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Challenges associated with leadership practices are rapidly increasing, thereby assigning more qualities to leaders. One of the recent theoretical issues that interest many scholars is ethical leadership development, using industrial revolution 4.0. This method does not only follow the traditional leadership styles, rather it is associated with universal qualities such as respect, service, fairness, honesty, and responsibility. For communities, increasing assertions is one of the essential foundations used to help leaders influence their subordinates' actions. This means that ethical leadership is the motto of the spirit of service leadership, especially for Vietnam leaders, a country with a strong transformation from a planned economy to a socialist-oriented market. Therefore, leadership values need to be adjusted, supplemented, and developed to keep up with the Industrial Revolution's requirements 4.0.

Methane gas is one of the most serious dangers of undergroundcoal mining as its buildup can lead to methane gas explosion. InQuangNinh province- Vietnam, several coal mines such as TrangKhe II-IIIcoal mine, Khe Cham coal mine, especially MaoKhe mine that have highmethane content. At the MaoKhe coal mine,experimental data showedthatthe concentration of methane in coal seams at different depths were notsimilar.In order to ensure safety, this report has been undertaken todetermine a pattern of changing methane contents of coal seams atdifferent exploitation depths in MaoKhe underground coal mine.

Introduction The purpose of this study was to analyse the outcomes of endovascular aneurysm repair (EVAR) in patients with aortic aneurysms with short and angulated aortic neck. Methods This was a retrospective case series of single centre experience. Patients diagnosed with infrarenal abdominal aneurysm with or without iliac aneurysm who underwent endovascular treatment between May 2012 and August 2020 were included in the study. Results Standardised information of 95 patients who met the inclusion criteria was documented (71 males, 24 females; average age: 73.8 ± 17.6 years). There were 45 patients in group H (short and/or angulated aortic neck anatomy) and 54 patients in group F (control group). The clinical presentations, intervention-related characteristics, and early as well as mid-term results were not statistically different between the two groups. In group H, cases of short aortic neck had higher risk of early type IA endoleak (4 patients, 57.1%). Conclusion Endovascular aneurysm repair in the treatment of infrarenal abdominal aortic aneurysm is considered safe and effective in cases of both groups. Treatment outcomes and complications were not statistically different between the groups. Nevertheless, cases of aortic short neck had a greater risk of early type IA endoleak and reintervention.

Mine ventilation aims to dilute toxic gas concentrations, dilute dust concentrations, remove them from the mine and ensure pleasant microclimate conditions in the mine, especially at work sites. Currently, in underground coal mines in general and in Giap Khau mine area, Hon Gai coal company, in particular, is in the process of converting the mining area into deep, as well as increasing output. Therefore, it is important to ensure that ventilation is a top priority in long-term occupational safety and meets the plan to increase coal production. In this study, we have evaluated the current state of ventilation in Giap Khau mine area. From those research results, on the basis of computational research methods, we have come up with reasonable solutions to change and improve ventilation efficiency for the mine in the condition of complicated mining plan and technology characteristics are still limited compared to those in the world. Specific solutions solve 2 problems: First, ensure ventilation for the current mining operation stage; Secondly, we have researched and proposing suitable solutions for ventilation of Giap Khau area mine when it has to increase production and move down to an adjacent project at a deeper level.

We propose a 4x4 small size optical mode switch applied for photonics integrated circuits. The proposed device consists of four Multimode Interference (MMI) couplers based on silicon material and ten phase shifters appropriately placed between ones. The fundamental modes at the input are selectively switched to the desired outputs by controlling the phase shifters. Through a beam propagation simulation method (BPM) combined with an effective index method (EIM), we evaluate the efficiency of optical conversion when transmitting signals from any input to arbitrary outputs of the device. At the center wavelength of 1.55 µm, the insertion loss is always less than 0.3 dB, and the crosstalk is always from -80 dB to -30 dB in the entire C-band.

In the next time, deepening exploitation and increasing capacity in underground mines are extremely necessary to meet the demand of using coal for developing economies. This problem is not only done in underground mines but also in areas that cannot be exploited by open-pit methods such as the open-pit edge. When exploiting deep underground mines, there are many difficulties for tasks such as: controlling ground pressure; ventilation; drainage, transportation etc. When cutting coal in longwall, it will create a goaf, causing a natural imbalance of stress in the ground, leading to the phenomenon of displacement of rock deformation and destruction of roadways, which creates a risk of unsafety labour. The L7 seam at the west wing area of the Mong Duong coal mine has an average thickness of 7m, an average slope angle of 15o, located near the edge of the 790 open pit site. According to the production plan, this mine will exploit this reservoir with blasting-drilling technology, longwall support by the semi-mechanized shield (self-moving hydraulic frame GK/1600/16/24/HTD). The preliminary assessment of hydrogeological conditions of the mine shows that this is a potential area with a high risk of water burst into the longwall. Until nowthis mine has not yet given a specific solution to this problem. Finding a reasonable mining solution to ensure production safety and reduce resources loss is extremely important problem not only for the Mong Duong coal mine but also for mines that have similar mining conditions of Vietnam National Coal – Mineral Industries Holding Limited (Vinacomin), Vietnam.

The extraction with higher cutting height for extra-thick seam is the new research orientation in longwall caving technology. Due to the increase of top coal thickness and of cutting height which leads to the change of cutting/caving height ratio, the rule of roof failure (including top coal caving) and the distribution of stress around the face alter correspondingly. This paper is based on the geological conditions of face 8102 of Tashan-DaTong mine, employing the numerical model by UDEC2D code, analysing the effect of cutting/caving height ratio on the law of stress distribution ahead of the face. When the ratio of cutting/caving height decreases and the cutting height increases, the results of the research have shown that: (i)- peak stress redistributes further ahead of the face and its value manifestly drops; (ii)- the plastic deformation ahead of face significant increases and the zone of plastic strain also expands. It is therefore concluded that the variation of cutting/caving height ratio results in the redistribution of roof pressure, which contributes to the control of roof failure and face stability.

In this work, we report on the structural and thermoelectric properties of Sb2Te3 films deposited on GaSb(111) substrates by using molecular beam epitaxy. The effects of the growth temperature on the microstructure and thermoelectric properties of the films were investigated. The results show that Sb2Te3 films grow on GaSb(111) along (00l) axis normal to the substrate and have a hexagonal structure with a layer-by-layer growth mode in growth temperature range from 200 to 250 °C while at 175 and 300 °C, the films show an island growth mode. Te and Sb2Te3 phases coexist at a growth temperature of 175 °C. The films exhibit a metallic behavior for growth temperatures below 250 °C and a semiconductor behavior at 300 °C. By changing growth temperature, we were able to vary the carrier density from 9.96×1018 to 4.55×1019 cm −3. At room temperature, the Seebeck coefficients are 110, 146, and 138 μV/K for growth temperatures of 175, 200 and 250 °C, respectively, and a large value of the power factor 61.67 μW/cm-K2 is achieved for the film grown at 250 °C.

Facial micro-expression recognition has attracted researchers in terms of its objectiveness to reveal the true emotion of a person. However, the limited number of publicly available datasets on micro-expression and its low intensity of facial movements have posed a great challenge to training robust data-driven models for recognition task. In 2019, Facial Micro-Expression Grand Challenge combines three popular datasets, i.e. SMIC, CASME II, and SAMM into a single cross-database which requires the generalization of proposed method on a wider range of subject characteristics. In this paper, we propose a simple yet effective CapsuleNet for micro-expression recognition. The effectiveness of our proposed methods was evaluated on the cross-database micro-expression benchmark using the Leave-One-Object-Out cross-validation. The experiments show that our method achieved superiorly higher results than the baseline method (LBP-TOP) provided and other state-of-the-art CNN models.

Although accurate, two-stage face detectors usually require more inference time than single-stage detectors do. This paper proposes a simple yet effective single-stage model for real-time face detection with a prominently high accuracy. We build our single-stage model on the top of the ResNet-101 backbone and analyze some problems with the baseline single-stage detector in order to design several strategies for reducing the false positive rate. The design leverages the context information from the deeper layers in order to increase recall rate while maintaining a low false positive rate. In addition, we reduce the detection time by an improved inference procedure for decoding outputs faster. The inference time of a VGA ($640{\times}480$) image was only approximately 26 ms with a Titan X GPU. The effectiveness of our proposed method was evaluated on several face detection benchmarks (Wider Face, AFW, Pascal Face, and FDDB). The experiments show that our method achieved competitive results on these popular datasets with a faster runtime than the current best two-stage practices.

This paper presents the free vibration of a cracked double-beam carrying a concentrated mass located at an arbitrary position. The double-beam consisting of two different simply supported beams connected by an elastic medium is modelled by using finite element method. The influence of the concentrated mass on the frequencies and mode shapes is investigated. The relationship between the natural frequency and the location of concentrated mass is established and related to the mode shapes. The numerical simulations show that when there is a crack, the frequency of the double-beam changes sharply when the concentrated mass is located close to the crack position. This sharp change can be amplified by wavelet transform and this is useful for crack detection. The crack location can be determined by the location of peaks in the wavelet transform of the relationship between frequency and mass location.

A novel Heusler ferrimagnet Ti2MnAl film has been grown on Si(001) substrate using magnetron sputtering. Characteristics of its magnetic and transport properties reveal the spin-gapless-semiconductor (SGS) nature of the stoichiometric Ti2MnAl, in agreement with theoretical prediction. The as-grown SGS-like Ti2MnAl film demonstrated high Curie temperature, nearly compensated ferrimagnetic properties with small coercivity and low magnetization. It also showed semiconductor-like behavior at room temperature allowing good compatibility with commercial Si-based semiconductor. In this regards, Ti2MnAl film is a potential candidate material for spintronics application, especially for the minimization of energy consumption of device. (© 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)

We forecasted potential impacts of climate change on the ability of a network of key sites for bird conservation (Important Bird Areas; IBAs) to provide suitable climate for 370 bird species of current conservation concern in two Asian biodiversity hotspots: the Eastern Himalaya and Lower Mekong. Comparable studies have largely not accounted for uncertainty, which may lead to inappropriate conclusions. We quantified the contribution of four sources of variation (choice of general circulation models, emission scenarios and species distribution modelling methods and variation in species distribution data) to uncertainty in forecasts and tested if our projections were robust to these uncertainties. Declines in the availability of suitable climate within the IBA network by 2100 were forecast as ‘extremely likely’ for 45% of species, whereas increases were projected for only 2%. Thus, we predict almost 24 times as many ‘losers’ as ‘winners’. However, for no species was suitable climate ‘extremely likely’ to be completely lost from the network. Considerable turnover (median = 43%, 95% CI = 35–69%) in species compositions of most IBAs were projected by 2100. Climatic conditions in 47% of IBAs were projected as ‘extremely likely’ to become suitable for fewer priority species. However, no IBA was forecast to become suitable for more species. Variation among General Circulation Models and Species Distribution Models contributed most to uncertainty among forecasts. This uncertainty precluded firm conclusions for 53% of species and IBAs because 95% confidence intervals included projections of no change. Considering this uncertainty, however, allows robust recommendations concerning the remaining species and IBAs. Overall, while the IBA network will continue to sustain bird conservation, climate change will modify which species each site will be suitable for. Thus, adaptive management of the network, including modified site conservation strategies and facilitating species' movement among sites, is critical to ensure effective future conservation.