405 research outputs found
SLOWPIXELS: Slow-design for reflective retrieval of personal photos
Department of Creative Design EngineeringWe introduced the design and findings in our user study of SLOWPIXELS, a photo printer which aims to stimulate reflection & memory recall through the re-materialization of digital photos. Photos were serendipitously retrieved dependent upon position of two sliders: When did I take the photo (photo date slider) & Where did I take the photo (distance from home slider). SLOWPIXELS used its owner???s Instagram account metadata. We tested SLOWPIXELS to 20 participants for 11 days to investigate how the Slow-design could support reflective retrieval of personal photos. Findings revealed that SLOWPIXELS encourage users to reflect their past by unexpected pictures and promote their social bond. We also found that SLOWPIXELS has a design possibility in the public space for event-like situation. For example, in caf?? or student community centre. These findings suggested several contributions, such as designing for revisiting serendipitous memories on the past, empowering social communication, and new way of retrieval of photography while exploring the slow-design agenda within the Design Research community.clos
Finding branch-decompositions of matroids, hypergraphs, and more
Given subspaces of a finite-dimensional vector space over a fixed finite
field , we wish to find a "branch-decomposition" of these subspaces
of width at most , that is a subcubic tree with leaves mapped
bijectively to the subspaces such that for every edge of , the sum of
subspaces associated with leaves in one component of and the sum of
subspaces associated with leaves in the other component have the intersection
of dimension at most . This problem includes the problems of computing
branch-width of -represented matroids, rank-width of graphs,
branch-width of hypergraphs, and carving-width of graphs.
We present a fixed-parameter algorithm to construct such a
branch-decomposition of width at most , if it exists, for input subspaces of
a finite-dimensional vector space over . Our algorithm is analogous
to the algorithm of Bodlaender and Kloks (1996) on tree-width of graphs. To
extend their framework to branch-decompositions of vector spaces, we developed
highly generic tools for branch-decompositions on vector spaces. The only known
previous fixed-parameter algorithm for branch-width of -represented
matroids was due to Hlin\v{e}n\'y and Oum (2008) that runs in time
where is the number of elements of the input -represented
matroid. But their method is highly indirect. Their algorithm uses the
non-trivial fact by Geelen et al. (2003) that the number of forbidden minors is
finite and uses the algorithm of Hlin\v{e}n\'y (2005) on checking monadic
second-order formulas on -represented matroids of small
branch-width. Our result does not depend on such a fact and is completely
self-contained, and yet matches their asymptotic running time for each fixed
.Comment: 73 pages, 10 figure
Introduction to the R package TDA
We present a short tutorial and introduction to using the R package TDA,
which provides some tools for Topological Data Analysis. In particular, it
includes implementations of functions that, given some data, provide
topological information about the underlying space, such as the distance
function, the distance to a measure, the kNN density estimator, the kernel
density estimator, and the kernel distance. The salient topological features of
the sublevel sets (or superlevel sets) of these functions can be quantified
with persistent homology. We provide an R interface for the efficient
algorithms of the C++ libraries GUDHI, Dionysus and PHAT, including a function
for the persistent homology of the Rips filtration, and one for the persistent
homology of sublevel sets (or superlevel sets) of arbitrary functions evaluated
over a grid of points. The significance of the features in the resulting
persistence diagrams can be analyzed with functions that implement recently
developed statistical methods. The R package TDA also includes the
implementation of an algorithm for density clustering, which allows us to
identify the spatial organization of the probability mass associated to a
density function and visualize it by means of a dendrogram, the cluster tree
LEARNING ANALYTICS IN POST-SECONDARY BUSINESS EDUCATION: A SCOPING REVIEW OF REVIEWS PROTOCOL
Learning Analytics is a growing discipline as educational institutions aim to exploit data and data analytics for several reasons, especially in higher education. Unfortunately, there is a lack of consensus on how learning analytics should be defined and what subjects fall under the purview of learning analytics. The blurred boundaries of what learning analytics encompasses have given rise to multiple studies and systematic reviews that have been published without any consistent agreement to develop the field in a particular direction. Consequently, we are outlining a protocol for a scoping review to map and summarize existing scoping reviews that have been published regarding learning analytics. More specifically, the scoping review of reviews will focus on learning analytics in business education as a use case when it involves machine learning to inform educational interventions. This scoping review will hopefully be the first step in unifying learning analytics for all stakeholders to further develop it into a field of study where it can benefit everyone relying on learning analytics
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