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1. chinaXiv:202201.00057 [pdf]

Ladderpath Approach: How Tinkering and Reuse Enhance Complexity and Information

Liu, Yu; Di, Zengru; Gerlee, Philip
Subjects: Information Science and Systems Science >> Basic Disciplines of Information Science and Systems Science

The notion of information and complexity are important concepts in many scientific fields such as molecular biology, evolutionary theory, and exobiology. Most measures of these quantities, such as Shannon entropy and related complexity measures, are only defined for objects drawn from a statistical ensemble and cannot be computed for single objects. Based on assembly theory, we attempt to fill this gap by introducing the notion of a ladderpath which describes how an object can be decomposed into a hierarchical structure using repetitive elements. From the ladderpath two measures naturally emerge: the ladderpath-index and the order-index, which represent two axes of complexity. We show how the ladderpath approach can be applied to both strings and spatial patterns and argue that all systems that undergo evolution can be described as ladderpaths. Further, we discuss possible applications to human language and the origins of life. The ladderpath approach provides a novel characterization of the information that is contained in a single object (or a system) and could aid in our understanding of evolving systems and the origin of life in particular.

submitted time 2022-04-26 Hits5340Downloads522 Comment 0

2. chinaXiv:202202.00011 [pdf]

Exact Decomposition of Multifrequency Discrete Real and Complex Signals

刘保国
Subjects: Electronics and Communication Technology >> Information Processing
Subjects: Mechanical Engineering >> Other Disciplines of Mechanical Engineering

‘The spectral leakage (SL) from windowing and the picket fence effect (PEF) from discretization’ have been among the standard contents in textbooks for many decades. The SL and PEF would cause the distortions in amplitude, frequency, and phase of signals, which have always been of concern, and attempts have been made to solve them. This paper proposes two novel decomposition theorems that can totally eliminate the SL and PEF, they could broaden the knowledge of signal processing. First, two generalized eigenvalue equations are constructed for multifrequency discrete real signals and complex signals. The two decomposition theorems are then proved. On these bases, exact decomposition methods for real and complex signals are proposed. For a noise-free multifrequency real signal with m sinusoidal components, the frequency, amplitude, and phase of each component can be exactly calculated by using just 4m–1 discrete values and its second-order derivatives. For a multifrequency complex signal, only 2m–1 discrete values and its first-order derivatives are needed. The numerical experiments show that the proposed methods have very high resolution, and the sampling rate does not necessarily obey the Nyquist sampling theorem. With noisy signals, the proposed methods have extraordinary accuracy.

submitted time 2022-02-08 Hits3156Downloads407 Comment 0

3. chinaXiv:202004.00020 [pdf]

Printed Organic Transistors-based Impedance Biosensor

Qi Huang; Kai Jin; Yukun Huang; Zhe Liu; Linrun Feng; Xiaojun Guo; Hanbin Ma
Subjects: Engineering and technical science >> Biomedical Engineering

Electrochemical impedance biosensors measure the impedance varies of the solution during the biochemical process, so it can realize label-free biological detection. However, the biological signal to be detected is very weak, thus requiring signal amplification circuit. Printed organic thin film transistor (OTFT) has many advantages such as low cost, flexible bending, biocompatibility, which is suitable for biological detection. This work built up amplification circuit for electrochemical impedance test based on OTFT, different concentrations of phosphate buffer solution (PBS) used as test samples were measured with the above circuit. The results show that OTFT-based circuit has a good implementation of signal amplification, which lay a foundation for the application of printed OTFT in the electrochemical impedance biosensors.

submitted time 2020-04-05 Hits12577Downloads2493 Comment 0

4. chinaXiv:201810.00282 [pdf]

奖赏通过增强信号监测提升认知控制

王宴庆; 胡学平; 尹首航; 陈安涛
Subjects: Psychology >> Other Disciplines of Psychology

认知控制是动态的、过程性的认知调控, 涉及监测和控制两个过程。先前研究表明奖赏可以提升认知控制, 但是奖赏是通过增强信号监测来提升认知控制的, 还是作用于控制过程来提升认知控制的, 是一个有待研究的重要问题。在本研究中, 我们设计了三个实验来调查这一问题。实验一采用Stop-Signal任务验证奖赏是否能提升认知控制; 实验二通过改变反应规则将Stop-Signal任务信号监测加工分离出来, 探讨实验一中奖赏的提升作用是否来源于奖赏对信号监测的增强; 实验三通过操纵注意资源损耗分析, 考察注意资源分配对信号监测的促进作用。实验一结果显示, 个体能更快的根据奖赏信息做出抑制反应。实验二结果表明, 在信号监测任务中, 个体能更加快速的监测到与当前抑制状态相冲突且和奖赏相关的反应信号, 据此可认为奖赏通过增强对相关信号的监测, 有助于个体更早地启动奖赏刺激信号所对应的反应, 更高效地控制冲突。实验三结果说明, 当任务难度增大, 注意资源损耗, 奖赏相关信号的反应时和正确率仍优于无奖赏信号, 说明注意资源的分配可以调节相关信号的监测速度。总体来看, 本研究通过一系列实验表明, 以目标为导向的行为发生过程中, 奖赏能有效提升认知控制效率, 其关键机制在于通过注意资源分配增强相关信号的监测。

submitted time 2018-10-26 Cooperative journals:《心理学报》 Hits2354Downloads1426 Comment 0

5. chinaXiv:201705.00501 [pdf]

Close-packed assemblies of discrete tiny silver nanoparticles on triangular gold nanoplates as a high performance SERS probe

Huang, YJ [Huang, Youju][ 1 ]; Kannan, P [Kannan, Palanisamy][ 2 ]; Zhang, L [Zhang, Lei][ 1 ]; Rong, Y [Rong, Yun][ 1 ]; Dai, LW [Dai, Liwei][ 1 ]; Huang, RQ [Huang, Rongqin][ 3 ]; Chen, T [Chen, Tao][ 1 ]
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Bimetallic nanocatalysts often display enhanced physical and chemical properties compared to those of their monometallic counterparts. Herein, we introduce a simple method to fabricate an island like array of tiny Ag nanoparticles bounded on triangular Au nanoplates as the surface-enhanced Raman scattering (SERS) substrate. The surface morphology of the synthesized nanoparticles was characterized via field emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM). Rhodamine 6G (R6G) is used as a model analyte to evaluate the performance of the tiny Ag nanoparticle bounded triangular Au nanoplates as a SERS-active substrate and validate the SERS effect. The fabricated SERS substrate showed drastically enhanced intensity with a SERS enhancement factor as high as 107, which is enough to detect a single molecule, and excellent reproducibility (less than `5%) of the signal intensity. This is because of the island-like tiny Ag nanoparticle bounded triangular Au nanoplates and their large number of “hot spots”. This substrate could also be used for label-free immunoassays, biosensing, and nanoscale optical antennas and light sources.

submitted time 2017-05-02 Hits1145Downloads613 Comment 0

6. chinaXiv:201703.00302 [pdf]

Design of a W-band four-channel dual-polarization waveguide slot antenna

Guo, Xi; Hao, Luo; Hou-Jun, Sun
Subjects: Geosciences >> Space Physics

The W-band full-polarization radar detection system is in need of a new type of antenna feed with good performance. The waveguide slot array antenna, has the advantages of low profile, high radiation efficiency, easy access to high gain. It has been become the research emphasis in the field of millimeter wave detection. In order to satisfy the need of developing complete polarization radar detection system, a W-band four-channel dual-polarization waveguide slot antenna is designed. The results of the simulation and optimization tests show that, the antenna has outstanding technical characteristics in double polarization. The antenna gain is higher than 13dB, and the cross-polarization level lower than -34dB. The bandwidth below VSWR 1.5 is better than 2.8GHz. High isolation of over 50dB is achieved between different polarization input ports.

submitted time 2017-03-10 Hits1897Downloads683 Comment 0

7. chinaXiv:201612.00199 [pdf]

Echo Signal Quality Analysis During HY-2A Radar Altimeter Calibration Campaign Using Reconstructive Transponder

Junzhi Wan; Wei Guo; Fei Zhao; Caiyun Wang; Peng Liu; Mingsen Lin; Hailong Peng; Chuan Xu
Subjects: Geosciences >> Space Physics

A reconstructive transponder has been utilized for the in-orbit calibration campaign of the HY-2A radar altimeter since March 2012. The precision of final calibration result is influenced by echo signal's quality in the HY-2A altimeter's range window. As an indicator of the signal's quality, echo signal dwell time is analyzed considering its influence on signal quality and its uncertainty. In HY-2A altimeter calibration, the echo signal dwell time is determined by the radial orbit prediction uncertainty and the real-time signal processing mechanism of the reconstructive transponder. The real-time signal processing mechanism of the reconstructive transponder utilizes some incoming signal samples without sending echo signals before transmitting. Comparing with the length of the HY-2A altimeter's range window, the radial orbit prediction uncertainty is large. Large radial orbit prediction uncertainty and signal processing mechanism of the reconstructive transponder are two main factors that limit the echo signal dwell time in HY-2A altimeter calibration. Finally, approaches for increasing echo signal dwell time are briefly proposed.

submitted time 2016-12-26 Hits3079Downloads1226 Comment 0

8. chinaXiv:201608.00034 [pdf]

A search for an excited muon decaying to a muon and two jets in pp collisions at ps = 8 TeV with the ATLAS detector

Aad, Georges and others
Subjects: Physics >> Nuclear Physics

A new search signature for excited leptons is explored. Excited muons are sought in the channel pp→μμ?→μμ jet jet, assuming both the production and decay occur via a contact interaction. The analysis is based on 20.3 fb?1 of pp collision data at a centre-of-mass energy of s√ = 8 TeV taken with the ATLAS detector at the Large Hadron Collider. No evidence of excited muons is found, and limits are set at the 95% confidence level on the cross section times branching ratio as a function of the excited-muon mass mμ?. For mμ? between 1.3 TeV and 3.0 TeV, the upper limit on σB(μ?→μqq?) is between 0.6 and 1 fb. Limits on σB are converted to lower bounds on the compositeness scale Λ. In the limiting case Λ=mμ?, excited muons with a mass below 2.8 TeV are excluded. With the same model assumptions, these limits at larger μ? masses improve upon previous limits from traditional searches based on the gauge-mediated decay μ?→μγ.

submitted time 2016-08-16 Hits201Downloads108 Comment 0

9. chinaXiv:201605.01705 [pdf]

Little Higgs theory confronted with the LHC Higgs data

Han, Xiao-Fang; Wang, Lei; Yang, Jin Min; Zhu, Jingya
Subjects: Physics >> The Physics of Elementary Particles and Fields

We confront the little Higgs theory with the LHC Higgs search data (up to 17 fb(-1) of the combined 7 and 8 TeV run). Considering some typical models, namely, the littlest Higgs model, the littlest Higgs model with T parity (LHT-A and LHT-B), and the simplest little Higgs model, we scan over the parameter space in the region allowed by current experiments. We find that in these models the inclusive and exclusive (via gluon-gluon fusion) diphoton and ZZ* signal rates of the Higgs boson are always suppressed and approach the standard model predictions for a large-scale f. Thus, the ZZ* signal rate is within the 1 sigma range of the experimental data while the inclusive diphoton signal rate is always outside the 2 sigma range. Especially, in the LHT-A the diphoton signal rate is outside the 3 sigma range of the experimental data for f < 800 GeV. We also perform a global chi(2) fit to the available LHC and Tevatron Higgs data, and find that these models provide no better global fit to the whole data set (only for some special channels a better fit can be obtained, especially in the LHT-B). DOI: 10.1103/PhysRevD.87.055004

submitted time 2016-05-14 Hits1886Downloads1059 Comment 0

10. chinaXiv:201605.01549 [pdf]

Performance Enhancement of Aperture Antennas Used for Estimation of Direction of Arrival (DOA)

Wang, Weibo; Gu, Xiang; Mittra, Raj
Subjects: Geosciences >> Space Physics

In this paper, we propose a method based on signal processing techniques to improve the performance of aperture antennas, such as a parabolic reflector, used to estimate the Direction of Arrival (DOA) of a signal. Three signal processing algorithms are investigated, including the correlation method, which is used to make an initial estimate of the incidence angle within a certain range. Then inverse matrix method and singular value decomposition method are subsequently utilized to refine the estimate within this range.

submitted time 2016-05-12 Hits1627Downloads968 Comment 0

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