Strategic Executions of Choreographed Timed Normative Multi-Agent Systems

This paper proposes a combined mechanism for coordinating agents in timed normative multi-agent systems. Timing constraints in a multi-agent system make it possible to force action execution to happen before certain time invariants are violated. In such multiagent systems we achieve coordination at two orthogonal levels with respect to states and actions. On the one hand, the behaviour of individual agents is regulated by means of social and organisational inspired concepts like norms and sanctions. On the other hand, the behaviour of sets of agents is restricted according to action-based coordination mechanisms called choreographies. In both cases, the resulting behaviour is constrained by time

Strategies used as spectroscopy of financial markets reveal new stylized facts

We propose a new set of stylized facts quantifying the structure of financial markets. The key idea is to study the combined structure of both investment strategies and prices in order to open a qualitatively new level of understanding of financial and economic markets. We study the detailed order flow on the Shenzhen Stock Exchange of China for the whole year of 2003. This enormous dataset allows us to compare (i) a closed national market (A-shares) with an international market (B-shares), (ii) individuals and institutions and (iii) real investors to random strategies with respect to timing that share otherwise all other characteristics. We find that more trading results in smaller net return due to trading frictions. We unveiled quantitative power laws with non-trivial exponents, that quantify the deterioration of performance with frequency and with holding period of the strategies used by investors. Random strategies are found to perform much better than real ones, both for winners and losers. Surprising large arbitrage opportunities exist, especially when using zero-intelligence strategies. This is a diagnostic of possible inefficiencies of these financial markets.Comment: 13 pages including 5 figures and 1 tabl

Basic completion strategies as another application of the Maude strategy language

The two levels of data and actions on those data provided by the separation between equations and rules in rewriting logic are completed by a third level of strategies to control the application of those actions. This level is implemented on top of Maude as a strategy language, which has been successfully used in a wide range of applications. First we summarize the Maude strategy language design and review some of its applications; then, we describe a new case study, namely the description of completion procedures as transition rules + control, as proposed by Lescanne.Comment: In Proceedings WRS 2011, arXiv:1204.531

Психолінгвістичні фактори опосередкованого перекладу в українському літературному та релігійному контекстах

The study of indirect translations (IT) into Ukrainian, viewed from a psycholinguistic perspective, will contribute to a better understanding of Soviet national policies and the post-Soviet linguistic and cultural condition. The paper pioneers a discussion of the strategies and types of IT via Russian in the domains of literature and religion. In many cases the corresponding Russian translation, which serves as a source text for the Ukrainian one, cannot be established with confidence, and the “sticking-out ears” of Russian mediation may only be monitored at the level of sentence structure, when Russian wording underlies the Ukrainian text and distorts its natural fluency. The discussion substantiates the strategies and singles out the types of IT, in particular, (1) Soviet lower-quality retranslations of the recent, and mostly high-quality, translations of literary classics, which deliberately imitated lexical, grammatical, and stylistic patterns of the Russian language (became massive in scope in the mid1930s); (2) the translationfrom-crib type, or translations via the Russian interlinear version, which have been especially common in poetry after WWII, from the languages of the USSR nationalities and the socialist camp countries; (3) overt relayed translations, based on the published and intended for the audience Russian translations that can be clearly defined as the source texts for the IT into Ukrainian; this phenomenon may be best illustrated with Patriarch Filaret Version of the Holy Scripture, translated from the Russian Synodal Bible (the translation started in the early 1970s); and, finally, (4) later Soviet (from the mid1950s) and post-Soviet (during Independence period) hidden relayed translations of literary works, which have been declared as direct ones but in fact appeared in print shortly after the publication of the respective works in Russian translation and mirrored Russian lexical and stylistic patterns.Дослідження опосередкованих перекладів українською мовою з перспективи психолінгвістики допоможе глибше збагнути радянську національну політику та пострадянську мовно-культурну ситуацію. У статті вперше встановлюються й цілісно окреслюються стратегії та типи перекладів, опосередкованих російською мовою, в галузях літератури і релігії. У багатьох випадках неможливо однозначно вказати на відповідні російські переклади, які виступають джерелом для українських текстів, і лише на синтаксичному рівні вдається простежити як крізь українські слова прозирають російські тексти, які руйнують природний плин української мови. Авторка обґрунтовує стратегії та окреслює типи опосередкованого перекладу, зокрема 1) радянські повторні переклади нижчої якості, ніж нещодавно зроблені якісні переклади класичних творів, які зумисно імітують лексичні, граматичні та стилістичні зразки російської мови (цей тип набув масового характеру з середини 1930-х років); 2) переклад-зі-шпаргалки, тобто переклади через російські підрядники, які були особливо поширеними в жанрі поезії після другої світової війни; 3) відкриті естафетні переклади, які спираються на опубліковані для російської аудиторії російськомовні переклади, що їх можна легко ідентифікувати як джерельні тексти для опосередкованих українських перекладів; найкраще це явище вдалося проілюструвати перекладами Святого Письма, зробленими Патріархом Філаретом з російської синодальної Біблії (цю справу було розпочато ще на початку 1970-х років); нарешті, 4) пізньорадянські (з середини 1950-х років) та пострадянські (протягом періоду незалежності) приховані естафетні переклади художніх творів, про які видавці заявляють як про прямі переклади, але їхня фактична поява відразу після публікації відповідних творів російською мовою та лексико-стилістична схожіть на російські відповідники свідчить про їхню опосередкованість

On the Feasibility of Power and Status Ranking in Traditional Setups

This paper aims at a better understanding of the conditions under which unequal rank or power positions may get permanently established through asymmetric gift exchange when a gift brings pride to the donor and shame to the recipient. Such a framework matches numerous observations reported in the sociological and anthropological literature dealing with patronage relations in traditional setups. A central result derived from our model is that an asymmetric gift exchange equilibrium can occur only if the importance attached to social shame by a recipient is smaller than that attached to social esteem by a donor. Moreover, if this (necessary) condition is fulfilled, an asymmetric gift exchange will take place only if the recipient's productivity is neither too high nor too low. Finally, the possibility of a parasitic response of the gift recipient is more likely to be observed when the donee's sensitivity to social shame is low, or when his productivity is high.Social esteem; status; power; patronage; gift exchange

Geometric vulnerability of democratic institutions against lobbying: a sociophysics approach

An alternative voting scheme is proposed to fill the democratic gap between a president elected democratically via universal suffrage (deterministic outcome, the actual majority decides), and a president elected by one person randomly selected from the population (probabilistic outcome depending on respective supports). Moving from one voting agent to a group of r randomly selected voting agents reduces the probabilistic character of the outcome. Building r such groups, each one electing its president, to constitute a group of the groups with the r local presidents electing a higher-level president, does reduce further the outcome probabilistic aspect. Repeating the process n times leads to a n-level bottom-up pyramidal structure. The hierarchy top president is still elected with a probability but the distance from a deterministic outcome reduces quickly with increasing n. At a critical value n_{c,r} the outcome turns deterministic recovering the same result a universal suffrage would yield. The scheme yields several social advantages like the distribution of local power to the competing minority making the structure more resilient, yet preserving the presidency allocation to the actual majority. An area is produced around fifty percent for which the president is elected with an almost equiprobability slightly biased in favor of the actual majority. However, our results reveal the existence of a severe geometric vulnerability to lobbying. A tiny lobbying group is able to kill the democratic balance by seizing the presidency democratically. It is sufficient to complete a correlated distribution of a few agents at the hierarchy bottom. Moreover, at the present stage, identifying an actual killing distribution is not feasible, which sheds a disturbing light on the devastating effect geometric lobbying can have on democratic hierarchical institutions.Comment: 52 pages, 22 figures, to appear in Mathematical Models and Methods in Applied Science

Agent-Based Facilitation of Water Allocation: Case Study in the Drome River Valley

International audienceThe purpose of the 1992 French Water Act is to encourage negotiation and dialogue among local stakeholderswithin a framework which is very similar to a patrimonial approach. Potential use of models in such post-normalapproaches is analyzed. Two kinds of models are compared: one is agent-based, the other follows a more classicalapproach. They are compared according to their contributions as negotiation support tools. This comparisonis based on a specific collective decision process dealing with water allocation at the sub-basin scale, in whichauthors are involved. Both are used to support collective decision processes through simulation of resource usedynamics. Agent-Based Models entail the broadening of spatial information of actors in the process, revealinginter-connected topics not taken into consideration earlier. This makes it possible to remain relevant, despite thesometimes rapidly evolving stakes. The central point of this paper is the implementation, within a practical application,of theories advocating the use of ABM as a collective decision support system. This application promotesa better understanding of the kind of support ABM provides and the way it does so. This is broughtabout more by re-framing the discussion and modifying the representation of the system on the part of thestakeholders than by providing specific agreements

An executable Theory of Multi-Agent Systems Refinement

Complex applications such as incident management, social simulations, manufacturing applications, electronic auctions, e-institutions, and business to business applications are pervasive and important nowadays. Agent-oriented methodology is an advance in abstractionwhich can be used by software developers to naturally model and develop systems for suchapplications. In general, with respect to design methodologies, what it may be important tostress is that control structures should be added at later stages of design, in a natural top-downmanner going from specifications to implementations, by refinement. Too much detail (be itfor the sake of efficiency) in specifications often turns out to be harmful. To paraphrase D.E.Knuth, “Premature optimization is the root of all evil” (quoted in ‘The Unix ProgrammingEnvironment’ by Kernighan and Pine, p. 91).The aim of this thesis is to adapt formal techniques to the agent-oriented methodologyinto an executable theory of refinement. The justification for doing so is to provide correctagent-based software by design. The underlying logical framework of the theory we proposeis based on rewriting logic, thus the theory is executable in the same sense as rewriting logicis. The storyline is as follows. We first motivate and explain constituting elements of agentlanguages chosen to represent both abstract and concrete levels of design. We then proposea definition of refinement between agents written in such languages. This notion of refinement ensures that concrete agents are correct with respect to the abstract ones. The advantageof the definition is that it easily leads to formulating a proof technique for refinement viathe classical notion of simulation. This makes it possible to effectively verify refinement bymodel-checking. Additionally, we propose a weakest precondition calculus as a deductivemethod based on assertions which allow to prove correctness of infinite state agents. Wegeneralise the refinement relation from single agents to multi-agent systems in order to ensure that concrete multi-agent systems refine their abstractions. We see multi-agent systemsas collections of coordinated agents, and we consider coordination artefacts as being basedeither on actions or on normative rules. We integrate these two orthogonal coordinationmechanisms within the same refinement theory extended to a timed framework. Finally, wediscuss implementation aspects.LEI Universiteit LeidenFoundations of Software Technolog

Industry 4.0 and the digitalisation of society: Curse or cure?

The central aim of this article is to sketch and outline a brief and critical presentation, overview and assessment of the (radically ambivalent) dynamics of the large family of technological developments pertaining to the Fourth Industrial Revolution (Industry 4.0), as well as of the so-called digitalisation of society. This assessment attempts to comprehensively overcome relevant analytical dualisms and the one-sided “either-or” logic, in favor of a synthetic, open and creative “both-and” framework of interdisciplinary thought