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基于非平稳型流量队列模型的Internet流量测量研究

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电子学报 2004年第5期32卷 727-730页

作者：杨家海吴建平 c Liu 清华大学信息网络工程研究中心北京100084 美国贝尔实验室

针对大规模细粒度网络流量测量的现实困难 ,本文引入一种非平稳型流量队列模型NTT ,直接对粗粒度的流量采样进行建模 .NTT模型是大量活跃的流量队列的迭加 ,每个队列内部的流量变化过程用分形高斯噪声过程FGN描述 ,队列的到达过程形成... 详细信息

针对大规模细粒度网络流量测量的现实困难 ,本文引入一种非平稳型流量队列模型NTT ,直接对粗粒度的流量采样进行建模 .NTT模型是大量活跃的流量队列的迭加 ,每个队列内部的流量变化过程用分形高斯噪声过程FGN描述 ,队列的到达过程形成非同构的泊松过程 ,队列的生存周期服从指数分布 .对cERNET主干网的实际流量测量分析验证了NTT模型的有效性 ,证实了NTT模型可用于基于各种粒度的流量测量的网络行为研究 .

关键词：互联网网络测量网络流量网络行为非平稳流量队列模型NTT

ON cOUNTING THE FREQUENcY DISTRIBUTION OF STRING MOTIFS IN MOLEcULAR SEQUENcES

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International Journal of Biomathematics 2012年第6期5卷 121-139页

作者： MATTIA c. F. PROSPERI LUcIANO PROSPERI REBEccA R. GRAY MARcO SALEMI Department of Pathology Immunology and Laboratory Medicinecollege of Medicine Emerging Pathogens Institute University of Florida Department of ZoologyUniversity of Oxford Oxford UK Department of PathologyImmunology and Laboratory Medicine college of Medicine Emerging Pathogens Institute University of FloridaP. O. Box 103633 2055 Mowry Road GainesviUe FL 32610-3633 USA

This work investigates frequency distributions of strings within a text. The mathematical derivation accounts for variable alphabet size, character probabilities, and string/text lengths, under both the Bernoullian and the Markovian model for string generation. The analysis is limited to the set of nonclumpable strings, that cannot overlap with them selves. Two formulae （exact and approximated） are derived, calculating the frequency distribution of a string of length m found inside a text of length n （with m 〈： n）. The approximated formula has a constant complexity （in contrast to an exponential com plexity of the exact） and makes it applicable to very long texts. The proposed formulae were applied to analyze string frequencies in a portion of the human genome, and to recalculate frequencies of known repeated motif within genes, associated to genetic dis eases. A comparison with stateoftheart methods was provided. The formulae presentedhere can be of use in the statistical evaluation of specific motif frequencies within very long texts （e.g. genes or genomes） and help in characterizing motifs in pathologic conditions.

关键词： combinatorics genetics genomics.

ON THE PHYSIcS OF FLOW-DRIVEN SEDIMENTS (BED-LOAD)

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International Journal of Sediment Research 2001年第1期16卷 1-18页

作者： Ulrich c. E. ZANKE Prof, Institute of Hydraulic Engineering, University of Technology, Darmstadt, Germany Institute of Hydraulic Engineering University of Technology Darmstadt Germany

More than three dozen significant formulae for bed-load transport have been developed over a period of more than 100 years with varying degrees of success. Major problems have been the use of completely or partly empirical approaches and too few data for fitting. This paper presents an analytical formulation for bed-load transport. It is based on a balance of forces for the determination of the thickness of the moving bed-load layer and on the determination of the velocity of this layer. The formula derived is compared to a set of approx. 2000 data published by 32 authors. It is demonstrated that the basic form of the MPM-formula is a special case of the analytical solution. The derivation also includes the effect of bed features such as ripples and dunes on quantitative transport.

关键词： Bed-load transport Meyer-Peter/Mueller formula Moving bed-load layer Threshold concept Suspended load

consensus-based dispatch optimization of a microgrid considering meta-heuristic-based demand response scheduling and network packet loss characterization

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Energy and AI 2023年第1期11卷 71-89页

作者： Ali M.Jasim Basil H.Jasim Soheil Mohseni Alan c.Brent Electrical Engineering Department University of BasrahBasrah61001Iraq Department of communications Engineering Iraq University CollegeBasrahIraq Sustainable Energy Systems Wellington Faculty of EngineeringVictoria University of WellingtonWellington6140New Zealand Department of Industrial Engineering and the centre for Renewable and Sustainable Energy Studies Stellenbosch UniversityStellenbosch7600South Africa

The uncertainty inherent in power load forecasts represents a major factor in the mismatches between supply and demand in renewables-rich electricity networks, which consequently increases the energy bills and curtailed generation. As the transition to a power grid founded on the so-called grid-of-grids becomes more evident, the need for distributed control algorithms capable of handling computationally challenging problems in the energy sector does so as well. In this light, the consensus-based distributed algorithm has recently been shown to provide an effective platform for solving the complex energy management problem in microgrids. More specifically, in a microgrid context, the consensus-based distributed algorithm requires reliable information exchange with customers to achieve convergence. However, packet losses remain an important issue, which can potentially result in the failure of the overall system. In this setting, this paper introduces a novel method to effectively characterize such packet losses during information exchange between the customers and the microgrid operator, whilst solving the microgrid scheduling optimization problem for a multi-agent-based microgrid. More specifically, the proposed framework leverages the virulence optimization algorithm and the earth-worm optimization algorithm to optimally shift the energy consumption during peak periods to lower-priced off-peak hours. The effectiveness of the proposed method in minimizing the overall active power mismatches in the presence of packet losses has also been demonstrated based on benchmarking the results against the business-as-usual iterative scheduling algorithm. Also, the robustness of the overall meta-heuristic- and multi-agent-based method in producing optimal results is confirmed based on comparing the results obtained by several well-established meta-heuristic optimization algorithms, including the binary particle swarm optimization, the genetic algorithm, and the cuckoo search op

关键词： Demand-side management Optimal scheduling Microgrids Distribution generation consensus algorithm Meta-heuristics

Mild cognitive impairment in Parkinson’s disease:a distinct clinical entity?

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Translational Neurodegeneration 2017年第1期6卷 225-231页

作者： Ming-ching Wen Ling Ling chan Louis c.S.Tan Eng King Tan Department of Research National Neuroscience InstituteSingaporeSingapore Department of Neurology National Neuroscience Institute11 Jalan Tan Tock SengSingapore 308433Singapore Department of Diagnostic Radiology Singapore General HospitalSingaporeSingapore Duke-NUS Medical School SingaporeSingapore

Background:Mild cognitive impairment in Parkinson’s disease(PD-McI)is a common clinical *** its pathology and clinical features is important for early intervention before the onset of *** the past,variable definitions and differences in neuropsychological batteries generated divergent results of the affected cognitive *** body:The introduction of PD-McI criteria by the Movement Disorders Society(MDS)Task Force provides a more uniform system for defining and measuring PD-McI and may improve the validity of future ***-McI is likely to be heterogeneous since it can coexist with Alzheimer’s disease and/or Lewy body pathologies in *** of neuropsychiatric disturbances,such as depression,anxiety and apathy,are associated with PD with or without *** addition,cognitive reserve formed by patients’unique life experiences may influence the outward cognitive performance despite the presence of the aforementioned pathogeneses and hence alter the diagnosis of ***:The overlap of cognitive impairment across different neurodegenerative diseases suggests that PD-McI is likely to result from a mixture of complex pathophysiologies,rather than being a distinct pathologic *** McI from other organic symptoms in PD would facilitate novel therapeutic strategies.

关键词： Mild cognitive impairment Parkinson’s disease Alzheimer disease Lewy body Neuropsychiatric comorbidities cognitive reserve

Risk factors of treatment default and death among tuberculosis patients in a resource-limited setting

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Asian Pacific Journal of Tropical Medicine 2014年第12期7卷 977-984页

作者： Isaac Alobu Sarah N.Oshi Daniel c.Oshi Kingsley N.Ukwaja National Tuberculosis and Leprosy control Programme Ministry of HealthAbakalikiEbonyi StateNigeria centre for Development and Reproductive Health Enugu.Enugu StateNigeria Department of Internal Medicine Federal Teaching HospitalAbakalikiEbonyi StateNigeria

Objective:To evaluate the rates,timing and determinants of default and death among adult tuberculosis patients in ***:Routine surveillance data were used.A retrospective cohort study of adult tuberculosis patients treated during 2011 and 2012 in two large health facilities in Ebonyi *** was *** logistic regression analyses were used to tdentify independent predictors for treatment default and ***:Of 1668 treated patients,the default rate was 157(9.4%),whilst 165(9.9%) ***,35.7%(56) of the treatment defaults and 151(91.5%) of deaths occurred during the intensive phase of *** of default increased with increasing age(adjusted odds ratio(aOR) 1.2;95%confidence interval(cI)1.1-1.9).smear-negative TB case(aOR 2.3:cI 1.5-3.6).extrapulmonary TB case(aOR 2.7:cI 1.3-5.2).and patients who received the longer treatment regimen(aOR 1,6;1.1-2.2).Risk of death was highest in extrapulmonary TB(aOR 3.0:cI 1.4-6.1) and smear-negative TB cases(aOR 2.4:*** residents(aOR 1.7:cI 1.2-2.6),HIV co-infected(aOR 2.5:cI 1.7-3.6),not receiving antiretroviral therapy(aOR 1.6:cI 1.1-2.9),and not receiving cotrimoxazole prophylaxis(aOR 1.7:cI 1.2—2.6).conclusions:Targeted interventions to improve treatment adherence for patients with the highest risk of default or death are urgently *** needs to he urgently addressed by the National Tuberculosis Programme.

关键词： Tuberculosis Epidemiology Treatment default Mortality Treatment outcome Health services Nigeria

Trends in incidence and management of cancer of the ampulla of Vater

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World Journal of Gastroenterology 2014年第29期20卷 10144-10150页

作者： Florian Rostain Samia Hamza Antoine Drouillard Jean Faivre Anne-Marie Bouvier c?me Lepage Registre Bourguignon des cancers Digestifs INSERM U866CHU de DijonFaculté de Médecine21079 Dijon CedexFrance

AIM: To provide trends in incidence, management and survival of cancer of the ampulla of Vater in a well-defined French population.

关键词： cancer of the ampulla of Vater Incidence Survival Treatment Epidemiology

An Immersed Interface Method for the Simulation of Inextensible Interfaces in Viscous Fluids

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communications in computational Physics 2012年第3期11卷 925-950页

作者： Zhijun Tan D.V.Le K.M.Lim B.c.Khoo Guangdong Province Key Laboratory of computational Science&School of Mathematics and computational Science Sun Yat-senUniversityGuangzhou 510275China Institute of High Performance computing 1 Fusionopolis Way#16-16 ConnexisSingapore 138632Singapore Singapore-MIT Alliance 4 Engineering Drive 3National University of SingaporeSingapore 117576Singapore Department of Mechanical Engineering National University of Singapore10 Kent Ridge CrescentSingapore 119260Singapore

In this paper,an immersed interface method is presented to simulate the dynamics of inextensible interfaces in an incompressible *** tension is introduced as an augmented variable to satisfy the constraint of interface inextensibility,and the resulting augmented system is solved by the GMRES *** this work,the arclength of the interface is locally and globally conserved as the enclosed region undergoes *** forces at the interface are calculated from the configuration of the interface and the computed augmented variable,and then applied to the fluid through the related jump *** governing equations are discretized on a MAc grid via a second-order finite difference scheme which incorporates jump contributions and solved by the conjugate gradient Uzawa-type *** proposed method is applied to several examples including the deformation of a liquid capsule with inextensible interfaces in a shear *** results reveal that both the area enclosed by interface and arclength of interface are conserved well *** provide further evidence on the capability of the present method to simulate incompressible flows involving inextensible interfaces.

关键词： Inextensible interface Stokes flows singular force immersed interface method cGUzawa method front tracking

格位选择激发下Eu[cr_(0.1)Al_(0.9)(OH)_6Mo_6O_(18)]·11H_2O的光谱特性

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光谱学与光谱分析 2005年第3期25卷 326-328页

作者：尹民 Krupa J c Yusov A B Fedosseev A M 中国科学技术大学结构分析重点实验室物理系安徽合肥230026 原子核物理研究所 orsaycedex法国91406 物理化学研究所 moscow俄罗斯119991

详细研究了Eu[cr0. 1Al0 . 9(OH) 6Mo6O18]·11H2 O中Eu3 + 的发光特性。通过对实验结果的分析 ,确定了体系中Eu3 + 离子有 3种发光中心 ,其中一种占主导地位。样品中存在的Eu3 + 到cr3 + 的能量传递 ,也发生在这个中心。利用低温下的... 详细信息

详细研究了Eu[cr0. 1Al0 . 9(OH) 6Mo6O18]·11H2 O中Eu3 + 的发光特性。通过对实验结果的分析 ,确定了体系中Eu3 + 离子有 3种发光中心 ,其中一种占主导地位。样品中存在的Eu3 + 到cr3 + 的能量传递 ,也发生在这个中心。利用低温下的格位选择激发 ,成功地分离了 3种发光中心的发射光谱。结果显示 ,主要发光中心的格位对称性为c1,与以前的研究结果一致 ;另外两种发光中心则具有较高的对称性。在共振激发条件下 ,测量了不同发光中心在低温下的荧光衰减曲线 ,拟合计算给出中心 1(主要发光中心 )和中心 3的5D0能级的寿命分别为 107和 599μs,相差近 6倍。说明中心 3的对称性比中心 1高 ,和从光谱测量得到的结论一致。

关键词：发光中心 Eu^3+ OH 对称性荧光衰减 cr^3+ 研究结果低温实验结果