THE TAX COMPLIANCE RISK FOR BANK PAYMENT TRANSACTIONS IN THE TAX ADMINISTRATION CONTEXT IN VIETNAM

The article provides the reference on tax compliance risk for bank transactions payments by businesses in the context of developing countries such as Vietnam, as tax departments are gradually modernizing the tax administration, the use of taxpayer data between tax department and banks are not good. The review of the materials examines the issues involved in the field of tax compliance risk management and to identify gaps in the study of a tax compliance risk

A multifunctional dynamic voltage restorer for power quality improvement

Power quality is a major concern in electrical power systems. The power quality disturbances such as sags, swells, harmonic distortion and other interruptions have an impact on the electrical devices and machines and in severe cases can cause serious damages. Therefore it is necessary to recognize and compensate all types of disturbances at an earliest time to ensure normal and efficient operation of the power system. To solve these problems, many types of power devices are used. At the present time, one of those devices, Dynamic Voltage Restorer (DVR) is the most efficient and effective device used in power distribution systems. In this paper, design and modeling of a new structure and a new control method of multifunctional DVRs for voltage quality correction are presented. The new control method was built in the stationary frame by combining Proportional Resonant controllers and Sequence-Decouple Resonant controllers. The performance of the device and this method under different conditions such as voltage swell, voltage sag due to symmetrical and unsymmetrical short circuit, starting of motors, and voltage distortion are described. Simulation result show the superior capability of the proposed DVR to improve power quality under different operating conditions and the effectiveness of the proposed method. The proposed new DVR controller is able to detect the voltage disturbances and control the converter to inject appropriate voltages independently for each phase and compensate to load voltage through three single-phase transformers.Web of Science116art. no. 135

Advanced Control of the dynamic voltage restorer for mitigating voltage sags in power systems

The paper presents a vector control with two cascaded loops to improve the properties of Dynamic Voltage Restorer (DVR) to minimize Voltage Sags on the grid. Thereby, a vector controlled structure was built on the rotating dq-coordinate system with the combination of voltage control and the current control. The proposed DVR control method is modelled using MATLAB-Simulink. It is tested using balanced/ unbalanced voltage sags as well as fluctuant and distorted voltages. As a result, by using this controlling method, the dynamic characteristics of the system have been improved significantly. The system performed with higher accuracy, faster response and lower distortion in the voltage sags compensation. The paper presents real time experimental results to verify the performance of the proposed method in real environments

Load Flow Analysis in Power System Network Incorporating STATCOM: A Comparison of the Direct and Indirect Algorithm of the Newton-Raphson Method

This paper presents load flow analysis and the mathematical steady-state modeling of Static Synchronous Compensator (STATCOM) to study its effect on the power system network. More precisely, we propose a new approach method so-called direct algorithm and then compare it with the indirect algorithm in testing cases: IEEE 5-bus, IEEE 14-bus, and IEEE 30-bus systems. We compare the accuracy, the number of iterations and the computational time. The simulation results show that the direct algorithm is effective in terms of accuracy, speed of computation and various practical applications

VNHSGE: VietNamese High School Graduation Examination Dataset for Large Language Models

The VNHSGE (VietNamese High School Graduation Examination) dataset, developed exclusively for evaluating large language models (LLMs), is introduced in this article. The dataset, which covers nine subjects, was generated from the Vietnamese National High School Graduation Examination and comparable tests. 300 literary essays have been included, and there are over 19,000 multiple-choice questions on a range of topics. The dataset assesses LLMs in multitasking situations such as question answering, text generation, reading comprehension, visual question answering, and more by including both textual data and accompanying images. Using ChatGPT and BingChat, we evaluated LLMs on the VNHSGE dataset and contrasted their performance with that of Vietnamese students to see how well they performed. The results show that ChatGPT and BingChat both perform at a human level in a number of areas, including literature, English, history, geography, and civics education. They still have space to grow, though, especially in the areas of mathematics, physics, chemistry, and biology. The VNHSGE dataset seeks to provide an adequate benchmark for assessing the abilities of LLMs with its wide-ranging coverage and variety of activities. We intend to promote future developments in the creation of LLMs by making this dataset available to the scientific community, especially in resolving LLMs' limits in disciplines involving mathematics and the natural sciences.Comment: 74 pages, 44 figure

Associations of Underlying Health Conditions With Anxiety and Depression Among Outpatients: Modification Effects of Suspected COVID-19 Symptoms, Health-Related and Preventive Behaviors

Objectives: We explored the association of underlying health conditions (UHC) with depression and anxiety, and examined the modification effects of suspected COVID-19 symptoms (S-COVID-19-S), health-related behaviors (HB), and preventive behaviors (PB).Methods: A cross-sectional study was conducted on 8,291 outpatients aged 18–85 years, in 18 hospitals and health centers across Vietnam from 14th February to May 31, 2020. We collected the data regarding participant's characteristics, UHC, HB, PB, depression, and anxiety.Results: People with UHC had higher odds of depression (OR = 2.11; p < 0.001) and anxiety (OR = 2.86; p < 0.001) than those without UHC. The odds of depression and anxiety were significantly higher for those with UHC and S-COVID-19-S (p < 0.001); and were significantly lower for those had UHC and interacted with “unchanged/more” physical activity (p < 0.001), or “unchanged/more” drinking (p < 0.001 for only anxiety), or “unchanged/healthier” eating (p < 0.001), and high PB score (p < 0.001), as compared to those without UHC and without S-COVID-19-S, “never/stopped/less” physical activity, drinking, “less healthy” eating, and low PB score, respectively.Conclusion: S-COVID-19-S worsen psychological health in patients with UHC. Physical activity, drinking, healthier eating, and high PB score were protective factors

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

A Multifunctional Dynamic Voltage Restorer for Power Quality Improvement

Power quality is a major concern in electrical power systems. The power quality disturbances such as sags, swells, harmonic distortion and other interruptions have an impact on the electrical devices and machines and in severe cases can cause serious damages. Therefore it is necessary to recognize and compensate all types of disturbances at an earliest time to ensure normal and efficient operation of the power system. To solve these problems, many types of power devices are used. At the present time, one of those devices, Dynamic Voltage Restorer (DVR) is the most efficient and effective device used in power distribution systems. In this paper, design and modeling of a new structure and a new control method of multifunctional DVRs for voltage quality correction are presented. The new control method was built in the stationary frame by combining Proportional Resonant controllers and Sequence-Decouple Resonant controllers. The performance of the device and this method under different conditions such as voltage swell, voltage sag due to symmetrical and unsymmetrical short circuit, starting of motors, and voltage distortion are described. Simulation result show the superior capability of the proposed DVR to improve power quality under different operating conditions and the effectiveness of the proposed method. The proposed new DVR controller is able to detect the voltage disturbances and control the converter to inject appropriate voltages independently for each phase and compensate to load voltage through three single-phase transformers

Zvýšení kvality dodávky elektrické energie

Power quality (PQ) has become an important issue in recent times for the customers, service suppliers and equipment manufacturers. The suppliers consider PQ from the system reliability and their competitiveness in the electricity market, the equipment manufacturers consider PQ because of its effects on the proper operations and the price of their equipment, whereas customers consider good PQ that ensures the normal operations of processes, and extends the lifespan of devices. In an attempt to better the power quality of supplies to satisfy customers' demand, installing custom power devices is considered as the most efficient method. This thesis concentrates on two most effective devices: Dynamic Voltage Restorer (DVR) and Static synchronous compensator (STATCOM). The DVR is a series connected device which can protect the sensitive load against some power quality disturbances. Unlike other researches in which DVR is controlled and designed for one or several functions, we focus on the design and control of DVR with multifunction, including voltage swell, voltage sag due to symmetrical and unsymmetrical short circuit, starting of motors, and voltage distortion. In this thesis, we present a new structure and propose two new control methods of multifunctional DVR for voltage quality correction. Simulation results show the superior capability of the proposed DVR to improve power quality under different operating conditions and the effectiveness of the proposed method in terms of efficiency, accuracy and fast response time. The STATCOM is known as an effective device which can regulate the voltage quickly, improve transient stability and compensate variable reactive power. The control method of STATCOM was presented in a number of publications, and therefore we focus on load flow analysis which studies the steady state of the power system network. The load flow analysis in the power system incorporating STATCOM is an important issue in power system analysis, power quality, power planning and system operating. For this task, we present a new approach which is an improvement of the Newton-Raphson algorithm. Results show that, the accuracy and the speed of computation are enhanced. Furthermore, a software called Load Flow Analysis which can analyze the power system with and without STATCOM is developed. This software is a useful tool for the teaching, learning and practicing purpose. It can help engineers and operators calculate the local power system in order to improve power quality, and to optimize the operation of the power system. The goal of the power system is to provide electrical energy for its customers an acceptable degree of quality. Therefore, reliability evaluation is one of the most important factors in designing and planning a distribution system. Unlike a transmission system, evaluating the reliability indices of a distribution system is more difficult because of the complexity of the operation status. To solve this problem, we improve the analytical technique, program and apply it to evaluate the reliability of the distribution system. Compare with Monte Carlo simulation, the proposed method is simple, flexible and fast. Therefore, it is suitable to apply for the distribution system.Power quality (PQ) has become an important issue in recent times for the customers, service suppliers and equipment manufacturers. The suppliers consider PQ from the system reliability and their competitiveness in the electricity market, the equipment manufacturers consider PQ because of its effects on the proper operations and the price of their equipment, whereas customers consider good PQ that ensures the normal operations of processes, and extends the lifespan of devices. In an attempt to better the power quality of supplies to satisfy customers' demand, installing custom power devices is considered as the most efficient method. This thesis concentrates on two most effective devices: Dynamic Voltage Restorer (DVR) and Static synchronous compensator (STATCOM). The DVR is a series connected device which can protect the sensitive load against some power quality disturbances. Unlike other researches in which DVR is controlled and designed for one or several functions, we focus on the design and control of DVR with multifunction, including voltage swell, voltage sag due to symmetrical and unsymmetrical short circuit, starting of motors, and voltage distortion. In this thesis, we present a new structure and propose two new control methods of multifunctional DVR for voltage quality correction. Simulation results show the superior capability of the proposed DVR to improve power quality under different operating conditions and the effectiveness of the proposed method in terms of efficiency, accuracy and fast response time. The STATCOM is known as an effective device which can regulate the voltage quickly, improve transient stability and compensate variable reactive power. The control method of STATCOM was presented in a number of publications, and therefore we focus on load flow analysis which studies the steady state of the power system network. The load flow analysis in the power system incorporating STATCOM is an important issue in power system analysis, power quality, power planning and system operating. For this task, we present a new approach which is an improvement of the Newton-Raphson algorithm. Results show that, the accuracy and the speed of computation are enhanced. Furthermore, a software called Load Flow Analysis which can analyze the power system with and without STATCOM is developed. This software is a useful tool for the teaching, learning and practicing purpose. It can help engineers and operators calculate the local power system in order to improve power quality, and to optimize the operation of the power system. The goal of the power system is to provide electrical energy for its customers an acceptable degree of quality. Therefore, reliability evaluation is one of the most important factors in designing and planning a distribution system. Unlike a transmission system, evaluating the reliability indices of a distribution system is more difficult because of the complexity of the operation status. To solve this problem, we improve the analytical technique, program and apply it to evaluate the reliability of the distribution system. Compare with Monte Carlo simulation, the proposed method is simple, flexible and fast. Therefore, it is suitable to apply for the distribution system.410 - Katedra elektroenergetikyvyhově