DFCWs Design Based on Improved DPSO

2013 ◽  
Vol 333-335 ◽  
pp. 623-627
Author(s):  
Jing Jun Li ◽  
Yong Hua Jiang ◽  
Bo Dan ◽  
Wei Wei Gao

Orthogonal discrete frequency coding waveforms(DFCWs) is an ideal quasi-orthogonal waveform. This paper analyses the ambiguity function of DFCWs and the results indicate that the correlation characteristics of DFCWs have only relationship with the code length and coding order. Based on the theoretical analysis, we defined the cross-correlation energy as the cost function, and used the improved discrete particle swarmoptimization(DPSO) to optimize the order of DFCWs. The new signal can effectively restrain the cross-correlation level between the two DFCWs. Simulation results verify the effectiveness of the designed DFCWs.

2010 ◽  
Vol 439-440 ◽  
pp. 715-720
Author(s):  
Jun Yao Gao ◽  
Jing Shu Yang ◽  
Jia Zhao

The paper investigates the cross correlation mitigation (CCM) technique in the multipath propagating environment. It analyses the impact of cross correlation firstly, then expounds the universal technique in CCM, at last presents an improved DPIC (Delayed Parallel Interference Cancellation) method based on MEDLL. The algorithm estimates the parameters of multipath by using MEDLL, reconstructs the strong signals IF utilizing these parameters, and mitigates the cross correlation with the aid of DPIC method. At last, simulation results prove the validity of this method.


2021 ◽  
Vol 4 ◽  
Author(s):  
Francisco S. Melo ◽  
Manuel Lopes

In this paper, we propose the first machine teaching algorithm for multiple inverse reinforcement learners. As our initial contribution, we formalize the problem of optimally teaching a sequential task to a heterogeneous class of learners. We then contribute a theoretical analysis of such problem, identifying conditions under which it is possible to conduct such teaching using the same demonstration for all learners. Our analysis shows that, contrary to other teaching problems, teaching a sequential task to a heterogeneous class of learners with a single demonstration may not be possible, as the differences between individual agents increase. We then contribute two algorithms that address the main difficulties identified by our theoretical analysis. The first algorithm, which we dub SplitTeach, starts by teaching the class as a whole until all students have learned all that they can learn as a group; it then teaches each student individually, ensuring that all students are able to perfectly acquire the target task. The second approach, which we dub JointTeach, selects a single demonstration to be provided to the whole class so that all students learn the target task as well as a single demonstration allows. While SplitTeach ensures optimal teaching at the cost of a bigger teaching effort, JointTeach ensures minimal effort, although the learners are not guaranteed to perfectly recover the target task. We conclude by illustrating our methods in several simulation domains. The simulation results agree with our theoretical findings, showcasing that indeed class teaching is not possible in the presence of heterogeneous students. At the same time, they also illustrate the main properties of our proposed algorithms: in all domains, SplitTeach guarantees perfect teaching and, in terms of teaching effort, is always at least as good as individualized teaching (often better); on the other hand, JointTeach attains minimal teaching effort in all domains, even if sometimes it compromises the teaching performance.


Author(s):  
Matthias Weber ◽  
Anja Niehoff ◽  
Markus A. Rothschild

AbstractThis work deals with the examination of tool marks in human cartilage. We compared the effectiveness of several cleaning methods on cut marks in porcine cartilage. The method cleaning by multiple casts achieved the significantly highest scores (P = 0.02). Furthermore, we examined the grain-like elevations (dots) located on casts of cut cartilage. The results of this study suggest that the casting material forms these dots when penetrating cartilage cavities, which are areas where the strong collagen fibres leave space for the chondrocytes. We performed fixation experiments to avoid this, without success. In addition, 31 casting materials were compared regarding contrast under light-microscope and 3D tool marks scanner. Under the light-microscope, brown materials achieved significantly higher values than grey (P = 0.02) or black (P = 0.00) whereas under the 3D scanner, black materials reached higher contrast values than grey (P = 0.04) or brown (P = 0.047). To compare the accuracy and reproducibility of 6 test materials for cartilage, we used 10 knives to create cut marks that were subsequently scanned. During the alignment of the individual signals of each mark, the cross-correlation coefficients (Xmax) and lags (LXmax) were calculated. The signals of the marks in agarose were aligned with significantly fewer lags and achieved significantly higher cross-correlation coefficients compared to all tested materials (both P = 0.00). Moreover, we determined the cross-correlation coefficients (XC) for known-matches (KM) per material. Agarose achieved significantly higher values than AccuTrans®, Clear Ballistics™, and gelatine (all P = 0.00). The results of this work provide valuable insights for the forensic investigation of marks in human costal cartilage.


2019 ◽  
Vol 11 (12) ◽  
pp. 1428 ◽  
Author(s):  
Yong Jia ◽  
Yong Guo ◽  
Chao Yan ◽  
Haoxuan Sheng ◽  
Guolong Cui ◽  
...  

This paper demonstrates the feasibility of detection and localization of multiple stationary human targets based on cross-correlation of the dual-station stepped-frequency continuous-wave (SFCW) radars. Firstly, a cross-correlation operation is performed on the preprocessed pulse signals of two SFCW radars at different locations to obtain the correlation coefficient matrix. Then, the constant false alarm rate (CFAR) detection is applied to extract the ranges between each target and the two radars, respectively, from the correlation matrix. Finally, the locations of human targets is calculated with the triangulation localization algorithm. This cross-correlation operation mainly brings about two advantages. On the one hand, the cross-correlation explores the correlation feature of target respiratory signals, which can effectively detect all targets with different signal intensities, avoiding the missed detection of weak targets. On the other hand, the pairing of two ranges between each target and two radars is implemented simultaneously with the cross-correlation. Experimental results verify the effectiveness of this algorithm.


Author(s):  
Mark S. Oude Alink ◽  
Andre B. J. Kokkeler ◽  
Eric A. M. Klumperink ◽  
Gerard J. M. Smit ◽  
Bram Nauta

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jiun-Wei Horng

This paper describes a current-mode third-order quadrature oscillator based on current differencing transconductance amplifiers (CDTAs). Outputs of two current-mode sinusoids with90°phase difference are available in the quadrature oscillator circuit. The oscillation condition and oscillation frequency are orthogonal controllable. The proposed circuit employs only grounded capacitors and is ideal for integration. Simulation results are included to confirm the theoretical analysis.


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