Trang: 1-10 Chu Tien DungTóm tắtUnderstanding pedestrian platoon dispersion at signalized crosswalk is essential not only for improving pedestrian safety but also for estimating pedestrian crossing time requirement. This paper proposed platoon dispersion ratio (PDR) as an index to analyse the effects pedestrian demand and crosswalk length upon pedestrian platoon dispersion at signalized crosswalk. The result shows that the heavier pedestrian demand usually corresponds to greater platoon dispersion. Regarding the influence of crosswalk length, it is revealed that the dispersion tends to increase as the crosswalk length increases
Trang: 11-17 Vu Thi HuongTóm tắtIn this paper, we consider the stochastic evolution of two particles with electrostatic repulsion and restoring force which is modeled by a system of stochastic differential equations driven by fractional Brownian motion where the diffusion coefficients are constant. This is the simplest case for some classes of non- colliding particle systems such as Dyson Brownian motions, Brownian particles systems with nearest neighbour repulsion. We will prove that the equation has a unique non- colliding solution in path- wise sense.
Trang: 18-26 Bui Thi Thanh Mai, Nguyen Huy Cuong, Ngo Dang Quang, Dinh Huu TaiTóm tắtTextile-reinforced concrete (TRC) is a new composite material made of high-strength textiles embedded within fine grained concrete (FGC). The application of TRC leads to the design of thin and slender structures or for repairing and strengthening of existing structural members. Autoclaved aerated concrete (AAC) is an ultra-lightweight concrete, which can be combined with high strength TRC to form some kinds of precast curtain panels in construction. The concept of the TRC-AAC panel is based on the theory of sandwich construction with strong and stiff skins, like TRC layers, bonded to a lightweight AAC core. The resulting hybrid TRC-AAC panel can be used as structural or non-structural member for the housing construction. In this paper, the flexural and shear performance of hybrid TRC-AAC sandwich panels is presented by means of experimental results. The sandwich panels use three layers of different materials: TRC for the tensile layer, AAC for the core material and FGC for the compressive layer. Three different types of glass textile were used as reinforcements in the TRC layers.
A study on memory data retention in high-temperature environments for automotive
Trang: 27-36 Dao Thanh ToanTóm tắtThe automotive memory devices especially work in high-temperature because they are located close to engine, exhaust units; those require high reliable operation and long-life data retention in high-temperature environments. This paper reports on the investigation of memory data retention of a nano-organic material-based nonvolatile memory in high-temperature environments. The decay of memory state current was theoretically presented as a stretched-exponential law. By fitting the measured currents to the stretched-exponential equation at different temperatures, the activation energy of decay and acceleration factor was deduced, which allows to predict the device performance at high-temperature environment like in a car. The method presented in study can be applied to estimate the memory data retention at high-temperature for other car memories
Trang: 37-45 Nguyen Huy Cuong, Ngo Dang QuangTóm tắtThe application of prestressing steel is restricted in highly corrosive environment area due to corrosion of prestressing steel, which leads to reduction in strength and it may cause sudden failure. Carbon textile is considered as an alternate material due to its corrosive resistance property, high tensile strength and perfectly elastic. In this study, an experimental investigation was carried out to study the flexural behavior of prestressed and non-prestressed carbon textile reinforced concrete plates. This study also focuses on the influences of textile reinforcement ratios, prestress grades on the flexural behavior of carbon textile reinforced concrete (TRC). Fifteen precast TRC plates were tested, of which six were prestressed to various levels with carbon textile. The obtained results show that prestressing of textile reinforcement results in a higher load bearing capacity, stiffness and crack resistance for TRC plates.
Reinforcing cementitious material using single-walled carbon nanotube - nylon 66 nanofibers
Trang: 46-55 Jung J. Kim, Tri N.M. Nguyen, Xuan Tung Nguyen, Ta Duy HienTóm tắtBased on the increase in tensile strength and toughness (43% and 30%, respectively), the feasibility of the hybrid nanofibers containing Single-walled carbon nanotubes and Nylon 66 on reinforcing cementitious materials has been clarified. The well-linking effect of nanofibers in the microstructure of hardened cement pastes has been found by scanning electron microscope (SEM) analysis and well-explained for the increase in mechanical strengths. Besides, field emission transmission electron microscope (FE-TEM) analysis has also been conducted to analyze the properties of the hybrid nanofibers.
