Performance analysis with wireless power transfer constraint policies in full-duplex relaying networks

In practice, full-duplex (FD) transmission mode not only helps extend the coverage but also lengthen network lifetime. In this paper, we develop wireless power supply policies, namely separated power (SP) and harvested power (HP) to propose a flexible architecture at the relay node in FD decode-and-forward (DF) relaying networks considering time switching-based relaying protocol (TSR) to achieve optimal time used for a communication process. This transmission mode requires more processing procedure at the relay, i.e. antenna installations and radio frequency (RF) self-interference cancellation. We evaluate the optimal power constraints in case of SP and HP to achieve better power consumption efficiency at the relay node. More importantly, closed-form expressions for outage probability and throughput are provided, and we also use numerical and simulation results to compare SP with HP.Web of Science234767

The emerging business of science in Vietnam

Manh-Tung Ho, Khanh-Linh Hoang, Minh-Hoang Nguyen, Manh-Toan Ho (2019). Chapter 8. The emerging business of science in Vietnam. In Quan-Hoang Vuong, Trung Tran (Eds.), The Vietnamese Social Sciences at a Fork in the Road (pp. 163–177). Warsaw, Poland: De Gruyter. DOI:10.2478/9783110686081-013. Online ISBN: 9783110686081 © 2019 Sciendo / De Gruyte

Analysis of tool wear and surface roughness in high-speed milling process of aluminum alloy Al6061

In this study, the influence of cutting parameters and machining time on the tool wear and surface roughness was investigated in high-speed milling process of Al6061 using face carbide inserts. Taguchi experimental matrix (L9) was chosen to design and conduct the experimental research with three input parameters (feed rate, cutting speed, and axial depth of cut). Tool wear (VB) and surface roughness (Ra) after different machining strokes (after 10, 30, and 50 machining strokes) were selected as the output parameters. In almost cases of high-speed face milling process, the most significant factor that influenced on the tool wear was cutting speed (84.94 % after 10 machining strokes, 52.13 % after 30 machining strokes, and 68.58 % after 50 machining strokes), and the most significant factors that influenced on the surface roughness were depth of cut and feed rate (70.54 % after 10 machining strokes, 43.28 % after 30 machining strokes, and 30.97 % after 50 machining strokes for depth of cut. And 22.01 % after 10 machining strokes, 44.39 % after 30 machining strokes, and 66.58 % after 50 machining strokes for feed rate). Linear regression was the most suitable regression of VB and Ra with the determination coefficients (R2) from 88.00 % to 91.99 % for VB, and from 90.24 % to 96.84 % for Ra. These regression models were successfully verified by comparison between predicted and measured results of VB and Ra. Besides, the relationship of VB, Ra, and different machining strokes was also investigated and evaluated. Tool wear, surface roughness models, and their relationship that were found in this study can be used to improve the surface quality and reduce the tool wear in the high-speed face milling of aluminum alloy Al606

INVESTMENT TRENDS OF VIETNAMESE YOUNG PEOPLE

To examine the investment trends of Vietnamese young people, the research team surveyed the investment trends of young people living, studying, and working in Vietnam. Survey results show that the investment trends of young people today are diverse in investment types such as (1) Real estate investment, (2) Financial investment, (3) Gold investment; (4) Bank deposit… The research team also learned from survey participants about their priorities for investment channels and clarified the investment characteristics of young people. Through analyzing survey data, the research team had some discussions on investment trends of young people, raising young people's awareness of investment activities and choosing appropriate investment channels to optimize profitability for young investors and minimize risks

Conductivity in Half-filled Ionic Hubbard Model

We calculate the temperature dependent conductivity in the half-filled ionic Hubbard model with an on-site Coulomb repulsion $U$ and an ionic energy $\Delta$ by mean of the coherent potential approximation. It is shown that for intermediate and large $\Delta$ the largest conductivity occurs near the special value $U = 2 \Delta$ at all temperatures $T$, for a fixed $\Delta$ the region of finite conductivity $[U_{c1}, U_{c2}]$ expands and its maximum decreases with increasing $T$. Our results are in good agreement with those derived from the determinant quantum Monte Carlo simulation

THE FACTORS IMPACT ON THE TRAVEL INTENTION OF HANOI'S PEOPLE AFTER COVID-19 PANDEMIC

The article studies the factors that affect the intention to travel after the Covid-19 pandemic of Hanoi citizens. The research team uses a model of factors that affects the travel intention of people in Hanoi city after the Covid-19 pandemic, including (1) Attitude, (2) Social influence, (3) Image of Destination, (4) Risk perception, (5) Trip expenses, (6) Propulsion. With 303 participants in the survey, the research results show that the factor "The influence of propulsion" had the largest average score (3.99), indicating that the motivation of desire to relax and explore are vital factors that affect the travel intention of Hanoi people after the Covid-19 epidemic. The factor "Effect of perception of risk" has the lowest score (3.56) but shows some concerns such as weather forecasting, trip expenses' estimation, transportation problems, inadequate information, epidemic prevention, and food safety issues, which will not hinder people's intention to travel. That partly shows that Vietnam's tourism industry has been invested, cared for, and is on the way to development in recent years. From the research results, within the framework of the article, the research team also proposed some measures to stimulate tourism demand after the Covid-19 pandemic

Healthcare consumers’ sensitivity to costs: a reflection on behavioural economics from an emerging market

Decision-making regarding healthcare expenditure hinges heavily on an individual's health status and the certainty about the future. This study uses data on propensity of general health exam (GHE) spending to show that despite the debate on the necessity of GHE, its objective is clear—to obtain more information and certainty about one’s health so as to minimise future risks. Most studies on this topic, however, focus only on factors associated with GHE uptake and overlook the shifts in behaviours and attitudes regarding different levels of cost. To fill the gap, this study analyses a dataset of 2068 subjects collected from Hanoi (Vietnam) and its vicinities using the baseline-category logit method. We evaluate the sensitivity of Vietnamese healthcare consumers against two groups of factors (demographic and socioeconomic-cognitive) regarding payment for periodic GHE, which is not covered by insurance. Our study shows that uninsured, married and employed individuals are less sensitive to cost than their counterparts because they value the information in reducing future health uncertainty. The empirical results challenge the objections to periodic health screening by highlighting its utility. The relevance of behavioural economics is further highlighted through a look at the bounded rationality of healthcare consumers and private insurance companies in using and providing the service, respectively

On the Interference Alignment Designs for Secure Multiuser MIMO Systems

In this paper, we propose two secure multiuser multiple-input multiple-output transmission approaches based on interference alignment (IA) in the presence of an eavesdropper. To deal with the information leakage to the eavesdropper as well as the interference signals from undesired transmitters (Txs) at desired receivers (Rxs), our approaches aim to design the transmit precoding and receive subspace matrices to minimize both the total inter-main-link interference and the wiretapped signals (WSs). The first proposed IA scheme focuses on aligning the WSs into proper subspaces while the second one imposes a new structure on the precoding matrices to force the WSs to zero. When the channel state information is perfectly known at all Txs, in each proposed IA scheme, the precoding matrices at Txs and the receive subspaces at Rxs or the eavesdropper are alternatively selected to minimize the cost function of an convex optimization problem for every iteration. We provide the feasible conditions and the proofs of convergence for both IA approaches. The simulation results indicate that our two IA approaches outperform the conventional IA algorithm in terms of average secrecy sum rate.Comment: Updated version, updated author list, accepted to be appear in IEICE Transaction

Surveying entrepreneurial readiness of Business Administration students - A case study in the University of Labour & Social Affairs (ULSA)

This research is conducted to explore the entrepreneurial readiness, along with its related factors, of business administration students from ULSA. Based on the Theory of Planned Behavior by Ajzen, I., (1991), the researchers used the survey focusing on the influence of four factors: (1) the Entrepreneurial ability of students; (2) Motives/ Goals for students' entrepreneurship; (3) The impact of society on student entrepreneurship; (4) The impact of activities to support student entrepreneurship on "entrepreneurial readiness of students majoring in Business Administration at ULSA". The yielded results show that most factors have an average impact of 3/5 or more. Regarding the average impact, “Motives/ Goals for students’ entrepreneurship” has the highest rate of 4,06; followed by “The impact of society on student entrepreneurship” at 3,72; “The impact of activities to support student entrepreneurship” at 3,35; “Entrepreneurial ability of students” at 3,29