1,328 research outputs found
Signals of New Gauge Bosons in Gauged Two Higgs Doublet Model
Recently a gauged two Higgs doublet model, in which the two Higgs doublets
are embedded into the fundamental representation of an extra local
group, is constructed. Both the new gauge bosons and are electrically neutral. While can be singly produced at
colliders, , which is heavier, must be pair produced. We
explore the constraints of using the current Drell-Yan type data
from the Large Hadron Collider. Anticipating optimistically that can
be discovered via the clean Drell-Yan type signals at high luminosity upgrade
of the collider, we explore the detectability of extra heavy fermions in the
model via the two leptons/jets plus missing transverse energy signals from the
exotic decay modes of . For the pair production in
a future 100 TeV proton-proton collider, we demonstrate certain kinematical
distributions for the two/four leptons plus missing energy signals have
distinguishable features from the Standard Model background. In addition,
comparisons of these kinematical distributions between the gauged two Higgs
doublet model and the littlest Higgs model with T-parity, the latter of which
can give rise to the same signals with competitive if not larger cross
sections, are also presented.Comment: 39 pages, 23 figures, 7 tables and two new appendixes, to appear in
EPJ
Unsteady separation process and vorticity balance on unsteady airfoils
Low momentum fluid erupts at the unsteady separation region and forms a local shear layer at the viscous-inviscid interface. At the shear layer, the vorticity lumps into a vortex and protrudes into the inviscid region. This process initiates the separation process. The response of airfoils in unsteady free stream was investigated based on this vortex generation and convection concept. This approach enabled us to understand the complicated unsteady aerodynamics from a fundamental point of view
The Taiwan ECDFS Near-Infrared Survey: Ultra-deep J and Ks Imaging in the Extended Chandra Deep Field-South
We present ultra-deep J and Ks imaging observations covering a 30' * 30' area
of the Extended Chandra Deep Field-South (ECDFS) carried out by our Taiwan
ECDFS Near-Infrared Survey (TENIS). The median 5-sigma limiting magnitudes for
all detected objects in the ECDFS reach 24.5 and 23.9 mag (AB) for J and Ks,
respectively. In the inner 400 arcmin^2 region where the sensitivity is more
uniform, objects as faint as 25.6 and 25.0 mag are detected at 5-sigma. So this
is by far the deepest J and Ks datasets available for the ECDFS. To combine the
TENIS with the Spitzer IRAC data for obtaining better spectral energy
distributions of high-redshift objects, we developed a novel deconvolution
technique (IRACLEAN) to accurately estimate the IRAC fluxes. IRACLEAN can
minimize the effect of blending in the IRAC images caused by the large
point-spread functions and reduce the confusion noise. We applied IRACLEAN to
the images from the Spitzer IRAC/MUSYC Public Legacy in the ECDFS survey
(SIMPLE) and generated a J+Ks selected multi-wavelength catalog including the
photometry of both the TENIS near-infrared and the SIMPLE IRAC data. We
publicly release the data products derived from this work, including the J and
Ks images and the J+Ks selected multiwavelength catalog.Comment: 25 pages, 25 figures, ApJS in pres
Toward Optimal Resource Allocation of Virtualized Network Functions for Hierarchical Datacenters
Telecommunications service providers (TSPs) previously provided network functions to end users with dedicated hardware, but they are resorting to virtualized infrastructure for reducing costs and increasing flexibility in resource allocation. A representative case is the Central Office Re-architected as Datacenter (CORD) project from AT&T, which aims to deploy virtualized network functions (VNFs) to over 4000 central offices (COs) across the U.S. However, there is a wide spectrum of options for deploying VNFs over the COs, varying from highly distributed to highly centralized manners. The former benefits end users with short response time but has its inherent limitation on utilizing geographically dispersed resources, while the latter allows resources to be better utilized at a cost of longer response time. In this work, we model the TSP's virtualized infrastructure as hierarchical datacenters, namely hierarchical CORD, and provide a resource allocation solution to strike the optimal balance between the two extreme options. Our evaluations reveal that in general, the 3-tier architecture incurs the least cost in case of deploying VNFs under moderate or loose delay constraints. Furthermore, the margin of improvement on the resource allocation cost increases inversely with the overall system utilization rate. Our results also suggest that as heavy request load overwhelms the network infrastructure, the relevant VNFs shall be migrated to lower-tier edge datacenters or to some nearby datacenters with superior network capacity. The evaluations also demonstrate that the proposed model allows highly adaptive VNF deployment in the hierarchical architecture under various conditions.This work was supported in part by H2020 Collaborative Europe/Taiwan Research Project 5G-CORAL under Grant 761586, and in part by the Ministry of Science and Technology, Taiwan, under Grant MOST-106-2218-E-009-018 and Grant MOST-106-2221-E-194-021-MY3
Three-stage binarization of color document images based on discrete wavelet transform and generative adversarial networks
The efficient segmentation of foreground text information from the background
in degraded color document images is a hot research topic. Due to the imperfect
preservation of ancient documents over a long period of time, various types of
degradation, including staining, yellowing, and ink seepage, have seriously
affected the results of image binarization. In this paper, a three-stage method
is proposed for image enhancement and binarization of degraded color document
images by using discrete wavelet transform (DWT) and generative adversarial
network (GAN). In Stage-1, we use DWT and retain the LL subband images to
achieve the image enhancement. In Stage-2, the original input image is split
into four (Red, Green, Blue and Gray) single-channel images, each of which
trains the independent adversarial networks. The trained adversarial network
models are used to extract the color foreground information from the images. In
Stage-3, in order to combine global and local features, the output image from
Stage-2 and the original input image are used to train the independent
adversarial networks for document binarization. The experimental results
demonstrate that our proposed method outperforms many classical and
state-of-the-art (SOTA) methods on the Document Image Binarization Contest
(DIBCO) dataset. We release our implementation code at
https://github.com/abcpp12383/ThreeStageBinarization
Sampling of basement fluids via circulation obviation retrofit kits (CORKs) for dissolved gases, fluid fixation at the seafloor, and the characterization of organic carbon
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Lin, H. T., Hsieh, C. C., Repeta, D. J., & Rappé, M. S. Sampling of basement fluids via circulation obviation retrofit kits (CORKs) for dissolved gases, fluid fixation at the seafloor, and the characterization of organic carbon. Methodsx, 7, (2020): 101033, doi:10.1016/j.mex.2020.101033.The advanced instrumented GeoMICROBE sleds (Cowen et al., 2012) facilitate the collection of hydrothermal fluids and suspended particles in the subseafloor (basaltic) basement through Circulation Obviation Retrofit Kits (CORKs) installed within boreholes of the Integrated Ocean Drilling Program. The main components of the GeoMICROBE can be converted into a mobile pumping system (MPS) that is installed on the front basket of a submersible or remotely-operated-vehicle (ROV). Here, we provide details of a hydrothermal fluid-trap used on the MPS, through which a gastight sampler can withdraw fluids. We also applied the MPS to demonstrate the value of fixing samples at the seafloor in order to determine redox-sensitive dissolved iron concentrations and speciation measurements. To make the best use of the GeoMICROBE sleds, we describe a miniature and mobile version of the GeoMICROBE sled, which permits rapid turn-over and is relatively easy for preparation and operation. Similar to GeoMICROBE sleds, the Mobile GeoMICROBE (MGM) is capable of collecting fluid samples, filtration of suspended particles, and extraction of organics. We validate this approach by demonstrating the seafloor extraction of hydrophobic organics from a large volume (247L) of hydrothermal fluids.
• We describe the design of a hydrothermal fluid-trap for use with a gastight sampler, as well as the use of seafloor fixation, through ROV- or submersible assisted mobile pumping systems.
• We describe the design of a Mobile GeoMICROBE (MGM) that enhances large volume hydrothermal fluid sampling, suspended particle filtration, and organic matter extraction on the seafloor.
• We provide an example of organic matter extracted and characterized from hydrothermal fluids via a MGM.We dedicate this work to Dr. James P. Cowen, who had envisioned and constructed the integrated instrumentation, GeoMICROBE, to monitor the sub-basement biosphere. We thank the chief scientists, captains, crews, and science teams on board R/V Atlantis cruises AT15-35, AT15-51, AT15-66, AT18-07, MSM20-5, AT26-03, and AT26-18, and the pilots and crews of ROV Jason II and HOV Alvin. We thank our student assistants, Natalie Hamada, Kathryn Hu, Ryan Matzumoto, Everette Omori, and Fan-Chieh Chuang. This work was supported by the National Science Foundation-Microbial Observatory Project (NSF-MCB06-04014 to J. P. Cowen), Center for Dark Energy Biosphere Investigations (C-DEBI; NSF award OCE-0939564 to M. S. Rappé), NSF award OCE-1260723 (to M. S. Rappé), and the Ministry of Science and Technology of Taiwan award (MOST 105-2119-M-002-034, MOST 107-2611-M-002-002, MOST 108-2611-M-002-006, and MOST109-2611-M-002-008 to H.-T. Lin). Ministry of Education (MOE) Republic of China (Taiwan) 109L892601 to H.-T. Lin. NSF award OCE-1634080 (to D. J. Repeta), the Simons Foundation-Simons Collaboration on Ocean Processes and Ecology (SCOPE) award 329108 (to D. J. Repeta), the Gordon and Betty Moore Foundation award 6000 (to D. J. Repeta).
This paper is SOEST contribution number 11121, HIMB contribution 1804 and C-DEBI contribution number 543
Palpation of preoperatively inserted indwelling angiocatheter facilitates intraoperative localization of obscure gastrointestinal bleeding of small intestinal origin
SummaryBackgroundPalpation of the indwelling angiographic catheter inserted before operation to localize obscure gastrointestinal bleeding of small intestinal origin during laparotomy has rarely been reported in the literature.PurposeThe purpose of the study is to investigate the role of palpable indwelling angiocatheter inserted before operation in localizing obscure gastrointestinal bleeding of small intestinal origin during laparotomy.MethodsBetween January 2003 and December 2010, seven patients who had a clinical impression of obscure gastrointestinal bleeding of small intestinal origin and angiographic extravasation from the mesenteric artery had an angiocatheter inserted into the distal mesenteric branch. During laparotomy the catheter was palpated to guide subsequent resection of the intestine. The clinical outcomes of these patients were retrospectively reviewed.ResultsDuring laparotomy the retained catheter failed to be palpated in one patient. Six patients underwent segmental resection of intestine under guidance of the palpated catheter. All six patients had positive identification of small bowel bleeding. The yield rate of intraoperative localization was 86% (6 out of 7). Two of the six patients ceased bleeding after operation, but died of underlying disease progression. Four of the six patients had an uneventful postoperative clinical course without recurrent bleeding after a median follow-up period of 25 months.ConclusionPalpation of the indwelling angiographic catheter selectively left before operation is effective for precisely locating obscure gastrointestinal bleeding of small intestinal origin during laparotomy
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