A study on application of SFCL in vietnam power distribution system with distributed generators (DGs)

As the power load demand is rapidly increasing nowadays, many new power generation units are continuously connected to the power system such as small hydropower, wind power, solar cell, and so on. However, in a distribution system, the presence of Distributed Generators (DGs) would generally change the distribution system's behavior. This change can affect to the operation and protection of devices in power system and the original parameters will be deviated. Especially, the fault current of power system with DGs is dramatically increasing, and Superconducting Fault Current Limiter (SFCL) has attracted lots of attention as one of the best correctives to solve these issues. This paper proposes a strategy on application of SFCL in distribution system to solve the problems related to excessive short-circuit current and the mitigation of voltage sag due to the introduction of the DGs. Firstly, a Resistive-type SFCL (R_SFCL) is modeled by Matlab/Simulink. Next, a distribution system of Southern Vietnam power system is selected and simulated. Finally, according to the simulation results, the short circuit current and voltage sag improvements can be validated

Modeling and Analyzing Academic Researcher Behavior

 Abstract. This paper suggests a theoretical framework for analyzing the mechanism of the behavior of academic researchers whose interests are tangled and vary widely in academic factors (the intrinsic satisfaction in conducting research, the improvement in individual research ability, etc.) or non-academic factors (career rewards, financial rewards, etc.). Furthermore, each researcher also has his/her different academic stances in their preferences about academic freedom and academic entrepreneurship. Understanding the behavior of academic researchers will contribute to nurture young researchers, to improve the standard of research and education as well as to boost collaboration in academia-industry. In particular, as open innovation is increasingly in need of the involvement of university researchers, to establish a successful approach to entice researchers into enterprises’ research, companies must comprehend the behavior of university researchers who have multiple complex motivations. The paper explores academic researchers' behaviors through optimizing their utility functions, i.e. the satisfaction obtained by their research outputs. This paper characterizes these outputs as the results of researchers' 3C: Competence (the ability to implement the research), Commitment (the effort to do the research), and Contribution (finding meaning in the research). Most of the previous research utilized the empirical methods to study researcher's motivation. Without adopting economic theory into the analysis, the past literature could not offer a deeper understanding of researcher's behavior. Our contribution is important both conceptually and practically because it provides the first theoretical framework to study the mechanism of researcher's behavior.Keywords:  Academia-Industry, researcher behavior, ulrich model’s 3C

Application of green-emitting ZnS:Eu2+ for boosting the spectrum of white light-emitting diode packages

Through utilizing a nonlinear application to acquire the best lumen efficiency (LE) for radiation (also known as LER) when color rendering index (CRI) value, especially CRI of R9 for strong red exceeds 90 with correlated color temperature (CCT) range of 2700-6500 K, the white light emitting diodes (WLED) package with adjustable CCT value and comprised of mixed-type light-emitting diodes (LEDs) can be acquired. The WLED model here contains blue and red LEDs with direct emission and a phosphorconversion blue LED or pc/B-LED (including orange and green phosphors mixed with blue LED colorant). The peak wavelengths of each LED constituent are 465 and 628 nm for LEDs in blue and red, 452 nm for the blue LED colorant, 530 and 586 nm for the phosphors exhibiting green and orange colors. Under the CCT of 2722-6464 K, the attained actual LED package, either with conversion phosphor, in red or in blue, possibly displays both CRI and R9 values measured from 90 to 96, color quality scale (CQS) values measured from 89 to 94, with LERs and LEs of 303-358 lm/W and 105-119 lm/W, respectively

Higher chromatic rendition with Cr3+-doped yellow Y3Al5O12:Ce3+ for double-layer remote phosphor white-light-emitting diodes

Remote phosphor designs of white-light-emitting diodes (WLEDs) have been recognized for their high thermal stability and excellent luminous efficiency but not for the chromatic rendering. The study presents an approach for the remote phosphor structure to overcome the low-color-rendering issue by enriching its red-light spectral intensity through co-doping Cr3+ and Ce3+ ions into the yellow  Y3Al5O12 (YAG) phosphor compound. This ion co-doping process probably enhances emission spectra in the far-red range because of the energy transfer of the integrated ions: Ce3+ Cr3+. Additionally, the luminescence and color properties of the phosphor layer significantly depend on the doped concentration of the Cr3+ ion. Here, with 0.008% Cr3+ in the phosphor composite, either internal or external quantum performances of the dual-layer WLED light are enhanced, which achieved the number of 58.9% and 46.7%, respectively. The color rendering index (CRI) would also be higher if Cr3+ is added, about 77.9, compared to the CRI of 63.2 when using the original  YAG:Ce3+ phosphor layer

SOLUTIONS OF TEACHING AND LEARNING PHYSICAL EDUCATION AT HO CHI MINH CITY COLLEGE OF ECONOMICS, VIETNAM

Physical education is one of the compulsory courses at Ho Chi Minh City College of Economics. However, students have been observed to be less engaged in physical activities. Therefore, this study aims to investigate the solutions of teaching and learning physical education at this institution. In particular, fifteen solutions are proposed to enhance the quality of teaching and learning physical education.  Article visualizations

Utilizing CaCO3, CaF2, SiO2, and TiO2 phosphors as approaches to the improved color uniformity and lumen efficacy of WLEDs

The two elements that are most favorable in the quality evaluation for phosphor-converted LEDs (pcLEDs) these days are the chromatic homogeneity and the lumen output. In this study, a thorough research on enhancing color uniformity and luminous flux of pcLEDs that have a high correlated color temperature (CCT) of 8500K is carried out. The scattering enhancement particles (SEPs): CaCO3, CaF2, SiO2, and TiO2 are used to accomplish the goal by adding them to a yellow phosphor compounding Y3Al5O12:Ce3+, and comparing their characteristics afterwards. LightTools program is used to build an optical simulation and Mie-scattering theory helps to examine the achieved results. Specifically, the parameters included in SEPs’ scattering calculation are the scattering coefficients, the anisotropic scattering, the reduced scattering, and the scattering amplitudes at 455 nm and 595 nm. The outcomes presented that compared to other SEPs, TiO2 particles can yield the highest chromatic homogeneity. However, the lumen output reduces considerably as TiO2 concentration greatly increases while it can be bettered when using SiO2 particles with any particle size. For CaCO3 particles, the color deviation of 620 K CCT can be reduced with 30% concentration, leading to the recommendation of using CaCO3 to promote the CCT homogeneity and luminescence efficiency

Applying calcium fluoride and silica particles: A solution to improve color homogeneity of pc-WLEDS

This article focuses on enhancing the lighting efficiency of pc-WLEDs, a new and advanced lighting solution that has received lots of attention. To adapt to the demand of modern lighting, the lighting performance of pc-WLEDs must be improved, especially the color homogeneity and luminous flux, two of the most important quality indicators of pc-WLEDs. Through experiments, this article proposes using the scattering enhancement particles (SEPs) such as CaF2 and SiO2 with yellow phosphor Y3Al5O12:Ce3+ in pc-WLEDs configuration. The pc-WLEDs model is created by using the LightTools program and set at 8500 K correlated color temperature, while the experimental results yielded from this simulation will be verified by Mie-scattering theory. The information from this article reveals the scattering coefficients of SEPs at 455 nm and 595 nm wavelengths. Moreover, it is confirmed that the employment of CaF2 is effective in promoting the color but may damage the luminous efficiency if the concentration is too high while the SEP material, SiO2, exhibits high luminous efficiency at all concentration

Reversal learning and associative memory impairments in a BACHD rat model for Huntington disease

Chorea and psychiatric symptoms are hallmarks of Huntington disease (HD), a neurodegenerative disorder, genetically characterized by the presence of expanded CAG repeats (&gt;35) in the HUNTINGTIN (HTT) gene. HD patients present psychiatric symptoms prior to the onset of motor symptoms and we recently found a similar emergence of non motor and motor deficits in BACHD rats carrying the human full length mutated HTT (97 CAG-CAA repeats). We evaluated cognitive performance in reversal learning and associative memory tests in different age cohorts of BACHD rats. Male wild type (WT) and transgenic (TG) rats between 2 and 12 months of age were tested. Learning and strategy shifting were assessed in a cross-maze test. Associative memory was evaluated in different fear conditioning paradigms (context, delay and trace). The possible confound of a fear conditioning phenotype by altered sensitivity to a 'painful' stimulus was assessed in a flinch-jump test. In the cross maze, 6 months old TG rats showed a mild impairment in reversal learning. In the fear conditioning tasks, 4, 6 and 12 months old TG rats showed a marked reduction in contextual fear conditioning. In addition, TG rats showed impaired delay conditioning (9 months) and trace fear conditioning (3 months). This phenotype was unlikely to be affected by a change in 'pain' sensitivity as WT and TG rats showed no difference in their threshold response in the flinch-jump test. Our results suggest that BACHD rats have a profound associative memory deficit and, possibly, a deficit in reversal learning as assessed in a cross maze task. The time course for the emergence of these symptoms (i.e., before the occurrence of motor symptoms) in this rat model for HD appears similar to the time course in patients. These data suggest that BACHD rats may be a useful model for preclinical drug discovery.</p

A data-driven approach for Network Intrusion Detection and Monitoring based on Kernel Null Space

International audienceIn this study, we propose a new approach to determine intrusions of network in real-time based on statistical process control technique and kernel null space method. The training samples in a class are mapped to a single point using the Kernel Null Foley-Sammon Transform. The Novelty Score are computed from testing samples in order to determine the threshold for the real-time detection of anomaly. The efficiency of the proposed method is illustrated over the KDD99 data set. The experimental results show that our new method outperforms the OCSVM and the original Kernel Null Space method by 1.53% and 3.86% respectively in terms of accuracy

Genetic diversity of local rice varieties (Oryza sativa L.) in Vietnam’s Mekong Delta based on SSR markers and morphological characteristics

Based on target traits, use of the genetic diversity of rice is beneficial for crop improvement. In this study, 41 rice varieties local to Vietnam’s Mekong Delta were evaluated on the basis of 11 quantitative morphological traits, along with the assessment of genetic diversity according to 50 SSR markers. The actual yield had a significance level of 0.05, while plant height and panicles per square meter had a high significance level of 0.001. Cluster analysis based on 11 quantitative traits also revealed that two were the optimal number of clusters used in this study. The highest polymorphic information content (PIC) value obtained was for RM286 (0.49), with a range of 0.00 to 0.49 and an average PIC of 0.14. Both structure and phylogenetic tree analyses as inferred from 50 SSR markers by the unweighted pair‐group method with arithmetic mean (UPGMA) also indicated that the 41 local rice varieties could be divided into two major groups. This study provides a useful information for Mot bui do cao CM, and Mot bui five varieties for improvements in the yield and intermediate amylose content of local rice‐breeding programs in future, especially for the Mekong Delta region