基于标签分组的RFID防碰撞算法

针对无线射频识别技术中的读写碰撞问题提出了一种新的标签防碰撞算法。该算法利用陪集分解理论将电子标签分组,限定每组标签在规定的时隙响应。根据查询码和碰撞特征位,阅读器可在一个时隙内识别出一组标签。Matlab仿真结果表明,在多标签时该算法的时隙利用率和吞吐率优于二进制搜索算法和动态帧时隙算法。     

一种优化标签的矩阵分解推荐算法

个性化推荐研究中,垃圾标签不仅会导致数据稀疏性问题,同时影响推荐的实时性和精确性。因此提出一种优化标签的矩阵分解推荐算法OTMFR,该算法分为两个阶段：首先优化标签,在建立三部网络图的基础上提出一种标签排序算法,利用互增强的关系得到关于标签流行度的排序,去除排序靠后的垃圾标签;然后在此基础上利用用户和资源对标签的偏好信息构建用户-资源偏好矩阵,并从矩阵分解的角度为用户产生推荐。在Delicious数据集上的实验结果表明,该算法在推荐精准度上有较为明显的效果。     

基于粗精二次估计的RFID标签数目估算方法

为了解决航空物联网信息采集领域RFID标签估算方法存在的估算精度和运算量之间的矛盾,以及标签读取过程随机性所导致的估算方法性能不稳定的问题,结合粗估计的快速、精估计的准确和二次估计算法性能的稳定性,提出一种基于粗精二次估计的RFID标签数目估算方法。首先,对帧时隙ALOHA算法标签读取过程进行建模,分析得出碰撞时隙中的平均标签数目和碰撞时隙所占比例之间的数学模型;然后,基于上述数学模型进行标签数目粗估计,评估粗估计值是否需要进行二次精估计。在二次精估计中,将粗估计值作为先验知识,采用基于先验知识的最大后验概率（MAP）估计算法提高估算准确度,相比原始后验概率估计算法的搜索范围可减少90%。仿真实验表明,基于粗精估计的RFID标签数目估算平均误差为3.8%,估算方法性能稳定性显著提高,运算量大幅下降,可有效地应用于航空物联网信息采集过程。     

基于语义相似度的标签优化

为解决社交媒体中标签的缺失、错误等问题,提出一种基于内容相似度和语义相似度的标签优化方法。首先利用TF-IDF(term frequency-inverse document frequency)计算文本间相似度,然后利用文本间相似度与标签相似度的一致性定义了目标函数,最后加入了修正项来减少优化前后用户提供标签的偏差。将目标函数应用到豆瓣电影标签进行优化,并将结果与原标签进行比较分析。与原标签相比,优化后的标签准确性得到了提高。试验结果表明,该方法能够有效地优化标签,有效解决标签缺失和错误等问题。     

Fluorescent tags to visualize defects in Al2O3 thin films grown using atomic layer deposition

Defects and cracks in thin film barriers that are coated on polymers allow the leakage of reactive species through the polymer substrate. Fluorescent tags have been developed to visualize defects and cracks in thin film barriers and to inspect rapidly the barrier quality with minimal sample preparation. For Al₂O₃ films with a thickness of 25 nm deposited on polyethylene naphthalate polymer substrates using atomic layer deposition techniques, the fluorescent tags have identified cracks ~ 20 nm in width after applied strain and have observed individual defects as small as ~ 200 nm in diameter.     

罗克韦尔ControlLogix系统在炼铜转炉生产自动化过程的应用

简单介绍了谦比希铜冶炼公司炼铜转炉的生产流程以及Rockwell公司ControlLogix控制系统主要特点,详细描述了如何利用ControlLogix系统冗余功能实现转炉控制系统的稳定可靠运行;利用生产者和消费者标签功能实现控制DCS控制器与远程PLC的快速稳定的数据传输;使用顺序控制流程图实现转炉停送风的自动控制;如何实现远程控制转炉送风机。实践证明,由ControlLogix系统组建的转炉控制系统完全满足转炉生产的需要,实现转炉生产高度的自动化。     

Analysis of Expressed Sequence Tags from Chinese Bayberry Fruit (Myrica rubra Sieb. and Zucc.) at Different Ripening Stages and Their Association with Fruit Quality Development

A total of 2000 EST sequences were produced from cDNA libraries generated from Chinese bayberry fruit (Myrica rubra Sieb. and Zucc. cv. “Biqi”) at four different ripening stages. After cluster and assembly analysis of the datasets by UniProt, 395 unigenes were identified, and their presumed functions were assigned to 14 putative cellular roles. Furthermore, a sequence BLAST was done for the top ten highly expressed genes in the ESTs, and genes associated with disease/defense and anthocyanin accumulation were analyzed. Gene-encoding elements associated with ethylene biosynthesis and signal transductions, in addition to other senescence-regulating proteins, as well as those associated with quality formation during fruit ripening, were also identified. Their possible roles were subsequently discussed.     

Development of Trityl Group Anchored Solubilizing Tags for Peptide and Protein Synthesis

Recently, solubilizing tag methods (Trt-K and Trt-R method) were developed for the challenging synthesis of peptides/proteins by means of native chemical ligation. In this system, the solubilizing tag can be attached to the Cys side chain by simply mixing the tag-introducing reagent under acidic conditions. The tagged peptides/proteins exhibited high water solubility thanks to the introduction of redundant oligo-Lys/Arg. In the final reaction, the tag can be quickly and cleanly detached by a standard deprotection reaction with trifluoroacetic acid. Herein, the development and application of these methods are described.     

Covalent Protein Labeling by SpyTag–SpyCatcher in Fixed Cells for Super‐Resolution Microscopy

Labeling proteins with high specificity and efficiency is a fundamental prerequisite for microscopic visualization of subcellular protein structures and interactions. Although the comparatively small size of epitope tags makes them less perturbative to fusion proteins, they require the use of large antibodies that often limit probe accessibility and effective resolution. Here we use the covalent SpyTag–SpyCatcher system as an epitope‐like tag for fluorescent labeling of intracellular proteins in fixed cells for both conventional and super‐resolution microscopy. We also applied this method to endogenous proteins by gene editing, demonstrating its high labeling efficiency and capability for isoform‐specific labeling.     

Creation of Nanotips on ITO Electrode by Nanoparticle Deposition: An Easy Way to Enhance the Performance of Electrically Responsive Photonic Crystal and Fabricate Electrically Triggered Anticounterfeiting Tags

Electrically responsive photonic crystals (ERPC) are promising materials for electrophoretic displays, smart windows, and tunable optical devices. However, the high working voltage limits the application of most polar ERPCs because it damages color saturation, response stability, and reversibility. Herein, an easy but general method based on the modification of electrodes with nanoparticles is developed to improve ERPC's performance. The deposition of Au, Cu, or Cu₂O nanoparticles created nanotip structures on the electrode, which enhanced the charge injection and local electric field strength, lowered 43% of the working voltage, and increased the color saturation. Meanwhile, the lowered voltage inhibited the electrodeposition of colloidal particles and the electrochemical reaction, which also improved the stability and reversibility of the electrical response. Based on the region-selective modification of the electrode and the resulting asymmetric electrical response, an electrically triggered tag with a “pattern showing/hiding” effect is fabricated for anticounterfeiting purposes.