Journal articles: 'HIGH BEAM GLOBAL'

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Qiang, Ji. "Advances in global optimization of high brightness beams." International Journal of Modern Physics A 34, no. 36 (December 11, 2019): 1942016. http://dx.doi.org/10.1142/s0217751x19420168.

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High brightness electron beams play an important role in accelerator-based applications such as driving X-ray free electron laser (FEL) radiation. In this paper, we report on advances in global beam dynamics optimization of an accelerator design using start-to-end simulations and a new parallel multi-objective differential evolution optimization method. The global optimization results in significant improvement of the final electron beam brightness.

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Ayuddin, Ayuddin. "GLOBAL STRUCTURAL ANALYSIS OF HIGH-RISE HOSPITAL BUILDING USING EARTHQUAKE RESISTANT DESIGN APPROACH." SINERGI 24, no. 2 (April 17, 2020): 95. http://dx.doi.org/10.22441/sinergi.2020.2.003.

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Building designed has 1 to 8 floors with the quality of concrete f'c of 33.2 MPa, steel quality (fy) 400 MPa, and shear stress of 240 MPa. The building is analyzed by 3D structure modeling through ETABS Version 9.7 program by following all the rules and regulations applicable in Indonesia, such as the guidance of building structure and non-building, SNI 1726: 2012. This building design system is a high-rise building structure planned with a portal frame system with beams and columns as the main elements of structures made of conventional concrete. The beam carries the load transversely of its length and transfers the load to the vertical columns that accumulate it. The column accepts the load axially by the beam and transfers the load to the foundation. This building structure uses a special moment frame structure system (SRPMK) structure, considering that the hospital building is safe against earthquakes and complains about the strong column weak beam concept.

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Leung, Shingyu, Jianliang Qian, and Robert Burridge. "Eulerian Gaussian beams for high-frequency wave propagation." GEOPHYSICS 72, no. 5 (September 2007): SM61—SM76. http://dx.doi.org/10.1190/1.2752136.

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We design an Eulerian Gaussian beam summation method for solving Helmholtz equations in the high-frequency regime. The traditional Gaussian beam summation method is based on Lagrangian ray tracing and local ray-centered coordinates. We propose a new Eulerian formulation of Gaussian beam theory which adopts global Cartesian coordinates, level sets, and Liouville equations, yielding uniformly distributed Eulerian traveltimes and amplitudes in phase space simultaneously for multiple sources. The time harmonic wavefield can be constructed by summing up Gaussian beams with ingredients provided by the new Eulerian formulation. The conventional Gaussian beam summation method can be derived from the proposed method. There are three advantages of the new method: (1) We have uniform resolution of ray distribution. (2) We can obtain wavefields excited at different sources by varying only source locations in the summation formula. (3) We can obtain wavefields excited at different frequencies by varying only frequencies in the summation formula. Numerical experiments indicate that the Gaussian beam summation method yields accurate asymptotic wavefields even at caustics. The new method may be used for seismic modeling and migration.

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Nghiem, P. A. P., N. Chauvin, M. Comunian, O. Delferrière, R. Duperrier, A. Mosnier, C. Oliver, W. Simeoni, and D. Uriot. "Dynamics of the IFMIF very high-intensity beam." Laser and Particle Beams 32, no. 1 (January 22, 2014): 109–18. http://dx.doi.org/10.1017/s0263034613001055.

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AbstractFor the purpose of material studies for future nuclear fusion reactors, the IFMIF deuteron beams present a simultaneous combination of unprecedentedly high intensity (2 × 125 mA CW), power (2 × 5 MW) and space charge. Special considerations and new concepts have been developed in order to overcome these challenges. The global strategy for beam dynamics design of the 40 MeV IFMIF accelerators is presented, stressing on the control of micro-losses, and the possibility of online fine tuning. Start-to-end simulations without and with errors are presented for the prototype accelerator. Considerations about conflicts between halo and emittance minimization are then discussed in this very high space charge context.

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Cao, MS, W. Xu, Z. Su, W. Ostachowicz, and N. Xia. "Local coordinate systems-based method to analyze high-order modes of n-step Timoshenko beam." Journal of Vibration and Control 23, no. 1 (August 9, 2016): 89–102. http://dx.doi.org/10.1177/1077546315573919.

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High-frequency transverse vibration of stepped beams has attracted increasing attention in various industrial areas. For an n-step Timoshenko beam, the governing differential equations of transverse vibration have been well established in the literature on the basis of assembling classic Timoshenko beam equations for uniform beam segments. However, solving the governing differential equation has not been resolved well to date, manifested by a computational bottleneck: only the first k modes ( k ≤ 12) are solvable for i-step ( i ≥ 0) Timoshenko beams. This bottleneck diminishes the completeness of stepped Timoshenko beam theory. To address this problem, this study first reveals the root cause of the bottleneck in solving the governing differential equations for high-order modes, and then creates a sophisticated method, based on local coordinate systems, that can overcome the bottleneck to accomplish high-order mode shapes of an n-step Timoshenko beam. The proposed method uses a set of local coordinate systems in place of the conventional global coordinate system to characterize the transverse vibration of an n-step Timoshenko beam. With the method, the local coordinate systems can simplify the frequency equation for the vibration of an n-step Timoshenko beam, making it possible to obtain high-order modes of the beam. The accuracy, capacity, and efficiency of the method based on local coordinate systems in acquiring high-order modes are corroborated using the well-known exact dynamic stiffness method underpinned by the Wittrick-Williams algorithm as a reference. Removal of the bottlenecks in solving the governing differential equations for high-order modes contributes usefully to the completeness of stepped Timoshenko beam theory.

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Frühwirth, R., T. Bergauer, M. Friedl, H. Gjersdal, C. Irmler, T. Spielauer, A. Strandlie, and M. Valentan. "Analysis of beam test data by global optimization methods." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 732 (December 2013): 79–82. http://dx.doi.org/10.1016/j.nima.2013.05.038.

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Kaye, S. M., and R. J. Goldston. "Global energy confinement scaling for neutral-beam-heated tokamaks." Nuclear Fusion 25, no. 1 (January 1, 1985): 65–69. http://dx.doi.org/10.1088/0029-5515/25/1/006.

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Kasal, Bohumil, and Andreas Heiduschke. "The Use of High-Strength Composites in the Reinforcement of Timber." Advanced Materials Research 133-134 (October 2010): 941–46. http://dx.doi.org/10.4028/www.scientific.net/amr.133-134.941.

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The use of high-strength composites in the reinforcement of structural timber has been documented to enhance the strength and stiffness of wood structural members. Global reinforcement is applied over the entire surface of the reinforced member. Local reinforcement is a targeted strengthening of highly-stressed zones susceptible to failure. Both types of reinforcement enhance the capacity of the reinforced members and mitigate brittle failure modes. This paper presents an overview of the application of fiber-based composites in the reinforcement of beams, columns and connections of timber structures and discusses the state-of-the-art technologies in reinforcement. The applications are illustrated on the reinforcement of beams, arches, frames and beam-to-column connections.

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Pushkar, Svetlana, and Yuri Ribakov. "ENVIRONMENTAL BENEFIT OF TWO-LAYER STEEL FIBERED HIGH-PERFORMANCE CONCRETE BEAMS." Journal of Green Building 16, no. 3 (June 1, 2021): 237–50. http://dx.doi.org/10.3992/jgb.16.3.237.

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ABSTRACT This study evaluated Life-Cycle Assessment (LCA) of two different designs of high-performance concrete beam: (1) a single-layer beam (SLB) that consisted of steel fibered high-strength concrete in both the compression and tensile zones and (2) a two-layer beam (TLB) that consisted of steel fibered high-strength concrete and normal-strength concrete in the compression and tensile zones, respectively. The SLB and steel fibered high-strength concrete layer of the TLB were of the same concrete class C70/85. LCAs of the SLB and TLB were conducted using the ReCiPe2016 midpoint and endpoint-single-score methods. The difference between the two endpoint-single-score results was evaluated using a two-stage nested analysis of variance. The ReCiPe2016 midpoint results showed that replacing the SLB with the TLB reduces the environmental impact of global warming potential, terrestrial ecotoxicity, water consumption, and scarcity of fossil resources by 15%, 17%, 11%, and 17%, respectively. The ReCiPe2016 endpoint-single-score results showed that the environmental damage from the TLB compared to the SLB was statistically reduced (p = 0.0256). Therefore, considering two different designs of steel fibered high-strength concrete beams, the TLB design was found environmentally preferable to SLB design on both, midpoint and endpoint-single-score evaluations.

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Choi, Insub, JunHee Kim, and DongWon Kim. "LCA-Based Investigation of Environmental Impacts for Novel Double-Beam Floor System Subjected to High Gravity Loads." Sustainability 12, no. 21 (November 5, 2020): 9193. http://dx.doi.org/10.3390/su12219193.

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In populated downtown areas, a floor system with secured environmental performance is needed to reduce greenhouse gases (GHGs) and global warming problems related to buildings. This study aims to assess environmental impacts on a novel double-beam floor system subjected to high gravity loads. Life cycle assessment (LCA) was conducted to investigate the environmental impacts on the reduction in construction materials by calculating global warming potential (GWP) in the structural design phase. For different structural systems, the environmental performance was compared based on the GWP, and the contributions of structural elements to the GWP in each structural system were analyzed. The rotational constraints induced by the beam-end concrete panel can significantly reduce the GWP of the double-beam floor system by up to 13.8% compared to the conventional beam-girder system. Thus, the double-beam floor system reinforced with the concrete panel can be a candidate for eco-friendly structural systems in underground structures requiring high gravity loads. This result provides valuable findings that the structural effect on the rotational constraint of the concrete panel was quantitatively evaluated by converting it into an environmental impact.

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Dai, Jian Feng, Qing Wang, Wei Xue Li, Yong Fu Cui, Feng Zhang, and Henry I. Smith. "The Fabrication of 2-D Global Fiducial Grid with High Resolution for Spatial Phase Locked e-Beam Lithography." Materials Science Forum 575-578 (April 2008): 1252–57. http://dx.doi.org/10.4028/www.scientific.net/msf.575-578.1252.

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The spatial phase locked scanning electron beam lithography systems (SPLEBL) is a new lithography technique with a pattern placement precision of about 1 nm. The SPLEBL technique can solve the major problem of poor placement accuracy existed in the conventional scanning electron beam lithography for that it uses a Fourier technique to detect the beam position in real time during exposure. The fiducial grid plays a key role in SPLEBL. The two-dimensional global fiducial grid with a grid period of 250 nm placed on top of the e-beam resist used in SPLEBL with high contrast, high brightness, long-range spatial-phase coherence, large area and a pattern placement precision of about 1 nm is fabricated using optical interference lithography in this article. The detail fabrication process is described and the SEM images of the fabricated grid are also presented in this paper. Only one evaporation step and several spin-coating steps are required in the fabrication process, so it is simple and user friendly.

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Santarsiero, Giuseppe, and Angelo Masi. "Key Mechanisms of the Seismic Behaviour of External RC Wide Beam–column Joints." Open Construction & Building Technology Journal 13, no. 1 (February 28, 2019): 36–51. http://dx.doi.org/10.2174/1874836801913010036.

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Background: Reinforced concrete beam-column connections provided with wide beams are widely used in the European residential building stock. Several seismic codes indicate some limitation to be applied to this kind of reinforced concrete buildings due to their reduced performances with respect to those provided with conventional beams. Objective: The paper is focused on improving the knowledge of wide beam-column joints, highlighting the key degradation mechanisms affecting them, mainly related to slip phenomena of beam rebars, especially the rebars placed outside the column width. Methods: The behavior of wide beam-column joints has been evaluated by means of both experimental tests under cyclic loading and accurate nonlinear finite element analyses. The FE models predicted satisfactorily experimental results, thus enabling to carry out additional numerical analyses aimed at checking the effect of the longitudinal reinforcement amount in the beam member. Results: Experimental results show that wide beam-column joints conforming to the Italian seismic code do not exhibit a sufficiently ductile behavior due to damage in the non-confined concrete region, where beam rebars external to the joint core are anchored. Numerical simulations allowed to monitor bond slip of beam rebars as a function of the applied global displacement, showing differences between bars placed inside and outside the column width. Conclusion: Numerical simulations showed that different behavior is expected in case additional beam rebars are placed either inside or outside column width. In the first case, higher peak load and ductility values can be achieved, provided that the amount of beam reinforcement is not high enough to shift damage towards the column or cause high shear stress to the joint core and its consequent fragile failure.

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Yurchenko, Daniil, Lucas Queiroz Machado, Junlei Wang, Chris Bowen, Suleiman Sharkh, Mohamed Moshrefi-Torbati, and Dimitri V. Val. "Global optimisation approach for designing high-efficiency piezoelectric beam-based energy harvesting devices." Nano Energy 93 (March 2022): 106684. http://dx.doi.org/10.1016/j.nanoen.2021.106684.

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Khanh, Trinh Duy, Nguyen Minh Tuyen, and Bui Hung Cuong. "Effects of end-plate on the critical moment of I-section cantilever beam with free end restrained laterally." Journal of Science and Technology in Civil Engineering (STCE) - NUCE 15, no. 1 (January 22, 2021): 102–9. http://dx.doi.org/10.31814/stce.nuce2021-15(1)-09.

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Effects of end-plate on the lateral buckling of doubly symmetrical I-section cantilever beam with free end restrained laterally are analyzed using the software COMSOL and linear shell finite elements. The torsional stiffness of the end-plate prevents the free warping of flanges and decreases the warping effective length of the cantilever beam. A parametric study is conducted on 3231 cantilever beams under uniform bending to propose an approximative formula to determine the warping effective length factor which depends on the ratio between the torsional constant of the end-plate and the warping stiffness of the beam. The small standard deviation and high coefficient of determination show a very good correlation between analytical formulas and numerical results. Numerical applications are applied to analyze some cantilever beams subjected to uniform bending to demonstrate the reliability of the proposed formula and the effects of the end-plate on the enhancement of the global stability of cantilever beams with free end restrained laterally. Keywords: cantilever lateral buckling; end-plate; edge stiffener; flexural-torsional buckling; warping effective length; warping effective length factor.

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15

Hillis, Andrew J., Simon A. Neild, Bruce W. Drinkwater, and Paul D. Wilcox. "Global crack detection using bispectral analysis." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 462, no. 2069 (February 8, 2006): 1515–30. http://dx.doi.org/10.1098/rspa.2005.1620.

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This paper describes a global non-destructive testing technique for detecting fatigue cracking in engineering components. The technique measures the mixing of two ultrasonic sinusoidal waves which are excited by a small piezoceramic disc bonded to the test structure. This input signal excites very high-order modes of vibration of the test structure within the ultrasonic frequency range. The response of the structure is measured by a second piezoceramic disc and the received waveform is analysed using the bispectrum signal processing technique. Frequency mixing occurs as a result of nonlinearities within the test structure and fatigue cracking is shown to produce a strong mixing effect. The bispectrum is shown to be particularly suitable for this application due to its known insensitivity to noise. Experimental results on steel beams are used to show that fatigue cracks, corresponding to a reduction in the beam section of 8%, can be detected. It is also shown that the bispectrum can be used to quantify the extent of the cracking. A simple nonlinear spring model is used to interpret the results and demonstrate the robustness of the bispectrum for this application.

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Vaganov, R. B., I. P. Korshunov, E. N. Korshunova, and A. D. Shatrov. "Microwave-beam power supply of high-altitude platforms of the global radio-relay network." Journal of Communications Technology and Electronics 56, no. 11 (November 2011): 1290–97. http://dx.doi.org/10.1134/s1064226911110167.

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Naito, O., N. Hosogane, S. Tsuji, K. Ushigusa, and H. Yoshida. "Global energy confinement in JT-60 neutral beam heated L-mode discharges." Nuclear Fusion 30, no. 2 (February 1, 1990): 195–203. http://dx.doi.org/10.1088/0029-5515/30/2/001.

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Li, Xuyang, Zhiqiang Wan, Xiaozhe Wang, and Chao Yang. "Aeroelastic Optimization Design of the Global Stiffness for a Joined Wing Aircraft." Applied Sciences 11, no. 24 (December 12, 2021): 11800. http://dx.doi.org/10.3390/app112411800.

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Due to the complexity and particularity of the joined wing layout, traditional design methods for the global stiffness of a high-aspect wing are not applicable for a joined wing. Herein, a beam-frame model and a three-dimensional wing-box model are built to solve the global stiffness aeroelastic optimization design problem for a joined wing. The goal is to minimize the weight, and the constraints are the overall aeroelastic requirements. Based on a genetic algorithm, two methods for the beam-frame model and one method for the three-dimensional model are used for comparative analysis. The results show that the optimization method for a diagonal beam section and the optimization method for an exponential/linear combination function fit are adequate for optimizing and designating the joined wing global stiffness. The distributions obtained using the two methods have good consistency and are similar to the distribution of the three-dimensional model. The stiffness distribution data and the beam section parameters can be converted from each other, which is convenient for redesigning the structure parameters using the stiffness distribution data, and is valuable for engineering applications.

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Smith, Henry I. "A new approach to high fidelity e-beam and ion-beam lithography based on an in situ global-fiducial grid." Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures 9, no. 6 (November 1991): 2992. http://dx.doi.org/10.1116/1.585355.

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Dahl, Nathan A., and David S. Nolan. "Using High-Resolution Simulations to Quantify Errors in Radar Estimates of Tornado Intensity." Monthly Weather Review 146, no. 7 (July 1, 2018): 2271–96. http://dx.doi.org/10.1175/mwr-d-17-0333.1.

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Abstract Observation experiments are performed on a set of high-resolution large-eddy simulations of translating tornado-like vortices. Near-surface Doppler wind measurements are taken by emulating a mobile radar positioned from 1 to 10 km south of each vortex track and conducting single-level scans every 2 s. The departure of each observed gust (wind measurement averaged over two successive scans) from the corresponding true maximum 3-s gust at 10 m AGL (“S10–3s”) is partitioned into error sources associated with resolution volume size, wind direction relative to the radar beam, beam elevation, and temporal sampling. The distributions of each error type are diagrammed as functions of range, observed wind speed, and predicted deviation between the wind direction and the radar beam. The results indicate that the deviation between the wind direction and the radar beam is the predominant source of error in these rapid scan scenarios, although range is also a substantial factor. The median total error is ~10% for small deviation at close range, but it approximately doubles if the range is increased from 1 to 10 km; a more pronounced increase in both the median value and the variance of the total error is seen as the deviation becomes large. Because of this, the underestimate of the global maximum S10–3s approaches 30–40 m s−1 at a longer range, although the global maximum of the time-averaged observed wind speed gives a reasonable approximation of the time-mean maximum S10–3s in many cases. Because of simplifying assumptions and the limited number of cases examined, these results are intended as a baseline for further research.

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Amillo, Ana Gracia, Lucky Ntsangwane, Thomas Huld, and Jörg Trentmann. "Comparison of satellite-retrieved high-resolution solar radiation datasets for South Africa." Journal of Energy in Southern Africa 29, no. 2 (June 22, 2018): 63–76. http://dx.doi.org/10.17159/2413-3051/2018/v29i2a3376.

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This study compares the performance of two satellite-based solar radiation methodologies for estimating the solar resource available in South Africa. Data from thirteen stations distributed in six climatic regions were considered. More than one year of hourly values of global horizontal and beam normal irradiance were examined in the validation of the satellite-retrieved estimates at every location. The best satellite method resulted in an overall relative mean bias of 1.41% for the global horizontal irradiance corresponding to almost 3 Wm-2 and exhibited a relative mean bias of 2.85% for the beam normal irradiance estimation (about 7 Wm-2). This satellite-based method was implemented into a geographical information system module, which contained high-resolution terrain data and allowed the effect of the surrounding topography on the estimation of the available solar resource to be considered. These estimates can, therefore, be used as input data for further analysis or applications. As an example, maps of the potential output that could be expected in South Africa from photovoltaic systems were created.

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Shimada, M., A. T. Ramsey, D. K. Owens, H. F. Dylla, R. V. Budny, P. H. Lomarche, J. F. Schivell, R. J. Groebner, D. Heifetz, and M. Murakami. "Global particle recycling with ohmic and neutral beam heating in TFTR." Journal of Nuclear Materials 145-147 (February 1987): 544–50. http://dx.doi.org/10.1016/0022-3115(87)90397-7.

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Bochenski, Marcin, Jaroslaw Gawryluk, and Andrzej Teter. "Influence of Hole Localization on Local and Global Dynamic Response of Thin-Walled Laminated Cantilever Beam." Materials 14, no. 23 (December 3, 2021): 7409. http://dx.doi.org/10.3390/ma14237409.

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In this study, we discuss the effects of the diameter and position of a hole on the dynamic response of a thin-walled cantilever beam made of carbon-epoxy laminate. Eigen-frequencies and corresponding global and local eigen-modes were considered, where deformations of the beam wall were dominant, without significant deformation of the beam axis. The study was focused on the circumferentially uniform stiffness (CUS) beam configuration. The laminate layers were arranged as [90/15(3)/90/15(3)/90]T. The finite element method was employed for numerical tests, using the Abaqus software package. Moreover, a few numerical results of the structure’s behaviour, with and without a hole, were verified experimentally. The experimental eigen-frequencies and the corresponding modes were obtained using an experimental modal analysis, comprising the LMS system with modal hammer. We found that the size and location of the hole affected the eigen-frequencies and corresponding modes. Furthermore, even a small hole in a beam could significantly change the shape of its local modes. The numerical and experimental results were observed to have high qualitative compliance.

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Pellicano, F., and F. Vestroni. "Nonlinear Dynamics and Bifurcations of an Axially Moving Beam." Journal of Vibration and Acoustics 122, no. 1 (August 1, 1999): 21–30. http://dx.doi.org/10.1115/1.568433.

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The present paper analyzes the dynamic behavior of a simply supported beam subjected to an axial transport of mass. The Galerkin method is used to discretize the problem: a high dimensional system of ordinary differential equations with linear gyroscopic part and cubic nonlinearities is obtained. The system is studied in the sub and super-critical speed ranges with emphasis on the stability and the global dynamics that exhibits special features after the first bifurcation. A sample case of a physical beam is developed and numerical results are presented concerning the convergence of the series expansion, linear subcritical behavior, bifurcation analysis and stability, and direct simulation of global postcritical dynamics. A homoclinic orbit is found in a high dimensional phase space and its stability and collapse are studied. [S0739-3717(00)00501-8]

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Liu, Peng, Kun Lin, Hongjun Liu, and Rong Qin. "Free Transverse Vibration Analysis of Axially Functionally Graded Tapered Euler-Bernoulli Beams through Spline Finite Point Method." Shock and Vibration 2016 (2016): 1–23. http://dx.doi.org/10.1155/2016/5891030.

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A new model for the free transverse vibration of axially functionally graded (FG) tapered Euler-Bernoulli beams is developed through the spline finite point method (SFPM) by investigating the effects of the variation of cross-sectional and material properties along the longitudinal directions. In the proposed method, the beam is discretized with a set of uniformly scattered spline nodes along the beam axis instead of meshes, and the displacement field is approximated by the particularly constructed cubic B-spline interpolation functions with good adaptability for various boundary conditions. Unlike traditional discretization and modeling methods, the global structural stiffness and mass matrices for beams of the proposed model are directly generated after spline discretization without needing element meshes, generation, and assembling. The proposed method shows the distinguished features of high modeling efficiency, low computational cost, and convenience for boundary condition treatment. The performance of the proposed method is verified through numerical examples available in the published literature. All results demonstrate that the proposed method can analyze the free vibration of axially FG tapered Euler-Bernoulli beams with various boundary conditions. Moreover, high accuracy and efficiency can be achieved.

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Cai, Song Bai, Da Zhi Li, Chang Wan Kim, and Pu Sheng Shen. "A Simple Co-Rotational Finite Planar Beam Element of Geometrical and Material Nonlinearity." Applied Mechanics and Materials 268-270 (December 2012): 1163–67. http://dx.doi.org/10.4028/www.scientific.net/amm.268-270.1163.

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A simple geometrical and material nonlinear co-rotational planar beam element of field consistency is proposed. Herein the element which produces a local stiffness matrix of 3 by 3 other than 6 by 6 is developed. Material nonlinearity is taken into account on the base of yield function of element internal forces. By applying static equilibrium relationship of classic beam theory for the transferring of local element nodal force to global element nodal force, a new transformation matrix different from the nodal displacement transformation matrix is established. Although this results in an asymmetric global tangential stiffness matrix, the new transformation is simpler, and gives rise to field consistency and makes it possible to compute very large beam deflection without remeshing of the deformed structure. Computations of numerical example indicates that formulations for the nonlinear beam element are of validation and high efficiency

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Teo, C. Y., A. Weller, C. Konrad, W7-AS Team, and NBI Team. "Further observations of neutral beam driven global Alfvén eigenmodes in Wendelstein W7-AS." Nuclear Fusion 38, no. 3 (March 1998): 409–17. http://dx.doi.org/10.1088/0029-5515/38/3/307.

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ZHANG, W., and M. H. YAO. "THEORIES OF MULTI-PULSE GLOBAL BIFURCATIONS FOR HIGH-DIMENSIONAL SYSTEMS AND APPLICATION TO CANTILEVER BEAM." International Journal of Modern Physics B 22, no. 24 (September 30, 2008): 4089–141. http://dx.doi.org/10.1142/s021797920804898x.

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The aim of this survey paper is to illustrate the perspectives on the theories of the single- and multi-pulse global bifurcations and chaotic dynamics of high-dimensional nonlinear systems and applications to several engineering problems in the past two decades. Two main methods for studying the Shilnikov type multi-pulse homoclinic and heteroclinic orbits in high-dimensional nonlinear systems, which are the energy-phase method and generalized Melnikov method, are briefly demonstrated in the theoretical frame. In addition, the theory of normal form and an improved adjoint operator method for high-dimensional nonlinear systems is also applied to describe a reducing procedure to high-dimensional nonlinear systems. The aforementioned methods are utilized to investigate the Shilnikov type multi-pulse homoclinic bifurcations and chaotic dynamics for the nonlinear nonplanar oscillations of the cantilever beam subjected to a harmonic axial excitation and two transverse excitations at the free end. How to employ these methods to analyze the Shilnikov type multi-pulse homoclinic and heteroclinic bifurcations and chaotic dynamics of high-dimensional nonlinear systems in engineering applications is demonstrated through this example.

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Ebisawa, Takashi, and Ken Takayama. "3D beam-envelope approach for an asymmetric beam in a high intensity linac with a solenoid channel." AIP Advances 13, no. 4 (April 1, 2023): 045316. http://dx.doi.org/10.1063/5.0146071.

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Presented here is a theory model based on the beam-envelope approach to determine the global behavior of a charged beam propagating through a high intensity linac with a solenoid channel, namely, the orbital evolution of the root-mean-square beam size in the transverse and longitudinal direction. The model is applied to the Gaussian particle distribution, where the motion of an individual particle is governed by linear focusing/defocusing forces in the solenoid channel and RF fields, except for space-charge forces. In this model, highly nonlinear effects that originated from space-charge forces disappear by averaging over the harmonic motions such as the betatron motion and phase motion in the moving direction and the Gaussian distribution. All particles making up a 3D Gaussian bunch obey the same linear equations of motion where all information of nonlinearity in the space-charge forces and the particle distribution are carried in. The theory is validated using Gaussian macro-particle simulation and one of the widely used photonic integrated circuit codes, TraceWin. As an example, the model is applied to the case of an international fusion materials irradiation facility superconducting linac with solenoid guiding and half wave RF acceleration. The results are compared with results obtained by this model and other two approaches.

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Yang, Chao, Vicenţiu D. Rădulescu, Runzhang Xu, and Mingyou Zhang. "Global well-posedness analysis for the nonlinear extensible beam equations in a class of modified Woinowsky-Krieger models." Advanced Nonlinear Studies 22, no. 1 (January 1, 2022): 436–68. http://dx.doi.org/10.1515/ans-2022-0024.

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Abstract For studying the evolution of the transverse deflection of an extensible beam derived from the connection mechanics, we investigate the initial boundary value problem of nonlinear extensible beam equation with linear strong damping term, nonlinear weak damping term, and nonlinear source term. The key idea of our analysis is to describe the invariant manifold via Nehari manifold. To establish the results of global well-posedness of solution, we consider the problem at three different initial energy levels, i.e., subcritical initial energy level, critical initial energy level, and arbitrarily high initial energy level. We first obtain the local existence of the solution by using the contraction mapping principle. Then, in the framework of potential well, we obtain global existence, nonexistence, and asymptotic behavior of solution for both subcritical initial energy level and critical initial energy level. In the end, we establish the global nonexistence of solution for the problem with linear weak damping and strong damping at the arbitrarily high initial energy level.

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31

Zanuy, Carlos, and Gonzalo S. D. Ulzurrun. "Impact Resisting Mechanisms of Shear-Critical Reinforced Concrete Beams Strengthened with High-Performance FRC." Applied Sciences 10, no. 9 (May 1, 2020): 3154. http://dx.doi.org/10.3390/app10093154.

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Reinforced concrete (RC) structures typically present brittle failures by shear or punching under impact loading. High-performance fiber-reinforced concrete (HPFRC) has great potential due to its superior strength and energy absorption. The higher price and environmental cost of HPFRC compared to conventional RC can be effectively overcome by partially strengthening impact-sensitive RC members with HPFRC. To study the feasibility of this technique, HPFRC was applied as a tensile layer at the bottom of RC beams. Drop weight impact tests were carried out on beams with two values (35 and 55 mm) of HPFRC thickness, in addition to companion RC beams. Results show that the impact response can be divided into two stages: a first stage governed by local effects and shear plug formation at midspan, and a second stage governed by global beam behavior with formation of shear web cracks. A new resisting mechanism was observed for beams strengthened with HPFRC, as the strengthening layer worked similarly to a stress ribbon retaining the damaged RC and reducing fragmentation-induced debris. Such mechanism was fully achieved by the specimens with 35 mm HPFRC layer but was limited for the specimens with 55 mm HPFRC layer due to impact-induced interface debonding.

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32

Habtour, Ed M., Daniel P. Cole, Christopher M. Kube, Todd C. Henry, Robert A. Haynes, Frank Gardea, Tomoko Sano, and Tiedo Tinga. "Structural state awareness through integration of global dynamic and local material behavior." Journal of Intelligent Material Systems and Structures 30, no. 9 (February 24, 2019): 1355–65. http://dx.doi.org/10.1177/1045389x19828489.

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Structural health monitoring and nondestructive inspection techniques typically assess the lifecycle and reliability of high-value aerospace, mechanical, and civil systems. Maintenance and inspection intervals are typically time-based and dependent on the structural health monitoring/nondestructive inspection technique to detect macroscale damage resulting from fatigue or environmental damage. The current work proposes an integrated materials-structures-dynamics approach for providing state awareness of structural health. The proposed approach shifts the conventional structural health monitoring/nondestructive inspection focus of searching for cracks to a health state awareness based on tracking changes in the energetics of the materials-structures-dynamics states. Energy variations are tracked in a cantilevered structure exposed to nonlinear harmonic oscillation, where the strain energy of the beam was derived and used to determine a health state index. Nanoindentation was used to probe the near-surface mechanical properties of the beam to characterize local material variations as a function of fatigue cycles. A nonlinear ultrasonic approach was considered in order to connect the local material behavior changes to the variations in the dynamic performance of the beam. The intent of the investigation was to connect the traditionally detached materials, structural, and dynamics approaches to structural health monitoring/nondestructive inspection, while providing a framework for enabling damage precursor detection.

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33

Ventura, Tiago, Humberto Rocha, Brigida da Costa Ferreira, Joana Dias, and Maria do Carmo Lopes. "Comparison of non-coplanar optimization of static beams and arc trajectories for intensity-modulated treatments of meningioma cases." Physical and Engineering Sciences in Medicine 44, no. 4 (October 7, 2021): 1273–83. http://dx.doi.org/10.1007/s13246-021-01061-8.

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AbstractTwo methods for non-coplanar beam direction optimization, one for static beams and another for arc trajectories, were proposed for intracranial tumours. The results of the beam angle optimizations were compared with the beam directions used in the clinical plans. Ten meningioma cases already treated were selected for this retrospective planning study. Algorithms for non-coplanar beam angle optimization (BAO) and arc trajectory optimization (ATO) were used to generate the corresponding plans. A plan quality score, calculated by a graphical method for plan assessment and comparison, was used to guide the beam angle optimization process. For each patient, the clinical plans (CLIN), created with the static beam orientations used for treatment, and coplanar VMAT approximated plans (VMAT) were also generated. To make fair plan comparisons, all plan optimizations were performed in an automated multicriteria calculation engine and the dosimetric plan quality was assessed. BAO and ATO plans presented, on average, moderate global plan score improvements over VMAT and CLIN plans. Nevertheless, while BAO and CLIN plans assured a more efficient OARs sparing, the ATO and VMAT plans presented a higher coverage and conformity of the PTV. Globally, all plans presented high-quality dose distributions. No statistically significant quality differences were found, on average, between BAO, ATO and CLIN plans. However, automated plan solution optimizations (BAO or ATO) may improve plan generation efficiency and standardization. In some individual patients, plan quality improvements were achieved with ATO plans, demonstrating the possible benefits of this automated optimized delivery technique.

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34

Ahmed, Mizan, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, and Muhammad N. S. Hadi. "Local-global interaction buckling of square high strength concrete-filled double steel tubular slender beam-columns." Thin-Walled Structures 143 (October 2019): 106244. http://dx.doi.org/10.1016/j.tws.2019.106244.

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35

Luo, Wen Jun, Xiao Yan Lei, Song Liang Lian, and Lin Ya Liu. "The Characteristic Analysis of Vibration for High-Speed Train-Ballastless Track-Bridge System Base on A Hybrid FE-SEA Method." Applied Mechanics and Materials 226-228 (November 2012): 387–91. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.387.

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A hybrid method combining FE and SEA was recently presented for predicting the steady-state response of vibro-acoustic systems. The new method is presented for the analysis of complex dynamic systems which is based on partitioning the system degrees of freedom into a ‘‘global’’ set and a ‘‘local’’ set. The global equations of motion are formulated and solved by using the finite element method (FEM).The local equations of motion are formulated and solved by using statistical energy analysis (SEA). The power input from the global degrees of freedom. This paper deduces the theory for the beam element , and Train-Ballastless Track-Bridge System provides an application, and it showed that the method yields very good results .

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36

Artemenko, I. I., M. S. Krygin, D. A. Serebryakov, E. N. Nerush, and I. Yu Kostyukov. "Global constant field approximation for radiation reaction in collision of high-intensity laser pulse with electron beam." Plasma Physics and Controlled Fusion 61, no. 7 (May 24, 2019): 074003. http://dx.doi.org/10.1088/1361-6587/ab1712.

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37

Quan, Guan, Shan-Shan Huang, and Ian Burgess. "PARAMETRIC STUDIES ON THE COMPONENT-BASED APPROACH TO MODELLING BEAM BOTTOM FLANGE BUCKLING AT ELEVATED TEMPERATURES." Acta Polytechnica 56, no. 2 (April 30, 2016): 132. http://dx.doi.org/10.14311/ap.2016.56.0132.

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<p>In this study, an analytical model of the combination of beam-web shear buckling and bottom-flange buckling at elevated temperatures has been introduced. This analytical model is able to track the force-deflection path during post-buckling. A range of 3D finite element models has been created using the ABAQUS software. Comparisons have been carried out between the proposed analytical model, finite element modelling and an existing theoretical model by Dharma (2007). Comparisons indicate that the proposed method is able to provide accurate predictions for Class 1 and Class 2 beams, and performs better than the existing Dharma model, especially for beams with high flange-to-web thickness ratios. A component-based model has been created on the basis of the analytical model, and will in due course be implemented in the software Vulcan for global structural fire analysis.</p>

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38

Petrucci, Maria Carmela. "THE ZEUS MICROVERTEX DETECTOR." International Journal of Modern Physics A 16, supp01c (September 2001): 1078–80. http://dx.doi.org/10.1142/s0217751x01008941.

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A new silicon microvertex detector (MVD) will be installed in the ZEUS experiment during the 2000 HERA luminosity upgrade. Such a high precision detector will improve the global tracking system and allow to identity events with secondary vertices originating from the decays of long-lived states. It will be placed in the proximity to the beam pipe to surround the interaction region. The barrel part is a 60 cm long cylinder consisting of three double layers of single-sided silicon detectors, the forward part is made of four double shaped layers, called wheels, extending 42 cm along the beam. A test beam has been setup in order to characterize the performance of the detector modules and readout electronics (i.e. track position resolution, signal to noise ratio, detection efficiency). The detector layout and some selected test beam results are presented.

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39

Haga, K., T. Honda, M. Tadano, T. Obina, and T. Kasuga. "New beam-position monitor system for upgraded Photon Factory storage ring." Journal of Synchrotron Radiation 5, no. 3 (May 1, 1998): 624–26. http://dx.doi.org/10.1107/s0909049597014349.

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Accompanying the brilliance-upgrading project at the Photon Factory storage ring, the beam-position monitor (BPM) system has been renovated. The new system was designed to enable precise and fast measurements to correct the closed-orbit distortion (COD), as well as to feed back the orbit position during user runs. There are 42 BPMs newly installed, amounting to a total of 65 BPMs. All of the BPMs are calibrated on the test bench using a coaxially strung metallic wire. The measured electrical offsets are typically 200 µm in both directions, which is 1/2–1/3 of those of the old-type BPMs. In the signal-processing system, PIN diode switches are employed in order to improve reliability. In the fastest mode, this system is capable of measuring COD within about 10 ms; this fast acquisition will allow fast suppression of the beam movement for frequencies up to 50 Hz using a global feedback system.

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40

Pushkar, Svetlana, and Yuri Ribakov. "Life-Cycle Assessment of Strengthening Pre-Stressed Normal-Strength Concrete Beams with Different Steel-Fibered Concrete Layers." Sustainability 12, no. 19 (September 25, 2020): 7958. http://dx.doi.org/10.3390/su12197958.

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This study aimed to determine the difference between two alternatives for pre-stressed normal-strength concrete beams according to life-cycle assessments (LCAs): strengthening the PNSC (pre-stressed normal-strength concrete) beam on one side with a 70 mm width, steel-fibered, high-strength concrete layer (Case 1) and strengthening the PNSC beams by jacketing on three sides with 30 mm width, ultra-high-performance, fiber-reinforced concrete layers (Case 2). We conducted LCAs of these cases using the ReCiPe2016 midpoint and endpoint-single-score methods. The differences among the beams’ endpoint-single-score results were evaluated using a two-stage nested analysis of variance. The ReCiPe2016 midpoint results showed that compared to Case 2, Case 1 reduced the global warming potential, terrestrial ecotoxicity, water consumption, and fossil-resource-scarcity impacts by 73–80%. The ReCiPe2016 endpoint-single-score results showed that the environmental damage from Case 1 was significantly lower (p = 0.0003) than that from Case 2. These findings could be promising and useful for studying sustainability in construction.

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41

Aubry, Rémy, Matthieu Debal, Stéphane Aubert, and Yann Rogaume. "Experimental Study on U-Beam Separator Device for Separating Solids from Gases." Energies 16, no. 13 (June 27, 2023): 4975. http://dx.doi.org/10.3390/en16134975.

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The inertial separator, developed for fluidized beds, is a key component for optimizing large installations that separate solids from gases. Despite industrial interest and numerous patents, few studies have been conducted on this subject. In this paper, the geometric arrangement conditions were studied and evaluated. The efficiency of separating solids from gas depends on several factors, such as the granulometry, density, particle size distribution, velocity, humidity, and temperature of the system. For the mid-range of fluidized bed boilers (1–20 MWth), the experimental study selected all data to be in the same condition as the industrial technology. The global performance of the system can be increased by 15% by selecting a better combination of the U-beam. Three rows of U-beams are a good compromise between performance and cost for high Reynolds numbers, while only two rows seem to be enough for lower Reynolds numbers.

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42

Zhu, Xiaoxiao, Sheng Nie, Cheng Wang, Xiaohuan Xi, Dong Li, Guoyuan Li, Pu Wang, Di Cao, and Xuebo Yang. "Estimating Terrain Slope from ICESat-2 Data in Forest Environments." Remote Sensing 12, no. 20 (October 11, 2020): 3300. http://dx.doi.org/10.3390/rs12203300.

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The global digital elevation measurement (DEM) products such as SRTM DEM and GDEM have been widely used for terrain slope retrieval in forests. However, the slope estimation accuracy is generally limited due to the DEMs’ low vertical accuracy over complex forest environments. The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) mission shows excellent potential for slope estimation because of the high elevation accuracy and unique design of beam pairs. This study aimed to explore the possibility of ICESat-2 data for terrain slope retrieval in the United States forests. First, raw ICESat-2 data were processed to obtain accurate ground surfaces. Second, two different methods based on beam pairs were proposed to derive terrain slopes from the ground surfaces. Third, the estimated slopes were validated by airborne LiDAR-derived slopes and compared with SRTM-derived slopes and GDEM-derived slopes. Finally, we further explored the influence of surface topography and ground elevation error on slope estimation from ICESat-2 data. The results show that the ground surface can be accurately extracted from all scenarios of ICESat-2 data, even weak beams in the daytime, which provides the basis for terrain slope retrieval from ICESat-2 beam pairs. The estimated slope has a strong correlation with airborne LiDAR-derived slopes regardless of slope estimation methods, which demonstrates that the ICESat-2 data are appropriate for terrain slope estimation in complex forest environments. Compared with the method based on along- and across-track analysis (method 1), the method based on plane fitting of beam pairs (method 2) has a high estimation accuracy of terrain slopes, which indicates that method 2 is more suitable for slope estimation because it takes full advantage of more ground surface information. Additionally, the results also indicate that ICESat-2 performs much better than SRTM DEMs and GDEMs in estimating terrain slopes. Both ground elevation error and surface topography have a significant impact on terrain slope retrieval from ICESat-2 data, and ground surface extraction should be improved to ensure the accuracy of terrain slope retrieval over extremely complex environments. This study demonstrates for the first time that ICESat-2 has a strong capability in terrain slope retrieval. Additionally, this paper also provides effective solutions to accurately estimate terrain slopes from ICESat-2 data. The ICESat-2 slopes have many potential applications, including the generation of global slope products, the improvement of terrain slopes derived from the existing global DEM products, and the correction of vegetation biophysical parameters retrieved from space-borne LiDAR waveform data.

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43

Gou, Xingrui. "Measurements of global and local polarization of hyperons in isobar collisions at 200 GeV from STAR." EPJ Web of Conferences 276 (2023): 04007. http://dx.doi.org/10.1051/epjconf/202327604007.

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In heavy-ion collisions, the observation of the global and local polarization of hyperons has revealed the existence of large vorticities perpendicular to reaction plane due to system’s orbital angular momentum and along beam direction due to collective velocity field, respectively. With the high-statistics data from isobar collisions of Ru+Ru and Zr+Zr at √SNN = 200 GeV collected by the STAR experiment, we present differential measurements of global polarization for Λ/Λ¯ as a function of centrality. These measurements allow us to study the possible magnetic field driven effects through the polarization difference between Ru+Ru and Zr+Zr, owing to a larger magnetic field in the former. Furthermore, the first measurements of Λ hyperon local polarization along beam direction relative to the third-order event plane as well as the second-order event plane are presented. A comparison of results from isobar and Au+Au collisions provides important new insights into the collision system size dependence of the vorticities in heavy-ion collisions.

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44

Ma, E. "Effects of global versus non-overlapping thermal spikes on ion beam mixing efficiency in metals." Radiation Effects and Defects in Solids 133, no. 1 (March 1995): 35–43. http://dx.doi.org/10.1080/10420159508225754.

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45

Wilks, Gavin. "Global spin alignment of ɸ and K*⁰ vector mesons in Au+Au collisions from RHIC BES-II program." EPJ Web of Conferences 276 (2023): 01029. http://dx.doi.org/10.1051/epjconf/202327601029.

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Global spin alignment is a preferential alignment of a particle’s spin along the orbital angular momentum produced in heavy-ion collisions. The global spin alignment of vector mesons (JP = 1−) ϕ and K*0 may be sensitive to the vorticity in the medium and hadronization mechanisms. The second phase of RHIC Beam Energy Scan (BES-II) program provides higher statistics data sets for Au+Au collisions at √SNN = 7.7 - 19.6 GeV. From this data, we can make high precision measurements of ϕ and K*0 global spin alignment, allowing for more differential studies not possible with the BES-I data. We can also compare global spin alignment between ϕ and K*0, where the lifetime of ϕ is roughly ten times larger than that of K*0 and the latter is more sensitive to hadronic rescattering. We report high precision measurements for the global spin alignment of ϕ at √SNN = 19.6 GeV from BES-II.

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46

Xin, Mingzhen, Fanlin Yang, Faxing Wang, Bo Shi, Kai Zhang, and Hui Liu. "A TOA/AOA Underwater Acoustic Positioning System Based on the Equivalent Sound Speed." Journal of Navigation 71, no. 6 (June 5, 2018): 1431–40. http://dx.doi.org/10.1017/s037346331800036x.

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High-precision underwater positioning must eliminate the influence of refraction artefacts. Since a Time Of Arrival - Global Navigation Satellite System Intelligent Buoys (TOA-GIB) system does not measure incident beam angles, common refraction correction methods cannot be directly used for refraction artefacts. An Equivalent Sound Speed (ESS) iteration method is proposed and is based on the transformation relations between depth, the ESS gradient and the incident beam angle. On this basis, a TOA/AOA-GIB system without a real-time Sound Speed Profile (SSP) is proposed to estimate the target position and the ESS gradient as unknown parameters. The results from a simulation experiment show that the positioning accuracy of a TOA/AOA-GIB system is better than 0·07% of water depth when the accuracy of the incident beam angle is 0·1°.

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Yang, Xiao Mei. "Double-Superposition Assumption for Piezoelectric Laminate Beam Theory." Advanced Materials Research 163-167 (December 2010): 2101–5. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.2101.

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An attempt is made to extend the double superposition hypothesis for elastic laminate analysis to piezoelectric laminate structure analysis. In addition to the displacement, the double superposition technique is also applied to the electric potential. The double-superposition hypothesis for piezoelectric laminate analysis can predict the zigzag feature of the field variables along the transverse direction in piezoelectric laminates. Moreover, the elastic field computational cost of double superposition assumption is no more than that of high-order shear theories for global coordinates, and the degrees of freedom by double superposition assumption for electric potential are much fewer than those by layerwise models for electric potential. It will be seen from the numerical examples that the good accuracy and lower computational cost can be presented by the double-superposition assumption for piezoelectric laminate beams.

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48

Zhang, Zhigang, Zhaohui Qi, Zhigang Wu, and Huiqing Fang. "A Spatial Euler-Bernoulli Beam Element for Rigid-Flexible Coupling Dynamic Analysis of Flexible Structures." Shock and Vibration 2015 (2015): 1–15. http://dx.doi.org/10.1155/2015/208127.

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A two-node spatial beam element with the Euler-Bernoulli assumption is developed for the nonlinear dynamic analysis of slender beams undergoing arbitrary rigid motions and large deformations. During the analysis, the global displacement and rotation vectors with six degrees of freedom are selected as the nodal coordinates. In addition, the “shear locking” problem is avoided successfully since the beam cross-sections are always perpendicular to the current neutral axes by employing a special coupled interpolation of the centroid position and the cross-section orientation. Then a scheme is presented where the original transient strains representing the nodal forces are replaced by proposed average strains over a small time interval. Thus all the high frequencies can be filtered out and a corresponding equivalent internal damping will be produced in this new formulation, which can improve the computation performance of the proposed element for solving the stiff problem and evaluate the governing equations even by using the nonstiff ordinary differential equation solver. Finally, several numerical examples are carried out to verify the validation and efficiency of this proposed formulation by comparison with the analytical solutions and other research works.

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49

Wei, Peng Sheng, and Lih Ren Chiou. "Molten Metal Flow Around the Base of a Cavity During a High-Energy Beam Penetrating Process." Journal of Heat Transfer 110, no. 4a (November 1, 1988): 918–23. http://dx.doi.org/10.1115/1.3250593.

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An axisymmetric, quasi-steady-state model for the flow of molten metal in a thin layer surrounding the lower region of a vapor-filled cavity formed during a high-energy beam penetrating process is investigated for the first time. The shape of the vapor–liquid interface is determined by solving the momentum and energy equations and satisfying global mass conservation. Results show that the effective surface pressure and the force caused by the surface tension induce the upward flow of the liquid layer, which is responsible for the formation of the cavity. Distributions of the cavity temperatures, the liquid layer thickness, and the tangential velocity are also presented in this initial study.

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Wu, Jian, Xiaomei Tang, Long Huang, Shaojie Ni, and Feixue Wang. "Blind Adaptive Beamforming for a Global Navigation Satellite System Array Receiver Based on Direction Lock Loop." Remote Sensing 15, no. 13 (July 3, 2023): 3387. http://dx.doi.org/10.3390/rs15133387.

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The adaptive beamforming algorithm can realize interference suppression and navigation signal enhancement, and has been widely used. However, achieving high-precision real-time estimation of the direction of arrival (DOA) parameters of navigation signals in strong-interference scenarios with low complexity is still a challenge. In this paper, a blind adaptive beamforming algorithm for a Global Navigation Satellite System (GNSS) array receiver based on direction lock loop is proposed without using the prior information of the DOA parameter. The direction lock loop is used for DOA tracking and estimation after interference suppression, which uses the spatial correlation of the array beam pattern to construct a closed direction-tracking loop. The DOA estimation value is adjusted in real time based on the loop errors. A blind beamformer is constructed using the DOA estimation results to provide gain by forming a beam in the satellite direction. This method improves the accuracy and dynamic adaptability of DOA estimation while significantly reducing the computational complexity. The theoretical analysis and simulation results verify the effectiveness of the proposed algorithm.

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Journal articles on the topic 'HIGH BEAM GLOBAL'

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