Chest wall osteochondroma resection with biologic acellular bovine dermal mesh reconstruction in pediatric hereditary multiple exostoses:A case report and review of literature

BACKGROUND Hereditary multiple exostoses is a rare genetic disorder characterized by the growth of multiple osteochondromas affecting primarily long bones.Chest wall lesions may represent a challenge,particularly in pediatric patients.Pain is a common manifestation.However,life-threatening complications can result from direct involvement of adjacent structures.Surgical resection with appropriate reconstruction is often required.CASE SUMMARY A 5-year-old male who was diagnosed with hereditary multiple exostoses presented with significant pain from a large growing chest wall exostosis lesion.After appropriate preoperative investigations,he underwent surgical resection with reconstruction of his chest wall using a biologic bovine dermal matrix mesh.CONCLUSION Resection of chest wall lesions in children represents a challenge.Preoperative planning to determine the appropriate reconstruction strategy is essential.

Heterogeneous information phase space reconstruction and stability prediction of filling body–surrounding rock combination

Traditional research believes that the filling body can effectively control stress concentration while ignoring the problems of unknown stability and the complex and changeable stress distribution of the filling body–surrounding rock combination under high-stress conditions.Current monitoring data processing methods cannot fully consider the complexity of monitoring objects,the diversity of monitoring methods,and the dynamics of monitoring data.To solve this problem,this paper proposes a phase space reconstruction and stability prediction method to process heterogeneous information of backfill–surrounding rock combinations.The three-dimensional monitoring system of a large-area filling body–surrounding rock combination in Longshou Mine was constructed by using drilling stress,multipoint displacement meter,and inclinometer.Varied information,such as the stress and displacement of the filling body–surrounding rock combination,was continuously obtained.Combined with the average mutual information method and the false nearest neighbor point method,the phase space of the heterogeneous information of the filling body–surrounding rock combination was then constructed.In this paper,the distance between the phase point and its nearest point was used as the index evaluation distance to evaluate the stability of the filling body–surrounding rock combination.The evaluated distances(ED)revealed a high sensitivity to the stability of the filling body–surrounding rock combination.The new method was then applied to calculate the time series of historically ED for 12 measuring points located at Longshou Mine.The moments of mutation in these time series were at least 3 months ahead of the roadway return dates.In the ED prediction experiments,the autoregressive integrated moving average model showed a higher prediction accuracy than the deep learning models(long short-term memory and Transformer).Furthermore,the root-mean-square error distribution of the prediction results peaked at 0.26,thus outperforming the no-prediction method in 70%of the cases.

Three-dimensional positions of scattering centers reconstruction from multiple SAR images based on radargrammetry

A method and procedure is presented to reconstruct three-dimensional(3D) positions of scattering centers from multiple synthetic aperture radar(SAR) images. Firstly, two-dimensional(2D) attribute scattering centers of targets are extracted from 2D SAR images. Secondly, similarity measure is developed based on 2D attributed scatter centers' location, type, and radargrammetry principle between multiple SAR images. By this similarity, we can associate 2D scatter centers and then obtain candidate 3D scattering centers. Thirdly, these candidate scattering centers are clustered in 3D space to reconstruct final 3D positions. Compared with presented methods, the proposed method has a capability of describing distributed scattering center, reduces false and missing 3D scattering centers, and has fewer restrictionson modeling data. Finally, results of experiments have demonstrated the effectiveness of the proposed method.

Reservoir reconstruction technologies for coalbed methane recovery in deep and multiple seams

Multiple coal seams widely develop in the deep Chinese coal-bearing strata. Ground in situ stress and coal seam gas pressure increase continuously with the increase of the mining depth, and coal and gas outburst disasters become increasingly severe. When the coal is very deep, the gas content and pressure will elevate and thus coal seams tends to outburst-prone seams. The safety and economics of exploited firstmined coal seams are tremendously restricted. Meanwhile, the multiple seams occurrence conditions resulted in different methane pressure systems in the coal-bearing strata, which made the reservoir reconstruction of coal difficult. Given the characteristics of low saturation, low permeability, strong anisotropy and soft coal of Chinese coal seams, a single hydraulic fracturing surface well for reservoir reconstruction to pre-drain the coalbed methane(CBM) of multiple seams concurrently under the different gas pressure systems has not yet gained any breakthroughs. Based on analyses of the main features of deep CBM reservoirs in China, current gas control methods and the existing challenges in deep and multiple seams, we proposed a new technology for deep CBM reservoir reconstruction to realize simultaneous high-efficiency coal mining and gas extraction. In particular, we determined the first-mined seam according to the principles of effectiveness and economics, and used hydraulic fracturing surface well to reconstruct the first-mined seam which enlarges the selection range of the first-mined seam. During the process of mining first-mined seam, adjacent coal seams could be reconstructed under the mining effect which promoted high-efficiency pressure relief gas extraction by using spatial and comprehensive gas drainage methods(combination of underground and ground CBM extraction methods). A typical integrated reservoir reconstruction technology, ‘‘One well for triple use", was detailed introduced and successfully applied in the Luling coal mine. The application showed that the proposed technology could effectively promote coal mining safety and simultaneously high-efficiency gas extraction.

Multiple helical scans and the reconstruction of over FOV-sized objects in cone-beam CT

In cone-beam computed tomography （CBCT）, there are often cases where the size of the specimen is larger than the field of view （FOV） （referred to as over FOV-sized （OFS））. To acquire the complete projection data for OFS objects, some scan modes have been developed for long objects and short but over-wide objects. However, these modes still cannot meet the requirements for both longitudinally long and transversely wide objects. In this paper, we propose a multiple helical scan mode and a corresponding reconstruction algorithm for both longitudinally long and transversely wide objects. The simulation results show that our model can deal with the problem and that the results are acceptable, while the OFS object is twice as long compared with the FOV in the same latitude.

Cultural Reconstruction:The Game of Multiple Subjects

Cultural reconstruction is the application of cultural capitalization,and the process of the game between multiple subjects.This paper discusses the demands of various stakeholders and presents the challenges faced by the cultural reconstruction led by the government’s centralized leadership.The conclusion is that the government should vigorously organize multiple forces to participate in cultural reconstruction in order to form a multiple-participation-mechanism under a centralized leadership.

A MULTIPLE STRUCTURE RECONSTRUCTION ALGORITHM BASED ON WIRE FRAME MODEL

A “LAG & RLC” visualization algorithm has been presented to display a clear three dimensional structure from stereo slice data which has the characteristics of multiple layer structure. This algorithm is based on wire frame model which can do multiple logical operations and has multiple display effects. It has wide use in biomedical science and computer graphics. The practical system is based on PC with a TVGA adapter at least 512k byte display memory and 2M byte extended memory.

基于SPSO优化Multiple Kernel-TWSVM的滚动轴承故障诊断

双子支持向量机(twin support vector machine,简称TWSVM)的核函数选择对其分类性能有着重要影响,TWSVM其核函数一般是局部核函数或者全局核函数,这两种核函数的泛化能力和分类性能不能兼顾。笔者利用综合加权的高斯局部核函数和多项式全局核函数方法组成双核函数来改进TWSVM以提高其泛化能力和分类性能,并采用简化粒子群优化(simple particle swarm optimization,简称SPSO)方法来对权值和参数进行优化,提出了SPSO优化Multiple Kernel-TWSVM模型,将该模型应用到滚动轴承故障诊断模式识别中。实验结果表明,双核TWSVM比单核TWSVM和反向传播(back propagation,简称BP)神经网络具有更高的分类准确率。

One-stage resection of four genotypes of bilateral multiple primary lung adenocarcinoma:A case report

BACKGROUND The incidence of multiple primary lung cancer(MPLC)in China is 0.52%-2.45%.Most primary lung cancer cases have reported two lesions or three in rare cases.We report a rare case of bilateral simultaneous multiple primary lung adenocarcinoma of four different genotypes.CASE SUMMARY A 58-year-old woman was admitted to our hospital on June 29,2021,and upon physical examination,four multiple pulmonary nodules were identified in both lungs.Further computed tomography(CT)images revealed the presence of ground glass nodules,predicted to be high-risk cancer lesions by artificial intelligence.With the guidance of three-dimensional reconstruction of preo-perative CT images,the nodules were resected under thoracoscopy.Postoperative pathological investigation revealed that the nodule types were adenocarcinoma in situ,invasive alveolar adenocarcinoma,and microinvasive adenocarcinoma.The excised nodules were further sequenced using high-throughput sequencing(semiconductor sequencing method)of 26 lung cancer genes to confirm that the four lesions were not homologous.The patient was discharged on postoperative day 8,that is,on July 15,2021.One month later,she returned to the hospital for followup and reexamination.Chest CT examination showed that she had re-covered well,and no obvious exudation and effusion were found in both pleural cavities.Evaluation of postoperative pulmonary function showed that her forced vital capacity was 1.40 L(preoperative value,2.27 L)and forced expiratory volume was 1.24 L(preoperative value,2.23 L).CONCLUSION The surgical plan for multiple pulmonary nodules should be carefully considered.For carefully selected patients with concurrently occurring multiple lung nodules in both lungs,sublobectomy is a safe and feasible plan for concurrent bilateral resection of the lesions.Genetic sequencing is necessary for MPLC diagnosis and treatment.

基于功率重构和时序特性约束的长预见期光伏集群功率预测

光伏装机容量的逐渐增大为大规模的光伏并网带来了巨大挑战,突破更长预见期的光伏功率预测有助于电力系统的安全稳定运行。现有研究及应用最长预见期为7 d,为将预见期延长至8~15 d,提出了一种基于功率重构和时序特性约束的长预见期光伏集群功率预测方法。首先,采用近似积分计算日电量和辐照能;其次,基于麻雀搜索算法优化变分模态分解以分解电量及辐照能序列,并采用多元线性回归模型对不同频率的分量进行预测叠加得到电量预测结果;然后,根据出力特性建立约束过程,将电量预测结果重构为光伏功率;最后,将所提方法应用于中国甘肃省某光伏集群,模型在不同季节典型月功率预测的均方根误差平均降低2.55%,验证了方法的有效性。

核酸检测的重排算法及其数值模拟

2022年春季上海遭受到奥密克戎变异株的侵袭,核酸检测是筛查新冠阳性病例的重要手段之一。目前社区常用核酸检测方式是10人/20人混合检测,重点人群单人单管复测。考虑到检测数量的庞大,二次复核易对非阳性人员造成恐慌,仿照CT成像原理,设计一种核酸检测重排方法,每人检测后将检测液分别随机置于多组不同试管中,根据不同组试管中的检测结果(投影数据),利用反投影方法,确定进入二次检测人员。计算机仿真结果表明,上述所设计的重排算法能够实现减少总检测数量和提高进入二次检测人员精度的目的。因此以上重排方法有望进一步应用到智能化的核酸采样机器人上,达到高效检测的目的。

基于深度学习的三维人脸重建抗遮挡网络

对人脸单遮挡模型和人脸多遮挡模型进行了研究,提出了一种基于深度学习的三维人脸重建抗遮挡网络,实现了对遮挡人脸的有效重建。改进的单遮挡模型通过预训练和权重的修改有效地实现了人脸图像上下文信息的捕获。改进的多遮挡模型通过特征扭曲和变换,使用分布的损失函数和不同的微分器得出重建的人脸图像。实验结果表明,提出的方法能够在多种遮挡情况下生成更为准确的三维人脸模型,具有更好的鲁棒性和抗遮挡能力。

结合竞争交互策略和淘汰重组机制的异构多蚁群算法

针对传统的蚁群算法在解决旅行商问题时(traveling salesman problem,TSP)存在着收敛速度慢、容易陷入局部最优等问题,提出了一种结合竞争交互策略和淘汰重组机制的异构多蚁群算法。建立一个异构多种群系统,算法采用竞争交互策略,根据不同时期各种群的汉明距离来自适应的调节交互周期;并利用竞争系数来差异化匹配交互对象,经过匹配后的交互对象之间通过最优解和信息素矩阵进行交互,通过该机制实现了算法收敛速度和多样性的平衡。算法采用了淘汰重组机制,会定期对寻优能力差的种群进行淘汰与重组,以加快算法的求解精度。采用多组不同规模的TSP算例进行仿真实验,结果表明,该算法在提高求解精度和收敛速度方面表现更优。

方位多波束弧形阵列SAR成像方法研究

弧形阵列合成孔径雷达(Synthetic Aperture Radar,简称SAR)是一种广域观测的新体制微波成像系统,相比于线性阵列合成孔径雷达,弧形阵列SAR能够有效克服常规成像雷达前视、侧视、下视等观测视角单一的问题,弥补了常规成像模式的不足。方位多波束技术是星载合成孔径雷达系统获取高分辨宽覆盖测绘能力的重要技术途径。本文首先构建了多波束弧形阵列SAR系统的方位向多通道信号模型,并通过传统的方位多通道重建方法进行成像仿真,成像结果出现虚假目标,由于传统的多通道重建方法适用于大多数线性阵列,所以通过分析回波斜距的数学几何模型推导出了多波束弧形阵列SAR相比于线性阵列SAR多了一个附加相位,与弧形阵列天线结构相结合,附加相位由子孔径角度引起,因此方位多通道回波数据中相位误差是由多通道弧形阵列SAR的子孔径角度引起,从而导致多通道不均衡,所以传统的多通道重建方法不能够直接用于弧形阵列SAR的成像处理中,为了实现弧形阵列SAR系统的静止目标聚焦成像,提出了适用于弧形阵列SAR系统的方位多通道重建方法,在进行多通道重构和合并之前,对方位通道间的附加相位进行补偿,避免方位欠采样,然后根据弧形阵列方位多通道脉冲响应重构方位多通道数据,该方法可以很好的抑制了虚假目标,最后通过仿真实验验证了该方法的可行性。

基于Transformer增强型U-net的CT图像稀疏重建与伪影抑制

实现低剂量计算机断层成像(CT)的一个有效办法是减少投影角度,但投影角度较少会产生严重的条状伪影,降低图像的临床使用价值。针对该问题,提出一种耦合卷积神经网络(CNN)和多种注意力机制的U型网络(TE-unet)。首先采用U型架构提取多尺度特征信息;其次提出一个包含CNN和多种注意力的模块提取图像特征;最后在跳跃连接处加入Transformer块过滤信息,抑制不相关特征,突出重要特征。所提网络结合CNN的局部特征提取能力和Transformer的全局信息捕获能力,辅以多种注意力机制,实现了良好的去条状伪影能力。在60个投影角度下,与经典的Uformer网络相比,峰值信噪比(PSNR)高出0.3178 dB,结构相似度(SSIM)高出0.002,均方根误差(RMSE)降低0.0005。实验结果表明,所提TE-unet重建的图像精度更高,图像细节保留的更好,可以更好地压制条状伪影。

多视影像三维线云重建技术及其智能化发展展望

三维线云是具有几何结构与语义信息的三维线段集合,可以作为实景三维构建中高效的引导,控制与抽象表达元素,弥补点云的边缘描述缺陷与初始结构的缺失,是改变传统三维模型“一张皮”(不同对象相互粘连,难以指导空间分析与决策)的重要结构化特征。然而,如何从多视影像中重建好用的线云,将线云在实景三维中用好,一直是本领域的难点问题。本文回顾三维线云的发展,介绍相关的重建方法,分析存在的难点与不足;结合从数字化走向智能化的测绘科技转型背景,论述线云在实景三维中建什么,如何建与怎么用,对线云重建和应用的智能化发展予以介绍和展望,希望为实景三维重建与线云研究的相关人员提供参考。

基于ADMM的SAR多运动目标成像方法

为提高合成孔径雷达(SAR)多运动目标同时聚焦性能和成像效率,利用多运动目标信号的多分量线性调频信号形式和稀疏先验知识,提出基于交替方向乘子法(ADMM)的SAR多运动目标成像方法。通过建立SAR多运动目标稀疏观测模型,将多运动目标成像问题建模为稀疏特征约束下的逆问题求解。基于自适应Chirplet分解方法对目标多普勒调频率进行估计,从而实现观测矩阵设计。为获得较高的动态响应范围和较低的旁瓣响应,采用ADMM对多运动目标进行稀疏重构,ADMM将复杂的凸优化问题分解为多个交替寻找最优解的子优化问题,从而实现多运动目标图像精确且高效重构。最后通过仿真实验和机载SAR实测数据验证所提算法在聚焦成像质量和工作效率方面优于其他成像方法。

基于加权多新息卡尔曼滤波算法的响应重构

针对卡尔曼滤波算法容易受到噪声的影响,使得响应重构精度降低甚至发散的问题,提出一种基于加权多新息卡尔曼滤波算法的响应重构方法。首先在融合多新息理论和卡尔曼滤波算法的基础上,引入加权矩阵动态调整新息矩阵的权重以降低历史干扰数据的累积影响。随后将该方法用于响应重构中,使用有限的加速度响应对其余未知位置处的加速度、速度以及位移响应进行重构。最后分别对起重机桁架和简支梁进行数值模拟和试验验证,结果表明与卡尔曼滤波算法和多新息卡尔曼滤波算法的响应重构方法相比,所提方法的滤波稳定性和估计精度得到改善,其能在运行时间增加很小的情况下有更高的重构精度。

基于联合多重重建自编码器的桁架损伤识别

针对桁架杆单元存在不同损伤类型时损伤特征信息难以捕捉且识别结果不准确的问题,提出了利用联合多重重建自编码器(JMRAE)进行损伤识别的方法。首先,运用JMRAE按照不同尺度数分段截取信号,将Sigmoid函数和ReLU函数进行组合以提取特征量,引入零相位成分分析(ZCA)降低特征量维度,以保留重要信息并减少数据冗余。然后,运用SoftMax分类器求解隐含层中不同片段的局部特征量,并进行特征量融合以判断结构状态。最后,运用三维桁架结构数值模型和实验室搭建桁架进行验证,并与精细复合多尺度散布熵(RCMDE)、峰度和反向传播(BP)神经网络方法进行对比研究,结果表明所提方法具有更高的损伤识别准确性。