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Analysis of Fluid Model Modulated by an M/PH/1 Working Vacation Queue

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Journal of Systems Science and Systems Engineering 2019年第2期28卷 132-140页

作者： xiuli xu Huining Wang School of Science Yanshan University Qinhuangdao 066004 China

We propose a fluid model driven by the queue length process of a working vacation queue with PH service distribution, which can be applied to the Ad Hoc network with every data group. We obtain the stationary distribution of the queue length in driving process based on a quasi-birth-and-death process. Then, we analyze the fluid model, and derive the differential equations satisfied by the stationary joint distribution of the fluid queue based on the balance equation. Moreover, we obtain some performance indices, such as, the average throughput, server utilization and the mean buffer content. These indices are relevant to pack transmission in the network, and they can be obtained by using the Laplace Transform (LT) and the Laplace-Stieltjes Transform (LST). Finally, some numerical examples have been discussed with respect to the effect of several parameters on the system performance indices.

关键词： Fluid model M/PH/1 queue average throughput server utilization buffer content Ad Hoc network

THE MIMIc QUEUE WITH (e, d) SETUP TIME

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维普期刊数据库

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Journal of Systems Science & Complexity 2008年第3期21卷 446-455页

作者： xiuli xu Naishuo TIAN The Colleae of Sciences Yanshan University Qinhuanqdao 066004 China

The authors present a new queueing model with （e, d） setup time. Using the quasi-birth-and-death process and matrix-geometric method, the authors obtain the stationary distribution of queue length and the LST of waiting time of a customer in the system. Furthermore, the conditional stochastic decomposition results of queue length and waiting time are given.

关键词： Conditional stochastic decomposition (e d) policy matrix-geometric method setup time

Product Form Solution of a Queuing-Inventory System with Lost Sales and Server Vacation

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Journal of Systems Science & Complexity 2024年第2期37卷 729-758页

作者： YUE Dequan ZHANG Yuying xu xiuli YUE Wuyi School of Science Yanshan UniversityQinhuangdao 066004China School of Economics and Management Yanshan UniversityQinhuangdao 066004China The Kyoto College of Graduate Studies for Informatics Kyoto City 606-8225Japan

In this study,the authors consider an M/M/1 queuing system with attached inventory under an(s,S)control *** server takes multiple vacations whenever the inventory is *** is assumed that the lead time and the vacation time follow exponential *** authors formulate the model as a quasi-birth-and-dearth(QBD)process and derive the stability condition of the ***,the stationary distribution in product form for the joint process of the queue length,the inventory level,and the server’s status is ***,the conditional distributions of the inventory level when the server is on and operational,and when it is off due to a vacation,are *** the stationary distribution,the authors obtain some performance measures of the *** authors investigate analytically the effect of the server’s vacation on the performance ***,several numerical examples are presented to investigate the effects of some parameters on the performance measures,the optimal policy,and the optimal cost.

关键词： Cost function multiple vacations product form solution queuing-inventory system (s S)control policy

Effects of Water-table Depth and Soil Moisture on Plant Biomass, Diversity, and Distribution at a Seasonally Flooded Wetland of Poyang Lake, China

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Chinese Geographical Science 2015年第6期25卷 739-756页

作者： xu xiuli ZHANG Qi TAN Zhiqiang LI Yunliang WANG Xiaolong Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and Limnology Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education Jiangxi Normal University

Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetland. Poyang Lake, the largest freshwater lake in China, has been encountering dramatic changes in hydrological conditions in last decade, which greatly influenced the wetland vegetations. To explore the relationships between hydrology and vegetation distri- bution, water-table depth, soil moisture, species composition, diversity and biomass were measured at a seasonally flooded wetland section at Wucheng National Nature Reserve. Three plant communities, Artemisia capillaris, Phragmites australis and Carex cineras- cens communities, were examined which are zonally distributed from upland to lakeshore with decreasing elevation. Canonical corre- spondence analysis （CCA）, spearmen correlation and logistic regression were adopted to analyze the relationships between vegetation characteristics and hydrological variables of water-table depth and soil moisture. Results show that significant hydrological gradient exist along the wetland transect. Water-table demonstrates a seasonal variation and is consistently deepest in A. capillaris community （ranging from q）.5 m above ground to ＋10.3 m below ground）, intermediate in P. australis community （-2.6 m to ＋7.8 m） and shallow- est in C. cinerascens community （-4.5 m to ＋6.1 m）. Soil moisture is lowest and most variable in A. capillaris community, highest and least variable in P. australis community, and intermediate and moderate variable in C. cinerascens community. The CCA ordination indicated that variables of water-table depth and soil moisture are strongly related to community distribution, which explained 81.7% of the vegetation variations. Species diversity indices are significantly positively correlated with soil moisture and negatively correlated with moisture variability, while above- and belowground biomass are positively correlated with moisture. Above- and belowground biomass presen

关键词： water-table depth soil moisture species diversity biomass Gaussian model Poyang Lake wetland

Effectiveness of tonifying-kidney and regulating-liver therapy on diminished ovarian reserve: a systematic review and Meta-analysis of randomized controlled trials

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Journal of Traditional Chinese Medicine 2020年第3期40卷 343-354页

作者： Liu Liuqing Liu Yanfeng Yang Ming xu Guiqin Li Ruiqi xu xiuli Pan xue Liang Jialing Department of Gynecology the 1st Clinical Medical College of Beijing University of Chinese MedicineBeijing 100700China Department of Gynecology Dongzhimen Hospital of Beijing University of Chinese MedicineBeijing 100700China Center for Evidence Based Chinese Medicine Beijing University of Chinese MedicineBeijing 100029China Department of Scientific Research Management the 1st Affiliated Hospital of Anhui University of Chinese MedicineHefei 230001China Department of Gynecology Shunyi HospitalBeijing Hospital of Traditional Chinese MedicineBeijing 101300China

OBJECTIVE: To evaluate the effectiveness of the Traditional Chinese Medicine tonifying-kidney and regulating-liver therapy on diminished ovarian reserve(DOR).METHODS: The literature was comprehensively searched up to August 2019 using four Chinese and three English electronic databases to extract randomized clinical trials(RCTs) comparing Traditional Chinese Medicine tonifying-kidney and regulating-liver prescriptions(combined with hormone therapy or not) with Western Medicine. Data quality evaluation was conducted using the Cochrane risk of bias tool. Meta-analysis was conducted using Revman 5.3 software with effect estimates presented as mean difference(MD), risk ratio(RR), and95% confidence interval(CI).RESULTS: A total of nine RCTs with 512 participants were extracted and eligible for *** were no significant differences between Chinese medicine and Western Medicine on basal serum follicle-stimulating hormone(FSH) level(MD0.11, 95% CI-0.52 to 0.74, 392 participants, seven trials), anti-Müllerian hormone level(MD 0.48, 95%CI-0.62 to 1.58, 95 participants, two trials), and the FSH and luteinizing hormone ratio(MD 0.01,95% CI-0.95 to 0.96, 115 participants, two trials).Chinese medicine was more effective at improving Traditional Chinese Medicine symptom scores(TCMSS)(MD-2.39, 95% CI-3.83 to-0.94, 160 participants, three trials), effective rate of TCMSS(RR1.18, 95% CI 1.02 to 1.36, 160 participants, three trials), antral follicle count(AFC)(MD 0.55, 95% CI 0.05 to 1.04, 155 participants, three trials), and FSH levels at 3 months post-treatment(MD-4.77, 95% CI-6.09 to-3.45, 137 participants, two trials).CONCLUSION: Compared with Western Medicine,tonifying-kidney and regulating-liver therapy is more effective at relieving symptoms and improving AFC and FSH at 3 months post-treatment.

关键词： Ovarian reserve Tonifying kidney and regulating liver Randomized controlled trial Systematic review Meta-analysis

An Arctic sea ice thickness variability revealed from satellite altimetric measurements

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Acta Oceanologica Sinica 2014年第11期33卷 134-140页

作者： BI Haibo HUANG Haijun SU Qiao YAN Liwen LIU Yanxia xu xiuli Key laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of Sciences The First Institute of Oceanology State Oceanic Administration

A modified algorithm taking into account the first year（FY） and multiyear（MY） ice densities is used to derive a sea ice thickness from freeboard measurements acquired by satellite altimetry ICESat（2003–2008）. Estimates agree with various independent in situ measurements within 0.21 m. Both the fall and winter campaigns see a dramatic extent retreat of thicker MY ice that survives at least one summer melting season. There were strong seasonal and interannual variabilities with regard to the mean thickness. Seasonal increases of 0.53 m for FY the ice and 0.29 m for the MY ice between the autumn and the winter ICESat campaigns, roughly 4–5 month separation, were found. Interannually, the significant MY ice thickness declines over the consecutive four ICESat winter campaigns（2005–2008） leads to a pronounced thickness drop of 0.8 m in MY sea ice zones. No clear trend was identified from the averaged thickness of thinner, FY ice that emerges in autumn and winter and melts in summer. Uncertainty estimates for our calculated thickness, caused by the standard deviations of multiple input parameters including freeboard, ice density, snow density, snow depth, show large errors more than 0.5 m in thicker MY ice zones and relatively small standard deviations under 0.5 m elsewhere. Moreover, a sensitivity analysis is implemented to determine the separate impact on the thickness estimate in the dependence of an individual input variable as mentioned above. The results show systematic bias of the estimated ice thickness appears to be mainly caused by the variations of freeboard as well as the ice density whereas the snow density and depth brings about relatively insignificant errors.

关键词： satellite altimetry ice thickness Arctic first-year ice multiyear ice

Stresses of orthotropic laminated beams subjected to high temperature and mechanical load

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Theoretical & Applied Mechanics Letters 2019年第5期9卷 279-284,I0003页

作者： Zhong Zhang Ding Zhou xiuli xu xuehong Li College of Civil Engineering Nanjing Tech University

Thermo-elastic analysis of simply-supported orthotropic laminated beams subjected to high temperature and mechanical load is presented on the basis of the exact two-dimensional thermoelasticity *** beam is composed of several orthotropic layers,each with temperaturedependent material *** governing equation for each layer is analytically solved using the state space *** displacement and stress solutions of the beam are obtained using the transfer-matrix method.A numerical example is included to study the effects of temperature on the mechanical responses of a sandwich *** results reveal two main effects of temperature:(i)inducing deformations and stresses by itself;(ii)affecting the deformations and stresses induced by the mechanical load.

关键词： Orthotropic laminated beams Temperature-dependent material properties Thermo-elasticity theory State space method Transfer-matrix method

Arctic sea ice thickness changes in terms of sea ice age

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Acta Oceanologica Sinica 2016年第10期35卷 1-10页

作者： BI Haibo FU Min SUN Ke LIU Yilin xu xiuli HUANG Haijun Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China National Marine Environmental Forecasting Center Beijing 100081China The First Institute of Oceanology State Oceanic AdministrationQingdao 266061China

In this study, changes in Arctic sea ice thickness for each ice age category were examined based on satellite observations and modelled results. Interannual changes obtained from Ice, Cloud, and Land Elevation Satellite（ICESat）-based results show a thickness reduction over perennial sea ice（ice that survives at least one melt season with an age of no less than 2 year） up to approximately 0.5–1.0 m and 0.6–0.8 m（depending on ice age） during the investigated winter and autumn ICESat periods, respectively. Pan-Arctic Ice Ocean Modeling and Assimilation System（PIOMAS）-based results provide a view of a continued thickness reduction over the past four decades. Compared to 1980 s, there is a clear thickness drop of roughly 0.50 m in 2010 s for perennial ice. This overall decrease in sea ice thickness can be in part attributed to the amplified warming climate in north latitudes. Besides, we figure out that strongly anomalous southerly summer surface winds may play an important role in prompting the thickness decline in perennial ice zone through transporting heat deposited in open water（primarily via albedo feedback） in Eurasian sector deep into a broader sea ice regime in central Arctic Ocean. This heat source is responsible for enhanced ice bottom melting, leading to further reduction in ice thickness.

关键词： sea ice thickness age ICESat PIOMAS

Increasing Winter Conductive Heat Transfer in the Arctic Sea-ice-covered Areas: 1979–2014

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Journal of Ocean University of China 2017年第6期16卷 1061-1071页

作者： FAN Xieyu BI Haibo WANG Yunhe FU Min ZHOU xuan xu xiuli HUANG Haijun Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation College of Resources and Environmental Science Fujian Agriculture and Forestry University Fuzhou 350002 P. R. China Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of SciencesQingdao 266071 P. R. China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266200 P. R. China National Marine Environmental Forecasting Center Beijing 100081 P. R. China Institute of Electronics Chinese Academy of Sciences Beijing 100190 P. R. China University of Chinese Academy of Sciences Beijing 100049 P. R. China

Sea ice is a quite sensitive indicator in response to regional and global climate changes. Based on monthly mean PanArctic Ice Ocean Modeling and Assimilation System(PIOMAS) sea ice thickness fields, we computed the conductive heat flux(CHF) in the Arctic Ocean in the four winter months(November–February) for a long period of 36 years(1979–2014). The calculated results for each month manifest the increasing extension of the domain with high CHF values since 1979 till 2014. In 2014, regions of roughly 90% of the central Arctic Ocean have been dominated by the CHF values larger than 18 Wm^(-2)(November–December) and 12 Wm^(-2)(January–February), especially significant in the shelf seas around the Arctic Ocean. Moreover, the population distribution frequency(PDF) patterns of the CHF with time show gradually peak shifting toward increased CHF values. The spatiotemporal patterns in terms of the trends in sea ice thickness and other three geophysical parameters, surface air temperature(SAT), sea ice thickness(SIT), and CHF, are well coupled. This suggests that the thinner sea ice cover preconditions for the more oceanic heat loss into atmosphere(as suggested by increased CHF values), which probably contributes to warmer atmosphere which in turn in the long run will cause thinner ice cover. This represents a positive feedback mechanism of which the overall effects would amplify the Arctic climate changes.

关键词： conductive heat flux sea ice Arctic Ocean