Directions of Trade Flows and Labor Movements between High- And Low-Population Growth Countries: An Overlapping Generations General Equilibrium Analysis

This paper considers a two-country world where the population in one country grows faster than the other, and investigates the implications of the addition of non-stationary population dynamics to a simple 2- commodity, 2-factor model of international trade within an overlapping- generations framework. The two countries in the world considered are assumed to be identical in every respect except, for their population growth rates initially. The effects of differential speed of population growth on relative factor endowments and patterns of international trade are explored by comparing simulation results obtained from the overlapping-generations general equilibrium model under autarky and trade scenarios. Unequal population growth rates are shown to give rise to differentials in wage rates and rentals for capital under autarky conditions. This, in turn, causes costs of production and relative prices to differ, creating the grounds for trade in the sense of Heckscher-Ohlin (HO). Yet, the results from simulation exercises indicate that static welfare results from the standard 2x2x2 HO model can not be generalized to hold in a dynamic setting with overlapping generations of individuals.Unequal population growth rates, labor migration, international trade, overlapping-generations

Generalizing the Sampling Property of the Q-function for Error Rate Analysis of Cooperative Communication in Fading Channels

This paper extends some approximation methods that are used to identify closed form Bit Error Rate (BER) expressions which are frequently utilized in investigation and comparison of performance for wireless communication systems in the literature. By using this group of approximation methods, some expectation integrals, which are complicated to analyze and have high computational complexity to evaluate through Monte Carlo simulations, are computed. For these integrals, by using the sampling property of the integrand functions of one or more arguments, reliable BER expressions revealing the diversity and coding gains are derived. Although the methods we present are valid for a larger class of integration problems, in this work we show the step by step derivation of the BER expressions for a canonical cooperative communication scenario in addition to a network coded system starting from basic building blocks. The derived expressions agree with the simulation results for a very wide range of signal-to-noise ratio (SNR) values.Comment: 5 pages, 5 figures, Submitted to IEEE International Symposium on Information Theory, ISIT 2013, Istanbul, Turke

Error Rate Analysis of GF(q) Network Coded Detect-and-Forward Wireless Relay Networks Using Equivalent Relay Channel Models

This paper investigates simple means of analyzing the error rate performance of a general q-ary Galois Field network coded detect-and-forward cooperative relay network with known relay error statistics at the destination. Equivalent relay channels are used in obtaining an approximate error rate of the relay network, from which the diversity order is found. Error rate analyses using equivalent relay channel models are shown to be closely matched with simulation results. Using the equivalent relay channels, low complexity receivers are developed whose performances are close to that of the optimal maximum likelihood receiver.Comment: 28 pages, 10 figures. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Dynamics of Foreign Currency Lending in Turkey

On June 16 2009, in what authorities called ``a surprise development'' the Turkish Government removed a provision from its existing laws that had allowed Turkish residents to borrow in foreign currency from banks operating in Turkey. The development ended a long era of foreign currency lending in Turkey at least in the sense of consumer loans. This paper studies the determinants and consequences of foreign currency lending for banks in Turkey in the run-up to this significant policy change. Our analysis uses detailed foreign and Turkish currency composition bank data for 21 commercial banks in Turkey between 2002 and 2010. We evaluate drivers of saving and lending in foreign currency(FX) in Turkey along with consequences for the banking system in particular and for the economy in general. We highlight possible risks to the Turkish banking system as a result of system's heavy exposure to both channels. In doing so, we show that the policy change was not necessarily a surprise but a cautionary step in the right direction to help keep Turkish banking system stable.Dollarization, bank performance, bank profitability, Turkish economy

Nanomechanical resonators using functional nanowires

Nanoelectromechanical systems (NEMS) have seen a surge of active interest in the 21st century. NEMS resonators have been initially employed for mass and force sensing as well as quantum mechanical measurements. With the recent developments in readout techniques at room temperature, NEMS have also proven promising in telecommunications and signal processing applications. Excitingly, NEMS devices operate at the sub-picowatt regime, which is many orders of magnitudes smaller than today’s digital signal processing blocks. Thus, nanomechanical signal processing is becoming an exciting area of research, with the aim of developing effective ways for transducing and tuning mechanical resonances. Currently, active tuning of NEMS is achieved by stress-tuning methods, which rely on the application of net forces to the resonator via electromagnetic fields. However, stress-tuning is volatile, which requires constant electrical stimuli (i.e. quiescent power) to maintain the tuned frequency. Stress-tuning also suffers from reliability issues and alters the quality (Q) factors of the resonators. To overcome these challenges, this thesis investigates a novel technique of tuning nanomechanical resonances by exploiting the Young’s modulus change in chalcogenide-based phase-change materials (PCMs). PCMs can be permanently yet reversibly switched between amorphous and crystalline states, which exhibit different elastic properties. This can be employed as a non-volatile tuning mechanism in NEMS resonators. Recent advances have also shown that nanowire configurations offer a more reliable and homogenous phase transition compared to thin-film PCMs. By using nanosecond-fast electrical pulses for phase-change and employing a piezoresistive readout scheme, the first instance of a non-volatile (power-free) tuning scheme in NEMS has been demonstrated within a range of ~30% using GeTe nanowires. The effect of phase-change on Q factors, phase noise, and piezoresistive gauge factors have also been studied. With non-changing Q factors over 16,000 and a decent phase noise performance, the GeTe nanowires have also been utilised in a frequency-hopping radio transmission. The promises of such a functional resonator are lower power consumption, faster tuning speeds, and better phase noise performance in commercial frequency synthesisers. To improve the signal-to-noise ratio for real-world applications, a novel transduction scheme for nanowires based on cavity optomechanics has further been demonstrated in this thesis, with transduction gain levels of 1.46 mV nm-1 for InP nanowires and 2.02 mV nm-1 for GeTe nanowires at an optical probe power < 75 µW. This thesis also investigates theoretically that these gain levels can be further improved by a factor ~200, extending the field of NEMS beyond academia for the first time, with imminent applications in signal processing and telecommunications. To assemble such a functional platform into a hand-held device, a novel pick-and-place technique has also been developed here, integrating single-crystal nanowires with on-chip devices with a placement precision below 1 µm

A social choice approach to theorizing justice

Mainstream theorizing of justice, initiated by John Rawls seminal work A Theory of Justice1, has recently come under criticism for its ability to devise satisfying answers to these questions. Within a debate on how to conceptualize ideal and non-ideal theorizing of justice, a number of theorists have pointed out a serious gap between contemporary theorizing of justice and actual problems. In response, those who believe that theorizing justice should address real problems argue for ways to breach the gap, while others have retreated to their ivory towers. Methodological chapters containing empirical and theoretical assumptions as well as issues of implementation, feasibility and accessibility are now considered more seriously. The debate has resulted in important insights for improving the ability of theorizing to relate to actual problems. Nevertheless, this thesis argues that theorizing justice in the Rawlsian framework is inherently flawed in guiding action in real world circumstances. Due to its two stage method consisting in first theorizing ideal principles that govern the perfectly just society, and then implementing them in actual circumstances, the framework is unable to incorporate an essential aspect of real world circumstances. Namely, that there are equally valid reasons for upholding different principles of justice and equally valid reasons for different ways of implementing them in particular contexts. This failure has major implications for the capacity of theorizing to guide action in real world circumstances. The two stage method is either insufficient in guiding action or detrimental by making false judgments. Incorporating disagreement into the theorizing of actual injustices, however, implies a different idea of justice, which I argue is best comprehended by a social choice approach. The critical part of this dissertation argues against Rawls' two stage method due to the problems arising from the fact of pervasive disagreement. The constructive part develops Amartya Sen's social choice approach to justice as a method that can deliver concrete judgments in comparing policies. I take up both tasks in Chapter 2. In Chapter 3 and Chapter 4, I respectively analyze two cases of policy choice in different domains of justice: the first regards implementing global taxes on natural resources; the second, reforming the European Union asylum policy. In Chapter 5, I conclude by emphasizing the main points of the social choice approach that I develop