60 research outputs found

    Exploring the law of text geographic information

    Full text link
    Textual geographic information is indispensable and heavily relied upon in practical applications. The absence of clear distribution poses challenges in effectively harnessing geographic information, thereby driving our quest for exploration. We contend that geographic information is influenced by human behavior, cognition, expression, and thought processes, and given our intuitive understanding of natural systems, we hypothesize its conformity to the Gamma distribution. Through rigorous experiments on a diverse range of 24 datasets encompassing different languages and types, we have substantiated this hypothesis, unearthing the underlying regularities governing the dimensions of quantity, length, and distance in geographic information. Furthermore, theoretical analyses and comparisons with Gaussian distributions and Zipf's law have refuted the contingency of these laws. Significantly, we have estimated the upper bounds of human utilization of geographic information, pointing towards the existence of uncharted territories. Also, we provide guidance in geographic information extraction. Hope we peer its true countenance uncovering the veil of geographic information.Comment: IP

    Performance Evaluation of MDO Architectures within a Variable Complexity Problem

    Get PDF
    Though quite a number of multidisciplinary design optimization (MDO) architectures have been proposed for the optimal design of large-scale multidisciplinary systems, how their performance changes with the complexity of MDO problem varied is not well studied. In order to solve this problem, this paper presents a variable complexity problem which allows people to obtain a MDO problem with arbitrary complexity by specifying its changeable parameters, such as the number of disciplines and the numbers of design variables. Then four investigations are performed to evaluate how the performance of different MDO architectures changes with the number of disciplines, global variables, local variables, and coupling variables varied, respectively. Finally, the results supply guidance for the selection of MDO architectures in solving practical engineering problems with different complexity

    Realization of a two-dimensional checkerboard lattice in monolayer Cu2_2N

    Full text link
    Two-dimensional checkerboard lattice, the simplest line-graph lattice, has been intensively studied as a toy model, while material design and synthesis remain elusive. Here, we report theoretical prediction and experimental realization of the checkerboard lattice in monolayer Cu2_2N. Experimentally, monolayer Cu2_2N can be realized in the well-known N/Cu(100) and N/Cu(111) systems that were previously mistakenly believed to be insulators. Combined angle-resolved photoemission spectroscopy measurements, first-principles calculations, and tight-binding analysis show that both systems host checkerboard-derived hole pockets near the Fermi level. In addition, monolayer Cu2_2N has outstanding stability in air and organic solvents, which is crucial for further device applications.Comment: Nano Letters, in pres

    An adaptive LIC based geographic flow field visualization method by means of rotation distance

    No full text
    Geographic visualization is essential for explaining and describing spatiotemporal geographical processes in flow fields. However, due to multi-scale structures and irregular spatial distribution of vortices in complex geographic flow fields, existing two-dimensional visualization methods are susceptible to the effects of data accuracy and sampling resolution, resulting in incomplete and inaccurate vortex information. To address this, we propose an adaptive Line Integral Convolution (LIC) based geographic flow field visualization method by means of rotation distance. Our novel framework of rotation distance and its quantification allows for the effective identification and extraction of vortex features in flow fields effectively. We then improve the LIC algorithm using rotation distance by constructing high-frequency noise from it as input to the convolution, with the integration step size adjusted. This approach allows us to effectively distinguish between vortex and non-vortex fields and adaptively represent the details of vortex features in complex geographic flow fields. Our experimental results show that the proposed method leads to more accurate and effective visualization of the geographic flow fields

    Prevalence and associated factors of post-traumatic stress disorder in burned patients and their family members

    No full text
    Background: Post-traumatic stress disorder (PTSD) is common among burn patients and their family members. The objective of this study was to document the prevalence of PTSD and explore the sociodemographic and burn-specific associated factors of PTSD among Chinese burn survivors and their family members. Methods: A total of 131 adult patients with unintentional burns and 194 family members of burn patients were recruited from two burn units. All participants completed a general information form and the PTSD Checklist for the DSM-5 (PCL-5). Results: Fifty-five (42.0%) burn victims and ninety-nine (51.0%) family members of burn victims met the criteria for PTSD; the average score of the sample was 31.21 +/- 21.56 and 33.16 +/- 19.30. Logistic regression analysis revealed that middle age (45-55 years), poor economic status, greater total body surface area (TBSA) and longer time since the burn incident positively predicted the PTSD of patients and that female family members had a higher risk of PTSD. Conclusions: Burn patients and their family members are susceptible to PTSD. Suitable and long-term psychological intervention programmes should be executed for burn patients and their family members. (c) 2020 Published by Elsevier Ltd

    <tex>Lp\mathrm{L}_p</tex> Quasi Norm State Estimator for Power Systems

    No full text
    This paper proposes an Lp (0&#x003C;p&#x003C;1) quasi norm state estimator for power system static state estimation. Compared with the existing L, and L2 norm estimators, the proposed estimator can suppress the bad data more effectively. The robustness of the proposed estimator is discussed, and an analysis shows that its ability to suppress bad data increases as pp decreases. Moreover, an algorithm is suggested to solve the non-convex state estimation problem. By introducing a relaxation factor in the mathematical model of the proposed estimator, the algorithm can prevent the solution from converging to a local optimum as much as possible. Finally, simulations on a 3-bus DC system, the IEEE 14-bus and IEEE 300-bus systems as well as a 1204-bus provincial system verify the high computation efficiency and robustness of the proposed estimator

    Correction: Interspecific Phylogenic Relationships within Genus Melilotus Based on Nuclear and Chloroplast DNA.

    No full text
    [This corrects the article DOI: 10.1371/journal.pone.0132596.]
    corecore