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Why China needs data sharing to address its air-quality challenge

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National Science Review 2017年第6期4卷 794-797页

作者： Patrick Funk Lan Xue Zheng Liang Kelly S.Gallagher Peter F. Cowhey Erica R.H.Fuchs Department of Engineering and Public Policy Carnegie Mellon University school of Public Policy and Management Tsinghua University the fletcher school Tufts University school of Global Policy and Strategy University of California San Diego

In the fight against air pollution,sharing data within China and forming scientists’consensus on data-driven policy recommendations are at least as important as data *** scale of data publicly available can have dram... 详细信息

关键词： Why China needs data sharing to address its air-quality challenge

Respiratory Volume Monitoring to Assess the Effect of Airway Maneuvers on Ventilation during Upper Endoscopy

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Open Journal of Anesthesiology 2014年第11期4卷 281-290页

作者： Katherine Holley Donald Mathews Diane Ladd Lisa Campana Howard Schapiro Department of Anesthesiology Fletcher Allen Health Care University of Vermont College of Medicine Burlington USA school of Nursing West Virginia University Morgantown USA Respiratory Motion Inc. Waltham USA

Introduction: Propofol use during endoscopic procedures has become increasingly popular and assessing and maintaining airway patency is a significant challenge. Anesthesiologists often use airway maneuvers to maintain airway patency and ventilation during procedural sedation. A novel, non-invasive, Respiratory Volume Monitor (RVM) that provided continuous, real-time measurements of minute ventilation (MV), tidal volume (TV) and respiratory rate (RR) was used to monitor respiratory performance before, during, and after endoscopic procedures, quantify MV changes before and after airway maneuvers, and to quantify propofol-induced respiratory depression. Methods: RVM traces were obtained from 25 patients undergoing sedation for endoscopic procedures. Airway maneuvers were performed in 19/25 patients. All 25 patients received propofol as the primary sedative. Results: Forty-five airway maneuvers were performed. During these maneuvers, all respiratory parameters increased relative to pre-maneuver levels. On average, MV increased by 24% ± 5% (mean ± SEM), TV 14% ± 5% and RR: 17% ± 6%. The cohort average MVBASELINE was 9.5 ± 0.7 L/min (TV = 670 ± 60 ml, RR = 15 ± 0.7). Following propofol MV decreased transiently, reaching nadir five minutes after the last dose of propofol at 82% ± 10% of baseline (MV = 7.5 ± 1.0 L/min). The reduction in MV was driven by reduction in TV, not RR. Conclusions: Data demonstrated that RVM was able to track changes in ventilation and was able to quantify respiratory changes following airway maneuvers. All patients had a significant reduction in ventilatory volumes after propofol. Five minutes after the last dose of propofol, MV and TV were significantly reduced while RR was not, suggesting that monitoring respiratory rate alone was not a sufficient indicator of respiratory status.

关键词： Non-Invasive Respiratory Volume Monitoring Minute Ventilation Airway Maneuvers Procedural Sedation Endoscopy

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向软实力取经——在21世纪需要“软治愈”

英国医学杂志中文版 2016年第3期19卷 125-126页

作者： Dariush Mozaffarian Jordan A Blashek James Stavridis 梁立智 Friedman school ofNutrition Science andPolicy TuftsUniversity BostonMA 02111 USA Yale Law school New Haven CT the fletcher school Tufts UniversityBoston MA 首都医科大学卫生管理与教育学院

为了实现对外政策而采取直接军事干预，这一“硬实力”的局限性在国际外交事务中正日益凸显。如今，政策制定者、军事领导者和情报专家们认识到预防策略，这一“软实力”在解决多方根本性争端和不稳定因素方面的重要作用。

关键词：医疗卫生系统软治愈积极主动预防宣传教育经济激励跨国合作策略

Multi-modality liver image registration based on multilevel B-splines free-form deformation and L-BFGS optimal algorithm

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Journal of Central South University 2014年第1期21卷 287-292页

作者：宋红李佳佳王树良马婧婷 school of Software Beijing Institute of Technology school of Computer Science Beijing Institute of Technology

A new coarse-to-fine strategy was proposed for nonrigid registration of computed tomography(CT) and magnetic resonance(MR) images of a *** hierarchical framework consisted of an affine transformation and a B-splines free-form deformation(FFD).The affine transformation performed a rough registration targeting the mismatch between the CT and MR *** B-splines FFD transformation performed a finer registration by correcting local motion *** the registration algorithm,the normalized mutual information(NMI) was used as similarity measure,and the limited memory Broyden-fletcher- Goldfarb-Shannon(L-BFGS) optimization method was applied for optimization *** algorithm was applied to the fully automated registration of liver CT and MR images in three *** results demonstrate that the proposed method not only significantly improves the registration accuracy but also reduces the running time,which is effective and efficient for nonrigid registration.

关键词： multi-modal image registration affine transformation B-splines free-form deformation (FFD) L-BFGS

Kernel Estimation of Truncated Volterra Filter Model Based on DFP Technique and Its Application to Chaotic Time Series Prediction

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Chinese Journal of Electronics 2019年第1期28卷 127-135页

作者： ZHANG Yumei BAI Shulin LU Gang WU Xiaojun Key Laboratory of Modern Teaching Technology Ministry of EducationShaanxi Normal University school of Computer Science Shaanxi Normal University school of Electronics and Information Northwestern Polytechnical University

In order to overcome some problems caused by improper parameters selection when applying Least mean square(LMS), Normalized LMS(NLMS) or Recursive least square(RLS) algorithms to estimate coefficients of second-order Volterra filter, a novel Davidonfletcher-Powell-based Second-order Volterra filter(DFPSOVF) is proposed. Analysis of computational complexity and stability are presented. Simulation results of system parameter identification show that the DFP algorithm has fast convergence and excellent robustness than LMS and RLS algorithm. Prediction results of applying DFPSOVF model to single step predictions for Lorenz chaotic time series illustrate stability and convergence and there have not divergence problems. For the measured multiframe speech signals, prediction accuracy using DFPSOVF model is better than that of Linear prediction(LP).The DFP-SOVF model can better predict chaotic time series and the real measured speech signal series.

关键词： Chaos Davidon-fletcher-Powell algorithm Prediction model Second-order Volterra filter Speech signal

Clinical implications of doubling time of gastrointestinal submucosal tumors

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World Journal of Gastroenterology 2016年第45期22卷 10015-10023页

作者： Shuko Koizumi Mitsuhiro Kida Hiroshi Yamauchi Kosuke Okuwaki Tomohisa Iwai Shiro Miyazawa Miyoko Takezawa Hiroshi Imaizumi Wasaburo Koizumi Department of Gastroenterology Kitasato University School of Medicine

AIM To evaluate the efficacy of doubling time(DT) of gastrointestinal submucosal tumors(GIST).METHODS From April 1987 through November 2012, a total of 323 patients were given a final histopathological diagnosis of GISTs on surgical resection or endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA) in Kitasato University East Hospital or Kitasato University Hospital. We studied 53 of these patients(34 with resected tumors and 19 with unresected tumors) whose tumors could be measured on EUS on at least two successive occasions. The histopathological diagnosis was GIST in 34 patients, leiomyoma in 5, schwannoma in 3, ectopic pancreas in 1, hamartoma in 1, cyst in 1, Brunner's adenoma in 1, and spindle-cell tumor in 7. We retrospectively calculated the DT of GISTs on the basis of the time course of EUS findings to estimate the growth rate of such *** The DT was 17.2 mo for GIST, as compared with 231.2 mo for leiomyoma, 104.7 mo for schwannoma, 274.9mo for ectopic pancreas, 61.2 mo for hamartoma, 49.0 mo for cyst, and 134.7 mo for Brunner's adenoma. The GISTs were divided into risk classes on the basis of tumor diameters and mitotic figures(fletcher's classification). The classification was extremely low risk or low risk in 28 patients, intermediate risk in 3, and high risk in 3. DT of GIST according to risk was 24.0 mo for extremely low-risk plus low-risk GIST, 17.1 mo for intermediate-risk GIST, and 3.9 mo for high-risk GIST. DT of GIST was significantly shorter than that of leiomyoma plus schwannoma(P < 0.05), and DT of high-risk GIST was significantly shorter than that of extremely low-risk plus low-risk GIST(P < 0.05).CONCLUSION For GIST, a higher risk grade was associated with a significantly shorter DT. Small SMTs should initially be followed up within 6 mo after detection.

关键词： Gastrointestinal submucosal tumor Doubling time Submucosal tumor Initial observational duration Endoscopic ultrasonography Endoscopic ultrasonography-guided fine needle aspiration fletcher’s classification

Aerodynamic optimization design for high pressure turbines based on the adjoint approach

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Chinese Journal of Aeronautics 2015年第3期28卷 757-769页

作者： Chen Lei Chen Jiang Heavy Engineering Research Association school of Energy and Power Engineering Beihang University

Abstract A first study on the continuous adjoint formulation for aerodynamic optimization design of high pressure turbines based on S2 surface governed by the Euler equations with source terms is presented. The objective function is defined as an integral function along the boundaries, and the adjoint equations and the boundary conditions are derived by introducing the adjoint variable vec- tors. The gradient expression of the objective function then includes only the terms related to phys- ical shape variations. The numerical solution of the adjoint equation is conducted by a finite- difference method with the Jameson spatial scheme employing the first and the third order dissipa- tive fluxes. A gradient-based aerodynamic optimization system is established by integrating the blade stagger angles, the stacking lines and the passage perturbation parameterization with the quasi-Newton method of Broyden fletcher Goldfarb-Shanno （BFGS）. The application of the continuous adjoint method is validated through a single stage high pressure turbine optimization case. The adiabatic efficiency increases from 0.8875 to 0.8931, whilst the mass flow rate and the pressure ratio remain almost unchanged. The optimization design is shown to reduce the passage vortex loss as well as the mixing loss due to the cooling air injection.

关键词： Adjoint method Aerodynamic design High pressure turbineOptimization design Objective function

Melt Pond Scheme Parameter Estimation Using an Adjoint Model

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Advances in Atmospheric Sciences 2021年第9期38卷 1525-1536页

作者： Yang LU Xiaochun WANG Jihai DONG school of Marine Sciences Nanjing University of Information Science and TechnologyNanjing 210044China

Melt ponds significantly affect Arctic sea ice thermodynamic *** melt pond parameterization scheme in the Los Alamos sea ice model(CICE6.0) can predict the volume,area fraction(the ratio between melt pond area to sea ice area in a model grid),and depth of melt ***,this scheme has some uncertain parameters that affect melt pond *** parameters could be determined through a conventional parameter estimation method,which requires a large number of sensitivity *** adjoint model can calculate the parameter sensitivity *** the present research,an adjoint model was developed for the CESM(Community Earth System Model) melt pond scheme.A melt pond parameter estimation algorithm was then developed based on the CICE6.0 sea ice model,melt pond adjoint model,and L-BFGS(Limited-memory Broyden-fletcher-Goldfard-Shanno) minimization *** parameter estimation algorithm was verified under idealized *** using MODIS(Moderate Resolution Imaging Spectroradiometer)melt pond fraction observation as a constraint and the developed parameter estimation algorithm,the melt pond aspect ratio parameter in CESM scheme,which is defined as the ratio between pond depth and pond area fraction,was estimated every eight days during summertime for two different regions in the *** region was covered by multi-year ice(MYI) and the other by first-year ice(FYI).The estimated parameter was then used in simulations and the results show that:(1) the estimated parameter varies over time and is quite different for MYI and FYI;(2) the estimated parameter improved the simulation of the melt pond fraction.

关键词： CICE6.0 Sea ice model Melt pond Parameterization scheme Adjoint Model Parameter estimation Arctic

An Algorithm for Determination of Projectile Attitude Angles in Projectile Trajectory Prediction

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第2期35卷 361-370页

作者： Zha Qicheng Rui Xiaoting Yu Hailong Zhou Qinbo Institute of Launch Dynamics School of Energy and Power EngineeringNanjing University of Science and Technology

A fast and accurate algorithm is established in this paper to increase the precision of ballistic trajectory *** algorithm is based on the six-degree-of-freedom(6 DOF)trajectory equations,to estimate the projectile attitude angles in every measuring ***,the algorithm utilizes the Davidon-fletcher-Powell(DFP)method to solve nonlinear equations and Doppler radar trajectory test information containing only position coordinates of the projectile to reconstruct the angular ***″position coordinates by the test″and″angular displacements by reconstruction″at the end phase of the radar measurement are used as an initial value for the trajectory computation to extrapolate the trajectory impact *** numerical simulations validate the proposed method and demonstrate that the estimated impact point agrees very well with the real ***,other artillery trajectory can be predicted by the algorithm,and other trajectory models,such as 4 DOF and 5 DOF models,can also be incorporated into the proposed algorithm.

关键词： ballistic trajectory impact point prediction Davidon-fletcher-Powell method six-degree-of-freedom trajectory model Doppler radar data