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Bayesian doubly adaptive randomization in clinical trials

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Science China Mathematics 2017年第12期60卷 2503-2514页

作者： XIAO YiKe LIU ZhongQiang hu feifang School of Statistics Renmin University of China School of Mathematics and Information Science Henan Polytechnic University Department of Statistics George Washington University

Bayesian adaptive randomization has attracted increasingly attention in the literature and has been implemented in many phase II clinical trials. Doubly adaptive biased coin design(DBCD) is a superior choice in response-adaptive designs owing to its promising properties. In this paper, we propose a randomized design by combining Bayesian adaptive randomization with doubly adaptive biased coin design. By selecting a fixed tuning parameter, the proposed randomization procedure can target an explicit allocation proportion, and assign more patients to the better treatment simultaneously. Moreover, the proposed randomization is efficient to detect treatment differences. We illustrate the proposed design by its applications to both discrete and continuous responses, and evaluate its operating features through simulation studies.

关键词： Bayesian approach doubly adaptive biased coin design power type I error allocation variability

Multi-arm covariate-adaptive randomization

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Science China Mathematics 2023年第1期66卷 163-190页

作者： feifang hu Xiaoqing Ye Li-Xin Zhang Department of Statistics The George Washington UniversityWashingtonDC 20052USA Institute of Statistics and Big Data Renmin University of ChinaBeijing 100872China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China

Simultaneously investigating multiple treatments in a single study achieves considerable efficiency in contrast to the traditional two-arm *** treatment allocation for influential covariates has become increasingly important in today’s clinical *** multi-arm covariate-adaptive randomized clinical trial is one of the most powerful tools to incorporate covariate information and multiple treatments in a single *** and Simon’s procedure has been extended to the multi-arm ***,the theoretical properties of multi-arm covariate-adaptive randomization have remained largely elusive for *** this paper,we propose a general framework for multi-arm covariate-adaptive designs which also includes the two-arm case,and establish the corresponding theory under widely satisfied *** theoretical results provide new insights into the balance properties of covariate-adaptive randomization procedures and make foundations for most existing statistical inferences under two-arm covariate-adaptive ***,these open a door to study the theoretical properties of statistical inferences for clinical trials based on multi-arm covariateadaptive randomization procedures.

关键词： multiple treatment balancing covariate clinical trial marginal balance Markov chain hu and hu’s general procedure Pocock and Simon’s procedure stratified permuted block design

Covariate-adaptive designs with missing covariates in clinical trials

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Science China Mathematics 2015年第6期58卷 1191-1202页

作者： LIU ZhongQiang YIN JianXin hu feifang Center for Applied Statistics and School of Statistics Renmin University of China School of Mathematics and Information Science Henan Polytechnic University

Many covariate-adaptive randomization procedures have been proposed and implemented to balance important covariates in clinical trials. These methods are usually based on fully observed covariates. In practice,the covariates of a patient are often partially missing. We propose a novel covariate-adaptive design to deal with missing covariates and study its properties. For the proposed design, we show that as the number of patients increases, the overall imbalance, observed margin imbalance and fully observed stratum imbalance are bounded in probability. Under certain covariate-dependent missing mechanism, the proposed design can balance missing covariates as if the covariates are observed. Finally, we explore our methods and theoretical findings through simulations.

关键词： missing stratum imbalance restored strata absolute partially minimization margin exclusive

In honor of the 65th birthday of Professor Zhidong Bai

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Science China Mathematics 2009年第6期52卷 1233-1234页

作者： hu feifang & CHEN Zehua Univ Virginia Charlottesville VA 22903 USA Natl Univ Singapore Singapore Singapore

We are thankful to Science in China Series A: Mathematics for the publication of this special issue in honor of Professor Zhidong Bai of his 65th birthday. Professor Bai is a leading statis-

关键词： Zhang

Comment on‘Inference after covariate-adaptive randomisation:aspects of methodology and theory’

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Statistical Theory and Related Fields 2021年第3期5卷 187-189页

作者： Wei Ma Li-Xin Zhang feifang hu Institute of Statistics and Big Data Renmin University of ChinaBeijingPeople’s Republic of China School of Mathematical Sciences Zhejiang UniversityZhejiangPeople’s Republic of China Department of Statistics George Washington UniversityWashingtonDCUSA

In the past decade,significant progress has been made regarding inference under covariate-adaptive *** thank *** for a timely review of the growing literature about the *** paper is focused on the most important and commonly used class of covariate-adaptive randomisation methods,i.e.,those balancing discrete *** recent advances in robust inference are emphasised and discussed in *** types of outcomes,such as continuous and time-to-event data,are *** here provide some additional recent results from the following five perspectives.

关键词： random variate thank

A KIND OF URN MODEL FOR ADAPTIVE SEQUENTIAL DESIGN

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Acta Mathematica Scientia 2001年第2期21卷 224-228页

作者：白志东陈桂景胡飞芳 Natl Univ Singapore Dept Stat & Appl Probabil Singapore 117548 Singapore Anhui Univ Dept Math Hefei 230039 Peoples R China

This paper proposes a new kind of generalized Friendman's urn model,which with adaptive nonhomogeneous generating *** model may be applied in sequential medical *** this model some limit theorems (strong consistency a... 详细信息

关键词： Generalized Friedman's urn,adaptive sequetial design,generating matrix strong consistency,asymptotical normality

带有时序趋势的序贯试验概率罐子模型中的极限定理

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数学年刊（A辑） 2001年第1期22卷 89-96页

作者：白志东陈桂景胡飞芳 Department of Statistics & Applied Probability 安徽大学数学系合肥230039 Department of Statistics& Applied Prabability National University of Singapore.

本文研究了带有未知的时序趋势的序贯试验概率罐子模型，对于时序趋势构造了一种估计量，从而建立了一种广义的Ｆｒｉｅｄｍａｎ概率带子模型，并且在这种序贯试验模型下获得了强相合性、渐近正态性等极限定理，这些结果为临床试验设计... 详细信息

本文研究了带有未知的时序趋势的序贯试验概率罐子模型，对于时序趋势构造了一种估计量，从而建立了一种广义的Ｆｒｉｅｄｍａｎ概率带子模型，并且在这种序贯试验模型下获得了强相合性、渐近正态性等极限定理，这些结果为临床试验设计的应用提供了一定的理论根据．

关键词：广义Friedman罐子自适应序贯设计时序趋势强相合性渐近正态性序贯试验 GFV模型

Photo‑Energized MoS_(2)/CNT Cathode for High‑Performance Li–CO_(2)Batteries in a Wide‑Temperature Range

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Nano-Micro Letters 2025年第1期17卷 160-175页

作者： Tingsong hu Wenyi Lian Kang hu Qiuju Li Xueliang Cui Tengyu Yao Laifa Shen Jiangsu Key Laboratory of Materials and Technologies for Energy Storage College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China

Li–CO_(2) batteries are considered promising energy storage systems in extreme environments such as Mars;however,severe performance degradation will occur at a subzero temperature owning to the sluggish reaction ***,a photo-energized strategy adopting sustainable solar energy in wide working temperature range Li–CO_(2) battery was achieved with a binder-free MoS_(2)/carbon nanotube(CNT)photo-electrode as *** unique layered structure and excellent photoelectric properties of MoS_(2) facilitate the abundant generation and rapid transfer of photo-excited carriers,which accelerate the CO_(2) reduction and Li_(2)CO_(3) decomposition upon *** illuminated battery at room temperature exhibited high discharge voltage of 2.95 V and mitigated charge voltage of 3.27 V,attaining superior energy efficiency of 90.2%and excellent cycling stability of over 120 *** at an extremely low temperature of−30℃,the battery with same electrolyte can still deliver a small polarization of 0.45 V by the photoelectric and photothermal synergistic mechanism of MoS_(2)/CNT *** work demonstrates the promising potential of the photo-energized wide working temperature range Li–CO_(2) battery in addressing the obstacle of charge overpotential and energy efficiency.

关键词： Li-CO_(2)batteries Photo-energized Wide operation-temperature Kinetics MoS_(2)

Fabrication and Mechano-sensing Characteristics of Bending Polypyrrole Actuator

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 240-245页

作者： CHEN Jinyou hu Wei School of Automotive Engineering Hunan Financial&Industrial Vocational-technical CollegeHengyang 421002China College of Mechanical and Electrical Engineering Hunan Agricultural UniversityChangsha 410128China

To prepare a conductive polymer actuator with decent performance,a self-built experimental platform for the preparation of polypyrrole film is *** of the essential goals is to examine the mechanical characteristics of the actuator in the presence of various combinations of process parameters,combined with the orthogonal test method of"four factors and three levels".The bending and sensing characteristics of actuators of various sizes are methodically examined using a self-made bending polypyrrole *** functional relationship between the bending displacement and the output voltage signal is established by studying the characteristics of the actuator sensor subjected to various degrees of *** experimental results reveal that the bending displacement of the actuator tip almost exhibits a linear variation as a function of length and *** the voltage reaches 0.8 V,the bending speed of the actuator tends to be ***,the mechanical properties of the self-assembled polypyrrole actuator are verified by the design and fabrication of the microgripper.

关键词： conductive polymer polypyrrole mechanical characteristics actuators sensing characteristics