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Results 251-260 of 698 (Search time: 0.001 seconds).
  • Authors: Nguyen, Manh Long; Tran, Thi Thu Huong; Nguyen, Tuan Anh; Nguyen, Duc Ngoc; Dang, Ngoc Duyen;  Advisor: -;  Co-Author: - (2022)

    This paper introduces the LQR control algorithm for the active suspension system. Because the model of the vehicle dynamics used in this paper includes a hydraulic actuator, therefore, this model will include five state variables. Besides, the process of linearization of the hydraulic actuator is also shown in this paper. This is a completely novel and original method. It is possible to describe almost all the characteristics of hydraulic actuators with just one linear differential equation. Also, the parameters of the LQR controller are optimized through the in-loop optimization algorithm. The results of the research showed that the values of displacement and acceleration of the sprung mass were significantly reduced when this algorithm was used. In the investigation cases, these v...

  • Authors: Manh-Toan Ho; Thanh-Huyen T. Nguyen; Minh-Hoang Nguyen;  Advisor: -;  Co-Author: - (2022)

    Video games have the potential to be a tool for communicating pro-environmental values. The present study examines the correlation between players’ environmental attitudes and their interaction with virtual natural resources. This study constructs Bayesian ordinal logistic models to analyze survey data of 640 Animal Crossing: New Horizon (ACNH) players from 29 countries. Results show that the frequency of catching in-game animals (fish and insects) is positively correlated with the level of human centeredness in environmental attitudes. In addition, less anthropocentric players tend to use more sustainable methods to collect woods in ACNH. Such a particular way of interacting with in-game animals and trees based on their species may be attributable to players’ environmental attitude...

  • Authors: Huan, Thanh Duong; Hieu, Chi Phan; Tien, Thinh Le;  Advisor: -;  Co-Author: - (2022)

    Functionally Graded Materials (FGM) is the advanced material that covers the advantages of both metal and ceramic which contain FGM. Due to the perfect combination, FGM plate is widely developed with the requirement for the practical application to avoid the difficulties from conventional approaches. Consequently, the study establishes the database from analytical model and uses it for developing a machine learning model in the desire of finding an alternative model to predict critical buckling load of the plate. Such a machine learning model is crucial for predicting critical buckling load of the FGM plate without complexity of analytical developments or finite element resources. The Gaussian Process Regression model has been developed based on the database containing 1000 labeled ...

  • Authors: Karsten, Eichholz; Tuan Hiep, Tran; Coraline, Chéneau; Thi Thu Phuong, Tran; Océane, Paris;  Advisor: -;  Co-Author: - (2022)

    Intramuscular delivery of human adenovirus (HAdV)-based vaccines leads to rapid recruitment of neutrophils, which then release antimicrobial peptides/proteins (AMPs). How these AMPs influence vaccine efficacy over the subsequent 24 h is poorly understood. In this study, we asked if human neutrophil protein 1 (HNP-1), an α-defensin that influences direct and indirect innate immune responses to a range of pathogens, impacts the response of human phagocytes to three HAdV species/types (HAdV-C5, -D26, -B35). We show that HNP-1 binds to the capsids and redirects HAdV-C5, -D26, and -B35 to Toll-like receptor 4 (TLR4), which leads to internalization, an NLRP3-mediated inflammasome response, and interleukin 1 beta (IL-1β) release. Surprisingly, IL-1β release was not associated with notable ...

  • Authors: Vu Huu Nhu;  Advisor: -;  Co-Author: - (2021)

    This work is concerned with second-order necessary and sufficient optimality conditions for optimal control of a non-smooth semilinear elliptic partial differential equation, where the nonlinearity is the non-smooth max-function and thus the associated control-to-state operator is, in general, not Gâteaux-differentiable. In addition to standing assumptions, two main hypotheses are imposed. The first one is the Gâteaux-differentiability at the considered control of the objective functional and it is precisely characterized by the vanishing of an adjoint state on the set of all zeros of the corresponding state. The second one is a structural assumption on the sets of all points at which the values of the interested state are ‘close’ to the non-differentiability point of the max-functi...

  • Authors: Trinh, Thanh; Luu, Thanh Binh; Le, Thi Trang Ha; Nguyen, Huy Duong; Tran, Van Trong; Nguyen, Thi Hai Van; Nguyen, Khanh Quoc; Nguyen Thi Lien;  Advisor: -;  Co-Author: - (2022)

    Landslide susceptibility maps (LSMs) are very crucial for planning policies in hazardous areas. However, the accuracy and reliability of LSMs depend on available data and the selection of suitable methods. This study is conducted to produce LSMs by combinations of machine learning methods and weighting techniques for Ha Giang province, Vietnam, where has limited data. In study area, we gather 11 landslide conditioning factors and establish a landslide inventory map. Computing the weights of classes (or factors) is very important to prepare data for machine learning methods to generate LSMs. We first use frequency ratio (FR) and analytic hierarchy process (AHP) techniques to generate the weights. Then, random forest (RF), support vector machine (SVM), logistic regression (LR), and AH...

  • Authors: Huu-Quang Nguyen; Dajeong, Hwang; Sejeong, Park; My-Chi Thi Nguyen;  Advisor: -;  Co-Author: - (2022)

    One-dimensional hybrid nanostructures composed of a plasmonic gold nanowire core covered by a shell of magnetic oxide nanoparticles (Au@FexOy NWs) were synthesized by a one-pot solvothermal synthesis process. The effects of reaction temperature, time, reducing agent, and precursor as well as postsynthesis treatment were optimized to produce highly uniform NWs with a diameter of 226 ± 25 nm and a plasmonic core aspect ratio of 25 to 82. By exploiting the interaction of NWs with an external magnetic field, precise arrangements into highly periodic photonic structures were achieved, which can generate distinctive structural colors that are vividly iridescent and polarization-sensitive. Furthermore, a Bouligand-type chiral nematic film consisting of multistacked unidirectional layers of...

  • Authors: Le, Kha Hoa; Bui, Gia Phi; Do, Quang Chan; Dang, Van Hieu;  Advisor: -;  Co-Author: - (2022)

    In this article, an analytical method is proposed to analyze of the linear buckling behavior of the FG porous truncated conical shells subjected to a uniform axial compressive load and resting on the Pasternak elastic foundation. The material properties including Young's modulus, shear modulus and density are assumed to vary in the thickness direction. Three types of FG porous distributions including symmetric porosity distribution, non-symmetric porosity and uniform porosity distribution are considered. The governing equations of the FG porous truncated conical shells are obtained by using the first-order shear deformation theory (FSDT). With the help of the Galerkin method, the expressions for critical buckling loads are obtained in closed forms. The reliability of the obtained re...

  • Authors: Truong, V. Vu; Binh, D. Pham; Ho, Xuan Nang; Hung, V. Vu;  Advisor: -;  Co-Author: - (2022)

    This study presents a front-tracking-based numerical analysis of the forced convection solidification of a sessile droplet on a cooling surface. The droplet, a hollow (or compound) droplet with an encapsulated gas core, undergoes a liquid-to-solid phase change in its shell. This phase change starts from the surface. Meanwhile, the surrounding gas, which is characterized by its Reynolds number Re and temperature, moves toward the droplet parallel to the axis of symmetry. When the temperature of the forced flow is below the solidification value (i.e., cold-forced convection), increasing the strength of the forced flow shortens the solidification process. In contrast, increasing the Re number of a hot-forced convection system prolongs solidification. In other words, an increase in the ...