Improved strategies for the load-bearing capacity of aluminum-PVC foam sandwich floors of a high-speed train

Haifeng Chang,Lele Zhang,Weiyuan Dou,Haifeng Zhang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.2

For high-speed trains (HSTs), interface failures often occur in their aluminumPVC foam sandwich floor, the service life of which can affect the maintenance economy significantly. In this study, a floor model considering crushable foam layer and cohesive element was implemented to validate its bending behavior, with which the load-bearing capacity of actual floor structures under different loading conditions was analyzed. Accordingly, two strategies were presented for improving the load-bearing capacity of the floor: adding grid stiffened ribs on the aluminum layer and adjusting the layout of the supporting seats appropriately. The numerical simulation results indicated that the position of the maximum stress concentration was on the edge of the floor foam layer, and the limits of the load-bearing capacity were 50 and 575 kPa with respect to two operation conditions. By varying the supporting seats with different layouts or adding reinforced structures, the maximum stress and deflection in the critical zones were reduced significantly compared with those of the original design.

Factors affecting households' meat purchase and future meat consumption changes in China: a demand system approach

Haifeng Zhang,Jun Wang,Wayne Martin 한국식품연구원 2018 Journal of Ethnic Foods Vol.5 No.1

Background China is the world's largest meat market. If consumption of meat in China continues to grow, there will likely be greater business opportunities for meat producers both in and outside of China. As a result, meat exporting countries such as the U.S. may be influenced by changes in meat consumption in China. A better understanding of future meat demand in China will benefit both producers and exporters. The aim of this study was to evaluate factors that affect households' meat purchase and to estimate future meat consumption changes in China. Methods This study was based on primary data collected from a consumer survey in Guangzhou city in 2014. A total of 617 completed questionnaires were obtained from the consumer survey. An advanced linear approximated almost ideal demand system was used for data analysis. Results The results indicated that the average household monthly purchase of pork, chicken, beef, and mutton was 2.90 kg, 1.47 kg, 0.77 kg, and 0.33 kg, respectively. Estimated expenditure elasticities for each meat item were 0.78, 1.02, 1.34, and 1.83, respectively. The uncompensated own price elasticities for each corresponding meat item were −0.79, −0.75, −0.70, and −0.25, respectively. The compensated own price elasticities were −0.44, −0.47, −0.46, and −0.14, respectively. High-income households purchased more meat, especially pork, chicken and mutton, than low-income households. Meat consumption pattern will be affected by income changes. Conclusion Collectively these results suggest that there will be a potential meat market expansion in China, and that pork consumption will increase at a quantity much larger than other meat items in the near future, assuming that consumer income will continue to increase. China's projected increase in meat demand will eventually stimulate greater meat imports, which may have a significant influence on meat exporting countries in the world.

An Integrated Epidemiological and Economic Analysis of Vaccination against Highly Pathogenic Porcine Reproductive and Respiratory Syndrome (PRRS) in Thua Thien Hue Province, Vietnam

Zhang, Haifeng,Kono, Hiroichi,Kubota, Satoko Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.10

The purposes of this study are to assess pig farmers' preference for highly pathogenic porcine reproductive and respiratory syndrome (PRRS) vaccine, and estimate the cost and benefit of PRRS vaccination in Vietnam. This study employed an integrated epidemiological and economic analysis which combined susceptible-infectious-recovered (SIR) model, choice experiment (CE) and cost-benefit analysis (CBA) together. The result of SIR model showed the basic reproduction number ($R_0$) of PRRS transmission in this study is 1.3, consequently, the optimal vaccination percentage is 26%. The results of CE in this study indicate that Vietnam pig farmers are showing a high preference for the PRRS vaccine. However, their mean willingness to pay is lower than the potential cost of PRRS vaccine. It can be considered to be one of the reasons that the PRRS vaccination ratio is still low in Vietnam. The results of CBA specified from the whole society's point of view (Social perspective), the benefits of PRRS vaccination are 2.3 to 4.5 times larger than the costs. To support policy making for increasing the PRRS vaccination proportion, this study indicates two ways to increase the vaccination proportion: i) decrease vaccine price by providing a subsidy, ii) provide compensation of culling only for PRRS vaccinated pigs.

Mechanical Performances of Concrete Produced with Desert Sand After Elevated Temperature

Haifeng Liu,Xiaolong Chen,Jialing Che,Ning Liu,Minghu Zhang 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.4

Currently, fire in building is one of the most serious disasters. With the increase of basic construction items in western China, ordinary medium sand resource no longer met with the need of engineering. Compressive strength experiments of concrete produced with desert sand after elevated temperature were carried out in this paper. The effects of desert sand replacement rate (DSRR), temperature and cooling regime on the mechanical performances of concrete produced with desert sand were analyzed. XRD and SEM experiments were also conducted to study the microstructure of concrete produced with desert sand after elevated temperature. Experimental results showed that the cubic compressive strength of concrete produced with desert sand increased firstly, and then declined with temperature. Whereas, the prismatic compressive strength and elasticity modulus of concrete produced with desert sand under static compression declined with temperature. With the enhancement of DSRR, the elasticity modulus under static compression, cubic compressive strength and prismatic compressive strength of concrete produced with desert sand after elevated temperature increased firstly, and then declined, the maximum value of which was reached when DSRR amounted to 40%. Regression models were established to predict the mechanical performances of concrete produced with desert sand after elevated temperature, which were in good agreement with experimental results.

Mining Implicit Correlations between Users with the Same Role for Trust-Aware Recommendation

( Haifeng Liu ),( Zhuo Yang ),( Jun Zhang ),( Xiaomei Bai ),( Wei Wang ),( Feng Xia ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.12

Trust as one of important social relations has attracted much attention from researchers in the field of social network-based recommender systems. In trust network-based recommender systems, there exist normally two roles for users, truster and trustee. Most of trust-based methods generally utilize explicit links between truster and trustee to find similar neighbors for recommendation. However, there possibly exist implicit correlations between users, especially for users with the same role (truster or trustee). In this paper, we propose a novel Collaborative Filtering method called CF-TC, which exploits Trust Context to discover implicit correlation between users with the same role for recommendation. In this method, each user is first represented by the same-role users who are co-occurring with the user. Then, similarities between users with the same role are measured based on obtained user representation. Finally, two variants of our method are proposed to fuse these computed similarities into traditional collaborative filtering for rating prediction. Using two publicly available real-world Epinions and Ciao datasets, we conduct comprehensive experiments to compare the performance of our proposed method with some existing benchmark methods. The results show that CF-TC outperforms other baseline methods in terms of RMSE, MAE, and recall.

Research on Model of Free Piston Linear Generator based on Location Domain and Real-Time Motion Control Strategy

Zhang Qingzhi,Lu Haifeng,Li Yongdong,Chai Jianyun 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Free Piston Linear Generator (FPLG) is an ideal power resource in Hybrid Electric Vehicle (HEV) for its potential advantages of low friction loss, variable compression ratio, being suitable for various fuels, high thermal efficiency, etc. No FPLG has been successfully applied to an actual vehicle as lack of reliable control. The first part of this paper consists of introduction to FPLG and its research status. Structure and working principle of FPLG are analyzed in the second part. Then the thermodynamic process is analyzed and mathematical models of all kinds of FPLG using real-time motion control strategy based on location domain are established. After these, verifying work of the six different models established before and the realtime control strategy is carried out. Results show that the mathematical models of FPLG based on location domain work well and the control strategy effects with proper linear generator.

Lifshitz Transitions Induced by Temperature and Surface Doping in Type-II Weyl Semimetal Candidate T_<i>d</i> -WTe₂

Zhang, Qihang,Liu, Zhongkai,Sun, Yan,Yang, Haifeng,Jiang, Juan,Mo, Sung-Kwan,Hussain, Zahid,Qian, Xiaofeng,Fu, Liang,Yao, Shuhua,Lu, Minghui,Felser, Claudia,Yan, Binghai,Chen, Yulin,Yang, Lexian Wiley (John WileySons) 2017 Physica Status Solidi. Rapid Research Letters Vol.11 No.12

Enhanced corrosion resistance by polypyrrole and Ti3C2Tx-acrylic epoxy double-layer coating for 304SS bipolar plates of PEMFC

Haifeng Bian,Guoli Zhang,Qingxi Zhai,Yanyan Du,Yujie Ma,Beibei Yang,Shaochun Tang,Duan Bin,Xiangkang Meng,Hongbin Lu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-

Stainless steel (SS) is a promising material for designing bipolar plates (BPs), but their further applicationis limited by serious corrosion problems in the acidic environment. Ti3C2Tx is expected to be used for SSBPs coatings, while galvanic corrosion will occur after the damage of Ti3C2Tx coating. Herein, a PPY/Ti3C2Tx-AE double-layer coating (DC) is well-designed and prepared on 304SS BP, which is composedof an inner electropolymerized PPY layer and an outer Ti3C2Tx-acrylic epoxy layer. When tested in0.2 M HCl solution, the corrosion potential and corrosion current density of the DC are 38 mV and0.00927 lA cm2 respectively, which are superior to those of the PPY coating and the Ti3C2Tx coating. Moreover, the DC presents the best long-term stability among the three coatings. The excellent corrosionresistance is attributed to the barrier and anodic protection effects as well as the solution of galvanic corrosion. The new coating system provides a new insight into the design of DC coatings of SS BPs.

Point In Triangle Testing Based Trilateration Localization Algorithm In Wireless Sensor Networks

( Aiqing Zhang ),( Xinrong Ye ),( Haifeng Hu ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.10

Localization of sensor nodes is a key technology in Wireless Sensor Networks(WSNs). Trilateration is an important position determination strategy. To further improve the localization accuracy, a novel Trilateration based on Point In Triangle testing Localization (TPITL)algorithm is proposed in the paper. Unlike the traditional trilateration localization algorithm which randomly selects three neighbor anchors, the proposed TPITL algorithm selects three special neighbor anchors of the unknown node for trilateration. The three anchors construct the smallest anchor triangle which encloses the unknown node. To choose the optimized anchors, we propose Point In Triangle testing based on Distance(PITD) method, which applies the estimated distances for trilateration to reduce the PIT testing errors. Simulation results show that the PIT testing errors of PITD are much lower than Approximation PIT(APIT) method and the proposed TPITL algorithm significantly improves the localization accuracy.

Algorithm for Detection of Fire Smoke in a Video Based on Wavelet Energy Slope Fitting

Yi Zhang,Haifeng Wang,Xin Fan 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.3

The existing methods for detection of fire smoke in a video easily lead to misjudgment of cloud, fog and movingdistractors, such as a moving person, a moving vehicle and other non-smoke moving objects. Therefore, analgorithm for detection of fire smoke in a video based on wavelet energy slope fitting is proposed in this paper. The change in wavelet energy of the moving target foreground is used as the basis, and a time window of 40continuous frames is set to fit the wavelet energy slope of the suspected area in every 20 frames, thusestablishing a wavelet-energy-based smoke judgment criterion. The experimental data show that the algorithmdescribed in this paper not only can detect smoke more quickly and more accurately, but also can effectivelyavoid the distraction of cloud, fog and moving object and prevent false alarm.