Regime-Switching Cointegration

We develop methods for Bayesian inference in vector error correction models which are subject to a variety of switches in regime (e.g. Markov switches in regime or structural breaks). An important aspect of our approach is that we allow both the cointegrating vectors and the number of cointegrating relationships to change when the regime changes. We show how Bayesian model averaging or model selection methods can be used to deal with the high-dimensional model space that results. Our methods are used in an empirical study of the Fisher effect.

What drives urban consumption in mainland china? The role of property price dynamics

This paper adds to the literature on wealth effects on consumption by disentangling house price effects on consumption for mainland China. In a stochastic modelling framework, the riskiness, rate of increase and persistence of house price movements have different implications for the consumption/housing ratio. We exploit the geographical variation in property prices by using a quarterly city-level panel dataset for the period 1998Q1 – 2009Q4 and rely on a panel error correction model. Overall, the results suggest a significant long run impact of property prices on consumption. They also broadly confirm the predictions from the theoretical model.

Regime-Switching Cointegration

We develop methods for Bayesian inference in vector error correction models which are subject to a variety of switches in regime (e.g. Markov switches in regime or structural breaks). An important aspect of our approach is that we allow both the cointegrating vectors and the number of cointegrating relationships to change when the regime changes. We show how Bayesian model averaging or model selection methods can be used to deal with the high-dimensional model space that results. Our methods are used in an empirical study of the Fisher e ffect.

Productivity shocks and aggregate fluctuations in an estimated endogenous growth model with human capital

Employing an endogenous growth model with human capital, this paper explores how productivity shocks in the goods and human capital producing sectors contribute to explaining aggregate fluctuations in output, consumption, investment and hours. Given the importance of accounting for both the dynamics and the trends in the data not captured by the theoretical growth model, we introduce a vector error correction model (VECM) of the measurement errors and estimate the model’s posterior density function using Bayesian methods. To contextualize our findings with those in the literature, we also assess whether the endogenous growth model or the standard real business cycle model better explains the observed variation in these aggregates. In addressing these issues we contribute to both the methods of analysis and the ongoing debate regarding the effects of innovations to productivity on macroeconomic activity.

Analysis and optimization of the satellite-to-plane link of an aeronautical global system

En aquest projecte s’ha analitzat i optimitzat l’enllaç satèl·lit amb avió per a un sistema aeronàutic global. Aquest nou sistema anomenat ANTARES està dissenyat per a comunicar avions amb estacions base mitjançant un satèl·lit. Aquesta és una iniciativa on hi participen institucions oficials en l’aviació com ara l’ECAC i que és desenvolupat en una col·laboració europea d’universitats i empreses. El treball dut a terme en el projecte compren bàsicament tres aspectes. El disseny i anàlisi de la gestió de recursos. La idoneïtat d’utilitzar correcció d’errors en la capa d’enllaç i en cas que sigui necessària dissenyar una opció de codificació preliminar. Finalment, estudiar i analitzar l’efecte de la interferència co-canal en sistemes multifeix. Tots aquests temes són considerats només per al “forward link”. L’estructura que segueix el projecte és primer presentar les característiques globals del sistema, després centrar-se i analitzar els temes mencionats per a poder donar resultats i extreure conclusions.

On codes, matroids, and secure multiparty computation from linear secret-sharing schemes

Error-correcting codes and matroids have been widely used in the study of ordinary secret sharing schemes. In this paper, the connections between codes, matroids, and a special class of secret sharing schemes, namely, multiplicative linear secret sharing schemes (LSSSs), are studied. Such schemes are known to enable multiparty computation protocols secure against general (nonthreshold) adversaries.Two open problems related to the complexity of multiplicative LSSSs are considered in this paper. The first one deals with strongly multiplicative LSSSs. As opposed to the case of multiplicative LSSSs, it is not known whether there is an efficient method to transform an LSSS into a strongly multiplicative LSSS for the same access structure with a polynomial increase of the complexity. A property of strongly multiplicative LSSSs that could be useful in solving this problem is proved. Namely, using a suitable generalization of the well-known Berlekamp–Welch decoder, it is shown that all strongly multiplicative LSSSs enable efficient reconstruction of a shared secret in the presence of malicious faults. The second one is to characterize the access structures of ideal multiplicative LSSSs. Specifically, the considered open problem is to determine whether all self-dual vector space access structures are in this situation. By the aforementioned connection, this in fact constitutes an open problem about matroid theory, since it can be restated in terms of representability of identically self-dual matroids by self-dual codes. A new concept is introduced, the flat-partition, that provides a useful classification of identically self-dual matroids. Uniform identically self-dual matroids, which are known to be representable by self-dual codes, form one of the classes. It is proved that this property also holds for the family of matroids that, in a natural way, is the next class in the above classification: the identically self-dual bipartite matroids.

Transfer of MPEG-2 Transport Stream over MPLS

This study examines how MPEG-2 Transport Stream, used in DVB-T video transmission, can be reliably and efficiently transferred to remote locations over an MPLS network. All the relevant technologies used in this scenario are also discussed in the study. This study was done for Digita Oy, which is a major radio and television content distributor in Finland. The theoretical part of the study begins with the introduction to MPLS technology and continues with explanation of IP Multicast and its components. The fourth section discusses MPEG-2 and the formation and content of MPEG-2 Transport Stream. These technologies were studied in relevant literature and RFC documentation. After the theoretical part of the study, the test setup and the test cases are presented. The results of the test cases, and the conclusions that can be drawn based on them, are discussed in the last section of the study. The tests showed that it is possible to transfer digital video quite reliably over an MPLS network using IP Multicast. By configuring the equipment correctly, the recovery time of the network in case of a failure can be shortened remarkably. Also, the unwanted effect of other traffic on the critical video traffic can be eliminated by defining the Quality of Service parameters correctly. There are, however, some issues that need to be tested further before this setup can be used in broadcast networks. Reliable operation of IP Multicast and proper error correction are the main subjects for future testing.

The dynamic adjustment of local government budgets : Does Spain behave differently?

[spa] El objetivo de este trabajo es analizar si los municipios españoles se ajustan en presencia de un shock presupuestario y (si es así) qué elementos del presupuesto son los que realizan el ajuste. La metodología utilizada para contestar estas preguntas es un mecanismo de corrección del error, VECM, que estimamos con un panel de datos de los municipios españoles durante el período 1988-2006. Nuestros resultados confirman que, en primer lugar, los municipios se ajustan en presencia de un shock fiscal (es decir, el déficit es estacionario en el largo plazo). En segundo lugar, obtenemos que cuando el shock afecta a los ingresos el ajuste lo soporta principalmente el municipio reduciendo el gasto, las transferencias tienen un papel muy reducido en este proceso de ajuste. Por el contrario, cuando el shock afecta al gasto, el ajuste es compartido en términos similares entre el municipio – incrementado los impuestos – y los gobiernos de niveles superiores – incrementando las transferencias. Estos resultados sugieren que la viabilidad de las finanzas pública locales es factible con diferentes entornos institucionales.

The dynamic adjustment of local government budgets : Does Spain behave differently?

[spa] El objetivo de este trabajo es analizar si los municipios españoles se ajustan en presencia de un shock presupuestario y (si es así) qué elementos del presupuesto son los que realizan el ajuste. La metodología utilizada para contestar estas preguntas es un mecanismo de corrección del error, VECM, que estimamos con un panel de datos de los municipios españoles durante el período 1988-2006. Nuestros resultados confirman que, en primer lugar, los municipios se ajustan en presencia de un shock fiscal (es decir, el déficit es estacionario en el largo plazo). En segundo lugar, obtenemos que cuando el shock afecta a los ingresos el ajuste lo soporta principalmente el municipio reduciendo el gasto, las transferencias tienen un papel muy reducido en este proceso de ajuste. Por el contrario, cuando el shock afecta al gasto, el ajuste es compartido en términos similares entre el municipio – incrementado los impuestos – y los gobiernos de niveles superiores – incrementando las transferencias. Estos resultados sugieren que la viabilidad de las finanzas pública locales es factible con diferentes entornos institucionales.

Gold investments and short- and long-run price determinants of the price of gold

Tämän tutkielman tavoitteena on tutkia tekijöitä jotkavaikuttavat lyhyellä ja pitkällä aikavälillä kullan hintaan. Toiseksi tutkielmassa selvitetään mitä eri sijoitusmahdollisuuksia löytyy kultaan sijoitettaessa. Aineistona käytetään kuukausitasoista dataa Yhdysvaltain ja maailman hintaindekseistä, Yhdysvaltain ja maailman inflaatiosta ja inflaation volatiliteetista, kullan beetasta, kullan lainahinnasta, luottoriskistä ja Yhdysvaltojen ja maailman valuuttakurssi indeksistä joulukuulta 1972 elokuulle 2006. Yhteisintegraatio regressiotekniikoita käytettiin muodostamaan malli jonka avullatutkittiin päätekijöitä jotka vaikuttavat kullan hintaan. Kirjallisuutta tutkimalla selvitettiin miten kultaan voidaan sijoittaa. Empiirisettulokset ovat yhteneväisiä edellisten tutkimusten kanssa. Tukea löytyi sille, että kulta on pitkän ajan suoja inflaatiota vastaan ja kulta ja Yhdysvaltojen inflaatio liikkuvat pitkällä aikavälillä yhdessä. Kullan hintaan vaikuttavat kuitenkin lyhyen ajan tekijät pitkän ajan tekijöitä enemmän. Kulta on myös sijoittajalle helppo sijoituskohde, koska se on hyvin saatavilla markkinoilla ja eri instrumentteja on lukuisia.

Pass-through in dollarized countries: should Ecuador abandon the U.S. Dollar?

In this article we examine the convenience of dollarization for Ecuador today. As Ecuador is strongly integrated financially and commercially with the United States, the exchange rate pass-through should be zero. However, we sustain that rising rates of imports from trade partners other than the United States and subsequent real effective exchange rate depreciations are causing the pass-through to move away from zero. Here, in the framework of the Vector Error Correction Model, we analyse the impulse response function and variance decomposition of the inflation variable. We show that the developing economy of Ecuador is importing inflation from its main trading partners, most of them emerging countries with appreciated currencies. We argue that if Ecuador recovered both its monetary and exchange rate instruments it would be able to fight against inflation. We believe such an analysis could be extended to other countries with pegged exchange rate regimes.

Power line communication in motor cables of variable-speed electric drives − analysis and

Data transmission between an electric motor and a frequency converter is required in variablespeed electric drives because of sensors installed at the motor. Sensor information can be used for various useful applications to improve the system reliability and its properties. Traditionally, the communication medium is implemented by an additional cabling. However, the costs of the traditional method may be an obstacle to the wider application of data transmission between a motor and a frequency converter. In any case, a power cable is always installed between a motor and a frequency converter for power supply, and hence it may be applied as a communication medium for sensor level data. This thesis considers power line communication (PLC) in inverter-fed motor power cables. The motor cable is studied as a communication channel in the frequency band of 100 kHz−30 MHz. The communication channel and noise characteristics are described. All the individual components included in a variable-speed electric drive are presented in detail. A channel model is developed, and it is verified by measurements. A theoretical channel information capacity analysis is carried out to estimate the opportunities of a communication medium. Suitable communication and forward error correction (FEC) methods are suggested. A general method to implement a broadband and Ethernet-based communication medium between a motor and a frequency converter is proposed. A coupling interface is also developed that allows to install the communication device safely to a three-phase inverter-fed motor power cable. Practical tests are carried out, and the results are analyzed. Possible applications for the proposed method are presented. A speed feedback motor control application is verified in detail by simulations and laboratory tests because of restrictions for the delay in the feedback loop caused by PLC. Other possible applications are discussed at a more general level.

Uma introdução à espectroscopia atômica: II - o espectro do sódio

The present article is devoted to Chemistry or Physics undergraduate students, given their difficulty to understand fundamental concepts and technical language used in atomic spectroscopy and quantum mechanics. An easy approach is shown in the treatment of the emission spectrum of the sodium atom without any involved calculations. In a previous article, the hydrogen spectrum was considered and the energy degeneracy of the angular momentum quantum number was observed. For the sodium spectrum, due to the valence electron penetration into internal shells, a breakdown of this degeneracy occurs and a dependence of this penetration on the angular momentum quantum number is observed. The eigenvalues are determined introducing the quantum defect correction (Rydberg correction) in the denominator of the Balmer equation, and the energy diagram is obtained. The intensity ratio for the observed doublets is explained by introducing new wave functions, containing the magnetic quantum number of the total angular momentum.

Omakotitalojen hintadynamiikka Suomessa

Tämän tutkielma tutkii omakotitalojen hintadynamiikkaa Suomessa 1985Q1-2009Q2 välisenä aikana. Tarkoituksena on luoda pitkänaikavälin tasapainomalli sekä lyhyenajan vektorivirheenkorjausmalli, jonka avulla voidaan selvittää asuntojen hintojen mukautumisnopeus kohti tasapainotilaa. Pitkänajan tasapainomallin mukaan omakotitalojen hintaan vaikuttavat eniten kotitalouksien käytettävissä olevat tulot sekä suhteellinen velkaantuneisuus. Koron merkitys jäi mallissa suhteellisen pieneksi. Sekä tulot että velkaantuneisuus vaikuttavat omakotitalojen hintaan positiivisesti. Asuntojen hintojen mukautumisnopeus kohti tasapainotilaa on kohtalaisen nopeaa. Mallin mukaan Suomessa ei ole havaittavissa selvää asuntojen hintakuplaa.