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Cooper, Matthew
Alternative names
Publications (10 of 67) Show all publications
Hassan, K. A., Rönnberg, N., Forsell, C., Cooper, M. & Johansson, J. (2019). A Study on 2D and 3D Parallel Coordinates for Pattern Identification in Temporal Multivariate Data. In: : . Paper presented at 2019 23rd International Conference Information Visualization (IV) (pp. 145-150). IV 2019: IEEE conference proceedings
Open this publication in new window or tab >>A Study on 2D and 3D Parallel Coordinates for Pattern Identification in Temporal Multivariate Data
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2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

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.

Place, publisher, year, edition, pages
IV 2019: IEEE conference proceedings, 2019
Series
IV 2019, ISSN 2375-0138
Keywords
Temporal Data, User Evaluation, 2D Parallel Coordinates, 3D Parallel Coordinates
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:liu:diva-159079 (URN)10.1109/IV.2019.00033 (DOI)
Conference
2019 23rd International Conference Information Visualization (IV)
Available from: 2019-07-22 Created: 2019-07-22 Last updated: 2019-07-22
Muthumanickam, P., Vrotsou, K., Vitoria, A., Johansson, J. & Cooper, M. (2018). Identification of Temporally Varying Areas of Interest in Long-Duration Eye-Tracking Data Sets. IEEE Transactions on Visualization and Computer Graphics
Open this publication in new window or tab >>Identification of Temporally Varying Areas of Interest in Long-Duration Eye-Tracking Data Sets
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2018 (English)In: IEEE Transactions on Visualization and Computer Graphics, ISSN 1077-2626, E-ISSN 1941-0506Article in journal (Refereed) Published
Abstract [en]

Eye-tracking has become an invaluable tool for the analysis of working practices in many technological fields of activity. Typically studies focus on short tasks and use static expected areas of interest (AoI) in the display to explore subjects’ behaviour, making the analyst’s task quite straightforward. In long-duration studies, where the observations may last several hours over a complete work session, the AoIs may change over time in response to altering workload, emergencies or other variables making the analysis more difficult. This work puts forward a novel method to automatically identify spatial AoIs changing over time through a combination of clustering and cluster merging in the temporal domain. A visual analysis system based on the proposed methods is also presented. Finally, we illustrate our approach within the domain of air traffic control, a complex task sensitive to prevailing conditions over long durations, though it is applicable to other domains such as monitoring of complex systems. 

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2018
Keywords
Eye-tracking data, areas of interest, clustering, minimum spanning tree, temporal data, spatio-temporal data
National Category
Computer Systems
Identifiers
urn:nbn:se:liu:diva-152714 (URN)10.1109/TVCG.2018.2865042 (DOI)000452640000009 ()30183636 (PubMedID)2-s2.0-85052788669 (Scopus ID)
Note

Funding agencies: Swedish Research Council [2013-4939]; RESKILL project - Swedish Transport Administration; Swedish Maritime Administration; Swedish Air Navigation Service Provider LFV

Available from: 2018-11-16 Created: 2018-11-16 Last updated: 2019-01-07Bibliographically approved
Forsell, C. & Cooper, M. (2014). An Introduction and Guide to Evaluation of Visualization Techniques Through User Studies. In: Weidong Huang (Ed.), Handbook of human centric visualization: (pp. 285-313). New York: Springer
Open this publication in new window or tab >>An Introduction and Guide to Evaluation of Visualization Techniques Through User Studies
2014 (English)In: Handbook of human centric visualization / [ed] Weidong Huang, New York: Springer, 2014, p. 285-313Chapter in book (Refereed)
Place, publisher, year, edition, pages
New York: Springer, 2014
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:liu:diva-108553 (URN)10.1007/978-1-4614-7485-2_11 (DOI)9781461474845 (ISBN)9781461474852 (ISBN)
Available from: 2014-06-30 Created: 2014-06-30 Last updated: 2018-07-19Bibliographically approved
Vrotsou, K., Ynnerman, A. & Cooper, M. (2014). Are we what we do? Exploring group behaviour through user-defined event-sequence similarity. Information Visualization, 13(3), 232-247
Open this publication in new window or tab >>Are we what we do? Exploring group behaviour through user-defined event-sequence similarity
2014 (English)In: Information Visualization, ISSN 1473-8716, E-ISSN 1473-8724, Vol. 13, no 3, p. 232-247Article in journal (Refereed) Published
Abstract [en]

The study of human activity in space and time is an inherent part of human geography. In order to perform such studies, data on the time use of individuals, in terms of sequence and timing of performed activities, are collected and analysed. A common assumption when analysing individuals’ time use is that groups that exhibit similar background and demographic characteristics also display similarities in how they use their time to structure their daily lives. In this article, we set out to investigate the correctness of such assumptions. We propose a visual analytics process based on sequence similarity measures tailored to event-based data such as performed activity sequences. The process allows an analyst to retrieve similarly behaving records according to user-selected similarity preferences and interactively explore aspects of this similarity in a multiple linked-view environment.

Place, publisher, year, edition, pages
Sage Publications, 2014
Keywords
Event-based data, event-sequences, similarity measures, clustering, activity diaries, time-use data
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:liu:diva-90151 (URN)10.1177/1473871613477852 (DOI)000337711400004 ()
Available from: 2013-03-20 Created: 2013-03-20 Last updated: 2018-01-11
Johansson, J., Forsell, C. & Cooper, M. (2014). On the usability of three-dimensional display in parallel coordinates: Evaluating the efficiency of identifying two-dimensional relationships. Information Visualization, 13(1), 29-41
Open this publication in new window or tab >>On the usability of three-dimensional display in parallel coordinates: Evaluating the efficiency of identifying two-dimensional relationships
2014 (English)In: Information Visualization, ISSN 1473-8716, E-ISSN 1473-8724, Vol. 13, no 1, p. 29-41Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
Sage Publications, 2014
Keywords
Information visualization, evaluation, usability, parallel coordinates, 3D parallel coordinates
National Category
Media and Communication Technology
Identifiers
urn:nbn:se:liu:diva-102653 (URN)10.1177/1473871613477091 (DOI)000331375900003 ()
Available from: 2013-12-18 Created: 2013-12-18 Last updated: 2018-01-11Bibliographically approved
Vrotsou, K., Bergqvist, M., Cooper, M. & Ellegård, K. (2014). PODD: A Portable Diary Data Collection System. In: AVI '14 Proceedings of the 2014 International Working Conference on Advanced Visual Interfaces: . Paper presented at 2014 International Working Conference on Advanced Visual Interfaces (AVI '14) (pp. 381-382). New York: Association for Computing Machinery (ACM)
Open this publication in new window or tab >>PODD: A Portable Diary Data Collection System
2014 (English)In: AVI '14 Proceedings of the 2014 International Working Conference on Advanced Visual Interfaces, New York: Association for Computing Machinery (ACM), 2014, p. 381-382Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Activity diaries are a powerful data source for studying the time use of individuals and for creating awareness of individuals' daily activity patterns. The presented project is concerned with the development of an easily accessible method for collecting and analyzing diary data which will be applicable across a wide range of industrial, governmental, social science and medical domains. The PODD (POrtable Diary Data collection) is composed of a smartphone application for data registration, a web interface for user registration and an administration system for configuring the application according to the focus of the data collection.

Place, publisher, year, edition, pages
New York: Association for Computing Machinery (ACM), 2014
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:liu:diva-115879 (URN)10.1145/2598153.2600046 (DOI)000381001200077 ()978-1-4503-2775-6 (ISBN)
Conference
2014 International Working Conference on Advanced Visual Interfaces (AVI '14)
Available from: 2015-03-20 Created: 2015-03-20 Last updated: 2018-01-11
Kocak, U., Lundin Palmerius, K. & Cooper, M. (2013). Anisotropic Virtual Coupling with Energy-Based Deflection for Palpating Inhomogeneous Compliant Objects. In: Proceedings of the IEEE World Haptics Conference: . Paper presented at IEEE World Haptics Conference, WHC 2013; Daejeon; South Korea (pp. 115-120). IEEE
Open this publication in new window or tab >>Anisotropic Virtual Coupling with Energy-Based Deflection for Palpating Inhomogeneous Compliant Objects
2013 (English)In: Proceedings of the IEEE World Haptics Conference, IEEE , 2013, p. 115-120Conference paper, Published paper (Refereed)
Abstract [en]

Virtual coupling, a spring-damper system between the haptic probe and its virtual representation, the proxy, is one of the most common approaches for haptic rendering. We have extended the virtual coupling by updating the spring stiffness, sometimes used to simulate compliance of a material, depending on the direction between the proxy and the probe. This anisotropic variation of the stiffness is used in exploring inhomogeneities beneath the surface allowing detection of rigid structures even when they are obscured by another structure beneath the surface. In addition, we also compensate for the energy variation of the spring to maintain passivity and increase realism. User studies were performed to survey the success rate in the detection of obscured rigid bodies beneath the surface with the modified virtual coupling algorithm and the improvement of shape perception for sub-surface objects with the additional energy compensation term providing gradient information. We also discuss potential benefits of the proposed methods as basic extensions to well-known haptic rendering algorithms which are both simpler and yield improved performance over traditional deformation simulationtechniques.

Place, publisher, year, edition, pages
IEEE, 2013
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-92802 (URN)10.1109/WHC.2013.6548394 (DOI)978-1-4799-0087-9 (ISBN)
Conference
IEEE World Haptics Conference, WHC 2013; Daejeon; South Korea
Available from: 2013-05-22 Created: 2013-05-22 Last updated: 2014-12-04Bibliographically approved
Kocak, U., Lundin Palmerius, K. & Cooper, M. (2013). High Resolution Enhancement in Deformation via Anisotropic Virtual Coupling.
Open this publication in new window or tab >>High Resolution Enhancement in Deformation via Anisotropic Virtual Coupling
2013 (English)Manuscript (preprint) (Other academic)
Abstract [en]

Achieving sufficient realism in deformation simulations requires consideration  of complex physical properties. The computational burden of modelling these properties requires the use of low resolution meshes to attain real time interactive performance. Medical data such as MR and CT, on the other hand, have much higher resolutions than can be practically used in deformation simulations. This results in significant amount of information loss, degenerating the ability to perceive variations in the data, especially inhomogeneities. In this paper, we address this issue by employing surfacerendering algorithms which can provide high resolution information from beneath the surface. An experiment was performed in a scenario simulating inhomogeneities of bone structure under the skin. Results have shown significant improvement for detecting inhomogeneities within deformable data while palpating the surface.

Keywords
Deformation, virtual coupling, anisotropy, haptics
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-92803 (URN)
Available from: 2013-05-22 Created: 2013-05-22 Last updated: 2014-10-08Bibliographically approved
Kocak, U., Lundin Palmerius, K. & Cooper, M. (2012). An Error Analysis Model for Adaptive Deformation Simulation. Paper presented at ACHI 2012, The Fifth International Conference on Advances in Computer-Human Interactions, January 30 2011, to February 4 2012, Valencia, Spain.
Open this publication in new window or tab >>An Error Analysis Model for Adaptive Deformation Simulation
2012 (English)Conference paper, Published paper (Other academic)
Abstract [en]

With the widespread use of deformation simulations in medical applications, the realism of the force feedback has become an important issue. In order to reach real-time performance with sufficient realism the approach of adaptivity, solution of different parts of the system with different resolutions and refresh rates, has been commonly deployed. The change in accuracy resulting from the use of adaptivity, however, has been been paid scant attention in the deformation simulation field. Presentation of error metrics is rare, while more focus is given to the real-time stability. We propose an abstract pipeline to perform error analysis for different types of deformation techniques which can consider different simulation parameters. A case study is also performed using the pipeline, and the various uses of the error estimation are discussed.

Keywords
physically-based, deformation, multiresolution, perception, error, analysis
National Category
Interaction Technologies
Identifiers
urn:nbn:se:liu:diva-79904 (URN)978-1-61208-177-9 (ISBN)
Conference
ACHI 2012, The Fifth International Conference on Advances in Computer-Human Interactions, January 30 2011, to February 4 2012, Valencia, Spain
Available from: 2012-08-28 Created: 2012-08-15 Last updated: 2014-10-08Bibliographically approved
Forsell, C. & Cooper, M. (2012). Questionnaires for evaluation in information visualization. In: BELIV '12 Proceedings of the 2012 BELIV Workshop: Beyond Time and Errors - Novel Evaluation Methods for Visualization. Paper presented at BELIV '12 Beyond Time and Errors - Novel Evaluation Methods for Visualization , October 14–15, 2012, Seattle, WA, USA. New York: ACM Press
Open this publication in new window or tab >>Questionnaires for evaluation in information visualization
2012 (English)In: BELIV '12 Proceedings of the 2012 BELIV Workshop: Beyond Time and Errors - Novel Evaluation Methods for Visualization, New York: ACM Press, 2012Conference paper, Published paper (Refereed)
Abstract [en]

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.

Place, publisher, year, edition, pages
New York: ACM Press, 2012
Keywords
Information visualization, evaluation, subjective usability measurement.
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:liu:diva-108563 (URN)10.1145/2442576.2442592 (DOI)978-1-4503-1791-7 (ISBN)
Conference
BELIV '12 Beyond Time and Errors - Novel Evaluation Methods for Visualization , October 14–15, 2012, Seattle, WA, USA
Available from: 2014-06-30 Created: 2014-06-30 Last updated: 2018-01-11Bibliographically approved
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