Pricing Strategies of Social Commerce Platform under Network Externalities

Wei Zhang,Wei Ma,Zhonghua Li,Naixue Xiong 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.12

Although the theory of two-sided markets is popular nowadays, little attention was paid on self-network externalities and UGC (User Generated Content) produced by buyers which are the major features of social commerce two-sided markets. This article studies percentages of buyers who generated UGC, self-network externalities of buyers and cross-group externalities between two groups. The three factors influence the pricing strategy of social commerce platforms based on two-sided markets. With analyzing the special characteristics of social commerce, the study unveils that the optimal price of buyers charged by social commerce platform shows a negative correlation with self-network externalities and it also shows a negative correlation with the probability of UGC generated by buyers. The study also shows that the equilibrium price of buyers declines with the augment of cross-group externalities of buyers to sellers, and the equilibrium price of sellers declines with the augment of cross-group work externalities of sellers to buyers. The social commerce platforms on the basis of interest graph, lower UGC threshold and more interactive among customers gain the competitive advantages. Compared to other platforms, the two-sided social commerce platforms give consumers and retailers more subsidies.

Tribological Properties of Ti(C,N)-based Cermet after Hot Isostatic Pressing at High Nitrogen Pressure

Xiong Wei-hao,Zheng Li-yun,Yan Xian-mei 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Sintered Ti(C,N)-based cermets were treated with hot isostatic pressing (HIP) at different nitrogen pressures. The tribological properties of the treated cermets have been evaluated. The results show that a hard near-surface area rich in TiN formed after HIP treatment. The cermets treated at higher pressure had a relatively lower friction coefficient and specific wear rate. In all cases the microhardness of treated cermets is higher than that without HIP natridation. The wear mechanisms of cermets were hard particle flaking-off and ploughing. It was also found that the HIP natridation is well-suited for improving the tribological properties of cermets.

Parecoxib: an Enhancer of Radiation Therapy for Colorectal Cancer

Xiong, Wei,Li, Wen-Hui,Jiang, Yong-Xin,Liu, Shan,Ai, Yi-Qin,Liu, Rong,Chang, Li,Zhang, Ming,Wang, Xiao-Li,Bai, Han,Wang, Hong,Zheng, Rui,Tan, Jing Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Background: To study the effect of parecoxib, a novel cyclooxygenase-2 selective inhibitor, on the radiation response of colorectal cancer (CRC) cells and its underlying mechanisms. Materials and Methods: Both in vitro colony formation and apoptosis assays as well as in vivo mouse xenograft experiments were used to explore the radiosensitizing effects of parecoxib in human HCT116 and HT29 CRC cells. Results: Parecoxib sensitized CRC cells to radiation in vitro with a sensitivity enhancement ratio of 1.32 for HCT116 cells and 1.15 for HT29 cells at a surviving fraction of 0.37. This effect was partially attributable to enhanced apoptosis induction by parecoxib combined with radiation, as illustrated using an in vitro apoptosis assays. Parecoxib augmented the tumor response of HCT116 xenografts to radiation, achieving growth delay more than 20 days and an enhancement factor of 1.53. In accordance with the in vitro results, parecoxib combined with radiation resulted in less proliferation and more apoptosis in tumors than radiation alone. Radiation monotherapy decreased microvessel density (MVD) and microvessel intensity (MVI), but increased the hypoxia level in xenografts. Parecoxib did not affect MVD, but it increased MVI and attenuated hypoxia. Conclusions: Parecoxib can effectively enhance radiation sensitivity in CRC cells through direct effects on tumor cells and indirect effects on tumor vasculature.

Energy Consumption Evaluation in Stamping Workshops via a Discrete Event Simulation-Based Approach

Wei Xiong,Haihong Huang,Lei Li,Lei Gan,Libin Zhu,Zhifeng Liu 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.6

Stamping is employed in a wide range of applications in industry, which is composed of discrete flow energy-intensive processes. Durations of stamping activities are much shorter than that of mold changing and transportation, which makes energy consumption in stamping workshops greatly affected by the production scheme and the proportion of transportation volume. Different from machining that has been widely discussed, there is less research on energy saving in stamping workshops. This paper aims to evaluate the energy consumption of stamping on the workshop level. A theoretical model and a discrete event simulation model were developed based on energy flow and material flow in the workshop. The theoretical model was used to calculate each component of energy consumption based on production-related data. The simulation model was used to predict the overall energy required in the workshop when subjected to changes in its production conditions. Impacts of influence factors, including machine failure rate, proportion of transportation volume, and production scheme on energy consumption, makespan, and machine utilization rates, were studied to find opportunities for energy reduction and production efficiency improvement. Finally, a case study of a stamping workshop for forklifts validated the proposed approach, and optimization measures were suggested, implemented, and verified. Results have found that under the same production scheme (suppose each press has the same failure rate), the balance between energy use and makespan was achieved when the proportion of transportation volume was 1/2. This simulation-based approach provides a useful tool for evaluating and reducing energy consumption and helps operators to perform energy-saving actions in stamping workshops.

Simultaneous variable selection and parametric estimation for quantile regression

Wei Xiong,Maozai Tian 한국통계학회 2015 Journal of the Korean Statistical Society Vol.44 No.1

In this paper, variable selection techniques in the linear quantile regression modelare mainly considered. Based on the penalized quantile regression model, a one-stepprocedure that can simultaneously perform variable selection and coefficient estimationis proposed. The proposed procedure has three distinctive features: (1) By consideringquantile regression, the set of relevant variables can vary across quantiles, thus makingit more flexible to model heterogeneous data; (2) The one-step estimator has niceproperties in both theory and practice. By applying SCAD penalty (Fan and Li, 2001)and Adaptive-LASSO penalty (Zou, 2006), we establish the oracle property for the sparsequantile regression under mild conditions. Computationally, the one-step estimator is fast,dramatically reducing the computation cost; (3) We suggest a BIC-like tuning parameterselector for the penalized quantile regression and demonstrate the consistency of thiscriterion. That is to say the true model can be identified consistently based on the BIC-likecriterion, making our one-step estimator more reliable practically. Monte Carlo simulationstudies are conducted to examine the finite-sample performance of this procedure. Finally,we conclude with a real data analysis. The results are promising.

Efficient and Facile Fabrication of Hierarchical Carbon Foams with Abundant Nanoscale Pores for Use in Supercapacitors

Wei Xiong,Guijun Yang,양태현,Shantang Liu,정용주 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.3

Hierarchical carbon foams (HCFs) with micro-, meso-, and macropores were successfully synthesized via a two-step process: (1) polymerization in oil-in-water (O/W) emulsions without any hard templates and (2) carbonization at 850°C. With the aim of both enhancing the stability of the emulsion and forming a micro- and mesoporous structure during the carbonization process, potassium citrate was introduced in an aqueous solution of resorcinol and formaldehyde. A series of HCFs were fabricated by changing the mass ratio of potassium citrate to total carbon sources from 0.25 to 1.5. The effect of potassium citrate on the porous structure of HCFs was investigated through nitrogen sorption tests. The prepared HCFs exhibited well-developed porous structures of micro-, meso- and macropores and high surface areas. The structural characteristics of the HCFs, including pore size distribution, surface area, and porosity, were significantly dependent on the amount of potassium citrate. It was concluded that potassium citrate greatly contributed to the formation of carbon foams with nano-sized pore structures and high porosity. Interestingly, it was found that when the mass ratio of potassium citrate to total carbon sources was 0.5, the HCFs showed the highest specific surface area (~1360 m2/g). Furthermore, the capacitive performances of the HCFs were evaluated in a 6.0 M KOH aqueous solution using typical electrochemical methods such as cyclic voltammetry and galvanostatic charge/discharge tests. The capacitance of the HCFs tended to increase with the increase in surface area. In particular, the HCFs with the highest surface area also exhibited excellent electrochemical properties (high capacitance of 224 F/g at 1.0 A/g, high rate capability of 191 F/g at 10.0 A/g). These features may be attributed to both the resulting interconnected pore structure that is easily accessible to ions and the high surface area. We believe that this synthesis strategy can be easily extended to the preparation of hierarchical porous carbon materials with a desirable pore structure by tuning the organic monomer.

Cryptochrome 1 functions as nuclear co-receptor independence of circadian clock

Wei Xiong,Tao Cai 한국유전학회 2016 Genes & Genomics Vol.38 No.4

Cryptochrome 1 (CRY1) is well known as a circadian clock repressor. Recent studies have shown that it could intimately associate with nuclear receptors and either activate or inhibit its targets at the transcriptional level. In the present study, we applied publicly available transcriptional factors Chromatin Immunoprecipitation coupled high throughput sequencing data to prove that CRY1 associates with various nuclear receptors at the genomewide level, which is independent of its canonical role as a circadian clock repressor. Furthermore, we have also shown that CRY1 is a confident co-receptor of retinoid X receptor, alpha (RXRa). We have also further shown that CRY1 could directly interact with RXRa. The interaction was regulated by retinoic acid treatment in a dose-dependent manner. In addition, CRY activator could antagonized RA-medicated PCK1 and G6PC expression, which in turn antagonize glucose production. Our findings indicate that CRYs could be potential targets in relieving side effects of RA-oriented treatment for diseases such as leukemia, acne, and psoriasis.

Cancer Registration in the Peoples Republic of China

Wei, Kuang-Rong,Chen, Wan-Qing,Zhang, Si-Wei,Liang, Zhi-Heng,Zheng, Rong-Shou,Ou, Zhi-Xiong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

The current situation of cancer registration in China was systematically reviewed. So far, cancer registration in China has been making a great progress in the following aspects: the number of cancer registries and covered population have increased dramatically; a registration network has been established and completed gradually; regulations and rules improved remarkably; more attention is being paid by every level of government; a lot of registration software has been created and financial support ensured. However, we are still facing some problems and challenges, such as no stable groups of registrars, shortage of training opportunities, poor data quality, insufficient utilization and lack of multidisciplinary mechanisms, so that the cancer registration system still needs to be enhanced and improved. Along with the development of economy, science and information technology, methods and patterns of cancer registration is changing. It is to be expected that cancer registration will be automatic, nationwide and integrated with community healthcare in the near future.

A Study on the Recognition of English Pronunciation Features in Teaching by Machine Learning Algorithms

Wei Xiong 한국정보과학회 2023 Journal of Computing Science and Engineering Vol.17 No.3

Topology optimization of locally resonant acoustic metamaterials to maximize bandgap using effective mass density

Xiong Wei Yang,Joong Seok Lee,Yoon Young Kim 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11