21,688 research outputs found
An Improved Algorithm for Incremental DFS Tree in Undirected Graphs
Full text linkDepth first search (DFS) tree is one of the most well-known data structures for designing efficient graph algorithms. Given an undirected graph G=(V,E) with n vertices and m edges, the textbook algorithm takes O(n+m) time to construct a DFS tree. In this paper, we study the problem of maintaining a DFS tree when the graph is undergoing incremental updates. Formally, we show:
Given an arbitrary online sequence of edge or vertex insertions, there is an algorithm that reports a DFS tree in O(n) worst case time per operation, and requires O (min {m log n, n^2}) preprocessing time.
Our result improves the previous O(n log^3 n) worst case update time algorithm by Baswana et al. [Baswana et al., 2016] and the O(n log n) time by Nakamura and Sadakane [Nakamura and Sadakane, 2017], and matches the trivial Omega(n) lower bound when it is required to explicitly output a DFS tree.
Our result builds on the framework introduced in the breakthrough work by Baswana et al. [Baswana et al., 2016], together with a novel use of a tree-partition lemma by Duan and Zhang [Duan and Zhang, 2016], and the celebrated fractional cascading technique by Chazelle and Guibas [Chazelle and Guibas, 1986a; Chazelle and Guibas, 1986b]
Optimal approximation with exponential sums by a maximum likelihood modification of Prony’s method
No full textJingguaeshna ZHENG & LI & ZHAO & ZHANG 2021, gen. nov.
No full textJingguaeshna Zheng & Zhang, gen. nov. Type species. Jingguaeshna taoae Zheng & Zhang, sp. nov. Etymology. Named after the combination of ‘ Jinggu ’ (the locality yielding the holotype) and Aeshna. Diagnosis. About twenty postnodal crossveins present before Pt; IR1 well-defined, originating several cells basad of Pt; RP2 curved; IR2 forked, branches separated by two rows of cells at level of Pt base; Rspl well defined, parallel with lower branch of IR2, separated by one row of cells; Mspl well defined, undulating, somewhat parallel with MA, separated by one row of cells; two rows of cells between MA and RP3/4 near posterior margin of wing; CuAa with at least four posterior branches.Published as part of ZHENG, DA-RAN, LI, SHA, ZHAO, YI-SHAN & ZHANG, HAI-CHUN, 2021, A potential telephlebiid dragonfly (Odonata: Anisoptera: Aeshnoidea) from Miocene of Yunnan, southwestern China, pp. 237-242 in Palaeoentomology 4 (3) on page 238, DOI: 10.11646/palaeoentomology.4.3.11, http://zenodo.org/record/550781
Computer Science Research Interest: Wen-ran Zhang
No full textComputer Science Research Interest: Wen-ran Zhan
Access control and handoff policy design for RAN slicing
No full textNetwork slicing (NS) has been identified as one of the most promising architectural technologies for future mobile network systems to meet the extremely diversified service requirements of users. In radio access networks (RAN) slicing, service provisioning for slice users becomes much more complicated than that in traditional mobile networks, as the constraints of both user physical association with base station (BS) and logical association with NS should be considered. In other words, the user‐BS‐NS three layer association relationship should be addressed in provisioning tailored service for diversified use cases with various quality of service (QoS) requirements. Therefore, user association (including handoff scheme) in RAN slicing becomes an essential yet challenging issue for 5G‐and‐beyond systems. In this chapter, we propose to solve two fundamental problems: user access control and mobile user handoff policy design for RAN slicing to achieve satisfactory QoS of users
Isolation-Aware 5G RAN Slice Mapping over WDM Metro-Aggregation Networks
Full text linkTo accommodate the heterogeneous requirements of emerging 5G services, 5G Radio Access Network (RAN) will support the rising paradigm of network slicing, where a single physical RAN infrastructure is divided into multiple logical networks characterized by diverse requirements in terms of performance, cost, latency, and security, etc. The optimality of RAN slicing depends on various factors, such as slice requirements, resource availability and adopted network architecture. In 4G, RAN architecture evolved from a distributed architecture towards a 2-layer architecture that separates remote radio heads (RRHs) from baseband processing units (BBUs). However, this architecture has soon shown scalability limitations. To address this problem, the concept of flexible 5G functional split has been proposed, where RAN functions are distributed on a 3-layer architecture featuring a radio unit (RU), a distributed unit (DU), and a central unit (CU). Besides RAN architecture, isolation among different slices, which is necessary for slicing security, has a significant influence on the RAN slicing. In this work, we consider the isolation-aware RAN slice mapping problem considering advanced functional splits and a 3-layer RAN architecture. We propose a dual-objective heuristic algorithm for RAN slice mapping over a physical infrastructure represented by a wavelength division multiplexing (WDM) metro-aggregation networks. The proposed heuristic targets the minimization of 1) the number of active COs (i.e, hosting DUs and/or CUs) and 2) the number of established wavelength channels under constraints of network capacity and latency requirements. As our algorithm is also designed to map the RAN slices with least amount of physical resources for a given level of isolation, we also investigate the impact of slice isolation on resource utilization. Results show how higher isolation results in higher network cost
Photocatalytic carbon dioxide Reduction: Identification and Elimination of False-Positive Results
No full textNo abstract availableYanzhao Zhang, Dazhi Yao, Bingquan Xia, Mietek Jaroniec, Jingrun Ran, and Shi-Zhang Qia
THE PROBLEM OF TAXING FARMERS IN CHINA
Full text linkReplaced with revised version of paper 08/25/03.Agricultural Finance, H22, O53,
sj-docx-1-tva-10.1177_15248380231209436 – Supplemental material for The Association Between Child Abuse and Internet Addiction: A Three-Level Meta-Analysis
No full textSupplemental material, sj-docx-1-tva-10.1177_15248380231209436 for The Association Between Child Abuse and Internet Addiction: A Three-Level Meta-Analysis by Qiongzhi Zhang, Qi Zhang, Guangming Ran and Yishuang Liu in Trauma, Violence, & Abuse</p
sj-docx-1-tva-10.1177_15248380221129596 – Supplemental material for The Association Between Child Abuse and Aggressive Behavior: A Three-Level Meta-Analysis
No full textSupplemental material, sj-docx-1-tva-10.1177_15248380221129596 for The Association Between Child Abuse and Aggressive Behavior: A Three-Level Meta-Analysis by Guangming Ran, Qiongzhi Zhang, Qi Zhang, Jun Li and Jing Chen in Trauma, Violence, & Abuse</p
- …
