Improving Traffic Efficiency in a Road Network by Adopting Decentralised Multi-Agent Reinforcement Learning and Smart Navigation

In the future, mixed traffic flow will consist of human-driven vehicles (HDVs) and connected autonomous vehicles (CAVs). Effective traffic management is a global challenge, especially in urban areas with many intersections. Much research has focused on solving this problem to increase intersection network performance. Reinforcement learning (RL) is a new approach to optimising traffic signal lights that overcomes the disadvantages of traditional methods. In this paper, we propose an integrated approach that combines the multi-agent advantage actor-critic (MA-A2C) and smart navigation (SN) to solve the congestion problem in a road network under mixed traffic conditions. The A2C algorithm combines the advantages of value-based and policy-based methods to stabilise the training by reducing the variance. It also overcomes the limitations of centralised and independent MARL. In addition, the SN technique reroutes traffic load to alternate paths to avoid congestion at intersections. To evaluate the robustness of our approach, we compare our model against independent-A2C (I-A2C) and max pressure (MP). These results show that our proposed approach performs more efficiently than others regarding average waiting time, speed and queue length. In addition, the simulation results also suggest that the model is effective as the CAV penetration rate is greater than 20%

AUTOMATIC IDENTIFICATION OF VIETNAMESE DIALECTS

The dialect identification was studied for many languages over the world nevertheless the research on signal processing for Vietnamese dialects is still limited and there were not many published works. There are many different dialects for Vietnamese. The influence of dialectal features on speech recognition systems is important. If the information about dialects is known during speech recognition process, the performance of recognition systems will be better because the corpus of these systems is normally organized according to different dialects. This paper will present the combination of MFCC coefficients and fundamental frequency features of Vietnamese for dialectal identification based on GMM. The experiment result for the dialect corpus of Vietnamese shows that the performance of dialectal identification is increased from 59% for the case using only MFCC coefficients to 71% for the case using MFCC coefficients and the information of fundamental frequency

Experiments and optimization for the WEDM process: A trade-off analysis between surface quality and production rate

This work addressed a parameter optimization to simultaneously decrease the root mean square roughness (Rq) as well as the thickness of the white layer (TW) and improve the material removal rate (MRR) for the wire electro-discharge machining (WEDM) of a stainless steel 304 (SS304). The factors considered are the discharge current (C), the gap voltage (VO), the pulse on time (POT), and the wire drum speed (SP). The interpolative radius basic function (RBF) is applied to show the correlation between the varied factors and WEDM performances measured. The optimal selection is chosen using the multi-objective particle swarm optimization (MOPSO). Moreover, a traditional one using the response surface method (RSM) and desirability approach (DA) is adopted to compare the working efficiency of two optimization techniques. The results showed that the optimal findings of the C, POT, VO, and SP are 5.0 A, 1.0 µs, 61.0 V, and 8.0 m/min, respectively. The values of the Rq and TW are decreased by approximately 33.33% and 23.53%, respectively, while the MRR enhances 47.42% at the optimal selection, as compared to the common values used. The BRF-MOPSO can provide better performance than the RSM-DA

Lecane (Rotifera: Lecanidae) community in psammon habitat in Central Coast Vietnam: Diversity and relation to environmental condition

Characteristics of the Lecane (Rotifera) community in psammon in Central Coast Vietnam were investigated. A total of 50 taxa were identified in samples collected at hygropsammon zones of temporary pools, contributing 4 new species to rotifers' record of Vietnam. Psammonxenic species accounted for the largest percentage of Lecane community with 82%, followed by psammophiles (12%) and psammonbionts (6%). Influences of some environmental factors on the distribution of psammic lecanids were also observed. This group of organisms showed a slight tendency towards sand with grain sizes larger than 125 µm. Besides, other abiotic factors including pH, total phosphorus (TP) and total dissolved solids (TDS) were also found to significantly related to the distribution of some common Lecane species

The effects of firm’s innovation on customer’s loyalty: A case study of Saigon COOP

Identifying how the innovation affects the customer’s loyalty via the consumer perceived value and customer satisfactions from products or services provided by the Coopmart Retailers System in Ho Chi Minh City, Vietnam is the purpose of this search. This research also draws some suggestions for the firm’s future development. The research was conducted through 2 phases: a qualitative pilot study and quantitative analysis. The pilot study was conducted with 5 people who are working in Coopmart as department heads, deputy heads, and managers with at least 10 years’ experience. The qualitative survey will be distributed in the Ho Chi Minh City Coopmart system’s customers with member cards where 291 valid surveys were qualified for further analysis. This research’s insight is the impacts of innovation on the consumer perceived value, which has few focuses from previous studies. The outcome of the research has shown different aspects of the innovation to the consumer perceived value and customer satisfactions

GRADIENT KIẾN TẠO HIỆN ĐẠI KHU VỰC NINH THUẬN VÀ LÂN CẬN

The estimation of the present day tectonic movement and tectonic gradient (strain rate) has an important practical signification in the assessment of active fault and seismic hazards for the selection of Ninh Thuan nuclear power plant. Based on the three campaigns of GPS measurement between 2012 - 2013, we used BERNESE 5.0 software to determine present day slip rates of 13 stations in ITRF08 frame. The GPS stations move eastwards at the slip rates of 22 - 25 mm/yr, southwards at the velocities of 5 - 10 mm/yr. The standard errors in latitudinal and longitudinal directions are 1.2 mm/yr and 0.9 mm/yr, respectively. Combined with GPS data from the project of the study on actual geodynamics in Tay Nguyen TN3/06, we determined the strain rate ranging from 50 to 100 nanostrains with the standard error of 50 nanostrains. The direction of  maximum compressive strain rate is from northwest - southeast to east - west.Đánh giá vận tốc chuyển động kiến tạo hiện đại và gradient kiến tạo hiện đại có ý nghĩa thực tiễn quan trọng trong việc đánh giá đứt gãy hoạt động nguy hiểm động đất phục vụ xây dụng nhà máy điện hạt nhân Ninh Thuận. Trên cơ sở đo 3 chu kỳ GPS vào các năm 2012 - 2013, sử dụng phần mềm BERNESE 5.0, chúng tôi đã xác lập được vận tốc chuyển động kiến tạo hiện đại tại 13 điểm đo GPS trong khu vực lân cận bao gồm kéo dài từ Nha Trang tới đảo Phú Quý. Vận tốc chuyển dịch kiến tạo hiện đại về phía đông thay đổi từ 22 - 25 mm/năm và chuyển dịch về phía nam với vận tốc giao động từ 5 - 10 mm/năm trên hệ tọa độ toàn cầu ITRF08. Sai số vận tốc chuyển dịch kiến tạo về phía đông giao động trong khoảng 1,2 - 1,5 mm/năm và về phía nam giao động trong khoảng 0,9 - 1,2 mm/năm. Liên kết với giá trị đo GPS từ đề tài nghiên cứu địa động lực hiện đại khu vực Tây Nguyên mã số TN3/T06, chúng tôi đã xác định được giá trị vận tốc biến dạng giao động từ 50 nano tới 100 nano biến dạng với sai số giao động trong khoảng 50 nano biến dạng. Trục biến dạng nén cực đại giao động theo phương thay đổi từ bắc nam sang đông bắc - tây nam. Trục biến dạng căng cực đại có phương thay đổi từ tây bắc - đông nam sang phương đông - tây

A preliminary study to establish the transfected CHO cell lines which highly express Trastuzumab - A biosimilar product of Herceptin

Human epidermal growth factor receptor 2 (HER2) has been identified as a molecular target for breast cancer therapy, such as Trastuzumab (Herceptin®). This has been shown to improve patient survival substantially. The current study is aiming to locally produce an anti-HER2 monoclonal antibody (named Trastuzumab) which has an equivalent biological properties in comparison with the original version, Herceptin®). In silico design and construction of recombinant vectors, as well as the establishment of transfected cell lines with high expression of Trastuzumab were performed. Based on the protein sequences obtained from the Drugbank, the DNA sequences encoding for the light chain (Tras-Lc) and heavy chain (Tras-Hc) of Trastuzumab were optimized and integrated into pNanogen-Hygro and pNanogen-Puro vectors, respectively. The Neon Transfection System was used to co-transfect the pNanogen-Tras-Lc-Hygro and pNanogen-Tras-Hc-Puro constructs into CHO cells. Different co-transfected single-cell-colonies selected on media supplemented with hygromycin and puromycin were used for ELISA and SDS-PAGE assays to identify the CHO cell lines which highly express Trastuzumab. Based on the present results, 30μg of both constructs were suitable for DNA co-transfection. After 07 days of culture, the highest amount of Trastuzumab (561 µg/ml) was obtained from the H06LD68 cell line

PRESENT DAY DEFORMATION IN THE EAST VIETNAM SEA AND SURROUNDING REGIONS

This paper presents velocities of present-day tectonic movement and strain rate in the East Vietnam Sea (South China Sea) and surroundings determined from GPS campaigns between 2007 and 2010. We determine absolute velocities of GPS stations in the ITRF05 frame. The result indicates that GPS stations in the North of East Vietnam Sea move eastwards with the slip rate of 30 - 39 mm/yr, southwards at the velocities of 8 - 11 mm/yr. Song Tu Tay offshore moves eastwards at the rate of ~24 mm/yr and southwards at ~9 mm/yr. GPS stations in the South of East Vietnam Sea move to the east at the rate of ~22 mm/yr and to the south at the velocities of 7 - 11 mm/yr. The effect of relative movement shows that the Western Margin Fault Zone activates as left lateral fault zone at the slip rate less than 4 mm/year.In Western plateau, the first result from 2012 - 2013 GPS measurement shows that the velocities to the east vary from 21.5 mm/yr to 24.7 mm/year. The velocities to the south vary from 10.5 mm/yr to 14.6 mm/year. GPS solutions determined from our campaigns are combined with data from various authors and international projects to determine the strain rate in the East Vietnam Sea. Principal strain rate changes from 15 nanostrain/yr to 9 nanostrain/yr in the East Vietnam Sea. Principal strain rate and maximum shear strain rate along the Red River Fault Zone are in order of 10 nanostrain/year. East Vietnam Sea is considered to belong to the Sunda block

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions