Innovation flow through social networks: Productivity distribution

A detailed empirical analysis of the productivity of non financial firms across several countries and years shows that productivity follows a non-Gaussian distribution with power law tails. We demonstrate that these empirical findings can be interpreted as consequence of a mechanism of exchanges in a social network where firms improve their productivity by direct innovation or/and by imitation of other firm's technological and organizational solutions. The type of network-connectivity determines how fast and how efficiently information can diffuse and how quickly innovation will permeate or behaviors will be imitated. From a model for innovation flow through a complex network we obtain that the expectation values of the productivity level are proportional to the connectivity of the network of links between firms. The comparison with the empirical distributions reveals that such a network must be of a scale-free type with a power-law degree distribution in the large connectivity range.Comment: 14 pages, 4 figures, submitted to Phys. Rev.

Near-surface soil moisture assimilation for quantifying effective soil hydraulic properties using genetic algorithms: 2. Using airborne remote sensing during SGP97 and SMEX02

Pixel-based effective soil hydraulic parameters are crucial inputs for large-scale hydroclimatic modeling. In this paper, we extend/apply a genetic algorithm (GA) approach for estimating these parameters at the scale of an airborne remote sensing (RS) footprint. To estimate these parameters, we used a time series of near-surface RS soil moisture data to invert a physically based soil-water-atmosphere-plant (SWAP) model with a (multipopulated) modified-microGA. Uncertainties in the solutions were examined in two ways: (1) by solving the inverse problem under various combinations of modeling conditions in a respective way; and (2) the same as the first method but the inverse solutions were determined in a collective way aimed at finding the robust solutions for all the modeling conditions (ensembles). A cross validation of the derived soil hydraulic parameters was done to check their effectiveness for all the modeling conditions used. For our case studies, we considered three electronically scanned thinned array radiometer (ESTAR) footprints in Oklahoma and four polarimetric scanning radiometer (PSR) footprints in Iowa during the Southern Great Plains 1997 (SGP97) Hydrology Experiment and Soil Moisture Experiment 2002 (SMEX02) campaigns, respectively. The results clearly showed the promising potentials of near-surface RS soil moisture data combined with inverse modeling for determining average soil hydrologic properties at the footprint scale. Our cross validation showed that parameters derived by method 1 under water table (bottom boundary) conditions are applicable also for free-draining conditions. However, parameters derived under free-draining conditions generally produced too wet near-surface soil moisture when applied under water table conditions. Method 2, on the other hand, produced robust parameter sets applicable for all modeling conditions used. These results were validated using distributed in situ soil moisture and soil hydraulic properties measurements, and texture-based data from the UNSODA database. In this study, we conclude that inverse modeling of RS soil moisture data is a promising approach for parameter estimation at large measurement support scale. Nevertheless, the derived effective soil hydraulic parameters are subject to the uncertainties of remotely sensed soil moisture data and from the assumptions used in the soil-water-atmosphere-plant modeling. Method 2 provides a flexible framework for accounting these sources of uncertainties in the inverse estimation of large-scale soil hydraulic properties. We have illustrated this flexibility by combining multiple data sources and various modeling conditions in our large-scale inverse modeling

A modern guide to quantitative spectroscopy of massive OB stars

Quantitative spectroscopy is a powerful technique from which we can extract information about the physical properties and surface chemical composition of stars. In this chapter, I guide the reader through the main ideas required to get initiated in the learning process to become an expert in the application of state-of-the-art quantitative spectroscopic techniques to the study of massive OB stars. NB: This chapter is intended to serve to young students as a first approach to a field which has attracted my attention during the last 20 years. I should note that, despite its importance, at present, the number of real experts in the field around the world is limited to less than 50 people, and about one third of them are close to retirement. Hence, I consider that this is a good moment to write a summary text on the subject to serve as guideline for the next generations of students interested in joining the massive star crew. If you are one of them, please, use this chapter as a first working notebook. Do not stop here. Dig also, for further details, into the literature I quote along the text. And, once there, dig even deeper to find all the original sources explaining in more detail the physical and technical concepts that are presently incorporated into our modern (almost) automatized tools.Comment: Accepted for publication in the book "Reviews in Frontiers of Modern Astrophysics: From Space Debris to Cosmology" (eds Kabath, Jones and Skarka; publisher Springer Nature) funded by the European Union Erasmus+ Strategic Partnership grant "Per Aspera Ad Astra Simul" 2017-1-CZ01-KA203-03556

Fiscal Year 2007

The purpose of this Phased Construction Completion Report (PCCR) is to present the fiscal year (FY) 2007 results of characterization activities and recommended remedial actions (RAs) for 11 exposure units (EUs) in Zone 2 (Z2-01, Z2-03, Z2-08, Z2-23, Z2-24, Z2-28, Z2-34, Z2-37, Z2-41, Z2-43, and Z2-44) at the East Tennessee Technology Park (ETTP), which is located in the northwest corner of the U.S. Department of Energy (DOE) Oak Ridge Reservation in Oak Ridge, Tennessee (Fig. 1). ETTP encompasses a total land area of approximately 5000 acres that has been subdivided into three zones--Zone 1 ({approx}1400 acres), Zone 2 ({approx}800 acres), and the Boundary Area ({approx}2800 acres). Zone 2, which encompasses the highly industrialized portion of ETTP shown in Fig. 1, consists of all formerly secured areas of the facility, including the large processing buildings and direct support facilities; experimental laboratories and chemical and materials handling facilities; materials storage and waste disposal facilities; secure document records libraries; and shipping and receiving warehouses. The Zone 2 Record of Decision for Soil, Buried Waste, and Subsurface Structure Actions in Zone 2, East Tennessee Technology Park, Oak Ridge, Tennessee (DOE 2005) (Zone 2 ROD) specifies the future end use for Zone 2 acreage as uncontrolled industrial for the upper 10 ft of soils. Characterization activities in these areas were conducted in compliance with the Zone 2 ROD and the Dynamic Verification Strategy (DVS) and data quality objectives (DQOs) presented in the Remedial Design Report/Remedial Action Work Plan for Zone 2 Soils, Slabs, and Subsurface Structures, East Tennessee Technology Park, Oak Ridge, Tennessee (DOE 2007) (Zone 2 RDR/RAWP). The purpose of this PCCR is to address the following: (1) Document DVS characterization results for the accessible EUs in FY 2007; (2) Describe and document the risk evaluation for each EU, and determine if the EU met the Zone 2 ROD requirements for unrestricted industrial use to 10 ft bgs; (3) Identify additional areas not defined in the Zone 2 ROD that require remediation based on the DVS evaluation results; and (4) Describe the RAs performed in Zone 2. The Zone 2 ROD divided the Zone 2 area into 7 geographic areas and 44 EUs. To facilitate the DQOs of the DVS process, the Zone 2 RDR/RAWP regrouped the 44 EUs into 12 DQO scoping EU groups. These groups facilitated the DQO process by placing similar facilities and their support facilities together and allowed identification of data gaps. The EU groups were no longer pertinent after DQO planning was completed, and characterization was conducted as areas became accessible. As the opportunity to complete characterization became available, the planned DVS program was executed and completed in FY 2007 for the 11 EUs addressed in this document. The main body of this report describes both the DVS process and scope of work performed and the RAs completed. The scope and approach for performing DVS activities performed in FY 2007 that lead to action/no further action decisions are presented in Sects. 2 through 4. RAs performed in FY 2007 are presented in Sects. 5 through 10. Future land use is described in Sect. 11, and the status of all Zone 2 EUs as of this PCCR is presented in Sect. 12

Roadway Safety Institute News (Summer 2016, vol. 3, no. 3)

Articles include: Research explores how road sign alternatives might affect driver safety; Institute teaches transportation concepts, safety to summer campers; Workshops highlight innovative applications of LIDAR; Researcher spotlight: Brian Davis; New videos highlight Institute work

Roadway Safety Institute News (Fall 2017, vol. 4, no. 2)

Articles include: Research shows pedestrians and bicyclists benefit from "safety in numbers"; In-vehicle warnings show promise for improving work-zone safety; Investigating unintended effects of I-35W safety improvements; Summer camps spark students' interest in transportation; Infrastructure award to improve University's driving simulators; Morris named HumanFIRST Lab director; Seminar series moving to spring semeste

Roadway Safety Institute News (Spring 2019, vol. 6, no. 1)

Articles include: Research explores ways to improve GPS accuracy for traffic safety applications; Better prediction of train arrival times promises safety benefits; Transporting crash modification factors to a future with automated vehicles; Sensor technology key to automated vehicles; Sleep apnea study honored with research partnership award; Institute awards Student of the Yea

Roadway Safety Institute News (Spring 2017, vol. 4, no. 1)

Articles include: Charting a path toward automated speed enforcement; New ‘hot-spot’ mapping to help combat impaired driving; Improving safety through partnerships with tribal communities; New exhibit teaches kids about reflectivity and safety; Research shared—and awarded—at TRB national conference; Institute selects Student of the Year, travel awards; Workshop shares ways to improve pedestrian safety, cultur