Weibull distribution

Weibull 分布
  • 文章类型: Journal Article
    在当代统计研究中,围绕Marshall-Olkin-G分布的建议扩展,引起了人们的兴趣。与其父分布相比,本扩展具有更高的灵活性。以类似的方式,在这种情况下,我们提出了统计学者提出的Marshall-Olkin-G分布的扩展。这项研究利用了扩展的特定变体,称为马歇尔-奥尔金-威布尔对数模型,它适用于完整数据集和审查数据集。显然,上述模型在准确表征寿命可靠性问题中的完整观测值和删失观测值方面具有很强的竞争力,与本研究工作中讨论的其他比较模型相比。
    In contemporary statistical research, there has been a notable surge of interest surrounding a suggested extension of the Marshall-Olkin-G distributions. The present extension exhibits a higher degree of flexibility in comparison to its parent distributions. In a similar manner, we present in this context an expansion of the Marshall-Olkin-G distributions proposed by statistical scholars. This study utilizes a specific variant of the extension known as the Marshall-Olkin-Weibull Logarithmic model, which is applied to both complete and censored data sets. It is evident that the aforementioned model has strong competitiveness in accurately characterizing both complete and censored observations in lifetime reliability issues, when compared to other comparative models discussed in this research work.
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  • 文章类型: Journal Article
    在过去的几十年中,碳排放量的大量增加给科学界带来了环境挑战。目前的研究提出了一种对高碳排放燃料征税的方法。为此,对三种最常用的燃料(汽油,液化石油气(LPG),和压缩天然气(CNG))。测试引擎的速度以400RPM的增量从1800到4200转/分钟(RPM)变化。性能参数(制动功率(BP),制动热效率(BTHE),和制动比燃料消耗(BSFC))使用水力测功机测量。排放分析,包括二氧化碳(CO2),一氧化碳(CO),未燃烧的碳氢化合物(HC),和氮氧化物(NOx),使用TESTO350分析仪进行。Weibull分布的95%置信区间的应用,在排放数据上,解释了数据的充分性。在测试燃料中,CNG作为一种环保燃料出现,二氧化碳、二氧化碳、二氧化碳和二氧化碳的排放量分别减少了16%、42%和43%。与汽油相比,HC。此外,CNG的BTHE和BSFC优于其他替代品。此外,与汽油和液化石油气相比,CNG燃料的碳排放量分别降低了32%和20.8%。该研究提供了一种通过基于碳排放量的经济分析来评估燃料对环境的影响的新方法。此外,这个想法在通过碳税促进联合国(UN)的可持续发展目标(SDG)方面是新颖的。
    The humongous increase in carbon emissions in the past few decades presents an environmental challenge to the scientific community. The current study proposes a method of taxation on high-carbon emission fuels. For this purpose, a comparative enviro-economic analysis is carried out on the three most commonly used fuels (gasoline, Liquefied Petroleum Gas (LPG), and Compressed Natural Gas (CNG)). The speed of the test engine varied from 1800 to 4200 Revolution per Minute (RPM) in increments of 400 RPM. Performance parameters (Brake Power (BP), Brake Thermal Efficiency (BTHE), and Brake Specific Fuel Consumption (BSFC)) were measured using a hydro dynamometer. Emission analysis, including Carbon Dioxide (CO2), Carbon Monoxide (CO), Unburned Hydrocarbons (HC), and Nitrogen Oxide (NOx), was conducted using the TESTO 350 analyzer. The application of Weibull distribution with a 95 % confidence interval, on emission data, explained the adequacy of the data. Among test fuels, CNG emerged as an environment-friendly fuel with an emission reduction of 16, 42, and 43 percent for CO2, CO, and HC in comparison to gasoline. Also, BTHE and BSFC of CNG were better than other alternatives. Moreover, the carbon penalty for CNG fuel showed a price reduction of 32 and 20.8 percent in comparison to gasoline and LPG respectively. The study provides a novel approach to assess the environmental impact of fuels by economic analysis based on emitted carbon quantity. In addition, this very idea is novel in promoting the Sustainable Development Goals (SDG) of the United Nations (UN) through carbon taxation.
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  • 文章类型: Journal Article
    由于覆盖间隔是广泛使用的测量不确定度的表达式,本贡献回顾了《测量不确定度表达指南》(GUM)中定义的覆盖间隔,并将它们与应用统计学和测量科学中常用的概率区间的主要类型进行比较。虽然形式上与传统的均值置信区间相同,GUM将覆盖间隔更多地解释为贝叶斯可信间隔,或公差间隔。我们专注,特别是,关于从GUM补充1(GUM-S1)的蒙特卡洛方法的结果得出的间隔的常见误解,并为这些间隔提供新颖的解释,我们相信这将培养人们对它们能提供什么的现实期望,以及它们如何以及何时在实践中有用。
    Since coverage intervals are widely used expressions of measurement uncertainty, this contribution reviews coverage intervals as defined in the Guide to the Expression of Uncertainty in Measurement (GUM), and compares them against the principal types of probabilistic intervals that are commonly used in applied statistics and in measurement science. Although formally identical to conventional confidence intervals for means, the GUM interprets coverage intervals more as if they were Bayesian credible intervals, or tolerance intervals. We focus, in particular, on a common misunderstanding about the intervals derived from the results of the Monte Carlo method of the GUM Supplement 1 (GUM-S1), and offer a novel interpretation for these intervals that we believe will foster realistic expectations about what they can deliver, and how and when they can be useful in practice.
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  • 文章类型: Journal Article
    概率分布在应用科学中被广泛使用,尤其是在生物医学领域。生物医学数据通常表现出正偏度,必须使用灵活的,偏斜分布来有效地模拟这种现象。在这项研究中,我们引入了一种新的方法来表征新的寿命分布,被称为新的灵活指数电源(NFEP)系列。这涉及向现有分布添加新参数。建议类中的特定子模型,被称为新灵活指数力量威布尔(NFEP-Wei),是为了说明灵活性的概念。我们采用完善的最大似然估计(MLE)方法来估计该分布族中的未知参数。进行了模拟研究,以评估各种情况下估计器的行为。为了衡量NFEP-Wei分布的灵活性和有效性,我们将其与AP-Wei(阿尔法幂Weibull)进行比较,莫维(奥尔金·威布尔元帅),古典魏(威布尔),NEP-Wei(新指数威布尔),FRLog-Wei(柔性对数简化Weibull),和Kum-Wei(KumaraswamyWeibull)分布通过分析四个不同的生物医学数据集。结果表明,NFEP-Wei分布优于比较分布。
    Probability distributions are widely utilized in applied sciences, especially in the field of biomedical science. Biomedical data typically exhibit positive skewness, necessitating the use of flexible, skewed distributions to effectively model such phenomena. In this study, we introduce a novel approach to characterize new lifetime distributions, known as the New Flexible Exponent Power (NFEP) Family of distributions. This involves the addition of a new parameter to existing distributions. A specific sub-model within the proposed class, known as the New Flexible Exponent Power Weibull (NFEP-Wei), is derived to illustrate the concept of flexibility. We employ the well-established Maximum Likelihood Estimation (MLE) method to estimate the unknown parameters in this family of distributions. A simulation study is conducted to assess the behavior of the estimators in various scenarios. To gauge the flexibility and effectiveness of the NFEP-Wei distribution, we compare it with the AP-Wei (alpha power Weibull), MO-Wei (Marshal Olkin Weibull), classical Wei (Weibull), NEP-Wei (new exponent power Weibull), FRLog-Wei (flexible reduced logarithmic Weibull), and Kum-Wei (Kumaraswamy Weibull) distributions by analyzing four distinct biomedical datasets. The results demonstrate that the NFEP-Wei distribution outperforms the compared distributions.
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  • 文章类型: Journal Article
    本文提出了一种分析双变量阳性数据的新方法,考虑到协变量向量和左删失观测值,通过引入层次贝叶斯分析。所提出的方法假定边际Weibull分布,并采用通常的Weibull似然或Weibull-Tobit似然方法。模型中包括潜在变量或脆弱,以捕获同一采样单元的双变量响应之间的可能相关性。通过马尔可夫链蒙特卡罗方法获得感兴趣的后验摘要。为了证明所提出的方法的有效性,我们将其应用于来自恒星天文学的双变量数据集,其中包括左删失观测和协变量。我们的结果表明,新的双变量模型方法,它包含了潜在的因素来捕捉两种感兴趣的反应之间的潜在依赖性,产生准确的推理结果。我们还在应用程序中使用不同的似然方法(Weibull或Weibull-Tobit似然)比较了两个模型。总的来说,我们的研究结果表明,提出的分层贝叶斯分析是一种有前景的方法,用于分析具有左删失观测值和协变量信息的双变量阳性数据.
    This paper presents a novel approach for analyzing bivariate positive data, taking into account a covariate vector and left-censored observations, by introducing a hierarchical Bayesian analysis. The proposed method assumes marginal Weibull distributions and employs either a usual Weibull likelihood or Weibull-Tobit likelihood approaches. A latent variable or frailty is included in the model to capture the possible correlation between the bivariate responses for the same sampling unit. The posterior summaries of interest are obtained through Markov Chain Monte Carlo methods. To demonstrate the effectiveness of the proposed methodology, we apply it to a bivariate data set from stellar astronomy that includes left-censored observations and covariates. Our results indicate that the new bivariate model approach, which incorporates the latent factor to capture the potential dependence between the two responses of interest, produces accurate inference results. We also compare the two models using the different likelihood approaches (Weibull or Weibull-Tobit likelihoods) in the application. Overall, our findings suggest that the proposed hierarchical Bayesian analysis is a promising approach for analyzing bivariate positive data with left-censored observations and covariate information.
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  • 文章类型: Journal Article
    本文介绍了使用改进的自适应II型渐进式审查方案来研究Weibull分布的估计的方法。该方案有效地保证了实验时间不会超过预定时间。使用两种经典估计方法进行点和区间估计,即最大似然和间距的最大乘积,被认为是估计未知参数以及可靠性和危险率函数。这些量的近似置信区间是根据间距方法的最大似然和最大乘积的渐近正态获得的。还使用基于两种经典方法的MCMC技术来考虑贝叶斯估计。进行了广泛的仿真研究,以比较不同方法的性能。Further,我们建议使用各种最优性标准来找到最优抽样方案。最后,一个真实的数据集是用来显示如何提出的估计和最优性标准在现实生活中的工作。数值结果表明,使用间距函数的可能性和乘积的贝叶斯估计比经典估计更好。
    This paper presents an effort to investigate the estimations of the Weibull distribution using an improved adaptive Type-II progressive censoring scheme. This scheme effectively guarantees that the experimental time will not exceed a pre-fixed time. The point and interval estimations using two classical estimation methods, namely maximum likelihood and maximum product of spacing, are considered to estimate the unknown parameters as well as the reliability and hazard rate functions. The approximate confidence intervals of these quantities are obtained based on the asymptotic normality of the maximum likelihood and maximum product of spacing methods. The Bayesian estimations are also considered using MCMC techniques based on the two classical approaches. An extensive simulation study is implemented to compare the performance of the different methods. Further, we propose the use of various optimality criteria to find the optimal sampling scheme. Finally, one real data set is applied to show how the proposed estimators and the optimality criteria work in real-life scenarios. The numerical outcomes demonstrated that the Bayesian estimates using the likelihood and product of spacing functions performed better than the classical estimates.
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  • 文章类型: Journal Article
    一个完整的预测不同作战条件下海杂波属性的框架,由风速指定,风向,放牧角度,和两极分化,这是第一次提出。该框架由经验光谱组成,以表征不同风速下的海面剖面,蒙特卡罗方法生成海面剖面的实现,从单个海面实现计算归一化雷达横截面(NRCS)的物理光学方法,以及NRCS数据(海杂波)的回归,其经验概率密度函数(PDF)以一些统计参数为特征。采用JONSWAP和Hwang海浪谱来实现低风速和高风速下的海面剖面,分别。NRCS的概率密度函数用K和Weibull分布进行回归,每个都有两个参数。弱信号和强信号的异常区域中的概率密度函数用幂律分布进行回归,每个都以索引为特征。在不同的运行条件下,首次得出了K和Weibull分布的统计参数和幂律指数。该研究揭示了海杂波的简洁信息,可用于改善各种复杂海洋环境中的雷达性能。提出的框架可以用作设计未来测量任务的参考或指南,以增强现有的海浪谱经验模型,归一化雷达截面,等等。
    A complete framework of predicting the attributes of sea clutter under different operational conditions, specified by wind speed, wind direction, grazing angle, and polarization, is proposed for the first time. This framework is composed of empirical spectra to characterize sea-surface profiles under different wind speeds, the Monte Carlo method to generate realizations of sea-surface profiles, the physical-optics method to compute the normalized radar cross-sections (NRCSs) from individual sea-surface realizations, and regression of NRCS data (sea clutter) with an empirical probability density function (PDF) characterized by a few statistical parameters. JONSWAP and Hwang ocean-wave spectra are adopted to generate realizations of sea-surface profiles at low and high wind speeds, respectively. The probability density functions of NRCSs are regressed with K and Weibull distributions, each characterized by two parameters. The probability density functions in the outlier regions of weak and strong signals are regressed with a power-law distribution, each characterized by an index. The statistical parameters and power-law indices of the K and Weibull distributions are derived for the first time under different operational conditions. The study reveals succinct information of sea clutter that can be used to improve the radar performance in a wide variety of complicated ocean environments. The proposed framework can be used as a reference or guidelines for designing future measurement tasks to enhance the existing empirical models on ocean-wave spectra, normalized radar cross-sections, and so on.
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  • 文章类型: Journal Article
    老化强度(AI),定义为瞬时危险率和基线危险率的比率,是描述与寿命相对应的随机变量的可靠性属性的有用工具。在这项工作中,在步进应力加速寿命测试(SSALT)实验中引入了人工智能的概念,为模型提供新的见解,并能够进一步澄清两种常用的累积暴露(CE)和篡改故障率(TFR)模型之间的差异。提出了新的基于AI的SSALT模型参数估计器,并根据示例和仿真研究与MLE进行了比较。
    The aging intensity (AI), defined as the ratio of the instantaneous hazard rate and a baseline hazard rate, is a useful tool for the describing reliability properties of a random variable corresponding to a lifetime. In this work, the concept of AI is introduced in step-stress accelerated life testing (SSALT) experiments, providing new insights to the model and enabling the further clarification of the differences between the two commonly employed cumulative exposure (CE) and tampered failure rate (TFR) models. New AI-based estimators for the parameters of a SSALT model are proposed and compared to the MLEs in terms of examples and a simulation study.
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  • 文章类型: Journal Article
    在气候变化的背景下,了解和利用可再生能源潜力对于发展中国家至关重要。然而,亚穆苏克罗的风潜力,科特迪瓦,仍未充分探索。这项研究采用了纵向观察研究设计,以1分钟的间隔获取数据以捕获动态风特性。该研究的重点是使用DAVISPro气象站完善地面数据并估算风势,该气象站带有杯式风速计的速度和风向标的方向。风速和风向以米/秒和度为单位测量。数据分析采用两种不同的方法:算术和立方平均值提供代表性值,和两参数威布尔概率分布函数,通过瞬间的方法确定,提供对风分布模式的见解。研究结果表明,在8小时的时间段内,风的潜力允许获得53,38kW/h/m2的年发电量,这是一个宝贵的机会之窗。雨季,尤其是五月,月平均风速最高,而12月的旱季最低。此外,玫瑰风分析显示,盛行风从南向北吹,进一步凸显了该地区的风力潜力。结果确认Yamoussoukro具有中等的风潜力,适当地利用通过垂直轴风力涡轮机(VAWT)。这一发现对可持续发展具有重要意义。突出城市向绿色过渡的潜力,更节能的经济。亚穆苏克罗准备通过释放尚未开发的风能潜力,为可再生能源和减缓气候变化的努力做出重大贡献。
    Understanding and harnessing renewable energy potential is imperative for developing nations in the context of climate change. However, the wind potential of Yamoussoukro, Côte d\'Ivoire, remains inadequately explored. This study employs a Longitudinal Observational Study design, acquiring data at 1-min intervals to capture the dynamic wind characteristics. The research focuses on refining ground data and estimating wind potential using a DAVIS Pro weather station with a cup anemometer for speed and a wind vane for direction. Wind speed and direction are measured in meters per second and degrees. Two distinct approaches are employed for data analysis: arithmetic and cubic averages provide representative values, and the Two-Parameter Weibull Probability Distribution Functions, determined through the method of moments, offer insights into the wind distribution pattern. The study\'s findings indicate an 8-h time slot during which the wind potential permits obtaining an annual energy production of 53,38 kW/h/m2, a valuable window of opportunity. The rainy season, particularly May, has the highest average monthly wind speed, while the dry season in December has the lowest. Furthermore, the wind rose analysis reveals that the prevailing winds blow from south to north, further highlighting the region\'s wind potential. The results affirm that Yamoussoukro harbors a moderate wind potential, aptly harnessed through Vertical Axis Wind Turbines (VAWT). This discovery holds significant implications for sustainable development, highlighting the city\'s potential to transition towards a greener, more energy-efficient economy. Yamoussoukro is poised to contribute substantially to renewable energy and climate change mitigation efforts by unlocking the untapped wind energy potential.
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  • 文章类型: Journal Article
    在汤加的一个地点进行了为期12个月的测量,在地面以上34m和20m的高度进行了测量。每日,计算每月和每年的平均值。研究了风切变分析及其日变化,并与温度变化进行了比较。在整个测量期间以及一些典型的日子里,估计了两个高度的湍流水平。为了估计威布尔参数,采用了11种方法,以及拟合优度和误差估计,以找到最佳方法。在整个研究期间,在高于地面34m处,总平均风速估计为4.41m/s。汤加的主要风向是东南方向。“矩”被认为是确定精确威布尔参数的最佳方法。一台Vergnet275kW风力涡轮机的年平均净能源产量为198.57MWh。通过在测量位置附近安装五台涡轮机,估计投资回收期为8.95年,这在投资方面非常令人鼓舞。安装风力涡轮机将降低该国对进口化石燃料的严重依赖,并有助于实现可持续发展目标7。
    of wind characteristics and assessment of wind energy resource is carried out at a location in Tonga with the help of twelve months of measurements carried out at 34 m and 20 m heights above ground level. The daily, monthly and annual averages are computed. The wind shear analysis and its diurnal variation were studied and compared with the temperature variation. The turbulence levels at the two heights were estimated for the entire measurement period as well as for some typical days. For estimating the Weibull parameters, eleven methods were employed along with goodness of fit and error estimates to find the best method. The overall averaged wind speed for the entire period of study is estimated to be 4.41 m/s at 34 m above ground level. The predominant wind direction was south-east for Tonga. \'Moments\' is seen to be the best method to determine accurate Weibull parameters. The average net annual energy production from one Vergnet 275 kW wind turbine is 198.57 MWh. A payback period of 8.95 years by installing five turbines near the measurement location was estimated, which is very encouraging in terms of investment. Installing wind turbines will lower the heavy reliance on the imported fossil fuels in the country and also help in achieving Sustainable Development Goal 7.
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