bluuebunny/crossref_metadata_2025 huggingface dataset:
Advancements in Diagnostic Strategy of Neurological and Neuropsychiatric Disorders: From Conventional Methods to Point-of-Care Approaches
Authors: Rahaman Alisha , Hulgutte Parth , Shaligram Shraddha , Pawar Shrikant P.
Published: October 2024

Neurological and neuropsychiatric disorders such as Alzheimer’s, Parkinson’s, Epilepsy, Stroke, etc. are commonly being diagnosed in the human population nowadays due to changing lifestyle and other factors.  Every year, for nearly 10 million deaths and 10 million DALYs have been reported of Neurological disorders. This study overviews the advancements in conventional methods using machine learning or deep learning techniques and the development of point-of-care detection techniques to diagnose these diseases. Some of the non-invasive techniques such as EEG, MRI, Magnetic encephalography are expensive, time consuming and require sophisticated instrumentation facilities. Thus, to overcome these challenges point-of-care detection is an alternative for diagnosis which employs lateral Flow Assays, biosensors that are simple to use, cost effective, less time consuming, can be performed at low resource settings, and are sensitive, specific and accurate. Point-of-care detection involves detection of specific biomarkers in the body fluids of patients for early detection of the disease.
Neglected Tropical Diseases in India: Enhancing POC based Diagnosis towards Elimination
Authors: Shaligram Shraddha , Chauhan Shikha , Naik Vinay , Rahaman Alisha , Pawar Shrikant P. , Pawar Shrikant P.
Published: October 2024

Neglected tropical diseases (NTDs) represent a significant global health challenge, particularly in regions with limited access to healthcare and sanitation facilities. India, with its vast population and diverse landscape, faces a substantial burden of NTDs, including lymphatic filariasis (LF), visceral leishmaniasis (VL), and dengue along with other coinfections. The Government of India has undertaken various initiatives to eliminate these diseases, aligning with global objectives. However, challenges persist, including the need for accurate disease burden estimation, resource allocation, and disease diagnosis.Efforts to eliminate NTDs in India require comprehensive strategies, including mass drug administration and vector control programs. Thus, accurate and accessible diagnostic tools are essential for disease surveillance and treatment monitoring. Point-of-care testing including molecular and serological-based techniques facilitates swift diagnosis and disease surveillance, particularly in resource-limited settings. Thus, by prioritizing investments in innovative diagnostic and therapeutic strategies, India can make significant strides toward improving patient survival and decrease mortality rates.
Analysis of Determining Order Quantity of Spare Parts in Oil and Gas Well Service Activities Using Monte Carlo Simulation
Authors: Tikupadang Lakun , Rusdiansyah Ahmad
Published: October 2024

This research aims to explore the analysis of determining the order quantity of spare parts in well service activities in the oil and gas (Migas) industry using the Monte Carlo simulation approach. The Migas industry requires efficient inventory management to maintain operational smoothness, but this need must be balanced with efforts to minimize excessive storage costs. Therefore, it is important to determine the optimal order quantity to meet operational needs while avoiding unnecessary inventory accumulation. The Monte Carlo simulation method was chosen because of its ability to address uncertainty in inventory analysis, allowing for modeling variations in demand, delivery lead times, and other factors affecting inventory management. It is expected that this approach will provide a better understanding of how decisions regarding the order quantity can be made more effectively in the context of well service activities in the Migas industry. The main expectation of this research is the development of a model that can assist Migas companies in optimizing the management of their spare parts inventory. Thus, it is hoped that this research will make a significant contribution to improving operational efficiency, reducing storage costs, and increasing customer service levels in the Migas industry. It is also hoped that the results of this research will pave the way for the development of inventory management strategies that are more adaptive and responsive to dynamic business environments.
A INFLUÊNCIA DOS PREÇOS INTERNACIONAIS NA FORMAÇÃO DE PREÇOS DE PORDUTOS DA CESTA BÁSICA EM ANÁPOLIS
Authors: Silva Priscila de Amorim e , Rocha Marcio Dourado
Published: October 2024

O presente estudo traz à tona a importância da alimentação básica para a qualidade de vida das pessoas, propondo uma análise abrangente da formação de uma cesta básica ideal em Anápolis. Para isso utilizou-se como base os dados coletados pelo PROCON entre os meses de janeiro e junho de 2023, buscando identificar os valores cobrados pelos supermercados na compra dos 13 alimentos que compõem a cesta básica brasileira, além de analisar as variações nos preços desses itens ao longo do primeiro semestre do ano, considerando as variações nos índices inflacionários e as cotações de dólar no período em análise. O estudo buscou identificar a influência de fatores internacionais na formação dos preços da cesta básica. Após aplicação da metodologia proposta, o estudo verificou que há uma maior correlação de preços com o cenário internacional para produtos atrelados ao dólar, ou seja, considerados mais dolarizados e dependentes. Os dados obtidos pelo PROCON fornecem análises valiosas das oscilações de preço ao longo do tempo. Assim, parte-se de uma abordagem quantitativa, baseada em números estatísticos disponibilizados pela Fundação de Proteção e Defesa ao Consumidor (PROCON), pelas planilhas e relatórios de Cestas básicas coletadas a partir do site da organização. O objetivo do estudo é analisar a cesta básica dentro da formação dos preços médios considerados justos e acessíveis na cidade de Anápolis, no primeiro semestre de 2023.
O ESTADO DA ARTE DA PRODUÇÃO CIENTÍFICA SOBRE INOVAÇÃO NO SETOR PÚBLICO
Authors: GOMES JORDÂNIA DE SOUSA , AQUINO CABRAL AUGUSTO CÉZAR DE , SANTOS SANDRA MARIA DOS
Published: October 2024

A inovação no setor público tem sido o meio pelo quais as práticas, outrora já ultrapassadas, em razão da complexidade das demandas sociais, têm passado por mudanças significativas, a fim de proporcionar melhorias e trazer soluções mais eficientes aos cidadãos. Nesse cenário, propõe-se a realização de um estudo bibliométrico que prima  por  investigar o estado da arte da produção científica sobre a inovação no setor público. Para isso, foi realizado um estudo exploratório-descritivo, com abordagem quantitativa, usando como fonte de dados das publicações nacionais e internacionais, as bases  da Web of Science e da Scopus, dos últimos 5 anos. Obteve-se o resultado de 723 artigos, sendo 68 na base Web of Science e 655 na base Scopus. Após, a fase de seleção do material seguindo os critérios de inclusão e exclusão, foram selecionados os estudos que apresentaram maior repercussão acadêmica. Assim, ficou evidenciado que o perfil de autoria dos estudos sobre o tema tem sido pesquisadores da europa, os principais periódicos são o Journal of industrial ecology (75) e  o International journal of medical informatics (62). Os temas correlatos são ecologia, licitações sustentáveis, tecnologia e saúde. Com relação à evolução da produção científica, percebeu-se um pico entre os anos de 2020 a 2022, tendo uma leve queda em 2023. Quanto aos aspectos metodológicos, os mais destacados foram análises de dados primários e secundários, revisões sistemáticas e estudos de caso.
Morphological Analysis of Public Spaces and Their Contribution to Urban Resilience in Guelma, Algeria
Authors: Bechlem Rayen , Djouad Fatima-Zahra , Salah-Salah Hana
Published: October 2024

Modern Algerian cities are facing various uncertainties, both natural and human-made. To address these risks, urban areas need to be more adaptable and responsive. The increasing impact of climate change and the recent pandemic have emphasized the importance of outdoor spaces. As people spend a significant amount of time in these areas, public spaces have become essential for urban life. This study conducts a comparative analysis of public spaces, using a grid-based methodology to identify similarities and differences between two resilient public spaces and the square of Guelma. The analysis is preceded by a literature review that establishes key conceptual frameworks. The main objective is to develop recommendations for resilient public spaces and their contribution to a city's environmental resilience, particularly its capacity to withstand climate change. By understanding how these spaces can mitigate the effects of climate change, this research aims to guide the design and management of urban environments.
Hermeneutic Cartography for the Restitution of a Lost Antique Seaport
Authors: OUARET LADJOUZE Manel , Ahmed Brara
Published: October 2024

This article deals with the reconstruction of an ancient seaport in the town of Bejaia, known as Muslubium Horrea. This settlement, ignored by the official historiography, would nevertheless have played an important role in wheat exports and trade with the Roman port of Ostia. Moreover, of all the ancient ports known to date, the Algerian coast has only two port warehouses, and Muslubium Horrea is the only granary belonging to the Roman province of Mauretania Sitifensis (400AD). The methodology adopted to locate and reconstruct the topography and the settlement’s structures is based on the concept of cartographic hermeneutics. The compilation of existing historical accounts and the interpretation derived from the superimposition of ancient geographical maps and 19th century archaeological and geological maps identified all the natural resources necessary for its construction, in particular the abundance of water sources and deposits of geomaterials for construction (clay, stone, gypse, marble, etc.). These data were confirmed by field and photogrammetric surveys, resulting in a map showing the archaeological context of the Muslubium Horrea port and the remains of structures still visible today. The approach adopted allowed to delineate the size of the port site and scale the structures that make it up, as well as identify the water supply source and its primitive topography prior to its establishment.
Contemporary Urban Challenges for The Preservation of Values Associated with Settlements in Andalusian Mountainous Areas: The Case of Castaño Del Robledo in the Sierra De Huelva, Spain
Authors: Coronado Sánchez Ana
Published: October 2024

The landscapes linked to settlements such as Castaño del Robledo are one of the main elements of heritage interest in the complex and diverse Sierra de Huelva, a border territory between Spain and Portugal in the northwest of Andalusia. They reflect the physical and functional integration between the houses and the environment, where roads, historical infrastructure networks, walls and small buildings are intertwined with the cultivation areas, the embodiment of a very elaborate peasant culture. The aim of this work is to advance in the ways of approaching the knowledge of the singular values and fragility of these landscapes, with the main contribution of integrating a transversal view in their urban-heritage reading. The study starts with a first phase of analysis and diagnosis of the physical environmental support, the territory and the landscapes, and a second phase of evaluation to identify the challenges they currently face.
Towards A City of Good Dwelling
Authors: Somma Sharon Anna , Colarossi Paolo , Colarossi Francesco
Published: October 2024

One of the main issues in contemporary urban planning is the fragmentation of urban spaces (Batty 2009) due to the relentless processes of land transformation. This phenomenon can lead to the creation of isolated urban islands and a lack of high-quality public areas. Such weaknesses particularly affect the socio-economic conditions of marginal areas within the existing city, especially those on the outskirts near rural areas. Public spaces (Low et al 2006) are essential for social interaction, community building, and improving the overall quality of urban life. They are spaces where cultural, economic, and social activities converge, contributing to the city's vibrancy and inclusiveness. Are considered the key of the new processes of urban regeneration and it contributes significantly to the making of the city of "good dwelling" (Beauregard 2020). To obtain the conditions for a good dwelling, it is proposed to apply the seven principles contained in the "Manifesto della Città del Buon Abitare"(Colarossi et al 2023): the city of good dwelling must assume the general principles of hospitality, urbanity and beauty of its public spaces. The paper proposes as innovative approach, the use of an urban planning tool with which it is possible to apply the principles of the Manifesto of the city of good living and which is called "Plan-program of public space planning and public and private services" (P.A.S.S.i.). The effort of this research is to identify a general planning tool for the redevelopment to the existing city. The multi-scalar approach of the research tool simultaneously allows an overall vision of the program and a qualitative control of each individual project.
Exploring the Vital Role of Colors and Shapes in Architectural Design and Education
Authors: Moreira Pinto Luis , Matos Ruben
Published: October 2024

This study investigates the crucial influence of color and form on architectural design and architecture education, highlighting how these elements shape the aesthetics of the built environment and impact human experiences. The central problem addressed is the need to understand the interaction between color and form in creating spaces that evoke specific emotions and cultural narratives, contributing to an architecture that goes beyond functionality. The importance of this study lies in demonstrating how the careful integration of these elements can enrich the built environment and improve the quality of architectural education. The methodology adopted includes the analysis of case studies and expert opinions, along with the exploration of innovative methods in the teaching of architecture, which combine practical learning, virtual simulations and interdisciplinary collaboration. The results indicate that an in-depth understanding of the dynamic relationship between colors and shapes allows architects, but also society in general, to enhance their creativity, contributing to a more culturally significant and aesthetically impactful built environment.
The seventh species of the newt genus Tylototriton in Thailand: a new species (Urodela, Salamandridae) from Tak Province, northwestern Thailand
Authors: Pomchote Porrawee , Peerachidacho Parada , Khonsue Wichase , Sapewisut Pitak , Hernandez Axel , Phalaraksh Chitchol , Siriput Parunchai , Nishikawa Kanto
Published: October 2024

A new species of the crocodile newt genus Tylototriton from Doi Soi Malai located at Mae Tuen Wildlife Sanctuary, Tak Province, northwestern Thailand is described based on molecular and morphological evidence, and named as Tylototriton soimalaisp. nov. The new species is the seventh recorded species of the genus Tylototriton reported in Thailand. It differs morphologically from its congeners by a combination of the following morphological characteristics: head longer than wide; snout blunt or truncate; sagittal ridge on head narrow, short and distinct; dorsolateral bony ridges on head pronounced and rough; parotoids distinct; vertebral ridge prominent, wide and not segmented; 14–16 distinct, rounded and isolated rib nodules but posterior nodules connected; tips of fore- and hind limbs overlapping when adpressed along the body. The body background color is black, while the color markings are orange. Molecular analysis indicated that Tylototriton soimalaisp. nov. is a distinct lineage and sister to T. uyenoi with a 4.1% genetic sequence divergence based on the mitochondrial NADH dehydrogenase subunit 2 gene. The new species is currently restricted to the hill evergreen forests of Doi Soi Malai. The implementation of a strategic plan is recommended to protect both the species and its habitat from anthropogenic activities.
Estimates related to Caputo derivatives using generalized modified $ h $-convex functions
Authors: Benali Halim , Souid Mohammed Said , Günerhan Hatıra , Fernandez-Gamiz Unai
Published: October 2024

In the present work, we have established some new fractional integral inequalities for functions whose $ k $th-derivatives are generalized modified $ h $-convex and symmetric about the midpoint involving the Caputo fractional derivatives. Many particular cases are obtained by using the findings.
Robust Anti-windup Design for Active Trailing Edge Flaps in Active Rotor Applications
Authors:   University of Leicester, Morales Rafael , Turner Matthew
Published: October 2024

Active trailing edge flap actuators play a significant role in active rotor applications whereby certain performance aspects, such as reduction of vibratory hub loads, are able to be improved in more economical ways in comparison to other active approaches. Feedback control systems are expected to be required in order to offer a desired actuator performance in the face of air loads and actuator uncertainty. However the operation of feedback controllers under significant air loads and varying RPM conditions may cause the controller to make demands beyond those achievable with the physical device, resulting in significant performance degradation. For this reason, this paper explore the use of more advanced control tools, known as anti-windup systems, to deal with these control signal constraints and hence offer graceful performance degradation when operating in such a demanding regime. One specific anti-windup technique is explored in this work for vibration reduction applications. The benefits of this approach are shown to be significant and clearly exposed through a simulation example.
Integrated Aeromechanics with Three-Dimensional Solid-Multibody Structures
Authors:   ST Corp.- US Army AFDD, Datta Anubhav ,   NASA Ames Research Center, Johnson Wayne
Published: October 2024

A full three-dimensional finite element-multibody structural dynamic solver is coupled to a three-dimensional Reynolds-averaged Navier-Stokes solver for the prediction of integrated aeromechanical stresses and strains on a rotor blade in forward flight. The objective is to lay the foundations of all major pieces of an integrated three-dimensional rotor dynamic analysis - from model construction to aeromechanical solution to stress/strain calculation. The primary focus is on the aeromechanical solution. Two types of three-dimensional CFD/CSD interfaces are constructed for this purpose with an emphasis on resolving errors from geometry mis-match so that initial-stage approximate structural geometries can also be effectively analyzed. A three-dimensional structural model is constructed as an approximation to a UH-60A-like fully articulated rotor. The aerodynamic model is identical to the UH-60A rotor. For preliminary validation measurements from a UH-60A high speed flight is used where CFD coupling is essential to capture the advancing side tip transonic effects. The key conclusion is that an integrated aeromechanical analysis is indeed possible with three-dimensional structural dynamics but requires a careful description of its geometry and discretization of its parts.
Simulation Testing of Advanced Response Types for Ship-Based Rotorcraft
Authors:   Pennsylvania State University, Soneson Gregory , Horn Joseph
Published: October 2024

Piloted simulation tests were conducted to develop and evaluate advanced control laws and optimal response types for ship-based rotorcraft. Simulations used the GENHEL-PSU model integrated with the Penn State rotorcraft flight simulator. The simulation includes ship motion, a visual model of a FFG-7 frigate, and the Control Equivalent Turbulence Input (CETI) model for airwake turbulence. The controller uses a Non-Linear Dynamic Inversion scheme to accurately track a variety of response types. An Attitude Command / Attitude Hold (ACAH) control mode was used as the baseline control law. Different variants of Acceleration Command / Velocity Hold (ACVH) and Translational Rate Command / Position Hold (TRC/PH) response types were designed to make use of ship deck motion measurements. Filtered deck states are fed into the control laws to command velocity and position relative to the landing spot. Piloted simulation tests were performed for a variety of control configurations with and without ship motion and airwake turbulence effects using a maritime MTE. Pilot comments and preliminary handling qualities ratings indicated that the best performance was achieved using an ACVH response type for the pitch axis on approach, which then automatically transitions to TRC/PH over the ship deck. A 3.5 HQR improvement over the baseline ACAH control mode was achieved when using the optimized ship-relative ACVH/TRC/PH control mode. Simulation results indicated that it is best to filter out most of the dynamic ship deck motion (primarily ship roll) and to maximize the lateral axis TRC bandwidth.
Glenn Hammond Curtiss, the Aerial Experiment Association and the John Newton Williams Helicopter of 1908
Authors:   US Army (Retired), Fardink Paul
Published: October 2024

The theme of the AHS 70th Annual Forum and Technology Display in Montréal, Québec, Canada, is "Celebrating International Cooperation in Vertical Flight Technology." Perhaps no finer example exists of this type of cooperation than with Alexander Graham Bell's Aerial Experiment Association, a Canadian-American aeronautical research group formed on October 1, 1907, at Baddeck, Nova Scotia. According to Bell, the A.E.A. was a "co-operative scientific association, not for gain but for the love of the art and for doing what we can to help one another," and dedicated to the construction of a practical flying machine. Between1907 and 1909, the A.E.A. produced several different aircraft in quick succession, each an improvement over the previous one. The group introduced key technical innovations, notably wingtip ailerons and the tricycle landing gear, and, working with John Newton Williams, they would witness the first lifting of a person using rotary-wings in America.
Wing Commander Kenneth H. Wallis: The Triumphs, Tragedy and Enigma of an Extraordinary Life in Autogyro Aviation
Authors:   Hofstra University, Charnov Bruce
Published: October 2024

In 1958 Wing Commander Kenneth H. Wallis RAF, while on an exchange tour of duty with SAC, purchased the plans for the Bensen B7M Gyrocopter. Returning to England in 1959, Wallis constructed the Bensen aircraft and, by fortuitous encounter, was granted 'developer' status by the British Civil Aviation authorities, giving him the sui generis ability to develop new aircraft providing that he reported on his developmental activities. For over 55 years his was an extraordinary life with the autogyro, and at the time of his death on September 2, 2013, Wallis still held half of the autogyro world records. A self-taught aeronautical engineer, often called an engineering genius, Wallis was much-recognized with trophies, awards and honorary doctoral degrees and had international recognition, due largely to his spectacular performance in the 1967 James Bond movie You Only Live Twice. His influence on the European popular rotorcraft movement was, however, extremely limited and derivative, primarily to those who have attempted to copy his designs (what Wallis referred to as "eyeball engineering"). Therein is to be found the enigma of Wallis - given the acknowledged quality and public admiration for his autogyro designs, why did he not have a more significant impact on popular rotorcraft movements? The answer is to be found in the tragedy of fatal crash of a Wallis-117 autogyro and the death of John "Pee Wee" Judge at the 1970 Farnborough Air Show and the subsequent official investigation. While Wallis cooperated with authorities and was exonerated in the Official Report, issued almost four years later, his reaction was to refrain from the amateur-built market, becoming a champion of the "autogyro as working aircraft" - the result being that while he flourished, even winning a NATO contract for a 100 aircraft for battlefield damage assessment in 1968 (which was bungled by the manufacturer and eventually cancelled), he had no practical impact on the British popular rotorcraft movement.
Rotor Track and Balance Improvements
Authors:   Cornell University, Fang Austin ,   Green Power Monitoring Systems, Bechhoefer Eric , Garcia Epharim
Published: October 2024

Vibration derived from the main rotor dynamics and imbalance causes premature wear to the aircraft components, and can cause pilot fatigue. While improvements have been made in rotor track and balance (RTB) techniques; there is room to enhance the quality of the recommended RTB adjustments. One aspect that limits the development of RTB algorithms is the difficulty in quantifying the performance of new algorithms. This is because there are limited data sets to work on, and no agreed upon metrics on which to measure RTB performance. This paper develops a methodology to simulate the vibration due to injecting a fault into the rotor system, and demonstrates metrics to evaluate the performance of a RTB algorithm. A new Bayes RTB method is evaluated against a standard least squares technique. In addition, an Expert System technique is presented to automate the selection of active adjustments.
Achieving HUMS Program Financial Benefits - 12 years of day to day HUMS operations on the CH-146 Griffon fleet
Authors:   Bell Helicopter, Heroux-Theriault Alexandre
Published: October 2024

Over the years, the cost/benefit balance of Health & Usage Monitoring Systems (HUMS) available for rotorcraft have generated much debate, especially at the procurement phase of new aircraft. Currently, there is consensus within and outside the HUMS community regarding the safety benefits of having a HUMS system installed. The Royal Canadian Air Force worked in conjunction with the HUMS support team from Bell Helicopter Canada to establish the direct quantitative cost savings of running the HUMS program on their fleet of 85 CH-146 (Bell 412CF) Griffon helicopters. Accepting the safety benefits, the objective was to determine whether the cost savings generated by the program would offset the annual investment required. Using the HUMS database and the various military tracking systems, the number of events for which HUMS provided sufficient data to deviate from either a maintenance action or from a conditional inspection was compiled for a 5 year period from the beginning of 2008 to the end 2012. The total saving was conservatively estimated at $2.1M per year which definitively surpasses the annual investment required to keep the program running.
Applications of Virtual Monitoring of Loads to Engineering Decision Making
Authors:   Sikorsky Aircraft, J. Raymond
Published: October 2024

A virtual tail rotor torque load model was applied to over 500,000 flight hours of operational parametric data from the fleet of S-92® rotorcraft and was used to develop design load spectrum prorates for the design, qualification, and certification of drivetrain components. Fleet parametric data was recorded by an onboard Health and Usage Monitoring System and archived at Sikorsky Aircraft for all active tail numbers since inception. Model training and blind validation was performed using production structural flight load survey test data. To extract meaningful and reliable loads information from such a large fleet database, a multistep process was developed to ensure data quality, identify questionable torque events for engineer review, and reduce the calculated time histories into individual tail number torque spectrums. All tail number torque spectrums were combined into a single composite worst case torque spectrum, which was compared against the existing design load spectrum to identify areas where the design load spectrum is overly conservative and where usage prorates could be developed. A usage monitor reliability factor was then applied against the fleet composite worst case load spectrum to ensure the reliability of the resulting usage prorates. The newly developed usage prorates increased the critical component retirement time by more than a factor of 3. As the first in-depth application of virtual monitoring of loads to affect the design or qualification process, this project paves the way for more sophisticated fleet and tail number based credits and design methods that more fully exploit the ability to monitor key loads.
A Higher-Order Free-Wake Method for a Helicopter Rotor in Forward Flight Using Distributed Vorticity Elements
Authors:   The Pennsylvania State University, Choephel Tenzin , Maughmer Mark
Published: October 2024

The wake has a strong influence on the aerodynamics of a helicopter rotor operating in various flight modes. An accurate prediction of its geometry is critical for an improved understanding of aerodynamic performance, vibration and acoustics characteristics. In this paper, a higher-order lifting-surface method is discussed that uses singularity elements having distributed vorticity to model the lifting surfaces and shed wakes, and applies it to the problem of computing the free-wake geometry of a helicopter rotor in forward flight. Such distributed vorticity elements allow the representation of a force-free wake-vortex sheet that does not suffer from numerical singularities and is numerically robust with regard to the wake roll-up behavior. In contrast with other free-wake methods that use discrete vortex filaments, the new method does not require the implementation of vortex core models etc. Using this new method, the distorted wake geometry of a rotor in forward flight are computed, along with the capability of accounting for the effect of inboard active devices on wake development, airloads and downwash distribution.
Real-Time Simulation of Rotorcraft Downwash in Proximity of Complex Obstacles using Grid-Based Approaches
Authors:   Technische Universität München, Friedmann Ludwig , Ohmer Phillip , Hajek Manfred
Published: October 2024

This paper describes the development and verification of a model for real-time simulation of rotorcraft downwash. Downwash gains importance in rotorcraft flight close to terrain and obstacles where strong aerodynamic forces may act on nearby persons and objects. In areas of loose soil composition, it may further entrain dust or snow and cause dense clouds degrading the pilot's vision (Brownout/Whiteout). Taking into account these effects in training simulation is necessary to prepare pilots and crews for critical situations. The developed methods open up the possibility to capture complex boundary conditions and to calculate rotorcraft- and flight-state specific flow fields underneath rotorcraft at low-level flight. In contrast to existing approaches, recognition of boundary conditions is performed at simulation run-time using ray-tracing algorithms. Thus, the model's grid-based flow field calculation is able to incorporate arbitrary dynamic obstacles and their effect on the downwash. Output of the model can be used for high-fidelity Brownout/Whiteout simulation and for the determination of fluid forces acting on personnel and objects.
Subjective and Objective Metrics for the Evaluation of Motion Cueing Fidelity for a Roll-Lateral Reposition Maneuver
Authors:   TU Delft, Pool Daan ,   MPI for Biological Cybernetics, Drop Frank , Paassen Rene , Mulder Max , Wiskemann Moritz , Bülthoff Heinrich
Published: October 2024

This paper describes an experiment conducted to investigate the effects of roll-lateral motion cueing algorithm settings on motion fidelity for helicopter roll-lateral repositioning tasks. A total of 13 motion conditions, comprising two roll gain settings, two degrees of roll-lateral coordination and three roll washout intensities, were tested by four pilots on the CyberMotion Simulator at the Max Planck Institute for Biological Cybernetics. An emphasis was put on the use of objective measurements for motion fidelity determination, in addition to collected subjective handling quality ratings (HQR) and motion fidelity ratings (MFS). Higher roll gains were found to have a beneficial effect on both the subjective and the objective metrics, which is in line with previous findings. Reducing the degree of coordination had a negative effect on subjective ratings, but did not show a consistent negative effect for the considered objective metrics. Stronger roll washout had a large and consistent negative effect on the subjective ratings. This is confirmed by the obtained objective measurements, which show high control activity and less realistic vehicle trajectories during the deceleration and stabilization phase of the maneuver for conditions with strong roll washout. We conclude that roll and lateral gain are more effective than roll washout to attenuate the simulated motion.
Effects of Motion Filter Parameters on Simulation Fidelity Ratings
Authors:   NASA, Reardon Scott , Beard Steven , Aponso Bimal
Published: October 2024

An experiment at NASA Ames' Vertical Motion Simulator (VMS) evaluated simulation motion fidelity using a Bob-up task with a UH60 Blackhawk helicopter model. The experiment used ten different motion cueing configurations that varied the motion gain and washout frequency in the high-pass motion filter located between the aircraft math model and motion system. Ideally the actual aircraft would represent the Baseline configuration, however this can be a prohibitive constraint. The VMS' large motion envelop enabled an unfiltered, one-to-one, motion configuration as a surrogate for the actual aircraft. The Simulation Fidelity Rating (SFR) scale developed by the University of Liverpool and the Canadian National Research Council was used to subjectively rate the motion fidelity. The SFR scale requires the pilot to subjectively compare their performance and technique adaptation in the simulator to that of a baseline. All but two of the configurations tested were characterized as "Fidelity Warrants Improvement" on the SFR scale. The only configuration assessed as "Fit for Purpose" on the SFR scale was the Baseline configuration. The results from the technique adaptation portion of the SFR ratings showed some similarities with the Modified Sinacori Criteria. This indicates that the pilot's technique adaptation level in the simulator may be predicted based on motion filter parameters.
The Bell 525 Relentless, The World's First "Next Generation" Fly-by-Wire Commercial Helicopter
Authors:   Bell Helicopter Textron, Kim Sung , Bothwell Mike , Fortenbaugh Robert
Published: October 2024

Since its formal launch in 2012, designers of the Bell 525 Relentless have sought feedback and utilized input from a Customer Advisory Panel (CAP) comprised of industry-leading global helicopter operators. The top initiative of this group is to adopt the features of a next generation helicopter that provides enhanced margins of flight safety. In response, the Bell 525 will be the first commercial helicopter to offer full authority fly-by-wire digital flight controls. Helicopter safety reviews have consistently found that human factors and situational awareness are the leading cause of helicopter accidents. With this history, safety clearly points to the need for careful consideration of pilot workload, especially in demanding situations such as hovering near multiple obstacles or performing in Degraded Visual Environments (DVE). Design-for-safety enhancements include Translational Rate Command / Position Hold control laws at low speed, automatic computer assisted entry into autorotation in the event of a dual engine failure, automatic OEI compensation, load alleviation provisions, and control axis decoupling. This paper describes the process of incorporating requirements for modern handling qualities design criteria into the control system design and examines the real-time testing scheduled for the 525's first flight.
Integrated Methods to Model and Update Rotorcraft Simulations with Experimental Data
Authors:   Bell Helicopters, Roberts Brad ,   Sunflyte Enterprises, Morelli Eugene ,   Barron Associates Inc., Cooper Jared ,   Naval Air Systems Command, Roark Sean , Xiao Sid , Schlapkohl Thomas , Gaublomme Donald
Published: October 2024

Updating simulation models based on flight, or other external data, is a laborious process. Despite this, simulation updates are necessary for high-fidelity simulations used in analysis, control development, handling qualities prediction, fleet training, etc. Recent development has yielded an integrated modeling and simulation update suite known as AUSPEX: Algorithms to Update Simulation Parameters with EXperimental Data. AUSPEX combines the steps of the simulation-update process into a single environment and provides a framework to track updates and associated metadata. Mathematically sound and statistically rigorous techniques are used to calculate updates of current model parameters, thereby improving correlation with observed vehicle response. The software can also suggest additional terms to the dynamic equations if these terms are missing from the simulation due to simplifying assumptions made in the modeling phase. Creation of a new model is also possible. This article describes application of AUSPEX to the V-22 tiltrotor specifically, and rotorcraft in general, using a statistically-based frequency domain method. The capability to accurately and automatically update a simulation database to account for nonlinear and unsteady aerodynamic effects embodied in the flight data is demonstrated. Useful features of this novel frequency domain approach are highlighted, including computational efficiency, noise rejection, automated model structure determination in the frequency domain for nonlinear and unsteady aerodynamics, and the ability to generate simulation updates without air flow angle measurements in the flight data. Examples are presented using V-22 simulation and flight test data with the vehicle in airplane, conversion, and helicopter modes. Analysis was performed with both the NAVAIR and Bell simulations of the V-22 hosted in GTRSIM.
Turboshaft After-Market Positioning: A Strategy Based Approach
Authors:   Pratt and Whitney Canada, Carpentier Pierre
Published: October 2024

Due to its subjective nature, the concept of value is not one that is easily defined. Marketers often refer to a product's 'value proposition' as an explanation to why an operator should buy a product or use a service. This statement should convince a potential operator that one particular product or service will add more value or better solve a problem than other similar offerings. In the rotorcraft market, this value proposition is often tied to capabilities of the helicopter and is typically defined as a composite metric. This metric is then compared to the acquisition cost to get a sense of helicopter value. Helicopter manufacturer's marketing and sales departments then go to the market and sell the benefits, either in range, take-off weight, reliability, operating cost, etc… One major difference in the value stream of rotorcraft products as compared to typical consumer products is that it is standard for a second-level supplier, in this case the engine manufacturer, to offer its own services and support. This creates an environment where both the helicopter and engine manufacturer have direct contact with the end operator and can influence their perception of value. A method for an engine manufacturer to define value can aid the helicopter manufacturer, and ultimately, the operator, to make an informed decision regarding the right product for their mission objectives.
In order to derive a metric for the concept of value for a helicopter engine, one must understand the important aspects from an operational perspective, as opposed to the technical focus typically associated to this type of product. This paper focuses on the derivation of such a composite metric by using terms that represent a product's reliability, maintainability, and capability as compared to its direct operating cost as the acquisition cost of the engine is transparent to the end operator. Looking at the helicopter engine competitive environment in such a way serves two purposes: one for the engine manufacturer to be able to gauge the competitiveness of their product, and one for the operators to understand an engine's value proposition and how it fits into the helicopter capabilities. The details of how the metric of engine productivity were derived will not be elaborated as they are considered intellectual property to Pratt and Whitney Canada, but the benefits and concepts of viewing helicopter engines in such a way can be discussed.
Dependence of Vibration Characteristics on Grease Service Levels in an AH-64D Intermediate Gearbox
Authors:   University of South Carolina, Patterson Andrew , Edwards Travis , Bayoumi Abdel
Published: October 2024

The purpose of this experiment is to determine if the intermediate gearbox (IGB) grease service level can be characterized through existing condition-based maintenance (CBM) practices, which include vibration monitoring sensors and analysis algorithms, in the IGB of the AH-64D. A secondary objective is to quantify a common phenomenon in the gearbox–the expulsion of lubrication during different times of operation. If both goals are achieved then common maintenance practices on the aircraft can be changed to reduce workload. Three different gearboxes of similar condition were used for this experiment. Each gearbox was run in a two hour test under different loading conditions five separate times. In each iteration, the gearbox contained a different volume of grease that increased in 25% increments of the standard service level (0%, 25%, 50%, 75%, and 100%). The vibration data analyzed was collected through the modern signal processing unit (MSPU) to find a trend against the different amounts of grease. To complete the secondary goal, the amount of grease ejected during the initial parts of the runs was captured and weighed. This will be used to obtain a constant number at which to service the IGB and prevent the "burping" of grease during operation. . More research should be conducted to discover whether higher-order vibrations analysis will allow this fault to be detected.
Enabling Sustainable Engine Design: LCA and Eco Design Strategies
Authors:   Pratt and Whitney Canada Corp., Hendershot Scott
Published: October 2024

The impacts of an aircraft engine throughout its life cycle can be evaluated using established Life Cycle Assessment (LCA) methodologies. LCAs can highlight the opportunities to reduce impacts within the engine life cycle phases including Extraction, Manufacture, Transport, Assembly, Use, Maintenance and End of Life. Screening level LCAs of aviation engines show us that an aircraft engine's life cycle impacts are dominated by fuel production/use and resulting combustion gases emitted through the use of the engine over its service life, but these impacts truly begin when the first shovel hits the ground to extract raw materials for that first component and continue all the way through to the end of life disposition for the thousands of parts in each engine. The focus of this paper is on the non-fuel burn related impacts which are often overshadowed by the focus on fuel use and its effects.
Fatigue-Free Platforms: Vision for Future Army Rotorcraft
Authors:   US Army, Le Dy ,   US Army AMRDEC, Bordick Nathaniel , Weiss Volker , Riddick Jaret , Miller Bradley
Published: October 2024

The goal for Army aviation platform sustainment is "zero-maintenance". Scientists and engineers from the U.S. Army are exploring the underpinning science and technology (S&T), which can be used to achieve this vision. Researchers from the Army Aviation and Missile Research, Development and Engineering Center (AMRDEC) and Army Research Laboratory (ARL) have recently developed a holistic system approach, "Virtual Risk-informed Aviation Maneuver Sustainment" (VRAMS), which integrates a wide range of technologies including the material "genome", damage precursors, self-healing, real-time risk assessment, autonomous state awareness at the material level, and stress-reduction methods. The Army S&T efforts aim at (a) developing superior materials, (b) understanding damage precursors and exploring advanced sensing strategies to detect them prior to the onset of microcracks or degradations, (c) advancing the capability for the intelligent self-repair of degrading components at the microscopic level before performance degradation and critical failure, (d) integrating in situ sensing elements and intelligent data collection with minimum hardware and wiring accessories, and (e) developing a robust risk assessment capability and adaptive maneuvering limitations in real time to ensure acceptable stress levels to sustain "fatigue-free" structural components without maintenance over a desirable time intervals.
Phase Gradient Approach for Detailed Damage Localization in Composite Rotorcraft Components
Authors:   Georgia Institute of Technology, Darnton Aaron , Ruzzene Massimo
Published: October 2024

Detection, localization and characterization of damage to composite plates are an important topic in today's rotorcraft industry. New methods are required to increase an inspector's ability to assess the criticality of suspected damage. This study explores a new method for mapping damaged materials using the acoustic wave reflection caused by the damage. This paper studies a series of analytical, numerical and experimental simulations to assess the method's ability to determine damaged area's shape. By tracing the gradient of the unwrapped phase of the reflected wave, the reflector, and thus damage can be mapped. To do this analysis a single mode of a reflected wave is isolated separated. When adequately filtered the reflected wave is successfully traced to its origin and mapped.
Chordwise Implementation of Pneumatic Artificial Muscles to Actuate a Trailing Edge Flap
Authors:   InnoVital Systems Inc., Kothera Curt ,   University of Maryland, III Robert , Wereley Norman
Published: October 2024

This work describes the theoretical design and experimental validation of a rotorcraft-specific trailing edge flap powered by pneumatic artificial muscle (PAM) actuators. The actuators in this work are co-located outboard on the rotor blade with the flap and arranged with a chordwise orientation where diameter and length restrictions can severely limit the operating range of the system. Techniques for addressing this configuration, such as introducing a bias contraction and mechanism optimization, are discussed and a numerical optimization is performed for an actuation system sized for implementation on a medium utility helicopter rotor. The optimized design achieves ±10 degrees of deflection at 1/rev, and maintains at least ±2 degrees half peak-to-peak deflection out to 10/rev, indicating that the system has the actuation authority and bandwidth necessary for both primary control and vibration/noise reduction.