85,622 research outputs found
Analysis of group evolution prediction in complex networks
In the world, in which acceptance and the identification with social
communities are highly desired, the ability to predict evolution of groups over
time appears to be a vital but very complex research problem. Therefore, we
propose a new, adaptable, generic and mutli-stage method for Group Evolution
Prediction (GEP) in complex networks, that facilitates reasoning about the
future states of the recently discovered groups. The precise GEP modularity
enabled us to carry out extensive and versatile empirical studies on many
real-world complex / social networks to analyze the impact of numerous setups
and parameters like time window type and size, group detection method,
evolution chain length, prediction models, etc. Additionally, many new
predictive features reflecting the group state at a given time have been
identified and tested. Some other research problems like enriching learning
evolution chains with external data have been analyzed as well
Human gesture classification by brute-force machine learning for exergaming in physiotherapy
In this paper, a novel approach for human gesture classification on skeletal data is proposed for the application of exergaming in physiotherapy. Unlike existing methods, we propose to use a general classifier like Random Forests to recognize dynamic gestures. The temporal dimension is handled afterwards by majority voting in a sliding window over the consecutive predictions of the classifier. The gestures can have partially similar postures, such that the classifier will decide on the dissimilar postures. This brute-force classification strategy is permitted, because dynamic human gestures show sufficient dissimilar postures. Online continuous human gesture recognition can classify dynamic gestures in an early stage, which is a crucial advantage when controlling a game by automatic gesture recognition. Also, ground truth can be easily obtained, since all postures in a gesture get the same label, without any discretization into consecutive postures. This way, new gestures can be easily added, which is advantageous in adaptive game development. We evaluate our strategy by a leave-one-subject-out cross-validation on a self-captured stealth game gesture dataset and the publicly available Microsoft Research Cambridge-12 Kinect (MSRC-12) dataset. On the first dataset we achieve an excellent accuracy rate of 96.72%. Furthermore, we show that Random Forests perform better than Support Vector Machines. On the second dataset we achieve an accuracy rate of 98.37%, which is on average 3.57% better then existing methods
Efficient Genomic Interval Queries Using Augmented Range Trees
Efficient large-scale annotation of genomic intervals is essential for
personal genome interpretation in the realm of precision medicine. There are 13
possible relations between two intervals according to Allen's interval algebra.
Conventional interval trees are routinely used to identify the genomic
intervals satisfying a coarse relation with a query interval, but cannot
support efficient query for more refined relations such as all Allen's
relations. We design and implement a novel approach to address this unmet need.
Through rewriting Allen's interval relations, we transform an interval query to
a range query, then adapt and utilize the range trees for querying. We
implement two types of range trees: a basic 2-dimensional range tree (2D-RT)
and an augmented range tree with fractional cascading (RTFC) and compare them
with the conventional interval tree (IT). Theoretical analysis shows that RTFC
can achieve the best time complexity for interval queries regarding all Allen's
relations among the three trees. We also perform comparative experiments on the
efficiency of RTFC, 2D-RT and IT in querying noncoding element annotations in a
large collection of personal genomes. Our experimental results show that 2D-RT
is more efficient than IT for interval queries regarding most of Allen's
relations, RTFC is even more efficient than 2D-RT. The results demonstrate that
RTFC is an efficient data structure for querying large-scale datasets regarding
Allen's relations between genomic intervals, such as those required by
interpreting genome-wide variation in large populations.Comment: 4 figures, 4 table
Generalized Lineage-Aware Temporal Windows: Supporting Outer and Anti Joins in Temporal-Probabilistic Databases
The result of a temporal-probabilistic (TP) join with negation includes, at
each time point, the probability with which a tuple of a positive relation
matches none of the tuples in a negative relation , for a
given join condition . TP outer and anti joins thus resemble the
characteristics of relational outer and anti joins also in the case when there
exist time points at which input tuples from have non-zero
probabilities to be and input tuples from have non-zero
probabilities to be , respectively. For the computation of TP joins with
negation, we introduce generalized lineage-aware temporal windows, a mechanism
that binds an output interval to the lineages of all the matching valid tuples
of each input relation. We group the windows of two TP relations into three
disjoint sets based on the way attributes, lineage expressions and intervals
are produced. We compute all windows in an incremental manner, and we show that
pipelined computations allow for the direct integration of our approach into
PostgreSQL. We thereby alleviate the prevalent redundancies in the interval
computations of existing approaches, which is proven by an extensive
experimental evaluation with real-world datasets
Direct-to-Patient Survey for Diagnosis of Benign Paroxysmal Positional Vertigo
Given the high incidence of dizziness and its frequent misdiagnosis, we aim to create a clinical support system to classify the presence or absence of benign paroxysmal positional vertigo with high accuracy and specificity. This paper describes a three-phase study currently underway for classification of benign paroxysmal positional vertigo, which includes diagnosis by a specialist in a clinical setting. Patient background information is collected by a survey on an Android tablet and machine learning techniques are applied for classification. Decision trees and wrappers are employed for their ability to provide information about the question set. One goal of the study is to attain an optimal question set. Each phase of the study presents a unique set and style of questions. Results achieved in the first two phases of the survey indicate that our approach using decision trees with filters or wrappers does a good job of identifying benign paroxysmal positional vertigo
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