1,401 research outputs found

    Extended network and algorithm finding maximal flows

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    Graph is a powerful mathematical tool applied in many fields as transportation, communication, informatics, economy, In ordinary graph the weights of edges and vertexes are considered independently where the length of a path is the sum of weights of the edges and the vertexes on this path. However, in many practical problems, weights at a vertex are not the same for all paths passing this vertex, but depend on coming and leaving edges. The paper develops a model of extended network that can be applied to modelling many practical problems more exactly and effectively. The main contribution of this paper is algorithm finding maximal flows on extended networks

    Enhancing Security and Robustness for SDN-Enabled Cloud Networks

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    Software-Defined Networking is an emerging network architecture which promises to solve the limitations associated with current cloud computing systems based on traditional network. The main idea behind SDN is to separate control plane from networking devices, thereby providing a centralized control layer integrable to cloud-based infrastructure. The integration of SDN and Cloud Computing brings an immense benefits to network deployment and management, however, this model still faces many critical challenges with regards to availability, scalability and security. In this study, we present a security and robustness SDN-Enabled Cloud model using OpenStack and OpenDaylight. In particular, we design and implement a security clustering-based SDN Controller for monitoring and managing cloud networking, and a hardware platform to accelerate packet processing in virtual switches. We evaluate our proposed model on a practical cloud testbed consisting of several physical and virtual nodes. The experiment results show that the SDN controller cluster significantly improve robustness for the network even in case of being attacked by abnormal network traffic; while the hardware-accelerated switches can be operated in highperformance and well-adapted to the cloud environment

    Combined adaptive lattice reduction-aided detection and antenna shuffling for DSTTD-OFDM systems

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    In this paper, we consider lattice reduction (LR) aided linear detection in a DSTTD-OFDM (double space-time transmit diversity- orthogonal frequency division multiplexing) system with antenna shuffling. We first derive an antenna shuffling criterion for the LR-aided DSTTD-OFDM system. Next, we propose a combined reduced-feedback and adaptive LR algorithm by exploiting the correlation between OFDM subcarriers in the frequency domain. The LR-aided DSTTD OFDM system with this algorithm requires low computational effort for the LR operation and small feedback information. Simulation results show that a significant improvement could be achieved in the proposed system compared to previous (non-LR-aided) systems under spatially correlated channels. Also, the proposed complexity-reduced approach could greatly lower the system complexity while exhibiting a slight performance loss

    Using Pictures As Non-Verbal Language Motivating Students With English Speaking Lessons At Vietnam Primary Schools

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    The study investigates the reality of students' low participation in speaking activities and the possibility of using pictures to increase their participation in classroom speaking activities if necessary. The reason for this research is the lack of using pictures as the visual aids to teach speaking skill for the students in Vietnam’s context. Although several studies have been conducted on these subjects with different approaches, Vietnamese students, especially the primary ones, are not paid much attention as an investigated object. By using methods of questionnaires and tests (pre-tests and post-tests) combined with qualitative analytical analysis, as well as taking 50 students in grade 4 of a primary school in Hanoi as the objects to assess their current situation of learning English with pictures. The research findings indicate that students are more interested in learning English speaking when using pictures. Moreover, the students’ learning strategies and students’ attitude towards learning English are the two main causes that make them have low motivation in learning. In all, motivation and performance of students after the process of applying pictures in learning English presented an improvement. The results of this study are expected to be beneficial for the teachers in conducting the teaching curriculum as they can apply pictures as effective supporters

    K.Marx-Engels and Ho Chi Minh Viewpoints on Journalism - and Two Fake News Publishing Cases of Thanhnien.vn and Tuoitre.vn (Online Magazines) in Vietnam and Lessons from Indonesia, Japan Approaches

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    In this paper, by using qualitative analytical analysis with 2 case examples of Thanh nien and Tuoi tre newspapers (online) in Vietnam, in which there are history of publishing fakes news online from 2015, 2016, 2018, 2022 (with very bad editors Nguyen Ngoc Toan and Dang Thi Phuong Thao), as well as giaoduc.edu.vn and vietnamnet.vn in 2022 so we will address some points in this study based on answers for question: “What are regulatory lessons from Indonesia and Japan approaches on publishing fake news?”. We would suggest that there are penalties for negative behaviors of posting fake news online (any fake information) in the context of covid 19 epidemic. Tapsell (2019) defined ‘hoax news’ as similar to the more globally recognized term ‘fake news’: material deliberately fabricated and masqueraded as truth. At last, we will draw some lessons from K.Marx and Ho Chi Minh viewpoints on journalism for educating young generation in emerging markets such as Vietnam

    Rethinking urban streams : opportunities for the Nhieu Loc -- Thi Nghe River

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    Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2008.Includes bibliographical references (p. 109-114).In the process of rapid expansion, many cities have turned their backs on the rivers that helped form and nurture them. Due to the perceived low cost of their existing infrastructure, many rivers have become open or enclosed sewerage and drainage channels. In the past few decades, better scientific understanding and improved management practices have spurred a global river restoration and conservation movement. This thesis studies the paradigm shift from controlling urban streams as landscape features and liabilities to managing whole watersheds as ecosystems and assets. It examines examples of successful river restoration and conservation projects, and uses the lessons learned from these examples to suggest improvements to the management of the Nhieu Loc - Thi Nghe River in Ho Chi Minh City, Vietnam. The Ho Chi Minh City River Environmental Sanitation project of the late 1990s in the Nhieu Loc - Thi Nghe Basin was the first of its kind in Ho Chi Minh City. The project has been hailed as a successful urban regeneration project which exemplifies good practice. This thesis analyses the merits and missed opportunities of these projects and suggests ways to incorporate other ecological and cultural functions into the Nhieu Loc Thi Nghe River, drawing on lessons from successful river restorations in the United States and South Korea.by Tran N. Le.M.C.P
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