scholarly journals Escher's Ants as Metaphor: Topological Marching for the Well-Composed, Genus Zero Crowd

2010 ◽  
Author(s):  
Nicholas J. Tustison ◽  
Brian Avants ◽  
Marcelo Siqueira ◽  
James Gee
Keyword(s):  
Level Set ◽  
Image Data ◽  
Theoretical Discussion ◽  
Brain Segmentation ◽  
Genus Zero ◽  
Brain Images ◽  
Original Topology ◽  
Constrained Evolution ◽  
Initial Seed ◽  
Definition Of

Topological considerations for segmentation results are important for such applications as proper brain segmentation from digital image data. We present an enhancement of the FastMarchingImageFilter which allows for topologically constrained evolution of the level set. Identical to the original functionality of the FastMarchingImageFilter, the evolution of the level set of a single or multiple genus zero, well-composed seed objects proceeds according to the specified parameters. With our proposed enhancements, the user can either choose to prevent the level set from merging with itself such that the original topology of the initial seed object(s) is not violated or that no handles are created during the evolution process. However, in contrast to earlier approaches which relied on the concept of the simple point implicitly requiring the definition of a user-specified foreground/background connectivity, we use the related, but more restrictive concept of well-composed sets to topologically constrain the evolution of the level set. Utility of our submission is demonstrated on both 2-D and 3-D brain images. Note that this submission is a companion piece to a more theoretical discussion of our work given in [9]

Neuroanatomical Segmentation in MRI: Technological Objectives

1997 ◽  
Vol 11 (08) ◽  
pp. 1161-1187 ◽  
Author(s):  
Andrew J. Worth ◽  
Nikos Makris ◽  
Verne S. Caviness Jr. ◽  
David N. Kennedy
Keyword(s):  
Image Data ◽  
Insufficient Information ◽  
Mr Image ◽  
Brain Images ◽  
Morphometric Analyses ◽  
Definition Of ◽  
Automated Methods ◽  
Signal Intensities

This paper offers a definition of precise, comprehensive, robust and practical neuroanatomical segmentation in magnetic resonance brain images with the goal of performing quantitative morphometric analyses. The main types of difficulties experienced with such problems are described, including those relating to the classification of MR signal intensities and the fact that there is insufficient information in the 2D image. To illustrate the details of obtaining a morphometric description, a case study of semi-automated methods is presented for segmenting the lateral ventricles and caudate nucleus in T1 coronal MR image data. The most significant remaining difficulties are summarized and are offered as objectives for further research.

Regional and indigenous identities in the high north: enacting social boundaries

Polar Record ◽  
2012 ◽  
Vol 48 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Sidsel Saugestad
Keyword(s):  
Coming Out ◽  
The State ◽  
The Other ◽  
Social Boundaries ◽  
Cultural Tradition ◽  
Theoretical Discussion ◽  
The North ◽  
Communicative Strategies ◽  
Time And Being ◽  
Definition Of

ABSTRACTThis paper addresses two processes of social and cultural mobilisation. The first example is a regional movement, as manifested in social and cultural expressions of a north Norwegian identity that was particularly marked in the 1970s and early 80s. The other is the Saami movement, coming out strongly at about the same time, and being part of a global process of indigenous mobilisation. It is argued that although they are similar in the way they articulate a sense of identity and belonging in contrast to an overarching and encompassing state, they are different in their stated objectives, in their relation to the state and the type of achievements gained. The north Norwegian regional movement strived for inclusion into a wider national cultural tradition, and integration has been achieved by broadening the definition of what is considered Norwegian culture. The objective of the Saami movement was the opposite: to gain recognition as a people with a distinct culture, different from but equal in value with the Norwegian culture. The article is introduced by a theoretical discussion of the issues involved, framing the analysis of communicative strategies.

Vague Language That Is Rarely VagueP: A Case Study of “Thing” in L1 and L2 Discourse

2012 ◽  
Vol 4 (1) ◽  
pp. 3-28 ◽  
Author(s):  
Denise Gassner
Keyword(s):  
Employment Interview ◽  
Interview Data ◽  
Special Focus ◽  
Theoretical Discussion ◽  
Job Interviews ◽  
Definition Of ◽  
L1 And L2 ◽  
Vague Language ◽  
Two Populations

This paper investigates the use of “vague language” (Channell, 1994) in English L1 and L2 speaker discourse. In particular, the item “thing”, which is used about 2.5 times more often by the L1 than the L2 speakers, is analysed in job interviews in Australia. Since “thing” has been termed “vague language” this paper will first provide a theoretical discussion of the notion of vagueness with a special focus on “thing”. The discussion of vagueness is mainly based on the “underdeterminacy thesis” (Carston, 1988, 2002; Atlas, 2005) and is, thus, closely linked to explicature construction and the notion of saturation. The theoretical discussion will lead to a definition of vagueness as a pragmatic hearer based phenomenon (vaguenessP) which will be applied to an analysis of “thing” in the L1 and L2 employment interview data collected. The analysis will show that “thing” is used differently by the two populations with regards to the notion of vaguenessPbut also with respect to the saturation requirement of this item. While the analysis shows that “thing” is not inherently vagueP, some instances of “thing” in the L2 data do seem to introduce the phenomenon of vaguenessP. Furthermore, the preference of L1 and L2 speakers for different saturation processes has an influence on the effect achieved by “thing”.

Comparison of EM-based and level set partial volume segmentations of MR brain images

2008 ◽  
Author(s):  
Hemant D. Tagare ◽  
Yunmei Chen ◽  
Robert K. Fulbright
Keyword(s):  
Level Set ◽  
Brain Images ◽  
Partial Volume ◽  
Mr Brain Images ◽  
Mr Brain

scholarly journals Stochastic Level Set Dynamics to Track Closed Curves Through Image Data

2013 ◽  
Vol 49 (2) ◽  
pp. 296-316 ◽  
Author(s):  
C. Avenel ◽  
E. Mémin ◽  
P. Pérez
Keyword(s):  
Level Set ◽  
Image Data ◽  
Closed Curves

scholarly journals Prefrontal Cortex Definitions and Their Use in Distinguishing Pornography Addicted Juveniles

2021 ◽  
Author(s):  
Pukovisa Prawiroharjo ◽  
Rizki Edmi Edison ◽  
Hainah Ellydar ◽  
Peter Pratama ◽  
Sitti Evangeline Imelda Suaidy ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Inferior Frontal Gyrus ◽  
Functional Brain Imaging ◽  
Anterior Cingulate ◽  
Brain Segmentation ◽  
Volumetric Mri ◽  
Suitable Definition ◽  
Pornography Addiction ◽  
Mean Differences ◽  
Definition Of

Background and aims: Increasing popularity of Internet has exposed our children pornography addiction. As in other types of addiction, it affects a brain region known as prefrontal cortex (PFC), which is important in executive functions and inhibitory control. However, this region was loosely defined, and there was no consensus for that definition. We aimed to use volumetric MRI in finding the defining region of PFC which would be suitable in distinguishing pornography addicted juveniles. Methods: We enrolled 30 juveniles (12-16 y.o.) consisting of 15 pornography addiction and 15 non-addiction subjects. We proposed several models of PFC definition from mix-and-matched subregions, consisting of orbitofrontal (OFC), inferior frontal gyrus (IFG; pars orbitalis, opercularis, and triangularis), dorsolateral PFC (DLPFC), and anterior cingulate (ACC). Suitable PFC definition was defined as models which volume statistically different between both groups. Brain volumetric was measured using 3D-T1 3T MRI images and analyzed using FreeSurfer for automatic cortical reconstruction and brain segmentation (recon-all command). Results: We found significant differences between groups in 6 models, which mainly included OFC, ACC, and DLPFC, with models devoid of DLPFC had lowest mean differences. Conclusion: The most suitable definition of PFC for pornography addiction study should consist of OFC, ACC, and especially DLPFC. Inferior frontal gyrus pars orbitalis was not necessary for this purpose, but may increase effect size if it is included. Keywords: Addiction, Juvenile, Pornography, Functional Brain Imaging, Defining Area.

scholarly journals Guarantee in Islamic Law Perspectives: A Theoretical discussion of Fiqh Al-Muqārin/Madhāhib Comparison

2019 ◽  
Vol 6 (1) ◽  
pp. 1-9
Author(s):  
Muhajirin Muhajirin
Keyword(s):  
Islamic Law ◽  
Material Failure ◽  
State Law ◽  
Theoretical Discussion ◽  
Trade Practice ◽  
Definition Of

Guarantee in Islamic Law Perspectives: Guarantee is a system that usually comes in the selling of automotive or electronics product, including others. The reason for this guarantee application for producer is basically to increase the selling rate of one product. While for the consumers this is a form of protection to the item they have purchased. There is indeed a mutualism relationship in this practice. The discussion of the application of guarantee in an Islam Law of trade practice is still being argued whether it is legal or not among the scholars. This happens because of the differences of foundation they use in establishing the legality of guarantee in Islam trade. The definition of guarantee in Indonesia state Law can be found in verse 1316 of Law Book, which is: guarantee is an enclose later from a product saying that the producers ensure a  particular product from any worker mistakes and material failure during certain time. The result of this research is the enclosing of Guarantee given in trade as a promise between seller and buyer to ensure the satisfaction of the buyer. The consequence would be to replace the item by justifying its damage.

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