Horizontal and Vertical Multiple Implementations in a Model of Industrial Districts

In this paper we discuss strategies concerning the implementation of an agent-based simulation of complex phenomena. The model we consider accounts for population decomposition and interaction in industrial districts. The approach we follow is twofold: on one hand, we implement progressively more complex models using different approaches (vertical multiple implementations); on the other hand, we replicate the agent-based simulation with different implementations using jESOF, JAS and plain C++ (horizontal multiple implementations). By using both different implementation approaches and a multiple implementation strategy, we highlight the benefits that arise when the same model is implemented on radically different simulation environments, comparing the advantages of multiple modeling implementations. Our findings provide some important suggestions in terms of model validation, showing how models of complex systems tend to be extremely sensitive to implementation details. Finally we point out how statistical techniques may be necessary when comparing different platform implementations of a single model.Replication of Models; Model Validation; Agent-Based Simulation

Systemic risk in artificial worlds, using a new tool in the ABM perspective

We propose SLAPP, or Swarm-Like Agent Protocol in Python, as a simplified application of the original Swarm protocol, choosing Python as a simultaneously simple and complete object-oriented framework. With SLAPP we develop two test models in the Agent-Based Models (ABM) perspective, building an artificial world related to the actual important issue of interbank payment and liquidity

A Comparison between Maximum Likelihood and Bayesian Estimation Methods for a Shape Parameter of the Weibull-Exponential Distribution

We considered the Bayesian analysis of a shape parameter of the Weibull-Exponential distribution in this paper. We assumed a class of non-informative priors in deriving the corresponding posterior distributions. In particular, the Bayes estimators and associated risks were calculated under three different loss functions. The performance of the Bayes estimators was evaluated and compared to the method of maximum likelihood under a comprehensive simulation study. It was discovered that for the said parameters to be estimated, the quadratic loss function under both uniform and Jeffrey’s priors should be used for decreasing parameter values while the use of precautionary loss function can be preferred for increasing parameter values irrespective of the variations in sample size

Factors affecting the lower risk of colorectal cancer in Nigeria

Examine the factors affecting the low incidence colorectal carcinoma in Nigeria compared to the population of European countries and USA

GROWTH INHIBITION OF ROT FUNGI BY COMPETITIVE GROWTHOF TRICHODERMA VIRIDE

A study was carried out in vitro to evaluate the antagonistic growth potential of a Trichoderma viride strain in the biological control of some common post-harvest and storage rot fungi of food crops. The experiment was set up in Completely Randomized Design (CRD) with three treatments and two replicates. Data obtained were analyzed by Analysis of Variance (ANOVA) at 5 % level of probability using SPSS software version seventeen. 5 mm diameter agar discs of 2-7 days old cultures of antagonist and rot fungi obtained using a sterile 5mm diameter cork borer were cultured simultaneously in dual cultures on Potato Dextrose Agar (PDA) in 8.5 mm diameter petri dishes and incubated for a total duration of 9 days at 280C. Radial growth inhibition of rot fungi increased steadily from the 1st to the 9th day of post-inoculation. Radial growth of Aspergillus flavus was inhibited the most (42.94 %), followed by Aspergillus niger (30.88%) and lastly Fusarium oxysporum (30.65 %). In pairing with A. flavus, massive sporulation of T. viride on growth surface of rot fungus was accompanied with extensive degradation of mycelia of A. flavus by T. viride after 9 days post-inoculation. Zones of mycelia growth inhibition were observed in dual cultures of T. viride with A. flavus and F. oxysporum. Differences in growth inhibition of rot fungi by T. viride were significant (P<0.05) except between pairing with A. niger and F. oxysporum. The T. viride strain used in the study exhibited significant biocontrol potential through competitive growth against the test fungi and could be applied in biocontrol of rot fungi in storage as a means of enhancing shelf life as well as preserving the market value of harvested farm produce

Perceived Parental Care, Self-Esteem and Depression among Adolescents in Makurdi Secondary Schools

This study was aimed at exploring whether perceived parental care and self-esteem relates to depression among adolescents in Makurdi. An ex-post-facto design was adopted. Three hundred and sixty two (362) students participated in the study. Three measuring instruments were also used for data collection. Findings indicate that, perceived parental care and self-esteem relates to depression among adolescents in Makurdi. The finding also showed a strong correlation between the three variables. Based on the findings it was therefore recommended that, clinical psychologist and counseling psychologist must be aware of the role parental care has on their children and how self-esteem influences adolescent depression. Parents’ involvement in the treatment of depression should also be considered. School administrators and counsillors as well as psychologist should educate parents on styles of parenting. Keywords: Parental care, Self-esteem, Depression and Adolescent