Experiment-based Comparative Analysis of Nonlinear Speed Control Methods for Induction Motors

Field-oriented control (FOC) for induction motors is widely used in industrial applications. By using a fast and accurate torque controller based on a stator current controller it is possible to flexibly implement advanced speed control methods to achieve proper performance both in transient and steady-state states. In this study, a deadbeat controller was used for the current loop. The nonlinear methods used for the outer loop controller were backstepping, flatness-based control, and exact feedback linearization with state derivative. The dynamic responses of these three controls were compared through various experimental results. The advantages and disadvantages of the different control structures were analyzed and evaluated in detail. Based on this evaluation, an appropriate scheme can be specified when deployed in practice

The Efficiency and the Performance of the Logistics Global Supply Chain Activities to Vietnam Exportation: an Empirical Case Study

Purpose: This research paper aims to determine the factors affecting the efficiency and logistics performance index (LPI) of Vietnam's exports to foreign partners during 2018-2022 are due to the impact of the COVID-19 pandemic.   Theoretical Framework: Based on the primary factors affecting the efficiency and performance of global supply chain activities in logistics for Vietnam's exports, including practical impact and logistics results of enterprises in Vietnam. Based on the primary factors affecting the efficiency and performance of global supply chain activities in logistics for Vietnam's exports, including (1). Customs efficiency (speed, simplicity and predictability of customs clearance procedures) (2). Quality of infrastructure related to trade and transport, including Roads, railways, ports, airports, warehouses and information technology ...(3). The level of ease when arranging to transport import and export goods with competitive prices (costs such as warehousing fees, port fees, tolls ... ) (4). Capacity and quality of logistics service providers ... (5). Ability to track and trace shipments. (6). Timeliness of the shipment to the destination within the specified time limit. The practical impact and logistics results of enterprises in Vietnam.   Method: The panel approach allows the authors to explore the heterogeneity in data across countries. Fixed effects (FE) and random effects (RE) models were used to estimate the model. Then, the Hausman test is carried out to decide which model is appropriate. The data were collected from 240 observations from Vietnam and 80 major export partner countries of Vietnam.   Findings: The research results show that the cost, time and capacity of providing logistics services have the most significant impact on Vietnam's exports.   Practical & social implications: Overall, to increase the efficiency and logistics efficiency of enterprises. The Vietnamese Government needs to cooperate and propose ideas to partner countries to improve logistics activities for exports from Vietnam. Logistics is beginning to play an increasingly important role in the competitiveness of economies.   Originality values: This study also confirms the sustainability of the extended gravity model using OLS and RE methods by substituting different variables for the country's logistics efficiency and solving the endogenous problem in the model while applying the regression method to industrial variables. We find that an 1% improvement in Vietnam's logistics would increase Vietnam's exports by 1.443%, and an 1% improvement in a partner country’s performance would help promote Vietnam's exports to this country by 0.546%

Forms and Factors Affecting Collective Adaptation to Saline Intrusion: A case of Kien Giang Province, Vietnam

Saline intrusion (SI) is causing serious risks for agriculture and coastal life in the Vietnamese Mekong Delta. Maintaining agricultural production under that challenging condition places more tremendous pressure on rural societies. This study aimed to get insight into adaptive adaptation's forms and factors influencing farmers' participation process by applying the social and ecological approach. The research was conducted in An Bien district, Kien Giang province, a province in the Mekong Delta in Vietnam. A mixed-method integrating quantitative and qualitative methods were used to collect data using key informant panel interviews, group discussion, and household survey. The results showed that local farmers had changed the farming system from double rice crops to shrimp-rice models to deal with the impacts of SI. Group response has emerged as the appropriate adaption in both formal and informal forms. The adaptive group plays an essential role in connecting community members, and two forms of adaptation have worked closely to adapt to SI. Factors affecting the informal group related to relatives, households living close to each other; For the formal group, the main factor affecting participation is when joining the group, the members receive benefits from the group. Besides, prestige and having a lot of experience in the leader's production activities affect the official group participation. In addition to the positive factors, two negative factors affect group adaptation: unfavorable farm location and distrus

Industrial Clustering Policy and Economic Restructuring in Vietnam

This paper reviews the industrial agglomeration and evaluates the industrial clustering policy in Vietnam. Base on the Kuchiki flowchart on the building of industrial clustering policy for developing countries, the authors suggest a policy framework for Vietnam

Industrial Clustering Policy and Economic Restructuring in Vietnam

This paper reviews the industrial agglomeration and evaluates the industrial clustering policy in Vietnam. Base on the Kuchiki flowchart on the building of industrial clustering policy for developing countries, the authors suggest a policy framework for Vietnam

A Hybrid of Adaptation and Dynamic Routing based on SDN for Improving QoE in HTTP Adaptive VBR Video Streaming

Recently, HTTP Adaptive Streaming HAS has received significant attention from both industry and academia based on its ability to enhancing media streaming services over the Internet. Recent research solutions that have tried to improve HAS by adaptation at the client side only may not be completely effective without interacting with routing decisions in the upper layers. In this paper, we address the aforementioned issue by proposing a dynamic bandwidth allocation and management architecture for streaming video flows to improve users satisfaction. We also introduce an initial cross layer hybrid method that combines quality adaptation of variable bitrate video streaming over the HTTP protocol at the client side and SDN based dynamical routing. This scheme is enabled by the Software Defined Networking architecture that is now being considered as an emerging paradigm that disassociates the forwarding process from the routing process. SDN brings flexibility and the ability to flexibly change routing solutions, in turn resulting in dynamically improving the services provided in the application layer. Our experimental results show that the proposed solution offers significantly higher overall bitrates as well as smoother viewing experience than existing methods.Comment: 14 pages, 17 figures, IJCSNS International Journal of Computer Science and Network Security, http://paper.ijcsns.org/07_book/201907/20190708.pd

Synthesis of some derivatives of n-(2,3,4,6-tetra-o-acetyl-õ-d-glucopyranosyl)-n’-(benzothiazole-2’-yl) thioureas

Some compounds of N-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-N’-(benzothiazole-2’-yl)thioureas have been synthesized from corresponding 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate and the substituted derivatives of  2-aminobenzothiazoles executing in home microwave oven. Their spectroscopic properties have been recorded and the relationships between their structures and spectral properties (IR, 1H- and 13C-NMR) have been discussed

Chemical components and biological properties from acetone extracts of Conamomum vietnamense

Conamomum vietnamense is an endemic and rare species from Vietnam. The aim of this study is to determine the chemical compositions, antibacterial and antioxidant properties of the acetone extracts obtained from the different organs of this species for the first time. A total of 82 components were identified from the acetone extracts of leaf, flower, and rhizome of C. vietnamense using Gas chromatography–mass spectrometry (GC/MS) technique. Furthermore, the agar disk-diffusion method was also used to determine the antibacterial activity of the C. vietnamense extracts. Accordingly, the leaf extract was found to be effective against eight out of nine bacterial strains while the flower and rhizome extracts displayed activity against four out of nine tested bacteria. In addition, the three organs of C. vietnamense also possessed the high DPPH scavenging properties. The results of this study indicate that C. vietnamense extracts have the potential to be developed into pharmaceutical products in the future

Factors Affecting the Agricultural Restructuration: A Case of Cham Community in Chau Phu District, An Giang Province, Vietnam

The national policy of agricultural restructuring plays a vital role in adapting to climate change's effects and economic development in the Mekong Delta of Vietnam. Unproductive areas have been converted into other crops with higher efficiency. Drawn by the sustainable livelihoods approach, this article explores the current situation and factors challenging the Cham community in implementing the agricultural restructuring. The mixed method included in-depth interviews, focus group discussions, and a questionnaire survey. The results showed that the Xuong Com Vang longan (Dimocarpus longan) variety has occurred in Khanh Hoa commune for a long time as an indigenous fruit tree of this area. In terms of the farming system, the polyculture system combining fruit trees and upland crops brought more income sources than the monoculture system. The asset abilities of the Cham farmers are various from one to the others. Soil and weather conditions are appropriate for planting. But farm size is small, which is one of the difficulties of developing fruit areas. Human and social assets were good since farmers had enough knowledge to manage the gardens, and a close connection existed among the Cham community. It was not a case of the financial status since a lot of money needs to be invested in the starting year. Therefore, the private loan still exists as one of the farmer's choices. For better future development, land management and financial resource should be considered for better agricultural restructuring aims. To increase farmers' incomes, create production chains helping enterprises and farmers work more efficiently for the better life of Cham gardeners in An Giang province in Vietnam

The Current Status of Secondary School Teacher’s Perception of Happiness in Nam Dinh Province during the Implementation Period of the 2018 General Education Program

In the current context of a major revolution in the Vietnamese education system, teachers’ perception of happiness makes an important criterion in evaluating effectiveness of the changes made to educational programs. The initial investigation of the positive effects of this renovation was conducted on the scale of Nam Dinh province and the results show multidimensional sources of information. In addition to positive information, there is still information that raises many questions for leaders to pay attention to. The outcome of the investigation suggests the evaluation of “The job is meaningful” is 3.10 out of 5 points, which is the lowest in assessment criteria. Meanwhile, the rates for “Completely disbelieve” and “Slightly disbelieve” in happiness of their profession in the future take up a large proportion (24.4%). However, other criteria namely “Being satisfied with current position” and “Feeling motivated with the job” received higher evaluation scores, respectively 4.05/5 points and 4.11/5 points. Via the results of the research, the author is looking forward to appropriate actions taken by the Ministry of Education and Training of Vietnam with a view to enhancing the perception of happiness among teachers