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231.
Despite the increasing applications, demands, and capabilities of drones, in practice they have only limited autonomy for accomplishing complex missions, resulting in slow and vulnerable operations and difficulty adapting to dynamic environments. To lessen these weaknesses, we present a computational framework for deducing the original intent of drone swarms by monitoring their movements. We focus on interference, a phenomenon that is not initially anticipated by drones but results in complicated operations due to its significant impact on performance and its challenging nature. We infer interference from predictability by first applying various machine learning methods, including deep learning, and then computing entropy to compare against interference. Our computational framework begins by building a set of computational models called double transition models from the drone movements and revealing reward distributions using inverse reinforcement learning. These reward distributions are then used to compute the entropy and interference across a variety of drone scenarios specified by combining multiple combat strategies and command styles. Our analysis confirmed that drone scenarios experienced more interference, higher performance, and higher entropy as they became more heterogeneous. However, the direction of interference (positive vs. negative) was more dependent on combinations of combat strategies and command styles than homogeneity. 相似文献
232.
Ali H. Abdollahi Bafghi Mahtab Mirmohseni Masoumeh Nasiri-Kenari 《Entropy (Basel, Switzerland)》2022,24(8)
In this paper, we study the degrees of freedom (DoF) of a frequency-selective K-user interference channel in the presence of an instantaneous relay (IR) with multiple receiving and transmitting antennas. We investigate two scenarios based on the IR antennas’ cooperation ability. First, we assume that the IR receiving and transmitting antennas can coordinate with each other and that the transmitted signal of each transmitting antenna can depend on the received signals of all receiving antennas, and we derive lower and upper bounds for the sum DoF of this model. In an interference alignment scheme, we divide receivers into two groups called clean and dirty receivers. We design our scheme such that a part of the messages of clean receivers can be de-multiplexed at the IR. Thus, the IR can use these message streams for an interference cancellation at the clean receivers. Next, we consider an IR, the antennas of which do not have coordination with each other and where the transmitted signal of each transmitting antenna depends only on the received signal of its corresponding receiving antenna. We also derive lower and upper bounds for the sum DoF for this model of IR. We show that the achievable sum DoF decreases considerably compared with the coordinated case. In both of these models, our schemes achieve the maximum K sum DoF if the number of transmitting and receiving antennas is more than a finite threshold. 相似文献
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234.
随着技术的进步,无线通信呈现出更高数据率与支持更快移动性两大发展趋势.文中针对下一代地面数字多媒体广播(Advanced Terrestrial Digital Multimedia Broadcasting,DTMB-A)所采用高阶调制在移动环境下性能较差的挑战,提出一种频分多业务的系统方案和适用移动业务的DTMBA时频域结构.根据所提广播帧结构和移动信道时频域多变的特点,通过对不同子载波间隔对抗载波间干扰(Inter Carrier Interference,ICI)的能力进行建模,选择不同移动速度下系统信道容量最佳的数学模型,并通过虚拟子载波、时域加窗等方法降低移动业务对于固定业务的带外干扰.仿真表明该方案将邻带干扰降至-30 dB以下,使DTMB-A系统在提供无线高数据率通信的同时,能够满足日益增长的移动接收需求. 相似文献
235.
为了研究雷电电磁脉冲场对连续波多普勒引信安全性能的影响,确定引信的能量耦合通道和效应规律,构建了引信雷电电磁脉冲辐照试验系统,并开展了该引信雷电电磁脉冲辐照效应试验。试验结果表明:受试引信最佳能量耦合姿态为引信竖直向上,弹体轴线与辐射场传播方向垂直,三角环天线平面垂直于辐射场传播方向; 主要能量耦合通道为弹体; 不同辐照波形下引信的临界干扰场强不同,在配用152 mm弹体时,1.2/50,5.4/70,0.25/100和10/350 s波形的临界干扰场强分别约为74,60,65和75 kV/m。雷电电磁脉冲对受试引信的作用机理为:辐射能量通过弹体耦合到执行电路输入端,由于感应信号脉冲宽度满足触发脉冲宽度的最低要求,从而推动引信执行电路误动作。 相似文献
236.
心电信号检测是医生诊断治疗心血管疾病的重要辅助手段,但由于心电信号检测实际条件不理想,心电信号中常混有各种干扰信号,常见有肌电干扰、基线漂移和工频干扰。文中针对肌电干扰,采用数字滤波方法进行了去除噪声的滤波器设计。并通过对心电图信号滤波器的设计,不仅提高了ECG信号滤波器的去噪效果,且提高了工作效率。 相似文献
237.
The measurements of the ΔI = 1 part of the parity violating nuclear force when combined with information on neutral current couplings from neutrino
scattering and pion production experiments allow an estimate of the isoscalar admixture in the neutral current if it has a
vector axial-vector structure has been shown. 相似文献
238.
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240.
Effect of Signature Sequence on the Performance of an Asynchronous Multiple-Chip-Rate DS/CDMA System
Dugin Lyu 《Wireless Personal Communications》2003,24(4):449-462
The effects of signature sequence on the performance of an asynchronousmultiple-chip-rate (MCR)-DS/CDMA system are considered.The equations for the multiple access interference (MAI)and the variance of the MAI are developed.The bit error rate is derived by using the Gaussianapproximation.The deterministic signature sequences such as maximal-lengthsequences and Gold sequences are compared with random signature sequencesin terms of the variance of the MAI and bit error rate.We find that the performance of signature sequences in an asynchronousMCR-DS/CDMA system depends not onlyon the crosscorrelation properties of sequences but also on the carrierfrequencyseparation between the interfering and desired users. 相似文献