Measurement of acoustic properties of South Pole ice for neutrino astronomy

South Pole ice is predicted to be the best medium for acoustic neutrino detection. Moreover, ice is the only medium in which all three dense-medium detection methods (optical, radio, and acoustic) can be used to monitor the same interaction volume. Events detected in coincidence between two methods allow significant background rejection confidence, which is necessary to study rare GZK neutrinos. In 2007 and 2008 the South Pole Acoustic Test Setup (SPATS) was installed as a research and development project associated with the IceCube experiment. The purpose of SPATS is to measure the acoustic ice properties at the South Pole in order to determine the feasibility of a future large hybrid array. The deployment and performance of SPATS are described, as are first results and work in progress on the sound speed, background noise, and attenuation.Comment: 8 pages, 6 figures, 1 table, uses elsart5p.cls, to appear in the proceedings of the Acoustic and Radio EeV Neutrino detection Activities (ARENA) 2008 conferenc

The EU and social protection: What should the European Convention propose?

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The American Frontier: Technology versus Immigration

What drove western population growth in the U.S. during the 19th century? The facts are: (i) Natural increase was higher in the West than in the East; and (ii) in the early stages of the settlement process, net migration could account for up to 80% of population growth in some regions. A general equilibrium model is proposed, with three ingredients: endogenous fertility, investment in land, and migration. The relative abundance of land in the West promotes higher fertility. The model is simulated. It accounts well for the time-series decomposition of population growth between migration and fertility.Population growth, migration, fertility, westward expansion

Trend in Hours: The U.S. from 1900 to 1950

During the first half of the 20th century the workweek in the United States declined, and the distribution of hours across wage deciles narrowed. At the same time, the distribution of wages narrowed too. The hypothesis proposed is (i) Households have access to an increasing number of leisure activities which enhance the value of non-market time; (ii) The rise of education accounts for the narrowing of the wage and hours distribution. Such mechanisms, embedded into a neoclassical growth model, quantitatively account for the observations. The rise in wages is the main contributor to the decline in hours. The decline in the price of leisure goods is second in importance, yet its contribution is large.Hours worked, leisure, home production, technological progress

Living lab approach for developing massmarket IoT products and services

Internet of Things (IoT) has emerged as a central concept in both the industrial as in the academic world. In this context, Living Lab research has been shown as an effective means for the design, implementation, development, testing and validation of Internet of Things system’s pervasiveness. However, IoT products are not yet designed based on the needs of a larger, non-technical group of end-users. Therefore, in this paper we describe the AllThingsTalk Living Lab research track in which tangible end-user products are defined to be implemented on an online IoT platform. More specifically, by using both qualitative and quantitative methodologies (i.e., desk research, online survey, probe research and co-creation) and by selecting different types of users (i.e., based on Rogers’ adoption profiles) for these interaction moments, we were able to combine the input of these users to define tangible products that meet the needs of a heterogeneous group of end-users

A Search for Cosmic-ray Proton Anisotropy with the Fermi Large Area Telescope

In eight years of operation, the Fermi Large Area Telescope (LAT) has detected a large sample of cosmic-ray protons. The LAT's wide field of view and full-sky coverage make it an excellent instrument for studying anisotropy in the arrival directions of protons at all angular scales. These capabilities enable the LAT to make a full-sky 2D measurement of cosmic-ray proton anisotropy complementary to many recent TeV measurements, which are only sensitive to the right ascension component of the anisotropy. Any detected anisotropy probes the structure of the local interstellar magnetic field or could indicate the presence of a nearby source. We present the first results from the Fermi-LAT Collaboration on the full-sky angular power spectrum of protons from approximately 100 GeV - 10 TeV.Comment: Presented at ICRC 2017 in Busan, Korea - PoS(ICRC2017)17

Selective Laser Melting of Biocompatible Metals for Rapid Manufacturing of Medical Parts

In recent years, digitizing and automation have gained an important place in fabrication of medical parts. Rapid Manufacturing could be very suitable for medical applications due to their complex geometry, low volume and strong individualization. The presented study investigates the possibility to produce medical or dental parts by Selective Laser Melting (SLM). The SLMprocess is optimized and fully characterized for two biocompatible metal alloys: TiAl6V4 and CoCrMo. This paper reports on mechanical and chemical properties and discusses geometrical feasibility including accuracy and surface roughness. The potential of SLM as medical manufacturing technique is proved by a developed procedure to fabricate frameworks for complex dental prostheses.Mechanical Engineerin

Hours Worked: Long-Run Trends

For 200 years the average number of hours worked per worker declined, both in the market place and at home. Technological progress is the engine of such transformation. Three mechanisms are stressed: (i) The rise in real wages and its corresponding wealth effect; (ii) The enhanced value of time off from work, due to the advent of time-using leisure goods; (iii) The reduced need for housework, due to the introduction of time-saving appliances. These mechanisms are incorporated into a model of household production. The notion of Edgeworth-Pareto complementarity/substitutability is key to the analysis. Numerical examples link theory and data. This note has been prepared for The New Palgrave Dictionary of Economics, 2nd edition, edited by Lawrence E. Blume and Steven N. Durlauf (London: Palgrave Macmillan).

A quantitative analysis of China’s structural transformation

Between 1978 and 2003 the Chinese economy experienced a remarkable 5.7 percent annual growth of GDP per labor. At the same time, there has been a noticeable transformation of the economy: the share of workers in agriculture decreased from over 70 percent to less than 50 percent. We distinguish three sectors: private agriculture and nonagriculture and public nonagriculture. A growth accounting exercise reveals that the main source of growth was TFP in the private nonagricultural sector. The reallocation of labor from agriculture to nonagriculture accounted for 1.9 percent out of the 5.7 percent growth in output per labor. The reallocation of labor from the public to the private sector also accounted for a significant part of growth in the 1996-2003 period. We calibrate a general equilibrium model where the driving forces are public investment and employment, as well as sectorial TFP derived from our growth accounting exercise. The model tracks the historical employment share of agriculture and the labor productivities of all three sectors quite well.China