LOWER EXTREMITY INJURY OF VIETNAMESE PEDESTRIAN IN CRASH BY A SEDAN USING NUMERICAL SIMULATION

Phu Thuong Luu Nguyen,Hung Anh Ly,Thien Phu Nguyen 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.1

Pedestrians are among the most vulnerable road users, who often suffer serious injuries in road collisions. Therefore, evaluating the injury of a pedestrian is absolutely necessary. This paper aims to evaluate the lower extremity injuries for Vietnamese people by numerical simulation using a Human Body Model (HBM) – Total Human Model for Safety (THUMS). Considering that the HBM has the anthropometrical and biomechanical properties of the North American and European bodies, it is required to scale it down to represent Vietnamese anthropometry. Furthermore, it is necessary to develop a scaling algorithm to scale the published lower extremity injury criteria to properly assess the injury risk of a Vietnamese. After a Vietnamese-sized HBM is obtained from the scaling procedure, its posture is adjusted to represent a walking pedestrian. A sedan is employed for simulating the pedestrian collision with the impact velocity ranging from 20 to 50 km/h. The car models are simplified to reduce computational time. The findings illustrate that the bending moment and resultant force of femur and tibia increase with respect to the impact velocity. The knee ligaments have been injured at high risk.

Synthesis of Crosslinked Sulfonated Poly(phenylene sulfide sulfone nitrile) for Direct Methanol Fuel Cell Applications

Phu, Duong Sang,Lee, Chang Hyun,Park, Chi Hoon,Lee, So Young,Lee, Young Moo WILEY-VCH Verlag 2009 Macromolecular Rapid Communications Vol.30 No.1

<P>With a view towards direct methanol fuel cell applications, novel sulfonated poly(phenylene sulfide sulfone nitrile) (sPPSSfN) has been prepared and subsequently crosslinked by a Friedel-Craft reaction using 4,4′-oxybis(benzoic acid) as a crosslinker to achieve lower water swelling and lower methanol permeability. The dimensional change of SPPSSfN40 is 43.7% in 90 °C liquid water but that of the crosslinked membrane, XsPPSSfN40, is 23.3% while maintaining proton conductivity at 0.22 S · cm<SUP>−1</SUP>. These results show that the Friedel-Craft crosslinking of the novel sPPSSfN membrane effectively reduces water uptake and the degree of swelling while improving the dimensional stability and maintaining high proton conductivity.</P><P> <img src='wiley_img/10221336-2009-30-1-MARC200800496-gra001.gif' alt='wiley_img/10221336-2009-30-1-MARC200800496-gra001'> </P>

Synthesis of Maltoheptaose Fatty Ester by Yeast Lipase and Their Emulsion Functions

Phu Cuong Nguyen,Thi My Tuyen Nguyen,Chang-KyuLee,Il-NamOh,Min-Jee Yoo,Kyu-BeenPark,Jae-HanKim,Hyun-JooAn,Jong-TaePark 한국당과학회 2018 한국당과학회 학술대회 Vol.2018 No.07

Enzymatic syntheses of sugar fatty acid (FA) esters are important because of their wide range of applications in the food, cosmetic, and pharmaceutical industries. These molecules are commonly synthesized from F As and mono-, or di-saccharides by chemical or enzymatic esterification. Previously, sugar esters were produced using oligosaccharide, and interfacial tension values and inhibitory effects towards tumor cell lines were improved when higher DP saccharides were used. In this study, the direct esterification of maltoheptaose (G7) with vanous length of F As was investigated by the catalytic action of Candida antartica lipase B. Among the F As palmitic acid (PA) was the best substrate for the G7 ester formation. Optimal reaction conditions including solvent composition and molar ratio of G 7: P A were established for the G7-PA. The conversion yield and sugar ester structure were analyzed using various instrumental analyses. The results showed that G7-PA monoester was successfully synthesized with a molar ratio of I :20 (G7: PA) in I 0% DMSO of t-butanol at 60°C, and the conversion yield was over than 21%. The position of ester bond formation was identified that PA was attached to C-6 of the reducing end glucosyl moiety. The melting temperature of G7- PA monoester was reached at 56 °C, lower than that of pure G7 and PA. In addition, the G7- p A esters and commercial sucrose esters were compared as emulsifiers. Both type of sugar esters prevented coalescence during 7 days and showed good emulsifying properties in 0/W emulsions since the droplets diameter did not have significant change during the storage.

Synthesizing Challenging Pose Images for 2D Human Pose Estimation

Phu M. Vuong,Dohun Lim(임도훈),Hyeonseok Lee(이현석),Sungchan Kim(김성찬) 한국정보과학회 2022 한국정보과학회 학술발표논문집 Vol.2022 No.06

Time-Slicing Control Strategy for Rotary SMA Actuators

Phu Van Do,이병룡 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

A new control strategy that can be applied efficiently to rotary SMA actuators was investigated. This type of controller primarily focuses on adjusting the amount of time to apply a voltage or current to actuators while the traditional controllers have been widely used to compute amplitude of signals fed to the actuators. To prove the effectiveness as well as the capability of the proposed strategy in controlling rotary SMA actuators, a simple time-slicing PID controller was developed. The experimental results showed that the proposed time-slicing PID controller attained a better tracking performance compared to the traditional one.

Invasive Non-typhoidal <i>Salmonella</i> Infections in Asia: Clinical Observations, Disease Outcome and Dominant Serovars from an Infectious Disease Hospital in Vietnam

Phu Huong Lan, Nguyen,Le Thi Phuong, Tu,Nguyen Huu, Hien,Thuy, Le,Mather, Alison E.,Park, Se Eun,Marks, Florian,Thwaites, Guy E.,Van Vinh Chau, Nguyen,Thompson, Corinne N.,Baker, Stephen Public Library of Science 2016 PLoS neglected tropical diseases Vol.10 No.8

<▼1><P>Invasive non-typhoidal <I>Salmonella</I> (iNTS) infections are now a well-described cause of morbidity and mortality in children and HIV-infected adults in sub-Saharan Africa. In contrast, the epidemiology and clinical manifestations of iNTS disease in Asia are not well documented. We retrospectively identified >100 cases of iNTS infections in an infectious disease hospital in Southern Vietnam between 2008 and 2013. Clinical records were accessed to evaluate demographic and clinical factors associated with iNTS infection and to identify risk factors associated with death. Multi-locus sequence typing and antimicrobial susceptibility testing was performed on all organisms. Of 102 iNTS patients, 71% were HIV-infected, >90% were adults, 71% were male and 33% reported intravenous drug use. Twenty-six/92 (28%) patients with a known outcome died; HIV infection was significantly associated with death (<I>p</I> = 0.039). <I>S</I>. Enteritidis (Sequence Types (ST)11) (48%, 43/89) and <I>S</I>. Typhimurium (ST19, 34 and 1544) (26%, 23/89) were the most commonly identified serovars; <I>S</I>. Typhimurium was significantly more common in HIV-infected individuals (<I>p</I> = 0.003). Isolates from HIV-infected patients were more likely to exhibit reduced susceptibility against trimethoprim-sulfamethoxazole than HIV-negative patients (<I>p</I> = 0.037). We conclude that iNTS disease is a severe infection in Vietnam with a high mortality rate. As in sub-Saharan Africa, HIV infection was a risk factor for death, with the majority of the burden in this population found in HIV-infected adult men.</P></▼1><▼2><P><B>Author Summary</B></P><P>Invasive non-typhoidal <I>Salmonella</I> (iNTS) infections occur when <I>Salmonella</I> bacteria, which normally cause diarrhea, enter the bloodstream and spread through the body. Invasive NTS infections have become a common cause of infection and death in children with malaria and adults with HIV in sub-Saharan Africa. However, it is unknown whether iNTS is as common or as severe outside sub-Saharan Africa. We evaluated over 100 iNTS cases from an infectious disease hospital in southern Vietnam admitted between 2008–2013. We used hospital records to determine the clinical features of iNTS disease and to identify risk factors associated with death and performed typing of the isolated organisms. The majority of patients were HIV positive (72/102, 71%), >90% of patients were adults, 71% were male and 33% reported intravenous drug use. The mortality rate of iNTS patients was 28% (26/92), and HIV infection was a significant risk factor for fatal outcome (<I>p</I> = 0.039). The serovars most commonly identified were <I>S</I>. Enteritidis and <I>S</I>. Typhimurium; <I>S</I>. Typhimurium was found more frequently in HIV-positive individuals (<I>p</I> = 0.003). We report that iNTS disease is a severe infection in Vietnam with a high mortality rate. Similar to sub-Saharan Africa, HIV infection was a strong risk factor for death.</P></▼2>

Vibration control of a vehicle’s seat suspension featuring a magnetorheological damper based on a new adaptive fuzzy sliding-mode controller

Phu, Do Xuan,Choi, Seung-Bok,Lee, Yang-Sub,Han, Moon-Sihk Professional Engineering Publishing Ltd 2016 Proceedings of the Institution of Mechanical Engin Vol. No.

<P>This work presents a new design for adaptive fuzzy sliding-mode control based on two methodologies, namely H control and sliding-mode control, and its control effectiveness. This is achieved by implementing a control scheme for vibration control of a vehicle with a seat suspension on which a magnetorheological damper is installed. The sliding surface of sliding-mode control is analysed by separation into two matrices: a Hurwitz-constants matrix and a constant matrix. These matrices are the basis for establishing the proposed control scheme combined with the H technique. The control scheme consisting of the combination of H control and sliding-mode control is reinforced by a new robustness function featuring an exponential function. In this work, a fuzzy logic model, which is well known to be an excellent model for uncertain dynamic systems, is integrated with the proposed control algorithm. The fuzzy logic model adopted in this work is an interval type-2 fuzzy model featuring fast computation of the output. The effectiveness of the proposed control scheme is evaluated through both computer simulations and experimental realization on a vehicle with a seat suspension which is equipped with a magnetorheological damper. In addition, in this work, two existing adaptive controllers are modified and implemented for comparative work with the proposed control scheme. It is shown that the proposed control scheme exhibits a much better vibration control performance than the two existing adaptive controllers do.</P>

A Fully Integrated Multimode Wireless Power Charger IC With Adaptive Supply Control and Built-In Resistance Compensation

Phu Ho Van Quang,Thanh Tien Ha,Jong-Wook Lee Institute of Electrical and Electronics Engineers 2015 IEEE transactions on industrial electronics Vol. No.

<P>We present a fully integrated multimode lithium-ion battery charger integrated circuit (IC) for wireless power charging applications. The proposed charger IC integrates an analog block for battery charging, a digital control block, an analog-to-digital converter, and memory on a single chip. To improve the charging efficiency, the supply voltage of the charger IC is controlled by an adaptive low-dropout (LDO) regulator. A series-voltage feedback path is formed along the LDO regulator and multimode level shifter, which regulates the supply voltage to closely follow the battery voltage. For a smooth transition during multimode charging, we propose a new approach for built-in resistance compensation. The digital control block of the charger IC is designed in accordance with the Qi standard. The battery charger IC is fabricated in a one-poly six-metal 0.18-μm CMOS process. Integrated with the digital control block and memory, the core area of the multimode charger IC is 0.9 × 1.4 mm<SUP>2</SUP>. The input voltage ranges from 4.8 to 5 V. The output voltage is 4.2 V in constant-voltage mode. The charging current in constant-current mode is 450 mA. The maximum and average charging efficiencies are 83% and 79%, respectively.</P>

Power allocation strategies for dual-hop relay protocols with best relay selection under constraint of intercept probability

Phu Tran Tin,Tran Trung Duy 한국통신학회 2019 ICT Express Vol.5 No.1

In this letter, we propose two power allocation strategies, named Optimal Power Allocation (OPA) and Equal Intercept Probability (EIP), for dual-hop cooperative decode-and-forward (DF) relaying networks under constraint of intercept probability (IP). Particularly, with knowledge of channel statistics of the eavesdropping links, the transmitters such as source and relays adjust their transmit power to control the value of IP by a desired level. A max–min relay selection method is applied to enhance the e2e outage probability (OP). We derive expressions of transmit power for the source and the selected relay. Then, Monte Carlo simulations were performed to verify analytical results.

Advanced analysis for planar steel frames with semi-rigid connections using plastic-zone methodAdvanced analysis for planar steel frames with semi-rigid connections using plastic-zone method

Phu-Cuong Nguyen,김승억 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.5

This paper presents a displacement-based finite element procedure for second-order distributed plasticity analysis of planar steel frames with semi-rigid beam-to-column connections under static loadings. A partially strain-hardening elastic-plastic beam-column element, which directly takes into account geometric nonlinearity, gradual yielding of material, and flexibility of semi-rigid connections, is proposed. The second-order effects and distributed plasticity are considered by dividing the member into several sub-elements and meshing the cross-section into several fibers. A new nonlinear solution procedure based on the combination of the Newton-Raphson equilibrium iterative algorithm and the constant work method for adjusting the incremental load factor is proposed for solving nonlinear equilibrium equations. The nonlinear inelastic behavior predicted by the proposed program compares well with previous studies. Coupling effects of three primary sources of nonlinearity, geometric imperfections, and residual stress are investigated and discussed in this paper.