Side-Information Coding with Turbo Codes and its Application to Quantum Key Distribution

Turbo coding is a powerful class of forward error correcting codes, which can achieve performances close to the Shannon limit. The turbo principle can be applied to the problem of side-information source coding, and we investigate here its application to the reconciliation problem occurring in a continuous-variable quantum key distribution protocol.Comment: 3 pages, submitted to ISITA 200

State of charge estimation for lithium-ion batteries connected in series using two sigma point Kalman filters

This paper proposes a method to estimate state of charge (SoC) for Lithium-ion battery pack (LIB) with series-connected cells. The cell’s model is represented by a second-order equivalent circuit model taking into account the measurement disturbances and the current sensor bias. By using two sigma point Kalman filters (SPKF), the SoC of cells in the pack is calculated by the sum of the pack’s average SoC estimated by the first SPKF and SoC differences estimated by the second SPKF. The advantage of this method is the SoC estimation algorithm performed only two times instead of times in each sampling time interval, so the computational burden is reduced. The test of the proposed SoC estimation algorithm for 7 samsung ICR18650 Lithium-ion battery cells connected in series is implemented in the continuous charge and discharge scenario in one hour time. The estimated SoCs of the cells in the pack are quite accurate, the 3-sigma criterion of estimated SoC error distributions is 0.5%

Computing Graph Roots Without Short Cycles

Graph G is the square of graph H if two vertices x, y have an edge in G if and only if x, y are of distance at most two in H. Given H it is easy to compute its square H2, however Motwani and Sudan proved that it is NP-complete to determine if a given graph G is the square of some graph H (of girth 3). In this paper we consider the characterization and recognition problems of graphs that are squares of graphs of small girth, i.e. to determine if G = H2 for some graph H of small girth. The main results are the following. - There is a graph theoretical characterization for graphs that are squares of some graph of girth at least 7. A corollary is that if a graph G has a square root H of girth at least 7 then H is unique up to isomorphism. - There is a polynomial time algorithm to recognize if G = H2 for some graph H of girth at least 6. - It is NP-complete to recognize if G = H2 for some graph H of girth 4. These results almost provide a dichotomy theorem for the complexity of the recognition problem in terms of girth of the square roots. The algorithmic and graph theoretical results generalize previous results on tree square roots, and provide polynomial time algorithms to compute a graph square root of small girth if it exists. Some open questions and conjectures will also be discussed

Online learning negotiation: Native-speaker versus nonnative speaker teachers and Vietnamese EFL learners

Online English language teaching can now be facilitated by communication technology, which allows easy access to interaction with native speakers. Nevertheless, this industry subscribes to an assumption that native speaker English teachers (NESTs) are the gold standard of language whereas the non-native speaker English teachers (NNESTs) are inferior educators (Walkinshaw & Duong, 2014). Rare research has provided evidence of the negotiation produced by NESTs versus NNESTs with EFL learners online and its impact on the learners’ output. Thus, the current study narrows this empirical gap. Drawing upon a database of 30 five-minute interaction sessions between 30 teachers (15 NESTs and 15 NNESTs) and 30 basic level Vietnamese EFL adult learners, the study revealed similar negotiation of meaning functions as reported in previous research. However, the NESTs used more elaboration while the NNESTs used more confirmation checks, clarification requests, and reply clarification. Qualitative analysis further indicated that the NNESTs provided more productive support, encouraging the learners’ output, than the NESTs did. This implies that although online voice interaction creates an environment for EFL learners to practice, language educators and teachers, regardless of status, should heed how to handle it so that online learners can benefit from both comprehensible input and opportunities for pushed output

Copyright in Universities: An Exploratory Study from Vietnam

International law and the laws of most nations today acknowledge and safeguard the intellectual property rights of both organizations and individuals. This recognition serves to stimulate innovative and creative endeavors, facilitate the dissemination of scientific, technological, cultural, and artistic advancements, foster economic and societal development, and enhance the overall quality of life. Intellectual property assumes a critical role as a driving force behind innovation and creativity, fostering the growth of a nation's intellectual assets in terms of both quantity and value. This, in turn, contributes to bolstering creative capabilities and fostering a healthy competitive environment. Nevertheless, intellectual property rights violations are not uncommon, particularly in the context of higher education institutions in Vietnam. In this article, the authors employ qualitative research methods, following the "three-step test" outlined in the Berne Convention of 1971 for the protection of literary and artistic works, in conjunction with the stipulations of Vietnamese Intellectual Property Law. The results of this examination aid in the identification and location of infringements on the author's rights, such as inappropriate citation and plagiarism within university settings. Subsequently, the authors propose various solutions, which include legal adjustments, strategies for managing intellectual property, the establishment of cross-sectoral and inter-university networks, and the regulation of the responsibilities of scientific councils. These measures are intended to mitigate instances of intellectual property rights violations within Vietnamese universities in the present day. Keywords: Copyright, three-step test, intellectual property rights, infringement, universities… DOI: 10.7176/JLPG/137-02 Publication date:October 31st 202

Energy-efficient routing in the proximity of a complicated hole in wireless sensor networks

AbstractA quest for geographic routing schemes of wireless sensor networks when sensor nodes are deployed in areas with obstacles has resulted in numerous ingenious proposals and techniques. However, there is a lack of solutions for complicated cases wherein the source or the sink nodes are located close to a specific hole, especially in cavern-like regions of large complex-shaped holes. In this paper, we propose a geographic routing scheme to deal with the existence of complicated-shape holes in an effective manner. Our proposed routing scheme achieves routes around holes with the (1+$$\epsilon$$ ϵ )-stretch. Experimental results show that our routing scheme yields the highest load balancing and the most extended network lifetime compared to other well-known routing algorithms as well

Optimal Design of V-Shaped Fin Heat Sink for Active Antenna Unit of 5G Base Station

The active antenna unit (AAU) is one of the main parts of the 5G base station, which has a large size and a high density of chipsets, and operates at a significantly high temperature. This systematic study presents an optimal design for the heat sink of an AAU with a V-shaped fin arrangement. First, a simulation of the heat dissipation was conducted on two designs of the heat sink – in-line and V-shaped fins – which was validated by experimental results. The result shows that the heat sink with V-shaped fins performed better compared to conventional models such as heat sinks with in-line fins. Secondly, computational fluid dynamics (CFD) and the Lagrange interpolation method were applied to find out an optimal set of design parameters for the heat sink. It is worth noting that the optimal parameters of the orientation angle and fin spacing considerably affected the heat sink’s performance.