The Scope for Monetary Autonomy in Hong Kong and Singapore

The monetary trilemma autonomy has been at the heart of a great deal of international monetary analysis. It implies that countries with fixed exchange rates and no capital controls will lose monetary autonomy. What is often not recognized, however, is that the trilemma need not hold in the short run. If capital mobility is less than perfect, then countries can sterilize reserve flows and maintain a degree of monetary autonomy in the short run. Hong Kong is a natural case to test this possibility since it has a credibly fixed exchange rate against the dollar and no major capital controls. We investigate this issue using two approaches. One is to estimate the effects of changes in U.S. interest rates on those in Hong Kong. As with earlier literature, we find that the pass-through, while considerable, is substantially less than one, indicating imperfect capital mobility. The second is to estimate whether Hong Kong has been able to engage in some degree of sterilization. This has not been done before. An important issue here is how to measure Hong Kong\u27s monetary base. Because of the particular institutional arrangements in Hong Kong, the Monetary Authority uses a measure of the monetary base that differs from the standard IMF definition. By both measures, we find that Hong Kong has been able to practice partial sterilization of international reserve flows in the short run and hence does have some degree of monetary autonomy. Another challenge the standard trilemma analysis faces focuses on the effectiveness of flexible exchange rates in monetary insulation. Rey (2013) argued that dilemma not trilemma —an economy could not have monetary autonomy unless capital controls are used regardless of exchange rate regimes. The argument can be usefully examined with the cases of Singapore and Hong Kong. Both economies are small and open, but they choose different exchange rate regimes—the Monetary Authority of Singapore (MAS) uses a managed floating exchange rate. We also estimate the interest rate pass-through from the U.S. to Singapore and Singapore\u27s offset and sterilization coefficients. Our results show that Singapore\u27s economy is insulated from oversea monetary shocks to a more considerable extent than Hong Kong. It suggests that the trilemma has not become a dilemma and that flexible exchange rates are effective in helping a small open economy to maintain a degree of monetary independence

Colloidal behavior of nanobubbles and their application in enhancing plant growth: mechanisms of nanobubble interactions with microbial and soil species

Climate change has resulted in increasing uncertainties of water resources and disturbance on agricultural activities. For example, the shortage of water resources, land erosion and pollution from runoff significantly affect agricultural sustainability. This dissertation research focuses on the fundamental studies of nanobubble (NB) water and explores the benefits for irrigation to enhance plant germination and growth. Unlike bulk bubbles, NBs exhibit prolonged stability in water and possess large surface areas that facilitate efficient mass transfer and potential tailored reactions (e.g., disinfection). However, the enhancement mechanisms for NBs on seed germination and plant growth remain elusive. This research first evaluated the membrane bubbling method to produce NBs in water and provided insights into the optimization of bubble water with desirable quality such as high bubble concentrations and small bubble sizes. The results demonstrate that the ceramic membranes with a hydrophilic surface and hydrophobic pores produced greater levels of NBs with small sizes compared to the pristine or surface hydrophobized membranes. Additionally, this study discovered that dissolution kinetics of oxygen NBs are strongly influenced by the initial bubble size and the dissolution could lead to shrinkage or expansion of bubbles in water. Smaller NBs exhibit a faster increase in DO, while larger NBs can result in higher equilibrium dissolved oxygen (DO) levels. Oxygen NBs significantly enhanced the oxygen transfer efficiency compared to microbubble aeration, exhibiting a remarkable increase of up to 300%, as well as a mass transfer coefficient of 21.05 h-1. Lastly, this study provides compelling evidence that NBs have a positive impact on seed germination and plant growth through changing various soil properties such as soil pH, oxygen content, redox potential and nutrient release, enzymatic activities and microbial communities. For example, oxygen NBs significantly boosted peroxidase activity in tomato leaves, with an impressive increase of 100%-1000%. The composition and structure of rhizosphere microbial communities in early tomato plants were found to be influenced by irrigation frequency, NB concentration, and the specific types of NBs used. Through discovering and characterizing these intriguing nanoscale phenomena and processes, this research aims to deliver new insight into novel sustainable agricultural practices using NB water that may increase agricultural production and reduce water and chemical fertilizer uses

Optimization of template selection for signal detection systems with additive internal noise

According to studies done by M. I. Trifonov, the form of the optimal detection template for an observer model with additive internal noise depends not only on the signal to be detected, but also on the internal-external noise ratio. The optimal detection template described by Trifonov\u27s theory indeed exhibited superior performance over the conventional matched filter template, but the mathematical procedure Trifonov proposed for proving his theory was insufficient. During the course of this thesis project, an extensive research was carried out to study Trifonov\u27s theory and its implications. As a result of this research, a new mathematical technique was developed to fully prove Trifonov\u27s theory. My contributions presented in this thesis also include the extension of the study to two dimensional signals and the Monte Carlo simulation experiments which were conducted to verify the mathematical theory. The experiment results were found to be in agreement with Trifonov\u27s theory

Fourth generation Majorana neutrino, dark matter and Higgs physics

We consider extensions of the standard model with fourth generation fermions (SM4) in which extra symmetries are introduced such that the transitions between the fourth generation fermions and the ones in the first three generations are forbidden. In these models, the stringent lower bounds on the masses of fourth generation quarks from direct searches are relaxed, and the lightest fourth neutrino is allowed to be stable and light enough to trigger the Higgs boson invisible decay. In addition, the fourth Majorana neutrino can be a subdominant but highly detectable dark matter component. We perform a global analysis of the current LHC data on the Higgs production and decay in this type of SM4. The results show that the mass of the lightest fourth Majorana neutrino is confined in the range $\sim 41-59$ GeV. Within the allowed parameter space, the predicted effective cross-section for spin-independent DM-nucleus scattering is $\sim 3\times 10^{-48}-6\times 10^{-46} \text{cm}^{2}$, which is close to the current Xenon100 upper limit and is within the reach of the Xenon1T experiment in the near future. The predicted spin-dependent cross sections can also reach $\sim 8\times 10^{-40}\text{cm}^{2}$.Comment: arXiv admin note: substantial text overlap with arXiv:1110.293

Mechanical and biodeterioration behaviours of a clayey soil strengthened with combined carrageenan and casein

In the last decade, biopolymers have been used as organic soil binders in ground improvement and earthen construction material modification. Although biopolymer-treated soils have substantially enhanced mechanical strength, the deformation characteristics under external loads and material durability (e.g. biodeterioration due to microbial activity) have not yet been fully understood, which limits the in situ practical application of the biopolymer-based soil treatment technology. This study investigated the efficiency of combined carrageenan and casein in strengthening a clayey soil with the biodeterioration consideration. Both mechanical tests (e.g. unconfined compressive strength and one-dimensional consolidation) and biological tests (e.g. high throughput sequencing and rating of mould growth) were conducted. Results indicated that the usage of the carrageenan–casein mixture induced a higher soil compressive strength compared with either carrageen or casein, due to the formation of a three-dimensional gel network. In addition, carrageenan–casein mixture and casein decreased the compressibility of the clayey soil, which might be attributed to the casein’s peculiarity of self-associating into micelles, leading to minimal interactions with water molecules. Carrageenan, due to its affinity for water, increased the soil compressibility. Under the impact of microbial activity, the biopolymer-treated soils underwent deterioration in both surface appearance (i.e. coloured stains and patches caused by mould growth) and compressive strength. A linear relationship was proposed, in which a reduction in compressive strength by approximately 11% is expected while the rating of mould growth is increased by one in a five-rating system. The current research demonstrates that the soil reinforcement with combined carrageenan and casein is able to improve both soil strength and deformation behaviours. It is also suggested to take into account the biodeterioration considerations in the design and implementation of biopolymer-based soil reinforcement practices