http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Lan Ngoc Vuong,Tu Hoang Kim Trinh,Tuan Diep Tran,Duy Le Pham,Vinh Nhu Nguyen,Quan Tran Thien Vu,Toan Duong Pham,Phong Hoai Nguyen,Minh Kieu Le,Diem Dinh Kieu Truong,Vu Anh Hoang,Nghia Huynh,Dat Quoc N 연세대학교의과대학 2024 Yonsei medical journal Vol.65 No.9
Purpose: Although some immune protection from close contact with individuals who have coronavirus disease 2019 (COVID-19) has been documented, there is limited data on the seroprevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in individuals who were in lockdown with confirmed COVID-19 cases. This study investigated immunogenicity against SARS-CoV-2 in household members and people who lived near home-quarantined patients with COVID-19. Materials and Methods: This cross-sectional study was conducted during the community-based care that took place during lockdowns in District 10, Ho Chi Minh City, Vietnam from July to September 2021. SARS-CoV-2 antibody levels were determined in index cases of COVID-19, household contacts, and a no-contact group from the same area. Results: A total of 770 participants were included (355 index cases, 103 household contacts, and 312 no contacts). All index cases were unvaccinated, but >90% of individuals in the household and no-contact groups had received ≥1 vaccine dose. SARS-CoV-2 neutralizing antibodies (Nabs) were present in >77% of unvaccinated index cases versus 64%/65.4% in the household/no-contact groups (p=0.001). Antibody concentrations in unvaccinated index cases were significantly higher than those in household contacts and no contacts, with no difference between the latter groups. In all cases, antibody levels declined markedly ≥6 weeks after infection, and failed to persist beyond this time in the household and no-contact groups. Conclusion: Community-based care may have helped to create community immunogenicity, but Nabs did not persist, highlighting a need for vaccination for all individuals before, or from 6 weeks after, infection with SARS-CoV-2.
Hoang Vu Dao,Xuan Dinh To,Hoai Vu Anh Truong,Tri-Cuong Do,Cong Minh Ho,Tri Dung Dang,안경관 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.4
Fuel cell hybrid electric construction equipment (FCHECE) is known as a promising solution to achieve the goal of energy saving and environment protection. Energy management strategy is a key technology of FCHECE, which splits the energy fl ow between power sources. This paper presents a novel optimal energy management strategy for a hybrid electric-powered hydraulic excavator system to enhance power performance, power sources lifespan, and fuel economy. As for the proposed powertrain configuration, fuel cell serves as a primary energy source, and supercapacitor and battery are considered as energy storages. The integration of supercapacitor and battery in fuel cell vehicle has advantages of improving power performance and storing the regenerative energy for future usage. An energy management strategy based on fuzzy logic control and a rule-based algorithm is proposed to effectively distribute the power between the three sources and reuse the regenerative energy. Furthermore, the parameters of the fuzzy logic system are optimized using the combination of a backtracking search algorithm which provides a good direction to the global optimal region and sequential dynamic programming as a local search method to fi ne-tune the optimal solution in order to reduce the hydrogen consumption and prolong the lifetime of the power sources. Simulation results show that the proposed energy management strategy enhances the vehicle performance, improves fuel economy of the FCHECE by 10.919%, increase battery and supercapacitor charge-sustaining capability as well as efficiency of the fuel cell system.
Nguyen Hoang Linh,Nguyen Minh Son,Tran The Quang,Nguyen Van Hoi,Vuong Thanh,Do Van Truong Materials Research Society of Korea 2023 한국재료학회지 Vol.33 No.5
This study uses first-principles calculations to investigate the mechanical properties and effect of strain on the electronic properties of the 2D material 1H-PbX<sub>2</sub> (X: S, Se). Firstly, the stability of the 1H Pb-dichalcogenide structures was evaluated using Born's criteria. The obtained results show that the 1H-PbS<sub>2</sub> material possesses the greatest ideal strength of 3.48 N/m, with 3.68 N/m for 1H-PbSe<sub>2</sub> in biaxial strain. In addition, 1H-PbS<sub>2</sub> and 1H-PbSe<sub>2</sub> are direct semiconductors at equilibrium with band gaps of 2.30 eV and 1.90 eV, respectively. The band gap was investigated and remained almost unchanged under the strain ε<sub>xx</sub> but altered significantly at strains ε<sub>yy</sub> and ε<sub>bia</sub>. At the fracture strain in the biaxial direction (19 %), the band gap of 1H-PbS<sub>2</sub> decreases about 60 %, and that of 1H-PbSe<sub>2</sub> decreases about 50 %. 1H-PbS<sub>2</sub> and 1H-PbSe<sub>2</sub> can convert from direct to indirect semiconductor under the strain ε<sub>yy</sub>. Our findings reveal that the two structures have significant potential for application in nanoelectronic devices.
Huong, Truong Thu,Bac, Ta Phuong,Thang, Bui Doan,Long, Dao Minh,Quang, Le Anh,Dan, Nguyen Minh,Hoang, Nguyen Viet International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.6
Since machine learning was invented, there have been many different machine learning-based algorithms, from shallow learning to deep learning models, that provide solutions to the classification tasks. But then it poses a problem in choosing a suitable classification algorithm that can improve the classification/detection efficiency for a certain network context. With that comes whether an algorithm provides good performance, why it works in some problems and not in others. In this paper, we present a data-centric analysis to provide a way for selecting a suitable classification algorithm. This data-centric approach is a new viewpoint in exploring relationships between classification performance and facts and figures of data sets.
Effects of non-vertical linear motions of a hemispherical-float wave energy converter
Do, Hoang-Thinh,Dinh, Quang-Truong,Nguyen, Minh-Tri,Phan, Cong-Binh,Dang, Tri-Dung,Lee, Seyoung,Park, Hyung-Gyu,Ahn, Kyoung-Kwan Elsevier 2015 Ocean engineering Vol.109 No.-
<P><B>Abstract</B></P> <P>The hydraulic power-take-off mechanism (HPTO) is one of the most popular methods in wave energy converter (WECs). However, the conventional HPTO with only one direction motion has some drawbacks which limit its power capture capability. This paper proposes an <I>adjustable slope angle wave energy converter</I> (ASAWEC) and investigates the effect of slope angle on the performance of the proposed wave energy converter to find the optimal slope angle with the purpose to increase the power capture capability as well as energy efficiency. A mathematical model of components from a floating buoy to a hydraulic motor was modeled. A small scale WEC test rig was fabricated to verify the power capture capability and efficiency of the proposed system throughout experiments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper proposed an adjustable moving angle wave energy converter (AMAWEC). </LI> <LI> Mathematical model of AMAWEC was presented and simulated. </LI> <LI> An AMAWEC test rig were fabricated to do the experiment in variety of wave conditions and moving angle in the water tank. </LI> <LI> The effect of moving angle on the performance of a wave energy converter was investigated to find the optimal moving angle in each wave condition. </LI> <LI> Finally, the effectiveness of AMAWEC has been verified by experimental results. </LI> </UL> </P>
Experimental study on mechanical behaviors of injection molded PC/PMMA blends
Van Thanh Hoang,Quang Bang Tao,Bich-Tram Truong-Le,Minh Sang Tran,Duc Binh Luu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.9
Mechanical property is one of the quite important factors of optical articles. Most of pure plastics materials are rarely found to have both high strength and toughness. The paper aims to investigate mechanical properties of polymethyl methacrylate and polycarbonate (PC/PMMA) blends by means of injection molding process and optimization technique. In this study, four factors including composition, packing pressure, melt temperature, and cooling time are taken into account. Experimental results show that the composition is found as the most significant factor for improving the mechanical properties of PC/PMMA blends with confidence level of 95 %. Meanwhile, melt temperature and cooling time are also the most significant parameters for enhancing impact strength with 95 % confidence level. In addition, the mechanical properties of the PC/PMMA plastics composites have been enhanced significantly. Specifically, average tensile yield strength, impact strength, and average elongation are 76.5 MPa, 7429.5 J/m 2 , and 17.5 mm, respectively.
Chemical constituents of Trichosanthes kirilowii and their cytotoxic activities
Chau Van Minh,Nguyen Xuan Nhiem,Hoang Thi Yen,Phan Van Kiem,Bui Huu Tai,Hoang Le Tuan Anh,Truong Thi Thu Hien,박선주,김나영,김승현 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.8
One new lignan, trichobenzolignan (1), and seven known compounds, ligballinol (2), (-)-pinoresinol (3), ehletianol C (4), luteolin 7-O-b-D-glucopyranoside (5), chrysoeriol-7- O-b-D-glucopyranoside (6), 10a-cucurbita5,24-dien-3b-ol (7), and arvenin I (8). Their structures were established on the basis of spectral and chemical evidence, which were in agreement with those reported in literature. The cytotoxic activities of these compounds were evaluated on four cancer cell lines such as A-549 (human lung cancer), HT-29 (human colon adenocarcinoma), OVCAR (human ovarian carcinoma), and MCF-7 (human breast cancer). As the results, compound 7 showed significant activity on HT-29 and OVCAR cancer cell lines with IC50 of 4.1 and 6.5 lM, respectively. Compounds 1, 5, 6, and 8 exhibited moderate activities in all cancer cell lines with IC50 ranging from 11.3 to 42.8 lM.
Tri, Nguyen Minh,Truong, Dinh Quang,Thinh, Do Hoang,Binh, Phan Cong,Dung, Dang Tri,Lee, Seyoung,Park, Hyung Gyu,Ahn, Kyoung Kwan Elsevier 2016 RENEWABLE ENERGY Vol.97 No.-
<P><B>Abstract</B></P> <P>This paper introduces a novel control approach to maximizing the output energy of an adjustable slope angle wave energy converter (ASAWEC) with oil-hydraulic power take-off. Different from typical floating-buoy WECs, the ASAWEC is capable of capturing wave energy from both heave and surge modes of wave motions. For different waves, online determination of the titling angle plays a significant role in optimizing the overall efficiency of the ASAWEC. To enhance this task, the proposed method was developed based on a learning vector quantitative neural network (LVQNN) algorithm. First, the LVQNN-based supervisor controller detects wave conditions and directly produces the optimal titling angles. Second, a so-called efficiency optimization mechanism (EOM) with a secondary controller was designed to regulate automatically the ASAWEC slope angle to the desired value sent from the supervisor controller. A prototype of the ASAWEC was fabricated and a series of simulations and experiments was performed to train the supervisor controller and validate the effectiveness of the proposed control approach with regular waves. The results indicated that the system could reach the optimal angle within 2s and subsequently, the output energy could be maximized. Compared to the performance of a system with a vertically fixed slope angle, an increase of 5% in the overall efficiency was achieved. In addition, simulations of the controlled system were performed with irregular waves to confirm the applicability of the proposed approach in practice.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper proposes a novel energy maximization algorithm of a sliding-buoy wave energy converter (SBWEC). </LI> <LI> An efficiency optimization mechanism is designed and integrated into the SBWEC. </LI> <LI> The control logic is based on a learning vector quantitative neural network for classifying the wave information. </LI> <LI> The effectiveness of the proposed approach is verified through both simulations and experiments. </LI> </UL> </P>