112 research outputs found
Duration-adaptive Video Highlight Pre-caching for Vehicular Communication Network
Video traffic in vehicular communication networks (VCNs) faces exponential
growth. However, different segments of most videos reveal various
attractiveness for viewers, and the pre-caching decision is greatly affected by
the dynamic service duration that edge nodes can provide services for mobile
vehicles driving along a road. In this paper, we propose an efficient video
highlight pre-caching scheme in the vehicular communication network, adapting
to the service duration. Specifically, a highlight entropy model is devised
with the consideration of the segments' popularity and continuity between
segments within a period of time, based on which, an optimization problem of
video highlight pre-caching is formulated. As this problem is non-convex and
lacks a closed-form expression of the objective function, we decouple multiple
variables by deriving candidate highlight segmentations of videos through
wavelet transform, which can significantly reduce the complexity of highlight
pre-caching. Then the problem is solved iteratively by a highlight-direction
trimming algorithm, which is proven to be locally optimal. Simulation results
based on real-world video datasets demonstrate significant improvement in
highlight entropy and jitter compared to benchmark schemes
Greenhouse gas emissions associated with urban water infrastructure:What we have learnt from China's practice
Municipal water and wastewater services have complicated sources of greenhouse gas (GHG) emissions, and quantifying their roles is critical for tackling global environmental challenges. In this study we provide a systematic review of the state-of-the-art on GHG emission characterizations of China's urban water infrastructure with the aim of shedding light on global implications for sustainable development. We started by synthesizing a framework on GHG emissions associated with water and wastewater infrastructure. Then we analyzed the different sources of GHG emissions in drinking water and wastewater treatment systems. In drinking water services, electricity consumption is the largest source of GHG emissions. A particular concern in China is the common use of secondary pumping for high-rise buildings. Optimized pressure management with an efficient pumping system should be prioritized. In wastewater services, non-CO 2 emissions such as methane (CH 4) and nitrous oxide (N 2O) emissions are substantial, but vary greatly depending on regional and technological differences. Further research directions may include GHG inventory development for urban water systems at the plant level, quantifications of GHG emissions from sewer systems, emission reduction measures via water reclamation, renewable energy recovery, energy efficiency improvement, cost–benefit analyses, and characterizations of Scope 3 emissions. This article is categorized under: Engineering Water > Sustainable Engineering of Water Science of Water > Water and Environmental Change Engineering Water > Planning Water. </p
Isolated congenital megacystis without intestinal obstruction: a mild variant of chronic intestinal pseudoobstruction syndrome?
Identification and comprehensive analyses of the CBL and CIPK gene families in wheat (Triticum aestivum L.)
Identification and Analysis of Amygdalin, Neoamygdalin and Amygdalin Amide in Different Processed Bitter Almonds by HPLC-ESI-MS/MS and HPLC-DAD
Processing is a traditional pharmacy technology based on traditional Chinese medicine theory. The traditional Chinese medicine (TCM) ingredients should be processed before being used as a medicine. Processed bitter almonds are widely used in the clinic in TCM for the treatment of cough and asthma. In this work the amygdalin profile of three producing areas in China was determined, with respect to three differently processed bitter almond products: raw, stir-fried and scalded. Identification of the compounds was done by using high performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-MS/MS). Results indicated that amygdalin, neoamygdalin and amygdalin amide were identified in the different processed bitter almonds. Meanwhile, amygdalin was used as a standard to calculate the quantification of amygdalin and the concentration ratio of neoamygdalin and total amygdalin by HPLC-DAD. The data suggested that composition of amygdalin isomers in bitter almonds was influenced by the processing method. It also gives a new understanding of the processing principle of bitter almonds. Moreover, the classification of different processed bitter almonds can be achieved on the basis of amygdalin isomers levels
Coordinated Voltage Control of Active Distribution Network
This paper presents a centralized coordinated voltage control method for active distribution network to solve off-limit problem of voltage after incorporation of distributed generation (DG). The proposed method consists of two parts, it coordinated primal-dual interior point method-based voltage regulation schemes of DG reactive powers and capacitors with centralized on-load tap changer (OLTC) controlling method which utilizes system’s maximum and minimum voltages, to improve the qualified rate of voltage and reduce the operation numbers of OLTC. The proposed coordination has considered the cost of capacitors. The method is tested using a radial edited IEEE-33 nodes distribution network which is modelled using MATLAB
Coordinated Voltage Control of Active Distribution Network
This paper presents a centralized coordinated voltage control method for active distribution network to solve off-limit problem of voltage after incorporation of distributed generation (DG). The proposed method consists of two parts, it coordinated primal-dual interior point method-based voltage regulation schemes of DG reactive powers and capacitors with centralized on-load tap changer (OLTC) controlling method which utilizes system’s maximum and minimum voltages, to improve the qualified rate of voltage and reduce the operation numbers of OLTC. The proposed coordination has considered the cost of capacitors. The method is tested using a radial edited IEEE-33 nodes distribution network which is modelled using MATLAB
Nonthermal plasma-sustained CO2 methanation over Ru-based multi-metallic catalysts (Invited)
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