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- Abreu, P., et al.
(författare)
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Measurement of the GAMMA(B-B-OVER-BAR)/GAMMA(HAD) branching ratio of thez by double hemisphere tagging
- 1995
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Ingår i: Zeitschrift für Physik C Particles and Fields. - 0170-9739 .- 1431-5858. ; 65:4, s. 555-568
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Tidskriftsartikel (refereegranskat)abstract
- Two measurements of Γbbˉ/Γhad are presented. Both measurements use 250000Z decays taken with the DELPHI detector in 1991 and rely mainly on the precision of the microvertex detector. One tagging method is as simple as possible so that background rates can be reliably predicted by simulation. The other one uses a more involved tagging technique and reduces the dependence on simulation as much as possible. Combining both results, Γbbˉ/Γhad is found to be 0.2209±0.0041(stat.)±0.0042(syst.)±0.0018 Γccˉ .
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2. |
- Adam, W, et al.
(författare)
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Alignment and Cherenkov angle resolution of the DELPHI RICH
- 1996
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Ingår i: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT. - : ELSEVIER SCIENCE BV. - 0168-9002. ; 371:1-2, s. 228-231
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The particle separation power of a RICH depends crucially on the obtained resolution in Cherenkov angle. In order to obtain the highest possible resolution, a precise knowledge of the positions of detector elements, the refractive indices and the photon d
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4. |
- Harrysson, Fredrik, et al.
(författare)
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Efficient experimental evaluation of a MIMO handset with user influence
- 2010
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Ingår i: IEEE Transactions on Wireless Communications. - 1536-1276. ; 9:2, s. 853-863
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Tidskriftsartikel (refereegranskat)abstract
- The immediate environment of handset antennas, including the casings and the users holding the handsets, has a strong impact on the radio channel in mobile communication. In this paper we investigate a composite channel method that synthetically combines double-directional measurements of the userless propagation channel with measured super-antenna patterns, i.e., patterns of the combined antenna-casing-user arrangement. We experimentally evaluate the method by comparing results (power, capacity, and eigenvalue distribution) obtained from this composite method with direct measurements in the same environment. The measurements were done in two static 8 × 4 MIMO scenarios at 2.6 GHz, with the user indoors and the base station located outdoors and indoors, respectively. A realistic user phantom together with a “smart-phone” handset mock-up with four antenna elements was used, and different configurations and orientations were tested. The method gives statistical distributions of the MIMO eigenvalues, that are close to the measured. By using the composite method, we found that the user, apart from introducing hand and body loss that mainly decreases the SNR of the channel, slightly increases the correlation between the fading at the antenna elements.
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5. |
- Harrysson, Fredrik, et al.
(författare)
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The composite channel method : Efficient experimental evaluation of a realistic MIMO terminal in the presence of a human body
- 2008
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Ingår i: 2008 IEEE 67th Vehicular Technology Conference-Spring, VTC. - 1550-2252. - 9781424416455 ; , s. 473-477
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Konferensbidrag (refereegranskat)abstract
- The immediate environment of the transmit (TX) and receive (RX) antennas, including the antenna casings and the users holding the antennas, has a strong impact on the propagation channel and thus on wireless systems. In this paper we experimentally evaluate a method that synthetically combines double-directional measurements of the propagation channel (without the user influence) with measured antenna patterns of antennas-plus-users, by comparing obtained sample results with direct measurements in the same environment. The measurements are done for a static microcell 8×4 MIMO scenario at 2.6 GHz. A realistic user phantom was used together with a test terminal prototype with four antenna elements, and a number of different configurations and orientations of the phantom were tested. In average over all test cases, the mean signal power deviation between composite channel method and measurements was well within 1 dB. The composite method shows 6% higher terminal antenna correlation but similar statistical distributions as the measured. The differences between the model and measurements for the strongest eigenvalue (relevant for MRC combining) was found to be within 1 dB above 10% outage level. Relative deviations in the ergodic MIMO capacity were smaller than 10%.
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6. |
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7. |
- Kihlberg, Steve, et al.
(författare)
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Integrate Ergonomics into Production System Design
- 2001
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Ingår i: 16th International Conference on Production Research : ICPR - 16 ; 29 July - 3 August 2001, Prague, Czech Republic, Editors: D. Hanus an Talácko, J.. - 8002014383
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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8. |
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9. |
- Mathiassen, S.E., et al.
(författare)
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Integrating production engineering and ergonomics in production system design
- 2000
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Ingår i: Ergonomics for the New Millenium : proceedings of the XIVth Triennial Congress of the International Ergonomics Association and 44th Annual Meeting of the Human Factors and Ergonomics society, July 29 through August 4, 2000, San Diego, California USA.. - 0945289138 ; 5, s. 501-504
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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10. |
- Neumann, Patrick, et al.
(författare)
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A case study evaluating the ergonomic and productivity impacts of partial automation strategies in the electronics industry
- 2002
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Ingår i: International Journal of Production Research. - : Informa UK Limited. - 0020-7543 .- 1366-588X. ; 40:16, s. 4059-4075
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Tidskriftsartikel (refereegranskat)abstract
- A case study is presented that evaluates the impact of partial automation strategies on productivity and ergonomics. A company partly automated its assembly and transportation functions while moving from a parallel-batch to a serial line-based production system. Data obtained from company records and key informants were combined with detailed video analysis, biomechanical modelling data and field observations of the system. The new line system was observed to have 51% higher production volumes with 21% less per product labour input and lower work-in-process levels than the old batch-cart system. Partial automation of assembly operations was seen to reduce the total repetitive assembly work at the system level by 34%. Automation of transportation reduced transport labour by 63%. The strategic decision to implement line-transportation was found to increase movement repetitiveness for operators at manual assembly stations, even though workstations were constructed with consideration to ergonomics. Average shoulder elevation at these stations increased 30% and average shoulder moment increased 14%. It is concluded that strategic decisions made by designers and managers early in the production system design phase have considerable impact on ergonomic conditions in the resulting system. Automation of transport and assembly both lead to increased productivity, but only elements related to the automatic line system also increased mechanical loads on operators and hence increased the risk for work-related disorders. Suggestions for integrating the consideration of ergonomics into production system design are made.
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