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Uniform Experimental Design Of Constrained Region Based On Evolutionary Algorithm, Jianing Wei, Hao Hao, Qutong Chang, Lin Tao, Zhang Hu Jul 2021

Uniform Experimental Design Of Constrained Region Based On Evolutionary Algorithm, Jianing Wei, Hao Hao, Qutong Chang, Lin Tao, Zhang Hu

Journal of System Simulation

Abstract: The parameters of a simulation system are usually generated by the experimental design. Aiming at high design difficulty and computational cost of the uniform experimental design, of the constraint region, a two-stage differential evolutionary algorithm is further improved. The design is modeled as a constrained optimization problem. A strategy combining distribution estimation algorithm (EDA) and differential evolution (DE) is adopted. A point-deletion method is proposed to reduce the time complexity of optimizing the population uniformity. To demonstrate the advantages, the test instances and engineering applications are used in experimental analysis. The experimental results show that the performance, stability, and …

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Research On Agile Reentry Method For Maneuvering Vehicle, Lin Yue, Yingmin Jia, Songtao Fan Jul 2021

Research On Agile Reentry Method For Maneuvering Vehicle, Lin Yue, Yingmin Jia, Songtao Fan

Journal of System Simulation

Abstract: Alarge-scale orbit maneuver method is proposed and analyzed for hypersonic space reentry vehicles, and the air assisted methods are adopted to conduct space orbit maneuvers by complying with the energy balance strategy of the aircraft. By the L/D ratio of aircraft, the efficiency of the propellant use during orbital maneuvers is elevated, and the maneuverability is also enhanced, while the risk of aircraft being tracked in space can be reduced. Aero-assisted guidance technology is applied based on full-coefficient adaptive prediction-correction technology which significantly simplifies the computation of the GNC computer, while such application ensures the convergence and enhances the …

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Study On Interior Space Pedestrian Evacuation Model Elite Chaos Search Strategy, Wei Juan, Zhongyu Li, You Lei, Yangyong Guo, Zhihai Tang, Zhouyi Hu Jul 2021

Study On Interior Space Pedestrian Evacuation Model Elite Chaos Search Strategy, Wei Juan, Zhongyu Li, You Lei, Yangyong Guo, Zhihai Tang, Zhouyi Hu

Journal of System Simulation

Abstract: In order to improve traditional field model of easily falling into the queue problem during simulating the evacuation of dense crowds, an improved pedestrian evacuation model in interior space is proposed based on the elite chaos search strategy. The pedestrian mobile income at each moment is calculated in combination with the field value, capacity and average speed, and a field model for pedestrian evacuation is presented. On this basis, the objective optimization function of the minimum evacuation time and minimum queue length is given, and the elite chaos search strategy is used to achieve the above objective function solution, …

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Research On Performance Modeling And Simulation Method Based On Dense Crowd, Yihao Li, Tianyu Huang, Li Peng, Gangyi Ding Jul 2021

Research On Performance Modeling And Simulation Method Based On Dense Crowd, Yihao Li, Tianyu Huang, Li Peng, Gangyi Ding

Journal of System Simulation

Abstract: Due to the high complexity of crowd organization and the difficulty of abstracting the performance, the performance simulation of dense crowds relies heavily on manual work, and it is difficult to establish a highly automated simulation model. In order to reduce the sensitivity of creative modification and design risks, a performance model based on dense crowd is proposed. Through the strategy of time dimension slicing and spatial layering, a highly automated crowd performance simulation method that could meet the director's creativity is realized. Through the construction of simulation experiments, the generation effect and calculation efficiency of the crowd …

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Fast Alignment Of Bim Products Based On Structure Matching, Xiaojun Liu, Changyan He, Liu Chang, Jinyuan Jia Jul 2021

Fast Alignment Of Bim Products Based On Structure Matching, Xiaojun Liu, Changyan He, Liu Chang, Jinyuan Jia

Journal of System Simulation

Abstract: The fast alignment of BIM products based on structure matching is realized. An Item-based Structure Graph (ISG) is proposed as the structure-aware shape descriptor for BIM products. An improved graph matching algorithm upon Factorized Graph Matching (FGM) is implemented in ISG matching, in which the mismatch caused by symmetry switching is avoided. Further extension is made to support the alignment under partial matching for BIM products from the same family. The experiment result shows that ISG can meet the characteristics of BIM products, improve the efficiency and accuracy, and can be applied in dealing with products alignment, BIM data …

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Design And Engine Implementation Of Submarine Combat System Simulation Based On Lvc, Jinping Wu, Minghua Lu, Changyou Xue Jul 2021

Design And Engine Implementation Of Submarine Combat System Simulation Based On Lvc, Jinping Wu, Minghua Lu, Changyou Xue

Journal of System Simulation

Abstract: Submarine combat system simulation is one of the key and most important content in submarine combat simulation. On the basis of LVC simulation technology, practicing simulation-as-a-service idea, the LVC integration simulation method of submarine combat system is proposed and the LVC integration simulation environment is constructed. The composition and relationship of LVC simulation system are researched. The compositional structure of LVC simulation engine was designed. Based on the component design and development specifications in Java/EJB technological infrastructure, in use of software component technology, the simulation engine components are designed and implemented. The LVC integration simulation of submarine combat system …

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Position And Attitude Estimation Based On Combination Matching In Calibration Area, Cai Peng, Chaoping Shen, Hongyan Li Jul 2021

Position And Attitude Estimation Based On Combination Matching In Calibration Area, Cai Peng, Chaoping Shen, Hongyan Li

Journal of System Simulation

Abstract: Vision navigation technology of scene matching needs hardware to measure the distance and attitude of the camera. A method of position and attitude estimation based on the combination of feature points in the calibration area is proposed. The software can get the camera position and attitude of the real-time image by selecting the best set of Scale-Invariant Feature Transform(SIFT) feature matching points of the reference image calibration area of the real-time image, and calculating the local coordinates of the ground of SIFT feature matching points based on the triangle internal linear interpolation method, using space resection, avoids the defect …

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High Adaptability Vehicle Network Communication Protocol Based On Aodv, Wang Tong, Gao Shan, Tianshu Dai Jul 2021

High Adaptability Vehicle Network Communication Protocol Based On Aodv, Wang Tong, Gao Shan, Tianshu Dai

Journal of System Simulation

Abstract: Routing protocol is an essential part of vehicular ad-hoc network (VANET). According to the characteristics of frequent changes of vehicle node location in urban environment, an AODV routing protocol based on Network Topology Changes (NTCAODV) is proposed. According to the speed and relative position information, by calculating the stability coefficient of nodes, the link connection is established on the basis of principle of "optimal stability", and the idea of extended loop is improved according to recorded the link establishment time. Simulation results show that NTCAODV routing protocol has good performance in various urban environments, improves …

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Evaluation Method On Multi-Stage Bayes Information Fusion For Scatters Hwil Simulation, Yecheng Wang, Ma Jing, Congjun Jin, Jie Li, Bin Shi Jul 2021

Evaluation Method On Multi-Stage Bayes Information Fusion For Scatters Hwil Simulation, Yecheng Wang, Ma Jing, Congjun Jin, Jie Li, Bin Shi

Journal of System Simulation

Abstract: In order to simulate the complex 3D target in the RF HWIL (hardware in the loop simulation) system, the equivalence framework of multiple scattering centers of complex 3D target for three stages of outfield test data, mathematics simulation data and HWIL data are introduced. Using the pre-test information as each stage for transmission, evaluation method is designed by multi-stage Bayes information fusion for HWIL simulation. Based on prior information of outfield test data and mathematics simulation data, by using Bayes information fusion theory, the average data reconstruction of each stage is obtained and compared and high reliability …

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Collaborative Optimization Of Ship Stowage Plan And Yard Container Unloading For Container Terminal, Zhixiong Liu, Hanwen Qian, Jialan Yan Jul 2021

Collaborative Optimization Of Ship Stowage Plan And Yard Container Unloading For Container Terminal, Zhixiong Liu, Hanwen Qian, Jialan Yan

Journal of System Simulation

Abstract: Stowage plan is an important component of the operation production for the container terminal, which directly affects the handling efficiency and shipping safety. The aim is minimizing the total reloading numbers of both the yard and the ship bay, in view of the constraint of ship heeling moment and loading for light upon heavy, the model is employed for collaborative optimization of stowage plan and yard unloading for multiple destination ports and multiple bays. The hybrid evolutionary strategy algorithm is adopted with the local search algorithm. As to ship stowage play for multiple bays, a heuristic rule for the …

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Transmission Process Prediction Of Novel Coronavirus Based On System Dynamics, Xuepeng Lu, Shang Jiao, Junhui Zhao, Lulu Lü, Zhou Li Jul 2021

Transmission Process Prediction Of Novel Coronavirus Based On System Dynamics, Xuepeng Lu, Shang Jiao, Junhui Zhao, Lulu Lü, Zhou Li

Journal of System Simulation

Abstract: The transmission characteristics of novel coronavirus is considered and a new SE4IR2 model based on the principle of system dynamics is proposed. The US epidemic data from June to November is used to set the isolation rate and other parameters, and the SE4IR2 model is used to fit, analyze and predict the development of the epidemic trend in the next stage. The empirical part uses the data from June to November in the United States to achieve the parameters of the SE4IR2 model, obtains the parameter values in December and January through the time series prediction model, and compares …

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Research On Simulation Experiment Support Technology For Complex Sos Of Live And Constructive Symbiosis, Wu Xi, Ma Jun Jul 2021

Research On Simulation Experiment Support Technology For Complex Sos Of Live And Constructive Symbiosis, Wu Xi, Ma Jun

Journal of System Simulation

Abstract: The technology of simulation experiment for System of Systems (SoS) is very important in research of complex SoS. The operation SoS is typical complex SoS.Based on the concept of parallel system, symbiotic simulation, digital twin, etc., the main characteristics of the technology are summarized. Focus on the architecture of complex system simulation experiment environment, the experiment environment architecture, hybrid simulation driving mechanism and virtual real data access mode are studied. A feasible method is provided to carry out the complex SoS experiment of multi domain joint, data fusion, resource integration and human-computer integration, and the comprehensive application of …

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Research On Control Strategy Of Isolated Ac-Dc Matrix Converter Under Input Unbalance, Wenlang Deng, Li Yong, Hongbin Pan Jul 2021

Research On Control Strategy Of Isolated Ac-Dc Matrix Converter Under Input Unbalance, Wenlang Deng, Li Yong, Hongbin Pan

Journal of System Simulation

Abstract: To reduce the active power fluctuation of the isolated AC-DC matrix converter (IAMC) under the input unbalance and to suppress the resonance of the LC filter, a deadbeat direct power control strategy based on active damping is proposed. The strategy uses the grid-side current and its delay component to calculate the IAMC input side filter capacitor voltage, which eliminates the high-precision voltage sensor of traditional active damping control, reduces the hardware cost, without the rotation coordinate transformation and phase-locked loops, so the calculation cost is small. The simulation results show that the proposed control strategy can effectively …

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“The Child Is Father Of The Man”, Thomas M. Columbus Jul 2021

“The Child Is Father Of The Man”, Thomas M. Columbus

Materials from the University of Dayton Magazine Website

Wordsworth said it. Director Jonathan Judge ’93 lives it.

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Fast Maritime Simulator Scene Modeling Method Based On Aerial Images, Lijia Chen, Wang Kai, Shigang Li, Yanfei Tian Jul 2021

Fast Maritime Simulator Scene Modeling Method Based On Aerial Images, Lijia Chen, Wang Kai, Shigang Li, Yanfei Tian

Journal of System Simulation

Abstract: Artificial Modeling using Computer Aid Design software are frequently applied in maritime simulator scene modeling,but with low accuracy, low efficiency and complicate workflow. It's not the ideal method of modeling a large-scale area. A modeling method is proposed based on aerial images in combination with tilt photography modeling, procedural modeling and image semantic segmentation method. It's a fast and highly automated modeling method specially for the maritime simulator. A water area near Tianxingzhou Yangtze River Bridge is chosen as the model. Experiment results show that the proposed method is of fast speed, high precision, high degree of automation, …

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Using Big Data Analytics To Optimize Practical Large Databases, Po-Chun Lu Jul 2021

Using Big Data Analytics To Optimize Practical Large Databases, Po-Chun Lu

Master of Science in Computer Science Theses

Big data analytics is gaining popularity for enterprises in optimizing their business processes ranging from retailers, supply chains, to online shopping stores. Existing practical raw data are far from usable to achieve the goal. Therefore, a good data pre-processing approach is required and is a key step to success. We propose to research on the effectiveness of data pre-processing and the business process based on a real world database. Our methodology involves natural language processing. Our key goal is to study appropriate methods with big data analysis techniques that can handle errors, ambiguity, and repeated descriptions caused by human languages. …

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Bim-Based Generative Modular Housing Design And Implications For Post-Disaster Housing Recovery, Pedram Ghannad Jul 2021

Bim-Based Generative Modular Housing Design And Implications For Post-Disaster Housing Recovery, Pedram Ghannad

LSU Doctoral Dissertations

The adverse social and financial impacts of catastrophic disasters are increasing as population centers grow. After disastrous events, the government agencies must respond to post-disaster housing issues quickly and efficiently and provide sufficient resources for the reconstruction of destroyed and damaged houses for full rehabilitation. However, post-disaster housing reconstruction is a highly complex process because of the large number of projects, shortage of resources, and heavy pressure for delivery of the projects after a disastrous event. This complexity and lack of an inconsistent, systematic approach for planning lead to an ad-hoc decision-making process and inefficient recovery. This research explored modular …

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Contents Jul 2021

Contents

Bulletin of Chinese Academy of Sciences (Chinese Version)

No abstract provided.

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Rational Examination Of Cultivation Of Talent Reserve For Scientific And Technological Innovation In China, Yonghe Zhang, Jingying Wang, Xinying Li, Xuanyang Yang, Yong Xie Jul 2021

Rational Examination Of Cultivation Of Talent Reserve For Scientific And Technological Innovation In China, Yonghe Zhang, Jingying Wang, Xinying Li, Xuanyang Yang, Yong Xie

Bulletin of Chinese Academy of Sciences (Chinese Version)

It is an important guarantee for China to win the first chance in the future international competition to vigorously cultivate the talent reserve of scientific and technological innovation. This study first proposes that China urgently needs to pay attention to the early training of scientific and technological innovation talents from the international situation, existing policies, and the current educational situation. Then it dynamically examines the training theory and practical experience of scientific and technological innovation talent reserve from an international perspective, and further considers the critical understanding and key issues of early training. Finally, some suggestions are given on the …

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Comparative Study On Development Of Science Education Worldwide: Advance In Ideas, Themes And Practice, Xinning Pei, Tainian Zheng Jul 2021

Comparative Study On Development Of Science Education Worldwide: Advance In Ideas, Themes And Practice, Xinning Pei, Tainian Zheng

Bulletin of Chinese Academy of Sciences (Chinese Version)

The importance of science education lies not in delivering factual knowledge to learners, but in using knowledge as a way for them to know the world and cope with the uncertainty. The development of science education worldwide in the 21st century presents the following themes:the sustainable development of human beings as the main context, cultivating scientific literacy as the goal, paying attention to understanding the nature of science, building a "common foundation" for science learning through in-depth and coherent curriculum, using information technology to stimulate and integrate science education innovation, emphasizing the unity of science and humanities, giving full play …

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From Strategy Consulting Research To Science Of Think Tank, Xin Wang, Huiqin Zhang, Changpu Sun Jul 2021

From Strategy Consulting Research To Science Of Think Tank, Xin Wang, Huiqin Zhang, Changpu Sun

Bulletin of Chinese Academy of Sciences (Chinese Version)

Think tank researches are the main element to advance the modernization of China's capacity for governance, and they are multidisciplinary related to many research areas. The suggestions of think tank researches may have massive influences as long as they are adapted. In this study, we recommend that the think tank researches should be advanced to the science of think tank. The think tank researches should follow the widely recognized scientific research character-falsifiability. Based on solid data and evidences, think tank researches build objective models, develop qualitative methods and quantitative tools, and generate objective strategic consulting proposals with predictive ability. By …

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Developing Responsible Digital Economy, Qingfeng Yang, Jinluan Ren Jul 2021

Developing Responsible Digital Economy, Qingfeng Yang, Jinluan Ren

Bulletin of Chinese Academy of Sciences (Chinese Version)

The nature of technological-economic paradigm shift in digital economy determines that it is fundamentally different from traditional economy in terms of thinking principles and operating mechanism. Therefore, it shows the typical double-sided functions. On the one hand, it promotes the high-quality development of economy, activates social innovation, drives the transformation, and brings more welfare to the public. On the other hand, it has a lot of negative effects in the fields of work, innovation, market, and society. This research integrates the concept of responsibility into the digital economy, puts forward the concept and framework of responsible digital economy, and provides …

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Networked Simulation And It's Development Trend, Duan Hong, Xiaogang Qiu Jul 2021

Networked Simulation And It's Development Trend, Duan Hong, Xiaogang Qiu

Journal of System Simulation

Abstract: Carrying out simulating whenever and wherever possible as well as the large-scale trend of simulation lead to the demand of networked simulation.. Through the changes of range, from model interconnection, experimental collaboration and domain simulation collaboration, three layers of meanings of networked simulation are analyzed; The characteristics of networked simulation are summarized from five aspects, pattern, application, target, focus, and morphology. The idea that the networked simulation will bring changes to the simulation application of the activity scope and method, resource construction, resource verification, organizational structure, and so on is proposed. By sorting out the development process …

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Numerical Simulation Of Aerodynamic Characteristics For Double-All-Wing Unmanned Aerial Vehicle Based On Computational Fluid Dynamics Theory, Kuizhi Yue, Zhang Yuan, Liangliang Cheng, Dazhao Yu Jul 2021

Numerical Simulation Of Aerodynamic Characteristics For Double-All-Wing Unmanned Aerial Vehicle Based On Computational Fluid Dynamics Theory, Kuizhi Yue, Zhang Yuan, Liangliang Cheng, Dazhao Yu

Journal of System Simulation

Abstract: Follow the rapid progress of the nation's blue ocean strategic projection capability of sea power, an Unmanned Aerial Vehicle (UAV) with double-all-wing configuration is studied to match the trend. The UAV is conceptually designed by CATIA software, the aerodynamic characteristic of the model is numerically simulated by computational fluid dynamics (Computational Fluid Dynamics, CFD) theory, and the performance of the UAV to take off from the aircraft carrier is also analyzed. The lift coefficient, drag coefficient and lift-drag ratio of the double-all-wing UAV model with a angle of attack of 0 can reach 0.596 2, 0.037 6 and 15.824 …

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Simulation Evaluation For Service Facilities Distribution And Flow Lines Optimization On Urban Rail Transfer Station, Liu Feng, Chunfu Shao, Hongfei Jia, Chunjiao Dong Jul 2021

Simulation Evaluation For Service Facilities Distribution And Flow Lines Optimization On Urban Rail Transfer Station, Liu Feng, Chunfu Shao, Hongfei Jia, Chunjiao Dong

Journal of System Simulation

Abstract: The rationality of passenger flow lines design and service facilities distribution inside urban rail transfer station directly affects the passenger's transfer efficiency. The Simulation technology are used to evaluate the station's transfer efficiency, and the optimal plan can be proposed, which can not only avoid the crowded passenger flow, but also improve the efficiency. The features of peak passenger flow are considered, the service level of the passenger's stay time is given, the change of congested area's passenger flow density is expressed in the form of time-varying chart. Combined with the overall chart of the average passenger flow density, …

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Mix Design Effects On The Durability Of Alkali-Activated Slag Concrete In A Hydrochloric Acid Environment, Mohammad Teymouri, Kiachehr Behfarnia, Amirhosein Shabani Jul 2021

Mix Design Effects On The Durability Of Alkali-Activated Slag Concrete In A Hydrochloric Acid Environment, Mohammad Teymouri, Kiachehr Behfarnia, Amirhosein Shabani

Department of Civil and Environmental Engineering: Faculty Publications

Because of its high strength, energy reduction, and low environmental impact, researchers have encouraged considering alkali-activated slag concrete (AASC) as a potential alternative to conventional concrete. In this study, the impact of mix design parameters on the durability of AASC, made with ground granulated blast furnace slag and activated with different alkaline solutions (NaOH, KOH, and Na2SiO3 ) immersed up to six months in a hydrochloric acid bath with pH = 3, has been investigated. A total of 13 mix designs were made in a way that, in addition to the type of alkaline solution, considered three other parameters, namely …

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Research On A Dynamically Perceptive Connectivity Restoration Method, Hua Xiang, Baohua Li, Hongjuan Yao, Wang Zhao, Jiaxian Zuo Jul 2021

Research On A Dynamically Perceptive Connectivity Restoration Method, Hua Xiang, Baohua Li, Hongjuan Yao, Wang Zhao, Jiaxian Zuo

Journal of System Simulation

Abstract: The cluster communication network has the characteristics of time-varying topology, strong node mobility, and unstable link status, etc. It is difficult to maintain a stable topology. The network is divided into disconnected subgroups. In order to solve the communication problem between different groups, the cooperative relay node is introduced and a dynamic-sensing connection recovery method is proposed. A cooperative communication model is built and the mathematical expression of link quality indicators is deduced, which designs a multi-objective link evaluation function and achieves the optimal relay location planning through a multi-objective connectivity recovery algorithm. Simulation results show that the …

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Simulation And Optimization Of Supersonic Drag Characteristics Of Blunt Cone Ascender, Xiazhen Liu, Yuan Wu, Li Qi, Zhao Rui, Zhang Jian, Zhonghua Lu Jul 2021

Simulation And Optimization Of Supersonic Drag Characteristics Of Blunt Cone Ascender, Xiazhen Liu, Yuan Wu, Li Qi, Zhao Rui, Zhang Jian, Zhonghua Lu

Journal of System Simulation

Abstract: Reducing shock drag is an important objective of the aerodynamic optimization of Mars ascenders. The CFD(Computational Fluid Dynamics) method is used to study the supersonic drag characteristics of a typical blunt cone ascender. Under the design constraints of slenderness ratio of 0.42, 13 groups busbar shape set of zero-lift drag are compared, and the longitudinal static and dynamic stability are discussed. The research results show that, under the design constraints, the blunt shape with large bulbous and a gently sloped conical surface has low drag characteristics. The reason is that, after passing through the bulbous, the supersonic airflow …

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Optimization Of Urban Metro-Based Underground Logistics System Network With Hub-And-Spoke Layout, Ren Rui, Wanjie Hu, Jianjun Dong, Zhilong Chen Jul 2021

Optimization Of Urban Metro-Based Underground Logistics System Network With Hub-And-Spoke Layout, Ren Rui, Wanjie Hu, Jianjun Dong, Zhilong Chen

Journal of System Simulation

Abstract: Dual application of passenger commuting and underground logistics based on urban metro (M-ULS) provides a solution for traffic congestion. A three-stage optimization approach for the hub-and-spoke M-ULS network is proposed. An Entropy-TOPSIS model for underground flow screening was established based on indicators of freight flows unity, order priority and regional accessibility, considering facility capacity constraints, a location-allocation-routing combinatorial model with construction and operation costs objectives is proposed, Set Coverage Exact Algorithm, Adaptive Immunity Clone Selection Algorithm and Floyd-Warshall Algorithm are developed. Geographic information statistics of Nanjing is applied as the benchmark for real-world simulation. Results show that the modeling …

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Type Ii Photosensitized Oxidation In Senescent Microalgal Cells At Different Latitudes: Does Low Under-Ice Irradiance In Polar Regions Enhance Efficiency?, Jean François Rontani, Rémi Amiraux, Lukas Smik, Stuart G. Wakeham, Aurélien Paulmier, Frédéric Vaultier, Ha Sun-Yong, Min Jun-Oh, Simon T. Belt Jul 2021

Type Ii Photosensitized Oxidation In Senescent Microalgal Cells At Different Latitudes: Does Low Under-Ice Irradiance In Polar Regions Enhance Efficiency?, Jean François Rontani, Rémi Amiraux, Lukas Smik, Stuart G. Wakeham, Aurélien Paulmier, Frédéric Vaultier, Ha Sun-Yong, Min Jun-Oh, Simon T. Belt

School of Geography, Earth and Environmental Sciences

No abstract provided.

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