An improvement of non-integrated defect relation for meromorphic maps from Kahler manifolds with arbitrary hypersurfaces

Our purpose in this paper is to establish a non-integrated defect relation for meromorphic mappings from a complete Kahler manifold into a projective variety intersecting an arbitrary family of hypersurfaces with explicit truncation level. In our result, both the above bound of the total defect and the truncation level are estimated independently of the number of involving hypersurfaces. Our result generalizes and improves the previous results in this topic.Comment: 15 pages. arXiv admin note: text overlap with arXiv:1712.0569

Analysis of flow characteristics of cylindrical and helical type multi-lobe roots blower

Roots blower is a positive displacement machine that has the advantage of a larger flow than conventional blowers. Roots blowers are widely used in industrial production such as chemicals, food, medical, etc. However, during actual operation, this type of machine often achieves low performance. One of the issues that greatly affect performance is the flow characteristics of the blower. Flow characteristics include factors related to flow rate, pressure, and flow phenomena in the blower chamber. Flow characteristic analysis is a complex problem in hydraulic machines. Flow analysis helps to investigate the motion of the flow to design high-performance machines. This study uses a mathematical model of gear theory to design the rotor profile with cylindrical and helical lobes of the multi-lobe Roots blower. The rotor profile is formed on the principle that the ellipse rolls without slipping on the base circle. On the basis of the mathematical model of the rotor profile, the paper compares the flow rate and pressure characteristics of the two blowers. The fluid dynamics analysis model was built on ANSYS software. The structural grid model is also built to increase the computational efficiency of the mathematical model. The lobes are embedded and rotated in the blower chamber. The results show that with the same radial and axial dimensions, the cylindrical lobe has a larger flow. However, the helical lobe has a more stable flow quality than the cylindrical lobe (15.2 % less flow fluctuation). In terms of pressure, the helical lobe type has a higher pressure than the cylindrical lobe type. In addition, the helical lobe type also reduces the influence of eddy currents acting on the blower chamber walls and rotors. That results in increased blower efficiency. The results of the paper will be a reliable basis for reducing time in the development of multi-lobe Roots blowers with high performanc

Determinants Influencing Liquidity of Listed Steel Firms in Vietnam

This study is conducted to investigate the impact levels of determinants influencing liquidity of listed steel firms on Vietnam Stock Exchange. Data were collected from audited financial statements of 25 listed food processing firms from 2014 to 2017. This research employs the least squares method (OLS) and tests to determine the influence of factors on the liquidity of listed sample firms. The results indicate that return on assets (ROA), operating period (AGE) and asset structure (AS) have positive impacts on the liquidity. In contrast, the firm size and debt ratio has the opposite effects. Based on the findings, a number of recommendations are proposed to increase the liquidity ratio of listed firms in the future. Keywords: Liquidity, steel firms, determinants, Vietnam Stock Exchange DOI: 10.7176/EJBM/11-7-10 Publication date:March 31st 201

Strengthen roles of commercial banks in vietnam economy– a case of eximbank

Is it the time for us to evaluate roles of Vietnam commercial banks and importance of risk management activities? This paper uses both quantitative analysis with statistical data and charts, combined with qualitative analysis including synthesis, inductive and explanatory methods in order to estimate and compare market risk via beta CAPM of Eximbank (EIB) and Asia Commercial Bank (ACB), 2 big listed joint stock banks in Vietnam. Research findings show us that market risk of Eximbank is higher and increase during post-low (L) inflation stage, compared to pre-L inflation time. Results may be used for policy implications and research models can be references for other countries including emerging markets

Improvement of Tuning Fork Gyroscope Drive-mode Oscillation Matched using a Differential Driving Suspension Frame

This paper presents a novel design of a vibration tuning fork gyroscope (TFG) based on a differential driving suspension coupling spring between two gyroscopes. The proposed TFG is equivalent to a transistor differential amplifier circuit. The mechanical vibrations of driving frames are, therefore, well matched. The matching level depends on stiffness of spring. When three various TFG structures respond to differential stiffness of spring, their the driving frame mechanical vibration is well matched in case the input excitation driving differential phase is less than 3.5°, 2.5°, and 4°, respectively. The fabricated tuning fork gyroscope linearly operates in the range from -200 to +200 degree/s with the resolution of about 0.45 mV/degree/s

Catalytic Dye Oxidation over CeO2 Nanoparticles Supported on Regenerated Cellulose Membrane

A novel regenerated cellulose (RC) membrane containing cerium oxide (CeO2) nanoparticles is described in detail. In this work, CeO2 nanoparticles with high surface area and mesoporosity were prepared by a modified template-assisted precipitation method. Successful synthesis was achieved using cerium nitrate as a precursor, adjusting the final pH solution to around 11 by ammonium hydroxide and ethylene diamine, and annealing at 550 °C for 3 hours under a protective gas flow. This resulted in a surface area of 55.55 m².g–1 for the nanoparticles. The regenerated cellulose membrane containing CeO2 particles was synthesized by the novel and environmentally friendly method. The catalyst CeO2 and cellulose/CeO2 membrane were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Electron paramagnetic resonance (EPR), and Brunauer-Emmett-Teller (BET) measurements. The g-value of 2.276 has confirmed the presence of the surface superoxide species of CeO2 nanoparticles in EPR. The photocatalytic activity of the catalyst and the membrane containing the catalyst was evaluated through the degradation of methylene blue under visible light irradiation by UV-VIS measurements. The cellulose/CeO2 membrane degraded 80% of the methylene blue solution in 120 minutes, showing a better photocatalytic activity than the CeO2 catalyst, which degraded approximately 62% in the same period. It has been proven that the RC membrane is not only a good transparent supporting material but also a good adsorption for high-performance of CeO2 catalyst. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Effects of Internal Factors on Financial Performance of Listed Construction-Material Companies: The Case of Vietnam

The research aims to assess internal factors affecting to financial performance so that feasible suggestions could be provided for construction-material firms which are currently listing in the stock market of Vietnam. The authors applied regression for panel data which collected from 30 listed construction-material firms. The findings show that firms’ financial performance are positively affected by the firms’ size, capital structure, capitalization expenditure, and accounts receivable management. The research results also reflect positive relation between firms’ financial performance and business risk. Upon the research results we recommend that the changes should be focus on improving policies about capitalization expenditure; reasonable capital structure and management of inventories. Keywords: financial performance, construction-material, listed firms, Vietna

Domestic Enterprises in Supply Chains of Multinational Corporations: Vietnam Case Study

Abstract—Vietnam’s international integration has also changed rapidly with the trend of gradually entering the global supply chain (GSC) and global value chain (GVC) that help create a powerful dynamic for national economic development. However, the main activities of the manufacturing subsidiaries of reputable MNCs located in Vietnam often specialize in the final product assembly (final assembly schedule-FAS). Correlatively, some Vietnam’s domestic enterprises (VDEs) are engaged either in outsourcing, or become MNC suppliers, but their position in the SCs is unstable. In this article, synthesis methodology and framework of analysis were used to clarify the status of Vietnam’s suppliers and their limited power in buyer-supplier relationships and to make some recommendations that may be useful to related parties. The article also provides an overview of the unprecedented impacts of the COVID-19 pandemic on Vietnamese businesses, and the appropriate responses to reshape and strengthen SCs for production in VietNam

Building Footprint Extraction in Dense Areas using Super Resolution and Frame Field Learning

Despite notable results on standard aerial datasets, current state-of-the-arts fail to produce accurate building footprints in dense areas due to challenging properties posed by these areas and limited data availability. In this paper, we propose a framework to address such issues in polygonal building extraction. First, super resolution is employed to enhance the spatial resolution of aerial image, allowing for finer details to be captured. This enhanced imagery serves as input to a multitask learning module, which consists of a segmentation head and a frame field learning head to effectively handle the irregular building structures. Our model is supervised by adaptive loss weighting, enabling extraction of sharp edges and fine-grained polygons which is difficult due to overlapping buildings and low data quality. Extensive experiments on a slum area in India that mimics a dense area demonstrate that our proposed approach significantly outperforms the current state-of-the-art methods by a large margin.Comment: Accepted at The 12th International Conference on Awareness Science and Technolog