基于智能算法的无人机航迹规划

文中针对多无人机在复杂约束条件下编队协同、巡航范围内覆盖率高的问题,基于K-means算法和Hop-field神经网络算法实现了一种无人机整体航迹规划方法。对任务要求的禁飞区域、目标区域建立任务区域的数字地图模型,进行模型分解合理的将有效区域分解为多个子目标点。随后采用K-means算法对无人机巡航的目标点进行聚类,并结合Hop-field神经网络算法对同类子目标点进行无人机航迹规划。以无人机在抗震救灾中的真实数据为实例,通过仿真实现了巡航区域90%的覆盖率,验证了文中方法的鲁棒性和有效性。     

基于单向链路的Ad Hoc路由研究

提出一种适用于单向链路（非对称链路）的AdHoc网络路由方案——单向链路的跳数机制（LILHM）。该方案是根据路由的跳数来选取合适的路径,并限制了一定的广播洪泛。仿真结果表明该方案适用于普遍存在的单向链路的无线移动AdHoc网络。     

The multisensory perception of hop essential oil: a review

Hops are a key ingredient to add bitterness, aroma and flavour to beer, one of the most consumed beverages worldwide. Essential oils from different hop varieties are characterised by similar classes of chemical compounds and complexity, but their contribution to sensory characteristics in beer differs considerably. Volatiles in hop oil are categorised into several chemical classes. These induce diverse aroma and flavour sensations in beer being described as ‘floral’, ‘fruity’ (e.g. contributed by alcohols, esters, sulphur-containing compounds), ‘spicy’, ‘woody’, ‘herbal’ (sesquiterpenes, oxygenated sesquiterpenoids), and ‘green’ (aldehydes). The perception of hop volatiles depends on their concentrations and combinations, but also on threshold levels in different beer matrices or model systems. Several studies attributed modified taste and mouthfeel sensations to the presence of hop volatiles contributing to a multisensory perception of hop flavour. Linalool is frequently observed to show additive and synergistic-type behaviour and to affect aroma perception if combined with geraniol. Linalool has also been found to be involved in aroma-taste interactions, modifying the perception of bitterness qualities in beer. Particularly oxygenated sesquiterpenoids are suggested to be responsible for an irritating, tingling sensation indicating the activation of trigeminal receptors. The majority of these sensory interactions have been discovered almost by accident and a systematic research approach is required to gain a broad understanding of these complex phenomena. This review provides an overview of factors affecting the perception of hop derived volatiles involved in different sensory characteristics of beer, while illustrating the latest advances and highlighting research gaps from a sensory science perspective. © 2020 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling     

宽带跳频信号捕获分析技术

当前跳频通信技术已广泛的应用于军事和雷达通信中,本文介绍了基于FPGA的跳频信号捕获分析方法,通过高速数字信号处理,能对跳频速率、跳频驻留时间、跳频带宽、跳频图案、频率合成稳定时间等参数进行测量,解决了高速数字下变频、高速移相及抽取滤波、实时FFT、跳频参数计算等关键技术。实验测试表明,该方法捕获速率快、重构性强,可实现对实时带宽高达175MHz的高速跳频信号的实时捕获。     

弹性光网络非中断频谱碎片整理方法综述

随着信息技术的高速发展,网络中传输的信息量呈爆炸性增长。弹性光网络(EON)凭借其灵活的频谱资源分配特点,被用来逐步替代传统WDM网络。但是如果不消除弹性光网络中产生的频谱碎片,则会造成交通阻塞,从而影响网络传输效率。对弹性光网络中的三种非中断频谱碎片整理方法进行简述,提出一些需要解决的问题。     

基于压缩NH表的高速IP路由查找算法的研究

由于因特网速度不断提高、网络流量不断增加和路由表规模不断扩大,IP路由查找已经成为制约核心路由器性能的主要原因,因而受到了广泛重视.目前人们已经提出几种高速IP路由查找算法,但没有一种是理想的.本文提出一种使用压缩NH表进行IP路由查找的方法,它具有查找速率高、更新时间快、存储代价低、易于实现等特点,能满足10Gbps速率核心路由器环境的要求.     

2000m2布袋收尘器收尘系统的改进

2 0 0 0m2 布袋收尘器的螺旋输送机改为减压仓后 ,为烟化炉生产赢得了时间 ,改善了操作环境 ,降低了工人劳动强度。     

Use of thiolysis hyphenated to RP-HPLC-ESI(-)-MS/MS for the analysis of flavanoids in fresh lager beers

Proanthocyanidins are well known for their involvement in haze and colour development during beer ageing. New methodologies are needed, however, to understand what happens to them in the bottled beer. For the first time in the brewing field, thiolysis was hyphenated to RP-HPLC-ESI(-)-MS/MS to investigate these flavanoids. Thirty minutes at 40 °C followed by 10 h at room temperature emerged as the best conditions for complete depolymerisation. NP-HPLC-ESI(-)-MS/MS was used to quantify and isolate fractions from monomers to trimers in a Sephadex LH20 acetone/water (70/30, v/v) beer extract. Unsurprisingly, a lower dimer/monomer ratio was evidenced in PVPP-treated beers than in silica gel-filtered beers. Most beer dimers are procyanidins B3 (two catechin units) whilst most trimers are prodelphinidins (catechin in terminal units and gallocatechins or catechins in extension units). Gallocatechin appeared to come mainly from malt. Despite the absence of chromatographic peaks corresponding to oligomers above trimers, an apparent degree of polymerisation close to six was calculated in the total LH20 extract. Still higher mean degrees of polymerisation (mDPs) were calculated for malt and hop, indicating selective extraction or depolymerisation from raw materials to beer. The main part of beer polyphenols is composed of complex undefined structures not degraded by toluene-α-thiol.     

ALPHA-ACID—1,2-DIAMINOBENZENE COMPLEX: A CONVENIENT STANDARD FOR ALPHA-ACID ANALYSIS

A convenient preparation of the complex of alpha-acid and 1,2-diaminobenzene (o-phenylene diamine) is given. Use of the complex as an external standard for HPLC analysis of hops is described. Pure alpha-acid can be recovered from the complex by treatment with ion-exchange resin. The complex is stable in the absence of light and can easily be made in sufficient quantity and purity for distribution as a primary alpha-acid standard.     

无线Ad hoc网络上的自适应多描述编码*

为了在带宽较小、拓扑实时变化、易受外界影响的无线Ad hoc网络中实行视频的可靠通信,提出了一种自适应多相变换多描述编码策略。通过不同的相位点来产生多种描述,利用OLSR路由协议中的Hop和ETX来动态改变各描述的量化步长,以适应实时变化的Ad hoc网络。仿真实验证明,与传统的单描述编码（如H.264/AVC）相比,自适应多相变换多描述编码在提高信噪比、降低丢包率和平均失真方面比传统方式均有明显改善。仿真实验证明了所提出方案传输视频是优越的、可行的。