| 1. |
- Akram Hassan, Kahin, 1990-, et al.
(författare)
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On the Performance of Stereoscopic Versus Monoscopic 3D Parallel Coordinates
- 2016
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Konferensbidrag (refereegranskat)abstract
- This work presents the results from an evaluation of stereoscopic versus monoscopic 3D parallel coordinates. The objective of the evaluation was to investigate if stereopsis increases user performance. The results show that stereoscopy has no effect at all on user performance compared to monoscopy. This result is important when it comes to the potential use of stereopsis within the information visualization community.
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| 2. |
- Bivall, Petter, et al.
(författare)
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Haptic Just Noticeable Difference in Continuous Probing of Volume Data
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Just noticeable difference (JND) describes how much two perceptual sensory inputs must differ in order to be distinguishable from each other. Knowledge of the JND is vital when two features in a dataset are to be separably represented. JND has received a lot of attention in haptic research and this study makes a contribution to the field by determining JNDs during users' probing of volumetric data at two force levels. We also investigated whether these JNDs were affected by where in the haptic workspace the probing occurred. Reference force magnitudes were 0.1 N and 0.8 N, and the volume data was presented in rectangular blocks positioned at the eight corners of a cube 10 cm3 in size. Results showed that the JNDs varied significantly for the two force levels, with mean values of 38.5% and 8.8% obtained for the 0.1 N and 0.8 N levels, respectively, and that the JND was influenced by where the data was positioned.
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| 3. |
- Forsell, Camilla
(författare)
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A Guide to Scientific Evaluation in Information Visualization
- 2010
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Ingår i: 14th International Conference Information Visualization IV 2010. - 9781424478460 ; , s. 162-169
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Konferensbidrag (refereegranskat)abstract
- This paper addresses some fundamental and practical issues that should be considered when pursuing evaluation studies in Information Visualization. The main focus is on quantitative experimental research but the general information applies to all kinds of studies. The purpose is to increase awareness of what constitutes a sound scientific approach to evaluation and to point out common pitfalls and mistakes during the phases of such study. These phases cover how to plan, design, conduct and analyse the outcome of an evaluation and finally how to report in a way that enhances readability, provides details relevant to the outcome and that allows replication. The paper could be used as a guide when conducting evaluation and it could also be helpful when reviewing publications since the same rules apply.
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| 4. |
- Forsell, Camilla, et al.
(författare)
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An Heuristic Set for Evaluation in Information Visualization
- 2010
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Ingår i: Advanced Visual Interfaces, AVI10. - New York, USA : ACM press. - 9781450300766 ; , s. 199-206
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Konferensbidrag (refereegranskat)abstract
- Evaluation is a key research challenge within the international Information Visualization (InfoVis) community, and Heuristic Evaluation is one recognized method. Various sets of heuristics have been proposed but there remains no consensus as to which heuristics are most useful for addressing aspects specific to the complex interactive visual displays used in modern InfoVis systems. This paper presents a first effort to empirically determine a new set of such general heuristics tailored for Heuristic Evaluation of common and important usability problems in InfoVis techniques. Participants in the study rated how well a total of 63 heuristics from 6 earlier published heuristic sets could explain a collection of 74 usability problems derived from earlier InfoVis evaluations. The results were used to synthesize 10 heuristics that, as a set, provided the highest explanatory coverage. The paper also stresses the challenges for future research to validate and further improve upon this set.
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| 5. |
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| 6. |
- Forsell, Camilla, 1971-
(författare)
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Perceptually Motivated Constraints on 3D Visualizations
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis addresses some important characteristics of human visual perception and their implications for three-dimensional (3D) information visualization. The effort can be divided into two parts. First, findings from vision science are explored and validated. As a starting point, the compilation of perceptually motivated evidence about what constitutes an effective and efficient method for mapping of data is undertaken. Second, the knowledge obtained is used to create candidate visualizations and to demonstrate the predictive power of the findings.Results indicate a general difficulty to convey metric, i.e. quantitative, information in 3D visualizations. Structure as defined by Euclidean geometry is not perceived with accuracy and information encoded by such distinctions are misunderstood or overlooked. On the other hand, qualitative properties as defined by affine geometry are salient are perceived with accuracy (paper I). These findings are also characteristic of two-dimensional (2D) visualizations when these need to be rapidly examined (paper II). A novel method (3D surface glyphs) for abstract multivariate data sets was developed to investigate the possible merit of encoding information by qualitative distinctions, (paper III). Evaluations showed that the information conveyed was successfully utilized and that these types of glyph have great potential. The study also illustrated the predictive power of the earlier findings. These issues were further demonstrated when investigating how 3D perspective displays are unaffected by distortions in data when the patterns displayed were defined by affine properties (paper IV). In addition, a new metric for measuring the efficiency of visualizations is presented (paper III). It is concluded that as long as visualizations are specified by qualitative properties, they could most probably be effectively and efficiently used. The need for user studies to determine if, when and how to choose a certain visualization technique for a given task is thereby significantly reduced.
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| 7. |
- Forsell, Camilla, et al.
(författare)
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Questionnaires for evaluation in information visualization
- 2012
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Ingår i: BELIV '12 Proceedings of the 2012 BELIV Workshop. - New York : ACM Press. - 9781450317917
-
Konferensbidrag (refereegranskat)abstract
- The position taken in this paper is that the availability of standardized questionnaires specifically developed for measuring users' perception of usability in evaluation studies in information visualization would provide the community with an excellent additional instrument. The need for such an instrument is evident for several important reasons. Pursuing the development, validation and use of questionnaires will add significantly to the evidence base necessary for the community to guide the production of high-quality visualization techniques, facilitate adoption by users, promote successful commercialization and guide future research tasks.
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| 8. |
- Forsell, Camilla, et al.
(författare)
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Simple 3D glyphs for Spatial Multivariate Data
- 2005
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Ingår i: IEEE Symposium on Information Visualization. - 078039464X ; , s. 244-, s. 119-124
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Konferensbidrag (refereegranskat)abstract
- We present an effort to evaluate the possible utility of a new type of 3D glyphs intended for visualizations of multivariate spatial data. They are based on results from vision research suggesting that our perception of metric 3D structure is distorted and imprecise relative to the actual scene before us (e.g., [1]); only a class of qualitative properties of the scene is perceived with accuracy. These properties are best characterized as being invariant over affine but not Euclidean transformations. They are related, but not identical to, the non-accidental properties (NAPs) described by Lowe [2] on which the notion of geons is based [3]. A large number of possible 3D glyphs for the visualization of spatial data can be constructed using such properties. One group is based on the local sign of surface curvature. We investigated these properties in a visualization experiment. The results are promising and the implications for visualization are discussed.
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| 9. |
- Forsell, Camilla, et al.
(författare)
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Surface Glyphs for Efficient Visualization of Spatial Multivariate Data
- 2006
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Ingår i: Information Visualization. - 1473-8716. ; 5, s. 112-124
-
Tidskriftsartikel (refereegranskat)abstract
- We present a first effort to evaluate the possible utility of a new type of surface glyphs intended for visualizations of multivariate spatial data. The glyphs are based on results from vision research suggesting that our perception of metric 3D structure is distorted and imprecise relative to the actual scene before us; only a class of qualitative properties of the scene is perceived with accuracy. These properties are best characterized as being invariant over affine but not Euclidean transformations. A large number of possible 3D glyphs for the visualization of spatial data can be constructed using such properties. One group is based on the local sign of surface curvature. We investigated these properties in two visualization experiments. The results show that available sources of 3D structural information were sufficient for our subjects to make fast and accurate judgments. Some implications for visualization are discussed.
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| 10. |
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| 11. |
- Forsell, Camilla, et al.
(författare)
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Task-based evaluation of multi-relational 3D and standard 2D parallel coordinates
- 2007
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Ingår i: Visualization and Data Analysis 2007. - Bellingham, WA / Springfield, Virginia, USA : SPIE. - 9780819466082 ; , s. C4950-C4950
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Konferensbidrag (refereegranskat)abstract
- Multivariate data sets exist in a wide variety of fields and parallel coordinates visualizations are commonly used for analysing such data. This paper presents a usability evaluation where we compare three types of parallel coordinates visualization for exploratory analysis of multivariate data. We use a standard parallel coordinates display with manual permutation of axes, a standard parallel coordinates display with automatic permutation of axes, and a multi-relational 3D parallel coordinates display with manual permutation of axes. We investigate whether a 3D layout showing more relations simultaneously, but distorted by perspective effects, is advantageous when compared with a standard 2D layout. The evaluation is accomplished by means of an experiment comparing performance differences for a class of task known to be well-supported by parallel coordinates. Two levels of difficulty of the task are used and both require the user to find relationships between variables in a multivariate data set. Our results show that for the manual exploration of a complex interrelated multivariate data set, the user performance with multi-relational 3D parallel coordinates is significantly faster. In simpler tasks, however, the difference is negligible. The study adds to the body of work examining the utility of 3D representations and what properties of structure in 3D space can be successfully used in 3D representations of multivariate data.
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| 12. |
- Gorenko, Ivar, et al.
(författare)
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Supporting Astrophysical Visualization with Sonification
- 2024
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Konferensbidrag (refereegranskat)abstract
- This poster presents initial design steps exploring how sonification can be used to support visualization for comprehension of space and time in astronomical data. Radio signals travel at the speed of light. With a visualization of the universe, it is possible to travel faster than light and pass the radio waves leaving earth. We can then travel back in time. We propose to use sonification consisting of songs representing each year as a musical journey through space and time to create an engaging experience.
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| 13. |
- Granvik, Christoffer, et al.
(författare)
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Olfactory dysfunction as an early predictor for post-COVID condition at 1-year follow-up
- 2024
-
Ingår i: Brain and Behavior. - : John Wiley & Sons. - 2162-3279. ; 14:6
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Olfactory dysfunction together with neurological and cognitive symptoms are common after COVID-19. We aimed to study whether performance on olfactory and neuropsychological tests following infection predict post-COVID condition (PCC), persisting symptoms, and reduced health-related quality of life.Methods: Both hospitalized (N = 10) and non-hospitalized individuals (N = 56) were enrolled in this prospective cohort study. Participants were evaluated 1–3 months after infection with an olfactory threshold test and neuropsychological tests, which was used as predictors of PCC. A questionnaire outlining persisting symptoms and the validated instrument EuroQol five-dimension five-level for health-related quality of life assessment were used as outcome data 1 year after infection (N = 59). Principal component analysis was used to identify relevant predictors for PCC at 1 year.Results: Objectively assessed olfactory dysfunction at 1–3 months post infection, but not subjective olfactory symptoms, predicted post-COVID condition with reduced health-related quality of life (PCC+) at 1 year. The PCC+ group scored more often below the cut off for mild cognitive impairment on the Montreal Cognitive Assessment (61.5% vs. 21.7%) and higher on the Multidimensional Fatigue Inventory-20, compared to the group without PCC+.Conclusion: Our results indicate that objectively assessed, olfactory dysfunction is a predictor for PCC+. These findings underscore the importance of objective olfactory testing. We propose that olfactory screening in the early post-acute phase of COVID-19 infection might identify individuals that are at higher risk of developing long-term health sequalae.
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| 14. |
- Hassan, Kahin Akram, et al.
(författare)
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A Study on 2D and 3D Parallel Coordinates for Pattern Identification in Temporal Multivariate Data
- 2019
-
Konferensbidrag (refereegranskat)abstract
- Parallel coordinates are commonly used for non-temporal multivariate data, but there is little support for their usability for displaying temporal multivariate data. In this paper, we introduce a study evaluating the usability of 2D and 3D parallel coordinates for pattern identification in temporal multivariate data. The results indicate that 3D parallel coordinates have higher usability, as measured with higher accuracy and faster response time as well as subjective ratings, compared to 2D.
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| 15. |
- Hassan, Kahin Akram, 1990-, et al.
(författare)
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On the Use of Parallel Coordinates for Temporal Multivariate Data
- 2017
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This work presents the results from a user centered evaluation of visual representations of temporal multivariate data using 2D and3D parallel coordinates. The objective of the evaluation was to investigate whether 2D or 3D representations increase user performance when the data consists of temporal multivariate data and the visual representation contains interactive user tools. The results show that the 3D parallel coordinates representation outperforms 2D parallel coordinates with regards to both accuracy and response time.This result is of interest to the information visualization community, since it shows the usefulness of visual representations of temporal multivariate data.
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Johansson, Jimmy, et al.
(författare)
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Evaluation of Parallel Coordinates: Overview, Categorization and Guidelines for Future Research
- 2016
-
Ingår i: IEEE Transactions on Visualization and Computer Graphics. - : IEEE COMPUTER SOC. - 1077-2626 .- 1941-0506. ; 22:1, s. 579-588
-
Tidskriftsartikel (refereegranskat)abstract
- The parallel coordinates technique is widely used for the analysis of multivariate data. During recent decades significant research efforts have been devoted to exploring the applicability of the technique and to expand upon it. resulting in a variety of extensions. Of these many research activities, a surprisingly small number concerns user-centred evaluations investigating actual use and usability issues for different tasks, data and domains. The result is a clear lack of convincing evidence to support and guide uptake by users as well as future research directions. To address these issues this paper contributes a thorough literature survey of what has been done in the area of user-centred evaluation of parallel coordinates. These evaluations are divided into four categories based on characterization of use, derived from the survey. Based on the data from the survey and the categorization combined with the authors experience of working with parallel coordinates, a set of guidelines for future research directions is proposed.
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| 20. |
- Johansson, Jimmy, et al.
(författare)
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On the usability of three-dimensional display in parallel coordinates: Evaluating the efficiency of identifying two-dimensional relationships
- 2014
-
Ingår i: Information Visualization. - : Sage Publications. - 1473-8716 .- 1473-8724. ; 13:1, s. 29-41
-
Tidskriftsartikel (refereegranskat)abstract
- In recent years, several different attempts have been made to extend the well-known technique of parallel coordinates using a three-dimensional display. This article presents an evaluation that investigates the performance of the three-dimensional parallel coordinates technique and compares it with standard, two-dimensional parallel coordinates for analysis of two-dimensional relationships. Three-dimensional parallel coordinates, based on parallel planes instead of parallel axes, have been used for many years within the information visualization community for a variety of applications. Despite its quite common use, no formal evaluation detailing its usefulness for different tasks has been conducted. The evaluation presented in this article is the first step towards determining the usefulness of this type of three-dimensional parallel coordinates. The study compared three-dimensional parallel coordinates, using two different axis configurations commonly seen in the literature, with standard two-dimensional parallel coordinates for identification of two-dimensional relationships between variables in multivariate data. This type of task and the relationships to be judged are known to be well supported by two-dimensional parallel coordinates and multi-relational three-dimensional parallel coordinates. The results show that for identification of two-dimensional relationships, two-dimensional parallel coordinates are superior to the three-dimensional extensions, in terms of both response time and accuracy. Subjective opinions were also in favour of two-dimensional parallel coordinates. This study adds to the much-needed body of work examining the usability of three-dimensional representations in information visualization and for what tasks and data a proposed method is or is not appropriate.
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| 21. |
- Johansson, Jimmy, et al.
(författare)
-
Perceiving patterns in parallel coordinates: determining thresholds for identification of relationships
- 2008
-
Ingår i: Information Visualization. - : Palgrave macmillan. - 1473-8716 .- 1473-8724. ; 7:2, s. 152-162
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents a study that investigates the ability of humans to perceive relationships (patterns) in parallel coordinates, an ability that is crucial to the use of this popular visualization technique. It introduces a visual quality metric, acceptable distortions of patterns, which establishes the level of noise that may be present in data while allowing accurate identification of patterns. This metric was used to assess perceptual performance of standard 2D parallel coordinates and multi-relational 3D parallel coordinates in two experiments. In multi-relational 3D parallel coordinates the axes are placed on a circle with a focus axis in the centre, allowing a simultaneous analysis between the focus variable and all other variables. The experiments aimed to determine the maximum number of variables that can be, from a user's point of view, efficiently used in a multi-relational 3D parallel coordinates display and to present a first attempt to study users' ability to analyse noisy data in parallel coordinates. The results show that, in terms of the acceptable level of noise in data, a multi-relational 3D parallel coordinates visualization having 11 axes (variables) is as efficient as standard 2D parallel coordinates. Visualizing a larger number of variables would possibly require a greater amount of manipulation of the visualization and thus be less efficient.
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| 22. |
- Jönsson, Daniel, et al.
(författare)
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A Visual Environment for Hypothesis Formation and Reasoning in Studies with fMRI and Multivariate Clinical Data
- 2019
-
Ingår i: Eurographics Workshop on Visual Computing for Biology and Medicine. - 9783038680819
-
Konferensbidrag (refereegranskat)abstract
- We present an interactive visual environment for linked analysis of brain imaging and clinical measurements. The environment is developed in an iterative participatory design process involving neuroscientists investigating the causes of brain-related complex diseases. The hypotheses formation process about correlations between active brain regions and physiological or psychological factors in studies with hundreds of subjects is a central part of the investigation. Observing the reasoning patterns during hypotheses formation, we concluded that while existing tools provide powerful analysis options, they lack effective interactive exploration, thus limiting the scientific scope and preventing extraction of knowledge from available data.Based on these observations, we designed methods that support neuroscientists by integrating their existing statistical analysis of multivariate subject data with interactive visual explorationto enable them to better understand differences between patient groups and the complex bidirectional interplay between clinical measurement and the brain. These exploration concepts enable neuroscientists, for the first time during their investigations, to interactively move between and reason about questions such as ‘which clinical measurements are correlated with a specific brain region?’ or ‘are there differences in brain activity between depressed young and old subjects?’. The environment uses parallel coordinates for effective overview and selection of subject groups, Welch's t-test to filter out brain regions with statistically significant differences, and multiple visualizations of Pearson correlations between brain regions and clinical parameters to facilitate correlation analysis. A qualitative user study was performed with three neuroscientists from different domains. The study shows that the developed environment supports simultaneous analysis of more parameters, provides rapid pathways to insights, and is an effective support tool for hypothesis formation.
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| 23. |
- Jönsson, Daniel, et al.
(författare)
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VisualNeuro : A Hypothesis Formation and Reasoning Application for Multi-Variate Brain Cohort Study Data
- 2020
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Ingår i: Computer graphics forum (Print). - : Wiley-Blackwell Publishing Inc.. - 0167-7055 .- 1467-8659. ; 39:6, s. 392-407
-
Tidskriftsartikel (refereegranskat)abstract
- We present an application, and its development process, for interactive visual analysis of brain imaging data and clinical measurements. The application targets neuroscientists interested in understanding the correlations between active brain regions and physiological or psychological factors. The application has been developed in a participatory design process and has subsequently been released as the free software VisualNeuro. From initial observations of the neuroscientists workflow, we concluded that while existing tools provide powerful analysis options, they lack effective interactive exploration requiring the use of many tools side by side. Consequently, our application has been designed to simplify the workflow combining statistical analysis with interactive visual exploration. The resulting environment comprises parallel coordinates for effective overview and selection, Welchs t-test to filter out brain regions with statistically significant differences and multiple visualizations for comparison between brain regions and clinical parameters. These exploration concepts enable neuroscientists to interactively explore the complex bidirectional interplay between clinical and brain measurements and easily compare different patient groups. A qualitative user study has been performed with three neuroscientists from different domains. The study shows that the developed environment supports simultaneous analysis of more parameters, provides rapid pathways to insights and is an effective tool for hypothesis formation.
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| 24. |
- Kocak, Umut, 1981-, et al.
(författare)
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Analysis of the JND of Stiness in Three Modesof Comparison
- 2011
-
Ingår i: HAID'11 Proceedings of the 6th international conference on Haptic and audio interaction design. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642229497 - 9783642229503 ; , s. 22-31
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Understanding and explaining perception of touch is a non-trivial task. Even seemingly trivial differences in exploration may potentially have a significant impact on perception and levels of discrimination. In this study, we explore different aspects of contact related to stiffness perception and their effects on the just noticeable difference (JND) of stiffness are surveyed. An experiment has been performed on non-deformable, compliant objects in a virtual environment with three different types of contact: Discontinuous pressure, continuous pressure and continuous lateral motion. The result shows a significantly better discrimination performance in the case of continuous pressure (a special case of nonlinearity), which can be explained by the concept of haptic memory. Moreover, it is found that the perception is worse for the changes that occur along the lateral axis than the normal axis.
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| 25. |
- Kocak, Umut, 1981-, et al.
(författare)
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The Effect of the Stiffness Gradient on the Just Noticeable Difference between Surface Regions
- 2012
-
Ingår i: Haptics: Perception, Devices, Mobility, and Communication. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642314001 - 9783642314018 ; , s. 282-292
-
Bokkapitel (refereegranskat)abstract
- This book and its companion volume, LNCS 7282 and 7283, constitute the refereed proceedings of the 8th International Conference, EuroHaptics 2012, held in Tampere, Finland, in June 2012. The 99 papers (56 full papers, 32 short papers, and 11 demo papers) presented were carefully reviewed and selected from 153 submissions. Part I contains the full papers whereas Part II contains the short papers and the demo papers.
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| 26. |
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| 27. |
- Lind, Mats, et al.
(författare)
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Metric structure in visualization
- 2003
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Ingår i: Information Visualization. - 1473-8716. ; 2, s. 51-57
-
Tidskriftsartikel (refereegranskat)
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| 28. |
- Lind, Mats, et al.
(författare)
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The Illusion of Perceived metric Structure
- 2002
-
Ingår i: Proceedings of InfoVis 2002, IEEE Symposium on Information Visualization. ; , s. 51-56
-
Konferensbidrag (refereegranskat)abstract
- We present a first effort to evaluate the possible utility of a new type of surface glyphs intended for visualizations of multivariate spatial data. The glyphs are based on results from vision research suggesting that our perception of metric 3D structure is distorted and imprecise relative to the actual scene before us; only a class of qualitative properties of the scene is perceived with accuracy. These properties are best characterized as being invariant over affine but not Euclidean transformations. A large number of possible 3D glyphs for the visualization of spatial data can be constructed using such properties. One group is based on the local sign of surface curvature. We investigated these properties in two visualization experiments. The results show that available sources of 3D structural information were sufficient for our subjects to make fast and accurate judgments. Some implications for visualization are discussed.
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| 29. |
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| 30. |
- Lundberg, Jonas, 1974-, et al.
(författare)
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The Use of Conflict Detection Tools in Air Traffic Management – an Unobtrusive Eye Tracking Field Experiment During Controller Competence Assurance
- 2014
-
Ingår i: HCI-Aero 2014 - International Conference on Human-Computer Interaction in Aerospace. - Mountain View, CA, USA : ACM Press.
-
Konferensbidrag (refereegranskat)abstract
- This study aims at explaining loss of separation events over the Swedish air space in 2011- 2012, which occurred despite an automated conflict detection tool working as designed. The study suggests that there may be a trade-off between spending visual scan time on own conflict detection versus visual scan time spent on examining potential conflicts presented by the conflict detection automation. The issue is hard to solve, and is unfortunately far from resolved. This area of research requires a substantial applied research effort, if the goal is to both increase safety and capacity of ATM through the use of automation.
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| 31. |
- Lundblad, Patrik, et al.
(författare)
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Voyage Analysis Applied to Geovisual Analytics
- 2008
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Ingår i: Proceedings of the 12th IEEE International Conference on Information Visualisation. - Los Alamitos : IEEE Society Press. - 9780769532684 ; , s. 381-388
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Konferensbidrag (refereegranskat)abstract
- This paper demonstrates the synergy of common InfoVis and GeoVis interaction techniques and the logistic application domain demonstrated in the customized visualize performance data (VISPER) application. In VISPER multi-dimensional, multi-source, time-varying and geospatial digital information from voyage analysis is represented to facilitate decision-making. Using common InfoVis components for multivariate data together with logistics visualization in a new synergy aids the users in their work examining ship and route performance. An evaluation of the usability was performed to gather insights for future development. The results from the evaluation show that the overall impression of VISPER was highly positive and participants enjoyed using it. Feedback obtained was highly valuable and directly applicable for improvements and further development.
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| 32. |
- Lundin Palmerius, Karljohan, et al.
(författare)
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The impact of feedback design in haptic volume visualization
- 2009
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Ingår i: Third Joint EuroHaptics conference, 2009 and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems. World Haptics 2009.. - Piscataway, New Jersey, USA : IEEE. - 9781424438587 ; , s. 154-159
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Konferensbidrag (refereegranskat)abstract
- Enhancing volume visualization with additional cues from our sense of touch has shown the potential to increase both speed and accuracy in the data exploration. Research in the area display a wide array of modes of interaction and many of these have been evaluated to demonstrate their capabilities. There are, however, few studies performed that compare different approaches for their strengths and weaknesses and there is a lack of guidelines on how the haptic feedback should be designed to allow for best performance. This paper describes a study on the influence of the basic principle chosen for data representation on the ability to identify faint structures in the data. Three metaphors are compaired, two types of shape metaphors and one force metaphor. Based on statistical analysis on evaluation data, interviews and observations a set of guidelines on the design of haptic visualization is described.
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| 33. |
- Lundström, Claes, et al.
(författare)
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Multi-Touch Table System for Medical Visualization: Application to Orthopedic Surgery Planning
- 2011
-
Ingår i: IEEE Transactions on Visualization and Computer Graphics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-2626 .- 1941-0506. ; 17:12, s. 1775-1784
-
Tidskriftsartikel (refereegranskat)abstract
- Medical imaging plays a central role in a vast range of healthcare practices. The usefulness of 3D visualizations has been demonstrated for many types of treatment planning. Nevertheless, full access to 3D renderings outside of the radiology department is still scarce even for many image-centric specialties. Our work stems from the hypothesis that this under-utilization is partly due to existing visualization systems not taking the prerequisites of this application domain fully into account. We have developed a medical visualization table intended to better fit the clinical reality. The overall design goals were two-fold: similarity to a real physical situation and a very low learning threshold. This paper describes the development of the visualization table with focus on key design decisions. The developed features include two novel interaction components for touch tables. A user study including five orthopedic surgeons demonstrates that the system is appropriate and useful for this application domain.
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| 34. |
- Muthumanickam, Prithiviraj, et al.
(författare)
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Supporting Exploration of Eye Tracking Data: Identifying Changing Behaviour Over Long Durations
- 2016
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Ingår i: BEYOND TIME AND ERRORS: NOVEL EVALUATION METHODS FOR VISUALIZATION, BELIV 2016. - New York, NY, USA : ASSOC COMPUTING MACHINERY. - 9781450348188 ; , s. 70-77
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Konferensbidrag (refereegranskat)abstract
- Visual analytics of eye tracking data is a common tool for evaluation studies across diverse fields. In this position paper we propose a novel user-driven interactive data exploration tool for understanding the characteristics of eye gaze movements and the changes in these behaviours over time. Eye tracking experiments generate multidimensional scan path data with sequential information. Many mathematical methods in the past have analysed one or a few of the attributes of the scan path data and derived attributes such as Area of Interest (AoI), statistical measures, geometry, domain specific features etc. In our work we are interested in visual analytics of one of the derived attributes of sequential data-the: AoI and the sequences of visits to these AoIs over time. In the case of static stimuli, such as images, or dynamic stimuli, like videos, having predefined or fixed AoIs is not an efficient way of analysing scan path patterns. The AoI of a user over a stimulus may evolve over time and hence determining the AoIs dynamically through temporal clustering could be a better method for analysing the eye gaze patterns. In this work we primarily focus on the challenges in analysis and visualization of the temporal evolution of AoIs. This paper discusses the existing methods, their shortcomings and scope for improvement by adopting visual analytics methods for event-based temporal data to the analysis of eye tracking data.
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| 35. |
- Nguyen, Tan Khoa, et al.
(författare)
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Concurrent Volume Visualization of Real-Time fMRI
- 2010
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Ingår i: Proceedings of the 8th IEEE/EG International Symposium on Volume Graphics. - Goslar, Germany : Eurographics - European Association for Computer Graphics. - 9783905674231 ; , s. 53-60
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Konferensbidrag (refereegranskat)abstract
- We present a novel approach to interactive and concurrent volume visualization of functional Magnetic Resonance Imaging (fMRI). While the patient is in the scanner, data is extracted in real-time using state-of-the-art signal processing techniques. The fMRI signal is treated as light emission when rendering a patient-specific high resolution reference MRI volume, obtained at the beginning of the experiment. As a result, the brain glows and emits light from active regions. The low resolution fMRI signal is thus effectively fused with the reference brain with the current transfer function settings yielding an effective focus and context visualization. The delay from a change in the fMRI signal to the visualization is approximately 2 seconds. The advantage of our method over standard 2D slice based methods is shown in a user study. We demonstrate our technique through experiments providing interactive visualization to the fMRI operator and also to the test subject in the scanner through a head mounted display.
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| 36. |
- Persson, Eva M., et al.
(författare)
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Improved understanding of the effect of food on drug absorption and bioavailability for lipophilic compounds using an intestinal pig perfusion model
- 2008
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Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 34:1, s. 22-29
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to investigate the relative importance of mechanisms behind the effect of food on the intestinal absorption and bioavailability for low solubility compounds by applying a porcine single-pass perfusion model. Nanoparticle suspensions of the model compounds, danazol and cyclosporine were perfused through the jejunum in isotonic fluid alone (control) and isotonic fluid with a P-glycoprotein (P-gp) inhibitor (verapamil) or dietary and endogenous lipids added. The drugs were also administered as saturated solutions in the isotonic fluid containing lipids. Administration of cyclosporine together with verapamil increased the absorption compared to the control (1.6 times) suggesting an effect on jejunal permeability. However, addition of dietary lipids to the media led to a 50% reduction in the absorption of cyclosporine indicating lack of major effects by P-gp inhibition by lipids in vivo. The absorption of danazol was increased (2.6 times) when administered as a nanosuspension in lipid containing media compared to the control, but decreased (60%) when administered as a solution in the same media. This shows how important dissolution of the drug nanoparticles is in drug absorption. The difference in the effect of lipids in the absorption of cyclosporine and danazol when administered as nanosuspensions may be due to different distribution to the colloidal structures present in the media, thereby rendering the drugs' different diffusion rates in the perfused segment. In conclusion, solubilisation seems to be a more important factor than P-gp inhibition as an explanation for the food-drug interaction observed for several low solubility drugs. In addition, the partition into different colloidal structures seems to play a major role in the dissolution and absorption of poorly soluble drugs.
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| 37. |
- Rönnberg, Niklas, 1973-, et al.
(författare)
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Questionnaires assessing usability of audio-visual representations
- 2022
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Konferensbidrag (refereegranskat)abstract
- In this position paper we argue for the need of using standardized questionnaires for assessing usability in audio-visual representations. By using standardized measures of usability, comparability and validity of research studies in this field will be improved. However, it is not clear which questionnaire that is most suitable for assessing usability in audio-visual representations, neither when assessing the modalities individually or the combination. We present a variety of different questionnaires available, and argue for the need of combining different measures as well as developing new.
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| 38. |
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| 39. |
- Scandurra, Isabella, 1973-, et al.
(författare)
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Advancing the State-of-the-Art for Virtual Autopsies : Initial Forensic Workflow Study
- 2010
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Ingår i: Studies in Health Technology and Informatics. - : IOS Press. - 0926-9630 .- 1879-8365. ; 160, s. 639-643
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Tidskriftsartikel (refereegranskat)abstract
- There are numerous advantages described of how imaging technology can support forensic examinations. However, postmortem examinations of bodies are mainly performed to address demands which differ from those of traditional clinical image processing. This needs to be kept in mind when gathering information from image data sets for forensic purposes. To support radiologists and forensicclinicians using Virtual Autopsy technologies, an initial workflow study regarding post-mortem imaging has been performed, aiming to receive an improved understanding of how Virtual Autopsyworkstations, image data sets and processes can be adjusted to support and improve conventional autopsies. This paper presents potential impacts and a current forensic Virtual Autopsy workflowaiming to form a foundation for collaborative procedures that increase the value of Virtual Autopsy. The workflow study will provide an increased and mutual understanding of involved professionals. In addition, insight into future forensic workflows based on demands from both forensic and radiologist perspectives bring visualization and medical informatics researchers together to develop and improvethe technology and software needed.
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| 40. |
- Stahlgren, Malin, et al.
(författare)
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Information needs in patients with bladder cancer undergoing radical cystectomy - A qualitative review with thematic synthesis
- 2022
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Ingår i: European Journal of Oncology Nursing. - : ELSEVIER SCI LTD. - 1462-3889 .- 1532-2122. ; 61
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Forskningsöversikt (refereegranskat)abstract
- Purpose: Worldwide, bladder cancer is the eleventh most common cancer. Self-care is significant after surgery and optimal information needs to be individualized. This will help the patient to understand and become involved in their own care. This study investigated experiences of information needs in patients with bladder cancer un-dergoing radical cystectomy.Methods: A qualitative review study with a thematic synthesis according to the PRISMA Statement Guidelines was performed. Results: Thirteen peer-reviewed original articles were included. This review highlighted that patient experienced unmet information needs about postoperative care and self-care. Patients also experienced receiving too much information in a limited time. This led to difficulties in understanding and processing the information. Patients also experienced limited information about sexual and psychological support and requested more information about physical activity.Conclusion: Information is essential but needs to be adapted and based on person-centred care principles related to the patients needs and wishes. Unmet needs impact patients lives and are associated with misunderstandings and insecurity, which need to be considered in cancer nursing.Clinical trial registration: The review was not registered.
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| 41. |
- Svensson, Åsa, 1988-, et al.
(författare)
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Automation, teamwork, and the feared loss of safety : Air traffic controllers’ experiences and expectations on current and future ATM systems
- 2021
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Ingår i: 32nd European Conference on Cognitive Ergonomics: Designing Virtual and Physical Interactive Systems, ECCE 2021. - New York, NY, USA : ACM Digital Library. - 9781450387576 ; , s. -8
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Konferensbidrag (refereegranskat)abstract
- In various control systems, automation is implemented to increase efficiency and safety. With increased automation, it becomes increasingly relevant to view the automation as a team member, rather than as a tool. In best cases, human-automation teamwork keeps workload within acceptable limits, increase situation awareness, and keeps the operator in the control loop. However, human-automation teamwork will only flourish if the automation is developed with the human operator in mind. Therefore, investigations of the current experiences and expectations regarding automation and teamwork are important for the development of automation. Through a questionnaire among Air Traffic Controllers (ATCOs), the present study aims to investigate how ATCOs perceive automation and safety in current and future air traffic control systems and the importance of different teamwork factors for human-human and human-automation collaboration. The results indicate that the ATCOs believe that safety will increase in the future along with increasing automation as long as the automation is working as expected. The ATCOs expressed a fear of deskilling and losing situation awareness with automation, a fear associated with a new ATCO role of monitoring the system and take over when the automation fails. The results suggest that design for human-automation teamwork aspects that ATCOs value, such as adaptability or mutual performance monitoring, could be a way forward.
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| 42. |
- Svensson, Åsa, 1988-
(författare)
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Human-automation teamwork : Current practices and future directions in air traffic control
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation explores the topic of human-automation teamwork in Air Traffic Control (ATC). ATC is a high stakes environment where complex automation is being introduced while the human operator has the legal responsibility. With increasing demands on productivity in various industries (as also in ATC), automation is introduced for efficiency, maintaining safety, and to keep the workload of the human operator within acceptable limits. However, previous research has shown that automation may cause negative effects on the human operator and performance, such as forcing the operator out of the control loop, which might lead to problems or confusion. Previous research suggests a need for strengthening human-automation collaboration where automation is seen as a team member to keep the operator in the loop. In order to achieve such teamwork, the design of the automation needs to be human-centred, i.e. that the automation is designed for the underlying need of the operator.The aim of this dissertation is to explore teamwork in ATC from several angles to understand how the air traffic controllers are working in current ATC environments and how automation could be designed to support human-automation teamwork. The included studies rely on interviews, simulations, and questionnaires, all with operational air traffic controllers as participants.The results indicate that for both human-human teamwork and human-automation teamwork, teamwork factors such as adaptability and mutual performance monitoring (knowing what the other team members are doing) are important for the work performance in current ATC environments, where mutual performance monitoring is especially important during stressful situations.When designing automation, lessons learned from human-human teamwork should be considered. The work within the scope of this dissertation identifies and concerns two human-automation teamwork aspects: boundary awareness and implicit communication. These are proposed to support the operator’s knowledge about the automation and the communication flow between the operator and the automation. Boundary awareness is the operator’s knowledge of the automation’s abilities, its boundaries (what it can or cannot manage), and about consequences if it would go outside of these boundaries. Implicit communication is the unspoken or implied small cues that the operator and the automation can use to communicate with each other. It is proposed that implicit communication can be based on the work patterns of the operator. The knowledge gained through the work in this dissertation can be used as a foundation for further research and design of automation regarding operator knowledge about the automation boundaries and the communication within the team.
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| 43. |
- Tominski, Christian, et al.
(författare)
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Interaction Support for Visual Comparison Inspired by Natural Behavior
- 2012
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Ingår i: IEEE Transactions on Visualization and Computer Graphics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-2626 .- 1941-0506. ; 18:12, s. 2719-2728
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Tidskriftsartikel (refereegranskat)abstract
- Visual comparison is an intrinsic part of interactive data exploration and analysis. The literature provides a large body of existing solutions that help users accomplish comparison tasks. These solutions are mostly of visual nature and custom-made for specific data. We ask the question if a more general support is possible by focusing on the interaction aspect of comparison tasks. As an answer to this question, we propose a novel interaction concept that is inspired by real-world behavior of people comparing information printed on paper. In line with real-world interaction, our approach supports users (1) in interactively specifying pieces of graphical information to be compared, (2) in flexibly arranging these pieces on the screen, and (3) in performing the actual comparison of side-by-side and overlapping arrangements of the graphical information. Complementary visual cues and add-ons further assist users in carrying out comparison tasks. Our concept and the integrated interaction techniques are generally applicable and can be coupled with different visualization techniques. We implemented an interactive prototype and conducted a qualitative user study to assess the concepts usefulness in the context of three different visualization techniques. The obtained feedback indicates that our interaction techniques mimic the natural behavior quite well, can be learned quickly, and are easy to apply to visual comparison tasks.
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| 44. |
- Vrotsou, Katerina, 1980-, et al.
(författare)
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2D and 3D Representations for Feature Recognition in Time Geographical Diary Data
- 2010
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Ingår i: Information Visualization. - : Palgrave Macmillan Ltd. - 1473-8716 .- 1473-8724. ; 9:4, s. 263-276
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Tidskriftsartikel (refereegranskat)abstract
- Time geographical representations are becoming a common approach to analysing spatio-temporal data. Such representations appear intuitive in the process of identifying patterns and features as paths of populations form tracks through the 3D space, which can be seen converging and diverging over time. In this article, we compare 2D and 3D representations within a time geographical visual analysis tool for activity diary data. We identify a representative task and evaluate task performance between the two representations. The results show that the 3D representation has benefits over the 2D representation for feature identification but also indicate that these benefits can be lost if the 3D representation is not carefully constructed to help the user to see them.
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| 45. |
- Vrotsou, Katerina, et al.
(författare)
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A Qualitative Study of Similarity Measures in Event-Based Data
- 2011
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Ingår i: Human Interface and the Management of Information. Interacting with Information. - Berlin/Heidelberg : Springer. - 9783642217920 - 9783642217937 ; , s. 170-179
-
Bokkapitel (refereegranskat)abstract
- This paper presents an interview-based study of the definition of sequence similarity in different application areas of event-based data. The applicability of nine identified measures across these areas is investigated and discussed. The work helps highlight what are the core characteristics sought when analysing event-based data and performs a first validation of this across disciplines. The results of the study make a solid basis for follow-up evaluations of the practical applicability and usability of the similarity measures.
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| 46. |
- Ynnerman, Anders, 1963-, et al.
(författare)
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Multi-Touch Table System for Medical Visualization
- 2015
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Ingår i: Eurographics 2015. - : Eurographics - European Association for Computer Graphics.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Medical imaging plays a central role in a vast range of healthcare practices. While the usefulness of 3D visualizations is well known, the adoption of such technology has previously been limited in many medical areas. This paper, awarded the Dirk Bartz Prize for Visual Computing in Medicine 2015, describes the development of a medical multi-touch visualization table that successfully has reached its aim to bring 3D visualization to a wider clinical audience. The descriptions summarize the targeted clinical scenarios, the key characteristics of the system, and the user feedback obtained.
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