基于CU特征差异的VVC帧内快速划分算法

针对通用视频编码(versatile video coding,VVC)在编码单元(coding unit,CU)划分中引入了多类型树划分结构导致编码复杂度增加的问题,提出了一种基于CU子块方向特性与空间复杂度的快速划分算法。首先利用CU整体的纹理复杂度对当前CU进行分类,筛选出不划分CU;然后利用子块不同划分方向的特性差异提前决策CU划分方向;最后利用CU中间区域与边缘区域的复杂度差异特征判断是否跳过三叉树(ternary tree,TT)划分,进一步减少候选列表划分模式数量。实验结果表明,与官方测试平台VTM10.0相比,编码器在平均输出比特率增加1.12%的代价下,编码时间减少了40.25%,说明该算法在通用视频编码中能以较小的质量损失实现更短的编码时间。

UNIT-RATE COMPLEX ORTHOGONAL SPACE-TIME BLOCK CODE CONCATENATED WITH TURBO CODING

Space-Time Block (STB) code has been an effective transmit diversity technique for combating fading due to its orthogonal design, simple decoding and high diversity gains. In this paper, a unit-rate complex orthogonal STB code for multiple antennas in Time Division Duplex (TDD) mode is proposed. Meanwhile, Turbo Coding (TC) is employed to improve the performance of proposed STB code further by utilizing its good ability to combat the burst error of fading channel. Compared with full-diversity multiple antennas STB codes, the proposed code can implement unit rate and partial diversity; and it has much smaller computational complexity under the same system throughput. Moreover, the application of TC can effectively make up for the performance loss due to partial diversity. Simulation results show that on the condition of same system throughput and concatenation of TC, the proposed code has lower Bit Error Rate (BER) than those full-diversity codes.

Data Combination over Physical Layer Using Network Coding with PUM Turbo Codes

The Base Station (BS) or access point is the building block of wireless networks, so, we propose exploiting it together with the Network Coding (NC) principle. NC suffers from the complexity of the decoding processes, i.e., complicated Jordan Gaussian Elimination (JGE) processes. So, this paper proposes a deterministic NC algorithm to reduce the number of sequential network decoding steps, and hence minimizing the complexity of JGE process resulting to better time delay and processing time. We propose an algorithm that combines higher number of the transmitted packets resulting to better data-rate but worse Bet Error Rate (BER). However, using such strong Forward error correction channel code, which is Partial Unit Memory Turbo Code (PUMTC) results to minimize the losses in the BER to a very acceptable lever, in fact, in Decode-and-Forward (DF) BS, the BER can be regarded as minimum. Simulation results, for both Amplify-and-Forward (AF) and DF BS schemes using PUMTC based on (8, 4, 3, 8) component codes, confirm that using PUMTC mitigates the problem of noise aggregation resulting from applying NC in the proposed schemes.

Security System in United Storage Network and Its Implementation

With development of networked storage and its applications, united storage network (USN) combined with network attached storage (NAS) and storage area network (SAN) has emerged. It has such advantages as high performance, low cost, good connectivity, etc. However the security issue has been complicated because USN responds to block I/O and file I/O requests simultaneously. In this paper, a security system module is developed to prevent many types of attacks against USN based on NAS head. The module not only uses effective authentication to prevent unauthorized access to the system data, but also checks the data integrity. Experimental results show that the security module can not only resist remote attacks and attacks from those who has physical access to the USN, but can also be seamlessly integrated into underlying file systems, with little influence on their performance.

基于时空域复杂度特征的LCU级码率分配算法

提出一种新的最大编码单元(Largest Coding Unit,LCU)级码率分配算法,在保证码率准确性的前提下提升视频质量。首先,选择更符合人眼视觉特性的结构相似性(Structural Similarity,SSIM)图像评价算法来衡量每个LCU的空域复杂度,通过已编码帧的失真度来衡量每个LCU的时域复杂度,基于多元线性回归函数对时空域复杂度特征与实际编码比特数之间的关系进行数学建模。最后,依据时空域复杂度特征因子指导编码帧中每个LCU分配合理的目标码率。实验结果表明,在保证码率精确性的情况下,所提的LCU级码率分配算法具有较高的编码效率,率失真性能平均提高了1.25%。

Research on the Security of the United Storage Network Based on NAS

A multi-user view file system (MUVFS) and a security scheme are developed to improve the security of the united storage network (USN) that integrates a network attached storage (NAS) and a storage area network (SAN). The MUVFS offers a storage volume view for each authorized user who can access only the data in his own storage volume, the security scheme enables all users to encrypt and decrypt the data of their own storage view at client-side, and the USN server needs only to check the users’ identities and the data’s integrity. Experiments were performed to compare the sequential read, write and read/write rates of NFS+MUVFS+secure_module with those of NFS. The results indicate that the security of the USN is improved greatly with little influence on the system performance when the MUVFS and the security scheme are integrated into it.

基于注意力机制和特征融合的股票预测方法

基于人工智能在金融数据中的应用,提出了一种新的股票预测方法,称为AFG。AFG使用位置编码和时间编码获取股票数据的位置信息和时间信息,然后通过门控循环单元和多头自注意力机制对股票数据分别进行特征提取。在将两类股票特征融合之后,由全连接层导出最终的股票预测曲线。

水热条件下Cu_2O的连生习性

Cu2 O具有立方体、八面体、菱形十二面体、四角三八面体、三角三八面体等多种单形。其形貌特征因不同的制备方法而各异。本文首次发现在水热条件下 ,Cu2 O出现取向连生的形貌特征。{ 10 0 }面为连生面。

草酸根桥联的双核铜髤配合物[Cu_2(phen)_2(H_2O)_2(μ_2-C_2O_4)](NO_3)_2的合成及晶体结构

A new binuclear copper(Ⅱ) complex, [Cu2(phen)2(H2O)2( μ2-C2O4)](NO3)2, has been synthesized and characterized by elemental analysis, IR and UV-Vis spectrum. Its crystal structure was determined by single crystal X-ray diffraction techniques. Crystal data: monoclinic, space group P21/c, a=0.712 21(8) nm, b=1.170 93(14) nm, c=1.783 7(2) nm, β=111.828(2)°, and V=1.380 8(3) nm3, Dc=1.769 Mg·m-3, Z=2, F(000)=744, R1=0.025 4, wR2=0.069 5, Gof=1.077, Δρ=328^-455 e·nm-3. The complex is packed by one centrosymmetry binuclear copper(Ⅱ) unit, oxalate dianion and NO3- anion. In the molecule structure of the title complex, two Cu(Ⅱ) ions are bridged by oxalate dianion and each Cu(Ⅱ) ions coordinates with two nitrogen atoms from 1,10-phenanthroline ligand and one oxygen atom from water to form a five-coordinate distorted square-pyramidal configuration. The hydrogen bonds are observed between coordinated water molecules and NO3- anions. The analysis of the crystal structure indicates that the complex has a two-dimensional stacking network structure, which is formed by intramolecular hydrogen bonds, intermolecular hydrogen bonds and stacking effect of aromatic ring. CCDC: 255345.

Tokamak第一壁上W/Cu材料的连接和界面应力的研究

重点讨论了适合于磁约束核聚变实验装置(Tokamak)第一壁上W/Cu复合材料连接的几种方法:电子束焊、钎焊、热等静压连接、烧结熔渗法、等离子体喷涂法,并列举了第一壁材料与热沉材料成功连接时电子束辐照热负荷实验的情况。探讨了在此连接方式下复合材料热负荷实验时应力求解方法和应力分布情况。

Cu^(2+)掺杂对In_2O_3电导和气敏性能的影响

为寻求新型气敏材料,用化学共沉淀法制备了Cu2+掺杂In2O3,研究了其相结构、电导和气敏性能。结果表明:900℃热处理4h所得掺2%Cu2+的In2O3微粉制作的元件对C2H5OH有较高的灵敏度和较好的选择性,有良好的应用前景。

结合率失真代价预测的HEVC快速CU划分

针对高效率视频编码(high efficiency video coding,HEVC)标准编码复杂度较高的问题,提出了一种快速编码单元(coding unit,CU)划分方法。首先,结合拉格朗日率失真优化理论及相关实验数据分析得到相邻CU深度对应的失真及码率分别满足线性关系,并利用此关系,建立了率失真代价的预测模型。利用此模型,可以在编码当前CU深度后快速预测得到下一CU深度的率失真代价,并最终通过代价比较,判断是否需要继续进行CU划分。实验结果表明,相比于HEVC测试模型HM12.0,针对低时延与随机接入编码结构,提出的方法的BD-rate分别增加了0.2%与0.6%,同时,编码时间分别减少了33.2%和38.9%。

基于ISO 26262标准的高压共轨ECU监控单元的设计与开发

进行了高压共轨ECU监控单元硬件电路和监控策略的设计与开发,提出了三层监控架构并对其中的问询/应答通信监控策略进行开发。利用Matlab/Simulink工具对监控策略进行模型搭建与仿真,利用Real-Time Workshop工具实现模型到代码的自动生成,运用满足ISO 26262标准的工具链和开发流程对代码进行优化,最后在高压共轨柴油机上进行试验验证。试验结果证明此监控单元能有效检测主CPU故障并及时作出响应,极大提高了高压共轨系统的稳定性。

JUCC:一种基于JUnit框架展示代码覆盖的交互式测试工具

当前测试驱动的开发模式已成为软件开发的主要模式之一,而JUnit是测试开发领域中常用的一种测试框架.基于JUnit的各种测试技术和方法经常出现在各种软件测试研究与实践中.本文基于JUnit框架,提出一种添加代码覆盖展示的新型交互式测试工具JUCC.JUCC在JUnit测试结束后根据测试过程中记录的信息,图形化地显示测试代码的覆盖率,这样,测试人员可根据代码覆盖情况针对没有被覆盖的代码再次进行测试用例的编写,迭代地进行测试,直到达到满意的测试效果.

汽车ECU测试系统的研究与实现

汽车电子在汽车上应用越来越广泛,CAN总线越来越受欢迎,因此基于CAN总线的汽车故障诊断显得越来越重要。传统的故障诊断方法是采用汽车原厂的故障诊断仪,但是它价格昂贵、通用性差。虽然市面上有价格便宜的国产设备,但是处理能力和存储容量有限,不能满足汽车下线电控检测要求。为了在汽车下线前,对其电控系统进行检测以确保汽车的质量,设计和实现了汽车下线检测系统,该系统实现了基于CAN总线的诊断标准ISO15765,通过与汽车内部的ECU进行通信,读取故障码和数据流来判断汽车电控系统是否处于正常状态,并将结果存入SQL数据库,便于以后的分析和维护。最后该系统进行了实车测试,测试结果表明该系统的实用性。

一种基于视觉显著性的码率控制算法

针对当前高效视频编码的码率控制算法未能充分确保视频显著区域的图像质量问题,提出了一种基于视觉显著性的码率控制算法。首先,采用基于图的流形排序显著检测算法获取视频的显著区域;其次,在图像编码过程中,为每个编码单元(Coding Unit,CU)建立基于视觉显著性的加权失真公式,将显著性值作为权重;最后,通过求解得到拉格朗日乘子λ,并根据原始码率控制算法中的λ与量化参数(Quantization Parameter,QP)的关系为每个CU确定QP。试验结果表明,该算法有效地根据视频内容的显著性权重实现了码率的合理分配,并在保持码率控制准确性的同时,提升了视频显著区域的图像质量。

相关噪声下基于深度学习的LDPC码联合降噪译码算法设计

为了改善采用低密度奇偶校验(LDPC)码和高阶调制的无线通信系统在相关噪声下的译码性能,提出了一种联合优化降噪和译码的深度学习算法。降噪器中采用了残余收缩模块(RSBU),译码器采用了基于循环神经网络的神经网络最小和译码算法。在提出的联合降噪译码(JDD)算法中,利用复数神经网络在处理复信号方面比实数神经网络更有优势的特点,提出了一个复数RSCNN(CRSCNN),接收的复信号直接输入CRSCNN并利用新颖的联合优化降噪损失函数和译码损失函数的多任务学习策略来改善译码性能。仿真结果显示基于CRSCNN的JDD算法获得了比基于循环神经网络的神经网络最小和译码算法更好的译码性能。

基于卷积神经网络的HEVC帧内预测算法优化

作为HEVC标准中最基础、最重要的技术之一,帧内预测对实现视频编码的高速、高质量和高压缩率具有重要的作用。文中针对帧内预测复杂性问题进行研究,提出一种基于深度卷积神经网络(CNN)的方法,通过学习来预测CTU的划分,从而减少HEVC帧内编码的复杂性。通过建立一个大规模的CTU划分数据库,并利用CNN的能力学习各种CTU划分模式,能够准确地预测CTU的划分,从而避免了传统的穷举搜索,实现了HEVC编码复杂性的显著降低,提高了编码效率。实验结果表明,提出的方法在测试序列和图像上分别将帧内编码时间减少了62.25%和69.06%,与其他最先进的方法相比,比特率分别仅增加了2.12%和1.13%,达到了优化的目的。

基于“深水地平线”钻井平台事故的MODU Code修正案技术要求分析

基于“深水地平线钻井平台”事故的经验教训,国际海事组织对《2009年海上移动式钻井平台构造和设备规则》(2009MODUCode)进行了修订,修订内容涉及海上移动式钻井平台的防火安全、防爆安全、救生设备和应急指挥。文中结合事故调查结果、修正案的编制背景,分析修正案技术要求的原理及其对平台设计、建造与操作的影响,并对平台井喷火灾爆炸防护提出建议。