4,577 research outputs found
Strong invariance principles for sequential Bahadur--Kiefer and Vervaat error processes of long-range dependent sequences
In this paper we study strong approximations (invariance principles) of the
sequential uniform and general Bahadur--Kiefer processes of long-range
dependent sequences. We also investigate the strong and weak asymptotic
behavior of the sequential Vervaat process, that is, the integrated sequential
Bahadur--Kiefer process, properly normalized, as well as that of its deviation
from its limiting process, the so-called Vervaat error process. It is well
known that the Bahadur--Kiefer and the Vervaat error processes cannot converge
weakly in the i.i.d. case. In contrast to this, we conclude that the
Bahadur--Kiefer and Vervaat error processes, as well as their sequential
versions, do converge weakly to a Dehling--Taqqu type limit process for certain
long-range dependent sequences.Comment: Published at http://dx.doi.org/10.1214/009053606000000164 in the
Annals of Statistics (http://www.imstat.org/aos/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Knowledge Graph Embedding with Iterative Guidance from Soft Rules
Embedding knowledge graphs (KGs) into continuous vector spaces is a focus of
current research. Combining such an embedding model with logic rules has
recently attracted increasing attention. Most previous attempts made a one-time
injection of logic rules, ignoring the interactive nature between embedding
learning and logical inference. And they focused only on hard rules, which
always hold with no exception and usually require extensive manual effort to
create or validate. In this paper, we propose Rule-Guided Embedding (RUGE), a
novel paradigm of KG embedding with iterative guidance from soft rules. RUGE
enables an embedding model to learn simultaneously from 1) labeled triples that
have been directly observed in a given KG, 2) unlabeled triples whose labels
are going to be predicted iteratively, and 3) soft rules with various
confidence levels extracted automatically from the KG. In the learning process,
RUGE iteratively queries rules to obtain soft labels for unlabeled triples, and
integrates such newly labeled triples to update the embedding model. Through
this iterative procedure, knowledge embodied in logic rules may be better
transferred into the learned embeddings. We evaluate RUGE in link prediction on
Freebase and YAGO. Experimental results show that: 1) with rule knowledge
injected iteratively, RUGE achieves significant and consistent improvements
over state-of-the-art baselines; and 2) despite their uncertainties,
automatically extracted soft rules are highly beneficial to KG embedding, even
those with moderate confidence levels. The code and data used for this paper
can be obtained from https://github.com/iieir-km/RUGE.Comment: To appear in AAAI 201
In vivo super-resolution photoacoustic computed tomography by localization of single dyed droplets
The spatial resolution of photoacoustic (PA) computed tomography (PACT) is limited by acoustic diffraction. Here, we report in vivo superresolution PACT, which breaks the acoustic diffraction limit by localizing the centers of single dyed droplets. The dyed droplets generate much stronger PA signals than blood and can flow smoothly in blood vessels; thus, they are excellent tracers for localization-based superresolution imaging. The flowing droplets were first localized, and then their center positions were used to construct a superresolution image that exhibits sharper features and more finely resolved vascular details. A 6-fold improvement in spatial resolution has been realized in vivo
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