http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Free-Positioning Wireless Power Transfer Using a 3D Transmitting Coil for Portable Devices
Nam Ha-Van,Hoang Le-Huu,Minh Thuy Le,Kwangsuk Park,Chulhun Seo 한국전자파학회JEES 2020 Journal of Electromagnetic Engineering and Science Vol.20 No.4
The free-positioning wireless power transfer (WPT) system has drawn attention in recent years. Traditionally, a WPT system can transfer energy in one or two directions on the same plane, but it leads the restrictions of angle and axis misalignment between a transmitter and a receiver coil. In this paper, we propose a free-positioning WPT system using a three-dimensional cubic-shaped transmitting coil for portable device charging. A small receiving coil is placed inside the transmitter to achieve the transferred energy through the magnetic resonant coupling. In addition, the equivalent circuit and the mutual inductance between the Tx and Rx coils are analyzed. Finally, a practical experiment is implemented to verify the transfer performance, which can reach up to about 50% power transfer efficiency. The proposed system can charge in spatial freedom.
A Single-Feeding Port HF-UHF Dual-Band RFID Tag Antenna
Nam Ha-Van,Chulhun Seo 한국전자파학회JEES 2017 Journal of Electromagnetic Engineering and Science Vol.17 No.4
In this paper, a dual-band high frequency (HF) and ultra-high frequency (UHF) radio-frequency identification (RFID) tag antenna is presented that operates in the 13.56 MHz band as well as in the 920 MHz band. A spiral coil along the edges of the antenna substrate is designed to handle the HF band, and a novel meander open complementary split ring resonator (MOCSRR) dipole antenna is utilized to generate the UHF band. The dual-band antenna is supported by a single-feeding port for mono-chip RFID applications. The antenna is fabricated using an FR4 substrate to verify theoretical and simulation designs, and it has compact dimensions of 80 mm × 40 mm × 0.8 mm. The proposed antenna also has an omnidirectional characteristic with a gain of approximately 1 dBi.
Ha-Van, Nam,Seo, Chulhun Institute of Electrical and Electronics Engineers 2018 IEEE transactions on industrial electronics Vol.65 No.2
<P>In recent years, wireless power technology has been promoted for recharging systems for portable devices that are used in everyday life. The conventional technology used for this purpose, which is based on magnetically coupled resonators, has provided promising results but is limited in range and direction at the receiving terminal. In this paper, we propose an omnidirectional wireless power transfer (WPT) system with a novel cubic transmitter to achieve relatively high efficiency. Specifically, a single power source is utilized to drive the current of the transmitter without phase and current control methodology. Energy delivery is transmitted to the receiver through magnetic resonant coupling in the medium-range WPT mode. In addition, an equivalent circuit model of a coupling two-coil system is derived and mathematically analyzed. The efficiency of the proposed omnidirectional WPT system depending on the various distances between the transmitter and the receiver, as well as the transmitter structure, is evaluated via analysis and implementation. Finally, practical experimental results from the resonant coupling system confirm the theoretical analysis of the cubic transmitter and the omnidirectional power transfer capability, which demonstrate approximately 60% power transfer efficiency.</P>
Ultra-broadband and flexible metamaterial absorber based on MoS2 cuboids with Mie resonances
Ha Duong Thi,Nam Man Hoai,Tung Bui Son,Khuyen Bui Xuan,Lam Vu Dinh,Le-Van Quynh 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.82 No.11
In this work, we present a type of fexible and broadband metamaterial absorber operating in the GHz range. The proposed structure consists of three layers: a periodic square-shaped array made of molybdenum disulfde (MoS2) on the top, a continuous polyimide layer in the middle and a continuous copper layer at the bottom. For fat model, the proposed absorber exhibits a broadband absorption in the frequency range of 10.1–17.6 GHz with an absorption of more than 90% under normal incidence. Due to the symmetry of structure, the absorption feature is polarization-insensitive. The absorption remains above 80% in the frequency range of 11.1–15.6 GHz when the incident angle is up to 60° for TE-polarized wave, while the absorption is higher than 90% in the frequency range of 13.5–18 GHz for incident angles up to 60° for TM-polarized wave. For bending model, the absorption is signifcantly expanded when the bending radius decreases to under 100 mm. The physical mechanism of the absorption properties is explained in detail by the electric feld distribution, the magnetic feld distribution following the Mie resonance theory and infuence of the loss of MoS2. Obtained results in the work might contribute to the development of potential applications based on metamaterials in the microwave region such as imaging, protecting and light emitting devices.
Van Nam MAI,Quoc Nghi NGUYEN,Du Ha Long NGUYEN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.8
Service failures are fairly common these days, and recovering from them is difficult. If service failures are not addressed quickly, the service provider may lose revenue and customers. A good service recovery strategy will positively impact the business results of the service provider. The study aims to demonstrate the impact of service recovery on the satisfaction and word of mouth of international visitors towards homestays in the Mekong Delta, Vietnam. The research data was collected from 320 international visitors who have used services at homestays and experienced service failures in the Mekong Delta, Vietnam. Structural equation modeling was applied to analyze the data. The result shows that 3 dimensions constitute service recovery which are distributive justice, interactional justice, and procedural justice. Most importantly, the study has proved the positive impact of service recovery on both satisfaction and word of mouth of overseas tourists towards homestays in the Mekong Delta, Vietnam. The results have stressed the importance of service recovery to tourists’ perceptions of service quality and service image. In addition to this, the study suggests that homestay owners should develop risk handling and risk prevention plans for their services.
Photodiode-Based Chua's Circuit with Light Controllability
Nam, Sang Guk,Nguyen, Van Ha,Song, Hanjung Science Press 2014 CHINESE PHYSICS LETTERS Vol.31 No.6
<P>We present a photodiode-based Chua's chaotic circuit that is controllable by light. The proposed circuit consists of an inductor, two passive capacitors, a photodiode-based variable resistor, and a positive feedback transconductor with negative nonlinearity. The chaotic dynamics of the circuit were verified by using the simulation program with integrated circuit emphasis analysis using the 0.35μm complementary metal-oxide-semiconductor process parameters. The gain results (such as the time waveform, frequency analysis, three-dimensional attractor, bifurcation and Lyapunov exponents diagrams) confirm that the chaotic behavior of the circuit could be controlled by light intensity via the photodiode-based variable resistor.</P>
Van, Kyujung,Ha, Bo-Keun,Kim, Moon Young,Moon, Joong Kyung,Paek, Nam-Chon,Heu, Sunggi,Lee, Suk-Ha 한국유전학회 2004 Genes & Genomics Vol.26 No.1
Bacterial leaf pustule (BLP), caused by xanthomonas axonopodis pv. glycines, is one of the most prevalent bacterial diseases in plants. Qualtitative trait loci (QTLs) for resistance to BLP in soybean (Clycine max [Glycine max [L.] Merr.) were identified using simple sequence repeat (SSR) markers, and the consistency of QTL detection across bacterial isolates as well as across greenhouse and field experiments was examined. Recombinant inbred lines (RILs) derived from a cross of BLP-susceptible 'Suwon157' and BLP-resistant 'Danbaekkong' were utilized to identify QTLs conditioning resistance to BLP with 76 SSR markers. For phenotypic analysis, six isolates of X. axonopodis were collected from different geographical locations. A combination of single-factor analysis of variance and multiple regression analysis revealed that three QTLs conditioned resistance to BLP in the field.. Under greenhouse conditions, one to four QULs were revealed to be associated with resistance to each isolate. Satt372 on linkage group (LG) D2 was associated with resistance to all six isolates under greenhouse and field conditions, indicating that resistance to BLP was mainly controlled by a single major gene tightly linked to Satt372. Several minor QTLs of LG A1, C1, F, L, and O were also found to condition resistance to various isolates.
Bioinformatic identification and expression analysis of the chicken B cell lymphoma (BCL) gene
Van Thai Than,Ha Thi Thanh Tran,Duc Viet Ly,Hoang Vu Dang,Minh Nam Nguyen,Anh Duc Truong 한국유전학회 2019 Genes & Genomics Vol.41 No.10
Background B cell lymphoma (BCL) families play an important role in apoptosis as a growth factor, cell death programming, cytokine expression and immune-related genes expression. Objectives In this study, to investigate the roles of BCLs, we performed genome-wide identification, expression and functional analyses of the BCL family in chicken. Methods Chicken BCLs genes were identified and analyzed by using bioinformatics approach. Expression profiles and Hierarchical cluster analysis of the BCLs genes in different chicken tissues were obtained from the genome-wide RNA-seq in the GEO, and Cluster and Java Treeview, respectively. Results A total of 16 BCLs genes were identified from the chicken genome, which could be further classified into five distinct groups in the phylogenetic tree. On the other hand, the interaction among BCLs proteins and between BCLs proteins with NF-κB subunits are limited, indicating that the remaining the functions of BCLs protein could be investigated in chicken. Moreover, KEGG pathway analysis indicated that BCL gene family was involved in regulation of apoptotic and immune response. Finally, BCL gene family was differentially expressed in chicken tissues, pathogen infection and growth stages of early chicken early embryo. Conclusion This study provides significant insights into the potential functions of BCLs in chicken, including the regulation of apoptosis, cell death and expression of immune-related genes.
Outpatient Satisfaction at Private General Hospitals in Ho Chi Minh City, Vietnam
GIAO, Ha Nam Khanh,THY, Nguyen Thi Anh,VUONG, Bui Nhat,KIET, Truong Van,LIEN, Le Thi Phuong Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.7
The quality of hospital services remains a concern of both the manager and the patient. The study aims to identify factors affecting outpatient satisfaction at private general hospitals in Ho Chi Minh City, establishing a scale for measuring them. Some 450 outpatients who were treated in five top private hospitals in Ho Chi Minh city (HCMC) in 2019 - An Sinh General Hospital, Hoan My General Hospital, Columbia Asia International Hospital, FV Hospital, and Vu Anh International General Hospital - were interviewed directly in the last quarter of 2019 to obtain the information. The SERVPERF model, plus the cost, together with the SPSS software, have been used to process information by Cronbach's alpha analysis, Exploratory Factor analysis, and linear regression analysis. The results show that there are five factors influencing outpatient satisfaction at private general hospitals in HCMC, in which four factors affects positively in the order of decreasing importance: treatment outcome, doctors and nurses' professional capacity, facilities and environment of the hospital, hospital care, and the treatment time factor affects negatively. The results of the study provide private hospital in HCMC managers with a number of suggestions to increase the level of hospital service quality, so that increase outpatients satisfaction.