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Science China(Information Sciences) 2012年第11期55卷 2604-2610页

作者： stevan berber Department of Electrical and Computer Engineering University of AucklandAuckland 1142New Zealand

A time-domain(TD) least square(LS) channel estimator is first proposed to estimate channel parameters of OFDM system with IQ imbalances at both transmitter and ***,an iterative shrinkage(IS) algorithm from compressed sensing is adopted to further improve the estimation performance by using the TD-LS solution as the initial value of IS in the case of sparse *** shows that our algorithm combining TD-LS and IS performs better on bit error rate than the frequency-domain LS and matching pursuit in sparse Hilly Terrain channel when the same LS equalizer is adopted.

关键词： iterative shrinkage time-domain least square IQ imbalance channel estimation

ML integer frequency offset estimation for OFDM systems with null subcarriers:Estimation range and pilot design

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Science China(Information Sciences) 2010年第12期53卷 2567-2575页

作者： berber stevan Department of Electrical Engineering and Computer Engineering the University of Auckland

In this paper the estimation range(ERG) of any null subcarriers(NSC) placement is further investigated and sufficient and necessary conditions of an NSC allocation that achieves a full ERG are ***,a perfect distributed NSC allocation with the NSC distance larger than coherent bandwidth is devised to fully exploit frequency diversity of wireless channels and achieve a full *** confirmed that the propsoed FFT-based ML method of using this NSC placement has a smaller bandwidth overhead,achieves a fuller ERG and provides a better performance than the existing methods of using the consecutive NSC allocation at middle and high signal-to-noise ratios(SNRs).

关键词： orthogonal frequency division multiplexing(OFDM) null subcarrier estimation range integer carrier frequency offset false detection probability frequency-selective fading

稀疏多径信道环境中MIMO-OFDM系统的IQ不平衡和信道联合估计

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电子与信息学报 2013年第2期35卷 280-284页

作者：梁彦束锋张一晋 berber stevan 南京理工大学电子工程与光电技术学院南京210094 东南大学移动通信国家重点实验室南京210096 奥克兰大学电子与计算机工程系奥克兰新西兰

该文针对稀疏多径信道环境中的MIMO-OFDM系统所存在的IQ不平衡问题,提出了一种IQ不平衡参数和信道的联合估计方法。推导了联合估计的时域模型,提出了基于1 2l-l优化模型和平行坐标下降算法的联合估计算法。仿真结果表明,所提方法与传统... 详细信息

该文针对稀疏多径信道环境中的MIMO-OFDM系统所存在的IQ不平衡问题,提出了一种IQ不平衡参数和信道的联合估计方法。推导了联合估计的时域模型,提出了基于1 2l-l优化模型和平行坐标下降算法的联合估计算法。仿真结果表明,所提方法与传统的频域最小二乘算法和匹配追踪算法相比,显著提高了系统性能。

关键词：无线通信 MIMO OFDM IQ不平衡稀疏多径信道估计

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Neoadjuvant treatment of pancreatic ductal adenocarcinoma:Whom,when and how

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1223-1230页

作者： Nebojsa Manojlovic Goran Savic stevan Manojlovic Clinic for Gastroenterology and Hepatology Military Medical AcademyFaculty of Medicine of the Military Medical AcademyUniversity of DefenceBelgrade 11000Serbia Military Medical Academy Faculty of Medicine of the Military Medical AcademyUniversity of DefenceBelgrade 11000Serbia Faculty of Medicine University of BelgradeBelgrade 11000Serbia

Pancreatic ductal adenocarcinoma(PDAC),which is notorious for its aggressiveness and poor prognosis,remains an area of great unmet medical need,with a 5-year survival rate of 10%-the lowest of all solid *** diagnosis,only 20%of patients have resectable pancreatic cancer(RPC)or borderline RPC(BRPC)disease,while 80%of patients have unresectable tumours that are locally advanced pancreatic cancer(LAPC)or have distant *** 60%of patients who undergo upfront surgery for RPC are unable to receive adequate adjuvant chemotherapy(CHT)because of postoperative complications and early cancer *** important paradigm shift to achieve better outcomes has been the sequence of therapy,with neoadjuvant CHT preceding *** surgical stages have emerged for the preoperative assessment of nonmetastatic pancreatic cancers:RPC,BRPC,and *** main goal of neoadjuvant treatment(NAT)is to improve postoperative outcomes through enhanced selection of candidates for curative-intent surgery by identifying patients with aggressive or metastatic disease during initial CHT,reducing tumour volume before surgery to improve the rate of margin-negative resection(R0 resection,a microscopic margin-negative resection),reducing the rate of positive lymph node occurrence at surgery,providing early treatment of occult micrometastatic disease,and assessing tumour chemosensitivity and tolerance to treatment as potential surgical *** this editorial,we summarize evidence concerning NAT of PDAC,providing insights into future practice and study *** research is needed to establish predictive biomarkers,measures of therapeutic response,and multidisciplinary stra tegies to improve patient-centered outcomes.

关键词： Pancreatic adenocarcinoma Neoadjuvant treatment Chemotherapy Upfront surgery Radiotherapy Response evaluation

Observer canonical form based robust fault detection and estimation for hyperbolic spatiotemporal dynamic systems

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IET Cyber-Systems and Robotics 2020年第4期2卷 168-180页

作者： Xiaodong Xu Yuncheng Du stevan Dubljevic McKetta Department of Chemical Engineering University of Texas at AustinAustinTX 78712USA Department of Chemical and Biomolecular Engineering Clarkson UniversityPostdamP.O.Box 5705USA Department of Chemical and Materials Engineering University of AlbertaEdmontonAlbertaT6G 2V4Canada

In this study,the authors propose a novel state and a fault estimation scheme for a class of hyperbolic spatiotemporal dynamic systems in the presence of unknown external *** consider the occurrence of multiplicative actuator and sensor *** detail,they consider two cases of fault occurrence:(i)only one type(actuator or sensor)of fault happens;(ii)two types of faults occur *** study discusses the fault detectability conditions by proposing a fault detection *** complete the estimation problem,three difficulties arise:(i)no prior information shows the type of faults;(ii)the observer design is non-linear due to multiplication between plant signals(state or input)and unknown fault parameters;(iii)only one boundary measurement is *** convert the original faulty plant into its observer canonical *** proposing two filters based on the resulting observer canonical form,they develop novel parameter update laws for fault parameter *** the proposed update laws,the true state of the faulty plant can be estimated by the proposed *** selecting appropriate Lyapunov functions,they prove that estimation error of state and fault parameters exponentially decays to an arbitrarily small neighbourhood of zero despite unknown external disturbance.

关键词： estimation. estimation canonical

Reforestation Programs in Southwest China:Reported Success,Observed Failure, and the Reasons Why

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Journal of Mountain Science 2007年第4期4卷 275-292页

作者： Christine Jane Trac stevan Harrell Thomas M. Hinckley Amanda C. Henck Department of Biology University of Washington Department of Anthropology Box 353010 University of Washington Seattle WA 98195 USA College of Forest Resources University of Washington Department of Earth and Space Sciences University of Washington

Ever since the disastrous floods of 1998, the Chinese government has used the Natural Forest Protection and Sloping Land Conversion Programs to promote afforestation and reforestation as means to reduce runoff, control erosion, and stabilize local livelihoods. These two ambitious programs have been reported as large-scale successes, contributing to an overall increase in China’s forest cover and to the stated goals of environmental stabilization. A small-scale field study at the project level of the implementation of these two programs in Baiwu Township, Yanyuan County, Sichuan, casts doubt upon the accuracy and reliability of these claims of success; ground observations revealed utter failure in some sites and only marginal success in others. Reasons for this discrepancy are posited as involving ecological, economic, and bureaucratic factors. Further research is suggested to determine whether these discrepancies are merely local aberrations or represent larger-scale failures in reforestation programs.

关键词： Forests afforestation reforestation grain-to-green natural forest protection plan China Sichuan Liangshan

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Plasma Membrane-Associated SCAR Complex Subunits Promote Cortical F-Actin Accumulation and Normal Growth Characteristics in Arabidopsis Roots

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Molecular Plant 2008年第6期1卷 990-1006页

作者： Julia Dyachok Mon-Ray Shao Kevin Vaughn Andrew Bowling Michelle Facette stevan Djakovic Lauren Clark Laurie Smith Section of Cell and Developmental Biology University of California San Diego 9500 Gilman Drive La Jolla CA 92093-0116 USA Southern Weed Science Research Unit USDA-ARS 141 Experiment Station Road Stoneville MS 38776 USA Carnegie Institution Department of Plant Biology 260 Panama Street Stanford CA 94305 USA Present address: Division of Plant Biology The Samuel Roberts Noble Foundation 2510 Sam Noble Pkwy Ardmore OK 73401 USA Present address: Section of Neurobiology University of California San Diego 9500 Gilman Drive La Jolla CA 92093-0116 USA

The ARP2/3 complex, a highly conserved nucleator of F-actin polymerization, and its activator, the SCAR complex, have been shown to play important roles in leaf epidermal cell morphogenesis in Arabidopsis. However, the intracellular site（s） and function（s） of SCAR and ARP2/3 complex-dependent actin polymerization in plant cells remain unclear. We demonstrate that putative SCAR complex subunits BRK1 and SCAR1 are localized to the plasma membrane at sites of cell growth and wall deposition in expanding cells of leaves and roots. BRK1 localization is SCAR-dependent, providing further evidence of an association between these proteins in vivo. Consistent with plasma membrane localization of SCAR complex subunits, cortical F-actin accumulation in root tip cells is reduced in brkl mutants. Moreover, mutations disrupting the SCAR or ARP2/3 complex reduce the growth rate of roots and their ability to penetrate semi-solid medium, suggesting reduced rigidity. Cell walls of mutant roots exhibit abnormal structure and composition at intercellular junctions where BRK1 and SCAR1 are enriched in the adjacent plasma membrane. Taken together, our results suggest that SCAR and ARP2/3 complex-dependent actin polymerization promotes processes at the plasma membrane that are important for normal growth and wall assembly.

关键词： cell expansion cell morphogenesis cytoskeleton root biology Arabidopsis.

Influence of Human Pressure on Forest Resources and Productivity at Stand and Tree Scales: The Case Study of Yunnan Pine in SW China

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Journal of Mountain Science 2013年第5期10卷 824-832页

作者： Thomas M.HINCKLEY Phillip CHI Keala HAGMANN stevan HARRELL Amanda Henck SCHMIDT Lauren URGENSON Zong-yong ZENG School of Environmental and Forest Sciences University of Washington Department of Anthropology and School of Environmental and Forest Sciences University of Washington Geology Department Oberlin College College of Life Sciences Sichuan University

This paper examines human impact on stands and individual trees of Pinus yunnanensis growing near the small mountain villages of Pianshui and Yangjuan in southwestern Sichuan Province,*** an effort to assess whether use of these forests was sustainable,we examined the effects of human use in two ***,we directly measured the effect of cutting branches,for fuel and fodder,on tree *** hypothesized that branch cutting would negatively impact tree *** established 12 plots on four hills and compared 14 pairs of trees,one tree in each pair with an apparently full crown and the other with a considerable portion of the crown ***,we assessed stand and tree properties over a 500 m elevation gradient above the villages where we hypothesized that as elevation increases,stand and tree properties should show fewer human *** extensive branch cutting reduced the live crown,tree height and diameter,compensatory processes likely enabled trees to recover and to add basal area increments(BAIs) similar to those added by trees with full *** and stands close to villages showed less growth and lower basal areas,respectively,than stands and trees at intermediate or distant elevations from *** relatively close to the villages showed considerable effects of human-related disturbances such as branch cutting,grazing,tree and shrub removal,losses of litter,and human and animal *** areas had increased soil erosion and often loss of the ‘A' *** close to villages had younger trees,lower stand basal areas,smaller basal area increments,and more *** results suggest an increasingly vulnerable interface between occupants of these two villages and their surrounding forests.

关键词： Pinus yunnanensis Tree growth Standbasal areas Basal area increment Ring width

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欧洲共同体委员会促进情报服务市场发展的政策

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国外情报科学 1993年第3期11卷 35-41页

作者： stevan,G 陈昭楠

鉴于情报对于商业、工业和研究工作的发展日益重要,自l97蛑以来,欧洲共同体鬻员会(如下简称欧共体)已开始进行各种活动,旨在不断加强欧洲情报产业的地位。欧共休在这方面的某些行动构成了它在情报技术,通信和情报市场方面的全面政策的... 详细信息

鉴于情报对于商业、工业和研究工作的发展日益重要,自l97蛑以来,欧洲共同体鬻员会(如下简称欧共体)已开始进行各种活动,旨在不断加强欧洲情报产业的地位。欧共休在这方面的某些行动构成了它在情报技术,通信和情报市场方面的全面政策的组成部分。近几年来,朝着信息社会发展以及这种发展对于情报服务产业所起的突出作用,促使欧共体在这方面活动的稳步加强。欧共体在发展情报市场方面的某些活动,可看成是为建立知识的生产和知识的应用之间进行有效的联系所作的努力。[第一段]

关键词：欧共体情报服务情报市场

Role of clinical pathway in improving the quality of care for patients with faecal incontinence:A randomised trial

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World Journal of Gastrointestinal Pharmacology and Therapeutics 2017年第1期8卷 81-89页

作者： Zeiad I Hussain Michael Lim stevan Stojkovic Interventional Radiology Guys and St Thomas Hospital Department of Colorectal Surgery Raigmore Hospital stevan Stojkovic Department of Colorectal SurgeryYork Hospital

AIMTo assess the development and implementation of the Integrated Rapid Assessment and Treatment (IRAT) pathway for the management of patients with fecal incontinence and measure its impact on patients’ care. METHODSPatients referred to the colorectal unit in our hospital for the management of faecal incontinence were randomised to either the Standard Care pathway or the newly developed IRAT pathway in this feasibility study. The IRAT pathway is designed to provide a seamless multidisciplinary care to patients with faecal incontinence in a timely fashion. On the other hand, patients in the Standard Pathway were managed in the general colorectal clinic. Percentage improvements in St. Marks Incontinence Score, Cleveland Clinic Incontinence Score and Rockwood Faecal Incontinence Quality of Life Scale after completion of treatment in both groups were the primary outcome measures. Secondary endpoints were the time required to complete the management and patients’ satisfaction score. χ2, Mann-Whitney-U and Kendall tau-c correlation coefficient tests were used for comparison of outcomes of the two study groups. A P value of 0.05 or less was considered significant. RESULTSThirty-nine patients, 34 females, consented to participate. Thirty-one (79.5%) patients completed the final assessment and were included in the outcome analysis. There was no significant difference in the quality of life scales and incontinence scores. Patients in the IRAT pathway were more satisfied with the time required to complete management (P = 0.033) and had stronger agreement that all aspects of their problem were covered (P = 0.006). CONCLUSIONDespite of the lack of significant difference in outcome measures, the new pathway has positively influenced patient’s mindset, which was reflected in a higher satisfaction score.

关键词： Pathway Fecal incontinence Quality improvement