Geographica: A Benchmark for Geospatial RDF Stores

Geospatial extensions of SPARQL like GeoSPARQL and stSPARQL have recently been defined and corresponding geospatial RDF stores have been implemented. However, there is no widely used benchmark for evaluating geospatial RDF stores which takes into account recent advances to the state of the art in this area. In this paper, we develop a benchmark, called Geographica, which uses both real-world and synthetic data to test the offered functionality and the performance of some prominent geospatial RDF stores

The Rise and Fall of the dot com Entrepreneurs

This paper looks at the dot com phenomenon drawing mainly on examples from the USA where the boom started and was most pronounced, but also from the UK which had a number of high profile dot coms. It starts by asking the question, ‘Who were the dot coms?’. it then goes on to consider the factors which led to the emergence of the dot coms such as the emergence of the commercial Internet, the lowering of entry barriers which followed from this and the funding available for new businesses through venture capital. The article also looks at the reasons why it was believed that the dot coms represented a threat to established businesses. The article then looks at the booming IPO market for dot coms and the opportunities this provided for exit by venture capital investors. The crash of 2000 is considered, lessons are drawn for entrepreneurs and investors and finally the article will look at future prospects for the dot com sector

The Universe at Extreme Scale: Multi-Petaflop Sky Simulation on the BG/Q

Remarkable observational advances have established a compelling cross-validated model of the Universe. Yet, two key pillars of this model -- dark matter and dark energy -- remain mysterious. Sky surveys that map billions of galaxies to explore the `Dark Universe', demand a corresponding extreme-scale simulation capability; the HACC (Hybrid/Hardware Accelerated Cosmology Code) framework has been designed to deliver this level of performance now, and into the future. With its novel algorithmic structure, HACC allows flexible tuning across diverse architectures, including accelerated and multi-core systems. On the IBM BG/Q, HACC attains unprecedented scalable performance -- currently 13.94 PFlops at 69.2% of peak and 90% parallel efficiency on 1,572,864 cores with an equal number of MPI ranks, and a concurrency of 6.3 million. This level of performance was achieved at extreme problem sizes, including a benchmark run with more than 3.6 trillion particles, significantly larger than any cosmological simulation yet performed.Comment: 11 pages, 11 figures, final version of paper for talk presented at SC1

Moa and the multi-model architecture: a new perspective on XNF2

Advanced non-traditional application domains such as geographic information systems and digital library systems demand advanced data management support. In an effort to cope with this demand, we present the concept of a novel multi-model DBMS architecture which provides evaluation of queries on complexly structured data without sacrificing efficiency. A vital role in this architecture is played by the Moa language featuring a nested relational data model based on XNF2, in which we placed renewed interest. Furthermore, extensibility in Moa avoids optimization obstacles due to black-box treatment of ADTs. The combination of a mapping of queries on complexly structured data to an efficient physical algebra expression via a nested relational algebra, extensibility open to optimization, and the consequently better integration of domain-specific algorithms, makes that the Moa system can efficiently and effectively handle complex queries from non-traditional application domains

Human-caused climate change in United States national parks and solutions for the future

Human-caused climate change has exposed the US national park area to more severe increases in heat and aridity than the country as a whole and caused widespread impacts on ecosystems and resources. Reducing carbon dioxide emissions from cars, power plants, and other human sources would reduce future risks. Since 1895, annual average temperature of the area of the 419 national parks has increased at a rate of 1.0 ± 0.2ºC (1.8 ± 0.4ºF) per century, double the rate of the US as a whole, while precipitation has declined significantly on 12% of national park area, compared with 3% of the US. This occurs because extensive areas of national parks are located in extreme environments. Scientific research in national parks has detected numerous changes that analyses have attributed primarily to human-caused climate change. These include a doubling of the area burned by wildfire across the western US, including Yosemite National Park, melting of glaciers in Glacier Bay National Park, a doubling of tree mortality across the western US, including Sequoia National Park, a loss of bird species from Death Valley National Park, a shift of trees onto tundra in Noatak National Preserve, sea level rise of 42 cm (17 in.) near the Statue of Liberty National Monument, and other impacts. Without emissions reductions, climate change could increase temperatures across the national parks, up to 9ºC (16ºF) by 2100 in parks in Alaska. This could melt all glaciers from Glacier National Park, raise sea level enough to inundate half of Everglades National Park, dissolve coral reefs in Virgin Islands National Park through ocean acidification, and damage many other natural and cultural resources. Adaptation measures, including conservation of refugia in Joshua Tree National Park and raising heat-resistant local corals in Biscayne National Park, can strengthen ecosystem integrity. Yet, reducing greenhouse gas emissions from human activities is the only solution that prevents the pollution that causes climate change. Energy conservation and efficiency improvements, renewable energy, public transit, and other actions could lower projected heating by two-thirds, reducing risks to our national parks

Nontraditional Investors

In recent years, nontraditional investors have become a major player in the startup ecosystem. Under the regulatory regime of U.S. securities law, those in the public realm are heavily regulated, while those in the private realm are largely left alone. This public-private divide, which is a fundamental organizing principle of securities law, has eroded with the rise of nontraditional investors. While legal scholars have addressed the impact of some of these nontraditional investors individually, their collective impact on deal terms, deal timelines, due diligence, and board configuration has not been discussed in a holistic manner; neither has their impact on the investor landscape and securities law. This Article provides the first descriptive account of nontraditional investors throughout startups’ lifecycles and the normative implications of their participation in the venture capital ecosystem. Ultimately, nontraditional investors helped to facilitate the rise of unicorns which contributed to the “breakdown” of the public-private divide, with the attendant problems related to investor protection, corporate governance, valuation bubbles, and the like. Once thought of as outliers, nontraditional investors have influenced the venture capital market and the ways in which deals were conducted in significant ways. They drove capital investment trends and created an increasingly competitive deal environment in venture capital. Outsized funds became the norm, and the size and valuation of venture capital deals at each stage of a startup grew ever larger. In some cases, it led to less investor oversight and due diligence. Although one of the hallmarks of venture capital investors is their hands-on approach, that is not the case for all of the nontraditional investors. Board dynamics and economics and control—the two underlying principles of venture capital deals—shifted in favor of the founders as nontraditional investors proliferated and the economy remained strong. However, the recent economic downturn has led to a recalibration of nontraditional investors’ influence. In this environment, founders are no longer able to dictate the terms of venture capital financings, the investment pace has slowed, and while some nontraditional investors may retreat and reassess, their influence in the venture capital ecosystem will continue to reverberate in the years to come