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- 摘要
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- 实验方案
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Dynamics Modeling and Theoretical Study of the Two-Axis Four-Gimbal Coarsea??Fine Composite UAV Electro-Optical Pod
摘要： In the UAV electro-optical pod of the two-axis four-gimbal, the characteristics of a coarse–fine composite structure and the complexity of dynamics modeling affect the entire system’s high precision control performance. The core goal of this paper is to solve the high precision control of a two-axis four-gimbal electro-optical pod through dynamic modeling and theoretical study. In response to this problem, we used finite element analysis (FEA) and stress study of the key component to design the structure. The gimbals adopt the aerospace material 7075-t3510 aluminum alloy in order to meet the requirements of an ultralight weight of less than 1 kg. According to the Euler rigid body dynamics model, the transmission path and kinematics coupling compensation matrix between the two-axis four-gimbal structures are obtained. The coarse–fine composite self-correction drive equation in the Cartesian system is derived to solve the pre-selection and check problem of the mechatronic under high-precision control. Finally, the modeling method is substituted into the disturbance observer (DOB) disturbance suppression experiment, which can monitor and compensate for the motion coupling between gimbal structures in real time. Results show that the disturbance suppression impact of the DOB method with dynamics model is increased by up to 90% compared to PID (Proportion Integration Differentiation method) and is 25% better than the traditional DOB method.
关键词： dynamics modeling,coarse–fine composite,electro-optical pod,two-axis four-gimbal
更新于2025-09-23 15:19:57
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Understanding Tree-to-Tree Variations in Stone Pine (Pinus pinea L.) Cone Production Using Terrestrial Laser Scanner
摘要： Kernels found in stone pinecones are of great economic value, often surpassing timber income for most forest owners. Visually evaluating cone production on standing trees is challenging since the cones are located in the sun-exposed part of the crown, and covered by two vegetative shoots. Very few studies were carried out in evaluating how new remote sensing technologies such as terrestrial laser scanners (TLS) can be used in assessing cone production, or in trying to explain the tree-to-tree variability within a given stand. Using data from 129 trees in 26 plots located in the Spanish Northern Plateau, the gain observed by using TLS data when compared to traditional inventory data in predicting the presence, the number, and the average weight of the cones in an individual tree was evaluated. The models using TLS-derived metrics consistently showed better fit statistics, when compared to models using traditional inventory data pertaining to site and tree levels. Crown dimensions such as projected crown area and crown volume, crown density, and crown asymmetry were the key TLS-derived drivers in understanding the variability in inter-tree cone production. These results underline the importance of crown characteristics in assessing cone production in stone pine. Moreover, as cone production (number of cones and average weight) is higher in crowns with lower density, the use of crown pruning, abandoned over 30 years ago, might be the key to increasing production in combination with stand density management.
关键词： modeling,terrestrial laser scanner,inter-tree variability,stone pinecone production,crown characteristics
更新于2025-09-23 15:19:57
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Optimized Operation of Quantum-Dot Intermediate-Band Solar Cells Deduced from Electronic Transport Modeling
摘要： Study of the physics of quantum electronic transport has not tackled the problems raised by quantum-dot intermediate-band solar cells. Our study shows that this physics imposes design rules for the intersubband transition. We develop an analytical model that correctly treats, from a quantum point of view, the trade-off between the absorption, the recombination, and the electronic transport occurring in this transition. Our results clearly indicate that it is essential to control the transit rate between the excited state of the quantum dot and the embedding semiconductor. For that, we propose assuming the dot in a tunnel shell whose main characteristics can be obtained by a simple analytical formula. Moreover, we show that in a realistic case, the energy transition needs to be larger than only 0.27 eV to obtain a quasi-Fermi-level-splitting. This quite small value designates the quantum-dot solar cell as a serious candidate to be an efficient intermediate-band solar cell. This work gives a framework to design efficient intersubband transitions and opens new opportunities for quantum-dot intermediate-band solar cells.
关键词： quantum-dot,intersubband transition,electronic transport modeling,intermediate-band solar cells,quasi-Fermi-level-splitting
更新于2025-09-23 15:19:57
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CMOS Backplane Pixel Circuit With Leakage and Voltage Drop Compensation for an Micro-LED Display Achieving 5000 PPI or Higher
摘要： Smart grids are electric networks that employ advanced monitoring, control, and communication technologies to deliver reliable and secure energy supply, enhance operation efficiency for generators and distributors, and provide flexible choices for prosumers. Smart grids are a combination of complex physical network systems and cyber systems that face many technological challenges. In this paper, we will first present an overview of these challenges in the context of cyber–physical systems. We will then outline potential contributions that cyber–physical systems can make to smart grids, as well as the challenges that smart grids present to cyber–physical systems. Finally, implications of current technological advances to smart grids are outlined.
关键词： control,cyber–physical systems,modeling,smart grids,Big data,optimization,renewable energy,cloud computing,multiagent systems,intelligent systems,complex networks
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 15th Brazilian Power Electronics Conference and 5th IEEE Southern Power Electronics Conference (COBEP/SPEC) - Santos, Brazil (2019.12.1-2019.12.4)] 2019 IEEE 15th Brazilian Power Electronics Conference and 5th IEEE Southern Power Electronics Conference (COBEP/SPEC) - A Curve Tracer for Photovoltaic Modules Based on The Capacitive Load Method
摘要： This work presents the development of a current versus voltage (I-V) curve tracer of photovoltaic (PV) modules based on the capacitive load method, being this an important approach for checking the integrity of PV devices and also the extraction of intrinsic parameters for modeling purposes. The tracer employs a microcontroller to manipulate the data required from current and voltage sensors associated with the module output quantities. For comparison purposes, three different values of capacitance are used to trace the I-V characteristic of a 5-Wp module, as it is possible to verify that the capacitor charging time has direct influence on the number of acquired points that constitute the curve.
关键词： photovoltaic solar energy,photovoltaic system modeling,curve tracer,capacitive load method
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 15th Brazilian Power Electronics Conference and 5th IEEE Southern Power Electronics Conference (COBEP/SPEC) - Santos, Brazil (2019.12.1-2019.12.4)] 2019 IEEE 15th Brazilian Power Electronics Conference and 5th IEEE Southern Power Electronics Conference (COBEP/SPEC) - On the Influence of Area Variations of the Photovoltaic ;Surface in Solar Cell Antennas
摘要： Some low power applications where antennas and solar cells are integrated into the same system have limitations and requirements imposed by the radiation characteristics that, usually, are ful?lled by varying solar cell physical parameters. The negative in?uences of those variations are not profoundly discussed in the literature that studies the extremely low-power systems, where radiofrequency and photovoltaic devices share the same structure. In this context, this work models a photovoltaic cell used as an antenna and analyzes the consequences of the solar cell area variation, imposed by the fabrication process of the radiating element. The parameters of the one-diode equivalent circuit model are extracted and used to simulated the I-V curves for different irradiance levels, validating the simulations with experimental measurements performed in the laboratory. Also, the solar cell ?ll factor, energy conversion ef?ciency, and current density are analyzed.
关键词： low power devices,Solar cell modeling,energy harvesting,solar cell and antenna integration
更新于2025-09-23 15:19:57
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An Efficient Non-Invasive Method to Fabricate In-Fiber Microcavities Using a Continuous-Wave Laser
摘要： Natural ecosystems exhibit complex dynamics of interacting species. Man-made ecosystems exhibit similar dynamics and, in the case of mobile app stores, can be said to perform optimization as developers seek to maximize app downloads. This work aims to understand stability and instability within app store dynamics and how it affects ?tness. The investigation is carried out with AppEco, a model of the iOS App Store, which was extended for this paper and updated to model the store from 2008 to 2014. AppEco models apps containing features, developers who build the apps, users who download apps according to their preferences, and an app store that presents apps to the users. It also models developers who use commonly observed strategies to build their apps: innovator, milker, optimizer, copycat, and ?exible (the ability to choose any strategy). Results show that despite the success of the copycat strategy, there is a clear stable state for low proportion of copycats in developer populations, mirroring results in theoretical biology for producer–scrounger systems. The results also show that the best ?tness is achieved when the evolutionary optimizer (as producer) and copycat (as scrounger) strategies coexist together in stable proportions.
关键词： mobile app developers,Agent-based simulation,evolutionary ecosystem model,genetic algorithms,app stores,producer–scrounger systems,computational modeling
更新于2025-09-23 15:19:57
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Ultrafast pulse generation for Er- and Tm- doped fiber lasers with Sb thin film saturable absorber
摘要： General principles are developed using a finite element model regarding how time-dependent power dissipation of magnetic nanoparticles can be used to optimize hyperthermia selectivity. To make the simulation more realistic, the finite size and spatial location of each individual nanoparticle is taken into consideration. When energy input into the system and duration of treatment is held constant, increasing the maximum power dissipation of nanoparticles increases concentrations of energy in the tumor. Furthermore, when the power dissipation of magnetic nanoparticles rises linearly, the temperature gradient on the edge of the tumor increases exponentially. With energy input held constant, the location and duration of maximum power dissipation in the treatment time scheme will affect the final energy concentration inside the tumor. Finally, connections are made between the simulation results and optimization of the design of nanoparticle power dissipation time-schemes for hyperthermia.
关键词： treatment planning,finite-element modeling,Hyperthermia optimization,magnetic nanoparticles
更新于2025-09-23 15:19:57
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Hybrid 2Da??0D SnS <sub/>2</sub> Nanoflakes/CTS QDs-Based Broadband (UV-Visible-NIR) Photodetector
摘要： Future and current high-performance computing applications will have to change and adapt as node architectures evolve. The application of advanced architecture simulators will play a crucial role for the design and optimization of future data intensive applications. In this paper, we present our simulation-based framework for analyzing the scalability and performance of a number of critical optimizations of a massively parallel genomic search application, mpiBLAST, using an advanced macroscale simulator (SST/macro). We report the use of our framework for the evaluation of three potential improvements of mpiBLAST: 1) enabling high-performance parallel output; 2) an approach for caching database fragments in memory; and 3) a methodology for pre-distributing database segments. In our experimental setup, we performed query sequence matching on the genome of the yellow fever mosquito, Aedes aegypti.
关键词： Exascale architecture simulator,message passing interface,multiprocessor programming,mpiBLAST,performance and scalability modeling
更新于2025-09-23 15:19:57
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Simplified Technique of Technological Support for the Operation of Laser Beam Processing of Materials
摘要： In the design of a working operation with a multicriteria estimation of results a stage in the procedure is selecting technology regulations for the implementation. A modified optimization algorithm is proposed that simplifies the content of the factor space by eliminating critical values in searching for an optimum processing mode. The influence of these values is compensated by changing the strategy of the working operation, in particular, by using the method of fitting the critical index to the required level with a decreasing controlled increment of the value. To implement various operations with an adaptive form of their organization (precision hole machining, formation of dimensional slits, and surface heating with a normalized depth of the zone), a number of process installations and devices have been developed, whose circuits are presented in this work. Their application improves the reproducibility of the processing results in the case of a simplified procedure for selecting the regulations by which the technology is operated.
关键词： adaptive operation organization,selection method,laser beam,processing mode,optimization,laser,technological operation,technological support of process modeling
更新于2025-09-23 15:19:57