The Lasserre/Sum-of-Squares hierarchy is a systematic procedure to strengthen LP relaxations by constructing a sequence of increasingly tight formulations. For a wide variety of optimization problems, this approach captures the convex relaxations used in the best available approximation algorithms. The capacitated covering IP is an integer program of the form min{cx : Ux ≥ d, 0 ≤ x ≤ b, x ∈ Z+}...

The nature of the verb deficit in Alzheimer’s disease (AD) was investigated with a special focus on thematic-role assignment, employing verbs whose argument realization follows canonical thematic hierarchy, with Agent and Theme as main roles (e.g., The hunter killed the deer), and verbs whose argument realization deviates from canonical hierarchy, such as psych verbs (e.g., fear, frighten). Sub...

We consider the problem of proving circuit lower bounds against the polynomialtime hierarchy. We first revisit a lower bound given by Kannan [Kan82], and for any fixed integer k > 0, we give an explicit Σp2 language, recognizable by a Σ p 2-machine with running time O(nk 2+k), that requires circuit size > nk. Next, as our main results, we give relativized results showing the difficulty of provi...

While big data is revolutionizing scientific research, the tasks of data management and analytics are becoming more challenging than ever. One way to remit the difficulty is to obtain the multilevel hierarchy embedded in the data. Knowing the hierarchy enables not only the revelation of the nature of the data, it is also often the first step in big data analytics. However, current algorithms fo...

Competent design of hierarchical interfaces for hardware/software systems needs the convergence of three concurrent research directions: the study of hierarchy types, the intelligent communication between different domains, the formalization of verification/test. We aim to extend the theory of hierarchy types, in order to integrate communication properties as well as correctness and testability...

Keyword search is by far the most popular technique for searching linked data on the web. The simplicity of keyword search on data graphs comes with at least two drawbacks: difficulty in identifying results relevant to the user intent among an overwhelming number of candidates and performance scalability problems. In this paper, we claim that result ranking and top-k processing which adapt sche...

Elastic network models (ENMs) and, in particular, the Gaussian Network Model (GNM) have been widely used in recent years to gain insights into the machinery of proteins. The extension of ENMs to supramolecular assemblies presents computational challenges, because of the difficulty in retaining atomic details in mode decomposition of large protein dynamics. Here, we present a novel approach to a...

The original Yahoo! search engine consists of manually organized topic hierarchy of webpages for easy browsing. Modern search engines (such as Google and Bing), on the other hand, return a flat list of webpages based on keywords. It would be ideal if hierarchical browsing and keyword search can be seamlessly combined. The main difficulty in doing so is to automatically (i.e., not manually) clas...

OBJECTIVE To determine if there is a hierarchy of improvement program adoption by hospitals and outline that hierarchy. DATA SOURCES Primary data were collected in the spring of 2007 via e-survey from 210 individuals representing 109 Minnesota hospitals. Secondary data from 2006 were assembled from the Leapfrog database. STUDY DESIGN As part of a larger survey, respondents were given a list...