scholarly journals Complexity of Shift Bribery in Committee Elections

2021 ◽  
Vol 13 (3) ◽  
pp. 1-25
Author(s):  
Robert Bredereck ◽  
Piotr Faliszewski ◽  
Rolf Niedermeier ◽  
Nimrod Talmon
Keyword(s):  
Computational Complexity ◽  
Voting Rules ◽  
Preference Orders ◽  
The Given

Given an election, a preferred candidate  p , and a budget, the S HIFT B RIBERY problem asks whether  p can win the election after shifting  p higher in some voters’ preference orders. Of course, shifting comes at a price (depending on the voter and on the extent of the shift) and one must not exceed the given budget. We study the (parameterized) computational complexity of S HIFT B RIBERY for multiwinner voting rules where winning the election means to be part of some winning committee. We focus on the well-established SNTV, Bloc, k -Borda, and Chamberlin-Courant rules, as well as on approximate variants of the Chamberlin-Courant rule. We show that S HIFT B RIBERY tends to be harder in the multiwinner setting than in the single-winner one by showing settings where S HIFT B RIBERY is computationally easy in the single-winner cases, but is hard (and hard to approximate) in the multiwinner ones.

Algorithm to construct integro splines

2021 ◽  
Vol 63 ◽  
pp. 359-375
Author(s):  
Renchin-Ochir Mijiddorj ◽  
Tugal Zhanlav
Keyword(s):  
Computational Complexity ◽  
Real Time ◽  
Linear Equations ◽  
System Of Linear Equations ◽  
Band Matrices ◽  
Low Computational Complexity ◽  
Computational Costs ◽  
The Given

We study some properties of integro splines. Using these properties, we design an algorithm to construct splines \(S_{m+1}(x)\) of neighbouring degrees to the given spline \(S_{m}(x)\) with degree \(m\). A local integro-sextic spline is constructed with the proposed algorithm. The local integro splines work efficiently, that is, they have low computational complexity, and they are effective for use in real time. The construction of nonlocal integro splines usually leads to solving a system of linear equations with band matrices, which yields high computational costs.   doi:10.1017/S1446181121000316

scholarly journals Blotch Detection in Archive Films Based on Visual Saliency Map

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Yildiz Aydin ◽  
Bekir Dizdaroğlu
Keyword(s):  
Computational Complexity ◽  
Cultural Heritage ◽  
False Alarm ◽  
Detection Method ◽  
Visual Saliency ◽  
Saliency Map ◽  
Saliency Maps ◽  
Block Based ◽  
The Given ◽  
Blotch Detection

Degradations frequently occur in archive films that symbolize the historical and cultural heritage of a nation. In this study, the problem of detection blotches commonly encountered in archive films is handled. Here, a block-based blotch detection method is proposed based on a visual saliency map. The visual saliency map reveals prominent areas in an input frame and thus enables more accurate results in the blotch detection. A simple and effective visual saliency map method is taken into consideration in order to reduce computational complexity for the detection phase. After the visual saliency maps of the given frames are obtained, blotch regions are estimated by considered spatiotemporal patches—without the requirement for motion estimation—around the saliency pixels, which are subjected to a prethresholding process. Experimental results show that the proposed block-based blotch detection method provides a significant advantage with reducing false alarm rates over HOG feature (Yous and Serir, 2017), LBP feature (Yous and Serir, 2017), and regions-matching (Yous and Serir, 2016) methods presented in recent years.

scholarly journals Computational Social Choice Meets Databases

2018 ◽  
Author(s):  
Benny Kimelfeld ◽  
Phokion G. Kolaitis ◽  
Julia Stoyanovich
Keyword(s):  
Computational Complexity ◽  
Social Choice ◽  
Relational Database ◽  
Database Management ◽  
Plurality Rule ◽  
Technical Level ◽  
Computational Social Choice ◽  
Conceptual Level ◽  
Voting Rules ◽  
Conjunctive Queries

We develop a novel framework that aims to create bridges between the computational social choice and the database management communities. This framework enriches the tasks currently supported in computational social choice with relational database context, thus making it possible to formulate sophisticated queries about voting rules, candidates, voters, issues, and positions. At the conceptual level, we give rigorous semantics to queries in this framework by introducing the notions of necessary answers and possible answers to queries. At the technical level, we embark on an investigation of the computational complexity of the necessary answers. In particular, we establish a number of results about the complexity of the necessary answers of conjunctive queries involving the plurality rule that contrast sharply with earlier results about the complexity of the necessary winners under the plurality rule.

scholarly journals Computational complexity in the design of voting rules

2015 ◽  
Vol 80 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Koji Takamiya ◽  
Akira Tanaka
Keyword(s):  
Computational Complexity ◽  
Voting Rules

scholarly journals Towards completing the puzzle: complexity of control by replacing, adding, and deleting candidates or voters

2021 ◽  
Vol 35 (2) ◽  
Author(s):  
Gábor Erdélyi ◽  
Marc Neveling ◽  
Christian Reger ◽  
Jörg Rothe ◽  
Yongjie Yang ◽  
...  
Keyword(s):  
Computational Complexity ◽  
Structural Changes ◽  
Voting Rules ◽  
Control Actions ◽  
Electoral Control ◽  
Range Voting

AbstractWe investigate the computational complexity of electoral control in elections. Electoral control describes the scenario where the election chair seeks to alter the outcome of the election by structural changes such as adding, deleting, or replacing either candidates or voters. Such control actions have been studied in the literature for a lot of prominent voting rules. We complement those results by solving several open cases for Copeland$$^{\alpha }$$ α , maximin, k-veto, plurality with runoff, veto with runoff, Condorcet, fallback, range voting, and normalized range voting.

scholarly journals Well-Structured Committees

2020 ◽  
Author(s):  
Sushmita Gupta ◽  
Pallavi Jain ◽  
Saket Saurabh
Keyword(s):  
Standard Model ◽  
Parameterized Complexity ◽  
Independent Set ◽  
Combinatorial Problems ◽  
Voting Rules ◽  
Voter Preferences ◽  
Candidate Network ◽  
Graph Properties ◽  
The Standard Model ◽  
The Given

In the standard model of committee selection, we are given a set of ordinal votes over a set of candidates and a desired committee size, and the task is to select a committee that relates to the given votes. Motivated by possible interactions and dependencies between candidates, we study a generalization of committee selection in which the candidates are connected via a network and the task is to select a committee that relates to the given votes while also satisfy certain properties with respect to this candidate network. To accommodate certain correspondences to the voter preferences, we consider three standard voting rules (in particular, $k$-Borda, Chamberlin-Courant, and Gehrlein stability); to model different aspects of interactions and dependencies between candidates, we consider two graph properties (in particular, Independent Set and Connectivity). We study the parameterized complexity of the corresponding combinatorial problems and discuss certain implications of our algorithmic results.

Choices and their Consequences - Explaining Acceptable Sets in Abstract Argumentation Frameworks

2021 ◽  
Author(s):  
Ringo Baumann ◽  
Markus Ulbricht
Keyword(s):  
Computational Complexity ◽  
Characteristic Function ◽  
Decision Problems ◽  
Argumentation Framework ◽  
Abstract Argumentation ◽  
Exhaustive Study ◽  
The Given ◽  
Made In

We develop a notion of explanations for acceptance of arguments in an abstract argumentation framework. To this end we show that extensions returned by Dung's standard semantics can be decomposed into i) non-deterministic choices made on even cycles of the given argumentation graph and then ii) deterministic iteration of the so-called characteristic function. Naturally, the choice made in i) can be viewed as an explanation for the corresponding extension and thus the arguments it contains. We proceed to propose desirable criteria a reasonable notion of an explanation should satisfy. We present an exhaustive study of the newly introduced notion w.r.t. these criteria. Finally some interesting decision problems arise from our analysis and we examine their computational complexity, obtaining some surprising tractability results.

Optimal enforcement of liveness for decentralized systems of flexible manufacturing systems using Petri nets

2020 ◽  
Vol 42 (12) ◽  
pp. 2206-2220
Author(s):  
Muhammad Bashir
Keyword(s):  
Computational Complexity ◽  
Petri Nets ◽  
Petri Net ◽  
Supervisory Control ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Common Elements ◽  
Decentralized Controllers ◽  
The Given

The decentralized supervisory structure has drawn much attention in recent years. Many studies are reported in the paradigm of automata while few can be found in the Petri net model. This paper proposes a new method for decentralized supervisory control using the Petri net paradigm. Two efficient Algorithms are developed in the proposed method. Algorithm 1 is used to compute decentralized working zones from the given LS3PR Petri net model for flexible manufacturing systems. Algorithm 2 is used to compute the decentralized controllers that enforced liveness to the decentralized working zones. The sequential assembling is used to reconnect and controlled the working zones via decentralized controllers. The decentralized controller is added to the decentralized working zones that have common elements, that is, common transitions. The proposed method has the following advantages: (i) it can be applied to a complex Petri net model for flexible manufacturing systems, (ii) the proposed methods has less computational complexity when compared with the previous methods, (iii) the proposed method can obtain a minimal number of decentralized controllers that enforce liveness of the uncontrolled Petri net model. Experimental examples are presented to explore the applicability of the proposed methods.

ALGORITHM TO CONSTRUCT INTEGRO SPLINES

2021 ◽  
pp. 1-17
Author(s):  
R. MIJIDDORJ ◽  
T. ZHANLAV
Keyword(s):  
Computational Complexity ◽  
Real Time ◽  
Linear Equations ◽  
System Of Linear Equations ◽  
Band Matrices ◽  
Low Computational Complexity ◽  
Computational Costs ◽  
The Given

Abstract We study some properties of integro splines. Using these properties, we design an algorithm to construct splines $S_{m+1}(x)$ of neighbouring degrees to the given spline $S_m(x)$ with degree m. A local integro-sextic spline is constructed with the proposed algorithm. The local integro splines work efficiently, that is, they have low computational complexity, and they are effective for use in real time. The construction of nonlocal integro splines usually leads to solving a system of linear equations with band matrices, which yields high computational costs.

scholarly journals Elections with Few Voters: Candidate Control Can Be Easy

2017 ◽  
Vol 60 ◽  
pp. 937-1002 ◽  
Author(s):  
Jiehua Chen ◽  
Piotr Faliszewski ◽  
Rolf Niedermeier ◽  
Nimrod Talmon
Keyword(s):  
Computational Complexity ◽  
Parameterized Complexity ◽  
Voting Rules ◽  
Standard Scenario ◽  
Candidate Control

We study the computational complexity of candidate control in elections with few voters, that is, we consider the parameterized complexity of candidate control in elections with respect to the number of voters as a parameter. We consider both the standard scenario of adding and deleting candidates, where one asks whether a given candidate can become a winner (or, in the destructive case, can be precluded from winning) by adding or deleting few candidates, as well as a combinatorial scenario where adding/deleting a candidate automatically means adding or deleting a whole group of candidates. Considering several fundamental voting rules, our results show that the parameterized complexity of candidate control, with the number of voters as the parameter, is much more varied than in the setting with many voters.

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