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We consider a Darwinian (evolutionary game theoretic) version of a standard susceptible-infectious SI model in which the resistance of the disease causing pathogen to a treatment that prevents death to infected individuals is subject to evolutionary adaptation. We determine the existence and stability of all equilibria, both disease-free and endemic, and use the results to determine conditions under which the treatment will succeed or fail. Of particular interest are conditions under which a successful treatment in the absence of resistance adaptation (i.e. one that leads to a stable disease-free equilibrium) will succeed or fail when pathogen resistance is adaptive. These conditions are determined by the relative breadths of treatment effectiveness and infection transmission rate distributions as functions of pathogen resistance.

Abstract Recognizing territories is essential to decide behavior of population either human or animals, and interaction between groups or individuals according to the territorial awareness is universal. Understanding various mechanisms which affect on such species behaviors can be possible by evolutionary games, and in particular, the rock–paper–scissors (RPS) game has been played a key role as a paradigmatic model to explore biodiversity from microbiota to societies. Among paramount mechanisms in systems of RPS, the role of intraspecific interaction has been recently noted in terms of promoting biodiversity. Since intraspecific interaction is defined by an invasive reaction between individuals in the same group, the interaction may be also sensitive to the territorial awareness. To explore how territorial awareness-based intraspecific interaction can affect species biodiversity, we endow species with the mechanism in the classic RPS game. By means of the Monte-Carlo method, we find the phenomenon that the presence of species’ territorial awareness has an impact on intraspecific interaction which ultimately affects species biodiversity. At the same time, we also find that territorial awareness can play a significant role to the average waiting time for extinction which is numerically elucidated by exploiting the quantity: interface width statistic. Unlike prior research that concentrated solely on the relationship between interaction frequency and species diversity, our results shed lights on the important role of territorial awareness in models of RPS, and they reveal fascinating evolutionary outcomes in structured populations that are a unique consequence of such awareness behavior.

This paper examines the influence of distance to biorefinery plants on agricultural land value. The research utilizes micro-level data on characteristics of parcels and the locations of ethanol facilities in Central Nebraska, USA. I employ a theoretical model and an empirical hedonic approach to determine the effect of proximity. To address potential endogeneity, the econometric model adopts an instrumental variable. Estimates from the model provide evidence that land values significantly decrease as the distance from a parcel to a biorefinery plant increases. The results also reveal a non-linearity pattern in the model, with land prices falling at a decreasing rate with distance from ethanol plants.

Abstract Evolutionary games of cyclic competitions have been extensively studied to gain insights into one of the most fundamental phenomena in nature: biodiversity that seems to be excluded by the principle of natural selection. The Rock-Paper-Scissors (RPS) game of three species and its extensions [e.g., the Rock-Paper-Scissors-Lizard-Spock (RPSLS) game] are paradigmatic models in this field. In all previous studies, the intrinsic symmetry associated with cyclic competitions imposes a limitation on the resulting coexistence states, leading to only selective types of such states. We investigate the effect of nonuniform intraspecific competitions on coexistence and find that a wider spectrum of coexistence states can emerge and persist. This surprising finding is substantiated using three classes of cyclic game models through stability analysis, Monte Carlo simulations and continuous spatiotemporal dynamical evolution from partial differential equations. Our finding indicates that intraspecific competitions or alternative symmetry-breaking mechanisms can promote biodiversity to a broader extent than previously thought.

This paper examines how proximity to an ethanol plant influences land-use and crop choice among producers. We estimated a Tobit model of crop choice within parcels located in Central Nebraska in a 2014 sample period in order to analyze changes in land-use and crop choice. We employed Geographic Information System (GIS) databases to access relevant data on crop choice and other land uses in the study area parcels, in addition to detailed information on the location and capacity of irrigation wells. We utilized an instrumental variable approach to account for the endogeneity of crop choice with ethanol refinery locations in the study area. Our regional model also took into account specific characteristics of the local processing markets for grains, including animal food manufacturers and livestock as well as ethanol plants. Our estimates revealed that ethanol plants alter land-use in several ways. We found that proximity to an ethanol plant increases the share of land allocated to corn cultivation up to a distance of 30 miles and that the portion of land parcels allocated to corn production falls with distance from an ethanol plant in a non-linear pattern. We also find that land allocation to grassland and pasture rises with distance from ethanol plants.

As more GPS receivers are used in navigation systems to obtain precise position information, concerns about GPS jamming vulnerability are growing. The most effective way to overcome this jamming weakness is to use an array antenna that consists of many antenna elements and RF channels. However, an array antenna causes two side effects: a nulling pattern and a time delay error in positioning performance. We analyze the effects on the positioning accuracy of a GPS receiver equipped with a precise time-delay-compensated array antenna to overcome jamming situations. We present an analysis of the theoretical gain pattern of a 4-array antenna and experimental verification of GPS signal attenuation by obtaining a satellite's CN0 value in the near jamming direction. We show the results of the time delay measurement in the array antenna system using two independent methods and present a new baseband linear interpolation algorithm that is evaluated as having a 0.95 ns RMS error after compensating for the invariant RF time delays. Finally, using the realistic gain pattern and time-delay-compensation results, we assess the position error of the GPS receiver and show the possibility of attaining a precise navigation system in jamming environments. [ABSTRACT FROM AUTHOR]

We study the dynamics of cyclic competing mobile five species on spatially extended systems originated from asymmetric initial populations and investigate the basins for the three possible asymptotic states, coexistence of all species, existences of only two independent species, and the extinction. Through extensive numerical simulations, we find a prosperous dependence on initial conditions for species biodiversity. In particular, for fixed given equal densities of two relevant species, we find that only five basins for the existence of two independent species exist and they are spirally entangled for high mobility. A basin of coexistence is outbreaking when the mobility parameter is decreased through a critical value and surrounded by the other five basins. For fixed given equal densities of two independent species, however, we find that basin structures are not spirally entangled. Further, final states of two independent species are totally different. For all possible considerations, the extinction state is not witnessed which is verified by the survival probability. To provide the validity of basin structures from lattice simulations, we analyze the system in mean-field manners. Consequently, results on macroscopic levels are matched to direct lattice simulations for high mobility regimes. These findings provide a good insight into the fundamental issue of the biodiversity among many species than previous cases. [ABSTRACT FROM AUTHOR]

This study investigated the anti-spoofing capability of a Commercial-Off-The-Shelf (COTS) Global Positioning System (GPS) receiver and proposes a spoofing detection method with minimum user complexity. A spoofing test environment with a GPS simulator was developed to test a conventional GPS receiver with an in-line radio frequency (RF) signal. The tests on a geodetic-grade receiver revealed a vulnerability in the COTS GPS receiver against spoofing attacks. Receiver Autonomous Integrity Monitoring (RAIM) was not capable of handling a spoofing attack sufficiently, but could manage a low-level attack. Thus, a spoofing detection method based on the simulation results is proposed as a feasibility check. [ABSTRACT FROM AUTHOR]

In this paper we introduce a discrete model of brucellosis happened in Korean livestock farms and numerically analyze its dynamical features. To do it, we consider parameters data supported by Livestock Cooperatives. To control brucellosis, we investigate the relationship among key parameters, as applications of our model. We hope that our model may be used to reduce brucellosis in Korean livestock farms. [ABSTRACT FROM AUTHOR]

We study the spatial rock-paper-scissors game with adaptive mutation which may describe imitation behaviors of two competing species. We introduce an adaptive mutation where one of the species may tend to mutate the other by implementing a fundamental mutation mechanism with respect to local fitness of two competing species by comparing payoffs of its origin with the updated one when it mutates to the other. By means of Monte Carlo simulations, we show that species coexistence can be promoted by the intensification of adaptive mutation at certain high mobility regimes which lead the extinction traditionally, even if extremely high mobility results in the extinction as well. In addition, by measuring the extinction probability for extensive scales of spatial domains, we also found that the critical mobility to lead extinction is shifted according to the rate of adaptive mutation. Ultimately, our findings may indicate that adaptive mutation can be a significant role to maintain coexistence for moderately strong individuals' mobilities. [ABSTRACT FROM AUTHOR]