China’s goal of eventually having the renminbi (RMB) be “fully convertible” necessarily requires that its capital account be fully liberated; this paper investigates the on-going changes of the implemented capital controls by China and China’s progress on liberalizing the country’s capital account. The first portion of the paper studies deviations of the covered interest parity, a common measure of capital controls. Econometrical analysis provides evidence for significant and persistent RMB/USD interest rate differentials, calculated from monthly data of 1-month yields for the sample period of 1999 to 2014. At the same time, evidence for cointegration between the onshore and offshore yield suggests that capital flows are not fully restrictive in the long run. The second portion of the paper analyzes constructed de jure capital control indices based on IMF’s AREAER documents following Chen and Qian (2015), and actual capital account flows based on China’s Balance of Payments. The constructed de jure indices quantify the intensity of changes of capital controls, capturing the gradualist style that China adopts in implementing its policies. The index reveals that China has been increasing its pace of capital account liberalization in the recent years compared to the past, and in particular, prioritizes liberalizing controls on outward FDI flows and equity securities inflows. The constructed de jure indices and the respective flows for FDI and equity securities are found to be highly correlated, implying that flows have been responsive to changes in the controls. It also indicates that prior to the restriction lift offs, the capital controls had been relatively effective.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / With the discovery of Turbo Codes in 1993, interest in developing error control coding schemes that approach channel capacity has intensified. Some of this interest has been focused on lowdensity parity-check (LDPC) codes due to their high performance characteristics and reasonable decoding complexity. A great deal of literature has focused on performance of regular and irregular LDPC codes of various rates and on a variety of channels. This paper presents the simulated performance results of a serial concatenated LDPC coding system on an AWGN channel. Performance and complexity comparisons between this serial LDPC system and typical LDPC systems are made.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A joint source-channel coding scheme (JSCCS) used in applications, like sending images, voice, music etc. over internet/ wireless networks, involves source coding to compress the information and channel coding to detect/ correct errors, introduced by the channel. In this paper, we investigate the unequal error protection (UEP) capability of a class of low-density parity-check (LDPC) codes in a JSCCS. This class of irregular LDPC codes is constructed from cyclic difference families (CDFs).

A country’s economy is becoming more and more dynamic and complicated in its scale and mobility. So, the concerns of exchange rate economics have become more popular. My research interest is in international economics with its major factor, exchange rates and other macroeconomic variables. Chapter 1 presents a brief introduction of the three studies. Chapter Two investigate the role of exchange rate changes with particular attention to international capital flows. With liberalization of capital movements, international capital movements became free and unrestricted in many emerging market economies as well as developed countries. Using a Vector Auto-regressive (VAR) model for a small open economy in which the endogeneity of exchange rate changes is fully taken into account, I find that capital movements are more likely to be a cause of output fluctuations and current account deficits in developing countries than a channel of equilibrium changes. I also find that domestic currency depreciation is far more likely to be contractionary on domestic output in developing countries than in developed countries. Interestingly, the trade balance improves after depreciation regardless of its output consequence. These findings suggest that there are important differences between developed and developing economies in the way capital movements and exchange rate changes affect and are affected. Chapter Three demonstrates the dynamic relationship between the current account and the real exchange rate in response to permanent and temporary shocks using structural VAR models for seven developed countries and five developing countries. Special focus is given to the issue of the stationarity of the current account. Capital flows are also included to capture external shocks as well as potential structural breaks due to financial liberalization. I find that the results for unit root tests for the current account are ambiguous. By testing two different VAR models, each taking an opposing stance on the stationarity of the current account, I conclude that responses based on a stationary current account are a better fit to the current theoretical view than those based on a nonstationary current account process. Additionally, the real exchange rate and the current account are positively correlated under a permanent shock while two variables are negatively correlated under a monetary shock. I also find that real exchange rate is an endogenous variable, which is not closely related to the temporary factors that affect the current account in the short run. Chapter Four examines the long-run mean reverting behavior of the real exchange rates with its six different definitions for 27 economies using annual data from 1974 to 2003. I find that Purchasing Power Parity (PPP) holds better, and the half-life of the real exchange rates is shorter when the wholesale price index, rather than consumer price index, is used as price level measure. Somewhat surprisingly, there is no evidence that PPP holds better with trade-weighted real exchange rates than with bilateral ones regardless of the price index used. Strong evidence for PPP emerges only with the use of Im, Pesaran, and Shin (2003) panel tests but not with the Levine, Lin, and Chu (2002).

Free-Space Optical (FSO) communication through the terrestrial atmospheric channel offers many benefits in the wireless communications arena, like power efficiency; suitability for secure communications; absence of electromagnetic interference; and potentially very high bandwidth. An optical beam propagating through the atmosphere is subject to optical turbulence. Optical turbulence is a random process that distorts the intensity and phase structure of a propagating optical beam and induces a varying signal at the receiver of an FSO communication link. This phenomenon (usually referred to as scintillation) degrades the performance of the FSO link by increasing the probability of error. In this dissertation we seek to characterize the effects of the scintillation-induced power fluctuations by determining the channel capacity of the optical link using numerical methods. We find that capacity decreases monotonically with increasing turbulence strength in weak turbulence conditions, but it is non-monotonic in strong turbulence conditions. We show that low-density parity-check (LDPC) codes provide strong error control capabilities in this channel if a perfect interleaver is used. Multiple transmit optical beams can be used to reduce scintillation. We characterize the spatial correlation of the atmospheric optical channel and determine a scintillation model for the multiple-beam scheme. With this model we can predict the effective reduction in scintillation as a function of the system design parameters. A Multi-channel FSO communications system based on orbital angular momentum (OAM)-carrying beams is studied. We analyze the effects of turbulence on the system and find that turbulence induces attenuation and crosstalk among OAM channels. Based on a model in which the constituent channels are binary symmetric and crosstalk is a Gaussian noise source, we find optimal sets of OAM states at each turbulence condition studied, and determine the aggregate capacity of the multi-channel system at those conditions. At very high data rates the FSO channel shows inter-symbol interference (ISI). We address the problem of joint sequence detection in ISI channels and decoding of LDPC codes. We derive the belief propagation equations that allow the simultaneous detection and decoding of a LDPC codeword in a ISI channel.

No description available.

<p>This paper tested the purchasing power parity hypothesis for Botswana and South Africa using cointegration analysis. The data used are the spot exchange rate between the two countries (rand and pula) and their consumer price indices.</p>

The safety and functionality of engineering systems can be affected adversely by faults or wear in system components. Therefore, methods for detecting such faults/wear and ameliorating their effects to avoid system failure are important. Designing schemes for the detection and diagnosis of faults is becoming increasingly important in engineering due to the complexity of modern industrial systems and growing demands for quality, cost efficiency, reliability, and the safety issue. In safety/mission critical applications, fault detection can be combined with accommodation/reconfiguration (after a fault) to achieve fault tolerance allowing the system to complete or abort its function in a way that is sub-optimal but does achieve the design objective. This thesis discusses research carried-out on the development and validation of a model-based fault detection and isolation (FDI) system for a pneumatically actuated Stewart platform. The Stewart-Gough platform provides six degrees of freedom consisting of three translational and three rotational degrees of freedom (x, y, z, pitch, roll, & yaw). As these platforms can be fast acting (rapid motion) and can handle reasonable loads, they can become dangerous, especially when fault(s) in the platform mechanism, drivetrain or control system occur. Therefore, as a safety critical application it is imperative that fault tolerant schemes are applied in order to provide a safe working environment. The design concept of the FDI scheme for the full Stewart-Gough platform is first designed using a single cylinder set-up. This modular concept is adopted so that a robust fault tolerant control scheme can be designed basically off-line (i.e. not attached to the Stewart Gough platform). This approach is adopted as requirements are easier to understand using a single cylinder set-up. The modular design approach subdivides the whole system into smaller sections (modules) that can be independently created and then used in the complete Stewart-Gough platform. The main contributions of the work are that a pneumatically actuated Stewart-Gough platform has been designed, built, and commissioned. A mathematical model has been developed and has been validated against experimental results. Two control approaches have been designed and compared. A fundamental comparative study of parity equations and Kalman filter observer banks for fault detection in pneumatic actuators has been conducted. The parity equations and Kalman filter approaches have been extended to provide a combined fault detection scheme. The FDI and control schemes have been combined in a modular Fault Tolerant Control (FTC) scheme for a pneumatic cylinder. The resulting FTC scheme has been validated by experimentation and demonstrated on the single cylinder test rig. The FTC scheme has been extended to all 6 cylinders (and including fault management at top level) of Stewart-Gough platform. The FTC scheme has been validated by experimentation and demonstrated on the Stewart-Gough platform test rig.

LHCb is an experiment designed to make precision measurements of Charge- Parity violation in the B meson system. We report a measurement of the B± crosssection and production asymmetry, using B± → J/u K± decays collected at the LHCb detector in 2010 and 2011. Using 27.6 pb-1 of pp collisions at a centre-of-mass energy 7 TeV, we obtain a B± cross-section of [41.6 ± 0.6 (stat.) ± 3.0 (sys.) ± 4.2 (lumi.)] μb in the rapidity region 2 to 4.5. Using 371.1 pb-1 of pp collisions at a centre-of-mass energy 7 TeV, we obtain a B± production asymmetry of [-2.09 ± 1.20 ± 0.8 (CP) ]% in the same rapidity region. The Ring Imaging Cherenkov system of LHCb uses Hybrid photon detectors (HPDs) for single photon detection. This thesis summarises the use of ion feedback measurements as indicators of HPD vacuum quality.

Despite decades of theoretical and experimental investigation, the fundamental interactions between nucleons remains poorly understood. While the strong interaction is responsible for binding quarks into nucleons, and nucleons into nuclei, there is no consistent description of these processes. At the low energies where nucleon binding occurs, the interactions are in principle calculable from quantum chromodynamics, but the required non-perturbative calculations are not possible. Instead, different models have been created to describe different phenomena. These models require experimental input to constrain them. As the expected weak interaction effects are not seen in the strangeness-conserving systems as have been seen in other systems, it is believed that the strong interaction interferes with the weak interaction. Therefore by measuring parity-violating observables that occur due to the weak interaction, information can be gained about the strong interaction. The NPDGamma and n3He experiments are two complementary experiments that measured a parity violating observables in a few nucleon system. They ran on the Fundamental Neutron Physics Beamline at the Spallation Neutron Source. The NPDGamma experiment measured the parity violating directional asymmetry in the gamma ray's emission direction after polarized cold neutron capture on a liquid parahydrogen target using an array of 48 CsI detectors. The n3He experiment measured the parity violating directional asymmetry in the proton emission direction after polarized cold neutron capture on a gaseous $^{3}$He target. The capture occurs inside an ionization chamber that measures the proton emission direction. Both experiments have completed data taking with data analysis in an advanced state. These experiments should be able to be used with a number of already existing experimental results to constrain the models. I designed and assembled a pair of $^{3}$He ionization chambers that were used as beam monitors during the experiments. Using the lessons learned from the beam monitors, I then designed and assembled the ionization chamber that is the combined target and detector for the n3He experiment. The monitors and target chamber were examined to determine their charge collection properties and linearity after installation. One of the monitors was calibrated to determine the neutron flux from the output current. / February 2017