Research on Aircraft Target Detection Probability for OTHR

2014 ◽  
Vol 644-650 ◽  
pp. 1261-1265
Author(s):  
Jing Jia ◽  
Wen Sheng ◽  
Lu Zhang
Keyword(s):  
Simulation Model ◽  
Target Detection ◽  
Detection Probability ◽  
Great Influence ◽  
Simulation Method ◽  
Detection Range

In this paper, a simulation method of detection probability of aircraft target for Over-The-Horizon Radar (OTHR) by computer is proposed. The effects of different ionosphere states on detection range for OTHR is concluded, which become constraint on simulation of detection probability. Taking variety of target RCS with attitude during flight through given track into consideration, simulation model of target dynamic RCS is established. Models of instantaneous detection probability and comprehensive detection probability are also presented. Then, detection probability of aircraft can be obtained through utilizing all models above based on given calculation steps. Simulations show that ionosphere state and target RCS have a great influence on detection probability.

Stochastic simulation for determining the design flood of cascade reservoir systems

2012 ◽  
Vol 43 (1-2) ◽  
pp. 54-63 ◽  
Author(s):  
Baohong Lu ◽  
Huanghe Gu ◽  
Ziyin Xie ◽  
Jiufu Liu ◽  
Lejun Ma ◽  
...  
Keyword(s):  
Simulation Model ◽  
Stochastic Simulation ◽  
Southern China ◽  
Flow Simulation ◽  
Simulation Method ◽  
Simulation Approach ◽  
Design Flood ◽  
Design Values ◽  
Stochastic Simulation Model ◽  
The Impact

Stochastic simulation is widely applied for estimating the design flood of various hydrosystems. The design flood at a reservoir site should consider the impact of upstream reservoirs, along with any development of hydropower. This paper investigates and applies a stochastic simulation approach for determining the design flood of a complex cascade of reservoirs in the Longtan watershed, southern China. The magnitude of the design flood when the impact of the upstream reservoirs is considered is less than that without considering them. In particular, the stochastic simulation model takes into account both systematic and historical flood records. As the reliability of the frequency analysis increases with more representative samples, it is desirable to incorporate historical flood records, if available, into the stochastic simulation model. This study shows that the design values from the stochastic simulation method with historical flood records are higher than those without historical flood records. The paper demonstrates the advantages of adopting a stochastic flow simulation approach to address design-flood-related issues for a complex cascade reservoir system.

scholarly journals Clutter Cancellation and Long Time Integration for GNSS-Based Passive Bistatic Radar

2021 ◽  
Vol 13 (4) ◽  
pp. 701 ◽  
Author(s):  
Binbin Wang ◽  
Hao Cha ◽  
Zibo Zhou ◽  
Bin Tian
Keyword(s):  
Fourier Transform ◽  
Target Detection ◽  
Time Integration ◽  
Detection Performance ◽  
Bistatic Radar ◽  
Detection Range ◽  
Robust Detection ◽  
Coherent Integration ◽  
Long Time ◽  
Long Time Integration

Clutter cancellation and long time integration are two vital steps for global navigation satellite system (GNSS)-based bistatic radar target detection. The former eliminates the influence of direct and multipath signals on the target detection performance, and the latter improves the radar detection range. In this paper, the extensive cancellation algorithm (ECA), which projects the surveillance channel signal in the subspace orthogonal to the clutter subspace, is first applied in GNSS-based bistatic radar. As a result, the clutter has been removed from the surveillance channel effectively. For long time integration, a modified version of the Fourier transform (FT), called long-time integration Fourier transform (LIFT), is proposed to obtain a high coherent processing gain. Relative acceleration (RA) is defined to describe the Doppler variation results from the motion of the target and long integration time. With the estimated RA, the Doppler frequency shift compensation is carried out in the LIFT. This method achieves a better and robust detection performance when comparing with the traditional coherent integration method. The simulation results demonstrate the effectiveness and advantages of the proposed processing method.

scholarly journals Detection of contaminant plumes released from landfills

2006 ◽  
Vol 3 (3) ◽  
pp. 819-857
Author(s):  
N. B. Yenigül ◽  
A.T. Hendsbergen ◽  
A. M. M. Elfeki ◽  
F. M. Dekking
Keyword(s):  
Simulation Model ◽  
Contaminant Transport ◽  
Analytical Model ◽  
Detection Probability ◽  
Average Concentration ◽  
Contaminant Plume ◽  
Contaminant Plumes ◽  
Heterogeneous Aquifer ◽  
Monitoring Well ◽  
Detection Probabilities

Abstract. Contaminant leaks released from landfills are a significant threat to groundwater quality. The groundwater detection monitoring systems installed in the vicinity of such facilities are vital. In this study the detection probability of a contaminant plume released from a landfill has been investigated by means of both a simulation and an analytical model for both homogeneous and heterogeneous aquifer conditions. The results of the two models are compared for homogeneous aquifer conditions to illustrate the errors that might be encountered with the simulation model. For heterogeneous aquifer conditions contaminant transport is modelled by an analytical model using effective (macro) dispersivities. The results of the analysis show that the simulation model gives the concentration values correctly over most of the plume length for homogeneous aquifer conditions, and that the detection probability of a contaminant plume at given monitoring well locations match quite well. For heterogeneous aquifer conditions the approximating analytical model based on effective (macro) dispersivities yields the average concentration distribution satisfactorily. However, it is insufficient in monitoring system design since the discrepancy between the detection probabilities of contaminant plumes at given monitoring well locations computed by the two models is significant, particularly with high dispersivity and heterogeneity.

scholarly journals Developing Hybrid Simulation Model to Improve Road Traffic Management

2020 ◽  
Vol 4 (01) ◽  
pp. 56-65
Author(s):  
Hayati Mukti Asih
Keyword(s):  
Simulation Model ◽  
Urban Areas ◽  
Traffic Management ◽  
Road Traffic ◽  
Hybrid Simulation ◽  
Simulation Method ◽  
Vital Role ◽  
Light Cycle ◽  
Traffic Light ◽  
Traffic Lights

Yogyakarta has increasing trends in the number of vehicles and consequently intensifying the traffic volume and will effect to higher emission and air pollution. Traffic lights duration plays a vital role in congestion mitigation in the critical intersections of urban areas. This study has objective to minimize the number of vehicles waiting in line by developing the hybrid simulation method. First of all, the MKJI and Webster method were calculated to determine the green traffic light. Then, the simulation model was developed to evaluate the number of vehicles waiting in line according to different duration of green traffic lights from MKJI and Webster method. A case study will then be provided in Pelemgurih intersection located in Yogyakarta, Indonesia for demonstrating the applicability of the developed method. The result shows that the duration of green traffic lights calculated by Webster method provides lower number of vehicles waiting in line. It is due to the short duration of green traffic light resulted by Webster method so that the traffic light cycle becomes shorter and it effects the number of vehicles waiting in line which is lower than MKJI method. The results obtained can help the generating desired decision alternatives that will important for Department of Transportation, Indonesia to enhance the road traffic management with low number of vehicles waiting in line.

scholarly journals Impact of simulation model fidelity and simulation method on ship operational performance evaluation in sea passage scenarios

2019 ◽  
Vol 188 ◽  
pp. 106268 ◽  
Author(s):  
Jørgen Bremnes Nielsen ◽  
Endre Sandvik ◽  
Eilif Pedersen ◽  
Bjørn Egil Asbjørnslett ◽  
Kjetil Fagerholt
Keyword(s):  
Performance Evaluation ◽  
Simulation Model ◽  
Simulation Method ◽  
Operational Performance ◽  
Model Fidelity

Optimization of geometrical design of clinching tools in clinching process with extensible dies

2016 ◽  
Vol 231 (21) ◽  
pp. 3889-3897 ◽  
Author(s):  
Xiaolan Han ◽  
Shengdun Zhao ◽  
Chen Liu ◽  
Chao Chen ◽  
Fan Xu
Keyword(s):  
Experimental Design ◽  
Simulation Model ◽  
Simulation Method ◽  
Orthogonal Experimental Design ◽  
Optimal Parameters ◽  
Geometrical Design ◽  
Reasonable Range ◽  
Simulation Results ◽  
Sliding Distance ◽  
Good Agreement

Due to the importance of geometrical design of clinching tools, the clinching process with extensible dies was investigated numerically and experimentally to seek for optimal parameters of clinching tools in this study. The joining parameters, including punch corner radius, sliding distance, die depth and bottom thickness, were optimized using the orthogonal experimental design simulation method based on the evaluation of tensile strength. The simulation results were validated through an experimental setup testing on material aluminum alloy Al5052. The orthogonal experimental design simulation results showed reasonably good agreement with the experimental results. To further investigate the validation of the simulation model, the different bottom thicknesses within a reasonable range of value were studied. The results also indicated that the simulation model could be employed to predict the joint forming by the clinching process with extensible dies.

Influencing Factors on Rotate Vector Reducer Dynamic Transmission Error

2019 ◽  
Vol 13 (4) ◽  
pp. 545-556 ◽  
Author(s):  
Shou-Song Jin ◽  
◽  
Xiao-Tao Tong ◽  
Ya-Liang Wang
Keyword(s):  
Influencing Factors ◽  
Elastic Deformation ◽  
Great Influence ◽  
Simulation Method ◽  
Transmission Error ◽  
Dynamics Simulation ◽  
Load Fluctuation ◽  
Circle Center ◽  
Dynamic Transmission Error ◽  
Rv Reducer

The factors influencing rotate vector (RV) reducer dynamic transmission error were studied using virtual prototyping technology, which contained the elastic deformation, working load, part manufacturing error, and assembly clearance. According to the error transmission relationship of the RV reducer, 15 influencing factors were selected to design an orthogonal simulation test. The virtual prototype of the RV reducer was built using CREO and ANSYS, and imported into ADAMS for multi-body dynamics simulation. The simulation method reliability was verified via experiments. The results show that the circle center radius error of the pin gear, the amount of equidistant modification of the cycloid gear, the amount of radial-moving modification of the cycloid gear, the clearance between the support bushing and planet carrier, and the clearance between the crankshaft and the support bushing were positively correlated with the RV reducer dynamic transmission error. Among these, the circle center radius error of the pin gear has the greatest influence on the dynamic transmission error of the RV reducer followed by the amount of equidistant modification of the cycloid gear. The elastic deformation of the part and the load fluctuation show a certain gain effect on the transmission error, the elastic deformation of the cycloid gear has a great influence, and the elastic deformation of the pin gear has the least.

Simulation Analysis of Motor Vehicle Ride Comfort Based on Adams

2012 ◽  
Vol 224 ◽  
pp. 243-247
Author(s):  
Cai Bin Li ◽  
Fu Yun Liu ◽  
Ju Cai Deng
Keyword(s):  
Simulation Model ◽  
Motor Vehicle ◽  
Ride Comfort ◽  
Simulation Analysis ◽  
Simulation Method ◽  
Damping Force ◽  
Vibration Experiment ◽  
Heavy Truck ◽  
Vibration Simulation ◽  
Stiffness And Damping

Applying ADAMS to vibration control field of heavy truck. The vibration simulation model of a truck is established. With the simulation model, different acceleration responses under different suspension stiffness and damping force are simulated. The simulation result is close to the actual result. It shows that the simulation method is benefit to reduce the number of vibration experiment and to forecast the vibration response of heavy truck.

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