• Nuclear Engineering and Technology
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• 제53권1호
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• pp.30-43
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• 2021

In the 2D/1D method, a global adjoint CMFD based on the generalized equivalence theory is built to synthesize the 2D radial MOC adjoint and 1D axial NEM adjoint calculation and also to accelerate the iteration convergence of 3D whole-core adjoint transport calculation. Even more important, an advanced yet accurate two-level (TL) CMFD acceleration technique is proposed, in which an equivalent one-group adjoint CMFD is established to accelerate the multi-group adjoint CMFD and then to accelerate the 3D whole-core adjoint transport calculation efficiently. Based on these method, a new code is developed to perform 3D adjoint neutron flux calculation. Then a set of VERA and C5G7 benchmark problems are chosen to verify the capability of the 3D adjoint calculations and the effectiveness of TL CMFD acceleration. The numerical results demonstrate that acceptable accuracy of 2D/1D adjoint calculations and superior acceleration of TL CMFD are achievable.

• Wind and Structures
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• 제35권5호
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• pp.353-368
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• 2022

Wind turbine blades are adjusted in real-time according to the wind conditions and blade deformations to improve power generation efficiency. It is necessary to predict and reduce the aeroelastic deformations of wind turbine blades. In this paper, the equivalent model of the blade is established by the finite element method (FEM), and the aerodynamic load of the blade is evaluated based on the blade element momentum (BEM) theory. The aeroelastic coupling model is established, in which the bending-torsion coupling effect of the blade is taken into account. The steady and dynamic aeroelastic deformations are calculated. The influences of the blade section's shear centre position and the blade's sweepback design on the deformations are analyzed. The novel approaches of reducing the twist angle of the blade by changing the shear centre position and sweepback of the blade are presented and proven to be feasible.

• Advances in nano research
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• 제15권3호
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• pp.239-251
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• 2023

In the present study, we aim to use nanotechnology sensors/actuators to capture pressure and frequency of voice singers and to send signals for improving breathing pressure. In this regard, a circular composite structure having 3 different layers are used. The core layer is nano-composite material reinforced with graphene nanoplatelets. The face sheets are piezo electric materials connected to electrical circuit capable of measuring and applying voltage to the piezoelectric layers. This sensors have extremely smaller size than conventional sensors attached to the neck of singer and, hence, minimizes the influences on the output voice of the singer. A brief theoretical framework are presented for nonlocal strain gradient theory and geometry of the sensor is described in detail. The controlling procedure along with experimental results on 20 amateur and professional singer participants are also presented. The results of the study indicate that the participants could gain benefit from the device for improving their ability in phonation and keeping their frequency at a constant level although they have difficulty in the beginning of the experiment getting used to the device.

• Current Optics and Photonics
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• 제8권3호
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• pp.300-306
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• 2024

To solve the nozzle swing angle non-contact measurement problem, we present a nozzle pose estimation algorithm involving weighted measurement uncertainty based on rotation parameters. Firstly, the instantaneous axis of the rocket nozzle is constructed and used to model the pivot point and the nozzle coordinate system. Then, the rotation matrix and translation vector are parameterized by Cayley-Gibbs-Rodriguez parameters, and the novel object space collinearity error equation involving weighted measurement uncertainty of feature points is constructed. The nozzle pose is obtained at this step by the Gröbner basis method. Finally, the swing angle is calculated based on the conversion relationship between the nozzle static coordinate system and the nozzle dynamic coordinate system. Experimental results prove the high accuracy and robustness of the proposed method. In the space of 1.5 m × 1.5 m × 1.5 m, the maximum angle error of nozzle swing is 0.103°.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.410-418
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• 2024

Study of flow behavior within rod bundles has been an active topic. Surface modification technologies are important parts of the design of the fourth generation reactor, which can increase the strength of the secondary flow within the rod bundle lattices. Quasi-periodic large-scale vortex structure (QLVS) is introduced by arranging micro ribs on the surface of rod bundles, which enhanced the scale of the secondary flow between the rod bundle lattices. Using computational fluid dynamics (CFD) and water experiments, the flow field distribution and drag coefficient of the rod-bundle lattices are studied. The secondary flow between the micro-ribbed rod-bundle lattice is significantly enhanced compared to the standard rod-bundle lattice. The numerical simulation results agree well with the experimental results.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1267-1276
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• 2024

The emerging technologies at the industrial level have deployed rapidly within the energy transition process innovations. The nuclear industry incorporates several technologies like Artificial Intelligence (AI), Machine Learning (ML), Digital Twins, High-Performance-Computing (HPC) and Quantum Computing (QC), among others. Factors identifications are explained to set up a regulatory framework in the digitalization era, providing new capabilities paths for nuclear technologies in the forthcoming years. The Analytical Network Process (ANP) integrates the quantitative-qualitative decision-making analysis to assess the implementation of different aspects in the digital transformation for the New-Energy Transition Era (NETE) with a Nuclear Power Infrastructure Development (NPID).

• Journal of Information Processing Systems
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• 제20권3호
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• pp.409-417
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• 2024

Excellent apparel design can increase market competitiveness. This article briefly introduced the theory of fractals and its application in the field of apparel design. The convolutional neural network (CNN) algorithm was used to assist in the evaluation of apparel designs. In the case analysis, the accuracy of the evaluation was validated by comparing the CNN algorithm with two other intelligent algorithms, support vector machine (SVM) and back propagation (BP). The evaluation of the proposed design showed that compared with SVM and BP algorithms, the CNN algorithm had higher accuracy in evaluating apparel designs. The evaluation result of the proposed apparel design not only further verifies the effectiveness of the CNN algorithm, but also demonstrates that the theory of fractals can be effectively applied in apparel design to provide more innovative designs.

• 충청수학회지
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• 제26권4호
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• pp.869-878
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• 2013

We study boundedness of solutions of dynamic equations on time scales by using Lyapunov-type functions.

• 대한수학회지
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• 제26권2호
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• pp.223-229
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• 1989

• Korean Journal of Mathematics
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• 제5권2호
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• pp.227-232
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• 1997

Banach-Steinhaus type results are established for sequentially continuous operators and bounded operators between locally convex spaces without barrelledness.