An Optimal Linear Time Algorithm for Quasi-Monotonic Segmentation

Monotonicity is a simple yet significant qualitative characteristic. We consider the problem of segmenting a sequence in up to K segments. We want segments to be as monotonic as possible and to alternate signs. We propose a quality metric for this problem using the l_inf norm, and we present an optimal linear time algorithm based on novel formalism. Moreover, given a precomputation in time O(n log n) consisting of a labeling of all extrema, we compute any optimal segmentation in constant time. We compare experimentally its performance to two piecewise linear segmentation heuristics (top-down and bottom-up). We show that our algorithm is faster and more accurate. Applications include pattern recognition and qualitative modeling.Comment: This is the extended version of our ICDM'05 paper (arXiv:cs/0702142

Practical Evaluation of Lempel-Ziv-78 and Lempel-Ziv-Welch Tries

We present the first thorough practical study of the Lempel-Ziv-78 and the Lempel-Ziv-Welch computation based on trie data structures. With a careful selection of trie representations we can beat well-tuned popular trie data structures like Judy, m-Bonsai or Cedar

Hierarchical Bin Buffering: Online Local Moments for Dynamic External Memory Arrays

Local moments are used for local regression, to compute statistical measures such as sums, averages, and standard deviations, and to approximate probability distributions. We consider the case where the data source is a very large I/O array of size n and we want to compute the first N local moments, for some constant N. Without precomputation, this requires O(n) time. We develop a sequence of algorithms of increasing sophistication that use precomputation and additional buffer space to speed up queries. The simpler algorithms partition the I/O array into consecutive ranges called bins, and they are applicable not only to local-moment queries, but also to algebraic queries (MAX, AVERAGE, SUM, etc.). With N buffers of size sqrt{n}, time complexity drops to O(sqrt n). A more sophisticated approach uses hierarchical buffering and has a logarithmic time complexity (O(b log_b n)), when using N hierarchical buffers of size n/b. Using Overlapped Bin Buffering, we show that only a single buffer is needed, as with wavelet-based algorithms, but using much less storage. Applications exist in multidimensional and statistical databases over massive data sets, interactive image processing, and visualization

Apache Calcite: A Foundational Framework for Optimized Query Processing Over Heterogeneous Data Sources

Apache Calcite is a foundational software framework that provides query processing, optimization, and query language support to many popular open-source data processing systems such as Apache Hive, Apache Storm, Apache Flink, Druid, and MapD. Calcite's architecture consists of a modular and extensible query optimizer with hundreds of built-in optimization rules, a query processor capable of processing a variety of query languages, an adapter architecture designed for extensibility, and support for heterogeneous data models and stores (relational, semi-structured, streaming, and geospatial). This flexible, embeddable, and extensible architecture is what makes Calcite an attractive choice for adoption in big-data frameworks. It is an active project that continues to introduce support for the new types of data sources, query languages, and approaches to query processing and optimization.Comment: SIGMOD'1

Reduction deduction: Facets as a key ingredient to searching effectively in a discovery layer

One of the benefits of a discovery layer is the large number and variety of results. In order to search effectively, students must learn to narrow down those results in a meaningful way. This activity helps students tap into prior learning by exploring their natural use of facets and limiters in commercial online shopping. Students are then asked to transfer their shopping behaviors into the discovery layer using the facets and limiters

Antimicrobial activity of biogenically produced spherical Se-nanomaterials embedded in organic material against Pseudomonas aeruginosa and Staphylococcus aureus strains on hydroxyapatite-coated surfaces

In an effort to prevent the formation of pathogenic biofilms on hydroxyapatite (HA)-based clinical devices and surfaces, we present a study evaluating the antimicrobial efficacy of Spherical biogenic Se-Nanostructures Embedded in Organic material (Bio Se-NEMO-S) produced by Bacillus mycoides SelTE01 in comparison with two different chemical selenium nanoparticle (SeNP) classes. These nanomaterials have been studied as potential antimicrobials for eradication of established HA-grown biofilms, for preventing biofilm formation on HA-coated surfaces and for inhibition of planktonic cell growth of Pseudomonas aeruginosa NCTC 12934 and Staphylococcus aureus ATCC 25923. Bio Se-NEMO resulted more efficacious than those chemically produced in all tested scenarios. Bio Se-NEMO produced by B. mycoides SelTE01 after 6 or 24 h of Na 2 SeO 3 exposure show the same effective antibiofilm activity towards both P. aeruginosa and S. aureus strains at 0.078 mg ml −1 (Bio Se-NEMO 6 ) and 0.3125 mg ml −1 (Bio Se-NEMO 24 ). Meanwhile, chemically synthesized SeNPs at the highest tested concentration (2.5 mg ml −1 ) have moderate antimicrobial activity. The confocal laser scanning micrographs demonstrate that the majority of the P. aeruginosa and S. aureus cells exposed to biogenic SeNPs within the biofilm are killed or eradicated. Bio Se-NEMO therefore displayed good antimicrobial activity towards HA-grown biofilms and planktonic cells, becoming possible candidates as new antimicrobials

Discrete group transforms on SU(2) X SU(2) and SU(3)

Discrete group transforms on SU(2) X SU(2) and SU(3

Strategy, intentionality, and impact: A purchasing plan for library promotional swag

The labor and expense involved in developing a comprehensive outreach program can be overwhelming. There are often additional expenditures for marketing and promotional items to support the outreach events that go beyond costs of planning and staffing outreach activities. The Texas A&M University Libraries boast a robust outreach program—library employees participate in more than 100 outreach activities each calendar year. We developed programmatic strategies for improving the cost and labor efficiency of both purchasing and managing the distribution of library-branded promotional items as a part of these outreach efforts. Colloquially, these items are known as swag. This chapter will provide insight into why and how we created a swag inventory system to support our outreach program

Libr-AR-y Tours: Increasing Engagement and Scalability of Library Tours Using Augmented Reality

The Version of Record of this manuscript has been published and is available in College & Undergraduate Libraries, August 2018, https://doi.org/10.1080/10691316.2018.1480445Orienting patrons to library spaces, collections, and services is an important, but time-intensive, challenge for many librarians. Library tours are one strategy commonly employed to familiarize patrons with library spaces and services. Augmented reality provides a new opportunity for librarians to develop engaging and interactive unmediated tours. Augmented reality tours provide participants with an opportunity to explore library spaces and service points while affording librarians the chance to share valuable information about those spaces and services. This article details how one library constructed an augmented reality tour and shares assessment-based insights into participant responses to the augmented reality format

First Generation Success: Mixed-Methods Information Literacy Skills Assessment for First Year Writing Students

As universities seek to improve retention and graduation rates, more attention is being paid to populations that are statistically less likely to persist, such as first-generation students. Engaging with a campus-wide initiative targeting first-generation college students, librarians at a research university were awarded a grant to study the information literacy skills of this special population and to develop intervention strategies to help retain students. Partnering with the English department and a campus provisional admission program, librarians developed and taught special sections of the first year composition course, ENGL 104. These sections were designed to seamlessly embed information literacy concepts into the traditional ENGL 104 curriculum and to thoroughly assess the impact of this approach. This study was designed using a mixed-methods approach to better understand the information literacy knowledge and skills of first-generation students and to evaluate the impact of embedding information literacy into a course required for their degree plans