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Articles 56791 - 56820 of 302569

Full-Text Articles in Physical Sciences and Mathematics

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 …


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 …


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 …


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. …


Final 2021 Residential Metals Abatement Program (Rmap) School Soil Sampling Field Sampling Plan (Fsp) Submittal #3 [Covering Emerson Elementary, Headstart (Former Lincoln School), Headstart (Former Monroe School), & Margaret Leary Elementary], Pioneer Technical Services, Inc. Jul 2021

Final 2021 Residential Metals Abatement Program (Rmap) School Soil Sampling Field Sampling Plan (Fsp) Submittal #3 [Covering Emerson Elementary, Headstart (Former Lincoln School), Headstart (Former Monroe School), & Margaret Leary Elementary], Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Final 2021 Residential Metals Abatement Program (Rmap) School Soil Sampling Field Sampling Plan (Fsp) Submittal #4 [Covering Butte Central Elementary & Middle School, Butte Central High School, Butte High School/Annex, East Middle School, Jeremy Bullock Soccer Fields, Webster Garfield School, & Whittier Elementary], Pioneer Technical Services, Inc. Jul 2021

Final 2021 Residential Metals Abatement Program (Rmap) School Soil Sampling Field Sampling Plan (Fsp) Submittal #4 [Covering Butte Central Elementary & Middle School, Butte Central High School, Butte High School/Annex, East Middle School, Jeremy Bullock Soccer Fields, Webster Garfield School, & Whittier Elementary], Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Research On Generating Technology For Equipment Standard Set Based On Uaf Modeling, Shuofang Zheng, Ruiheng He, Wenming Ren Jul 2021

Research On Generating Technology For Equipment Standard Set Based On Uaf Modeling, Shuofang Zheng, Ruiheng He, Wenming Ren

Journal of System Simulation

Abstract: In order to meet the requirements of equipment standardization work of top-down design of current era, the modeling principles and methods of Unified Architecture Frame (UAF) are studied. Focus on the construction of four standard view models specified by UAF, Standards taxonomy, Standards structure, Standards roadmap, Standards traceability, the correlation model of operation perspective, requirement perspective and resource perspective are analyzed to form the requirement-driven equipment standard set generation technology. A new standard generation mechanism oriented to use scenarios and closely related to equipment development needs is established, and a new entry point for equipment standardization is proposed. The …


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 …


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 …


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, …


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 …


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 …


Plasma Agriculture: Characterization Of Dbd Plasma Jet And Analysis Of Effects When Treated On Sweet Basil (Ocimum Basilicum), William Davis Jul 2021

Plasma Agriculture: Characterization Of Dbd Plasma Jet And Analysis Of Effects When Treated On Sweet Basil (Ocimum Basilicum), William Davis

Seton Hall University Dissertations and Theses (ETDs)

Plasma agriculture is an increasingly diverse field, where effects of nonthermal or cold plasma are measured by their influence on plant physiology and growth rate. Effects range from sterilization, germination, increased growth rate, cell metabolism, and so forth. This study aims to investigate the understanding of the generation of specific reactive oxygen and nitrogen species (RONS) from a nonthermal atmospheric DBD helium-based plasma jet and identify quantifiable effects that can directly translate to different applications related to plasma agriculture. Basil plants were separated into treated and control groups and grown hydroponically. The treated plants received a 30 second exposure treatment …


Ice-Crystal Traces Imply Ephemeral Freezing In Early Permian Equatorial Pangea, Lily S. Pfeifer, Brooke A. Birkett, Jean Van Den Driessche, Stephane Pochat, Geriliyn S. Soreghan Jul 2021

Ice-Crystal Traces Imply Ephemeral Freezing In Early Permian Equatorial Pangea, Lily S. Pfeifer, Brooke A. Birkett, Jean Van Den Driessche, Stephane Pochat, Geriliyn S. Soreghan

School of Earth & Environment Departmental Research

Delicate impressions in lacustrine strata of the lower Permian (lower Cisuralian) Usclas Formation record ephemeral freezing in equatorial Pangea. These sediments accumulated in the paleoequatorial and intramontane Lodève Basin (southern Massif Central, France) during peak icehouse conditions of the Late Paleozoic Ice Age. Experimental replication of these features supports the interpretation that they are ice-crystal molds. Evidence for films of ice in marginal-lacustrine sediment at such low latitudes and inferred low to moderate altitudes (1–2 km) calls for a reevaluation of climate conditions in eastern equatorial Pangea. Ephemeral freezing implies either cold tropical temperatures (~5 °C cooler than the Last …


The Development And Application Of Instrumental Methods For The Identification Of Materials And Processes Used In The Manufacture Of Orotone, Hand-Colored Orotone, And Silvertone Photographs, Ivanny Jeannette Jácome-Valladares Jul 2021

The Development And Application Of Instrumental Methods For The Identification Of Materials And Processes Used In The Manufacture Of Orotone, Hand-Colored Orotone, And Silvertone Photographs, Ivanny Jeannette Jácome-Valladares

Dissertations and Theses

Orotone photographs are positive photographic images on glass with a gold-colored metallic coating or backing. Although the materials and process used in the production of orotones have been previously documented, there is limited published scientific research on the subject. This study focused on expanding those published works by analyzing a greater number of photographs, including eleven orotones, four hand-colored orotones, two silvertones, and one uncoated orotone. The photographs, dating from the early to mid-20th century, were from the University of Washington (UW) Libraries' collection, except for one orotone that was from the Portland Art Museum.

X-ray Fluorescence (XRF) spectroscopy, …


An Analysis Of Capillary Flow In Finite Length Interior Corners, Samuel Shaw Mohler Jul 2021

An Analysis Of Capillary Flow In Finite Length Interior Corners, Samuel Shaw Mohler

Dissertations and Theses

We analyze the mathematical robustness of slow massively parallel interior corner flows in low gravity environments. An interior corner provides a preferential orientation in low gravity environments. This is a luxury usually only found on earth. It also provides a passive pumping mechanism due to geometry of a conduit. The driving force for this flow is a pressure difference due to local surface curvature gradients. An alternative reasoning is that due to the geometrical constraints the interior corner surface energy is unbounded below. This results in the liquid wicking into corners indefinitely. Interior corner flow's main quantity of interest is …


A Mechanical Model For Magnetized Relativistic Blastwaves, Shunke Ai, Bing Zhang Jul 2021

A Mechanical Model For Magnetized Relativistic Blastwaves, Shunke Ai, Bing Zhang

Physics & Astronomy Faculty Research

The evolution of a relativistic blastwave is usually delineated under the assumption of pressure balance between forward- and reverse-shocked regions. However, such a treatment usually violates the energy conservation law, and is inconsistent with existing magnetohydrodynamic numerical simulation results. A mechanical model of non-magnetized blastwaves was proposed in previous work to solve the problem. In this paper, we generalize the mechanical model to the case of a blastwave driven by an ejecta with an arbitrary magnetization parameter $\sigma_{\rm ej}$. We test our modified mechanical model by considering a long-lasting magnetized ejecta and found that it is much better than the …


Plot Extraction And The Visualization Of Narrative Flow, Michael A. Debuse Jul 2021

Plot Extraction And The Visualization Of Narrative Flow, Michael A. Debuse

Theses and Dissertations

In order to facilitate the automated extraction of complex features and structures within narrative, namely plot in this study, two proof-of-concept methods of narrative visualization are presented with the goal of representing the plot of the narrative. Plot is defined to give a basis for quality assessment and comparison. The first visualization presented is a scatter-plot of entities within the story, but due to failing to uphold the definition of plot, in-depth analysis is not performed. The second visualization presented is a graph structure that better represents a mapping of the plot of the story. Narrative structures commonly found within …


Study On Universal Characteristics Of Insect Population Ecological Network, Guilan Luo, Hongjun Hao, Wang Xiao, Zhang Mei Jul 2021

Study On Universal Characteristics Of Insect Population Ecological Network, Guilan Luo, Hongjun Hao, Wang Xiao, Zhang Mei

Journal of System Simulation

Abstract: In order to evaluate the current state of insect ecological development in Erhai wetland, complex network theory is used to construct a topological structure model of insect ecological network with insect populations as network nodes and correlations as edges. By analyzing the characteristic parameters of the model, it is concluded that the insect ecological network conforms to the characteristics of small world and scale-free network, and the node degree distribution obeys the power law distribution. The method of destroying the topology is used to simulate the dynamic evolution of the network ecology. The study shows that the disappearance of …


Research On Active Suspension Control Of High-Speed Train Based On Fuzzy Compound Strategy, Jianjun Meng, Zhongjun Wang, Ruxun Xu, Decang Li Jul 2021

Research On Active Suspension Control Of High-Speed Train Based On Fuzzy Compound Strategy, Jianjun Meng, Zhongjun Wang, Ruxun Xu, Decang Li

Journal of System Simulation

Abstract: In order to improve the running stability of high-speed train, a semi-vertical six-degree-of- freedom state space model is established based on the active suspension system. Based on fuzzy control theory, the fuzzy controllers and fuzzy PID controllers are designed. Aiming at the defects of strong subjectivity of fuzzy PID control which needs manual adjustment, particle swarm optimization is used to optimize the initial parameters of the controller to make the suspension system be more correspond with the objective reality. In order to verify the advance of this strategy, with the sky-hook damping strategy for comparison, the controller model …


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, …


Study On Task Allocation Of Uav Swarm Based On Cognitive Control, Ruixuan Wei, Zichen Wu Jul 2021

Study On Task Allocation Of Uav Swarm Based On Cognitive Control, Ruixuan Wei, Zichen Wu

Journal of System Simulation

Abstract: A centralized allocation method for Unmanned Aerial Vehicle (UAV) swarm real-time task allocation is proposed. Based on the real-time battlefield situation, this method relies on the coordination scheduling layer to make allocation decisions, generates the strike order according to the strike efficiency ratio, and makes rolling optimization for real-time battlefield situation, so that the allocation results can always maintain the balance between optimization and efficiency within the current cognitive range. Particle swarm optimization (PSO) is used to solve the task assignment problem. In particular, a 2-D particle 0-1 coding and correction method for nonstandard particles is designed. The simulation …


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 …


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 …


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 …


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 …


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 …


Getting Scale Right: Multi Stakeholder Forums For Large Scale Management Of Mobile Livestock Production Systems In The Republic Of Niger, Thomas Sommerhalter Jul 2021

Getting Scale Right: Multi Stakeholder Forums For Large Scale Management Of Mobile Livestock Production Systems In The Republic Of Niger, Thomas Sommerhalter

IGC Proceedings (1993-2023)

No abstract provided.


Knowledge Evolution And Policy Changes In Rangeland Management Of Hkh Region, Karma Phunthso, Shaoliang Yi Jul 2021

Knowledge Evolution And Policy Changes In Rangeland Management Of Hkh Region, Karma Phunthso, Shaoliang Yi

IGC Proceedings (1993-2023)

No abstract provided.


Grassland — A Resource For Sustenance In South India, B. K. Trivedi, Anil Kumar, S. Natrajan, Nagaratna Biradar Jul 2021

Grassland — A Resource For Sustenance In South India, B. K. Trivedi, Anil Kumar, S. Natrajan, Nagaratna Biradar

IGC Proceedings (1993-2023)

No abstract provided.