Using real interpolation method for adaptive identification of nonlinear inverted pendulum system

In this paper, we investigate the inverted pendulum system by using real interpolation method (RIM) algorithm. In the first stage, the mathematical model of the inverted pendulum system and the RIM algorithm are presented. After that, the identification of the inverted pendulum system by using the RIM algorithm is proposed. Finally, the comparison of the linear analytical model, RIM model, and nonlinear model is carried out. From the results, it is found that the inverted pendulum system by using RIM algorithm has simplicity, low computer source requirement, high accuracy and adaptiveness in the advantages

Self-Centering Prestressed Concrete Pier Considering the Effect of Vertical Earthquake Motions with External Aluminum Dissipators

A prototype self-centering prestressed concrete (SCPC) bridge pier and conventional reinforced concrete (RC) pier with similar backbone curves are designed and modeled. The objective of this study is to investigate the seismic performance of the SCPC bridge pier considering the effect of vertical earthquake ground motions. Under a severe vertical earthquake motion, the RC pier damage is much greater than the SCPC pier. The SCPC bridge pier shows a great capability in reducing residual drift at the top of the structure, therefore, the probability of bridge survival is increased. In this study, the external aluminum bars were used to reduce the seismic energy impacts on the bridge pier structure. In addition, The averages of the maximum and residual drifts of bridge piers under a set of 20 earthquake ground motion records impact with different vertical-to-horizontal peak acceleration ratios on the bridge seismic response are presented. The results are compared with the case of horizontal-only excitations, to clarify the effect of the vertical earthquake on the SCPC and RC bridge pier. Hence, the designers can find good solutions for structures in earthquakes resistance

La eficiencia de aplicar muestreo comprimido y resolución múltiple en tomografía por ultrasonido

Introduction: This publication is the product of  research developed within the research lines of the Smart Sensing, Signal Processing, and Applications (3SPA)  research  group  throughout  2018,  which  supports  the  work  of  a  doctor’s degree at VNU University of Engineering & Technology, Vietnam. Problem: The limitations of diagnostic ultrasound techniques using echo information has motivated the study of new imaging models in order to create additional quantitative ultrasound information in multi-model imaging devices. A promising solution is to use image sound contrast because it is capable of detecting changes in diseased tissue structures. Ultrasound tomography shows speed-of-sound changes in the propagation medium of sound waves. This technique is primarily used for imaging cancer-causing cells in womens’ breasts. The Distorted Born Iterative Method (DBIM), based on the first-order Born approximation, is an efficient diffraction tomography approach. The compressed sensing technique is utilized for DBIM to obtain the high-quality ultrasound image, although the image reconstruction process is quite long. Objective: The objective of the research is to propose an combined method for the efficient ultrasound tomography. Methodology: In this paper, we proposed an approach to enhance the imaging quality and to reduce the imaging time by applying the compressed sensing technique along with the multi-resolution technique for the DBIM. Results: The simulation results indicate that the imaging time is reduced by 33% and the imaging quality is improved by 83%. Conclusion: This project seeks to propose an improvement in ultrasound tomography. The simulated results confirmed the realibility of the propsed method. Originality: Through this research, a combined method of compressed sensing and multiple resolution are formulated for the first time in ultrasound tomography. Limitations: The lack of experiments to confirm the proposed method.Introducción: esta publicación es el producto de la investigación desarrollada dentro de las líneas del grupode investigación Detección Inteligente, Procesamiento de Señales y Aplicaciones (3SPA, Smart Sensing, Signal Processing, and Applications) a lo largo de 2018, que respalda el trabajo de un doctorado en la Universidad deIngeniería y Tecnología de VNU, Vietnam. Problema: las limitaciones de las técnicas de diagnóstico por ultrasonido que utilizan información de eco han motivado el estudio de nuevos modelos de imágenes para crear información cuantitativa adicional de ultrasonidos en dispositivos de imágenes de modelos múltiples. Una solución prometedora es utilizar el contraste de sonido de la imagen porque es capaz de detectar cambios en las estructuras de los tejidos enfermos. La tomografía por ultrasonido muestra los cambios en la velocidad del sonido en el medio de propagación de las ondas sonoras. Esta técnica se usa principalmente para obtener imágenes de células que causan cáncer en los senos de las mujeres.  Objetivo: el objetivo de la investigación es proponer un método combinado para la tomografía de ultrasonido eficiente. Metodología: en este documento se propuso un enfoque para mejorar la calidad de la imagen y reducir el tiempo diante la aplicación de la técnica de detección comprimida junto con la técnica de resolución múltiplepara el DBIM. Resultados: los resultados de la simulación indican que el tiempo de imagen se reduce en un 33 % y la calidad de imagen se mejora en un 83 %. Conclusión: este proyecto busca proponer una mejora en la tomografía por ultrasonido. Los resultados simulados confirmaron la viabilidad del método sugerido. Originalidad: a través de esta investigación, se formula por primera vez un método combinado de detección comprimida y resolución múltiple en la tomografía por ultrasonido. Limitaciones: la falta de experimentos para confirmar el método propuesto

Mechanical response of outer frames in tuning fork gyroscope model with connecting diamond-shaped frame

In tuning fork micro-gyroscopes, two outer frames are connected by using the linking elements. The driving vibrations of the two outer frames are required to be exactly opposite to generate the opposite sensing modes perpendicular to driving direction. These opposite driving vibrations are provided by a mechanical structure named the diamond-shaped frame. This paper presents mechanical responses of two outer frames in a proposed model of tuning fork gyroscope when an external force with different types is applied to them. The results show that the presence of a diamond-shaped frame guarantees the absolute anti-phase mode for the driving vibrations of outer frames

Increasing the Level of Agreement of Taxpayers on Tax Audit Conclusions-Recommendations to Vietnamese Tax Authorities

A person’s agreement on a decision usually attaches to their own benefits. However, in most situations, a single decision will impact on different people with different benefits, therefore, a person’s judgment regarding fairness will decide their agreement. Basing on the fact that tax audit conclusions usually impact on economic benefits of taxpayers and a theory of “awareness of fairness”, we would like to apply the quantitative method to identify and verify different drivers of taxpayer’s agreement on tax audit conclusions by assessing reliability and suitability of different scales; verifying research model and research hypothesis, and determining drivers’ impact through questionnaires given to 256 firms. As a result, we propose recommendations to Vietnamese tax authorities in terms of restructuring procedures, completing auditing method and enhancing tax supervising activities in order to increase the level of agreement of taxpayers on tax audit conclusions, improving Vietnamese tax audit effectiveness. Keywords: Tax audit, taxpayers’ agreement, tax audit conclusions, drivers

Eruptive-volcanic-basalt structures in the Truong Sa-Spratly Islands and adjacent areas from interpreting gravity and magnetic data

In the Spratly Islands (Truong Sa Islands) and adjacent areas, volcanic activities are quite strong after the sea-floor spreading in the Cenozoic Era. However, it is difficult to define their ranges and spatial locations. Based on the different characteristic between eruptive volcanic basalt and sedimentary rocks near the surface, it can be said that, the blocks which are higher density and magnetization than those surroundings could be identified as eruptive volcanic basalt. This paper presents the methods of reduction to the magnetic equator in low latitudes to bring out a better correlation between magnetic anomalies and their causing-sources; High-frequency filtering is to separate gravity and magnetic anomalies as well as information about the volcanic basalts in the upper part of the Earth's crust; 3D total gradient is to define the spatial location of high density and magnetic bodies. The potential structures of eruptive volcanic basalt are predictively determined by multi-dimensional correlation analysis between high-frequency gravity and magnetic anomalies with weighted total gradient 3D. The results from the above-mentioned methods have shown that the distribution of the eruptive volcanic basalt mainly concentrates along the Spratly Island’s seafloor-spreading axis, transitional crust, Manila trench and some large fault zones. These results are improved by available  seismic data in the study area.References Baranov, V., 1957. A new method for interpretation of aeromagnetic maps: Pseudo-gravimetric anomalies: Geophysics, 22, 359-383. Bhattacharyya, B. K., 1966. Continuous spectrum of the total magnetic field anomaly due to a rectangular prismatic body. Geophysics, 31, 197-212. Bracewell, R., 1999. The Fourier transform and its applications (3nd edition): McGraw-Hill. 496p. Bui Cong Que, Tran Tuan Dung, 2008. Study of crustal structure and Geodynamics in the East Vietnam Sea and adjacent areas. Vietnam Journal of Earth Sciences, 30(4), 481-490. Dang Van Bat, Do Dinh Tat, Mai Thanh Tan, 1994. Characteristics of  lithology and fossils of the Oligocene eruption.  Vietnam Journal of Earth Sciences, 16(2), 59- 66. Hanoi. Flower M.F.J., Zhang M., Chen C-Y., Tu K., Xie G., 1992. Magmatism in the South China Basin, 2. Post-spreading Quaternary basalts from Hainan Island, south China. Chem. Geol., 97, 65-87. Ian N. MacLeod, Keith Jones, Ting Fan Dai, 1993. 3-D Analytic Signal in the Interpretation of Total Magnetic Field Data at Low Magnetic Latitudes. Exploration Geophysics, 24, 679-688. Karoly I. K, 1990. Transfer properties of the reduction of magnetic anomalies to the pole and to the equator. Geophysics. 55(9), 1141-1147. Le Huy Minh, Luu Viet Hung, Vo Thanh Son, 2003. Reduction to the pole at low latitude and interpretation of the magnetic anomaly map of Vietnam. Vietnam Journal of Earth Sciences, 24(2), 164-174. Lee T-Y., Lo C-H., Chung S-L., Chen C-Y., Wang P-L., Lin W-P., Hoang N., Cung T.C., Nguyen T.Y., 1998. 40Ar/39Ar dating result of Neogene basalts in Vietnam and its tectonic implication. In: M.F.J. Flower et al (Eds.). Mantle Dynamics and Plate Interactions in East Asia. Geodynamics Ser., 27, 317-330. Amer. Geol. Union. Leu, L.-K., 1981. Use of reduction-to-equator process for magnetic data interpretation: Presented at the 51st Ann. Internat. Mtg., Sot. Exnl. Geonhv.: Geophysics, 47. Li S-L., Meng X-H., Guo L-H., Yao C-L., Chen Z-X., Li H-Q., 2011. Gravity and magnetic anomalies field characteristics of the East Vietnam Sea and its application for interpretation of igneous rocks, Applied geophysics, 7(4), 295-305. Li Y., D. W. Oldenburg, 2001. Stable reduction to the pole at the magnetic equator, Geophysics, 66, 571-578. MacLeod, I.N., K. Jones and T.F. Dai, 1993. 3-D analytic signal in the interpretation of total magnetic field data at low magnetic latitudes. Exploration Geophysics, 24(4), 679-688. McElhinny, M.W., 1973. Palaeomagnetism and Plate Tectonics, Cambridge, London, 356pp. Chapter 1 presents an introduction to the geomagnetic field. Nabighian MN, 1984. Toward a three-dimensional automatic interpretation of potential field data via generalized Hilbert transforms: Fundamental relations. Geophysics, 49, 780-786. Nguyen Hoang, Phan Trong Trinh, 2009. Characteristics of lithological and geochemical of Neogene - Quaternary volcanic rocks and mantle dynamics in the East Vietnam Sea and adjacent. Journal of Geology, 312. Pham Tich Xuan, Nguyen Trong Yem, 1999. Volcanic activities in late Cenozoic in Vietnam. Vietnam Journal of Earth Sciences, 12(2), 128-135. Phillips, J. D., 1997. Potential-Field Geophysical Software for the PC, version 2.2: USGS open-File Report , 97-725. Roest, W.R., J. Verhoef and M. Pilkington, 1992. Magnetic interpretation using the 3-D analytic signal: Geophysics, 57(1), 116-125. Sandwell, D. T., Garcia E., Soofi K., Wessel P., and Smith W. H. F, 2013. Towards 1 mGal Global Marine Gravity from CryoSat-­2, Envisat, and Jason-1, The Leading Edge, 32(8), 892-899. doi: 10.1190/tle32080892.1. Spector A and Grant FS, 1970. Statistical models for interpreting Aeromagnetic data. Geophys, 35(2), 293-302. Sudhir Jain, 1988. Total magnetic field reduction - The pole or equator? A model study, Canadian journal of exploration in geophysics, 24(2), 185-192. Tran Tuan Dung, 2013. Characteristics of the structure - tectonic in the deep water of the East Sea of Vietnam based on interpretation of gravity and magnetic anomaly data. The 35th Conference of Vietnam Petroleum Institute, 55-66. Tran Tuan Dung, Bui Cong Que, Nguyen Hong Phuong, 2013. The Cenozoic basement structure of the Spratly Islands and adjacent areas by modeling and interpreting gravity data. Russian Journal of Pacific Geology. 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Fast degradation of dyes in water using manganese-oxide-coated diatomite for environmental remediation

By a simple wet-chemical procedure using a permanganate in the acidic medium, diatomite coated with amorphous manganese oxide nanoparticles was synthesized. The structural, microstructural and morphological characterizations of the as-synthesized catalysts confirmed the nanostructure of MnO2 and its stabilization on the support - diatomite. The highly efficient and rapid degradation of methylene blue and methyl orange over synthesized MnO2 coated Diatomite has been carried out. The results revealed considerably faster degradation of the dyes against the previously reported data. The proposed mechanism of the dye-degradation is considered to be a combinatorial effect of chemical, physicochemical and physical processes. Therefore, the fabricated catalysts have potential application in waste water treatment, and pollution degradation for environmental remediation

Determinants Influencing Tax Audit Services: The Case of Vietnam

Unlike former researches on tax audit activities in Vietnam which often use qualitative method to analyze and give recommendations, this research uses quantitative method to identify and verify determinants influencing tax audit activities, by assessing reliability and suitability of measuring scales; verifying research model and research hypothesis; determining impact levels of different drivers of tax audit activities (regarding tax audit conclusions) over 268 tax auditors through questionnaires. The research results are recommendations for Vietnamese tax authorities to consider enhancing the supervision of tax audit activities; build a database to serve tax audit activities and restructure procedures, finalize tax audit methods to increase tax audit performance. Keywords: tax audit, tax audit conclusions, drivers, audit supervision, audit process, database about taxpayers

How heterogeneous are the determinants of total factor productivity in manufacturing sectors? Panel-data evidence from vietnam

One of the remaining challenges in explaining differences in total factor productivity is heterogeneity between sectors and within a specific sector in terms of labor and capital. This paper employs the generalized method of moments (GMM) to identify factors that affect total factor productivity across 21 manufacturing sectors and to clarify the heterogeneous determinants of total factor productivity within manufacturing sectors for the period 2010–2015. Our estimations show that large firms have significantly greater total factor productivity levels than small firms in some fragmentations of firms in terms of both labor and total capital and in some manufacturing sectors. It is suggested that firm characteristics should be considered by the government in establishing relevant policies for enhancing firm productivity