di Panti Jompo Pusaka 41 Yayasan Al-Madiniyah. Jenis penelitian ialah eksperimental dengan desain potong lintang dan menggunakan kuesioner berisi 15 pertanyaan. Pengambilan data dilakukan sebanyak empat kali, yaitu sebelum diberikan video; kontrol I, sehari setelah pemberian video; kontrol II, satu minggu setelah kontrol I; dan kontrol III, dua minggu setelah kontrol II. Perubahan perilaku lansia diuji menggunakan uji Friedman. Hasil penelitian ini mendapatkan 22 lansia sebagai subjek penelitian. Perilaku lansia mengalami perubahan paling bermakna pada saat kontrol I dengan hasil uji p=0,001. Simpulan penelitian ini ialah waktu kontrol terbaik yang memberikan peningkatan perilaku paling bermakna ialah kontrol I, yaitu sehari setelah pemberian instruksi berupa video.
Kata kunci: lanjut usia; gigi tiruan lengkap; waktu kontrol; video edukasi
IMPLEMENTATION MULTI-CRITERIA DECISION MAKING FOR SUPPLIER SELECTION ALUMINUM INGOT IN CV. SL
Authors: Faqiha Selvy Athia
Published: March 2024

The purpose of this study is to determine the priority order of the criteria, sub- criteria, then determine which suppliers CV SL company can choose. The population in this study is the decision maker and management of CV SL.The sampling technique used was purposive sampling in order to obtain 7 people. The data analysis technique in this study used the Analytical Hierarchy Process (AHP), while the analytical tool used was expert choice 11. The results of the analysis of this study obtained the importance weight of the criteria with the first priority is quality (0.34), price (0.26) , availability (0.15), delivery (0.12), performance history (0.07), warranty & complaint service (0.06). Meanwhile, the results of the assessment of the importance of alternatives in supplier selection show that the LN supplier (0.0786) has the highest weight, the two IS suppliers (0.0760), the three MJ suppliers (0.0733), the four TL suppliers (0.0711), the fifth supplier FI (0.0703), the sixth supplier LM (0.0684). The results of this calculation can be used by the company as a consideration in determining the next supplier selection policy.
PENGARUH SOFT SKILL, HARD SKILL DAN MEDIASI BUDAYA ORGANISASI TERHADAP KAPABILITAS INOVASI DOSEN
Authors: Nur Layli Fatikhatun Nissa  , Larassaty Ayu Lucy
Published: March 2024

Penelitian ini bertujuan mengukur pengaruh soft skill dan hard skill terhadap kemampuan inovatif dosen Universitas Nahdlatul Ulama Sidoarjo yang dimediasi oleh budaya organisasi. Menerapkan jenis penelitian kuantitatif dengan cara purposive sampling melalui penyebaran kuisioner terhadap dosen PGSD di Universitas Nahdlatul Ulama Sidoarjo yang kemudian diolah menggunakan SmartPLS. Dari hasil penelitian diketahui bahwa soft skill tidak berpengaruh terhadap kapabilitas inovasi dosen. Hard skill tidak berpengaruh terhadap kapabilitas inovasi dosen. Kapabilitas inovasi dosen berpengaruh terhadap budaya organisasi. Fenomena dalam penelitian ini yaitu bagaimana dosen dalam meningkatkan kreativitas dan menciptakan ide-ide pembelajaran baru yang dapat memperkaya pengalaman belajar mahasiswa.
PENGARUH CUSTOMER SERVICE DAN WORD OF MOUTH TERHADAP MINAT BELI KONSUMEN AL AZIZIAH TOUR AND TRAVEL
Authors: Baladhika Nicole Kansa Kostra , Syahputra Syahputra
Published: March 2024

After the end of the Covid-19 pandemic, the world economy began to show signs of improvement with economic growth in various countries. The economic growth then triggered business development in Indonesia which occurred in various sectors, including the tourism and service sectors such as Hajj and Umrah travel agency companies. With such high competition, Umrah travel organizers need an appropriate way to compete. One of the efforts that can be carried out to compete is to improve the quality of marketing. In obtaining consumers, one of the crucial aspects to keep in mind is the buying interest of Umrah pilgrims, because it can play a role in the success of the Umrah travel agency business. One of the aspects that have an impact on buying interest is service quality, including the customer service section or more commonly referred to as customer service and verbal word of mouth communication or commonly referred to as word of mouth. This study was conducted on Al Aziziah Tour and Travel. Al Aziziah Tour and Travel is a travel agency that organizes umrah in Indonesia. It was founded in 2013 and is headquartered in Bekasi. The purpose of this study is to examine the influence of customer service and word-of-mouth on Al Aziziah's customer purchase intention. A quantitative approach based on a descriptive causal research type was used in this investigation. A total of 325 participants were polled using a non-probability sampling technique. Descriptive statistics and multiple linear regression were employed for data analysis. The data were processed using SPSS Version 23 software. The findings revealed that the customer service factor exhibited a positive and noteworthy impact on purchase intention, with a significance level of 0.000, indicating its significance at a 5% level of significance. The t-value of 7.122 surpassed the t-table value of 1.967. Similarly, the word-of-mouth variable demonstrated a positive and significant influence on purchase intention, with a significance level of 0.000, also surpassing the t-table value with a t-value of 7.435. When considered simultaneously, both customer service and word of mouth significantly affected purchase intention, with a significance level of 0.000 and an F-value of 171.302, exceeding the F-table value of 3.0237. The combined influence of the independent variables, word of mouth, and customer service, accounted for 51.6% of the variation in purchase intention, while the remaining 48.4% was attributed to unexamined factors in this research.
HONOUR KILLING AND CRIMINAL JUSTICE SYSTEM IN PAKISTAN
Authors: Ghazi Aqsa , Farooq Salamat Umar
Published: March 2024

This article examines the factors that contribute to gender inequality and violence against women in Punjab, Pakistan. It focuses on District Gujranwala and examines patriarchal power structures, cultural norms, and restrictive gender roles. The article analyzes court decisions in District Gujranwala from 2012 to 2023, which show a high number of acquittals, mostly because of retracted eyewitness testimony. We argue that despite statutory reforms, there exists an over-reliance on visual evidence that undermines justice. We suggest that a comprehensive policy is needed that challenges cultural norms, advances gender equality, fortifies legal frameworks, and reforms investigation and prosecution techniques to effectively prevent honour killings and increase conviction rates.
FIXING THE CHAIN: THE DATA ENRICHMENT CYCLE IN PROGNOSTIC HEALTH MONITORING
Authors: Akkermans Henk , Kempen Paul van
Published: March 2024

Only a very modest percentage of maintenance of capital goods is done condition-based, as opposed to plan-based or corrective. Doing much more would be very beneficial from a safety and operations perspective. Moreover, the basic methods have been known for some time. This paper addresses the question that, if condition-based maintenance (CBM) or Prognostic Health Management (PHM), as the terms commonly used to denote the same maintenance policy, is so logical and beneficial, why is it currently not more often applied in practice?This paper suggests that the answer lies in a complex interplay of technical and organizational issues. This interplay is best conceptualized as a data enrichment  chain, which starts and ends at the physical asset to be maintained and ends at the actual prognostic maintenance being executed and evaluated. This chain is described in more detail, and illustrated with examples from an open innovation project in the process industry in the Netherlands, the CAMPIONE fieldlab. From this description, it becomes evident that this chain is currently broken in many places. If CBM/PHM is to become more established as a business practice, these breaks will need to be fixed. The paper discusses several of the options of how to fix this data enrichment chain in practice.
Qualitative Fault Isolation of Hybrid Systems: A Structural Model Decomposition-Based Approach
Authors: Bregon Anibal , Daigle Matthew , Roychoudhury Indranil
Published: March 2024

Quick and robust fault diagnosis is critical to ensuring safe operation of complex engineering systems. A large number of techniques are available to provide fault diagnosis in systems with continuous dynamics. However, many systems in aerospace and industrial environments are best represented as hybrid systems that consist of discrete behavioral modes, each with its own continuous dynamics. These hybrid dynamics make the on-line fault diagnosis task computationally more complex due to the large number of possible system modes and the existence of autonomous mode transitions This paper presents a qualitative fault isolation framework for hybrid systems based on structural model decomposition. The fault isolation is performed by  analyzing the qualitative information of the residual deviations. However, in hybrid systems this process becomes complex due to possible existence of observation delays, which can cause observed deviations to be inconsistent with the expected deviations for the current mode in the system. The great advantage of structural model decomposition is that (i) it allows to design residuals that respond to only a subset of the faults, and (ii) every time a mode change occurs, only a subset of the residuals will need to be reconfigured, thus reducing the complexity of the reasoning process for isolation purposes. To demonstrate and test the validity of our approach, we use an electric circuit simulation as the case study.
Twin-Control: A New Concept Towards Machine Tool Health Management
Authors: Armendia Mikel , Peysson Flavien , Euhus Dirk
Published: March 2024

Twin-Control (http://twincontrol.eu/) is a new concept for machine tool and machining process performance optimization. It is based on a new simulation model that integrates the different aspects that affect machine tool and machining performance. This holistic approach will allow a better estimation of machining performance than single featured simulation packages, including lifecycle concepts like energy consumption and end-life of components.This theoretical representation of the machine is complemented with real process data by the monitoring of the most important variables of the machining process and machine condition. This monitored information, combined with the developed models, is used at machine level to perform model-based control actions and/or warn about damaged components of the machine tool. In addition, a fleet-level data management system is used for a proper health management and optimize the maintenance actions on the machine tools.
ADEPS: A Methodology for Designing Prognostic Applications
Authors: Aizpurua Jose Ignacio , Catterson Victoria M.
Published: March 2024

Prognostics applications predict the future evolution of an asset under study, by diagnosing the actual health state and modeling the future degradation. Due to rapidly growing interest in prognostics, different prediction techniques have been developed independently without a consistent and systematic design. In this paper we formalize the prognostics design process with a novel methodology entitled ADEPS (Assisted Design for Engineering Prognostic Systems). ADEPS combines prognostics concepts with model-based safety assessment, criticality analysis, knowledge engineering and formal verification approaches. The main activities of ADEPS include synthesis of the safety assessment model from the design model, prioritization of the system failure modes, systematic prognostics model selection and verification of the adequacy of the prognostics results with respect to design requirements. By linking system-level safety assessment models and prognostics results, design and safety models are updated with online information about different failure modes. This step enables system-level health assessment includingprognostics predictions of different failure modes. The endto-end application of themethodology for the design and evaluation of a power transformer demonstrates the benefits of the proposed approach including reduced design time and effort, complete consideration of prognostics algorithms and updated system-level health assessment.
Condition Based Reliability, Availability, Maintainability, and Safety (CB-RAMS) model: Improving RAMS predictions by combining condition-monitoring (CM) data with RAMS calculations
Authors: Shalev Dan M. , Tiran Joseph , Katoshevski David , Bortman Jacob
Published: March 2024

The goal of this paper is to present a practical method for the enhancement of systems Reliability, Availability, Maintainability, and Safety (RAMS) assessments. During the last decades Condition Monitoring (CM) methods have been improved and extensively implement. A method for integration the CM data with RAMS calculations is suggests. Implementing the method as a practical tool and updating RAMS prognostics assessment according to deterioration condition, is demonstrated by examples that emphasize the method’s contribution and advantages. The method is basedon conducting correlations between deterioration stages and Remaining Useful Life. Reliability is continuously updated according to pre-calculated Weibull parameters based on historic deterioration stages accumulated data and concurrent CM findings. The updated assessment represents the real system condition along its deterioration stages. The method enables improved decision making operation and maintenance action thus lower the Life Cycle Cost (LCC). The method named "Condition Based-RAMS" (CB-RAMS). Analyzing systems by CB-RAMS in conjunction with Monte-Carlo Simulation software tool, and CM data, is a practical and efficient method to eliminate surprising dangerous and costly events. The paper introduces the method and improvements that are achievable by implementing it. The contribution of the paper is the applicable detailed procedure to use any sort of CM data to enhance his RAMS predictions. The significance of this paper is that presented approach will enhance the importance of implementing CM on systems to lower LCC and increase safety.
Diagnosis of bearing creep in wind turbine gearboxes
Authors: Skrimpas Georgios Alexandros , Liu Zhenyan , Hilmisson Reynir , Sweeney Christian Walsted , Holboell Joachim
Published: March 2024

One of the most wide spread gearbox topologies in the wind energy sector consists of a slow rotating planetary stage, an intermediate speed parallel stage and finally a high speed parallel stage driving the generator rotor. The shafts of the two latter stages are supported by ball or roller bearings where their outer races are fixed to the gearbox and their inner races rotate at the corresponding shaft speed. Bearing inner race defects are frequently encountered in gearboxes leading to either replacement of the whole unit or exchange of the shaft or bearing where feasible. The present work deals with the evaluation of the development of an inner race defect from surface pitting to race axial crack resulting in excessive rotational looseness, also referred to as bearing creep. It is shown that an inner race defect can be identified efficiently at an early stage by employing well known vibration condition indicators, e.g. crest factor, whereas development to rotational looseness is expressed as increased sideband activity between the gear mesh frequencies spaced at the shaft speed supported by the defective bearing due to abnormal meshing. The condition of the gears and the shaft during the final stage of the above described failure mode is essential in regards to the possibility of uptower repairs or their use in refurbished gearboxes. Case studies from operating multi-megawatt wind turbines are presented, illustrating the progression of the fault via continuous trending of condition indicators and detailed spectral analysis of high resolution vibration signals.
Equipment diagnostics based on comparison of past abnormal behaviors using a big data platform
Authors: MAI Carole , CHEVALIER Robin
Published: March 2024

Nuclear monitoring systems provide an increasing amount of realtime measurements to analyse equipment condition. Storage, retrieval, and effective use of information must therefore be made as efficient as possible in order to achieve reliability goals and additional reductions in operating costs. Combining them with other data sources like equipment characteristics, maintenance logs and previous expertise reports will help make better diagnostics while minimizing the time dedicated to an analysis hence leading to better maintenance decisions. This paper presents an overview of the project under study at EDF to develop a case based reasoning platform enabling experts to efficiently retrieve similarities between past events and the current situation. Several technical barriers are encountered such as the comparison of multidimensional time series, of textual information and the extraction of signal features. The problem is here framed as a pattern classification problem where the classes correspond to equipment faults. Similarity criteria have been defined and evaluated against nuclear power plants data for the diagnosis of abnormal patterns on critical equipment. The classification results are compared with service and expertise reports using clustering and classification algorithms. The prospect of this diagnosis is to support the adjustment of maintenance schedule by estimating the remaining useful life of critical equipment.
Benefits Analysis of Prognostics & Health Monitoring to Aircraft Maintenance using System Dynamics
Authors: Hussain Yameen M. , Burrow Stephen , Henson Leigh , Keogh Patrick
Published: March 2024

The benefits of applying Prognostics & Health Monitoring (PHM) techniques to Aircraft Maintenance are evaluated using System Dynamics (SD). It is well known that a key motivation for PHM is to increase aircraft availability by reducing unscheduled removals and downtime, ultimately reducing Direct Maintenance Costs (DMC). The benefits to aircraft maintenance are tested by modelling two maintenance philosophies using SD: the traditional approach driven by scheduled & reactive maintenance; and through Condition Based Maintenance (CBM) by considering PHM functionality in maintenance practice. The study is focused on an Electromechanical Actuator (EMA) for an aircraft flight control system across a fleet of 25 aircraft over an 8 year maintenance overhaul period. The study indicated there were fewer unscheduled removals as a result of CBM in comparison to the traditional approach. Further sensitivity studies on varying degradation patterns led to instability in maintenance planning with more reactive maintenance due to more abrupt failures of the EMA. The cost effectiveness of CBM as a function of PHM efficiency is demonstrated through DMC accumulation where it was found that CBM is no longer cost-beneficial when over 85% of the EMA life has been used. Overall, the SD models presented a general level of systems understanding of the causalities that are inherent within the two maintenance policies and are a useful methodology to consider PHM benefits through analysing the impact of different policies on the system behaviour.
Influence of Environmental Loading Factors on System Design
Authors: Conroy Paddy , Stecki Jacek , Thorn Andrew
Published: March 2024

A closed-loop, iterative FMEA/FMECA process is vital for a safe design, but the challenge is in performing these analyses in such a way that alternate scenarios can be rapidly considered, and changes implemented to improve the design. This paper identifies an explicit model-based method to optimise system design by linking the failure identification process to specific operating scenarios and environmental conditions (Environment Loading Factors (ELF)). Current methods exist to define operating scenarios for FMEA/FMECA, but are limited by the lack of connectivity and traceability between the two. Without connectivity a failure mode analysis is limited in scope, and emergent scenarios cannot be easily understood without repeating the entire analysis process. This paper outlines a model-based method to define operating scenarios, each with a user defined Operating Environment (OE). The OE is defined by a set of Environmental Factors (based on a taxonomy) and is then used to modify the expected criticality of associated physical failures of the system. By linking physical failures to an operating scenario, changes to the operating scenarios can be made to automatically update and advise failure mode changes to the design FMEA/FMECA. The linkage can be used to explore a wider variety of operating conditions and use-cases, including the ability to perform trade studies to compare different environments and examine their impact on the design. By comparing and assessing operating environments concurrently in the design process, a safer and more robust design can be realised.
Towards the implementation of a predictive maintenance strategy: Lessons learned from a case study within a waste processing plant
Authors: Gebler Owen Freeman , Hicks Ben , Harrison Andrew , Barker Matt , Stirling Pete
Published: March 2024

Successful implementations of predictive approaches to maintenance are seeing an increasing level of reporting in literature. While much of this relates to high value manufacturing industries, such as Aerospace, the potential of these maintenance approaches within low-value processing industries, such as Waste Management, where system availability is also critical, is receiving increasing interest. However, these industries vary significantly in terms of the asset volumes handled, life costs, safety criticality and the sophistication of equipment/plant. Consequentially, the implementation of predictive maintenance in these contexts is likely to present different requirements. In order to understand the potential differences, this paper seeks to explore the potential issues/challenges for predictive maintenance in this context through a qualitative study of maintenance personnel within the Waste Management industry and reflections on the implementation o f a prototype condition monitoring system. The findings from these two aspects provide the basis for elicitation of a set of potentially generalizable issues for the processing industries, which it is proposed must be addressed before successful implementation of the technology can be realised. The main issues highlighted with predictive maintenance implementation within Waste Management plant concern industry characterisation, socio-technical and technical considerations, perceptions of value in predictive maintenance, measurement of maintenance performance and barriers to both implementing and realising beneficial and sustainable success of predictive maintenance.
NARX Time Series Model for Remaining Useful Life Estimation of Gas Turbine Engines
Authors: Bektas Oguz , Jones Jeffrey A.
Published: March 2024

Prognostics is a promising approach used in condition based maintenance due to its ability to forecast complex systems' remaining useful life. In gas turbine maintenance applications,data-driven prognostic methods develop an understanding of system degradation by using regularly stored condition monitoring data, and then can automatically monitor and evaluate the future health index of the system. This paper presents such a technique for fault prognosis for turbofan engines. A prognostic model based on a nonlinear autoregressive neural network design with exogenous input is designed to determine how the future values of wear can be predicted. The research applies the life prediction as a type of dynamic filtering, in which training time series are used to predict the future values of test series. The results demonstrate the relationship between the historical performance deterioration of an engine's prior operating period with the current life prediction.
The Backlash Gap size Estimation for Electromechanical Actuator in an Operational Behavior
Authors: Mansouri Badr , Piaton Jerome , Guyamier Alexandre
Published: March 2024

More electric aircraft are lighter and more energy efficient than conventional aircraft. Hence, the design of electromechanical devices and its preventive maintenance strategies are in increasing need and challenge for flight control systems. One of the most significant mechanical parameter for aging is the backlash gap size. Hence, it presents a good indicator for failure detection, diagnosis and prognostic. In this work, an estimation method of this parameter is proposed for any electromechanical actuator (EMA); rotary or linear with roller screw or ball screw, used to actuate any flight control surface of the aircraft; flaps, ailerons…etc. This method presents a simple and easy technique for implementation in real time based on a Linear Kalman Filtering (LKF).
Towards a model-based condition assessment of complex marine machinery systems using systems engineering
Authors: Zymaris Alexandros S. , Alnes Øystein Åsheim , Knutsen Knut Erik , Kakalis Nikolaos M.P.
Published: March 2024

In the present paper, a systems engineering methodology is presented for the analysis and condition assessment of complex marine machinery systems. Two important characteristics of these systems are (i) that they comprise of a multitude of subcomponents which influence the overall system condition/performance and (ii) the continuously varying operating and environmental conditions. The methodology presented herein is capable to evaluate the system level effects of component degradation and faulty states under realistic system operation. By virtue of this, it is employed along with sensor signal data for the identification of degraded states and the allocation of the problem to specific system components. The modelling platform used in this work is the DNVGL COSSMOS (Complex Ship System Modelling & Simulation).At the methodological level, an automated model-based sensitivity analysis is conducted with respect to a set of component degradation/failure modes. The latter is used along with a clustering algorithm for the precise allocation of the failure to specific components and system particulars. The selected case-study is the Diesel-electric marine propulsion system of a 2300 tonnes DWT (deadweight tonnage) anchor handling vessel embedded with its cooling network. Based on the results, the approach is capable to successfully identify faults at various subcomponents of the cooling network system including pumps, regulating valves, heat exchangers and piping. Due to the fact that the system is treated in an integrated manner, a fault can be identified in a component using sensor signals placed in other system locations.
Vibration-based bearing fault detection on experimental wind turbine gearbox data
Authors: Peeters Cédric , Guillaume Patrick , Helsen Jan
Published: March 2024

Rolling element bearing faults are one of the most common defects in rotating machinery. The detection of these faults has lately attracted an increasing amount of attention in the industry. Detecting the faults in their incipient phase can prevent a more catastrophic breakdown of a machine and can save a company time and money. An often occurring problem in analyzing vibration measurements of a rotating machine is the presence of harmonic signal components originating from different machine parts. This paper focuses on separating the bearing fault signals from other masking signal content coming from elements like gears or rotating shafts. The separation is based on the assumption that signal components of gears or shafts are deterministic and appear as clear peaks in the frequency spectrum, whereas bearing signals are stochastic due to random jitter on their fundamental period and can be classified as cyclostationary. A technique that has recently gained more attention for separating these two types of signals is the cepstral editing procedure (CEP). This preprocessing method is investigated further in this paper as an automated procedure. The cepstral editing procedure makes use of the fact that deterministic components appear in the cepstrum as narrow peaks and removal of these cepstral peaks reduces the amplitude of the corresponding discrete components. The residual stochastic signal after cepstral editing should consist mainly out of bearing fault signals in certain frequency bands. To analyze the residual signal the squared envelope spectrum is examined. The issue of selecting the proper frequency band where to demodulate the signal necessary for enveloping is addressed through the use of spectral kurtosis. The performance of the developed methods will be validated on experimental data from the National Renewable Energy Laboratory (NREL). This data has been made available by NREL in the context of the wind turbine gearbox condition monitoring round robin study. As such other research teams from around the world have analyzed this data as well and published their findings. The measurements were done on a wind turbine gearbox in a healthy and damaged condition and the setup is documented extensively, making it well suited fora performance comparison. A summary of the findings on the NREL data is discussed in this paper.
Maintenance optimization of an aircraft fleet considering IVHM based on cost and availability considering the use of additive manufacturing
Authors: Cubillo Adrian , Perinpanayagam Suresh , Esperon-Miguez Manuel
Published: March 2024

PHM and Integrated Vehicle Health Management (IVHM) are extensive areas of research. Whereas a lot of work has been done in diagnostics and prognostics, the economic viability is also an important aspect. The availability of aircraft in the aerospace sector is a critical factor; thus, cost and downtime are the main parameters to assess the impact of IVHM. Additionally, new technologies such as additive manufacturing have the potential to become standard repair procedures and its viability also has to be assessed. However, to accurately study the impact of these factors the particularities of the aerospace sector have to be taken into account. Several systems of the aircraft are considered as part of a single Line Replaceable Unit (LRU) that is replaced, and later repaired in the workshop without affecting the availability of the aircraft when a subcomponent fails; whereas other parts can be repaired while the aircraft is on the ground and assembled again in the same aircraft. This aspect affects the cost and downtime, and also has to be taken into account to assess the viability of any new technology or IVHM system.This paper describes an extensive cost and downtime model to take into account all these scenarios including the impact of using different types of IVHM systems. The impact of IVHM and new repair technologies are discussed comparing maintenance cost and downtime of parts of LRUs and parts repaired on the ground.