28 research outputs found
Scalable Estimation of Dirichlet Process Mixture Models on Distributed Data
We consider the estimation of Dirichlet Process Mixture Models (DPMMs) in
distributed environments, where data are distributed across multiple computing
nodes. A key advantage of Bayesian nonparametric models such as DPMMs is that
they allow new components to be introduced on the fly as needed. This, however,
posts an important challenge to distributed estimation -- how to handle new
components efficiently and consistently. To tackle this problem, we propose a
new estimation method, which allows new components to be created locally in
individual computing nodes. Components corresponding to the same cluster will
be identified and merged via a probabilistic consolidation scheme. In this way,
we can maintain the consistency of estimation with very low communication cost.
Experiments on large real-world data sets show that the proposed method can
achieve high scalability in distributed and asynchronous environments without
compromising the mixing performance.Comment: This paper is published on IJCAI 2017.
https://www.ijcai.org/proceedings/2017/64
Highly-elliptical-core fiber with stress-induced birefringence for mode multiplexing
We report the polarization–maintaining properties of a highly–elliptical–core fiber surrounded by a trench that was designed to optimize the modal effective indices and bending loss for a total of five spatial modes with twofold polarization degeneracy (ten channels). In addition to the asymmetric core structure, the birefringence
of the fiber is increased by the thermal stress introduced during the fabrication. We examine this effect and
compare the calculated modal effective index differences to experimentally measured values. The results show
a modal birefringence larger than 10-4 for all guided spatial modes. The fiber has a propagation loss, averaged
over all mode groups, of 0.45 dB/km. The mode stability to bending is evaluated by selectively
exciting/detecting each spatial mode while perturbing the fiber. This few–mode polarization–maintaining
fiber is of interest for MIMO–free mode division multiplexing transmission systems
High-risk subtype: Clinical manifestations and molecular characteristics of submandibular gland adenoid cystic carcinoma
ObjectiveAdenoid cystic carcinoma of the head and neck mainly occurs in the major salivary glands, of which the parotid gland and submandibular gland are the most common. The purpose of this study was to clarify the site-specific differences in prognosis and molecular expression characteristics of the patients and to achieve stratified risk management of the clinical prognosis.MaterialsBy performing a single-centre retrospective analysis combined with analyses of the Surveillance, Epidemiology, and End Results (SEER) database, cBioPortal and GEO databases, the clinical prognostic characteristics and the differences in molecular expression patterns of ACC in the submandibular gland and parotid gland were analysed. Cox regression analysis, the chi-square test, Fisher’s test and the log-rank test were used to compare the significance of differences.ResultsCompared with patients with parotid gland ACC, the submandibular gland ACC is more likely to have metastases in the cervical lymph node (21.7% vs. 3.3%) and shows a higher rate of distant metastasis within 1 year after the primary site diagnosis (47.8% vs. 23.3%), a worse overall prognosis, more frequent mutations of MYB/MYBL1 (50% vs. 25%) and abnormal upregulation of the phosphatidylinositol-3 kinase (PI3K) pathway.ConclusionsSubmandibular gland ACC is associated with site-specific early cervical lymph node metastasis and hidden distant metastasis, along with rapid progression and a poor prognosis. A high MYB/MYBL1 mutation rate and abnormal upregulation of the PI3K pathway with MYB involvement were identified
Intrinsic Fabry-Perot Interferometeric Sensor Based on Microfiber Created by Chemical Etching
An intrinsic Fabry-Perot interferometeric sensor based on a microfiber has been demonstrated. The micro-size suspended core is created by chemical etching a photonics crystal fiber, of which the cladding has a micrometer-spaced, hexagonal array of air holes. The sensing head is fabricated by chemical etching a short section of photonics crystal fiber spliced with a single mode fiber. The temperature sensing characteristic of the interferometer has also been demonstrated and a sensitivity 14.3 pm/°C is obtained
Seismic Intelligent Prediction of Thin Interbedded Sand Body--Taking Heidimiao Reservoir in X43 Block as an Example
The Upper Cretaceous Nenjiang Formation in Songliao Basin is characterized by delta front subfacies, with a large area of thin channel sand and sheet sand, which is a typical problem of thin interbed identification. In this paper, based on the theoretical basis of seismic sedimentology and artificial intelligence algorithm, the application layer slicing technology and seismic data after 90 ° phase shift processing are used to carry out artificial intelligence prediction of thin interbedded sand bodies, which is in good agreement with wells
Design of a Four-Port Flexible UWB-MIMO Antenna with High Isolation for Wearable and IoT Applications
A 2 × 2 ultra-wideband MIMO flexible antenna with a low profile and good isolation was designed for Internet of Things (IoT) realms and wearable devices. The antenna elements were placed on a novel flexible substrate of liquid crystal polymer (LCP) with compact dimensions fed by a coplanar waveguide (CPW). In order to ameliorate isolation, the cross-shaped decoupling branches were placed among the antenna elements. The proposed UWB antenna can operate from 2.9 GHz to 10.86 GHz with a good reflection coefficient of S11 < −10 dB as well as a high isolation better than 22 dB. Its operating bands include 5G, WiFi, X-band, etc. Moreover, the parameters of diversity performance were also tested. These parameters included an average gain of approximately 4 dB, a low ECC of less than 0.01, and good diversity gain of 9.999. The flexible MIMO antenna performs well in bending and on-body conditions. To sum up, the antenna has good prospects in IoT applications and wearable fields
Fringe Visibility Enhanced Fiber-Optic Fabry-Perot Interferometric Sensor for Highly Sensitive Ultrasound Detection
A fringe visibility enhanced fiber-optic Fabry-Perot functionalized diaphragm based ultrasonic sensor is proposed and experimentally demonstrated for ultrasound sensing. [...