BEHAVIORAL FUNCTIONS IMPLEMENTATION ON SPIKING NEURAL NETWORKS

The question of behavioral functions modeling of animals (in particular, the modeling and implementation of the conditioned reflex) is considered. The analysis of the current state of neural networks with the possibility of structural reconfiguration is carried out. The modeling is carried out by means of neural networks, which are built on the basis of a compartmental spiking model of a neuron with the possibility of structural adaptation to the input pulse pattern. The compartmental spike model of a neuron is able to change its structure (the size of the cell body, the number and length of dendrites, the number of synapses) depending on the incoming pulse pattern at its inputs. A brief description of the compartmental spiking model of a neuron is given, and its main features are noted in terms of the possibility of its structural reconfiguration. The method of structural adaptation of the compartmental spiking model of the neuron to the input pulse pattern is described. To study the work of the proposed model of a neuron in a network, the choice of a conditioned reflex as a special case of the formation of associative connections is justified as an example. The structural scheme and algorithm of formation of a conditioned reflex with both positive and negative reinforcement are described. The article presents a step-by-step description of experiments on the associative connection’s formation in general and conditioned reflex (both with positive and negative reinforcement), in particular. The conclusion is made about the prospects of using spiking compartmental models of neurons to improve the efficiency of the implementation of behavioral functions in neuromorphic control systems. Further promising directions for the development of neuromorphic systems based on spiking compartmental models of the neuron are considered.

Households’ Willingness to Pay for Substituting Natural Gas with Renewable Methane: A Contingent Valuation Experiment in South Korea

South Korea is planning to substitute some residential natural gas (NG), a fossil fuel that relies on imports, with renewable methane (RM) from bio-gas, a renewable energy source. Thus, information about households’ willingness to pay (WTP) for implementing the plan is widely needed. This article, therefore, examines the WTP using an economic approach of contingent valuation (CV). More specifically, 1000 households were asked about the additional WTP for RM over NG through in-person face-to-face surveys across the country, adopting a dichotomous choice question format, during August 2018. As a few interviewees responded zero WTP for various reasons, a spike model that could reflect zero WTP observations was utilized. The household additional WTP for RM over NG was estimated, with statistical significance, as 191.46 Korean won (USD 0.17) per m3 and worth 31.9% of the average price of residential NG. This value means a price premium for RM compared to NG. In other words, this study found that South Korean consumers value residential RM about 1.32 times as much as residential NG. These results from the CV experiment could be a useful reference in establishing and implementing RM-related policies.

Public Perspective on Increasing the Numbers of an Endangered Species, Loggerhead Turtles in South Korea: A Contingent Valuation

The loggerhead turtle is one of the representative endangered marine species in South Korea. Thus, the country’s government is trying to push ahead with a project to increase the number of loggerhead turtles through the research and development of technology to hatch them artificially and release them into the wild. This article attempts to investigate the public perspective on the project using contingent valuation (CV). To this end, a CV survey of one thousand households across the country was implemented using in-person interviews. They were asked whether they were willing to pay a specified amount presented for carrying out the project. As many households reported zero willingness to pay, a spike model was employed to analyze the response data. It was found that the yearly public value ensuing from accomplishing the project was statistically significantly computed to be KRW 2360 (USD 1.99) per household. When the value was expanded nationwide, it reached KRW 44.72 billion (USD 37.74 million) per year. This public value could be compared with the cost of carrying out the project to determine if the project is socially beneficial.

Public Acceptance of the “Renewable Energy 3020 Plan”: Evidence from a Contingent Valuation Study in South Korea

South Korea is promoting the “Renewable Energy 3020 Plan” to expand the proportion of renewable energy (RE) from 2.2% in 2016 to 20% in 2030. Since the plan could lead to an increase in electricity rates, public acceptance of it is an important key to determining its success. This article examines the public acceptance of the plan by employing contingent valuation (CV). A nationwide CV survey of 1000 households was performed to collect the data on the willingness to pay (WTP) for implementing the plan using electricity charges as a payment vehicle during October 2018. More specifically, a dichotomous choice question to ask interviewees whether they have an intention of paying an offered bid and a spike model to treat the zero WTP observations were employed. The estimate for monthly WTP was KRW 3646 (USD 3.27) per household. When 10 years of the payment period presented in the survey and forecasted values of residential RE electricity consumption from 2018 to 2030 were used, the WTP was worth KRW 60.4 (USD 0.05) per kWh in 2018 constant price. The WTP amounts to 56.5% of the price for residential electricity (KRW 106.9 or USD 0.10 per kWh). That is, the RE electricity produced through implementing the plan has a premium of 56.5% over the current electricity. Overall, it is concluded that public acceptance of the plan has been secured.

“Thermal Spike” model applied to thin targets irradiated with swift heavy ion beams at few MeV/u

High electronic excitations in radiation of metallic targets with swift heavy ion beams at the coulomb barrier play a dominant role in the damaging processes of some metals. The inelastic thermal spike model was developed to describe tracks in materials and is applied in this paper to some systems beams/targets employed recently in some nuclear physics experiments. Taking into account the experimental conditions and the approved electron-phonon coupling factors, the results of the calculation enable to interpret the observation of the fast deformation of some targets.

Ultraviolet and Infrared luminescent Au-rich nanostructure growth in SiO2 by burrowing and inverse Oswald ripening process

We study the evolution of nanoparticle morphology through successive stages when Au-Si bilayer on SiO2 is irradiated with 500 keV Xe-ions and resulting luminescence in the UV, Visible and infrared range. An array of nanoscale island morphology is developed on the silica surface in the initial stage of evolution which undergoes gradual burrowing in the silica matrix accompanied by elongation of large ones in the direction of incident ions under cumulative ion irradiation. Burrowing is found to occur in order to minimize the surface free energy of the nanoparticles. Numerical simulation based on the unified thermal spike model shows formation of molten latent tracks due to ions energy release which drive the dewetting of the metal layer and further give mobility to nanoparticle atoms leading to burrowing in the later stage of evolution and elongation of large nanoparticles. Satellite nanoparticles are observed to grow around Au nanoparticles embedded in silica through nucleation of Au atoms dissolved in the matrix by incident ions. The varying diameters of the Au satellite nanoparticles seem to result in luminescence in the UV and infrared range. The observed structure may find application in surface enhanced Raman scattering, catalysis, and LEDs.