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We demonstrate the theoretical and experimental implementation of the iterative adaptive sensing (IAS) protocol to precisely determine the frequency splitting of a high Q nanomechanical two-mode system. The protocol is based on the application of the Magnus-based strategy to the coherent control pulses to overcome experimental constraints. The system under investigation consists of the strongly coupled fundamental flexural in-plane and out-of-plane mode of a nanostring resonator. Wir implementieren das iterative adaptive Sensing (IAS) Protokoll experimentell, um die Frequenzspaltung eines nanomechanischen Zweimode-Systems mit hoher Güte präzise zu bestimmen. Mit kohärenten Kontrollimpulsen tauschen die Modi Energie schneller als die Zerfallszeit aus, sodass die Systemdynamik in zeitaufgelösten Messungen untersucht werden kann. Die experimentellen Ergebnisse stimmen mit der theoretischen Vorhersage überein und liefern genaue Frequenzschätzungen für die Modenaufspaltung.

Nội dung bài 7

Converter interfaced distributed generations in a microgrid feed the modulated current of limited magnitude during fault conditions. The protection design and its operation are thus challenging due to limited fault current which is further reduced by Petersen coil grounding in medium‐voltage (MV) level. This paper aims to address this challenge by developing a current‐only directional relay algorithm for the protection of converter dominated MV microgrid with Petersen coil grounding. The relay's operating principle is based on the sign of the change in phase angle of the fault current with respect to the prefault which indicates the direction of fault. The negative and positive changes in current's phase angle determine the fault in forward and reverse direction, respectively. The tripping decision is derived by comparing the binary output of the relay at both ends of the line segment under protection. This requires a simple, flexible and low bandwidth communication channel. Both theoretical analyses and simulation studies have been performed on a typical distribution grid intended to be operated as microgrid. The proposed protection method is suitable for microgrid having the converters with and without reactive power support. Various operating conditions are evaluated, including bidirectional power flow, high resistance fault, different fault types, loading conditions and signals with noise.

This study attempts to utilize cold-bonded fly ash based artificial lightweight aggregate (ALWA) and retrieved unground rice husk ash (URHA) as internal curing (IC) agents for improving performance of typical super-sulfaed cement (SSC) mortar fabricated with ternary mixture of 85% slag, 10% gypsum, and only 5% blended Portland cement (PCB). The ALWA partially replacing fine aggregate (FA) at four values of 25, 50, 75, and 100 vol.% was used. For evaluating impact of using hybrid addition of IC agents on performances of SSC mortars, the ALWA amount after being optimized was partially replaced by URHA at four levels of 25, 50, 75, and 100 vol.%. Experimental results showed that, ALWA partially replacing FA up to 50 vol.% led to the SSC mortars with remarkably increased workability and uncompromised impacts on the strengths and durability. Addition of URHA partially replacing ALWA significantly improved the fresh properties and flexural strength but it negatively impacted the durability performances of the resultant SSC mortars in terms of increased water absorption, decreased UPV, and increased drying shrinkage.

The Vietnamese Mekong Delta (VMD) has experienced a series of unprecedented disasters in the last decade, resulting from a combination of drought and saline intrusion in the 2015-2016 and 2019-2020 dry seasons. These events have severely impacted the region's agricultural sustainability and people's livelihoods, prompting an urgent need to explore their root causes and derive lessons for future prevention. Despite a growing body of literature on disaster vulnerability, little has been done to address these questions in the Vietnamese context. This article seeks to bridge this gap by critically examining Vietnam's food politics and agricultural modernisation policies in relation to changes in water resource management, disaster risk management and farming practices. Through a case study of Tan Hung commune in Soc Trang province, the article argues that the current vulnerability to disasters, exemplified by the unsustainable system of triple rice cultivation, is an unintended consequence of Vietnam's agricultural reform and biased water management approach, which relies heavily on large-scale irrigation infrastructure.

The objective of the study is to evaluate the factors affecting the intention to return to a tourist destination in Da Nang, Vietnam. The study conducted a survey for 2 months, from April to June 2022, and the results were 586 valid questionnaires. The data was analyzed using SmartPLS 3.3 software. The results show that destination image has a positive impact on tourists' perception of value and quality. At the same time, the destination image and the perception of quality and value create visitor satisfaction. In addition, visitor satisfaction has a positive effect on tourists' intention to return to Danang. Finally, the income modifier is statistically significant in the relationship between visitor satisfaction and the intention to return to Da Nang. From there, the study makes recommendations for tourism businesses and tourism management agencies in Da Nang to be able to attract more new tourists and encourage tourists who have been to Da Nang to return to Da Nang.

The purpose of the article is to determine the factors affecting the satisfaction of Duy Tan University students for online learning during the acute respiratory infection caused by the new strain of Coronavirus (Covid-19). Based on survey, analysis, processing and evaluation of the obtained results, the article aims to focus the analysis within specific limits with the goal of honestly reflecting and thereby offering solutions for the effective use of online learning in the learning process of students. The results show that there are five factors affecting student satisfaction, in order of influence, as follows: (1) Tuition fees; (2) Teaching staff; (3) Interoperability; (4) Facilities and (5) Training programs. Based on these results, the Board of Directors of Duy Tan University will change several factors in order to improve student satisfaction in online learning in the near future.

This paper presents a novel DSO support tool with visualisation capability for forecasting network congestion in distribution systems with a high level of renewables. To incorporate the uncertainties in the distribution systems, the probabilistic power flow framework has been utilised. An advanced photovoltaic production forecast based on sky images and a load forecast using an artificial neural network is used as the input to the tool. In addition, advanced load models and operating modes of photovoltaic inverters have been incorporated into the tool. The tool has been applied in case studies to perform congestion forecasts for two real distribution systems to validate its usability and scalability. The results from case studies demonstrated that the tool performs satisfactorily for both small and large networks and is able to visualise the cumulative probabilities of nodes voltage deviation and network components (branches and transformers) congestion for a variety of forecast horizons as desired by the DSO. The results have also shown that explicit inclusion of load‐voltage dependency models would improve the accuracy of the congestion forecast. For demonstrating the applicability of the tool, it has been integrated into an existing distribution management system via the IoT platform of a DMS vendor, Atos Worldgrid.

Sufficient conditions are given for the existence of solutions of bifunction-set optimization problems, whose underlying sets are complete metric spaces. The main result of this paper is formulated in Theorem 3.1, with the help of some new data. The advantage of introducing the new data is that, by choosing suitable new data, we can obtain existence results with assumptions, that are imposed directly on the objective maps, or that are formulated via scalarization. The main result is applied successfully to Kuroiwa set optimization problems and Ky Fan vector inequality problems. We also discuss equivalences between the existence of solutions of the bifunction-set optimization problem, an Ekeland-type variational principle and a Caristi-type fixed point theorem. Examples are provided.

Highlights • HPV infection in men having sex with men (MSM) was studied in two cities of Vietnam • Prevalence of any HPV and HPV16/18 among MSM was 32.3% and 11.0%, respectively • High-risk HPV infections in MSM were associated with risky sexual behaviours • A targeted HPV vaccination strategy would be beneficial for MSM in Vietnam, Objectives Men who have sex with men (MSM) are at risk of human papillomavirus (HPV)-related cancers, while published data are scarce. This study determined HPV prevalence and risk factors in MSM in Vietnam to inform HPV prevention strategies in this key population. Methods A cross-sectional study of 799 MSM aged 16-50 years was conducted in Vietnam in 2017-2018. Information was collected on risk behaviours, and knowledge of HPV and anal cancer; rectal swabs were taken to detect anal HPV infection. An in-house polymerase chain reaction and Genoflow HPV array test kit were used for HPV detection and genotyping. Results The median age of the study participants was 25 years (range 18-52). Overall prevalence of any HPV and HPV16/18 infection was 32.3% and 11.0%, respectively. A higher prevalence of high-risk HPV infection to all 14 types tested was found in Ho Chi Minh City (30.9%) than in Hanoi (18.4%). High-risk HPV infection was associated with inconsistent condom use and history of engaging in sex under the influence of drugs (adjusted odds ratio (aOR), 2.27; 95% CI, 1.48-10.67), as well as having multiple sexual partners (aOR, 1.01; 95% CI, 1.00–1.02). Conclusions High-risk anal HPV infections in Vietnamese MSM were significantly associated with risky sexual behaviours. A targeted HPV vaccination strategy would have substantial benefit for MSM in Vietnam.

By mailing questionnaires to high school students in Hanoi, who are between the ages of 15 and 18, this study seeks to understand the factors that influence the intention of tourists. This research shows that the empirical findings are consistent with earlier literature reviews with the help of SPSS version 2016 and STATA version 22. Research hypotheses include service quality, motivation, destination perception, and perceived value are strongly and favorably connected with museum visits as determined by traveler intention. Furthermore, compared to women, men are less likely to return to the museum yet are more interested in going there first. The likelihood of visiting the museum is also higher for people with better incomes and educational backgrounds than for those with lower levels of both. Last but not least, the research findings indicate that parents' attitudes and the family's class are essential factors in motivating kids to increase their intention to frequent museums; nevertheless, high-class families' kids are less likely to have high intentions of tourists.

Background. MicroRNA-1246 (miR-1246), an oncomiR that regulates the expression of multiple cancer-related genes, has been attracted and studied as a promising indicator of various tumors. However, diverse conclusions on diagnostic accuracy have been shown due to the small sample size and limited studies included. This meta-analysis is aimed at systematically assessing the performance of extracellular circulating miR-1246 in screening common cancers. Methods. We searched the PubMed/MEDLINE, Web of Science, Cochrane Library, and Google Scholar databases for relevant studies until November 28, 2022. Then, the summary receiver operating characteristic (SROC) curves were drawn and calculated area under the curve (AUC), diagnostic odds ratio (DOR), sensitivity, and specificity values of circulating miR-1246 in the cancer surveillance. Results. After selection and quality assessment, 29 eligible studies with 5914 samples (3232 cases and 2682 controls) enrolled in the final analysis. The pooled AUC, DOR, sensitivity, and specificity of circulating miR-1246 in screening cancers were 0.885 (95% confidence interval (CI): 0.827-0.892), 27.7 (95% CI: 17.1-45.0), 84.2% (95% CI: 79.4-88.1), and 85.3% (95% CI: 80.5-89.2), respectively. Among cancer types, superior performance was noted for breast cancer (AUC=0.950,DOR=98.5) compared to colorectal cancer (AUC=0.905,DOR=47.6), esophageal squamous cell carcinoma (AUC=0.757,DOR=8.0), hepatocellular carcinoma (AUC=0.872,DOR=18.6), pancreatic cancer (AUC=0.767,DOR=12.3), and others (AUC=0.887,DOR=27.5,P=0.007). No significant publication bias in DOR was observed in the meta-analysis (funnel plot asymmetry test with P=0.652; skewness value=0.672, P=0.071). Conclusion. Extracellular circulating miR-1246 may serve as a reliable biomarker with good sensitivity and specificity in screening cancers, especially breast cancer.

Throughout history, Vietnamese people have received positive elements of foreign beliefs and religions. Up to now, folk beliefs have been preserved, playing an important role in the spiritual life of people. The role of Vietnamese folk beliefs is expressed in the interpretation of natural and human phenomena; in moral education; promote democracy, solidarity and preserve the cultural identity of the Vietnamese people. This study analyzes and assesses the current situation of folk cultural activities of people in Dong Nai province, Vietnam.

One of the most important challenges in controlling a Microgrid is to enable a multi-mode operation with a smooth change from different modes. Recently, hierarchical control is considered as an effective approach to control and manage a Microgrid. This paper proposes a compatible hierarchical control strategy, leveraging the superior characteristics of Andronov-Hopf Oscillator, that enables both grid-connected and islanded operation, as well as seamless, reliable transition between operation modes. The proposed control strategy includes a PI-based Power Tracking Control loop, a Power Sharing Control loop using average consensus approach, a PR-based Synchronization Control, and a Fault Initiated Islanding Detection based on wideband, online impedance estimation. The results in MATLAB/Simulink are provided to validate the effectiveness of the proposed strategy.

Lower and upper semicontinuity results for the approximate solution mapping of the parametric bifunction-set optimization problem are established under new assumptions that are quite different from the ones used previously in the case of exact solution mapping. Applications to the stability study of the approximate solution mapping of a parametric Kuroiwa set optimization problem and a parametric vector Ky Fan inequality problem are given. To our knowledge, our stability results are original. Several examples are provided.

This research studied the impact of internal control on financial performance of small and medium-sized enterprises (SMEs) in an emerging economy. The studying framework was derived from the Agency Theory to examine the relationship between internal control and organizational performance in SMEs. The paper used a survey and non-probability sampling and applied regression analysis to assess this effect on SMEs in Hanoi, Vietnam. Internal control consisted of five elements (including control environment, risk assessment, control activities, information and communication systems, and monitoring activities) by COSO. SME’s performance was measured by ROA primarily. This research analyzed data using SPSS and SmartPLS softwares. Using a sample of 94 respondents, the results show that the control environment which is a dimension of internal control has a positive influence on the performance of SMEs in this case. Other dimensions of internal control that are control activities, information and communication system, risk assessment, and monitoring activities showed insignificant impacts on performance of SMEs but the results still give some meaningful insights for SMEs in Vietnam. The results of this paper provide practical insights on the role of internal control for researchers and business managers. Keywords: internal control, performance, small and medium-sized enterprises

Over the last decades, Vietnam has increased its rice production substantially, which has resulted in environmental degradation and adverse health effects. The present study aimed to document the i...

Sprout by-product is a nutrient-rich organic material but difficult to biodegrade in natural environmental conditions. Sprout by-product includes used media, part of the sprout stems and roots left after harvest. The accumulation of this waste with increasing amounts over time can cause serious environmental pollution in production areas. To reduce waste volume at the resource, this study provided several treatment methods of sprout by-product to effectively recycle it for safe sprout production. The treatment methods proposed for sprout by-product were i) To incubate with microbial product called as EMUNIV for 30 days to create the first organic growing medium - GT2, pre-treat with 1% lime solution; ii) Mix with dried soybean husk at a ratio of 1:1 to create the second organic growing medium - GT3; or iii) Mix with dried soybean husk in a 1:1 ratio to create the third organic growing medium - GT4. The results showed that the created organic growing media had neutral pH, high organic matter, and nitrogen, phosphorus, potassium content. The treated substrates were not contaminated with some heavy metals (Pb, Cd, As) and pathogenic microorganisms (E.coli, Salmonella). Raphanus sativus var. radicula sprouts grown on new organic media had the seed germination rate of 95-98%, normal growing with higher productivity than the control from 1.14 to 1.2 times, crude protein, vitamin C content also higher than the control. Sprouts grown using this recycled media were assessed safe because of not being polluted by heavy metals (Pb, Cd), pathogenic microorganisms (E.coli, Salmonella) and nitrate. The treatment of sprout by-product according to the method for creating organic medium GT2 was most suitable and recommended for sprout production areas.

This work is concerned with the Hardy inequalityon time scales. It finds the condition for the existence of a constant C such that where p is a fixed number satisfying .

We conducted this research to determine the NAT2 gene-phenotype characteristics and pharmacokinetics (PK) parameters of isoniazid among patients with non-MDR pulmonary tuberculosis. Data were collected from 132 patients diagnosed with newly acquired or relapsed tuberculosis and treated at 03 hospitals: Hanoi Lung Hospital, Central Lung Hospital, and National K74 Hospital. PK samples were collected one day from the 10th – 14th day after commencing treatment. The average age of the recruited patients was 45.43 ± 15.76 years; the majority were male (74.24%). The slow and medium acetylator types, as indicated by NAT2 phenotypes, were the two major types (37.88% and 35.6%, respectively). 61.12% of the patients had their Bayesian isoniazid-acetyl isoniazid population PK modeling - determined Cmax value within the therapeutic range of 3 – 6 µg/mL. Acelytator type showed a statistically significant correlation with Cmax. Keywords: Isoniazid, pharmacokinetics, Cmax, tuberculosis.

In this paper, self-adaptive controllers for renewable energy communities based on data-driven approach are proposed to mitigate the voltage rise and transformer congestion at the community level. In the proposed approach, the transformer loading percentage is estimated by the trained data-driven model, which uses the extreme gradient boosting regression algorithm based on a measurement set acquired from critical coupling points of the communities. To avoid voltage rise issues, the droop control parameters (i.e., voltage threshold for P − V , Q−V curves) are adaptively tuned based on the solar irradiance availability and estimated transformer loading. The proposed approach has been tested in the IEEE European LV distribution network. Results showed that the control approach could effectively reduce 22.2% of the total overloaded instances, while still keeping voltage magnitude in the operation range. This method can help DSOs manage voltage violation and congestion without further communication.

A cross-sectional study using the take-all sampling method was conducted among patients in the unique MMT private clinic in Vietnam in 2018. The study aimed to describe treatment adherence status and related factors of the patients. Data on socioeconomic characteristics, behaviours, treatment process, level of social/family support were collected and analyzed. The results showed that 88.2% of MMT patients completely adhere to the treatment program. Factors positively related to treatment adherence of MMT patients were living with spouse/partner (OR = 3.02 95% CI: 1.11 – 8.19), not using illicit drugs during MMT treatment (OR = 5.88; 95% CI: 1.77 – 19.56). The methadone clinic should pay attention to the factors positively related to treatment adherence in the counselling and support process for the patients.

This paper presents the experimental validation of a transmission line protection scheme based on dynamic state estimation for different fault types and conditions. The protection scheme utilizes real-time high-frequency sampled measurements from advanced sensors and evaluates the operating condition of the transmission line based on which a tripping signal is generated in case a fault occurs. The validation is performed using a physical scaled-down model of a power system, consisting of a transmission line, transformer, synchronous generator, and loads. The following faults are examined during the validation: unbalanced faults under different load conditions, high impedance fault, fault current fed from both ends, hidden failure, external fault, and load change conditions. The results show that the scheme performs as intended and thus proves its efficacy to detect various types of faults. The maximum fault detection time is calculated to be 42.5 milliseconds, while the maximum fault clearing time comes out to be 82.5 milliseconds, on par with currently employed protection methods. The obtained results demonstrate the ability of the scheme to detect different fault types under varying conditions and avoid potential issues with relay coordination

Linezolid is an antibiotic of last resort for the treatment of infections caused by Gram-positive bacteria, including vancomycin-resistant enterococci. Enterococcus faecalis, a member of enterococci, is a significant pathogen in nosocomial infections. E. faecalis resistance to linezolid is frequently related to the presence of optrA, which is often co-carried with fex, phenicol exporter genes, and erm genes encoding macrolide resistance. Therefore, the common use of antibiotics in veterinary might promote the occurrence of optrA in livestock settings. This is a cross-sectional study aiming to investigate the prevalence of optrA positive E. faecalis (OPEfs) in 6 reservoirs in farms in Ha Nam province, Vietnam, and its associated factors and to explore genetic relationships of OPEfs isolates. Among 639 collected samples, the prevalence of OPEfs was highest in flies, 46.8% (51/109), followed by chickens 37.3% (72/193), dogs 33.3% (17/51), humans 18.7% (26/139), wastewater 16.4% (11/67) and pigs 11.3%, (14/80). The total feeding area and total livestock unit of the farm were associated with the presence of OPEfs in chickens, flies, and wastewater. Among 186 OPEfs strains, 86% were resistant to linezolid. The presence of optrA was also related to the resistant phenotype against linezolid and levofloxacin of E. faecalis isolates. Close genotypic relationships identified by Pulsed Field Gel Electrophoresis between OPEfs isolates recovered from flies and other reservoirs including chickens, pigs, dogs, and wastewater suggested the role of flies in the transmission of antibiotic-resistant pathogens. These results provided warnings of linezolid resistance although it is not used in livestock.

The objective of a cross sectional study is to describe the situation of human papillomavirus (HPV) infection and risk behaviours among 800 men who have sex with men (MSM) in Hanoi and Ho Chi Minh City (HCMC) from December 2017 to May 2018 using respondent - driven sampling method (RDS). The results showed that the prevalence of any type of HPV infection was 29.8% (33% in HCMC, 26.5% in Hanoi) and the prevalence of any high - risk type of HPV infection was 24.0% (29.0% in HCMC, 19.0% in Hanoi). The risk behaviours to HPV among MSM in both cities included: Alcohol use (69.9%), smoking (30.7%), drug use (8.5%), having frst sexual intercourse under 18 years old (31.8%), having group sex (10.5%), having sex with both men and women (21.7%). The factors which had statistically signifcant differences with HPV status in MSM group included: City, age group, and marital status. These results showed that there is a need for medical interventions for MSM to improve individual health as well as to minimize the transmission of HPV in this population.

This article presents a model for energy management system of a building microgrid coupled with a battery energy storage. The model can be used to dispatch the battery as a flexible energy resource using a market-based setting. The battery is modeled considering battery degradation and real-life operation characteristics derived from measurements at a residential building. The performance of the model was evaluated first with simulations and integrated afterwards to an energy management system, which was demonstrated at a real residential building (HSB Living Lab) equipped with photovoltaic and battery storage systems. The simulation results showed that the building owner, and subsequently the residents, could benefit from the proposed model in reduced annual cost up to 3.1% under the considered pricing scheme. The demonstration results showed that dispatch under the measurement-based model could decrease the undelivered energy over the daily requested amount from the battery from 13.3% to 3.7%. Thus, the proposed model, which couples the measurement-based dispatch with battery degradation, can lead to a more accurate estimation of the building operation cost and an improved overall performance of battery as a flexible resource in building microgrids.

Habenaria diphylla (Nimmo) Dalzell is reported for the first time as a new discovery for the flora of Vietnam based on the specimens collected in Binh Chau-Phuoc Buu Nature Reserve, Ba Ria-Vung Tau Province. The present study provided the detailed characteristics of the species including detailed photographs of the morphological characteristics, the cross section of the leaf, inflorescence axis and root. Furthermore, the information about the species, including distribution, habitat, ecology and conservation status were also provided.

Along with the increased installation of the distributed energy resources (DER) in distribution system, long-term voltage stability at the transmission level can be improved if proper coordination is developed between DERs and the existing grid controllers, e.g., load tap changer (LTC). This paper analyzes the problem of long-term voltage instability and presenting possible countermeasures. The study summarizes essential aspects for modelling, including LTC, DERs, and especially voltage dependent load. A coordination between DERs and LTC is proposed to allocate better power supply, especially at the coupling points between transmission and distribution networks, i.e. primary substation. A case study is performed using a modified CIGRE medium-voltage benchmark network. The simulation results have shown that the coordination has substantially improved the long-term voltage stability in the way of using the reactive power support from DERs and increasing the LTC position instated of decreasing as the traditional method.

Objectives: Describe the current status of village health care workers (VHWs) in non-communicable diseases (NCDs) with people in Dap Thanh commune, Ba Che district, Quang Ninh province in 2019. Subjects and methods: Direct interview with people in Dap Thanh commune, Ba Che district, Quang Ninh province: 151 people aged 18 and over. Information related to exposure to messages about NCD risk factors and primary health care activities of VHWs. Results: Most of the respondents heard about NCD risk factors messages in the past 30 days, from 56.3% (messages in physical inactivity), and 59.6% (notifications). on diet), 75.5% (messages on alcohol use) to 79.5% (messages for smoking). Radio / television is the most popular source of messages (between 91.8% and 95.8%) and the majority of people hear these messages from one source (from 77.1% to 80.9%). Most of the respondents said that there is no local village health worker (53.6%). Among localities with village health workers, the most common services provided were health communication and education (54.3%), while only 30% received NCD management services. These services are rated effective and moderate (6.6 - 7.7 points). Farmers who smoke and have diabetes are more likely to hear health messages than the rest of the population. Conclusion: The results show that the primary health care activities for non-communicable diseases of the people in the Dap Thanh commune are not really effective, the role of health workers as an official source of information has not yet promoted their tasks mine. VHWs are not fully involved in primary health care activities of the people. Efforts should be made to improve the capacity and participation of VHWs in health care activities, especially those NCDs managed by local VHWs.

Large scale supercapacitor electrodes were prepared by 3D-printing directly on a graphite paper substrate from ink solution containing manganese cobalt sulfide/reduced graphene oxide (MCS/rGO) nanocomposites. The MCS/rGO composite solution was synthesized through the dispersion of MCS NPs and rGO in dimethylformamide (DMF) solvent at room temperature. Their morphology and composition were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray diffraction (EDS). The role of rGO on decreasing charge transfer resistance and enhancing ion exchange was discussed. The MCS/rGO electrode exhibits an excellent specific capacitance of 3812.5 F g

This paper develops a new method for voltage instability prediction using a recurrent neural network with long short-term memory. The method is aimed to be used as a supplementary warning system for system operators, capable of assessing whether the current state will cause voltage instability issues several minutes into the future. The proposed method use a long sequence-based network, where both real-time and historic data are used to enhance the classification accuracy. The network is trained and tested on the Nordic32 test system, wherecombinations of different operating conditions and contingency scenarios are generated using time-domain simulations. The method shows that almost all N-1 contingency test cases were predicted correctly, and N-1-1 contingency test cases were predicted with over 93 % accuracy only seconds after a disturbance. Further, the impact of sequence length is examined, showing that the proposed long sequenced-based method provides significantly better classification accuracy than both a feedforward neural network and a network using a shorter sequence., Comment: 8 pages

Using three actuators, in this article, we construct a control system for rubber-tired gantry (RTG) cranes to track three actuated outputs and stabilize two unactuated outputs. The controller is designed by utilizing the fast-terminal sliding mode, fractional calculus, and backstepping. Considering that RTG cranes encounter with uncertainties and random winds, an adaptive mechanism is constituted using neural networks to estimate uncertain parameters and unknown winds. A neural observer that reduces the number of sensors by half is also proposed for approximating feedback velocities. By applying these advanced techniques, the control system is endowed with adaptive and robust features. The quality and effectiveness of the control system are investigated by simulation and experimentation.

Over the last few decades Vietnam has benefited from a rapid intensification of rice production ensuing high yields and economic gains. However, this has led to environmental degradation and adverse health effects. As a result, complex sustainable rice farming packages have been introduced but adoption still appears to be low. The present study aimed to investigate the factors affecting the adoption of sustainable rice farming practices combined in the national program “One Must Do, Five Reductions” (1M5R). Furthermore, a special focus was placed on identifying adoption constraints. Adoption was investigated by means of a survey questionnaire with 465 farmers in An Giang and Can Tho Province. Overall, results show that almost all farmers followed the requirements of pesticide reduction, post-harvest loss reduction, and the use of certified seeds. However, farmers had problems reducing their fertilizer use, water use, and seed rate. Results show that farmers perceive these practices to be difficult to implement, they do not fit farmers’ cropping pattern and the weather conditions hindered the implementation. The study further shows that ease of implementation, education, satisfaction and non-rice income are the main drivers for adopting the whole package. Adoption of the individual requirements is mainly driven by the ease of implementation and non-rice income for practices with lower adoption rates. This shows that farmers face physical adoption barriers, and that farmer satisfaction with the whole program is essential for a successful implementation. Results highlight the need for adoption monitoring and the continuation of extension services for the specific requirements specified under 1M5R.

In this research, the performance of a cementless eco-binder, a mixture of waste materials including slag, circulating fluidized bed combustion ash (CFA), and rice husk ash (RHA) was investigated, in which CFA acted as an activator. One hundred and twenty paste samples were prepared by using the RHA/(slag + RHA) ratios of 0, 15, 30, 45% while keeping a constant ratio of CFA/(slag + RHA) at 25%. The setting period, compressive strength, the ultrasonic pulse velocity (UPV), and drying shrinkage of paste samples were determined at the samples’ age of up to 91 days. In addition, the microstructures of all paste samples were also characterized by scanning electron microscopy (SEM). It was found that the use of cementless eco-binder significantly increased the setting times, lower compressive strength, drying shrinkage, and UPV values compared to the control OPC sample. The maximum 91-day-old compressive strength gained by the binary binder of slag and CFA (R00C25) was 90% of that of the control specimen. Incorporation of RHA with higher replacement levels up to 45% resulted in a significant decrease in compressive strength up to 50%. Moreover, the SEM analysis revealed that there was a large difference in the microstructures of the control and the cementless eco-binder samples, in which the main hydration products were C-S-H/C-A-S-H gels and ettringite (AFt) due to relatively high amount of SO3 and SiO2 in the CFA and RHA, respectively. Thus, it can be realized that the potential for the use of slag, CFA, and RHA as a sustainable cement-free binder is promising in the construction industry, especially for lower strength or no required early high strength structures. Keywords: cementless eco-binder; circulating fluidized bed combustion; rice husk ash; slag; microstructure; compressive strength; drying shrinkage; setting time; ultrasonic pulse velocity.

This paper develops a machine learning-based method for fast estimation of the dynamic voltage security margin (DVSM). The DVSM can incorporate the dynamic system response following a disturbance and it generally provides a better measure of security than the more commonly used static voltage security margin (VSM). Using the concept of transient P-V curves, the paper first establishes and visualizes the circumstances when the DVSM is to prefer to the static VSM. To overcome the computational difficulties in estimating the DVSM, the paper proposes a method based on training two separate neural networks on a data set composed of combinations of different operating conditions and contingency scenarios generated using time-domain simulations. The trained neural networks are used to improve the search algorithm and significantly increase the computational efficiency in estimating the DVSM. The machine learning-based approach is thus applied to support the estimation of the DVSM, while the actual margin is validated using time-domain simulations. The proposed method was tested on the Nordic32 test system and the number of time-domain simulations was possible to reduce with approximately 70 %, allowing system operators to perform the estimations in near real-time.

The aim of this article is to consider the existence, uniqueness and uniformly exponential p-stability of the solution for ∇-delay stochastic dynamic equations on time scales via Lyapunov functions...

We develop an iterative, adaptive frequency sensing protocol based on Ramsey interferometry of a two-level system. Our scheme allows one to estimate unknown frequencies with a high precision from short, finite signals. It avoids several issues related to processing of decaying signals and reduces the experimental overhead related to sampling. High precision is achieved by enhancing the Ramsey sequence to prepare with high fidelity both the sensing and readout state and by using an iterative procedure built to mitigate systematic errors when estimating frequencies from Fourier transforms.

The aim of this paper is to evaluate the effect of the load forecasting errors to the operation costs of a grid-connected microgrid. To this end, a microgrid energy scheduling optimization model was tested with deterministic and stochastic formulations under two solution approaches i.e., day-ahead and rolling horizon optimization. In total, twelve simulation test cases were designed receiving as input the forecasts provided by one of the three implemented machine learning models: linear regression, artificial neural network with backpropagation, and long short-term memory. Simulation results of the weekly operation of a real residential building (HSB Living Lab) showed no significant differences among the costs of the test cases for a daily mean absolute percentage forecast error of about 12%. These results suggest that operators of similar microgrid systems could use simplifying approaches, such as day-ahead deterministic optimization, and forecasts of similar, non-negligible accuracy without substantially affecting the microgrid's total cost as compared to the ideal case of perfect forecast. Improving the accuracy would mainly reduce the microgrid's peak power cost as shown by its 20.2% increase in comparison to the ideal case.