1,721,613 research outputs found
Efficient Decentralized Parallel Task Allocation for Multiple Robots
No full textThis article deals with large-scale decentralized task allocation problems for multiple heterogeneous robots. One of the grand challenges with decentralized task allocation problems is the NP-hardness for computation and communication. This article proposes a decentralized decreasing threshold task allocation (DTTA) algorithm that enables parallel allocation by leveraging a decreasing threshold to handle the NP-hardness. DTTA can release both computation and communication burdens for multiple robots in a decentralized network. In addition, DTTA provides a theoretical guarantee of the quality of the solution for maximizing submodular utility functions. Theoretical analysis indicates that DTTA can provide an optimality guarantee of (1-ϵ)/2 with computation complexity of (Formula presented) for each robot, where ϵ is the parameter controlling the decreasing speed of the threshold, r is the number of tasks. To examine the performance of the proposed algorithm, we conduct numerical simulations based on a multitarget surveillance scenario. Simulation results demonstrate that DTTA delivers comparable solution quality significantly faster than state-of-the-art task allocation algorithms. Its advantages are particularly pronounced in large-scale missions with thousands of tasks and robots.
A sample decreasing threshold greedy‑based algorithm for big data summarisation
Full text linkAs the scale of datasets used for big data applications expands rapidly, there have been increased efforts to develop faster algorithms. This paper addresses big data summarisation problems using the submodular maximisation approach and proposes an efficient algorithm for maximising general non-negative submodular objective functions subject to k-extendible system constraints. Leveraging a random sampling process and a decreasing threshold strategy, this work proposes an algorithm, named Sample Decreasing Threshold Greedy (SDTG). The proposed algorithm obtains an expected approximation guarantee of 11+k−ϵ for maximising monotone submodular functions and of k(1+k)2−ϵ in non-monotone cases with expected computational complexity of O(n(1+k)ϵlnrϵ). Here, r is the largest size of feasible solutions, and ϵ∈(0,11+k) is an adjustable designing parameter for the trade-off between the approximation ratio and the computational complexity. The performance of the proposed algorithm is validated and compared with that of benchmark algorithms through experiments with a movie recommendation system based on a real database
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Division and Unity: The History and Historiography of the Pennsylvania Constitution
Full text linkAbout the author:
Wen Li Teng is pursuing a double major in History and Political Science at the University of Chicago
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The Menkaure Triad, Numerical Thinking, and Divine Configurations in Ancient Egypt
Full text linkAbout the Author
Formerly an undergraduate at the University of California, Los Angeles, Wen Li Teng is a transfer student at the University of Chicago. Wen Li is currently pursuing a major in History
- …
