| 1. |
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| 2. |
- Haake, Magnus, et al.
(författare)
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Visual Stereotypes and Virtual Pedagogical Agents
- 2008
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Ingår i: Educational Technology & Society. - Palmerston North : International Forum of Educational Technology & Society. - 1176-3647 .- 1436-4522. ; 11:4, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- The paper deals with the use of visual stereotypes in virtual pedagogical agents and its potential impact in digital learning environments. An analysis of the concept of visual stereotypes is followed by a discussion of affordances and drawbacks as to their use in the context of traditional media. Next, the paper explores whether virtual pedagogical characters introduce anything novel with regard to the use of visual stereotypes - as compared both to real life interaction between humans and to the use of visual stereotypes in traditional non-interactive media such as magazines, film, television and video. It is proposed that novel affordances, as well as novel drawbacks, indeed are being introduced with the use of visual stereotypes in virtual characters. The conclusion of the paper is that knowledge on these matters can be useful both for developers of educational systems and for educators in enabling them to strengthen some pedagogical settings and activities.
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| 3. |
- Pauletto, Sandra, et al.
(författare)
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Interactive sonification of complex data
- 2009
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Ingår i: International journal of human-computer studies. - : Elsevier. - 1071-5819 .- 1095-9300. ; 67:11, s. 923-933
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we present two experiments on implementing interaction in sonification displays: the first focuses on recorded data (interactive navigation) and the second on data gathered in real time (auditory feedback). Complex synthesised data are explored in the first experiment to evaluate how well the known characteristics present in the data are distinguished using different interaction methods, while real medical data (from physiotherapy) are used for the second. The addition of interaction to the exploration of sonified recorded data improves the system usability (efficiency, effectiveness and user satisfaction), and the real-time sonification of complex physiotherapy data can produce sounds with timbral characteristics that audibly change when important characteristics present in the data vary.
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Berg, Jan, et al.
(författare)
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Perceived properties of parameterised music for interactive applications
- 2006
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Ingår i: Journal of Systemics, Cybernetics and Informatics. - 1690-4532 .- 1690-4524. ; 4:2, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- Traditional implementations of sound and music in interactive contexts have their limitations. One way to overcome these and to expand the possibilities of music is to handle the music in a parameterised form. To better understand the properties of the musical parameters resulting from parameterisation, two experiments were carried out. The first experiment investigated selected parameters' capability to change the music; the second experiment examined how the parameters can contribute to express emotions. From these experiments, it is concluded that users without musical training perform differently from musicians on some of the parameters. There is also a clear association between the parameters and the expressed basic emotions. The paper is concluded with observations on how parameterisation might be used in interactive applications.
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| 8. |
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| 9. |
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| 10. |
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| 11. |
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| 12. |
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| 13. |
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| 14. |
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| 15. |
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| 16. |
- Blomqvist, Ulf, et al.
(författare)
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DRM – Intrusion or Solution?
- 2005
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Ingår i: Innovation and the knowledge economy. - Amsterdam : IOS Press. ; , s. 925-933
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Konferensbidrag (refereegranskat)abstract
- DRM could be the solution to the content industry’s P2P dilemma, but content owners’ desire to monitor and control the consumer’s use of content can be perceived as an intrusion of privacy. High control makes consumers less active and low control invites them to experiment and to gain experience. Digital music files can easily be spread. Therefore legal services prefer keeping control over the music. This study reveals that consumers are one step ahead of the content industry, finding ways to circumvent protection and laws, and that the music industry is awaiting the "right" DRM business model. Online Music sellers basically rely on B2C DRM business models, but attempts have been made with C2C models, using consumers as distributors, and ISP models, where ISPs pay to collecting societies for all file trans-fers of copyrighted material in their networks. Future models include licensing mod-els, micro models, and no copyright at all.
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| 17. |
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| 18. |
- Bäcke, Maria, 1969-
(författare)
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Self, Setting, and Situation in Second Life
- 2009
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Ingår i: Literary Art in Digital Performance. - New York : Continuum. - 9780826436009 ; , s. 109-142
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Bokkapitel (refereegranskat)abstract
- Linden Lab, the company behind the online world Second Life (SL), invites multiplic- ity with slogans like “Your World. Your Imagination.”1 Yet many SL residents’2 profiles give evidence of adjustment to group narratives or norms in various social spaces inside the world. They seem to favor already established social and cultural conventions when creating an online identity; hence they also adjust to already existing hierarchies. I argue that residents in SL recreate social orders and power structures similar to ones already existing outside SL, even though they are of course under no obligation to do so. In that sense social and cultural patterns are reproduced and in some cases even amplified. My aim here is to trace social dynamics evident in three groups within this digital space and my hypothesis is that the rules of these social spaces then function as a foundation and guideline for identity formation, and in fact almost seem to prescribe a certain way of acting or behaving. Two of the groups have a clear role-playing profile, based on books and movies, whereas role-playing is not required, although possible, in the third group. All of them are thus removed from the lifeworld by constituting either purely fictive or, conversely, historical constructs, but they can nevertheless provide clues to how the residents think in an environment that is not primarily “real life” based, and in which anything, even a utopia, can be possible. By reading group charters and profile descriptions found in the SL search engine, and studying articles and blogs functioning either as group information channels or journals for individuals in each community, I examine the motivations and power structures driving avatar and online identity construction in role-playing communities, with a focus on the interac- tion between the overarching “state” power, the Linden Lab, the three communities, their respective role-models, and the rules that govern them, as well as the individuals that are a part of them.
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| 19. |
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| 20. |
- Enlund, Nils, et al.
(författare)
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Mediated masterclass teaching
- 2007
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Ingår i: Proc. of Developing Innovative Video Resources for Students Everywhere. - Lillehammer : Høgskolen i Lillehammer.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 21. |
- Enlund, Nils, 1946-
(författare)
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Morgondagens teknik finns i dagens laboratorier
- 2008. - 4
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Ingår i: På väg mot medievärlden 2020. - Lund : Studentlitteratur. - 9789144053158 ; , s. 211-227
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 22. |
- Enlund, Nils, 1946-, et al.
(författare)
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The early days of computer aided newspaper productions systems
- 2007
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Ingår i: History of Nordic Computing. - Åbo : Turku University. ; , s. 32-34
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Konferensbidrag (refereegranskat)abstract
- During the years 1970-1973, an ambitious research project, the Computer Graphics Project (CGP), was carried out at the laboratory of Information Processing Science at the Helsinki University of Technology. The initial objective of the project was to develop application oriented system solutions for the emerging computer graphics technology, but the activities were soon focused on the problems of producing newspaper text, advertisement, and complete pages using interactive computer graphics. The project and its commercial spin-off, Typlan Systems Projects Oy Ab, as well as the BUNPAPS continuation project 1973-1975 at Brown University, Providence, Rhode Island, created a number of innovative, pioneering solutions for computer aided newspaper production, laying the foundation for the digitalization of media production in the 1980’es. This paper describes the ideas, research, innovations, and products generated by the members of these groups in the period 1970-1975.
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| 23. |
- Enlund, Nils, 1946-, et al.
(författare)
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The early days of computer aided newspaper productions systems
- 2009
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Ingår i: History of Nordic Computing 2. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642037566 - 9783642037573 ; , s. 238-249
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Bokkapitel (refereegranskat)abstract
- During the years 1970-1973, the Laboratory of Information Processing Science at the Helsinki Uni versity of Technology carried out the Computer Graph ics Pro ject (CGP). The activities foc us ed on the problems of producing news paper text, ad vert isements, and com plete pages using inter act ive computer graphics. The project and its commercial spin-off, Typlan, as well as the BUNPAPS continuation project 1973-1975, cre ated a num ber of innovative, pioneering solutions for computer aided news pap er production, laying the found at ion for the digitalization of media production.
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Eriksson, Lars-Erik, et al.
(författare)
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Open Source / Open content and other emerging e-business models; a complement to or on a collision course with the existing IPR / Patent regime
- 2007
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Ingår i: Expanding the knowledge economy. - Amsterdam : IOS Press. ; , s. 1557-1563
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Konferensbidrag (refereegranskat)abstract
- Throughout the 1990s, the emerging policy debate on the potential of a digital networks society stressed the need to balance two possibly opposing features. The protection of immaterial rights, via the IPR / Patent regime, should not be so rigorous as to hinder the development of new business models suited to the digital world. As a more focused debate on e-inclusion, interactivity, consumer as creators etc. developed, the focus shifted to the need for a balance between content owners, content owners IPRs and the reasonable interests of consumers.Technology, however, has made it possible for consumers to circumnavigate content owners´ interests with the result that cultural diversity has moved from main stream media to the Internet. Technology has turned content, which has been exclusive to many due to cost and the necessity to have certain hardware (CD players etc) into collective goods. User generated content (UGC) has become a means to bridge the gap between consumption and production. The Open Source movement has developed rapidly, with thousands of experienced Internet users collaborating in the development of new software applications, often in parallel with the growth of proprietary solutions protected by the IPR/ patent regime.This paper looks at the significance of these developments for creativity and innovation in general and more specifically for the current wave of emerging open source / open content-based business models. We argue a) that new business models are often at odds with the legal regime, b) that consumer privacy is increasingly at odds with the legal regime, and c) that innovation may be a victim since improving existing ideas is the basis of creativity.
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| 29. |
- Eriksson, Lars-Erik, et al.
(författare)
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User Oriented Business Models in Peer-to-Peer Services
- 2006
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Ingår i: Exploiting the knowledge economy. - Amsterdam : IOS Press. ; , s. 1797-1804
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Konferensbidrag (refereegranskat)abstract
- A limited number of business and legal solutions have been used over the decades to solve the content industry’s "problems" arising from new technology. Content industry has been lagging behind technology developers especially when it comes to different file-sharing (Peer-2-Peer) technologies and systems. The paper shows that P2P technology will be necessary in the future. Research has shown that it is possible to group file-sharers in three major gropus – "free riders", "samplers" and "squirrells". Studying the properties of these groups a number of business models can be defined. This study show that business models such as licensing, subscription, retail and e-commerce models can be derived from these groups of users. This study also concludes that new underpinning technologies such as DRM and a natural language approach to content mark up are necessary to be able to develop solutions to make these business models satisfactory for both users and content owners.
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| 30. |
- Findahl, Olle, et al.
(författare)
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The IPR Regime and The Open Source/Open Content Movement – An Alternative Stimulus for Creativity or on a Collision Course?
- 2006
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Ingår i: Exploiting the Knowledge Economy. - Amsterdam : IOS Press. ; , s. 1804-1811
-
Konferensbidrag (refereegranskat)abstract
- The Open source and Open content movement is in progress. This paper analyses the emergence of new business opportunities, as well as potential conflicts with legal frameworks designed for IPR owners. Data is presented from interviews with a representative sample of Swedes as well as a questionnaire to a more specialized sample of experienced users with an IT background. What kind of activities are they engaged in? What are the driving forces? Ordinary Internet users are usually not aware of open source programs even if they use them. But they are participating more and more producing content and sharing content on websites and online communities. The more experienced and advanced users are well acquainted with both, they are using it and a lot of them take part in the creation of content and the development of the software. However, it seems that the open source/open content movement is rapidly emerging as an essential alternative incentive for creativity compared to the traditional IPR regime. Maybe the two approaches are even on a collision course.
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| 31. |
- Hadwiger, Markus, et al.
(författare)
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Advanced Illumination Techniques for GPU-Based Volume Raycasting
- 2009
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Volume raycasting techniques are important for both visual arts and visualization. They allow an efficient generation of visual effects and the visualization of scientific data obtained by tomography or numerical simulation. Thanks to their flexibility, experts agree that GPU-based raycasting is the state-of-the art technique for interactive volume rendering. It will most likely replace existing slice-based techniques in the near future. Volume rendering techniques are also effective for the direct rendering of implicit surfaces used for soft body animation and constructive solid geometry.The lecture starts off with an in-depth introduction to the concepts behind GPU-based ray-casting to provide a common base for the following parts. The focus of this course is on advanced illumination techniques which approximate the physically-based light transport more convincingly. Such techniques include interactive implementation of soft and hard shadows, ambient occlusion and simple Monte-Carlo based approaches to global illumination including translucency and scattering. With the proposed techniques, users are able to interactively create convincing images from volumetric data whose visual quality goes far beyond traditional approaches. The optical properties in participating media are defined using the phase function. Many approximations to the physically based light transport applied for rendering natural phenomena such as clouds or smoke assume a rather homogenous phase function model. For rendering volumetric scans on the other hand different phase function models are required to account for both surface-like structures and fuzzy boundaries in the data. Using volume rendering techniques, artists who create medical visualization for science magazines may now work on tomographic scans directly, without the necessity to fall back to creating polygonal models of anatomical structures.
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| 32. |
- Hadwiger, Markus, et al.
(författare)
-
Advanced illumination techniques for GPU volume raycasting
- 2008
-
Ingår i: ACM Siggraph Asia 2008 Courses. ; , s. 1-11
-
Konferensbidrag (refereegranskat)abstract
- Volume raycasting techniques are important for both visual arts and visualization. They allow an efficient generation of visual effects and the visualization of scientific data obtained by tomography or numerical simulation. Thanks to their flexibility, experts agree that GPU-based raycasting is the state-of-the art technique for interactive volume rendering. It will most likely replace existing slice-based techniques in the near future. Volume rendering techniques are also effective for the direct rendering of implicit surfaces used for soft body animation and constructive solid geometry.The lecture starts off with an in-depth introduction to the concepts behind GPU-based ray-casting to provide a common base for the following parts. The focus of this course is on advanced illumination techniques which approximate the physically-based light transport more convincingly. Such techniques include interactive implementation of soft and hard shadows, ambient occlusion and simple Monte-Carlo based approaches to global illumination including translucency and scattering. With the proposed techniques, users are able to interactively create convincing images from volumetric data whose visual quality goes far beyond traditional approaches. The optical properties in participating media are defined using the phase function. Many approximations to the physically based light transport applied for rendering natural phenomena such as clouds or smoke assume a rather homogenous phase function model. For rendering volumetric scans on the other hand different phase function models are required to account for both surface-like structures and fuzzy boundaries in the data. Using volume rendering techniques, artists who create medical visualization for science magazines may now work on tomographic scans directly, without the necessity to fall back to creating polygonal models of anatomical structures.
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| 33. |
- Handberg, Leif, 1962-, et al.
(författare)
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Community building through cultural exchange in mediated performance events : a conference 2005
- 2005
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Ingår i: The Virtual — a room without borders?. - : School of Communication, Technology and Design Södertörn College University.
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Konferensbidrag (refereegranskat)abstract
- A rich sense of togetherness can be achieved in distributed audiences by using scenography, dramaturgy, story telling (narratives), conscientiously applied on a foundation of advances in media technology. This paper describes the findings from a series of full-scale performances, nicknamed the "Point 25". This event was launched as a joint venture between The Royal Institute of Technology in Stockholm (KTH) and Stanford University in Palo Alto, CA within the Connected Performance Spaces Project (a.k.a COPS), funded by WGLN (Wallenberg Global Learning Network). Each performance consisted of two performing nodes (each hosting two musicians) and two audience nodes, respectively located in the universities' performance spaces, separated by 10 000 km and nine time zones. The physical scenography was based on a hexagonal boundary with a number of large projection screens, cameras, microphones, speakers et cetera. In this common “performer-audience” scene, there were designated "hot" capture areas for the performers to work in, assisted by auxiliary video feeds for real-time transitions and immersive blending. On each side of the intercontinental performance, there was a ”presence producer” in action, changing the characteristics of the interactive spaces for the performers, thus exploring new narrative tools and developing new experiences for the audience. This type of event implies that enriched convergence between media-related disciplines, will move the boundaries of what is possible to do today. To work together inevitably leads to a deeper understanding of each others’ research areas, and ultimately to what we refer to as concept calibration – a starting point for breaking new ground within presence production. It shows that it is possible to build communities between humans separated both by large distances as well as previously disjunctive fields of research, arts and performance
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| 34. |
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| 35. |
- Handberg, Leif, 1962-, et al.
(författare)
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Living with a continuously produced presence – experiences from an extended office space.
- 2007
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Konferensbidrag (refereegranskat)abstract
- What is it actually like to share your office space - all day, every day - in realtime collaboration with your peer professionals, located in distributed geographical locations - in our case also involving multiple countries – yet interconnected with audiovisual technology. This empirical study aims to examine how telepresence affects various communication modes at the workplace; teamwork, reflective, leisure activities and so forth. The research team members have identified some key factors that together contribute to a sense of presence, each of them affecting the level of trust and co-existence between two or more parties. Secondly, the report attempts to address the overall notion of communication quality as such; what actually constitutes communication quality in a telepresence context, to what extent is this quality measurable in technical terms, how does the user's perceived sense of quality correlate to measurements, and how does communication quality affect the sense of presence, bonds of trust and feeling of togetherness for members of a virtually co-located, yet geographically separated, working group. This study was carried out by a joint team of researchers at Høgskolen i Lillehammer, Høgskolen i Gjøvik, both in Norway and Kungliga Tekniska Högskolan in Stockholm, Sweden during 2004-2007.
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| 36. |
- Handberg, Leif, 1962-, et al.
(författare)
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The Mediated Museum
- 2008
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Annan publikation (refereegranskat)
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| 37. |
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| 38. |
- Holzapfel, André, 1976-, et al.
(författare)
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A scale transform based method for rhythmic similarity of music
- 2009
-
Ingår i: Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP). - : IEEE conference proceedings. ; , s. 317-320
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Konferensbidrag (refereegranskat)abstract
- This paper introduces scale transforms to measure rhythmic similarity between two musical pieces. The rhythm of a piece of music is described by the scale transform magnitude, computed by transforming the sample autocorrelation of its onset strength signal to the scale domain. Then, two pieces can be compared without the impact of tempo differences by using simple distances between these descriptors like the cosine distance. A widely used dance music dataset has been chosen for proof of concept. On this data set, the proposed method based on scale transform achieves classification results as high as other state of the art approaches. On a second data set, which is characterized by much larger intra-class tempo variance, the scale transform based measure improves classification compared to previously presented measures by 41%.
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| 39. |
- Holzapfel, André, 1976-, et al.
(författare)
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A statistical approach to musical genre classification using Non-negative Matrix Factorization
- 2007
-
Ingår i: Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP). - : IEEE Press. ; , s. 693-696
-
Konferensbidrag (refereegranskat)abstract
- This paper introduces a new feature set based on a Non-negtive Matrix Factorization approach for the classification of musical signals into genres, only using synchronous organization of music events (vertical dimension of music). This feature set generates a vector space to describe the spectrogram representation of a music Signal. The space is modeled statistically by a mixture of Gaussians (GMM). A new signal is classified by considering the likelihoods over all the estimated feature vectors given these statistical models, without constructing a model for the signal itself. Cross-validation tests on two commonly utilized datasets for this task show the superiority of the proposed features compared to the widely used MFCC type of representation based on classification accuracies (over 9% of improvement), as well as on a stability measure introduced in this paper for GMM.
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| 40. |
- Holzapfel, André, 1976-, et al.
(författare)
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Beat tracking using group delay based onset detection
- 2008
-
Ingår i: Proceedings of ISMIR - International Conference on Music Information Retrieval. - : ISMIR. ; , s. 653-658
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Konferensbidrag (refereegranskat)abstract
- This paper introduces a novel approach to estimate onsets in musical signals based on the phase spectrum and specifically using the average of the group delay function. A frame-by-frame analysis of a music signal provides the evolution of group delay over time, referred to as phase slope function. Onsets are then detected simply by locating the positive zero-crossings of the phase slope function. The proposed approach is compared to an amplitude-based onset detection approach in the framework of a state-of-the-art system for beat tracking. On a data set of music with less percussive content, the beat tracking accuracy achieved by the system is improved by 82% when the suggested phase-based onset detection approach is used instead of the amplitudebased approach, while on a set of music with stronger percussive characteristics both onset detection approaches provide comparable results of accuracy.
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| 41. |
- Holzapfel, André, 1976-, et al.
(författare)
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Musical genre classification using Nonnegative Matrix Factorization based features
- 2008
-
Ingår i: IEEE Transactions on Audio, Speech, and Language Processing. - : IEEE Press. - 1558-7916 .- 1558-7924. ; 16:2, s. 424-434
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Tidskriftsartikel (refereegranskat)abstract
- Nonnegative matrix factorization (NMF) is used to derive a novel description for the timbre of musical sounds. Using NMF, a spectrogram is factorized providing a characteristic spectral basis. Assuming a set of spectrograms given a musical genre, the space spanned by the vectors of the obtained spectral bases is modeled statistically using mixtures of Gaussians, resulting in a description of the spectral base for this musical genre. This description is shown to improve classification results by up to 23.3% compared to MFCC-based models, while the compression performed by the factorization decreases training time significantly. Using a distance-based stability measure this compression is shown to reduce the noise present in the data set resulting in more stable classification models. In addition, we compare the mean squared errors of the approximation to a spectrogram using independent component analysis and nonnegative matrix factorization, showing the superiority of the latter approach.
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| 42. |
- Holzapfel, André, 1976-, et al.
(författare)
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Rhythmic Similarity in Traditional Turkish Music
- 2009
-
Ingår i: Proceedings of ISMIR - International Conference on Music Information Retrieval. - : ISMIR. ; , s. 99-104
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Konferensbidrag (refereegranskat)abstract
- In this paper, the problem of automatically assigning a piece of traditional Turkish music into a class of rhythm referred to as usul is addressed. For this, an approach for rhythmic similarity measurement based on scale transforms has been evaluated on a set of MIDI data. Because this task is related to time signature estimation, the accuracy of the proposed method is evaluated and compared with a state of the art time signature estimation approach. The results indicate that the proposed method can be successfully applied to audio signals of Turkish music and that it captures relevant properties of the individual usul.
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| 43. |
- Holzapfel, André, 1976-, et al.
(författare)
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Singer Identification in Rembetiko Music
- 2007
-
Ingår i: Proceedings of the Conference on Sound and Music Computing (SMC). - : Sound and music Computing network. ; , s. 326-329
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Konferensbidrag (refereegranskat)abstract
- In this paper, the problem of the automatic identification of a singer is investigated using methods known from speaker identification. Ways for using world models are presented and the usage of Cepstral Mean Subtraction (CMS) is evaluated. In order to minimize the difference due to musical style we use a novel data set, consisting of samples from greekRembetiko music, being very similar in style. The data set also explores for the first time the influence of the recording quality, by including many historical gramophone recordings. Experimental evaluations show the benefits of world models for frame selection and CMS, resulting in an average classification accuracy of about 81% among 21 different singers.
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| 44. |
- Johansson, Sara, et al.
(författare)
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Interactive Dimensionality Reduction Through User-defined Combinations of Quality Metrics
- 2009
-
Ingår i: IEEE Transactions on Visualization and Computer Graphics. - 1077-2626 .- 1941-0506. ; 15:6, s. 993-1000
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Tidskriftsartikel (refereegranskat)abstract
- Multivariate data sets including hundreds of variables are increasingly common in many application areas. Most multivariate visualization techniques are unable to display such data effectively, and a common approach is to employ dimensionality reduction prior to visualization. Most existing dimensionality reduction systems focus on preserving one or a few significant structures in data. For many analysis tasks, however, several types of structures can be of high significance and the importance of a certain structure compared to the importance of another is often task-dependent. This paper introduces a system for dimensionality reduction by combining user-defined quality metrics using weight functions to preserve as many important structures as possible. The system aims at effective visualization and exploration of structures within large multivariate data sets and provides enhancement of diverse structures by supplying a range of automatic variable orderings. Furthermore it enables a quality-guided reduction of variables through an interactive display facilitating investigation of trade-offs between loss of structure and the number of variables to keep. The generality and interactivity of the system is demonstrated through a case scenario.
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| 45. |
- Johansson, Sara, et al.
(författare)
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Interactive Quantification of Categorical Variables in Mixed Data Sets
- 2008
-
Ingår i: Information Visualisation, 2008. IV '08. 12th International Conference. - Los Alamitos, California : IEEE Computer Society. - 9780769532684 ; , s. 3-10
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Konferensbidrag (refereegranskat)abstract
- Data sets containing a combination of categorical and continuous variables (mixed data sets) are difficult to analyse since no generalized similarity measure exists for categorical variables. Quantification of categorical variables makes it possible to represent this type of data using techniques designed for numerical data. This paper presents a quantification process of categorical variables in mixed data sets that incorporates information on relationships among the continuous variables into the process, as well as utilizing the domain knowledge of a user. An interactive visualization environment using parallel coordinates as a visual interface is provided, where the user is able to control the quantification process and analyse the result. The efficiency of the approach is demonstrated using two mixed data sets.
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| 46. |
- Johansson, Sara, et al.
(författare)
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Visual Analysis of Mixed Data Sets Using Interactive Quantification
- 2009
-
Ingår i: ACM SIGKDD Explorations Newsletter. - New York : ACM. - 1931-0145 .- 1931-0153. ; 11:2, s. 29-38
-
Tidskriftsartikel (refereegranskat)abstract
- It is often diffcult to analyse data sets including a combi-nation of categorical and numerical variables (mixed datasets) since there does not exist any similarity measure whichis as straight forward and general as the numerical distancebetween numerical items. Quantication of categorical vari-ables enables analysis using commonly used visual represen-tations and analysis techniques for numerical data. Thispaper presents a tool for exploratory analysis of categoricaland mixed data which uses a quantication process intro-duced in [Johansson2008]. The application enables analysis of mixeddata sets by providing an environment for exploratory anal-ysis using common visual representations in multiple coordi-nated views and algorithmic analysis that facilitates detec-tion of potentially interesting patterns within combinationsof categorical and numerical variables. The generality andusefulness of the quantication process and of the featuresof the application is demonstrated through a case scenariousing a data set from the IEEE VAST 2008 Challenge.
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| 47. |
- Johansson, Sara, 1980-
(författare)
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Visual Exploration of Categorical and Mixed Data Sets
- 2009
-
Ingår i: Proceeding VAKD '09 Proceedings of the ACM SIGKDD Workshop on Visual Analytics and Knowledge Discovery: Integrating Automated Analysis with Interactive Exploration. - New York, USA : ACM Press. - 9781605586700 ; , s. 21-29
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Konferensbidrag (refereegranskat)abstract
- For categorical data there does not exist any similarity measurewhich is as straight forward and general as the numericaldistance between numerical items. Due to this it is often difficultto analyse data sets including categorical variables or a combination of categorical and numerical variables (mixeddata sets). Quantification of categorical variables enablesanalysis using commonly used visual representations andanalysis techniques for numerical data. This paper presents a tool for exploratory analysis of categorical and mixed data, which uses a quantification process introduced in [Johansson2008]. The application enables analysis of mixed data sets by providingan environment for exploratory analysis using commonvisual representations in multiple coordinated views and algorithmic analysis that facilitates detection of potentially interesting patterns within combinations of categorical and numerical variables. The effectiveness of the quantificationprocess and of the features of the application is demonstratedthrough a case scenario.
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| 48. |
- Jovanovic, Tatjana, et al.
(författare)
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(Inter)facing the Wall-Integration of digital and building technology
- 2006
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Ingår i: Proceedings of the International Conference on Education and Research in Computer Aided Architectural Design in Europe. - : eCAADe. - 2684-1843. ; , s. 640-643
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Konferensbidrag (refereegranskat)abstract
- The paper examines possible transformation of an existing school info-board massive brick wall in the building entrance area, into a ‘Smart’ one, combining electronics, internet, IT and computer graphics with building technology. The project as a whole aims to improve communication and interaction between users within one building and to provide the reliable visual information which influences users’ activities in real-time.
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| 49. |
- Lindstrand, Mikael, 1970-
(författare)
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Spatially and angularly resolved high dynamic range reflectance measurements for forensic document inspection
- 2008
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Ingår i: Optical Document Security. - : Reconnaissance International. - 9781617389108 ; , s. 223-235
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Konferensbidrag (refereegranskat)abstract
- Detailed optical characterization of the relevant features of optically variable devices (OVD) is in general a challenge. Adding to the in general high both spatial and angular resolved characteristics, the high dynamic range of reflection, including high intensity specular reflections and low intensity reflections of other geometries make the metrology even more demanding. A trichromatic reflectance measurement service recently made commercially available, addresses the stated challenges. The resulting data may be described as a spatially resolved trichromatic goniophotometric characterization. The massive data set generated may be approached either by developed visualization tools (static images and dynamic videos) or processed mathematically into higher-order characterizations. The number of potential relevant applications is abundant – one example may be a detailed angular characterization of the iridescent color shifts; how the iridescence function is distorted due to the topography of the underlying paper. The application is demanding in part because the analysis involves spatial and angular dimensions over a high dynamic range of reflectance (specular and non-specular). Besides the OVD, there are other optical document security functions that are challenging to characterize in detail, and where this novel service may prove a useful tool for the professionals in the business.
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| 50. |
- Ljung, Patric, 1968-, et al.
(författare)
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Full Body Virtual Autopsies Using A State-of-the-art Volume Rendering Pipeline
- 2006
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Ingår i: IEEE Transactions on Visualization and Computer Graphics. - 1077-2626 .- 1941-0506. ; 12:5, s. 869-876
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a procedure for virtual autopsies based on interactive 3D visualizations of large scale, high resolutiondata from CT-scans of human cadavers. The procedure is described using examples from forensic medicine and the added valueand future potential of virtual autopsies is shown from a medical and forensic perspective. Based on the technical demands ofthe procedure state-of-the-art volume rendering techniques are applied and refined to enable real-time, full body virtual autopsiesinvolving gigabyte sized data on standard GPUs. The techniques applied include transfer function based data reduction using levelof-detail selection and multi-resolution rendering techniques. The paper also describes a data management component for large,out-of-core data sets and an extension to the GPU-based raycaster for efficient dual TF rendering. Detailed benchmarks of thepipeline are presented using data sets from forensic cases.
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