Normal Distribution

正态分布
  • 文章类型: Journal Article
    在这篇文章中,我们开发了一种基于指数加权移动平均(EWMA)统计量的新控制图,称为新的扩展指数加权移动平均(NEEWMA)统计量,旨在识别过程中的轻微变化。我们推导了NEEWMA统计量的均值和方差的表达式,确保对均值的无偏估计,与传统的EWMA图相比,模拟结果显示出更低的方差。使用平均运行长度(ARL)评估其性能,我们的分析表明,NEEWMA控制图在快速识别过程均值的变化方面优于EWMA和扩展EWMA(EEWMA)图。通过蒙特卡罗模拟说明其操作方法,还提供了一个使用实际数据的说明性示例来展示其有效性。
    In this article, we develop a new control chart based on the Exponentially Weighted Moving Average (EWMA) statistic, termed the New Extended Exponentially Weighted Moving Average (NEEWMA) statistic, designed to recognize slight changes in the process mean. We derive expressions for the mean and variance of the NEEWMA statistic, ensuring an unbiased estimation of the mean, with simulation results showing lower variance compared to traditional EWMA charts. Evaluating its performance using Average Run Length (ARL), our analysis reveals that the NEEWMA control chart outperforms EWMA and Extended EWMA (EEWMA) charts in swiftly recognizing shifts in the process mean. Illustrating its operational methodology through Monte Carlo simulations, an illustrative example using practical data is also provided to showcase its effectiveness.
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  • 文章类型: Journal Article
    HGSHS:A是最常用的催眠暗示指标之一。然而,由于时间要求超过1小时,该测试的可行性较低,来自正常人口的可疑代表。最近,开发并发布了HGSHS-5:G的简短版本,现在第一个结果是可用的。这项调查的范围是验证同等位置和正态分布分数的假设,在许多不同的研究中,使用HGSHS的完整或简短版本,并将11项得分与5项得分的结果进行比较,后者是从完整版本或短版本测试中计算的。
    分析了21项HGSHS测试研究的数据,15使用HGSHS:完整版,6使用HGSHS-5:G短版,共2529个数据集。测试了11项得分和5项得分的位置和分布。线性回归分析用于比较两个得分,以及交叉表和加权科恩的kappa,以确定分组为低暗示性和高暗示性的匹配。为了评估研究结果中观察到的差异的影响因素,进行了多因素方差分析.
    在不同的研究中,分数的位置和分布,以及低暗示和高暗示的团体规模,varieted.发现所有得分分布均为非正态,并从中间得分向右移动;11项得分的变化更为广泛。从完整版测试计算的两个分数之间的相关性是中等的(R2=0.69),暗示性分组的匹配也是如此(κ=0.58)。使用涉及较少学生为主的人群的简短版本的研究显示出与完整版本的一致性,但较低的分数是由零分数的增加引起的。
    在HGSHS的大多数应用中都不代表正常人群,分为低和高暗示性不同,主要是由于分数分布的位置不同。在同一受试者中测试的HGSHS的完整和简短版本的直接比较仍然缺失。
    UNASSIGNED: The HGSHS:A is one of the most commonly used measures of hypnotic suggestibility. However, this test suffers from low feasibility due to a time requirement exceeding 1 h, and from a questionable representation of the normal population. Recently, a short version of HGSHS-5:G was developed and published, and now the first results are available. The scope of this investigation was to verify the assumption of equally positioned and normally distributed scores, resulting in equally sized suggestibility groups in a number of different studies with full or short versions of HGSHS, and to compare the results of the 11-item score with the 5-item score, the latter being calculated from either the full version or the short version test.
    UNASSIGNED: Data from 21 studies with testing for HGSHS were analyzed, 15 using the HGSHS:A full version and six using the HGSHS-5:G short version, for a total of 2,529 data sets. Position and distribution of both the 11-item score and the 5-item score were tested. Linear regression analysis was used to compare the two scores, as well as cross-table and weighted Cohen\'s kappa to determine the match of grouping into low and high suggestibility. To evaluate contributing factors to the observed differences in the study results, a multifactorial analysis of variance was performed.
    UNASSIGNED: In the different studies, position and distribution of scores, as well as group sizes for low and high suggestibles, varied. All score distributions were found to be non-normal and shifted to the right from the middle score; the shift was more extensive with the 11-item score. The correlation between both scores calculated from full version tests was moderate (R 2 = 0.69), as was the match of suggestibility grouping (κ = 0.58). Studies using the short version involving less student-dominated populations showed sufficient agreement with the full version, but lower scores were caused by an increase in the zero score.
    UNASSIGNED: A normal population is not represented in most applications of HGSHS, and grouping into low and high suggestibles varies, mainly due to different positions of score distributions. A direct comparison of full and short versions of HGSHS tested in the same subjects is still missing.
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  • 文章类型: Journal Article
    抑制MDM2-p53相互作用被认为是癌症治疗的有效模式。在我们目前的研究中,高斯加速分子动力学(GaMD),深度学习(DL),和结合自由能计算组合在一起以探测非肽抑制剂K23和0Y7以及肽抑制剂PDI6W和PDI与MDM2的结合机制。基于GaMD轨迹的DL方法成功识别了重要的功能域,主要位于螺旋α2和α2',以及α2和α2之间的β链和环。GaMD模拟的后处理分析表明,抑制剂结合会高度影响MDM2的结构灵活性和集体运动。分子力学广义Born表面积(MM-GBSA)和溶剂化相互作用能(SIE)的计算不仅表明计算的束缚自由能的排序与实验结果一致,但也验证了vanderWalls相互作用是导致抑制剂-MDM2结合的主要力量。我们的发现还表明,与非肽抑制剂相比,肽抑制剂与MDM2产生更多的相互作用接触。主成分分析(PCA)和自由能景观(FEL)分析表明,哌啶酮抑制剂0Y7对MDM2的自由能曲线显示出最明显的影响,哌啶酮抑制剂沿主要特征向量显示出更高的波动幅度。通过基于残基的自由能估计揭示的MDM2的热点为针对MDM2的药物设计提供了目标位点。这项研究有望为开发MDM2家族成员的选择性抑制剂提供有用的理论帮助。
    Inhibiting MDM2-p53 interaction is considered an efficient mode of cancer treatment. In our current study, Gaussian-accelerated molecular dynamics (GaMD), deep learning (DL), and binding free energy calculations were combined together to probe the binding mechanism of non-peptide inhibitors K23 and 0Y7 and peptide ones PDI6W and PDI to MDM2. The GaMD trajectory-based DL approach successfully identified significant functional domains, predominantly located at the helixes α2 and α2\', as well as the β-strands and loops between α2 and α2\'. The post-processing analysis of the GaMD simulations indicated that inhibitor binding highly influences the structural flexibility and collective motions of MDM2. Calculations of molecular mechanics-generalized Born surface area (MM-GBSA) and solvated interaction energy (SIE) not only suggest that the ranking of the calculated binding free energies is in agreement with that of the experimental results, but also verify that van der Walls interactions are the primary forces responsible for inhibitor-MDM2 binding. Our findings also indicate that peptide inhibitors yield more interaction contacts with MDM2 compared to non-peptide inhibitors. Principal component analysis (PCA) and free energy landscape (FEL) analysis indicated that the piperidinone inhibitor 0Y7 shows the most pronounced impact on the free energy profiles of MDM2, with the piperidinone inhibitor demonstrating higher fluctuation amplitudes along primary eigenvectors. The hot spots of MDM2 revealed by residue-based free energy estimation provide target sites for drug design toward MDM2. This study is expected to provide useful theoretical aid for the development of selective inhibitors of MDM2 family members.
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  • 文章类型: Journal Article
    预测蛋白质-肽相互作用对于理解肽结合过程和设计肽药物至关重要。然而,传统的计算建模方法在准确预测肽-蛋白质结合结构方面面临挑战,因为肽的缓慢动力学和高度灵活性。这里,我们引入了一种新的工作流程,称为“PepBinding”,用于预测肽结合结构,结合了肽对接,使用肽高斯加速分子动力学(Pep-GaMD)方法的全原子增强采样模拟,和结构聚类。已经在7种不同的模型肽上证明了肽结合。在使用HPEPDOCK的肽对接中,其结合构象相对于X射线结构的肽骨架均方根偏差(RMSD)范围为3.8至16.0。根据关键的相互作用预测评估(CAPRI)标准,对应于中等到不准确的质量模型。仅执行200ns的Pep-GaMD模拟显着改善了对接模型,产生五个中等和两个可接受的质量模型。因此,PepBinding是预测肽结合结构的有效工作流程,可在https://github.com/MiaoLab20/PepBinding上公开获得。
    Predicting protein-peptide interactions is crucial for understanding peptide binding processes and designing peptide drugs. However, traditional computational modeling approaches face challenges in accurately predicting peptide-protein binding structures due to the slow dynamics and high flexibility of the peptides. Here, we introduce a new workflow termed \"PepBinding\" for predicting peptide binding structures, which combines peptide docking, all-atom enhanced sampling simulations using the Peptide Gaussian accelerated Molecular Dynamics (Pep-GaMD) method, and structural clustering. PepBinding has been demonstrated on seven distinct model peptides. In peptide docking using HPEPDOCK, the peptide backbone root-mean-square deviations (RMSDs) of their bound conformations relative to X-ray structures ranged from 3.8 to 16.0 Å, corresponding to the medium to inaccurate quality models according to the Critical Assessment of PRediction of Interactions (CAPRI) criteria. The Pep-GaMD simulations performed for only 200 ns significantly improved the docking models, resulting in five medium and two acceptable quality models. Therefore, PepBinding is an efficient workflow for predicting peptide binding structures and is publicly available at https://github.com/MiaoLab20/PepBinding.
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  • 文章类型: Journal Article
    控制疾病传播的动力学很难建模,因为感染是潜在病原体以及人类或动物行为的功能。当建模疾病如何在不同空间位置之间传播时,这一挑战就增加了。许多提出的空间流行病学模型需要权衡取舍才能适应,要么通过抽象理论传播动力学,拟合确定性模型,或需要大量的计算资源进行许多模拟。我们提出了一种用高斯过程近似复杂空间扩展动力学的方法。我们首先提出了对众所周知的SIR随机过程的灵活空间扩展,然后我们推导出这个随机过程的矩闭包近似。这种矩闭合近似产生了常微分方程,用于随时间变化的易感性和传染性的均值和协方差的演化。因为这些ODE是MCMC拟合我们模型的瓶颈,我们使用低等级模拟器来近似它们。这种近似作为我们的嘈杂分层模型的基础,按空间位置和时间漏报的新感染计数。我们展示了使用我们的模型对来自底层的模拟感染进行推断,真正的空间SIR跳跃过程。然后,我们将我们的方法应用于2015年底至2016年初巴西新寨卡病毒感染的模型计数。
    The dynamics that govern disease spread are hard to model because infections are functions of both the underlying pathogen as well as human or animal behavior. This challenge is increased when modeling how diseases spread between different spatial locations. Many proposed spatial epidemiological models require trade-offs to fit, either by abstracting away theoretical spread dynamics, fitting a deterministic model, or by requiring large computational resources for many simulations. We propose an approach that approximates the complex spatial spread dynamics with a Gaussian process. We first propose a flexible spatial extension to the well-known SIR stochastic process, and then we derive a moment-closure approximation to this stochastic process. This moment-closure approximation yields ordinary differential equations for the evolution of the means and covariances of the susceptibles and infectious through time. Because these ODEs are a bottleneck to fitting our model by MCMC, we approximate them using a low-rank emulator. This approximation serves as the basis for our hierarchical model for noisy, underreported counts of new infections by spatial location and time. We demonstrate using our model to conduct inference on simulated infections from the underlying, true spatial SIR jump process. We then apply our method to model counts of new Zika infections in Brazil from late 2015 through early 2016.
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  • 文章类型: Journal Article
    神经活动的降维通过将内部神经模式再激活的测量与外部变量调节的测量分离,为无监督神经解码铺平了道路。仅假设潜在动力学和内部调谐曲线的光滑度,泊松高斯过程潜变量模型(P-GPLVM;Wu等人。,2017)是发现高维尖峰列车的低维潜在结构的强大工具。然而,当给出新的神经数据时,原始模型缺乏一种方法来推断他们在学习的潜在空间中的潜在轨迹,限制了其估计神经再激活的能力。这里,我们扩展了P-GPLVM,以实现受先前学习的平滑度和映射信息约束的新数据的潜在变量推断。我们还描述了一种用于时间压缩活动模式的约束潜在变量推断的原则性方法,例如在海马锐波波纹期间的人口爆发事件中发现的,以及评估神经模式再激活有效性和推断编码经验的指标。在主动迷宫探索过程中,将这些方法应用于海马合奏记录,我们复制了P-GPLVM学习编码动物位置的潜在空间的结果。我们进一步证明了这个潜在空间可以区分一个迷宫上下文。通过推断跑步过程中新神经数据的潜在变量,观察到某些神经模式会重新激活,根据训练数据流形中附近神经轨迹编码的经验的相似性。最后,神经模式的再激活也可以估计在人口爆发事件期间的神经活动,允许识别通用行为和更一般体验的重放事件。因此,我们对神经活动无监督分析的P-GPLVM框架的扩展可用于回答与科学发现相关的关键问题.
    Dimension reduction on neural activity paves a way for unsupervised neural decoding by dissociating the measurement of internal neural pattern reactivation from the measurement of external variable tuning. With assumptions only on the smoothness of latent dynamics and of internal tuning curves, the Poisson gaussian-process latent variable model (P-GPLVM; Wu et al., 2017) is a powerful tool to discover the low-dimensional latent structure for high-dimensional spike trains. However, when given novel neural data, the original model lacks a method to infer their latent trajectories in the learned latent space, limiting its ability for estimating the neural reactivation. Here, we extend the P-GPLVM to enable the latent variable inference of new data constrained by previously learned smoothness and mapping information. We also describe a principled approach for the constrained latent variable inference for temporally compressed patterns of activity, such as those found in population burst events during hippocampal sharp-wave ripples, as well as metrics for assessing the validity of neural pattern reactivation and inferring the encoded experience. Applying these approaches to hippocampal ensemble recordings during active maze exploration, we replicate the result that P-GPLVM learns a latent space encoding the animal\'s position. We further demonstrate that this latent space can differentiate one maze context from another. By inferring the latent variables of new neural data during running, certain neural patterns are observed to reactivate, in accordance with the similarity of experiences encoded by its nearby neural trajectories in the training data manifold. Finally, reactivation of neural patterns can be estimated for neural activity during population burst events as well, allowing the identification for replay events of versatile behaviors and more general experiences. Thus, our extension of the P-GPLVM framework for unsupervised analysis of neural activity can be used to answer critical questions related to scientific discovery.
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  • 文章类型: Journal Article
    乳腺标本中的浸润性导管癌(IDC)已在象限乳腺区域中检测到:(I)上外侧,(二)上部内侧,(III)下部内部,和(IV)通过高斯弛豫时间分布(EIT-GRTD)实现的电阻抗层析成像的较低外部区域。EIT-GRTD包括两个步骤,即1)最佳频率选择和2)乳房成像重建的时间常数增强。以弛豫时间分布函数γ的多数测量对中的峰值为特征的foptis,这表明IDC的存在。γ表示电导率的倒数并且基于Voigt电路模型指示乳房组织对跨变化频率的电流的响应。EIT-GRTD通过使用模拟乳房的半球容器的多物理场模拟进行定量评估,由IDC和脂肪组织组成,作为正常乳腺组织,在一种情况下,已知IDC位于象限乳腺区域II。仿真结果表明,EIT-GRTD能够在fopt=30,170Hz的情况下检测四层IDC。通过使用来自IDC患者的六个乳房切除术标本将EIT-GRTD应用于真实乳房。将乳房切除术标本放置在半球容器中是象限乳房区域重建成功的重要因素。为了进行评估,将EIT-GRTD重建图像与CT扫描图像进行比较。实验结果表明,EIS-GRTD在与CT扫描图像进行定性比较时,可以熟练地检测象限乳腺区域的IDC。
    Invasive ductal carcinoma (IDC) in breast specimens has been detected in the quadrant breast area: (I) upper outer, (II) upper inner, (III) lower inner, and (IV) lower outer areas by electrical impedance tomography implemented with Gaussian relaxation-time distribution (EIT-GRTD). The EIT-GRTD consists of two steps which are (1) the optimum frequencyfoptselection and (2) the time constant enhancement of breast imaging reconstruction.foptis characterized by a peak in the majority measurement pair of the relaxation-time distribution functionγ,which indicates the presence of IDC.γrepresents the inverse of conductivity and indicates the response of breast tissues to electrical currents across varying frequencies based on the Voigt circuit model. The EIT-GRTD is quantitatively evaluated by multi-physics simulations using a hemisphere container of mimic breast, consisting of IDC and adipose tissues as normal breast tissue under one condition with known IDC in quadrant breast area II. The simulation results show that EIT-GRTD is able to detect the IDC in four layers atfopt= 30, 170 Hz. EIT-GRTD is applied in the real breast by employed six mastectomy specimens from IDC patients. The placement of the mastectomy specimens in a hemisphere container is an important factor in the success of quadrant breast area reconstruction. In order to perform the evaluation, EIT-GRTD reconstruction images are compared to the CT scan images. The experimental results demonstrate that EIS-GRTD exhibits proficiency in the detection of the IDC in quadrant breast areas while compared qualitatively to CT scan images.
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  • 文章类型: Journal Article
    Cook等人提出的响应包络模型。(2010)是在多元线性回归模型的背景下估计回归系数的有效方法。它通过识别响应的实质性和非实质性部分并消除非实质性变化来提高估计效率。仅针对连续响应变量研究了响应包络模型。在本文中,我们提出了具有潜在包络的多元概率模型,简而言之,probit包络模型,作为多元二元响应变量的响应包络模型。probit包络模型利用响应包络模型的思想,考虑了多变量probit模型的高斯潜变量之间的关系。我们通过采用基本的可识别性概念来解决probit包络模型的可识别性,并提出了一种用于参数估计的贝叶斯方法。我们通过仿真研究和实际数据分析来说明概率包络模型。仿真研究表明,与多变量probit模型相比,probit包络模型具有提高估计效率的潜力。实际数据分析表明,probit包络模型对于多标签分类是有用的。
    The response envelope model proposed by Cook et al. (2010) is an efficient method to estimate the regression coefficient under the context of the multivariate linear regression model. It improves estimation efficiency by identifying material and immaterial parts of responses and removing the immaterial variation. The response envelope model has been investigated only for continuous response variables. In this paper, we propose the multivariate probit model with latent envelope, in short, the probit envelope model, as a response envelope model for multivariate binary response variables. The probit envelope model takes into account relations between Gaussian latent variables of the multivariate probit model by using the idea of the response envelope model. We address the identifiability of the probit envelope model by employing the essential identifiability concept and suggest a Bayesian method for the parameter estimation. We illustrate the probit envelope model via simulation studies and real-data analysis. The simulation studies show that the probit envelope model has the potential to gain efficiency in estimation compared to the multivariate probit model. The real data analysis shows that the probit envelope model is useful for multi-label classification.
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  • 文章类型: Journal Article
    在实际工程中,获得标记的高质量故障样本提出了挑战。传统的基于深度学习的故障诊断方法难以从细粒度的角度辨别机械故障的根本原因,由于注释数据的稀缺性。为了解决这些问题,我们提出了一种新的半监督高斯混合变分自编码器方法,SeGMVAE,旨在获取可以跨细粒度故障诊断任务传输的无监督表示,启用仅使用少量标记的样本来识别先前未发现的故障。最初,高斯混合被引入作为变分自动编码器的多峰先验分布。通过期望最大化(EM)算法为每个任务动态优化此分布,构建桥接任务和未标记样本的潜在表示。随后,提出了一套变分后验方法,将每个任务样本编码到潜在空间中,促进元学习。最后,半监督EM通过获取特定任务的参数来集成标记数据的后验,以诊断看不见的故障。两个实验的结果表明,SeGMVAE擅长识别新的细粒度故障,并在跨不同机器的跨域故障诊断中表现出出色的性能。我们的代码可在https://github.com/zhiqan/SeGMVAE获得。
    In practical engineering, obtaining labeled high-quality fault samples poses challenges. Conventional fault diagnosis methods based on deep learning struggle to discern the underlying causes of mechanical faults from a fine-grained perspective, due to the scarcity of annotated data. To tackle those issue, we propose a novel semi-supervised Gaussian Mixed Variational Autoencoder method, SeGMVAE, aimed at acquiring unsupervised representations that can be transferred across fine-grained fault diagnostic tasks, enabling the identification of previously unseen faults using only the small number of labeled samples. Initially, Gaussian mixtures are introduced as a multimodal prior distribution for the Variational Autoencoder. This distribution is dynamically optimized for each task through an expectation-maximization (EM) algorithm, constructing a latent representation of the bridging task and unlabeled samples. Subsequently, a set variational posterior approach is presented to encode each task sample into the latent space, facilitating meta-learning. Finally, semi-supervised EM integrates the posterior of labeled data by acquiring task-specific parameters for diagnosing unseen faults. Results from two experiments demonstrate that SeGMVAE excels in identifying new fine-grained faults and exhibits outstanding performance in cross-domain fault diagnosis across different machines. Our code is available at https://github.com/zhiqan/SeGMVAE.
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  • 文章类型: Journal Article
    在生物种群的研究中,Allee效应检测到一个临界密度,低于该密度,人口将受到严重威胁并面临灭绝的危险。这种效应取代了经典的逻辑模型,由于缺乏竞争,低密度是有利的,包括与遗传池赤字有关的情况,近交抑郁症,matelimitations,由于缺乏特异性,协作策略不可用,等。本文的目标是对Allee效应提供详细的数学分析。在回顾了与Allee效应相关的常微分方程之后,我们将考虑扩散人口的情况。这个种群的分散是相当普遍的,可以包括经典的布朗运动,以及Lévy的飞行模式,还有一种“混合”情况,其中一些人进行经典的随机游走,而另一些人则采用Lévy飞行(这也是自然界中观察到的一种情况)。我们研究了平稳解的存在性和不存在性,这表明人口在平衡状态下的生存机会。我们还分析了相关的进化问题,鉴于总人口的时间单调性,能源考虑,和长时间的渐近性。此外,我们还考虑了“逆”Allee效应的情况,低密度人群可能会获得额外的好处。
    In the study of biological populations, the Allee effect detects a critical density below which the population is severely endangered and at risk of extinction. This effect supersedes the classical logistic model, in which low densities are favorable due to lack of competition, and includes situations related to deficit of genetic pools, inbreeding depression, mate limitations, unavailability of collaborative strategies due to lack of conspecifics, etc. The goal of this paper is to provide a detailed mathematical analysis of the Allee effect. After recalling the ordinary differential equation related to the Allee effect, we will consider the situation of a diffusive population. The dispersal of this population is quite general and can include the classical Brownian motion, as well as a Lévy flight pattern, and also a \"mixed\" situation in which some individuals perform classical random walks and others adopt Lévy flights (which is also a case observed in nature). We study the existence and nonexistence of stationary solutions, which are an indication of the survival chance of a population at the equilibrium. We also analyze the associated evolution problem, in view of monotonicity in time of the total population, energy consideration, and long-time asymptotics. Furthermore, we also consider the case of an \"inverse\" Allee effect, in which low density populations may access additional benefits.
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