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GSM-MRF based classification approach for real-time moving object detection

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第2期9卷 250-255页

作者： Xiang PAN yi-jun WU Institute of Information and Communication Engineering Zhejiang University Hangzhou 310027 China

Statistical and contextual information are typically used to detect moving regions in image sequences for a fixed *** this paper,we propose a fast and stable linear discriminant approach based on Gaussian Single Model(GSM)and Markov Random Field(MRF).The performance of GSM is analyzed first,and then two main improvements corresponding to the drawbacks of GSM are proposed:the latest filtered data based update scheme of the background model and the linear classification judgment rule based on spatial-temporal feature specified by *** results show that the proposed method runs more rapidly and accurately when compared with other methods.

关键词： Moving object detection Markov Random Field (MRF) Gaussian Single Model (GSM) Fisher Linear Discriminant Analysis (FLDA)

Optimal Dividend and Dynamic Reinsurance Strategies with Capital Injections and Proportional Costs

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Acta Mathematicae Applicatae Sinica 2012年第3期28卷 505-524页

作者： yi-dong WU jun-yi GUO School of Mathematical Sciences and LPMC Nankai UniversityTianjin 300071China School of Economics Yunnan UniversityKunming 650091China

We consider an optimization problem of an insurance company in the diffusion setting, which controls the dividends payout as well as the capital injections. To maximize the cumulative expected discounted dividends minus the penalized discounted capital injections until the ruin time, there is a possibility of （cheap or non-cheap） proportional reinsurance. We solve the control problems by constructing two categories of suboptimal models, one without capital injections and one with no bankruptcy by capital injection. Then we derive the explicit solutions for the value function and totally characterize the optimal strategies. Particularly, for cheap reinsurance, they axe the same as those in the model of no bankruptcy.

关键词： proportional reinsurance non-cheap optimal dividend capital injections

Stable Label-Specific Features Generation for Multi-Label Learning via Mixture-Based Clustering Ensemble

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IEEE/CAA Journal of Automatica Sinica 2022年第7期9卷 1248-1261页

作者： yi-Bo Wang jun-yi Hang Min-Ling Zhang School of Computer Science and Engineering Southeast UniversityNanjing 210096China IEEE

Multi-label learning deals with objects associated with multiple class labels,and aims to induce a predictive model which can assign a set of relevant class labels for an unseen *** each class might possess its own characteristics,the strategy of extracting label-specific features has been widely employed to improve the discrimination process in multi-label learning,where the predictive model is induced based on tailored features specific to each class label instead of the identical instance *** a representative approach,LIFT generates label-specific features by conducting clustering ***,its performance may be degraded due to the inherent instability of the single clustering *** improve this,a novel multi-label learning approach named SENCE(stable label-Specific features gENeration for multi-label learning via mixture-based Clustering Ensemble)is proposed,which stabilizes the generation process of label-specific features via clustering ensemble ***,more stable clustering results are obtained by firstly augmenting the original instance repre-sentation with cluster assignments from base clusters and then fitting a mixture model via the expectation-maximization(EM)*** experiments on eighteen benchmark data sets show that SENCE performs better than LIFT and other well-established multi-label learning algorithms.

关键词： Clustering ensemble expectation-maximization al-gorithm label-specific features multi-label learning

Influences of the Welding Heat Input and the Repeated Repair Welding on Ti–3Al–2.5V Titanium Alloy

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Acta Metallurgica Sinica(English Letters) 2015年第6期28卷 684-691页

作者： Hui-jun yi Yong-jun Lee Kwang-O Lee School of Mechanical Engineering Pusan National University

The primary purpose of this study was to determine the effects of gas tungsten arc welding heat input on the high-temperature tensile properties, toughness, and microstructural features of titanium alloy Ti-3A1-2.5V. The secondary objective was to examine the effect of the repeated repair welding on the properties of the alloy. It was also found that the mechanical properties progressively decreased with increasing the repair welding cycles, especially in the case of the weldment after the first welding repair. It was observed that the sizes of the acicular and prior β grain boundaries as well as the volume fraction of the acicular phases increased with increasing the welding heat input. In addition, the amount and size of the acicular a1 phases were found to increase with increasing the repair welding cycles.

关键词： Ti-3AI-2.5V Repair welding Heat input Tensile properties Microstructure

Optimal proportional reinsurance and dividend payments with transaction costs and internal competition

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Applied Mathematics(A Journal of Chinese Universities) 2016年第1期31卷 89-102页

作者： LIU Wei HU yi-jun School of Mathematics and System Sciences Xinjiang University School of Mathematics and Statistics Wuhan University

We study the dividend optimization problem for an insurance company under the consideration of internal competition between different units inside company and transaction costs when dividends occur. The management of the company controls the reinsurance rate, the timing and the amount of dividends paid out to maximize the expected total dividends paid out to the shareholders until ruin time. By solving the corresponding quasi-variational inequality, we obtain the optimal return function and the optimal strategy.

关键词： Dividend proportional reinsurance transaction costs internal competition quasi-variational inequality.

The Optimal Policy for Insurance Company Under Consideration of Internal Competition and the Time Value of Ruin

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Acta Mathematicae Applicatae Sinica 2014年第3期30卷 807-818页

作者： Wei LIU yi-jun HU School of Mathematics and System Sciences Xinjiang University School of Mathematics and Statistics Wuhan University

This paper considers the dividend optimization problem for an insurance company under the consideration of internal competition between different units inside the company. The objective is to find a reinsurance policy and a dividend payment scheme so as to maximize the expected discounted value of the dividend payment, and the expected present value of an amount which the insurer earns until the time of ruin. By solving the corresponding constrained Hamilton-Jacobi-Bellman （HJB） equation, we obtain the value function and the optimal reinsurance policy and dividend payment.

关键词： dividend payment proportional reinsurance internal competition Hamilton-Jacobi-Bellman (HJB)equation

Radiofrequency ablation in the treatment of small hepatocellular carcinoma:A meta analysis

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World Journal of Gastroenterology 2010年第27期16卷 3450-3456页

作者： jun-Guo Liu yi-jun Wang Zhi Du Department of Hepatobiliary Surgery Third Central Hospital Tianjin 300170 China The Key Laboratory of Artificial Cells China

AIM:To evaluate survival and recurrence after radiofrequency ablation(RFA) for the treatment of small hepatocellular carcinoma(HCC) using a ***:Literature on RFA vs surgical resection for the treatment of small HCC published between January 1990 and December 2008 was retrieved.A metaanalysis was conducted to estimate pooled survival and recurrence ratios.A fixed or random effect model was established to collect the ***:The differences in overall survival at 1-year,3-years and at end of follow-up were not statistically significant between the RFA and surgery groups(P > 0.05).There were no differences in 1-year and 3-year recurrences between the RFA and surgery groups(P > 0.05).However,recurrence in the RFA group was lower than that in the surgery group up to the end of follow-up(P = 0.03).Survival was not significantly *** was a significant difference in recurrences at the end of follow-up after RFA compared with surgical ***:RFA did not decrease the number of overall recurrences,and had no effect on survival when compared with surgical resection in a selected group of patients.

关键词： Hepatectomy Hepatocellular carcinoma Meta-analysis Radiofrequency ablation Recurrence Survival

Quantum Fisher information of a qubit-qutrit system in Garfinkle–Horowitz–Strominger dilation space–time

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Communications in Theoretical Physics 2021年第8期73卷 82-89页

作者： yi-jun Lian Jin-Ming Liu State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200241China

We investigate the quantum Fisher information(QFI) of a qubit-qutrit system in the background of Garfinkle–Horowitz–Strominger dilation black hole. After deriving the analytical expression of the QFI, we examine its dynamics with respect to the dilation parameter D and the state parameter γ of the system. Our results show that the QFI for the estimation of γ is a fixed value,which is independent of the parameters D and γ. And the QFI for the estimation of D varies with the parameters D and γ. Additionally, we propose an effective strategy to steer the QFI by introducing weak measurement reversal. We find that the QFI can be remarkably enhanced by adjusting the appropriate reversing measurement strengths. Our findings might provide some useful insights for the study on parameter estimation of hybrid systems in the framework of relativity theory.

关键词： quantum Fisher information Garfinkle-Horowitz-Strominger space-time weak measurement reversal

Normalization of seismic quantities and units

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Acta Seismologica Sinica(English Edition) 2002年第2期15卷 234-238页

作者： FENG yi-jun (冯义钧) Institute of Geophysics China Seismological Bureau Beijing 100081 China

In the seismological field, attention paid to the problem concerning the normalization of seismic quantities and their units has not been enough all along.

关键词： seismic quantity unit normalization