A Pareto-metaheuristic for a bi-objective winner determination problem in a combinatorial reverse auction

The bi-objective winner determination problem (2WDP-SC) of a combinatorial procurement auction for transport contracts comes up to a multi-criteria set covering problem. We are given a set B of bundle bids. A bundle bid b in B consists of a bidding carrier c_b, a bid price p_b, and a set tau_b of transport contracts which is a subset of the set T of tendered transport contracts. Additionally, the transport quality q_t,c_b is given which is expected to be realized when a transport contract t is executed by a carrier c_b. The task of the auctioneer is to find a set X of winning bids (X is subset of B), such that each transport contract is part of at least one winning bid, the total procurement costs are minimized, and the total transport quality is maximized. This article presents a metaheuristic approach for the 2WDP-SC which integrates the greedy randomized adaptive search procedure, large neighborhood search, and self-adaptive parameter setting in order to find a competitive set of non-dominated solutions. The procedure outperforms existing heuristics. Computational experiments performed on a set of benchmark instances show that, for small instances, the presented procedure is the sole approach that succeeds to find all Pareto-optimal solutions. For each of the large benchmark instances, according to common multi-criteria quality indicators of the literature, it attains new best-known solution sets.Pareto optimization; multi-criteria winner determination; combinatorial auction; GRASP; LNS

Characterization Of Phosphorus, Nitrogen, And Sulfur Concentrations In A Paired Disturbed And Natural Wetland In Northwest Minnesota

A degraded wetland with a history of human-induced hydrologic alterations lies within northwestern Minnesota\u27s Skull Lake Wildlife Management Area (WMA). Although conservation practices have been enacted by the Minnesota Department of Natural Resources (MNDNR), there remains interest in the wetland\u27s potential for ecological restoration. Restoration should not be undertaken without an understanding of underlying factors leading to degradation. A paired study between the disturbed wetland at Skull Lake WMA and the relatively natural wetland in the nearby Caribou WMA was designed to help understand near surface pore water geochemistry in an effort to determine causes of degradation and the potential for reversal. Shallow groundwater samples collected along and perpendicular to a major ditch flowing through the wetland were analyzed for pH, Eh, sulfide (H2S), soluble reactive phosphorus (SRP), sulfate (SO4), nitrate (NO3), and nitrite (NO2). Data revealed nutrient gradients and characterized nutrient transport relative to State Ditch 84. Wetland geochemistry comparisons between the disturbed cattail marsh and undisturbed sedge meadow showed increased concentrations of SRP, Eh, and pH. This indicates that Caribou WMA is a low nutrient ecosystem and suggests that Skull Lake WMA has become a phosphorus sink. Correlation between distance to State Ditch 84 and geochemical constituents indicated increased acidity and nitrite concentrations and possible SRP export out of the system during the fall. Ecological restoration through prescribed burning and water level control may reduce invasive macrophyte communities, but altered pore water chemistry and increased pore water SRP concentrations may inhibit the full restoration potential of Skull Lake WMAs wetland

Variations on a Theme of Robert Schumann: Intertextual References and Private Meaning in Clara Schumann’s Opus 20 and Johannes Brahms’s Opus 9

Buer, Karin. Variations on a Theme of Robert Schumann: Intertextual References and Private Meaning in Clara Schumann’s Opus 20 and Johannes Brahms’s Opus 9. Published Doctor of Arts dissertation, University of Northern Colorado, 2020. For centuries, composers have used their music as an expressive tool, imbuing it with publicly accessible meaning that often reflects the time and place in which the composer lived. Throughout the nineteenth century, the view of music as a means of expression, specifically self-expression, became crystallized as never before. Robert Schumann and other literary-minded nineteenth-century composers thus communicated, through their art, meanings which were both public and private, turning to extracompositional and extramusical references as a frequent means of doing so. Consequently, an intertextual approach to their music can reveal additional layers of expressive meaning and can allow current performers and listeners to interpret the music from the perspective of a romantic-era insider. Both Robert and Clara Schumann, and later Johannes Brahms, used their music to communicate amongst themselves and with close associates, especially in more intimate genres such as piano variations. Two works which are particularly ripe with intertextual references and private meaning are Clara’s Variations on a Theme of Robert Schumann, Op. 20, which she gave to Robert as a birthday present in 1853, and Brahms’s Op. 9 variations on the same theme, which he wrote for Clara the following year. In her Op. 20 variations, Clara includes quotations and allusions to a number of Robert’s works as well as to works she was performing and therefore practicing at the time, rendering the piece the ultimate birthday present. Brahms, in response to Clara’s variations, composes a set which interweaves references to several of Robert’s works and one of Clara’s, often by layering multiple allusions within the same variation. In doing so, he pays respect to his beloved mentor—the recently institutionalized Robert—while privately providing comfort to and sharing the grief with Clara. A strong historical awareness rooted in documentary evidence, combined with a robust music-theoretical analysis drawing upon Schenkerian analytical methods, provides a mechanism for testing the strength of the connections found within these pieces

Orkney pilgrimage: perspectives of the cult of St. Magnus

The early Christian cults of saints and relics as well as the act and process of pilgrimage were central themes in the religious practice of the Middle Ages. The veneration of saints and relics, the belief in miracles, and the act of pilgrimage were aspects of Christianity rapidly adopted by the converted population of the North Atlantic. This thesis focuses on St Magnus, Earl of Orkney († c. 1116), the cult and pilgrimage process which emerged about a century after the conversion of the Northern Isles. The physical monuments and primary sources, are seen as defining the cult, the pilgrimage process, as well as outlining a trace of the route. St Magnus cult and pilgrimage are also discussed within a comparative context; of the Norse cultural sphere, and of the medieval Universal Church

Surveys For Rare and Endangered Mussel Species In Kansas: Traditional Methods and Environmental DNA Analysis

The Mucket (Actinonaias ligamentina) is one of the rarest freshwater mussel species in the state of Kansas. It historically occurred in the Kansas and Osage River systems in the state. The Mucket has been extirpated from most streams and rivers in Kansas where it historically occurred, and few specimens have been documented in recent years. The objective of my project was to determine the conservation status of the Mucket by conducting qualitative surveys in the Osage River system of eastern Kansas. My goals were to collect information that will aid in the recovery of the Mucket and to provide information regarding the mussel communities in these streams. During the summer of 2016, I surveyed 14 sites on the Marais des Cygnes River, 5 sites on Pottawatomie Creek, and 4 sites on the Marmaton River. I collected one live Mucket on Pottawatomie Creek. During the course of the survey, I collected 2,993 live mussels representing 19 species