Shared Spatio-temporal Attention Convolution Optimization Network for Traffic Prediction

Pengcheng Li,Changjiu Ke,Hongyu Tu,Houbing Zhang,Xu Zhang 한국정보처리학회 2023 Journal of information processing systems Vol.19 No.1

The traffic flow in an urban area is affected by the date, weather, and regional traffic flow. The existing methodsare weak to model the dynamic road network features, which results in inadequate long-term prediction performance. To solve the problems regarding insufficient capacity for dynamic modeling of road network structuresand insufficient mining of dynamic spatio-temporal features. In this study, we propose a novel traffic flowprediction framework called shared spatio-temporal attention convolution optimization network (SSTACON). The shared spatio-temporal attention convolution layer shares a spatio-temporal attention structure, that isdesigned to extract dynamic spatio-temporal features from historical traffic conditions. Subsequently, the graphoptimization module is used to model the dynamic road network structure. The experimental evaluationconducted on two datasets shows that the proposed method outperforms state-of-the-art methods at all timeintervals.

How Does an Extra-Long Freeway Tunnel Influence Driving Performance? A Comparative Study of Driving Simulation

Pengcheng Qin,Jie He,Changjian Zhang,Yuntao Ye,Hao Zhang,Mingnian Wang,Tao Yan 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.9

Extra-long tunnels have adverse effects on driving performance since drivers will be affected by the enclosed, dimly lit, and monotonous environment for a longer time. In the context of the increasing number of extra-long tunnels, this study aims to investigate the effects of extra-long freeway tunnels with a length of 20 km on driving performance using driving simulation tests. Factors including the tunnel environment, driving time, traffic flow, and gender were considered as influencing factors. Performance indicators including the brake reaction time, standard deviation of driving speed, and standard deviation of lateral position were collected. A total of 60 drivers were recruited for the driving simulation study, and the relationships between the driving performance indicators and influencing factors were analyzed by establishing linear mixed models with random intercept. The results demonstrate that driving performance significantly degraded after 5 − 6 min of driving in the extra-long tunnel although drivers were more cautious and presented a better performance when just entering the tunnel. Moderately higher traffic flow could improve driving performance in the extra-long tunnel but not on the open road. Meanwhile, female drivers had better lateral and longitudinal stability in the extra-long tunnel, while no significant difference was witnessed in reaction ability and driving performance on the open road.

Effect of Different Levels of Nitrogen, Phosphorus, and Potassium on Root Activity and Chlorophyll Content in Leaves of Brassica oleracea Seedlings Grown in Vegetable Nursery Substrate

Jian Zhang,Yan Wang,Pengcheng Wang,Qi an Zhang,Congsheng Yan,Feifei Yu,Jianqun Yi,Ling Fang 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.1

Nutrients in the substrate are important for plant growth, particularly during the development of vegetableseedlings. The continued development of intensive methods to produce seedlings has made growing healthy and high-gradeseedlings a requirement for nurseries. This study evaluated the effect of nitrogen (N), phosphorus (P), and potassium(K) on the root activity, dry weight, and chlorophyll content in leaves of Brassica oleracea seedlings. D-optimal designwas used in this study because of its accuracy. A total of 10 treatments (T1–T10) were designed, and differentconcentrations were chosen in the following ranges: N (0.6-5.0 g·kg-1), P (0.2-6.0 g·kg-1), and K (0.7-7.0 g·kg-1). Our studyshows that the application of N, P, and K to the substrate significantly influenced the growth of B. oleracea seedlings. T6significantly increased root activity, root dry weight, chlorophyll content in leaves when compared with the control T1,which had added nutrient concentrations at normal levels. However, the addition of high levels of N (5.0 g·kg-1) withhigh (7.0 g·kg-1) or low (0.7 g·kg-1) levels of K (T2 and T9) not only significantly decreased the root dry weight but alsodecreased leaf area. Our results suggest that N, P, and K can be added to the substrate at an appropriate ratio togrow vigorous B. oleracea seedlings under intensive seedling production conditions. The present results give insightinto the nutrient requirements during early growth of B. oleracea seedlings in growth substrate.

Dual-Amplifier Driving in Sequence Method with Switches for Piezoelectric Stack Actuators to Reduce Hysteresis

Liansheng Zhang,Shuang Hao,Pengcheng Zhang,Qiangxian Huang,Rongjun Cheng,Ruijun Li,Ping Wang 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.12

Piezoelectric actuators have been widely applied to precision positioning platforms. However, the positioning accuracy of piezoelectric ceramic has been significantly affected by its characteristics of hysteresis. Owing to the voltage-keeping feature of capacitive load for piezoelectric ceramic, this paper has proposed a switch-based driving in sequence method, which alternately drives each layer of PZT by using switches. Based on the driving in sequence method, the proposed method is capable of reducing the hysteresis to 1/N of the hysteresis under traditional voltage driving method, while significantly lowering the scale and cost of hardware, compared with the previous driving in sequence method. Thus, it allows for application to hundreds of layers of piezoelectric ceramic. According to experiment results, the hysteresis under different frequencies from 0.1 to 500 Hz for homemade seven-layer piezoelectric ceramic can be reduced from 12.5 to 2.1%. Furtherly, the residual hysteresis can be corrected by applying a simple quadratic-polynomial feedforward control, and the hysteresis is constrained within 0.8%, even with feedforward parameters that are not strictly calibrated. The dual-amplifier driving in sequence method proposed in this paper can significantly reduce the hysteresis in open-loop control of piezoelectric stack actuators, effectively improving the positioning and driving performance and saving cost.

Effect of Co Content on the Microstructure and Corrosion Behavior of Al0.3CoxCrFeNi High Entropy Alloys

Zequn Zhang,Qijuan Dong,Zhibin Chen,Junsheng Wu,Jiuyang Xia,Kang Huang,Pengcheng Zuo,Wei Xue,Bowei Zhang 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.2

The influence of Co content on the microstructure and corrosion behavior of Al0.3CoxCrFeNi (x = 0.25, 0.5 and 1.0) highentropy alloys were investigated. The results indicated that the increased content of Co improve the corrosion resistanceof alloy, which can be attributed to the distinction of phase composition in alloys caused by different Co content. TheAl0.3CoxCrFeNi alloy shows a double-phase (FCC + BCC) structure for x = 0.25 and 0.5, and BCC phase consists of (Al,Ni)-rich B2 phase and (Cr, Fe, Co)-rich A2 phase. The increase of Co content induces the transformations of crystalstructuresfrom BCC to FCC, resulting in the decrease of BCC phase proportion. The Al0.3CoCrFeNi alloy exhibits thesingle FCC structure, and all elements tend to be homogeneously distributed. The difference in the potential of FCC andBCC phases indicates the BCC phase acts as anode resulting to localized corrosion, while B2 phase preferentially dissolvescompared to the A2 phase due to the lower potential. Therefore, the existence of selective corrosion is found in thealloys with double-phase, by contrast, the alloy with single FCC phase shows random pitting corrosion.

Effect of different short-term high ambient temperature on chicken meat quality and ultra–structure

Minghao Zhang,Lixian Zhu,Yimin Zhang,Yanwei Mao,Mingyue Zhang,Pengcheng Dong,Lebao Niu,Xin Luo,Rongrong Liang 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.5

Objective: This study investigated the effect of different acute heat stress (HS) levels on chicken meat quality and ultra-structure. Methods: Chickens were randomly divided into 7 groups to receive different HS treatments: i) 36°C for 1 h, ii) 36°C for 2 h, iii) 38°C for 1 h, iv) 38°C for 2 h, v) 40°C for 1 h, vi) 40°C for 2 h, and vii) un-stressed control group (25°C). Blood cortisol level, breasts initial temperature, color, pH, water holding capacity (WHC), protein solubility and ultra-structure were analyzed. Results: HS temperatures had significant effects on breast meat temperature, lightness (L*), redness (a*), cooking loss and protein solubility (p<0.05). The HS at 36°C increased L*24 h value (p<0.01) and increased the cooking loss (p<0.05), but decreased a*24 h value (p<0.05). However, as the temperature increased to 38°C and 40°C, all the values of L*24 h, cooking loss and protein denaturation level decreased, and the differences disappeared compared to control group (p> 0.05). Only the ultimate pH24 h at 40°C decreased compared to the control group (p<0.01). The pH in 36°C group declined greater than other heat-stressed group in the first hour postmortem, which contributed breast muscle protein degeneration combining with high body temperature, and these variations reflected on poor meat quality parameters. The muscle fiber integrity level in group 40°C was much better than those in 36°C with the denatured position mainly focused on the interval of muscle fibers which probably contributes WHC and light reflection. Conclusion: HS at higher temperature (above 38°C) before slaughter did not always lead to more pale and lower WHC breast meat. Breast meat quality parameters had a regression trend as HS temperature raised from 36°C. The interval of muscle fibers at 24 h postmortem and greater pH decline rate with high body temperature in early postmortem period could be a reasonable explanation for the variation of meat quality parameters.

Histone demethylase KDM4A plays an oncogenic role in nasopharyngeal carcinoma by promoting cell migration and invasion

Zhao Jingyi,Li Bingyan,Ren Yongxia,Liang Tiansong,Wang Juan,Zhai Suna,Zhang Xiqian,Zhou Pengcheng,Zhang Xiangxian,Pan Yuanyuan,Gao Fangfang,Zhang Sulan,Li Liming,Yang Yongqiang,Deng Xiaoyu,Li Xiaole,C 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Compelling evidence has indicated the vital role of lysine-specific demethylase 4 A (KDM4A), hypoxia-inducible factor-1α (HIF1α) and the mechanistic target of rapamycin (mTOR) signaling pathway in nasopharyngeal carcinoma (NPC). Therefore, we aimed to investigate whether KDM4A affects NPC progression by regulating the HIF1α/DDIT4/mTOR signaling pathway. First, NPC and adjacent tissue samples were collected, and KDM4A protein expression was examined by immunohistochemistry. Then, the interactions among KDM4A, HIF1α and DDIT4 were assessed. Gain- and loss-of-function approaches were used to alter KDM4A, HIF1α and DDIT4 expression in NPC cells. The mechanism of KDM4A in NPC was evaluated both in vivo and in vitro via RT-qPCR, Western blot analysis, MTT assay, Transwell assay, flow cytometry and tumor formation experiments. KDM4A, HIF1α, and DDIT4 were highly expressed in NPC tissues and cells. Mechanistically, KDM4A inhibited the enrichment of histone H3 lysine 9 trimethylation (H3K9me3) in the HIF1α promoter region and thus inhibited the methylation of HIF1α to promote HIF1α expression, thus upregulating DDIT4 and activating the mTOR signaling pathway. Overexpression of KDM4A, HIF1α, or DDIT4 or activation of the mTOR signaling pathway promoted SUNE1 cell proliferation, migration, and invasion but inhibited apoptosis. KDM4A silencing blocked the mTOR signaling pathway by inhibiting the HIF1α/DDIT4 axis to inhibit the growth of SUNE1 cells in vivo. Collectively, KDM4A silencing could inhibit NPC progression by blocking the activation of the HIF1α/DDIT4/mTOR signaling pathway by increasing H3K9me3, highlighting a promising therapeutic target for NPC.

Five-axis finishing tool path generation for a mesh blade based on linear morphing cone

Zhang, Rong,Hu, Pengcheng,Tang, Kai Society for Computational Design and Engineering 2015 Journal of computational design and engineering Vol.2 No.4

Blisk is an essential component in aero engines. To maintain good aero-dynamic performance, one critical machining requirement for blades on blisk is that the generated five-axis tool path should be boundary-conformed. For a blade discretely modeled as a point cloud or mesh, most existing popular tool path generation methods are unable to meet this requirement. To address this issue, a novel five-axis tool path generation method for a discretized blade on blisk is presented in this paper. An idea called Linear Morphing Cone (LMC) is first proposed, which sets the boundary of the blade as the constraint. Based on this LMC, a CC curve generation and expansion method is then proposed with the specified machining accuracy upheld. Using the proposed tool path generation method, experiments on discretized blades are carried out, whose results show that the generated tool paths are both uniform and boundary-conformed.

Performance evaluation of Accident Tolerant Fuel under station blackout accident in PWR nuclear power plant by improved ISAA code

Zhang Bin,Gao Pengcheng,Xu Tao,Gui Miao,Shan Jianqiang 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.7

The Accident Tolerant Fuel (ATF) is a new concept of fuel, which can not only withstand the consequences of the accident for a longer time, but also maintain or improve the performance under operating conditions. ISAA is a self-developed severe accident analysis code, which uses modular structures to simulate the development processes of severe accidents in nuclear plants. The basic version of ISAA is developed based on UO2eZr fuel. To study the potential safety gain of ATF cladding, an improved version of ISAA, referred to as ISAA-ATF, is introduced to analyze the station blackout accident of PWR using ATF cladding. The results show that ATF cladding enable the core to maintain a longer time compared to zirconium alloy cladding, thereby enhancing the accident mitigation capability. Meanwhile, the generation of hydrogen is significantly reduced and delayed, which proves that ATF can improve the safety characteristics of the nuclear reactor.

Development of mechanistic cladding rupture model for severe accident analysis and application in PHEBUS FPT3 experiment

Pengcheng Gao,Bin Zhang,Jishen Li,Jianqiang Shan 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.1

Cladding ballooning and rupture are the important phenomena at the early stage of a severe accident. Most severe accident analysis codes determine the cladding rupture based on simple parameter models. In this paper, a FRTMB module was developed using the thermal-mechanical model to analyze the fuel mechanical behavior. The purpose is to judge the cladding rupture with the severe accident analysis code. The FRTMB module was integrated into the self-developed severe accident analysis code ISAA to simulate the PHEBUS FPT3 experiment. The predicted rupture time and temperature of the cladding were basically consistent with the measured values, which verified the correctness and effectiveness of the FRTMB module. The results showed that the rising of gas pressure in the fuel rod and high temperature led to cladding ballooning. Consequently, the cladding hoop strain exceeded the strain limit, and the cladding burst. The developed FRTMB module can be applied not only to rod-type fuel, but also to plate-type fuel and other types of reactor fuel rods. Moreover, the FRTMB module can improve the channel blockage model of ISAA code and make contributions to analyzing the effect of clad ballooning on transient and subsequent parts of core degradation.