F-OFDM仿真系统设计与时频同步算法

针对新一代5G波形的F-OFDM技术开展了研究,通过把一个宽带分为若干个子带,对每个子带进行滤波处理以实现更好的通信效能。基于Simulink平台进行了F-OFDM仿真系统的搭建,重点对F-OFDM符号同步方法和频偏估计方法进行了研究与仿真分析。实验结果表明,基于Chu序列相比采用PN序列可以获得更好的同步效果,基于导频的Classen频偏估计算法相比基于CP的CFO估计算法和基于训练序列的Moose估计方法可以获得更好的频偏估计效果。     

无线传感器网络自适应声音目标定位算法

基于声音能量的无线传感器网络目标定位算法因简单易行而受到广泛的关注。传统算法未考虑环境对衰减因子的影响,定位精度较差;提出一套辨识衰减因子的方案,并针对不同环境自适应改变衰减因子以优化加权质心算法的权重,设计了一种自适应加权质心定位算法。实验结果表明,本文算法较之传统加权质心定位算法大幅度提高了定位精度,且适用于更复杂的场景中。     

普格高铁高碳煤系硬质高岭土矿选矿加工技术研究

阐述了影响煤系硬质高岭土矿用于造纸涂料的主要因素和解决途径，并以四川普格高岭土矿加工利用研究为例，论述了该矿的矿石性质、加工工艺及其特点。通过研究最终获得了高档级涂布原料、中档级涂布原料和造纸填料三种产品，并进行了产品应用试验和技术经济分析。     

融合循环知识图谱和协同过滤电影推荐算法

推荐系统对筛选有效信息和提高信息获取效率具有重大的意义。传统的推荐系统会面临数据稀松和冷启动等问题。利用外部评分和物品内涵知识相结合,提出一种基于循环知识图谱和协同过滤的电影推荐模型--RKGE-CF。在充分考虑物品、用户、评分之间的相关性后,利用基于物品和用户的协同过滤进行Top-[K]推荐;将物品的外部附加数据和用户偏好数据加入知识图谱,提取实体相互之间的依赖关系,构建用户和物品之间的交互信息,以便揭示实体与关系之间的语义,帮助理解用户兴趣;将多种推荐结果按不同方法融合进行对比;模型训练时使用多组不同的负样本作为对比,以优化模型;最后利用真实电影数Movielens和IMDB映射连接成新数据集进行测试。实验结果证明该模型对于推荐效果的准确率有显著的提升,同时能更好地解释推荐背后的原因。     

混凝土损伤自修复仿真分析与试验研究

利用修复胶粘剂对裂缝的填充及修复特性,研究了一种内置胶囊自修复混凝土。通过有限元分析软件ANSYS,对内置胶囊混凝土的损伤自修复全过程进行了计算分析,揭示了损伤自修复的机理。通过试验验证了计算分析方法的正确性和合理性。试验结果表明:内置胶囊混凝土具有良好的自修复能力,一旦混凝土中出现损伤或裂缝,修复胶囊及时破裂,其中的修复胶粘剂流出,使其修复;修复后的混凝土试件,其性能有所提高。     

基于深度学习的轴端编号识别算法设计

随着制造业能力的不断提升,产品生产过程的自动化程度越来越高。对于传统的视觉识别算法,需要拥有大量工程技术和专业领域知识的人才能对视觉识别进行建模,并且设计的算法只能适应单一工况不具有通用性;而深度学习算法是一种通用的学习算法,通过训练可以识别不同种类的不同目标。基于此,针对某企业曳引轴加工过程中轴端编号的识别,设计了可进行端到端训练的识别算法。系统通过高精度工业相机获取目标图像,获得的原始RGB图像不需要进行预处理便可输入到网络当中,由深度学习算法对目标进行识别。实验表明所设计算法鲁棒性好且准确率高。     

PLC多功能开关用于袋除尘器参数设定的研究及应用

讨论了小型袋除尘器控制装置的多种参数设定方案,介绍了应用多功能开关技术实现袋除尘器参数修改的技术方案及应用。     

Thermoplastic Starch Processing and Characteristics—A Review

Canola Council of Canada, Winnipeg, Manitoba, Canada The rising costs of nonrenewable feedstocks and environmental concerns with their industrial usage have encouraged the study and development of renewable products, including thermoplastic starch (TPS). Starch is an abundant, plant-based biodegradable material with interesting physicochemical characteristics that can be exploited, and this has received attention for development of TPS products. Starch exhibits usable thermoplastic properties when plasticizers, elevated temperatures, and shear are present. The choice of plasticizer has an effect on TPS, even when these have similar plasticization principles. Most TPS have glass transition temperature, T_g, in the range of approximately ?75 to 10°C. Glassy transition of TPS is detected by differential scanning calorimeter (DSC) and thermodynamic analyzer (DMA), although DMA has been found to be more sensitive and effective. TPS has low tensile properties, typically below 6 MPa in tensile strength (TS). The addition of synthetic polymers, nanoclay, and fiber can improve TS and water-resistance ability. The moisture sorption behavior of TPS is described in GAB and BET models, from which monolayer moisture content and specific area are derived. Current studies on surface tension, gas permeability, crystallinity, and so on of the TPS are also reviewed.     

Mechanical and Thermal Characteristics of Pea Starch Films Plasticized with Monosaccharides and Polyols

Edible starch films were produced from pea starch and various plasticizers (mannose, glucose, fructose, and glycerol and sorbitol) at the ratio of 4.34, 6.50, 8.69, and 10.87 mmol plasticizer per gram of starch. After film specimens were conditioned at 50% relative humidity, mechanical properties (tensile strength, elongation, and modulus of elasticity), water vapor permeability (WVP), moisture content, and thermomechanical properties (G’ and tan8) were determined as a function of plasticizer concentration. At all concentration levels, monosaccharides (mannose, glucose, and fructose) made the starch films stronger (higher tensile strength) and more stretchable than polyols (glycerol and sorbitol), while WVP of monosaccharide‐plasticized starch films were lower than those of polyol‐plasticized starch films, especially at higher plasticizer concentration levels. Except for 4.34 mmol/g of mannose‐plasticized film, all the other films showed similar modulus of elasticity at the same plasticizer concentration. Polyol‐plasticized films had lower T than the monosaccharide‐plasticized films. Glucose‐ and sorbitol‐plasticized films needed more activation energy to go through glass transition than others. After all, research results showed that not only the polyols but also the monosaccharides were effective in plasticizing starch films. It is concluded that molecular size, configuration, total number of functional hydroxyl group of the plasticizer as well as its compatibility of the plasticizers with the polymer could affect the interactions between the plasticizers and starch molecules, and consequently the effectiveness of plasticization.     

基于声能衰减模型的WSNs目标定位算法

声音目标定位是无线传感器网络研究领域的一个热点;传统定位算法假定声音信号在无障碍的自由空间中传播,声能衰减因子取理想值2,由于未考虑场景对衰减因子的影响,导致定位精度普遍较差。提出一种新颖的基于声能衰减模型的无线传感器网络目标定位算法,视衰减因子为未知参数,应用极大似然原理将目标定位转换为函数极值优化问题;实验结果表明,算法定位精度有明显改善,且能辨识出场景的衰减因子,因而也可作为认知未知场景的参考依据。