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A new type of the Gronwall-Bellman inequality and its application to fractional stochastic differential equations
Qiong Wu
Mathematics , 2015,
Abstract: This paper presents a new type of Gronwall-Bellman inequality, which arises from a class of integral equations with a mixture of nonsingular and singular integrals. The new idea is to use a binomial function to combine the known Gronwall-Bellman inequalities for integral equations having nonsingular integrals with those having singular integrals. Based on this new type of Gronwall-Bellman inequality, we investigate the existence and uniqueness of the solution to a fractional stochastic differential equation (SDE) with fractional order on (0, 1). This result generalizes the existence and uniqueness theorem related to fractional order (1/2 1) appearing in [1]. Finally, the fractional type Fokker-Planck-Kolmogorov equation associated to the solution of the fractional SDE is derived using It^o's formula.
Computational Curiosity (A Book Draft)
Qiong Wu
Computer Science , 2015,
Abstract: This book discusses computational curiosity, from the psychology of curiosity to the computational models of curiosity, and then showcases several interesting applications of computational curiosity. A brief overview of the book is given as follows. Chapter 1 discusses the underpinnings of curiosity in human beings, including the major categories of curiosity, curiosity-related emotions and behaviors, and the benefits of curiosity. Chapter 2 reviews the arousal theories of curiosity in psychology and summarizes a general two-step process model for computational curiosity. Base on the perspective of the two-step process model, Chapter 3 reviews and analyzes some of the traditional computational models of curiosity. Chapter 4 introduces a novel generic computational model of curiosity, which is developed based on the arousal theories of curiosity. After the discussion of computational models of curiosity, we outline the important applications where computational curiosity may bring significant impacts in Chapter 5. Chapter 6 discusses the application of the generic computational model of curiosity in a machine learning framework. Chapter 7 discusses the application of the generic computational model of curiosity in a recommender system. In Chapter 8 and Chapter 9, the generic computational model of curiosity is studied in two types of pedagogical agents. In Chapter 8, a curious peer learner is studied. It is a non-player character that aims to provide a believable virtual learning environment for users. In Chapter 9, a curious learning companion is studied. It aims to enhance users' learning experience through providing meaningful interactions with them. Chapter 10 discusses open questions in the research field of computation curiosity.
When do literacy skills begin to decline among Chinese adults?
Qiong Wu
- , 2018, DOI: 10.1177/2057150X18775874
Abstract: Literacy skills have been used in some studies as a proxy for premorbid intelligence because they are considered relatively resistant to normal aging. This study aims to explore whether there are signs of decline with aging in literacy skills among Chinese adults with average lower levels of education than their Western peers. Drawing on data from a nationally representative survey, the study uses two repeated literacy tests administered at four-year intervals to investigate at what age literacy skills begin to decline and the effects of possible risk factors. On average, literacy skills have been shown to decline at age 45 and above among Chinese adults. While gender, education, marital status, income, urban status, and subjective cognitive impairment were all associated with the level of literacy skills at baseline, only gender and education were predictive of change over time. Females declined at a slower rate, and the decline appeared to be statistically significant only for those with low education levels. The use of literacy skills as an indicator of premorbid intelligence may need to be reconsidered for the poorly educated. These findings highlight the greater burden of cognitive aging in China due to average low education levels
Power Allocation in Primary User-Assisted Multi-Channel Cognitive Radio Networks  [PDF]
Qiong Wu, Junni Zou, Kangning Zhu
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.53B2044
Abstract: This paper addresses power allocation problem for spectrum sharing multi-band cognitive radio networks, where the primary user (PU) allows secondary users (SUs) to transmit simultaneously with it by coding SU's signal together with its own signal. The PU acts as the relay for the SUs and sells its transmit power to the SUs to increase its benefit, and the SUs bid for the PU's transmit power for maximizing their utilities. We propose a power allocation scheme based on traditional ascending clock auction, in which the SUs iteratively submit the optimal power demand to the PU according to the PU's announced price, and the PU updates that price based on all SUs' total power demands. Then we mathematically prove the convergence property of the proposed auction algorithm (i.e., the auction algorithm converges in a finite number of clocks), and show that the proposed power auction algorithm can maximize the social welfare. Finally, the performance of the proposed scheme is verified by the simulation results.
Coprime sampling for nonstationary signal in radar signal processing
Qiong Wu and Qilian Liang
EURASIP Journal on Wireless Communications and Networking , 2013, DOI: 10.1186/1687-1499-2013-58
Abstract: Estimating the spectrogram of non-stationary signal relates to many important applications in radar signal processing. In recent years, coprime sampling and array attract attention for their potential of sparse sensing with derivative to estimate autocorrelation coefficients with all lags, which could in turn calculate the power spectrum density. But this theoretical merit is based on the premise that the input signals are wide-sense stationary. In this article, we discuss how to implement coprime sampling for non-stationary signal, especially how to attain the benefits of coprime sampling meanwhile limiting the disadvantages due to lack of observations for estimations. Furthermore, we investigate the usage of coprime sampling for calculating ambiguity function of matched filter in radar system. We also examine the effect of it and conclude several useful guidelines of choosing configuration to conduct the sparse sensing while retain the detection quality.
Environmental-Interaction Robotic Systems: Compliant Actuation Approach
Reza Ghorbani,Qiong Wu
International Journal of Advanced Robotic Systems , 2008,
Abstract: Many successful designs of compliant actuators have been recently proposed. However, the challenge of providing passive and active motion in one actuator has remained. In this paper, a novel mechanism for changing the stiffness of the series elastic actuator over a wide range is presented. An accurate force source is provided by introducing the force control using velocity control of the DC motor. Performance and behaviour of the system and controller is investigated through simulation.
Clinical detection of cerebral microbleeds with quantitative susceptibility mapping in essential hypertension
Guang Yao Wu,Qiong Wu
- , 2017,
Abstract: Objective: To evaluate the magnetic susceptibility of Cerebral Microbleeds (CMBs) in patients with Essential Hypertension (EH) by Quantitative Susceptibility Mapping (QSM) sequence and to explore the application value of QSM sequence in CMBs of EH patients. Materials and Methods: A total of 33 EH patients with CMBs were enrolled in this study. The routine scan and QSM sequence were performed using the 3.0T Discovery750 Superconducting Magnetic Resonance Scanner. The distribution of CMBs in the spatial space was analyzed statistically. The relationship between the magnetic susceptibility of CMBs and the baseline data of EH patients was analyzed. Results: 178 CMBs were observed with QSM sequence, which was significantly more than those of the conventional sequences. The number of CMBs was the largest in the basal ganglia-thalamus region, followed by the cortical-subcortical region. The magnetic susceptibility of CMBs was in the range of 0.112-0.494 and the mean value was 0.267, which was statistically different between the risk stratification groups. The susceptibility of basal ganglia-thalamus lesion was associated with risk stratification, systolic blood pressure, diastolic blood pressure, age and course of disease in EH patients. There was a positive correlation between the area of the QSM original image and the magnetic susceptibility value of the lesion in each region. Conclusion: The QSM sequence can measure CMBs better than the conventional sequences. The CMBs of EH patients have the best incidence in the basal ganglia and the thalamus region, followed by the cortical-cortical area. The QSM sequence can provide favourable information for scientific studies and clinical applications in EH patients. And it can provide more imaging basis to understand the impact of hypertension on cerebral blood vessels and the occurrence of CMBs lesions, development, etc
Income Inequality in Transitional Urban China: The Effect of Market versus State  [PDF]
Qiong Wu, Barry Goetz, David Hartmann, Yuan-Kang Wang
Sociology Mind (SM) , 2012, DOI: 10.4236/sm.2012.24049
Abstract: The rise of inequality in China is one of the most serious social problems in the reform era in China. Previous studies have debated the relative importance of human capital, political capital, and other factors in determining personal income. Using a new dataset from 2006 China General Social Survey (CGSS, 2006), the first author replicates earlier tests to measure whether the market or state has more impact on incomes as a way to the competing hypotheses related to human versus political capital. The results of the ordinary least squares regression analysis show no significance in party membership, state ownership, and work experience, while the first author does find high returns to education, which supports Nee’s market transition theory. Moreover, the findings indicate that market sectors, including domestic private enterprises and foreign enterprises have remarkable advantages in earnings, and there is a great income gap between different regions, sectors, and within the sectors. To summarize, the market and state play a dual role in determining income in transitional urban China.
Effects of Duration and Contents of Mindfulness Training on Depression  [PDF]
Qiong Wu, Lin Shi, Zhipeng Xia, Lida Lu
Psychology (PSYCH) , 2013, DOI: 10.4236/psych.2013.46A1002
Abstract:

This study aimed to find a simple and effective mindfulness training method for intervening depression. 95 university students with moderate or severe depression participated in the study and they were divided into three mindfulness training groups: 8-week complete group, 8-week informal group, and 4-week group. All subjects completed Beck Depression Inventory (BDI-Ⅱ) and Five Fact Mindfulness Questionnaire (FFMQ) before the intervention, after which, 55 subjects completed the assessments once more. Results showed the scores of specific dimensions representing mindfulness levels were different. For the 4-week group, scores of description, action aware and nonjudge significantly were improved, while the other two groups were improved significantly on all the five dimensions, especially the informal training group. In the discussion, it focused more on the effects of training time and training contents, and briefly discussed the relation of subjects dropout, subjects attendance, homework completion status and intervention effects. In conclusion, all the three intervention modes have magnificent intervention effects. Integrated many sided, 8-week informal training is of the best effects, which may be considered as a better mindfulness training mode henceforth, however, the comparison between the formal training and informal training still needs further study.

Boundary Phosphate Transport of the East China Sea and Its Influence on Biological Process  [PDF]
Zhijian Lin, Xiaochun Wang, Peng Xiu, Fei Chai, Qiong Wu
Journal of Geoscience and Environment Protection (GEP) , 2019, DOI: 10.4236/gep.2019.79007
Abstract:
The East China Sea (ECS) is one of the largest marginal seas in the Northwest Pacific, and also one of the most productive regions of the global ocean. Using a three-dimensional Pacific physical-biological model, we investigate the interannual variation of phosphate transport via Kuroshio intrusion (KIPT) in the eastern boundary of the East China Sea (ECS) and its influence on the ECS biological process during 1997 to 2016. The KIPT into the ECS mainly occurs in the northeast of Taiwan and southwest of Kyushu, with stronger interannual variability in the northeast of Taiwan. The variation of the KIPT is more significant in the near-bottom water, and is dominated by volume transport. On the interannual timescale, the KIPT changes in response to the shift of the Kuroshio axis and to the bottom upwelling in the ECS eastern boundary. When the Kuroshio axis is closer to (farther away from) the ECS shelf, the strength of the bottom upwelling increases (decreases). This process induces more (less) significant topographic beta spiral, which causes an anticyclonic (cyclonic) eddy-like bottom velocity feature in the northeast of Taiwan. Eventually, more phosphate is transported to the ECS inner shelf, which increases chlorophyll concentration around the Zhoushan Islands and Yangtze Estuary but reduces chlorophyll concentration in the ECS outer shelf. Conversely, the chlorophyll increases in the ECS outer shelf but decreases around the Zhoushan Islands and Yangtze Estuary when there is less phosphate transport. This study highlights the importance of Kuroshio intrusion in connecting the inner and outer shelves of the ECS on the interannual timescale. Phosphate transport into the East China Sea via Kuroshio intrusion shows great interannual variability in the northeast of Taiwan. On the interannual timescale, the variation of phosphate transport into the East China Sea via Kuroshio intrusion is dominated by volume transport. When the Kuroshio axis is closer to the East China Sea shelf, there is more phosphate transport into the East China Sea, and chlorophyll increases around the Zhoushan Islands and Yangtze Estuary.
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