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Enhanced geographic information system-based mapping of local climate zones in Beijing, China

Science China(Technological Sciences) 2019年第12期62卷 2243-2260页

作者： QUAN JinLing State Key Laboratory of Resources and Environmental Information system Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences

The vague urban-rural dichotomy severely restricts effective comparisons and communications among urban heat island studies.A local climate zone(LCZ) scheme has therefore been developed to classify urban and natural landscapes in a standardized and universal manner. Despite LCZ mapping efforts in worldwide cities, this study attempts to propose an enhanced geographic information system-based workflow to enable the hierarchical classification of LCZs with fewer indicators but higher accuracies while considering supplementary classes and subclasses. Specifically, five morphological and coverage indicators that were easily obtained and well differentiated among LCZs were derived from a city street map and satellite images, and 25 LCZs(including 16 standard, 3 supplementary, and 6 sub-classified zones) were determined at a block-level according to the indicator hierarchy and criteria. The method was performed over Beijing, China, and evaluations by field surveys and google earth images showed a high accuracy with little noise and sharp boundaries, outperforming the widely-used remote sensing-based method of the World Urban Database and Access Portal Tools, particularly in terms of building height and heavy industry. Results also demonstrate that the Beijing core was dominated by open(including extremely open) mid-rise buildings(28.7%) and open lowrise buildings(12.8%), forming an inner-low-middle-high-outer-low annular building-height pattern. Significant land surface temperature differences were detected among the LCZs, where the low-rise and compact LCZs had higher temperatures than the mid-/high-rise and open LCZs during daytime, and subclasses LCZ XB/C/D(LCZ XE/F) generated lower(higher) temperatures than their parent classes in May. This method was proposed to augment the LCZ mapping system and further support applications(e.g., urban planning/management and climate/weather modeling) in high-density cities similar to Beijing.

关键词： geographic information system(GIS) remote sensing local climate zone(LCZ) land surface temperature urban morphology

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Parameters Sensitivity Characteristics of Highly Integrated Valve-Controlled Cylinder Force Control system

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Chinese Journal of Mechanical Engineering 2018年第2期31卷 159-175页

作者： Kai-Xian Ba Bin Yu Xiang-Dong Kong Chun-He Li Qi-Xin Zhu Hua-Long Zhao Ling-Jian Kong School of Mechanical Engineering Yanshan University State Key Laboratory of Fluid Power and Mechatronic system Zhejiang University Columbia University

Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.

关键词： Highly integrated valve?controlled cylinder system Force control system Matrix sensitivity analysis Orthogonal test design Sensitivity index

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Application of BeiDou navigation satellite system in emergency rescue of natural hazards: a case study for field geological survey of Qinghai−Tibet plateau

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Geo-Spatial Information Science 2018年第4期21卷 294-301页

作者： Ming Hao Jianlong Zhang Ruiqing Niu Changrong Deng Hong Liang National Engineering Research Center for Geographic Information system WuhanChina Chengdu Center of China Geological Survey ChengduChina

In recent years,geological and mineral resources exploration in China has expanded to deep hinterland of the Qinghai−Tibet Plateau and other regions with complex geological *** special natural conditions of Qinghai−Tibet Plateau determine the characteristics of“life-forbidden zone”that is characterized by alpine hypoxia,changeable weather,complex road conditions,and beast *** particular,the work in wild depopulated zones with severe environment and poor communications imposes serious threats to the life safety of geological ***,how to guarantee the safety of geological personnel working on the Qinghai−Tibet Plateau and how to reduce or even avoid casualty of geological personnel have currently become the urgent *** this study,an emergency rescue information system for field geological survey is constructed based on BeiDou Navigation Satellite system.A case study of emergency rescue has been conducted in the depopulated zone of the Qinghai−Tibet Plateau and good effects have been achieved,providing security assurance for personnel engaged in field geological survey on the Qinghai−Tibet Plateau and technical support for the emergency rescue in case of natural hazards on the Qinghai−Tibet *** BeiDou Navigation Satellite system(BDS)can be effectively used to locate and communicate in the emergency rescue for rigorous Geological survey task where there is no network signal for the mobile phone,and the emergency rescue guarantee system is independent,reliable,and relatively *** application value of BDS is demonstrated in the geological field.

关键词： BeiDou navigation satellite system(BDS) natural hazard emergency rescue Qinghai−Tibet plateau

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Global exponential synchronization between Lü system and Chen system with unknown parameters and channel time-delay

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Chinese Physics B 2011年第5期20卷 204-209页

作者：马铁东浮洁 College of Automation Chongqing University Key Laboratory of Optoelectronic Technology and system of Ministry of Education College of Optoelectronic EngineeringChongqing University

This paper proposes a nonlinear feedback control method to realize global exponential synchronization with channel time-delay between the Lfi system and Chen system, which are regarded as the drive system and the response system respectiveiy. Some effective observers are produced to identify the unknown parameters of the Lii system. Based on the Lyapunov stability theory and linear matrix inequality technique, some sufficient conditions of global exponential synchronization of the two chaotic systems are derived. Simulation results show the effectiveness and feasibility of the proposed controller.

关键词： global exponential synchronization unknown parameters channel time-delay Lyapunovstability theory

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Research on Digital Twin system Platform Framework and Key Technologies of Unmanned Ground Equipment

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Complex system Modeling and Simulation 2024年第2期4卷 109-123页

作者： Kunyu Wang Lin Zhang Cheng Xu Han Lu Zhen Chen Hongbo Cheng Rui Guo the School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China the State Key Laboratory of Intelligent Manufacturing system Technology Beijing 100854China the Beijing Institute of Electronic system Engineering Beijing 100854China

As an emerging technology,digital twin is expected to bring novel application modes to the whole life cycle process of unmanned ground equipment,including research and development,design,control optimization,operation and maintenance,*** highly dynamic,complex,and uncertain characteristics of unmanned ground equipment and the battlefield environment also pose new challenges for digital twin *** from the new challenges faced by the digital twin of unmanned ground equipment,this paper designs a service-oriented cloud-edge-end collaborative platform architecture of the digital twin system of unmanned ground equipment,and further analyzes several key technologies supporting the implementation of the platform architecture.

关键词： unmanned ground equipment digital twin native cloud platform Modeling and Simulation(M&S) artificial intelligence

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Simulation of Control and Guidance system for the Spinning Missile

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Journal of systems Engineering and Electronics 1994年第3期5卷 49-56页

作者： Meng Daikui (China Changfeng system Engineering Corporation, P.O.Box 142-30, Beiging 100854, China) China Changfeng system Engineering Corporation P.O. Box 142-30 Beiging 100854 China

Adopted for some small-size short range surface-to-air missiles and antitank guided missiles is a single-channel control method of making missile rotating around its longitudinal axis. In hardware-in-the-loop simulations of the guidance and control system for these kinds of spinning missiles, improper use of special simulation equipment and test method will cause significant errors, even lead to failure of the simulation. In this article, the author gives an analysis of the causes of significant errors and failure of the simulation, and puts forward a solution, which is improved workable in making the hardward-in-the-loop simulation successful.

关键词： Computer simulation Error analysis Computer system recovery Missiles

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First endoscopic procedure for diagnosis and staging of mediastinal lymphadenopathy

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World Journal of Gastroenterology 2009年第48期15卷 6096-6101页

作者： Kay-Leong Khoo Khek-Yu Ho Christopher Jen-Lock Khor Barbro Nilsson Tow-Keang Lim Department of Medicine National University Health System Department of Gastroenterology National University Health System Department of Pathology National University Health System

AIM:To compare a first diagnostic procedure of transbronchial needle aspiration(TBNA)with selection of endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA)or TBNA for mediastinal ***:Sixty-eight consecutive patients with mediastinal lymphadenopathy on computed tomography(CT),who required cytopathological diagnosis,were *** first 34 underwent a sequential approach in which TBNA was performed first,followed by EUS-FNA if TBNA was *** next 34 underwent a selective approach where either TBNA or EUS-FNA was selected as the first procedure based on the CT ***:The diagnostic yield of TBNA as the first diagnostic procedure in the sequential approach was 62%.In the selective approach,the diagnostic yield of the first procedure was 71%.There was no significant difference in the overall diagnostic yield,but there were significantly fewer combined procedures with the selective ***:Selecting either EUS-FNA or TBNA as the first diagnostic procedure achieved a comparable diagnostic yield with significantly fewer procedures than performing TBNA first in all patients.

关键词： Aspiration biopsy Needle biopsy Endoscopy Ultrasound Mediastinum Lymphadenopathy Lung neoplasms Diagnosis Neoplasms staging

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SecIngress:An API Gateway Framework to Secure Cloud Applications Based on N-Variant system

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China Communications 2021年第8期18卷 17-34页

作者： Dacheng Zhou Hongchang Chen Guozhen Cheng Weizhen He Lingshu Li National Digital Switching system Engineering and Technological R&D Center ZhengzhouHenan 450002China

Based on the diversified technology and the cross-validation mechanism,the N-variant system provides a secure service architecture for cloud providers to protect the cloud applications from attacks by executing multiple variants of a single software in parallel and then checking their behaviors’***,it is complex to upgrade current Software as a Service(SaaS)applications to adapt N-variant system *** arise from the inability of tenants to adjust the application architecture in the cloud environment,and the difficulty for cloud service providers to implement N-variant systems using existing API *** paper proposes SecIngress,an API gateway framework,to overcome the challenge that it is hard in the cloud environment to upgrade the applications based on N-variants *** design a two-stage timeout processing method to lessen the service latency and an Analytic Hierarchy Process Voting under the Metadata mechanism(AHPVM)to enhance voting *** implement a prototype in a testbed environment and analyze the security and performance metrics before and after deploying the prototype to show the effectiveness of *** results reveal that SecIngress enhances the reliability of cloud applications with acceptable performance degradation.

关键词： N-variant system API gateway cloud security analytic hierarchy process

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A delayed predator-prey system with impulsive diffusion between two patches

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International Journal of Biomathematics 2017年第1期10卷 175-194页

作者： Hong-Li Li Long Zhang Zhi-Dong Teng Yao-Lin Jiang College of Mathematics and system SciencesXinjiang University Urumqi 830046 P. R. China

In most models of population dynamics, diffusion between two patches is assumed to be either continuous or discrete. However, in the real world, it is often the case that diffusion occurs at certain moment every year, impulsive diffusion can provide a more suitable manner to model the actual dispersal （or migration） behaviors for many eco- logical species. In addition, it is generally recognized that some kinds of time delays are inevitable in population interactions. In view of these facts, a delayed predator-prey system with impulsive diffusion between two patches is proposed. By using compari- son theorem of impulsive differential equation and some analysis techniques, criteria on the global attractivity of predator-extinction periodic solution are established, sufficient conditions for the permanence of system are obtained. Finally, numerical simulations are presented to illustrate our theoretical results.

关键词： Predator-prey delay impulsive diffusion global attractivity permanence.

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MDKB-Bot:A Practical Framework for Multi-Domain Task-Oriented Dialogue system

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Data Intelligence 2019年第2期1卷 176-186页

作者： Yadi Lao Weijie Liu Sheng Gao Si Li Pattern Recognition and Intelligence system Laboratory Beijing University of Posts and TelecommunicationsBeijing 100876China

One of the major challenges to build a task-oriented dialogue system is that dialogue state transition frequently happens between multiple domains such as booking hotels or ***,the encoder-decoder model based on the end-to-end neural network has become an attractive approach to meet this ***,it usually requires a sufficiently large amount of training data and it is not flexible to handle dialogue state *** paper addresses these problems by proposing a simple but practical framework called Multi-Domain KB-BOT(MDKB-BOT),which leverages both neural networks and rule-based strategy in natural language understanding(NLU)and dialogue management(DM).Experiments on the data set of the Chinese Human-Computer Dialogue Technology Evaluation Campaign show that MDKB-BOT achieves competitive performance on several evaluation metrics,including task completion rate and user satisfaction.

关键词： Dialogue system Knowledge base Natural language understanding Slot filling Natural language generation

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