IS THE U.S. SHALE GAS BOOM HAVING AN EFFECT ON THE EUROPEAN GAS MARKET?

This thesis focuses on the impact of the American shale gas boom on the European natural gas market. The study presents different tests in order to analyze the dynamics of natural gas prices in the U.S., U.K. and German natural gas market. The question of cointegration between these different markets are analyzed using several tests. More specifically, the ADF tests for the presence of a unit root. The error correction model test and the Johansen cointegration procedure are applied in order to accept or reject the hypothesis of an integrated market. The results suggest no evidence of cointegration between these markets. There currently is no evidence of an impact of the U.S. shale gas boom on the European market.

Traffic-Adaptive and Link-Quality-Aware Communication in Wireless Sensor Networks

This paper is a summary of the main contribu- tions of the PhD thesis published in [1]. The main research contributions of the thesis are driven by the research question how to design simple, yet efficient and robust run-time adaptive resource allocation schemes within the commu- nication stack of Wireless Sensor Network (WSN) nodes. The thesis addresses several problem domains with con- tributions on different layers of the WSN communication stack. The main contributions can be summarized as follows: First, a a novel run-time adaptive MAC protocol is intro- duced, which stepwise allocates the power-hungry radio interface in an on-demand manner when the encountered traffic load requires it. Second, the thesis outlines a metho- dology for robust, reliable and accurate software-based energy-estimation, which is calculated at network run- time on the sensor node itself. Third, the thesis evaluates several Forward Error Correction (FEC) strategies to adap- tively allocate the correctional power of Error Correcting Codes (ECCs) to cope with timely and spatially variable bit error rates. Fourth, in the context of TCP-based communi- cations in WSNs, the thesis evaluates distributed caching and local retransmission strategies to overcome the perfor- mance degrading effects of packet corruption and trans- mission failures when transmitting data over multiple hops. The performance of all developed protocols are eval- uated on a self-developed real-world WSN testbed and achieve superior performance over selected existing ap- proaches, especially where traffic load and channel condi- tions are suspect to rapid variations over time.

Mechanisms of cell competition: Themes and variations

Cell competition is the short-range elimination of slow-dividing cells through apoptosis when confronted with a faster growing population. It is based on the comparison of relative cell fitness between neighboring cells and is a striking example of tissue adaptability that could play a central role in developmental error correction and cancer progression in both Drosophila melanogaster and mammals. Cell competition has led to the discovery of multiple pathways that affect cell fitness and drive cell elimination. The diversity of these pathways could reflect unrelated phenomena, yet recent evidence suggests some common wiring and the existence of a bona fide fitness comparison pathway.

The Time-Series Properties on Housing Prices: A Case Study of the Southern California Market

We examine the time-series relationship between housing prices in eight Southern California metropolitan statistical areas (MSAs). First, we perform cointegration tests of the housing price indexes for the MSAs, finding seven cointegrating vectors. Thus, the evidence suggests that one common trend links the housing prices in these eight MSAs, a purchasing power parity finding for the housing prices in Southern California. Second, we perform temporal Granger causality tests revealing intertwined temporal relationships. The Santa Anna MSA leads the pack in temporally causing housing prices in six of the other seven MSAs, excluding only the San Luis Obispo MSA. The Oxnard MSA experienced the largest number of temporal effects from other MSAs, six of the seven, excluding only Los Angeles. The Santa Barbara MSA proved the most isolated in that it temporally caused housing prices in only two other MSAs (Los Angels and Oxnard) and housing prices in the Santa Anna MSA temporally caused prices in Santa Barbara. Third, we calculate out-of-sample forecasts in each MSA, using various vector autoregressive (VAR) and vector error-correction (VEC) models, as well as Bayesian, spatial, and causality versions of these models with various priors. Different specifications provide superior forecasts in the different MSAs. Finally, we consider the ability of theses time-series models to provide accurate out-of-sample predictions of turning points in housing prices that occurred in 2006:Q4. Recursive forecasts, where the sample is updated each quarter, provide reasonably good forecasts of turning points.

The Aggregate Demand for Private Health Insurance Coverage in the U.S.

This paper estimates the aggregate demand for private health insurance coverage in the U.S. using an error-correction model and by recognizing that people are without private health insurance for voluntary, structural, frictional, and cyclical reasons and because of public alternatives. Insurance coverage is measured both by the percentage of the population enrolled in private health insurance plans and the completeness of the insurance coverage. Annual data for the period 1966-1999 are used and both short and long run price and income elasticities of demand are estimated. The empirical findings indicate that both private insurance enrollment and completeness are relatively inelastic with respect to changes in price and income in the short and long run. Moreover, private health insurance enrollment is found to be inversely related to the poverty rate, particularly in the short-run. Finally, our results suggest that an increase in the number cyclically uninsured generates less of a welfare loss than an increase in the structurally uninsured.

The Real Exchange Rate in Small Open Developed Economies: Evidence from Cointegration Analysis

We examine the effects of the terms of trade and the expected real interest rate differential on the real exchange rate in a sample of small open developed economies. We employ cointegration analysis to search for possible long-term linkages. We find that while both the terms of trade and the expected real interest rate differentials affect the real exchange rate in the long run, the role of the terms of trade generally proves more consistent across countries. The speed of adjustment for the expected real interest rate differential in the error-correction model, however, is quantitatively larger than it is for the terms of trade.

"Ripple Effects" and Forecasting Home Prices in Los Angeles, Las Vegas, and Phoenix

We examine the time-series relationship between housing prices in Los Angeles, Las Vegas, and Phoenix. First, temporal Granger causality tests reveal that Los Angeles housing prices cause housing prices in Las Vegas (directly) and Phoenix (indirectly). In addition, Las Vegas housing prices cause housing prices in Phoenix. Los Angeles housing prices prove exogenous in a temporal sense and Phoenix housing prices do not cause prices in the other two markets. Second, we calculate out-of-sample forecasts in each market, using various vector autoregessive (VAR) and vector error-correction (VEC) models, as well as Bayesian, spatial, and causality versions of these models with various priors. Different specifications provide superior forecasts in the different cities. Finally, we consider the ability of theses time-series models to provide accurate out-of-sample predictions of turning points in housing prices that occurred in 2006:Q4. Recursive forecasts, where the sample is updated each quarter, provide reasonably good forecasts of turning points.

Countervailing Duties in the USA

This paper reveals the characteristics of the ITC's decisions on countervailing duties, which have seldom been studied. The empirical evidences based on time series data show that there is a long run equilibrium relationship between affirmative countervailing decisions and macroeconomic variables such as economic growth rates and import penetration ratios. The error correction models show that there is a unidirectional causality from affirmative countervailing decisions to slower economic growth.

DEVELOPMENT OF NOVEL METHODS TO MINIMIZE THE IMPACT OF SEQUENCING ERRORS IN THE NEXT-GENERATION SEQUENCING DATA ANALYSIS

Next-generation sequencing (NGS) technology has become a prominent tool in biological and biomedical research. However, NGS data analysis, such as de novo assembly, mapping and variants detection is far from maturity, and the high sequencing error-rate is one of the major problems. . To minimize the impact of sequencing errors, we developed a highly robust and efficient method, MTM, to correct the errors in NGS reads. We demonstrated the effectiveness of MTM on both single-cell data with highly non-uniform coverage and normal data with uniformly high coverage, reflecting that MTM’s performance does not rely on the coverage of the sequencing reads. MTM was also compared with Hammer and Quake, the best methods for correcting non-uniform and uniform data respectively. For non-uniform data, MTM outperformed both Hammer and Quake. For uniform data, MTM showed better performance than Quake and comparable results to Hammer. By making better error correction with MTM, the quality of downstream analysis, such as mapping and SNP detection, was improved. SNP calling is a major application of NGS technologies. However, the existence of sequencing errors complicates this process, especially for the low coverage (

U-Pb (zircon) geochronologic analyses for rocks of the Transantarctic Mountains (Table 4.3-1)

The Byrd Glacier discontinuity us a major boundary crossing the Ross Orogen, with crystalline rocks to the north and primarily sedimentary rocks to the south. Most models for the tectonic development of the Ross Orogen in the central Transantarctic Mountains consits of two-dimensional transects across the belt, but do not adress the major longitudinal contrast at Byrd Glacier. This paper presents a tectonic model centering on the Byrd Glacier discontinuity. Rifting in the Neoproterozoic producede a crustal promontory in the craton margin to the north of Byrd Glacier. Oblique convergence of the terrane (Beardmore microcontinent) during the latest Neroproterozoic and Early Cambrian was accompanied by subduction along the craton margin of East Antarctica. New data presented herein in the support of this hypothesis are U-Pb dates of 545.7 ± 6.8 Ma and 531.0 ± 7.5 Ma on plutonic rocks from the Britannia Range, subduction stepped out, and Byrd Glacier. After docking of the terrane, subduction stepped out, and Byrd Group was deposited during the Atdabanian-Botomian across the inner margin of the terrane. Beginning in the upper Botomian, reactivation of the sutured boundaries of the terrane resulted in an outpouring of clastic sediment and folding and faulting of the Byrd Group.

The Chilean wheat market and its price support mechanism : a spatial market integration analysis

This research investigates the spatial market integration of the Chilean wheat market in relation with its most representative international markets by using a vector error correction model (VECM) and how a price support policy, as a price band, affect it. The international market was characterized by two relevant wheat prices: PAN from Argentina and Hard Red Winter from the United States. The spatial market integration level, expressed in the error correction term (ECT), allowed concluding that there is a high integration degree among these markets with a variable influence of the price band mechanism mainly related with its estimation methodology. Moreover, this paper showed that Chile can be seen as price taker as long as the speed of its adjustment to international shocks, being these reactions faster than in the United States and Argentina. Finally, the results validated the "Law of the One Price", which assumes price equalization across all local markets in the long run.

Tab. 1: U-Pb analyses of zircons from rock samples in MT. Newton and Cumpston Massif, East Antarctica

We present new U-Pb zircon (SHRIMP) data on rocks from Mt Newton and Cumpston Massif in the southern Prince Charles Mountains. Our data demonstrate that Mt Newton was affected by a newly proposed Palaeoproterozoic "Newton" Orogeny at c. 2100-2200 Ma. Sedimentation, felsic volcanism (c. 2200 Ma), metamorphism and folding, followed by granite intrusion (c. 2100 Ma), suggest development of a trough or aulacogene in the area during the early Palaeoproterozoic. An orthogneiss from Cumpston Massif yielded an age of c. 3180 Ma for granitic protolith emplacement, which is in good agreement with many U-Pb zircon ages from similar rocks in the southern Mawson Escarpment. A syn- to late-tectonic muscovite-bearing pegmatite from Cumpston Massif yielded a c. 2500 Ma date of emplacement, which indicates early Palaeoproterozoic activity in this block, probably in response to a tectono-magmatic episode in the Lambert Terrane bordering the Ruker Terrane in the northeast. The correlation of tectono-magmatic events in both the Ruker and Lambert terranes of the southern Prince Charles Mountains provides evidence for their common evolution during the Proterozoic.

A Video-Aware FEC-Based Unequal Loss Protection Scheme for RTP Video Streaming

A video-aware unequal loss protection (ULP) system for protecting RTP video streaming in bursty packet loss networks is proposed. Just considering the relevance of the frame, the state of the channel and the bitrate constraints of the protection bitstream, our algorithm selects in real time the most suitable frames to be protected through forward error correction (FEC) techniques. It benefits from a wise RTP encapsulation that allows working at a frame level without requiring any further process than that of parsing RTP headers, so it is perfectly suitable to be included in commercial transmitters. The simulation results show how our proposed ULP technique outperforms non-smart schemes.

Inter-Packet Symbol Approach To Reed-Solomon FEC Codes For RTP-Multimedia Stream Protection

This paper presents an alternative Forward Error Correction scheme, based on Reed-Solomon codes, with the aim of protecting the transmission of RTP-multimedia streams: the inter-packet symbol approach. This scheme is based on an alternative bit structure that allocates each symbol of the Reed-Solomon code in several RTP-media packets. This characteristic permits to exploit better the recovery capability of Reed-Solomon codes against bursty packet losses. The performance of our approach has been studied in terms of encoding/decoding time versus recovery capability, and compared with other proposed schemes in the literature. The theoretical analysis has shown that our approach allows the use of a lower size of the Galois Fields compared to other solutions. This lower size results in a decrease of the required encoding/decoding time while keeping a comparable recovery capability. Finally, experimental results have been carried out to assess the performance of our approach compared to other schemes in a simulated environment, where models for wireless and wireline channels have been considered.

Sistema de instrumentação e controle para células a combustível

Este trabajo presenta un estudio sobre el funcionamiento y aplicaciones de las células de combustible de membrana tipo PEM, o de intercambio de protones, alimentadas con hidrógeno puro y oxigeno obtenido de aire comprimido. Una vez evaluado el proceso de dichas células y las variables que intervienen en el mismo, como presión, humedad y temperatura, se presenta una variedad de métodos para la instrumentación de tales variables así como métodos y sistemas para la estabilidad y control de las mismas, en torno a los valores óptimos para una mayor eficacia en el proceso. Tomando como variable principal a controlar la temperatura del proceso, y exponiendo los valores concretos en torno a 80 grados centígrados entre los que debe situarse, es realizado un modelo del proceso de calentamiento y evolución de la temperatura en función de la potencia del calentador resistivo en el dominio de la frecuencia compleja, y a su vez implementado un sistema de medición mediante sensores termopar de tipo K de respuesta casi lineal. La señal medida por los sensores es amplificada de manera diferencial mediante amplificadores de instrumentación INA2126, y es desarrollado un algoritmo de corrección de error de unión fría (error producido por la inclusión de nuevos metales del conector en el efecto termopar). Son incluidos los datos de test referentes al sistema de medición de temperatura , incluyendo las desviaciones o error respecto a los valores ideales de medida. Para la adquisición de datos y implementación de algoritmos de control, es utilizado un PC con el software Labview de National Instruments, que permite una programación intuitiva, versátil y visual, y poder realizar interfaces de usuario gráficas simples. La conexión entre el hardware de instrumentación y control de la célula y el PC se realiza mediante un interface de adquisición de datos USB NI 6800 que cuenta con un amplio número de salidas y entradas analógicas. Una vez digitalizadas las muestras de la señal medida, y corregido el error de unión fría anteriormente apuntado, es implementado en dicho software un controlador de tipo PID ( proporcional-integral-derivativo) , que se presenta como uno de los métodos más adecuados por su simplicidad de programación y su eficacia para el control de este tipo de variables. Para la evaluación del comportamiento del sistema son expuestas simulaciones mediante el software Matlab y Simulink determinando por tanto las mejores estrategias para desarrollar el control PID, así como los posibles resultados del proceso. En cuanto al sistema de calentamiento de los fluidos, es empleado un elemento resistor calentador, cuya potencia es controlada mediante un circuito electrónico compuesto por un detector de cruce por cero de la onda AC de alimentación y un sistema formado por un elemento TRIAC y su circuito de accionamiento. De manera análoga se expone el sistema de instrumentación para la presión de los gases en el circuito, variable que oscila en valores próximos a 3 atmosferas, para ello es empleado un sensor de presión con salida en corriente mediante bucle 4-20 mA, y un convertidor simple corriente a tensión para la entrada al sistema de adquisición de datos. Consecuentemente se presenta el esquema y componentes necesarios para la canalización, calentamiento y humidificación de los gases empleados en el proceso así como la situación de los sensores y actuadores. Por último el trabajo expone la relación de algoritmos desarrollados y un apéndice con información relativa al software Labview. ABTRACT This document presents a study about the operation and applications of PEM fuel cells (Proton exchange membrane fuel cells), fed with pure hydrogen and oxygen obtained from compressed air. Having evaluated the process of these cells and the variables involved on it, such as pressure, humidity and temperature, there is a variety of methods for implementing their control and to set up them around optimal values for greater efficiency in the process. Taking as primary process variable the temperature, and exposing its correct values around 80 degrees centigrade, between which must be placed, is carried out a model of the heating process and the temperature evolution related with the resistive heater power on the complex frequency domain, and is implemented a measuring system with thermocouple sensor type K performing a almost linear response. The differential signal measured by the sensor is amplified through INA2126 instrumentation amplifiers, and is developed a cold junction error correction algorithm (error produced by the inclusion of additional metals of connectors on the thermocouple effect). Data from the test concerning the temperature measurement system are included , including deviations or error regarding the ideal values of measurement. For data acquisition and implementation of control algorithms, is used a PC with LabVIEW software from National Instruments, which makes programming intuitive, versatile, visual, and useful to perform simple user interfaces. The connection between the instrumentation and control hardware of the cell and the PC interface is via a USB data acquisition NI 6800 that has a large number of analog inputs and outputs. Once stored the samples of the measured signal, and correct the error noted above junction, is implemented a software controller PID (proportional-integral-derivative), which is presented as one of the best methods for their programming simplicity and effectiveness for the control of such variables. To evaluate the performance of the system are presented simulations using Matlab and Simulink software thereby determining the best strategies to develop PID control, and possible outcomes of the process. As fluid heating system, is employed a heater resistor element whose power is controlled by an electronic circuit comprising a zero crossing detector of the AC power wave and a system consisting of a Triac and its drive circuit. As made with temperature variable it is developed an instrumentation system for gas pressure in the circuit, variable ranging in values around 3 atmospheres, it is employed a pressure sensor with a current output via 4-20 mA loop, and a single current to voltage converter to adequate the input to the data acquisition system. Consequently is developed the scheme and components needed for circulation, heating and humidification of the gases used in the process as well as the location of sensors and actuators. Finally the document presents the list of algorithms and an appendix with information about Labview software.