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Heteroscedastic regression analysis method for mixed data

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航空动力学报 2011年第4期26卷 721-726页

作者： fu Hui-min YUE xiao-rui Research Center of Small Sample Technology Beijing University of Aeronautics and Astronautics Beijing 100191 China

The heteroscedastic regression model was established and the heteroscedastic regression analysis method was presented for mixed data composed of complete data,type-Ⅰ censored data and type-Ⅱ censored data from the location-scale *** best unbiased estimations of regression coefficients,as well as the confidence limits of the location parameter and scale parameter were ***,the point estimations and confidence limits of percentiles were ***,the traditional multiple regression analysis method which is only suitable to the complete data from normal distribution can be extended to the cases of heteroscedastic mixed data and the location-scale *** the presented method has a broad range of promising applications.

关键词： heteroscedastic regression analysis censored data performance test life prediction reliability analysis

Combustion instability of pilot flame in a pilot bluff body stabilized combustor

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Chinese Journal of Aeronautics 2015年第6期28卷 1606-1615页

作者： fu xiao Yang fujiang Guo Zhihui National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics School of Energy and Power Engineering Beihang University

Combustion instability of pilot flame has been investigated in a model pilot bluff body stabilized combustor by running the pilot flame only. The primary objectives are to investigate the pilot flame dynamics and to provide bases for the study of the interaction mechanisms between the pilot flame and the main flame. Dynamic pressures are measured by dynamic pressure transduc- ers. A high speed camera with CH＊ bandpass filter is used to capture the pilot flame dynamics. The proper orthogonal decomposition （POD） is used to further analyze the high speed images. With the increase of the pilot fuel mass flow rate, the pilot flame changes from stable to unstable state grad- ually. The combustion instability frequency is 136 Hz when the pilot flame is unstable. Numerical simulation results show that the equivalence ratios in both the shear layer and the recirculation zone increase as the pilot fuel mass flow rate increases. The mechanism of the instability of the pilot flame can be attributed to the coupling between the second order acoustic mode and the unsteady heat release due to symmetric vortex shedding. These results illustrate that the pilot fuel mass flow rate has significant influences on the dynamic stability of the pilot flame.

关键词： Combustion instability High speed image Pilot flame Proper orthogonal decom-position (POD) Vortex shedding

Malicious code passive propagation model and vaccine distribution model of P2P networks

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Journal of Systems Engineering and Electronics 2010年第1期21卷 161-167页

作者： xiaolong Xu Ruchuan Wang fu xiao School of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 E R. China State Key Laboratory for Novel Software Technology Nanjing University Nanjing 210093 P. R. China

To fight against malicious codes of P2P networks, it is necessary to study the malicious code propagation model of P2P networks in depth. The epidemic of malicious code threatening P2P systems can be divided into the active and passive propagation models and a new passive propagation model of malicious code is proposed, which differentiates peers into 4 kinds of state and fits better for actual P2P networks. From the propagation model of malicious code, it is easy to find that quickly making peers get their patched and upgraded anti-virus system is the key way of immunization and damage control. To distribute patches and immune modules efficiently, a new exponential tree plus （ET＋） and vaccine distribution algorithm based on ET＋ are also proposed. The performance analysis and test results show that the vaccine distribution algorithm based on ET＋ is robust, efficient and much more suitable for P2P networks.

关键词： data security and computer security computer virus,peer-to-peer computing propagation immune exponential tree.

Research on new type of fast-opening mechanism in steam turbine regulating system and optimization of operation tactic

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第5期9卷 633-639页

作者： xiao-xiao LI Xuan-yin WANG fu-shang LI The State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China Shandong Electrical Power Institute Jinan 250002 China

With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathematical model of system is built up. With the use of AMESIM software, the displacement curve of the piston, the force curve of the cartridge valve spool, the pressure curve and the flux curve in the regulation process are obtained based on simulation. The performances of three fast-opening systems composed of cartridge valves with different diameters are compared. Based on the analysis on factors that affect the execution time of fast-opening, the dead zone of the fast-opening system is put forward. To overcome the defect, dif- ferent operation modes are adopted for different zones. The result shows that with the increase of the valve diameter, the regulating time in the dead zone significantly exceeds the fast-opening time in the whole journey. Accordingly, the optimization operation tactic in the dead zone and the qualification conditions are brought forward. The fast-opening system composed of 32 mm cartridge valves is taken as an example with use of the tactic. The simulation result shows that the maximum regulating time is shortened by 509 ms.

关键词： Steam turbine Fast-opening Regulating system AMESIM

A TRANSFER FORECASTING MODEL FOR CONTAINER THROUGHPUT GUIDED BY DISCRETE PSO

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Journal of Systems Science & Complexity 2014年第1期27卷 181-192页

作者： xiao Jin xiao Yi fu Julei LAI Kin Keung Business School Sichuan University Chengdu 610064 China. School of Information Management Central China Normal University Wuhan 430079 China Academy ofMathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China. Information System & Management National University of Defense Technology Changsha 410073 China. Department of Management Sciences City University of Hong Kong Hong Kong China.

Abstract Accurate forecast of future container throughput of a port is very important for its con struction, upgrading, and operation management. This study proposes a transfer forecasting model guided by discrete particle swarm optimization algorithm （TF-DPSO）. It firstly transfers some related time series in source domain to assist in modeling the target time series by transfer learning technique, and then constructs the forecasting model by a pattern matching method called analog complexing. Finally, the discrete particle swarm optimization algorithm is introduced to find the optimal match between the two important parameters in TF-DPSO. The container throughput time series of two im portant ports in China, Shanghai Port and Ningbo Port are used for empirical analysis, and the results show the effectiveness of the proposed model.

关键词： Analog complexing container throughput forecasting discrete particle swarm optimiza-tion transfer forecasting model.

Cell and gene therapy for arrhythmias： Repair of cardiac conduction damage

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Journal of Geriatric Cardiology 2011年第3期8卷 147-158页

作者： Yong-fu xiao Cardiac Rhythm Disease Management Medtronic lnc. 8200 Coral Sea Street NE Mounds View MN 55112 USA

Action potentials generated in the sinoatrial node （SAN） dominate the rhythm and rate of a healthy human heart. Subsequently, these action potentials propagate to the whole heart via its conduction system. Abnormalities of impulse generation and/or propagation in a heart can cause arrhythmias. For example, SAN dysfunction or conduction block of the atrioventricular node can lead to serious bradycardia which is currently treated with an implanted electronic pacemaker. On the other hand, conduction damage may cause reentrant tachyarrhythmias which are primarily treated pharmacologically or by medical device-based therapies, including defibrillation and tissue ablation. However, drug therapies sometimes may not be effective or are associated with serious side effects. Device-based therapies for cardiac arrhythmias, even with well developed technology, still face inadequacies, limitations, hardware complications, and other challenges. Therefore, scientists are actively seeking other alternatives for antiarrhythmic therapy. In particular, cells and genes used for repairing cardiac conduction damage/defect have been investigated in various studies both in vitro and in vivo. Despite the complexities of the excitation and conduction systems of the heart, cell and gene-based strategies provide novel alternatives for treatment or cure of cardiac arrhythmias. This review summarizes some highlights of recent research progress in this field.

关键词： cell therapy gene therapy conduction repair arrhythmia

Repair cell first,then regenerate the tissues and organs

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Military Medical Research 2021年第4期8卷 579-580页

作者： xiao-Bing fu Wound Healing Unit Medical Innovation Department and the Fourth Medical CenterChinese PLA General Hospital and PLA Medical CollegeBeijing 100853China

Wound healing,tissue repair and regenerative medicine are in great demand,and great achievements in these fields have been *** traditional strategy of tissue repair and regeneration has focused on the level of tissues and organs directly;however,the basic process of repair at the cell level is often *** the cell is the basic unit of organism structure and function;cell damage is caused first by ischemia or ischemia-reperfusion after severe trauma and ***,damage to tissues and organs occurs with massive cell damage,apoptosis and even cell ***,how to achieve the aim of perfect repair and regeneration?The basic process of tissue or organ repair and regeneration should involve repair of cells first,then tissues and *** this manuscript,it is my consideration about how to repair the cell first,then regenerate the tissues and organs.

关键词： Cell repair Tissue repair Regenerative medicine Tissue engineering

DIAGNOSTIC VALUE OF WHOLE BODY DIFfuSION WEIGHTED IMAGING FOR SCREENING PRIMARY TUMORS OF PATIENTS WITH METASTASES

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Chinese Medical Sciences Journal 2008年第3期23卷 145-150页

作者： Tai-fu Gu Xin-lan xiao Fei Sun Jian-hua Yin Hai Zhao Department of Radiology the Second Affiliated Hospital of Nanchang University Nanchang 330006 MR Modality General Electric Healthcare China Beijing 100172

Objective To evaluate the values of whole body diffusion weighted imaging （DWI） in screenmg pnmary unknown tumor in patients with metastases. Methods Totally, 34 patients with metastases of primary unknown tumors were scanned with whole body DWI, and conventional magnetic resonance （MR） imaging was performed if suspected lesions were detected. All the metastases including 27 cases of osseous metastases, 2 brain metastases, 2 liver metastases, 1 pulmonary multiple metastasis, 1 neck metastasis and 1 malignant ascites, were diagnosed by computed tomography, single photon emission computed tomography, or MR imaging. For the proven primary tumors diagnosed by biopsy or pathology of surgical specimens, apparent diffusion coefficient （ADC） values of the primary and metastatic lesions were measured respectively. The sensitivity and specificity of this technique for screening primary tumors were cvaluated. Results We found 24 cases with suspected primary lesions, in which 23 lesions were proved to be primary tumors, and 1 was proved to be benign lesion. And no definite primary lesion was found in 10 cases on whole body DWI, but in which 1 case was diagnosed with primary tumor by biopsy later, and the other 9 cases remained unknown within follow-up of over halfa year. The difference was not significant in ADC values between primary and metastatic lesions （P〉0.05）. The sensitivity and specificity of whole body DWI for searching primary tumors was 95.8% and 90.0%, respectively. Conclusion Combined with conventional MR scanning, whole body DWI can help to search primary lesions of patients with metastases.

关键词： diffusion weighted imaging primary tumor neoplasm metastasis whole body

Two-dimensional materials for light emitting applications:Achievement,challenge and future perspectives

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Nano Research 2021年第6期14卷 1912-1936页

作者： Yi Zhu Xueqian Sun Yilin Tang lan fu Yuerui Lu Engineering and Computer Science the Australian National UniversityCanberraACT2601Australia Department of Electronic Materials Engineering Research School of Physics and Engineeringthe Australian National UniversityCanberraACT2601Australia

The two-dimensional(2D)materials have been widely developed recently in material characteristics with advanced optical and electrical properties,and they have been extensively studied as candidates for the next generation of optoelectronic *** review will mainly focus on the preparation methods and the light emitting applications of 2D transition metal dichalcogenides(TMDs),2D black phosphorene(BP)and 2D *** review will first introduce the preparation methods for TMDs and *** to the variations of band structure,exciton binding energies and light-matter interaction in TMDs and BP,the different light emitting devices(LEDs)designs based on TMDs and BP will be discussed and *** the review will turn the focus to 2D perovskites,starting with a description of the preparation methods for the different structural *** order to review and summarize the achievements of 2D perovskites-based LEDs,the high efficiency perovskites LEDs are ***,the review will present challenges,opportunities,and outlook for the future development of 2D materials-based light emitting applications.

关键词： two-dimensional materials light emitting devices optoelectronic devices perovskite transition metal dichalcogenides(TMDs) perovskite light emitting device(LED)