Cutting Cycles of Conditional Preference Networks with Feedback Set Approach

As a tool of qualitative representation, conditional preference network (CP-net) has recently become a hot research topic in the field of artificial intelligence. The semantics of CP-nets does not restrict the generation of cycles, but the existence of the cycles would affect the property of CP-nets such as satisfaction and consistency. This paper attempts to use the feedback set problem theory including feedback vertex set (FVS) and feedback arc set (FAS) to cut cycles in CP-nets. Because of great time complexity of the problem in general, this paper defines a class of the parent vertices in a ring CP-nets firstly and then gives corresponding algorithm, respectively, based on FVS and FAS. Finally, the experiment shows that the running time and the expressive ability of the two methods are compared.

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Tight Localizations of Feedback Sets

Journal of Experimental Algorithmics ◽

10.1145/3447652 ◽

2021 ◽

Vol 26 ◽

pp. 1-19

Author(s):

Michael Hecht ◽

Krzysztof Gonciarz ◽

Szabolcs Horvát

Keyword(s):

Lower Bound ◽

Error Bounds ◽

Empirical Validation ◽

Constant Ratio ◽

Circuit Testing ◽

Feedback Vertex Set ◽

Sparse Graphs ◽

Feedback Arc Set ◽

Vertex Set ◽

Feedback Vertex Set Problem

The classical NP–hard feedback arc set problem (FASP) and feedback vertex set problem (FVSP) ask for a minimum set of arcs ε ⊆ E or vertices ν ⊆ V whose removal G ∖ ε, G ∖ ν makes a given multi–digraph G =( V , E ) acyclic, respectively. Though both problems are known to be APX–hard, constant ratio approximations or proofs of inapproximability are unknown. We propose a new universal O (| V || E | 4 )–heuristic for the directed FASP. While a ratio of r ≈ 1.3606 is known to be a lower bound for the APX–hardness, at least by empirical validation we achieve an approximation of r ≤ 2. Most of the relevant applications, such as circuit testing , ask for solving the FASP on large sparse graphs, which can be done efficiently within tight error bounds with our approach.

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Parameterized complexity of fair feedback vertex set problem

Theoretical Computer Science ◽

10.1016/j.tcs.2021.03.008 ◽

2021 ◽

Vol 867 ◽

pp. 1-12

Author(s):

Lawqueen Kanesh ◽

Soumen Maity ◽

Komal Muluk ◽

Saket Saurabh

Keyword(s):

Parameterized Complexity ◽

Feedback Vertex Set ◽

Vertex Set ◽

Feedback Vertex Set Problem

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Parameterized Algorithms for Generalizations of Directed Feedback Vertex Set

Lecture Notes in Computer Science - Algorithms and Complexity ◽

10.1007/978-3-030-17402-6_21 ◽

2019 ◽

pp. 249-261

Author(s):

Alexander Göke ◽

Dániel Marx ◽

Matthias Mnich

Keyword(s):

Parameterized Algorithms ◽

Feedback Vertex Set ◽

Vertex Set ◽

Directed Feedback Vertex Set

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On Structural Parameterizations of the Edge Disjoint Paths Problem

Algorithmica ◽

10.1007/s00453-020-00795-3 ◽

2021 ◽

Author(s):

Robert Ganian ◽

Sebastian Ordyniak ◽

M. S. Ramanujan

Keyword(s):

Polynomial Time ◽

Disjoint Paths ◽

Structural Parameter ◽

Input Graph ◽

Feedback Vertex Set ◽

Fpt Algorithms ◽

Edge Disjoint ◽

Fpt Algorithm ◽

Vertex Set ◽

Terminal Pair

AbstractIn this paper we revisit the classical edge disjoint paths (EDP) problem, where one is given an undirected graph G and a set of terminal pairs P and asks whether G contains a set of pairwise edge-disjoint paths connecting every terminal pair in P. Our focus lies on structural parameterizations for the problem that allow for efficient (polynomial-time or FPT) algorithms. As our first result, we answer an open question stated in Fleszar et al. (Proceedings of the ESA, 2016), by showing that the problem can be solved in polynomial time if the input graph has a feedback vertex set of size one. We also show that EDP parameterized by the treewidth and the maximum degree of the input graph is fixed-parameter tractable. Having developed two novel algorithms for EDP using structural restrictions on the input graph, we then turn our attention towards the augmented graph, i.e., the graph obtained from the input graph after adding one edge between every terminal pair. In constrast to the input graph, where EDP is known to remain -hard even for treewidth two, a result by Zhou et al. (Algorithmica 26(1):3--30, 2000) shows that EDP can be solved in non-uniform polynomial time if the augmented graph has constant treewidth; we note that the possible improvement of this result to an FPT-algorithm has remained open since then. We show that this is highly unlikely by establishing the [1]-hardness of the problem parameterized by the treewidth (and even feedback vertex set) of the augmented graph. Finally, we develop an FPT-algorithm for EDP by exploiting a novel structural parameter of the augmented graph.

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Top-k retrieval using conditional preference networks

Proceedings of the 21st ACM international conference on Information and knowledge management - CIKM '12 ◽

10.1145/2396761.2398576 ◽

2012 ◽

Author(s):

Hongbing Wang ◽

Xuan Zhou ◽

Wujin Chen ◽

Peisheng Ma

Keyword(s):

Conditional Preference ◽

Conditional Preference Networks

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Comparative study of cloud platforms to develop a Chatbot

International Journal of Engineering & Technology ◽

10.14419/ijet.v6i3.7628 ◽

2017 ◽

Vol 6 (3) ◽

pp. 57 ◽

Cited By ~ 10

Author(s):

Amit Patil ◽

Marimuthu K ◽

Nagaraja Rao A ◽

Niranchana R

Keyword(s):

Artificial Intelligence ◽

Comparative Study ◽

Time Complexity ◽

Completion Time ◽

Setup Time ◽

Human Being ◽

Cloud Platform ◽

New Era ◽

Ibm Watson ◽

Aws Lambda

Before chatbots there were simply bots: The invention of a chatbot brought us to the new era of technology, the era of conversation service. A chatbot is a virtual person that can effectively talk to any human being with the help of interactive conversion textual skill. Now a days there are many cloud-based platforms available for developing and deploying the chatbot such as Microsoft bot framework, IBM Watson, Kore, AWS lambda, Microsoft Azure bot service, Chatfuel, Heroku and many more but all those techniques has some drawbacks such as built-in Artificial Intelligence, NLP, conversion service, programming etc. This paper represents the comparison between all cloud-based chatbot technologies with some constraint such as built-in AI, setup time, completion time, complexity etc. Finally, by the comparison, we will get to know that which cloud platform is efficient and suitable for developing chatbot.

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