77 research outputs found
On Uni-Modal Feature Learning in Supervised Multi-Modal Learning
We abstract the features (i.e. learned representations) of multi-modal data
into 1) uni-modal features, which can be learned from uni-modal training, and
2) paired features, which can only be learned from cross-modal interactions.
Multi-modal models are expected to benefit from cross-modal interactions on the
basis of ensuring uni-modal feature learning. However, recent supervised
multi-modal late-fusion training approaches still suffer from insufficient
learning of uni-modal features on each modality. We prove that this phenomenon
does hurt the model's generalization ability. To this end, we propose to choose
a targeted late-fusion learning method for the given supervised multi-modal
task from Uni-Modal Ensemble(UME) and the proposed Uni-Modal Teacher(UMT),
according to the distribution of uni-modal and paired features. We demonstrate
that, under a simple guiding strategy, we can achieve comparable results to
other complex late-fusion or intermediate-fusion methods on various multi-modal
datasets, including VGG-Sound, Kinetics-400, UCF101, and ModelNet40
Upcycling of PET oligomers from chemical recycling processes to PHA by microbial co-cultivation
Polyethylene terephthalate (PET) is the most widely consumed polyester plastic and can be recycled by many chemical processes, of which glycolysis is most cost-effective and commercially viable. However, PET glycolysis produces oligomers due to incomplete depolymerization, which are undesirable by-products and require proper disposal. In this study, the PET oligomers from chemical recycling processes were completely bio-depolymerized into monomers and then used for the biosynthesis of biodegradable plastics polyhydroxyalkanoates (PHA) by cocultivation of two engineered microorganisms Escherichia coli BL21 (DE3)-LCCICCG and Pseudomonas putida KT2440-ΔRDt-ΔZP46C-M. E. coli BL21 (DE3)-LCCICCG was used to secrete the PET hydrolase LCCICCG into the medium to directly depolymerize PET oligomers. P. putida KT2440-ΔRDt-ΔZP46C-M that mastered the metabolism of aromatic compounds was engineered to accelerate the hydrolysis of intermediate products mono-2- (hydroxyethyl) terephthalate (MHET) by expressing IsMHETase, and biosynthesize PHA using ultimate products terephthalate and ethylene glycol depolymerized from the PET oligomers. The population ratios of the two microorganisms during the co-cultivation were characterized by fluorescent reporter system, and revealed the collaboration of the two microorganisms to bio-depolymerize and bioconversion of PET oligomers in a single process. This study provides a biological strategy for the upcycling of PET oligomers and promotes the plastic circular economy
A thermo-hydro-mechanical finite element model of freezing in porous media-thermo-mechanically consistent formulation and application to ground source heat pumps
Freezing phenomena in porous media have attracted great attention in geotechnics,
construction engineering and geothermal energy. For shallow geothermal applications where heat
pumps are connected to borehole heat exchangers (BHEs), soil freezing around the BHEs is a
potential problem due to persistent heat extraction or inappropriate design which can sig-
nificantly influence the temperature distribution as well as groundwater flow patterns
in the subsurface, and even lead to frost heave. A fully coupled thermo-hydro-mechanical freezing
model is required for advanced system design and scenario analyses. In the framework
of the Theory of Porous Media, a triphasic freezing model is derived and solved with the finite
element method. Ice formation in the porous medium results from a coupled heat and mass transfer
problem with phase change and is accompanied by volume expansion. The model is able to capture
various coupled physical phenomena during freezing, e.g., the latent heat ef- fect, groundwater
flow with porosity change and mechanical deformation. The current paper is focused primarily on the
theoretical derivation of the conceptual model. Its numerical implementation is verified against analytical solutions of selected phenomena including pure phase
change and thermo-hydro-mechanical process couplings
Human Mediator Enhances Activator-Facilitated Recruitment of RNA Polymerase II and Promoter Recognition by TATA-Binding Protein (TBP) Independently of TBP-Associated Factors
Mediator is a general cofactor implicated in the functions of many transcriptional activators. Although Mediator with different protein compositions has been isolated, it remains unclear how Mediator facilitates activator-dependent transcription, independent of its general stimulation of basal transcription. To define the mechanisms of Mediator function, we isolated two forms of human Mediator complexes (Mediator-P.5 and Mediator-P.85) and demonstrated that Mediator-P.5 clearly functions by enhancing activator-mediated recruitment of RNA polymerase II (pol II), whereas Mediator-P.85 works mainly by stimulating overall basal transcription. The coactivator function of Mediator-P.5 was not impaired when TATA-binding protein (TBP) was used in place of TFIID, but it was abolished when another general cofactor, PC4, was omitted from the reaction or when Mediator-P.5 was added after pol II entry into the preinitiation complex. Moreover, Mediator- P.5 is able to enhance TBP binding to the TATA box in an activator-dependent manner. Our data provides biochemical evidence that Mediator functions by facilitating activator-mediated recruitment of pol II and also promoter recognition by TBP, both of which can occur in the absence of TBP-associated factors in TFIID
Effect of Liquid Natural Rubber on Properties of Natural Rubber/Silica Composite Prepared by Wet Compounding
Natural rubber/silica composites (NR/SiO2) was prepared by wet compounding technology with liquid natural rubber(LNR) as compatibilizer. Curing characteristics, processing properties, filler dispersion and mechanical properties were investigated.The results showe that the optimum cure time is decreased 4.16 min, the processing properties of the composites were improved with the incorporation of LNR; better silica dispersion in NR in presence of LNR; the when silica is 60 phr, tensile strength and tear strength of the vulcanizates were increase 25.73% and 66.59%respectively; as far as the dynamic mechanical properties are concerned, the W(NR/SiO2) composites with LNR owned a combination of high wet skid resistance and low rolling resistance. It is revealed that LNR has better compatibility, which is attributed to LNR reaction with both NR and SiO2 to form compatibilizing interface
A scalable distribution network risk evaluation framework via symbolic dynamics.
Evaluations of electric power distribution network risks must address the problems of incomplete information and changing dynamics. A risk evaluation framework should be adaptable to a specific situation and an evolving understanding of risk.This study investigates the use of symbolic dynamics to abstract raw data. After introducing symbolic dynamics operators, Kolmogorov-Sinai entropy and Kullback-Leibler relative entropy are used to quantitatively evaluate relationships between risk sub-factors and main factors. For layered risk indicators, where the factors are categorized into four main factors - device, structure, load and special operation - a merging algorithm using operators to calculate the risk factors is discussed. Finally, an example from the Sanya Power Company is given to demonstrate the feasibility of the proposed method.Distribution networks are exposed and can be affected by many things. The topology and the operating mode of a distribution network are dynamic, so the faults and their consequences are probabilistic
Research on the Earth Pressure and Internal Force of a High-Fill Open-Cut Tunnel Using a Bilayer Lining Design: A Field Test Using an FBG Automatic Data Acquisition System
When there are railway tunnels on both sides of a valley, a bridge is usually built to let trains pass. However, if the valley is very close to an urban area, building an open-cut tunnel at the portal and then backfilling it to create available land resources for the city and to prevent excavation slag from polluting the environment would be a wise choice. This has led to the emergence of a new type of structure, namely, the high-fill open-cut tunnel. In this paper, by performing an automatic long-term field test on the first high-fill open-cut tunnel using a bilayer design in China, the variations of earth pressure and structural internal force during the backfilling process were obtained, and different tunnel foundation types were studied. The results showed that the earth pressure significantly exceeded the soil column weight, with a maximum earth pressure coefficient between 1.341 and 2.278. During the backfilling process, the earth pressure coefficient increased at first and then decreased slowly to a relatively stable value, and a stiffer foundation would make the structure bear higher earth pressure (1.69 times the normal one observed during monitoring). The change of internal force had two stages during backfilling: before the backfill soil reached the arch crown, the internal force of the lining changed slowly and then grew linearly as the backfill process continued. Moreover, the axial force ratio of the inner and outer linings was close to their thickness proportion, and the interaction mode between the two layers was very similar to the composite beam
Emerging Roles of RNF168 in Tumor Progression
RING finger protein 168 (RNF168) is an E3 ubiquitin ligase with the RING finger domain. It is an important protein contributing to the DNA double-strand damage repair pathway. Recent studies have found that RNF168 is significantly implicated in the occurrence and development of various cancers. Additionally, RNF168 contributes to the drug resistance of tumor cells by enhancing their DNA repair ability or regulating the degradation of target proteins. This paper summarizes and prospects the research progress of the structure and main functions of RNF168, especially its roles and the underlying mechanisms in tumorigenesis
Risk assessment for the cascading failure of electric cyber-physical system considering multiple information factors
A risk assessment approach for the cascading failure of electric cyber-physical system (ECPS) considering multiple information factors is proposed. First, considering hardware, software and personnel factors existing in the information system, the reliability model of the control function of the information system is established. Second, the reliability model of the physical component considering the control function of the information system is established. Finally, the risk assessment approach for the cascading failure of ECPS is introduced, and the probability of the cascading failure and the expected energy not supplied are used as the risk indices. Test results on an improved RTS-79 system show the effectiveness and significance of the method for choosing the optimal power communication network topology and the measures to reduce the risk
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