213 research outputs found
RNN‐EdgeQL: An auto‐scaling and placement approach for SFC
No full textThis paper proposes a prediction-based scaling and placement of service function chains (SFCs) to improve service level agreement (SLA) and reduce operation cost. We used a variant of recurrent neural network (RNN) called gated recurrent unit (GRU) for resource demand prediction. Then, considering these predictions, we built an intuitive scale in/out algorithm. We also developed an algorithm that applies Q-Learning on Edge computing environment (EdgeQL) to place these scaled-out VNFs in appropriate locations. The integrated algorithm that combines prediction, scaling, and placement are called RNN-EdgeQL. RNN-EdgeQL (v2) is further improved to achieve application agnostic group level elasticity in the chain, independent of applications installed on the VNFs. We tested our algorithm on two realistic temporal dynamic load models including Internet traffic (Abilene) and an application specific traffic (Wiki) on an OpenStack testbed. The contribution of this article is threefold. First, prediction model prepares the target SFC for the upcoming load. Second, an application agnostic characteristics of the algorithm achieves the group-level elasticity in SFC. Finally, the EdgeQL placement model minimizes the end-to-end path of an SFC in multi-access edge computing (MEC) environment. As a result, RNN-EdgeQL (v2) gives the lowest overall latency, lowest SLA violations, and lowest VNFs requirement, compared to RNN-EdgeQL (v1) and Threshold-Openstack default placement.11Nsciescopu
Current clinical application of intracardiac flow analysis using echocardiography
No full textIn evaluating the cardiac function, it is important to have a comprehensive assessment of structural factors, such as the myocardial or valvular function and intracardiac flow dynamics that pass the heart. Vortex flow that form during left ventricular filling have specific geometry and anatomical location that are critical determinants of directed blood flow during ejection. The formation of abnormal vortices relates to the abnormal cardiac function. Therefore, vortex flow may offer a novel index of cardiac dysfunction. Intracardiac flow visualization using ultrasound technique has definite advantages with a higher temporal resolution and availability in real time clinical setting. Vector flow mapping based on color-Doppler and contrast echocardiography using particle image velocimetry is currently being used for visualizing the intracardiac flow. The purpose of this review is to provide readers with an update on the current method for analyzing intracardiac flow using echocardiography and its clinical applications
Differences in aortic vortex flow pattern between normal and patients with stroke: qualitative and quantitative assessment using transesophageal contrast echocardiography
No full textThe flow in the aorta forms a vortex, which is a critical determinant of the flow dynamics in the aorta. Arteriosclerosis can alter the blood flow pattern of the aorta and cause characteristic alterations of the vortex. However, this change in aortic vortex has not yet been studied. This study aimed to characterize aortic vortex flow pattern using transesophageal contrast echocardiography in normal and stroke patients. A total of 85 patients who diagnosed with ischemic stroke and 16 normal controls were recruited for this study. The 16 normal control subjects were designated as the control group, and the 85 ischemic stroke patients were designated as the stroke group. All subjects underwent contrast transesophageal echocardiography (TEE), and particle image velocimetry was used to assess aortic vortex flow. Qualitative and quantitative analyses of vortex flow morphology, location, phasic variation, and pulsatility were undertaken and compared between the groups. In the control group, multiple irregularly-shaped vortices were observed in a peripheral location in the descending thoracic aorta. In contrast, the stroke group had a single, round, merged, and more centrally located aortic vortex flow. In the quantitative analysis of vortex, vortex depth, which represents the location of the major vortex in the aorta, was significantly higher in the control group than in the stroke group (0.599\ua0±\ua00.159 vs. 0.522\ua0±\ua00.101, respectively, P\ua0=\ua00.013). Vortex relative strength, which is the pulsatility parameter of the vortex itself, was significantly higher in the stroke group than in the control group (0.367\ua0±\ua00.148 vs. 0.304\ua0±\ua00.087, respectively, P\ua0=\ua00.025). It was feasible to visualize and quantify the characteristic morphology and pulsatility of the aortic vortex flow using contrast TEE, and aortic vortex pattern significantly differed between normal and stroke patients
Visible-Light-Induced Organophotocatalytic Difunctionallization: Open-Air Hydroxysulfurization of Aryl Alkenes with Aryl Thiols
No full text© 2022 American Chemical Society. All rights reserved.Herein, we report a regioselective visible-light-induced organophotoredox catalytic difunctionalization method to prepare β-hydroxysulfides using aryl alkenes and aryl thiols as substrates. The reaction provides a wide substrate scope of aryl alkenes (from simple styrene to complex bioactive compounds) and aryl thiols (from diverse heteroaromatic thiols to nonheteroaromatic thiols) (total 45 examples, up to 88% yield). Based on the combined experimental and computational studies, we demonstrate that in situ generated hydroperoxyl radicals from O2 in air react with benzylic radicals, which restrains the reaction between benzylic radicals and the acidic form of thiols in a classical thiol-ene radical reaction. We show that difunctionalization is possible due to the choice of bases, diluted substrate concentrations, increment in catalyst loading, and selection of suitable aryl thiols under aerobic conditions. Considering the biological importance of heteroaromatic thiols and the lack of methods to install them, our approach offers a platform to derive various β-hydroxysulfides that contain aromatic elements.11Nsciescopu
which external resource matter?
No full textThesis(Master) --KDI School:Master of Development Policy,2015Least developed countries, a group of poorest countries in the world, are trapped under economic underdevelopment, unable to escape the deplorable state by themselves. A stimulating external force in the form of foreign capital inflows are, therefore, important source of capital for least developed countries. Among different types of foreign capital inflows, which external resource contributes most to economic growth for least developed countries is a key research question for this paper. I use panel data of 43 least developed countries from the period 2003 to 2014 to estimate the impact of different types of Official development assistance and Private capital on GDP per capita growth of least developed nations. Using random effect model, FDI proved to have significant positive effect on the economy, while all types ODAs showed no meaningful result. This paper implies that least developed countries should target toward attracting private FDI rather than government to government transfer of ODAs, as high corruption rate of governance and poor legal system are not the perfect environment for ODAs to unfold the worth.masterpublishedMinji HONG
Author Correction: Multi-target mode of action of silver against Staphylococcus aureus endows it with capability to combat antibiotic resistance
No full textThe original version of this Article contained an error in the author affiliations. Affiliation 1 incorrectly read “Department of Chemistry, The University of Hong Kong, Hong Kong S.A.R., People’s Republic of China”. This has now been corrected to “Department of Chemistry, State Key Laboratory of Synthetic Chemistry, CAS-HKU Joint Laboratory of Metallomics on Health and Environment, The University of Hong Kong, Hong Kong S.A.R., People’s Republic of China”. in both the PDF and HTML versions of the Article.link_to_OA_fulltex
MAP4-regulated dynein-dependent trafficking of BTN3A1 controls the TBK1-IRF3 signaling axis
No full textThe innate immune system detects viral nucleic acids and induces type I interferon (IFN) responses. The RNA- and DNA-sensing pathways converge on the protein kinase TANK-binding kinase 1 (TBK1) and the transcription factor IFN-regulatory factor 3 (IRF3). Activation of the IFN signaling pathway is known to trigger the redistribution of key signaling molecules to punctate perinuclear structures, but the mediators of this spatiotemporal regulation have yet to be defined. Here we identify butyrophilin 3A1 (BTN3A1) as a positive regulator of nucleic acid-mediated type I IFN signaling. Depletion of BTN3A1 inhibits the cytoplasmic nucleic acid- or virus-triggered activation of IFN-β production. In the resting state, BTN3A1 is constitutively associated with TBK1. Stimulation with nucleic acids induces the redistribution of the BTN3A1-TBK1 complex to the perinuclear region, where BTN3A1 mediates the interaction between TBK1 and IRF3, leading to the phosphorylation of IRF3. Furthermore, we show that microtubule-associated protein 4 (MAP4) controls the dynein-dependent transport of BTN3A1 in response to nucleic acid stimulation, thereby identifying MAP4 as an upstream regulator of BTN3A1. Thus, the depletion of either MAP4 or BTN3A1 impairs cytosolic DNA- or RNA-mediated type I IFN responses. Our findings demonstrate a critical role for MAP4 and BTN3A1 in the spatiotemporal regulation of TBK1, a central player in the intracellular nucleic acid-sensing pathways involved in antiviral signaling.1551sciescopu
Sequential failure-based fragility assessment of a transmission tower under debris flows
No full textThis study proposes a fragility assessment framework for transmission towers under debris flow impact, emphasizing the distinct roles of front and rear legs. Using a coupled SPH-FEM approach, we simulate a wide range of debris flow scenarios (100-6,000 m3) and quantify structural damage based on plastic energy dissipation. The analysis reveals a sequential failure mechanism: front legs absorb energy and fail earlier, while rear legs engage later under higher intensity. By developing component-wise vulnerability and fragility curves with respect to debris flow potential energy, the study offers a novel perspective on transmission tower performance and enables risk-informed design for debris-prone regions.
Network coding for speedup in switches
No full textThesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 69-71).Network coding, which allows mixing of data at intermediate network nodes, is known to increase the throughput of networks. In particular, it is known that linear network coding in a crossbar switch can sustain traffic patterns that cannot be served if network coding were not allowed. Thus, network coding leads to a larger rate region in a multicast crossbar switch. This thesis quantities the gain in rate region in a multicast crossbar switch in terms of speedup. We present a graph theoretic upper bound on speedup needed to achieve 100% throughput in a multicast switch using network coding. By bounding speedup, we show the equivalence between network coding and speedup in multicast switches - i.e. network coding, which is usually implemented using software, can in many cases substitute speedup, which is often achieved by adding extra switch fabrics. This bound is based on an approach to network coding problems called the "enhanced conflict graph". We show that the "imperfection ratio" of the enhanced conflict graph gives an upper bound on speedup. In particular, we apply this result to K x N switches with traffic patterns consisting of unicasts and broadcasts only to obtain an upper bound of min(2K-1/K, 2N/N+1).by MinJi Kim.M.Eng
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Whitewashed Cosmopolitanism: Making of Cosmopolitan Identity in International Schools in Asia
No full textInternational schools in Asia claim to offer cosmopolitan education to their students. The representative ideological goal of international schools is to cultivate “cosmopolitan elites,” who appreciate cultural differences and diversity and share concerns over global issues such as human rights and environmental protections as global citizens. However, this study shows that students who attended international schools maintain racialized sentiments that are far from the ideological goal that international schools claim to offer. This study showcases how Asians from privileged backgrounds become active agents in reproducing a cultural hierarchy to privilege Western- oriented cultural dispositions and Whiteness. Drawing from the 35 in-depth interviews with participants who attended international schools, this study examines how pedagogical approaches in international schools unintentionally reinforce and reproduce the racialized cultural hierarchy. The participants from 10 nationalities attended 37 international schools across 10 East and Southeast Asian countries/ regions during their K-12 education. The findings highlight that 1) the cosmopolitan teachings of international schools are Whitewashed and indoctrinated by Westernized ideology, and 2) the internalization of the racialized cultural hierarchy among international school students becomes a strategy to signal their privileged family background
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