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Nguyen T.T.,Ho Chi Minh City University of Transport | Chan T.M.,Hong Kong Polytechnic University | Mottram J.T.,University of Warwick
Composite Structures | Year: 2015

This paper presents an investigation into the development of a design procedure for Pultruded Fibre Reinforced Polymers (PFRP) beams failing by the elastic buckling mode of Lateral-Torsional Buckling (LTB). The design procedure is based on the European design approach for uniform members in bending of structural steel. In particular, the calibration method adopts the general case 'resistance' formula in Eurocode 3 (EN 1993-1-1:2005), and follows a standard design from testing procedure given in Eurocode 0 (EN 1990:2002) when calibrating the 'design model' to determine the partial factor γM for a member instability check. The test population for calibration has 114 LTB buckling resistances using four PFRP section sizes of I and channel shapes. The non-dimensional slenderness parameter is defined using the local flange buckling strength instead of the yield strength. An imperfection factor of 0.34 and partial factor of 1.3 are shown to be appropriate for calculation of the LTB moment of resistance. © 2015 Elsevier Ltd.


Ke T.N.,Ton Duc Thang University | Khanh H.N.P.,Ho Chi Minh City University of Transport
Procedia Engineering | Year: 2016

Load capacity of pile foundation is larger than shallow foundation because the loads are transferred deeper into de stiffer layers of soil. Piles and the ground under the pile cap work simultaneously to lift and hold the above structure. The determination of cross section, length and arrangement piles accordance with load, geotechnical, construction equipment, conditions is a big challenge in the designing of pile foundation to achieve efficiency economy. Analysing the relationship between the stress of the ground and pile's load capacity to choose cross section, length and arrangement piles accordance with load, geotechnical, construction equipment, conditions will bring economy efficiency. In this paper a new method for determining the load capacity of pile based on the consideration stress in the ground under the tip of the pile and along the pile is presented. The loading capacity of a pile predicted using the proposed method is compared with the result of the static compression test carried out at the field. The analysis based on this comparison showed that this method efficiently help the designer in determining correctly the load capacity of piles after having results of the pile static compression tests. © 2016 The Authors. Published by Elsevier Ltd.


Bao V.N.Q.,Posts And Telecom Institute Of Technology | Phuong B.P.L.,International University | Thanh T.T.,Ho Chi Minh City University of Transport
2012 4th International Conference on Communications and Electronics, ICCE 2012 | Year: 2012

We first propose transmit antenna selection/selection combining (TAS/SC) based MIMO decode-and-forward (DF) relaying networks to simultaneously employ advantages offered by multi-hop relaying and TAS/SC. To investigate the system, we further propose to approximate the distribution of the end-to-end signal-to-noise ratio (SNR). The advantage of the proposed approximation resides mainly in the fact that it results in simple and mathematically tractable closed-form expression of the system performance metrics such as outage probability, ergodic capacity, symbol error rate and bit error rate thus offering clear insights on system behaviors. Monte-Carlo simulation results have been performed to cross-check the accuracy of the theoretical analysis showing that our proposed protocol outperforms the single-antenna-equipped multi-hop network in all range of operating SNRs. Under the constraint of spectral efficiency, the optimal number of hops is existed and a function of modulation schemes and path loss exponent. © 2012 IEEE.


Vu V.T.,Ho Chi Minh City University of Transport
Journal of Pressure Vessel Technology, Transactions of the ASME | Year: 2013

The paper presents the optimization of toroidal shell cross-sections under internal pressure. The wall thickness distribution along a circular centerline is derived in an analytical form. In membrane solution, this cross-section gives a constant Mises stress all over the shell. Therefore, it leads to material saving and contained volume increase in comparison with the traditional cross-section of circular constant thickness. The optimum shapes are designed for two states of shell, one is elasticity and the other is up to destruction. The maximum material saving can reach 70% in some configurations of toroid. Results of the proposed method are as good as or better than those found in literature. © 2013 by ASME.


Nguyen L.V.,University of Texas at Arlington | Tran H.-D.,Ho Chi Minh City University of Transport | Johnson T.T.,University of Texas at Arlington
IEEE Transactions on Energy Conversion | Year: 2014

In this paper, we present virtual prototyping of the distributed control for a modular multilevel inverter used as a grid-tie interface for photovoltaics. Due to the distributed control and inherent redundancy in the system composed of many panels and inverter modules, the system topology exhibits fault-tolerance capabilities that we study through virtual prototyping. The fault-tolerance is enabled by several distributed algorithms, such as services to identify which, if any, agents controlling inverter modules have failed. A distributed identifier algorithm allows the system to keep track of the number of operating panels to appropriately regulate the dc voltage output of the panels using buck-boost converters and determine appropriate switching times for H-bridges in the grid-tie. We evaluate the distributed inverter, its control strategy, and fault-tolerance through thousands of simulation scenarios in Mathworks Simulink/Stateflow. Our virtual prototyping framework allows for generating multilevel inverters composed of many inverter modules, and we evaluate inverters composed of five to dozens of inverter modules. Our analysis suggests the achievable total harmonic distortion of the modular multilevel inverter may allow for operating solar arrays in spite of failures of the power electronics, control software, and other subcomponents. © 2014 IEEE.


Nguyen L.A.T.,Ho Chi Minh City University of Transport | Nguyen H.K.,Ho Chi Minh City University of Transport
2015 10th Asian Control Conference: Emerging Control Techniques for a Sustainable World, ASCC 2015 | Year: 2015

The explosive growth of Internet commerce has made phishers who may attempt to create phishing sites aimed to steal personal information such as password, banking account and credit card account details, etc. Most of these phishing pages look similar to the real pages in terms of interface and uniform resource locator (URL) address. Many techniques have been proposed to identify phishing sites. However, the numbers of victims have been increasing due to inefficient protection technique. In this paper, we develop a fuzzy model for phishing identification efficiently. The model eliminates the subjective factors to improve efficiency such as if-then rule sets, the parameters of membership functions, etc. Moreover, the efficiency features for identifying phishing were used for the fuzzy model. The proposed technique is evaluated with the datasets of 11,660 phishing sites and 5,000 legitimate sites. The results show that the proposed technique can identify over 99% phishing sites. © 2015 IEEE.


Nguyen L.A.T.,Ho Chi Minh City University of Transport | Nguyen H.K.,Ho Chi Minh City University of Transport
2015 10th Asian Control Conference: Emerging Control Techniques for a Sustainable World, ASCC 2015 | Year: 2015

The Internet has brought enormous benefits to mankind, but it could be many potential risks. Internet crimes are growing rapidly, phishing is one of the new type of online crime. Phishing site is a fake-site aimed to steal personal information such as password, banking account and credit card information, etc. Most of these phishing pages look similar to the real pages in terms of interface and uniform resource locator (URL) address. Many techniques have been proposed to identify phishing sites. However, the numbers of victims have been increasing due to inefficient protection technique. In this paper, we develop a neuro-fuzzy model for phishing identification efficiently. The model eliminates the subjective factors to improve efficiency such as if-then rule sets, the parameters of membership functions, etc. Moreover, the efficiency features to identify phishing were used for the neuro-fuzzy model. The effectiveness of the proposed technique is examined with large-scale datasets collected from phishing sites and legitimate sites. The results show that the proposed technique can identify over 99% phishing sites. © 2015 IEEE.


Dang T.,Ho Chi Minh City University of Transport | Bargstadt H.-J.,Bauhaus University Weimar
Journal of Construction Engineering and Management | Year: 2016

Four-dimensional (4D) schedules have proven successful in planning with their visualization capabilities allowing for coordination and time-space conflict detection. However, when considered in depth, internal aspects of 4D scheduling techniques have not made significant advances from traditional two-dimensional (2D) scheduling. What is missing from 4D scheduling? Why has the interaction between activities, their relationships, and three-dimensional (3D) components not been flexible and adaptive enough? In light of these questions, this paper analyzes the current state of 4D scheduling. The missing element in 4D scheduling is found to be 4D relationships (4DRs). A prototype of 4DRs has therefore been developed to improve 4D scheduling. Finally, guidance on the application of 4DRs in 4D scheduling is presented to help the users come to a thorough understanding of its advantages and disadvantages and potential applications. © 2015 American Society of Civil Engineers.


Tran T.N.,Ho Chi Minh City University of Transport | Ton T.N.T.,Ho Chi Minh City University of Transport
Composite Structures | Year: 2016

One of the important topics in impact engineering was lateral crushing behaviour of thin-walled tube. In this study, crushing behaviours of rectangular and square tubes are investigated through lateral crushing testing and theoretical analysis. The average crushing force of the rectangular tube is smaller than that of the square tube. These two types of tubes have identical crushing mechanism, including two crushing stages. Plastic models are built based on the observed crushing behaviour. Theoretical solution for each stage is developed to predict the average crushing force of rectangular and square tubes. © 2016 Elsevier Ltd


Vu V.T.,Ho Chi Minh City University of Transport
International Journal of Geomechanics | Year: 2015

An approach to finding the optimal layout of prefabricated vertical drains (PVDs) in soft soil treatment, which has the minimum amount of PVDs and meets the requirements for the degree of consolidation, is proposed. Because explicit functions for settlement and consolidation in a multilayer ground for PVDs are not available, the current study uses the differential evolution method. The results show a stable relation between the optimal value with elapsed time, degree of consolidation, and embankment height. © 2014 American Society of Civil Engineers.

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