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Articles 34741 - 34770 of 302422

Full-Text Articles in Physical Sciences and Mathematics

Digital Evidence In Appeals Of Criminal Cases Before The U.S. Courts Of Appeal: A Review Of Decisions And Examination Of The Legal Landscape From 2016 – 2020, Martin Novak Jan 2022

Digital Evidence In Appeals Of Criminal Cases Before The U.S. Courts Of Appeal: A Review Of Decisions And Examination Of The Legal Landscape From 2016 – 2020, Martin Novak

Journal of Digital Forensics, Security and Law

This study is a follow-up to Digital Evidence in Criminal Cases before the U.S. Courts of Appeal: Trends and Issues for Consideration – 2010 to 2015. The current study examines appeals of criminal cases before the United States Courts of Appeal from January 2016 through August 2020, where one or more appeal claims were related to digital evidence. The purpose of this research was to determine if the legal landscape has changed since 2015; examine the most relevant legal issues related to digital evidence; and analyze how precedential cases may have affected digital forensics as evidence.


Research On Optimal Allocation Method Of Aircraft Towing Rules Based On Multi-Agent, Zhao Zheng, Hu Li, Yuanyuan Qian, Jin Hui, Aiping Jia Jan 2022

Research On Optimal Allocation Method Of Aircraft Towing Rules Based On Multi-Agent, Zhao Zheng, Hu Li, Yuanyuan Qian, Jin Hui, Aiping Jia

Journal of System Simulation

Abstract: In order to study and optimize the effect of aircraft towing rules on aircraft on bridge rate and flight normality, a towing rule configuration method based on surface capacity and demand balance is proposed. By constructing a multi-agent discrete simulation model based on surface operation, the collaborative optimization effect of aircraft on bridge rate and flight regularity is achieved, and which is verified by the example of Beijing Daxing International Airport. The results show that the towing rule configuration method based on airfield capacity and demand balance can obviously improve the aircraft on bridge rate and flight normality, …


Coupling Between Alfvén Wave And Kelvin–Helmholtz Waves In The Low Latitude Boundary Layer, Eun-Hwa Kim, Jay R. Johnson Jan 2022

Coupling Between Alfvén Wave And Kelvin–Helmholtz Waves In The Low Latitude Boundary Layer, Eun-Hwa Kim, Jay R. Johnson

Faculty Publications

The Kelvin–Helmholtz (KH) instability of magnetohydrodynamic surface waves at the low latitude boundary layer is examined using both an eigenfrequency analysis and a time-dependent wave simulation. The analysis includes the effects of sheared flow and Alfvén velocity gradient. When the magnetosheath flows are perpendicular to the ambient magnetic field direction, unstable KH waves that propagate obliquely to the sheared flow direction occur at the sheared flow surface when the Alfvén Mach number is higher than an instability threshold. Including a shear transition layer between the magnetosphere and magnetosheath leads to secondary KH waves (driven by the sheared flow) that are …


Design And Implementation Of Photovoltaic Energy Harvesting Automaton, Iskandar Askarov Jan 2022

Design And Implementation Of Photovoltaic Energy Harvesting Automaton, Iskandar Askarov

Theses

Global domestic electricity consumption has been rapidly increasing in the past three decades. In fact, from 1990 to 2020, consumption has more than doubled from 10,120 TWh to 23,177 TWh [1]. Moreover, consumers have been turning more towards clean, renewable energy sources such as Photovoltaic. According to International Energy Agency, global Solar power generation alone in 2019 has reached almost 3% [4] of the electricity supply. Even though the efficiency of photovoltaic panels has been growing, presently, the highest efficiency solar panels available to an average consumer range only from 20%-22% [14]. Many research papers have been published to increase …


Time-Varying Output Formation Tracking Control Of Discrete-Time Heterogeneous Multi-Agent Systems, Xiaolong Qi, Xuguang Yang Jan 2022

Time-Varying Output Formation Tracking Control Of Discrete-Time Heterogeneous Multi-Agent Systems, Xiaolong Qi, Xuguang Yang

Journal of System Simulation

Abstract: Aiming at the discrete-time heterogeneous multi-agent systems with different dimensions and parameters, the time-varying output formation tracking control is studied by using the output regulation method. Assuming that the multi-agents system is consisted of multiple followers and multiple leaders, and the followers can't obtain the leaders' states, the distributed observers are designed by using the neighboring relative information. Based on the states of the distributed observers, the time-varying output formation tracking protocols and algorithm are presented by using the states feedback, and the sufficient conditions that guarantee the protocols' effectiveness are also given. The simulation results show that, …


Research On Intelligent Vehicle Trajectory Tracking Control Based On Robust Model Prediction, Hongguang Lu, Shuen Zhao Jan 2022

Research On Intelligent Vehicle Trajectory Tracking Control Based On Robust Model Prediction, Hongguang Lu, Shuen Zhao

Journal of System Simulation

Abstract: Aiming at the low control accuracy and poor robustness of traditional trajectory tracking controller based on the tracking error model in complex driving environment, a robust model predictive trajectory tracking control strategy is designed. The vehicle convex multicellular dynamic model is used to explicitly describe the vehicle dynamic characteristics, and the robust performance objective function is designed in combination with the trajectory tracking multi-objective constraint, and the state feedback control law is solved through the linear matrix inequality optimization. Feedforward control is introduced to eliminate the steady-state errors and improve the tracking accuracy. The simulation result shows that …


Increased Above-Ground Biomass And Plant Species Decline Related To The Presence Of Eragrostis Curvula Across Multiple Grazing Grasslands In The Snowy Monaro Region Of Australia, J. Brown, L. Ingram Jan 2022

Increased Above-Ground Biomass And Plant Species Decline Related To The Presence Of Eragrostis Curvula Across Multiple Grazing Grasslands In The Snowy Monaro Region Of Australia, J. Brown, L. Ingram

IGC Proceedings (1993-2023)

"It will be noticed that invasions most often come to cultivated land, or to land much modified by human practice." This quote was published in 1958 by Charles Elton, and holds true today, backed by empirical evidence suggesting mechanisms of disturbance, plant functional traits and propagule pressure can push a cultivated system towards an invaded state. 17 farms, with either a current or previous history of grazing and land modification, within the Snowy Monaro Region, NSW, Australia, were surveyed to explore the relationship between the non-native C4 perennial tussock grass Eragrostis curvula [Schrad.] Nees. and species richness. As E. curvula …


Impact Of Enclosures On Range Productivity In Chepareria West Pokot County Kenya, Regina W. Waiganjo, P. N. Mwangi, Rebecca H. Karanja Jan 2022

Impact Of Enclosures On Range Productivity In Chepareria West Pokot County Kenya, Regina W. Waiganjo, P. N. Mwangi, Rebecca H. Karanja

IGC Proceedings (1993-2023)

In the semi-arid areas of West Pokot particularly Chepareria, majority of the people live semi sedentary lives while others are nomadic pastoralists. In the last three decades, there have been concerted efforts to restore and improve rangeland in this area. Use of enclosures, which is one of the key interventions, by the Vi Agro- forestry a Non-Governmental Organisation, enhancing with many ecological processes such as disturbance, is a method of rehabilitating degraded rangeland, which in turn affects vegetation dynamics. Adoption of these strategies by farmers has been gradual and some areas are still open and degraded. The aim of this …


Stocking Rate And Supplementation Effects On Performance Of Lambs Grazing Triticale And Ryegrass Sward In Uruguay, R. San Julián, Fabio Montossi, L. Guarino, F. Pittaluga Jan 2022

Stocking Rate And Supplementation Effects On Performance Of Lambs Grazing Triticale And Ryegrass Sward In Uruguay, R. San Julián, Fabio Montossi, L. Guarino, F. Pittaluga

IGC Proceedings (1993-2023)

An experiment was carried out from 9 June to 2 October 1997, using a Lolium multiflorum Lom. (Ryegrass) and X Triticosecale Wittmack (triticale) sward to evaluate the effect of stocking rate (SR; 20, 30 and 40 lambs/ha), and supplementation (S; with or without) on Corriedale lamb performance. SR had a significant effect on: liveweight gain (160, 130 and 90 g/an/d, P< 0.01); greasy fleece weight (2.8, 2.7 and 2.3 kg, P< 0.01); fiber diameter (28, 27, and 26 microns, P< 0.05); rib eye depth (2.4, 2.1 and 2.0 cm, P< 0.05); fat cover (3.2, 2.1 and 1.5 cm, P< 0.01); hot carcass weight (17.7, 15.6 and 13.5 kg/an, P< 0.01); GR (10.5, 6.6 and 4.2 mm, P< 0.01) and boneless leg weight (1.56, 1.42 and 1.24 kg, P< 0.05), for 20, 30 and 40 lambs per ha, respectively. At the highest SR, lambs increased grazing time (59 vs 52%) and biting rate (29 vs 26 bites/lamb/min). The mayor influence of S on lamb performance was found in grazing behavior variables: (grazing time (63 vs 50%, P< 0.01); biting rate (26.8 vs 28.4 bites/lamb/min, P< 0.01)), carcass characteristics: (hot carcass weight (15.3 vs 16.0 kg, P< 0.05); GR (7.9 and 6.3 mm, P< 0.05)) for with and without supplement, respectively. Over the experimental period (115 days), liveweight production and wool production ranged from 358 to 437 kg/ha for 20 and 30 lambs/ha respectively, and wool production from 55 to 93 kg/ha for 20 and 40 lambs/ha respectively. These results show the potential use of mixed ryegrass and triticale swards to produce high quality lamb meat even at high SRs, and the convenience of using supplements only when sward conditions are not sufficient to maintain an adequate lamb performance, particularly when high lamb SRs are used.


The Use Of Open Communal Grazing Designs To Screen Options For Grazing Management, David R. Kemp, D. L. Michalk, P. M. Dowling, G. Millar Jan 2022

The Use Of Open Communal Grazing Designs To Screen Options For Grazing Management, David R. Kemp, D. L. Michalk, P. M. Dowling, G. Millar

IGC Proceedings (1993-2023)

An open communal grazing design is described that enables a large number of grazing tactics to be concurrently evaluated in small plots under common grazing conditions. Pasture data indicated that the same level of utilisation occurred inside the experimental plots as in the surrounding field. However, differential grazing may occur where plots have divergent composition. The open communal design was economical using < 5% of the land, livestock and fencing resources of alternative designs. The limitations of the open communal design as a research tool are also discussed.


Lamb Stocking Rate And Supplementation Effects On Mixed Triticale And Ryegrass Swards Characteristics, R. San Julián, Fabio Montossi, L. Guarino, F. Pittaluga Jan 2022

Lamb Stocking Rate And Supplementation Effects On Mixed Triticale And Ryegrass Swards Characteristics, R. San Julián, Fabio Montossi, L. Guarino, F. Pittaluga

IGC Proceedings (1993-2023)

An experiment was carried out from 9 June to 22 October 1997, using a Lolium multiflorum L. (ryegrass) and Triticosecale Wittmack (triticale) mixed sward grazed by lambs in a rotational grazing system, to determine the effect of stocking rate (SR; 20, 30 and 40 lambs/ha) and supplementation (S; with or without) on herbage production, composition and nutritive value. SR affected significantly before and after grazing herbage mass and sward height, being higher the values of these variables at the lower SR (3232, 2611 and 2345 kg DM ha-1, P < 0.05; 2557, 1761 and 1612 kg DM ha-1, P < 0.01; 17, 11 and 9 cm, P < 0.01 respectively). Increments in SR had an effect on post grazing sward composition, increasing the proportion of ryegrass (32, 36 and 47 %, P< 0.05) and decreasing triticale contribution (68, 64 and 55 %, P< 0.05) for 20, 30 and 40 lambs/ha. The effect of SR on sward nutritive value was not very clear. Before grazing, S affected significantly herbage mass, being higher the values at the supplemented treatments (2787 vs. 2672 kg DM ha-1, P < 0.10). This experiment showed the high potential of forage production and nutritive value of ryegrass and triticale swards for lamb production in the sandy soil region of Uruguay, and the dominant effect of SR, compared to S, on most of the sward variables considered.


Putting Light To Work Jan 2022

Putting Light To Work

Thomas Jefferson University Research Magazine

Jefferson researchers are using light in new ways: using blue light to drive chemical processes, and creating products that illuminate in ultraviolet light. Their work reflects a convergence of disciplines such as physics, chemistry, textile engineering and nanotechnology that is driving applications with practical benefits for people and the environment.

John Milligan, PhD, assistant professor of chemical and biological sciences, is leading development of environmentally sustainable ways to spur chemical reactions using blue LED light. The work is an example of the “photoredox” subfield of organic chemistry, which has proven to be an increasingly effective method for building organic molecules. …


Saving The Campus Farm: One Approach To Leveraging Institutional Support For A Campus Farm Space, Julia L. Angstmann Jan 2022

Saving The Campus Farm: One Approach To Leveraging Institutional Support For A Campus Farm Space, Julia L. Angstmann

Scholarship and Professional Work - LAS

The number of university and college campus farms have increased 13-fold since 1992 to over 300 campuses (LaCharite, 2016). According to reporting by the Association for the Advancement of Sustainability in Higher Education (AASHE) (2018), 80% of campus farm spaces are less than 5 acres in size and 86% are located on campuses with no agriculture school (AASHE, 2018). Campus farms provide a rich interdisciplinary social context of community based, sustainable agriculture that spans the entire suite of social and physical sciences as well as non-STEM fields such as business, religious studies, and communication. Yet, the majority of these farm …


Exploring Old Data With New Tricks: Long-Term Monitoring Indicates Spatial And Temporal Changes In Populations Of Sympatric Prairie Grouse In The Nebraska Sandhills, Danielle J. Berger, Jeffrey J. Lusk, Larkin A. Powell, John P. Carroll Jan 2022

Exploring Old Data With New Tricks: Long-Term Monitoring Indicates Spatial And Temporal Changes In Populations Of Sympatric Prairie Grouse In The Nebraska Sandhills, Danielle J. Berger, Jeffrey J. Lusk, Larkin A. Powell, John P. Carroll

School of Natural Resources: Faculty Publications

The contiguous grasslands of the Sandhills region in Nebraska, USA, provide habitat for two sympatric, grassland-obligate species of grouse, the greater prairie-chicken (Tympanuchus cupido pinnatus) and the plains sharp-tailed grouse (Tympanuchus phasianellus jamesi). Collectively referred to as prairie grouse, these birds are monitored and managed jointly by wildlife practitioners who face the novel challenge of conserving historically allopatric species in shared range. We reconstructed region-wide and route-specific prairie grouse population trends in the Sandhills, using a 63-year timeseries of breeding ground counts aggregated from old reports and paper archives. Our objective was to repurpose historical data …


Reef Sediments Can Act As A Stony Coral Tissue Loss Disease Vector, Michael S. Studivan, Ashley M. Rossin, Ewelina Rubin, Nash Soderberg, Daniel M. Holstein, Ian C. Enochs Jan 2022

Reef Sediments Can Act As A Stony Coral Tissue Loss Disease Vector, Michael S. Studivan, Ashley M. Rossin, Ewelina Rubin, Nash Soderberg, Daniel M. Holstein, Ian C. Enochs

Faculty Publications

Stony coral tissue loss disease (SCTLD) was first observed in 2014 near Virginia Key in Miami-Dade County, Florida. Field sampling, lab experiments, and modeling approaches have suggested that reef sediments may play a role in SCTLD transmission, though a positive link has not been tested experimentally. We conducted an ex situ transmission assay using a statistically-independent disease apparatus to test whether reef sediments can transmit SCTLD in the absence of direct contact between diseased and healthy coral tissue. We evaluated two methods of sediment inoculation: batch inoculation of sediments collected from southeast Florida using whole colonies of diseased Montastraea cavernosa, …


Survey Of Ship Detection In Video Surveillance Based On Shallow Machine Learning, Zhenbo Bi, Shiyou Zhang, Yang Hua, Yuanhong Wu Jan 2022

Survey Of Ship Detection In Video Surveillance Based On Shallow Machine Learning, Zhenbo Bi, Shiyou Zhang, Yang Hua, Yuanhong Wu

Journal of System Simulation

Abstract: At present, detection of ship targets in video surveillance based on shallow machine learning methods is still attracting attention in the fields of underwater cultural heritage protection, marine aquaculture, maritime traffic, and port management. This paper provides a review and discussion for this kind of ship detection methods. The ship target detection based on video surveillance is divided into five parts according to the key technologies involved: preprocessing, region of interest extraction, target segmentation, ship feature extraction and ship type recognition. According to different functional modules, the core problems involved in them are pointed out, and the core ideas, …


Research On Detection Data Driven Calibration Method Of Traffic Simulation Parameters, Wenxin Ma, Ruimin Li Jan 2022

Research On Detection Data Driven Calibration Method Of Traffic Simulation Parameters, Wenxin Ma, Ruimin Li

Journal of System Simulation

Abstract: To improve the accuracy of traffic simulation model and timely response of traffic demand and driving behavior changes, dynamic calibration method of simulation parameters based on detection data is proposed. Dynamic interaction between detection data and simulation platform is proposed. Intersection of Guanghua Road/Jintong East Road in Beijing and five consecutive intersections on Youyi Street in Baotou are Selected as study cases. Sensitivity analysis is conducted on initial parameter combinations. Based on the analysis results, parameters to be calibrated are selected. Models of cases are developed in VISSIM and driving behavior parameters are calibrated. Simulation results show that …


Research On Supply Chain Recovery Strategy Under Disruption Risks, Yang Yi, Peng Chen, Yujiu Yang, Yulong Wang Jan 2022

Research On Supply Chain Recovery Strategy Under Disruption Risks, Yang Yi, Peng Chen, Yujiu Yang, Yulong Wang

Journal of System Simulation

Abstract: Aiming at supply chain disruptions, two effective supply chain recovery strategies are proposed, namely, a supplier’s preset emergency inventory strategy and a manufacturer’s product change strategy, meanwhile, emergency inventory storage cost and products return rate after change are also taken into consideration. In order to maximize the manufacturer’s profit and customer satisfaction, a single-objective model and a bi-objective model are established, respectively. The optimization problems in the two models are transformed into mixed integer programming problems, moreover, corresponding solution algorithms are presented based on ILOG CPLEX. The simulation results show that the disruption recovery strategies proposed can not only …


Brief Review On Applying Reinforcement Learning To Job Shop Scheduling Problems, Xiaohan Wang, Zhang Lin, Ren Lei, Kunyu Xie, Kunyu Wang, Ye Fei, Chen Zhen Jan 2022

Brief Review On Applying Reinforcement Learning To Job Shop Scheduling Problems, Xiaohan Wang, Zhang Lin, Ren Lei, Kunyu Xie, Kunyu Wang, Ye Fei, Chen Zhen

Journal of System Simulation

Abstract: Reinforcement Learning (RL) achieves lower time response and better model generalization in Job Shop Scheduling Problem (JSSP). To explain the current overall research status of JSSP based on RL, summarize the current scheduling framework based on RL, and lay the foundation for follow-up research, the backgrounds of JSSP and RL are introduced. Two simulation techniques commonly used in JSSP are analyzed and two commonly used frameworks for RL to solve JSSP are given. In addition, some existing challenges are pointed out, and related research progress is introduced from three aspects: direct scheduling, feature representation-based scheduling, and parameter search-based scheduling.


Research On Digital Twin-Based Modeling And Monitoring Of Five-Axis Grinder, Xiao Tong, Haifan Jiang, Guofu Ding, Jiang Lei, Shuwen Ma Jan 2022

Research On Digital Twin-Based Modeling And Monitoring Of Five-Axis Grinder, Xiao Tong, Haifan Jiang, Guofu Ding, Jiang Lei, Shuwen Ma

Journal of System Simulation

Abstract: Aiming at the poor virtual-real interaction ability, single data presentation mode, and hysteretic abnormality handling in CNC machine tool status monitoring, a visual monitoring method for machine tool process based on digital twin is proposed, Which realizes the mapping of three subsystems of machine tool, machinery, control and electrical to the information space from three dimensions of geometry, logic and data. The verification of instructions and CNC programs, real-time status monitoring and abnormality handling during operation are carried out. A digital twin-based machine tool modeling and monitoring system is designed and developed. Taking a five-axis CNC …


Simulation Research On U-Automated Container Terminal, Ding Yi, Tiantian Li Jan 2022

Simulation Research On U-Automated Container Terminal, Ding Yi, Tiantian Li

Journal of System Simulation

Abstract: To analyze the new U-layout effect on the handling operation efficiency in automated container terminal, the U-automated container terminal simulation model is established by FlexTerm software to visualize the handling operation process. The traditional automated terminal simulation model is established to compare the working efficiency under different working modes. The working ability of terminal handling equipment such as AGV(Automated Guided Vehicle), yard cranes and rail-mounted gantry cranes are compared by simulation tests. Simulation results show that due to the creation of yard layout and handling technology, the superiority of U-layout is proved when the working efficiency of each handling …


Study And Effect Evaluation On The Setting Of Contraflow Left-Turn At Intersections, Zhao Dan, Xuejun Niu, Shuhao Zhang, Jiaxu Wei Jan 2022

Study And Effect Evaluation On The Setting Of Contraflow Left-Turn At Intersections, Zhao Dan, Xuejun Niu, Shuhao Zhang, Jiaxu Wei

Journal of System Simulation

Abstract: Contraflow left-turn is one of the traffic organization ways at intersections. By analyzing the setting parameters of the contraflow left-turn, the length and the range of the contraflow left-turn lane, the constrained conditions of the contraflow left-turn are determined, and the applicable conditions are determined from the road, traffic and signal control. VISSIM software is used to analyze a road intersection, simulate and evaluate the indicators related to the intersection entrance, optimize the timing plan of contraflow left-turn lane, and validate the feasibility and advantages of contraflow left-turn lane. The results show that the intersection delays are reduced by …


Variety Recognition Based On Deep Learning And Double-Sided Characteristics Of Maize Kernel, Feng Xiao, Zhang Hui, Zhou Rui, Qiao Lu, Wei Dong, Dandan Li, Yuyao Zhang, Guoqing Zheng Jan 2022

Variety Recognition Based On Deep Learning And Double-Sided Characteristics Of Maize Kernel, Feng Xiao, Zhang Hui, Zhou Rui, Qiao Lu, Wei Dong, Dandan Li, Yuyao Zhang, Guoqing Zheng

Journal of System Simulation

Abstract: In order to construct a maize kernel variety recognition model with high recognition accuracy and suitable for mobile phone application, a mobile phone is used to obtain maize kernel double-sided (embryonic and non-embryonic) images. Based on the lightweight convolutional neural network MobileNetV2 and transfer learning, a maize kernel image variety recognition model is constructed. In view of the existing research methods are mainly for single-sided recognition of maize kernel variety, the performance of single-sided and double-sided characteristics modeling and recognition is compared. The results show that the double-sided recognition accuracy of maize kernel double-sided characteristics modeling is 99.83%, which …


Silver Bow Creek Butte Area Npl Site 2022 Draft Butte Priority Soils Operable Unit Interim Site-Wide Groundwater Monitoring Qapp. Consent Decree- Civil Action No. Cv 89-039-Bu-She, Trec Inc., A Woodard And Curran Company Jan 2022

Silver Bow Creek Butte Area Npl Site 2022 Draft Butte Priority Soils Operable Unit Interim Site-Wide Groundwater Monitoring Qapp. Consent Decree- Civil Action No. Cv 89-039-Bu-She, Trec Inc., A Woodard And Curran Company

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Parametric And Reliability Estimation Of The Kumaraswamy Generalized Distribution Based On Record Values, Mohd. Arshad, Qazi J. Azhad Jan 2022

Parametric And Reliability Estimation Of The Kumaraswamy Generalized Distribution Based On Record Values, Mohd. Arshad, Qazi J. Azhad

Journal of Modern Applied Statistical Methods

A general family of distributions, namely Kumaraswamy generalized family of (Kw-G) distribution, is considered for estimation of the unknown parameters and reliability function based on record data from Kw-G distribution. The maximum likelihood estimators (MLEs) are derived for unknown parameters and reliability function, along with its confidence intervals. A Bayesian study is carried out under symmetric and asymmetric loss functions in order to find the Bayes estimators for unknown parameters and reliability function. Future record values are predicted using Bayesian approach and non Bayesian approach, based on numerical examples and a monte carlo simulation.


Real-Time Simulation Technology Of Fluid-Thermo-Solid Coupling Of Hypersonic Vehicle, Yunqin Liu, Li Ni, Luming Zhao, Jinpeng Bai, Tingjun Li, Chenguang Wang Jan 2022

Real-Time Simulation Technology Of Fluid-Thermo-Solid Coupling Of Hypersonic Vehicle, Yunqin Liu, Li Ni, Luming Zhao, Jinpeng Bai, Tingjun Li, Chenguang Wang

Journal of System Simulation

Abstract: The solution of the coupling characteristics of fluid-thermo-solid physics in the modeling of hypersonic vehicle is an unavoidable difficulty, and the real-time simulation of fluid-thermo-solid coupling is particularly challenging. Aiming at the conflicting problem of solution accuracy and solution efficiency in fluid-thermo-solid coupling real-time simulation, a CFD (Computational Fluid Dynamics)/ CSD (Computational Structural Dynamics)-based fluid-thermo-solid coupling characteristic solution method is established, which realizes the high-precision solution of the fluid, temperature, and structural deformation field coupling. According to the multi-condition offline solution set modeling method, by accumulating a large number of offline solutions as effective support for online …


Kinematics Analysis And Simulation Of Automatically Tracking Dental Surgery Lamp, Zerui Jiang, Lijun Yang, Li Jun, Xiaolong Jiao, Zheng Hang Jan 2022

Kinematics Analysis And Simulation Of Automatically Tracking Dental Surgery Lamp, Zerui Jiang, Lijun Yang, Li Jun, Xiaolong Jiao, Zheng Hang

Journal of System Simulation

Abstract: In order to solve the problem that the oral surgical lamp cannot automatically adjust the irradiation posture of the surgical lamp according to the face direction and oral cavity position, a six-degree-of-freedom automatic tracking visual manipulator solution is proposed. Coordinate conversion is achieved through binocular vision to obtain three-dimensional information of oral cavity position and face normal vector. The geometric method is introduced into the kinematics calculation, and the closed solution of the inverse kinematics is obtained. The correctness is verified by the Maltab programming and the introduction of numerical values. Five-degree polynomial motion planning is performed …


Predictive Control Method Of Peak Hour Passenger Flow At Urban Rail Station, Xiaohe Li, Jianping Wu, Depin Peng Jan 2022

Predictive Control Method Of Peak Hour Passenger Flow At Urban Rail Station, Xiaohe Li, Jianping Wu, Depin Peng

Journal of System Simulation

Abstract: With the rapid development of subway in China, the urban rail station, especially the transfer station, is prone to generate passenger congestion in the peak period. After analyzing the types of passenger flow in and out of the platform, a predictive control model of passenger flow is established based on the discrete linear quadratic optimal control theory. Taking Fuxingmen Station as an example, the simulation environment of the station is built by using the simulation software of Anylogic. The historical passenger flow data in peak period and the optimal passenger flow control sequence obtained by solving the passenger flow …


Methanol Decomposition On Ni(111) And O/Ni(111), Henrik Öström, Bingjie Zhang, Tiffany Vallejo, Bryn Merrill, Jeremy Huang, Jerry Larue Jan 2022

Methanol Decomposition On Ni(111) And O/Ni(111), Henrik Öström, Bingjie Zhang, Tiffany Vallejo, Bryn Merrill, Jeremy Huang, Jerry Larue

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Methanol decomposition on Ni(111) surfaces has been studied in the presence and absence of oxygen using temperature-programmed desorption and temperature-dependent sum frequency generation spectroscopy. Under both conditions the C–H and O–H bonds break, forming carbon monoxide and atomic hydrogen on the surface. No C–O bond scission was observed, limiting the number of reaction pathways. The O–H bonds break first (>150 K), forming surface methoxy, followed by C–H bond breakage (>250 K). All atomic hydrogen desorbs from the surface as H2 through H+H recombinative desorption. H2 desorbs at a higher temperature in the presence of oxygen (>300 K) …


An Evolutionary Multi-Objective Simulation Optimization Algorithm For Supply Chain With Uncertain Demands, Hongfeng Wang, Yitian Zhang, Jingze Chen Jan 2022

An Evolutionary Multi-Objective Simulation Optimization Algorithm For Supply Chain With Uncertain Demands, Hongfeng Wang, Yitian Zhang, Jingze Chen

Journal of System Simulation

Abstract: During the COVID-19 pandemic, supply chain of manufacturing companies is facing more severe product demand uncertainty, which is manifested in the sharp increase in demand for certain types of products and the increased fluctuations in supply for raw materials. For this supply chain optimization problem with demand uncertainty, a multi-objective stochastic programming model is developed in order to maximize the total profit and product order fulfillment rate simultaneously in this paper. For solving the investigated problem, a new evolutionary multi-objective simulation optimization algorithm is proposed by combining the mechanism of NSGA-II and simulation computing budget allocation adaptively. Experimental …