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When solving multi-objective optimization problems with complex Pareto fronts characteristics, previous work generally ignores the information related to Pareto fronts provided by the population during the evolution, which is detrimental to efficiently tackle them. In order to taking full advantage of information associated with a population evolution, a multi-objective evolutionary optimization method based on online perceiving Pareto front characteristics is proposed in this study. To this end, the information associated with the Pareto front of an optimization problem is first extracted from the population. Following that, the characteristics of the Pareto front in concavity/convexity and continuity are perceived online. For the purpose of each sub-front containing only one characteristic, a Pareto front is divided based on the concavity/convexity and continuity. According to the characteristic of each sub-front, different reference points are selected to refine the distribution of reference vectors. Finally, a multi-objective evolutionary algorithm is designed targeting the characteristics of the Pareto front. The performance of the proposed method is evaluated by comparing it with 8 state-of-the-art optimizers on 31 test problems. Further, the experimental results demonstrate that the proposed method is competitive in handling multi-objective optimization problems with irregular Pareto fronts.

In differential evolution algorithm (DE), it is a widely accepted method that selecting individuals with higher fitness to generate a mutant vector. In this case, the population evolution is under a fitness-based driving force. Although the driving force is beneficial for the exploitation, it sacrifices performance on the exploration. In this paper, a novelty-hybrid-fitness driving force is introduced to trade off contradictions between the exploration and the exploitation of DE. In the new proposed DE, named as NFDDE, both fitness and novelty values of individuals are considered when choosing individuals to create mutant vectors. In addition, two adaptive scaling factors are proposed to adjust the weights of the fitness-based driving force and the novelty-based driving force, respectively, and then distinct properties of the two driving forces can be effectively utilized. At last, to save computational resources, some individuals with lower novelty are deleted when the population has converged to a certain extent. The comprehensive performance of NFDDE is extensively evaluated by comparisons between it and other 9 state-of-art DE variants based on CEC2017 test suite. In addition, distinct properties of the newly introduced strategies and involved parameters are further confirmed by a set of experiments.

Population ageing represents a dramatic scenario and a progressive process inducing major changes in the dynamics of the population and especially in the age structure. The ageing population process is a phenomenon relevant to define not only demographic but also social, cultural, and territorial transformations in relation to the urban settlements. In this article, we present a case study regarding the ageing process persistent in urban areas from the counties of the Transylvania region. The present study emphasizing the evolution of the older adults age group between 2015 and 2019, drawing a forecast model for the prognosis period 2020–2050. The tendencies of the population decline process are revealed by the outcomes of the ageing index, outlining some long-term effects of population ageing over the years. The study of this phenomenon reveals an important framework at the regional level of Transylvania and points out the means to determine its existence in other regions or countries, since it affects the urban population evolution and its dynamics.

Aimed at early maturing and poor accuracy of multi-objective firefly algorithms, we propose a multi-objective firefly algorithm based on compensation factor and elite learning (CFMOFA). Based on iterations by introducing a compensation factor into the firefly learning formula, constraints by population can be overcome and the Pareto optimal solution can be approached in a reduced period. The non-inferior solutions produced in iterations were stored in the external archive and a random external archive particle was employed as the elite particle for population evolution. In this way, the detection range of firefly was extended and diversity and accuracy of non-inferior solution set were enhanced. The conventional algorithms, the improved algorithms and the proposed multi-objective optimization algorithm were tested and compared with each other. The results indicated great advantages of the proposed algorithm in convergence, diversity, and robustness and the proposed algorithm is an effective multi-objective optimization method.

The first part of the study has as it’s main objective to expose a brief socio-demographic analysis on the problem of aging population, both in Romania and in other European Union countries. The second part of the study follows the implications that the aging population phenomenon has on the Romanian state pension system. Also, the paper proposes an investigation of the risks to which the population aged 65 years and over is exposed in the context of the COVID-19 pandemic, based on specific comorbidities. To form an overview of these aspects, it will be used secondary data research, with information from public institutions such as: the National Institute of Statistics; Ministry of Internal Affairs; National House of Public Pensions; The Government of Romania; Financial Supervisory Authority; Eurostat; World Health Organization; United Nations Organization; Organization for Economic Co-operationand Development; as well as specific legislation and updated specialized literature. The last part of the study offers a series of conclusions which will result in several general solutions to the aging population problem.

Synthetic populations are tools widely spread in the agent-based community for representing a baseline population of interest whose dynamics and evolution will be simulated and studied. The dynamic evolution of the synthetic population has been typically performed using a discrete and fixed time step. A continuous approach based on the Gillespie algorithm is proposed in this research. Preliminary experiments illustrate the potential of the new method before future work are discussed.

Extreme learning machine (ELM) is an effective classification and prediction learning algorithm based on feedforward neural network (FNN). This paper presents the Phasmatodea (stick insect) population evolution algorithm (PPE), which is different from other algorithms, in which each solution represents a population and has two attributes: quantity and growth rate. Combining the concept of similar evolution and the model of population competition, it is a new local search method. The algorithm is compared with the other algorithms on benchmark functions and engineering problems. Then use it to enhance a variant of the ELM model. The results show that the proposed algorithm has a certain competitiveness.

Cellular automata studies have been instrumental in computational and biological studies for simulating life contours based on simple rule-based strategies. Game of Life (GoL) presented us with one of the earliest automata studies that led the way in exemplifying non-linear spatial representations, such as large-scale population evolution scenarios depicting species dominance, species equilibrium, and species extinction. However, the GoL was driven by interactions among vegetative entities comprising live and die states only. This paper extends GoL to gendered-GoL (g-GoL) in which male phenotypes and female phenotypes interact in an extended world to procreate. Using the g-GoL, we have demonstrated many evolution contours by applying gender-based dependence rules. Evolution scenarios have been simulated with skewed gender ratios that favor the birth of male offspring. Preference for a male child is common in certain cultures; therefore, empirical data realized with skewed gender settings in g-GoL can reveal the long-term impact of non-egalitarian gender societal structures. Our model provides a tool for the study of emergent life contours and brings awareness on current gender imbalances to strengthen multi-disciplinary research inquiry in the areas of social practices, mathematical modeling, and use of computational technologies.

Brain storm optimization (BSO) is a novel evolutionary algorithm which originates from the human brainstorming process. The successful applications of BSO on various problems demonstrate its validity and efficiency. To theoretically analyze the performance of algorithm from the viewpoint of population evolution, the population interaction network (PIN) is used to construct the relationship among individuals in BSO. Four experiments in different dimensions, parameters, combinatorial parameter settings and related algorithms are implemented, respectively. The experimental results indicate the frequency of average degree of BSO meets a power law distribution in the functions with low dimension, which shows the best performance of algorithm among three kinds of dimensions. The parameters of BSO are investigated to find the influence of the population interaction with the power law distribution on the performance of algorithm, and respective parameter can change the relationship among individuals. In addition, the mutual effect among parameters is analyzed to find the best combinatorial result to significantly enhance the performance of BSO. The contrast among BSO, DE and PSO demonstrates a power law distribution is more effective for boosting the population interaction to enhance the performance of algorithm.

Resumen: El municipio de Moratalla, ubicado en la comarca del NO de Murcia (España) presenta por sus datos respecto a la evolución poblacional una de las pocas excepciones en el conjunto regional, ya que pierde población desde al menos cuatro décadas. Esta situación significa un progresivo deterioro en la actividad económica, el envejecimiento de la población y un importante abandono del casco histórico de la ciudad, así como en una serie de pedanías localizadas en un amplio término municipal de 954,82 km2, el tercero más extenso de la Región de Murcia que está compuesta por cuarenta y cinco términos municipales. Los análisis estadísticos, cuestionario tabulados y entrevistas de carácter cualitativo a expertos locales señalan un escenario para esta ciudad y su término municipal preocupante, que en caso de que no se consiga frenar podría desembocar a medio y largo plazo en una aguda regresión social y económica de este municipio. A través de la herramienta DAFO aplicada básicamente a la promoción turística de interior se harán propuestas que contribuyan a detener la sangría demográfica, diversificando la económica local basada en el sector primario y en la salida diaria de muchos vecinos a otras localidades, donde desarrollan sus puestos de trabajo. Palabras clave: Despoblación, vaciamiento, desarrollo local, Moratalla, estrategia territorial. Abstract: The municipality of Moratalla, located in the NW region of Murcia (Spain) presents, due to its data regarding population evolution, one of the few exceptions in the regional set, since it has lost population for at least four decades. This situation means a progressive deterioration in economic activity, the aging of the population and a significant abandonment of the historic center of the city, as well as in a series of districts located in a large municipal area of 954.82 km2, the third largest of the Murcia Region, which is made up of forty-five municipalities. Statistical analyzes, tabulated questionnaires and qualitative interviews with local experts indicate a worrying scenario for this city and its municipal area, which in the event of failure to stop could lead in the medium and long term into an acute social and economic regression of this municipality. Through the SWOT tool applied basically to inland tourism promotion, proposals will be made that help to stop demographic bleeding, diversifying the local economy based on the primary sector and the daily departure of many residents to other locations, where they develop their jobs of work. Key words: Depopulation, emptying, local development, Moratalla, territorial strategy.

Evolutionary dynamics is traditionally considered under either an infinite population or a finite population assumptions. The stochastic effects due to sampling of finite population system play imp...

Agent based modelling is nowadays widely used in transport and the social science. Forecasting population evolution and analysing the impact of hypothetical policies are often the main goal of these developments. Such models are based on sub-models defining the interactions of agents either with other agents or with their environment. Sometimes, several models represent phenomena arising at the same time in the real life. Hence, the question of the order in which these sub-models need to be applied is very relevant for simulation outcomes. This paper aims to analyse and quantify the impact of the change in the order of sub-models on an evolving population modelled using TransMob. This software simulates the evolution of the population of a metropolitan area in South East of Sydney (Australia). It includes five principal models: ageing, death, birth, marriage and divorce. Each possible order implies slightly different results mainly driven by how agents' ageing is defined with respect to death. Furthermore, we present a calendar-based approach for the ordering that decreases the variability of final populations. Finally, guidelines are provided proposing general advices and recommendations for researchers designing discrete time agent-based models.

The forward time simulation tool rSHAPE (R-package for Simulated Haploid Asexual Population Evolution) was designed to complement the theoretical and empirical study of evolution. Included with rSHAPE are functions to programmatically build, run, and initially process results of an evolutionary experiment defined by the range of experimental conditions. As experimental evolution often studies both the emergence and fate ofde novomutants, I validated rSHAPE by confirming its ability to replicate seminal theoretical expectations concerning changes in fitness through time and the fixation probability of mutants. As an example of how rSHAPE can support both theoretical and empirical research, I applied rSHAPE to study how the laboratory protocol of serial passaging, common in microbial experimental evolution, affects the fixation probability ofde novomutants. Unlike related theoretical work which modelled growth as effectively exponential (Wahlet al., 2002), this study considered populations experiencing logistic growth which is common to microbes undergoing serial passaging. In contrast to exponential growth, when a population undergoes logistic growth the probability of a mutant arising and eventually fixing depends upon when a mutant arises during a growth phase. Users can download software and documentation for rSHAPE through CRAN athttps://cran.r-project.org/web/packages/rSHAPE/index.html, or via GitHub athttps://www.github.com/Jdench/SHAPE_library/.

We consider the population dynamics of two species described by the mutualistic Lotka–Volterra model with a +/+ interaction in the presence of spatial diffusions. The results demonstrate that diffusion does not affect the system’s stability but it brings two situations: one is a win–win situation where both species propagate with the same largest speed; in the other situation the aggressive species has two propagating wave fronts and the other species travels with a single slow wave front. Our model may help to understand the evolution of mutualism.

Demand response (DR) has been recognized as a powerful tool to relieve energy imbalance in the smart grid. Most previous works have ignored the irrational behavior of energy consumers in DR project implementation. Accordingly, in this paper, we focus on solving two questions during the execution of DR. Firstly, considering the bounded rationality of residential users, a population dynamic model is proposed to describe the decision behavior on whether to participate in the DR project, and then the evolutionary process of consumers participating in DR is analyzed. Secondly, for the DR participants, they have to compete dispatching amounts for maximal profit in a day-ahead bidding market, hence, a non-cooperative game model is proposed to describe the competition behavior, and the uniqueness of the Nash equilibrium is analyzed with mathematical proof. Then, the distributed algorithm is designed to search the evolutionary result and the Nash equilibrium. Finally, a case study is performed to show the effectiveness of the formulated models.

We provide conditions for the existence of equilibrium and non-equilibrium solutions about nonlinear population evolution systems with fixed population.

Aim of study: The aim of this work is to test the positive effect of a substantially developed resin sector on rural demographic evolution. This work shows how in the period between 1970 and 2010 the demographic decline in the interior regions of Spain was more pronounced in areas characterized by the importance of resin-producing forest stands compared to other nearby rural municipalities where this natural resource is not present.Area of study: The study area consists of a set of rural municipalities in Central Spain, both resin and non-resin producing, in the provinces of Segovia, Avila, Valladolid, Burgos, Soria, Cuenca and Guadalajara.Material and methods: The relationship between resin production and population in resin and non-resin producing municipalities was modeled by means of linear regression analysis.Main results: Generally speaking, between 1950 and 1970 the production of resin halted demographic decline in the regions where this activity was substantially developed. However, when the resin sector entered into crisis in the 1970s, and the economic repercussions of this activity gradually ceased to be felt, the demographic decline in the regions which had been involved in resin production was much more acute than in other non-resin-producing rural areas.Research highlights: This work shows the relationship between resin extraction activity and population evolution in rural municipalities. Sustainable resin exploitation can contribute to the maintenance and development of rural communities, and should be used as a tool for generating employment in rural areas.Key words: demography; economic crisis; resin sector; rural development.

BACKGROUND A 7 year experiment was set up in 2002 to evaluate the long-term effects of weed management strategies based on graminicidal sulfonylureas (SUs) on the evolution of a Lolium rigidum population resistant to ACCase inhibitors in a continuous wheat cropping system. The strategies included the continued use of ALS inhibitors, the continued application of ACCase inhibitors and a simple resistance management strategy based on a biennial rotation of herbicide mode of action (MoA). RESULTS The efficacy of the tested SUs in the field decreased significantly, starting from the fourth treatment in all control strategies. Regardless of control strategy, the few survivors of the ALS treatment in the third season produced a significant number of ACCase- and ALS-resistant (multiple-resistant) progeny. Continuous ALS and biennial rotation of herbicides reduced weed densities, but L. rigidum conserved its ACCase resistance trait. Enhanced metabolism was detected in ALS-resistant plants, whereas target site was primarily involved in the ACCase-resistant individuals. CONCLUSION At the end of the experiment, multiple-resistant individuals were found in all samples coming from the control strategies investigated. The biennial rotation between ALS and other MoA appeared to delay the development of resistance to SUs over continuous treatments, but additional measures will likely need to be taken in order to make this sustainable in the long term, whereas the field efficacy of SUs remained relatively high until the end of the experiment. Integrated weed management with more diversity should be introduced in oversimplified cropping systems in order to sustainably manage resistant L. rigidum populations. Copyright © 2012 Society of Chemical Industry

Se presenta un estudio de la variación craneofacial en muestras del noroccidente de Suramérica, distribuidas ampliamente en un sentido espacial y temporal, con el objetivo de proponer hipótesis sobre el poblamiento inicial. Se llevaron a cabo diferentes análisis (matriz-R, correlación de matrices y morfometría geométrica) para estudiar la historia y la estructura poblacional a nivel regional. Los resultados sugieren una alta diversidad morfológica, así como la existencia de patrones de estructuración espacial y temporal; también indican que ciertos eventos poblacionales y la acción de fuerzas evolutivas afectaron notablemente la diversidad craneofacial a través del tiempo. A partir de la comparación de distintos tipos de evidencia se propone un modelo sobre la forma y el tiempo del poblamiento temprano de la región y la subsecuente evolución poblacional a lo largo del Holoceno.

The classic problem for a logistically evolving single species population being harvested involves three parameters: rate constant, carrying capacity and harvesting rate, which are taken to be positive constants. However, in real world situations, these parameters may vary with time. This paper considers the situation where these vary on a time scale much longer than that intrinsic to the population evolution itself. Application of a multiple time scale approach gives approximate explicit closed form expressions for the changing population, that compare favorably with those generated from numerical solutions.

In this paper, we proposed a LW-PSO (PSO using a local world evolving model) by combining a local world evolving model with the “survival of the fittest” evolution mechanism. The concept of population structural entropy, a new diversity measure is defined and used to control the evolution process of the population topology of LW-PSO so the balance between the exploration and exploitation can be preserved during the population evolution. The experimental results show that LW-PSO can outperform the standard PSO with the lbest topology and the gbest topology especially in the multimodal problems and the extra time cost is negligible.

Is there an overriding principle of nature, hitherto overlooked, that governs all population behavior? A single principle that drives all the regimes observed in nature - exponential-like growth, saturated growth, population decline, population extinction, oscillatory behavior? In current orthodox population theory, this diverse range of population behaviors is described by many different equations - each with its own specific justification. The signature of an overriding principle would be a differential equation which, in a single statement, embraces all the panoply of regimes. A candidate such governing equation is proposed. The principle from which the equation is derived is this: The effect on the environment of a population's success is to alter that environment in a way that opposes the success., Comment: Revised equation-numbering to correspond to published version

A population balance method in which continuum and discrete phases are integrated is developed to simulate the evolution of polydisperse population of bubbles in a turbulent pipeline flow. The investigation is focused on the effect of the coalescence efficiency on this evolution. A dilute system of bubbles under microgravity conditions is considered. It is found that if the initial coalescence efficiency is low, a slight increase produces a significant effect on the bubble coalescence rate, and thus on the evolution of the population. If, however, the initial coalescence efficiency is high, its increase results in a marginal effect on the way the population evolves. The results of simulations are validated against experimental data on the population mean.

A general population evolution model is considered. Any individual of the population is characterized by its score. Certain general conditions are assumed concerning the number of the individuals and their scores. Asymptotic theorems are obtained for the number of individuals having a fixed score. Then it is proved that the score distribution is scale free. The result is applied to obtain the weight distribution of cliques in a random graph evolution model.

This paper examines the introduction of neutrality as proposed by Kimura (Kimura, 1968) into the genotype-phenotype mapping of a Genetic Algorithm (GA). The paper looks at the evolution of both a simple GA (SGA) and a multi-layered GA (MGA) incorporating a layered genotype-phenotype mapping based on the biological concepts of Transcription and Translation. Previous research in comparing GAs often use performance statistics; in this paper an analysis of population dynamics is used for comparison. Results illustrate that the MGA population’s evolution trajectory is quite different to that of the SGA population over dynamic landscapes and that the introduction of neutrality implicitly maintains genetic diversity within the population primarily through genetic drift in association with selection. peer-reviewed

In this work, we study the differentiability of the stationary age-dependent population system based on parity progression. By using the semigroup approach, we prove that the solution semigroup of the population evolution equation is eventually differentiable.

In this paper, by using semigroup approach, we concerned with the regularity of the age-dependent population system with instantaneous time delay in the birth process. We prove that, under some additional condition, the solution semigroup { T ( t ) , t ⩾ 0 } of the population evolution equation is eventually differentiable, i.e., there exists t 0 > 0 such that T ( t ) is differentiable for t > t 0 .

Enrichment of mixed microbial cultures (MMCs) in polyhydroxyalkanoate (PHA)-storing microorganisms must take place to develop a successful PHA production process. Moreover, throughout the operational period of a MMC system, the population needs to be checked in order to understand the changes in the performance that eventually occurred. For these reasons, it is necessary to monitor the population evolution, in order to identify the different groups of microorganisms and relate them with the storage capacity and kinetics of the MMC. Regarding this particular process, several culture-independent molecular techniques were already applied, with the use of hybridization techniques such fluorescence in situ hybridization and also PCR-based methods like denaturing gradient gel electrophoresis, terminal restriction fragment length polymorphism, pyrosequencing, and quantitative PCR standing out. This review intends, thus, to look at the molecular methods currently applied in monitoring the PHA-storing population evolution and how they can be combined with the evolutionary engineering step in order to optimize the overall process.

We analyze the evolution of a Cantabrian chamois population affected by sarcoptic mange over a twelve-year period, from 1991 to 2002. This population is spread out over 83,000 ha and has reached an average density of 12.3 chamois/100 ha. The epidemic appeared an 1993, however the population continued to increase until 1995, after which it began to decrease reaching its minimum in 2001. Currently there are 35.9% of the specimens that were in evidence in 1995. The annual variation of population in sectors affected by sarcoptic mange was considerable, with maximum losses between 30-48%. The heaviest losses occurred between the first and the third year after the epidemic entered the area. Five or six years after the beginning of the epidemic, the population stablilized at a density level of 4.1-6.4 specimens/100 ha., [fr]Durant une période de 12 ans, entre 1991 et 2002, nous avons analysé l'évolution d'une population d'isard cantabrique qui a été affectée par une épidémie de gale. La population s'étend sur 83 000 ha, la densité étant de 12,3 isards/100 ha. Malgré le fait que l'épidémie soit apparue en 1993, la population a continué à augmenter jusqu'à 1995, puis a baissé jusqu'à un minimum en 2001. Actuellement, la population représente 35,9% de celle de 1995. La variation annuelle de la population dans les secteurs affectés par la gale était considérable, avec des pertes maximales entre 30 et 48%. Ainsi la plus forte perte a eu lieu entre la première et la troisième année après l'arrivée de la maladie. Puis, cinq ou six ans après l'initiation de l'épidémie, la population s'est stabilisée à un niveau de densité de 4,1-6,4 individus/100 ha. [es]Se analizó la evolución de una población de rebeco cantábrico afectada por sarna sarcóptica entre 1991 y 2002. Esta población abarca 83.000 hay ha alcanzado una densidad media de 12,3 rebecos/100 ha. La epidemia comenzó en 1993, aunque la población continuó aumentando hasta 1995, tras lo que empezó a decrecer, alcanzando su mínimo en 2001. Actualmente la población representa el 35,9% de la existente en 1995. La variación poblacional anual en zonas afectadas por la sarna sarcóptica fue considerable, con pérdidas máximas entre 30-48%. Las mayores mortalidades ocurrieron entre el primer y el tercer año tras la aparición de la epidemia en la zona. Cinco o seis años antes de la epidemia, la población se había estabilizado en una densidad de 4,1-6,4 individuos/100 ha.

We consider a two-dimensional model for the evolution of a population consisting of two subgroups. The model is described by a system of differential equations. A qualitative analysis of the system is conducted for various parameter values. Bifurcations of phase portraits are described. An example is considered.

A three-dimensional mathematical model of nonhomogeneous population dynamics with selection and birth-and-death processes is considered. Bifurcations of operating modes are determined and conditions for extinction, degeneration, and stabilization are established.

Computer study of population evolution in a modified Penna model is presented, where different thresholds T for bad mutation may be assigned to individuals. The model indicates a possible source of such fluctuations of T due to embryo period of life before birth. Changes in age characteristics of the population, survival rate and mutation distributions at equilibrium are discussed. Results of computer simulation are compared with the standard Penna model with no fluctuation in T. We obtained larger equilibrium population for the same environmental capacity. However, the survival rate is smaller and the age of the oldest individuals also decreases. This is also reflected in age distribution of the population, similar at older populations and with higher decrease rate among younger ones. Also, the mutation accumulation is similar for older ages, yet younger individuals may absorb more mutations as a result of the presence of some items with threshold value above the average T. We conclude that fluctuations in threshold T may alter population characteristics, also in terms of measurable statistics in population such as age distribution or the survival rate.

We propose, and solve via Monte-Carlo simulation, a model describing evolution of population subject to harmful mutations. The habitat changes periodically. The evolution of two, initially identical, populations is compared. One without any external ingerence and the second in which we eliminate all individuals which are ill-fitted to the changed environment (eugenics). We show that although in the short run the individuals in the latter are better adapted and live longer, after some more changes of the environment, the populations with eugenics become extinct, while the others live on.

Under the effect of strong genetic drift, it is highly probable to observe gene fixation or gene loss in a population, shown by singular peaks on a potential landscape. The genetic drift-induced noise gives rise to two-time-scale diffusion dynamics on the bipeaked landscape. We find that the logarithmically divergent (singular) peaks do not necessarily imply infinite escape times or biological fixations by iterating the Wright-Fisher model and approximating the average escape time. Our analytical results under weak mutation and weak selection extend Kramers's escape time formula to models with B (Beta) function-like equilibrium distributions and overcome constraints in previous methods. The constructed landscape provides a coherent description for the bistable system, supports the quantitative analysis of bipeaked dynamics, and generates mathematical insights for understanding the boundary behaviors of the diffusion model.

The last census of 20 October 2011, confirmed the decrease in the stable population in most localities, although this did not occur uniformly across the county. The analysis aims to highlight the stable population evolution in the last two censuses, which mainly led to decreases in existent disparities between localities, to a slight increase of the degree of uniformity in this regard. If in urban areas, all localities have recorded drops, in the rural areas there were 11 localities with population increases, especially large suburban cities. This led to a slight decrease in the degree of variation in the area, from a coefficient of 45,6% at the census of 2002 to 43,4% in 2011 and the reduction in the ratio of the largest and smallest area, from 7,84 times to 6,08 times. If in 2002 there were 21 local rural residents under 3000 inhabitants, in 2011 their number increased to 26, while more than 10 thousand people do not exist in any village in the county, compared to 2 as they were at the previous census. Territorial disparities are found also among the population by age, existing only 8 villages where the average age has decreased compared to 2002, these being mainly poor localities from Valea Siretului, where the birth rate is higher.

Computer experiment study of population evolution and its dynamics is presented for two competing species A and B which share two habitats (1 and 2) of limited environmental capacity. The Penna model of biological aging, based on concept of defective mutation accumulation was adopted for migrating population. In this paper we assume and concentrate on the case when only one species A is mobile. For isolated habitats and for any initial population, we get at equilibrium spatial population distribution (A, B) between the two locations - A occupies location 1 while B-species is present in 2. The effect of migration between habitats is reported for some migration scenarios. With increasing migration we get a sequence (A, B) -> (A, A&B) -> (A, A) -> (B, B) distribution. Another scenarios bring different sequences of population distribution, size and characteristics.

We explore with the use of multicore processing technologies for conducting simulations on population replacement of disease vectors. In our model, a native population of simulated vectors is inoculated with a small exogenous population of vectors that have been infected with theWolbachiabacteria, which confers immunity to the disease. We conducted a series of computational simulations to study the conditions required by the invading population to take over the native population. Given the computational burden of this study, we decided to take advantage of modern multicore processor technologies for reducing the time required for the simulations. Overall, the results seem promising both in terms of the application and the use of multicore technologies.

In this paper, an ADaptive Immune Algorithm (ADIA) based on the artificial immune system (AIS) is proposed for the dependent task scheduling on Network on Chip (NoC). We increase the diversity of population of AIS in two ways, and improve the output result of scheduling. On one hand, new calculation method of the number of clones and the probability of mutation are proposed to enlarge the search space appropriately. On the other hand, our algorithm adopts an adaptive strategy to enable the local search to drive the population evolution when evolution speed is low after many iterative processes. Moreover, the influences of different factors in the proposed algorithm are studied. The comparative simulation results show that our algorithm always outperforms the tradition algorithms. Keywords-component; AIS; Dependent Task Scheduling; Network on Chip; Population Diversification; Adaptive

In this paper we present some recent work we performed on the socio-economic impact of fibre access networks (FTTH/FTTx). We summarise some results from a pre-study on the effects of fibre deployments in Sweden. Specifically, we list and quantify savings in data and telecommunications costs for Swedish local governments, estimate the added values for fibre-connected citizens, and present a multivariate regression analysis of the early impact on employment and population evolution, building on data from 290 municipalities between 2007 and 2010: we find a weak but statistically significant correlation, and we are able to exclude backward causality.

This paper deals with the construction of a discrete mathematical model for addictive buying. Firstly, identifications of consumers buying behavior are performed by using multivariate statistical techniques based on real data bases and sociological approaches. Then the population is divided into appropriate groups according to the level of overbuying and a discrete compartmental model is constructed. The future short term addicted population is computed assuming several future economic scenarios. © 2010 Elsevier Ltd.

In the present paper propose two novel variants of Differential Evolution (DE), named IP-OBL and IP-NSDE, have been proposed. In IP-OBL the initial population is generated by using the intermediate positions between the uniformly generated random numbers and opposition based numbers. While in case of IP-NSDE, the initial population is generated as an intermediate of uniform random numbers and numbers generated by Nelder Mead Method. The proposed algorithms are further modified by selecting best NP/2 individuals to perform in population evolution. The modified variants are termed as MIP-OBL and MIP-NSDE. The numerical results of 10 benchmark problems indicate the competence of the proposed algorithms.

We employed the Penna model for computer simulation of population evolution when it is controlled by (a) hunting out some of the population as well as (b) to find out the role of fluctuations in threshold T for the maximum number of bad mutations on population growth dynamics. Extinction of population may be caused by too many mutations inherited by offspring. Overhunting acts in the same way and may also result in vanishing of the whole population. When both factors are present, we get a critical line that defines a sharp transition between existence and non-existence of the population. A distribution of T around its average value with some width Δ may reflect some individual resistance to illnesses, or some non-inherited somatic mutations. Structural changes in the final population as a result of overhunting or threshold T fluctuations are observed.

This paper presents an approach to analyze population evolution in classifier systems using a symbolic representation. Given a sequence of populations, representing the evolution of a solution, the method simplifies the classifiers in the populations by reducing them to their "canonical form". Then, it extracts all the subexpressions that appear in all the classifier conditions and, for each subexpression, it computes the number of occurrences in each population. Finally, it computes the trend of all the subexpressions considered. The expressions which show an increasing trend through the course of evolution are viewed as building blocks that the system has used to construct the solution.

"Quorum sensing" has been described as "the most consequential molecular microbiology story of the last decade" [1][2]. The purpose of this paper is to study the mechanism of quorum sensing, in order to obtain a deeper understanding of how and when this mechanism works. Our study focuses on the use of an Individual-based Modeling (IbM) method to simulate this phenomenon of "cell-to-cell communication" incorporated in bacterial foraging behavior, in both intracellular and population scales. The simulation results show that this IbM approach can reflect the bacterial behaviors and population evolution in time-varying environments, and provide plausible answers to the emerging question regarding to the significance of this phenomenon of bacterial foraging behaviors.

In the noisy Penna model of ageing, instead of counting the number of defective loci which eventually kill anindividual, the noise describing the health status of individuals is introduced. This white noise is composed oftwo components: the environmental one and the personal one. If the sum of both trespasses the limit set forthe individuals homeodynamics the individual dies. The energy of personal ”uctuations depends on the numberof defective loci expressed in the individuals genome. Environmental ”uctuations, the same for all individualscan include some signals, corresponding to the exposition to pathogens which could be dangerous for a fractionof the organisms. Personal noise and the component of random environmental ”uctuations, when superimposedon the signal can be life threatening if they are stronger than the limit set for individuals homeodynamics.Nevertheless, some organisms survive the period of dangerous signal and they may remember the signal in thefuture, like antigens are remembered by our immune sy stems. Unfortunately, this memory weakens with timeand, even worse, some additional defective genes are switched on during the ageing. If the same pathogens(signals) emerge during the lifespan of the population, a fraction of the population could remember it and couldrespond by increasing the resistance to it. Again, unfortunately for some individuals, their memory could be tooweak and their own health status has worsened due to the accumulated mutations they have to die. Though,a fraction of individuals can survive the pandemics due to the immune memory, but a fraction of populationhas no such a memory because they were born after the last pandemic or they didnt notice this pandemic. Oursimple model, by implementing the noise instead of determi nistic threshold of genetic defects, describes how theimpact of pandemics on populations depends on the time which elapsed between the two incidents and how thedierent age groups of populations can respond for the second pandemic.Keywords: Pandemics, ageing, Monte Carlo simulation, population evolution.

The Penna bit-string model successfully encompasses many phenomena of population evolution, including inheritance, mutation, evolution and ageing. If we consider social interactions among individuals in the Penna model, the population will form a complex network. In this paper, we first modify the Verhulst factor to control only the birth rate, and introduce activity-based preferential reproduction of offspring in the Penna model. The social interactions among individuals are generated by both inheritance and activity-based preferential increase. Then we study the properties of the complex network generated by the modified Penna model. We find that the resulting complex network has a small-world effect and the assortative mixing property., Comment: 4 pages, 3 figures

Turkish Abstract: Gokceada, Ege denizinin kuzeydogusunda Turkiye’nin en buyuk adasidir. Tarih boyunca Gokceada gocmenler adasi olmustur. Gokceada gocun prototipidir. Ic ve dis gocun bir arada yasanmasi nufusta rakamsal olarak buyuk degisiklikler yaratmamistir. Ancak, gocler adanin nufus profilini buyuk olcude degistirmistir. Bugun Gokceadalilari hem Rumlar hem de Anadolu’dan gelenler olusturmaktadir. Adanin Rum nufusu 1960’lardan beri %90’dan fazla azalmistir. Kentlesme orani giderek artan adanin 2000 nufus sayimina gore toplam nufusu 8894 olup, 7278’i ilce merkezinde ve 1616’si ise 9 koyde yasamaktadir. Goclerle birlikte sosyokulturel zenginlik artarken goc edenlerin memnuniyetsizlikleri olayi uluslar arasi platforma tasimistir. Bu calismada goc ve beraberinde getirdigi olumlu ve olumsuz etkiler verilmeye calisilmistir. English Abstract: Gokceada (Imbros) is the biggest island of Turkey in the northeast Aegean Sea. Throughout history, Gokceada has been the island of immigrant. Gokceada is the epitome of migration. Thanks to both in-migration and out-migration, Gokceada’s population has not been changed vastly. The islanders of Gokceada are either the Rums or from Anatolia. The Greek population of the island has fallen down by over 90 per cent since the 1960s. According to the 2000 Population Census, its population is 8894 and 7278 inhabitants live in the town centre, while 1616 of them live in the 9 villages of the island. In one hand it has socia-cultural wealth by migration, on the other hand, upon dissatisfied Rum migrants this subject has been discussed international platform. In this paper, migration throughout history has examined with this positive and negative effect.

This is a short history of the population evolution in the «Audiencia de Guatemala» from the years previous to the Conquest through the early 19th Century. As a consequence of historical research conducted in the latest decades, the authors focus on topics such as the Indigenous population following a span that covers the years before the Conquest and the decline of their numbers up to their slow recovery in the North and West of Central America. Other topics discussed are the voluntary migration of Spaniards and the forced migration of Africans, as well as interrelations between these groups and the Natives, in particular the impact of metissage and the genesis of the castes, including the «ladinos». It is particularly interesting the surprising impact, both socioeconomical and demographical, of the groups of African origins in the «Audiencia de Guatemala».

Recent evolution of the Mancha Occientals population. The Mancha Occidental has maintain similars tendencies at the national until 1960. From this moment has been begun divergents tendencies. The region show the first signs of the depopulate process happened in others Spain's regions. In this paper show some characteristics of the population and his recent evolution., Evolución reciente de la población de la Mancha Occidental. La Mancha Occidental ha mantenido tendencias similares a la nacional hasta 1960. A partir de este momento se han iniciado tendencias divergentes. La región manifesta los primeros síntomas del proceso despoblador sufrido en otras regiones españolas. En este artículo examinamos algunas de las características principales de la población y su evolución reciente. [fr] Evolution récente de la population de la Mancha Occidental. La Mancha a presenté certaines tendances démographiques semblables a la nationale jusque 1960. Depuis lors, diverses tendances ont commencé. La région présente les premiers symptômes d'un procédé de dépopulation souffert dans d'autres regions espagnoles. Au cours de cet article, nous examinerons quelques principales caractéristiques de la population et sa récente evolution.

The classical modeling approach to prey-predator systems relies on extensions of Lotka-Volterra differential equations. In this paper a Cellular Automata-based model is proposed as an alternative approach for the simulation of a two population ecosystem of mites. It is shown how several complex features affecting mite population evolution, such as the egg disclosure time, the sexual maturation time, the limited life time, the limited survival capability of predators in fasting condition, and juvenile mortality, can be embedded in the Cellular Automata framework. Preliminary simulation results, together with a comparison between data of a real experiment and data from simulation experiments, are reported. Experimental data are fitted quite well by predictions of the Cellular Automata-based model, whereas they are not by results from the analytical Lotka-Volterra model.