Optimal design of Raman fibre amplifier based on terminal value optimization strategy and shuffled frog leaping algorithm

This paper introduces an evolutionary algorithm, Shuffled Frog Leaping Algorithm (SFLA), to solve the optimization problem in designing the multi-pumped Raman Fibre Amplifier (RFA). SFLA is a powerful optimizer tool because of its efficient mathematical expressions and global search capability. We utilize SFLA to determine the optimal pump wavelengths and pump powers by minimizing the gain ripple of RFA. To accelerate calculations, a terminal value optimization strategy (TVOS) is incorporated into the evolution of SFLA. This proposed strategy takes the terminal power values of pumps as the decision variables in optimization. Then, the optimal original power values of the pumps are obtained by solving the Power Coupled Equations once, without using the traditional method of repetitive guesses.The combination of SFLA and TVOS enhances the efficiency of optimization and accelerates calculation, while satisfying the design requirements of RFA.The simulation results show that nearly 65% of computational time has been saved compared with the traditional average power analysis. The 4-pumped C+L band of backward multi-pumped RFA with the average net gain of 0 dB, 1 dB and 2 dB are designed individually, where the gain ripple is less than 0.64 dB. The combination of SFLA and TVOS enhance the optimization efficiency and improve the performance of RFA with good gain profile.     

多约束下距离加权最优滑模末制导律

为解决多约束下制导炮弹的精确制导问题,采用带有相对距离权函数的最优滑模末制导律,将权函数引入到最优制导律中,通过改变制导炮弹的运动轨迹、运动时间,进而增强制导精度。针对单权函数难以同时满足制导精度与导引头视线角、过载等约束的问题,采用不同权函数的分段加权方法解决加权最优末制导引起的制导问题。结合滑模变结构控制理论,设计分段加权最优滑模末制导律,增强制导系统的抗干扰能力。仿真验证结果表明,该末制导律既能解决过载、导引头视线角、落角等多约束情况下的精确制导问题,同时又具有一定的鲁棒性。     

Broadband MIMO Antenna System for 5G Operations in Mobile Phones

A broadband 8‐antenna multiple‐input and multiple‐output (MIMO) system working for 5G new radio N77 (3.3‐4.2 GHz) in mobile terminals is proposed. In particular, each antenna element/unit consists of a monopole‐type meandered branch and an inverted U‐shaped self‐isolated antenna branch; and the antenna unit is fed by the meandered branch. The antenna unit has two resonances generated separately by each branch of the antenna unit. Since the monopole couples strongly with the self‐isolated antenna element that has the inherent self‐isolation characteristics, quite good isolation for the broadband 8‐antenna MIMO system can be obtained. The results such as antenna efficiency, radiation patterns, envelope correlation coefficient, and channel capacity are also presented.     

全自动集装箱码头装卸系统质量管理

全自动集装箱码头装卸系统集成了当今世界各项先进技术,在研发、制造、调试过程中,都要坚持质量第一、安全第一的原则,确保各项技术参数可靠,设备运行稳定。在总结国内几个全自动码头装卸系统的质量管理方法与经验的基础上,结合自动化码头自身特点,给出全自动集装箱码头装卸系统主要质量管理方法,进一步丰富发展自动化码头装卸系统建造过程中的“不欠债离岸”质量管理理念。     

水产品及养殖水中丁香酚类化合物风险研究

目的 检测水产品及养殖水中丁香酚类化合物。方法 应用食品补充检验方法BJS 201908《水产品及水中丁香酚类化合物的测定》，以海水鱼、淡水鱼、海水虾、淡水虾及养殖水作为基质，测定6种丁香酚类化合物的含量。结果 通过对实际样品测定后发现，在水产品中检出了丁香酚类化合物，主要为丁香酚，检出率为28.9%，其中海水鱼相对突出。结论 本研究为丁香酚作为渔用麻醉剂提供了方法论，为丁香酚类化合物在水产运输的合理使用提供理论依据。     

基于PIN光电二极管的个人辐射探测器研制

为使公众能自行探测所处环境的辐射水平，本文利用PIN光电二极管直接测量X/γ射线的原理研制了便携式环境辐射探测系统，该系统采用智能终端控制探测设备。其中，探测模块中设计了弱信号放大电路，控制和通信模块的设计基于无线微控制器。该环境辐射探测器具有低成本、低功耗、体积小、易使用、易组网等特点。经国防科技工业电离辐射一级计量站检定，探测器各项指标均符合国家剂量仪鉴定规程JJG 521-2006的要求。     

基于RFID标签阵列的睡眠期间呼吸量连续监测系统

睡眠期间连续且准确的呼吸量监测有助于推断用户的睡眠阶段以及提供一些慢性疾病的线索。现有工作主要针对呼吸频率进行感知和监测,缺乏对呼吸量进行连续监测的手段。针对上述问题提出了一种基于商用无线射频识别(RFID)标签的无线感知用户睡眠期间呼吸量的系统——RF-SLEEP。RF-SLEEP通过阅读器连续收集附着在胸部表面的标签阵列返回的相位值及时间戳数据,计算出呼吸引起的胸部不同点的位移量,基于广义回归神经网络(GRNN)构建胸部不同点的位移量与呼吸量之间的关系模型,从而实现对用户睡眠期间呼吸量的评估。RF-SLEEP通过在用户肩膀处附着双参考标签,消除用户睡眠期间翻转身体对胸部位移计算造成的误差。实验结果表明,RFSLEEP对不同用户睡眠期间的呼吸量连续监测的平均精确度为92.49%。     

Multi-objective genetic algorithm for berth allocation problem considering daytime preference

Maximization of operational efficiency and minimization of cost are pursued by terminal operators, whereas daytime preference is increasingly emphasized by governments, terminal operators and workers. Daytime preference in berth allocation schedule refers to schedule the workloads in nights as fewer as possible, which improves working comfort, safety, and green and energy-savings degrees, but may decrease the throughput and total operational efficiency. By extending existing dynamic discrete berth allocation model, a bi-objective model considering daytime preference is established to minimize the delayed workloads and the workloads in nights. Based on the well known NSGA-II algorithm, a multi-objective genetic algorithm (moGA) is developed for solving the bi-objective model by using a two-part representation scheme. The sensitivities of the algorithmic parameters and tradeoffs between daytime preference and delayed workloads are analyzed by numerical experiments. The algorithmic aspects of the proposed approach and the effects of daytime preference on solutions are all examined. Finally, the managerial implications are discussed.     

隐蔽老火区立体式综合治理研究

对2320隐蔽老火区首先通过灌注泥浆对火区进行治理,同时对部分裂隙通道进行堵漏,然后对泥浆不能到达的区域注入高倍数三相泡沫灭火材料泡沫,瞬间将火源处覆盖,火源因隔绝氧气而窒息灭火。三相泡沫具有良好的堆积性和流动性,对煤体具有保水保湿,惰化遗煤氧化空间,并能够对松散煤体进行化学阻化,从本质上降低遗煤自然氧化速率,消灭了隐蔽老火区的火灾隐患,具有较高的推广价值。     

张家峁矿构建双重预防机制的实践

为了将风险控制在隐患形成之前、把隐患消灭在事故前面,以风险管控为核心,通过“基于风险”的PDCA全方位安全管理模式,构建了风险分级管控和隐患排查治理双重预防机制。以张家峁煤矿建立煤矿企业安全生产的长效机制为例,结合该矿在构建双重预防性工作机制方面的创新做法,分析了双重预防性工作机制的形成背景、建设过程及实施方法。分析认为,完善安全生产管理理论体系,能有效预防和遏制重特大事故的发生,对企业安全生产管理起到积极的推动作用。