• 제목/요약/키워드: Qingdao

검색결과 335건 처리시간 0.022초

Traffic Flow Prediction Model Based on Spatio-Temporal Dilated Graph Convolution

  • Sun, Xiufang;Li, Jianbo;Lv, Zhiqiang;Dong, Chuanhao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권9호
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    • pp.3598-3614
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    • 2020
  • With the increase of motor vehicles and tourism demand, some traffic problems gradually appear, such as traffic congestion, safety accidents and insufficient allocation of traffic resources. Facing these challenges, a model of Spatio-Temporal Dilated Convolutional Network (STDGCN) is proposed for assistance of extracting highly nonlinear and complex characteristics to accurately predict the future traffic flow. In particular, we model the traffic as undirected graphs, on which graph convolutions are built to extract spatial feature informations. Furthermore, a dilated convolution is deployed into graph convolution for capturing multi-scale contextual messages. The proposed STDGCN integrates the dilated convolution into the graph convolution, which realizes the extraction of the spatial and temporal characteristics of traffic flow data, as well as features of road occupancy. To observe the performance of the proposed model, we compare with it with four rivals. We also employ four indicators for evaluation. The experimental results show STDGCN's effectiveness. The prediction accuracy is improved by 17% in comparison with the traditional prediction methods on various real-world traffic datasets.

Ab Initio and Experimental Studies on Dibenzothiazyl-Disulfide

  • Jian, Fang-Fang;Zhang, Ke-Jie;Zhao, Pu-Su;Zheng, Jian
    • Bulletin of the Korean Chemical Society
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    • 제27권7호
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    • pp.1048-1052
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    • 2006
  • Ab initio calculations of the structure, atomic charges and natural bond orbital (NBO) have been performed at HF/6-311G** and B3LYP/6-311G** levels for the title compound of dibenzothiazyl-disulfide. The calculated results show that the two nitrogen atoms have the biggest negative charges and they are the potential sites to react with the metallic ions, which make the title compound become a di-dentate ligand. Vibrational frequencies of the title compound have been obtained and compared with the experimental value and the comparison indicates that B3LYP/6-311G** level is better than HF/6-311G** level to predict the vibrational frequencies for the system studied here. For the title compound, electronic absorption spectra calculated by time?ependent density functional theory (TD-DFT) are more accurate than Hartree-Focksingle-excitation CI (CI-Singles) method. NBO analyses show that the electronic transitions are mainly derived from the contribution of bands $\pi\rightarrow\pi^{*}$. Thermodynamic calculated results show that the formation of the title compound from 2-mercaptobenzothiazole is a spontaneous process at room temperature with the change of free Gibbs being negative value.

Strain rate effect of steel-concrete composite panel indented by a hemispherical rigid body

  • Zhao, Weiyi;Wang, Lin;Yang, Guotao;Wang, Ziguo;Gao, Zepeng;Guo, Quanquan
    • Steel and Composite Structures
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    • 재36권6호
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    • pp.703-710
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    • 2020
  • This paper presents numerical and theoretical investigations on the strain rate in steel-concrete composite (SC) panels under low-velocity impact of a hemispherical rigid body. Finite element analyses were performed on five specimens with different loading rates. The impact energy was kept constant to eliminate its influence by simultaneously altering the velocity and mass of the projectile. Results show that the strain rate in most parts of the specimens was low and its influence on bearing capacity and energy dissipation was limited in an average sense of space and time. Therefore, the strain rate effect can be ignored for the analyses of global deformation. However, the strain rate effect should be considered in local contact problems. Equations of the local strain and strain rate were theoretically derived.

Lipid Production by a $CO_2$-Tolerant Green Microalga, Chlorella sp. MRA-1

  • Zheng, Yanlin;Yuan, Cheng;Liu, Junhan;Hu, Guangrong;Li, Fuli
    • Journal of Microbiology and Biotechnology
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    • 제24권5호
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    • pp.683-689
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    • 2014
  • Since $CO_2$ concentrations in industrial flue gases are usually 10%-20%, one of the prerequisites for efficient $CO_2$ removal by algae is the level of tolerance of microalgal species to exposure to high concentrations of $CO_2$. A newly isolated microalgal strain, Chlorella sp. MRA-1, could retain growth with high concentrations of $CO_2$ up to 15%. The highest lipid productivity for Chlorella sp. MRA-1 was 0.118 g/l/day with a 5% $CO_2$ concentration. Octadecenoic acid and hexadecanoic acid, the main components of biodiesel, accounted for 70% of the total fatty acids. A lipid content of 52% of dry cell weight was achieved with limited amounts of nitrogen. Chlorella sp. MRA-1 seems to be an ideal candidate for biodiesel production when cultured with high concentrations of $CO_2$.

Road-friendliness of Fuzzy Hybrid Control Strategy Based on Hardware-in-the-Loop Simulations

  • Yan, Tian Yi;Li, Qiang;Ren, Kun Ru;Wang, Yu Lin;Zhang, Lu Zou
    • Journal of Biosystems Engineering
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    • 제37권3호
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    • pp.148-154
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    • 2012
  • Purpose: In order to improve road-friendliness of heavy vehicles, a fuzzy hybrid control strategy consisting of a hybrid control strategy and a fuzzy logic control module is proposed. The performance of the proposed strategy should be effectively evaluated using a hardware-in-the-loop (HIL) simulation model of a semi-active suspension system based on the fuzzy hybrid control strategy prior to real vehicle implementations. Methods: A hardware-in-the-loop (HIL) simulation system was synthesized by utilizing a self-developed electronic control unit (ECU), a PCI-1711 multi-functional data acquisition board as well as the previously developed quarter-car simulation model. Road-friendliness of a semi-active suspension system controlled by the proposed control strategy was simulated via the HIL system using Dynamic Load Coefficient (DLC) and Dynamic Load Stress Factor (DLSF) criteria. Results: Compared to a passive suspension, a semi-active suspension system based on the fuzzy hybrid control strategy reduced the DLC and DLSF values. Conclusions: The proposed control strategy of semi-active suspension systems can be employed to improve road-friendliness of road vehicles.

Croton Tiglium Extract Induces Apoptosis via Bax/Bcl-2 Pathways in Human Lung Cancer A549 Cells

  • Li, Changyou;Wu, Xiao;Sun, Rongli;Zhao, Peng;Liu, Fengjuan;Zhang, Chunling
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권11호
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    • pp.4893-4898
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    • 2016
  • Objective: To investigate the impact of a Croton tiglium extract on cellular proliferation and apoptosis in a non-small cell lung cancer cell line (A549) in vitro. Methods: A Croton tiglium seed methanol extract was prepare and assessed for effects on A549 cells regarding cellular proliferation, apoptotic rates, and expression of apoptosis related genes and proteins using real-time PCR and immunofluorescence. Results: The tested Croton tiglium extract inhibited A549 cell proliferation in a dose- and time-dependent manner, with significant elevation of apoptotic indexes at various concentrations after 24 h. In addition, rates in both early and late stages were higher in treated than untreated groups, the $100{\mu}g/ml$ dose causing the highest levels of apoptosis. RT-PCR showed that A549 cells treated with $100{\mu}g/ml$ Croton tiglium extract for 24 h has markedly higher Bax mRNA expression levels and obviously lower Bcl-2 expression levels than controls, equivalent results being observed for proteins by immunofluorescence. However, the mRNA expression levels of Fas and caspase-8 were not significantly altered. Conclusion: A Croton tiglium extract can inhibit proliferation of A549 cells and promote apoptosis though Bax/Bcl-2 pathways.

Effect of Grape Procyanidins on Tumor Angiogenesis in Liver Cancer Xenograft Models

  • Feng, Li-Li;Liu, Bing-Xia;Zhong, Jin-Yi;Sun, Li-Bin;Yu, Hong-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권2호
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    • pp.737-741
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    • 2014
  • Background: In recent years a wide variety of flavonoids or polyphenolic substances have been reported to possess substantial anti-carcinogenic and antimutagenic activities. Grape proanthocyanidins (GPC) are considered as good examples for which there is evidence of potential roles as anti-carcinogenic agents. Methods: A xenograft model was established using H22 cells subcutaneously injected into mice and used to assess different concentrations of grape proanthocyanidins (GPC) and Endostar. Treatments were maintained for 10 days, then levels of vascular endothelial growth factor (VEGF) and microvessel density (MVD) were examined by immunohistochemistry, while VEGF mRNA was determined by real-time PCR in tumor tissue. Results: The expression of MVD and VEGF decreased gradually as the concentration of GPC increased.There was a significant positive correlation between MVD and VEGF. Conclusions: These results suggest that GPC restrains the growth of tumor, possibly by inhibiting tumour angiogenesis.

Effect of Laparoscopic Nerve-sparing Radical Hysterectomy on Bladder Function, Intestinal Function Recovery and Quality of Sexual Life in Patients with Cervical Carcinoma

  • Chen, Long;Zhang, Wei-Na;Zhang, Sheng-Miao;Yang, Zhi-Hao;Zhang, Ping
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권24호
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    • pp.10971-10975
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    • 2015
  • Objective: To investigate bladder and intestinal function recovery and quality of sexual life after laparoscopic nerve-sparing radical hysterectomy (LNRH) for treatment of early invasive cervical carcinoma. Methods: Subjects included patients who underwent radical hysterectomy by laparotomy who were randomly assigned to 2 groups: 30 patients who underwent LNRH and 35 classical laparoscopic radical hysterectomy (LRH). We assessed the patients general clinical information, surgical characteristics, pathological findings, and adjuvant therapies. A urodynamic study was used to assess bladder function. Intestinal function recovery and quality of sexual life were evaluated by questionnaire. Results: No significant differences were found in age, surgery characteristics, pathological findings, adjuvant therapies, and main adverse effects between the 2 groups. The mean duration of the postoperative catheterization (DPC) in group LNRH was shorter than that in group LRH (P < 0.001). The maximum flow rate, maximum cystometric capacity, maximum detrusor pressure and urinary complications in group LNRH were better than those in group LRH. The quality of sexual life evaluated according to the female sexual function index (FSFI) was better in group LNRH than in those who underwent LRH. The intestinal function of patients in group LNRH also recovered better compared with patients in group LRH.

Modeling and Analysis of SEIG-STATCOM Systems Based on the Magnitude-Phase Dynamic Method

  • Wang, Haifeng;Wu, Xinzhen;You, Rui;Li, Jia
    • Journal of Power Electronics
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    • 제18권3호
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    • pp.944-953
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    • 2018
  • This paper proposes an analysis method based on the magnitude-phase dynamic theory for isolated power systems with static synchronous compensators (STATCOMs). The stability margin of an isolated power system is greatly reduced when a load is connected, due to the disadvantageous features of the self-excited induction generators (SEIGs). To analyze the control process for system stability and to grasp the dynamic characteristics in different timescales, the relationships between the active/reactive components and the phase/magnitude of the STATCOM output voltage are derived in the natural reference frame based on the magnitude/phase dynamic theory. Then STATCOM equivalent mechanical models in both the voltage time scale and the current time scale are built. The proportional coefficients and the integral coefficients of the control process are converted into damping coefficients, inertia coefficients and stiffness coefficients so that analyzing its controls, dynamic response characteristics as well as impacts on the system operations are easier. The effectiveness of the proposed analysis method is verified by simulation and experimental results.

Seroprevalence of Toxoplasma gondii Among Primary School Children in Shandong Province, China

  • Xin, Ke-Sheng;Liu, Hui;Wang, Hong-Bing;Yao, Zong-Liang
    • Parasites, Hosts and Diseases
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    • 제53권4호
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    • pp.489-492
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    • 2015
  • Although Toxoplasma gondii infection in primary school children has been investigated in many countries, limited surveys have been available in primary school children in China. In the present study, we report the seroprevalence of T. gondii infection in primary school children in Shandong province, China. Sera from 6,000 primary school children were evaluated for T. gondii antibodies with ELISA. The overall seroprevalence of T. gondii infection was 16.0% (961/6,000), of which 14.5% (870/6,000) were positive for anti-T. gondii IgG antibodies, 3.4% (206/6,000) positive for IgM, and 1.9% (115/6,000) were positive for both IgG and IgM. The results of the present investigation indicated a high seroprevalence of T. gondii infection in primary school children in Shandong province, China. Therefore, effective measures should be taken to prevent and control T. gondii infection in primary school children in this province. To the best of our knowledge, this is the first report of T. gondii seroprevalence in primary school children in Shandong province, China.