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MD-AVB: A Multi-Manifold Based Available Bandwidth Prediction Algorithm

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Tsinghua Science and Technology 2020年第1期25卷 140-148页

作者： Pei Zhang Changqing An Zhanfeng Wang Fengyuan Ma Institute of Network Technology Beijing University of Posts and TelecommunicationsBeijing 100876China Institute for Network Sciences and Cyberspace Tsinghua UniversityBeijing 100084China School of Computer Science and Engineering Southeast UniversityNanjing 211189China

The performance of Internet applications is heavily affected by the end-to-end available bandwidth. Thus,it is very important to examine how to accurately predict the available Internet bandwidth. A number of available bandwidth prediction algorithms have been proposed to date, but none of the existing solutions are able to achieve a high level of accuracy. In this paper, a Multi-manifold based Available Bandwidth prediction algorithm(MD-AVB)is proposed, based on the observation that the available bandwidth space on the Internet is multi-manifold and asymmetrical. In the proposed algorithm, the available bandwidth space is divided into multiple lower-dimensional domains iteratively, and each domain is embedded separately to predict the available bandwidth. Experiments on HP S^3 datasets demonstrate that the proposed algorithm is more accurate than existing approaches.

关键词： available bandwidth space performance prediction multi-manifold asymmetry

Seismic demand of plan-asymmetric structures:a revisit

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Earthquake Engineering and Engineering Vibration 2013年第1期12卷 99-117页

作者： Rana Roy Suvonkar Chakroborty Department of Aerospace Engineering & Applied Mechanics Bengal Engineering and Science UniversityShibpurIndia SMS India Pvt.Ltd. SMS GroupIndia

In view of the recognition of the importance of the interdependent behavior of strength and stiffness of walltype structural elements,the seismic demand of plan-asymmetric systems is revisited.Useful strength distribution strategies,i.e.,＇Center of Strength-Center of Mass（CV-CM） coinciding＇ and ＇Balanced Center of Strength-Center of Resistance（CVCR）＇ are adopted.Design charts for the seismic demand of classical uni-directionally and bi-directionally asymmetric systems are developed in a simple unified format.A conceptual framework is also outlined to conveniently apply the design charts.Illustrations are included to explain the use of the current recommendations in practical design.The study also highlights the relative performance of ＇CV-CM coinciding＇ and ＇Balanced CV-CR＇ criteria.

关键词： asymmetry seismic strength dependent stiffness design chart

A NOTE ON MORI-TANAKA'S METHOD

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Acta Mechanica Solida Sinica 2014年第3期27卷 234-244页

作者： Ling Liu Zhengming Huang School of Aerospace Engineering & Applied Mechanics Tongji University

Explicit expressions of Mori-Tanaka＇s tensor for a transversely isotropic fiber rein- forced UD composite are presented. Closed-form formulae for the effective elastic properties of the composite are obtained. In a 3D sense, the resulting compliance tensor of the composite is symmetric. Nevertheless, the 2D compliance tensor based on a deteriorated Mori-Tanaka＇s tensor is not symmetric. Nor is the compliance tensor defined upon a deteriorated 2D Eshelby＇s tensor. The in-plane effective elastic properties given by those three approaches are different. A detailed comparison between the predicted results obtained from those approaches with experimental data available for a number of UD composites is made.

关键词： micromechanics Eshelby-Mori-Tanaka＇s method effective elastic property asymmetry

DRUG PRICING PATTERN IN CHINA： DILEMMA AND COUNTERMEASURE

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Journal of Systems Science and Systems Engineering 2018年第3期27卷 340-366页

作者： Mingxi Wang Yi Hu Han Qiao Chuangyin Dang School of International Trade and Economics University of International Business and Economics Beijing 100029 China School of Economics and Management University of Chinese Academy of Sciences Beijing 100190 China Department of Systems Engineering and Engineering Management City University of Hong Kong Kowloon Hong Kong

Maybe it is the most important medical reform for current China to adopt the bid-and-procurement scheme to correct the distortion of pharmaceutical resources allocation. Nevertheless, overpriced drugs often happen. This article aims to identify potential factors leading to the overpriced. Based on the mechanism rules of the scheme, it is found that unethical doctors are crucial to high price markup in the pricing pattern of drugs. Under China＇s actual conditions, asymmetric ownership is identified to be another cause of the overpriced by developing an asymmetric bidding model. How are the impacts of these two factors to be alleviated？ Upon examination, several reform measures cannot effectively avoid the occurrence of the overpriced. Yet, the issue is very urgent for China because it is facing with the problem of population aging. Therefore, alternative options - a regulation-penalty tool and an investment subsidy policy - are proposed to improve China＇s health care.

关键词： The bid-and-procurement scheme overpriced drug asymmetry health-care reform

Influence of Center of Gravity Location on Flight Dynamic Stability in a Hovering Tailless FW-MAV: Lateral Motion

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Journal of Bionic Engineering 2020年第1期17卷 148-160页

作者： Loan Thi Kim Au Hoon Cheol Park Department of Smart Vehicle Engineering and Artificial Muscle Research Center Konkuk UniversitySeoul 05029Korea

This paper reports the effect of the Center of Gravity(CG)position on lateral flight dynamic stability of hovering KUBeetle,a tailless FW-MAV,providing further insights on the effects of asymmetries in body mass distribution and wing kinematics.For the current study,the standard linearized equations of motion were applied as in the previous work on longitudinal dynamic stability.The stability derivatives were acquired using the computational fluid dynamic methods via the commercial software of ANSYS Fluent.There exists a stable region for CG between 2.6%and 3.5%of the mean chord below the wing pivot point,in which the lateral motion of hovering KUBeetle is passively stable.For CG below the stable region,because of an unstable oscillatory mode,the lateral motion of the FW-MAV is unstable but can be stabilized using rolling rate feedback.For CG above the stable region,because of a divergence mode,the system remains unstable even with the rolling rate feedback.Comparison with other works on an FW-MAV based on a quasi-steady aerodynamic model and on insect showed similar characteristics for flapping flight.It is also interesting to note that the asymmetries in body mass and wing kinematics can enlarge the stable region of the system by a non-zero Ixz which approaches the root square of√IxIz,a negative LrNp,and a positive Ix2(Ir+Np).Combining the current result with that of the previous work on longitudinal motion,the most beneficial region of the CG for full 6-DOF flight dynamic stability of hovering KUBeetle was suggested.

关键词： FW-MAV center of gravity flight dynamic stability lateral motion asymmetry computational fluid dynamics bioinspired flight

Changes in classified precipitation in the urban, suburban, and mountain areas of Beijing

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Advances in Climate Change Research 2017年第4期8卷 279-285页

作者： YUAN Yu-Feng ZHAI Pan-Mao LI Jian CHEN Yang Key Laboratory of Meteorological Disaster of Ministry of Education Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and Technology Nanjing 210044 China State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China

In this paper, based on hourly precipitation observations in 1977e2013 in the Beijing area, China, hourly precipitation in summer (June?August) is classified into three categories: light (below the 50th percentile values), moderate (the 50th to 95th percentile values), and heavy (above the 95th percentile values). Results reveal that both light and moderate precipitation decreased significantly during the research period and thereby caused the decrease in summer totals. By contrast, pronounced trends failed to be detected in the heavy category. Since 2004, the contribution of heavy rainfall to the summer total precipitation in the urban area increased as compared to the suburban area, which is opposite to light rainfall. There are obvious differences in the diurnal variations of classified precipitation. Light precipitation shows a double peak structure in the early morning and at night, while moderate and heavy rainfall show a single peak at night. Light precipitation at the early morning peak time decreased significantly in the whole Beijing area. Compared with the suburban area, light precipitation in the urban area occurred less frequently whereas heavy precipitation occurred more frequently at evening peak time after 2004. The asymmetry of the rainfall is obvious, especially, for heavy precipitation. The asymmetry of heavy precipitation events in the urban area exhibits a significant increasing trend.

关键词： Hourly precipitation Classified precipitation Diurnal variation asymmetry Beijing

Distribution of central corneal thickness and intraocular pressure in emmetropic eyes of healthy children of Palestine: a representative cross-sectional study

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International Journal of Ophthalmology(English edition) 2019年第3期12卷 496-503页

作者： Hamed Tm Alkhodari Department of Optometry Faculty of Health Sciences Islamic University of Gaza

AIM: To determine the distributions of central corneal thickness(CCT) and intraocular pressure(IOP) in emmetropic eyes of healthy children of Palestine.METHODS: This representative cross sectional study included a total of 1156 eyes from 578 healthy school children aged 7-15 y. Inclusion criteria included emmetropia, no previous history of ocular or systemic diseases, no previous history of contact lens use, and the availability of both eyes. CCT and IOP were measured using ultrasound pachymeter and Goldmann applanation tonometer, respectively. The relationship of the results with age and gender was investigated.RESULTS: The mean age of school children was 11.13±2.8 y. Mean CCT was 542.2±37.4 and 544.3±39.2 μm for right and left eyes, respectively. Mean IOP was 12.5±2.2 and 12.3±2.2 mm Hg for right and left eyes, respectively. A positive correlation was observed between CCT and IOP of the right eye(P0.05). There were significant differences in mean CCT and IOP between right and left eyes(P=0.004, P=0.001, respectively).CONCLUSION: A population profile of CCT and IOP is established in Palestinian children for the first time. Mean CCT is comparable to some studies but differ from others. Mean IOP is considerably lower than that of majority children of other ethnic groups. Intereye difference of more than 36 μm in CCT, and 5 mm Hg in IOP should prompt evaluation for potential ocular disorders.

关键词： central corneal thickness intraocular pressure intereye asymmetry Goldmann applanation tonometer ultrasound pachymeter

Stem cells' centrosomes: How can organelles identified 130 years ago contribute to the future of regenerative medicine?

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World Journal of Stem Cells 2021年第9期13卷 1177-1196页

作者： Andreas Goutas Varvara Trachana Department of Biology Faculty of MedicineUniversity of ThessalyLarisa 41500BiopolisGreece

At the core of regenerative medicine lies the expectation of repair or replacementof damaged tissues or whole organs. Donor scarcity and transplant rejection aremajor obstacles, and exactly the obstacles that stem cell􀀀based therapy promisesto overcome. These therapies demand a comprehensive understanding of theasymmetric division of stem cells, i.e. their ability to produce cells with identicalpotency or differentiated cells. It is believed that with better understanding,researchers will be able to direct stem cell differentiation. Here, we describeextraordinary advances in manipulating stem cell fate that show that we need tofocus on the centrosome and the centrosome-derived primary cilium. This beliefcomes from the fact that this organelle is the vehicle that coordinates theasymmetric division of stem cells. This is supported by studies that report thesignificant role of the centrosome/cilium in orchestrating signaling pathways thatdictate stem cell fate. We anticipate that there is sufficient evidence to place thisorganelle at the center of efforts that will shape the future of regenerativemedicine.

关键词： Centrosome Primary cilium asymmetry Self-renewal Differentiation Stemness

Samarium diiodide induced asymmetric synthesis of γ-butyrolactone using chiral auxiliaries derived from isosorbide and isomannide

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Chinese Journal of Chemistry 1998年第6期16卷 561-564页

作者：徐明华林国强夏立钧 Shanghai Institute of Organic Chemistry Chinese Academy of SciencesShanghai 200032China

The asymmetric reductive coupling reaction of various acrylates derived from D-isosorbide and D-isomannide with acetophenone mediated by samarium diiodide to give both enantiomers of the optically active γ-butyrolact... 详细信息

关键词： asymmetry γ-butyrolactone isosorbide isomannide samarium diiodide