Journal Staff

An area of Artificial Intelligence, used for instance in optimization, is evolutionary algorithms. By using mechanisms similar to those that cause evolution, evolutionary algorithms can improve e.g. problem solving algorithms by artificial evolution.The purpose of this study was to show that it’s possible to simulate evolution by modelling it as an evolutionary algorithm. This was achieved by simulating the evolution of silverfish’ genes in two environments with the only difference of the presence of a threat. The results were considered to be successful as the majorityof the genes which were presumed to be important for survival changed in such away. The results could be repeated between simulations indicating that random change of the genes and deterministic factors in the environment shaped the genes of the silverfish and that after simulation the silverfish were optimally fit for the environment.Ett område inom Artificiell Intelligens som bl a används för optimering är evolutionära algoritmer. Genom att använda mekanismer liknande de som orsakar evolution så kan t ex algoritmer förbättras genom artificiell evolution. Syftet med den här studien var att visa att det är möjligt att simulera evolutionen genom att modellera den som en evolutionär algoritm. Detta gjordes genom att simulera evolutionen av silverfiskars gener i två miljöer vars enda skillnad var en förekomst av ett hot. Resultaten ansågs vara lyckade då merparten av de gener som förmodades vara viktiga för överlevnad förändrades på ett sådant sätt. Resultaten kunde upprepas mellan simuleringar vilket indikerar att genom stokastisk förändring av gener och deterministiska faktorer i miljön så optimerades silverfiskarnas gener för att göra det möjligt att överleva i respektive miljö

Emergent friction in two-dimensional Frenkel-Kontorova models

Simple models for friction are typically one-dimensional, but real interfaces are two-dimensional. We investigate the effects of the second dimension on static and dynamic friction by using the Frenkel-Kontorova (FK) model. We study the two most straightforward extensions of the FK model to two dimensions and simulate both the static and dynamic properties. We show that the behavior of the static friction is robust and remains similar in two dimensions for physically reasonable parameter values. The dynamic friction, however, is strongly influenced by the second dimension and the accompanying additional dynamics and parameters introduced into the models. We discuss our results in terms of the thermal equilibration and phonon dispersion relations of the lattices, establishing a physically realistic and suitable two-dimensional extension of the FK model. We find that the presence of additional dissipation channels can increase the friction and produces significantly different temperature-dependence when compared to the one-dimensional case. We also briefly study the anisotropy of the dynamic friction and show highly nontrivial effects, including that the friction anisotropy can lead to motion in different directions depending on the value of the initial velocity.Comment: 14 pages, 13 figure

Are Traditional Cooperatives an Endangered species? About Shrinking Satisfaction, Involvement and Trust

Several researchers, who have observed that traditional cooperatives have difficulties in modern markets, mention a number of behavioral concepts characterizing the members. This study attempts to empirically test these concepts. It is based on a survey among members of a large traditional Swedish cooperative. The members perceive the cooperative to be so large and complex that they have difficulties understanding the operations. Hence, they become dissatisfied and uninvolved, and they mistrust the leadership. Moreover, they do not believe that the cooperative can be remodeled to strengthen member control. The findings support the behavioral explanations presented in prior studies.agricultural cooperative, property rights, satisfaction, involvement, trust, Consumer/Household Economics,

Bounded Refinement Types

We present a notion of bounded quantification for refinement types and show how it expands the expressiveness of refinement typing by using it to develop typed combinators for: (1) relational algebra and safe database access, (2) Floyd-Hoare logic within a state transformer monad equipped with combinators for branching and looping, and (3) using the above to implement a refined IO monad that tracks capabilities and resource usage. This leap in expressiveness comes via a translation to "ghost" functions, which lets us retain the automated and decidable SMT based checking and inference that makes refinement typing effective in practice.Comment: 14 pages, International Conference on Functional Programming, ICFP 201

Modelling the Impact of Compulsory FMD Insurance

This paper compares two ways of financing the combating of Foot and Mouth Disease (FMD) in the EU and uses a simulation model to determine the welfare and production implications of the two systems. The two systems analysed are (i) financing by the tax payers, resembling the system currently in place, and (ii) a compulsory insurance scheme where all costs are converted into regionally differentiated insurance premiums that are paid by the producers. The analysis indicates that welfare gains may be realised by shifting from the former to the latter financing system.foot and mouth disease, insurance scheme, Risk and Uncertainty, D61, Q18,

The anatomy of Dryptosaurus aquilunguis (Dinosauria:Theropoda) and a review of its tyrannosauroid affinities

no. 371

The Effect of Repeated Listening Experiences on Upper Elementary Students' Tolerance Toward Non-Western Music

vi, 107 leaves. Advisor: James CoxThis study examined the effect of repeated listening experiences on upper elementary students' tolerance toward non-western music. Intact music classes were randomly assigned to control and experimental groups. During the pretest, students indicated their degree of liking for nonwestern musical excerpts. Following the pretest, experimental subjects (n=303) received twenty-two repeated listening experiences of the same non-western examples employed on the pretest. Control subjects (n=279) received regular music in struction. Following the treatment, all subjects were administered a posttest. An analysis of covariance determined significant gain differences between groups. Overall, results indicate highly signficant (p=.05) gain differences between groups toward all styles of non-western music. Analysis by grade indicates that fourth- and fifth- grade experimental subjects significantly improved, while sixth- grade students realized positive, but insignificant gains. Analysis by genre indicates that all experimental subjects significantly increased tolerance toward African and East Indian styles, but obtained insignificant gains toward Japanese music

Synthesis of Recursive ADT Transformations from Reusable Templates

Recent work has proposed a promising approach to improving scalability of program synthesis by allowing the user to supply a syntactic template that constrains the space of potential programs. Unfortunately, creating templates often requires nontrivial effort from the user, which impedes the usability of the synthesizer. We present a solution to this problem in the context of recursive transformations on algebraic data-types. Our approach relies on polymorphic synthesis constructs: a small but powerful extension to the language of syntactic templates, which makes it possible to define a program space in a concise and highly reusable manner, while at the same time retains the scalability benefits of conventional templates. This approach enables end-users to reuse predefined templates from a library for a wide variety of problems with little effort. The paper also describes a novel optimization that further improves the performance and scalability of the system. We evaluated the approach on a set of benchmarks that most notably includes desugaring functions for lambda calculus, which force the synthesizer to discover Church encodings for pairs and boolean operations

THE OSTEOLOGY OF ALIORAMUS, A GRACILE AND LONG-SNOUTED TYRANNOSAURID (DINOSAURIA: THEROPODA) FROM THE LATE CRETACEOUS OF MONGOLIA

Fig. 68: Closeup of right ilium of the holotype specimen of Alioramus altai (IGM 100/1844) in lateral view. Scale bar 5 5 cm. Abbreviations as in figure 66.Published as part of Brusatte, Stephen L., Carr, Thomas D. & Norell, Mark A., 2012, The Osteology Of Alioramus, A Gracile And Long-Snouted Tyrannosaurid (Dinosauria: Theropoda) From The Late Cretaceous Of Mongolia, pp. 1-197 in Bulletin of the American Museum of Natural History 2012 (366) on page 149, DOI: 10.1206/770.1, http://zenodo.org/record/539926

Supermonads: one notion to bind them all

Several popular generalizations of monads have been implemented in Haskell. Unfortunately, because the shape of the associated type constructors do not match the standard Haskell monad interface, each such implementation provides its own type class and versions of associated library functions. Furthermore, simultaneous use of different monadic notions can be cumbersome as it in general is necessary to be explicit about which notion is used where. In this paper we introduce supermonads: an encoding of monadic notions that captures several different generalizations along with a version of the standard library of monadic functions that work uniformly with all of them. As standard Haskell type inference does not work for supermonads due to their generality, our supermonad implementation is accompanied with a language extension, in the form of a plugin for the Glasgow Haskell Compiler (GHC), that allows type inference for supermonads, obviating the need for manual annotations