Post-processing

后处理
  • 文章类型: Journal Article
    传统的三维重建方法主要使用图像处理技术或深度学习分割模型进行肋骨提取。后处理后,实现了基于体素的肋骨重建。然而,这些方法的重建精度有限,计算效率低。为了克服这些限制,提出了一种基于点云自适应平滑和去噪的三维肋骨重建方法。我们将CT图像中的体素数据转换为多属性点云数据。然后,我们应用点云自适应平滑和去噪方法来消除点云中的噪声和非肋骨点。此外,采用高效的三维重建和后处理技术来实现高精度和全面的三维肋骨重建结果。实验计算表明,与基于体素的三维肋骨重建方法相比,通过所提出的方法生成的3D肋骨模型在重建精度方面实现了40%的提高,并且效率是前者的两倍。
    The traditional methods for 3D reconstruction mainly involve using image processing techniques or deep learning segmentation models for rib extraction. After post-processing, voxel-based rib reconstruction is achieved. However, these methods suffer from limited reconstruction accuracy and low computational efficiency. To overcome these limitations, this paper proposes a 3D rib reconstruction method based on point cloud adaptive smoothing and denoising. We converted voxel data from CT images to multi-attribute point cloud data. Then, we applied point cloud adaptive smoothing and denoising methods to eliminate noise and non-rib points in the point cloud. Additionally, efficient 3D reconstruction and post-processing techniques were employed to achieve high-accuracy and comprehensive 3D rib reconstruction results. Experimental calculations demonstrated that compared to voxel-based 3D rib reconstruction methods, the 3D rib models generated by the proposed method achieved a 40% improvement in reconstruction accuracy and were twice as efficient as the former.
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  • 文章类型: Journal Article
    路径规划是机器人学的一个重要研究领域。与其他路径规划算法相比,快速探索随机树(RRT)算法同时具有搜索和随机抽样特性,因此具有更多的潜力来生成可以平衡全局最优和局部最优的高质量路径。本文回顾了2021-2023年基于RRT的改进算法的研究,包括理论改进和应用实现。在理论层面,分支战略改进,抽样策略的改进,后处理改进,突出显示了模型驱动的RRT,在应用层面,RRT在焊接机器人下的应用场景,装配机器人,搜索和救援机器人,手术机器人,自由漂浮的太空机器人,和检测机器人是详细的,最后,总结了RRT在理论和应用层面面临的诸多挑战。这篇综述表明,尽管基于RRT的改进算法在大规模场景中具有优势,实时性能,和不确定的环境,一些难以定量描述的策略可以基于模型驱动的RRT来设计,基于RRT的改进算法仍然存在难以设计超参数和泛化能力弱的问题,在实际应用层面,控制器等硬件的可靠性和准确性,执行器,传感器,通信,电源和数据采集效率都对大规模非结构化场景下RRT的长期稳定性提出了挑战。作为自主机器人的一部分,RRT路径规划性能的上限还取决于机器人的定位和场景建模性能,在多机器人协作中仍然存在架构和战略选择,除了必须面对的伦理和道德。为了解决上述问题,我相信多类型机器人协作,人机协作,实时路径规划,超参数的自整定,面向任务或应用场景的算法和硬件设计,高度动态环境中的路径规划是未来的发展趋势。
    Path planning is an crucial research area in robotics. Compared to other path planning algorithms, the Rapidly-exploring Random Tree (RRT) algorithm possesses both search and random sampling properties, and thus has more potential to generate high-quality paths that can balance the global optimum and local optimum. This paper reviews the research on RRT-based improved algorithms from 2021 to 2023, including theoretical improvements and application implementations. At the theoretical level, branching strategy improvement, sampling strategy improvement, post-processing improvement, and model-driven RRT are highlighted, at the application level, application scenarios of RRT under welding robots, assembly robots, search and rescue robots, surgical robots, free-floating space robots, and inspection robots are detailed, and finally, many challenges faced by RRT at both the theoretical and application levels are summarized. This review suggests that although RRT-based improved algorithms has advantages in large-scale scenarios, real-time performance, and uncertain environments, and some strategies that are difficult to be quantitatively described can be designed based on model-driven RRT, RRT-based improved algorithms still suffer from the problems of difficult to design the hyper-parameters and weak generalization, and in the practical application level, the reliability and accuracy of the hardware such as controllers, actuators, sensors, communication, power supply and data acquisition efficiency all pose challenges to the long-term stability of RRT in large-scale unstructured scenarios. As a part of autonomous robots, the upper limit of RRT path planning performance also depends on the robot localization and scene modeling performance, and there are still architectural and strategic choices in multi-robot collaboration, in addition to the ethics and morality that has to be faced. To address the above issues, I believe that multi-type robot collaboration, human-robot collaboration, real-time path planning, self-tuning of hyper-parameters, task- or application-scene oriented algorithms and hardware design, and path planning in highly dynamic environments are future trends.
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  • 文章类型: Journal Article
    目的:为了研究离心法对表面特性的影响,弯曲性能,和增材制造的义齿基托聚合物的细胞毒性。
    方法:通过数字光处理(DLP)制备测试样品。使用离心法(CENT)除去残留的未固化树脂。此外,样品用不同的后冲洗溶液后处理:异丙醇(IPA),乙醇(EtOH),和三丙二醇单甲醚(TPM),分别。商业热聚合聚甲基丙烯酸甲酯用作参考(REF)。首先,表面形貌的值,算术平均高度(Sa),测量均方根高度(Sq)。接下来,评估弯曲强度(FS)和模量。最后,使用提取物试验评估细胞毒性。数据采用单向方差分析进行统计分析,其次是Tukey的多重比较测试,用于事后分析。
    结果:CENT组的Sa值低于IPA,EtOH,TPM,和REF组(p<0.001)。此外,CENT组的Sq值低于其他组(p<0.001).离心法显示出比EtOH(61.71±12.25MPa,80.92±8.65MPa)更高的FS值(80.92±8.65MPa,p<0.001)和TPM(67.01±9.751MPa,p=0.027),同时影响IPA(72.26±8.80MPa,p=0.268)和REF(71.39±10.44MPa,p=0.231)。此外,离心法无明显细胞毒作用。
    结论:用离心法处理的表面相对光滑。同时,通过离心增强了义齿基托聚合物的弯曲强度。最后,从不同的后处理程序中未观察到明显的细胞毒性作用.
    结论:离心法可以优化DLP印花义齿基托聚合物的表面质量和弯曲强度,而不影响细胞相容性,提供了一个替代传统的冲洗后处理。
    To investigate the impact of a centrifugation method on the surface characteristics, flexural properties, and cytotoxicity of an additively manufactured denture base polymer.
    The tested specimens were prepared by digital light processing (DLP). A centrifugation method (CENT) was used to remove the residual uncured resin. In addition, the specimens were post-processed with different post-rinsing solutions: isopropanol (IPA), ethanol (EtOH), and tripropylene glycol monomethyl ether (TPM), respectively. A commercial heat-polymerized polymethyl methacrylate was used as a reference (REF). First, the values of surface topography, arithmetical mean height (Sa), and root mean square height (Sq) were measured. Next, flexural strength (FS) and modulus were evaluated. Finally, cytotoxicity was assessed using an extract test. The data were statistically analyzed using a one-way analysis of variance, followed by Tukey\'s multiple comparison test for post-hoc analysis.
    The Sa value in the CENT group was lower than in the IPA, EtOH, TPM, and REF groups (p < 0.001). Moreover, the CENT group had lower Sq values than other groups (p < 0.001). The centrifugation method showed a higher FS value (80.92 ± 8.65 MPa) than the EtOH (61.71 ± 12.25 MPa, p < 0.001) and TPM (67.01 ± 9.751 MPa, p = 0.027), while affecting IPA (72.26 ± 8.80 MPa, p = 0.268) and REF (71.39 ± 10.44 MPa, p = 0.231). Also, the centrifugation method showed no evident cytotoxic effects.
    The surfaces treated with a centrifugation method were relatively smooth. Simultaneously, the flexural strength of denture base polymers was enhanced through centrifugation. Finally, no evident cytotoxic effects could be observed from different post-processing procedures.
    The centrifugation method could optimize surface quality and flexural strength of DLP-printed denture base polymers without compromising cytocompatibility, offering an alternative to conventional rinsing post-processing.
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  • 文章类型: Journal Article
    有效的后处理算法对于实现量子密钥分发中的高速率密钥生成至关重要。这项工作通过将三个主要步骤集成到一个统一的过程中,介绍了一种量子密钥分发后处理的方法:基于综合症的错误估计,利率适应性和解,和子块确认。所提出的方案采用低密度奇偶校验码来使用校正子信息估计量子误码率,基于Slepian-Wolf编码方案的速率自适应方法优化信道编码率。此外,该方案在子块确认过程中结合了基于多项式的哈希验证。数值结果表明,基于证候的估计显著提高了估计量子误码率的准确性和一致性,实现有效的码率优化,以实现码率自适应对账。统一的方法,它将速率自适应和解与基于综合征的估计和子块确认相结合,表现出卓越的效率,尽量减少实用信息泄露,减少交流回合,并保证收敛到相同的密钥。此外,仿真表明,在BB84量子密钥分发系统的背景下,该方法的秘密密钥吞吐量达到了理论极限。
    An effective post-processing algorithm is essential for achieving high rates of secret key generation in quantum key distribution. This work introduces an approach to quantum key distribution post-processing by integrating the three main steps into a unified procedure: syndrome-based error estimation, rate-adaptive reconciliation, and subblock confirmation. The proposed scheme employs low-density parity-check codes to estimate the quantum bit error rate using the syndrome information, and to optimize the channel coding rates based on the Slepian-Wolf coding scheme for the rate-adaptive method. Additionally, this scheme incorporates polynomial-based hash verification in the subblock confirmation process. The numerical results show that the syndrome-based estimation significantly enhances the accuracy and consistency of the estimated quantum bit error rate, enabling effective code rate optimization for rate-adaptive reconciliation. The unified approach, which integrates rate-adaptive reconciliation with syndrome-based estimation and subblock confirmation, exhibits superior efficiency, minimizes practical information leakage, reduces communication rounds, and guarantees convergence to the identical key. Furthermore, the simulations indicate that the secret key throughput of this approach achieves the theoretical limit in the context of a BB84 quantum key distribution system.
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  • 文章类型: Journal Article
    本研究旨在通过使用可持续复合材料来提高木塑复合材料选择性激光烧结(SLS)零件的机械强度,花生壳粉(PHP)/聚醚砜(PES)(PHPC)。该研究旨在通过鼓励SLS技术中的此类废物的生态友好利用来解决农业废物污染。为保证烧结质量和力学性能,防止烧结过程中的变形和翘曲,分析了PHP和PES粉末的热物理性能,以确定PHPC的合适预热温度。进行单层烧结测试以评估具有不同PHP粒度的PHPC试样的成形性。研究表明不同PHP粒径对PHPC零件力学性能的影响。评估涵盖PHPCSLS零件的各个方面,包括机械强度,密度,残余灰分含量,尺寸精度(DA),和表面粗糙度,不同的PHP颗粒大小。力学分析表明,以≤0.125mm的PHP颗粒制成的PHPC零件强度最高。具体来说,密度抗弯强度,残余灰分含量,拉伸,和冲击强度测量为1.1825g/cm3,14.1MPa,1.2%,6.076MPa,和2.12kJ/cm2。值得注意的是,蜡渗滤处理后,这些参数均有明显改善。SEM用于检查PHP和PES粉末颗粒,PHPC试样微观结构,和PHPCSLS零件之前和之后的机械测试和打蜡。因此,SEM分析完全证实了力学测试结果。
    This study intends to enhance the mechanical strength of wood-plastic composite selective laser sintering (SLS) parts by using a sustainable composite, peanut husk powder (PHP)/poly ether sulfone (PES) (PHPC). The study aims to address agricultural waste pollution by encouraging the eco-friendly utilization of such waste in SLS technology. To ensure the sintering quality and mechanical properties and prevent deformation and warping during sintering, the thermo-physical properties of PHP and PES powders were analyzed to determine a suitable preheating temperature for PHPC. Single-layer sintering tests were conducted to assess the formability of PHPC specimens with varying PHP particle sizes. The study showed the effects of different PHP particle sizes on the mechanical performance of PHPC parts. The evaluation covered various aspects of PHPC SLS parts, including mechanical strength, density, residual ash content, dimensional accuracy (DA), and surface roughness, with different PHP particle sizes. The mechanical analysis showed that PHPC parts made from PHP particles of ≤0.125 mm were the strongest. Specifically, the density bending strength, residual ash content, tensile, and impact strength were measured as 1.1825 g/cm3, 14.1 MPa, 1.2%, 6.076 MPa, and 2.12 kJ/cm2, respectively. Notably, these parameters showed significant improvement after the wax infiltration treatment. SEM was used to examine the PHP and PES powder particles, PHPC specimen microstructure, and PHPC SLS parts before and after the mechanical tests and waxing. Consequently, SEM analysis wholly confirmed the mechanical test results.
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  • 文章类型: Journal Article
    神经元形态分析是神经元细胞类型定义的重要组成部分。形态学重建是高通量形态学分析工作流程的瓶颈,以及由于密集神经元区域中的噪声和缠结而导致的错误的额外重建限制了自动重建结果的可用性。我们提议SNAP,基于结构的神经元形态学重建修剪管道,通过减少错误的额外重建和分裂纠缠的神经元来提高结果的可用性。
    对于重建中的四种不同类型的错误额外片段(由背景中的噪声引起,与附近神经元的树突纠缠,与其他神经元的轴突纠缠,和同一神经元内的纠缠),SNAP将特定的统计结构信息合并到错误的额外片段检测规则中,并实现了修剪和多个枝晶分裂。
    实验结果表明,该管道以令人满意的精度和召回率实现了修剪。它还展示了良好的多神经元分裂性能。作为后处理重建的有效工具,SNAP可以促进神经元形态分析。
    UNASSIGNED: Neuron morphology analysis is an essential component of neuron cell-type definition. Morphology reconstruction represents a bottleneck in high-throughput morphology analysis workflow, and erroneous extra reconstruction owing to noise and entanglements in dense neuron regions restricts the usability of automated reconstruction results. We propose SNAP, a structure-based neuron morphology reconstruction pruning pipeline, to improve the usability of results by reducing erroneous extra reconstruction and splitting entangled neurons.
    UNASSIGNED: For the four different types of erroneous extra segments in reconstruction (caused by noise in the background, entanglement with dendrites of close-by neurons, entanglement with axons of other neurons, and entanglement within the same neuron), SNAP incorporates specific statistical structure information into rules for erroneous extra segment detection and achieves pruning and multiple dendrite splitting.
    UNASSIGNED: Experimental results show that this pipeline accomplishes pruning with satisfactory precision and recall. It also demonstrates good multiple neuron-splitting performance. As an effective tool for post-processing reconstruction, SNAP can facilitate neuron morphology analysis.
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  • 文章类型: Journal Article
    在绿色低碳时代背景下,高效利用可再生生物质材料是促进生态可持续发展的重要选择之一。因此,3D打印是一种低能耗的先进制造技术,效率高,和易于定制。生物质3D打印技术近年来在材料领域受到越来越多的关注。本文主要综述了六种常见的生物质增材制造3D打印技术,包括熔融长丝制造(FFF),直接墨水书写(DIW),立体光刻外观(SLA),选择性激光烧结(SLS),层压物体制造(LOM)和液体沉积成型(LDM)。对印刷原理进行了系统的总结和详细的讨论,普通材料,技术进步,典型生物质3D打印技术的后处理及相关应用。扩大生物质资源的可获得性,丰富打印技术和推广应用是未来生物质3D打印的主要发展方向。相信丰富的生物质原料与先进的3D打印技术相结合,低碳高效的材料制造业可持续发展之路。
    Under the background of green and low-carbon era, efficiently utilization of renewable biomass materials is one of the important choices to promote ecologically sustainable development. Accordingly, 3D printing is an advanced manufacturing technology with low energy consumption, high efficiency, and easy customization. Biomass 3D printing technology has attracted more and more attentions recently in materials area. This paper mainly reviewed six common 3D printing technologies for biomass additive manufacturing, including Fused Filament Fabrication (FFF), Direct Ink Writing (DIW), Stereo Lithography Appearance (SLA), Selective Laser Sintering (SLS), Laminated Object Manufacturing (LOM) and Liquid Deposition Molding (LDM). A systematic summary and detailed discussion were conducted on the printing principles, common materials, technical progress, post-processing and related applications of typical biomass 3D printing technologies. Expanding the availability of biomass resources, enriching the printing technology and promoting its application was proposed to be the main developing directions of biomass 3D printing in the future. It is believed that the combination of abundant biomass feedstocks and advanced 3D printing technology will provide a green, low-carbon and efficient way for the sustainable development of materials manufacturing industry.
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  • 文章类型: Journal Article
    计算机断层扫描(CT)成像是一种有效的非侵入性检查。它广泛用于骨折的诊断,关节炎,肿瘤,以及患者的一些解剖学特征。密度值(Hounsfield单位,计算机断层扫描中材料的HU)对于具有不同元素组成的材料可以是相同的。该值取决于材料的质量密度和X射线衰减的程度。CT骨吸收测量(CTOAM)成像技术是在CT成像技术的基础上发展起来的。通过对关节表面应用伪彩色图像处理,它用于分析关节软骨下骨矿化的分布,评估假体植入的位置,追踪骨关节炎的进展,并确定关节损伤的预后。此外,该技术与压痕测试相结合,讨论了关节面高骨密度区域之间的关系,骨骼的机械强度,以及植入物的锚固稳定性,除了研究机械强度与骨密度之间的关系。本叙事研究讨论了医疗器械植入位置的术前和术后评估,骨科手术,骨损伤和变性的临床治疗。讨论了CTOAM技术在图像后处理工程中的研究现状以及骨材料与机械强度的关系。
    Computed Tomography (CT) imaging is an effective non-invasive examination. It is widely used in the diagnosis of fractures, arthritis, tumor, and some anatomical characteristics of patients. The density value (Hounsfield unit, HU) of a material in computed tomography can be the same for materials with varying elemental compositions. This value depends on the mass density of the material and the degree of X-ray attenuation. Computed Tomography Osteoabsorptiometry (CTOAM) imaging technology is developed on the basis of CT imaging technology. By applying pseudo-color image processing to the articular surface, it is used to analyze the distribution of bone mineralization under the articular cartilage, evaluate the position of prosthesis implantation, track the progression of osteoarthritis, and determine the joint injury prognosis. Furthermore, this technique was combined with indentation testing to discuss the relationship between the high bone density area of the articular surface, the mechanical strength of the bone, and the anchorage stability of the implant, in addition to the study of the relationship between mechanical strength and bone density. This narrative study discusses the pre- and postoperative evaluation of medical device implantation position, orthopedic surgery, and the clinical treatment of bone injury and degeneration. It also discusses the research status of CTOAM technology in image post-processing engineering and the relationship between bone material and mechanical strength.
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  • 文章类型: Journal Article
    癫痫发作的复发性和不可预测的性质可能导致意外伤害甚至死亡。脑电图(EEG)和人工智能(AI)技术的快速发展使通过脑机接口(BCI)实时预测癫痫发作成为可能,允许先进的干预。迄今为止,脑电图使用机器学习(ML)和深度学习(DL)构建的预测癫痫发作模型仍有很大的改进空间。但是,最关键的问题是如何提高模型的性能和泛化,这涉及到一些令人困惑的概念和方法问题。本文重点分析了影响癫痫发作预测模型性能的几个因素,侧重于后处理方面,癫痫发作发生期(SOP),癫痫发作预测范围(SPH),和算法。此外,本研究为未来建立高性能预测模型提出了一些新的方向和建议。旨在为今后相关领域的研究理清概念,提高预测模型的性能,为今后穿戴式癫痫检测设备的应用提供理论依据。
    The recurrent and unpredictable nature of seizures can lead to unintentional injuries and even death. The rapid development of electroencephalogram (EEG) and Artificial Intelligence (AI) technologies has made it possible to predict seizures in real-time through brain-machine interfaces (BCI), allowing advanced intervention. To date, there is still much room for improvement in predictive seizure models constructed by EEG using machine learning (ML) and deep learning (DL). But, the most critical issue is how to improve the performance and generalization of the model, which involves some confusing conceptual and methodological issues. This review focuses on analyzing several factors affecting the performance of seizure prediction models, focusing on the aspects of post-processing, seizure occurrence period (SOP), seizure prediction horizon (SPH), and algorithms. Furthermore, this study presents some new directions and suggestions for building high-performance prediction models in the future. We aimed to clarify the concept for future research in related fields and improve the performance of prediction models to provide a theoretical basis for future applications of wearable seizure detection devices.
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  • 文章类型: Journal Article
    未经评估:所提出的算法可以支持肺部疾病的准确定位。开发和验证与后处理算法相结合的自动化深度学习模型,以在正电子发射断层扫描/计算机断层扫描(PET/CT)扫描期间采集的胸部计算机断层扫描(CT)图像中分割六个肺解剖区域。肺部区域具有五个肺叶和气道树。
    UNASSIGNED:回顾性纳入接受PET/CT成像和额外胸部CT扫描的患者。CT中六个区域的肺分割是通过DenseVNet架构的卷积神经网络(CNN)和一些后处理算法进行的。三个评价指标用于评估该方法的性能,结合了深度学习和后处理方法。分析了组合模型与测试集中的地面实况分段之间的一致性。
    UNASSIGNED:共纳入640例病例。组合模型,其中涉及深度学习和后处理方法,具有比单一深度学习模型更高的性能。在测试集中,全瓣整体骰子系数,Hausdorff距离,Jaccard系数分别为0.972、12.025mm,和0.948。气道树骰子系数,Hausdorff距离,Jaccard系数分别为0.849,32.076mm,和0.815,分别。在每个情节中,我们的分割之间都观察到了很好的一致性。
    UNASSIGNED:提出的结合两种方法的模型可以在PET/CT中的胸部CT成像上自动分割五个肺叶和气道树。在测试集中的每个区域中,组合模型的性能都高于单个深度学习模型。
    UNASSIGNED: The proposed algorithm could support accurate localization of lung disease. To develop and validate an automated deep learning model combined with a post-processing algorithm to segment six pulmonary anatomical regions in chest computed tomography (CT) images acquired during positron emission tomography/computed tomography (PET/CT) scans. The pulmonary regions have five pulmonary lobes and airway trees.
    UNASSIGNED: Patients who underwent both PET/CT imaging with an extra chest CT scan were retrospectively enrolled. The pulmonary segmentation of six regions in CT was performed via a convolutional neural network (CNN) of DenseVNet architecture with some post-processing algorithms. Three evaluation metrics were used to assess the performance of this method, which combined deep learning and the post-processing method. The agreement between the combined model and ground truth segmentations in the test set was analyzed.
    UNASSIGNED: A total of 640 cases were enrolled. The combined model, which involved deep learning and post-processing methods, had a higher performance than the single deep learning model. In the test set, the all-lobes overall Dice coefficient, Hausdorff distance, and Jaccard coefficient were 0.972, 12.025 mm, and 0.948, respectively. The airway-tree Dice coefficient, Hausdorff distance, and Jaccard coefficient were 0.849, 32.076 mm, and 0.815, respectively. A good agreement was observed between our segmentation in every plot.
    UNASSIGNED: The proposed model combining two methods can automatically segment five pulmonary lobes and airway trees on chest CT imaging in PET/CT. The performance of the combined model was higher than the single deep learning model in each region in the test set.
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