Uniform designs are widely used in various scientific investigations and industrial applications. By considering all possible level permutation of the factors, a connection between average centered L2-discrepancy and generalized wordlength pattern for asymmetrical fractional factorial designs is derived. Moreover, we present new lower bounds to the average centered L2-discrepancy for symmetrical and asymmetrical U-type designs. For illustration of the theoretical results, the lower bounds for symmetrical and asymmetrical U-type designs are tabulated, and numerical results indicate that our lower bounds behave well and can be recommended for use in practice. 相似文献
In this paper, we consider the laws of large numbers for NSD random variables satisfying Pareto-type distributions with infinite means. Based on the Pareto-Zipf distributions, some weak laws of large numbers for weighted sums of NSD random variables are obtained. Meanwhile, we show that a weak law for Pareto-Zipf distributions cannot be extended to a strong law. Furthermore, based on the two tailed Pareto distribution, a strong law of large numbers for weighed NSD random variables is presented. Our results extend the corresponding earlier ones. 相似文献
We present APproximated Exhaustive Search (APES), which enables fast and approximated exhaustive variable selection in Generalised Linear Models (GLMs). While exhaustive variable selection remains as the gold standard in many model selection contexts, traditional exhaustive variable selection suffers from computational feasibility issues. More precisely, there is often a high cost associated with computing maximum likelihood estimates (MLE) for all subsets of GLMs. Efficient algorithms for exhaustive searches exist for linear models, most notably the leaps‐and‐bound algorithm and, more recently, the mixed integer optimisation (MIO) algorithm. The APES method learns from observational weights in a generalised linear regression super‐model and reformulates the GLM problem as a linear regression problem. In this way, APES can approximate a true exhaustive search in the original GLM space. Where exhaustive variable selection is not computationally feasible, we propose a best‐subset search, which also closely approximates a true exhaustive search. APES is made available in both as a standalone R package as well as part of the already existing mplot package. 相似文献
AStA Advances in Statistical Analysis - In this paper, we consider the single-index measurement error model with mismeasured covariates in the nonparametric part. To solve the problem, we develop a... 相似文献
This article focuses on the Global Compact for Safe, Orderly and Regular Migration (GCM), a landmark international document that builds on the momentum of a decade of initiatives at the international level on migration governance, and its impact on Asia from the perspective of South Asia, Southeast Asia, China, and South Korea. While none of these countries voted against the adoption of the GCM, there are significant differences in how individual countries approached the commitments made in the GCM. These perspectives were articulated in a webinar hosted by Metropolis Asia on 20 June 2018 and in governmental statements made at the UN international conference when the GCM was adopted. This article also discusses the challenges confronting the implementation of the GCM. While the Compact resulted from inclusive and intensive negotiations and many compromises, the road towards realizing its goals will be at least as challenging as the road that led to its adoption. In spite of these challenges, the GCM is a ground‐breaking representation of the first multilateral framework for migration governance. Its success rests upon the recognition that addressing the challenges and maximizing the benefits of migration require true international cooperation, renewed commitment and meaningful action on the commitments agreed to. 相似文献
Nowadays, many wicked problems such as environmental issues require organizations from multiple sectors to form cross-sectoral alliances. Cross-sectoral alliance networks can transfer resources and signal affiliations and value alignment between strategic partners. The communication of cross-sectoral alliances is a form of CSR communication that serves organizations’ strategic goals and objectives. Drawing on the literature on digital CSR communication and legitimacy theory, this article examines which legitimacy needs shape the formation of cross-sectoral ties on Facebook in addressing environmental and sustainable development issues in the United States. Combining data-mining, text-mining, social network analysis, and exponential graph modeling, this research investigates the structure of a network among 3071 organizations across multiple sectors. Findings show that organizations’ cross-sectoral tie formation is mainly driven by social legitimacy and alliance legitimacy needs. 相似文献
Through a thematic content analysis of 118 journal articles from interdisciplinary fields, this study reviews the research trends of online crisis communication literature in a Chinese post-truth society, where objective facts play a diminishing role, and Chinese people are losing their trust, despite the best efforts of organizations to deal with fake news in crises. Results of this study disclose some unique crisis communication strategies (e.g., strategic distraction, rumor-rebuttal, fabrication, acting cute, and content censorship) in crises of China. Influential contextual factors such as the political system, cultural values, and media features are identified as well. Theoretical and practical implications of this study are discussed, and a greater picture of online crisis communication in contexts is posited for future research. 相似文献
To maximize the ecological services of urban forests, a better understanding of the effects of urbanization on urban forest characteristics, landscape metrics, and their associations is needed for landscape-related regulations in space-limited green infrastructure of metropolitan regions. In this study, Harbin, a typical fast-growing provincial-capital city in Northeast China, is used as a case study. Based on remote sensing images, field surveys, and correlation and variation partitioning analyses, we conclude that landscape characteristics and forest attributes have large variations among different urbanization intensity (UI) regions. Forest patch density (PD), landscape shape index, woody plants species richness, and the Shannon–Wiener index (H′) increased linearly, while stem section area and tree height decreased linearly with the increasing of UIs. UI had a greater influence on tree size and forest community attributes than the forest landscape pattern. Accordingly, any landscape regulation on forest attributes should be implemented according to UIs. In addition, Euclidean nearest neighbor distance(ENN-MN), mean perimeter-area ratio (PARA-MN), fractal dimension index(FRAC-MN), and PD could probably indicate forest attributes the most, e.g., the increase of PARA-MN may be accompanied with taller trees in low and heavy UI regions, but lower woody plants species evenness in low and medium UI regions. More diversified woody plants species, and afforested areas should be advocated in a low UI region, while in a heavy UI region, the conservation of large trees should be implemented. Our results highlight that the implementation of urban forest management should vary according to different urbanization regions to maximize ecological services.