Simulation of colloidal suspension systems

The research work is focused on the development of a simulation platform for colloidal suspension. Based on discrete element method (DEM), the model developed takes into account the crucial interactions, i.e. the electrostatic repulsion, van der Waals attraction, Brownian force, hydration effects and hydrodynamic force. The mechanism of colloid particle diffusion in confined space and the combined influences of fluid flow field, geometrical confinement, and the interparticle interactions on the self-assembly process are investigated

Prediction of Commuter’s Daily Time Allocation

This paper presents a model system to predict the time allocation in commuters’ daily activity-travel pattern. The departure time and the arrival time are estimated with Ordered Probit model and Support Vector Regression is introduced for travel time and activity duration prediction. Applied in a real-world time allocation prediction experiment, the model system shows a satisfactory level of prediction accuracy. This study provides useful insights into commuters’ activity-travel time allocation decision by identifying the important influences, and the results are readily applied to a wide range of transportation practice, such as travel information system, by providing reliable forecast for variations in travel demand over time. By introducing the Support Vector Regression, it also makes a methodological contribution in enhancing prediction accuracy of travel time and activity duration prediction

Examination of staggered shifts impacts on travel behavior: a case study of Beijing, China

Staggered shifts is one of the popular TDM (Transportation Demand Management) policies, which can reduce commute travel volume during the AM and PM peak periods, and relieve traffic congestion. In order to make effective staggered shifts program, it is necessary to examine the effect of the program on commute travel behavior. This paper takes Beijing (China) as an example to evaluate the validity of staggered shifts policy. Based on data investigation, the commute travel behavior and the commuters’ preference for staggered shifts are analyzed. This paper makes four staggered shifts programs, and develops a commute departure time choice model with Multinomial Logit method to predict the influence of the programs on commute departure time, and develops a commute travel duration model to analyze the influence of the programs on commute travel time. Departure time prediction shows that Program B can reduce the traffic volumes in 6:30–8:30 period by 15.24%, and commute travel duration analysis indicate that Program B can reduce the home-to-work travel time by 21.73%. Therefore, Program B is proven to be the best staggered shifts program for Beijing. The results of this paper can provide valuable information on how to develop an effective staggered shifts program

A Transformer-Based Substitute Recommendation Model Incorporating Weakly Supervised Customer Behavior Data

The substitute-based recommendation is widely used in E-commerce to provide better alternatives to customers. However, existing research typically uses the customer behavior signals like co-view and view-but-purchase-another to capture the substitute relationship. Despite its intuitive soundness, we find that such an approach might ignore the functionality and characteristics of products. In this paper, we adapt substitute recommendation into language matching problem by taking product title description as model input to consider product functionality. We design a new transformation method to de-noise the signals derived from production data. In addition, we consider multilingual support from the engineering point of view. Our proposed end-to-end transformer-based model achieves both successes from offline and online experiments. The proposed model has been deployed in a large-scale E-commerce website for 11 marketplaces in 6 languages. Our proposed model is demonstrated to increase revenue by 19% based on an online A/B experiment.Comment: 6 pages, 3 figures, 5 tables, accepted in 21st IEEE International Conference on Machine Learning and Application

The Influence of Education and Scientific Research System on China's Science and Technology Innovation Capability

This article outlines their impact on China's technological innovation capabilities from nine aspects including primary and secondary education to university education, the shortcomings of scientific research evaluation system, the forward-looking of educational investment and the rationality of research funding, the negative feedback of the employment market on innovative research, intellectual property protection and incentive mechanism, The basic social system and its incentive mechanism combined with learning and research, the incentive mechanism and cultural atmosphere of enterprises and administrative institutions, and the origin of China's modern education model. The comprehensive analysis shows that changing the status quo of China's lack of innovation is a systematic project. A single ministry cannot complete many specific measures of reform, and must have a national-level top-level design. Through reform, the education and scientific research system has reasonable design and strong self-repairing ability. It is the need of innovation to promote industrial upgrading. Its effectiveness directly determines whether China can cross the middle income trap and the great rejuvenation of the Chinese nation

Sperm Associated Antigen 6 (SPAG6) Regulates Fibroblast Cell Growth, Morphology, Migration and Ciliogenesis

Mammalian Spag6 is the orthologue of Chlamydomonas PF16, which encodes a protein localized in the axoneme central apparatus, and regulates flagella/cilia motility. Most Spag6-deficient mice are smaller in size than their littermates. Because SPAG6 decorates microtubules, we hypothesized that SPAG6 has other roles related to microtubule function besides regulating flagellar/cilia motility. Mouse embryonic fibroblasts (MEFs) were isolated from Spag6-deficient and wild-type embryos for these studies. Both primary and immortalizedSpag6-deficient MEFs proliferated at a much slower rate than the wild-type MEFs, and they had a larger surface area. Re-expression of SPAG6 in the Spag6-deficient MEFs rescued the abnormal cell morphology. Spag6-deficient MEFs were less motile than wild-type MEFs, as shown by both chemotactic analysis and wound-healing assays. Spag6-deficient MEFs also showed reduced adhesion associated with a non-polarized F-actin distribution. Multiple centrosomes were observed in theSpag6-deficient MEF cultures. The percentage of cells with primary cilia was significantly reduced compared to the wild-type MEFs, and some Spag6-deficient MEFs developed multiple cilia. Furthermore, SPAG6 selectively increased expression of acetylated tubulin, a microtubule stability marker. The Spag6-deficient MEFs were more sensitive to paclitaxel, a microtubule stabilizer. Our studies reveal new roles for SPAG6 in modulation of cell morphology, proliferation, migration, and ciliogenesis

A comparison of intravenous and indirect intracoronary delivery of AAV5, AAV6 and AAV9 for cardiac gene transfer in mice

Cardiac gene transfer is a potentially useful treatment for patients with heart disease. The adeno-associated virus (AAV) is a frequently used vector in preclinical gene transfer, but the optimal AAV serotype and route of delivery has not been established. I examined the relative efficacy of three AAV serotypes (AAV5, AAV6, AAV9) and two vector delivery methods (indirect intracoronary, intravenous) to determine the combination that would provide the highest level of cardiac transgene expression in mice. Using enhanced green fluorescent protein (EGFP) as a reporter to quantify transgene expression, AAV5.EGFP, AAV6.EGFP, and AAV9.EGFP [5 x 10¹¹ genome copies (gc)] were delivered via indirect intracoronary or intravenous injection. Three weeks later hearts were removed and EGFP expression was quantified using fluorescent microscopy and immunoblotting. AAV DNA copy number was measured by quantitative PCR. Within each serotype, indirect intracoronary delivery was superior to intravenous delivery. Indirect intracoronary delivery of AAV9 provided the highest level of cardiac gene expression. This vector and delivery method should be used in preclinical studies in which a high level of transgene expression is require

Topology Optimization of Constrained Layer Damping Structures Subjected to Stationary Random Excitation

This paper deals with an optimal layout design of the constrained layer damping (CLD) treatment of vibrating structures subjected to stationary random excitation. The root mean square (RMS) of random response is defined as the objective function as it can be used to represent the vibration level in practice. To circumvent the computationally expensive sensitivity analysis, an efficient optimization procedure integrating the pseudoexcitation method (PEM) and the double complex modal superposition method is introduced into the dynamic topology optimization. The optimal layout of CLD treatment is obtained by using the method of moving asymptote (MMA). Numerical examples are given to demonstrate the validity of the proposed optimization procedure. The results show that the optimized CLD layouts can effectively reduce the vibration response of the structures subjected to stationary random excitation