201 research outputs found
Kinetics of liquid phase semiconductor photoassisted reactions : supporting observations for a pseudo-steady-state model
The kinetics of liquid phase semiconductor photocatalytic and photoassisted reactions are an area of some debate, reignited recently by an article by Ollis1 in which he proposed a simple pseudo-steady-state model to interpret the Langmuir-Hinshelwood type kinetics, commonly observed in such systems. In the current article, support for this model, over other models, is provided by a reinterpretation of the results of a study, reported initially in 1999,2 of the photoassisted mineralization of 4-chlorophenol, 4-CP, by titania films and dispersions as a function of incident light intensity, I. On the basis of this model, these results indicate that 4-CP is adsorbed more strongly on P25 TiO2 when it is in a dispersed, rather than a film form, due to a higher rate constant for adsorption, k1. In addition, the kinetics of 4-CP removal appear to depend on Iâ, where â ) 1 or 0.6 for when the TiO2 is in a film or a dispersed form, respectively. These findings are discussed both in terms of the pseudo-steady-state model and other popular kinetic models
Freeway travel time estimation based on the general motors model: a genetic algorithm calibration framework
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166267/1/itr2bf00710.pd
A rapid method of assessing the photocatalytic activity of thin TiO2 films using an ink based on the redox dye 2,6-dichloroindophenol
An indicator ink based on the redox dye 2,6-dichloroindophenol ( DCIP) is described, which allows the rapid assessment of the activity of thin, commercial photocatalytic films, such as Activ. The ink works via a photoreductive mechanism, DCIP being reduced to dihydro-DCIP within ca. 7.5 minutes exposure to UVA irradiation of moderate intensity ( ca. 4.8mW cm(-2)). The kinetics of photoreduction are found to be independent of the level of dye present in the ink formulation, but are highly sensitive to the level of glycerol. This latter observation may be associated with a solvatochromic effect, whereby the microenvironment in which the dye finds itself and, as a consequence, its reactivity is altered significantly by small changes in the glycerol content. The kinetics of photoreduction also appear linearly dependent on the UVA light intensity with an observed quantum efficiency of ca. 1.8 x 10(-3)
A rapid method of assessing the photocatalytic activity of thin TiO2 films using an ink based on the redox dye 2,6-dichloroindophenol
An indicator ink based on the redox dye 2,6-dichloroindophenol ( DCIP) is described, which allows the rapid assessment of the activity of thin, commercial photocatalytic films, such as Activ. The ink works via a photoreductive mechanism, DCIP being reduced to dihydro-DCIP within ca. 7.5 minutes exposure to UVA irradiation of moderate intensity ( ca. 4.8mW cm(-2)). The kinetics of photoreduction are found to be independent of the level of dye present in the ink formulation, but are highly sensitive to the level of glycerol. This latter observation may be associated with a solvatochromic effect, whereby the microenvironment in which the dye finds itself and, as a consequence, its reactivity is altered significantly by small changes in the glycerol content. The kinetics of photoreduction also appear linearly dependent on the UVA light intensity with an observed quantum efficiency of ca. 1.8 x 10(-3)
The Relationship Between Investor Sentiment and Stock Market Volatility: Based on the VAR Model
Using web crawling technology crawls investors’ comments of SANY stock(Stock Code: 600031) and Fujian Expressway stock(Stock Code: 600033) from February 11, 2015 to August 16, 2017. Then using semi-supervised machine learning method construct investor sentiment index. Moreover, collecting the daily closing stock price and trading volume data from Qianlong software explore the relationship between investor sentiment and stock market volatility based on VAR model and Granger Test Method. The results show that the rate of return and trading volume have a two-way Granger causality, while negative emotion and the rate of return have a one-way Granger causality. Furthermore, with the impulse response function and variance decomposition, the results show that trading volume has significant effects on rate of return and negative emotions of investors have significant negative effects on rate of return and trading volume
COP: Customized Deep Model Compression via Regularized Correlation-Based Filter-Level Pruning
Neural network compression empowers the effective yet unwieldy deep
convolutional neural networks (CNN) to be deployed in resource-constrained
scenarios. Most state-of-the-art approaches prune the model in filter-level
according to the "importance" of filters. Despite their success, we notice they
suffer from at least two of the following problems: 1) The redundancy among
filters is not considered because the importance is evaluated independently. 2)
Cross-layer filter comparison is unachievable since the importance is defined
locally within each layer. Consequently, we must manually specify layer-wise
pruning ratios. 3) They are prone to generate sub-optimal solutions because
they neglect the inequality between reducing parameters and reducing
computational cost. Reducing the same number of parameters in different
positions in the network may reduce different computational cost. To address
the above problems, we develop a novel algorithm named as COP
(correlation-based pruning), which can detect the redundant filters
efficiently. We enable the cross-layer filter comparison through global
normalization. We add parameter-quantity and computational-cost regularization
terms to the importance, which enables the users to customize the compression
according to their preference (smaller or faster). Extensive experiments have
shown COP outperforms the others significantly. The code is released at
https://github.com/ZJULearning/COP.Comment: 7 pages, 4 figures, has been accepted by IJCAI201
A Robust Integrated Multi-Strategy Bus Control System via Deep Reinforcement Learning
An efficient urban bus control system has the potential to significantly
reduce travel delays and streamline the allocation of transportation resources,
thereby offering enhanced and user-friendly transit services to passengers.
However, bus operation efficiency can be impacted by bus bunching. This problem
is notably exacerbated when the bus system operates along a signalized corridor
with unpredictable travel demand. To mitigate this challenge, we introduce a
multi-strategy fusion approach for the longitudinal control of connected and
automated buses. The approach is driven by a physics-informed deep
reinforcement learning (DRL) algorithm and takes into account a variety of
traffic conditions along urban signalized corridors. Taking advantage of
connected and autonomous vehicle (CAV) technology, the proposed approach can
leverage real-time information regarding bus operating conditions and road
traffic environment. By integrating the aforementioned information into the
DRL-based bus control framework, our designed physics-informed DRL state fusion
approach and reward function efficiently embed prior physics and leverage the
merits of equilibrium and consensus concepts from control theory. This
integration enables the framework to learn and adapt multiple control
strategies to effectively manage complex traffic conditions and fluctuating
passenger demands. Three control variables, i.e., dwell time at stops, speed
between stations, and signal priority, are formulated to minimize travel
duration and ensure bus stability with the aim of avoiding bus bunching. We
present simulation results to validate the effectiveness of the proposed
approach, underlining its superior performance when subjected to sensitivity
analysis, specifically considering factors such as traffic volume, desired
speed, and traffic signal conditions
With Brexit, inward investment will fall in the UK
Supply chains cross borders many times before components go into a final product in any EU country, write David Bailey, Nigel Driffield and Michail Karoglo
Lateral and torsional vibrations of cable-guided hoisting system with eccentric load
Theoretical investigation of the lateral and torsional vibrations of the hoisting cage in the cable-guided hoisting system caused by the eccentric load and the flexibility of the guiding cable is presented in this paper. The assumed modes method (AMM) is adopted to discretize the hoisting cable and two guiding cables, then Lagrange equations of the first kind are used to derive the equations of motion, while the geometric relationships between the hoisting cage and the cables are accounted for by the Lagrangian multiplier. Considering all the geometric matching conditions are approximately linear, the differential algebraic equations (DAEs) are transformed to the ordinary differential equations (ODEs). The dynamic responses of the hoisting cage are calculated, and especially the lateral displacements of the guiding cable and the constraints forces at the interfaces are obtained. Preload plays a vital role in affecting the cage vibration, thus, the effects of the total preload and the tension difference are analyzed. The numerical results indicate increasing the total preload can decrease the vibration displacements, while the tension difference has little impact on the vibration but can obviously change the constraint forces. In addition, the vibration displacements are directly proportional to the eccentric load, but less sensitive to the hoisting mass
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