Leader-Following Finite-Time Consensus in Second-order Multi-Agent Networks with Nonlinear Dynamics

Huaqing Li,Xiaofeng Liao,Guo Chen 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.2

Robust finite-time consensus problems in leader-following multi-agent directed networks with second-order nonlinear dynamics are considered in this paper. By using matrix theory, algebraic graph theory and finite-time control scheme, a class of continuous distributed control algorithms are designed in a quite unified way for each follower agent to reach consensus in a finite time. A numerical example is also employed to illustrate the effectiveness and correctness of our theoretical results.

Sorption-enhanced reforming of tar: Influence of the preparation method of CO2 absorbent

Huaqing Xie,Weidong Zhang,Xiangnan Zhao,Hao Chen,Qingbo Yu,Qin Qin 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.11

To remove tar and produce environment-friendly H2, one of the promising routes is the sorption-enhanced steam reforming (SESR) process, in which the CO2 sorbent is a key element. We prepared the CO2 sorbents with Ca12Al14O33 as carrier with various methods. Their characterizations were examined, and the sample prepared by solgel (SG) method showed the strongest CaO and Ca12Al14O33 phases and the most excellent pore structure among all the samples. Then, a thermogravimetric experiment was conducted, and the results showed that the sample prepared by sol-gel (SG) method had the best CO2 adsorption capacity and excellent long-term cyclic stability. Finally, the sorbent was used into the steam reforming experiments of tar. Under the action of the sorbent, the reforming reaction was enhanced in-situ, with the H2 yield and concentration improved obviously, and especially, H2 concentration can reach over 98.85%.

FDI对中国区域全要素生产率的溢出效应研究

두화경(Huaqing Du),고정식(Jeongsik Ko) 한국동북아경제학회 2023 동북아경제연구 Vol.35 No.2

本文采用DEA-Malmquist指数法计算2000~2018年我国30个省市自治州(西藏除外)的总尿素生产力,利用静态面板数据和动态面板数据,实证分析FDI对中国各地区尿素总生产率的波及效果。 现将实证分析结果总结如下。 一是2000—2018年我国30个省市尿素总生产力总体呈上升趋势。 在总尿素生产力成分中,技术进步指数已证实大于技术效率指数,因此目前我国总尿素生产率的提高主要依靠技术进步的提高。 其次,分析FDI和贸易扩大显著促进了我国地区总尿素生产率的提高,得出与现有研究“促进论”一致的结果。 这表明,中国地区总要素生产率的增加并不单纯依靠海外企业的技术示范和模仿等,而是通过FDI的技术传播和自主创新的结合得以提高。 第三, 通过发达国家引进、消化、吸收、再创新的循环过程,实现了技术进步,进而有助于提高总要素生产率,缩短了与发达国家的技术差距。第四, 进一步的研究结果表明,总尿素产量的增长是逐步积累的,可以说对外开放和FDI承包都是通过促进技术进步而不是技术效率来提高我国各地区总尿素产量的增长。 본 논문은 DEA-Malmquist 지수법을 이용하여 2000∼2018년까지 중국 30개성시자치주(티베트 제외)를 대상으로 총요소생산성을 산정하고 정태적 패널 데이터와 동태적 패널 데이터를 이용하여 FDI가 중국 각 지역의 총요소생산성에미치는 파급효과를 실증적으로 분석하였다. 실증분석 결과를 요약하면 다음과 같다. 첫째, 중국의 2000년부터 2018년까지 30개 성, 시의 총요소생산성은 전반적으로 상승 추세를 보였다. 총요소생산성 구성 요소 중 기술진보지수는 기술효율지수보다 큰 것으로 확인되었으며, 따라서 현재 중국의 총요소생산성 향상은 주로 기술진보의 제고에 의해서 이루어지고 있다. 둘째, FDI와 무역확대는 중국 지역의 총요소생산성의 증가를 현저하게 촉진시킨 것으로 분석되어 기존 연구들의 “촉진론”과 일치하는 결과가 도출되었다. 중국 지역의 총요소생산성 증가는 단순히 해외기업의 기술시범과 모방 등에만의존하지 않고 FDI의 기술파급과 자주적 혁신의 결합을 통해 향상될 수 있었음을 나타내고 있다. 셋째, 선진국의 고기술 도입, 소화, 흡수, 재혁신의 순환과정을 통해 기술진보가 이루어졌으며, 나아가 총요소생산성 향상에 기여하고 선진국과의 기술격차를 단축할 수 있었다. 넷째, 추가적인 연구 결과에 따르면, 총요소생산성의 증가는 점진적으로 누적된 것으로 나타났는데, 이는 대외개방과 FDI 도임은 모두 기술 효율이 아닌기술 진보를 촉진함으로써 중국 각 지역의 총요소생산성의 증가를 제고시키는것으로 이어졌다고 할 수 있다. This paper uses the DEA-Malmquist index method to calculate the total factor productivity and its composition of 30 provinces, autonomous prefectures (except Tibet) in China from 2000 to 2018, and then uses static panel data and dynamic panel data to analyze the spillover effect of FDI on China’s regional total factor productivity carried out empirical analysis. The results show that. Firstly, the total factor productivity of 30 provinces and cities in China showed an overall upward trend from 2000 to 2018. Among the components of total factor productivity, the technological progress index is greater than the technical efficiency index, that is, the current improvement of China’s total factor productivity mainly depends on the improvement of technological progress. Secondly, FDI and trade openness have significantly promoted the growth of China’s regional total factor productivity, which is consistent with the “facilitation theory” in previous studies. The improvement of China’s regional total factor productivity no longer relies solely on the absorption of spillover channels such as FDI technology demonstration and imitation, and can be improved to a certain extent through the combination of FDI technology spillover and independent innovation. Thirdly, through the introduction-digestion-absorption-re-innovation of advanced technologies from developed countries, technological progress can be obtained relatively easily, which will help improve total factor productivity and shorten the gap with developed countries. Fourthly, further research shows that the growth of total factor productivity is a process of gradual accumulation. Both trade openness and FDI increase China’s regional total factor productivity growth by promoting technological progress rather than technological efficiency.

Entropically driven self-assembling of softened multi-walled carbon nanotubes into a reversibly water dispersible coherent solid

Xie, Huaqing,Pikhitsa, Peter V.,Kim, Young Jeong,Youn, Wonjin,Altman, Igor S.,Nam, Jung Gun,Lee, Seung Jong,Choi, Mansoo American Institute of Physics 2006 JOURNAL OF APPLIED PHYSICS - Vol.99 No.10

Simulation of Optimized Evacuation Processes based on Sub-Goal CA Model

Zhiwen Hu,Huaqing Mao,Li Zhu 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.5

With the full swing of computer technology, evacuation models are constructed and simulated via computers to study the various phenomena and behaviors during the evacuation process. They open unique potential opportunity to evaluate the architectural design and provide the decision support for the emergency evacuation plans. This paper details a capacity constrained route planner (CCRP) algorithm, which is used to optimize evacuation path, and the distance map based on sub-goal cellular automata (CA) is also proposed to simulate the evacuation scenarios. Two evacuation scenarios are further discussed, and the experimental results strongly suggested that the sub-goal CA model could simulate the evacuation scenarios and evaluate the emergency evacuation plans effectively and finally help us penetrate to the essence of reality.

A sequential fuzzy diagnosis method for rotating machinery using ant colony optimization and possibility theory

Hao Sun,Ke Li,Huaqing Wang,Xueliang Ping,Yi Cao 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.4

This study proposes a novel intelligent fault diagnosis method for rotating machinery using ant colony optimization (ACO) and possibilitytheory. The non-dimensional symptom parameters (NSPs) in the frequency domain are defined to reflect the features of the vibrationsignals measured in each state. A sensitive evaluation method for selecting good symptom parameters using principal componentanalysis (PCA) is proposed for detecting and distinguishing faults in rotating machinery. By using ACO clustering algorithm, the synthesizingsymptom parameters (SSP) for condition diagnosis are obtained. A fuzzy diagnosis method using sequential inference and possibilitytheory is also proposed, by which the conditions of the machinery can be identified sequentially. Lastly, the proposed method iscompared with a conventional neural networks (NN) method. Practical examples of diagnosis for a V-belt driving equipment used in acentrifugal fan are provided to verify the effectiveness of the proposed method. The results verify that the faults that often occur in V-beltdriving equipment, such as a pulley defect state, a belt defect state and a belt looseness state, are effectively identified by the proposedmethod, while these faults are difficult to detect using conventional NN.

Comparative kinetic study of coal gasification with steam and CO2 in molten blast furnace slags

Fan Yang,Qingbo Yu,Huaqing Xie,Zongliang Zuo,Limin Hou,Qin Qin 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.8

To make a comparison between coal gasification in molten blast furnace slag (MBFS) in different ambience and choose an appropriate agent to recover BF slag’s waste heat entirely, coal gasification with steam and CO2 in molten blast furnace slags was studied by isothermal thermo-gravimetric analysis. The effects of temperature and addition of MBFS were studied. Carbon conversion and reaction rate increased with increasing temperature and MBFS. Volumetric model (VM), shrinking core model (SCM), and diffusion model (DM) were applied to describe the coal gasification behavior of FX coal. The most appropriate model describing the coal gasification was SCM in steam ambience and VM in CO2 ambience, respectively. The reaction rate constant k(T) in CO2 ambience is greater than that in steam ambience, which means the gasification reactivity of coal in CO2 ambience is better than that in steam ambience. BF slag can effectively reduce the activation energy EA of coal gasification reaction in different ambiences. But, the difference of activation energies is not large in different ambiences. Based on the results of kinetic analysis including k(T) and EA calculated by the established model, CO2 was chosen to be the most appropriate agent.

Systemic Family Therapy of Comorbidity of Anxiety and Depression with Epilepsy in Adolescents

Jing Li1,Xuefeng Wang,Huaqing Meng,Kebin Zeng,Fengying Quan,Fang Liu 대한신경정신의학회 2016 PSYCHIATRY INVESTIGATION Vol.13 No.3

ObjectiveaaThe aim of this study was to find if systemic family therapy (SFT) does work in anxiety and depression with epilepsy in adolescents (ADAE). Methodsaa104 adolescents with epilepsy, aged 13–20 years old, were included from December 2009 to December 2010, the enrolled patients were with anxiety [Hamilton Anxiety Scale (HAMA) score ≥14 points] or depression [Hamilton Depression Scale (HAMD) score ≥20 points]. The patients were randomly divided into the control group (n=52) treated with antiepileptic drugs (AED) and the intervention group (n=52) undergone Systemic Family Therapy (SFT) as well as AED. The AED improvements, anxiety and depression scores, Social Support Rating Scale (SSRS), Family Assessment Device (FAD) and scale of systemic family dynamics (SSFD) were observed after 3-month treatment. ResultsaaThe frequencies of epileptic seizures in intervention group was decreased much more significantly than the control group (4.22±3.54 times/month vs. 6.20±5.86 times/month, p=0.04); and the scores of anxiety (9.52±6.28 points vs. 13.48±8.47 points, p=0.01) and depression (13.86±9.17 points vs. 18.89±8.73 points, p=0.02) were significantly decreased than the control group; meanwhile, the family dynamics and family functions were significantly improved, and the social support was also increased (p<0.05). ConclusionaaSFT combined with AEDs had better efficacies than AEDs alone, not only the frequency of epileptic seizures was decreased, but also the patients’ anxiety and depression were improved, and the family dynamics, family functions and social support were improved.

Distributed Optimization over General Directed Networks with Random Sleep Scheme

Zheng Wang,Lifeng Zheng,Huaqing Li 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.10

Distributed optimization aims at optimizing a global objective function which is described by a sum of local objective functions through local information processing and sharing. This paper studies the problem of distributed optimization over a network in which underlying graph is generally directed strongly connected. Most existing distributed algorithms require each agent to observe the gradient of the local objective function per iteration, which leads to heavy computational cost. A computation-efficient distributed optimization algorithm incorporating a random sleep scheme is proposed by incorporating a rescaling gradient technique to address the unbalancedness of the directed graph. The implementation of the proposed algorithm allows agents not only locally allocates the weights on the received information, but also independently decides whether to execute gradient observation at each iteration. Theoretical analysis verifies that the proposed algorithm is able to seek the optimal solution with probability one. Simulations are shown to demonstrate the effectiveness of the proposed algorithm, show correctnessof the theoretical analysis, and investigate the tradeoffs between convergence performance and computation cost.

Optimization of Beam Shaping Assembly Based on D-T Neutron Generator and Dose Evaluation for BNCT

Hamza Naeem,Chaobin Chen,Huaqing Zheng,Jing Song 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.70 No.8

The feasibility of developing an epithermal neutron beam for a boron neutron capture therapy (BNCT) facility based on a high intensity D-T fusion neutron generator (HINEG) and using the Monte Carlo code SuperMC (Super Monte Carlo simulation program for nuclear and radiation process) is proposed in this study. The Monte Carlo code SuperMC is used to determine and optimize the final configuration of the beam shaping assembly (BSA). The optimal BSA design in a cylindrical geometry which consists of a natural uranium sphere (14 cm) as a neutron multiplier, AlF3 and TiF3 as moderators (20 cm each), Cd (1 mm) as a thermal neutron filter, Bi (5 cm) as a gamma shield, and Pb as a reflector and collimator to guide neutrons towards the exit window. The epithermal neutron beam flux of the proposed model is 5.73 × 109 n/cm2s, and other dosimetric parameters for the BNCT reported by IAEA-TECDOC-1223 have been verified. The phantom dose analysis shows that the designed BSA is accurate, efficient and suitable for BNCT applications. Thus, the Monte Carlo code SuperMC is concluded to be capable of simulating the BSA and the dose calculation for BNCT, and high epithermal flux can be achieved using proposed BSA.