Urban patterns, population density and optimal city dimension: The case of public infrastructure

Determination of the optimal city size underlies the economic rationality of infrastructure provision by local governments. We investigate the existence of decreasing average costs resulting from economies of scale, associated with larger urban dimensions in terms of population and housing, and economies of density, brought about by reductions in urban dispersion, and calculate optimal population densities when providing basic infrastructure. The methodology relies on novel definitions of scale and density economies and their estimation by way of flexible translog cost functions, extensively applied in the literature dealing with the provision of services—i.e., utilities, but extended here to their supporting infrastructure. Our results unveil the existence of latent economies of scale and density resulting in a cost excess in the provision of infrastructure due to the effect of urban sprawl that translates into suboptimal city sizes. Based on these findings several policy guidelines rationalizing urban development are suggested. The model is illustrated using Spanish statistical data collected from the nationwide local infrastructure and equipment survey, and prices from a new database that uses engineering cost benchmarks.Urban patterns; Optimal urban density; Scale and density economies; Translog cost function.

Teorías topológicas de campos cuánticos para variedades de caracteres

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Matemáticas, Departamento de Álgebra, Geometría y Topología, leída el 29-10-2018La presente tesis doctoral esta dedicada al estudio de las estructuras de Hodge de un tipo especial de variedades algebraicas complejas que reciben el nombre de variedades de caracteres. Para este n, proponemos utilizar una poderosa herramienta de naturaleza algebro-geometrica, proveniente de la física teorica, conocida como Teoría Topologica de Campos Cuanticos (TQFT por sus siglas en ingles). Con esta idea, en la presente tesis desarrollamos un formalismo que nos permite construir TQFTs a partir de dos piezas mas sencillas de informacion: una teoría de campos (informacion geometrica) y una cuantizacion (informacion algebraica). Como aplicacion, construimos una TQFT que calcula las estructuras de Hodge de variedades de representaciones y la usamos para calcular explícitamente los polinomios de Deligne-Hodge de SL2(C)-variedades de caracteres parabolicas.This PhD Thesis is devoted to the study of Hodge structure on a special type of complex algebraic varieties, the so-called character varieties. For this purpose, we propose to use a powerful algebrogeometric tool coming from theoretical physics, known as Topological Quantum Field Theory (TQFT). With this idea in mind, in the present Thesis we develop a formalism that allows us to construct TQFTs from two simpler pieces of data: a field theory (geometric data) and a quantisation (algebraic data). As an application, we construct a TQFT computing Hodge structures on representation varities and we use it for computing explicity the Deligne-Hodge polynomials of parabolic SL2(C)-character varieties.Depto. de Álgebra, Geometría y TopologíaFac. de Ciencias MatemáticasTRUEunpu

Virtual classes of parabolic SL2(C)\mathrm{SL}_2(\mathbb{C})-character varieties

In this paper, we compute the virtual classes in the Grothendieck ring of algebraic varieties of $\mathrm{SL}_2(\mathbb{C})$-character varieties over compact orientable surfaces with parabolic points of semi-simple type. When the parabolic punctures are chosen to be semi-simple non-generic, we show that a new interaction phenomenon appears generating a recursive pattern.Comment: 33 pages, 1 figure. Minor corrections adde

Return to dollar, generalized distance function and the fisher productivity index

Exploring the duality between a return to dollar definition of profit and the generalized distance function we establish the relationship between the Laspeyres, Paasche and Fisher productivity indexes and their alternative Malmquist indexes counterparts. By proceeding this way, we propose a consistent decomposition of these productivity indexes into two mutually exclusive components. A technical component represented by the Malmquist index and an economical component which can be identified with the contribution that allocative criteria make to productivity change. With regard to the Fisher index, we indicate how researchers can further decompose the Malmquist technical component rendering explicit the sources of productivity change. We also show how the proposed model can be implemented by means of Data Envelopment Analysis techniques, and illustrate the empirical process with an example data set

Artifact-Aware Analogue/Mixed-Signal Front-Ends for Neural Recording Applications

This paper presents a brief review of techniques to overcome the problems associated with artifacts in analog frontends for neural recording applications. These techniques are employed for handling Common-Mode (CM) Differential-Mode (DM) artifacts and include techniques such as Average Template Subtraction, Channel Blanking or Blind Adaptive Stimulation Artifact Rejection (ASAR), among others. Additionally, a new technique for DM artifacts compression is proposed. It allows to compress these artifacts to the requirements of the analog frontend and, afterwards, it allows to reconstruct the whole artifact or largely suppress it.Ministerio de Economía y Empresa TEC2016-80923-

A chaotic switched-capacitor circuit for characteristic CMOS noise distributions generation

A switched-capacitor circuit is proposed for the generation of noise resembling the typical noise spectral density of MOS devices. The circuit is based on the combination of two chaotic maps, one generating 1/f noise (hopping map) and the other generating white noise (Bernoulli map). Through a programmable weighted adder stage, the contribution of each map can be controlled and, thereby, the position of the corner frequency. Behavioral models simulations were carried out to prove the correct functionality of the proposed approach.Ministerio de Economía y Competitividad TEC2016-80923-

Sweet Tales of Sweet Potatoes in Edo Japan

Roasted, steamed, pureed, candied - sweet potatoes or satsumaimo are considered autumn delicacies in traditional Japanese cooking (washoku). Although native to the American continent, nowadays, they take part in the Japanese pantry. They arrived in Western Japan in the 17th century, where they prospered as a nutritious, hardy crop and spread eastwards in the following centuries. As a case study, this paper will present the sweet potato\u27s introduction, diffusion, and acceptance during the Edo period (1600-1868) when washoku took shape. Based on written sources and material culture, the main topics will be the naturalization and acculturation of a foreign entity and how a cuisine reacts and adapts to it