Face animation based on multiple sources and perspective alignment

Background Face image animation generates a synthetic human face video that harmoniously integrates the identity derived from the source image and facial motion obtained from the driving video.This technology could be beneficial in multiple medical fields,such as diagnosis and privacy protection.Previous studies on face animation often relied on a single source image to generate an output video.With a significant pose difference between the source image and the driving frame,the quality of the generated video is likely to be suboptimal because the source image may not provide sufficient features for the warped feature map.Methods In this study,we propose a novel face-animation scheme based on multiple sources and perspective alignment to address these issues.We first introduce a multiple-source sampling and selection module to screen the optimal source image set from the provided driving video.We then propose an inter-frame interpolation and alignment module to further eliminate the misalignment between the selected source image and the driving frame.Conclusions The proposed method exhibits superior performance in terms of objective metrics and visual quality in large-angle animation scenes compared to other state-of-the-art face animation methods.It indicates the effectiveness of the proposed method in addressing the distortion issues in large-angle animation.

Principle and Experimental Verification of Novel Dual Driving Face Rotary Ultrasonic Motor

Existing rotary ultrasonic motors operating in extreme environments cannot meet the requirements of good environmental adaptability and compact structure at same time,and existing ultrasonic motors with Langevin transducers show better environmental adaptability,but size of these motors are usually big due to the radial arrangement of the Langevin transducers.A novel dual driving face rotary ultrasonic motor is proposed,and its working principle is experimentally verified.The working principle of the novel ultrasonic motor is firstly proposed.The 5th in-plane flexural vibration travelling wave,excited by the Langevin transducers around the stator ring,is used to drive the rotors.Then the finite element method is used in the determination of dimensions of the prototype motor,and the confirmation of its working principle.After that,a laser Doppler vibrometer system is used for measuring the resonance frequency and vibration amplitude of the stator.At last,output characteristics of the prototype motor are measured,environmental adaptability is tested and performance for driving a metal ball is also investigated.At room temperature and 200 V(zero to peak) driving voltage,the motor’s no-load speed is 80 r/min,the stalling torque is 0.35 N·m and the maximum output power is 0.85 W.The response time of this motor is 0.96 ms at the room temperature,and it decreases or increases little in cold environment.A metal ball driven by the motor can rotate at 210 r/min with the driving voltage 300 V(zero to peak).Results indicate that the prototype motor has a large output torque and good environmental adaptability.A rotary ultrasonic motor owning compact structure and good environmental adaptability is proposed,and lays the foundations of ultrasonic motors’ applications in extreme environments.

Failure laws of narrow pillar and asymmetric control technique of gob-side entry driving in island coal face

In allusion to the problems of complex stress distribution in the surrounding rock and deformation failure laws, as well as the difficulty in roadway supporting of the gob-side entry driving in the island coal face, 2107 face in Chengjiao Colliery is researched as an engineering case. Through physical mechanical test of rock, theoretical and numerical simulation analyses of rock, the analysis model of the roadway overlying strata structure was established, and its parameters quantified. To reveal the deformation law of the surrounding rock, the stability of the overlying strata structure was studied before, during and after the roadway driving. According to the field conditions, the stress distribution in coal pillar was quantified, and the surrounding rock deformation feature studied with different widths of the pillars in gob-side entry driving. Finally, the pillar width of 4 m was considered as the most reasonable. The research results show that there is great difference in support conditions among roadway roof, entity coal side and narrow pillar side. Besides, the asymmetric control technique for support of the surrounding rock was proposed. The asymmetric control technique was proved to be reasonable by field monitoring, support by bolt-net, steel ladder and steel wire truss used in narrow pillar side.

Deformation mechanism of surrounding rocks and key control technology for a roadway driven along goaf in fully mechanized top-coal caving face

The variation of the stress in the bolted surrounding rocks structure of the roadway driven along goaf in a fully mechanized top coal caving face with moderate stable conditions are studied by using numerical calculation. The essential deformation characteristics of the surrounding rocks in this kind of roadway are obtained and the key technology of bolting support used under these conditions is put forward.

Simulation study of blast fume diffusion characters of driving face

Based on FLUENT software, studied the blast fume diffusion characteristics of a driving face under 8 situations, and analyzed the influence to fume diffusion of different drift length and different ventilation pipe outlet positions. Through regression analysis, functions of ventilation time to the drift length and ventilation pipe outlet position was obtained.

Influence Predictions of Contact Effects on Mesh Stiffness of Face Gear Drives with Spur Gear

Mesh stiffness is one of important base parameters of face gear dynamic studies.However,a calculation solution of mesh stiffness of face gear drives is not to be constructed due to complex geometric flakes of face gear teeth.Thus,a calculation solution of mesh stiffness of face gear drives with a spur gear,which is based on the proposed equivalent face gear teeth and Ishikawa model,is constructed,and the influence of contact effects on mesh stiffness of face gear drives is investigated.The results indicate the mesh stiffness of face gear drives is sensitive to contact effects under heavy loaded operating conditions,specially.These contributions will benefit to improve dynamic studies of face gear drives.

Study of mechanical principle of floor heave of roadway driving along next goaf in fully mechanized sub-level caving face

Abstract On the basis of analyzing floor strata mechanical circumstance of the roadway, the mechanical model was established. The relative displacement of roadway floor, narrow pillar floor coal mass and floor strata was calculated, the results showed that the high abutment pressure on coal mass beside the roadway was the main reason to lead to relative displacement of floor strata. And the roadway floor heave come mainly from three aspects. Firstly, the roadway floor strata is easily fractured by the stretch stress. Secondly, because the high abutment pressure is greater than the uniaxial compressive strength of floor strata, when the roadway floor strata are fractured, the coal mass floor strata at the same depth will be fractured, and broken rock will fluid into the open roadway. Thirdly, comparing with the coal mass floor, the roadway floor is relative ascending.

煤矿综掘工作面长压短抽除尘性能与尘源移动路径关系

长压短抽通风除尘是净化煤矿综掘工作面掘进区域高质量浓度粉尘的有效方法之一,特别是压抽配合产生的局部流场有利于对呼吸性粉尘的除降,而产尘源位置的动态变化对该方式除尘性能的影响不甚明晰。通过考虑产尘源位置沿横、纵2种方向的运动路径及往复次数,基于长压短抽试验平台设计了4种尘源移动路径,结合对长压短抽通风系统参数的调控,测试分析尘源在不同运动工况下对空间粉尘质量浓度、粉尘粒径质量浓度和粒径分布的影响。结果表明:在相同的通风参数下,横向路径对司机和行人呼吸带位置造成的粉尘质量浓度均低于纵向;而在横向路径中,当压风筒位于靠近抽风筒一侧且压风口位于司机前方约1 m区域时,司机与行人呼吸带位置的PM1、PM2.5和PM10粉尘粒径质量浓度最低,通风除尘效果最好。空间粉尘扩散表现为:粒径小于2.5µm的颗粒极易跟随抽风流场被抽尘口收集净化,而粒径大于10µm的颗粒则会从产尘源和抽尘区域逃逸到司机及其后方区域,并以自然沉降为主。基于前期试验所得最优尘源移动路径与通风参数,在陕北某煤矿2304综掘工作面开展现场试验。结果表明:横向路径下司机位置和行人呼吸带位置的总粉尘质量浓度分别降低至85.6 mg/m^(3)和21.9 mg/m^(3),降尘率最高达到76.9%;呼吸性粉尘质量浓度分别降低至15.3 mg/m^(3)和10.5 mg/m^(3),降尘率最高达到85.2%,除尘性能明显提升。

新型高分子抑尘剂对岩性颗粒物的抑制特性研究

为减轻综掘工作面粉尘逸散对巷道环境的污染以及人员、设备造成的损伤,以济宁市金桥煤矿西翼轨道巷为工程背景,以可吸入粉尘为研究对象,研发一种以表面活性剂为关键骨架、以无机盐和高分子黏附剂为辅助材料的强润湿性、强黏结性的环保型化学抑尘剂。现场验证结果表明,该抑尘剂对于岩性颗粒物具有较好的捕捉能力,能有效降低巷道内可吸入粉尘浓度。

多头双向螺旋面的加工方案研究

在介绍活齿端面谐波齿轮的传动原理及多头双向螺旋面含义的基础上,提出了2种加工多头双向螺旋面的方案,并进行了分析、比较。方案一:先采用三维建模软件(如NX等)对具有不同参数的多头双向螺旋面的零件进行建模,再利用数控立式加工中心进行加工;方案二:利用数控电火花线切割机床与数控回转工作台互相配合,按照多头双向螺旋面形成的原理进行加工。

岩巷掘进工作面控风净化除尘系统设计与应用

针对岩巷掘进工作面压风风流携带迎头粉尘弥漫扩散造成粉尘治理难度大的问题,提出了掘进面“控风—净化”综合粉尘治理方案,构建了由湿式旋流除尘器、易装拆控尘装置、便移式负压风筒等组成的岩巷掘进面高效除尘系统,对比分析了除尘系统的不同安装方案对除尘效果的影响;综合考虑现场除尘效果与劳动强度,明确了湿式旋流除尘器最佳安装方案以及负压风筒与控尘装置的最优安装位置。在某矿辅运大巷岩巷掘进面进行了现场应用,结果表明:当负压风筒安装至通风风筒对侧,吸尘口距巷道迎头3 m,控尘装置位于通风风筒压风口后方5 m时,迎头高浓度粉尘在通风风筒压风、控尘装置控风及除尘器抽尘共同作用下被控制在迎头附近,并不断向负压风筒吸尘口运移最终被除尘器抽入净化,除尘器前方全尘和呼尘除尘效率分别达到95.9%和94.9%以上,除尘器后方全尘和呼尘除尘效率分别达到96.5%和95.4%以上,显著提升了巷道可见度,有效解决了岩巷掘进面通风造成的粉尘治理难题。

大采高工作面柔模沿空留墙掘巷技术

柔模混凝土沿空留巷技术已应用多年,在中厚煤层和薄煤层开采下均取得了较好的支护效果,但在厚煤层大采高工作面,因巷道高、巷旁支护压力大、混凝土早期强度低易受压损坏难以有效支撑顶板。大采高工作面矿压显现剧烈,巷旁维护难度大,故此提出一种新型的预浇墙柔模混凝土沿空留墙掘巷新技术,即在上工作面回采前,刷煤扩帮后提前预浇柔模混凝土墙体,提高煤帮整体支撑力的同时,解决柔模混凝土墙短期无法有效承载顶板来压的难题;待回采一定距离后,再沿墙滞后掘进下工作面回采巷道,且掘进方向与上工作面回采方向一致,缓解接续紧张,最终实现无煤柱开采。以王庄煤业3503工作面回采留设预浇墙为工程背景,建立了沿空留墙掘巷围岩结构力学模型,理论计算得出墙体力学支护参数,并通过现场应用验证了该技术的可实施性。结果表明:理论计算分析确定了墙体高宽比为5 m×1.5 m,混凝土强度C30即可满足留墙支护要求;沿墙掘进巷道总体变形量小,顶底板和两帮最大移近量仅为260 mm和125 mm,墙体最大受压18 MPa,小于墙体自身承载力;下工作面临近巷道掘进115 m后即趋于稳定。该技术应用全阶段效果良好,满足巷道使用要求,有效解决了大采高工作面沿空留巷重大技术难题,也可为相似工况无煤柱开采提供技术借鉴。

深部孤岛充填工作面沿空掘巷围岩偏应力演化与控制

目的 为解决深部孤岛充填工作面沿空掘巷围岩控制问题,方法 以邢东矿12216运料巷为背景,采用FLAC3D数值模拟软件,研究孤岛面临侧采空区在不同充填率条件下沿空掘巷围岩偏应力分布规律,模拟分析孤岛工作面充填开采时,工作面超前段围岩受动压影响时的偏应力演化特征。结果 结果表明:(1)孤岛工作面沿空掘巷巷道煤柱帮受临侧采空区充填效应影响较大,临侧采空区充填率增加使煤柱上偏应力峰值区呈椭圆形并逐步向采空区侧转移;(2)孤岛充填工作面沿空掘巷顶底板偏应力场形成一个朝向采空区侧的弧形低值带;(3)孤岛充填动压扰动时期,最大偏应力区位于实体煤一侧,距工作面前方8 m左右,距巷道4.3 m左右,峰值可达34 MPa。结论 结合数值模拟分析结果,提出采用“高强度锚杆+大直径高延伸率锚索”协同支护方式,现场工程实践表明,该支护方式沿空巷道围岩控制效果良好。

掘进工作面煤岩动力灾害声电响应特征

为了监测、预警掘进过程中前方可能发生的危险,在掘进工作面布设声电监测预警系统,利用声发射技术和电磁辐射技术对掘进巷道进行动态实时监测和预警,通过对掘进过程中异常声电响应特征的研究得到突出危险发生的前兆规律特征,并根据现场实际情况进行了验证。结果表明,掘进过程中,声发射、电磁辐射强度整体变化趋势呈现3个阶段;煤与瓦斯突出危险发生时,声电强度参数响应剧烈,出现了明显的声增电降趋势,且声发射、电磁辐射强度与瓦斯浓度呈显著相关,瓦斯浓度突增与声电信号异常基本是同步发生的;声—电—瓦斯能够反映煤岩石动力演化过程中的变化情况,可将第一次声电异常波动定为瓦斯预警前兆开始时间,超前预警8 h左右。由此可以看出,通过研究声—电—瓦斯的异常响应,能够实现煤与瓦斯突出的预警预报。

动压影响孤岛工作面巷道围岩“卸-支平衡”协同控制技术

煤矿深部工作面回采过程中,经常受到强开采动压作用影响,矿压显现强烈,巷道围岩变形破坏程度大,尤其对于孤岛工作面,动压影响更加显著,围岩控制难度成倍增加。为了解决深部孤岛工作面强动压影响回采巷道围岩控制问题,以2308工作面为研究背景,采用理论分析、数值模拟、现场验证等方法,首先对巷道围岩结构模型进行分析,确定影响工作面围岩稳定的主要因素;进一步对煤柱宽度和钻孔卸压2种方案进行研究,并根据巷道围岩的实际变形情况,确定巷道围岩的非对称支护参数,实现受强动压影响回采巷道的“卸-支平衡”协同控制方案。经过现场实践验证,2308工作面巷道顶底板移近量为260 mm,两帮移近量为471 mm,巷道围岩的整体性得到增强,变形得到有效控制;采用“卸-支平衡”方案对受动压影响巷道围岩的控制效果显著。

鑫顺煤业迎采强扰动巷道围岩稳定性控制研究

为解决迎采对掘沿空掘巷过程中巷道围岩变形严重、支护困难等问题,以山西煤炭进出口集团左权鑫顺煤业某一轨道顺槽为研究对象,采用钻孔窥视和数值模拟等方法,研究了迎采对掘迎采强扰动巷道围岩稳定性控制的问题,确定巷道的支护方案为锚杆+锚索+锚网以及W型钢带等相互配合的联合支护方法。现场应用后对围岩变形进行监测,结果表明该支护措施有效抑制了围岩变形,达到了很好的支护效果。

复采掘进工作面综合防灭火技术及实践

为确保复采掘进工作面的安全生产,针对复采工作面煤层易自燃的问题,在对运河煤矿F1301复采工作面现场条件以及遗煤自然发火风险分析的基础上,提出了适用于矿井复采掘进工作面的综合防灭火技术。采用风流场调控、均压堵漏、惰化处理、监测探测等有效手段,定性分析了复采条件下的防灭火机理,规范了防灭火技术工艺,量化了防灭火技术参数。通过实施综合防灭火技术,有效控制了掘进期间采空区煤层自然发火风险,使得F1301复采掘进工作得以顺利进行,同时也为工作面的回采创造了良好的防火条件,实践经验可为类似条件下工作面开采提供工程经验支撑。

融合面部深度感知的音频驱动人脸重现方法

人脸重现是一项条件面部生成任务,现有的基于音频驱动的人脸重现方法难以生成完整且高质量的人脸。针对这一问题,提出一种融合面部深度信息的音频驱动下的人脸重现方法。该方法采用了轻量级的模型框架以降低模型尺寸和提高运行速度。实验在AnnVI数据集上与3种最新的音频驱动人脸重现方法进行了比较。结果表明,所提出的融合面部深度感知的人脸重现方法,极大地提高了音频驱动下生成人脸图像的质量。

汽车智能驾舱驾驶疲劳检测系统设计

疲劳驾驶是影响交通安全的主要因素,当前疲劳驾驶的检测方法普遍存在设备体积大、侵入性强、实时性差等弊端。文中设计的基于FPGA的疲劳驾驶检测系统,首先利用区域长宽比改进YCbCr人脸分割算法,提高算法在驾驶环境中对于人脸的辨识度;然后建立动态视频人眼跟踪模型,在人脸范围内定位人眼位置,采用三帧差算法检测眨眼动作,以眨眼率作为疲劳的评价指标,对司机状态进行实时监控;最后利用FPGA芯片完成实时图像数据的处理和疲劳驾驶检测。实验证明,该系统具备在光线昏暗和佩戴眼镜等场景下检测疲劳状态的能力,并且检测系统充分发挥FPGA芯片数据并行处理优势,具备体积小、速度快、集成度高,通电即可工作的特点,有利于在狭小的驾驶舱环境部署,具有一定的工程应用价值。

基于FPGA的疲劳驾驶检测硬件加速器设计

随着交通工具大幅使用,交通事故频繁发生,疲劳驾驶是导致交通事故的一项重要原因。该设计采用硬件加速器来处理OV7725摄像头采集的视频流数据,制定肤色阈值来搜索人脸区域的边界,实现视频流实时动态标识人脸,通过人脸特征在阈值内的累计时长来判断疲劳级别并及时预警。得益于硬件加速器的并行处理优势,使得疲劳检测和预警更加快速稳定。该文完成了基于FPGA的人脸识别算法和疲劳驾驶检测的硬件加速器设计,仿真并验证了功能,对性能进行了测试,结果证明可实现快速准确的三级疲劳驾驶判断,并证明了该方案的可行性。