Search results for "artifacts"
showing 10 items of 105 documents
Sketcching sonic interactions
2019
This chapter provides an overview of methods and practices for sketching sound in interactive contexts. The chapter stresses the role and importance of producing and interacting with provisional sound representations in conceptual sound design. The cognitive benefits of embodied sound sketching are discussed and outlined by means of practical examples and basic exercises. In particular, vocalizations and gestures are proposed as primary cognitive artifacts available to sound designers to enact sonic impressions and displays, cooperatively.
Directionlets: Anisotropic Multidirectional representation with separable filtering
2006
In spite of the success of the standard wavelet transform (WT) in image processing in recent years, the efficiency of its representation is limited by the spatial isotropy of its basis functions built in the horizontal and vertical directions. One-dimensional (1-D) discontinuities in images (edges and contours) that are very important elements in visual perception, intersect too many wavelet basis functions and lead to a nonsparse representation. To efficiently capture these anisotropic geometrical structures characterized by many more than the horizontal and vertical directions, a more complex multidirectional (M-DIR) and anisotropic transform is required. We present a new lattice-based pe…
Ero ja immersio. Tutkimus artefaktin ongelmasta ja aineellisen ja käsitteellisen välisistä suhteista
2021
Tutkimus on kulttuurifilosofinen ja kulttuurintutkimuksellinen väitöskirja aineellisen artefaktin ongelmasta ja filosofinen tutkimus aineellisen mieltämisen ehdoista. Ihmistekoisen statuksen uudelleen arvioinnin pohjalta kehitän siinä uuden tavan ajatella aineellista ja ruumiillista. Historiallisesti suhteellisen nuoreen artefaktin käsitteeseen on tullut materiaalisuuksien kasvun myötä sen painon sivuuttavaa itsestäänselvyyttä, kuten tapahtui ikivanhalle olemisen käsitteelle Martin Heideggerin käänteentekevän huomion mukaan. Käsitteen neutraloituminen onkin siitä välittymättömän aineellisuuden neutraloitumista, mitä kutsun konstituutioharhaksi. Konstituutioharha on modernissa vallitseva tap…
Evolution of Digital Innovations Based on Entrepreneurial Opportunities
2019
Digital innovations evolve unpredictable as the characteristics of digital technology provide diverse opportunities for entrepreneurs. The flexible, malleable, and unbounded nature of digital technologies makes the evolution process unpredictable as entrepreneurs can rarely estimate beforehand how new digital technologies might impact the evolution process. It is also hard to predict how customers will react to the changes enabled by digital technologies. In this longitudinal case study, we were interested in different competitive moves that entrepreneurs apply to effectuate changes in the evolutionary pathway of digital innovations. Further, we were fascinated by how the evolution of digit…
Value Co-Creation and Co-Destruction in an IS Artifact: Contradictions of Geocaching
2016
In this paper we study how value co-creation and value co-destruction are present in an IS artifact. We apply the concept of contradiction (structural tension) to study an IS artifact, geocaching. Based on the analysis of interview data and discussion forum postings, we identified the following contradictions: i) introducing secret society to outsiders, ii) geocaching by breaking its rules, iii) experiencing nature while consuming it, iv) building community occurs with competition. These contradictions show that value co-creation and co-destruction interacts in this IS artifact. Based on the results, we propose that IS research should adopt the concepts of value co-creation and co-destructi…
Artefacts in CBCT: a review
2011
Artefacts are common in today's cone beam CT (CBCT). They are induced by discrepancies between the mathematical modelling and the actual physical imaging process. Since artefacts may interfere with the diagnostic process performed on CBCT data sets, every user should be aware of their presence. This article aims to discuss the most prominent artefacts identified in the scientific literature and review the existing knowledge on these artefacts. We also briefly review the basic three-dimensional (3D) reconstruction concept applied by today's CBCT scanners, as all artefacts are more or less directly related to it.
Diffusion-weighted MRI of cholesteatomas of the petrous bone
2002
Purpose To investigate if primary cholesteatomas of the petrous bone show high signal in diffusion-weighted imaging (DWI). Materials and methods In this blinded study, we compared 15 patients with clinically certain cases and later surgically proven cholesteatomas vs. 12 patients with clinically acute otitis of the middle ear and 20 volunteers without petrous bone disease. Two blinded readers without knowledge of the clinical data decided in consensus agreement whether there was a pathologic signal increase in the petrous bone in an anisotropic single-shot echo-planar imaging (EPI) DWI sequence, an artifact, or no signal increase. Results Thirteen of 15 patients with cholesteatomas showed b…
Undetected Malignancies of the Breast: Dynamic Contrast-enhanced MR Imaging at 1.0 T
2002
To assess the prevalence and characteristics of malignant breast lesions not identified with magnetic resonance (MR) imaging.Breast tissue specimens were obtained in 464 of 967 patients who had undergone dynamic gadolinium-enhanced T1-weighted fast low-angle shot three-dimensional MR imaging of both breasts. A comparison of sensitivity, specificity, and predictive values of the prospectively recorded findings of mammography, ultrasonography (US), and MR imaging with the histopathologic results was performed with receiver operating characteristic (ROC) curve analysis. MR imaging examination findings that caused a false-negative diagnosis were reviewed to identify possible sources of error.Hi…
Pitfalls in whole body MRI with diffusion weighted imaging performed on patients with lymphoma: What radiologists should know
2016
The technological advances in radiological imaging and the relevance of a diagnostic tool that may reduce radiation-induced long-term effects have led to a widespread use of whole body magnetic resonance imaging (WB-MRI) with diffusion weighted imaging for oncologic patients. A lot of studies demonstrated the feasibility and reliability of WB-MRI as an alternative technique for lymphoma staging and response assessment during and after treatment. In this paper, taking advantage of our 2years of experience using WB-MRI for lymphoma, we discuss the main pitfalls and artifacts radiologists should know examining a WB-MRI performed on this typology of patients in order to avoid images misinterpre…
Implant-specific follow-up imaging of treated intracranial aneurysms: TOF-MRA vs. metal artifact reduced intravenous flat panel computed tomography a…
2017
Aim To compare the diagnostic quality of time-of-flight magnetic resonance angiography (TOF-MRA) and metal-artefact-reduction (MAR) flat-panel-detector computed tomography angiography (FPCTA) and to determine the imaging technique best suited for evaluation endovascular and surgically treated aneurysms. Methods The image quality of TOF-MRA and MAR-FPCTA of 44 intracranial implants (coiling: n= 20; clipping: n= 15; coiling + stenting: n= 9) in a patient cohort of 25 was evaluated by two independent readers. Images obtained using MAR-FPCTA (20 second scan time, 496 projections, intravenous contrast medium administration; Artis Zee, Siemens Healthcare, Forchheim) were compared with TOF-MRA-ima…