The Survival and Birth of Firms

Using a modified form of the location quotient, a "growth quotient," this study traces the survival and growth for the headquarters of publicly listed firms in the United States. At the county level, the spatial concentrations of headquarters listed in 1997 are correlated with the spatial concentrations of corporate headquarters that survived from 1986 though 1996. Counties that house the headquarters of many different survival firms continue to spawn new headquarters. Counties with headquarters of survival firms in only one or two industries tend to maintain and spawn firms in only those industries. These conclusions support the Porter thesis that firms will spatially cluster for competitive advantage.

Charge dynamics in two-electron quantum dots

We investigate charge dynamics in a two-electron double quantum dot. The quantum dot is manipulated by using a time-dependent external voltage that induces charge oscillations between the dots. We study the dependence of the charge dynamics on the external magnetic field and on the periodicity of the external potential. We find that for suitable parameter values, it is possible to induce both one-electron and two-electron oscillations between the dots.Comment: 4 pages, 7 figures, proceedings of the Quantum Dot 2010 conferenc

Spatial Patterns of Headquarters

This study of the spatial concentration of the headquarters of exchange-listed companies suggests that the relevancy of the "efficiency parameter" of agglomeration theory still holds in explaining the location of headquarters, especially when the production function is reinterpreted as a productivity function. The sample of 5189 headquarters exceeds previous studies of Fortune 500 firms. Across industries, a high degree of clustering is found: 40% of the nation's headquarters were found in twenty counties. Cluster analysis suggests grouping patterns for headquarters; discriminant analysis confirms the uniqueness of these spatial clustering patterns across 229 urban counties. For certain industries, the clustering occurs within small areas. The headquarters of these spatially-correlated groups of firms money and media, gas and electric, business services, and machining technology were mapped at the county and zipcode level for counties within major metropolitan areas. The spatial density patterns take on traditional urban forms: core, ring and wedge.

Spatial Concentration of Institutional Property Ownership: New Wave Atomistic or Traditional Urban Clustering

NCREIF investors acquire property in counties that meet socioeconomic filtering criteria. In contrast to atomistic predictions, these investors acquire their apartment buildings, offices, retail facilities, and warehouses in density clusters. These clusters follow a model of a negative exponential demand curve, a model that previously explained the technologically caused density gradient of urban areas. Institutional investors signal their belief that clustering of properties is a value dimension.

Because privacy: defining and legitimating privacy in ios development

Privacy is a critical challenge for the mobile application ecosystem. US policy approaches to mobile data protection rely on privacy by design: approaches that encourage developers to proactively implement privacy features to protect sensitive data. But we know little about how application developers define privacy, how they decide to implement privacy features, and what might motivate them to consider privacy as a primary design value. This project identifies these factors by investigating the discussion of privacy as a professional practice within a community of mobile application developers. Analyzing posts on an iOS forum reveals that privacy is a frequent topic of conversation in this community. This paper describes how iOS developers define and legitimate privacy, and reveals a challenge: iOS developers rely heavily on a definition of privacy provided by Apple which does not reflect current empirical or theoretical understandings of how users understand privacy. Understanding this challenge can help us shape better guidelines for privacy by design, and broach challenges to the widespread adoption of privacy by design principles

Risk Assessment Steeplechase: Hurdles to Becoming a Target Market

Framed in a quadrant model, the data sources that analysts use to predict the performance of core property types for the major metropolitan areas in the United States are reviewed. The hypothesis is that forecasters rely on information from the economic base, the property inventory and financial performance quadrants to generate forecasts. For each core property type, analysts are rather homogeneous in grouping metropolitan areas from best to worst. However, the property type determines what sets of economic, social, inventory and market information are used. The only consistent forecast factor used across all property types appears to be economic growth.

АНАЛИЗ СТРУКТУРЫ ПОЛИВИНИЛХЛОРИДА МЕТОДОМ СПЕКТРОСКОПИИ КОМБИНАЦИОННОГО РАССЕЯНИЯ СВЕТА

В работе анализируются возможности спектроскопии комбинационного рассеяния света для анализа структуры поливинилхлорида

Global Computer Science Education

As a Computing/ICT Head of Department in a large secondary comprehensive school in Birmingham England, crystal ball gazing was an exercise in which I had to be skilled. One of the things that I prided myself upon was my ability to predict new developments before they happened, and better still, begin implementing subtle changes so that when the crunch truly came, we were ready. So, when the then Secretary of State Michael Gove made a speech at the BETT Show in 2012 and said those words that would define and shape our future; that the Department for Education were to consult upon “withdrawing the existing National Curriculum Programme of Study for ICT from September” (http://bit.ly/gove12), it wasn’t a shock to me. The timescale surprised me, but then again, educational policy adjustment timescales often do

USE OF INHALANT ANESTHETICS IN THREE SNAKE SPECIES

Different snake species respond differently to various anesthetic agents. Hence, an anesthetic procedure developed for one species cannot necessarily be safely transferred to another species. The goal of this paper is to summarize our experience using inhalant anesthetics on three snake species, including both procedures that were successful and those we found to be less satisfactory. We found isoflurane delivered with a precision vaporizer to be the best agent to anesthetize black rat snakes (Elaphe o. obsoleta). Sex and mass did not seem to affect induction times in black rat snakes, but larger female rat snakes recovered faster from anesthesia than smaller females. Halothane delivered in the open method provided consistent anesthesia in northern water snakes (Nerodia s. sipedon), although it caused some mortality and should not be used on debilitated patients. Halothane delivered with a precision vaporizer may be used to anesthetize eastern massasauga rattlesnakes (Sistrurus c. catenatus). However, care must be taken to prevent mortality resulting from anesthetic overdose. Sex and mass had no effect on induction and recovery times in the rattlesnakes, but stressed animals require longer induction and recovery times

Qualitative approaches to cybersecurity research

Although billions of dollars are spent each year securing network infrastructure, devices, and resources against threats, the impact of cybersecurity arrangements on individuals remains largely unexamined. Unless cybersecurity technologies, policies, and processes are built with people, and their diversity, in mind, the needs of wide swaths of society—including children and teens, the elderly, women, low-income families, and people with disabilities—are unlikely to be addressed. Though many methods are important for investigating motivations, practices, and affect, qualitative methods are particularly necessary for nuanced ways of knowing about these phenomena. But qualitative research constitutes just a fraction of cybersecurity research. This fishbowl session will focus on research to enable usable, livable, and inclusive cybersecurity by exploring qualitative ways of knowing in cybersecurity research