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Purpose: The aim of this study is to explore the factors affect to auditor independence, and impacts auditor independence to audit quality of Supreme Audit Institution (SAI). Theoretical framework: This study explores factors affecting the auditor independence in public sector based on articles pertaining to public sector audits that were published in major publications in the 20th century. The theories were applied in order to build up research model about factors influencing the auditor independence and affects to SAI’s audit quality. Design/methodology/approach: Research using complex techniques to analyze complex relationships in the SEM model. This result tests research model in Vietnam from the perspective of the state auditors’ perception with 225 valid responses. Findings: The result found out three primary factors that affect the independence of public-sector auditors: political hegemony, auditor tenure and relationships with auditees. These factors have negative impact on state auditor’s independence, meanwhile auditor independence has a positive impact on SAI’s audit quality. Research, Practical & Social implications: The study contributes to existing literature by providing empirical evidence for there is no suitable audit quality measurement framework for SAIs. Originality/value: The results highlight strong importance of the auditor independence so that SAI Vietnam can have effective solutions to protect independence of state auditor from threats and improve the audit quality of SAI.

Background: Cardiovascular Center has implemented interventional cardiology techniques since 2009 including coronary stenting, congenital heart intervention and pacemaker placement. Percutaneous coronary intervention is currently an effective treatment method for coronary artery disease. Congenital heart diseases by Amplatzer device is an effective method of treatment of congenital heart diseases. Permanent pacemaker implantation is currently the most effective modern treatment for dangerous bradyarrhythmias. Methods: All cases of coronary artery stenosis with indications for intervention, congenital heart disease including atrial septal defect, ventricular septal defect, and ductus arteriosus with the indication for intervention by percutaneous occlusion, bradyarrhythmias have indications for pacemaker placement were included in the study. Methods of book research, retrospective. Results: 1) The rate of emergency coronary intervention 26.7%. The success rate of the procedure is 95.0%. The complication rate of coronary intervention in highrisk patients was 9.4%. 2) There were 254 (68.8%) cases of VVI(R) single-chamber pacemaker and 115 (31.2%) cases of dual-chamber pacing. The complication rate was 4.6%. The success rate of the procedure is 98.7%. 3) The results of the percutaneous septal defect occlusion procedure achieved a complete success of 93.33%, ductal occlusion achieved a complete success of 100%, and ventricular septal defect occlusion with the Amplatzer instrument achieved 100% success. 100% successful results after 3 months of follow-up. Complications in patients after occlusion of atrial septal defect with Amplatzer device were 6.67%, and no complications in the group with ductus arteriosus and ventricular septal defect were noted. Conclusion: Interventional coronary stenting, pacemaker placement, and congenital heart disease interventions are safe and effective methods with high success rates. Key words: Cardiovascular intervention, deployment

Porosities exist as pores of different sizes within a structure to fabricate lightweight materials and the sintering process. The porous structure gives a lower loading capacity than the perfect design. Crack propagation is also a complicated behavior in this structure. The hybrid phase-field approach is suitable to provide an effective computational tool to model the crack propagation of functionally graded materials with porosity effects. We show the influence of porosity on both the critical force and crack path of the FGM structure. In the framework of isogeometric analysis (IGA), a local refinement multi-patch algorithm based on the Virtual Uncommon-Knot-Inserted Master-Slave (VUKIMS) technique allows us to reduce the computational cost of the phase-field model significantly. The study revealed that cubic NURBS elements with the effective element size of half length-scale parameter could be used to achieve the desired accuracy while maintaining a reasonable computational cost.

This paper aims to develop a nonlocal strain gradient meshfree plate approach which combines the nonlocal strain gradient theory (NSGT), higher order shear deformation theory (HSDT) and meshfree method, for the bending and free vibration analyses of laminated composite and sandwich nanoplates. Mechanical characteristics of small-scale structures can be described by using two scale parameters related to the nonlocal and strain gradient effects. The weak form of governing equations is extracted from the virtual work principle. Exploiting the higher order derivatives of moving Kriging (MK) shape functions, the present approach satisfies the requirement of the third-order derivatives of weak approximations. The displacements and natural frequencies of laminated composite and sandwich nanoplates are then determined by utilizing the MK meshfree method. Numerical results show that the deflections and natural frequencies of laminated composite and sandwich nanoplates are significantly influenced by the boundary conditions, nonlocal parameter and strain gradient parameter, geometry, length-to-thickness ratios. As observed, a large difference between NSGT and classical HSDT results is reported and discussed. It is clear that the results of both models coincide when the nonlocal and strain gradient parameters are taken as zero.

We investigate the nonlinear bending behavior of nanoporous metal foam plates within the framework of isogeometric analysis (IGA) and higher-order plate theory. The nonlocal strain gradient theory (NSGT) taking into account the length scale and nonlocal parameters has been adopted to establish a scale dependent model of metal foam nanoscale plates. Von Karman nonlinear strains are then used to take up the geometric nonlinearity. Different pore dispersions, namely uniform, symmetric and asymmetric, are confirmed. By using the principle of virtual work, nonlinear governing equations are derived and then solved by using an isogeometric analysis and iterative Newton-Raphson method. Influences of the length scale parameter, porosity distributions, nonlocal parameter and nanoporous coefficient on the nonlinear deflection of the plate are numerically experimented in detail. Some findings would play an important role for designing metal foam structures.

We propose a size-dependent moving Kriging meshfree approach for bending, free vibration and buckling analyses of functionally graded (FG) microplates using the refined plate theory (RPT) and modified strain gradient theory (MSGT). The RPT retains only four variables and reduces one variable when comparing to the original higher order shear deformation theory. For microstructures, three length-scale parameters (LSPs) related to size effects are enhanced in the classical RPT. Material properties of FG microplates are calculated by a rule of mixture. The virtual work principle is used to form the weak forms, and the displacements, natural frequencies and buckling loads of FG microplates are then determined using moving Kriging meshfree method. Numerical validations are shown to evaluate effects of geometrical parameters, boundary conditions, volume fraction and LSPs on displacements, natural frequencies and buckling loads of FG microplates. As observed results, an increase and decrease of natural frequencies, buckling loads and displacements of FG microplates are respectively confirmed. In addition, the modified couple stress model or classical RPT model is recovered when a few LSPs are negligible.

Numerical methods studied the functionally graded piezoelectric porous (FGPP) microplates are still somewhat restricted. In this study, a size-dependent approach in the framework of isogeometric analysis (IGA) via the modified strain gradient theory (MSGT) and the higher-order shear deformation theory (HSDT) for electro-mechanical vibration analysis of FGPPo microplates is presented for the first time. A FGPP microplate is created from a mixture of two materials which their properties vary continuously through the thickness plate obeying a modified power-law expression. Two porosity distribution types including even and uneven are considered. An electric potential field which satisfies the Maxwell’s equation in the quasi-static approximation is adopted. To study size effects, MSGT is proposed with the addition of three material length scale parameters (MLSPs) into the elastic constants. It is general due to when two or three MLSPs are set equal to zeros, MSGT can be recovered into the modified couple stress theory model (MCST) or classical higher-order shear deformation theory, respectively. Governing equations deduced from the weak form of FGPP microplates are obtained by utilizing the principle of virtual work, subsequently, natural frequencies of FGPP microplates are determined by IGA. The influence of external electric voltages, power-law index, porosity coefficient, porosity distribution, various boundary conditions, and material length scale parameters on the natural frequencies of FGPP microplates is investigated. To demonstrate the reliability and effectiveness of the proposed method, the present results are compared with various available publications in the literature. Moreover, although there are no analytical solutions, we strongly furthermore present answers of some FGPP microplates being considered as reference results for upcoming studies.

1. 使用基于振动的损伤检测方法进行结构健康监测. 2. 基于材料力学性能评价提出一种新的结构健康监测方法. 1. 通过一个被称为损失函数 (LF) 的新指标描述材料粘弹性参数与振动参数之间的相关性. 2. 使用卷积神经网络 (CNN) 提取自动特征和损坏敏感性, 以评估结构状况. 1. 测量真实桥梁的振动响应. 2. 在频域中进行信号处理以揭示振动能量损失. 3. 基于深度学习和 CNN 对桥梁状况进行分类. 1. 在真实结构中总是会发生能量扩散. 2. 基于振动能量损失变化的 LF 评估, 可以对桥梁进行健康监测. 3. 基于深度学习的能量扩散评估是可实现的, 并且在多个实际桥梁中具有较高的可实施性.

In this paper, a size dependent numerical model for free vibration and bending analyses of hexagonal beryllium crystal (HBC) nanoplates is presented. Based on the nonlocal strain gradient theory (NSGT), both nonlocal and strain gradient effects are considered in the present model. In addition, the behavior of HBC material can be considered as an anisotropic one. By employing principle of virtual displacement (PVD), the governing equations of motion for a Galerkin weak for the higher-order shear deformation theory (HSDT) are deduced. Thereafter, the natural frequency and deflection of the HBC nanoplates are determined by solving those governing equations using an isogeometric analysis (IGA). Numerical results show that bending and vibration behaviors of the anisotropic nanoplates are affected by the geometry, boundary conditions, length-to-thickness ratios, exponential factor, nonlocal parameter and strain gradient parameter. On the other hand, when the material length scale parameter is smaller than or equal to the nonlocal parameter then the natural frequency predicted by nonlocal strain gradient theory is lower than that evaluated by classical continuum theory. Conversely, obtained results are higher than the referenced ones by classical continuum theory when the material length scale parameter is larger than or equal to the nonlocal parameter. Whilst, a contrary case occurs for the displacements. Furthermore, by respectively ignoring the strain gradient and nonlocal parameters, the pure nonlocal and strain gradient models can be recovered from the present model.

The purpose of this study is to present a quasi-three-dimensional (quasi-3D) shear deformation theory for static bending and free vibration analyses of porous sandwich functionally graded (FG) plates with graphene nanoplatelets (GPLs) reinforcement. In addition, we propose a novel sandwich plate model with various outstanding features in terms of structural performance. The quasi-3D theory-based isogeometric analysis (IGA) in conjunction with refined plate theory (RPT) is first exploited to capture adequately the thickness stretching effect for porous sandwich FG plate structures reinforced with GPLs. The Non-Uniform Rational B-Splines (NURBS)-based IGA is employed in order to describe exactly the geometry models as well as approximate the unknown field with higher-order derivatives and continuity requirements while the RPT model includes only four essential variables. The sandwich FG plates consist of a core layer containing internal pores reinforced by GPLs and two functionally graded materials (FGMs) skin layers. Effective mechanical properties can be evaluated by employing the Halpin-Tsai model along with the rule of mixture. Various combinations of two porosity distributions and three GPL dispersions in the core layer are thoroughly investigated. Several numerical investigations are conducted to examine the effects of several key parameters on the static bending and free vibration behaviors of sandwich FG plate structures.