The paper analyses the meaning of applying performance evaluation in university libraries,details the specific program for the application of 360° performance evaluation in university libraries and discusses the evaluation index and scales.
Infrared flight image sequences are the basis of flight guidance and target detection and recognition, but real infrared image sequences are not easy to obtain. So a flight vehicle infrared sequence simulation method is proposed to get 3D model of ground target by 3DMax simulation modeling, and analyze the target infrared characteristics, use ANSYS to calculate the temperature field of the target, then input it to the infrared radiation calculation module, and output the infrared radiation image. The positive downward looking infrared background is selected, the geodesic coordinate system is established, and the flight trajectory of the vehicle is simulated, the Euler angle between the vehicle and the ground target in the trajectory is calculated, and the simulated infrared sequence is obtained by using perspective transformation according to the Euler angle.
In this paper, we study how to improve the communication quality in millimeter-wave (mmWave) ground-to-unmanned aerial vehicle (UAV) communication systems. The system consists of a ground node with an antenna array and a UAV with a single antenna. Obviously, the communication quality can be maximally enhanced in the case that the trajectories of array beampattern peak and UAV coincide with each other. Achieving this objective through a traditional phased array (PA) approach requires considerable implementation costs, as the phase lags among array elements need to be frequently updated to change the beampattern peak direction. To alleviate this, we design an efficient method based on frequency diverse array (FDA), which tunes the frequency offsets among array elements. As a result, FDA generates a time-variant beampattern, such that the beampattern peak exhibits autonomous spatial movement. By using this characteristic, the complexity of the FDA method is reduced compared to PA, since we can design the beampattern peak trajectory without the necessity for real-time parameter updates. Specifically, subject to the constraints of UAV's speed, flight time and FDA's frequency offsets range, we jointly optimize the UAV movement and FDA frequency offsets to maximally align the trajectories of UAV and FDA beampattern peak, thereby improving beampattern gain. However, the formulated problem is non-convex with highly coupled variables. To handle this problem, we further design an algorithm based on penalty dual decomposition (PDD) method which circularly updates the variables, and finally yields a stationary solution of the problem. Simulation results demonstrate that, with the same implementation complexity, the FDA approach can achieve a higher communication quality compared to the PA approach and other benchmark schemes.
Joint admission control and power minimization are critical challenges in intelligent reflecting surface (IRS)-assisted networks. Traditional methods often rely on l 1 -norm approximations and alternating optimization (AO) techniques, which suffer from high computational complexity and lack robust convergence guarantees. To address these limitations, we propose a sigmoid-based approximation of the l 0 -norm AC indicator, enabling a more efficient and tractable reformulation of the problem. Additionally, we introduce a penalty dual decomposition (PDD) algorithm to jointly optimize beamforming and admission control, ensuring convergence to a stationary solution. This approach reduces computational complexity and supports distributed implementation. Moreover, it outperforms existing methods by achieving lower power consumption, accommodating more users, and reducing computational time.
the paper analyses the meaning of applying performance evaluation in libraries,details the concrete process and proposes some suggestions for the application of performance evaluation in libraries.
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