41 research outputs found
LIPIcs, Volume 261, ICALP 2023, Complete Volume
LIPIcs, Volume 261, ICALP 2023, Complete Volum
Optimal majority rules and quantitative Condorcet properties of setwise Kemeny voting schemes
The important Kemeny problem, which consists of computing median consensus
rankings of an election with respect to the Kemeny voting rule, admits
important applications in biology and computational social choice and was
generalized recently via an interesting setwise approach by Gilbert et. al. Our
first results establish optimal quantitative extensions of the Unanimity
property and the well-known -majority rule of Betzler et al. for the
classical Kemeny median problem. Moreover, by elaborating an exhaustive list of
quantified axiomatic properties (such as the Condorcet and Smith criteria, the
-majority rule, etc.) of the -wise Kemeny rule where not only pairwise
comparisons but also the discordance between the winners of subsets of three
candidates are also taken into account, we come to the conclusion that the
-wise Kemeny voting scheme induced by the -wise Kendall-tau distance
presents interesting advantages in comparison with the classical Kemeny rule.
For example, it satisfies several improved manipulation-proof properties. Since
the -wise Kemeny problem is NP-hard, our results also provide some of the
first useful space reduction techniques by determining the relative orders of
pairs of alternatives. Our works suggest similar interesting properties of
higher setwise Kemeny voting schemes which justify and compensate for the more
expensive computational cost than the classical Kemeny scheme
LIPIcs, Volume 274, ESA 2023, Complete Volume
LIPIcs, Volume 274, ESA 2023, Complete Volum
Collected Papers (on Neutrosophic Theory and Applications), Volume VIII
This eighth volume of Collected Papers includes 75 papers comprising 973 pages on (theoretic and applied) neutrosophics, written between 2010-2022 by the author alone or in collaboration with the following 102 co-authors (alphabetically ordered) from 24 countries: Mohamed Abdel-Basset, Abduallah Gamal, Firoz Ahmad, Ahmad Yusuf Adhami, Ahmed B. Al-Nafee, Ali Hassan, Mumtaz Ali, Akbar Rezaei, Assia Bakali, Ayoub Bahnasse, Azeddine Elhassouny, Durga Banerjee, Romualdas Bausys, Mircea Boșcoianu, Traian Alexandru Buda, Bui Cong Cuong, Emilia Calefariu, Ahmet Çevik, Chang Su Kim, Victor Christianto, Dae Wan Kim, Daud Ahmad, Arindam Dey, Partha Pratim Dey, Mamouni Dhar, H. A. Elagamy, Ahmed K. Essa, Sudipta Gayen, Bibhas C. Giri, Daniela Gîfu, Noel Batista Hernández, Hojjatollah Farahani, Huda E. Khalid, Irfan Deli, Saeid Jafari, Tèmítópé Gbóláhàn Jaíyéolá, Sripati Jha, Sudan Jha, Ilanthenral Kandasamy, W.B. Vasantha Kandasamy, Darjan Karabašević, M. Karthika, Kawther F. Alhasan, Giruta Kazakeviciute-Januskeviciene, Qaisar Khan, Kishore Kumar P K, Prem Kumar Singh, Ranjan Kumar, Maikel Leyva-Vázquez, Mahmoud Ismail, Tahir Mahmood, Hafsa Masood Malik, Mohammad Abobala, Mai Mohamed, Gunasekaran Manogaran, Seema Mehra, Kalyan Mondal, Mohamed Talea, Mullai Murugappan, Muhammad Akram, Muhammad Aslam Malik, Muhammad Khalid Mahmood, Nivetha Martin, Durga Nagarajan, Nguyen Van Dinh, Nguyen Xuan Thao, Lewis Nkenyereya, Jagan M. Obbineni, M. Parimala, S. K. Patro, Peide Liu, Pham Hong Phong, Surapati Pramanik, Gyanendra Prasad Joshi, Quek Shio Gai, R. Radha, A.A. Salama, S. Satham Hussain, Mehmet Șahin, Said Broumi, Ganeshsree Selvachandran, Selvaraj Ganesan, Shahbaz Ali, Shouzhen Zeng, Manjeet Singh, A. Stanis Arul Mary, Dragiša Stanujkić, Yusuf Șubaș, Rui-Pu Tan, Mirela Teodorescu, Selçuk Topal, Zenonas Turskis, Vakkas Uluçay, Norberto Valcárcel Izquierdo, V. Venkateswara Rao, Volkan Duran, Ying Li, Young Bae Jun, Wadei F. Al-Omeri, Jian-qiang Wang, Lihshing Leigh Wang, Edmundas Kazimieras Zavadskas
Rank Aggregation Using Scoring Rules
To aggregate rankings into a social ranking, one can use scoring systems such
as Plurality, Veto, and Borda. We distinguish three types of methods: ranking
by score, ranking by repeatedly choosing a winner that we delete and rank at
the top, and ranking by repeatedly choosing a loser that we delete and rank at
the bottom. The latter method captures the frequently studied voting rules
Single Transferable Vote (aka Instant Runoff Voting), Coombs, and Baldwin. In
an experimental analysis, we show that the three types of methods produce
different rankings in practice. We also provide evidence that sequentially
selecting winners is most suitable to detect the "true" ranking of candidates.
For different rules in our classes, we then study the (parameterized)
computational complexity of deciding in which positions a given candidate can
appear in the chosen ranking. As part of our analysis, we also consider the
Winner Determination problem for STV, Coombs, and Baldwin and determine their
complexity when there are few voters or candidates.Comment: 47 pages including appendi
On absolutely and simply popular rankings
Van Zuylen et al. introduced the notion of a popular ranking in a voting
context, where each voter submits a strictly-ordered list of all candidates. A
popular ranking of the candidates is at least as good as any other
ranking in the following sense: if we compare to , at
least half of all voters will always weakly prefer~. Whether a voter
prefers one ranking to another is calculated based on the Kendall distance.
A more traditional definition of popularity -- as applied to popular
matchings, a well-established topic in computational social choice -- is
stricter, because it requires at least half of the voters \emph{who are not
indifferent between and } to prefer~. In this paper, we
derive structural and algorithmic results in both settings, also improving upon
the results by van Zuylen et al. We also point out strong connections to the
famous open problem of finding a Kemeny consensus with 3 voters.Comment: full version of the AAMAS 2021 extended abstract 'On weakly and
strongly popular rankings
On Weakly and Strongly Popular Rankings
Van Zuylen et al. introduced the notion of a popular ranking in a voting context, where each voter submits a strictly-ordered list of all candidates. A popular ranking pi of the candidates is at least as good as any other ranking sigma in the following sense: if we compare pi to sigma, at least half of all voters will always weakly prefer pi. Whether a voter prefers one ranking to another is calculated based on the Kendall distance.
A more traditional definition of popularity---as applied to popular matchings, a well-established topic in computational social choice---is stricter, because it requires at least half of the voters who are not indifferent between pi and sigma to prefer pi. In this paper, we derive structural and algorithmic results in both settings, also improving upon the results by van Zylen et al. We also point out connections to the famous open problem of finding a Kemeny consensus with 3 voters
Towards completing the puzzle: complexity of control by replacing, adding, and deleting candidates or voters
We 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 Copelandα, maximin, k-veto, plurality with runoff, veto with runoff, Condorcet, fallback, range voting, and normalized range voting