| 1. |
- Samuelson, Lars, et al.
(författare)
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Semiconductor nanowires for 0D and 1D physics and applications
- 2004
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Ingår i: Physica E: Low-Dimensional Systems and Nanostructures. - : Elsevier BV. - 1386-9477. ; 25:2-3, s. 313-318
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Tidskriftsartikel (refereegranskat)abstract
- During the last 5 years the potential for applications of semiconductor nanowires has grown rapidly via the development of methods for catalytically induced nanowire growth using the, so-called vapor-liquid-solid (VLS) growth mode. The VLS method offers a high degree of control of parameters such as position, diameter, length and composition, including the realization of atomically abrupt heterostructure interfaces inside a nanowire. In this review, we summarize the progress and the standing of our research from the point of view of controlled growth, structural and electronic properties and in terms of different families of devices which have been possible to realize. (C) 2004 Elsevier B.V. All rights reserved.
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| 2. |
- Akkurt, I, et al.
(författare)
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Photoneutron yields from tungsten in the energy range of the giant dipole resonance
- 2003
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Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 1361-6560 .- 0031-9155. ; 48:20, s. 3345-3352
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Tidskriftsartikel (refereegranskat)abstract
- Photoneutron production on the nuclei of high-Z components of medical accelerator heads can lead to a significant secondary dose during a course of bremsstrahlung radiotherapy, However, a quantitative evaluation of secondary neutron dose requires improved data on the photoreaction yields. These have been measured as a function of photon energy, neutron energy and neutron angle for W-nat, using tagged photons at the MAX-Lab photonuclear facility in Sweden. This work presents neutron yields for W-nat(gamma, n) and compares these with the predictions of the Monte Carlo code MCNP-GN, developed specifically to simulate photoneutron production at medical accelerators.
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| 3. |
- Björk, Mikael, et al.
(författare)
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Few-electron quantum dots in nanowires
- 2004
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 4:9, s. 1621-1625
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate transport spectroscopy on bottom-up grown few-electron quantum dots in semiconductor nanowires. The dots are defined by InP double barrier heterostructures in InAs nanowires catalytically grown from nanoparticles. By changing the dot size, we can design devices ranging from single-electron transistors to few-electron quantum dots. In the latter case, electrons can be added one by one to the dots from 0 to similar to50 electrons while maintaining an almost constant charging energy, with addition spectra of the devices displaying shell structures as a result of spin and orbital degeneracies. The reduced dimensionality of the nanowire emitter gives rise to pronounced resonant tunneling peaks, where a gate can be used to control the peak positions.
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| 4. |
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| 5. |
- Gambäck, Björn, et al.
(författare)
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A spoken Swedish e-mail interface
- 2003. - 2
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Ingår i: Proceedings of the 14th Nordic Conference of Computational Linguistics.
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Konferensbidrag (refereegranskat)abstract
- The paper describes the Swedish involvement in the EU project DUMAS (Dynamic Universal Mobility for Adaptive Speech Interfaces), a project which aims at developing multilingual speech-based applications, and more specifically, investigating adaptive multilingual interaction techniques to handle both spoken and text input and to provide coordinated linguistic responses to the user. The project has a clear focus on Northern Europe with two of the eight partners coming from Sweden and four from Finland; and the languages we aim at treating are English, Swedish and Finnish. We will construct an agent-based generic framework for multilingual speech applications, supporting adaptivity to both the individual user and the particular domain. Applications based on the general architecture will benefit from the advantages of fault-tolerant semantic analysis, which combined with the dialogue management routines will handle user interaction in a very robust manner. As an initial such application, we are building a mobile phone-based e-mail interface that will deal with multilingual issues in several forms and environments, and whose functionality can be adapted to different users, different situations and tasks. Such a system produces speech output only (in the form of spoken responses and read e-mails) to the user, but gets two types of input: user speech and textual e-mail messages. It must be able to distinguish between languages, both in e-mails and in the user utterances. The contents of a user's inbox must be continuously analysed in order to enable advanced search functions.
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| 6. |
- Hansen, Preben, et al.
(författare)
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Cooperation, bookmarking, and thesaurus in interactive bilingual question answering
- 2004. - 1
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Ingår i: Multilingual Information Access for Text, Speech and Images (5th Workshop of the Cross-Language Evaluation Forum, CLEF 2004, Bath, UK, September 15-17, 2004, Revised Selected Papers). - Berlin, Heidelberg : Springer. - 9783540274209 ; , s. 343-347
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Bokkapitel (refereegranskat)abstract
- The study presented involves several different contextual aspects and is the latest in a continuing series of exploratory experiments on information access behaviour in a multi-lingual context [1, 2]. This year’s interactive cross-lingual information access experiment was designed to measure three parameters we expected would affect the performance of users in cross-lingual tasks in languages in which the users are less than fluent. Firstly, introducing new technology, we measure the effect of topic-tailored term expansion on query formulation. Secondly, introducing a new component in the interactive interface, we investigate - without measuring by using a control group - the effect of a bookmark panel on user confidence in the reported result. Thirdly, we ran subjects pair-wise and allowed them to communicate verbally, to investigate how people may cooperate and collaborate with a partner during a search session performing a similar but non-identical search task.
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| 7. |
- Lundin, Magnus, et al.
(författare)
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Compton scattering from the deuteron and extracted neutron polarizabilities
- 2003
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Ingår i: Physical Review Letters. - 1079-7114. ; 90:19
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Tidskriftsartikel (refereegranskat)abstract
- Differential cross sections for Compton scattering from the deuteron were measured at MAX-Lab for incident photon energies of 55 and 66 MeV at nominal laboratory angles of 45degrees, 125degrees, and 135degrees. Tagged photons were scattered from liquid deuterium and detected in three NaI spectrometers. By comparing the data with theoretical calculations in the framework of a one-boson-exchange potential model, the sum and the difference of the isospin-averaged nucleon polarizabilities, alpha(N) + beta(N) = 17.4 +/- 3.7 and alpha(N) - beta(N) = 6.4 +/- 2.4 (in units of 10(-4) fm(3)), have been determined. By combining the latter with the global-averaged value for alpha(p) - beta(p) and using the predictions of the Baldin sum rule for the sum of the nucleon polarizabilities, we have obtained values for the neutron electric and magnetic polarizabilities of alpha(n) = 8.8 +/- 2.4(total) +/- 3.0(model) and beta(n) = 6.5 -/+ 2.4(total) -/+ 3.0(model), respectively.
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| 8. |
- Sahlgren, Magnus, et al.
(författare)
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English-Japanese cross-lingual query expansion using random indexing of aligned bilingual text data
- 2002. - 1
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Konferensbidrag (refereegranskat)abstract
- Vector-space techniques can be used for extracting semantically similar words from the co-occurrence statistics of words in large text data. In this paper, we report on experiments with using the Random Indexing vector-space technique for extracting a cross-lingual thesaurus from aligned English-Japanese bilingual data. The cross-lingual thesaurus has been used for automatic cross-lingual query expansion in the NTCIR patent retrieval task.
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| 9. |
- Thelander, Claes, et al.
(författare)
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Electron transport in InAs nanowires and heterostructure nanowire devices
- 2004
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Ingår i: Solid State Communications. - : Elsevier BV. - 1879-2766 .- 0038-1098. ; 131:9-10, s. 573-579
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Tidskriftsartikel (refereegranskat)abstract
- Nanowires in the InAs/InP material system are grown with catalyst-assisted chemical beam epitaxy. Ohmic contacts are then fabricated to selected wires, allowing electron transport measurements to be carried out at room-temperature as well as at low T. InAs nanowires show strong quantum confinement effects, where thin wires (<30nm) are depleted from carriers. Measurements on InAs wires with a quantum point contact configuration indicate a scattering length in the order of 100 nm. Heterostructure barriers of InP are also incorporated into InAs wires to produce resonant tunneling diodes and single-electron transistors (SETs) with different dot lengths. Wires containing dots with a length of 100 nm function as ideal SETs, whereas the transport in wires with 15 nm long dots is strongly governed by quantum confinement and resonant tunneling. For the smaller dots it is possible to observe electron transport through excited states. (C) 2004 Elsevier Ltd. All rights reserved.
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| 10. |
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