21 research outputs found
Rethinking Pen Input Interaction: Enabling Freehand Sketching Through Improved Primitive Recognition
Online sketch recognition uses machine learning and artificial intelligence techniques
to interpret markings made by users via an electronic stylus or pen. The
goal of sketch recognition is to understand the intention and meaning of a particular
user's drawing. Diagramming applications have been the primary beneficiaries
of sketch recognition technology, as it is commonplace for the users of these tools to
rst create a rough sketch of a diagram on paper before translating it into a machine
understandable model, using computer-aided design tools, which can then be used to
perform simulations or other meaningful tasks.
Traditional methods for performing sketch recognition can be broken down into
three distinct categories: appearance-based, gesture-based, and geometric-based. Although
each approach has its advantages and disadvantages, geometric-based methods
have proven to be the most generalizable for multi-domain recognition. Tools, such as
the LADDER symbol description language, have shown to be capable of recognizing
sketches from over 30 different domains using generalizable, geometric techniques.
The LADDER system is limited, however, in the fact that it uses a low-level recognizer
that supports only a few primitive shapes, the building blocks for describing
higher-level symbols. Systems which support a larger number of primitive shapes have
been shown to have questionable accuracies as the number of primitives increase, or
they place constraints on how users must input shapes (e.g. circles can only be drawn
in a clockwise motion; rectangles must be drawn starting at the top-left corner).
This dissertation allows for a significant growth in the possibility of free-sketch
recognition systems, those which place little to no drawing constraints on users. In
this dissertation, we describe multiple techniques to recognize upwards of 18 primitive
shapes while maintaining high accuracy. We also provide methods for producing
confidence values and generating multiple interpretations, and explore the difficulties
of recognizing multi-stroke primitives. In addition, we show the need for a standardized
data repository for sketch recognition algorithm testing and propose SOUSA
(sketch-based online user study application), our online system for performing and
sharing user study sketch data. Finally, we will show how the principles we have
learned through our work extend to other domains, including activity recognition
using trained hand posture cues
Preventing and Treating Womenâs Postpartum Depression: A Qualitative Systematic Review on Partner-Inclusive Interventions
Partner-related factors associated with the occurrence of Postpartum Depression (PPD) may justify the partnerâs inclusion in preventive and treatment approaches. The aim of this qualitative systematic review was to synthesize the literature on partner-inclusive interventions designed to prevent or treat postpartum depression (PPD) in women. In accordance with the PRISMA guidelines, the systematic search of studies published between 1967 and May 2015 in PsycINFO and PubMed identified 26 studies that met the inclusion criteria, which reported on 24 interventions. The following partner parameters were analyzed: participation type, session content, mental health assessment, attendance assessment, and the effects of partnerâs participation on the womenâs response to the interventions. Total participation by the partner was mostly reported in the prevention studies, whereas partial participation was reported in the treatment studies. The session content was mostly based on psychoeducation about PPD and parenthood, coping strategies to facilitate the transition to parenthood such as the partnerâs emotional and instrumental support, and problem-solving and communication skills. Some benefits perceived by the couples underscore the relevance of the partnerâs inclusion in PPD interventions. However, the scarce information about the partnerâs attendance and the associated effects on the womenâs intervention outcomes, along with methodological limitations of the studies, made it difficult to determine if the partnerâs participation was associated with the interventionâs efficacy. Conclusions about the clinical value of including partners in PPD interventions are still limited. More research is warranted to better inform health policy strategies
Diversity of Secondary Structure in Catalytic Peptides with βâTurn-Biased Sequences
X-ray
crystallography has been applied to the structural analysis
of a series of tetrapeptides that were previously assessed for catalytic
activity in an atroposelective bromination reaction. Common to the
series is a central Pro-Xaa sequence, where Pro is either l- or d-proline, which was chosen to favor nucleation of
canonical β-turn secondary structures. Crystallographic analysis
of 35 different peptide sequences revealed a range of conformational
states. The observed differences appear not only in cases where the
Pro-Xaa loop-region is altered, but also when seemingly subtle alterations
to the flanking residues are introduced. In many instances, distinct
conformers of the same sequence were observed, either as symmetry-independent
molecules within the same unit cell or as polymorphs. Computational
studies using DFT provided additional insight into the analysis of
solid-state structural features. Select X-ray crystal structures were
compared to the corresponding solution structures derived from measured
proton chemical shifts, <sup>3</sup><i>J</i>-values, and <sup>1</sup>Hâ<sup>1</sup>H-NOESY contacts. These findings imply
that the conformational space available to simple peptide-based catalysts
is more diverse than precedent might suggest. The direct observation
of multiple ground state conformations for peptides of this family,
as well as the dynamic processes associated with conformational equilibria,
underscore not only the challenge of designing peptide-based catalysts,
but also the difficulty in predicting their accessible transition
states. These findings implicate the advantages of low-barrier interconversions
between conformations of peptide-based catalysts for multistep, enantioselective
reactions
Diversity of Secondary Structure in Catalytic Peptides with βâTurn-Biased Sequences
X-ray
crystallography has been applied to the structural analysis
of a series of tetrapeptides that were previously assessed for catalytic
activity in an atroposelective bromination reaction. Common to the
series is a central Pro-Xaa sequence, where Pro is either l- or d-proline, which was chosen to favor nucleation of
canonical β-turn secondary structures. Crystallographic analysis
of 35 different peptide sequences revealed a range of conformational
states. The observed differences appear not only in cases where the
Pro-Xaa loop-region is altered, but also when seemingly subtle alterations
to the flanking residues are introduced. In many instances, distinct
conformers of the same sequence were observed, either as symmetry-independent
molecules within the same unit cell or as polymorphs. Computational
studies using DFT provided additional insight into the analysis of
solid-state structural features. Select X-ray crystal structures were
compared to the corresponding solution structures derived from measured
proton chemical shifts, <sup>3</sup><i>J</i>-values, and <sup>1</sup>Hâ<sup>1</sup>H-NOESY contacts. These findings imply
that the conformational space available to simple peptide-based catalysts
is more diverse than precedent might suggest. The direct observation
of multiple ground state conformations for peptides of this family,
as well as the dynamic processes associated with conformational equilibria,
underscore not only the challenge of designing peptide-based catalysts,
but also the difficulty in predicting their accessible transition
states. These findings implicate the advantages of low-barrier interconversions
between conformations of peptide-based catalysts for multistep, enantioselective
reactions