基于GMM-UBM模型的说话人辨识研究

为了进一步提高基于传统的GMM模型的说话人辨识的识别率,引入了GMM-UBM模型,并且在特征提取方面采用多种特征参数组合来代替单一特征参数,以提高有效特征维数来弥补特征样本的不足,同时在说话人辨识的端点检测部分,用基于MFCC相似度和谱熵的端点检测方法来代替传统的基于短时能量和过零点的方法,以解决其对含噪语音检测不准确而影响说话人辨识的问题。实验表明,与传统的GMM模型相比,GMM-UBM模型能够有效地提高说话人辨识的性能,并且使用组合特征参数和利用基于MFCC相似度和谱熵的端点检测方法都可以进一步提高说话人辨识的性能。     

MOS门电路测试过程中功率损耗最小化

MOS逻辑门电路的功率损耗与其门电路的输出翻转成正比。在测试过程中,输出节点反转速率远高于正常使用时,很容易造成电路损坏。因此,在测试过程中减少逻辑门输出翻转速率具有重要意义。文章提出减少MOS门输出翻转速率的一些方法,有助于有效解决这一问题。该方法具有实现简单、编程方便等优点。     

A self-adaptive weighted affinity propagation clustering for key frames extraction on human action recognition

In this paper, we propose a novel approach for key frames extraction on human action recognition from 3D video sequences. To represent human actions, an Energy Feature (EF), combining kinetic energy and potential energy, is extracted from 3D video sequences. A Self-adaptive Weighted Affinity Propagation (SWAP) algorithm is then proposed to extract the key frames. Finally, we employ SVM to recognize human actions on the EFs of selected key frames. The experiments show the information including whole action course can be effectively extracted by our method, and we obtain good recognition performance without losing classification accuracy. Moreover, the recognition speed is greatly improved.     

基于谐振式反射器的脑活动探测天线设计

设计了一款用于脑活动探测的超宽带定向天线。该天线采用了平面菱形单极天线的宽频带特性,通过缺陷地结构实现小型化。为了增强天线的定向辐射能力,设计了一种花瓣形谐振式反射器,在较宽频带内产生同相反射,并可减少剖面高度至0.1λ0。该天线整体结构具有尺寸小、重量轻的特点。对天线结构进行仿真优化并加工实测,测试结果与仿真的一致性表明了该天线具有超宽带的特点,实测阻抗带宽为0.91~2.42 GHz(91%),且远场方向图表明了天线具有良好的定向性能,因而该天线可以应用于人脑活动探测等领域。     

PCB企业要优先选用民族品牌的产品——PCB企业的软实力(8)

文章概述了我们要依靠社会制度的优越性、依靠爱国主义精神与行动和依靠民族工业的发展与进步,才能建设成为伟大的社会主义的强国!     

No-reference image quality assessment using structural activity

Presuming that human visual perception is highly sensitive to the structural information in a scene, we propose the concept of structural activity (SA) together with a model of SA indicator in a new framework for no-reference (NR) image quality assessment (QA) in this study. The proposed framework estimates image quality based on the quantification of the SA information of different visual significance. We propose some alternative implementations of SA indicator in this paper as examples to demonstrate the effectiveness of the SA-motivated framework. Comprehensive testing demonstrates that the model of SA indicator exhibits satisfactory performance in comparison with subjective quality scores as well as representative full-reference (FR) image quality measures.     

Efficient RC low-power bus encoding methods for crosstalk reduction

In on-chip buses, the RC crosstalk effect leads to serious problems, such as wire propagation delay and dynamic power dissipation. This paper presents two efficient bus-coding methods. The proposed methods simultaneously reduce more dynamic power dissipation and wire propagation delay than existing bus encoding methods. Our methods also reduce more total power consumption than other encoding methods. Simulation results show that the proposed method I reduces coupling activity by 26.7-38.2% and switching activity by 3.7%-7% on 8-bit to 32-bit data buses, respectively. The proposed method II reduces coupling activity by 27.5-39.1% and switching activity by 5.3-9% on 8-bit to 32-bit data buses, respectively. Both the proposed methods reduce dynamic power by 23.9-35.3% on 8-bit to 32-bit data buses and total propagation delay by up to 30.7-44.6% on 32-bit data buses, and eliminate the Type-4 coupling. Our methods also reduce total power consumption by 23.6-33.9%, 23.9-34.3%, and 24.1-34.6% on 8-bit to 32-bit data buses with the 0.18, 0.13, and 0.09 μm technologies, respectively.     

光折变Bi12TiO20晶体中的波耦合性质

研究了光折变Bi12TiO20(TBO)晶体中的二波耦合矢量特性.对扩散记录全息求得信号光能量增益和偏振态改变的分析解,研究它们在3种制备可得的晶体切割面上随入射抽运光和信号光(不同)偏振方向、光栅取向以及晶体厚度的变化关系,并给出在任意光栅取向的取值范围.分析了信号光能量增益和偏振态改变量分别达到最大值时各向同性和各向异性耦合的作用,并研究旋光、压电及弹光效应在3种晶体切割面上对矢量波耦合的影响.     

WO3/TiO2 nanocomposites: Salt–ultrasonic assisted hydrothermal synthesis and enhanced photocatalytic activity

A series of WO₃/TiO₂ composite photocatalysts were fabricated via a facile salt–ultrasonic assisted hydrothermal process. The obtained samples were characterized by X-ray diffraction, scanning eletron microscopy, energy dispersive X-ray spectroscopy and UV–vis diffused reflectance spectroscopy. It was confirmed that anatase TiO₂ and monoclinic WO₃ coexisted in the composites. The photocatalytic activity of as-prepared WO₃/TiO₂ composites for degradation of Rhodamin B (RhB) under visible light irradiation was investigated. The results showed that WO₃/TiO₂ composites have a higher photocatalytic activity than those of pure TiO₂ and pure WO₃. First-principle calculations based on density functional theory were performed to explore the electronic structure and illustrate the photocatalytic mechanism of WO₃/TiO₂. The calculated energy gap was 2.53 eV, which was close to the experimental observation (2.58 eV). Due to the combination of WO₃/TiO₂, the photoinduced electrons and holes transfer between the WO₃ and TiO₂ in opposite directions, thus providing sufficient charge separation, which contributed to the photocatalytic activity enhancement.     

Antioxidative activity of summer savory (Satureja hortensis L.) and rosemary (Rosmarinus officinalis L.) in minced, cooked pork meat

The sensory intensity measured as theabsolute threshold value of spice andrecognition of spice was evaluated for summer savory and rosemary in meat balls. The values forabsolute threshold value of spice were found to be significantly lower for rosemary than for summer savory. The antioxidative activity of the spices was analysed in two accelerated model systems and in a storage experiment. In one of the model systems, oxidation was accelerated by heat and by an elevated pressure of oxygen. Both spices significantly improved the oxidative stability of the meat balls in this model system. In the second model system metal catalyst oxidation in a meat slurry was used and a reduction in the oxidative processes in samples containing the spices was again shown. In both model systems a slightly higher antioxidative activity was seen for rosemary compared to summer savory. In the storage experiment, the spices were added at a sensorially acceptable level and the heat-treated meat balls were stored at 5°C. A significant reduction in the development of warmed-over flavour (WOF) caused by the addition of spices was measured by a reduction in 2-thiobarbituricacid-reactivesubstances (TBARS) and in hexanal. A reduction in TBARS of approximately 30% in meat balls containing added spices was seen independently of packaging in 1% oxygen or in atmospheric air and the reduction (30%) was constant throughout the storage period.