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A perspective on recent methods on testing predictability of asset returns

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Applied Mathematics(A Journal of Chinese Universities) 2018年第2期33卷 127-144页

作者： LIAO Xiao-sai CAI Zong-wu CHEN hai-qiang The Wang Yanan Institute for Studies in Economics MOE Key Laboratory of Econometrics (Xiamen University) Fujian Provincial Key Laboratory of Statistical Science Xiamen University Department of Economics University of Kansas

This paper highlights some recent developments in testing predictability of asset returns with focuses on linear mean regressions, quantile regressions and nonlinear regression models. For these models, when predictors are highly persistent and their innovations are contemporarily correlated with dependent variable, the ordinary least squares estimator has a finite-sample bias, and its limiting distribution relies on some unknown nuisance parameter, which is not consistently estimable. Without correcting these issues, conventional test statistics are subject to a serious size distortion and generate a misleading conclusion in testing pre- dictability of asset returns in real applications. In the past two decades, sequential studies have contributed to this subject and proposed various kinds of solutions, including, but not limit to, the bias-correction procedures, the linear projection approach, the IVX filtering idea, the variable addition approaches, the weighted empirical likelihood method, and the double-weight robust approach. Particularly, to catch up with the fast-growing literature in the recent decade, we offer a selective overview of these methods. Finally, some future research topics, such as the econometric theory for predictive regressions with structural changes, and nonparametric predictive models, and predictive models under a more general data setting, are also discussed.

关键词： asset returns Heteroskedasticity high persistency nonlinearity predictability quantile regressions

Sequential dynamic resource allocation in multi-beam satellite systems:A learning-based optimization method

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Chinese Journal of Aeronautics 2023年第6期36卷 288-301页

作者： Yixin HUANG Shufan wu Zhankui ZENG Zeyu KANG Zhongcheng MU hai HUANG School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Academy of Spaceflight Technology Shanghai 200240China School of Astronautics Beihang UniversityBeijing 100191China

Multi-beam antenna and beam hopping technologies are an effective solution for scarce satellite frequency *** of the primary challenges accompanying with Multi-Beam Satellites(MBS)is an efficient Dynamic Resource Allocation(DRA)*** paper presents a learning-based Hybrid-Action Deep Q-Network(HADQN)algorithm to address the sequential decision-making optimization problem in *** using a parameterized hybrid action space,HADQN makes it possible to schedule the beam pattern and allocate transmitter power more *** pursue multiple long-term QoS requirements,HADQN adopts a multi-objective optimization method to decrease system transmission delay,loss ratio of data packets and power consumption load *** results demonstrate that the proposed HADQN algorithm is feasible and greatly reduces in-orbit energy consumption without compromising QoS performance.

关键词： Beam hopping Deep reinforcement learning Dynamic resource allocation Mixed-integer programming Multi-beam satellite systems Multi-objective optimization

First stirling-type cryocooler reaching lambda point of ~4He(2.17K) and its prospect in Chinese HUBS satellite project

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Science Bulletin 2019年第4期64卷 219-221页

作者： Jue Wang Changzhao Pan tong Zhang Kaiqi Luo Xiaotong Xi Xianlin wu Jianpeng Zheng Liubiao Chen Junjie Wang Yuan Zhou hai Jin Wei Cui University of Chinese Academy of Sciences CAS Key Laboratory of Cryogenics Technical Institute of Physics and Chemistry Chinese Academy of Sciences Laboratoire National de Métrologie Et d'essais-Conservatoire National des Arts et Métiers (LNE-Cnam) State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Department of Physics and Center for Astrophysics Tsinghua University

The issue of "missing baryons” is always an unsolved mystery in galaxy cosmology, and an important reason for the great uncertainty of the galaxies' formation and evolution. To find the "missing" baryons, extra high-resolution spectral observation and imaging of the soft X-ray band (<1 kev) is required. However, the existing observation methods cannot meet this requirement. Therefore, Tsinghua University leads and proposes the Chinese "Hot Universe Baryon Surveyor (HUBS)" satellite program.

关键词： missing baryons HUBS missing

Reinforcement learning based dynamic distributed routing scheme for mega LEO satellite networks

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Chinese Journal of Aeronautics 2023年第2期36卷 284-291页

作者： Yixin HUANG Shufan wu Zeyu KANG Zhongcheng MU hai HUANG Xiaofeng wu Andrew Jack TANG Xuebin CHENG School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China School of Astronautics Beihang UniversityBeijing 100191China School of Aerospace Mechanical and Mechatronic EngineeringThe University of SydneyCamperdown 2006Australia X-Laboratory The Second Academy of China Aerospace Science and Industry CorporationBeijing 100854China

Recently,mega Low Earth Orbit(LEO)Satellite Network(LSN)systems have gained more and more attention due to low latency,broadband communications and global coverage for ground *** of the primary challenges for LSN systems with inter-satellite links is the routing strategy calculation and maintenance,due to LSN constellation scale and dynamic network topology *** order to seek an efficient routing strategy,a Q-learning-based dynamic distributed Routing scheme for LSNs(QRLSN)is proposed in this *** achieve low end-toend delay and low network traffic overhead load in LSNs,QRLSN adopts a multi-objective optimization method to find the optimal next hop for forwarding data *** results demonstrate that the proposed scheme can effectively discover the initial routing strategy and provide long-term Quality of Service(QoS)optimization during the routing maintenance *** addition,comparison results demonstrate that QRLSN is superior to the virtual-topology-based shortest path routing algorithm.

关键词： LEO satellite networks Mega constellation Multi-objective optimization Routing algorithm Reinforcement learning

A NEW MODIFICATION OF TRANSANAL SOAVE PULL-THROUGH PROCEDURE FOR HIRSCHSPRUNG’S DISEASE

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Chinese Medical Journal 2006年第1期119卷 37-42页

作者： LI Ai-wu ZHANG Wen-tong LI Fu-hai CUI Xin-hai DUAN Xiang-sheng Department of Paediatric Surgery Qilu Hospital Shandong University Ji＇nan 250012 China

Background One stage transanal Soave pull-through procedure （TSPP） is a recent popular operation in the treatment of Hirschsprung＇s disease （HD）. With no visible scar and a short hospital stay, it is well accepted by surgeons and mothers. In the conventional Soave procedure, a long rectal muscular cuff left for anocolic anastomosis might increase the incidence of postoperative enterocolitis and constipation. This study presents a modified transanal Soave pull-through procedure （MTSPP） which includes an oblique mucosectomy and an oblique anastomosis with a short split muscular cuff.. Methods A review of two groups of HD patients was made： 112 underwent conventional transanal Soave procedure from 1999 to 2001 （group 1） and 140 underwent modified transanal Soave procedure from 2002 to 2004 （group 2）. A comparison was made between the two groups on operative data and postoperative complications. The data included： age at the operation, operating time, blood loss, time to feeds and hospital stay, occurrence of postoperative enterocolitis or constipation, need for anal dilatation, postoperative bowel function and perianal skin problems. Results There was no significant difference between two groups with respect to age, gender, length of colon resected, operating time, blood loss and hospital stay. However occurrence of postoperative enterocolitis, constipation, anastomotic stricture and time needed for anal dilatation were evidently less in group 2 （MTSPP）. The mean operating time in group 1 was （106 ± 39） minutes with a range of 60 to 170 minutes; in group 2 was （101 ± 36） minutes with a range of 66 to 190 minutes. The average length of the bowel resected in group 1 was （24 ± 7） cm, range 15 to 58 cm; in group 2 was （26 ± 8） cm, range 15 to 70 cm. Two patients, one in each group, required laparoscopic assistance because of long aganglionic colon. Another patient in group 2 required laparotomy because of total colonic aganglionosis. Postoperative complications in grou

关键词： transanal pull-through Hirschsprung's disease Soave modified procedure

Correlation of Seven Biological Factors(Hsp90α,p53,MDM2,Bcl-2,Bax,Cytochrome C,and Cleaved caspase3)with Clinical Outcomes of ALK+ Anaplastic Large-cell Lymphoma

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Biomedical and Environmental Sciences 2011年第6期24卷 630-641页

作者： LI Hui Ling HUANG Xue Ping ZHOU Xin Hua JI Tian hai wu Zi Qing WANG Zhi Qiang JIANG Hui Yong LIU Fan Rong ZHAO tong Department of Pathology Nanfang Hospital affiliated to Southern Medical University Guangzhou 510515 Guangdong China Department of Pathology School of Basic Medical Science Southern Medical University Guangzho 510515 Guangdong China

Objective To explore correlation of seven apoptosis-related proteins （Hsp9Oa, p53, MDM2, Bcl-2, Bax, Cytochrome C, and Cleaved caspase3） with clinical outcomes of ALK＋ anaplastic large-cell lymphoma （ALCL）. Methods Using immunohistochemistry and immunofluorescence double staining methods, the expressions of these seven apoptosis-associated proteins were studied to clarify their relationship with clinical outcomes of 36 ALK＋ and 25 ALK- systemic ALCL patients enrolled between 1996 and 2006. The relationship of these apoptosis-regulating proteins with NPM-ALK status was also evaluated with the tyrosine inhibitor herbimycin A （HA） in vitro by immunocytochemistry, Western blotting and flow cytometric assays. Results The presence of Hsp90a-, MDM2-, Bax-, Cytochrome C, and Cleaved caspase3-positive tumor cells was found significantly different in ALK＋ and ALK- ALCLs , which was correlated with highly favorable clinical outcome. The Bcl-2- and p53-positive tumor cells were found in groups of patients with unfavorable prognosis. Inhibition of NPM-ALK by HA could reactivate the p53 protein and subsequent apoptosis-related proteins and therefore induced apoptosis in ALK＋ ALCL cells. Conclusion Our results suggest that these seven proteins might be involved in apoptosis regulation and associated with clinical outcome of ALK＋ systemic ALCLs. We also reveal a dynamic chain relation that NPM-ALK regulates p53 expression and subsequent apoptosis cascade in ALK＋ ALCLs.

关键词： ALK+ALCL NPM-ALK Prognostic factors Apoptosis Herbimycin A

有界随机噪声激励下软弹簧Duffing振子的安全盆分叉

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物理学报 2005年第10期54卷 4610-4613页

作者：戎海武王向东徐伟方同佛山大学数学系佛山528000 西北工业大学应用数学系西安710072

研究了软弹簧Duffing振子在有界随机噪声激励下,系统安全盆的侵蚀现象,并提出了随机安全盆分叉的概念.计算表明,由于随机扰动的影响,系统的随机安全盆分叉点发生了偏移.

关键词： Duffing振子有界随机噪声安全盆分叉随机噪声激励分叉点软弹簧有界随机扰动计算表

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World Journal of Pediatrics 2022年第4期18卷 271-277页

作者： Yi Cao Wei-Hui Yan Li-Na Lu Yi-Jing Tao hai-Xia feng Qing-Qing wu Yi-Jing Chu Wei Cai Ying Wang Division of Pediatric Gastroenterology and Nutrition Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of MedicineNo.1665Kongjiang Rd.ShanghaiChina Shanghai Institute for Pediatric Research ShanghaiChina Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition No.1665Kongjiang Rd.ShanghaiChina

Background Children with intestinal failure(IF)have frequent catheter-related bloodstream infections(CRBSIs).This study aimed to analyze the clinical presentation and laboratory parameters of CRBSIs in children with *** This 6-year retrospective study was conducted among IF children with CRBSIs at an intestinal rehabilitation center in *** data were collected,including data of temperature and gastrointestinal ***/catheter culture,fecal tests,and calculation of inflammatory index were performed,which were obtained within 1 week since CRBSI *** Fifty children with 87 CRBSIs were identified,of which there were 17 suspected and 70 confirmed ***-two pathogens were cultured from 70 positive blood cultures:63%were Gram-positive organisms,23%were Gram-negative organisms,and 11%were fungal ***,48.6%were enteric organisms;47.2%of bacterial pathogens were consistent between fecal and blood ***,46.3%fecal routines showed abnormalities including increased white blood cells,occult blood positive and the presence of fat *** consistent symptom at onset of CRBSIs was fever and gastrointestinal symptoms including increased stool output,abdominal distension,or both.C-reactive protein(CRP)and procalcitonin(PCT)were elevated,i.e.,16.5 mg/L[interquartile range(IQR)8.7-44.7]and 0.48 ng/mL(IQR 0.2-1.76),*** IF children had a high rate of CRBSIs,of which larger proportions were due to Gram-positive and enteric *** and/or gastrointestinal symptoms,combined with elevated CRP and PCT,is conducive to the early diagnosis of CRBSIs in IF patients.

关键词： Enteric pathogens Fecal examination Gastrointestinal symptoms

Triple-negative breast cancer:new treatment strategies in the era of precision medicine

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Science China(Life Sciences) 2021年第3期64卷 372-388页

作者： Song-Yang wu hai Wang Zhi-Ming Shao Yi-Zhou Jiang Department of Breast Surgery Fudan University Shanghai Cancer CenterKey Laboratory of Breast Cancer in ShanghaiDepartment of OncologyShanghai Medical CollegeFudan UniversityShanghai 200032China

Triple-negative breast cancer(TNBC)remains the most aggressive cluster of all breast cancers,which is due to its rapid progression,high probabilities of early recurrence,and distant metastasis resistant to standard *** the advances in cancer genomics and transcriptomics that can illustrate the comprehensive profiling of this heterogeneous disease,it is now possible to identify different subclasses of TNBC according to both intrinsic signals and extrinsic microenvironment,which have a huge influence on predicting response to established therapies and picking up novel therapeutic targets for each *** this review,we summarize basic characteristics and critical subtyping systems of TNBC,and particularly discuss newly found prospective targets and relevant medications,which were proved promising in clinical trials,thus shedding light on the future development of precision treatment strategies.

关键词： triple-negative breast cancer molecular subtype targeted therapy precision medicine