Noise-Robust Voice Conversion

A persistent challenge in speech processing is the presence of noise that reduces the quality of speech signals. Whether natural speech is used as input or speech is the desirable output to be synthesized, noise degrades the performance of these systems and causes output speech to be unnatural. Speech enhancement deals with such a problem, typically seeking to improve the input speech or post-processes the (re)synthesized speech. An intriguing complement to post-processing speech signals is voice conversion, in which speech by one person (source speaker) is made to sound as if spoken by a different person (target speaker). Traditionally, the majority of speech enhancement and voice conversion methods rely on parametric modeling of speech. A promising complement to parametric models is an inventory-based approach, which is the focus of this work. In inventory-based speech systems, one records an inventory of clean speech signals as a reference. Noisy speech (in the case of enhancement) or target speech (in the case of conversion) can then be replaced by the best-matching clean speech in the inventory, which is found via a correlation search method. Such an approach has the potential to alleviate intelligibility and unnaturalness issues often encountered by parametric modeling speech processing systems. This work investigates and compares inventory-based speech enhancement methods with conventional ones. In addition, the inventory search method is applied to estimate source speaker characteristics for voice conversion in noisy environments. Two noisy-environment voice conversion systems were constructed for a comparative study: a direct voice conversion system and an inventory-based voice conversion system, both with limited noise filtering at the front end. Results from this work suggest that the inventory method offers encouraging improvements over the direct conversion method

Corporate governance of banks in Vietnam and their roles on banks’ risk-taking and efficiency : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Banking Studies at Massey University, Manawatu Campus, New Zealand

This thesis comprises three essays that investigate the effectiveness of corporate governance mechanisms associated with recent Vietnamese banking reform on Vietnamese banks’ risk-taking and efficiency. The thesis uses a hand-collected dataset on accounting and corporate governance data from annual statements published by commercial banks during the 2006-2016 period. The first essay examines the role of foreign directors on bank risk-taking, using data from 32 commercial banks in Vietnam in the 2006-2016 period. Our findings suggest foreign directors increased bank risk-taking after 2011. The relationship is robust after taking account of potential endogeneity problems and different measures of bank risk-taking. The explanation is that foreign directors are motivated to encourage management to increase risk-taking to earn short-term returns when there is uncertainty in macroeconomic conditions. Other characteristics such as female directors, family related directors, and board size on risk-taking are also discussed. There is no evidence showing that foreign directors are more or less risk-averse in listed banks vs unlisted banks or in state-owned banks vs private banks. The second essay investigates the impact of female directors on boards on bank efficiency, using data from 32 commercial banks, covering the 2006-2016 period. The relationship is estimated by employing one-stage stochastic frontier analysis, using the Battese and Coelli (1995) (BC95) approach. The two-stage distributional free approach proposed by Cornwell, Schmidt, and Sickles (1990) (CS90) is employed as a robustness check. The result shows a robust relationship between female directors and cost-efficiency. This suggests that female directors are associated with a decrease in cost efficiency. A possible explanation is that female directors are less experienced in management than male directors and have less access to environmental resources that benefit firms. The third essay examines the impact of mergers and acquisitions (M&As) on bank efficiency, using a balanced panel dataset from 22 commercial banks over the 2008-2016 period. The study employs a two-stage DEA window analysis. Our findings suggest that there is no significant relationship between M&As and bank efficiency, which is not surprising given the small number of M&A events so far. However, there is evidence that Vietnamese banks experienced less improvement in efficiency after M&As. A possible explanation for this is that the M&As might not be not driven by profit-maximization, but by the government encouragement to rescue weak banks. Also, the combined entities need to spend additional resources on resolving the bad debts transferred from the weak, targeted banks

The trend of using smart teaching devices in education in Vietnam

This study examines the growing integration of intelligent educational tools within the educational framework of Vietnam, underscoring the nation's swift shift towards a technology-centered learning environment. With 72.1 million internet users in Vietnam, marked by a 98.1% adoption rate of smartphones, 58.8% usage of laptops, and 35.5% ownership of tablets, these sophisticated devices have assumed a central role in the field of education. Notably, there exist governmental initiatives aimed at reinforcing the legal infrastructure, serving as a testament to Vietnam's dedication to advancing education through technological means. Smart educational devices have brought about a transformation in teaching techniques, rendering lessons more captivating, efficient, and accessible. The authors conducted a survey among a randomly selected group of 255 participants, revealing that the entire cohort utilizes smart devices for educational or work-related purposes. Nonetheless, certain students tend to employ smartphones for entertainment, which has raised inquiries regarding their scholastic impact. The paper explores the role of laptops, accentuating their revolutionary contribution to education and the necessity for further investigation to gain deeper insights into their effects. Furthermore, it investigates the obstacles encountered, encompassing technology-related distractions in educational contexts and disparities in technology access. Ultimately, this research underscores the significance of addressing these impediments to fully exploit the potential of intelligent educational devices in Vietnam's educational landscape, with the added benefit of drawing comparisons with global trends to glean valuable insights for further enhancing the educational domain

Influence of Ca[Mg3SiN4]Ce3+ phosphor’s concentration on optical properties of the 5600K RP-WLEDs

In this paper, we propose Ca[Mg3SiN4]Ce3+ Phosphor as a new material solution for improving the optical properties in terms of CRI, CQS. D-CCT, LO of the 5600K remote-packaging white LEDs (RP-WLEDs). In the first stage, we built and investigated the 5600K RP-WLEDs by adding the red phosphor to the phosphor layer. Then, the scattering processes inside the phosphor layer are investigated by Mat Lab software. From the research results, we discovered that the concentration of the adding phosphor significantly improved the optical properties of the5600K RP-WLEDs. All the results are convinced by Light Tools and Mat Lab software

Multi-source in DF cooperative networks with the PSR protocol based full-duplex energy harvesting over a Rayleigh fading channel: performance analysis

Due to the tremendous energy consumption growth with ever-increasing connected devices, alternative wireless information and power transfer techniques are important not only for theoretical research but also for saving operational costs and for a sustainable growth of wireless communications. In this paper, we investigate the multi-source in decode-and-forward cooperative networks with the power splitting protocol based full-duplex energy harvesting relaying network over a Rayleigh fading channel. In this system model, the multi-source and the destination communicate with each other by both the direct link and an intermediate helping relay. First, we investigate source selection for the best system performance. Then, the closed-form expression of the outage probability and the symbol error ratio are derived. Finally, the Monte Carlo simulation is used for validating the analytical expressions in connection with all main possible system parameters. The research results show that the analytical and simulation results matched well with each other.Web of Science68327526

The transmission mechanism of monetary policy in Vietnam: A VAR approach

This paper analyses monetary transmission mechanism in Vietnam by using a Vector Autoregression (VAR), focusing especially on how the economy dynamically responds money demand, interest rate, exchange rate, and asset price shocks. In this paper, we establish identification conditions to uncover the dynamic effects of monetary policy shocks. By using quarterly data over the period 1995-2010, a VAR model is developed to analyze various channels of monetary policy mechanism in a country with a large open and small economy like Vietnam. The empirical results show money demand and interest rates account for a major part of variations in output. And output is affected by monetary tightening in some lags, bottoming out after 5-6 quarters

Energy harvesting half-duplex AF power splitting protocol relay network over rician channel in case of maximizing capacity

In this letter, we propose a novel power splitting protocol for energy harvesting half-duplex AF relaying communication systems. In our proposed system, the relay harvests energy from the source transmissions, by employing adaptive PS protocol, for powering the retransmissions to the destination. The proposed model system is investigated in cases maximize and non-maximize ergodic capacity. Firstly, we perform the analytical mathematical analysis for deriving the integral closed-form expression of the outage probability and the ergodic capacity. Then, the analytical analysis of the system performance can be convinced by Monte-Carlo simulation with helping Mat Lab software. Finally, the numerical analysis provides practical insights into the effect of various system parameters on the system performance of the proposed system. This paper can be considered as a recommendation for the energy harvesting communication network

Genetic Influences on Mental Health

Mental and physical health are two most crucial factor that deciding the happiness and development of each individual in the world. Physical health problem is quite obvious and easy to be recognized through advanced and modern technology. However, mental health sometimes invisible and hard to be revealed by the machines and the patients themselves. It is believed that genetic factors play a significant role in the development of various mental health conditions. Based on extensive research, scientists categorize major mental illnesses into several types, including schizophrenia, bipolar disorder, depression, and anxiety disorders. The primary causes of these mental health issues are rooted in organic, psychological, abnormal physical structures, and endogenous factors. Treatment for mental health disorders includes a range of therapies such as medication, electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), psychotherapy, and rehabilitation. It is essential for individuals to adopt different measures such as regular exercise, maintaining a positive attitude towards life’s challenges, helping others, and following a healthy diet to escape from mental health issues. This research used a survey conducted with over 200 participants to understand more about the relationship between mental health and genetics, offering recommendations for reducing the incidence of mental health issues

Ba[Mg2Al2N4]Eu2+ phosphor for enhancing the optical quality of the 6600K CPW-LEDs

Compared with conventional lamps, LED-based light sources have a superior lifetime, efficiency, and reliability, which promise significant reductions in power consumption and pollution from fossil fuel power plants. The main purpose of this paper is proposed and investigated the effect of the concentration of Ba[Mg2Al2N4]Eu2+conversion phosphor on the CCT deviation (D-CCT) and lumen output (LO) of the 6600 K conformal-packaging white LEDs (CPW-LEDs). For this purpose, we used the Light Tools and Mat Lab software to investigate this problem. From the research results, we can state that the concentration of the red phosphor crucially influenced on the optical quality of the 6600 K CPW-LEDs. The D-CCT can be decreased from 4700K to 2500K, and the LO can be increased from 600 lm. to 1200 lm. This research can provide the new recommendation for LEDs industry at this time

Using real interpolation method for adaptive identification of nonlinear inverted pendulum system

In this paper, we investigate the inverted pendulum system by using real interpolation method (RIM) algorithm. In the first stage, the mathematical model of the inverted pendulum system and the RIM algorithm are presented. After that, the identification of the inverted pendulum system by using the RIM algorithm is proposed. Finally, the comparison of the linear analytical model, RIM model, and nonlinear model is carried out. From the results, it is found that the inverted pendulum system by using RIM algorithm has simplicity, low computer source requirement, high accuracy and adaptiveness in the advantages