Learning sparse representations of depth

This paper introduces a new method for learning and inferring sparse representations of depth (disparity) maps. The proposed algorithm relaxes the usual assumption of the stationary noise model in sparse coding. This enables learning from data corrupted with spatially varying noise or uncertainty, typically obtained by laser range scanners or structured light depth cameras. Sparse representations are learned from the Middlebury database disparity maps and then exploited in a two-layer graphical model for inferring depth from stereo, by including a sparsity prior on the learned features. Since they capture higher-order dependencies in the depth structure, these priors can complement smoothness priors commonly used in depth inference based on Markov Random Field (MRF) models. Inference on the proposed graph is achieved using an alternating iterative optimization technique, where the first layer is solved using an existing MRF-based stereo matching algorithm, then held fixed as the second layer is solved using the proposed non-stationary sparse coding algorithm. This leads to a general method for improving solutions of state of the art MRF-based depth estimation algorithms. Our experimental results first show that depth inference using learned representations leads to state of the art denoising of depth maps obtained from laser range scanners and a time of flight camera. Furthermore, we show that adding sparse priors improves the results of two depth estimation methods: the classical graph cut algorithm by Boykov et al. and the more recent algorithm of Woodford et al.Comment: 12 page

Understanding the Transition between High School and College Mathematics and Science

Mathematics and science education is gaining increasing recognition as key for the well-being of individuals and society. Accordingly, the transition from high school to college is particularly important to ensure that students are prepared for college mathematics and science. The goal of this study was to understand how high school mathematics and science course-taking related to performance in college. Specifically, the study employed a nonparametric regression method to examine the relationship between high school mathematics and science courses, and academic performance in college mathematics and science courses. The results provide some evidence pertaining to the positive benefits from high school course-taking. Namely, students who completed high school trigonometry and lab-based chemistry tended to earn higher grades in college algebra and general chemistry, respectively. However, there was also evidence that high school coursework in biology and physics did not improve course performance in general biology and college physics beyond standardized test scores. Interestingly, students who completed high school calculus earned better grades in general biology. The implications of the findings are discussed for high school curriculum and alignment in standards between high schools and colleges

Using Linked Data for Prosopographical Research of Historical Persons : Case U.S. Congress Legislators

This paper shows how biographical registries can be represented as Linked Data, enriched by data linking to related data sources, and used in Digital Humanities. As a use case, a database of 11 987 historical U.S. Congress Legislators in 1789–2018 was transformed into a knowledge graph. The data was published as a Linked Data service, including a SPARQL endpoint, on top of which tools for biographical and prosopographical research are implemented. A faceted browser named U.S. Congress Prosopographer with visualization tools for knowledge discovery is presented to provide new insights in political history.Peer reviewe

The Finnish Think Tank Landscape : A Mixture of Consensualism and Adversity?

As a common feature of Nordic countries, the Finnish landscape of thinks tanks has been populated by large corporatist interest organisations and government-funded research organisations. In addition to this, since 2005, party-affiliated think tanks form a notable part of the picture. Recently, several small think tanks that are oriented towards specific themes, such as international relations, the environment and feminism, have been founded. This article examines Finnish developments in the field of think tanks with two objectives. First, it gives a general overview of the Finnish think tank landscape. Second, by using interview data and public mission statements of the most prominent think tanks, it explores how these organisations see their role in Finnish society. What is their relationship with media and the political machinery, and how does this relate to their position and activities as either consensual or adversarial actors? It is concluded that redeeming the place of think tanks in the Finnish polity is a continuing challenge, and resorting to adversarial tactics is not a favourable way to do so. This approach has mostly been attempted by neoliberal think tanks that, in the past, have also profited from corporatist structures to enhance their objectives.Peer reviewe

Solution structure of a repeated unit of the ABA-1 nematode polyprotein allergen of ascaris reveals a novel fold and two discrete lipid-binding sites

Parasitic nematode worms cause serious health problems in humans and other animals. They can induce allergic-type immune responses, which can be harmful but may at the same time protect against the infections. Allergens are proteins that trigger allergic reactions and these parasites produce a type that is confined to nematodes, the nematode polyprotein allergens (NPAs). These are synthesized as large precursor proteins comprising repeating units of similar amino acid sequence that are subsequently cleaved into multiple copies of the allergen protein. NPAs bind small lipids such as fatty acids and retinol (Vitamin A) and probably transport these sensitive and insoluble compounds between the tissues of the worms. Nematodes cannot synthesize these lipids, so NPAs may also be crucial for extracting nutrients from their hosts. They may also be involved in altering immune responses by controlling the lipids by which the immune and inflammatory cells communicate. We describe the molecular structure of one unit of an NPA, the well-known ABA-1 allergen of Ascaris and find its structure to be of a type not previously found for lipid-binding proteins, and we describe the unusual sites where lipids bind within this structur

Poaching and firm-sponsored training: first clean evidence

A series of seminal theoretical papers argues that poaching of employees may hamper company-sponsored general training. However, the extent of poaching, its determinants and consequences, remains an open empirical question. We provide a novel empirical identification strategy for poaching and investigate its causes and consequences. We find that only a small number of training firms in Germany are poaching victims. Firms are more likely to poach employees during an economic downturn. Training firms respond to poaching by lowering the share of new apprentice intakes in the following years

Protection of Domestic bank Ownership in France and Germany: The Functional Equivalency of Institutional Diversity in Takeovers

We investigate the character of the market for corporate control (i.e. takeovers) in French and German banking. The key feature of this character is the marked ability of French and German banks to resist unsolicited takeover bids, especially – although not exclusively– those from foreign competitors. We present an institutional perspective to account for the restrained character of takeovers in French and German banking. Our perspective is composed of two elements. First, institutional arrangements are important since they structure power relations among firm stakeholders by providing opportunities, as well as imposing constraints, to influence the decision-making process in which takeover transactions take place. Second, institutional arrangements provide firm stakeholders with several potential opportunities, not just one, to block unsolicited bids since takeover contests are composed of sequences of decisions for which approval is needed at each stage. French and German banks have used different mixes of institutional arrangements, themselves located at different stages of takeover transactions, to secure restrained markets for corporate control. Our institutional analysis, in turn, also illustrates an important shortcoming of banking sector protectionism, namely the contribution of protection from unsolicited takeover bids to the building of banks carrying systemic risks