| 1. |
- Ljung, Patric, 1968-, et al.
(author)
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Forensic Virtual Autopsies by Direct Volume Rendering
- 2007
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In: IEEE signal processing magazine (Print). - Piscataway, NJ, USA : IEEE. - 1053-5888 .- 1558-0792. ; 24:6, s. 112-116
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Journal article (other academic/artistic)abstract
- This paper presents state-of-the-art methods, which address the technical challenges in visualizing large three-dimensional (3D) data and enable rendering at interactive frame rates.
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| 2. |
- Lundin (Palmerius), Karljohan, 1977-, et al.
(author)
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Enabling design and interactive selection of haptic modes
- 2007
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In: Virtual Reality. - : Springer Science and Business Media LLC. - 1359-4338 .- 1434-9957.
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Journal article (peer-reviewed)abstract
- The ever increasing size and complexity of volumetric data in a wide range of disciplines makes it useful to augment volume visualization tools with alternative modalities. Studies have shown that introducing haptics can significantly increase both exploration speed and precision. It is also capable of conveying material properties of data and thus has great potential to improve user performance in volume data exploration. In this paper we describe how recent advances in volume haptics can be used to build haptic modes-building blocks for haptic schemes. These modes have been used as base components of a toolkit allowing for more efficient development of haptic prototypes and applications. This toolkit allows interactive construction, configuration and fine-tuning of both visual and haptic representations of the data. The technology is also used in a pilot study to determine the most important issues and aspects in haptic volume data interaction and exploration, and how the use of haptic modes can facilitate the implementation of effective haptic schemes.
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| 3. |
- Lundström, Claes, 1973-, et al.
(author)
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Uncertainty Visualization in Medical Volume Rendering Using Probabilistic Animation
- 2007
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In: IEEE Transactions on Visualization and Computer Graphics. - 1077-2626 .- 1941-0506. ; 13:6, s. 1648-1655
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Journal article (peer-reviewed)abstract
- Direct volume rendering has proved to be an effective visualization method for medical data sets and has reached wide-spread clinical use. The diagnostic exploration, in essence, corresponds to a tissue classification task, which is often complex and time-consuming. Moreover, a major problem is the lack of information on the uncertainty of the classification, which can have dramatic consequences for the diagnosis. In this paper this problem is addressed by proposing animation methods to convey uncertainty in the rendering. The foundation is a probabilistic Transfer Function model which allows for direct user interaction with the classification. The rendering is animated by sampling the probability domain over time, which results in varying appearance for uncertain regions. A particularly promising application of this technique is a "sensitivity lens" applied to focus regions in the data set. The methods have been evaluated by radiologists in a study simulating the clinical task of stenosis assessment, in which the animation technique is shown to outperform traditional rendering in terms of assessment accuracy.
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| 4. |
- Nilsson, Anders, et al.
(author)
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Behavioral interference and facilitation in the foraging cycle shape the functional response
- 2007
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In: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 18:2, s. 354-357
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Journal article (peer-reviewed)abstract
- Individual forager behaviors should affect per capita intake rates and thereby population and consumer-resource properties. We consider and incorporate conspecific facilitation and interference during the separate foraging-cycle stages in a functional response model that links individual behavioral interactions with consumer-resource processes. Our analyses suggest that failing to properly consider and include all effects of behavioral interactions on foraging-cycle stage performances may either over- or underestimate effects of interactions on the shape of both functional responses and predator zero-growth isoclines. Incorporation of prey- and predator-dependent interactions among foragers in the model produces predator isoclines with potentials for highly complex consumer-resource dynamics. Facilitation and interference during the foraging cycle are therefore suggested as potent behavioral mechanisms to cause patterns of community dynamics. We emphasize that correct estimations of interaction-mediated foraging-cycle efficiencies should be considered in empirical and theoretical attempts to further our understanding of the mechanistic link between social behaviors and higher order processes.
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| 5. |
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| 6. |
- Axelsson, Karin, 1968-, et al.
(author)
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Communication Analysis of Public Forms : Discovering Multi-functional Purposes in Citizen and Government Communication
- 2007
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In: International Journal of Public Information Systems. - Sundsvall : MidSweden University. - 1653-4360. ; :3, s. 161-181
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Journal article (peer-reviewed)abstract
- This paper adopts a communication perspective on forms in public e-services. This perspective emphasizes that the main purpose of such forms is to facilitate communication between citizens and government agencies. The form is perceived as a tool for performing communicative actions. A communication analysis (CA) method, originally developed for systems requirements engineering, is applied on a public form; i.e. the medical certificate used in connection with a citizen’s application for a provisional driving license in Sweden. The CA method consists of a set of questions related tothree communicative categories; conditions, actions, and consequences. The CA method is used in order to explore the communicative roles of forms in public e-services. As a result of the communication analysis four multi-functional purposes of citizen and government agency communication are discovered. These purposes contribute to the understanding and evaluation of forms in public e-services. The communicative roles, and their multi-functional purposes, are important design features to focus in the development of e-services and electronic forms. Besides these findings, another outcomeis that the CA method has been tested in an e-government context. The communication perspective, as well as the CA method, contribute with useful insights in this context.
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| 7. |
- Cassou, K., et al.
(author)
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Optimization toward a high-average-brightness soft-x-ray laser pumped at grazing incidence
- 2007
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In: Optics Letters. - 0146-9592. ; 32:2, s. 139-141
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Journal article (peer-reviewed)abstract
- We report the near-field imaging characterization of a 10 Hz Ni-like 18.9 nm molybdenum soft-x-ray laser pumped in a grazing incidence pumping (GRIP) geometry with a table-top laser driver. We investigate the effect of varying the GRIP angle on the spatial behavior of the soft-x-ray laser source. After multiparameter optimization, we were able to find conditions to generate routinely a high-repetition-rate soft-x-ray laser with an energy level of up to 3 mu J/pulse and to 6 x 10(17) photons/s/mm(2)/mrad(2)/(0.1% bandwidth) average brightness and 1 x 10(28) photons/s/mm(2)/mrad(2)/(0.1% bandwidth) peak brightness. (c) 2006 Optical Society of America.
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| 8. |
- Dahlström, Nils, 1969-, et al.
(author)
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Contrast-enhanced magnetic resonance cholangiography with Gd-BOPTA and Gd-EOB-DTPA in healthy subjects
- 2007
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In: Acta Radiologica. - : Informa Healthcare. - 0284-1851 .- 1600-0455. ; 48:4, s. 362-368
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Journal article (peer-reviewed)abstract
- PURPOSE: To evaluate the biliary enhancement dynamics of the two gadolinium chelates Gd-BOPTA (MultiHance) and Gd-EOB-DTPA (Primovist) in normal healthy subjects. MATERIAL AND METHODS: Ten healthy volunteers were evaluated with both agents by magnetic resonance (MR) imaging at 1.5T using a breath-hold gradient-echo T1-weighted VIBE sequence. The relative signal intensity (SI) differences between the common hepatic duct (CHD) and liver parenchyma were measured before and 10, 20, 30, 40, 130, 240, and 300 min after contrast medium injection. RESULTS: Biliary enhancement was obvious 10 min post-injection for Gd-EOB-DTPA and was noted at 20 min for Gd-BOPTA. At 40 min delay, Gd-BOPTA reached its peak biliary enhancement, but at neither 30 nor 40 min delay was there any significant difference compared with that of Gd-EOB-DTPA. At later delays, the contrast between CHD and liver continued to increase for Gd-EOB-DTPA, whereas it decreased for Gd-BOPTA. CONCLUSION: The earlier onset and longer duration of a high contrast between CHD and liver for Gd-EOB-DTPA facilitates examination of hepatobiliary excretion. Therefore, Gd-EOB-DTPA may provide adequate hepatobiliary imaging within a shorter time span than Gd-BOPTA and facilitate scheduling at the MR unit. Further studies in patients are required to compare the imaging advantages of Gd-EOB-DTPA and Gd-BOPTA in clinical practice.
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| 9. |
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| 10. |
- Lindau, Filip, et al.
(author)
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Quantitative study of 10 Hz operation of a soft x-ray laser-energy stability and target considerations
- 2007
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In: Optics Express. - 1094-4087. ; 15:15, s. 9486-9493
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Journal article (peer-reviewed)abstract
- A soft x- ray laser from Ni- like Mo, pumped in grazing incidence ( GRIP), is analyzed with regard to high repetition rate operation. Reliable lasing is obtained, but with significant energy fluctuations attributed mainly to beam pointing jitter from the pump laser. Two modes of operation are compared: continuously moving target and stationary target. With a moving target the soft X- ray output is constant on average, whereas the repeated use of the same target position leads to a pulse energy which increases for several tens of shots. This effect might be caused by improved guiding of the pump laser in the formed groove and the removal, through laser ablation, of the oxide layer on the target surface. (c) 2007 Optical Society of America.
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