scholarly journals An Anti-Jamming Method against Two-Dimensional Deception Jamming by Spatial Location Feature Recognition

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7702
Author(s):  
Zhidong Liu ◽  
Qun Zhang ◽  
Kaiming Li
Keyword(s):  
Pulse Compression ◽  
Feature Recognition ◽  
Target Identification ◽  
Spatial Location ◽  
Two Dimensional ◽  
False Target ◽  
Spatial Distribution Characteristics ◽  
Transmitted Signal ◽  
Spatial Locations ◽  
The Mathematical Model

Interrupted sampling repeater jamming (ISRJ) is an effective method for implementing deception jamming on chirp radars. By means of frequency-shifting jamming processing of the target echo signal and pulse compression during image processing, a group of false targets will appear in different spatial locations around the true target. Extracting the features of these false targets is complex and limited to existing countering methods against ISRJ. This paper proposes an anti-jamming method to identify the spatial location characteristics of two-dimensional deception false targets. By adjusting the parameters of the radar transmitted signal, the method simultaneously transmits the anti-jamming signal and carries out false target identification and elimination in the range and azimuth dimensions. Eventually, the optimal signal parameter design of the anti-jamming signal is obtained by comparing different anti-jamming strategies in the range dimension. The validity of the proposed method is proved by deducing the mathematical model between the spatial distribution characteristics of the false targets and the radar transmitted signal parameters and demonstrated by simulations.

Dynamic Visual Noise Affects Visual Short-Term Memory for Surface Color, but not Spatial Location

2010 ◽  
Vol 57 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Kevin Dent
Keyword(s):  
Short Term Memory ◽  
Spatial Location ◽  
Visual Noise ◽  
Dynamic Visual Noise ◽  
Short Term ◽  
Surface Color ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Experimental Tool ◽  
Spatial Locations

In two experiments participants retained a single color or a set of four spatial locations in memory. During a 5 s retention interval participants viewed either flickering dynamic visual noise or a static matrix pattern. In Experiment 1 memory was assessed using a recognition procedure, in which participants indicated if a particular test stimulus matched the memorized stimulus or not. In Experiment 2 participants attempted to either reproduce the locations or they picked the color from a whole range of possibilities. Both experiments revealed effects of dynamic visual noise (DVN) on memory for colors but not for locations. The implications of the results for theories of working memory and the methodological prospects for DVN as an experimental tool are discussed.

Preceded False Target Groups Jamming Against LFM Pulse Compression Radars

2011 ◽  
Vol 30 (6) ◽  
pp. 1350-1353 ◽  
Author(s):  
Jian-cheng Liu ◽  
Xue-song Wang ◽  
Zhong Liu ◽  
Jian-hua Yang ◽  
Guo-yu Wang
Keyword(s):  
Pulse Compression ◽  
Target Groups ◽  
False Target

Numerical Simulation of Subsea Cluster Manifold Installation by the Sheave Method

2018 ◽  
Author(s):  
Yu Zhao ◽  
Yingying Wang ◽  
Liwei Li ◽  
Chao Yang ◽  
Yang Du ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
South China Sea ◽  
Deep Sea ◽  
High Reliability ◽  
Two Dimensional ◽  
Complex Environment ◽  
Lumped Mass ◽  
Lumped Mass Method ◽  
The Mathematical Model

The sheave installation method (SIM) is an effective and non-conventional method to solve the installation of subsea equipment in deep water (>1000m), which has been developed to deploy the 175t Roncador Manifold I into 1,885 meters water depth in 2002. With the weight increment of subsea cluster manifold, how to solve its installation with the high reliability in the deep sea is still a great challenge. In this paper, the installation of the 300t subsea cluster manifold using the SIM is studied in the two-dimensional coordinate system. The mathematical model is established and the lumped mass method is used to calculate the hydrodynamic forces of the wireropes. Taking into account the complex environment loads, the numerical simulation of the lowering process is carried out by OrcaFlex. The displacement and vibration of the subsea cluster manifold in the z-axis direction and the effective tension at the top of the wireropes can be gotten, which can provide guidance for the installation of the cluster manifold in the South China Sea.

Division and Classification

2019 ◽  
pp. 34-54
Author(s):  
Paolo Crivelli
Keyword(s):  
Spatial Location ◽  
One And Many ◽  
The Many ◽  
The One ◽  
Spatial Locations ◽  
Different Parts

The Philebus presents some arguments for the paradoxical claim that the many are one and the one many. The most serious of these arguments concerns the multiple spatial locations of an attribute. For instance, since the attribute man belongs to many men, it is in them, and it is therefore both one and many (for it is in them either by having different parts of itself contained in them or by being wholly contained in each of them). Plato maintains that this argument goes astray. He appeals to division and collection, the procedures linked with definition and classification. He probably has in mind a mereological model of particulars, whereby perceptible particulars are mixtures whose ingredients are the attributes which they partake of. Among the ingredients of a perceptible particular there are properties that specify its spatial location, so the problem of the multiple spatial location of an attribute evaporates.

scholarly journals Spatial Tree Mapping Using Photography

2010 ◽  
Vol 27 (2) ◽  
pp. 68-74 ◽  
Author(s):  
Adam R. Dick ◽  
John A. Kershaw ◽  
David A. MacLean
Keyword(s):  
Spatial Location ◽  
Growth And Yield ◽  
Absolute Distance ◽  
Widespread Application ◽  
Visualization Software ◽  
Dependent Growth ◽  
Spatial Locations ◽  
Growth And Yield Models ◽  
Field Plots ◽  
Forest Conditions

Abstract Stem maps describing the spatial location of trees sampled in a forest inventory are used increasingly to model relationships between neighboring trees in distance-dependent growth and yield models, as well as in stand visualization software. Current techniques and equipment available to acquire tree spatial locations prohibit widespread application because they are time-consuming, costly, and prone to measurement error. In this report, we present a technique to derive stem maps from a series of digital photographs processed to form a seamless 360° panorama plot image. Processes are described to derive distance from plot center and azimuth to each plot tree. The technique was tested on 46 field plots (1,398 sample trees) under a range of forest conditions and compared with traditional methods. Average absolute distance error was 0.38 ± 0.44 m, and average absolute azimuth error was 2.3 ± 2.5°. Computed average horizontal accuracy was 0.40 ± 0.42 m, with 85% of measured trees being within 0.5 m of the field-measured tree location.

scholarly journals From Antenna Design to High Fidelity, Full Physics Automotive Radar Sensor Corner Case Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Ushemadzoro Chipengo ◽  
Peter M. Krenz ◽  
Shawn Carpenter
Keyword(s):  
Target Identification ◽  
Pedestrian Detection ◽  
High Fidelity ◽  
Driver Assistance ◽  
Automotive Radar ◽  
Driver Assistance Systems ◽  
Advanced Driver Assistance Systems ◽  
Radar Systems ◽  
False Target ◽  
Assistance Systems

Advanced driver assistance systems (ADAS) have recently been thrust into the spotlight in the automotive industry as carmakers and technology companies pursue effective active safety systems and fully autonomous vehicles. Various sensors such as lidar (light detection and ranging), radar (radio detection and ranging), ultrasonic, and optical cameras are employed to provide situational awareness to vehicles in a highly dynamic environment. Radar has emerged as a primary sensor technology for both active/passive safety and comfort-advanced driver-assistance systems. Physically building and testing radar systems to demonstrate reliability is an expensive and time-consuming process. Simulation emerges as the most practical solution to designing and testing radar systems. This paper provides a complete, full physics simulation workflow for automotive radar using finite element method and asymptotic ray tracing electromagnetic solvers. The design and optimization of both transmitter and receiver antennas is presented. Antenna interaction with vehicle bumper and fascia is also investigated. A full physics-based radar scene corner case is modelled to obtain high-fidelity range-Doppler maps. Finally, this paper investigates the effects of inclined roads on late pedestrian detection and the effects of construction metal plate radar returns on false target identification. Possible solutions are suggested and validated. Results from this study show how pedestrian radar returns can be increased by over 16 dB for early detection along with a 27 dB reduction in road construction plate radar returns to suppress false target identification. Both solutions to the above corner cases can potentially save pedestrian lives and prevent future accidents.

A 2D Numerical Model for Simulation of Two-Dimensional Circular Dam-Break

2011 ◽  
Vol 130-134 ◽  
pp. 2993-2996
Author(s):  
Ming Qin Liu ◽  
Y.L. Liu
Keyword(s):  
Solution Procedure ◽  
Dam Break ◽  
Curvilinear Coordinates ◽  
Two Dimensional ◽  
Proposed Model ◽  
Curvilinear Coordinate ◽  
Orthogonal Curvilinear Coordinate System ◽  
Orthogonal Curvilinear Coordinates ◽  
Averaged Model ◽  
The Mathematical Model

The purpose of this paper is to present a 2D depth-averaged model under orthogonal curvilinear coordinates for simulating two-dimensional circular dam-break flows. The proposed model uses an orthogonal curvilinear coordinate system efficiently and accurately to simulate the flow field with irregular boundaries. As for the numerical solution procedure, The SIMPLEC solution procedure has been used for the transformed governing equations in the transformed domain. Practical application of the model is illustrated by an example, which demonstrates that the mathematical model can capture hydraulic discontinuities accurately such as steep fronts, hydraulic jump and drop, etc.

Co-constructing referential space in multimodal narratives

2014 ◽  
Vol 7 (1) ◽  
pp. 31-59 ◽  
Author(s):  
Kashmiri Stec ◽  
Mike Huiskes
Keyword(s):  
Recent Work ◽  
Meaning Making ◽  
Spatial Location ◽  
Multimodal Communication ◽  
Dynamic Processes ◽  
Multimodal Process ◽  
Spatial Locations ◽  
The Way

Abstract Meaning-making is a situated, multimodal process. Although most research has focused on conceptualization in individuals, recent work points to the way dynamic processes can affect both conceptualization and expression in multiple individuals (e.g. Özyürek 2002; Fusaroli and Tylén 2012; Narayan 2012). In light of this, we investigate the co-construction of referential space in dyadic multimodal communication. Referential space is the association of a referent with a particular spatial location (McNeill and Pedelty 1995). We focus on the multimodal means by which dyads collaboratively co-construct or co-use referential space, and use it to answer questions related to its use and stability in communication. Whereas previous work has focused on an individual's use of referential space (So et al. 2009), our data suggest that spatial locations are salient to both speakers and addressees: referents assigned to particular spatial locations can be mutually accessible to both participants, as well as stable across longer stretches of discourse.

scholarly journals An unusual way to validate regional chemistry-transport models

2016 ◽  
Author(s):  
Lauren Menut ◽  
Sylvain Mailler ◽  
Bertrand Bessagnet ◽  
Guillaume Siour ◽  
Augustin Colette ◽  
...  
Keyword(s):  
Model Evaluation ◽  
Temporal Correlation ◽  
Spatial Location ◽  
Reference Period ◽  
Evaluation Technique ◽  
Transport Models ◽  
Time Periods ◽  
The Difference ◽  
Spatial Locations

Abstract. A simple and exhaustive model evaluation technique for regional chemistry-transport is discussed. It is based on the concept that we can learn more on models performances by comparing the results to in situ measurements available for other time periods than the period originally targeted in the simulation. First, the usual scores (spatial and temporal correlation) are computed for a reference period, using the actual temporal synchronization and spatial location of measurements . Second, the same scores are calculated for several other years by conserving only the actual spatial locations and days of the year. The difference between the two score provides complementary insights to the following questions: (i) is the model performing well only because the situation is persistent? (ii) is the model representative enough of the measurements for all variables? (iii) if the pollutants concentrations are not well modelled, is it due to meteorology or chemistry? In order to synthetize the large amount of results, a new score is proposed: the "multi-year variability", designed to compare the several indicators between all the years of validation and to quantify if the studied period was well modelled and, if yes, for the good reasons.

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