Analysis of the mean squared derivative cost function

In this paper, we investigate the mean squared derivative cost functions that arise in various applications such as in motor control, biometrics and optimal transport theory. We provide qualitative properties, explicit analytical formulas and computational algorithms for the cost functions. We also perform numerical simulations to illustrate the analytical results. In addition, as a by-product of our analysis, we obtain an explicit formula for the inverse of a Wronskian matrix that is of independent interest in linear algebra and differential equations theory.Comment: 28 page

Real-time Optimal Resource Allocation for Embedded UAV Communication Systems

We consider device-to-device (D2D) wireless information and power transfer systems using an unmanned aerial vehicle (UAV) as a relay-assisted node. As the energy capacity and flight time of UAVs is limited, a significant issue in deploying UAV is to manage energy consumption in real-time application, which is proportional to the UAV transmit power. To tackle this important issue, we develop a real-time resource allocation algorithm for maximizing the energy efficiency by jointly optimizing the energy-harvesting time and power control for the considered (D2D) communication embedded with UAV. We demonstrate the effectiveness of the proposed algorithms as running time for solving them can be conducted in milliseconds.Comment: 11 pages, 5 figures, 1 table. This paper is accepted for publication on IEEE Wireless Communications Letter

Clean Energy and Sustainable Development lab activity report, 2014-09-31 to 2015-12-31

The Clean Energy and Sustainable Development laboratory – CleanED – was established in December 2014 with support from USTH and French Embassy in Hanoi. In September 2015, CleanED lab counted five researchers from France and Vietnam, five doctoral fellows and two internationally qualified staff. This international and interdisciplinary research team gets the mission to contribute to the green growth of the energy sector in Vietnam. Its expertise ranges from engineering to public policy on:Natural resources characterization and managementBiomass and waste to energy conversion process technologiesEnergy systems optimization from smart grid to national plan

Perspective of CO2 capture & storage (CCS) development in Vietnam: Results from expert interviews

International audienceThis paper summarizes expert opinions regarding crucial factors that mayinfluence Vietnam’s future use of carbon capture and storage (CCS) based onface-to-face interviews in December 2013 with 16 CCS-related experts fromthe Vietnamese government, research institutes, universities and the energyindustrial sector. This study finds that financial incentives and climate policyare the most important factors for the development of CCS technologies inVietnam in the next two decades. Financial incentives involve direct subsidiesfrom the government, such as tax exemptions for land use and the importationof CCS-related equipment. In addition, all the experts agree that internationalfinancial support is important to initiate a large deployment of CCStechnologies in Vietnam by implementing demonstrative/pilot projects to proveCCS’s working efficiency

Costs and Benefits of a Greener Alternative for the Development of Vietnam's power sector

International audienceIn this study, BAU (a scenario based on current trends) and ALT (a greener alternative with more renewables, higher energy efficiency) are developed. The external costs of CO 2 , NOx, SO 2 and PM 10 in the Vietnamese power sector are estimated at 20, 1328, 2047 and 1460 US$/ton, respectively. The authors find that the electricity price and the domestic trade balance in ALT are less sensitive to fluctuations in the international price of coal than in BAU. The total costs accumulated between period 2010-2040 would be lower in ALT: 632 billion US$ compared with 974 billion US$. This difference arises from several factors: lower investment in new capacity (226 vs 306 billion US$); lower local pollution costs (73 vs 137 billion US$); and lower expenditures on imported fuels (57 vs 115 billion US$). The outcomes of ALT are in accord with the targets in the most recent Green Growth Strategy of Vietnam

Low Carbon Scenario for the Power Sector of Vietnam: Externality and Comparison Approach

International audienceIn this paper, BAU (a scenario based on current trends) and ALT (a greener alternative with more renewables, higher energy efficiency) are developed. The external costs of CO2, NOx, SO2 and PM10 in the Vietnamese power sector are estimated at 20, 1328, 2047 and 1460 US$/ton, respectively. The authors find the electricity price and the domestic trade balance in ALT less sensitive to fluctuations in the international price of coal than in BAU. The total costs accumulated between the period of 2010-2040 would be lower in ALT: 632 billion US$ compared with 974 billion US$. This difference arises from several factors: lower investment in new capacity (226 vs 306 billion US$); lower local pollution costs (73 vs 137 billion US$); and lower expenditures on imported fuels (57 vs 115 billion US$). The outcomes of ALT are in accord with the targets in the most recent Green Growth Strategy of Vietnam and the Intended Nationally Determined Contributions (INDCs) of the country to UNFCCC and COP21

INVESTIGATING EFL TEACHERS’ PERCEPTIONS OF IMPLEMENTING ACTIVE LEARNING TECHNIQUES IN TEACHING SPEAKING

Active learning (AL) is widely implemented in Asia including Vietnam. However, to date, research on this method seems to be scarce, particularly in the context of Vietnam. This study aims to investigate teachers' perceptions of AL and its principles in teaching English speaking. In addition, the study also explores teachers’ attitudes about AL implementation and their concerns about applying this method to their teaching context. Ten teachers of English teaching at a university in the Mekong Delta, South of Vietnam participated in the study. A semi-structured interview activity was employed to collect data. The results showed that the teachers generally had a high level of understanding of AL teaching principles and showed positive attitudes toward the implementation of it. The results also revealed teachers’ concerns about implementing AL. In particular, three problems of large class size, students’ mixed language proficiency and time limitation were addressed. Accordingly, possible suggestions for a better implementation of AL in teaching English speaking in Vietnam and similar contexts elsewhere will be provided.  Article visualizations

Socio-economic impacts of co-firing in Vietnam: The case of Ninh Binh Coal Power Plant

International audienceCo-firing biomass with coal is a relatively low-cost technology to utilize biomass for electricity production compared to dedicated biomass power plant. Co-firing could help to reduce the negative impact of coal power plants to economy, environment and society. Vietnam has potential to develop co-firing base on the abundant of biomass resources and because Vietnam will continue to build more coal-fired power plant in the next 2 decades as stated in the latest National Power Development Plan.Among the co-firing technologies, direct co-firing is the most suitable for Vietnam context. Despite of low biomass ratio, direct co-firing offers low investment cost and could utilize most of the biomass feedstock. Vietnam has huge biomass potential, especially the agriculture and forestry residues. These biomasses should be considered first as feedstock for co-firing. Biomass pellets is also a good choice in term of technical features and local supply. However, the price of pellets is not yet competitive with coal or agricultural residues.Economic benefit of co-firing would be higher in the plants that has following features: assess to stable biomass supply, biomass price competitive with coal, incentives and support in term of market for renewable energy utilization and waste reduction. Vietnam should start experimenting co-firing in the coal power plants that located in the area where biomass resource is available, easy to collect and deliver to the plant, using imported coal such as Vinh Tan 2, Duyen Hai 1, Long Phuoc 1…; or the plants that are soon or already depreciated such as Ninh Binh, Uong Bi or Pha Lai to utilize the existing infrastructures.The case study of co-firing 5% rice straw with coal in Ninh Binh Coal Power Plant shows that co-firing could bring benefit to the plant owner in the condition that lack supporting mechanism for co-firing as well as with the absent of carbon credit. Farmers and workers that work in biomass supply chain also benefit from co-firing, especially farmers. In addition, co-firing provide significant positive externalities, in which the most notable is health benefit from reducing air-borne pollutants. Greenhouse gas emissions reduction adds a small part to the overall benefit of co-firing

Phân tích chi phí-lợi ích của đồng đốt sinh khối với than: Trường hợp nhà máy nhiệt điện Ninh Bình

National audienceĐồng đốt sinh khối với than là công nghệ tận dụng sinh khối để phát điện với mức chi phí thấp hơn rấtnhiều so với việc xây dựng nhà máy điện sinh khối. Đồng đốt giúp giảm bớt tác động của nhiệt điện thanđến kinh tế, môi trường và xã hội. Việt Nam có tiềm năng phát triển công nghệ này do có tiềm năng lớn vềsinh khối cũng như do Việt Nam sẽ tiếp tục phát triển các nhà máy nhiệt điện than trong vòng 2 thập kỷ tớitheo như Quy hoạch điện mới nhất.Trong số các công nghệ đồng đốt, đồng đốt trực tiếp là công nghệ phù hợp nhất đối với điều kiện Việt Namhiện nay. Mặc dù tỉ lệ đồng đốt thấp nhưng chi phí chuyển đối thấp nhất và có thể tận dụng hầu hết cácloại sinh khối. Việt Nam có nguồn sinh khối dồi dào, đặc biệt là nguồn phụ phẩm, phế phẩm nông nghiệp.Đây là các nguồn sinh khối nên được cân nhắc sử dụng trước tiên cho đồng đốt. Viên nén sinh khối cũnglà một lựa chọn tốt cho đồng đốt xét về các đặc tính kỹ thuật cũng như nguồn cung trong nước. Tuy nhiêngiá cả của viên nén chưa thực sự cạnh tranh được với than cũng như với nguồn phụ phẩm phế phẩm nôngnghiệp.Hiệu quả về mặt kinh tế của đồng đốt sinh khối với than sẽ cao hơn tại các nhà máy có các điều kiện nhưsau: sử dụng lò đốt than, tiếp cận được với nguồn cung sinh khối ổn định và có mức giá cạnh tranh, có giáthan cao, có các điều kiện ưu tiên về thị trường cũng như cơ chế đối với sử dụng năng lượng tái tạo vàgiảm rác thải. Việt Nam nên bắt đầu thí điểm với các nhà máy nhiệt điện than nằm tại các vùng có trữlượng sinh khối cao, thuận lợi cho việc thu gom và vận chuyển sinh khối, sử dụng than nhập khẩu có nguồncung than không ổn định và giá than cao như Vĩnh Tân 2, Duyên Hải 1, Long Phước 1...; hoặc các nhàmáy sắp hết thời gian khấu hao như Ninh Bình, Uông Bí hay Phả Lại 1 để tận dụng cơ sở hạ tầng sẵn có.Phân tích trường hợp đồng đốt 5% rơm với than tại nhà máy nhiệt điện Ninh Bình cho thấy đồng đốt đãmang lại hiệu quả kinh tế cho nhà máy trong điều kiện không có cơ chế chính sách hỗ trợ cho đồng đốtcũng như chưa có thị trường cacbon và doanh thu từ bán tro xỉ than. Mặt khác, lợi ích mà đồng đốt đemlại cho xã hội cũng như môi trường là rất đáng kể, đặc biệt là đối với người nông dân và sức khỏe cộngđồng. Các lợi ích này, nếu có cơ chế chia sẽ hợp lý sẽ có thể hỗ trợ cho nhà máy áp dụng đồng đốt đạthiệu quả cao hơn về mặt kinh tế

On the distribution of the number of internal equilibria in random evolutionary games

In this paper, we study the distribution of the number of internal equilibria of a multi-player two-strategy random evolutionary game. Using techniques from the random polynomial theory, we obtain a closed formula for the probability that the game has a certain number of internal equilibria. In addition, by employing Descartes' rule of signs and combinatorial methods, we provide useful estimates for this probability. Finally, we also compare our analytical results with those obtained from samplings.Comment: 31 pages, comments are welcome. arXiv admin note: substantial text overlap with arXiv:1708.0167