Learning curves : the economics behind high school economic education

Related links : http://www.richmondfed.org/publications/research/region_focus/2009/winter/feature4_weblinks.cfmEducation - Economic aspects

Graphulo Implementation of Server-Side Sparse Matrix Multiply in the Accumulo Database

The Apache Accumulo database excels at distributed storage and indexing and is ideally suited for storing graph data. Many big data analytics compute on graph data and persist their results back to the database. These graph calculations are often best performed inside the database server. The GraphBLAS standard provides a compact and efficient basis for a wide range of graph applications through a small number of sparse matrix operations. In this article, we implement GraphBLAS sparse matrix multiplication server-side by leveraging Accumulo's native, high-performance iterators. We compare the mathematics and performance of inner and outer product implementations, and show how an outer product implementation achieves optimal performance near Accumulo's peak write rate. We offer our work as a core component to the Graphulo library that will deliver matrix math primitives for graph analytics within Accumulo.Comment: To be presented at IEEE HPEC 2015: http://www.ieee-hpec.org

Some Notes on the Past and Future of Lisp-Stat

Lisp-Stat was originally developed as a framework for experimenting with dynamic graphics in statistics. To support this use, it evolved into a platform for more general statistical computing. The choice of the Lisp language as the basis of the system was in part coincidence and in part a very deliberate decision. This paper describes the background behind the choice of Lisp, as well as the advantages and disadvantages of this choice. The paper then discusses some lessons that can be drawn from experience with Lisp-Stat and with the R language to guide future development of Lisp-Stat, R, and similar systems.

Managing polyglot systems metadata with hypergraphs

A single type of data store can hardly fulfill every end-user requirements in the NoSQL world. Therefore, polyglot systems use different types of NoSQL datastores in combination. However, the heterogeneity of the data storage models makes managing the metadata a complex task in such systems, with only a handful of research carried out to address this. In this paper, we propose a hypergraph-based approach for representing the catalog of metadata in a polyglot system. Taking an existing common programming interface to NoSQL systems, we extend and formalize it as hypergraphs for managing metadata. Then, we define design constraints and query transformation rules for three representative data store types. Furthermore, we propose a simple query rewriting algorithm using the catalog itself for these data store types and provide a prototype implementation. Finally, we show the feasibility of our approach on a use case of an existing polyglot system.Peer ReviewedPostprint (author's final draft

Beyond the Tunnel Problem, Addressing Cross-Cutting Issues that Impact Vulnerable Youth

Across the country, mayors, commissioners, superintendents, governors, and state policymakers are innovating to address the needs of vulnerable youth. These efforts take many forms: restructuring high schools to improve graduation rates, creating developmentally appropriate interventions to reduce juvenile delinquency, and revamping child welfare practices to keep more youth safely in their homes are just a few of these strategies. Many initiatives, however, are plagued by "crosscutting problems" -- issues that cut across the different agencies that serve youth. Unless crosscutting issues are addressed proactively, they may undermine systemic reforms. This short paper is the first in a series of briefing papers designed to inform officials, practitioners, funders, advocates, scholars and the general public about crosscutting problems and possible solutions to these problems. This paper focuses primarily on the authors' experiences in New York City, though many of the crosscutting problems discussed are known to occur in many jurisdictions large and small. The series starts by presenting a typology of crosscutting issues. The next paper in this series will elaborate on a specific area -- namely, juvenile justice and education. Additional briefing papers will focus on local initiatives that tackle specific problems and more systemic attempts to solve crosscutting issues

The transformation of community hospitals through the transition to value-based care: Lessons from Massachusetts

Enabling community hospitals to provide efficient and effective care and maintain competition on par with their academic medical center (AMC) counterparts remain challenges for most states. Advancing accountable care readiness adds to the complexity of these challenges. Community hospitals experience narrower operating margins and more limited access to large populations than their AMC counterparts, making the shift to value-based care difficult. Massachusetts has taken legislative action to ensure a statewide focus on reducing healthcare costs, which includes a nearly $120-million grant program supporting community hospital and system transformation toward a value-based environment. The Massachusetts Health Policy Commission’s Community Hospital Acceleration, Revitalization and Transformation (CHART) investment program is the state’s largest effort to date aimed at readying community hospitals for value-based care. In doing so, Massachusetts has created the largest state-driven, all-payer (payer-blind) readmission reduction initiative in the country. n this paper, we examine the design and evolution of CHART Phases 1 and 2 and offer insights for other states contemplating innovative approaches to bolstering community hospital participation in value-based care models