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13 pages, 1606 KiB  
Article
Phylogeography of Coccoloba uvifera (Polygonaceae) Sampled across the Caribbean Basin
by Danny J. Gustafson, Logan A. Dix, Derek P. Webster, Benjamin K. Scott, Isabella E. Gustafson, Aidan D. Farrell and Daniel M. Koenemann
Diversity 2024, 16(9), 562; https://doi.org/10.3390/d16090562 - 8 Sep 2024
Abstract
Coccoloba uvifera L. (seagrape) is a primarily dioecious neotropical tree species which often grows in the beach–forest transitional ecotone of coastal strand vegetation. We used five maternally inherited non-coding chloroplast regions to characterize the phytogeography of C. uvifera collected across the Caribbean Basin [...] Read more.
Coccoloba uvifera L. (seagrape) is a primarily dioecious neotropical tree species which often grows in the beach–forest transitional ecotone of coastal strand vegetation. We used five maternally inherited non-coding chloroplast regions to characterize the phytogeography of C. uvifera collected across the Caribbean Basin and Florida. Bayesian analysis revealed divergence between the Aruba–Trinidad–Tobago–Antigua–Jamaica island group and the continental Belize–Florida–US Virgin Islands (USVI) group at 1.78 million years before present (mybp), divergence between the Belize and Florida–USVI groups at 1.08 mybp, and a split of Antigua–Jamaica from Aruba–Trinidad–Tobago at 0.217 mybp. Haplotype network analysis supports the three clades, with the island group possessing the oldest haplotype. Based on geology and proximity, these clades correspond to South American (oldest), Central American, and North American (most recent). Coccoloba uvifera demographic expansion occurred during the Pleistocene epoch and peaked near the end of the last glacial maximum (ca. 0.026–0.019 mybp) when the global sea levels were 125 m lower than today. Our findings also reveal that tropical cyclones, which often impact coastal strand vegetation, did not affect genetic diversity. However, there was a positive association between latitude and the average number of substitutions, further enriching our understanding of the species’ phytogeography. Full article
(This article belongs to the Section Biogeography and Macroecology)
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19 pages, 342 KiB  
Article
Overview of Embedded Rust Operating Systems and Frameworks
by Thibaut Vandervelden, Ruben De Smet, Diana Deac, Kris Steenhaut and An Braeken
Sensors 2024, 24(17), 5818; https://doi.org/10.3390/s24175818 - 7 Sep 2024
Abstract
Embedded Operating Systems (OSs) are often developed in the C programming language. Developers justify this choice by the performance that can be achieved, the low memory footprint, and the ease of mapping hardware to software, as well as the strong adoption by industry [...] Read more.
Embedded Operating Systems (OSs) are often developed in the C programming language. Developers justify this choice by the performance that can be achieved, the low memory footprint, and the ease of mapping hardware to software, as well as the strong adoption by industry of this programming language. The downside is that C is prone to security vulnerabilities unknowingly introduced by the software developer. Examples of such vulnerabilities are use-after-free, and buffer overflows. Like C, Rust is a compiled programming language that guarantees memory safety at compile time by adhering to a set of rules. There already exist a few OSs and frameworks that are entirely written in Rust, targeting sensor nodes. In this work, we give an overview of these OSs and frameworks and compare them on the basis of the features they provide, such as application isolation, scheduling, inter-process communication, and networking. Furthermore, we compare the OSs on the basis of the performance they provide, such as cycles and memory usage. Full article
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17 pages, 283 KiB  
Article
Impact of Industrial Intelligence on China’s Urban Land Green Utilization Efficiency
by Chunyan Zhao, Linjing Wang and Chaobo Zhou
Land 2024, 13(8), 1312; https://doi.org/10.3390/land13081312 - 19 Aug 2024
Viewed by 391
Abstract
Against the backdrop of the fourth technological revolution, industrial intelligence (INDI) represented by industrial robots has rapidly developed. This evolution provides favorable opportunities for precise decision-making in pollution control and achieving China’s “dual carbon” goals. Previous studies have mainly discussed the economic effects [...] Read more.
Against the backdrop of the fourth technological revolution, industrial intelligence (INDI) represented by industrial robots has rapidly developed. This evolution provides favorable opportunities for precise decision-making in pollution control and achieving China’s “dual carbon” goals. Previous studies have mainly discussed the economic effects of INDI from the perspective of the labor market. This study shifts its focus to examining the impact of INDI on the land green utilization efficiency (LGUE) in cities. Using the panel data of Chinese cities spanning 2009–2021, this study empirically tests the effect and transmission mechanism of INDI on LGUE. We find that urban INDI significantly enhances LGUE. In terms of its transmission mechanism, INDI drives improvements in urban LGUE through technological progress, energy structure optimization, and industrial structure upgrading. Urban infrastructure construction and financial agglomeration level can further strengthen the positive impact of INDI on LGUE. In addition, the improvement in LGUE due to INDI is more significant in non-resource-based and large-sized cities than resource-based and small and medium-sized cities. Therefore, each region should enhance the integration of intelligent technology with traditional industrial manufacturing. Doing so is essential to establish comprehensive assessment indicators that balance environmental protection and economic growth, strengthen regional information infrastructure construction, ensure steady financial flow, and support green development initiatives across regions. Full article
(This article belongs to the Section Land Environmental and Policy Impact Assessment)
23 pages, 3682 KiB  
Article
Adaptive Incremental Nonlinear Dynamic Inversion Control for Aerial Manipulators
by Chanhong Park, Alex Ramirez-Serrano and Mahdis Bisheban
Aerospace 2024, 11(8), 671; https://doi.org/10.3390/aerospace11080671 - 15 Aug 2024
Viewed by 433
Abstract
This paper proposes an adaptive incremental nonlinear dynamic inversion (INDI) controller for unmanned aerial manipulators (UAMs). A novel adaptive law is employed to enable aerial manipulators to manage the inertia parameter changes that occur when the manipulator moves or picks up unknown objects [...] Read more.
This paper proposes an adaptive incremental nonlinear dynamic inversion (INDI) controller for unmanned aerial manipulators (UAMs). A novel adaptive law is employed to enable aerial manipulators to manage the inertia parameter changes that occur when the manipulator moves or picks up unknown objects during any phase of the UAM’s flight maneuver. The adaptive law utilizes a Kalman filter to estimate a set of weighting factors employed to adjust the control gain matrix of a previously developed INDI control law formulated for the corresponding UAV (no manipulator included). The proposed adaptive control scheme uses acceleration and actuator input measurements of the UAV without necessitating any knowledge about the manipulator, its movements, or the objects being grasped, thus enabling the use of previously developed INDI UAV controllers for UAMs. The algorithm is validated through simulations demonstrating that the adaptive control gain matrix used in the UAV’s INDI controller is promptly updated based on the UAM maneuvers, resulting in effective UAV and robot arm control. Full article
(This article belongs to the Special Issue Challenges and Innovations in Aircraft Flight Control)
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13 pages, 3002 KiB  
Article
Using Citizen Science and Field Surveys to Document the Introduction, Establishment, and Rapid Spread of the Bare-Eyed Pigeon, Patagioenas corensis, on the Island of Saint-Martin, West Indies
by Christopher Cambrone, Anthony Levesque and Frank Cézilly
Biology 2024, 13(8), 585; https://doi.org/10.3390/biology13080585 - 1 Aug 2024
Viewed by 687
Abstract
Early reporting of the introduction and establishment of exotic species is of paramount importance for successful management. Here, we report the introduction and rapid spread of the Bare-eyed Pigeon, Patagioenas corensis, on the binational island of Saint-Martin, the West Indies. This range-restricted [...] Read more.
Early reporting of the introduction and establishment of exotic species is of paramount importance for successful management. Here, we report the introduction and rapid spread of the Bare-eyed Pigeon, Patagioenas corensis, on the binational island of Saint-Martin, the West Indies. This range-restricted species naturally occurs in arid coastal areas of Columbia and Venezuela and nearby islands. Its introduction on Saint-Martin represents an expansion of about 1000 km beyond its established native range. Using observations recorded in eBird and results from a recent field survey, we show that since its introduction, most probably between late 2012 and early 2013, the species has expanded fast in Saint-Martin and has recently broadened its habitat to include anthropized, built areas. The expansion of Bare-eyed Pigeon on Saint-Martin and the neighboring Leeward Islands, possibly facilitated by climate change in the future, could be a threat to both native columbid species and other bird species through competition for resources. We therefore recommend that local authorities and stakeholders rapidly eradicate the species or at least prevent its further spread on Saint-Martin, possibly though listing it as a game species, while it is still possible to do so. Full article
(This article belongs to the Section Conservation Biology and Biodiversity)
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23 pages, 21813 KiB  
Article
mRNA Profiling and Transcriptomics Analysis of Chickens Received Newcastle Disease Virus Genotype II and Genotype VII Vaccines
by Putri Pandarangga, Phuong Thi Kim Doan, Rick Tearle, Wai Yee Low, Yan Ren, Hanh Thi Hong Nguyen, Niluh Indi Dharmayanti and Farhid Hemmatzadeh
Pathogens 2024, 13(8), 638; https://doi.org/10.3390/pathogens13080638 - 30 Jul 2024
Viewed by 524
Abstract
Newcastle Disease Virus (NDV) genotype VII (GVII) is becoming the predominant strain of NDV in the poultry industry. It causes high mortality even in vaccinated chickens with a common NDV genotype II vaccine (GII-vacc). To overcome this, the killed GVII vaccine has been [...] Read more.
Newcastle Disease Virus (NDV) genotype VII (GVII) is becoming the predominant strain of NDV in the poultry industry. It causes high mortality even in vaccinated chickens with a common NDV genotype II vaccine (GII-vacc). To overcome this, the killed GVII vaccine has been used to prevent NDV outbreaks. However, the debate about vaccine differences remains ongoing. Hence, this study investigated the difference in chickens’ responses to the two vaccines at the molecular level. The spleen transcriptomes from vaccinated chickens reveal that GVII-vacc affected the immune response by downregulating neuroinflammation. It also enhanced a synaptogenesis pathway that operates typically in the nervous system, suggesting a mechanism for the neurotrophic effect of this strain. We speculated that the down-regulated immune system regulation correlated with protecting the nervous system from excess leukocytes and cytokine activity. In contrast, GII-vacc inhibited apoptosis by downregulating PERK/ATF4/CHOP as part of the unfolded protein response pathway but did not affect the expression of the same synaptogenesis pathway. Thus, the application of GVII-vacc needs to be considered in countries where GVII is the leading cause of NDV outbreaks. The predicted molecular signatures may also be used in developing new vaccines that trigger specific genes in the immune system in combating NDV outbreaks. Full article
(This article belongs to the Special Issue Host Immune Responses to RNA Viruses, Volume II)
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26 pages, 490 KiB  
Article
Trustworthy Environmental Monitoring Using Hardware-Assisted Security Mechanisms
by Laurent Segers, Borna Talebi, Bruno da Silva, Abdellah Touhafi and An Braeken
Sensors 2024, 24(14), 4720; https://doi.org/10.3390/s24144720 - 20 Jul 2024
Viewed by 607
Abstract
Environmental monitoring is essential for safeguarding the health of our planet and protecting human health and well-being. Without trust, the effectiveness of environmental monitoring and the ability to address environmental challenges are significantly compromised. In this paper, we present a sensor platform capable [...] Read more.
Environmental monitoring is essential for safeguarding the health of our planet and protecting human health and well-being. Without trust, the effectiveness of environmental monitoring and the ability to address environmental challenges are significantly compromised. In this paper, we present a sensor platform capable of performing authenticated and trustworthy measurements, together with a lightweight security protocol for sending the data from the sensor to a central server anonymously. Besides presenting a new and very efficient symmetric-key-based protocol, we also demonstrate on real hardware how existing embedded security modules can be utilized for this purpose. We provide an in-depth evaluation of the performance and a detailed security analysis. Full article
(This article belongs to the Section Communications)
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16 pages, 7251 KiB  
Article
Interactive Path Editing and Simulation System for Motion Planning and Control of a Collaborative Robot
by Taeho Yoo and Byoung Wook Choi
Electronics 2024, 13(14), 2857; https://doi.org/10.3390/electronics13142857 - 19 Jul 2024
Viewed by 408
Abstract
Robots in hazardous environments demand precise and advanced motion control, making extensive simulations crucial for verifying the safety of motion planning. This paper presents a simulation system that enables interactive path editing, allowing for motion planning in a simulated collaborative robot environment and [...] Read more.
Robots in hazardous environments demand precise and advanced motion control, making extensive simulations crucial for verifying the safety of motion planning. This paper presents a simulation system that enables interactive path editing, allowing for motion planning in a simulated collaborative robot environment and its real-world application. The system includes a simulation host, a control board, and a robot. Unity 3D on a Windows platform provides the simulation environment, while a virtual Linux environment runs ROS2 for execution. Unity sends edited motion paths to ROS2 using the Unity ROS TCP Connector package. The ROS2 MoveIt framework generates trajectories, which are synchronized back to Unity for simulation and real-world validation. To control the six-axis Indy7 collaborative robot, we used the MIO5272 embedded board as an EtherCAT master. Verified trajectories are sent to the target board, synchronizing the robot with the simulation in position and speed. Data are relayed from the host to the MIO5272 using ROS2 and the Data Distribution Service (DDS) to control the robot via EtherCAT communication. The system enables direct simulation and control of various trajectories for robots in hazardous environments. It represents a major advancement by providing safe and optimized trajectories through efficient motion planning and repeated simulations, offering a clear improvement over traditional time-consuming and error-prone teach pendant methods. Full article
(This article belongs to the Special Issue Multi-robot Systems: Collaboration, Control, and Path Planning)
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15 pages, 4965 KiB  
Article
The Increase in the Plasticity of Microcrystalline Cellulose Spheres’ When Loaded with a Plasticizer
by Artūrs Paulausks, Tetiana Kolisnyk and Valentyn Mohylyuk
Pharmaceutics 2024, 16(7), 945; https://doi.org/10.3390/pharmaceutics16070945 - 16 Jul 2024
Viewed by 707
Abstract
Compaction pressure can induce an undesirable solid-state polymorphic transition in drugs, fragmentation, loss of coated pellet integrity, and the decreased viability and vitality of microorganisms. Thus, the excipients with increased plasticity can be considered as an option to decrease the undesirable effects of [...] Read more.
Compaction pressure can induce an undesirable solid-state polymorphic transition in drugs, fragmentation, loss of coated pellet integrity, and the decreased viability and vitality of microorganisms. Thus, the excipients with increased plasticity can be considered as an option to decrease the undesirable effects of compaction pressure. This study aims to increase the plasticity (to reduce the mean yield pressure; Py) of dried microcrystalline cellulose (MCC) by loading it with a specially selected plasticizer. Diethyl citrate (DEC), water, and glycerol were the considered plasticizers. Computation of solubility parameters was used to predict the miscibility of MCC with plasticizers (possible plasticization effect). Plasticizer-loaded MCC spheres with 5.0 wt.% of water, 5.2 wt.% of DEC, and 4.2 wt.% glycerol were obtained via the solvent method, followed by solvent evaporation. Plasticizer-loaded formulations were characterised by TGA, DSC, pXRD, FTIR, pressure-displacement profiles, and in-die Heckel plots. Py was derived from the in-die Heckel analysis and was used as a plasticity parameter. In comparison with non-plasticized MCC (Py = 136.5 MPa), the plasticity of plasticizer-loaded formulations increased (and Py decreased) from DEC (124.7 MPa) to water (106.6 MPa) and glycerol (99.9 MPa), and that was in full accordance with the predicted miscibility likeliness order based on solubility parameters. Therefore, water and glycerol were able to decrease the Py of non-plasticized MCC spheres by 16.3 and 30.0%, respectively. This feasibility study showed the possibility of modifying the plasticity of MCC by loading it with a specially selected plasticizer. Full article
(This article belongs to the Section Physical Pharmacy and Formulation)
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11 pages, 509 KiB  
Brief Report
Utilizing Agricultural By-Products for Sustainable Agouti (Dasyprocta leporina) Diets: Evaluating Low-Cost Feed Alternatives in Trinidad and Tobago, West Indies
by Shecania Elysha Small, Eden Natalia John, Kavita Ranjeeta Lall and Kegan Romelle Jones
Sustainability 2024, 16(14), 5986; https://doi.org/10.3390/su16145986 - 12 Jul 2024
Viewed by 734
Abstract
The agouti (Dasyprocta leporina) is a promising protein source in the Caribbean, Mexico, and South America. This study assessed the impact of three by-product diet formulations on intensively reared agoutis, including a cost analysis and nutritional evaluation as well as the [...] Read more.
The agouti (Dasyprocta leporina) is a promising protein source in the Caribbean, Mexico, and South America. This study assessed the impact of three by-product diet formulations on intensively reared agoutis, including a cost analysis and nutritional evaluation as well as the nutritional composition, digestibility, and economic viability of three experimental diets. Sixteen adult male agoutis were individually housed at the University of the West Indies’ Field Station. After a two-week acclimatization, a four-week data collection phase followed. The four treatments included a control diet of commercial rabbit pellets and three experimental diets with varying by-product ratios. Key findings revealed that Treatment 2 had elevated Dry Matter, Crude Fat, and fiber but potentially compromised digestibility due to higher fiber and lignin. Treatment 1 resulted in the highest morbidity and was discontinued after two weeks due to significant weight loss but demonstrated the most cost-effective results, with the lowest variable cost per 45 kg, the lowest feeding cost to reach 3 kg, and the highest gross margin. Treatment 2 effectively maintained animal weight. Treatment 3 showed promising growth due to low levels of Neutral Detergent Fiber (NDF) and Acid Detergent Lignin (ADL). Alternative dietary feedstuffs from agricultural by-products show potential for sustaining body weight in adult male agoutis, but further research is needed to refine nutritional requirements for growing agoutis. Full article
(This article belongs to the Section Sustainable Agriculture)
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9 pages, 246 KiB  
Article
Malnutrition and Its Determinants among Older Adults Living in French Caribbean Nursing Homes: A Cross-Sectional Study
by Maturin Tabue Teguo, Laurys Letchimy, Leila Rinaldo, Michel Bonnet, Huidi Tchero, Nadine Simo-Tabue and Denis Boucaud-Maitre
Nutrients 2024, 16(14), 2208; https://doi.org/10.3390/nu16142208 - 10 Jul 2024
Viewed by 691
Abstract
Background: This study aimed to assess the prevalence of malnutrition and its determinants in older adults living in French Caribbean nursing homes. Methods: This cross-sectional study was taken from the KASEHAD (Karukera Study of Ageing in EHPAD) study. Nutritional status was assessed with [...] Read more.
Background: This study aimed to assess the prevalence of malnutrition and its determinants in older adults living in French Caribbean nursing homes. Methods: This cross-sectional study was taken from the KASEHAD (Karukera Study of Ageing in EHPAD) study. Nutritional status was assessed with the Mini Nutritional Assessment Short-Form (MNA-SF). Clinical characteristics and scores on geriatric scales (Mini-Mental State Examination (MMSE), Activities of Daily Living (ADL), Short Physical Performance Battery (SPPB), Center for Epidemiologic Studies-Depression (CESD) and Questionnaire Quality of Life Alzheimer’s Disease (QoL-AD)) were extracted. Bivariate analysis and logistic models adjusted were performed to test the association between nutritional status and both socio-demographic variables and geriatric scales. Results: A total of 332 older adults from six nursing homes were included in the KASEHPAD study. Among the participants, 319 had an MNA-SF score. The mean age was 81.3 ± 10.6 years, and half of the participants were men. The frequency of malnutrition (MNA-SF ≤ 7) was 27.6% (95% confidence interval (CI): 22.0–32.5) (n = 88). Based on the multivariable analysis, a low MMSE was associated with malnutrition (OR: 0.81 (0.68–0.92); p = 0.015) and there was a borderline significant link between a higher CESD score and malnutrition (OR: 1.05 (1.00–1.12); p = 0.07). Conclusions: Cognitive decline and a tendency toward depression were associated with malnutrition in nursing homes in the French West Indies. Although this study cannot establish causal relationships, the identification of these three geriatric syndromes in nursing homes is crucial for preventing adverse health events. Full article
(This article belongs to the Section Geriatric Nutrition)
17 pages, 4432 KiB  
Article
Towards Reliability in Smart Water Sensing Technology: Evaluating Classical Machine Learning Models for Outlier Detection
by Mimoun Lamrini, Bilal Ben Mahria, Mohamed Yassin Chkouri and Abdellah Touhafi
Sensors 2024, 24(13), 4084; https://doi.org/10.3390/s24134084 - 24 Jun 2024
Viewed by 601
Abstract
In recent years, smart water sensing technology has played a crucial role in water management, addressing the pressing need for efficient monitoring and control of water resources analysis. The challenge in smart water sensing technology resides in ensuring the reliability and accuracy of [...] Read more.
In recent years, smart water sensing technology has played a crucial role in water management, addressing the pressing need for efficient monitoring and control of water resources analysis. The challenge in smart water sensing technology resides in ensuring the reliability and accuracy of the data collected by sensors. Outliers are a well-known problem in smart sensing as they can negatively affect the viability of useful analysis and make it difficult to evaluate pertinent data. In this study, we evaluate the performance of four sensors: electrical conductivity (EC), dissolved oxygen (DO), temperature (Temp), and pH. We implement four classical machine learning models: support vector machine (SVM), artifical neural network (ANN), decision tree (DT), and isolated forest (iForest)-based outlier detection as a pre-processing step before visualizing the data. The dataset was collected by a real-time smart water sensing monitoring system installed in Brussels’ lakes, rivers, and ponds. The obtained results clearly show that the SVM outperforms the other models, showing 98.38% F1-score rates for pH, 96.98% F1-score rates for temp, 97.88% F1-score rates for DO, and 98.11% F1-score rates for EC. Furthermore, ANN also achieves a significant results, establishing it as a viable alternative. Full article
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20 pages, 3401 KiB  
Article
Incremental Nonlinear Dynamics Inversion and Incremental Backstepping: Experimental Attitude Control of a Tail-Sitter UAV
by Alexandre Athayde, Alexandra Moutinho and José Raul Azinheira
Actuators 2024, 13(6), 225; https://doi.org/10.3390/act13060225 - 17 Jun 2024
Viewed by 593
Abstract
Incremental control strategies such as Incremental Nonlinear Dynamics Inversion (INDI) and Incremental Backstepping (IBKS) provide undeniable advantages for controlling Uncrewed Aerial Vehicles (UAVs) due to their reduced model dependency and accurate tracking capacities, which is of particular relevance for tail-sitters as these perform [...] Read more.
Incremental control strategies such as Incremental Nonlinear Dynamics Inversion (INDI) and Incremental Backstepping (IBKS) provide undeniable advantages for controlling Uncrewed Aerial Vehicles (UAVs) due to their reduced model dependency and accurate tracking capacities, which is of particular relevance for tail-sitters as these perform complex, hard to model manoeuvres when transitioning to and from aerodynamic flight. In this research article, a quaternion-based form of IBKS is originally deduced and applied to the stabilization of a tail-sitter in vertical flight, which is then implemented in a flight controller and validated in a Hardware-in-the-Loop simulation, which is also made for the INDI controller. Experimental validation with indoor flight tests of both INDI and IBKS controllers follows, evaluating their performance in stabilizing the tail-sitter prototype in vertical flight. Lastly, the tracking results obtained from the experimental trials are analysed, allowing an objective comparison to be drawn between these controllers, evaluating their respective advantages and limitations. From the successfully conducted flight tests, it was found that both incremental solutions are suited to control a tail-sitter in vertical flight, providing accurate tracking capabilities with smooth actuation, and only requiring the actuation model. Furthermore, it was found that the IBKS is significantly more computationally demanding than the INDI, although having a global proof of stability that is of interest in aircraft control. Full article
(This article belongs to the Special Issue From Theory to Practice: Incremental Nonlinear Control)
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21 pages, 11127 KiB  
Article
Evaluation of the Functional Connectivity between the Mangomarca Fog Oasis and the Adjacent Urban Area Using Landscape Graphs
by Pedro Amaya, Violeta Vega, Doris Esenarro, Oscar Cuya and Vanessa Raymundo
Forests 2024, 15(6), 1003; https://doi.org/10.3390/f15061003 - 7 Jun 2024
Cited by 1 | Viewed by 671
Abstract
The present research aimed to measure the degree of connectivity and create a map of the ecological connectivity that highlights the real or potential presence of green, ecological, or ecotourism circuits integrating the green infrastructure of San Juan de Lurigancho and the Mangomarca [...] Read more.
The present research aimed to measure the degree of connectivity and create a map of the ecological connectivity that highlights the real or potential presence of green, ecological, or ecotourism circuits integrating the green infrastructure of San Juan de Lurigancho and the Mangomarca hills using graph theory applications implemented in the Graphab 2.8 software. Mangomarca and Huiracocha Park were selected for this study. In terms of the methodology, a simple approach based on landscape metrics, which are easy to interpret, was proposed to measure the connectivity of the mosaic of patches in the designated area. The IndiFrag software was used to obtain landscape metrics for the structural connectivity analysis. The Graphab software was employed for the functional connectivity analysis. Both tools proved effective in identifying vegetation gaps or the intensity of the greenery. Landsat 8 images from 8 July 2021 and 4 October 2021 were selected for this research due to the lower amount of cloud cover. Concerning the structural connectivity, the TMCl (patch size), NobCl (number of patches), and PerimCl (perimeter) metrics were effective in distinguishing the mosaic of urban landscape patches from the hill landscape. These indices confirm that the urban landscape patches have a higher number of fragments but are smaller in size compared to the hill landscape. Regarding the functional connectivity, it is evident that the patches are connected at lower-cost distances, averaging 7 cost units (210 m) during the wet season and 23 cost units (410 m) during the less humid season. However, these distances are too extensive and do not form ecological corridors. A survey of the population’s perception of the maximum separation distances between patches of vegetation cover that could still be considered a green corridor was included. The results indicate that a third of the sample (36%) prefer to walk down a hallway with a maximum separation distance of 10 m, while almost two-thirds (68%) would prefer a maximum separation distance of 50 m. Therefore, city planning should consider actions to reduce these distances and enable ecological connectivity in the area. It is recommended to continue researching the functional connectivity and determining the green corridors in the city to establish monitoring guidelines for the ecological connectivity of the city. Full article
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18 pages, 3329 KiB  
Article
Parameter Tuning Approach for Incremental Nonlinear Dynamic Inversion-Based Flight Controllers
by Mark Henkenjohann, Udo Nolte, Fabian Sion, Christian Henke and Ansgar Trächtler
Actuators 2024, 13(5), 187; https://doi.org/10.3390/act13050187 - 13 May 2024
Viewed by 962
Abstract
Incremental nonlinear dynamic inversion (INDI) is a widely used approach to controlling UAVs with highly nonlinear dynamics. One key element of INDI-based controllers is the control allocation realizing pseudo controls using available actuators. However, the tracking of commanded pseudo controls is not the [...] Read more.
Incremental nonlinear dynamic inversion (INDI) is a widely used approach to controlling UAVs with highly nonlinear dynamics. One key element of INDI-based controllers is the control allocation realizing pseudo controls using available actuators. However, the tracking of commanded pseudo controls is not the only objective considered during control allocation. Since the approach only works locally due to linearization and the solution is often ambiguous, additional aspects like control efforts or penalizing the deviation of certain states must be considered. Conducting the control allocation by solving a quadratic program this results in a considerable number of weighting parameters, which must be tuned during control design. Currently, this is conducted manually and is therefore time consuming. An automated approach for tuning these parameters is therefore highly beneficial. Thus, this paper presents and evaluates a model-based approach automatically tuning the control allocation parameters of a tiltrotor VTOL using an optimization algorithm. This optimization algorithm searches for optimal parameters minimizing a cost functional that reflects the design target. This cost functional is calculated based on a test mission for the VTOL which is conducted within a simulation environment. The test mission represents the common operating range of the VTOL. The simulation environment consists of an aircraft model as well as a model of the INDI-based controller which is dependent on the control allocation parameters. On this basis, model-based optimization is conducted and the optimal parameters are identified. Finally, successful real-world tests on a 4-degrees-of-freedom testbench using the identified parameters are presented. Since the control allocation parameters can significantly influence the aircraft’s stability, the 4-DOF testbench for the aircraft is required for rapid validation of the parameters at a minimum amount of risk. Full article
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