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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.
Phu, Do Xuan,Quoc, Nguyen Vien,Park, Joon-Hee,Choi, Seung-Bok Professional Engineering Publishing Ltd 2014 Proceedings of the Institution of Mechanical Engin Vol. No.
<P>This paper presents vibration control of a mixed-mode magnetorheological fluid-based mount system using a new robust fuzzy sliding mode controller. A novel model of controller is built based on adaptive hybrid control of interval type 2 fuzzy controller incorporating with a new modified sliding mode control. The interval type 2 fuzzy is optimized for computational cost by using enhanced iterative algorithm with stop condition, and a new modified switching surface of sliding mode control is designed for preventing the chattering of the system. The controller is then experimentally implemented under uncertain conditions in order to evaluate robust vibration control performance. In addition, in order to demonstrate the effectiveness of the proposed controller, two fuzzy sliding mode control algorithms proposed by Huang and Chan are adopted and modified. The principal control parameters of three controllers are updated online by adaptation laws to meet requirements of magnetorheological mount system which has two operation modes: flow mode and shear mode. It is shown from experimental realization of three controllers that the proposed control strategy performs the best under uncertain conditions compared with two other modified controllers. This merit is verified by presenting vibration control performances in both time and frequency domains.</P>
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>
Phu Tran Tin,Ph?m Minh Nam,Tran Trung Duy,Miroslav Voznak 대한전자공학회 2017 IEIE Transactions on Smart Processing & Computing Vol.6 No.3
In this paper, we investigate the tradeoff between security and reliability for a multi-hop protocol in cluster-based underlay cognitive radio networks. In the proposed protocol, a secondary source communicates with a secondary destination via the multi-hop relay method in the presence of a secondary eavesdropper. To enhance system performance under the joint impact of interference constraint required by multiple primary users and hardware impairments, the best relay node is selected at each hop to relay the source data to the destination. Moreover, the destination is equipped with multiple antennas and employs a selection combining (SC) technique to combine the received data. We derive closed-form expressions of the intercept probability (IP) for the eavesdropping links and the outage probability (OP) for the data links over a Rayleigh fading channel. Finally, the correction of our derivations is verified by Monte-Carlo simulations.
Enzymatic synthesis of pure maltodextrins and their novel derivatives
Phu Cuong Nguyen,My Tuyen Thi Nguyen,Chang-Kyu Lee,Wang-Hee Lee,Il-Nam Oh,Jae-Han Kim,Soon-Taek Hong,Jong-Tae Park 한국당과학회 2022 한국당과학회 학술대회 Vol.2022 No.07
Maltodextrin in specific length is of great interest because of its wide industrial applications. Previously, we have proven that Pyrococcus furiosus thermostable amylase (PFTA) produces high purity maltoheptaose (G7) from β-cyclodextrin (CD) at early reaction time. However, the production of pure G7 is a cost and time-consuming process. Therefore, this work has designed an optimal continuous process for pure G7 production from β-CD using PFTA with immobilization in a packed-bed reactor (PBR). The optimal conditions determined using the response surface method for the maximized G7-purity of 96.3% were predicted at 4.7 ml/min of flow rate, 1.1% substrate, and 48.7 °C. As a result, the immobilized PFTA in PBR retained 85% of the initial activity after six cycles of 24 h intervals, and the product purity was unchanged. Also, maltohexaose (G6) and maltooctaose (G8) at high purity (92-97%) were produced by continuously supplying CDs to the PFTA-PBR under the same optimized condition of G7. In addition, a new method based on preparative reversed-phase liquid chromatography was developed to purify maltodextrins in specific lengths (DP 3-26) with high purity from the reaction mixture of G6-G8 substrates with Thermotoga maritima maltosyltransferase. On the other hand, novel G7-based sugar esters were also synthesized and investigated for emulsifying properties. As a result, G7-fatty acids (C10–C16) esters were produced with a high conversion yield (90-95%) under the optimal conditions (10% of DMSO, 0.2 of G7/ fatty acids molar ratio, 33.5 U of immobilized Candida antarctica lipase B) for 24 h of incubation at 60 °C. Notable, G7-palmitate (PA) exhibited emulsifying properties better than commercial sucrose-PA ester, especially in acidic conditions. It is feasible that the number of the hydroxyl groups and the size of G7 moiety provide that distinctive property of G7-PA. Therefore, applications of G7-PA in foods, cosmetics, and drug delivery under extreme pH conditions are promising.
Enzymatic Synthesis of Pure Maltohexaose from α-Cyclodextrin
Phu Cuong Nguyen,Ji-Yun Kwak,Min-Jee Yoo,Jong-Tae Park,Kwan-Hwa Park 한국당과학회 2016 한국당과학회 학술대회 Vol.2016 No.01
Maltohexaose (G6) is a maltodextrin consisted of six-glucose in α-1,6-glycosidic linkages and essential research tool in food, cosmetic and pharmaceutical. In previous study, we have proven that the possibility of large-scale continuous production of pure maltodextrins from cyclodextrins (CDs) using Pyrococcus furiosus thermostable amylase with immobilization in a packed-bed reactor (PBR). In this study, we used this PBR for G6 production from α-CD. After enzyme reaction, 1-decanol was added to G6 mixture as precipitating agent with a 1:1 ratio of 1-decanol to α-CD. In which, the unreacted α-CD was precipitated, then it was separated by centrifugation. Finally, the G6-product was obtained in homogeneous form and high-purity (95 %). Through this study, we successfully demonstrated the enzymatic synthesis method to produce pure G6 from α-CD.