Fischer provided a new type of binomial determinant for the number alternating sign matrices involving third root unity. In this paper we prove that her formula, when replacing unity by an indeterminate q, actually gives (q?1+2+q)-enumeration matrices. By evaluating generalisation are able to reprove conjecture Mills, Robbins and Rumsey stating Q-enumeration is product two polynomials in Q. Fur...

For many election systems, bribery (and related) attacks have been shown NP-hard using constructions on combinatorially rich structures such as partitions and covers. This paper shows that for voters who follow the most central political-science model of electorates— single-peaked preferences—those hardness protections vanish. By using single-peaked preferences to simplify combinatorial coverin...

By modifying the Chen & Wu ansatz, we have investigated some Friedmann models in which Λ varies as ρ. In order to test the consistency of the models with observations, we study the angular size redshift relation for 256 ultracompact radio sources selected by Jackson & Dodgson. The angular sizes of these sources were determined by using very long-baseline interferometry in order to avoid any evo...

When agents need to make decisions on multiple issues, one solution is to vote on the issues sequentially. In this paper, we investigate how well the winner under the sequential voting process approximates the winners under some common voting rules. Some common voting rules, including Borda, k-approval, Copeland, maximin, Bucklin, and Dodgson, admit natural scoring functions that can serve as a...

In multivariate statistical analysis, several authors have studied the total positivity properties of the generalized (0F1) hypergeometric function of two real symmetric matrix arguments. In this paper, we make use of zonal polynomial expansions to obtain a new proof of a result that these 0F1 functions fail to satisfy certain pairwise total positivity properties; this proof extends both to arb...