604 research outputs found
Modeling Relation Paths for Representation Learning of Knowledge Bases
Representation learning of knowledge bases (KBs) aims to embed both entities
and relations into a low-dimensional space. Most existing methods only consider
direct relations in representation learning. We argue that multiple-step
relation paths also contain rich inference patterns between entities, and
propose a path-based representation learning model. This model considers
relation paths as translations between entities for representation learning,
and addresses two key challenges: (1) Since not all relation paths are
reliable, we design a path-constraint resource allocation algorithm to measure
the reliability of relation paths. (2) We represent relation paths via semantic
composition of relation embeddings. Experimental results on real-world datasets
show that, as compared with baselines, our model achieves significant and
consistent improvements on knowledge base completion and relation extraction
from text.Comment: 10 page
Alternating Direction Method of Multipliers Based on -norm for Multiple Measurement Vector Problem
In this paper, we propose an alternating direction method of multipliers
(ADMM)-based optimization algorithm to achieve better undersampling rate for
multiple measurement vector (MMV) problem. The core is to introduce the
-norm sparsity constraint to describe the joint-sparsity of the MMV
problem, which is different from the widely used -norm constraint
in the existing research. In order to illustrate the better performance of
-norm, first this paper proves the equivalence of the sparsity of
the row support set of a matrix and its -norm. Afterward, the MMV
problem based on -norm is proposed. Moreover, building on the
Kurdyka-Lojasiewicz property, this paper establishes that the sequence
generated by ADMM globally converges to the optimal point of the MMV problem.
Finally, the performance of our algorithm and comparison with other algorithms
under different conditions is studied by simulated examples.Comment: 24 pages, 5 figures, 4 table
Improved Total Variation based Image Compressive Sensing Recovery by Nonlocal Regularization
Recently, total variation (TV) based minimization algorithms have achieved
great success in compressive sensing (CS) recovery for natural images due to
its virtue of preserving edges. However, the use of TV is not able to recover
the fine details and textures, and often suffers from undesirable staircase
artifact. To reduce these effects, this letter presents an improved TV based
image CS recovery algorithm by introducing a new nonlocal regularization
constraint into CS optimization problem. The nonlocal regularization is built
on the well known nonlocal means (NLM) filtering and takes advantage of
self-similarity in images, which helps to suppress the staircase effect and
restore the fine details. Furthermore, an efficient augmented Lagrangian based
algorithm is developed to solve the above combined TV and nonlocal
regularization constrained problem. Experimental results demonstrate that the
proposed algorithm achieves significant performance improvements over the
state-of-the-art TV based algorithm in both PSNR and visual perception.Comment: 4 Pages, 1 figures, 3 tables, to be published at IEEE Int. Symposium
of Circuits and Systems (ISCAS) 201
K\"ahler Finsler manifolds with curvatures bounded from below
We obtain a partial parallelism of the complex structure on K\"ahler Finsler
manifolds. As applications, we prove Synge-Tsukamoto theorem and Bonnet-Myers
theorem for positively curved K\"ahler Finsler manifolds. Moreover, we
generalize a comparison theorem due to Ni-Zheng by introducing the notion of
orthogonal Ricci curvature to K\"ahler Finsler geometry
Expression, characterization, and localization of acetylcholinesterase-1 from the African malaria mosquito, Anopheles gambiae
Findings and Conclusions:Acetylcholinesterases (AChEs) play an essential role in neurotransmission at cholinergic synapses in vertebrates and invertebrates. Anopheles gambiae has two AChE genes, ace1 and ace2. The properties of AgAChEs remain unknown, and the complex resistance mechanisms can cause the problem to directly correlate a mutation with the resistance phenotype. The purposes of this study are to express and purify AChE1, characterize it in vitro, and localize its expression in vivo. In this study, a cDNA fragment of AChE1 from an A. gambiae EST was subcloned and expressed. The optimized three-step purification scheme took approximately eight hours and yielded 51% of the protein with a specific activity of 523U/mg. A pH of 7.0-8.0 is the best range for AgAChE1 reaction with acetylcholine. The enzyme size is 65 kDa and 130 kDa on SDS-polyacrylamide gels under reducing and nonreducing conditions, respectively. AgAChE1 hydrolyzes ATC 14-fold faster than BTC. The IC50, ki, and Kd demonstrated that AgAChE1 is highly sensitive to inhibition by BW284C51 instead of ethopropazine, and the affinity of BW284C51 is greater than that of ethopropazine. These findings indicate that Ag AChE1 is a true AChE, which exerts the physiological function of ACh hydrolysis at cholinergic synapses. In situ hybridization and immunohistochemistry showed that ace 1 is expressed mainly in the central nervous system. The procedures of Ag AChE1 purification and asymmetric PCR for making ISH probes could be used for similar studies in other insect species. The data are useful for understanding Ag AChE1 and for developing selective insecticides to control the African malaria mosquito
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