Varsovienne

https://digitalcommons.library.umaine.edu/mmb-ps/2940/thumbnail.jp

Harvard Caprice

https://digitalcommons.library.umaine.edu/mmb-me/1088/thumbnail.jp

The Berlin

https://digitalcommons.library.umaine.edu/mmb-ps/2781/thumbnail.jp

Rainbow matchings in Dirac bipartite graphs

This is the peer reviewed version of the following article: Coulson, M, Perarnau, G. Rainbow matchings in Dirac bipartite graphs. Random Struct Alg. 2019; 55: 271– 289., which has been published in final form at https://doi.org/10.1002/rsa.20835. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsWe show the existence of rainbow perfect matchings in µn-bounded edge colorings of Dirac bipartite graphs, for a sufficiently small µ¿>¿0. As an application of our results, we obtain several results on the existence of rainbow k-factors in Dirac graphs and rainbow spanning subgraphs of bounded maximum degree on graphs with large minimum degree

Matrix permanent and quantum entanglement of permutation invariant states

We point out that a geometric measure of quantum entanglement is related to the matrix permanent when restricted to permutation invariant states. This connection allows us to interpret the permanent as an angle between vectors. By employing a recently introduced permanent inequality by Carlen, Loss and Lieb, we can prove explicit formulas of the geometric measure for permutation invariant basis states in a simple way.Comment: 10 page

Temperatures experienced by fresh-cut leafy greens during retail storage and display

There has been limited published work in the United States on temperature profiling of fresh-cut, bagged leafy greens during their transport, retail storage, and retail display. This study utilized temperature monitors placed in backrooms and display cases at nine supermarkets located in southern California: the Central Coast (Santa Barbara to Los Osos), Greater Los Angeles (Burbank area), and Greater Palm Desert. Sensors were installed midway along each 8-foot display case section containing fresh-cut leafy greens. Monitors were placed at the front and back of shelves and in the lower bin. In storage rooms, sensors were placed 4 feet from the floor in each corner. High and low temperature abuse occurred in retail display cases, with slightly more than 40% of the sensors indicating temperatures \u3e7.22°C, and 17% of the sensors indicating temperatures \u3c-0.17°C, for at least 5% of the time. Temperatures in storage rooms were rarely too low, but were often too high: slightly more than 58% of the sensors indicated temperatures \u3e7.22°C more than 5% of the time, and five sensors measured continuous temperatures \u3e7.22°C for nearly a year. Overall, most temperature abuse of pre-cut leafy greens at the retail level occurred during backroom storage. This study should be expanded to include major grocery chains in cities across the United States in order to verify these results

Heat Sources within the Greenland Ice Sheet: Dissipation, Temperate Paleo-Firn and Cryo-Hydrologic Warming

Ice temperature profiles from the Greenland Ice Sheet contain information on the deformation history, past climates and recent warming. We present full-depth temperature profiles from two drill sites on a flow line passing through Swiss Camp, West Greenland. Numerical modeling reveals that ice temperatures are considerably higher than would be expected from heat diffusion and dissipation alone. The possible causes for this extra heat are evaluated using a Lagrangian heat flow model. The model results reveal that the observations can be explained with a combination of different processes: enhanced dissipation (strain heating) in ice-age ice, temperate paleo-firn, and cryo-hydrologic warming in deep crevasses

Families with infants: a general approach to solve hard partition problems

We introduce a general approach for solving partition problems where the goal is to represent a given set as a union (either disjoint or not) of subsets satisfying certain properties. Many NP-hard problems can be naturally stated as such partition problems. We show that if one can find a large enough system of so-called families with infants for a given problem, then this problem can be solved faster than by a straightforward algorithm. We use this approach to improve known bounds for several NP-hard problems as well as to simplify the proofs of several known results. For the chromatic number problem we present an algorithm with $O^*((2-\varepsilon(d))^n)$ time and exponential space for graphs of average degree $d$. This improves the algorithm by Bj\"{o}rklund et al. [Theory Comput. Syst. 2010] that works for graphs of bounded maximum (as opposed to average) degree and closes an open problem stated by Cygan and Pilipczuk [ICALP 2013]. For the traveling salesman problem we give an algorithm working in $O^*((2-\varepsilon(d))^n)$ time and polynomial space for graphs of average degree $d$. The previously known results of this kind is a polyspace algorithm by Bj\"{o}rklund et al. [ICALP 2008] for graphs of bounded maximum degree and an exponential space algorithm for bounded average degree by Cygan and Pilipczuk [ICALP 2013]. For counting perfect matching in graphs of average degree~$d$ we present an algorithm with running time $O^*((2-\varepsilon(d))^{n/2})$ and polynomial space. Recent algorithms of this kind due to Cygan, Pilipczuk [ICALP 2013] and Izumi, Wadayama [FOCS 2012] (for bipartite graphs only) use exponential space.Comment: 18 pages, a revised version of this paper is available at http://arxiv.org/abs/1410.220