bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing Acoustic Data Mobilization: A User-Friendly Data Platform for the Asian Soundscape Monitoring Network
Authors: Lee Chia-Yun , Lee Jin-Ying , Tuanmu Mao-Ning
Published: October 2024

Passive Acoustic Monitoring (PAM) has emerged as a crucial tool in monitoring efforts to track environmental changes and evaluate conservation measures in response to the biodiversity crisis (Sugai et al. 2018). PAM now offers long-term and continuous insights into biodiversity, using acoustic indices correlating with biodiversity and deep-learning tools to aid in the detection and identification of animal sounds (Sueur et al. 2014, Kahl et al. 2021, Wu et al. 2022). However, managing and mobilizing original recordings remains challenging due to their large size and lack of structure, hindering broader applications of these valuable data. Established in 2014 by Academia Sinica and Taiwan Forestry Research Institute, the Asian Soundscape Monitoring Network has amassed over 20 million minutes of audible and ultrasonic recordings from diverse landscapes, including forests, wetlands, urban parks and farmlands across Malaysia, Thailand, Taiwan and Vietnam. To enhance data mobilization and utilization, we developed a user-friendly data platform enabling browsing, searching, visualization, exploration and retrieval of the original recordings (Fig. 1), as well as derived data such as acoustic indices and species occurrences, and associated weather records (Fig. 2) The platform also allows users to visualize the temporal dynamics of the soundscape and identify acoustic events at monitoring sites by examining long-term spectrograms and time series of acoustic indices (Fig. 3). Detailed information about the monitoring sites and recorder deployment is provided. Each recording is tagged with a Creative Commons license, and a unique Archival Resource Key is assigned to every data retrieval for persistent identification, facilitating data reuse. Additionally, recordings containing human voices are identified and restricted to protect privacy. Our aim with this data platform is to streamline the mobilization of acoustic data, foster diverse applications, and enhance the overall value of the data.
Modelling of oxide fuel restructuring during first hours after a reactor reaches its power
Authors: Folomeev Vladimir I. , Ganina Svetlana M. , Astakhova Natalya E.
Published: October 2024

There is a substantial amount of experimental data that confirm the peculiarity of the oxide fuel behavior during the first hours after a reactor reaches its power. With an increase in temperature during the said period, oxide fuel pellets crack because of a significant temperature gradient. Further developments occur due to the accumulation and redistribution of fission products, and manifest themselves as changes in the fuel matrix porosity and the formation (or diameter increase) of a central hole. The zones that differ in their microstructure, density and thermal conductivity are formed along the fuel pellet radius. As the oxide fuel composition and restructuring result in its thermal conductivity change, it is important to pay attention to the formulas used in the stress-strain state calculations of a fuel element. The methodology for calculating changes in the oxide fuel porosity and the pellet’s internal diameter is proposed and based on the published research papers dedicated to the study of oxide fuel properties and behavior during the first hours after a reactor reaches its power. Тhe methodology was tested using real experimental data on the porosity redistribution along the fuel pellet radius. The presence and the size of the pellet’s inner hole, as well as changes in the fuel matrix porosity, have a noticeable effect on the maximum temperature value. Taking into account the pellet structure evolution while performing computational simulation of the fuel rod operation under irradiation allows assessing the fuel element’s operability more accurately. The proposed methodology can be used in computer codes designed to calculate the stress-strain state of cylindrical fuel elements of fast reactors.
Diagnosis and Treatment of Hematuria
Authors: Jung Jong Hwan
Published: October 2024

Hematuria is a common manifestation caused by various factors such as infection, inflammation, trauma, urinary stone and malignancy. Hematuria reflects pathological state of urinary system. Isolated microscopic hematuria without any abnormalities besides of hematuria on urine microscopic examination usually presents a good clinical course or outcome. However, significant proteinuria or hypertension, which accelerates renal dysfunction, can often develop during follow-up period in patients with isolated microscopic hematuria. Compared with non-glomerular hematuria, glomerular hematuria shows several characteristic findings such as dysmorphic red blood cell (RBC) or RBC casts or significant proteinuria on urinalysis. If glomerular hematuria is strongly suspected, a kidney biopsy may be required to differentiate the cause of glomerulonephritis. In this review, we tried to review the differential diagnosis and diagnostic approach and treatment of hematuria.
Optimizing Protection Against HPV-Related Cancer: Unveiling the Benefits and Overcoming Challenges of HPV Vaccination
Authors: Oliver Kristin , Shaw Jana , Suryadevara Manika , Stephens Ashley
Published: October 2024

Human papillomavirus (HPV) vaccine is an underutilized tool in cancer prevention. HPV vaccine completion rates in adolescents age 13 to 15 years remain low at 59%. The HPV vaccine can prevent more than 90% of cases of cancer caused by HPV, including cervical, oropharyngeal, anal, penile, vulvar, and vaginal. HPV vaccine is very safe and effective, as demonstrated by numerous large-scale studies. Practice-based strategies can improve vaccination rates, such as having providers give a strong presumptive recommendation for the vaccine, using motivational interviewing for hesitant families, and using electronic health record reminders to prompt providers to offer it, among other interventions. Offering HPV vaccine starting at age 9 years is another evidence-based strategy to improve HPV vaccine completion rates, which has been shown to be acceptable to both providers and parents.

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Pediatr Ann
. 2024;53(10):e372–e377.]
Intention Versus Implementation: Diversity, Equity, Inclusion, and Justice Efforts at Your Clinical Practice
Authors: Orionzi Bako
Published: October 2024

Diversity, equity, inclusion, and justice (DEIJ) are important factors to be considered in medical education, academic and community health centers, and health care policy. DEIJ efforts have been shown to have a strong influence in advancing health equity, yet these efforts tend to fall on a small group of providers, usually of historically marginalized or minority backgrounds (eg, race and ethnicity, gender identity, sexual orientation, religion). To combat this inequity, more research needs to be done to identify where the burden is falling and what strategies can be set in place to counteract this taxing imbalance. Providers should educate themselves on the anti-DEIJ legislation sweeping across the country, recogniz- ing the misinformation, and advocating for efforts pushing back against this movement. Providers can also advocate for ways their institution or practice can reduce the burden for historically marginalized providers by supporting recognition of DEIJ-related efforts in traditional promotional measures or taking on activities allowing for participation in scholarly work that will advance careers.

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Pediatr Ann
. 2024;53(10):e354–e357.]
Hepatitis-B disease modelling of fractional order and parameter calibration using real data from the USA
Authors: Yavuz Mehmet , Akyüz Kübra , Bayraktar Naime Büşra , Özdemir Feyza Nur
Published: October 2024

In this paper, a new mathematical model of Hepatitis B is studied to investigate the transmission dynamics of the Hepatitis B virus (HBV). Many diseases can start from the womb and find us humans throughout our lives. These diseases are specific abnormal conditions that negatively affect the structure or function of all or part of an organism and do not suddenly occur in any region due to external injury. In this study, we focus on HBV, and we state the graphics, interpretations, and detailed information about the disease and the newly established mathematical model of the disease. A fractional order differential equation system with a memory effect is used to model anomalous processes and to understand the effect of past infection events on the future spread dynamics of the system. In the model, susceptible, latent, acute, carrier, and recovered populations are taken into account by considering vertical transmission, which provides information about the inter-generational course of the disease. However, the migration effect is also used in the model due to the risk of disease transmission and increased migration in recent years. The course of the disease is examined using real data from the USA. Moreover, the model's positivity and boundedness are studied, and the equilibrium points are calculated. Additionally, the stability conditions for the disease-free equilibrium (DFE) are stated. A parameter calibration technique is used to determine the most accurate parameter values in the model. Finally, we provide numerical results and their biological interpretations to estimate the future course of the disease. The paper addresses the current migration problem with the migration parameter in the model. These differences from the literature can be regarded as important novelties of the paper.
Predictive analysis of doubly Type-Ⅱ censored models
Authors: Jeon Young Eun , Kim Yongku , Seo Jung-In
Published: October 2024

The application of a doubly Type-Ⅱ censoring scheme, where observations are censored at both the left and right ends, is often used in various fields including social science, psychology, and economics. However, the observed sample size under this censoring scheme may not be large enough to apply a likelihood-based approach due to the occurrence of censoring at both ends. To effectively respond to this difficulty, we propose a pivotal-based approach within a doubly Type-Ⅱ censoring framework, focusing on two key aspects: Estimation for parameters of interest and prediction for missing or censored samples. The proposed approach offers two prominent advantages, compared to the likelihood-based approach. First, this approach leads to exact confidence intervals for unknown parameters. Second, it addresses prediction problems in a closed-form manner, ensuring computational efficiency. Moreover, novel algorithms using a pseudorandom sequence, which are introduced to implement the proposed approach, have remarkable scalability. The superiority and applicability of the proposed approach are substantiated in Monte Carlo simulations and real-world case analysis through a comparison with the likelihood-based approach.
Affordability, negative experiences, perceived racism, and health care system distrust among black American women aged 45 and over
Authors: Wiltshire Jacqueline , Sampson Carla Jackie , Liu Echu , DeBose Myra Michelle , Musey Paul I , Elder Keith
Published: October 2024

Black Americans (AA) face a confluence of challenges when seeking care including unaffordable costs, negative experiences with providers, racism, and distrust in the healthcare system. This study utilized linear regressions and mediation analysis to explore the interconnectedness of these challenges within a community-based sample of 313 AA women aged 45 and older. Approximately 23% of participants reported affordability problems, while 44% had a negative experience with a provider. In the initial linear regression model excluding perceived racism, higher levels of distrust were observed among women reporting affordability problems (β = 2.66; p = 0.003) or negative experiences with a healthcare provider (β = 3.02; p = <0.001). However, upon including perceived racism in the model, it emerged as a significant predictor of distrust (β = 0.81; p = < 0.001), attenuating the relationships between affordability and distrust (β = 1.74; p = 0.030) and negative experience with a provider and distrust (β = 1.79; p = 0.009). Mediation analysis indicated that perceived racism mediated approximately 35% and 41% of the relationships between affordability and distrust and negative experience with a provider and distrust, respectively. These findings underscore the critical imperative of addressing racism in the efforts to mitigate racial disparities in healthcare. Future research should explore the applicability of these findings to other marginalized populations.
Automatic Irrigation System Using IoT
Authors: Limon-Molina Guillermo M. , Cota-Rivera E. Ivette , Raygoza-Limón Maria E. , Murrieta-Rico Fabian N. , Orduño-Osuna Jesus Heriberto , Jimenez-Sánchez Roxana , Bravo-Zanoguera Miguel E. , Mercado Abelardo
Published: October 2024

Water scarcity is nowadays a global problem, which requires innovative and sustainable solutions to reduce waste. The main uses are in the agricultural sector where in most cases flood irrigation is still used. In a lower degree the domestic use is considered; here the “automated” irrigation is via temporized solenoids that turn on and off the water circulation. These kinds of systems have proved inefficiency due to not considering the real need of water for the plants and cultivations. Considering the above issues, the authors proposed Automatic Irrigation System (AIS) that uses a mobile app and microcontroller to monitor cultivations in real time; this allows the user to take informed decisions to avoid water waste. The proposed system uses moisture and temperature sensors to monitor each type of cultivation needs; with this information the system can work in automatic mode or in manual mode to be activated individually or by sections for maintenance purposes.
Research Review on Task Scheduling Algorithm for Green Cloud Computing
Authors: Sadotra Parveen , Chouksey Pradeep , Chopra Mayank , Koser Rabia , Rawat Rishikesh
Published: October 2024

In green cloud computing, task scheduling entails assigning tasks to virtual machines in an approach that minimizes energy use whilst still reaching the performance targets. Green cloud computing is an evolving field that lowers the energy and carbon footprint of systems for using the cloud. In green cloud computing, task planning is a crucial problem because it determines how computational resources are allotted to workloads in order to decrease energy consumption and increase efficiency. Different task-scheduling techniques have been put forth in recent years for green cloud computing. The authors look at some current studies on task scheduling methods for green cloud computing in this overview of the literature.
Workplace Stress as a Predictor of Absenteeism of the Employees of Selected Manufacturing Firms in Lagos State, Nigeria
Authors: Aremo M. O. , Olanipekun L. O. , Ajayi A. M.
Published: October 2024

Absenteeism whether voluntary or involuntary is a manifestation of continued stress whose outcome is highly negatively engender poor results as well as low delivery of tasks among employees. One hundred and fifty (150) employees of five selected manufacturing firms in Lagos State served as respondents for the study through purposive and convenience sampling methods. Findings revealed that a significant and positive nexus was found between emotional exhaustion and voluntary absenteeism with “0.743>0.5”; also, a strong and positive correlation existed between psychological consequences and involuntary absenteeism with “0.913>0.5”. The study concluded that activities in the manufacturing environment is massive and has huge propensity to induce stress and high burnout rate thus culminating into high level of work alienation and absenteeism. Therefore, management should on a constant basis lookout for activities that poses stress on employees, such should be given rapt attention and curtailed to avoid work estrangement within and among employees.
Why People Procrastinate on Facebook: Case Study from Employed and Unemployed Facebook Users in Sri Lanka
Authors: Lakchan U. G. C. , Samaraweera G. C. , Rathnayake T. H.
Published: October 2024

Procrastination is the intentional postponing of a necessary or devoted task, which can have a number of adverse impacts, including distress, physiological health issues, poor work performance, and subpar academic success. The study aims to analyze and compare procrastination levels among employed and unemployed Facebook users, exploring the reasons behind their procrastination, which is crucial from both an economic and informational perspective. Additionally, it seeks to investigate the association between procrastination on Facebook and the users' education levels. The study also examines how procrastination on Facebook differs between males and females. Positivistic research Philosophy, deductive approach and explanatory research design were deployed for this study. The study used convenience sampling technique and, 300 employed and unemployed Facebook users were taken for analysis of Independent sample test, Anova test and post hoc-tukeys test. Accordingly, five factors namely notification features, immersive decision features, surveillance of presence, identification features, and interaction features were utilized to gauge the degree of procrastination. The findings of this study outlined the causes of procrastination and revealed a substantial difference between employed and unemployed Facebook users in terms of procrastination levels on social media sites. Additionally, results showed that there is a considerable variation between males and females too. The findings will provide a deep knowledge for marketers, psychologists and for academics as well.
Factors Affecting Failure of Rural Entrepreneurs: Special Reference to Teldeniya Divisional Secretariat Area in Kandy District, Sri Lanka
Authors: Madhuwanthi S. M. C. , Perera G. A. T. R. , Somasiri J. K. S. P.
Published: October 2024

This study aims at identifying factors affecting to failure of rural entrepreneurs and to examine moderate impact of financial literacy over the failure of rural entrepreneurs. This quantitative study investigates rural entrepreneurial failure in Sri Lanka's Teldeniya Divisional Secretarial Area. A sample of 187 entrepreneurs, who experienced failure, was surveyed, focusing on factors like risk aversion, perseverance, and financial literacy as a moderating influence. Objectives included identifying failure contributors and examining financial literacy's moderating impact on rural entrepreneurship. The study highlights key competencies and their relationship with failure, emphasizing financial literacy's role. It contributes valuable insights for governments, development organizations, and rural entrepreneurs to address failure causes and leverage financial literacy for improved outcomes. The findings hold practical applications for enhancing rural entrepreneurship in Teldeniya and similar areas.
Impact of Abusive Supervision on Affective Commitment with the Moderating Role of Self-Control Capacity of Non-Managerial Employees in Apparel Industry: A Sri Lankan Perspective
Authors: Sivapathasundharam S. , Jayasekara P.
Published: October 2024

The study examines the influence of abusive supervision on affective commitment among non-managerial employees in the Sri Lankan apparel industry, focusing on the potential moderating role of self-control capacity. Data was gathered from 257 randomly selected non-managerial employees from three knitted export organizations in Sri Lanka using self-administered questionnaires. The data were analyzed using SPSS 23. The results indicate a significant negative impact of abusive supervision on affective commitment, consistent with previous research findings. However, the study found that the moderating effect of self-control capacity was not statistically significant. This suggests that even though non-managerial employees may possess a moderate level of self-control capacity, it may not be adequate to mitigate the impact of abusive supervision on affective commitment. These findings highlight the critical necessity for organizations within the Sri Lankan apparel industry to address abusive supervision behaviours and to implement strategies aimed at enhancing employee retention in organizations.
Shattering the Glass Ceiling: Insights into Women's Pathways to Leadership in Sri Lanka
Authors: Herath H. M. T. S. , Surangi H. A. K. N. S. , Hemasiri T. N.
Published: October 2024

Although much research has been done on the glass ceiling phenomena in recent years, the question remains unsolved because the barriers themselves receive more attention than the ways in which women break through them. This study explores the factors that affected women who tried to break through the ceiling. This research follows a qualitative exploratory research approach. Seven semi-structured interviews with women in top positions in Sri Lanka provided the data for the study. Data were analysed and interpreted using thematic analysis. Findings revealed that three main factors affecting women's career advancement: individual factors like emotional stability and self-confidence, organizational factors like supportive work environments and policies, and cultural factors like attitudes towards Sri Lankan women. The findings offer recommendations for increasing female representation in top positions and suggest future research using a quantitative approach in different Sri Lankan contexts.
Exploring the Educational Landscape of ChatGPT: A Topic Modeling Approach on Twitter Data
Authors: Kuhaneswaran Banujan , Vadivel Abishethvarman , Wijeratne Ashansa , Ravikumar Nirubikaa , Kumara Samantha , Sivapalan Achchuthan , Vijayanandan Thanosan
Published: October 2024

In the rapidly evolving landscape of Artificial Intelligence (AI), platforms like ChatGPT are reshaping the educational domain, prompting deeper explorations into the nature and depth of this intersection. This study aimed to systematically uncover the prevailing sentiments, concerns and discussions on Twitter surrounding ChatGPT’s role in education. Through an extensive data collection process, over 3.8 million tweets were initially gathered, followed by rigorous refining processes that included expert-driven tweet labelling and subsequent classification using Machine Learning (ML) and deep learning models. The cleaned dataset underwent a series of preprocessing steps and feature extraction and was ultimately subjected to Latent Dirichlet Allocation (LDA) for topic modelling. Our findings unveiled 15 distinct topics that broadly spanned common discussions, AI implementation, and its potential impacts. The data’s visualisation using t-distributed stochastic neighbour embedding (t-SNE) showcased a dense central clustering of these topics. In conclusion, our research underscores the multi-faceted dialogues on AI, particularly ChatGPT, in education, emphasising the pressing need for continued discourse and research as AI tools further integrate into our educational paradigms.
Geo-Spatial Technology for Identifying Optimal Well Locations in Kolugala Pahalagama Grama Niladhari Division for Effective Groundwater Management
Authors: Ranasinghe L. A. , Patabandi K. P. L. Nishantha
Published: October 2024

This study utilized Geographic Information System (GIS) technology to pinpoint optimal locations for establishing wells, addressing the issue of declining water yields in the Kolugala Pahalagama Grama Niladhari Division (GND); a geographically diverse region. The research integrated geospatial data, including geolocations of sample wells, garbage pits and quarterly water level measurements collected through field surveys. Several thematic layers, namely, geology, elevation, slope, drainage density, soil type, and land use types were analysed to delineate groundwater potential zones within the GND. Satti's analysis hierarchy was employed to assign appropriate weights to these factors, reflecting their influence on groundwater recharge and well productivity. Spatial analysis revealed that 9.64% of the area displayed very good groundwater potential, 42.17% had good potential, 39.76% showed moderate potential, and 7.23% exhibited poor potential. The distribution of existing wells was also evaluated, showing that 6% were located in very good groundwater potential zones, 56% in good groundwater potential zones and 38% in moderate groundwater potential zones. Despite this, only 34% of the wells were placed in regions suitable for the establishment of wells, while the majority, 66%, were located in unsuitable areas. Notably, 18 wells displayed lower water levels, likely due to their excessive distance from neig-bouring wells. Further spatial analysis identified 29 hectares as unsuitable and 54 hectares as suitable for the future establishment of wells. These findings underscore the significance of geographic factors in the placement of wells, emphasising the need for strategic planning to ensure that wells are sited in areas with high groundwater potential, thus improving long-term water yield sustain-ability in the region.
A Virtual Pilot Algorithm for Synthetic HUMS Data Generation
Authors:   Georgia Institute of Technology, Fowler Lee , Rogers Jonathan
Published: October 2024

Regime recognition is an important tool for creation of usage spectra, component lifetime prediction, and fatigue loads analysis. During development of regime recognition (RR) codes, it is often necessary to establish baseline performance and accuracy of RR algorithms using scripted flight test data. However, various problems arise when using scripted flight test data as "truth" measurements upon which RR code accuracy is based. During scripted flight tests, maneuvers may be imprecisely flown or data may be perturbed by environmental disturbances. An alternative to scripted flight test data lies in simulated, or "synthetic" flight data produced from a flight simulation model. In this case, a maneuver script is flown in simulation and the model outputs are used to build a simulated Health and Usage Monitoring System (HUMS) dataset. An algorithm is needed to generate control inputs in a similar manner to a human pilot so that a maneuver sequence can be flown correctly in simulation. This paper presents a so-called virtual pilot algorithm that generates simulated control inputs for a given maneuver sequence. The virtual pilot receives a maneuver script as input, and streams control inputs to the flight simulator to perform the required maneuvers in an accurate and reliable manner. The virtual pilot proposed here is formulated as a variable structure controller where each maneuver is mapped to a single feedback control law. By switching between feedback laws, different maneuver regimes are flown. A smoothing technique called setpoint tracking bumpless transfer is used to smooth control transitions. Example results show that the virtual pilot can generate realistic synthetic HUMS data for a variety of maneuver sequences. Virtual pilot fidelity is demonstrated through both conformance to the ADS-33 standards for selected Mission Task Elements and comparison to actual HUMS data.
Employing Legacy HUMS Data to Support Aging Aircraft ASIP
Authors:   IMP Aerospace, Muise Aaron , Edmonds Anthony , Graham Keith
Published: October 2024

While Health and Usage Monitoring Systems (HUMS) continue to advance and provide increasingly refined Condition Based Maintenance (CBM) solutions (exemplified at References 1 through 6), HUMS-equipped aircraft procured before the maturation of these systems require consideration of novel approaches to maximize the benefit of available data. Presented as a case study, the Canadian Search and Rescue CH149 Cormorant helicopter, a variant of the Finmeccanica (AgustaWestland) EH-101, entered service for Canada in 2002 equipped with a HUMS. The following paper will present how HUMS data have been employed to support the CH149 fleet of 14 aircraft; specifically, how such data are used to (i) support fleet and individual aircraft usage monitoring, and (ii) identify adverse trends for additional detailed investigation. It is herein demonstrated that heavily processed data from a legacy HUMS, even without defined thresholds, may have value with proper consideration and validation.
Leveraging Massively Scalable Data Analytics Technologies to Enable Rapid HUMS-Based Fleet Management Decision Support
Authors:   Sikorsky Aircraft Corporation, Koelemay Michael , Sulcs Peter
Published: October 2024

Health and Usage Monitoring Systems (HUMS) generate a significant amount of data used for on-board and off-board monitoring of the health of the aircraft and its components. When this data is aggregated over the life of an aircraft, it becomes an invaluable resource that enables decision making for diagnostics, prognostics, and fleet management. At the fleet level, the amount of data being ingested, stored, and processed becomes a challenge in itself. The capability to easily handle data of this size is critical to be responsive to time-critical inquiries, iterate on data modeling, and enable efficient diagnostics and prognostics algorithm development. This paper discusses how massively scalable data analytics technologies have been used to enable rapid decision support using HUMS and other data sources. Several use cases are highlighted to show the novel opportunities enabled by these technologies along with associated challenges.
Gear Health Algorithm Solution For Drive System Design And Operations
Authors:   Sentient Science Corporation, Pulikollu Rajasekhar
Published: October 2024

This paper summarizes the development and implementation of material-based prognostic technology for modeling fatigue damage in rotorcraft drive system rotating components considering manufacturing process, contact pattern, lubrication effects, stresses, microstructure, and material variability. The AMS 6265 and AMS 6308 prognostic models were developed and applied to predict contact and bending fatigue damage in the planetary gear system. Prognostic model was verified by comparing fatigue life simulation results with industry test data. Prognostic model results were demonstrated and designed for integration with onboard and offboard elements of industry health monitoring/management systems. This paper includes details on predicting contact fatigue and bending fatigue life, endurance limits, maximum continuous power (MCP) rating, and overload effects. Prognostic model results show the application of this gear health algorithm solution in rotorcraft drive system transmission gear design, inspection, maintenance, and recommendation of safe operational powers.
On-Machine Inspection for Rotorcraft Manufacturing
Authors:   Bell Helicopter, Nissen Jeffrey , Torno Cody
Published: October 2024

The inspection step of rotorcraft component fabrication is critical to the manufacturing process. Inspection is essential for demonstrating that component quality meets engineering requirements and tolerances. Engineering specifications often require components to undergo coordinate measuring machine (CMM) inspections more than once during manufacturing. Off-line CMM inspection can introduce lengthy delays due to CMM backlogs and/or operator availability. The ability to perform inspections while the manufactured component remains in-position (on the machining platform) presents an opportunity to eliminate set-up time, reduce manufacturing span and lower inspection costs. The capability, referred to as On-Machine Inspection (OMI), has been implemented at Bell Helicopter on a large machining system to inspect several military and commercial composite components. An innovative calibration artifact and validation method is described. The approach ensures high inspection integrity and allows for rapid manufacturing resolution when data anomalies occur. The use of OMI on a main rotor yoke has resulted in a dramatic reduction in manufacturing span and inspection duration.
Optimizing the Fitness of Motion Cueing for Rotorcraft Flight Simulation
Authors:   German Aerospace Center - DLR, Jones Michael
Published: October 2024

Achieving good motion cueing in rotorcraft flight simulation is a long standing challenge in the simulation community. The current reliance upon subjective opinion leads to a wide range of motion configurations, which almost certainly do not offer the optimal level of vestibular cueing. Furthermore, without the understanding of the optimal motion settings, objective criteria are difficult to apply. This paper presents a new tool designed to optimize and evaluate the response of any motion platform, based upon the input to the system and the given motion system constraints. This tool is utilized in order to tune the motion platform of the Air Vehicle Simulator (AVES). Results show promise for the use of the optimization, as good fidelity is shown through pilot subjective comments and ratings.
A Generic Ground Dynamics Model for Slope Landing Analysis
Authors:   Turkish Aerospace Industries, Sansal Kaan , Kargin Volkan , Zengin Ugur
Published: October 2024

This paper demonstrates a new approach for modeling and simulating landing gear systems. A generic ground dynamics model is developed in MATLAB-Simulink® environment and it is integrated to a non-linear 6-DOF helicopter model. Non-linear helicopter model is constructed in an in-house comprehensive analysis code, TAI Indigenous Rotorcraft Simulation (TIRS). Other than simulating the helicopter motion after touchdown, this model is also applicable for trimming the helicopter on ground, which is useful for determining landing and take-off capabilities of a helicopter on either a flat or a sloped surface. Slope landing and take-off analysis can be hard to simulate without a pilot in the loop simulation. However, trimming the aircraft for a specific maneuver can show whether the aircraft is controllable during this maneuver or not. In other words, this method can show whether the control ranges are adequate or not during the design stage, which is a troublesome task during preliminary design. Further, this model can be utilized to perform the slope landing mission task element (MTE) defined in ADS-33E-PRF. This paper presents the algorithms used for trimming the helicopter on a sloped surface, together with the dynamics of a generic landing gear. Trim and simulation results over a sloped surface are also provided.
Estimation of Economic Effectiveness of HUMS Equipped AH-64 Aircraft: An ROI Approach
Authors:   University of South Carolina, Zaman Tanzina , Bayoumi Abdel
Published: October 2024

Cost-benefit analysis has always been a prime requirement to demonstrate the success of Condition-based Maintenance (CBM) practice in Army rotorcraft (Apache, Blackhawk, Kiowa, and Chinook, etc.). This study investigates whether the benefit of CBM practice in AH-64 aircraft over a 14-year period overweighs the investment cost. The benefit is calculated in terms of direct cost and operating cost analyzing maintenance logs and flight records. Direct cost is calculated in monetary value but operating cost is first calculated in hours and then converted into a monetary value. The direct and operating costs are addressed as replacement part cost, maintenance test flight cost, partial mission capable maintenance cost, and not-mission capable supply cost. All the cost categories show a clear indication of cost savings over the period of interest and the calculated ROI is 742% which stands as a sole indicator of economic effectiveness of CBM practice.
State of the Art of Helicopter Hybrid Propulsion
Authors:   Airbus Helicopters, Mercier Christian , Gazzino Marc , Mugnier Marc
Published: October 2024

State of the art of Helicopter hybrid Propulsion perspectives is presented. As done in the car industry, it can be envisaged replacing thermal energy necessary for helicopter propulsion and sustentation by electrical energy. Improvements on electrical technologies allow proposing electrical systems with attractive power to mass ratio to complement the thermal engine providing the mechanical power necessary for the helicopter propulsion. The differences between automotive functions devoted to hybridization and these possible in the case of a helicopter are explained. The different architectures (on turbine or on helicopter side) are reviewed and examples of possible applications on classical architecture helicopters (with main and antitorque rotors) are given, not only the case of AH light helicopter autorotation management improver successfully tested in 2011. The requirements on the electrical system for industrial applications are reviewed: electrical motor and power electronics, cooling systems, energy storage, resulting in development priorities.
A Combined Discrete and Continuum Fatigue Damage Characterization of a Hybrid Composite Flexbeam
Authors:   Global Engineering and Materials Inc., Lua Jim ,   Naval Air Warfare Center (PAX), Phan Nam , Fang Eugene , Rahman Anisur
Published: October 2024

Strength and life prediction of a nonlinear tapered hybrid composite flexbeam under combined axial tension and bending is a challenging problem due to the presence of a complex geometry, a hybrid composite material system with a combination of glass/epoxy and graphite/epoxy composites, and a variable thickness profile along the beam longitudinal direction. A hybrid approach based on the combination of discrete crack network (DCN) and continuum damage mechanics (CDM) is applied for fatigue damage prediction under pure bending and bending with axial loading. Abaqus solid shell elements (SC8R) with composite section were used to capture the stress distribution and its concentration at the ply drop location. A hybrid modeling strategy is developed based on Abaqus solid shell elements (SC8R) with a user-defined material model for non-critical damage zones, user-defined phantom paired solid elements for critical damage zones, and Abaqus elements for non-damaged regions. A comparative study is performed for a representative flexbeam with and without the application of an axial force.
Damage Assessment of Rotary Wing Aircraft Cabin Door using Continuum Damage Mechanics Model
Authors:   HAL, Rao Gangadhara ,   Jawaharlal Nehru Technological University, Rao Subba , Kumar R.
Published: October 2024

The prediction of ultimate strength remains the main challenge in the simulation of the mechanical response of composite structures. This paper examines continuum damage model to predict the strength and size effects for deformation and failure response of polymer composite laminates when subjected to complex state of stress. The paper also considers how the overall results of the exercise can be applied in design applications. The continuum damage model is described and the resulting prediction of size effects are compared against the standard benchmark solutions. The stress analysis for strength prediction of rotary wing aircraft cabin door is carried out. The goal of this study is to extend the proposed continuum damage model such that it can be accurately predict the failure around stress concentration regions. The finite element-based continuum damage mechanics model can be applied to the structures and components of arbitrary configurations where analytical solutions could not be developed.
Supportability of Advanced Composite Structures: Considerations for the Joint Multi-Role Technology Demonstration
Authors:   AMRDEC Prototype Integration Facility, Mellema Greg , Cockrell Kimberly , Featherston W.
Published: October 2024

Advanced composite materials are disrupting incumbent metallic materials in Army Aviation and creating new value networks that span the supply chain from raw material manufacturers to specialty equipment for sustainment of composite structures. In order to prepare Army Aviation for fielding and supporting an all-composite aircraft, many investment decisions need to be made today to facilitate the influx of training, tools, materials, and processes that will be necessary. This whitepaper walks through the defense acquisition lifecycle and discusses considerations for supportability of these advanced composite structures at each phase. Multiple case studies are presented to highlight opportunities to help inform the leaders and managers that are making the investment decisions now for tomorrow's weapon systems.
Blending Modern Multifunctional Materials with Traditional Structures: An Approach for a Greener and Cleaner Future
Authors:   Georgia Institute of Technology, Gupta Mohit ,   Indian Institute of Science, Harursampath Dineshkumar ,   Delft University of Technology, Ponnusami Sathiskumar ,   City University London, Veerasamy Dhamotharan , Agrawal Shashank , Ponnusami Sangheetha
Published: October 2024

The objective of the project is to propose a multifunctional composite material system for next generation rotorcraft's structural components. In particular, a hybrid composite termed as Piezo-Battery Fiber Reinforced Composite (P-BFRC) comprising of piezoelectric and battery fibers is proposed for the rotorcraft blades, which are arranged in an appropriate optimized fashion. The optimized layout will depend on the characteristic of vibrations in the rotor blades and associated structural components. For the fuselage skin panels, use of Battery Fiber Reinforced Composite (BFRC) is proposed. In the rotor blades and the regions where vibration amplitudes are larger, the P-BFRC structure aims to extract electrical energy from the structural vibrations using the piezoelectric panels and store it within the battery panels embedded in the structure itself. In the fuselage, the battery composite skin panels, upon charging from ground station, can serve as power source for operation for several rotorcraft's electrical and electronic components. Importantly, the proposed multifunctional structure is optimized such that the structural characteristics of the existing rotorcraft is not compromised, while simultaneously performing its multiple functions. In other words, introducing such multifunctional material does not increase overall weight nor reduce the structural load carrying capability. In addition, the proposed material system intend to make minimal modifications in the existing system as far as structure and power management systems are concerned, thereby a re-design of entire structural/power system is not necessary. Preliminary analyses have been conducted for to study the energy harvesting and storage characteristics of the multifunctional structure. This work focuses on detailed quantification of energy harvesting and storage capabilities of the proposed multifunctional system through appropriate electro-mechanical models. Altogether, the multifunctional structural system is found to be a promising step towards a cleaner and sustainable aviation.
High-Speed Experiments on Combustion-Powered Actuation for Dynamic Stall Suppression
Authors:   United Technologies Research Center, Matalanis Claude ,   Sikorsky Aircraft, Lorber Peter ,   Georgia Institute of Technology, Crittenden Tom ,   United Technologies Research Center, Min Byung-Young ,   NASA Langley Research Center, Schaeffler Norman , Bowles Patrick , Glezer Ari , Jee Solkeun , Wake Brian , Kuczek Andrzej
Published: October 2024

This work documents high-speed wind tunnel experiments conducted on a pitching airfoil equipped with an array of combustion-powered actuators (COMPACT). The main objective of these experiments was to demonstrate the stall-suppression capability of COMPACT on a high-lift rotorcraft airfoil, the VR-12, at relevant Mach numbers. Through dynamic pressure measurements at the airfoil surface, it was shown that COMPACT can positively affect the stall behavior of the VR-12 at Mach numbers up to 0.4. Static airfoil results demonstrated 25% and 50% increases in post-stall lift at Mach numbers of 0.4 and 0.3, respectively. Deep dynamic stall results showed cycleaveraged lift coefficient increases up to 11% at Mach 0.4. Furthermore, it was shown that these benefits could be achieved with relatively few pulses during down-stroke and with no need to pre-anticipate the stall event. The flow mechanisms responsible for stall suppression were investigated using particle image velocimetry.
Information-Based Analysis of Visual Cues in Human Guidance
Authors:   University of Minnesota, Feit Andrew , Mettler Berenice
Published: October 2024

Perception plays a central role in such humans' motion guidance skills as precision rotorcraft landing or driving a car. This paper investigates the information available in visible cues, relative to a first-person motion guidance task, in terms of sensory-motor guidance primitives. Human subjects performed a motion guidance task in a 3D simulation system, using only visual information. Guidance primitive patterns were identified from recorded subject motion and perception behavior. Information transfer between visual measurements and vehicle motion is quantified from the resulting data to identify both model-based and nonrepresentational guidance strategies. Results show that subjects use separate guidance primitive modes during distinct phases of a trajectory. This understanding of perceptual and guidance primitive elements in human behavior has applications ranging from improved augmented cuing for human pilots to advancing artificial perception in autonomous vehicle systems.
Wind Tunnel and Hover Performance Test Results for Multicopter UAS Vehicles
Authors:   NASA Ames Research Center, Russell Carl ,   Universities Space Research Association, Glasner Brett , Jung Jaewoo , Willink Gina
Published: October 2024

There is currently a lack of published data for the performance of multicopter unmanned aircraft system (UAS) vehicles, such as quadcopters and octocopters, often referred to collectively as drones. With the rapidly increasing popularity of multicopter UAS, there is interest in better characterizing the performance of this type of aircraft. By studying the performance of currently available vehicles, it will be possible to develop models for vehicles at this scale that can accurately predict performance and model trajectories. This paper describes a wind tunnel test that was recently performed in the U.S. Army's 7- by 10-ft Wind Tunnel at NASA Ames Research Center. During this wind tunnel entry, five multicopter UAS vehicles were tested to determine forces and moments as well as electrical power as a function of wind speed, rotor speed, and vehicle attitude. The test is described here in detail, and a selection of the key results from the test is presented.
Wind Farm Performance Improvement by Using Wake Transport
Authors:   Duke University, Su Keye , Bliss Donald
Published: October 2024

Wake shielding on wind farms substantially reduces the efficiency of downstream wind turbines due to the interaction with the energy-depleted wakes from upwind turbines. This research considers a method to mitigate the wake shielding effect by tilting the turbine axes upward producing a download that causes streamwise vorticity so that the energy depleted wakes transport upward alleviating shielding, and pumping more energetic fluid into downstream turbines. The wake steering effect for tipped turbines is verified and the degree of effectiveness is assessed. The simulations utilize a specially developed free-wake method, appropriate for wind turbines, that utilizes constant circulation contours with a large degree of downwind vorticity diffusion. This approach has been implemented to capture the natural behavior of multi-filament multi-blade complex turbine wakes, with relatively short simulation time. Detailed turbine wake structure is studied to obtain insights into how to strengthen the steering effect. Besides a single rotor tilted turbine, two unconventional turbine configurations, each consisting of two overlapping counter-rotating rotors, have been studied to assess their potential to increase the upward transport of their wakes. The three turbine configurations are compared along with a discussion of potential advantages and challenges, and additional research goals going forward. Initial promising results from preliminary wind tunnel studies of the wake of a single tipped turbine are briefly described.