| 281. |
- A. Mouris, Boules, et al.
(författare)
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A Dual-Polarized Multi-Antenna Structure for Simultaneous Transmission of Wireless Information and Power
- 2019
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Ingår i: 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, APSURSI 2019 - Proceedings. - : IEEE. ; , s. 1805-1806
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Konferensbidrag (refereegranskat)abstract
- In this paper, a dual-polarized multi-antenna structure is designed at 2.45 GHz with the goal of allowing simultaneous transmission of wireless information and power. Differential feeding was used to minimize the mutual coupling due to radiation leakage in addition to a mushroom-type EBG structure for suppressing the surface waves. Simulation results for the proposed structure show a mutual coupling level lower than -40 dB between the information transmitting antenna and the power transmitting antennas for both polarizations. The isolation level between the antennas is improved by at least 22 dB and 14 dB for the E-plane and H-plane coupling, respectively.
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| 282. |
- A. Mouris, Boules, et al.
(författare)
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Multi-tone Signal Optimization for Wireless Power Transfer in the Presence of Wireless Communication Links
- 2020
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Ingår i: IEEE Transactions on Wireless Communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 1536-1276 .- 1558-2248. ; 19:5, s. 3575-3590
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we study optimization of multi-tone signals for wireless power transfer (WPT) systems. We investigate different non-linear energy harvesting models. Two of them are adopted to optimize the multi-tone signal according to the channel state information available at the transmitter. We show that a second-order polynomial curve-fitting model can be utilized to optimize the multi-tone signal for any RF energy harvester design. We consider both single-antenna and multi-antenna WPT systems. In-band co-existing communication links are also considered in this work by imposing a constraint on the received power at the nearby information receiver to prevent its RF front end from saturation. We emphasize the importance of imposing such constraint by explaining how inter-modulation products, due to saturation, can cause high interference at the information receiver in the case of multi-tone signals. The multi-tone optimization problem is formulated as a non-convex linearly constrained quadratic program. Two globally optimal solution approaches using mixed-integer linear programming and finite branch-and-bound techniques are proposed to solve the problem. The achieved improvement resulting from applying both solution methods to the multi-tone optimization problem is highlighted through simulations and comparisons with other solutions existing in the literature.
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| 283. |
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| 284. |
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| 285. |
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A new partnership for African development : issues and parameters
- 1997
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Proceedings (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- As part of the on-going review by the Swedish government of the entire basis for its relations with Africa, a seminar on the theme Partnership Africa was convened in Abidjan in January 1997 under the auspices of Nordiska Afrikainstitutet and the African Development Institute of the African Development Bank. The Seminar was attended by some 25 scholars, development bankers, government officials and civil society activists from all parts of Sub-Saharan Africa and some 10 development co-operation officials and academics from Sweden and the other Nordic countries.The aim of the Abidjan seminar was to enable participants to explore the problems of and prospects for the establishment of a new partnership between Sweden and Africa in the context of the major changes that have taken place on the global and regional scenes over the last decade. For this purpose, various issues central to the history and dynamics of North-South relations generally and Swedish-Africa co-operation in particular were critically examined. Participants also sketched out what they considered to be the essential pre-conditions and parameters for a new partnership, one that would be premised on greater equality, mutual respect and a transparency of purpose and goals.This publication brings together in a volume, the various papers which were commissioned to serve as background materials for the debate that took place in Abidjan. The volume was edited for publication by Henock Kifle, Director of the African Development Institute of the ADB, Adebayo O. Olukoshi and Lennart Wohglemuth, respectively Senior Researcher and Director of Nordiska Afrikainstitutet.
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| 286. |
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A new scramble for Africa? : imperialism, investment and development
- 2009
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Dramatically escalating prices of raw materials, driven by rapid industrialisation in China and other countries of the global South as well as by looming world shortages, had for the few years preceding the financial meltdown and global recession of 2009 promoted a new scramble for Africa’s natural resources. It signalled a brisk turnaround in prospects for what The Economist had dubbed the ‘hopeless continent’ as recently as 1999. However, while average growth rates across the continent have increased, the implications for Africa’s development were and remain at best dubious.In this important volume, the new scramble for Africa is placed in the historical context of imperialism and the contributors show important continuities with the original nineteenth-century scramble. However, while the previous scramble was between major European powers, today the continent provides a battleground for competition between the US, the European Union, China and other emerging players such as India and South Africa.This book raises significant general questions relating to the nature of emerging global competition between the US and China; the centrality of the struggle for oil and minerals and resulting militarisation; the international battle to capture Africa’s markets; the marginalisation of African capitalism; and the ambiguous benefits that investment and production by multinational companies bring to African communities. Arguing that exploitation of the continent by comprador African elites remains central, the book concludes by raising important questions about the prospects for development in Africa.
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| 287. |
- A. Nojima,, et al.
(författare)
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Calculational aspects of electron-phonon coupling at surfaces
- 2008
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Ingår i: J. Phys: Condens. Matter. - : IOP Publishing. - 1361-648X .- 0953-8984. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- We study the validity of two frequently used approximations in calculations of electron–phonon coupling at surfaces. The rigid-ion approximation is a standard approximation used for the bulk metals. On the basis of density functional theory calculations, we find that for Be this approximation is as valid for surface atoms as for bulk atoms. In addition, the slab method for calculations of a phonon induced surface state lifetime is examined. The convergence of the electron–phonon matrix element with respect to the thickness of the slab is studied for several systems. When the number of slab layers is increased, the net effect of decreasing overlap and increasing number of final states depends strongly on the decay length of the surface state wavefunction and the band structure.
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| 288. |
- A. Nojima,, et al.
(författare)
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Model Eliashberg function for surface states
- 2008
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Ingår i: Applied Surface Science. ; 254:23
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Tidskriftsartikel (refereegranskat)abstract
- We present a simplified procedure for the analysis of the phonon-induced lifetimes of surface states. The model includes information about the electron and phonon structure and is thus more reliable than procedures based on phonon Debye models. We apply the model to calculate the lifetime broadening of Cu(1 1 1) and Al(0 0 1) surface states. The obtained Eliashberg functions and lifetimes are in reasonable agreement with previous detailed studies.
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| 289. |
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A Nordic Perspective on Co‐Operation for Sustainable Destination and Regional Development
- 2015
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- This research report contributes to a Nordic perspective on co-operation for sustainable destination- and regional development based on studies conducted within a Swedish-Danish Interreg project 2012-2014 (MARIFUS). An introduction chapter with major themes initiates this report followed by five chapters1 written by researchers from Aalborg University, Denmark (Incevida) and University West, Sweden (School of Business, Economics and IT). The purpose of this report is to give deeper nsights in Nordic destination and regional development by empirical case studies. These studies have been presented and discussed at seminars during international scientific conferences within regional science (the 16th Uddevalla Symposium 2013 in Kansas City, USA and the 17th Uddevalla Symposium 2014 in Uddevalla, Sweden) organized by University West. The contributions are nterdisciplinary in that sense that they are written by scholars from different scientific disciplines such as business administration, informatics, planning and culture studies. However, all scholars have a destination and/or regional perspective as a point of departure in the case studies conducted. The three-year project offered great opportunities to cross-border learning and applied research in close co-operation (Work integrated learning) with project partners and students.The studies are partly supported by the project MARIFUS “Maritime Inlands – past, present and future strengths” financed by the European Union Regional Development Fund (Interreg IV A). The editors express sincere gratitude to all authors and all partners of the MARIFUS project.
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| 290. |
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