1,269 research outputs found
Hung Quoc Nguyen, oboe
Full text linkJohann Sebastian BachWolfgang Amadeus MozartRalph Vaughan William
Hung Quoc Nguyen, oboe
No full textEmile PaladilheCharles Martin LoefflerHenri DutilleuxAntonio Pascull
On the Sobolev space of functions with derivative of logarithmic order
No full textTwo notions of “having a derivative of logarithmic order” have been studied. They come from the study of regularity of flows and renormalized solutions for the transport and continuity equation associated to weakly differentiable drifts
capacity development through social policies
Full text linkThesis(Master) --KDI School:Master of Economics and Public Policy,1999Chapter 1: Introduction And Evaluation Of The Economic Development Process In Viet Nam
Chapter 2: The Poverty Situation In Viet Nam
Chapter 3: Capacity Development Through Basic Education and Training
Chapter 4: Capacity Development Through Basic Health Services for The Rural Poor
Chapter 5: Capacity Development Through Strengthening Social Safety Nets
Chapter 6: Summary And Policy Suggestionsmasterpublishedby Nguyen Quoc Hung
Advection Diffusion Equations with Sobolev Velocity Field
No full textWe prove bounds on the enhanced dissipation rate for Sobolev velocity fields
Sharp regularity estimates for solutions of the continuity equation drifted by Sobolev vector fields
No full textWe prove sharp propagation of regularity for solutions to the ODE with Sobolev velocity field
Sobolev estimates for solutions of the transport equation and ODE flows associated to non-Lipschitz drifts
No full textWe prove dharp regularity estimates for flow maps associated to vector fields with exponentially integrable gradient
Dynamic Spectrum Management for Emerging Integrated SatCom and 5G Networks
Full text linkThe rapid growth of mobile traffic and emerging service requirements have accelerated the evolution of wireless networks, particularly through the integration of satellite communication (SatCom) systems and terrestrial networks (TNs). This convergence has led to Integrated Satellite-Terrestrial Networks (ISTNs), envisioned as a promising enabler of seamless, ubiquitous, and high-capacity connectivity in future 6G networks. By leveraging the strengths of both TNs and satellite networks (SatNets), ISTNs are able to enhance coverage, support direct-to-device (D2D) services, provide satellite-based backhaul, and improve spectrum utilization. However, several key challenges arise due to the dynamic behavior of non-geostationary satellites-especially low Earth orbit (LEO) satellites (LSats), heterogeneous terrestrial environments, uneven traffic demands, spectrum coexistence, and traditional fixed spectrum regulation.
Addressing these challenges necessitates a careful study of various technical issues. To efficiently deliver traffic demands under system constraints, critical technique issues must be addressed, including: (i) bandwidth (BW) allocation across services, systems, and satellite-based backhaul links, (ii) link association among users (UEs), base stations (BSs), LSats, (iii) ensuring seamless connectivity, (iv) comprehensive resource management, encompassing resource block (RB) assignment and power control; and (v) effective traffic management. These issues introduce various problems which must be addressed.
Driven by ISTN scenarios identified by standardization bodies and the aforementioned technique issues, within the scope of this thesis, three critical ISTN problems are considered:
(1) backhaul-link BW allocation and two-tier user association,
(2) throughput enhancement and seamless handover in C-band 5G-ISTNs, and
(3) resource management in dynamic spectrum sharing ISTNs.
The first problem investigates the ISTN scenarios wherein a LEO constellation provides backhaul links for TNs. To efficiently deliver data from UEs to BSs and from BSs to LSats, BW allocation backhaul links, a time-window-based optimization framework is proposed to minimize transmission time through jointly managing two-tier UE-BS-LSat association, backhaul BW allocation, subchannel assignment, and power control. To efficiently solve this challenging non-convex mixed-integer non-linear programming (MINLP) problem, a centralized algorithm is proposed by leveraging successive-convex-approximation (SCA) and compressed-sensing techniques. Furthermore, a decentralized algorithm is developed to support scalable and efficient deployment as well as to offload computations from central node.
The second problem explores ISTNs supporting the co-primary TN-SatNet spectrum use in urban environments, specifically for automotive UEs with both TN and SatNet direct-to-vehicle access. Accordingly, a joint UE association (UA) and power control mechanism is developed to maximize system throughput and minimize connection state changes. To deal with this problem efficiently, two algorithms are developed: an SCA-based algorithm addresses the full time-window problem while a prediction-based one enables the optimization in sequential sub-time-windows.
The third problem introduces a digital-twin (DT)-aided dynamic spectrum sharing (DSS) framework for D2D-enabled ISTNs, where the TN and SatNet share the same 5G-NR band.
The goal is to minimize system congestion via joint optimization of BW slicing, traffic steering, and radio resource management (RRM). This framework comprises two optimization problems: (i) a joint-RA problem based on DT-predicted data for network and resource decisions, and (ii) a refinement problem that updates decisions using real-time feedback. Corresponding algorithms are designed to align with the proposed system architecture.
Extensive simulations are conducted under practical settings, especially ray-tracing (RayT)-based evaluations using realistic 3D maps of London for the second and third problems. Numerical results demonstrate the superior performance of the proposed algorithms for each of the three problems compared to conventional benchmarks in terms of transmission time reduction, throughput improvement, minimized connection transition events, and congestion alleviation, respectively. Overall, this thesis contributes efficient RRM designs for ISTNs across diverse scenarios and highlights promising directions for future ISTN research
Research on the Influence of Electric Vehicle Integration in Island Microgrid, Vietnam
No full text<p><strong>Abstract: </strong>Vietnam's economy is developing strongly, and the demand for energy use will increase rapidly. The development of smart grids contributes significantly to the transition and sustainable development of energy from renewable energy sources to improve the quality of the national power supply and promote the sustainable use of electricity economically and efficiently. Thus, this is highly beneficial in reducing carbon emissions and other types of pollution. Besides, electrification in the transportation industry is developing rapidly, such as Electric Vehicles (EVs) and Metros in recent years. Integrating electric vehicles into the grid will enable two-way energy exchange, reactive power compensation and load balancing. However, the number of EVs participating in charging at a time will cause some conflicts, such as voltage and power loss at the nodes. Therefore, the balancing problem between load demand and generation source is a difficult task in planning operations. This paper presents a method to optimize island Microgrid (MG) operation with the participation of electric vehicles based on renewable energy sources. Optimization techniques in intelligent resource forecasting and management algorithms are built in MATLAB to achieve different requirements. The proposed Microgrid manages energy efficiency that adapts to the variability of Renewable Energy with improved efficiency.</p>
FIGURES 20–25 in Description of Chlorogomphus danhkyi sp. nov. from Vu Quang National Park, central Vietnam with notes on other congeners from the Park (Odonata Chlorogomphidae)
No full textFIGURES 20–25. Appendages of Chlorogomphus spp., ♂. (20, 21), C. nasutus; (22, 23), C. sachiyoae; (24, 25), C. tunti.Published as part of Phan, Quoc Toan, Karube, Haruki, Hung, Nguyen Viet & Anh, Tran Dinh, 2021, Description of Chlorogomphus danhkyi sp. nov. from Vu Quang National Park, central Vietnam with notes on other congeners from the Park (Odonata Chlorogomphidae), pp. 102-110 in Zootaxa 4985 (1) on page 108, DOI: 10.11646/zootaxa.4985.1.6, http://zenodo.org/record/493036
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