Journal articles on the topic 'Topographical surveying Computer simulation'
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Gao, Caiyun, and Qiutang Wu. "Design and Practice of Surveying Experiment System based on a Virtual Platform." International Journal of Emerging Technologies in Learning (iJET) 12, no. 04 (April 28, 2017): 53. http://dx.doi.org/10.3991/ijet.v12i04.6924.
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The experimental teaching of surveying is an effective method for students to acquire basic surveying skills and solve practical problems. By contrast, the traditional experimental teaching mode of surveying presents students with insufficient experimental opportunities and difficulties to achieve independent learning and interactive operation due to limitations in the allotted time for experiments, sites, instruments, and external environmental conditions. This study developed a virtual experimental system by combining network virtual reality technology and surveying experiment. The proposed system intends to provide students with additional experimental opportunities to achieve computer desktop-like virtual experimental devices and engineering construction scenes, thereby accomplishing the indoor simulation of field surveying. This virtual surveying experimental system mainly comprised four modules, namely, classroom teaching, classroom practice, teaching practice, and production practice. This system realized equipment, operation, and data virtualizations, as well as various highly realistic measurement experiments, such as topographic surveying, engineering setting out, and road surveying. Application results demonstrated that the proposed system was convenient for the independent study of students, stimulates their enthusiasm for learning, strengthens their operational ability, and achieves good teaching effect. Furthermore, this system provides a novel experimental teaching mode for surveying courses.
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Liu, Hui, Qing Xu, Guowang Jin, and Hongmin Zhang. "MIMO Antenna Polynomial Weighted Average Design Method of Downward-Looking Array SAR." International Journal of Antennas and Propagation 2017 (2017): 1–18. http://dx.doi.org/10.1155/2017/3029847.
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MIMO antenna polynomial weighted average design method of downward-looking array SAR was proposed from the angle of surveying and mapping in this paper, in order to solve the ill-posed problem that an equivalent virtual array can be implemented by a variety of physical transmitter-receiver arrays for bistatic MIMO linear array. For wave band, resolution, elevation precision, and working height concerned by the applications of surveying and mapping, the length of equivalent virtual array and actual physical array meeting the needs of large scale topographical mapping was solved. Then array numbers and position vectors of MIMO downward-looking array SAR of real aerial mapping platform were optimized. According to this design, some simulation experiments and comparisons were processed. The results proved the rationality and effectiveness of this array configuration by comparing the differences of 3D imaging results and the original simulation scene, counting mean and standard deviation of elevation reconstruction error eliminating the influence of shadow areas, and counting the probability of elevation reconstruction error within half a resolution of the whole scene and individual building area.
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Liu, D., S. K. Dew, M. J. Brett, T. Janacek, T. Smy, and W. Tsai. "Experimental study and computer simulation of collimated sputtering of titanium thin films over topographical features." Journal of Applied Physics 74, no. 2 (July 15, 1993): 1339–44. http://dx.doi.org/10.1063/1.354889.
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Qiang, Liu, and Lin Ling. "Engineering Surveying and Mapping System Based on 3D Point Cloud and Registration Communication Algorithm." Wireless Communications and Mobile Computing 2022 (March 17, 2022): 1–12. http://dx.doi.org/10.1155/2022/4579565.
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In order to improve the effect of engineering surveying and mapping system, this paper improves the three-dimensional point cloud technology. The problem of inaccurate measurement results caused by complex terrain is solved. At the same time, an improved greedy projection triangulation communication reconstruction algorithm is proposed. That is, while homogenizing the point cloud density, the point cloud redundant point removal algorithm is used to remove the overlapping points. The registration algorithm is applied to the engineering system. Combined with the improved algorithm, the system framework of the engineering surveying and mapping system is constructed, and the system algorithm is verified by a simulation example. Finally, combined with the actual situation of engineering communication surveying and mapping, the performance verification of the system is designed and tested, the research results are counted, and the algorithm is evaluated. The system carries out engineering surveying and mapping through three-dimensional point cloud and improves the surveying and mapping accuracy through registration algorithm. The engineering surveying and mapping system based on three-dimensional point cloud and registration algorithm proposed in this paper has high accuracy and can meet the needs of practical engineering. The system solves the problem of inaccurate measurement results caused by complex terrain, complex terrain, and complex terrain.
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Wibawanto, Hilmawan, Roemintoyo Roemintoyo, and Triana Rejekiningsih. "Simulation-based interactive multimedia to improve vocational students' learning outcomes." World Journal on Educational Technology: Current Issues 14, no. 6 (November 28, 2022): 1927–42. http://dx.doi.org/10.18844/wjet.v14i6.8363.
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Learning media supporting practical learning in vocational high school (VHS) is urgent during the COVID-19 pandemic. All VHS competencies, including land surveying techniques, cannot support students with the existing online learning facilities. This study explained the development and impact of using multimedia simulation on the learning outcomes of VHS students. The Alessi and Trollip development model with planning, design, and development phases were used to create the multimedia simulation. The participants in this research included teachers, students, material experts, and media experts. The pre-test and post-test of practical learning outcomes, as well as questionnaires, are selected to collect research data. The results based on the experts’ and teachers’ validation, and students’ assessment indicated that the multimedia simulation was 'feasible' to be used in practical learning. Based on students’ post-test results, the average score in the experimental class increased more than the average score in the control class. These findings suggested that learning land surveying techniques using multimedia simulation is more effective than classes without using multimedia simulation. Teachers and educational researchers might use this study as an example for creating learning materials to raise the standard of instruction in VHSs.
Keywords: multimedia, simulation, learning outcomes, practical learning, vocational
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Elter, Patrick, Regina Lange, R. Thull, and Ulrich Beck. "Protein Adsorption on Topographically Structured Surfaces: A Mesoscopic Computer Simulation for the Prediction of Prefered Adsorption Sites." Materials Science Forum 638-642 (January 2010): 542–47. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.542.
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In this study the influence of edges and spikes of a topographical nanostructure on the adsorption behavior of proteins at a solid-liquid interface is examined by a computer simulation. An algorithm has been developed, which combines a Finite Differences field calculation with Brownian Dynamics. A (16 nm)3 nano-cube with sharp edges as well as flat faces was chosen as model system and the adsorption of Hen Egg White Lysozyme was investigated. An increased adsorption rate along the edges of a the model cube is reached in the initial adsorption phase under consideration of electrostatic and dispersion interactions. At later times also the surfaces of the cube are covered, if the salt concentration is sufficient to screen the repelling protein-protein electrostatic interaction.
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Barliba, Livia Luminita, Costel Barliba, and Gabriel Eles. "Use of a digital information system to achive a topographical embossed plan in Farcasesti village, Gorj county." Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Horticulture 73, no. 2 (November 30, 2016): 304. http://dx.doi.org/10.15835/buasvmcn-hort:12275.
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The purpose of this paper is to obtain thematic maps and topographic analyzes determined on the field and processed through the basic programs of AutoCAD, TopoLT and Global Mapper which along with topogeodezical details high up in on the field create a database required to implement a feasibility study, as a previous step of the general cadastre in the Farcasesti village, Gorj county.Topographical surveying were made with GNSS technology using the RTK-Kinematic method, South V-82 type in Real Time and data processing was performed by specialized graphics programs.Field data collected with GPS RTK were transferred to a computer using specialized software LeicaGeo Combined Office and other software like Notepad, Excel, Word, AutoCad 2013. The imported data from the field in three spatial coordinates, respectively X, Y and Z, were the basis for drawing up planimetric situation plans by outlining the details of the terrain and elevation.In the present paper, we demonstrate that the use of GPS technology made possible topogeodezical data collection from a large area with high precision in a short time using reduced material and human resources. This allowed us to import data from the field by using topogeodezical specialized programs and accurately achieve the outlines of buildings and perimeter, as verified by superimposing them on orthophotomap. Achieving digital plans using AutoCAD Architectural demonstrated that they can be made with accuracy and precision permitting various analyzes of land, including the construction of contour in 2D and 3D.
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Awang Ali, Awang Nasrizal, and Junaidah Ariffin. "Model Reliability Assessment: A Hydrodynamic Modeling Approach for Flood Simulation in Damansara Catchment Using InfoWorks RS." Advanced Materials Research 250-253 (May 2011): 3769–75. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.3769.
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This paper presents the flood inundation model using a hydrodynamic approach for flood simulation. A Digital Elevation Model (DEM) for Damansara Catchment was developed and integrated into the InfoWorks River Simulation (RS) program. Hydrographic surveying activity was carried out to collect existing Damansara River cross-section. The 3D flood model was calibrated using the 26th February 2006 and 15th October 2008 flooding event data. The model was validated using the flooding event on 21st March 2007. This computer simulation results produced hydrograph that indicates the capability of the model in dealing with regional flood analysis for future usage in designing structural flood measures.
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Lin, Tzu-Jui, and Karl A. Stol. "Autonomous Surveying of Plantation Forests Using Multi-Rotor UAVs." Drones 6, no. 9 (September 16, 2022): 256. http://dx.doi.org/10.3390/drones6090256.
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Modern plantation forest procedures still rely heavily on manual data acquisition in the inventory process, limiting the quantity and quality of the collected data. This limitation in collection performance is often due to the difficulty of traversing the plantation forest environment on foot. This work presents an autonomous system for exploring plantation forest environments using multi-rotor UAVs. The proposed method consists of three parts: waypoint selection, trajectory generation, and trajectory following. Waypoint selection is accomplished by estimating the rows’ locations within the environment and selecting points between adjacent rows. Trajectory generation is completed using a non-linear optimization-based constant speed planner and the following is accomplished using a model predictive control approach. The proposed method is tested extensively in simulation against various procedurally generated forest environments, with results suggesting that it is robust against variations within the scene. Finally, flight testing is performed in a local plantation forest, demonstrating the successful application of our proposed method within a complex, uncontrolled environment.
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Liao, Shifang, Manzhu Ye, Rongcai Yuan, and Wanzhi Ma. "Unmanned Aerial Vehicle Surveying and Mapping Trajectory Scheduling and Autonomous Control for Landslide Monitoring." Journal of Robotics 2022 (March 24, 2022): 1–13. http://dx.doi.org/10.1155/2022/2365006.
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Real-time and efficient monitoring of geological disasters has received extensive attention in the application of UAV surveying and mapping control technology. The application of traditional landslide monitoring methods lacks the accuracy of control algorithms, which has become a hot issue currently facing. Based on the landslide surface subsidence monitoring method, this article designs the UAV trajectory scheduling subsidence monitoring software, which can monitor the UAV’s flight status and navigation information, and draw the flight trajectory in real time. At the same time, the model solves the problem of storage and management of landslide inspection results by the landslide inspection management system, and realizes the functions of entering and querying landslide information, viewing inspection results, landslide safety judgment, generating reports, and autonomous control. The simulation results show that the global accuracy reaches 0.975, and the algorithm recognition degree reaches 99.8%, which promotes the reliability of the landslide monitoring data for the identification of the surveying and mapping trajectory, and provides a decision-making basis for landslide treatment.
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HOMCHAUDHURI, BAISRAVAN, MANISH KUMAR, and KELLY COHEN. "GENETIC ALGORITHM BASED SIMULATION–OPTIMIZATION FOR FIGHTING WILDFIRES." International Journal of Computational Methods 10, no. 06 (May 2, 2013): 1350035. http://dx.doi.org/10.1142/s0219876213500357.
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Wildfire is one of the most significant disturbances responsible for reshaping the terrain and changing the ecosystem of a particular region. Its detrimental effects on environment as well as human lives and properties, and growing trend in terms of frequency and intensity of wildfires over the last decade have necessitated the development of efficient forest fire management techniques. During the last three decades, Forest Fire Decision Support Systems (FFDSS) have been developed to help in the decision-making processes during forest fires by providing necessary information on fire detection, their status and behavior, and other aspects of forest fires. However, most of these decision support systems lack the capability of developing intelligent fire suppression strategies based upon current status and predicted behavior of forest fire. This paper presents an approach for development of efficient fireline building strategies via intelligent resource allocation. A Genetic Algorithm based approach has been proposed in this paper for resource allocation and optimum fireline building that minimizes the total damage due to wildland fires. The approach is based on a simulation–optimization technique in which the Genetic Algorithm uses advanced forest fire propagation models based upon Huygens principles for evaluation of cost index of its solutions. Both homogeneous and heterogeneous environmental conditions have been considered. Uncertainties in weather conditions as well as imperfect knowledge about exact vegetation and topographical conditions make exact prediction of wildfires very difficult. The paper incorporates Monte-Carlo simulations to develop robust strategies in uncertain conditions. Extensive simulations demonstrate the effectiveness of the proposed approach in efficient resource allocation for fighting complex wildfires in uncertain and dynamic conditions.
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Mustafin, Murat, and Dmitry Bykasov. "Adjustment of Planned Surveying and Geodetic Networks Using Second-Order Nonlinear Programming Methods." Computation 9, no. 12 (December 3, 2021): 131. http://dx.doi.org/10.3390/computation9120131.
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Due to the huge amount of redundant data, the problem arises of finding a single integral solution that will satisfy numerous possible accuracy options. Mathematical processing of such measurements by traditional geodetic methods can take significant time and at the same time does not provide the required accuracy. This article discusses the application of nonlinear programming methods in the computational process for geodetic data. Thanks to the development of computer technology, a modern surveyor can solve new emerging production problems using nonlinear programming methods—preliminary computational experiments that allow evaluating the effectiveness of a particular method for solving a specific problem. The efficiency and performance comparison of various nonlinear programming methods in the course of trilateration network equalization on a plane is shown. An algorithm of the modified second-order Newton’s method is proposed, based on the use of the matrix of second partial derivatives and the Powell and the Davis–Sven–Kempy (DSK) method in the computational process. The new method makes it possible to simplify the computational process, allows the user not to calculate the preliminary values of the determined parameters with high accuracy, since the use of this method makes it possible to expand the region of convergence of the problem solution.
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Fehér, Krisztina, and Balázs Halmos. "Problems of surveying profile shapes of gothic architectural fragments." Pollack Periodica 13, no. 1 (April 2018): 217–24. http://dx.doi.org/10.1556/606.2018.13.1.19.
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Hu, Xiaowen. "Application of GPS Measurement Technology and Computer Technology in Visual Construction Simulation of Construction Engineering." Mobile Information Systems 2022 (August 12, 2022): 1–11. http://dx.doi.org/10.1155/2022/8374901.
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The traditional construction engineering survey has many construction problems, but also may produce large error, leading to the measurement results that cannot meet the actual requirements of the project. In this paper, a new measurement technology is proposed from the aspects of determining the angle and distance of GPS laser scanning, stitching and registration of surveying and mapping data, and GPS measurement of building engineering structures. The test results show that the measurement coincidence rate decreases with the increase of construction time. We can also obviously find the changes of visibility of different frequency points in middle and high frequency bands. The visibility of middle and high frequency band is less sensitive to construction than that of low frequency band. This method has high accuracy and can provide high accuracy for future construction and data storage. Throughout the current situation of the whole construction industry, people need to find a scientific, feasible, and efficient way to solve the problem of low efficiency and serious waste of resources. With the development of GPS measurement technology and computer technology, information technology has been deeply into various industries, such as manufacturing industry, aerospace industry, etc., through electronic information means to optimize the production technology and process, so that the production efficiency and quality have been significantly improved. Similarly, we can apply GPS measurement and computer technology to the construction industry, achieve scientific construction project management, standardize engineering technology standards, and finally achieve the ideal effect.
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Nayar, Hari, Junggon Kim, Brendan Chamberlain-Simon, Kalind Carpenter, Michael Hans, Anna Boettcher, Gareth Meirion-Griffith, Brian Wilcox, and Brian Bittner. "Design optimization of a lightweight rocker–bogie rover for ocean worlds applications." International Journal of Advanced Robotic Systems 16, no. 6 (November 1, 2019): 172988141988569. http://dx.doi.org/10.1177/1729881419885696.
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Relatively recent discoveries have shown that large quantities of water can be found on moons of some of the planets among the gas giants in our solar system. Robotic mobility systems can study the varied geology and origins of these bodies if they are able to navigate the complex terrains of ocean worlds. The topographical features of ocean worlds present a unique combination of challenges for mobility. These include cryogenic ice, penitentes, salt evaporites, chaotic regions, and regolith with uncertain shear and sinkage properties. Uncertainty in both terrain properties and geometry motivates design of a platform that is mobile within a large range of obstacle geometries and terrain properties. This article reports on a research effort to study the requirements and numerically optimize the kinematic parameters of the rover to satisfy these goals. The platforms selected in the process were further verified via simulation. A simulation and analysis of grousers generated suitable designs for interaction with similar ledges and rough terrain. From this analysis, a prototype was developed and tested to meet the wide range of topography and terramechanics conditions expected on these bodies.
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Saranam, Venkata Rajesh, Brigid Mullany, Ali Tabei, Subhasree Srenevas, Chris Evans, and Brian K. Paul. "Surface topographical effects in the diffusion bonding of 316 stainless steel." Journal of Materials Processing Technology 296 (October 2021): 117173. http://dx.doi.org/10.1016/j.jmatprotec.2021.117173.
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Crompton, Robin H., Todd C. Pataky, Russell Savage, Kristiaan D'Août, Matthew R. Bennett, Michael H. Day, Karl Bates, Sarita Morse, and William I. Sellers. "Human-like external function of the foot, and fully upright gait, confirmed in the 3.66 million year old Laetoli hominin footprints by topographic statistics, experimental footprint-formation and computer simulation." Journal of The Royal Society Interface 9, no. 69 (July 20, 2011): 707–19. http://dx.doi.org/10.1098/rsif.2011.0258.
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It is commonly held that the major functional features of the human foot (e.g. a functional longitudinal medial arch, lateral to medial force transfer and hallucal (big-toe) push-off) appear only in the last 2 Myr, but functional interpretations of footbones and footprints of early human ancestors (hominins) prior to 2 million years ago (Mya) remain contradictory. Pixel-wise topographical statistical analysis of Laetoli footprint morphology, compared with results from experimental studies of footprint formation; foot-pressure measurements in bipedalism of humans and non-human great apes; and computer simulation techniques, indicate that most of these functional features were already present, albeit less strongly expressed than in ourselves, in the maker of the Laetoli G-1 footprint trail, 3.66 Mya. This finding provides strong support to those previous studies which have interpreted the G-1 prints as generally modern in aspect.
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Ortloff, Charles R. "Surveying and Hydraulic Engineering of the Pre-Columbian Chimú State: ad 900–1450." Cambridge Archaeological Journal 5, no. 1 (April 1995): 55–74. http://dx.doi.org/10.1017/s0959774300001189.
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The Chimú state of northern coastal Peru (ad 900–1480) developed massive irrigation-based agricultural systems supplied by intricate networks of canals drawing water from river sources in coastal valleys under their political control. Further intervalley canal systems, some up to 50 miles in length, were constructed to shunt water between river valleys to augment intravalley supplies. A high degree of civil engineering skill was necessary to construct and maintain such complex systems; knowledge of surveying and of open channel flow hydraulics was paramount. Some of the technology used by the Chimú has been investigated: surveying instruments and calculating tools have been unearthed and analyzed to provide some understanding of the technical base used for canal design. Details of the hydraulics knowledge-base have been extracted from computer simulation of the functioning of ancient Chimú canal designs. This article assembles known pieces of information related to Chimú civil engineering practice and attempts to provide a plausible methodology that could have been implemented by the Chimú to survey the precise canal bed slopes necessary for proper hydraulic functioning of large canal systems through rugged Andean foothill and mountain areas.
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Morabito, Alessandro, Jan Spriet, Elena Vagnoni, and Patrick Hendrick. "Underground Pumped Storage Hydropower Case Studies in Belgium: Perspectives and Challenges." Energies 13, no. 15 (August 3, 2020): 4000. http://dx.doi.org/10.3390/en13154000.
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To avoid the geographical and topographical prerequisites of the conventional pumped hydro energy storage, the use of underground cavities as water reservoirs allows countries without steep topography, such as Belgium, to increase the potential of the energy storage capacity. Belgium abounds in disused mines and quarries convertible into water basins. In this article, two Belgian case studies are presented and discussed for their singularity. A slate quarry in Martelange is discussed in technical aspects proposing three operating scenarios. Moreover, a preliminary economic analysis of the underground pumped storage system and a greenhouse gas emission evaluation for the storage system’s lifetime are presented. The analysis for a 100 MW power plant estimates a total initial investment of over 12 million euros and two million of CO2 avoided over its lifetime. This article also proposes the use of the coal mine 500 m deep of Pérronnes-lez-Binche. The mine representation discussed here offers a high energy capacity, but the substantial head drop (from about 500 to 200 m) challenges the selection of the hydraulic turbomachinery. A 1D simulation computed in SIMSEN draws out the behaviour of the unusual hydraulic configuration of turbines in series.
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Li, Shaohui, Xuejin Sun, Riwei Zhang, and Chuanliang Zhang. "A Feasibility Study of Simulating the Micro-Scale Wind Field for Wind Energy Applications by NWP/CFD Model with Improved Coupling Method and Data Assimilation." Energies 12, no. 13 (July 2, 2019): 2549. http://dx.doi.org/10.3390/en12132549.
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Understanding the details of micro-scale wind fields is important in the development of wind energy. Research has proven that coupling Numerical Weather Prediction (NWP) and Computational Fluid Dynamics (CFD) models is a better approach for micro-scale wind field simulation. The main purpose of this work is to improve the NWP/CFD model performance in two parts: (i) developing a new coupling method that is more suitable for complex terrain between the NWP and CFD models, and (ii) applying a data assimilation system in the CFD model. Regarding part (i), in order to solve the problem of great topographical difference at the domain boundaries between the two models, Cressman interpolation is utilized to impose the NWP model wind on the CFD model boundaries. In part (ii), an assimilation method, nudging, to apply assimilation of observations into the CFD model is explored. Based on the Cressman interpolation coupling method, a preliminary implementation of data assimilation is performed. The results show that the NWP/CFD model with the improved coupling method may capture the details of micro-scale wind fields more accurately. Using data assimilation, the NWP/CFD model performance may be further improved by cooperating observation data.
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Felipe, Alexandre Luis Da Silva, and Lincoln Gehring Cardoso. "AVALIAÇÃO DE ÁREA E DISTÂNCIAS EM PLANTA OBTIDA VIA GOOGLE EARTH." ENERGIA NA AGRICULTURA 32, no. 2 (November 27, 2017): 189. http://dx.doi.org/10.17224/energagric.2017v32n2p189-194.
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O presente trabalho objetivou avaliar distâncias horizontais e área de um polígono obtido através de imagem do Google Earth tendo como referência levantamento topográfico realizado em campo utilizando-se Estação Total. O processamento dos dados do levantamento topográfico foi realizado através do programa computacional DataGeosis versão Office que acusou elevada precisão, garantindo sua condição de referência. As coordenadas obtidas pelo Google Earth foram submetidos ao software AutoCAD 13 para desenho. Com os dados assim obtidos foi possível a geração de plantas bem como cálculo de distâncias horizontais e áreas em ambos os casos. Foi possível se plotar ambas as plantas em único desenho por se considerar para o primeiro ponto da poligonal obtida por levantamento topográfico convencional, um par de coordenadas obtido por receptor GNSS no primeiro ponto da poligonal. Concluiu-se que valor de área obtida através do Google Earth ficando próximo do valor da referência, bem como seu entorno, não significa a precisão do polígono visto que comprometedoras diferenças em distâncias ora à maior ora à menor podem estar sendo compensadas, no entanto pode-se admitir esse procedimento comum para uso em planejamento rural.PALAVRAS-CHAVES: Levantamento topográfico; Imagem do Google EarthEVALUATION OF AREA AND DISTANCES IN A MAP OBTAINED BY GOOGLE EARTHABSTRACT: The purpose of this study was to compare horizontal distances and areas of a polygon obtained by Google Earth image based in a topographical survey as reference using total station. The processing of the survey was made by computer program Datageosis Office version accused high precision and so used as reference. The coordinates obtained on Google Earth was submitted to the AutoCAD 13 software for drawing. The data obtained enabled the maps generation and also to calculate horizontal distances and areas in both cases. It was possible to plot the two maps in a single drawing by considering for the first point of the polygon obtained by conventional surveying, a pair of coordinates obtained by a GPS receiver. It was concluded that the area value obtained through Google Earth being next to the reference value, does not means the polygon precision due to the fact of differences in distances sometimes the largest and sometimes the smallest being compensated, however it is possible to admit this procedure for use in general rural planning.KEYWORDS: Topographical survey ;Google Earth Image.
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Cho, Sung-Won, Jin-Hyoung Park, Hyun-Ji Park, and Seongmin Kim. "Multi-UAV Coverage Path Planning Based on Hexagonal Grid Decomposition in Maritime Search and Rescue." Mathematics 10, no. 1 (December 27, 2021): 83. http://dx.doi.org/10.3390/math10010083.
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In the event of a maritime accident, surveying the maximum area efficiently in the least amount of time is crucial for rescuing survivors. Increasingly, unmanned aerial vehicles (UAVs) are being used in search and rescue operations. This study proposes a method to generate a search path that covers all generated nodes in the shortest amount of time with multiple heterogeneous UAVs. The proposed model, which is a mixed-integer linear programming (MILP) model based on a hexagonal grid-based decomposition method, was verified through a simulation analysis based on the performance of an actual UAV. This study presents both the optimization technique’s calculation time as a function of the search area size and the various UAV routes derived as the search area grows. The results of this study can have wide-ranging applications for emergency search and rescue operations.
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Acerra, Ennia Mariapaola, Gian Franco Daniel Busquet, Marco Parente, Margherita Marinelli, Valeria Vignali, and Andrea Simone. "Building Information Modeling (BIM) Application for a Section of Bologna’s Red Tramway Line." Infrastructures 7, no. 12 (December 8, 2022): 168. http://dx.doi.org/10.3390/infrastructures7120168.
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New technologies such as the I-BIM (Infrastructure Building Information Modeling) are radically changing the infrastructure design and construction sector. In this study, the I-BIM approach has been used for the design of a portion of the future Bologna’s Red Tramway Line. Starting from the topographical survey of the area, a “federated” model was created, aggregating in a single digital environment all the models inherent to the individual disciplines involved. Interference analysis (Clash Detection) between the various disciplines was performed, subject to the preparation of a coordination matrix and the temporal simulation of the worksite phases (BIM 4D). The results have shown that the I-BIM approach represents a powerful tool for optimizing and validating infrastructure design, allowing users to see how the infrastructure integrates and fits into the real 3D environmental context.
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Peiravi, Mohammad Mohsen, Javad Alinejad, D. D. Ganji, and Soroush Maddah. "3D optimization of baffle arrangement in a multi-phase nanofluid natural convection based on numerical simulation." International Journal of Numerical Methods for Heat & Fluid Flow 30, no. 5 (July 31, 2019): 2583–605. http://dx.doi.org/10.1108/hff-01-2019-0012.
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Purpose The purpose of this study is investigating the effect of using multi-phase nanofluids, Rayleigh number and baffle arrangement simultaneously on the heat transfer rate and Predict the optimal arrangement type of baffles in the differentiation of Rayleigh number in a 3D enclosure. Design/methodology/approach Simulations were performed on the base of the L25 Taguchi orthogonal array, and each test was conducted under different height and baffle arrangement. The multi-phase thermal lattice Boltzmann based on the D3Q19 method was used for modeling fluid flow and temperature fields. Findings Streamlines, isotherms, nanofluid volume fraction distribution and Nusselt number along the wall surface for 104 < Ra < 108 have been demonstrated. Signal-to-noise ratios have been analyzed to predict optimal conditions of maximize and minimize the heat transfer rate. The results show that by choosing the appropriate height and arrangement of the baffles, the average Nusselt number can be changed by more than 57 per cent. Originality/value The value of this paper is surveying three-dimensional and two-phase simulation for nanofluid. Also using the Taguchi method for Predicting the optimal arrangement type of baffles in a multi-part enclosure. Finally statistical analysis of the results by using of two maximum and minimum target Function heat transfer rates.
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Fornshell, John A. "Acoustic Detection of Small Mesoplankton Such as Copepod Nauplii in the Marine Environment." Marine Technology Society Journal 42, no. 2 (June 1, 2008): 62–64. http://dx.doi.org/10.4031/002533208786829089.
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The feasibility of using acoustic surveying techniques to study the distribution of planktonic copepod nauplii in the marine environment is investigated using a computer simulation model. The models simulate the effects of sound frequency, density of sea water and target organisms and celerity on the acoustic signature of copepod nauplii using the polyarthran Coullana canadensis as a model. The advantage is that the acoustic sampling can be for much greater lengths than those for net sampling episodes before the net becomes clogged (in less than 200 meters towing distance). The volume of water sampled for a given tow length would be about the same as conventional net sampling methods. Acoustic sampling and enumeration of planktonic copepod nauplii is shown to be feasible, but has limitations which must be considered in planning a field survey.
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Reed, Jason, Carlin Hsueh, Miu-Ling Lam, Rachel Kjolby, Andrew Sundstrom, Bud Mishra, and J. K. Gimzewski. "Identifying individual DNA species in a complex mixture by precisely measuring the spacing between nicking restriction enzymes with atomic force microscope." Journal of The Royal Society Interface 9, no. 74 (March 28, 2012): 2341–50. http://dx.doi.org/10.1098/rsif.2012.0024.
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We discuss a novel atomic force microscope-based method for identifying individual short DNA molecules (<5000 bp) within a complex mixture by measuring the intra-molecular spacing of a few sequence-specific topographical labels in each molecule. Using this method, we accurately determined the relative abundance of individual DNA species in a 15-species mixture, with fewer than 100 copies per species sampled. To assess the scalability of our approach, we conducted a computer simulation, with realistic parameters, of the hypothetical problem of detecting abundance changes in individual gene transcripts between two single-cell human messenger RNA samples, each containing roughly 9000 species. We found that this approach can distinguish transcript species abundance changes accurately in most cases, including transcript isoforms which would be challenging to quantitate with traditional methods. Given its sensitivity and procedural simplicity, our approach could be used to identify transcript-derived complementary DNAs, where it would have substantial technical and practical advantages versus established techniques in situations where sample material is scarce.
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Trufanov, A., A. Rossodivita, A. Tikhomirov, A. Caruso, N. Dmitrienko, E. Gursky, R. Laporte, F. Linkov, and E. Shunbikov. "(P2-71) Topometric Agent-Based System for Disaster and Emergency Medicine." Prehospital and Disaster Medicine 26, S1 (May 2011): s158—s159. http://dx.doi.org/10.1017/s1049023x11005152.
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IntroductionA variety of models, methods, and computer-aided systems have been used to predict and analyze disasters and emergencies, and manage a pertinent medical response effectively. The list of these instruments traditionally comprises: computerized databases, geographic information systems (GISs), graph theory, complex networks, mathematical programming, simulation, and agent-based modeling. As a rule, each type of those is applied asunder. It makes sense to put in one silo diverse instruments to get multidisciplinary solution with its synergy effect for problems of disaster and emergency medicine.MethodsWithin this study, an original, agent-based model was developed. The model combines the advantages of the principal computer-aided instruments and considers all the types of information: semantic, topographical, metric, and topological. The model is severely dynamic, fits to real actors and principally covers all the disaster situation.ResultsIn line with the model, a so called Topometric Agent-Based System (TABS) with its key visualization component has been designed. A TABS-specific simulation to investigate behavior of the attacked network of vulnerable actors has been conducted leading to critical findings. It has been shown a severe significance of order within combination of threats: man-made + natural or those of natural + man-made. A well-balanced financial distribution to protect actors of diverse status also has been found.ConclusionsA TABS similar to GIS focuses on mapping. Topometric Agent-Based System mapping brings an efficient and clear language for information sharing not only within national emergency medical services but between experts from different fields and countries.
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Keymanesh, Mahmoudreza, Hasan Ziari, Samira Roudini, and Ali Nasrollahtabar Ahangar. "Identification and Prioritization of “Black Spots” without Using Accident Information." Modelling and Simulation in Engineering 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/1832654.
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It is attempted to identify and prioritize the accident prone points (black spots) in “Iraanshahr-Sarbaaz-Chabahar” road located in Baluchistan, Iran, without no use of accident data but rather using Analytic Hierarchy Process (AHP), which is the enhanced procedure of road safety audit technique. First, by surveying the whole route, all factors that could influence accidents in this road were specified; then the route was divided into eight sections; this division was performed based on the uniformity and homogeny of each section in terms of geometric design and regional conditions. In each section, potentially hazardous locations were identified and some questionnaires were prepared, which were filled by 5 road traffic experts familiar with the route; then the collected data were analyzed by Analytical Hierarchy Process (AHP) using Expert Choice Software and the black spots were identified and prioritized. Finally, these black spots were compared with the black spots that had been obtained by traffic police based on accident data.
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Andreassen, Tórur, Annemarie Surlykke, and John Hallam. "Semi-automatic long-term acoustic surveying: A case study with bats." Ecological Informatics 21 (May 2014): 13–24. http://dx.doi.org/10.1016/j.ecoinf.2013.12.010.
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Barsi, Árpád, András Csepinszky, János Máté Lógó, Nikol Krausz, and Vivien Potó. "The Role of Maps in Autonomous Driving Simulations." Periodica Polytechnica Transportation Engineering 48, no. 4 (August 13, 2020): 363–68. http://dx.doi.org/10.3311/pptr.15852.
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The vehicles of the conditional, high, and full automation levels have a common unique sensor, the map. The term map has undergone a significant change because the spatial resolution has been increased considerably, the road infrastructure and its neighborhood are represented with higher accuracy in 3D. The development of these vehicles requires enormous efforts, where computer-based techniques, like the simulations, can offer a helping hand. The autonomous simulations will be supported by high-quality map information, which generates interest in the best field data-capturing techniques. The paper provides an overview of the available modern surveying methodologies, then introduces the most preferred data formats – both in physical information storage and in exchanging information content between mapping systems. Some examples are presented to demonstrate the usage of the relevant map-making outputs in automotive simulators.
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Yang, Li, Haote Ruan, and Yunhan Zhang. "Autonomous Orbit Determination System of Navigation Satellite Based on Spaceborne GPS Technology." Security and Communication Networks 2022 (January 11, 2022): 1–10. http://dx.doi.org/10.1155/2022/7463315.
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In recent years, many low-orbit satellites have been widely used in the field of scientific research and national defense in China. In order to meet the demand of high-precision satellite orbit in China’s space, surveying and mapping, and other related fields, navigation satellites are of great significance. The UKF (unscented Kalman filter) method is applied to space targets’ spaceborne GPS autonomous orbit determination. In this paper, the UKF algorithm based on UT transformation is mainly introduced. In view of the situation that the system noise variance matrix is unknown or the dynamic model is not accurate, an adaptive UKF filtering algorithm is proposed. Simulation experiments are carried out with CHAMP satellite GPS data, and the results show that the filtering accuracy and stability are improved, which proves the algorithm’s effectiveness. The experimental results show that the Helmert variance component estimation considering the dynamics model can solve the problem of reasonable weight determination of BDS/GPS observations and effectively weaken the influence of coarse error and improve the accuracy of orbit determination. The accuracy of autonomous orbit determination by spaceborne BDS/GPS is 1.19 m and 2.35 mm/s, respectively.
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Rák, Olivér, and Dorottya Szilágyi. "Photogrammetry possibilities and rules focusing on architectural usage." Pollack Periodica 15, no. 1 (April 2020): 187–96. http://dx.doi.org/10.1556/606.2020.15.1.18.
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Abstract The article is presenting a consideration of the photogrammetry technology in the field of architectural usage. The technology overview is describing a basic knowledge to support the professionals. The processes, rules and best practices are examined through case studies, which introduce a dwelling house, an old precast concrete hall and a landscape surveying to cover most of the architectural usage. The purpose of the research is to give guidance for technical possibilities and assists in the development of the methodologies. The main part of the article is focusing on unmanned aerial vehicles as these tools provide many useful features.
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Xu, Xiang, Huade Guan, Grzegorz Skrzypek, and David G. Williams. "Topographical influences on foliar nitrogen concentration and stable isotope composition in a Mediterranean-climate catchment." Ecological Informatics 68 (May 2022): 101569. http://dx.doi.org/10.1016/j.ecoinf.2022.101569.
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Uchida, Takanori, and Susumu Takakuwa. "A Large-Eddy Simulation-Based Assessment of the Risk of Wind Turbine Failures Due to Terrain-Induced Turbulence over a Wind Farm in Complex Terrain." Energies 12, no. 10 (May 20, 2019): 1925. http://dx.doi.org/10.3390/en12101925.
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The first part of the present study investigated the relationship among the number of yaw gear and motor failures and turbulence intensity (TI) at all the wind turbines under investigation with the use of in situ data. The investigation revealed that wind turbine #7 (T7), which experienced a large number of failures, was affected by terrain-induced turbulence with TI that exceeded the TI presumed for the wind turbine design class to which T7 belongs. Subsequently, a computational fluid dynamics (CFD) simulation was performed to examine if the abovementioned observed wind flow characteristics could be successfully simulated. The CFD software package that was used in the present study was RIAM-COMPACT, which was developed by the first author of the present paper. RIAM-COMPACT is a nonlinear, unsteady wind prediction model that uses large-eddy simulation (LES) for the turbulence model. RIAM-COMPACT is capable of simulating flow collision, separation, and reattachment and also various unsteady turbulence–eddy phenomena that are caused by flow collision, separation, and reattachment. A close examination of computer animations of the streamwise (x) wind velocity revealed the following findings: As we predicted, wind flow that was separated from a micro-topographical feature (micro-scale terrain undulations) upstream of T7 generated large vortices. These vortices were shed downstream in a nearly periodic manner, which in turn generated terrain-induced turbulence, affecting T7 directly. Finally, the temporal change of the streamwise (x) wind velocity (a non-dimensional quantity) at the hub-height of T7 in the period from 600 to 800 in non-dimensional time was re-scaled in such a way that the average value of the streamwise (x) wind velocity for this period was 8.0 m/s, and the results of the analysis of the re-scaled data were discussed. With the re-scaled full-scale streamwise wind velocity (m/s) data (total number of data points: approximately 50,000; time interval: 0.3 s), the time-averaged streamwise (x) wind velocity and TI were evaluated using a common statistical processing procedure adopted for in situ data. Specifically, 10-min moving averaging (number of sample data points: 1932) was performed on the re-scaled data. Comparisons of the evaluated TI values to the TI values from the normal turbulence model in IEC61400-1 Ed.3 (2005) revealed the following: Although the evaluated TI values were not as large as those observed in situ, some of the evaluated TI values exceeded the values for turbulence class A, suggesting that the influence of terrain-induced turbulence on the wind turbine was well simulated.
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de Brito, Israel Barbosa, and Rafael T. de Sousa. "Development of an Open-Source Testbed Based on the Modbus Protocol for Cybersecurity Analysis of Nuclear Power Plants." Applied Sciences 12, no. 15 (August 8, 2022): 7942. http://dx.doi.org/10.3390/app12157942.
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The possibility of cyber-attacks against critical infrastructure, and in particular nuclear power plants, has prompted several efforts by academia. Many of these works aim to capture the vulnerabilities of the industrial control systems used in these plants through computer simulations and hardware in the loop configurations. However, general results in this area are limited by the cost and diversity of existing commercial equipment and protocols, as well as by the inherent complexity of the nuclear plants. In this context, this work introduces a testbed for the study of cyber-attacks against a realistic simulation of a nuclear power plant. Our approach consists in surveying issues regarding realistic simulations of nuclear power plants and to design and experimentally validate a software testbed for the controlled analysis of cyberattacks against the simulated nuclear plant. The proposal integrates a simulated Modbus/TCP network environment containing basic industrial control elements implemented with open-source software components. We validate the proposed testbed architecture by performing and analyzing a representative cyberattack in the developed environment, thus showing the principles for the analysis of other possible cybernetic attacks.
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Gonroudobou, Orou Berme Herve, Leonardo Huisacayna Silvestre, Yago Diez, Ha Trang Nguyen, and Maximo Larry Lopez Caceres. "Treetop Detection in Mountainous Forests Using UAV Terrain Awareness Function." Computation 10, no. 6 (June 2, 2022): 90. http://dx.doi.org/10.3390/computation10060090.
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Unmanned aerial vehicles (UAVs) are becoming essential tools for surveying and monitoring forest ecosystems. However, most forests are found on steep slopes, where capturing individual tree characteristics might be compromised by the difference in ground sampling distance (GSD) between slopes. Thus, we tested the performance of treetop detection using two algorithms on canopy height models (CHMs) obtained with a commercial UAV (Mavic 2 Pro) using the terrain awareness function (TAF). The area surveyed was on a steep slope covered predominantly by fir (Abies mariesii) trees, where the UAV was flown following (TAF) and not following the terrain (NTAF). Results showed that when the TAF was used, fir trees were clearly delimited, with lower branches clearly visible in the orthomosaic, regardless of the slope position. As a result, the dense point clouds (DPCs) were denser and more homogenously distributed along the slope when using TAF than when using NTAF. Two algorithms were applied for treetop detection: (connected components), and (morphological operators). (connected components) showed a 5% improvement in treetop detection accuracy when using TAF (86.55%), in comparison to NTAF (81.55%), at the minimum matching error of 1 m. In contrast, when using (morphological operators), treetop detection accuracy reached 76.23% when using TAF and 62.06% when using NTAF. Thus, for treetop detection alone, NTAF can be sufficient when using sophisticated algorithms. However, NTAF showed a higher number of repeated points, leading to an overestimation of detected treetop.
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M., TANER. "Designing Unmanned Underwater Vehicles through Biomimicry." Scientific Bulletin of Naval Academy XXIV, no. 1 (July 15, 2021): 61–73. http://dx.doi.org/10.21279/1454-864x-21-i1-007.
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Research vessels or small craft equipped for the specific purposes lead geological, geophysical and oceanographic research both at the coastal and offshore areas for constructing and surveying the engineering projects such as offshore structures, undersea pipelines, harbours, oil and natural gas extraction plants from resources etc., which require extensive labourship. However, this research method applied entails very high costs and can also include risks for occupational safety and property due to the harsh weather conditions at sea. In addition, high precision measurements cannot always function from the sea surface during such research projects above-mentioned. Thus, unmanned underwater vehicles (UUVs) have been designed and produced intensively in the last two decades. The aim of this study was to generate form design of a proper unmanned underwater surveying vehicle to be able to conduct research on the geological and geophysical structure of the sea bottom as well as oceanographic opinions. Therefore, computational fluid dynamics (CFD) analysis of the DARPA Suboff submarine model was created, and the validation of the results obtained in these analyses was provided with those of the experiments of this DARPA Suboff model performed by Liu and Huang [1]. After successful conformity of the simulations carried out using the commercial software STAR CCM+ (Simulation of Turbulent flow in Arbitrary Regions - Computational Continuum Mechanics, C++ based), the UUV forms were created by means of different way including biomimicry methodology. In this context, the models of a mature goose-beaked whale (ziphius cavirostris), a mature sperm whale (physeter macrocephalus) and two torpedo-shaped UUV models as well a hybrid model including parts of a whale and torpedo-forms with the same displacement were analysed, and the results obtained were discussed.
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Lin, Chen, Jinduo Xu, Ronghua Ma, Xuejun Duan, Ningning Liu, and Xuan Hou. "A mobile client oriented to subjective and objective information collection for township land resources surveying." Ecological Informatics 60 (November 2020): 101173. http://dx.doi.org/10.1016/j.ecoinf.2020.101173.
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Ou, Xun, Yuanming Liu, Chao Li, Xiaohan Zhou, Qingzhi Chen, Yuhang Zhou, and Quan Zhang. "Analysis of the Interaction Effects of Shield Structure Oblique Passing under an Existing Tunnel." Applied Sciences 12, no. 11 (May 30, 2022): 5569. http://dx.doi.org/10.3390/app12115569.
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The interaction mechanism between a two-lane shield tunnel and an existing tunnel during oblique underpass is a matter of widespread concern in the engineering community, and knowledge in this area remains crude. In the construction of subway tunnels in mountainous cities with huge topographical fluctuations, internal forces and deformations are inevitable in existing tunnels. To verify the applicability of existing shield construction technology and empirical parameters to the Guiyang area, a systematic and refined numerical analysis was conducted on the shield passing under the existing tunnel section of the Tao-Hua interval of Guiyang Metro Line 3. In this paper, the accuracy of the numerical simulation is verified by comparing the calculated results with the data measured in the field; the settlement pattern that appeared above the existing tunnel during the construction of the shield with slurry hardening is analyzed; the internal forces, lateral deformation, and torsional deformation of the existing tunnel caused during the excavation of the new tunnel are obtained based on the numerical simulation results; finally, the effect of the old and new tunnels on the torsional deformation and settlement of the existing tunnel under different spatial intersection angles is studied. The results show that the internal forces, lateral deformation, and surface settlement of the existing tunnel due to the diagonal underpass show obvious asymmetric characteristics. Additionally, the existing tunnel experiences local irrecoverable torsional deformation, with the maximum torsional deformation occurring at the intersection of the old and new tunnels, and the spatial intersection angle of the old and new tunnels has a great influence on the maximum settlement of the tunnel vault and arch bottom, which shows a negative correlation.
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Mittet, Rune. "High-order finite-difference simulations of marine CSEM surveys using a correspondence principle for wave and diffusion fields." GEOPHYSICS 75, no. 1 (January 2010): F33—F50. http://dx.doi.org/10.1190/1.3278525.
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The computer time required to solve a typical 3D marine controlled-source electromagnetic surveying (CSEM) simulation can be reduced by more than one order of magnitude by transforming low-frequency Maxwell equations in the quasi-static or diffusive limit to a hyperbolic set of partial differential equations that give a representation of electromagnetic fields in a fictitious wave domain. The dispersion and stability analysis can be made equivalent to that of other types of wave simulation problems such as seismic acoustic and elastic modeling. Second-order to eighth-order spatial derivative operators are implemented for flexibility. Fourth-order and sixth-order methods are the most numerically efficient implementations for this particular scheme. An implementation with high-order operators requires that both electric and magnetic fields are extrapolated simultaneously into the air layer. The stability condition given for high-order staggered-derivative operators here should be equally valid for seismic-wave simulation. The bandwidth of recovered fields in the diffusive domain is independent of the bandwidth of the fields in the fictitious wave domain. The fields in the fictitious wave domain do not represent observable fields. Propagation paths and interaction/reflection amplitudes are not altered by the transform from the fictitious wave domain to the diffusive frequency domain; however, the transform contains an exponential decay factor that damps down late arrivals in the fictitious wave domain. The propagation paths that contribute most to the diffusive domain fields are airwave (shallow water) plus typically postcritical events such as refracted and guided waves. The transform from the diffusive frequency domain to the fictitious wave domain is an ill-posed problem. The transform is nonunique. This gives a large degree of freedom in postulating temporal waveforms for boundary conditions in the fictitious wave domain that reproduce correct diffusive frequency-domain fields.
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Romanenko, Ihor, Yevhen Martseniuk, and Oleksandr Bilohub. "Modeling the Meshing Procedure of the External Gear Fuel Pump Using a CFD Tool." Computation 10, no. 7 (July 6, 2022): 114. http://dx.doi.org/10.3390/computation10070114.
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In modern aircraft engine technology, there is a tendency to replace the mechanical drive of external gear fuel pumps with an electric one. This significantly reduces the integral energy consumption for pumping fuel (kerosene). On the other hand, in order to reduce the dimensions of the structure, it is reasonable to increase the rotation speed of the pumping unit gears. The above considerations make it advisable to study the problems that may arise in the design of pumping units. Analysis of the existing designs of external gear fuel pumps shows that the flow processes in the meshing zone have a significant impact on the pump performance and lifetime. Incorrect truss plate geometry and the compensation system lead to an increase in the velocities when opening and closing the cavity in the meshing zone, which causes intense cavitation. To understand the causes and factors which influence this phenomenon, it is necessary to study the fluid flow behavior in the meshing zone gaps. High-speed cameras are used to experimentally study the flow behavior. However, this approach gives only a qualitative result but does not allow for determining the absolute values of pressure and load in terms of the angle of rotation. Nevertheless, high-speed surveying can be used as a basis for fluid flow model verification. In this paper, the model of the fluid flow in a high-pressure external gear pump was proposed. The verification of the simulation results for HDZ 46 HLP 68 oil operation was carried out according to the results of experimental data visualization. The influence of rotation speed on the position of cavitation zones was revealed and confirmed by operational data. The analysis of the flow process in meshing for kerosene as a working fluid was carried out.
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Long, Yue, Songling Huang, Lisha Peng, Wenzhi Wang, Shen Wang, and Wei Zhao. "High-Precision and Four-Dimensional Tracking System with Dual Receivers of Pipeline Inspection Gauge." Applied Sciences 11, no. 8 (April 8, 2021): 3366. http://dx.doi.org/10.3390/app11083366.
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Pipeline inspection gauges (PIGs) are widely used for nondestructive testing of oil and natural gas pipelines, while above ground markers (AGMs) can locate and track the PIG through a variety of methods, including magnetic flux leakage signals, acoustic signals, and extremely low-frequency (ELF) magnetic signals. Traditional AGMs have the disadvantages of low positioning accuracy and only one-dimensional tracking capability. In this paper, a newly-designed PIG tracking system based on the ELF magnetic field is proposed by assembling dual receivers. Moreover, this paper develops a magnetic field sign-integration algorithm to achieve high-precision and four-dimensional (4-D) tracking of PIG. The simulation and experiment results demonstrate that the tracking system has the capability of 4-D tracking. In comparison with the previously published work, the designed tracking system improves the positioning accuracy and orientation tracking accuracy by more than 50%. The dual receivers tracking system also has the characteristic of high-robustness. Even in the state of lateral offset or tilt, it can still achieve accurate tracking of PIG. The realization of PIG’s high-precision 4-D tracking can improve the accuracy of defect location. Moreover, it can also provide the latest pipeline network layout and facilitate pipeline maintenance and pipeline surveying applications.
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Deng, Zhao, Zhiming Guo, Liaoni Wu, and Yancheng You. "Trajectory Planning for Emergency Landing of VTOL Fixed-Wing Unmanned Aerial Vehicles." Mobile Information Systems 2021 (November 29, 2021): 1–15. http://dx.doi.org/10.1155/2021/6289822.
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In recent years, inspired by technological progress and the outstanding performance of Unmanned Aerial Vehicles (UAVs) in several local wars, the UAV industry has witnessed explosive development, widely used in communication relay, logistics, surveying and mapping, patrol, surveillance, and other fields. Vertical Take-Off and Landing fixed-wing UAV has both the advantages of vertical take-off and landing of rotorcraft and the advantages of long endurance of fixed-wing UAV, which broadened its application field and is the most popular UAV at present. Recently, fixed-wing UAV failure analysis highlights that cruise engine shutdown is the most common reason for emergency landing, which is also a governing factor for Vertical Take-Off and Landing (VTOL) fixed-wing UAV failures. Nevertheless, the emergency landing trajectory of the latter UAV type after engine shutdown is different from that of the conventional fixed-wing UAVs due to the VTOL power system. Hence, spurred by the requirement of a safe emergency landing trajectory for VTOL fixed-wing UAVs, this paper develops an architecture capable of safe emergency landing for such platforms. The suggested method develops a particle dynamics model of the VTOL UAV and analyzes its aerodynamic characteristics utilizing Computational Fluid Dynamics (CFD) results. The UAV’s trajectory is divided into three parts for enhanced planning. For the guidance stage, the initial position and heading angle are arbitrary. Hence, the Dubins shortest cross-range and the fastest descent trajectory are adopted to steer the UAV above the landing window quickly. The spiral stage comprises a conical and cylindrical part combined with a spiral descent trajectory of variable radius for energy management and landing course alignment. Given the limited energy storage of VTOL power systems, the landing stage exploits an optimal control trajectory problem solved by a Gaussian pseudospectral method, involving trajectory conventional landing planning, unpowered landing, distance optimal landing, and wind-resistant landing. All trajectories meet the dynamics constraints, terminal constraints, and sliding performance constraints and cover both 2-dimensional and 3-dimensional trajectories. A large number of simulation experiments demonstrate that the proposed trajectories manage broad applicability and strong feasibility for VTOL fixed-wing UAVs.
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Zhang, Fengrui, Jiaoyi Hou, Dayong Ning, and Yongjun Gong. "Depth Control of an Oil Bladder Type Deep-Sea AUV Based on Fuzzy Adaptive Linear Active Disturbance Rejection Control." Machines 10, no. 3 (February 22, 2022): 163. http://dx.doi.org/10.3390/machines10030163.
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The deep-sea autonomous underwater vehicle (AUV) is equipment of vital importance for ocean exploration, monitoring, and surveying. With a variable buoyancy system (VBS), AUV can achieve rising, diving, and hovering in the water column. This paper proposes a deep-sea AUV with an oil bladder type hydraulic VBS, which controls the oil flow rate with a proportional valve. However, the implementation of accurate depth control for AUV faces various challenges due to the varying water density with depth, the non-linear feature of the hydraulic system, and the disturbance from sea flows and currents. To tackle these problems, a third-order linear active disturbance rejection controller (LADRC) and its fuzzy adaptive version were designed and implemented in MATLAB/Simulink based on the state-space function of the proposed AUV system. Compared with the conventional PID controller, the simulation results indicate that the proposed LADRC controller shows strong robustness to disturbance, with other advantages including smaller steady-state error, overshoot, settling time, and response time. Moreover, the proposed fuzzy LADRC controller could further decrease the overshoot caused by the increasing target distance. The results prove that the designed depth controllers can meet the control requirements of the proposed deep-sea AUV.
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Arul Vinayakam Rajasimman, Mayuri, Ranjith Manoharan, Neelakandan Subramani, Manimaran Aridoss, and Mohammad Galety. "Robust Facial Expression Recognition Using An Evolutionary Algorithm with a Deep Learning Model." Applied Sciences 13, no. 1 (December 29, 2022): 468. http://dx.doi.org/10.3390/app13010468.
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The most important component that can express a person’s mental condition is facial expressions. A human can communicate around 55% of information non-verbally and the remaining 45% audibly. Automatic facial expression recognition (FER) has now become a challenging task in the surveying of computers. Applications of FER include understanding the behavior of humans and monitoring moods and psychological states. It even penetrates other domains—namely, robotics, criminology, smart healthcare systems, entertainment, security systems, holographic images, stress detection, and education. This study introduces a novel Robust Facial Expression Recognition using an Evolutionary Algorithm with Deep Learning (RFER-EADL) model. RFER-EADL aims to determine various kinds of emotions using computer vision and DL models. Primarily, RFER-EADL performs histogram equalization to normalize the intensity and contrast levels of the images of identical persons and expressions. Next, the deep convolutional neural network-based densely connected network (DenseNet-169) model is exploited with the chimp optimization algorithm (COA) as a hyperparameter-tuning approach. Finally, teaching and learning-based optimization (TLBO) with a long short-term memory (LSTM) model is employed for expression recognition and classification. The designs of COA and TLBO algorithms aided in the optimal parameter selection of the DenseNet and LSTM models, respectively. A brief simulation analysis of the benchmark dataset portrays the greater performance of the RFER-EADL model compared to other approaches.
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Zhou, Shuai, Changcheng Yang, Zhenning Su, Ping Yu, and Jian Jiao. "An Aeromagnetic Compensation Algorithm Based on Radial Basis Function Artificial Neural Network." Applied Sciences 13, no. 1 (December 22, 2022): 136. http://dx.doi.org/10.3390/app13010136.
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Aeromagnetic exploration is a magnetic exploration method that detects changes of the earth’s magnetic field by loading a magnetometer on an aircraft. With the miniaturization of magnetometers and the development of unmanned aerial vehicles (UAV) technology, UAV aeromagnetic surveying plays an increasingly important role in mineral exploration and other fields due to its advantages of low cost and safety. However, in the process of aeromagnetic measurement data, due to the ferromagnetic material of the aircraft itself and the change of flight direction and attitude, magnetic field interference will occur and affect the measurement of the geomagnetic field by the magnetometer. The work of aeromagnetic compensation is to compensate for this part of the magnetic interference and improve the magnetic measurement accuracy of the magnetometer. This paper focused on the problems of UAV aeromagnetic survey data processing and improved the accuracy of UAV based aeromagnetic data measurement. Based on the Tolles–Lawson model, a numerical simulation experiment of magnetic interference of UAV-based aeromagnetic data was carried out, and a radial basis function (RBF) artificial neural network (ANN) algorithm was proposed for the first time to compensate the aeromagnetic data. Compared with classical backpropagation (BP) ANN, the test results of the synthetic data and real measured magnetic data showed that the RBF-ANN has higher compensation accuracy and stronger generalization ability.
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Florin, Medeleanu. "Border security Wireless Integrated Network Sensor attack resistance analysis by integral cryptanalysis of AES cipher." Scientific Bulletin of Naval Academy XIX, no. 1 (July 15, 2018): 123–28. http://dx.doi.org/10.21279/1454-864x-18-i1-019.
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Wireless Integrated Network Sensor (WINS) make available monitoring and control capabilities for surveying the borders of a country. Applying these capabilities the illegal persons which cross the border by trespassing or unlawful activities which occur in a protected area can be easily identified. In order to achieve this objective, the protected area is split into a number of nodes. Each node communicates with each other and with the central node by the means of secured communication channels. In order to securely transmit the information to and from the nodes in a real system the cryptographic algorithm AES is often used. Integral cryptanalysis is an attack that makes use of chosen-plaintext and can subvert the security of cryptographic algorithm. This paper reports on analysis and results of integral cryptanalysis or square attack on a 4 round reduced version of the AES cipher (mini-AES).
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Strzałkowski, Piotr. "Predicting Mining Areas Deformations under the Condition of High Strength and Depth of Cover." Energies 15, no. 13 (June 24, 2022): 4627. http://dx.doi.org/10.3390/en15134627.
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This paper presents an analysis of mining area deformations in the rock mass consisting of high depth and strength strata deposited in the cover. The analysis of land surveying results enabled the identification of the parameters required to predict subsidence, which differed from the typical parameters for the Upper Silesian Coal Basin. The parameters of the Budryk–Knothe theory were determined based on the results of geodetic measurements. The calculations of the final state of deformations for planned mining were made using the average and characteristics for the study area parameter values. Based on experience, it is known that the range of subsidence trough depends on the mechanical properties of the rock mass. This study shows that the presence of high-strength rocks also reduces the value of the coefficient of roof control. Subsequently, calculations were made by a computer simulation of longwall mining to determine the course of indices of deformation over time. The calculations were conducted twice: on the assumption that the impact was immediate and on the assumption of the parameter values typical for the basin, and formula expressing the course of subsidence over time with the parameter values based on the measurement results. The obtained distributions of deformation indicators were diametrically opposed to each other. The results of the calculations with the parameter values appropriate for the region indicate that it is possible to carry out a planned mining operation without creating a risk to objects on the surface.
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Guarnieri, A., F. Fissore, A. Masiero, A. Di Donna, U. Coppa, and A. Vettore. "FROM SURVEY TO FEM ANALYSIS FOR DOCUMENTATION OF BUILT HERITAGE: THE CASE STUDY OF VILLA REVEDIN-BOLASCO." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-5/W1 (May 16, 2017): 527–33. http://dx.doi.org/10.5194/isprs-archives-xlii-5-w1-527-2017.
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In the last decade advances in the fields of close-range photogrammetry, terrestrial laser scanning (TLS) and computer vision (CV) have enabled to collect different kind of information about a Cultural Heritage objects and to carry out highly accurate 3D models. Additionally, the integration between laser scanning technology and Finite Element Analysis (FEA) is gaining particular interest in recent years for structural analysis of built heritage, since the increasing computational capabilities allow to manipulate large datasets. In this note we illustrate the approach adopted for surveying, 3D modeling and structural analysis of Villa Revedin-Bolasco, a magnificent historical building located in the small walled town of Castelfranco Veneto, in northern Italy. In 2012 CIRGEO was charged by the University of Padova to carry out a survey of the Villa and Park, as preliminary step for subsequent restoration works. The inner geometry of the Villa was captured with two Leica Disto D3a BT hand-held laser meters, while the outer walls of the building were surveyed with a Leica C10 and a Faro Focus 3D 120 terrestrial laser scanners. Ancillary GNSS measurements were also collected for 3D laser model georeferencing. A solid model was then generated from the laser global point cloud in Rhinoceros software, and portion of it was used for simulation in a Finite Element Analysis (FEA). In the paper we discuss in detail all the steps and challenges addressed and solutions adopted concerning the survey, solid modeling and FEA from laser scanning data of the historical complex of Villa Revedin-Bolasco.
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Diefenbach, Duane R., Daniel W. Brauning, and Jennifer A. Mattice. "Variability in Grassland Bird Counts Related to Observer Differences and Species Detection Rates." Auk 120, no. 4 (October 1, 2003): 1168–79. http://dx.doi.org/10.1093/auk/120.4.1168.
Full textAbstract:
Abstract Differences among observers in ability to detect and identify birds has been long recognized as a potential source of error when surveying terrestrial birds. However, few published studies address that issue in their methods or study design. We used distance sampling with line transects to investigate differences in detection probabilities among observers and among three species of grassland songbirds: Henslow's Sparrow (Ammodramus henslowii), Grasshopper Sparrow (A. savannarum), and Savannah Sparrow (Passerculus sandwichensis). Our review of 75 papers published in 1985–2001 found that the most commonly used methods were fixed-width transects (31%, 23 papers) and fixed-radius point counts (20%, 15 papers). The median half-width of fixed-width strip transects used by researchers was 50 m, but our results indicated detection probabilities were <1.0 at distances >25 m for most observers and species. Beyond 50 m from the transect line, we found that as many as 60% of birds were missed by observers and that the proportion missed differed among observers and species. Detection probabilities among observers ranged from 0.43 to 1.00 for Henslow's Sparrow, from 0.44 to 0.66 for Grasshopper Sparrow, and from 0.60 to 0.72 for Grasshopper Sparrow for birds detected within 58–100 m of the transect line. Using our estimates of detection probabilities for Henslow's Sparrows among six observers in a computer simulation of a monitoring program, we found that bird counts from fixed-width transects required an additional 2–3 years of monitoring to detect a given decline in abundance compared to density estimates that used a method to correct for missed birds. We recommend that researchers employ survey methods that correct for detection probabilities <1.0.