STDP-driven networks and the \emph{C. elegans} neuronal network

We study the dynamics of the structure of a formal neural network wherein the strengths of the synapses are governed by spike-timing-dependent plasticity (STDP). For properly chosen input signals, there exists a steady state with a residual network. We compare the motif profile of such a network with that of a real neural network of \emph{C. elegans} and identify robust qualitative similarities. In particular, our extensive numerical simulations show that this STDP-driven resulting network is robust under variations of the model parameters.Comment: 16 pages, 14 figure

The Gap between Intelligence and Mind

The feeling (quale) brings the "Hard Problem" to philosophy of mind. Does the subjective feeling have a non-ignorable impact on Intelligence? If so, can the feeling be realized in Artificial Intelligence (AI)? To discuss the problems, we have to figure out what the feeling means, by giving a clear definition. In this paper, we primarily give some mainstream perspectives on the topic of the mind, especially the topic of the feeling (or qualia, subjective experience, etc.). Then, a definition of the feeling is proposed through a thought experiment, the "semi-transparent room". The feeling, roughly to say, is defined as "a tendency of changing input representations by representing its inner state". Also, a formalized definition is given. The definition does not help to verify "having the feeling", but it helps to provide evidence. Based on the definition, we think these are the hard problems of intelligence — whether the "innate" feeling plays an important role in Intelligence, whether the difference between the "simulated" feeling and the "innate" feeling will have a significant influence on Artificial General Intelligence (AGI), and, if so, where the "innate" feeling comes from and how to make an artificial agent possess it

Main controlling factors and characterization of overburden fracture damage based on energy conduction mechanism

The migration and fracture of overlying strata during coal seam mining is an important factor affecting the strata behaviors in working face. By studying the damage and failure characteristics of overlying strata from the perspective of energy, the behavior law and potential risk of overlying rock migration and failure under the influence of mining can be better understood, which provides effective guidance for reasonable mining parameter design of longwall face. Based on the research background of Qinglongsi coal mine in Shenfu mining area, Shaanxi province, this paper studies the post-peak deformation and failure characteristics of overlying rock fracture damage from the perspective of two-dimensional plane and three-dimensional space through the energy dissipation theory. An innovative method has been proposed for calculating the total energy of overlying rock layers with gravity potential energy imparted by coal seam excavation. On the basis, an overburden damage degree characterization system was built based on energy conduction mechanism through the integration of numerical simulation and theoretical analysis. The finite difference equation for rock dissipative energy is derived based on energy balance and finite difference theory. This equation is then incorporated into the FLAC3D strain softening model using FISH language. This effectively supplements the software energy calculation module. This approach addresses the limitations of conventional qualitative characterization of damage degree and type resulting from engineering rock excavation due to plastic zone effects. The energy dissipation degree of the scale effect of the index parameter was quantitatively characterized by defining the damage degree index. Based on the geological conditions of the Qinglongsi coal mine longwall face, a simulation analysis was conducted to investigate the influence of longwall face length and advance speed on the damage degree of overlying strata. The overburden damage degree increases and decreases in an “S” shape with the increase of longwall face length and advancing speed, respectively. Finally, it was established that the optimal longwall face length should not exceed 303.26 m, while the appropriate range for the uniform advance speed is between 10.13 m/d and 18.00 m/d. If the parameters of the longwall face exceed the above-mentioned range, the mining-induced damage could result in the failure of key controlling layers in the overlying strata, leading to a significant increase in the damage ratio. Finally, the feasibility of the characterization system based on the energy transmission model was verified through an analysis of the advance speed and the corresponding strata pressure of the 5-20108 longwall face. It was found that the increase in the advancing speed of the longwall face resulted in an increase in the step distance of the periodical Weighting, an increase in the strength of the mining pressure manifestation, and a decrease in the overall degree of overburden damage

Reply to: Low-frequency quantum oscillations in LaRhIn5_5: Dirac point or nodal line?

We thank G.P. Mikitik and Yu.V. Sharlai for contributing this note and the cordial exchange about it. First and foremost, we note that the aim of our paper is to report a methodology to diagnose topological (semi)metals using magnetic quantum oscillations. Thus far, such diagnosis has been based on the phase offset of quantum oscillations, which is extracted from a "Landau fan plot". A thorough analysis of the Onsager-Lifshitz-Roth quantization rules has shown that the famous $\pi$-phase shift can equally well arise from orbital- or spin magnetic moments in topologically trivial systems with strong spin-orbit coupling or small effective masses. Therefore, the "Landau fan plot" does not by itself constitute a proof of a topologically nontrivial Fermi surface. In the paper at hand, we report an improved analysis method that exploits the strong energy-dependence of the effective mass in linearly dispersing bands. This leads to a characteristic temperature dependence of the oscillation frequency which is a strong indicator of nontrivial topology, even for multi-band metals with complex Fermi surfaces. Three materials, Cd$_3$As$_2$, Bi$_2$O$_2$Se and LaRhIn$_5$ served as test cases for this method. Linear band dispersions were detected for Cd$_3$As$_2$, as well as the $F$ $\approx$ 7 T pocket in LaRhIn$_5$.Comment: Response to Matter arising for Nature Communications 12, 6213 (2021

Fingerprint of topology in quantum oscillations at elevated temperatures

A versatile methodology to detect Dirac or Weyl fermions in topological semimetals by transport or thermodynamic measurements remains an open problem. It is often argued that a $\pi$ phase shift in quantum oscillations directly corresponds to the Berry phase of topological semimetals. However, the oscillation phase is complicated by multiple contributing factors including the orbital magnetic moment, rendering such correspondences ambiguous for a substantial fraction of topological semimetals. Here we propose the temperature dependence of the frequency, ${F}(T)$, rather than the oscillation phase, as a hallmark signature of topology in quantum oscillations. At temperatures comparable to the cyclotron energy, $F(T)$ encodes the energy-derivative of the cyclotron mass -- a quantity that vanishes for conventional Schr\"odinger-type fermions, yet equals the inverse square of the Fermi velocity for Dirac/Weyl fermions. We experimentally observe this temperature dependent frequency in the Dirac semimetal Cd$_3$As$_2$, and quantitatively describe it by a fitting-parameter-free model of Dirac Fermions. It is absent in the topologically trivial metal Bi$_2$O$_2$Se as expected while the material shows a $\pi$ shift of the quantum oscillation phase without any topological origin. We further identify Dirac fermions in LaRhIn$_5$, despite their co-existence with multiple, topologically trivial Fermi pockets contributing the vast majority of transport carriers. This approach requires no ab-initio calculation as input, and is able to identify topological Fermi pockets which are small compared to the Brillouin-zone volume -- both attributes being ideally suited to identify the topological character of heavy fermion materials

An Experimental Hyper-Chaos Spread Spectrum Communication System Based on CNN

A new hyper-chaos communication system based on cellular neural network (CNN) is proposed in this paper. Hyper-chaos is generated with fifteen-cell CNN, then it's transferred to a digital sequence. The chaotic sequence is better than gold sequence when they are utilized in direct sequence spread spectrum system. Compared with the traditional gold sequence system, there is 3dB improvement in CNN chaotic sequence system when the channel is multi-path channel. Because of the complex dynamic behavior of hyper-chaos, security signal could be transferred through wireless channel. The structure of hardware CNN spread spectrum system is also shown, and the security of CNN communication is analyzed at last.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000239485300026&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Artificial IntelligenceComputer Science, Theory & MethodsSCI(E)CPCI-S(ISTP)

Enhancing consensus in weighted networks with coupling time-delay

We study the consensus problem in a weighted and directed network composed of self-propelled agents. The weight which quantifies the relationship between the agents is adjusted according to their state incoherence to suppress the heterogeneity in state. The proposed consensus protocol enhances the convergence efficiency of consensus greatly and has better performance than that of two other protocols. The convergence efficiency can be further improved by adjusting the parameter of this protocol. Furthermore, the robustness of the system against coupling time-delay is significantly increased. Unlike most consensus acceleration methods, no topological information is needed in our model. Networks with different stuctures are investigated to demonstrate the generality of the method. (C) 2012 Elsevier B.V. All rights reserved.Physics, MultidisciplinarySCI(E)EI0ARTICLE113061-306839