| 1. |
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| 2. |
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| 3. |
- Adcox, K, et al.
(författare)
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PHENIX central arm tracking detectors
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 489-507
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX tracking system consists of Drift Chambers (DC), Pad Chambers (PC) and the Time Expansion Chamber (TEC). PC1/DC and PC2/TEC/PC3 form the inner and outer tracking units, respectively. These units link the track segments that transverse the RICH and extend to the EMCal. The DC measures charged particle trajectories in the r-phi direction to determine P-T of the particles and the invariant mass of particle pairs. The PCs perform 3D spatial point measurements for pattern recognition and longitudinal momentum reconstruction and provide spatial resolution of a few mm in both r-phi and z. The TEC tracks particles passing through the region between the RICH and the EMCal. The design and operational parameters of the detectors are presented and running experience during the first year of data taking with PHENIX is discussed. The observed spatial and momentum resolution is given which imposes a limitation on the identification and characterization of charged particles in various momentum ranges. (C) 2002 Published by Elsevier Science B.V.
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| 4. |
- Alerstam, Thomas, et al.
(författare)
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Migration Along Orthodromic Sun Compass Routes by Arctic Birds
- 2001
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 291:5502, s. 300-303
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Tidskriftsartikel (refereegranskat)abstract
- Flight directions of birds migrating at high geographic and magnetic latitudes can be used to test bird orientation by celestial or geomagnetic compass systems under polar conditions. Migration patterns of arctic shorebirds, revealed by tracking radar studies during an icebreaker expedition along the Northwest Passage in 1999, support predicted sun compass trajectories but cannot be reconciled with orientation along either geographic or magnetic loxodromes (rhumb lines). Sun compass routes are similar to orthodromes (great circle routes) at high latitudes, showing changing geographic courses as the birds traverse longitudes and their internal clock gets out of phase with local time. These routes bring the shorebirds from high arctic Canada to the east coast of North America, from which they make transoceanic flights to South America. The observations are also consistent with a migration link between Siberia and the Beaufort Sea region by way of sun compass routes across the Arctic Ocean.
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| 5. |
- Green, Anders, et al.
(författare)
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Applying the wizard-of-oz framework to cooperative service discovery and configuration
- 2004
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Ingår i: RO-MAN 2004: 13TH IEEE INTERNATIONAL WORKSHOP ON ROBOT AND HUMAN INTERACTIVE COMMUNICATION, PROCEEDINGS. - NEW YORK : IEEE. - 0780385705 ; , s. 575-580
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Konferensbidrag (refereegranskat)abstract
- This paper describes how the Wizard-of-Oz framework can be applied to a service robotics scenario. A scenario the Home Tour Scenario - involving a collaborative service discovery and configuration multimodal dialogue for the robot is described. The role of the wizard operators producing dialogue and robot movements is discussed as well as the specific simulation tools used: the Dialogue Production Tool and the Joystick Navigation Tool. Some attention will be paid to the pilot studies performed as a preparation for the unified Home Tour Scenario.
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| 6. |
- Green, Anders, et al.
(författare)
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Designing for learnability in human-robot communication
- 2003
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Ingår i: IEEE Transactions on Industrial Electronics. - 0278-0046 .- 1557-9948. ; 50:4, s. 644-650
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Tidskriftsartikel (refereegranskat)abstract
- In a future scenario where many devices can be controlled using the voice, easy and intuitive access will be crucial for avoiding cognitive overload when users are faced with many different systems and interaction models. We propose a model for interaction with spoken language interfaces applied to heterogeneous tasks for service robots, based on the idea of using a family of lifelike characters,, We argue that we can signal important features of the speech interface by using certain visual cues. The aim is to facilitate learning and transfer between interfaces. We discuss challenges for dialogue design affecting learnability in the light of the speech interface constructed for our full-scale robot prototype CERO.
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| 7. |
- Green, Anders, et al.
(författare)
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Task-oriented dialogues for CERO: A user-centered approach
- 2001
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Konferensbidrag (refereegranskat)abstract
- We describe a user-centered approach to the process of designing spoken dialogues for commanding robots. Using scenarios and synthetic dialogues followed by simulated trials with real users we built a spoken language interface for commanding an office robot. Initial evaluation with the implemented system has brought interesting questions concerning the feedback necessary for interacting with a robot that has no screen. We are using a small life-like character placed upon the robot who is able of displaying conversational gestures. We have performed initial evaluations on video recorded material which have raised issues concerning low-level feedback, timing and sequencing of commands in dialogue
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| 8. |
- Green, Anders, et al.
(författare)
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User centered design for intelligent service robots
- 2000
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Ingår i: IEEE RO-MAN 2000. - Piscataway : IEEE. - 078036273X ; , s. 161-166, s. 161-166
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Konferensbidrag (refereegranskat)abstract
- This paper describes the development of a fetch-and-carry robot to assist physically impaired people in an office environment. Different methods involving users are employed in the project, including the task analysis, Hi-Fi simulation trials and focus group sessions. Through an iterative design process, a prototype robot system has been developed, with an enhanced robot platform including a graphical user interface and natural language interface. The users' need for continuous feedback from the robot has led to the development of an animated character (CERO), which relates the two interface components and indicates the robot's current state by using simple gestures
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| 9. |
- Green, Martin, et al.
(författare)
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Do Arctic waders use adaptive wind drift?
- 2004
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Ingår i: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 35:4, s. 305-315
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Tidskriftsartikel (refereegranskat)abstract
- We analysed five data sets of night directions of migrating arctic waders ill relation to,winds, recorded by tracking radar and optical range finder, in order to find out if these birds compensate for wind drift, or allow themselves to be drifted by winds. Our purpose was to investigate whether arctic waders use adaptive wind drift strategies or not. The data sets were collected in Siberia (two sets) and Canada during post-breeding (autumn) migration, and in Mauritania and South Sweden during pre-breeding (spring) migration. Both significant drift and compensation effects were found in three of the data sets, Canada, Mauritania and South Sweden. Almost no compensation was found in birds departing in easterly directions from the Siberian tundra (complete drift), while no drift effect was found in birds departing in westerly directions (complete compensation). There were indications that at least some populations of waders may use an adaptive drift strategy consisting of drift at high altitude and/or in high wind speed combined with compensation at low altitude and/or in lower wind speeds, but support for this idea was rather weak and not consistent. Our results were instead more in accordance with the adaptive drift theory that predicts initial drift during the migratory journey, followed by compensation during later stages as the birds are approaching their destinations. Such a strategy implies that arctic waders, at least adult birds, have the capacity of true navigation. A comparison with earlier studies of migrating arctic waders from different parts of the world show that all results so far may be interpreted in accordance with this general adaptive drift strategy An element of non-adaptive drift can, however, not be completely ruled out.
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| 10. |
- Green, Mattias, 1971, et al.
(författare)
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Hydrographic response of Holandsfjord to changed freshwater runoff
- 2004
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Ingår i: Journal of Geophysical Research-Oceans. - 0148-0227. ; 109:C7
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Tidskriftsartikel (refereegranskat)abstract
- The observed hydrographic conditions in the upper layers of the Norwegian Holandsfjord are analyzed as functions of the location and strength of the freshwater discharge. The data sets were sampled over 21 years and consist of mostly fortnightly observations of salinity and temperature at several stations along the fjord and daily estimates or observations of the freshwater supply. The freshwater runoff to Holandsfjord was regulated and relocated to a hydroelectric power plant at the innermost end of the fjord in 1993, and by transfer of water from neighboring watersheds the yearly average freshwater discharge increased by a factor greater than 2. Before the regulation the freshwater content in the fjord was hydraulically controlled somewhere in the outer part of the fjord, and this control remains after the regulation and has been located. When the power plant is in operation a hydraulic control appears at Enganes, the narrow contraction between the outer and inner parts of the fjord. The present investigation also shows that the surface layer responds to the regulated freshwater supply with a decreased surface layer salinity, an increased freshwater content, and an increased rate of flushing. The mean value of the wind power mixing buoyancy in the surface layer is estimated to be 6-7 mW m(-2).
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| 11. |
- Gudmundsson, GA, et al.
(författare)
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Radar observations of Arctic bird migration at the Northwest Passage, Canada
- 2002
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Ingår i: Arctic. - 0004-0843. ; 55:1, s. 21-43
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Tidskriftsartikel (refereegranskat)abstract
- Bird migration was recorded by tracking radar and visual observation at 23 sites in the region of the Northwest Passage, between Baffin Island and Herschel Island in the Beaufort Sea. The studies took place during a ship-based expedition from 29 June to 3 September 1999. A total of 692 tracks (average duration 160 s) of bird flocks on postbreeding migration were recorded. Eastward migration was widespread, with the highest intensities at three sites in the southeastern Beaufort Sea. Mainly shorebirds were responsible for these movements, migrating along routes similar to great circles towards Nova Scotia and other parts of the Atlantic coast of North America (whence they depart on transoceanic flights towards South America). Some of the birds in this migration system probably originated from Siberia, as indicated by high-altitude eastward migration at a site 100 kin north of the coast in the Beaufort Sea. Another category of eastward migrants consisted of jaegers, tems, and red phalaropes traveling towards the Davis Strait region and into the Atlantic Ocean. Southward migration was recorded at Baffin Island. A westward migration was pronounced at King William Island (with simultaneous eastward migration) and Amundsen Gulf, while northward movements were important at Banks Island and Melville Island. Apart from westward molt migration of common eiders at Amundsen Gulf, the westward and northward tracks reflected mainly jaegers, terns, gulls, and red phalaropes. These birds were probably making northward flights to exploit pelagic food resources in waters where the ice had recently broken up before their westward migratory exodus from the Arctic region towards the Pacific Ocean. The mean altitude of migration was 793 in, with 27% of all tracks above 1000 in and a maximum height of 3.95 km. The altitude distribution was clearly lower than those of the corresponding migration in Siberia and the shorebird migration at Nova Scotia. The average ground speed (14.9 m/s) was only slightly faster than the mean air speed (13.8 m/s), and migrants gained in speed from the winds (ground speed exceeding air speed) in only 55% of all cases. This means that wind assistance in the study area was much less pronounced than that documented for the migrants in Siberia and Nova Scotia. Bird migration at the Northwest Passage may be characterized by, on average, lower altitudes, less favorable winds, shorter flight steps, and a more widespread accessibility to stopover sites than migration at the Northeast Passaae.
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| 12. |
- Hartley, M G, et al.
(författare)
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Protection afforded by heat shock protein 60 from Francisella tularensis is due to copurified lipopolysaccharide.
- 2004
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Ingår i: Infection and Immunity. - 0019-9567 .- 1098-5522. ; 72:7, s. 4109-13
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Tidskriftsartikel (refereegranskat)abstract
- Heat shock proteins (Hsps) have attracted significant attention as protective antigens against a range of diseases caused by bacterial pathogens. However, more recently there have been suggestions that the protective response is due to the presence of peptide components other than Hsps. We have shown that mice that had been immunized with purified heat shock protein 60 (Hsp60) isolated from Francisella tularensis were protected against a subsequent challenge with some strains of the bacterium. However, this protection appeared to be due to trace amounts of lipopolysaccharide, which were too low to be detected by using the Limulus amoebocyte lysate assay. This finding raises the possibility that the protection afforded by other bacterial Hsp60 proteins may be due to trace quantities of polysaccharide antigens carried by and acting in conjunction with the Hsps.
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| 13. |
- Hedenström, Anders, et al.
(författare)
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Adaptive variation of airspeed in relation to wind, altitude and climb rate by migrating birds in the Arctic
- 2002
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 1432-0762 .- 0340-5443. ; 52:4, s. 308-317
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Tidskriftsartikel (refereegranskat)abstract
- The power expenditure of flapping flight in birds is characterised by a U-shaped function of speed through the air. From this relationship and the assumption of limited power available from flight muscles, it is possible to predict changes in the birds' airspeed in relation to external factors such as wind. These predictions are derived from flight mechanical theory and optimality criteria concerning migration or transport flight economy. Using tracking radar we measured flight speeds of migrating birds at 12 sites along the Northwest Passage in arctic Canada. We analysed variation in airspeed (V-a) in relation to the wind effect (V-g-V-a, where V-g is the groundspeed), vertical speed (V-z), altitude (z) and the compensation for the amount of side wind (1/cosalpha, where cc is the angle between track and heading). We found significant effects on the variation in V-a for all four variables, revealed by multiple regression analysis, but the total variation explained was relatively small suggesting that other factors might be involved. The signs of the regression coefficients were as predicted, except for the effect of side wind where we found a negative relationship between V-a and 1/cosalpha, possibly because our sample included an unknown mixture of bird species. We also compiled information from the literature from studies reporting analyses of the effects of the four variables on V-a. Adjustment of V-a in relation to the wind effect seems nearly omnipresent among birds, while the effects of vertical speed and altitude have been reported surprisingly few times. An increased V-a with increasing alpha (and 1/cosalpha) has not been found yet, perhaps due to the lack of critical observation conditions.
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| 14. |
- Hüttenrauch, Helge, et al.
(författare)
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Involving users in the design of a mobile office robot
- 2004
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Ingår i: IEEE transactions on systems, man and cybernetics. Part C, Applications and reviews. - : IEEE. - 1094-6977 .- 1558-2442. ; 34:2, s. 113-124
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the experiences from the iterative design of a fetch-and-carry-robot, to be used by motion-impaired people in an office environment. A user-centered approach was chosen, involving several steps of information elicitation to inform the design. We describe the main elements of the design process, the communication and interaction components of the final prototype system, and an evaluation of the system in the form of a longitudinal study. Results from this study confirmed that continuous testing with users is extremely important in the design process for service robots. The trials have also revealed that interaction design for robots should not focus only on the individual user, but that other members in the environment can be seen "secondary users" or "bystanders" who tend to relate to the robot actively in various ways. We conclude that these social and collaborative issues should be studied in future research.
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| 15. |
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| 16. |
- Kvist, Anders, et al.
(författare)
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Carrying large fuel loads during sustained bird flight is cheaper than expected
- 2001
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 413:6857, s. 730-732
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Tidskriftsartikel (refereegranskat)abstract
- Birds on migration alternate between consuming fuel stores during flights and accumulating fuel stores during stopovers. The optimal timing and length of flights and stopovers for successful migration depend heavily on the extra metabolic power input (fuel use) required to carry the fuel stores during flight(1,2). The effect of large fuel loads on metabolic power input has never been empirically determined. We measured the total metabolic power input of a long-distance migrant, the red knot (Calidris canutus), flying for 6 to 10 h in a wind tunnel, using the doubly labelled water technique(3). Here we show that total metabolic power input increased with fuel load, but proportionally less than the predicted mechanical power output from the flight muscles. The most likely explanation is that the efficiency with which metabolic power input is converted into mechanical output by the flight muscles increases with fuel load. This will influence current models of bird flight and bird migration. It may also help to explain why some shorebirds, despite the high metabolic power input required to fly, routinely make nonstop flights of 4,000 km longer(4).
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| 17. |
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| 18. |
- Severinson-Eklundh, Kerstin, et al.
(författare)
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Social and collaborative aspects of interaction with a service robot
- 2003
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Ingår i: Robotics and Autonomous Systems. - : Elsevier. - 0921-8890 .- 1872-793X. ; 42:3-4, s. 223-234
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Tidskriftsartikel (refereegranskat)abstract
- To an increasing extent, robots are being designed to become a part of the lives of ordinary people. This calls for new models of the interaction between humans and robots, taking advantage of human social and communicative skills. Furthermore, human-robot relationships must be understood in the context of use of robots, and based on empirical studies of humans and robots in real settings. This paper discusses social aspects of interaction with a service robot, departing from our experiences of designing a fetch-and-carry robot for motion-impaired users in an office environment. We present the motivations behind the design of the Cero robot, especially its communication paradigm. Finally, we discuss experiences from a recent usage study, and research issues emerging from this work. A conclusion is that addressing only the primary user in service robotics is unsatisfactory, and that the focus should be on the setting, activities and social interactions of the group of people where the robot is to be used.
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| 19. |
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| 20. |
- Åkesson, Susanne, et al.
(författare)
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Migration
- 2004
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Ingår i: Bird ecology and conservation: a handbook of techniques. [Techniques in Ecology and Conservation Series.]. - 0198520867
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Abstract is not available
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