A study on characteristics of tectonic block motion and tectonic setting of strong earthquakes in northern part of the Shanxi fault depression zone

This paper makes a systematical study on characteristics of structure and motion of the tectonic blocks in northern part of the Shanxi fault depression zone by means of geometrical and kinematical analysis of the blocks. The ki-netic behavior of the blocks is discussed by comparing associated geomorphic features of fault movement. All analyses and studies are based on a Domino model. The block movement, fault basin extension and their regional distribution are systematically investigated. The result shows: (a) The studied region is divided into sub-regions by NW striking faults: the western, middle and eastern sub-region with crustal extension being 4.46 km, 2.80 km and 1.86 km, respectively. The extensional amount of each block in the region is estimated being generally about 1 km. The calculated result using the block motion model approximately fits the data of geologic survey. (b) Block kin-ematical features are obviously different between the northern and southern part, with the Hengshan block in be-tween, of the studied region. Moreover, the magnitude of the largest historical earthquake in the northern part is about 6, while that in the southern is 7. The faulted blocks in the northern sub-region show northwestward exten-sion, indicating a feature of extensional graben, while the blocks in the southern part manifest tilt motion, extend-ing southeastward, in the opposite sense of fault dipping. Additional tectonic stress generated by block rotation may be one of major factors affecting seismogenic process in the region. It is responsible for the difference in the movement of the block boundary faults and seismic activities between the two sub-regions.

Heterogeneity induced strain localization in block-in-matrix-soils subjected to uniaxial loading using real-time CT scanning

Block-in-matrix-soils(bimsoils)are geological mixtures that have distinct structures consisting of relatively strong rock blocks and weak matrix soils.It is still a challenge to evaluate the mechanical behaviors of bimsoils because of the heterogeneity,chaotic structure,and lithological variability.As a result,only very limited laboratory studies have been reported on the evolution of their internal deformation.In this study,the deformation evolution of bimsoils under uniaxial loading is investigated using real-time X-ray computed tomography(CT)and image correlation algorithm(with a rock block percentage(RBP)of 40%).Three parameters,i.e.heterogeneity coefficient(K),correlation coefficient(CC),and standard deviation(STD)of displacement fields,are proposed to quantify the heterogeneity of the motion of the rock blocks and the progressive deformation of the bimsoils.Experimental results show that the rock blocks in bimsoils are prone to forming clusters with increasing loading,and the sliding surface goes around only one side of a cluster.Based on the movement of the rock blocks recorded by STD and CC,the progressive deformation of the bimsoils is quantitatively divided into three stages:initialization of the rotation of rock blocks,formation of rock block clusters,and formation of a shear band by rock blocks with significant rotation.Moreover,the experimental results demonstrate that the meso-motion of rock blocks controls the macroscopic mechanical properties of the samples.

The initial establishment of the tectonic block motion model of China from space geodetic data

Using the velocity fields of 28 GPS sites in China and its contiguous area and International Terrestrial Reference Frame ITRF96, an initial tectonic block motion model of China was established. The model was quite consistent with those obtained from the geologic data. The model could show the sketch of China crustal horizontal motion.

Fast Approaches for Sub-pixel Precision Variable Block Size Motion Estimation

The new features of H. 264 video coding standard make the motion estimation module much more time consuming than before. Especially, the motion search is required for each of the 4 modes for inter prediction. In order to reduce the computational complexity, we analyze the statistics of results of motion estimation, such as the continuity of best modes of blocks in successive frames and the chance to give up a sub-partition mode （smaller than 16 × 16） after integer-pixel motion estimation, from which we suggest to make mode prediction based on the motion information of the previous frame and skip sub-pixel motion estimation in subpartition mode selectively. According to the experimental result, the proposed algorithm can save 75 % of the computational time with a slight degradation （0.03 dB） on PSNR compared with the pseudocode of fast search motion estimation in JM12.2.

基于FPGA的H.264可变块运动估计算法的优化及实现

可变块运动估计算法(Variable Block Size Motion Estimation,VBSME)是H.264标准中重要的组成部分。它不仅计算量大,而且耗时长。为了减少运动估计时间和计算量,本文采用硬件实现的方式,并提出了一种利用绝对差值和(Sum of Absolute Differences,SAD)计算的树状结构进行数据重用的方案。该方案使得各单元间的数据流向明确,结构更简单。同时,本文还考虑到了帧间模式决策(Mode Decision,MD)和SAD计算可以并行计算的可行性,设计了相应的并行流水线结构。利用Xilinx xc7v585tffg1761-1开发板进行了仿真验证。结果表明,该方案可以一次性处理输入的256个像素数据,提高了实时性,并且达到了100%的数据利用率。此外,该方案支持最大分辨率为1920×1080,帧率为60帧/s,并具备低编码延时,满足了绝大多数场合的实时性要求。

用于超声散斑跟踪血流测速的多角度平面波局部运动补偿

血流速度剖面用于计算壁面剪切率等血流动力学指标,与动脉粥样硬化病程发展密切相关。超快超声散斑跟踪广泛用于血流速度剖面估计,然而多角度平面波复合成像存在血流散射体的运动伪影,不利于流速估计。提出了一种多角度平面波复合成像的局部运动补偿法,对射频信号时间序列的相邻帧进行局部运动补偿来消除不同径向位置的运动伪影,从而提高流速测量准确性。相比直接相干复合,B-MoCo法将仿真、仿体实验中流速测量结果的归一化均方根误差平均减小了10.37%、37.82%,说明了B-MoCo法的有效性。基于兔骼动脉的实测实验进一步证明了B-MoCo法的临床可行性。综上,B-MoCo法能够有效提高血流速度剖面的测量精度,有助于相关心血管疾病的早期诊断与病程监测。

A Correlation Tracking Algorithm Based on Template Partition Motion Estimation

A correlation tracking algorithm based on template partition motion estimation proposed for improving real time performance of the conventional correlation matching algorithms. The target trajectory fitted using the least square with equal space in whole interval and the target prediction point is found out. According to the requirements of block motion estimation(BME) algorithm,the template divided into some macro blocks. The searching process is conducted by using diamond search algorithm around the prediction point and the optimal motion vector of each block is calculated. A point corresponding to the motion vector with the best matching is taken as a rough matching point of the template. The relation of relative position between the block with matching point and the searching area determined to decide whether to conduct precise matching search or to construct a new search area in the gradient direction. The target tracking experiment results show that over 70% time cost can be reduced caompared with the conventional correlation matching algorithm based on full search method.

Novel block-matching algorithms by subsampling both search candidates and pixels

A new faster block-matching algorithm （BMA） by using both search candidate and pixd sulzsamplings is proposed. Firstly a pixd-subsampling approach used in adjustable partial distortion search （APDS） is adjusted to visit about half points of all search candidates by subsampling them, using a spiral-scanning path with one skip. Two sdected candidates that have minimal and second minimal block distortion measures are obtained. Then a fine-tune step is taken around them to find the best one. Some analyses are given to approve the rationality of the approach of this paper. Experimental results show that, as compared to APDS, the proposed algorithm can enhance the block-matching speed by about 30% while maintaining its MSE performance very close to that of it. And it performs much better than many other BMAs such as TSS, NTSS, UCDBS and NPDS.

基于密集残差生成对抗网络的红外图像去模糊

红外图像拍摄过程中,由于摄像设备抖动或目标快速移动会导致图像出现运动模糊,极大影响了有效信息的提取和识别。针对上述问题,本文在DeblurGAN基础上提出一种基于密集残差生成对抗网络的红外图像去模糊方法。该方法首先采用多尺度卷积核,提取红外图像不同尺度和层次的特征。其次,采用密集残差块(residual-in-residual dense block,RRDB)代替原生成网络中的残差单元,改善恢复红外图像的细节信息。通过本课题组自制的红外图像数据集进行实验,结果表明所提出的方法与DeblurGAN相比PSNR提高3.60 dB,SSIM提高0.09,主观视觉去模糊效果较好,恢复后的红外图像边缘轮廓清晰且细节信息明显。

基于帧间跨越光流的视频超分辨率重建网络

面对运动幅度较大的复杂场景,当前的视频超分辨率(VSR)算法在处理长序列时无法充分利用不同距离的帧间信息,难以精确地恢复遮挡、边界和多细节区域。为解决上述问题,提出一种基于帧间跨越光流机制的VSR模型。首先,通过密集残差块(RDB)提取低分辨率视频帧(LR)的浅层特征;其次,通过光流空间金字塔网络(SPyNet)以不同时间长度的跨越光流对视频帧进行运动估计和运动补偿,并通过RDB对帧间信息进行深层特征提取与矫正;最后,融合浅层特征与深层特征,并通过上采样得到高分辨率视频帧(HR)。在REDS4公开数据集上的实验结果表明,所提模型与经典的非显式运动补偿的动态上采样滤波器视频超分辨率网络(DUF-VSR)相比,峰值信噪比(PSNR)和结构相似性(SSIM)分别提升了1.07 dB和0.06。验证了所提模型可有效提高视频图像重建的质量。

膝关节单髁置换中鸡尾酒疗法联合股神经阻滞的镇痛效果

背景:随着微创理念的进一步深入,膝关节单髁置换已成为膝骨关节炎的重要治疗手段,然而,置换后早期疼痛影响其康复进程,因此采取有效的镇痛措施十分必要。股神经阻滞和鸡尾酒疗法是目前膝关节单髁置换的常见镇痛方法,但二者联合应用的镇痛效果及安全性尚缺乏相关研究证实。目的:探究膝关节单髁置换过程中鸡尾酒疗法联合股神经阻滞的镇痛效果。方法:选取2021年10月至2023年1月接受膝关节单髁置换治疗的100例患者作为研究对象,采用随机数字表法将患者分为对照组(n=50)、研究组(n=50)。在膝关节单髁置换过程中,对照组采取股神经阻滞,研究组采取鸡尾酒疗法合并股神经阻滞,对比观察两组患者的镇痛效果、置换后2 d内注射地佐辛止痛频次、患侧膝关节活动度、KSS功能评分以及术后不良反应的发生情况。结果与结论:①研究组置换后12,24,48 h的静息和活动后目测类比评分均低于对照组(P<0.05);②研究组置换后2 d内注射地佐辛止痛频次少于对照组(P<0.05);③研究组置换后1,3 d的膝关节活动度均大于对照组(P<0.05),而两组置换后14 d的活动度比较差异无显著性意义(P>0.05);④研究组置换后2周的膝关节KSS评分大于对照组(P<0.05),而置换后6周至6个月,两组的膝关节KSS评分差异无显著性意义(P>0.05);⑤两组患者置换后14 d内的不良反应发生情况差异无显著性意义(P>0.05);⑥结果表明,在膝关节单髁置换过程中采用鸡尾酒疗法联合股神经阻滞,能明显降低患者的疼痛程度,提高镇痛效果,减少镇痛药物使用频次,改善患者早期膝关节活动度。

亚甲蓝复合罗哌卡因隐神经阻滞对全膝关节置换术患者术后镇痛效果的影响

目的探讨应用亚甲蓝复合罗哌卡因隐神经阻滞对全膝关节置换术(TKA)患者术后镇痛效果的影响。方法选择择期行全膝关节置换术患者60例,男24例,女36例,年龄60~75岁,BMI 18.5~30.0 kg/m^(2),ASAⅡ或Ⅲ级。采用随机数字表法将患者分为两组:亚甲蓝复合罗哌卡因组(MR组)和罗哌卡因组(R组),每组30例。腰-硬联合麻醉前,MR组采用0.10%亚甲蓝+0.25%罗哌卡因复合液20 ml行超声引导下隐神经阻滞,R组采用0.25%罗哌卡因20 ml行超声引导下隐神经阻滞。记录术后6、12、24、48、72 h患肢静息和活动时VAS疼痛评分,术后24、48、72 h患肢膝关节最大活动度(ROM)和股四头肌徒手肌力检查(MMT)评分,镇痛泵有效按压次数、补救镇痛例数和补救镇痛药首次追加时间。记录穿刺部位出血、感染、局部麻醉药物中毒、神经损伤、周围组织损伤等神经阻滞相关并发症的发生情况。结果与R组比较,MR组术后12、24、48、72 h静息时VAS疼痛评分明显降低(P<0.05),术后48、72 h活动时VAS疼痛评分明显降低(P<0.05),术后24、48、72 h患肢膝关节ROM明显增大(P<0.05),镇痛泵有效按压次数明显减少(P<0.05),补救镇痛率明显降低(P<0.05)。两组术后住院期间均未见神经阻滞相关并发症。结论超声引导下亚甲蓝复合罗哌卡因隐神经阻滞可增强TKA术后镇痛效果,延长镇痛作用时间,减少术后镇痛药的使用,有利于术后早期膝关节的功能锻炼。

定日镜场的输出热功率计算模型

基于全国大学生数学建模竞赛赛题的定日镜场分布数据,根据太阳视运动方法,建立太阳跟踪运动模型、阴影挡光效率理论模型、相邻定日镜遮挡选取模型与镜面反射光锥模型,得出了定日镜场的年平均光学效率、年平均输出热功率,以及单位面积的镜面年平均输出热功率,最后通过输出功率的拟合结果展现了模型的合理性。

某型机登机梯机构运动仿真及设计优化

某型机采用堵塞式门梯一体式登机梯机构,该登机梯机构运动包含抬升、锁定和下放运动。针对登机梯机构方案进行运动模拟和分析,寻求优化改进方向。设计优化是一个多轮迭代的过程,登机梯机构复杂、运动链长、涉及零件多,一般的理论计算和分析实施困难。因此,采用CATIA软件的DMU模块对登机梯机构进行运动仿真,针对仿真过程发现的问题进行原因分析,并提出了改进措施。

Propagating adaptive-weighted vector median filter for motion-field smoothing

In the field of predictive video coding and format conversion, there is an increasing attention towards estimation of the true inter-frame motion. The restoration of motion vector field computed by 3-D RS is addressed and a propagating adaptive-weighted vector median (PAWVM) post-filter is proposed. This approach decomposes blocks to make a better estimation on object borders and propagates good vectors in the scanning direction. Furthermore, a hard-thresholding method is introduced into calculating vector weights to improve the propagating. By exploiting both the spatial correlation of the vector field and the matching error of candidate vectors, PAWVM makes a good balance between the smoothness of vector field and the prediction error, and the output vector field is more valid to reflect the true motion.

Concurrent Validity of a Virtual Version of Box and Block Test for Patients with Neurological Disorders

Background: The Box and Block clinical test is a validated and standardized scale for use in the clinical environment that allows the assessment of rough manipulative dexterity. Proposing virtual methods to carry out these assessments is an attempt to eliminate some of the subjectivity that the test may entail depending on the observer and the way in which the patient gives instructions. Applied to the assessment of skills after neurological pathologies, previous experiences in stroke patients have been found. So, this work was centered on the Spinal Cord Injury. Objective: To present the virtual application of the Box and Block scale, as well as details about its design and development for its manipulation based on Leap Motion Controller. Methodology: The relationship between the results obtained in the actual test and in the virtual application in healthy subjects and, mostly, patients with cervical spinal cord injury is analyzed, obtaining a high correlation index between both tests’ performance. Results: A high correlation index was obtained between both tests performance, the real and virtual version of the Box and Block Test. Conclusion: This virtual test can serve as an element to evaluate in the future the effectiveness of the RehabHand prototype based on virtual reality applications with a therapeutic and a rehabilitative sense that, manipulated from Leap Motion Controller, allow the improvement of the manipulative dexterity in patients with neurological diseases such as spinal cord injury.

A Fast Depth-Map Generation Algorithm based on Motion Search from 2D Video Contents

Generation of a depth-map from 2D video is the kernel of DIBR (Depth Image Based Rendering) in 2D-3D video conversion systems. However it occupies over most of the system resource where the motion search module takes up 90% time-consuming in typical motion estimation-based depth-map generation algorithms. In order to reduce the computational complexity, in this paper a new fast depth-map generation algorithm based on motion search is developed, in which a fast diamond search algorithm is adopted to decide whether a 16x16 or 4x4 block size is used based on Sobel operator in the motion search module to obtain a sub-depth-map. Then the sub-depth-map will be fused with the sub-depth-maps gotten from depth from color component Cr and depth from linear perspective modules to compensate and refine detail of the depth-map, finally obtain a better depth-map. The simulation results demonstrate that the new approach can greatly reduce over 50% computational complexity compared to other existing methods.

BLOCK ADAPTIVE RECURSIVE ALGORITHM FOR VIDEO CONFERENCE CODING

This paper presents a new motion estimation algorithm for video conference signal coding. This type of algorithm is called block adaptive recursive algorithm (BARA). Simulation results show that this new algorithm has better performance than conventional ones.

Improvement of Matching Criterion for Motion Estimation in H.263

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Crustal Motion Characteristics in the Eastern Margin of the Tibetan Plateau and Adjacent Regions after the Wenchuan Earthquake

The Wenchuan earthquake has altered the crustal motion characteristics in the eastern margin of the Tibetan Plateau and adjacent regions.Using discontinuous GPS survey data for 2008–2012, the velocity field for the Eurasia reference framework has been obtained, and the general trend of contemporary crustal motion after the occurrence of the Wenchuan earthquake has been studied.In addition, using the velocity field, the block movement velocity has been estimated by least-squares fitting.Furthermore, the properties and displacement rates of main faults have been obtained from the differences in velocity vectors of the blocks on both sides of the faults.The results reveal that there are no obvious changes in the general characteristics of crustal motion in this area after the Wenchuan earthquake.The earthquake mainly changed the rate of the movement of the Chuan-Qing block and caused variation in the movement direction of the South China block.The effect of the earthquake on faults is mainly reflected in variations in fault displacement velocity; there is no fundamental change in the properties of fault activity.The displacement rates of the Xianshuihe fault decreased by 3–4 mm/a, the Longmenshan fault increased by 9–10 mm/a, and the northern segment of the Anninghe fault increased by approximately 9 mm/a.Furthermore, the displacement rates of the Minjiang, Xueshan, Huya, Longquanshan, and Xinjin faults increased by 2–3 mm/a.This implies that the effects of the Wenchuan earthquake on crustal movement can mainly be observed in the Chuan-Qing, South China, and N-Chuan-Dian blocks and their internal faults, as well as the Xianshuihe and Longmenshan faults and the northern section of the Anninghe fault.The reason for this is that the Wenchuan earthquake disturbed the kinematic and dynamic balance in the region.