Space-time correlations in urban sprawl

Understanding demographic and migrational patterns constitutes a great challenge. Millions of individual decisions, motivated by economic, political, demographic, rational, and/or emotional reasons underlie the high complexity of demographic dynamics. Significant advances in quantitatively understanding such complexity have been registered in recent years, as those involving the growth of cities [Bettencourt LMA, Lobo J, Helbing D, Kuehnert C, West GB (2007) Growth,. Innovation, Scaling, and the Pace of Life in Cities, Proc Natl Acad Sci USA 104 (17) 7301-7306] but many fundamental issues still defy comprehension. We present here compelling empirical evidence of a high level of regularity regarding time and spatial correlations in urban sprawl, unraveling patterns about the inertia in the growth of cities and their interaction with each other. By using one of the world's most exhaustive extant demographic data basis ---that of the Spanish Government's Institute INE, with records covering 111 years and (in 2011) 45 million people, distributed amongst more than 8000 population nuclei--- we show that the inertia of city growth has a characteristic time of 15 years, and its interaction with the growth of other cities has a characteristic distance of 70 km. Distance is shown to be the main factor that entangles two cities (a 60% of total correlations). We present a mathematical model for population flows that i) reproduces all these regularities and ii) can be used to predict the population-evolution of cities. The power of our current social theories is thereby enhanced

MaxEnt and dynamical information

The MaxEnt solutions are shown to display a variety of behaviors (beyond the traditional and customary exponential one) if adequate dynamical information is inserted into the concomitant entropic-variational principle. In particular, we show both theoretically and numerically that power laws and power laws with exponential cut-offs emerge as equilibrium densities in proportional and other dynamics

The Effect of Information Asimmetry on Earnings Management in Companies That Conduct an Initial Public Offering (IPO) on the Indonesia Stock Exchange (IDX)

This study aims: to determine the effect of information asymmetry on Earnings Management in companies that carry out initial public offering on the Indonesia Stock Exchange in the period before go public, when go public, or after go public.Design and methodology: Sampling in this study is to use the purposive sampling method, where the company to be studied must certain criteria. The number of companies used as research samples based on predetermined criteria is 142 companies. The population in this study are banking/financial companies, service companies, and trading companies that made initial public offering on the Indonesia Stock Exchange (IDX). Analysis techniques are carried out with simple linear regression analysis techniques. The analytical method uses descriptive statistics, data quality tests, and hypothesis testing. Test the quality of the data in the form of classic assumption test which includes: normality test, multicollinearity test, heteroscedasticity test and autocorrelation test. Hypothesis testing uses the t test to test the coefficient partially with a significant level of 5%.Results: The test results prove that information asymmetry has a significant effect on earnings management during and after conducting an IPO, but when go public does not pass the heteroscedasticity test. The test results also prove that information asymmetry has no significant effect on earnings management before the IPO. Regression results indicate that the coefficient of determination possessed by the variables observed before, during, and after the IPO are respectively R-square= 0.039, 0.121, and 0.221. This means that the influence of the independent variables on the dependent variable is 3.9%, 12.1% and 22.1%.Originality/value: the addition of research variables to the independent variables can be done considering there are about 96.1%, 87.9%, and 77.9% influenced by other variables not included in this research model

Effects of Reserve Requirements in an Inflation Targeting Regime: The Case of Colombia

The Colombian economy and financial system have coped reasonably well with the effects of the global financial crisis. Hence, "unconventional" policy measures have not been at the center of the policy decisions and discussions. Nominal short term interest rates have remained the main monetary policy tool and "Quantitative easing" measures have not been central in the policy response. The one "unconventional" monetary instrument used by the Central Bank in Colombia has been changes in reserve requirements (RR) on financial system deposits. Interestingly, they were adopted before the global financial crisis, as a reaction to domestic credit conditions. The effects of RR on interest rate and interest rate pass-through in an inflation targeting regime are not as straightforward as those under a monetary targeting regime. Conceptually, those effects depend on the degree of substitution between deposits and central bank credit as sources of funds for banks and on the extent to which RR changes affect the risks facing banks. The empirical results for Colombia suggest that RR are important long run determinants of business loan interest rates and have been effective in strengthening the pass-through from policy to deposit and lending interest rates.Reserve Requirements, Inflation Targeting, Interest rate pass-through. Classification JEL: E51, E52, E58, G21.

El Triásico del sector de Mansilla (Demanda Suroriental-LaRioja)

[ES] Sobre un zócalo paleozoico fuertemente plegado y erosionado se depositan discordantes series atribuibles al Triásico, en general de poco espesor y que en detalle tienen importantes variaciones de facies y potencia. Se reconocen los tres litotipos clásicos, Buntsandstein, Muschelkalk y Keuper. El Buntsandstein suele comenzar por un conglomerado de poco espesor, a veces brechoide, cuya textura, composición litológica y espesor está regulada por el paleorrelieve infrayacente, constituido por una «penillanura» con valles encajados que se rellenan por aportes con gran influencia local. Sobre estos rellenos se encuentra una serie de materiales detríticos que constituyen una grosera alternancia de areniscas y lutitas, con marcado carácter continental, donde predominan los depósitos fluviales, tanto de canal como de llanura de inundación, siendo asimismo patentes los procesos edáficos. Los últimos metros de este litotipo marcan un tránsito gradual al Muschelkalk, apreciándose en ellos una progresiva influencia marina. El Muschelkalk, de poco espesor (máximo 20 mil presenta muchas variaciones de potencia y distribución, llegando incluso a faltar. Las facies más frecuentes corresponden a depósitos carbonáticos con predominio de dolomías con abundantes estructuras algares, deformaciones y brechas atribuibles a la existencia de evaporitas, así como señales de emersión. En conjunto estos depósitos corresponden a un medio mareal carbonatado. Finalmente el Keuper, también de poco espesor (30-40 m. máximo), está formado por lutitas versicolores con sales dispersas que sólo localmente son abundantes. A techo se encuentran dolomías brechoides (carniolas) en contacto impreciso y a veces mecanizado. Por el momento no existen datos bioestratigráficos detallados de esta zona y las referencias bibliográficas, en base a faunas encontradas en el Muschelkalk, no aportan mayor precisión. Los minerales pesados, mayoritariamente turmalina, zircón y óxidos de titanio, revelan en los tramos basales del Buntsandstein una neta influencia del propio Paleozoico de la Sierra de la Demanda como área fuente, pasándose en la vertical a mezcla con aportes de otras áreas fuente más alejadas, caracterizado por la abundancia de micas y variaciones en la morfología de las turmalinas. El alto contenido en turmalina permite comparar estas series con las del Buntsandstein de áreas próximas, excluyendo provisionalmen. te la presencia en la base de facies saxonienses, con diferentes espectros mineralógicos.[EN] Triassic materials outcropping southeast of Sierra de la Demanda are basically represented by germanic type facies: Buntsandstein, Muschelkalk and Keuper. Buntsandstein facies are clastics, towards the bottom predominate conglomerates, occasionally brecciated. This facies lie unconformably over lower paleozoic sediments strongly folded. Unconformity shows areas where scour surfaces predominate here interpreted as ancient valleys. Facies distribution over the unconformity plane are mainly controlled by the pre-existing relief, also controlling its thickness and here interpreted as fluvial deposits. Muschelkalk facies is characterized by the occurrence of algal limestones and tidal associated deposits. Evaporites appear to-wards the top of the stratigraphical sections studied and are primarity composed of fine interbedded clastic with gypsum and associated salts. Heavy minerals occurring in the Buntsandstein facies are basically tourmaline, zircon and titanium oxides. Lacking of palaeontological data, hig tourmaline content suggests that this deposits are comparable to Buntsandstein matehais outcropping in nearly areas. Mineralogical content of the facies here studied suggests the possibility of considering this deposits as Buntsandstein, non existing the typical mineralogical facies characterizing the Saxonian, Permian in age.Este trabajo ha sido financiado por la CAICYT y C.S.I.C., proyecto número 452. 691Peer reviewe

List Decoding of Matrix-Product Codes from nested codes: an application to Quasi-Cyclic codes

A list decoding algorithm for matrix-product codes is provided when $C_1,..., C_s$ are nested linear codes and $A$ is a non-singular by columns matrix. We estimate the probability of getting more than one codeword as output when the constituent codes are Reed-Solomon codes. We extend this list decoding algorithm for matrix-product codes with polynomial units, which are quasi-cyclic codes. Furthermore, it allows us to consider unique decoding for matrix-product codes with polynomial units

The workings of the maximum entropy principle in collective human behaviour

We present an exhaustive study of the rank-distribution of city-population and population-dynamics of the 50 Spanish provinces (more than 8000 municipalities) in a time-window of 15 years (1996-2010). We exhibit compelling evidence regarding how well the MaxEnt principle describes the equilibrium distributions. We show that the microscopic dynamics that governs population growth is the deciding factor that originates the observed macroscopic distributions. The connection between microscopic dynamics and macroscopic distributions is unravelled via MaxEnt.Instituto de Física La Plat

A Proposal for a Multi-Drive Heterogeneous Modular Pipe- Inspection Micro-Robot

This paper presents the architecture used to develop a micro-robot for narrow pipes inspection. Both the electromechanical design and the control scheme will be described. In pipe environments it is very useful to have a method to retrieve information of the state of the inside part of the pipes in order to detect damages, breaks and holes. Due to the di_erent types of pipes that exists, a modular approach with di_erent types of modules has been chosen in order to be able to adapt to the shape of the pipe and to chose the most appropriate gait. The micro-robot has been designed for narrow pipes, a _eld in which there are not many prototypes. The robot incorporates a camera module for visual inspection and several drive modules for locomotion and turn (helicoidal, inchworm, two degrees of freedom rotation). The control scheme is based on semi-distributed behavior control and is also described. A simulation environment is also presented for prototypes testing

The workings of the maximum entropy principle in collective human behaviour

We present an exhaustive study of the rank-distribution of city-population and population-dynamics of the 50 Spanish provinces (more than 8000 municipalities) in a time-window of 15 years (1996-2010). We exhibit compelling evidence regarding how well the MaxEnt principle describes the equilibrium distributions. We show that the microscopic dynamics that governs population growth is the deciding factor that originates the observed macroscopic distributions. The connection between microscopic dynamics and macroscopic distributions is unravelled via MaxEnt.Instituto de Física La Plat