Impacts of foreign exchange auctions on the informal market rate in Myanmar

Since the abolition of the official peg and the introduction of a managed float in April 2012, the Central Bank of Myanmar has operated the daily two–way auctions of foreign exchange aimed at smoothing exchange rate fluctuations. Despite the reforms to the foreign exchange regime, however, informal trading of foreign exchange remains pervasive. Using the daily informal exchange rate and Central Bank auction data, this study examines the impacts of auctions on the informal market rate. First, a VAR analysis indicates that the official rate did not Granger cause the informal rate. Second, GARCH models indicate that the auctions did not reduce the conditional variance of the informal rate returns. Overall, the auctions have only a quite modest impact on the informal exchange rate.

On nonlinearity in neural encoding models applied to the primary visual cortex

Within the regression framework, we show how different levels of nonlinearity influence the instantaneous firing rate prediction of single neurons. Nonlinearity can be achieved in several ways. In particular, we can enrich the predictor set with basis expansions of the input variables (enlarging the number of inputs) or train a simple but different model for each area of the data domain. Spline-based models are popular within the first category. Kernel smoothing methods fall into the second category. Whereas the first choice is useful for globally characterizing complex functions, the second is very handy for temporal data and is able to include inner-state subject variations. Also, interactions among stimuli are considered. We compare state-of-the-art firing rate prediction methods with some more sophisticated spline-based nonlinear methods: multivariate adaptive regression splines and sparse additive models. We also study the impact of kernel smoothing. Finally, we explore the combination of various local models in an incremental learning procedure. Our goal is to demonstrate that appropriate nonlinearity treatment can greatly improve the results. We test our hypothesis on both synthetic data and real neuronal recordings in cat primary visual cortex, giving a plausible explanation of the results from a biological perspective.

W-singularities in cosmological models

Recently a new type of cosmological singularity has been postulated for infinite barotropic index w in the equation of state p = wρ of the cosmological fluid, but vanishing pressure and density at the singular event. Apparently the barotropic index w would be the only physical quantity to blow up at the singularity. In this talk we would like to discuss the strength of such singularities and compare them with other types. We show that they are weak singularities

Equation of state for hot dense matter using a relativistic screened hydrogenic model

The study of matter under conditions of high density, pressure, and temperature is a valuable subject for inertial confinement fusion (ICF), astrophysical phenomena, high-power laser interaction with matter, etc. In all these cases, matter is heated and compressed by strong shocks to high pressures and temperatures, becomes partially or completely ionized via thermal or pressure ionization, and is in the form of dense plasma. The thermodynamics and the hydrodynamics of hot dense plasmas cannot be predicted without the knowledge of the equation of state (EOS) that describes how a material reacts to pressure and how much energy is involved. Therefore, the equation of state often takes the form of pressure and energy as functions of density and temperature. Furthermore, EOS data must be obtained in a timely manner in order to be useful as input in hydrodynamic codes. By this reason, the use of fast, robust and reasonably accurate atomic models, is necessary for computing the EOS of a material.

Factored Translation Models for improving a Speech into Sign Language Translation System

This paper proposes the use of Factored Translation Models (FTMs) for improving a Speech into Sign Language Translation System. These FTMs allow incorporating syntactic-semantic information during the translation process. This new information permits to reduce significantly the translation error rate. This paper also analyses different alternatives for dealing with the non-relevant words. The speech into sign language translation system has been developed and evaluated in a specific application domain: the renewal of Identity Documents and Driver’s License. The translation system uses a phrase-based translation system (Moses). The evaluation results reveal that the BLEU (BiLingual Evaluation Understudy) has improved from 69.1% to 73.9% and the mSER (multiple references Sign Error Rate) has been reduced from 30.6% to 24.8%.

Reduced order adaptive models for systems of PDEs using POD

In this work we propose a method to accelerate time dependent numerical solvers of systems of PDEs that require a high cost in computational time and memory. The method is based on the combined use of such numerical solver with a proper orthogonal decomposition, from which we identify modes, a Galerkin projection (that provides a reduced system of equations) and the integration of the reduced system, studying the evolution of the modal amplitudes. We integrate the reduced model until our a priori error estimator indicates that our approximation in not accurate. At this point we use again our original numerical code in a short time interval to adapt the POD manifold and continue then with the integration of the reduced model. Application will be made to two model problems: the Ginzburg-Landau equation in transient chaos conditions and the two-dimensional pulsating cavity problem, which describes the motion of liquid in a box whose upper wall is moving back and forth in a quasi-periodic fashion. Finally, we will discuss a way of improving the performance of the method using experimental data or information from numerical simulations

Implicaciones de la accesibilidad configuracional en la movilidad peatonal. El caso de Madrid = The implications of configurational accessibility in pedestrian mobility. The case of Madrid

- Resumen La hipótesis que anima esta tesis doctoral es que algunas de las características del entorno urbano, en particular las que describen la accesibilidad de su red de espacio público, podrían estar relacionadas con la proporción de viajes a pie o reparto modal, que tiene cada zona o barrio de Madrid. Uno de los puntos de partida de dicha hipótesis que el entorno urbano tiene una mayor influencia sobre los viaje a pie que en sobre otros modos de transporte, por ejemplo que en los viajes de bicicleta o en transporte público; y es que parece razonable suponer que estos últimos van a estar más condicionadas por ejemplo por la disponibilidad de vías ciclistas, en el primer caso, o por la existencia de un servicio fiable y de calidad, en el segundo. Otra de las motivaciones del trabajo es que la investigación en este campo de la accesibilidad del espacio público, en concreto la denominada “Space Syntax”, ha probado en repetidas ocasiones la influencia de la red de espacio público en cómo se distribuye la intensidad del tráfico peatonal por la trama urbana, pero no se han encontrado referencias de la influencia de dicho elemento sobre el reparto modal. De acuerdo con la hipótesis y con otros trabajos anteriores se propone una metodología basada en el análisis empírico y cuantitativo. Su objetivo es comprobar si la red de espacio público, independientemente de otras variables como los usos del suelo, incluso de las variables de ajenas entorno no construido, como las socioeconómicas, está o no relacionada estadísticamente con la proporción de peatones viajes en las zonas urbanas. Las técnicas estadísticas se utilizan para comprobar sistemáticamente la asociación de las variables del entorno urbano, denominadas variables independientes, con el porcentaje de viajes a pie, la variable dependiente. En términos generales, la metodología es similar a la usada en otros trabajos en este campo como los de CERVERÓ y KOCKLEMAN (1997), CERVERÓ y DUNCAN (2003), o para los que se utilizan principalmente en la revisión general de TRB (2005) o, más recientemente, en ZEGRAS (2006) o CHATMAN (2009). Otras opciones metodológicas, como los métodos de preferencias declaradas (ver LOUVIERE, HENSHER y SWAIT, 2000) o el análisis basado en agentes (PENN & TURNER, 2004) fueron descartados, debido a una serie de razones, demasiado extensas para ser descritas aquí. El caso de estudio utilizado es la zona metropolitana de Madrid, abarcándola hasta la M-50, es decir en su mayor parte, con un tamaño aproximado de 31x34 Km y una población de 4.132.820 habitantes (aproximadamente el 80% de la población de la región). Las principales fuentes de datos son la Encuesta Domiciliaria de Movilidad de 2004 (EDM04), del Consorcio Regional de Transportes de Madrid que es la última disponible (muestra: > 35.000 familias,> 95.000 personas), y un modelo espacial del área metropolitana, integrando el modelo para calcular los índices de Space Syntax y un Sistema de Información Geográfica (SIG). La unidad de análisis, en este caso las unidades espaciales, son las zonas de transporte (con una población media de 7.063 personas) y los barrios (con una población media de 26.466 personas). Las variables del entorno urbano son claramente el centro del estudio. Un total de 20 índices (de 21) se seleccionan de entre los más relevantes encontrados en la revisión de la producción científica en este campo siendo que, al mismo tiempo, fueran accesibles. Nueve de ellos se utilizan para describir las características de los usos del suelo, mientras que otros once se usan para describir la red de espacios públicos. Estos últimos incluyen las variables de accesibilidad configuracional, que son, como se desprende de su título, el centro del estudio propuesto. La accesibilidad configuracional es un tipo especial de accesibilidad que se basa en la configuración de la trama urbana, según esta fue definida por HILLIER (1996), el autor de referencia dentro de esta línea de investigación de Space Syntax. Además se incluyen otras variables de la red de espacio público más habituales en los estudios de movilidad, y que aquí se denominan características geométricas de los elementos de la red, tales como su longitud, tipo de intersección, conectividad, etc. Por último se incluye además una variable socioeconómica, es decir ajena al entorno urbano, para evaluar la influencia de los factores externos, pues son varios los que pueden tener un impacto en la decisión de caminar (edad, género, nivel de estudios, ingresos, tasa de motorización, etc.). La asociación entre las variables se han establecido usando análisis de correlación (bivariante) y modelos de análisis multivariante. Las primeras se calculan entre por pares entre cada una de las 21 variables independientes y la dependiente, el porcentaje de viajes a pie. En cuanto a los segundos, se han realizado tres tipos de estudios: modelo multivariante general lineal, modelo multivariante general curvilíneo y análisis discriminante. Todos ellos son capaces de generar modelos de asociación entre diversas variables, pudiéndose de esta manera evaluar con bastante precisión en qué medida cada modelo reproduce el comportamiento de la variable dependiente, y además, el peso o influencia de cada variable en el modelo respecto a las otras. Los resultados fundamentales del estudio se expresan en dos modelos finales alternativos, que demuestran tener una significativa asociación con el porcentaje de viajes a pie (R2 = 0,6789, p <0,0001), al explicar las dos terceras partes de su variabilidad. En ellos, y en general en todo el estudio realizado, se da una influencia constante de tres índices en particular, que quedan como los principales. Dos de ellos, de acuerdo con muchos de los estudios previos, corresponden a la densidad y la mezcla de usos del suelo. Pero lo más novedoso de los resultados obtenidos es que el tercero es una medida de la accesibilidad de la red de espacio público, algo de lo que no había referencias hasta ahora. Pero, ¿cuál es la definición precisa y el peso relativo de cada uno en el modelo, es decir, en la variable independiente? El de mayor peso en la mayor parte de los análisis realizados es el índice de densidad total (n º residentes + n º puestos de trabajo + n º alumnos / Ha). Es decir, una densidad no sólo de población, sino que incluye algunas de las actividades más importantes que pueden darse una zona para generar movilidad a pie. El segundo que mayor peso adquiere, llegando a ser el primero en alguno de los análisis estadísticos efecturados, es el índice de accesibuilidad configuracional denominado integración de radio 5. Se trata de una medida de la accesibilidad de la zona, de su centralidad, a la escala de, más un menor, un distrito o comarca. En cuanto al tercero, obtiene una importancia bastante menor que los anteriores, y es que representa la mezcla de usos. En concreto es una medida del equilibrio entre los comercios especializados de venta al por menor y el número de residentes (n º de tiendas especializadas en alimentación, bebidas y tabaco / n º de habitantes). Por lo tanto, estos resultados confirman buena parte de los de estudios anteriores, especialmente los relativas a los usos del suelo, pero al mismo tiempo, apuntan a que la red de espacio público podría tener una influir mayor de la comprobada hasta ahora en la proporción de peatones sobre el resto de modos de transportes. Las razones de por qué esto puede ser así, se discuten ampliamente en las conclusiones. Finalmente se puede precisar que dicha conclusión principal se refiere a viajes de una sola etapa (no multimodales) que se dan en los barrios y zonas del área metropolitana de Madrid. Por supuesto, esta conclusión tiene en la actualidad, una validez limitada, ya que es el resultado de un solo caso — Abstract The research hypothesis for this Ph.D. Thesis is that some characteristics of the built environment, particularly those describing the accessibility of the public space network, could be associated with the proportion of pedestrians in all trips (modal split), found in the different parts of a city. The underlying idea is that walking trips are more sensitive to built environment than those by other transport modes, such as for example those by bicycle or by public transport, which could be more conditioned by, e.g. infrastructure availability or service frequency and quality. On the other hand, it has to be noted that the previously research on this field, in particular within Space Syntax’s where this study can be referred, have tested similar hypothesis using pedestrian volumes as the dependent variable, but never against modal split. According to such hypothesis, research methodology is based primarily on empirical quantitative analysis, and it is meant to be able to assess whether public space network, no matter other built environment and non-built environment variables, could have a relationship with the proportion of pedestrian trips in urban areas. Statistical techniques are used to check the association of independent variables with the percentage of walking in all trips, the dependent one. Broadly speaking this methodology is similar to that of previous studies in the field such as CERVERO&KOCKLEMAN (1997), CERVERO & DUNCAN (2003), or to those used mainly in the general review of T.R.B. (2005) or, more recently in ZEGRAS (2006) or CHATMAN (2009). Other methodological options such as stated choice methods (see LOUVIERE, HENSHER & SWAIT, 2000) or agent based analysis (PENN & TURNER, 2004), were discarded, due to a number of reasons, too long to be described here. The case study is not the entire Madrid’s metropolitan area, but almost (4.132.820 inhabitants, about 80% of region´s population). Main data sources are the Regional Mobility Home Based Survey 2004 (EDM04), which is the last available (sample: >35.000 families, > 95.000 individuals), and a spatial model of the metropolitan area, developed using Space Syntax and G.I.S. techniques. The analysis unit, in this case spatial units, are both transport zones (mean population = 7.063) and neighborhoods (mean population = 26.466). The variables of the built environment are clearly the core of the study. A total of 20 (out of 21) are selected from among those found in the literature while, at the same time, being accessible. Nine out of them are used to describe land use characteristics while another eleven describe the network of public spaces. Latter ones include configurational accessibility or Space Syntax variables. This is a particular sort of accessibility related with the concept of configuration, by HILLIER (1996), one of the main authors of Space Syntax, But it also include more customary variables used in mobility research to describe the urban design or spatial structure (here public space network), which here are called geometric characteristics of the such as its length, type of intersection, conectivity, density, etc. Finally a single socioeconomic variable was included in order to assess the influence non built environment factors that also may have an impact on walking (age, income, motorization rate, etc.). The association among variables is worked out using bi-variate correlation analysis and multivariate-analysis. Correlations are calculated among the 21 independent variables and the dependent one, the percentage of walking trips. Then, three types of multi-variate studies are run: general linear, curvilinear and discriminant multi-variate analysis. The latter are fully capable of generating complex association models among several variables, assessing quite precisely to what extent each model reproduces the behavior of the dependent variable, and also the weight or influence of each variable in the model. This study’s results show a consistent influence of three particular indexes in the two final alternative models of the multi-variate study (best, R2=0,6789, p<0,0000). Not surprisingly, two of them correspond to density and mix of land uses. But perhaps more interesting is that the third one is a measure of the accessibility of the public space network, a variable less important in the literature up to now. Additional precisions about them and their relative weight could also be of some interest. The density index is not only about population but includes most important activities in an area (nº residents + nº jobs+ nº students/Ha). The configurational index (radius 5 integration) is a measure of the accessibility of the area, i.e. centrality, at the scale of, more a less, a district. Regarding the mix of land uses index, this one is a measure of the balance between retail, in fact local basic retail, and the number of residents (nº of convenience shops / nº of residents). Referring to their weights, configurational index (radius 5 integration) gets the higher standardized coefficient of the final equation. However, in the final equations, there are a higher number of indexes coming from the density or land use mix categories than from public space network enter. Therefore, these findings seem to support part of the field’s knowledge, especially those concerning land uses, but at the same time they seem to bring in the idea that the configuration of the urban grid could have an influence in the proportion of walkers (as a part of total trips on any transport mode) that do single journey trips in the neighborhoods of Madrid, Spain. Of course this conclusion has, at present, a limited validity since it’s the result of a single case. The reasons of why this can be so, are discussed in the last part of the thesis.

Mutual Information and Perplexity based Clustering of Dialogue Information for Dynamic Adaptation of Language Models

We present two approaches to cluster dialogue-based information obtained by the speech understanding module and the dialogue manager of a spoken dialogue system. The purpose is to estimate a language model related to each cluster, and use them to dynamically modify the model of the speech recognizer at each dialogue turn. In the first approach we build the cluster tree using local decisions based on a Maximum Normalized Mutual Information criterion. In the second one we take global decisions, based on the optimization of the global perplexity of the combination of the cluster-related LMs. Our experiments show a relative reduction of the word error rate of 15.17%, which helps to improve the performance of the understanding and the dialogue manager modules.

New reynolds equation for line contact based on the carreau model modification by bair

This paper presents a new form of the one-dimensional Reynolds equation for lubricants whose rheological behaviour follows a modified Carreau rheological model proposed by Bair. The results of the shear stress and flow rate obtained through a new Reynolds–Carreau equation are shown and compared with the results obtained by other researchers.

Employment rate impacts of charging the Heavy Good Vehicle corridor (Madrid-Sevilla) across Spanish regions: a Random Utility Based Multiregional Input-Output approach

The implementation of a charging policy for heavy goods vehicles in European Union (EU) member countries has been imposed to reflect costs of construction and maintenance of infrastructure as well as externalities such as congestion, accidents and environmental impact. In this context, EU countries approved the Eurovignette directive (1999/62/EC) and its amending directive (2006 /38/EC) which established a legal framework to regulate the system of tolls. Even if that regulation seek s to increase the efficien cy of freight, it will trigger direct and indirect effects on Spain’s regional economies by increasing transport costs. This paper presents the development of a multiregional Input-Output methodology (MRIO) with elastic trade coefficients to predict in terregional trade, using transport attributes integrated in multinomial logit models. This method is highly useful to carry out an ex-ante evaluation of transport policies because it involves road freight transport cost sensitivity, and determine regional distributive and substitution economic effect s of countries like Spain, characterized by socio-demographic and economic attributes, differentiated region by region. It will thus be possible to determine cost-effective strategies, given different policy scenarios. MRIO mode l would then be used to determine the impact on the employment rate of imposing a charge in the Madrid-Sevilla corridor in Spain. This methodology is important for measuring the impact on the employment rate since it is one of the main macroeconomic indicators of Spain’s regional and national economic situation. A previous research developed (DESTINO) using a MRIO method estimated employment impacts of road pricing policy across Spanish regions considering a fuel tax charge (€/liter) in the entire shortest cost path network for freight transport. Actually, it found that the variation in employment is expected to be substantial for some regions, and negligible for others. For example, in this Spanish case study of regional employment has showed reductions between 16.1% (Rioja) and 1.4% (Madrid region). This variation range seems to be related to either the intensity of freight transport in each region or dependency of regions to transport intensive economic sect ors. In fact, regions with freight transport intensive sectors will lose more jobs while regions with a predominantly service economy undergo a fairly insignificant loss of employment. This paper is focused on evaluating a freight transport vehicle-kilometer charge (€/km) in a non-tolled motorway corridor (A-4) between Madrid-Sevilla (517 Km.). The consequences of the road pricing policy implementation show s that the employment reductions are not as high as the diminution stated in the previous research because this corridor does not affect the whole freight transport system of Spain.

Mutual Information and Perplexity based Clustering of Dialogue Information for Dynamic Adaptation of Language Models

We present two approaches to cluster dialogue-based information obtained by the speech understanding module and the dialogue manager of a spoken dialogue system. The purpose is to estimate a language model related to each cluster, and use them to dynamically modify the model of the speech recognizer at each dialogue turn. In the first approach we build the cluster tree using local decisions based on a Maximum Normalized Mutual Information criterion. In the second one we take global decisions, based on the optimization of the global perplexity of the combination of the cluster-related LMs. Our experiments show a relative reduction of the word error rate of 15.17%, which helps to improve the performance of the understanding and the dialogue manager modules.

Hard transition to chaotic dynamics in Alfven wave fronts

The derivative nonlinear Schrodinger DNLS equation, describing propagation of circularly polarized Alfven waves of finite amplitude in a cold plasma, is truncated to explore the coherent, weakly nonlinear, cubic coupling of three waves near resonance, one wave being linearly unstable and the other waves damped. In a reduced three-wave model equal dampings of daughter waves, three-dimensional flow for two wave amplitudes and one relative phase, no matter how small the growth rate of the unstable wave there exists a parametric domain with the flow exhibiting chaotic relaxation oscillations that are absent for zero growth rate. This hard transition in phase-space behavior occurs for left-hand LH polarized waves, paralleling the known fact that only LH time-harmonic solutions of the DNLS equation are modulationally unstable, with damping less than about unstable wave frequency 2/4 x ion cyclotron frequency. The structural stability of the transition was explored by going into a fully 3-wave model different dampings of daughter waves,four-dimensional flow; both models differ in significant phase-space features but keep common features essential for the transition.

Extension of the characteristic equation to absorption chillers with adiabatic absorbers

Various researchers have developed models of conventional H2O–LiBr absorption machines with the aim of predicting their performance. In this paper, the methodology of characteristic equations developed by Hellmann et al. (1998) is applied. This model is able to represent the capacity of single effect absorption chillers and heat pumps by means of simple algebraic equations. An extended characteristic equation based on a characteristic temperature difference has been obtained, considering the facility features. As a result, it is concluded that for adiabatic absorbers a subcooling temperature must be specified. The effect of evaporator overflow has been characterized. Its influence on cooling capacity has been included in the extended characteristic equation. Taking into account the particular design and operation features, a good agreement between experimental performance data and those obtained through the extended characteristic equation has been achieved at off-design operation. This allows its use for simulation and control purposes.

Comparison of particle dispersion obtained with simple stochastic models and les in pipe flow

A hybrid Eulerian-Lagrangian approach is employed to simulate heavy particle dispersion in turbulent pipe flow. The mean flow is provided by the Eulerian simulations developed by mean of JetCode, whereas the fluid fluctuations seen by particles are prescribed by a stochastic differential equation based on normalized Langevin. The statistics of particle velocity are compared to LES data which contain detailed statistics of velocity for particles with diameter equal to 20.4 µm. The model is in good agreement with the LES data for axial mean velocity whereas rms of axial and radial velocities should be adjusted.

Non-destructive measurement techniques for taper equation development: a study case in the Spanish Northern Iberian Range

In recent years, the technology for measuring the diameter and height of standing trees has improved significantly. These enhancements allow estimation of the volume of standing trees using stem taper equations, which traditionally have been constructed with data from felled trees, in an accurate and economically feasible way. A nondestructive method was evaluated with data from 38 pines and was validated with data from another 38 pines, both in the Northern Iberian Range (Spain). The electronic dendrometer Criterion RD1000 (Laser Technology Inc.) and the laser hypsometer TruPulse (Laser Technology Inc.) were used due to their accuracy and interoperability. The methodology was valid (unbiased and precise) measuring from a distance similar to the height of the tree. In this distance, statistical criteria and plots based on the residuals showed no clear advantage in volume estimation with models fitted with data from destructive methods against models fitted with data from the proposed non-destructive technique. This methodology can be considered useful for individual volume estimation and for developing taper equations.