Robustness

鲁棒性
  • 文章类型: Journal Article
    先前对相互依赖网络中的级联故障的研究主要强调了节点的耦合。然而,在实际网络中,交互通常不仅通过节点本身存在,而且还通过链接它们的连接(边缘)存在,一种称为边缘耦合相互依赖网络的配置。过去的研究表明,引入一定比例的加固节点或连接边可以防止灾难性的网络崩溃。然而,边缘耦合相互依存网络中增强层间链接的影响尚未解决。这里,我们通过引入一定比例的增强层间链接,并推导出巨型和有限分量以及渗流相变阈值的详细表达式,开发了一个理论框架,用于研究边缘耦合相互依存网络中的渗流模型。我们发现,存在所需的最小比例的加强层间链接,以防止突然的网络崩溃,作为区分网络不同相变类型的边界。我们为随机和无标度网络提供解析和数值解,证明了所提出的方法与层内链接加固策略相比具有更高的加固效率。理论分析,模拟结果,和实际网络系统验证了我们的模型,并表明引入特定比例的增强层间链接可以防止突然的系统故障并增强边缘耦合的相互依赖网络中的网络鲁棒性。
    Prior research on cascading failures within interdependent networks has predominantly emphasized the coupling of nodes. Nevertheless, in practical networks, interactions often exist not just through the nodes themselves but also via the connections (edges) linking them, a configuration referred to as edge-coupled interdependent networks. Past research has shown that introducing a certain percentage of reinforced nodes or connecting edges can prevent catastrophic network collapses. However, the effect of reinforced inter-layer links in edge-coupled interdependent networks has yet to be addressed. Here, we develop a theoretical framework for studying percolation models in edge-coupled interdependent networks by introducing a proportion of reinforced inter-layer links and deriving detailed expressions for the giant and finite components and the percolation phase transition threshold. We find that there exists a required minimum proportion of the reinforced inter-layer links to prevent abrupt network collapse, which serves as a boundary to distinguish different phase transition types of a network. We provide both analytical and numerical solutions for random and scale-free networks, demonstrating that the proposed method exhibits superior reinforcement efficiency compared to intra-layer link reinforcement strategies. Theoretical analysis, simulation results, and real network systems validate our model and indicate that introducing a specific proportion of reinforced inter-layer links can prevent abrupt system failure and enhance network robustness in edge-coupled interdependent networks.
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  • 文章类型: Journal Article
    本文旨在评估哮喘和非哮喘儿童和青少年的空气污染暴露与第一秒用力呼气量(FEV1)之间的统计关联。其中响应变量FEV1每月重复测量,表征纵向实验。由于数据的性质,鲁棒线性混合模型(RLMM),结合稳健的主成分分析(RPCA),建议处理协变量之间的多重共线性以及极端观测值(高水平的空气污染物)对估计值的影响。考虑Huber和Tukey损失函数以获得线性混合模型(LMM)中参数的鲁棒估计。在协变量遵循线性时间序列模型的情况下,进行了有限的样本量调查,其中有和没有加性异常值(AO)。研究了时间相关性和异常值对LMM中固定效应参数估计的影响。在真实的数据分析中,稳健的模型策略证明,RPCA表现出三个主成分(PC),主要与相对湿度(Hmd)有关,直径小于10μm的颗粒物(PM10)和直径小于2.5μm的颗粒物(PM2.5)。
    This paper aims to evaluate the statistical association between exposure to air pollution and forced expiratory volume in the first second (FEV1) in both asthmatic and non-asthmatic children and teenagers, in which the response variable FEV1 was repeatedly measured on a monthly basis, characterizing a longitudinal experiment. Due to the nature of the data, an robust linear mixed model (RLMM), combined with a robust principal component analysis (RPCA), is proposed to handle the multicollinearity among the covariates and the impact of extreme observations (high levels of air contaminants) on the estimates. The Huber and Tukey loss functions are considered to obtain robust estimators of the parameters in the linear mixed model (LMM). A finite sample size investigation is conducted under the scenario where the covariates follow linear time series models with and without additive outliers (AO). The impact of the time-correlation and the outliers on the estimates of the fixed effect parameters in the LMM is investigated. In the real data analysis, the robust model strategy evidenced that RPCA exhibits three principal component (PC), mainly related to relative humidity (Hmd), particulate matter with a diameter smaller than 10 μm (PM10) and particulate matter with a diameter smaller than 2.5 μm (PM2.5).
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  • 文章类型: Journal Article
    MR引导的放射治疗增加了磁共振成像(MRI)的精度,使线性加速器的治疗益处。在每次治疗之前,MRI可以生成大量的成像数据以供分析。影像组学站在医学成像和肿瘤学研究的最前沿,致力于挖掘定量成像属性以伪造预测模型。然而,这些模型的鲁棒性经常受到挑战。
    为了评估特征提取的鲁棒性,我们使用0.35TMR直线加速器系统进行了可重复性研究,同时使用专门的体模和患者衍生的图像,关注胰腺癌病例。我们提取了基于形状的,来自患者衍生图像的一阶和纹理特征,以及来自幻影衍生图像的仅一阶和纹理特征。还通过等效性测试评估了模拟和第一部分图像之间的延迟的影响。
    从评估的107个功能中,58(54%)被认为是不可再现的:18在体模和患者图像中一致不一致,9个特定于基于幻影的分析,和31到患者派生的数据。
    我们的发现表明,从该双重数据集中提取的显着比例的放射学特征是不可靠的。至关重要的是丢弃这些不可重复的元素,以完善和增强放射学模型的开发,特别是对于胰腺癌的MR引导放疗。
    UNASSIGNED: MR-guided radiotherapy adds the precision of magnetic resonance imaging (MRI) to the therapeutic benefits of a linear accelerator. Prior to each therapeutic session, an MRI generates a significant volume of imaging data ripe for analysis. Radiomics stands at the forefront of medical imaging and oncology research, dedicated to mining quantitative imaging attributes to forge predictive models. However, the robustness of these models is often challenged.
    UNASSIGNED: To assess the robustness of feature extraction, we conducted reproducibility studies using a 0.35 T MR-linac system, employing both a specialized phantom and patient-derived images, focusing on cases of pancreatic cancer. We extracted shape-based, first-order and textural features from patient-derived images and only first-order and textural features from phantom-derived images. The impact of the delay between simulation and first fraction images was also assessed with an equivalence test.
    UNASSIGNED: From 107 features evaluated, 58 (54 %) were considered as non-reproducible: 18 were uniformly inconsistent across both phantom and patient images, 9 were specific to phantom-based analysis, and 31 to patient-derived data.
    UNASSIGNED: Our findings show that a significant proportion of radiomic features extracted from this dual dataset were unreliable. It is essential to discard these non-reproducible elements to refine and enhance radiomic model development, particularly for MR-guided radiotherapy in pancreatic cancer.
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  • 文章类型: Journal Article
    研究U-Net模型在医学图像合成中对对抗扰动的鲁棒性,这项研究介绍了RobMedNAS,一种用于识别弹性U-Net配置的神经架构搜索策略。通过对MRI合成CT数据的回顾性分析,在关键解剖区域采用骰子系数和平均绝对误差度量,该研究评估了传统的U-Net模型和对抗攻击下的RobMedNAS优化模型。研究结果表明,RobMedNAS在不影响准确性的情况下增强U-Net弹性的功效,提出了一种鲁棒医学图像处理的新途径。 .
    Investigating U-Net model robustness in medical image synthesis against adversarial perturbations, this study introduces RobMedNAS, a neural architecture search strategy for identifying resilient U-Net configurations. Through retrospective analysis of synthesized CT from MRI data, employing Dice coefficient and mean absolute error metrics across critical anatomical areas, the study evaluates traditional U-Net models and RobMedNAS-optimized models under adversarial attacks. Findings demonstrate RobMedNAS\'s efficacy in enhancing U-Net resilience without compromising on accuracy, proposing a novel pathway for robust medical image processing.
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  • 文章类型: Journal Article
    基于非刚性表面的软组织配准对于手术导航系统至关重要,但是由于大量的自由度以及术中数据中存在的连续变化和复杂的表面结构,因此其采用仍然面临着一些挑战。通过采用非严格的注册,外科医生可以将术前图像整合到术中指导环境中,在共同的坐标系中提供患者复杂的术前和术中解剖结构的实时可视化,以提高导航精度。然而,许多现有的注册方法,包括肝脏应用,更广泛的社区无法进入。为了解决这个限制,我们对几种开源软件进行了比较分析,基于非刚性表面的肝脏配准算法,总体目标是对比他们的优势和劣势,并确定最佳解决方案。我们比较了三种基于优化和一种数据驱动的非刚性配准算法的鲁棒性,以响应降低的可见性比率(减少的表面部分视图)和增加的变形水平(平均位移),报告为术前和术中肝表面之间的均方根误差(RMSE)。我们的结果表明,高斯混合模型-有限元模型(GMM-FEM)方法在可见性比率降低和术中表面位移增加的情况下,始终比其他三种测试方法产生更低的配准后误差。因此为术前非刚性肝脏表面配准提供了一个潜在的有希望的解决方案。
    Non-rigid surface-based soft tissue registration is crucial for surgical navigation systems, but its adoption still faces several challenges due to the large number of degrees of freedom and the continuously varying and complex surface structures present in the intra-operative data. By employing non-rigid registration, surgeons can integrate the pre-operative images into the intra-operative guidance environment, providing real-time visualization of the patient\'s complex pre- and intra-operative anatomy in a common coordinate system to improve navigation accuracy. However, many of the existing registration methods, including those for liver applications, are inaccessible to the broader community. To address this limitation, we present a comparative analysis of several open-source, non-rigid surface-based liver registration algorithms, with the overall goal of contrasting their strength and weaknesses and identifying an optimal solution. We compared the robustness of three optimization-based and one data-driven nonrigid registration algorithms in response to a reduced visibility ratio (reduced partial views of the surface) and to an increasing deformation level (mean displacement), reported as the root mean square error (RMSE) between the pre-and intra-operative liver surface meshed following registration. Our results indicate that the Gaussian Mixture Model - Finite Element Model (GMM-FEM) method consistently yields a lower post-registration error than the other three tested methods in the presence of both reduced visibility ratio and increased intra-operative surface displacement, therefore offering a potentially promising solution for pre- to intra-operative nonrigid liver surface registration.
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  • 文章类型: Journal Article
    现代神经网络对随机噪声和蓄意攻击的脆弱性引起了人们对其鲁棒性的担忧,特别是它们越来越多地用于安全和安全关键应用。尽管最近的研究努力通过对抗性示例的重新训练或采用数据增强技术来增强鲁棒性,对训练数据扰动对模型鲁棒性的影响的全面研究仍然缺乏。本文提出了第一个广泛的实证研究,调查了模型再训练过程中数据扰动的影响。实验分析侧重于随机和对抗鲁棒性,遵循稳健性分析领域的既定做法。探索了数据集不同方面的各种类型的扰动,包括输入,标签,和抽样分布。进行单因素和多因素实验来评估个体扰动及其组合。这些发现为构建高质量的训练数据集提供了见解,以优化鲁棒性,并推荐适当程度的训练集扰动,以平衡鲁棒性和正确性,并有助于理解深度学习中的模型鲁棒性,并为通过扰动再训练增强模型性能提供实践指导,促进为安全关键型应用开发更可靠、更值得信赖的深度学习系统。
    The vulnerability of modern neural networks to random noise and deliberate attacks has raised concerns about their robustness, particularly as they are increasingly utilized in safety- and security-critical applications. Although recent research efforts were made to enhance robustness through retraining with adversarial examples or employing data augmentation techniques, a comprehensive investigation into the effects of training data perturbations on model robustness remains lacking. This paper presents the first extensive empirical study investigating the influence of data perturbations during model retraining. The experimental analysis focuses on both random and adversarial robustness, following established practices in the field of robustness analysis. Various types of perturbations in different aspects of the dataset are explored, including input, label, and sampling distribution. Single-factor and multi-factor experiments are conducted to assess individual perturbations and their combinations. The findings provide insights into constructing high-quality training datasets for optimizing robustness and recommend the appropriate degree of training set perturbations that balance robustness and correctness, and contribute to understanding model robustness in deep learning and offer practical guidance for enhancing model performance through perturbed retraining, promoting the development of more reliable and trustworthy deep learning systems for safety-critical applications.
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  • 文章类型: Journal Article
    反向着色为探索管道化的分子机制提供了机会。在这项研究中,在乳草虫的配相着色中探索了表观遗传调控潜在稳健性的作用,筋膜盘。Polycomb(Pc)和zeste增强剂(E(z)),分别编码Polycomb抑制复合物1(PRC1)和PRC2的成分,而京,它编码PRC2.2亚复合物的一个组成部分,被击倒在O.fasciatus的第四龄。这些基因的敲除导致小脑形态和黑化的改变。特别是,当PC被撞倒时,成年人的腹部高度黑化,头部和前爪在所有温度检查。相比之下,在不同温度下,E(z)和jing击倒导致背前黑化的可塑性增加。此外,精敲成虫在头部和胸部的背侧黑化表现出增加的可塑性。这些观察结果表明,组蛋白修饰剂可能在管道化过程中起关键作用,以赋予配相着色的鲁棒性。
    Aposematic coloration offers an opportunity to explore the molecular mechanisms underlying canalization. In this study, the role of epigenetic regulation underlying robustness was explored in the aposematic coloration of the milkweed bug, Oncopeltus fasciatus. Polycomb (Pc) and Enhancer of zeste (E(z)), which encode components of the Polycomb repressive complex 1 (PRC1) and PRC2, respectively, and jing, which encodes a component of the PRC2.2 subcomplex, were knocked down in the fourth instar of O. fasciatus. Knockdown of these genes led to alterations in scutellar morphology and melanization. In particular, when Pc was knocked down, the adults developed a highly melanized abdomen, head and forewings at all temperatures examined. In contrast, the E(z) and jing knockdown led to increased plasticity of the dorsal forewing melanization across different temperatures. Moreover, jing knockdown adults exhibited increased plasticity in the dorsal melanization of the head and the thorax. These observations demonstrate that histone modifiers may play a key role during the process of canalization to confer robustness in the aposematic coloration.
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  • 文章类型: Journal Article
    锁定的视野计划可以使左乳腺癌的心脏和肺器官剂量。
    本研究的目的是比较左侧乳腺癌调强放疗中场锁定和场分裂计划之间的剂量学差异,为了探索场锁定对低剂量区的影响,并评估其对放射治疗目标的鲁棒性,为临床放疗方案的选择提供参考。
    共选择了30例左乳癌根治术后的患者,并制定了7场锁定场和分裂场计划,以比较目标区域和每个危险器官之间的剂量差异(ΔD),并在六个方向上引入3、5和7毫米的偏移量,并重新计算扰动的剂量分布,并根据计划的鲁棒性比较原始计划和扰动计划之间的ΔD。
    结果显示,D98%,两种计划的计划目标体积(PTV)的D95%和D平均值差异不大,没有统计学差异。锁定的野外计划为左肺提供了更好的保护,右肺,心,右乳和左冠状动脉前降支。对于PTVΔD98%,PTVΔD95%,PTVΔDmean,锁定字段计划的ΔD较高,对于LungLΔ5、LungLΔ20和心脏Δ平均值,与原计划相比,ΔD较高。
    得出的结论是,磁场锁定计划可以减少受影响肺的低剂量区域,并为其余的关键器官提供更好的保护,并且现场锁定计划在保护关键器官方面更加强大。同时,现场锁定计划对目标PTV的位置偏差显示出更高的敏感性。
    UNASSIGNED: The locked vision plan can make the left breast cancer heart and lung organs dose.
    UNASSIGNED: The aim of the present study was to compare the dosimetric differences between field-locked and field-split plans in intensity-modulated radiotherapy for left-sided breast cancer, to explore the effect of field-locking on the low-dose region, and to evaluate its robustness to the radiotherapy target, in order to provide a reference for the selection of clinical radiotherapy protocols.
    UNASSIGNED: A total of 30 patients were selected after radical left breast cancer surgery, and 7-field locked-field and split-field plans were developed to compare the dose difference (∆D) between the target area and each organ at risk, and to introduce offsets of 3, 5 and 7 mm in six directions and recalculate the perturbed dose distributions, and to compare the ∆D between the original and the perturbed plans according to the robustness of the plans.
    UNASSIGNED: The results revealed that the D98%, D95% and Dmean values of the planning target volume (PTV) of the two plans differed little and were not statistically different. The locked field plan provided better protection for the left lung, right lung, heart, right breast and left anterior descending coronary artery. For PTV∆D98%, PTV∆D95%, PTV∆Dmean, the ∆D was higher for the Locked Fields plan, and for LungL∆5, LungL∆20 and Heart∆mean, the ∆D was higher for the original plan.
    UNASSIGNED: It was concluded that the field-locking plan could reduce the low-dose area of the affected lung and provide improved protection to the remaining critical organs, and the field-locking plan was more robust in protecting critical organs. Meanwhile, the field-locking plan showed higher sensitivity to positional deviation for target PTV.
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  • 文章类型: Journal Article
    我们最近揭示了各种蛋白质组学设施中蛋白质电晕表征的显着变异性,这表明独立研究之间的数据集没有可比性。这种异质性主要来自样品制备方案的差异,质谱工作流程,和原始数据处理。为了解决这个问题,我们制定了标准化的协议和统一的样品制备工作流程,从我们之前的研究中,将均匀的蛋白质电晕消化物分配到几个表现最好的蛋白质组学中心。我们还研究了使用类似的质谱仪器对数据均匀性,标准化的数据库搜索参数和数据处理工作流程的影响。我们的发现揭示了蛋白质电晕数据均匀性的显着逐步改善,使用类似的仪器和通过统一的数据库搜索,在不同的设施中,蛋白质鉴定的重叠度从11%增加到40%。我们确定了数据异质性背后的关键参数,并为设计实验提供了建议。我们的发现将显着提高蛋白质电晕分析在诊断和治疗应用中的稳健性。
    We recently revealed significant variability in protein corona characterization across various proteomics facilities, indicating that data sets are not comparable between independent studies. This heterogeneity mainly arises from differences in sample preparation protocols, mass spectrometry workflows, and raw data processing. To address this issue, we developed standardized protocols and unified sample preparation workflows, distributing uniform protein corona digests to several top-performing proteomics centers from our previous study. We also examined the influence of using similar mass spectrometry instruments on data homogeneity and standardized database search parameters and data processing workflows. Our findings reveal a remarkable stepwise improvement in protein corona data uniformity, increasing overlaps in protein identification from 11% to 40% across facilities using similar instruments and through a uniform database search. We identify the key parameters behind data heterogeneity and provide recommendations for designing experiments. Our findings should significantly advance the robustness of protein corona analysis for diagnostic and therapeutics applications.
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  • 文章类型: Journal Article
    效力测定的快速发展对于挽救生命的疫苗的发展至关重要。传统的噬斑测定或百分之五十的组织培养感染剂量(TCID50)测定用于测量活病毒疫苗的效力是耗时的,劳动密集型,低吞吐量和高可变性。这里描述的是两种呼吸道病毒感染疫苗的基于细胞的报告效力测定的开发和鉴定,一种基于重组水泡性口炎病毒(rVSV)骨架,在本文中称为疫苗1,另一个基于麻疹病毒媒介,称为疫苗2。报告效力测定使用经过改造以组成型表达NanuLuc®荧光素酶的VeroE6细胞系,称为VeroE6-NLuc或JM-1细胞系。活病毒感染JM-1细胞,如rVSV或麻疹病毒,引起细胞病变效应(CPE)并将NanuLuc®从细胞质释放到上清液中,其数量反映了病毒感染的强度。通过在对数-对数线性模型中使用平行线分析(PLA)与参考标准进行比较来计算相对效力。报告分析显示出良好的线性,准确度,和精度,因此适用于疫苗效力测定。对疫苗1报告物测定的进一步评估证明了对所选择的测定参数的一系列故意变化以及与噬斑测定的相关性的稳健性。总之,我们已经证明,使用JM-1细胞系的报告基因试验可用作支持多种活病毒疫苗生产和释放的效价试验.
    The rapid development of potency assays is critical in the development of life-saving vaccines. The traditional plaque assay or fifty percent tissue culture infectious dose (TCID50) assay used to measure the potency of live virus vaccines is time consuming, labor intensive, low throughput and with high variability. Described here is the development and qualification of a cell-based reporter potency assay for two vaccines for respiratory viral infection, one based on the recombinant vesicular stomatitis virus (rVSV) backbone, termed Vaccine 1 in this paper, and the other based on the measles virus vector, termed Vaccine 2. The reporter potency assay used a Vero E6 cell line engineered to constitutively express NanuLuc® luciferase, termed the VeroE6-NLuc or JM-1 cell line. Infection of JM-1 cells by a live virus, such as rVSV or measles virus, causes a cytopathic effect (CPE) and release of NanuLuc® from the cytoplasm into the supernatant, the amount of which reflects the intensity of the viral infection. The relative potency was calculated by comparison to a reference standard using parallel line analysis (PLA) in a log-log linear model. The reporter assay demonstrated good linearity, accuracy, and precision, and is therefore suitable for a vaccine potency assay. Further evaluation of the Vaccine 1 reporter assay demonstrated the robustness to a range of deliberate variation of the selected assay parameters and correlation with the plaque assay. In conclusion, we have demonstrated that the reporter assay using the JM-1 cell line could be used as a potency assay to support the manufacturing and release of multiple live virus vaccines.
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