150 research outputs found
The Impacts of Internal Audit Practices on the Quality of Internal Control in Vietnamese Smes
Purpose: This study examines the impacts of internal audit practices on internal control in Vietnamese SMEs.
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Theoretical framework: This paper employs the three lines of defense model framework to study the impact of internal audit practices on internal control in Vietnamese SMEs. Internal auditing practices were measured by the items listed in the attribute standards and performance standards of the International Professional Practices Framework (IPPF). Internal control quality includes control environment, risk assessment, control activities, information and communication, and monitoring which are provided by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) Framework.
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Design/methodology/approach: We collect primary data using questionnaire. Data collected from the questionnaire is divided into two groups (1) the measurement of the internal auditing practices and (2) the measurement of the quality of internal control system. We then use the Structural Equation Modelling (SEM) to test for the hypotheses related to the relationship between internal audit practices and internal control.
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Findings: Our results suggest that both attribute standards and performance standards have positive impacts on the control environment, risk assessment, control activities, and monitoring aspects of internal control. Meanwhile, internal audit seems to not influence the information and communication.
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Research, Practical & Social implications: The study contributes to the literature by shedding light on the impacts of internal audit practices on the quality of internal control in Vietnamese SMEs.
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Originality/value: This study examines the unique context of Vietnamese SMEs. Ultimately, the framework aims to provide a comprehensive understanding of how internal audit practices impact internal control quality in this specific context
Similarities and Differences of the Dam Giong Epics (Vietnam) and Reamker (Cambodia), Ramakien (Thailand), PhraLakPhra Lam (Laos) (Note 1)
There are a lot of similarities and differences in The Dam Giong epics of Bahnar ethnic in Central Highlands-Vietnam and Reamkerepic (Cambodia), Ramakien epic (Thailand) and PhraLakPhra Lam epic (Laos). Although there are some similarities in content and themes, these epics differ in capacity, structure, character system and some other artistic elements. Reamker, Ramakien, PhraLakPhra Lam are short independent epics, deriving from Ramayana epic (Indian). Meanwhile, The Dam Giong epics, about a hero named Giong, have a large capacity of hundreds of epics. These epics derive from myths, legends and creeds of Bahnar ethnic in the Central Highlands-Vietnam, especially, they are “living” epics. Nowadays, the epics of Dam Giong are still being circulated and they are developing in the lives of Bahnar ethnic. Currently, in Central Highlands-Vietnam, the epics of Dam Giong are still composed and the number of these epics is constantly increasing
Analysis of tool wear and surface roughness in high-speed milling process of aluminum alloy Al6061
In this study, the influence of cutting parameters and machining time on the tool wear and surface roughness was investigated in high-speed milling process of Al6061 using face carbide inserts. Taguchi experimental matrix (L9) was chosen to design and conduct the experimental research with three input parameters (feed rate, cutting speed, and axial depth of cut). Tool wear (VB) and surface roughness (Ra) after different machining strokes (after 10, 30, and 50 machining strokes) were selected as the output parameters. In almost cases of high-speed face milling process, the most significant factor that influenced on the tool wear was cutting speed (84.94 % after 10 machining strokes, 52.13 % after 30 machining strokes, and 68.58 % after 50 machining strokes), and the most significant factors that influenced on the surface roughness were depth of cut and feed rate (70.54 % after 10 machining strokes, 43.28 % after 30 machining strokes, and 30.97 % after 50 machining strokes for depth of cut. And 22.01 % after 10 machining strokes, 44.39 % after 30 machining strokes, and 66.58 % after 50 machining strokes for feed rate). Linear regression was the most suitable regression of VB and Ra with the determination coefficients (R2) from 88.00 % to 91.99 % for VB, and from 90.24 % to 96.84 % for Ra. These regression models were successfully verified by comparison between predicted and measured results of VB and Ra. Besides, the relationship of VB, Ra, and different machining strokes was also investigated and evaluated. Tool wear, surface roughness models, and their relationship that were found in this study can be used to improve the surface quality and reduce the tool wear in the high-speed face milling of aluminum alloy Al606
Research of multi-response optimization of milling process of hardened S50C steel using minimum quantity lubrication of Vietnamese peanut oil
This study aims to build a regression model when surveying the milling process on S50C steel using Minimum Quantity Lubrication (MQL) of Vietnamese peanut oil-based on Response Surface Methodology. The paper analyses and evaluates the effect of cutting parameters, flow rates, and pressures in minimum quantity lubrication system on cutting force and surface roughness in the milling process of S50C carbon steel materials after heat treatment (reaching a hardness of 52 HRC). The Taguchi method, one of the most effective experimental planning methods nowadays, is used in this study. The statistical analysis software, namely Minitab 19, is utilized to build a regression model between parameters of the cutting process, flow rates and pressures of the minimum quantity lubrication system and the cutting force, surface roughness of the part when machining on a 5-axis CNC milling machine. Thereby analyzing and predicting the effect of cutting parameters and minimum quantity lubrication conditions on the surface roughness and cutting force during machining to determine the influence level them. In this work, the regression models of Ra and F were achieved by using the optimizer tool in Minitab 19. Moreover, the multi-response optimization problem was solved. The optimum cutting parameters and lubricating conditions are as follows: Cutting velocity Vc=190.909 m/min, feed rate fz=0.02 mm/tooth, axial depth of cut ap=0.1 and nozzle pressure P=5.596 MPa, flow rate Q=108.887 ml/h. The output parameters obtained from the above parameters are Ra=0.0586 and F=162.035 N, respectively. This result not only provides the foundation for future research but also contributes reference data for the machining proces
A RESEARCH ON MULTI-OBJECTIVE OPTIMIZATION OF THE GRINDING PROCESS USING SEGMENTED GRINDING WHEEL BY TAGUCHI-DEAR METHOD
In this study, the mutil-objective optimization was applied for the surface grinding process of SAE420 steel. The aluminum oxide grinding wheels that were grooved by 15 grooves, 18 grooves, and 20 grooves were used in the experimental process. The Taguchi method was applied to design the experimental matrix. Four input parameters that were chosen for each experiment were the number of grooves in cylinder surface of grinding wheel, workpiece velocity, feed rate, and cutting depth. Four output parameters that were measured for each experimental were the machining surface roughness, the system vibrations in the three directions (X, Y, Z). The DEAR technique was applied to determine the values of the input parameters to obtaine the minimum values of machining surface roughness and vibrations in three directions. By using this technique, the optimum values of grinding wheel groove number, workpiece velocity, feed-rate, cutting depth were 18 grooves, 15 m/min, 2 mm/stroke, and 0.005 mm, respectively. The verified experimental was performed by using the optimum values of input parameters. The validation results of surface roughness and vibrations in X, Y, Z directions were 0.826 (µm), 0.531 (µm), 0.549 (µm), and 0. 646 (µm), respectively. These results were great improved in comparing to the normal experimental results. Taguchi method and DEAR technique can be applied to improve the quality of grinding surface and reduce the vibrations of the technology system to restrain the increasing of the cutting forces in the grinding process. Finally, the research direction was also proposed in this stud
Vehicle classification by estimation of the direction angle in a mixed traffic flow
The application of Intelligent Transportation System (ITS) is very important in developing societies nowadays. Vehicle monitoring is one of the primary tasks of ITS, where vehicles are classified by lanes for traffic management, especially in case of a mixed flow of motorcycles and other automobiles in the transport system of Vietnam. This paper proposes a new approach in vehicle classification, which is based on evaluation of the direction angle of the first primary axis of each coming vehicle detected in the captured video sequence and map into the predetermined database to mark it as motorcycle or automobiles instead of consideration of vehicle size. The experimental results show that the classification performance is promising, especially for motorcycles and cars, and therefore is applicable in detection of vehicle penalties moving in wrong lanes
Combined analysis of acoustic emission and vibration signals in monitoring tool wear, surface quality and chip formation when turning SCM440 steel using MQL
With modern production, Minimum Quantity Lubricant (MQL) technology has emerged as an alternative to conventional liquid cooling. The MQLs is an environmentally friendly lubricant method with low cost while meeting the requirements of machining conditions. In this study, the experimental and analytical results show that the obtained acoustic emission (AE) and vibration signal components can effectively monitor various circumstances in the SCM440 steel turning process with MQL, such as surface quality and chip formation as cutting tool conditions. The AE signals showed a significant response to the tool wear processes. In contrast, the vibration signal showed an excellent ability to reflect the surface roughness during turning with MQL. The chip formation process through the cutting mode parameters (cutting speed, feed and depth of cut) was detected through analysis amplitude of the vibration components Ax, Ay and Az and the AE signal. Finally, Gaussian process regression and adaptive neuro-fuzzy inference systems (GPR-ANFIS) algorithms were combined to predict the surface quality and tool wear parameters of the MQL turning process. Tool condition monitoring devices assist the operator in monitoring tool wear and surface quality limits, stopping the machine in case of imminent tool breakage or lower surface quality. With the unique combination of AE and vibration analysis model and the training and testing samples established by the experimental data, the corresponding average prediction accuracy is 97.57Â %. The highest prediction error is not more than 3.8Â %, with a confidence percentage of 98Â %. The proposed model can be used in industry to predict surface roughness and wear of the tools directly during turnin
Assessments of Use of Blended Radar–Numerical Weather Prediction Product in Short-Range Warning of Intense Rainstorms in Localized Systems (SWIRLS) for Quantitative Precipitation Forecast of Tropical Cyclone Landfall on Vietnam’s Coast
The role of classroom observation in the development and assessment of schoolteachers in Vietnam: a review of national policy and research
This paper focuses on the role of classroom observation in the development and assessment of schoolteachers in Vietnam through a narrative review of current policy and cognate research literature. The overall aim of this review was twofold. Firstly, to contribute to a growing bank of Vietnam-based studies to maximise the value of the insights from this scholarly work into recent policy reforms on teachers’ professional development in Vietnam. Secondly, to widen access and exposure to published work on the topic in Vietnamese that is not readily accessible to English-speaking scholars. This review revealed a long history and engrained culture of using observation as a teacher performance evaluation tool. In recent years, there have been policy reforms and research studies that have repositioned observation as a tool for teacher learning and development. However, the implementation of these reforms has been inconsistent across Vietnam, along with recent reform having encountered resistance from a culture of compliance in schools. This paper identifies some of the key issues that policy makers and educational leaders need to address in practice in order to ensure the effective and meaningful implementation of the reforms relating to the use of observation for learning and developmental purposes
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