A regional model of endogenous growth with creative destruction

We consider a two region growth model with vertical innovations where technical externalities in R&D lead to a technology leading region being the most attractive location for innovative firms. Innovations are produced in the form of quality improvements building on available knowledge and firms choose a technologically advanced location to maximise the productivity of R&D and maintain their niche monopoly. The partial nature of spillovers causes an additional force for agglomeration: the clustering effect. Agglomerated locations have the benefit of local inter-varietal knowledge spillovers for growth while peripheral locations depend on trade and regional knowledge spillovers

Cluster evolution as a probe of primordial density fluctuations

Although COBE's detection of large angle microwave background anisotropies fixes the amplitude of density fluctuations on length scales k exp -1 approximately = (300-6000) h(exp -1)Mpc, what is crucial for the level of large scale clustering is the amplitude of density fluctuations on scales (5-50) h(exp -1)Mpc. The level of dynamical clustering is usually parameterized by the size of the mass fluctuations in 8 h exp -1 Mpc spheres, sigma sub 8. For the cold dark matter model, COBE gives sigma sub 8 approximately = 1, while models with extra large scale power give sigma sub 8 approximately = 1/2. The most massive clusters of galaxies (greater than or approximately = 10 exp 15 solar mass) form from rare 'peak patches' found in the initial mass density distribution. Their abundance as a function of redshift is a sensitive probe of the wave number band k(exp -1) approx. (3-8) h(exp -1)Mpc, hence of sigma sub 8, and so cluster evolution can discriminate among models allowed by the COBE results. We use our Hierarchical Peaks Method, which accurately reproduces the results of P3M N-body simulations, to calculate the evolution of cluster x-ray flux counts, luminosity, and temperature functions as a function of sigma sub 8 for CDM models and those with more large scale power. We find that the EMSS and Edge et al. cluster samples support sigma sub 8 in the range from approx. 0.6-0.9, and that models with more large scale power (and hence flatter fluctuation spectra in the cluster regime) fit the x-ray bright end better

Primeval galaxies in the sub-mm and mm

Although the results of COBE's FIRAS experiment 1 constrain the deviation in energy from the CMB blackbody in the 500-5000 micron range to be delta E/E, sub cmb less than 0.005, primeval galaxies can still lead to a brilliant sub-mm sky of non-Gaussian sources that are detectable at 10 inch resolution from planned arrays such as SCUBA on the James Clerk Maxwell Telescope and, quite plausibly, at sub-arcsecond resolution in planned mm and sub-mm interferometers. Here, we apply our hierarchical peaks method to a CDM model to construct sub-mm and mm maps of bursting PG's appropriate for these instruments with minimum contours chosen to correspond to realistic observational parameters for them and which pass the FIRAS limits

“R.C.”: Rosicrucianism and Cartesianism in Joyce and Beckett

Nous observerons dans cet article les possibles implications théosophiques et philosophiques de l'usage récurrent par James Joyce des initiales “R. C.” dans Ulysse et Finnegans Wake. Historiquement, les initiales ont servi, d'une part, de sceau à La Fraternité Rosicrucienne, et de l'autre, de paraphe à René Descartes (René des Cartes). Nous considérerons ces deux hypothèses théoriques comme des points de références probables dans l'usage que fait Joyce des initiales, ceci en nous appuyant sur les premiers écrits de Beckett.This paper explores the possible theosophical and philosophical implications of James Joyce’s recurrent use of the initials “R. C.” in Ulysses and Finnegans Wake. Historically, the initials have been used both as the seal of the Rosicrucian Brotherhood and as the cachet of René Descartes (René des Cartes). We consider both of these theoretical frameworks as likely reference points for Joyce, making extensive use of the early works of Samuel Beckett in arguing for each case

Innovation and Growth: Theoretical Models and Analytical Simulations of Spatial, Clustering and Competition Effects

This thesis expands upon endogenous growth theory to incorporate a more detailed understanding of innovation. The similarities in modelling techniques between endogenous growth theory and the New Economic Geography (NEG) in the existing literature creates an opportunity to incorporate features of innovation within a model of both geography and growth. The thesis explores three key areas. Firstly, innovation is based on knowledge spillovers. But knowledge spillovers are also subject to spatial characteristics in its transfer between firms, locations, regions and nations. Similarly, knowledge is used by innovators in many sectors, not just the sector where the knowledge was originally developed. As a result, innovating firms have an incentive to agglomerate alongside other innovators to benefit from each other’s knowledge. The geographic constraints of knowledge spillovers are incorporated into a regional model of growth with creative destruction. However, spillovers between industries are not equal. Industries or firms producing products which are closely related have a strong incentive to locate in close proximity to benefit from related-technology spillovers. Some of these related innovation clusters could potentially be isolated, but sustainable due to knowledge transfer between related firms within the cluster. It is this innovation clustering which could provide the opportunity for distant or isolated economies to sustain high levels of productivity. Lastly, the thesis considers a way in which firms enter a market such that entry is not necessarily available to all potential entrants. This limit on the market supplied by innovating firms is characterised by discrete instead of free entry. Entry by discrete firms allows entering firms to invest in innovation in response to actual (instead of potential) competitors. They are able to escape competition by sustaining incremental innovations. Greater competition in larger markets has greater investment in innovation by all participants. This thesis provides new insights for endogenous growth theory, emphasising the need for policies regarding innovation and economic growth that are industry and location specific

Chip and Skim: cloning EMV cards with the pre-play attack

EMV, also known as "Chip and PIN", is the leading system for card payments worldwide. It is used throughout Europe and much of Asia, and is starting to be introduced in North America too. Payment cards contain a chip so they can execute an authentication protocol. This protocol requires point-of-sale (POS) terminals or ATMs to generate a nonce, called the unpredictable number, for each transaction to ensure it is fresh. We have discovered that some EMV implementers have merely used counters, timestamps or home-grown algorithms to supply this number. This exposes them to a "pre-play" attack which is indistinguishable from card cloning from the standpoint of the logs available to the card-issuing bank, and can be carried out even if it is impossible to clone a card physically (in the sense of extracting the key material and loading it into another card). Card cloning is the very type of fraud that EMV was supposed to prevent. We describe how we detected the vulnerability, a survey methodology we developed to chart the scope of the weakness, evidence from ATM and terminal experiments in the field, and our implementation of proof-of-concept attacks. We found flaws in widely-used ATMs from the largest manufacturers. We can now explain at least some of the increasing number of frauds in which victims are refused refunds by banks which claim that EMV cards cannot be cloned and that a customer involved in a dispute must therefore be mistaken or complicit. Pre-play attacks may also be carried out by malware in an ATM or POS terminal, or by a man-in-the-middle between the terminal and the acquirer. We explore the design and implementation mistakes that enabled the flaw to evade detection until now: shortcomings of the EMV specification, of the EMV kernel certification process, of implementation testing, formal analysis, or monitoring customer complaints. Finally we discuss countermeasures

RecDroid: a resource access permission control portal and recommendation service for smartphone users

The rapid growth of the smartphone applications market raises security concerns regarding untrusted applications. Studies have shown that most apps in markets request to collect data irrelevant to the main functions of the apps. Traditional Android permission control design based on one-time decisions on installation has been proven to be ineffective in protecting users’ privacy and poorly utilizes scarce mobile resources (e.g. battery). RecDroid is designed to help protect user data in a market where unauthorized data collection is prevalent in most applications. With RecDroid’s recommendation feature, which is based on expert analysis, the user will be able to avoid unnecessary privacy breach while retaining safe functionalities of many third party applications. RecDroid’s implementation consists of three distinct components: Application, OS modifications, and Recommendation Server. Firstly, RecDroid is exposed to the user as an application that allows them to manage permissions for installed applications and provides recommended permissions for new installations. In order to accomplish this, the Android OS needed to be modified to add two key functions to make our application work: editing the PackageManager class to handle user set permissions and to add a probation installation setting to let RecDroid know what applications to monitor. The last core component required for the RecDroid application is a server that collects participating users’ decisions sent by the application, makes recommendations based on stored decisions, and provides recommendations to the application. When RecDroid is fully implemented and has a sufficient user base, we expect to have a fully functional application that can effectively protect user data from dishonest applications that seek to overstep their essential reach. The server will continuously collect more data and recruit new users, which will correspondingly increase the confidence level and accuracy of RecDroid recommendations.https://scholarscompass.vcu.edu/capstone/1034/thumbnail.jp

Optimizing Collection of Trace Biological Samples from Vehicle Headrests

Tape-lifting and swabbing are two methods commonly used for collecting biological samples in the United Kingdom and United States to investigate vehicle crimes. Determining the optimal collection method may lead to an increase in generating DNA profiles and crime-solving. The objective of this study is to evaluate the efficiency of adhesive tape and the double-swab collection methods for investigating vehicle crimes with possible touch DNA samples. Two experiments were conducted to evaluate the use of tape-lifts and swabs on spiked common vehicle fabric materials. The efficiency of recovery between the two collection methods was performed using qPCR. The results from the collection of fabric materials indicated tape-lifts outperformed swabbing on cloth and vinyl substrates, while swabbing resulted in comparable recovery on leather substrates. By optimizing sample collection techniques, we aim to aid not only investigations involving vehicles but also other crimes with touch DNA evidence present

ErythropoieSIS stimulating agent (ESA) use is increased following missed dialysis sessions

Missed dialysis sessions can have a cascading effect on patient clinical outcomes. In addition to missing the dialysis itself, patients fail to receive medications—such as ESAs—that are dosed at each session. This analysis assessed ESA dose changes following missed session episodes in order to evaluate “catch-up dosing.”In a retrospective analysis, we assessed missed session and epoetin alfa (EPO) utilization data in 2010 from adult (≥ 18 yrs old), hemodialysis (HD) patients. Consecutive misses were considered part of a missed session “episode.” All misses were included (even if patient was hospitalized). Differences in EPO utilization in the periods 14 days, 30 days and 31-60 days before and after missed session episodes were calculated and stratified by length of episode, and whether additional sessions were missed in the before/after periods. Total monthly EPO dose was also calculated and stratified by number of missed sessions.Patients used significantly more EPO after a missed session episode, and differences in per session EPO dose were generally greater the longer the episode. For missed session episodes with no additional misses in the 30 day before/after period, increases of 18% to 30% per session were seen, depending on episode length. For longer episodes, usually due to hospitalization, differences were sustained over 60 days. Analyses which included additional missed sessions in the before/after period showed similar patterns. Beyond these per-session associations, the total amount of EPO used in a month increased with number of missed sessions (through up to 5 missed sessions), even though these patients (by definition) were not receiving as many administrations of EPO.Missed session episodes result in significant increases in ESA utilization in the post-miss period, and also in total monthly ESA use. Such increases should be considered in any assessment of impact of missed sessions: both clinical and economic