bluuebunny/crossref_metadata_2025 huggingface dataset:
Validación de una escala de perfeccionismo en niños peruanos
Authors: Ventura-León José , Jara-Avalos Stefani , Garcia-Pajuelo Carmen , Ortiz-Saenz Carlos
Published: April 2018

Este artículo validó la Escala de Perfeccionismo Infantil (EPI) de Oros en una población infantil peruana. Se contó con la participación de 1084 niños con edades comprendidas entre los 7 y 12 años (M = 9.75; DE = 1.23) de siete instituciones educativas, privadas y públicas. El Análisis Factorial Exploratorio reveló una escala bidimensional oblicua (Reacción ante el fracaso y Autodemandas); no obstante, tres ítems tuvieron una carga < .30. El Análisis Factorial Confirmatorio corroboró la estructura bidimensional oblicua con la salvedad de errores correlacionados. La fiabilidad fue estimada mediante el coeficiente Omega (ω = .810). Se concluye que la EPI cuenta con evidencia de validez y fiabilidad de las puntuaciones.
Updated checklist of estuarine caridean shrimps (Decapoda: Caridea) from the southern region of Laguna Madre, Tamaulipas, Mexico, with new records and a key for taxonomic identification
Authors: Herrera-Barquín Hiram , Leija-Tristán Antonio , Favela-Lara Susana
Published: April 2018

We provide an updated list of the caridean shrimp species from the southern region of the Laguna Madre, Tamaulipas, Mexico, along with a key for taxonomic identification. The survey was conducted in 3 sites during 3 temporal seasons. A total of 2,989 specimens were collected belonging to 12 species, 6 genera, and to the following 4 families: Alpheidae, Hippolytidae, Palaemonidae, and Processidae. Hippolytidae was the most abundant family, followed by Palaemonidae, Alpheidae, and Processidae. The hippolytid Hippolyte obliquimanus Dana, 1852, the palaemonids Palaemon floridanus Chace, 1942, and P. northropi (Rankin, 1898), and the alpheid Alpheus cf. packardii Kingsley, 1880 represent new records for the Laguna Madre and selected areas of the Gulf of Mexico.
First record of Swallow-tailed Cotinga, Phibalura flavirostris Vieillot, 1816 (Aves, Cotingidae) in Campo Grande, Mato Grosso do Sul, Brazil
Authors: Corral Allan , Rodrigues Silva Claudía Liz , Espinola Carvalho Cristiano Marcelo , Cheung Kwok Chiu , Valério Luciana Mendes
Published: April 2018

The Swallow-tailed Cotinga, Phibalura flavirostris, is a rare Neotropical bird. Its geographic distribution in Brazil is limited to the country’s south and south-east regions and a small area in the center of the state of Goiás. However, an adult individual was recorded in a fragment of Cerrado in the municipality of Campo Grande, in central Mato Grosso do Sul, indicating an expansion in the distribution of the species in Brazil.
The cubic non-linearity of order ε in the second approximation
Authors: Dinh Nguyen Van
Published: April 2018

None
Modal analysis of damaged structures by the modified finite element method
Authors: Menh Nguyen Cao , Khiem Nguyen Tien , Mai Dao Nhu , Khoa Nguyen Viet
Published: April 2018

The classical 3D beam element has been modified and developed as a new finite element for vibration analysis of frame structures with flexible connections and cracked members. The mass and stiffness matrices of the modified elements are established basing on a new form of shape functions, which are obtained in investigating a beam with flexible supports and crack modeled through equivalent springs. These shape functions remain the cubic polynomial form and contain flexible connection (or crack) parameters. They do not change standard procedure of the finite element method (FEM). Therefore, the presented method is easy for engineers in application and allows to analyze Eigen-parameters of structures as functions of the connection (or crack) parameters. The proposed approach has been applied to calculate natural frequencies and mode shape of typical frame structures in presented examples.
Longitudinal shock solid object onto the elastic bar placed on the visco-elastic foundation with constant resistance of a part of the bar side face
Authors: An Nguyen Thuc , Thanh Binh Nguyen Thi
Published: April 2018

None
Interaction between the forced and parametric excitations with different degrees of smallness
Authors: Dao Nguyen Van
Published: April 2018

The nonlinear system under consideration in this paper has a specification which can be stated as an interaction between the first order of smallness no resonance parametric excitation and the second order of smallness resonance forced excitation. In the first approximation these excitations have no effect. However, they do interact one with another in the second approximation.The equations for the amplitude and phase of oscillation are found by means of the asymptotic method. The stationary oscillations and their stability are of special interest.
Interaction between nonlinear parametric and forced oscillations
Authors: Dao Nguyen Van , Dinh Nguyen Van , Chi Tran Kim
Published: April 2018

None
Interaction between linear and cubic parametric excitations
Authors: Dinh Nguyen Van , Chi Tran Kim
Published: April 2018

None
Diffstochastic equivalent linearization based on the Fokker-Plank equation approach
Authors: Anh Nguyen Dong , Tinh Nguyen Duc
Published: April 2018

None
On the interaction between forced and parametric oscillations in a system with two degrees of freedom
Authors: Chi Tran Kim , Dinh Nguyen Van
Published: April 2018

None
Reduced impedance of branch component with hyperstatic interface
Authors: Si Nguyen Thac
Published: April 2018

None
Stability of the critical stationary oscillations
Authors: Dinh Nguyen Van
Published: April 2018

None
Non-linearities in a quasi-linear system subjected to external and parametric excitations of different orders
Authors: Dinh Nguyen Van
Published: April 2018

None
Stationary oscillations in degenerated case
Authors: Dinh Nguyen Van
Published: April 2018

In the present paper, some remarks about stationary oscillations in degenerated case are presented. It is shown that these oscillations may exist, may be stable or unstable and they are represented by singular points of the response curve.
Fundamental resonance in one generalized system of type Van der Pol
Authors: Dinh Nguyen Van , Chi Tran Kim
Published: April 2018

In the present paper, an oscillating system of type Vanderpol is considered. The fundamental resonance is examined, degenerated cases are analyzed in detail; singular points are used to distinguished various forms of the amplitude frequency curve.
Elasto-plastic state of curve beam system subjected to complex loading
Authors: Bay Vu Khac
Published: April 2018

Investigation of the elastic state of curve beam system had been considered in [3]. In this paper the elastic-plastic state of curve beam system in the form of cylindrical shell is analyzed by the elastic solution method. Numerical results of the problem and conclusion are given.
A method to solve stability problem of nonlinear cylindrical shell under transversal load
Authors: Hong Le Ngoc , Thach Le Ngoc
Published: April 2018

The stability problem of the cylindrical shell was studied by many researches, but most of those shells were circular. The present article considers a method to determine the critical load of noncircular cylindrical shell with the open or close section. The author used the small parameter method to obtain the stability equation of the shell. Analyzing quality of the solution, author determines the critical value of the transversal load for a shell with an elliptic close cross section and for an open shell.
A method for evaluation reliability of system
Authors: Pho Nguyen Van , Chinh Nguyen Xuan
Published: April 2018

In this paper, the authors have presented a method for evaluation reliability of system. The method includes three steps: - Deterministic calculation by finite element method to find inner forces of structure. In which aloes of design parameters and loads are chosen as their expectations. - To find reliability of every element according to statistic data's of design parameters and sternal loads. In which inner forces of structure are external force of element. - To evaluate reliability of system by to determine lower and upper bounds. For illustration, evaluation of reliability of multi-story frame of reinforce concrete is considered.
Elastic-plastic state of a short-circular cylinder subjected to axesymmetrical complex loading
Authors: Bay Vu Khac
Published: April 2018

The modified method of elastic solution in the theory of elastic-plastic deformation processes had been proposed in [1]. Through the numerical solution of some elastic-plastic plane problems, the convergence, the convergence rate and the stability of this iteration method had been considered [3, 4]. In this paper, also through the numerical solution of the elastic-plastic space problem, the characters of this iteration method are considered, and the influence of complex loading processes to elastic-plastic state is confirmed.
Stability of the equilibrium regime of a system of two degrees of freedom in amplitude-phase variables
Authors: Dinh Nguyen Van
Published: April 2018

None
Obtaining equation set for two-phase bubble dynamic description
Authors: Hai Duong Ngoc
Published: April 2018

None
Free convection flow in a vertical thin cylinder of finite height with power law fluids
Authors: Que Nguyen Van
Published: April 2018

None
Numerical solution for the problem on spread of pollution in underground water in Hanoi
Authors: Anh Nguyen Nam , Hien Ha Ngoc , Trung Mai Dinh
Published: April 2018

In this paper a mathematical model for problem of pollution transport in groundwater aquifer in Hanoi is presented. To obtain numerical solution of the problem a method of finite difference was applied. The result for practical case when pollution is contaminated only from hydrogeological windows in product layer has been obtained.
Modelling of turbidity water plume at estuaries
Authors: Ninh Pham Van , Duc Bui Minh , Vinh Phan Ngoc
Published: April 2018

In the paper results of numerical simulation of turbidity water plume based on the Random Walk technics are presented. A software which allows to describe the boundary and distribution of contaminant concentration of a plume with river and contaminant discharge, tide and wind currents and complicated topography of the basin taken into account, has been developed. The carried out numerical model has been verified well by remote sensing images for classification of the turbidity distribution of Red. Han and Me Kong estuaries. Some remarks have been made for using of the numerical model.
Anthropomorphous robot and kinematics model in general form
Authors: Phuc Nguyen Thien
Published: April 2018

In this paper is represented a model of anthropomorphous robot with "the biomechanical pairs". This is the general received various kinds of robot, because from here can be received various kinds of robots as the particular cases. Accordingly, the kinematics model of the robot is also represented in general form. The proposed algorithm for solving inverse problem for the anthromorphous robot with n-degrees of freedom allows to receive analytical forms for the control parameters.
The problem of longitudinal shock of two spherical end elastic bars with visco-elastic resistance force
Authors: An Nguyen Thuc , To Nguyen Dang , Son Nguyen Hung
Published: April 2018

None
Quadratic and cubic non-linearities in a quasi-linear forced system
Authors: Dinh Nguyen Van
Published: April 2018

In [3] the difference between the quadratic non-linearity and the cubic one in a quasi-linear parametrically-excited system has been analyzed. In the present paper, the same question will be examined for a quasi-linear forced system and analogous results as in [3] will be obtained.
Heat transfer of fluid with a moving heat source
Authors: Quang Vu Duy
Published: April 2018

Investigation of free, convection in fluid heated by front combustion synthesis is presented. Characteristic parameter for problem is received. Three stages of development of free convection are distinguished.
A method of technical diagnostics for offshore structures
Authors: Son Do
Published: April 2018

This paper describes the results of measurements and analysis of the parameters, characterizing technical state of offshore platforms in Vietnam Sea. Based on decreasing in time material characteristics because of corrosion and local destruction assessment on residual life time of platforms is given and variants for its repair are recommended. The results allowed to confirm advantage of proposed technical diagnostic method in comparison with others and have been used for oil and gas platform of Joint Venture "Vietsovpetro" in South Vietnam.
On the aerodynamical instability of cylindrical bars based on elastic support with viscous restraint
Authors: Bich Nguyen Dang , Thong Nguyen Vo
Published: April 2018

The aero dynamical instability is a special effect of the self-oscillation phenomenon. The occurrence condition of this effect is the change of the aerodynamic parameters, such as the increase and decrease of the Reynolds coefficients. In this paper the authors present an aerodynamic form, look for an exact solution to the non-linear differential equation with viscous restraint and analyze critical cases leading to the aerodynamic instability. The obtained result gives an idea in exactly solving some non-linear differential equation classes.
Stability and resolution of non-linear dynamic systems containing time delays
Authors: Le Nguyen Nhat
Published: April 2018

None
Dynamical simulation of a vibrating crush machine
Authors: Sanh Do
Published: April 2018

None
Về phương pháp mô phỏng quá trình ngẫu nhiên và dao dộng phi tuyến
Authors: Thinh Tran Ich
Published: April 2018

None
A note on nonlinear systems with different degrees of excitations
Authors: Dao Nguyen Van
Published: April 2018

None
Some solvable non-linear equations related to aerodynamic instability phenomena
Authors: Bich Nguyen Dang , Thong Nguyen Vo
Published: April 2018

This article proposes some forms of aerodynamic forces, looks for accurate solutions of core - pendent non-linear differential equations and analyses the characteristics of aerodynamic forces and of equation's solution. Found solutions proves that aerodynamic forces are formed from two elements: element of non-linear and dispersion, that single solutions are usually found and aerodynamic instability easy occurs.
The sensitivity problem of the structure with response functional is the reliability
Authors: Pho Nguyen Van
Published: April 2018

In this paper, the structural design sensitivity analysis is considered, in which the reliability is response functional. The author sets up the problem, proposes some methods for solving and apply the obtained results to a simple example.
The boundary conditions used for modeling tidal picture in the Gulf of Tonkin
Authors: Quynh Do Ngoc , Ninh Pham Van , Viet Lien Nguyen Thi
Published: April 2018

The two dimensional Saint-Venant equation system is used for tidal calculation in the Gulf of Tonkin with the impermeability given at coastal line and a variation of sea level given at liquid boundaries. It is clear that data at liquid boundaries usually are very rare, while at the coast of the gulf there is a lot of data of tidal harmonic constituents. In the paper the problem how to use these constituents at coast line in modelling for raising up accuracy of the solution is considered.
Investigating dynamics of beating vibration system with one degree of freedom on elastic foundation
Authors: Tuan Tran Van , Sanh Do , Thao Phan Van
Published: April 2018

In this paper an analytical method for studying dynamics of a beating-vibration system on elastic foundation with the aid of computer is presented. The obtained results will be applied to the calculation and optimal design of vibration machines worked by the above represented principle.
Random nonlinear vibration of wagon
Authors: Duc Kieu The
Published: April 2018

In this paper, the random nonlinear vibration of wagon in the model of two degrees of freedom is examined. Two kinds of nonlinear wagon have been considered: wagon with nonlinear spring and wagon with nonlinear damping force. The results are obtained by averaging method and FPK equations one.
Các lực thủy động tác động lên tàu mỏng khi lắc dọc trên nước sâu
Authors: Dat Nguyen Tien
Published: April 2018

None
Generalized diffusion theory of micromorphicly deformable particle-fluid continuum and bubble-liquid two-phase flows
Authors: Diep Nguyen Van
Published: April 2018

In the paper [1] the basic concepts and equations were derived for the micromorphicly deformable particle-fluid two-phase flows, the constitutive equations have been constructed. The flow us fluid with deformable spherical particles, when the particle only expands radially, rotates and translates, is considered in this paper. For this case one can obtain the full motion's equations system. These equation together with the constitutive equations are sufficient to determine all of unknowns, and they can be used to study the bubble- liquid two-phase flow. The problems of kinematic wave and acoustic wave propagation in the bubble-liquid two-phase flow is studied.
Stability of a parametrically - excited system under two excitations
Authors: Dinh Nguyen Van
Published: April 2018

In this paper, the stability of a parametrically - excited system under two excitations of different orders is studied. It is found that these excitations either enforce their actions or eliminate each other. Hence, the unstable region can be either expanded or restricted.
Development of numerical step-by-step method for calculating boundary layers
Authors: Mai Vu Ba
Published: April 2018

In this paper was proposed a development of numerical step-by-step method for calculating boundary layers. As an example showed all the coefficients an0 of initial velocity’s profile had been calculated by experiment.
Solution of discrete oscillating system on personal computer
Authors: Phong Dinh Van
Published: April 2018

The article is devoted an algorithm for deriving mass matrix, stiffness matrix and damping matrix for oscillating discrete system. The algorithm is common setting equation of motion. This technique enables solving different problems of oscillating system, especially a problem of parameters optimization, by numerical methods. Comparison of different methods realized on personal computers was done.
A numerical method for studying Hoof bifurcation of plane Poiseuille flow
Authors: Tran Tran Van
Published: April 2018

The Hoof bifurcation of plane Poiseuille flows is studied numerically. On the base of the rigorous theory worked out by Joseph and Stringer [1], a detailed effective and simple algorithm for numerical determination of the type of the above mentioned bifurcation is proposed. The obtained result shows that the bifurcation at the lower branch of the linear stability neutral curve is supercritical meantime at the upper branch the one is subscritical.
General invariant forms of the anisotropic failure criteria
Authors: Thinh Tran Ich
Published: April 2018

The general invariant forms of failure criteria for anisotropic solids were studied and applied to orthotropic composite materials. when subjected to three-dimensional stress states with rotational symmetry. The Hill criterion and the Tsai and Wu criterion are special cases of these general forms.
On an extension of the stochastic linearization
Authors: Mario Di Paola , Anh Nguyen Dong
Published: April 2018

Stochastic linearization method is one of the most useful tools for analysis of nonlinear systems under random excitation. The fundamental idea of the classical stochastic linearization consists in replacing the original nonlinear equation by a linear one in such a way that the difference between two equations is minimized in the mean square value. In this paper a new version of the stochastic linearization is proposed. It is shown that for two nonlinear systems considered the new version gives good results for both the weak and strong nonlinearities.
Stability of cylindrical shells subjected to axial compression and outside lateral pression
Authors: Dung Dao Van
Published: April 2018

The method for calculating critical forces of cylindrical shells subjected to axial compression and outside lateral press ion has been presented. A numerical comparison based on the theory of least plastic processes, the simple loading process theory and the theory of elasticity for this problem was given.
The motion equation of turbine blade by the finite element method
Authors: Tin Trinh Van
Published: April 2018

In this paper, the finite element method has been applied to deriving the motion equation of turbine blade in coupled bending - bending - torsion vibrations. These equations permit us to develop straightforwardly digital computer programs for studying vibration problems of turbine blades in turbo machinery as well as in other structural dynamic applications.
A new approach to the stability problem of plates subjected to arbitrary complex loading
Authors: Bich Dao Huy
Published: April 2018

The pre-buckling and post-buckling deformation processes are assumed to be less complicated, i.e. processes of average curvature, the influence of complex loading on the stability of plates was analyzed in [1]. In this paper eliminating this restriction, post buckling process may be arbitrary complicated, a generalized expression for determining critical force is formulated by Bubnov-Galiorkin's method and loading parameter method.
Thermal-hydraulic analysis of a research reactor on personal computer with TARR code
Authors: Can Ngo Huy , Lan Nguyen Manh , Tran Tran Van
Published: April 2018

The code has been created for thermal-hydraulic calculation of stationary regime of nuclear research reactor, using personal computer. The main objective of the code is to compute the thermal parameters in the reactor core in order to avoid any accident. The code can be applied for many fuel assemblies available in research reactors.
On the nonlinear parametric resonance of a torsional vibration system with variable generalized masses
Authors: Khang Nguyen Van , Son Tran Dinh
Published: April 2018

In this paper the nonlinear parametric resonance of a torsional vibration system with variable generalized masses is investigated. The small parameter method is applied to a weakly nonlinear system in order to find its solutions. The stability of the resonance vibrations is studied by the method of Schmidt.
Instability of flow with suspended sediment in an inclined channel
Authors: Diep Nguyen Van , Chung Dang Huu
Published: April 2018

In this work the authors had studied the instability and nonlinear evolution of steady flow suspended sediment in inclined channel with fixed and plane bed. With the linear analysis- it has been shown that at the critical inclined angle, an arbitrary disturbance will be splinted in three modes 3F0/2, F0/2, F0, in which F0/2 and F0 propagate downstream and deaden while mode 3F0/2 propagates downstream and its form is unchanged. In particular the waves of sediment concentration always propagate downstream with velocity F0 and unchanged form. The nonlinear analysis has shown that the concentration waves propagate downstream with velocity F and deaden when the time t is large.
Tần số riêng của dây mang khối lượng tập trung
Authors: Dinh Nguyen Van
Published: April 2018

None
Về một bài toán GYROSCOP có trục đối xứng đàn hồi
Authors: Mau Nguyen Thanh
Published: April 2018

None
Bài toán đối lưu nhiệt tự nhiên của chất lỏng quy luật mũ giữa hai hình trụ thẳng đứng
Authors: Quang Vu Duy , Que Nguyen
Published: April 2018

None
Về việc giải phương trình chuyển động và tính lực trong cơ cấu
Authors: Sanh Do , Khoi Phan Bui
Published: April 2018

None
Thermal-hydraulically calculation for the Dalat nuclear research reactor
Authors: Khang Ngo Phu
Published: April 2018

This paper concerns with thermal-hydraulically calculation for the core domain of the Dalat nuclear reactor in the nominal regime of works. On the base of this calculation some conclusions. On thermal safely of the reactor are conducted.
Lower bound on deformation for dynamically loaded rigid-plastic structures
Authors: The Vu Van , Tinh Tran Ba
Published: April 2018

None
theory of generalized diffusion on suspended sediment transport in the flows with mobile bed
Authors: Diep Nguyen Van , Chung Dang Huu
Published: April 2018

In this work the authors have used the theory of generalized diffusion to establish the one and two-dimensional models describing suspended sediment transport in the flows with mobile bed. Here the exchange between suspended sediment and bed-load is taken into account. The set of equations obtained is closed by using the known experiment formulas.
Một số bài toán xác định dạng vỏ tròn xoay không chịu uốn
Authors: Nhu Ngo Huong
Published: April 2018

None
On the propagation of weak nonlinear waves in the alluvial inclined channel when x >> 1
Authors: Diep Nguyen Van , Hung Pham
Published: April 2018

The propagation of weak nonlinear waves in the alluvial inclined channel when x >> 1 (here X = H0/ L0 sin α, H0 is the average depth, L0 is the characteristic length along the flow, α is the inclined angle between the undisturbed bottom and the horizontal direction) is investigated by the multistate method. It shows that arbitrary localized perturbations will be split into three modes. The nonlinear differential equations describing the evolution of those modes are delivered. Their solutions are thus analyzed.
Tự chấn của dây có một bộ tắt chấn động lực
Authors: Dinh Nguyen Van
Published: April 2018

None
Va chạm của vật rắn vào thanh đàn hồi cơ lực ma sát lớn ở mặt bên
Authors: An Nguyen Thuc , To Nguyen Dang
Published: April 2018

None
On the steady of heated micro polar fluid
Authors: Cau Ta Ngoc
Published: April 2018

None
Bài toán lắc của vật thể nổi trên sóng điều hòa
Authors: Hung Hoang Xuan
Published: April 2018

None
Ảnh hưởng của quá trình đặt tải phức tạp trong bài toán ổn định ngoài giới hạn đàn hồi của bản vỏ
Authors: Bich Dao Huy
Published: April 2018

None
Dynamic absorber for self-excited system in the case of limit source of energy
Authors: Dao Nguyen Van
Published: April 2018

None
Influence of heat-mass transfer on wave dynamics of two-phase media
Authors: Hai Duong Ngoc
Published: April 2018

None
On bound for displacement of dynamic apply loader rigid plastic beams II
Authors: The Vu Van
Published: April 2018

None
Tính màng mỏng đàn nhớt trực hướng có xét đến hiện tượng biến dạng rão
Authors: Thinh Nguyen Hoa , Xinhiaev O. V. , Korabenhikov G. IA.
Published: April 2018

None
Some remarks on tile effect of dynamic absorber
Authors: Dao Nguyen Van
Published: April 2018

In order to limit the vibration of mass m2 (fig. 1) while the mass m1 is subject ted to a harmonic force Q0sinωt, the dynamic absorber can be used. In this case the  system considered is of more than two degrees of freedom. The article presented dealer with some linear systems of this kind with various methods of attaching the dynamic absorbers. It seams that advantageous absorbers are those given in figures 2 and 3. Whereas two absorbers acting simultaneously as shown in figs 4, 5, 6 do not give more effectiveness.
Ổn định động của mô hình toa xe
Authors: Giang Le Viet , Pal Michelberger
Published: April 2018

None
A numerical method of solving a heat - mass transfer problem in porous media with moving boundary
Authors: Hai Duong Ngoc
Published: April 2018

In the framework of the methods, of multiphase media mechanics the thermo it hydrodynamic process induce by interaction between high-frequency electromagnet ic field and porous medium (first component) containing the second component, which can melt at the temperature Tm and the fluid phase of the latter can move to pressure gradient, is considered. This problem is solved by the combination of native method with sweep method. The effectiveness of iterative coefficient is ermined.
Tính toán các dạng riêng trong hệ nhiều bậc tự do có các tham số biến đổi
Authors: Khang Nguyen Van , Khiem Vu Van
Published: April 2018

None
Sự ổn định của các thanh đàn nhớt già không đồng nhất
Authors: Tan To Van
Published: April 2018

None
Dynamic load analysis in the cable lifting a sunken ship
Authors: Truong Nguyen
Published: April 2018

None
Đưa hệ phương trình vi phân về dạng tọa độ pháp
Authors: Dao Nguyen Van
Published: April 2018

None
Ổn định của vỏ mỏng chịu tải phức tạp
Authors: Dung Dao Van
Published: April 2018

None
Về một cách ghép bộ tắt chấn động lực cho hệ tự chấn
Authors: Dao Nguyen Van
Published: April 2018

None
Impact of a rigid body against a half-infinite elastic bar
Authors: To Nguyen Dang
Published: April 2018

The solution of the impact - problems of a rigid body against an elastic bar arc before based on the classical longitudinal vibration theory of elastic bar. In this paper, we are using a more precise theory to deal with the impact problem of a rigid body against a half -infinite elastic bar with an elastic gasket. This problem is solved completely.
Về sự phân nhánh của ổn định đối lưu nhiệt của chất lỏng vi cực
Authors: Duy Nguyen Xuan
Published: April 2018

None
On modal analysis of mechanical systems
Authors: Si Nguyen Thac
Published: April 2018

None
Ổn định của vỏ trụ trực hướng đàn nhớt và đàn hồi
Authors: Tan To Van
Published: April 2018

None
Instability of the interface of viscous fluids moving in a channel part I. A linear problem
Authors: Tran Tran Van , Ha Nguyen Trung
Published: April 2018

In this paper the linear problem of hydrodynamic stability of the interface between two viscous fluids, moving in a plane channel is considered. Thomas’s method of finite differences is used for solving this problem. The calculation indicates that the flow with an interface is more unstable than that of homogeneous fluid.
On the motion of heated fluid in a magnetic field
Authors: Cau Ta Ngoc
Published: April 2018

In these papers the steady motion of heated conducted fluid in a magnetic field is considered. The theorem of the existence of solution is proved and the conditions of solution uniqueness are indicated.
On the propagation of waves in the elasto- plastic medium with complex loading
Authors: Thang Duong Tat , Bich Dao Huy
Published: April 2018

In this paper is studied the propagation of  waves in the infinite tridinmensial plastic medium with compels loading, using the theory of elasto - plastic definition processes.
Ổn định của thanh từ vật liệu có tính già và di truyền
Authors: Tan To Van
Published: April 2018

None
THEOREM OF CHANGE IN THE ANGULAR MOMENTUM OF A SYSTEM WITH RESPECT TO A MOVING CENTER
Authors: To Nguyen Dang
Published: April 2018

The Literatures of theorical mechanics only present, the theorem of change in the angular momentum of a system with respect to a fixed center; with respect to the center of mass ... In this paper we developed that theorem With respect to any moving center in relative and absolute motion of system. Having applied this theorem in many special cases of plane motion of a rigid body; we can write directly the differential equation without reactions that describes the rotation of that body so as its integration will be more convenient.
Về nguyên lý cực tiểu và các định lý tổng quát của lý thuyết quá trình biến dạng đàn dẻo
Authors: Bich Dao Huy
Published: April 2018

None
Về trạng thái tới hạn của ổn định đối lưu nhiệt của chất lỏng vi cực
Authors: Huy Nguyen Xuan
Published: April 2018

None
Về sự ổn định của bản mỏng trong lý thuyết quá trình biến dạng đàn-dẻo
Authors: Dung Dao Van
Published: April 2018

None
A new displacement bound technique for rigid plastic continua subjected to strong dynamic loading at large deflections
Authors: The Vu Van , Tinh Tran Ba
Published: April 2018

A new displacement bound technique, which is based on concept of admissible fields has been developed for rigid Plastic continua subjected to strong dynamic loading at large deflections, the lower hound obtained (2.11) depends on kinematic ally admissible displacement  ui and kinematic ally admissible velocity ui* which must be chosen so that the condition (2.14) may be satiafidc. Parameter T* would be determinated by maximizing the right hand side of (2.11).
Sóng xung kích trong hỗn hợp dị thể chất lỏng với chất khí hoặc hơi
Authors: Hai Duong Ngoc
Published: April 2018

None
Large deformation dynamic analysis elastoplastic solids by the finite element method I. total lagrangian formulation.
Authors: Hien Tran Duong
Published: April 2018

An effective finite element formulation based upon the total Lagrangian desert potion is presen ted for nonlinear dynamic problems in deformable solids. Continuum is considered with large displacement, large strain and material elastoplasticity. A modified form of the Wilson ᶿ method for time integral ion of the increment equations of motion is proposed. This formulation is implementer and the results of some sample ana1yses are given.
Bài toán đối xứng trục LAMB trong môi trường đàn hồi phi tuyến có biến dạng ban đầu thuần nhất
Authors: Oanh Pham Thi
Published: April 2018

None
Về sự ổn định của vỏ mỏng trong lý thuyết quá trình biến dạng đàn – dẻo
Authors: Bich Dao Huy , Dung Dao Van
Published: April 2018

None
Sóng cầu trong môi trường đàn hồi phi tuyến với biến dạng ban đầu thuần nhất
Authors: Oanh Pham Thi
Published: April 2018

None
Damping flutter oscillation of suspension bridges
Authors: Tinh Nguyen Van
Published: April 2018

The paper deals with flutter problem of suspension bridges in regard to damping. The formulated expression makes possible to obtain the dependence of critical wind velocity and other structural parameters. Numerical calculation, is given of the Tacoma Narrows Bridge and for some values of parameters.
Độ dày lớp xáo trộn bề mặt và độ ổn định thẳng đứng của nước biển trên thềm lục địa nam Việt Nam
Authors: Lanh Vo Van , Sam Tran Van , Dung Nguyen Tien , Bien Nguyen The , Hoa Nguyen Kim
Published: April 2018

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Ổn định của thanh trong điều kiện từ biến
Authors: Tan To Van
Published: April 2018

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Phương pháp trung bình hóa của N.N.BÔ-GÔ-LIU-BÔP trong các bài toán cơ học phi tuyến
Authors: Mi-trô-pôn-xki A.
Published: April 2018

None
Rigid plastic plates at large deformations
Authors: The Vu Van
Published: April 2018

By being statically loaded plastic plates can support loads exceeding the bending collapse pressure, the behaviour of perfectly rigid plastic plates beyond the yield load depends on changes in geometry to the plastic flow. Therefore in post yield behaviour the deflection can not be considered small in comparison with the plate thickness. In this paper we employ the equations of plates at moderately large deflections and the approximate live behaviour of plates introduced in/2,3/ by dividing plates into a number of rigid regions which have been separated by line hinges situated at locations where their discontinue ties in w,i occur, an estimative method of the toad - deflection relationship of arbitrarily shaped plates having arbitrarily boundary conditions is developed. This method is directly extended to anisotropic and reinforced concrete plates.
Hệ phương trình biến phân theo biên độ pha ở hệ dao động á tuyến nhiều bậc tự do
Authors: Dinh Nguyen Van
Published: April 2018

None
Về một phương pháp xác định các đặc tính hình – động học ăn khớp
Authors: Phuc Nguyen Thien
Published: April 2018

None
On the covergence of an iteration method for solving the boundary value problem in tile theory of elasto - platic deformation processes
Authors: Bich Dao Huy , Hop Nguyen Cong
Published: April 2018

In this paper is proposed an iteration method, as the Iliousin' s method for solving the boundary value problem in the theory of elasto - plastic deformation processes. The convergence of this method, i. e. the existence and uniqueness of  solution of the boundary value problem are also considered.
Rigid plastic plates at large deformations
Authors: The Vu Van
Published: April 2018

The method developed in [8] is applied herein in order to obtain estimations of the load-deflection relationship of the hinge supported rectangular plates acted on by a uniformly distributed loading. The plate is made from rigid perfectly plastic material which yields according to the square yield condition and maximum normal yield condition. the plastic hinge line patterns shown  in figs. 1. 2. are chosen. The obtained results are presented in figs. 4, 5, 6, 8.
Một quan điểm mới đối với việc thành lập phương trình chuyển động của các hệ cơ học
Authors: Sanh Do
Published: April 2018

None
Optimal design of mast supported on prestressed anchorties
Authors: Loc Dang Dinh
Published: April 2018

In this paper, the author uses the method of mathematical programming for the optimal design of a mast with prestressed anchorties. The objective function is the minimun cost or material volume of the whole post and ties. The restrictions are mechanical and technical requirements such as the conditions of strength and stability, the deflections of anchored knots. By applying the design method for a direct problem, the author has found out the efficient prestress in the ties, without any previous suppositions of theses their volume, as commonly resolved This optimal design would save 12% of the mast weight in comparison with other design.
Bài toán tối ưu hóa kết cấu dầm chịu uốn trong trạng thái đàn dẻo
Authors: Son Do
Published: April 2018

None
On the theorem with uniqueness of solution in dynamics problem according to the theory of small elastoplastic deformations
Authors: Bich Nguyen Dang
Published: April 2018

In dynamics, the uniqueness of solutions was presented for elastic problem [1] and for rigid plastic problem based on the theory of plastic flow [2]. In this paper the theorem with uniqueness of solution in the dynamics problem according to the theory of small elastoplastic deformations is presented for a class of bodies subjected to time - dependent surface tractions with two impotant assumptions so that the theory of small elastoplastic deformations may be used. First, displacement will be assumed sufficiently small, that the original geomeuy may be used in writing the equilibrium equations. Second, external loads from the moment of their application increase proportionaly to the single parameter.
Generalized - diffusive theory of solid mixtures. III. Anisotropy and wave propagation in compozite material
Authors: Chanh Truong Minh
Published: April 2018

In this paper the linear elastic constitutive equations for anisotropic compozite mate rial are obtained. The wave propagation in this material is discussed.
Cấu trúc toán học của các vật thể đàn hồi. III. Các trạng thái riêng của các vật thể đẳng hướng ngang
Authors: J Rychlewski
Published: April 2018

None
Xác định độ tin cậy của các chi tiết máy có nhiều mặt cắt yếu
Authors: Khoi Phan Van
Published: April 2018

None
Sự truyền sóng mặt “rơ lây” trên mặt trụ của môi trường đàn hồi có biến dạng ban đầu
Authors: Oanh Pham Thi
Published: April 2018

None
Cấu trúc toán học của các vật thể đàn hồi. IV. Lý thuyết dẻo và các mở rộng khác
Authors: J Rychlewski
Published: April 2018

None
Nonstationary flow of roiling liquid
Authors: Hai Duong Ngoc
Published: April 2018

Steady one-dimensional nonstationary flow of boiling liquid from finite or infinit pipe in a consideration of the effect of the phase-boundary heat and mass transfer. The Received system of quasi-linear differential equations has been decided by the modificati on of Lax - wendroff method in IBM. Numerical results are compared as xperimental data.
Va chạm dọc của 2 thanh đàn hồi
Authors: An Nguyen Thuc , Nguyen Vu Van
Published: April 2018

None
Mở rộng định lý Levi – Sivita cho các phương trình chính tắc Poangcare - Tretaev
Authors: Huyen Pham
Published: April 2018

None
Tính toán động lực học hàm đo hai tiếp điểm ba bậc tự do
Authors: Khang Nguyen Van , Tho Ho Dac , Sanh Do , Hung Do Trong , Tho Banh Xuan
Published: April 2018

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Tính không gian kết cấu mỏng có gờ bằng phương pháp phần tử hữu hạn
Authors: Lang Vu Manh
Published: April 2018

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Tính cọc mềm chịu tác dụng của tổ hợp tải trọng, đông trong nền nhiều lớp bằng phương pháp ma trận chuyển tiếp
Authors: Dung Phan
Published: April 2018

None
Parametric oscillation of the prismatic beam with heredity of material
Authors: Da Hoang Van
Published: April 2018

In this work the method set up the equation of motion of the prismatic beam under parametric excitation with regard to the heredity of material. The solution of this problem were constructed by means of average and asymptotic method. It is shown that heredity of material exerts its it influence on the amplitude of the oscillation as does viscous friction for a system with soft characteristics.
Về phương trình dao động của vỏ mỏng
Authors: Hung Nguyen Xuan
Published: April 2018

None
Về vấn đề giải phương trình Fokker –planck – Kolmogorov cho hệ cơ học không otonom một bậc tự do bằng phương pháp khai triển theo tọa độ ẩn suy rộng
Authors: Anh Nguyen Dong
Published: April 2018

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Stability of a rotor excited by parameter and bedded on two radial bearings.
Authors: Hai Nguyen
Published: April 2018

The paper deals with the question of stability of a rotor bedded on two radial bearings, where the effect of the oil film has been taken into consideration.
Generalized-diffusive theory of solid mixtures. 1. Homogeneous thermo – elastic mixture
Authors: Chanh Trương Minh
Published: April 2018

None
Về một phương pháp xây dựng hàm Liapunov
Authors: Phu Nguyen Dinh
Published: April 2018

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Hệ tự chấn hai bậc tự do chịu kích động giới nội
Authors: Dinh Nguyen Van
Published: April 2018

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Finite element analysis of beams on no- tension foundation
Authors: Le Nguyen Van
Published: April 2018

In this paper a finite element analysis of beams on no-tension foundation is presented. To establish the algorithm the Winder's model of the foundation is used it is assumed that the total stiffness of the structure consists of the stiffness of the beam and the stiffness of the foundation. The no-tension property of the foundation is taken in-to account by eliminating the stiffness of the foundation at the place where the tensional reaction occurred. Some numerical examples are illustrated to point out the effect of the separation of the beam from the foundation to the internal forces or the beam.
Sự va chạm của vật rắn vào thanh đàn hồi tiết diện thay đổi
Authors: An Nguyen Thuc , Nguyen Vu Van
Published: April 2018

None
Về một nghiệm không dừng của phương trình Fokker – Planck – Kolmogorov đối với hệ động lực tuyến tính một bậc tự do
Authors: Anh Nguyen Dong
Published: April 2018

None
Truyền sóng đàn hồi trong vật liệu nén được phân lớp tuần hoàn có biến dạng trước thuần nhất
Authors: Khanh Le Minh
Published: April 2018

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Method of calculating the vertical velocity forced by the friction
Authors: Quang Le Dinh
Published: April 2018

Using the method of parametrization of boundary layer we elaborate method of calculating the vertical velocity forced by the friction.
Hiện tượng ổn định quan liên trong hệ á tuyến hai bậc tự do có kích động cưỡng bức
Authors: Dinh Nguyen Van
Published: April 2018

None
Ảnh hưởng của tham số dạng xung và độ chậm lên chế độ dao động của hệ
Authors: Lan Nguyen Khac
Published: April 2018

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Torsional vibration of suspension bridge with a variable cross section
Authors: Tinh Nguyen Van
Published: April 2018

The transfer matrix method to torsion’ al vibrations of a suspension bridge with variable cross sections is reported. The method described above is particularly suitable for implementing an efficient computer program. A numerical example is also givens.
Hiện tượng ổn định quan liên trong hệ á tuyến nhiều bậc tự do
Authors: Dinh Nguyen Van
Published: April 2018

None
On the comparison of the Gaussian heuristic with the statistical linearization methods in random vibrations
Authors: Menh Nguyen Cao
Published: April 2018

In this paper the cumulate description of random processes is used for obtaining general formulae of the Gaussian heuristic method in single-degree-of-freedom and multi-degree-of-freedom systems. These formulae can be easily applied to particular cases. Whereby he Gaussian heuristic method and the statistical linearization method are compared. It can be shown, that if the solution process and the excited process are assumed to be jointly Gaussian, then these two methods are equivalent. Besides, on the basis of the Gaussian heuristic method, the statistical linearization coefficients are presented by more simple expressions than that in the papers [1,7].
Dao động ngẫu nhiên trong hệ cấp ba dưới kích động ngẫu nhiên ồn trắng
Authors: Duc Kieu The , Anh Nguyen Dong
Published: April 2018

None
Influence of air and sea baroclinic effects on the structure of the boundary layers
Authors: Ly Le Ngoc
Published: April 2018

The influence of Air and Sea baroclinic effects on the boundary structure is studied by various numerical experiments for different baroclinic parametres Γxi, Γyi. The resulte obtained in calculation show that the baroclinic effects have strong influence on the structure of both boundary layers, especially on the profiles or Air and Sea turbulence coefficients.
Numerical simulation on morphological process for Thuan An coastal area
Authors: Chung Dang Huu
Published: April 2018

The 2DH model is developed and applied to evaluate sediment transport and bed level change in the coastal zone in central Vietnam. The model took the influences of waves and wind into account. Three different options for the flows with or without wind and two wave regimes are calculated. The computed results for flows are calibrated on the base of data measured in Thuan An station in April 1999. The final results from sediment transport model showed that the near shore area from Thuan An to Tu Hien are strongly affected by sediment transport process and the natural flow could change the morphological bed for very long time.
Stability analysis of steel frames with semi-rigid connections and rigid zones by using P-Delta effect
Authors: Anh Vu Quoc
Published: April 2018

Comparing with reinforced concrete structure, member rigidity of steel structure is less, and displacement of steel structure is larger than that of reinforced concrete structure, so the secondary moment due to axial force has to be considered, i e., the problem of P-Delta effect. For most building structures, especially tall steel buildings, the P-Delta effect of most concern occurs in the columns due to gravity load, including dead and live load. The column axial forces are compressive, making the structure more flexible against lateral loads. If compressive P-forces are present and are large enough, the structure may buckle. Local buckling of individual members or global buckling of the whole structure is possible. This paper presents the method to analysis stability of steel frames with semi-rigid connections and rigid zones by using P-Delta effect.
A reduced form of shakedown kinematic theorem
Authors: Chinh Pham Duc
Published: April 2018

A reduced form of the shakedown kinematic theorem without time integrals is deduced for Tresca material, which is equivalent to the original one when the principal directions of plastic deformations everywhere in a structure remain unchanged during loading cycles.
Numerical study of the recirculation zone behind a building in the neutral and stable atmospheric boundary layer
Authors: Hai Duong Ngoc , Duc Nguyen The
Published: April 2018

The objective of the paper is to study numerically, using k - Ɛ model, the circulation zone behind a building under neutral and stable conditions. The influences of wind speed, vertical gradient of the temperature, surface roughness and building height on the length and structure of the recirculation zone are investigated. The research result showed that the recirculation area extends from immediately behind the building to a distance of about 2.5 times, in maximum, of the dimension of the building. The recirculation zone's 1length increases with the increase of wind speed, decreases with the increase of vertical gradient of the temperature, decreases with the increase of roughness and increases with the increase of building height. Some exceptions of two last tendencies may occur for the cases of high surface roughness or high building, when the flow shift from a simple one-vortex to a complex multiple-vortex structure.