Conference on Current Trends in Theory and Practice of Informatics最新文献

Space-Efficient STR-IC-LCS Computation 空间高效的STR-IC-LCS计算

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2022-10-14 DOI: 10.48550/arXiv.2210.07979

Yuuki Yonemoto, Yuto Nakashima, Shunsuke Inenaga, H. Bannai

引用次数: 1

Visualizing Multispecies Coalescent Trees: Drawing Gene Trees Inside Species Trees 可视化多物种聚结树:在物种树内绘制基因树

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2022-10-13 DOI: 10.48550/arXiv.2210.06744

J. Klawitter, Felix Klesen, Moritz Niederer, A. Wolff

{"title":"Visualizing Multispecies Coalescent Trees: Drawing Gene Trees Inside Species Trees","authors":"J. Klawitter, Felix Klesen, Moritz Niederer, A. Wolff","doi":"10.48550/arXiv.2210.06744","DOIUrl":"https://doi.org/10.48550/arXiv.2210.06744","url":null,"abstract":". We consider the problem of drawing multiple gene trees inside a single species tree in order to visualize multispecies coalescent trees. Speciﬁcally, the drawing of the species tree ﬁlls a rectangle in which each of its edges is represented by a smaller rectangle, and the gene trees are drawn as rectangular cladograms (that is, orthogonally and down-ward, with one bend per edge) inside the drawing of the species tree. As an alternative, we also consider a style where the widths of the edges of the species tree are proportional to given eﬀective population sizes. In order to obtain readable visualizations, our aim is to minimize the number of crossings between edges of the gene trees in such drawings. We show that planar instances can be recognized in linear time and that the general problem is NP-hard. Therefore, we introduce two heuristics and give an integer linear programming (ILP) formulation that provides us with exact solutions in exponential time. We use the ILP to measure the quality of the heuristics on real-world instances. The heuristics yield surprisingly good solutions, and the ILP runs surprisingly fast.","PeriodicalId":266155,"journal":{"name":"Conference on Current Trends in Theory and Practice of Informatics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129529535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Morphing Planar Graph Drawings Through 3D 通过3D变形平面图形绘图

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2022-10-11 DOI: 10.48550/arXiv.2210.05384

K. Buchin, W. Evans, Fabrizio Frati, I. Kostitsyna, M. Löffler, Tim Ophelders, A. Wolff

引用次数: 1

Parameterized Approaches to Orthogonal Compaction 正交压实的参数化方法

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2022-10-10 DOI: 10.48550/arXiv.2210.05019

W. Didimo, Siddharth Gupta, P. Kindermann, G. Liotta, A. Wolff, M. Zehavi

{"title":"Parameterized Approaches to Orthogonal Compaction","authors":"W. Didimo, Siddharth Gupta, P. Kindermann, G. Liotta, A. Wolff, M. Zehavi","doi":"10.48550/arXiv.2210.05019","DOIUrl":"https://doi.org/10.48550/arXiv.2210.05019","url":null,"abstract":"Orthogonal graph drawings are used in applications such as UML diagrams, VLSI layout, cable plans, and metro maps. We focus on drawing planar graphs and assume that we are given an emph{orthogonal representation} that describes the desired shape, but not the exact coordinates of a drawing. Our aim is to compute an orthogonal drawing on the grid that has minimum area among all grid drawings that adhere to the given orthogonal representation. This problem is called orthogonal compaction (OC) and is known to be NP-hard, even for orthogonal representations of cycles [Evans et al., 2022]. We investigate the complexity of OC with respect to several parameters. Among others, we show that OC is fixed-parameter tractable with respect to the most natural of these parameters, namely, the number of emph{kitty corners} of the orthogonal representation: the presence of pairs of kitty corners in an orthogonal representation makes the OC problem hard. Informally speaking, a pair of kitty corners is a pair of reflex corners of a face that point at each other. Accordingly, the number of kitty corners is the number of corners that are involved in some pair of kitty corners.","PeriodicalId":266155,"journal":{"name":"Conference on Current Trends in Theory and Practice of Informatics","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124067056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Delivery to Safety with Two Cooperating Robots 两个协作机器人的安全配送

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2022-10-08 DOI: 10.48550/arXiv.2210.04080

Jared R Coleman, E. Kranakis, D. Krizanc, Oscar Morales Ponce

{"title":"Delivery to Safety with Two Cooperating Robots","authors":"Jared R Coleman, E. Kranakis, D. Krizanc, Oscar Morales Ponce","doi":"10.48550/arXiv.2210.04080","DOIUrl":"https://doi.org/10.48550/arXiv.2210.04080","url":null,"abstract":"Two cooperating, autonomous mobile robots with arbitrary nonzero max speeds are placed at arbitrary initial positions in the plane. A remotely detonated bomb is discovered at some source location and must be moved to a safe distance away from its initial location as quickly as possible. In the Bomb Squad problem, the robots cooperate by communicating face-to-face in order to pick up the bomb from the source and carry it away to the boundary of a disk centered at the source in the shortest possible time. The goal is to specify trajectories which define the robots' paths from start to finish and their meeting points which enable face-to-face collaboration by exchanging information and passing the bomb from robot to robot. We design algorithms reflecting the robots' knowledge about orientation and each other's speed and location. In the offline case, we design an optimal algorithm. For the limited knowledge cases, we provide online algorithms which consider robots' level of agreement on orientation as per OneAxis and NoAxis models, and knowledge of the boundary as per Visible, Discoverable, and Invisible. In all cases, we provide upper and lower bounds for the competitive ratios of the online problems.","PeriodicalId":266155,"journal":{"name":"Conference on Current Trends in Theory and Practice of Informatics","volume":"387 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133463157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

A spectral algorithm for finding maximum cliques in dense random intersection graphs 稠密随机相交图中寻找最大团的谱算法

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2022-10-05 DOI: 10.48550/arXiv.2210.02121

Filippos Christodoulou, S. Nikoletseas, C. Raptopoulos, P. Spirakis

{"title":"A spectral algorithm for finding maximum cliques in dense random intersection graphs","authors":"Filippos Christodoulou, S. Nikoletseas, C. Raptopoulos, P. Spirakis","doi":"10.48550/arXiv.2210.02121","DOIUrl":"https://doi.org/10.48550/arXiv.2210.02121","url":null,"abstract":"In a random intersection graph $G_{n,m,p}$, each of $n$ vertices selects a random subset of a set of $m$ labels by including each label independently with probability $p$ and edges are drawn between vertices that have at least one label in common. Among other applications, such graphs have been used to model social networks, in which individuals correspond to vertices and various features (e.g. ideas, interests) correspond to labels; individuals sharing at least one common feature are connected and this is abstracted by edges in random intersection graphs. In this paper, we consider the problem of finding maximum cliques when the input graph is $G_{n,m,p}$. Current algorithms for this problem are successful with high probability only for relatively sparse instances, leaving the dense case mostly unexplored. We present a spectral algorithm for finding large cliques that processes vertices according to respective values in the second largest eigenvector of the adjacency matrix of induced subgraphs of the input graph corresponding to common neighbors of small cliques. Leveraging on the Single Label Clique Theorem from [15], we were able to construct random instances, without the need to externally plant a large clique in the input graph. In particular, we used label choices to determine the maximum clique and then concealed label information by just giving the adjacency matrix of $G_{n, m, p}$ as input to the algorithm. Our experimental evaluation showed that our spectral algorithm clearly outperforms existing polynomial time algorithms, both with respect to the failure probability and the approximation guarantee metrics, especially in the dense regime, thus suggesting that spectral properties of random intersection graphs may be also used to construct efficient algorithms for other NP-hard graph theoretical problems as well.","PeriodicalId":266155,"journal":{"name":"Conference on Current Trends in Theory and Practice of Informatics","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132898522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

More Effort Towards Multiagent Knapsack 对多智能体背包的进一步努力

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2022-08-04 DOI: 10.48550/arXiv.2208.02766

Sushmita Gupta, P. Jain, Sanjay Seetharaman

引用次数: 0

Multi-Parameter Analysis of Finding Minors and Subgraphs in Edge Periodic Temporal Graphs 边周期时间图中查找子图和子图的多参数分析

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2022-03-14 DOI: 10.48550/arXiv.2203.07401

Emmanuel Arrighi, Niels Gruttemeier, Nils Morawietz, Frank Sommer, Petra Wolf

{"title":"Multi-Parameter Analysis of Finding Minors and Subgraphs in Edge Periodic Temporal Graphs","authors":"Emmanuel Arrighi, Niels Gruttemeier, Nils Morawietz, Frank Sommer, Petra Wolf","doi":"10.48550/arXiv.2203.07401","DOIUrl":"https://doi.org/10.48550/arXiv.2203.07401","url":null,"abstract":"We study the computational complexity of determining structural properties of edge periodic temporal graphs (EPGs). EPGs are time-varying graphs that compactly represent periodic behavior of components of a dynamic network, for example, train schedules on a rail network. In EPGs, for each edge $e$ of the graph, a binary string $s_e$ determines in which time steps the edge is present, namely $e$ is present in time step $t$ if and only if $s_e$ contains a $1$ at position $t mod |s_e|$. Due to this periodicity, EPGs serve as very compact representations of complex periodic systems and can even be exponentially smaller than classic temporal graphs representing one period of the same system, as the latter contain the whole sequence of graphs explicitly. In this paper, we study the computational complexity of fundamental questions of the new concept of EPGs such as what is the shortest traversal time between two vertices; is there a time step in which the graph (1) is minor-free; (2) contains a minor; (3) is subgraph-free; (4) contains a subgraph; with respect to a given minor or subgraph. We give a detailed parameterized analysis for multiple combinations of parameters for the problems stated above including several parameterized algorithms.","PeriodicalId":266155,"journal":{"name":"Conference on Current Trends in Theory and Practice of Informatics","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131427310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the Complexity of Scheduling Problems with a Fixed Number of Parallel Identical Machines 具有固定数量的平行相同机器的调度问题的复杂性

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2022-02-16 DOI: 10.1007/978-3-031-23101-8_13

K. Jansen, K. Kahler

引用次数: 0

Sorting by Multi-cut Rearrangements 多切口重排排序

Conference on Current Trends in Theory and Practice of Informatics Pub Date : 2021-05-29 DOI: 10.1007/978-3-030-67731-2_43

L. Bulteau, G. Fertin, Géraldine Jean, Christian Komusiewicz

引用次数: 3