基于重叠分段和FrFT的VCO非线性度检测方法*

VCO非线性度检测是实现其非线性度精确校正的前提,研究VCO非线性度检测方法具有重要理论意义和实用价值。针对目前基于微元法和分数阶傅里叶变换的VCO非线性度检测方法在抗噪性、实时性等方面存在的不足,提出了一种基于重叠分段和分数阶傅里叶变换的VCO非线性度检测方法。所提方法采取重叠分段的策略以抑制噪声干扰,在分数阶傅里叶变换域进行幅度峰值搜索时改用收敛速度快的黄金分割法以增强实时性。仿真实验表明所提方法具有良好的抗噪性,分段重叠率为0.25时其检测的均方根误差约为现有方法的1/2;当重叠率小于2/3时,其实时性也优于现有方法。     

Energy efficiency in cloud computing based on mixture power spectral density prediction

Due to the budget and environmental issues, adaptive energy efficiency receives a lot of attention these days, especially for cloud computing. In the previous research, we developed a combined methodology based on nonparametric prediction and convex optimization to produce proactive energy efficiency-oriented solution. In this work, the predictive analysis was further enhanced by deriving the mixture power spectral density to model the complex cloud monitoring statistics. By engaging the improved technique to the predictive analysis, the prediction process was more adaptive to handle the fluctuation in system utilization. As a consequence, the optimization process could subsequently produce more appropriate setting for energy savings. After the infrastructure setting has been made available, the instruction of virtual machine migration was created and implemented by the cloud orchestrator. This instruction condensed the services into the pool of active facilities, satisfying the objective of power efficiency. Eventually, any physical machine out of the power configuration would be gradually terminated. Compared to our former method, the effectiveness of the proposed technique has been proven by cutting down 4.92% of energy consumption, while still maintaining a similar quality of services.

     

融合指针网络的新闻文本摘要模型

本文针对实际党建领域中的新闻标题进行自动生成,提出了一种融合指针网络的自动文本摘要模型-Tri-PCN.相比于传统基于编码器-解码器框架的自动文本摘要模型,党建新闻标题生成模型还需要满足(1)从更长的文本序列提取特征;(2)保留关键的党建信息.针对党建新闻比普通文本摘要任务面临更长文本序列问题,论文使用Transformer模型在解码阶段提取多层次全局文本特征.针对党建新闻标题生成过程中需要保留关键的党建信息,论文引入指针生成网络模型的复制机制在新闻标题生成时可以直接从新闻文本中复制关键词信息.实验采用ROUGE值作为评测指标,结果表明本文提出的Tri-PCN模型在党建新闻领域自动文本摘要任务上效果明显优于基准模型,比其他模型具有更好的效果.     

Performance implications of internet channels in financial services: A comprehensive perspective

Advances in information technology (IT) have forced financial services firms to explore new organizational forms and deliver service innovation. Given the obvious differences in the business model in which the financial services sector provides online services, it is natural to ask whether the emergence of Internet channels leads to superior achievement. Using a sample of twenty-four Taiwanese publicly traded financial services firms from 1997 to 2003, this empirical study attempts to assess the Internet channel??s effect on firm performance by means of applying event study methodology and data envelopment analysis. Results show that the magnitudes of average abnormal returns are uniformly positive and increase the operating efficiency of firms following announcements via Internet channels. This work therefore concludes that Internet channels have positive influences on firm performance.     

表面贴装过程仿真系统的研究与开发

文章从表面贴装技术(SMT)现状及特点开始,介绍多品种小批量电子产品中使用表面贴装技术存在的问题。针对这一情况对表面贴装过程仿真系统的需求进行了分析,并详细论述了仿真系统的文件预处理、仿真以及数据库维护三大主要模块设计,主要介绍采用OpenGL实现仿真模块的方法,同时展示仿真系统实现结果。最后总结了仿真系统的特点。     

Utilizing an Animal Model to Identify Brain Neurodegeneration-Related Biomarkers in Aging

Glycine N-methyltransferase (GNMT) regulates S-adenosylmethionine (SAMe), a methyl donor in methylation. Over-expressed SAMe may cause neurogenic capacity reduction and memory impairment. GNMT knockout mice (GNMT-KO) was applied as an experimental model to evaluate its effect on neurons. In this study, proteins from brain tissues were studied using proteomic approaches, Haemotoxylin and Eosin staining, immunohistochemistry, Western blotting, and ingenuity pathway analysis. The expression of Receptor-interacting protein 1(RIPK1) and Caspase 3 were up-regulated and activity-dependent neuroprotective protein (ADNP) was down-regulated in GNMT-KO mice regardless of the age. Besides, proteins related to neuropathology, such as excitatory amino acid transporter 2, calcium/calmodulin-dependent protein kinase type II subunit alpha, and Cu-Zn superoxide dismutase were found only in the group of aged wild-type mice; 4-aminobutyrate amino transferase, limbic system-associated membrane protein, sodium- and chloride-dependent GABA transporter 3 and ProSAAS were found only in the group of young GNMT-KO mice and are related to function of neurons; serum albumin and Rho GDP dissociation inhibitor 1 were found only in the group of aged GNMT-KO mice and are connected to neurodegenerative disorders. With proteomic analyses, a pathway involving Gonadotropin-releasing hormone (GnRH) signal was found to be associated with aging. The GnRH pathway could provide additional information on the mechanism of aging and non-aging related neurodegeneration, and these protein markers may be served in developing future therapeutic treatments to ameliorate aging and prevent diseases.     

Ti(C,N)粉末制备技术的研究及进展

概括了国内外Ti(C,N)粉末的制备技术,特别系统地介绍了Ti(C,N)粉末的制备技术的最新进展,分析了这些制备技术的工艺过程和工艺特点,讨论了其存在的问题和发展趋势。     

碲铜系合金在饱和NH4Cl溶液中的腐蚀行为

用全浸失重法,研究了碲铜系合金在饱和NH4Cl溶液中的抗腐蚀性能,结合扫描电镜(SEM)、能谱仪(EDS)等测试方法,初步探讨了合金在饱和NH4Cl溶液中的腐蚀行为及腐蚀机制,结果表明碲铜系合金的抗腐蚀性优于纯铜,其腐蚀速率低于纯铜,原因在于碲、镁的加入,可降低纯铜中的非金属杂质含量,同时碲、镁的加入,可沿铜晶界以化合物的形式析出,有利地阻碍了纯铜的沿晶腐蚀.     

Hygroresponsive Torsional Yarns and Actuators Based on Cascade Amplification of the Deformation

Fiber-based hygroresponsive torsional actuators provide desirable merits, such as light weight and shapeability, for developing smart systems to harvest energy from moisture which is a ubiquitous natural resource. A key challenge in this development is to realize moisture-triggered actuation combining large actuation and rapid responses. Here, a multiscale design strategy is explored to create high-performance hygroresponsive torsional actuators consisting of chitosan and multiwalled carbon nanotubes (MWCNTs). The superior actuation performance arises from the synergism of contributing factors at different scales, including 1) MWNCTs accelerate the water transport in primary twisted fibers (PTFs), fostering the rotation of PTFs upon moisture stimuli; 2) in situ-formed hierarchically-assembled twists realize cascade amplification of moisture-triggered actuation. Specifically, PTFs are self-twisted to generate secondary helical yarns, that are subsequently over-twisted to yield tertiary coiled yarn. The resultant yarn actuator can reach a maximum rotation speed of 11 400 rpm in 5 s, output gravitational potential energy of 2.4 J kg⁻¹ and gravitational potential power of 0.053 W kg⁻¹ during contraction. This work represents the first design of fiber-based actuators by virtue of moisture-triggered in situ formation of yarns. The established principles of multiscale design will enable high-performance fiber-based hygroresponsive actuators toward advanced intelligent textile and soft robotics.     

Q390高强抗震钢板残余应力检测方法对比及分析

利用盲孔法、X-Ray法、中子衍射法和超声法对Q390高强抗震板及U形弯曲件进行残余应力检测,并对这4种方法测试得到的应力结果进行分析研究。结果表明,以上4种检测方法均要考虑其特定的检测应用范围,X-Ray法针对钢板表面下微米级深度的微米级晶格尺度范围局部点应力进行检测,中子衍射法可在毫米级尺度局部区域进行应力检测,盲孔法反映的是因毫米尺度钻孔导致的钢板表面孔周边的应力变化,超声法则可以通过连续扫描检测整个钢板残余应力的宏观分布变化。因此,对于工业钢板,超声法测试残余应力更加科学、合理、准确。同时,通过U形试样建立稳定的应力应变场,利用超声设备使用不同参考态对Q390高强抗震板弯曲件及退火弯曲件进行测试,结果表明,测试参考态的选取对应力测试结果影响很大,材料各向异性的影响对应力测试结果不可忽视。