F-measure Maximization in Multi-Label Classification with Conditionally Independent Label Subsets

We discuss a method to improve the exact F-measure maximization algorithm called GFM, proposed in (Dembczynski et al. 2011) for multi-label classification, assuming the label set can be can partitioned into conditionally independent subsets given the input features. If the labels were all independent, the estimation of only $m$ parameters ($m$ denoting the number of labels) would suffice to derive Bayes-optimal predictions in $O(m^2)$ operations. In the general case, $m^2+1$ parameters are required by GFM, to solve the problem in $O(m^3)$ operations. In this work, we show that the number of parameters can be reduced further to $m^2/n$, in the best case, assuming the label set can be partitioned into $n$ conditionally independent subsets. As this label partition needs to be estimated from the data beforehand, we use first the procedure proposed in (Gasse et al. 2015) that finds such partition and then infer the required parameters locally in each label subset. The latter are aggregated and serve as input to GFM to form the Bayes-optimal prediction. We show on a synthetic experiment that the reduction in the number of parameters brings about significant benefits in terms of performance

Remembering the Revolution: Monuments and Commemorations of American Revolutionary War Sites in New York

Memorials and monuments at military heritage sites track the ways American society constructs and then reconstructs its understandings of important events. They present enticing material culture for study by archaeologists seeking to analyze the layers of meaning and the social and chronological transformations in the heritage narratives at military sites. With the prominence of recent national discourses surrounding the heritage narratives presented by Civil War Confederate monuments, there is a paramount need for archaeologists to lend their expertise in material culture studies to these dialogues. I also believe it remains important to expand this critical examination of Civil War monuments to other wars. The use of monuments to support specific discourses about the past is not an aberration but an established, consistently used means of heritage discourse. Although elites use memorials to craft heritage narratives in support of their power, ethnic-based organizations have also used memorialization to engage and challenge oppressive national ideologies. This dissertation examines the monuments and signage constructed at five Revolutionary War sites within New York State: Oriskany Battlefield, Fort Stanwix National Monument, Saratoga Battlefield, Newtown Battlefield, and Old Fort Niagara. My dissertation foregrounds the agency of the Haudenosaunee (Iroquois), Irish, and Polish in asserting their own narratives since thelate 19 th century. My analysis challenges portrayals of heritage as monolithic narratives defined exclusively by elite, white, Anglo-Saxons while suggesting that non-dominant ethnicities only engaged in the construction of heritage within the last few decades. My research demonstrates how heritage narratives are transformed by numerous stakeholders. This research is especially relevant with the current national discourse on the meaning, symbolism, and memory of monuments in public spaces. I conclude that the Authorized Heritage Discourses presented at each site were more influenced by the descendants of those who fought at the site rather than whether the site was managed at the New York State or Federal level. At the same time, I observed a clear trend by ethnic organizations of Irish-Americans, Dutch-Americans, and Polish-Americans and by the various nations of theHaudenosaunee to engage with and sometimes challenge these Authorized Heritage Discourses at these sites

Colwyn Bay

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Distributional fixed point equations for island nucleation in one dimension: a retrospective approach for capture zone scaling

The distributions of inter-island gaps and captures zones for islands nucleated on a one-dimensional substrate during submonolayer deposition are considered using a novel retrospective view. This provides an alternative perspective on why scaling occurs in this continuously evolving system. Distributional fixed point equations for the gaps are derived both with and without a mean field approximation for nearest neighbour gap size correlation. Solutions to the equations show that correct consideration of fragmentation bias justifies the mean field approach which can be extended to provide closed-from equations for the capture zones. Our results compare favourably to Monte Carlo data for both point and extended islands using a range of critical island size $i=0,1,2,3$. We also find satisfactory agreement with theoretical models based on more traditional fragmentation theory approaches.Comment: 9 pages, 7 figures and 1 tabl

Estimation of ice shelf melt rate in the presence of a thermohaline staircase

Diffusive convection–favorable thermohaline staircases are observed directly beneath George VI Ice Shelf, Antarctica. A thermohaline staircase is one of the most pronounced manifestations of double-diffusive convection. Cooling and freshening of the ocean by melting ice produces cool, freshwater above the warmer, saltier water, the water mass distribution favorable to a type of double-diffusive convection known as diffusive convection. While the vertical distribution of water masses can be susceptible to diffusive convection, none of the observations beneath ice shelves so far have shown signals of this process and its effect on melting ice shelves is uncertain. The melt rate of ice shelves is commonly estimated using a parameterization based on a three-equation model, which assumes a fully developed, unstratified turbulent flow over hydraulically smooth surfaces. These prerequisites are clearly not met in the presence of a thermohaline staircase. The basal melt rate is estimated by applying an existing heat flux parameterization for diffusive convection in conjunction with the measurements of oceanic conditions at one site beneath George VI Ice Shelf. These estimates yield a possible range of melt rates between 0.1 and 1.3 m yr−1, where the observed melt rate of this site is ~1.4 m yr−1. Limitations of the formulation and implications of diffusive convection beneath ice shelves are discussed

Μελέτη και σχεδίαση Ε/Γ ‐ Ο/Γ πλοίου κλειστού τύπου

128 σ.Νικόλαος Ηρ. Παναγιωτακόπουλο

Characterizing Ranked Chinese Syllable-to-Character Mapping Spectrum: A Bridge Between the Spoken and Written Chinese Language

One important aspect of the relationship between spoken and written Chinese is the ranked syllable-to-character mapping spectrum, which is the ranked list of syllables by the number of characters that map to the syllable. Previously, this spectrum is analyzed for more than 400 syllables without distinguishing the four intonations. In the current study, the spectrum with 1280 toned syllables is analyzed by logarithmic function, Beta rank function, and piecewise logarithmic function. Out of the three fitting functions, the two-piece logarithmic function fits the data the best, both by the smallest sum of squared errors (SSE) and by the lowest Akaike information criterion (AIC) value. The Beta rank function is the close second. By sampling from a Poisson distribution whose parameter value is chosen from the observed data, we empirically estimate the $p$-value for testing the two-piece-logarithmic-function being better than the Beta rank function hypothesis, to be 0.16. For practical purposes, the piecewise logarithmic function and the Beta rank function can be considered a tie.Comment: 15 pages, 4 figure