Modeling COVID-19 with Mean Field Evolutionary Dynamics: Social Distancing and Seasonality

Hao Gao,Wuchen Li,Miao Pan,Zhu Han,H. Vincent Poor 한국통신학회 2021 Journal of communications and networks Vol.23 No.5

The coronavirus pandemic has been declared a world health emergency by the World Health Organization, which has raised the importance of an accurate epidemiological model to predict the evolution of COVID-19. In this paper, we propose mean field evolutionary dynamics (MFEDs), inspired by optimal transport theory and mean field games on graphs, to model the evolution of COVID-19. In the MFEDs, we derive the payoff functions for different individual states from the commonly used replicator dynamics (RDs) and employ them to govern the evolution of epidemics. We also compare epidemic modeling based on MFEDs with that based on RDs through numerical experiments. Moreover, we show the efficiency of the proposed MFED-based model by fitting it to the COVID-19 statistics of Wuhan, China. Finally, we analyze the effects of one-time social distancing as well as the seasonality of COVID- 19 through the post-pandemic period.

Name and Maintain Topological Faces in Rotating and Scanning Features

Gao Xue-Yao,Li Jia-Qi,Guo Hao,Gao Yun-Feng,Liu Yu-Hong 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.3

Features created in rotating and scanning operations are very complex. Naming and identifying their topological faces is an important problem in CAD fields. In this paper, a new method of coding topological faces in rotating and scanning features is proposed. Firstly, contour segments are numbered. Secondly, an angle between contour segment and rotating axis is computed. Thirdly, all topological faces are named based on contour segments’ numbers, rotating axis and other information. When a face splits and several subfaces merge, a method of processing their codes is given. The proposed method is applied to HUST-CAID feature modeling system. Experimental results show that it can name and identify topological faces effectively in operations.

中国行政区域划分研究—基于聚类分析与支持向量机方法的讨论

Gao Hao,Cui Jun-fu 중국지역학회 2016 중국지역연구 Vol.3 No.2

Any economic and social activities are inseparable from a specific area, and in different regions often mean different development policies. China attaches great importance to the division of the region to a certain area in order to develop targeted policies. Currently, all provinces in China are divided into eastern, central, and western regions, 11 provinces in eastern region, 12 provinces in western region, and 8 provinces in central region. Since the founding, especially since the reform and opening up, China’s regional policy has undergone so many alternates between comprehensive development and focusing development, each policy adjustments have had a significant impact on the development of the relation region. Compared to the current administrative division, this article uses clustering methods to classify China provinces, and support vector machine for testing. The study found that three regions administrative division of China currently used cannot adapt to the actual development of the current situation, we must make the appropriate adjustments in order to provide a basis for the development of more targeted regional policy. 任何经济社会活动都离不开特定的区域, 处于不同的区域往往意味着不同的发展政策。为增强宏观调控的有效性, 在中国的经济社会发展中非常重视将某一个地区划分到一类区域当中, 从而对该区域制定有针对性的政策。目前, 中国将所有省份分为东部、中部、西部三个区域, 东部11个省份, 西部12个省份, 中部8个省份。建国以来, 特别是改革开放以来, 中国的区域政策经历了重点发展、全面发展、重点发展与全面发展相结合等多次政策交替变换, 每次政策调整均对相应区域的发展产生了重大影响。本文使用聚类方法对中国省份进行了分类, 与目前东中西行政区域划分进行对比分析, 并使用支持向量机进行检验。研究发现, 中国目前采用的东中西行政区域划分已经不能适应目前的实际发展状况, 必须进行相应的调整, 以便为制定更有针对性的区域政策提供参考。

An Empirical Analysis on the Transfer of Agricultural Labor Surplus and the Farmers' Income Growth in China

Hao Jin,Su-Ying Gao,Ki-Woong Lee,Kyung-Hwan Song 한국국제농업개발학회 2003 韓國國際農業開發學會誌 Vol.15 No.4

Damping enhancement of the inerter on the viscous damper in mitigating cable vibrations

Hui Gao,Hao Wang,Jian Li,Zhi Hao Wang,Youhao Ni,Ruijun Liang 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.28 No.1

This paper systematically investigates the effect of the inerter on the damping enhancement of a cable with a viscous damper (VD) installed close to the cable end. Three cases are considered, including the inerter installed parallel with the VD (PVID), the inerter placed in series with the VD (SVID), and the inerter installed at a higher location of the VD (HVID). The asymptotic solutions of the three cases are derived, which can predict the cable modal damping ratio when the inerter and the VD cause minimal perturbation in the undamped frequency of the cable. The effect of the inerter on the modal behavior of the cable with the VD is investigated. Based on the constrained static output LQR method, the effects of the inerter on the damping enhancement of the VD in mitigating cable multi-mode vibrations are further evaluated. The results show that the inerter can improve the control performance of the VD when the inertance is less than the optimum value. Further increasing the inertance beyond the optimum value, the optimum modal damping ratio of the cable decreases, and mode crossover is observed for the cable with PVID and HVID. Compared with the case where the VD and the inerter are located at the same location, the case of the HVID is more effective in mitigating cable multi-mode vibrations.

Impact of cable sag on the efficiency of an inertial mass damper in controlling stay cable vibrations

Zhi-hao Wang,Hui Gao,Yan-wei Xu,Zheng-qing Chen,Hao Wang 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.1

Passive negative stiffness dampers (NSDs) that possess superior energy dissipation abilities, have been proved to be more efficient than commonly adopted passive viscous dampers in controlling stay cable vibrations. Recently, inertial mass dampers (IMDs) have attracted extensive attentions since their properties are similar to NSDs. It has been theoretically predicted that superior supplemental damping can be generated for a taut cable with an IMD. This paper aims to theoretically investigate the impact of the cable sag on the efficiency of an IMD in controlling stay cable vibrations, and experimentally validate superior vibration mitigation performance of the IMD. Both the numerical and asymptotic solutions were obtained for an inclined sag cable with an IMD installed close to the cable end. Based on the asymptotic solution, the cable attainable maximum modal damping ratio and the corresponding optimal damping coefficient of the IMD were derived for a given inertial mass. An electromagnetic IMD (EIMD) with adjustable inertial mass was developed to investigate the effects of inertial mass and cable sag on the vibration mitigation performance of two model cables with different sags through series of first modal free vibration tests. The results show that the sag generally reduces the attainable first modal damping ratio of the cable with a passive viscous damper, while tends to increase the cable maximum attainable modal damping ratio provided by the IMD. The cable sag also decreases the optimum damping coefficient of the IMD when the inertial mass is less than its optimal value. The theoretically predicted first modal damping ratio of the cable with an IMD, taking into account the sag generally, agrees well with that identified from experimental results, while it will be significantly overestimated with a taut-cable model, especially for the cable with large sag.

Effects of Sn and Mn Addition on the Microstructure and Mechanical Properties of As-Extruded Mg–2Al–1Zn Alloys

Fu‑Hao Gao,Bin‑Jiang Lv,Tie‑Wei Xu,Ning Cui,Feng Guo 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.11

The effects of low Sn (1.0 wt%) and Mn (0.5 wt%) content on the microstructures and mechanical properties of as-extrudedMg–2Al–1Zn (AZ21) alloys were systematically investigated. The combined addition of Sn and Mn significantly refinedthe grains of the AZ21 alloy, reducing the average grain size from 25.77 to 2.17 μm. The volume fraction of the dynamicallyrecrystallized (DRXed) grains decreased from 78.49 to 43.81% with Sn (1.0 wt%) and Mn (0.5 wt%) addition. The Al8Mn5,Al11Mn4,and Al9Mn4phases were formed in Mg–2Al–1Zn–1Sn–0.5Mn (AZTM2110) alloy, and the Mg17Al12phase disappeared. The orientation relationship between Al9Mn4and Al11Mn4was (002)Al11Mn4//(̄ 302)Al9Mn4, [ ̄ 100]Al11Mn4//[223]Al9Mn4,and the orientation relationship between Al8Mn5and α-Mg was ( ̄ 252)Al8Mn5//(̄ 12̄ 13)α−Mg. The Al9Mn4and Al11Mn4phasesgrew in the same direction. The intensity of basal fiber texture of AZTM2110 alloy decreased by 21.7%. The ultimatetensile strength, yield strength, and elongation of the AZ21 alloy increased by 29.03%, 65.05%, and 61.02%, respectively. Grain-refinement strengthening was the main mechanism underlying the improvement in AZTM2110 alloy strength. Grainrefinement and the weakened basal fiber texture improved the plasticity of the AZTM2110 alloy.

Exercise Reduces Airway Smooth Muscle Contraction in Asthmatic Rats via Inhibition of IL-4 Secretion and Store-Operated Ca2+ Entry Pathway

Huang Jun-Hao,Gao Hui-Wen,Gao Dong-Dong,Yang Wei-Yue,Zhao Meng-Ke,Shen Bing,Hu Min 대한천식알레르기학회 2023 Allergy, Asthma & Immunology Research Vol.15 No.3

Purpose: Increased evidence has shown that aerobic exercise reduces airway hyperresponsiveness in asthmatic individuals. However, the underlying mechanisms of action remain elusive. This study aimed to investigate the effect of exercise on airway smooth muscle (ASM) contractile function in asthmatic rats, and uncover the possible involvement of interleukin 4 (IL-4) and the store-operated Ca2+ entry (SOCE) pathway. Methods: In this study, chicken ovalbumin was used to induce asthma in male Sprague-Dawley rats. The exercise group received moderate-intensity aerobic exercise training for 4 weeks. IL-4 concentrations in bronchoalveolar lavage fluid (BALF) samples were evaluated by enzyme linked immunosorbent assay. The contractile function of the ASM was investigated using tracheal ring tension experiments and intracellular Ca2+ imaging techniques. Western blot analysis was used to evaluate expression levels of calcium-release activated calcium (CRAC) channel protein (Orai) and stromal interaction molecule 1 (STIM1) in ASM. Results: Our data showed that the carbachol-stimulated, SOCE-mediated contraction of rat ASM was significantly increased in asthmatic rats, which could be abolished by exercise. Pharmacological studies revealed that GSK5498A and BTP-2, selective blockers of CRAC channels significantly inhibited SOCE-induced ASM contraction. In addition, exercise inhibited the up-regulation of IL-4 in BALF as well as STIM1 and Orai expression in the ASM of asthmatic rats. In line with these observations, we demonstrated that pretreatment of the ASM with IL-4 up-regulated the expression level of STIM1, Orai1 and Orai2, thereby promoting SOCE-mediated ASM contraction. Conclusions: The data in this study reveal that aerobic exercise may improve the ASM contractile function in asthmatic rats by inhibiting IL-4 secretion and by down-regulating the expression of STIM1, Orai1 and Orai2, thus decreasing excessive SOCE-mediated ASM contraction in asthmatic rats.

A sigma class glutathione S-transferase gene regulated by the CncC pathway is required for phytochemical tolerance in the red flour beetle, Tribolium castaneum

Gao Shan-shan,Li Dong-yu,Huo Zhuang-kun,Zhang Yong-lei,Cao Yi-zhuo,Tan Yue-yao,Guo Xin-long,Zhang Jia-hao,Zhang Kun-peng,Li Rui-min 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.4

Insect glutathione S-transferases (GSTs) play a crucial role in the detoxification of exogenous compounds, especially insecticides and plant allelochemicals. A sigma class GST gene, TcGSTS7, mediates the response to eugenol in Tribolium castaneum. However, the mechanism underlying this effect remains largely unknown. In this study, TcGSTS7, which exhibits a structural motif and domain organization characteristic of GSTs, was cloned from the T. castaneum genome. Spatiotemporal expression analysis revealed that TcGSTS7 was most highly expressed at the late larva stage and was mainly expressed in the fat body and epidermis of larvae and adults, suggesting that TcGSTS7 may play a potential role in the protection against toxic xenobiotics in T. castaneum. Furthermore, the expression of TcGSTS7 was significantly induced after exposure to eugenol, while RNA inter ference (RNAi) targeting TcGSTS7 enhanced the sensitivity of the beetle to eugenol, indicating that TcGSTS7 is involved in the tolerance of T. castaneum to this insecticide. Interestingly, the depletion of TcCncC, which encodes a transcription factor of the CncC pathway that has been associated with the regulation of detoxification-related genes in insects, led to a reduction in the TcGSTS7 transcript level following exposure to eugenol, which suggests that TcGSTS7 acts downstream of the CncC pathway. Combined, these results indicated that TcGSTS7 partici pates in the tolerance of T. castaneum to phytochemicals in a CncC pathway-dependent manner. These findings have implications for the development of novel drugs for use in pest control.

Utility of Readout-Segmented Echo-Planar Imaging-Based Diffusion Kurtosis Imaging for Differentiating Malignant from Benign Masses in Head and Neck Region

Gao Ma,Xiao-Quan Xu,Hao Hu,Guo-Yi Su,Jie Shen,Hai-Bin Shi,Fei-Yun Wu 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.3

Objective: To compare the diagnostic performance of readout-segmented echo-planar imaging (RS-EPI)-based diffusion kurtosis imaging (DKI) and that of diffusion-weighted imaging (DWI) for differentiating malignant from benign masses in head and neck region. Materials and Methods: Between December 2014 and April 2016, we retrospectively enrolled 72 consecutive patients with head and neck masses who had undergone RS-EPI-based DKI scan (b value of 0, 500, 1000, and 1500 s/mm2) for pretreatment evaluation. Imaging data were post-processed by using monoexponential and diffusion kurtosis (DK) model for quantitation of apparent diffusion coefficient (ADC), apparent diffusion for Gaussian distribution (Dapp), and apparent kurtosis coefficient (Kapp). Unpaired t test and Mann-Whitney U test were used to compare differences of quantitative parameters between malignant and benign groups. Receiver operating characteristic curve analyses were performed to determine and compare the diagnostic ability of quantitative parameters in predicting malignancy. Results: Malignant group demonstrated significantly lower ADC (0.754 ± 0.167 vs. 1.222 ± 0.420, p < 0.001) and Dapp (1.029 ± 0.226 vs. 1.640 ± 0.445, p < 0.001) while higher Kapp (1.344 ± 0.309 vs. 0.715 ± 0.249, p < 0.001) than benign group. Using a combination of Dapp and Kapp as diagnostic index, significantly better differentiating performance was achieved than using ADC alone (area under curve: 0.956 vs. 0.876, p = 0.042). Conclusion: Compared to DWI, DKI could provide additional data related to tumor heterogeneity with significantly better differentiating performance. Its derived quantitative metrics could serve as a promising imaging biomarker for differentiating malignant from benign masses in head and neck region.