What should a robot learn from an infant? Mechanisms of action interpretation and observational learning in infancy

The paper provides a summary of our recent research on preverbal infants (using violation-of-expectation and observational learning paradigms) demonstrating that one-year-olds interpret and draw systematic inferences about other’s goal-directed actions, and can rely on such inferences when imitating other’s actions or emulating their goals. To account for these findings it is proposed that one-year-olds apply a non-mentalistic action interpretational system, the ’teleological stance’ that represents actions by relating relevant aspects of reality (action, goal-state, and situational constraints) through the principle of rational action, which assumes that actions function to realize goal-states by the most efficient means available in the actor’s situation. The relevance of these research findings and the proposed theoretical model for how to realize the goal of epigenetic robotics of building a ’socially relevant’ humanoid robot is discussed

Near-Optimal Rates for Limited-Delay Universal Lossy Source Coding

International audienceWe consider the problem of limited-delay lossy coding of individual sequences. Here, the goal is to design (fixed-rate) compression schemes to minimize the normalized expected distortion redundancy relative to a reference class of coding schemes, measured as the difference between the average distortion of the algorithm and that of the best coding scheme in the reference class. In compressing a sequence of length T, the best schemes available in the literature achieve an O(T^-1/3) normalized distortion redundancy relative to finite reference classes of limited delay and limited memory, and the same redundancy is achievable, up to logarithmic factors, when the reference class is the set of scalar quantizers. It has also been shown that the distortion redundancy is at least of order T^-1/2 in the latter case, and the lower bound can easily be extended to sufficiently powerful (possibly finite) reference coding schemes. In this paper, we narrow the gap between the upper and lower bounds, and give a compression scheme whose normalized distortion redundancy is O(ln(T)/ T^1/2) relative to any finite class of reference schemes, only a logarithmic factor larger than the lower bound. The method is based on the recently introduced shrinking dartboard prediction algorithm, a variant of exponentially weighted average prediction. The algorithm is also extended to the problem of joint source-channel coding over a (known) stochastic noisy channel and to the case when side information is also available to the decoder (the Wyner–Ziv setting). The same improvements are obtained for these settings as in the case of a noiseless channel. Our method is also applied to the problem of zero-delay scalar quantization, where O(ln(T)/ T^1/2) normalized distortion redundancy is achieved relative to the (infinite) class of scalar quantizers of a given rate, almost achieving the known lower bound of order 1/ T^-1/2. The computationally efficient algorithms known for scalar quantization and the Wyner–Ziv setting carry over to our (improved) coding schemes presented in this paper

A lakosság fogyasztási kereslete és annak hatása a jóléti elemzésekre - háztartás-szintű becslés Magyarországon 1993 és 2001 között = The consumption demand of the population and its effect on welfare analyses - a household level estimation between 1993 and 2001 for Hungary

A kutatás során Magyarország esetére is megbecsültük azt a nemzetközi viszonylatban már általános gyakorlattá vált közgazdasági modellt, amely a fogyasztói magatartást írja le (QUAIDS). A modell becslése elméleti eredményekkel is szolgált, és jelenős lépés abba az irányba, hogy kialakuljon a gyakorlati eredmények alkalmazásának szakpolitika gyakorlata. Verifikáltuk, hogy a kvadratikus jövedelemhatás bevonása, mely az egyes javak luxus és szükségleticikk jellegét befolyásolja, igen sok esetben elengedhetetlen. Megmutattuk ugyanakkor, hogy a háztartási preferenciák modellezése ezt a szükségességet tompíthatja. Bemutattuk, hogy a háztartási fogyasztás mikroadatokra alapuló vizsgálata törvényszerűen vezet olyan eredményekre az egyes háztartások szintjén, ami ellentétes a modellezés alapjául szolgáló elmélettel. Az élelmiszer termékcsoport érzékenyen reagált más termékcsoportok összevonására és szétválására. Ez a viselkedés, illetve a saját termelésű fogyasztás jelentősége a teljes fogyasztási rendszerben az élelmiszerek különleges, kitünetett, részleteiben alaposabban vizsgálandó jellegére mutat. Ezek a felismerések további kutatás alapjai lehetnek. Az eredmények három alkalmazását mutattuk be. Számítottunk a modell alapján hasznosság-konzisztens megélhetési indexeket, kiadási egységeket (ekvivalencia-skálát). Felhasználtuk a modellt áremelkedés jóléti hatásának számításához. Ez utóbbi két alkalmazás különösen fontos a gyakorlati felhasználás terén. | In our research, we have estimated the economic model of consumer behaviour (QUAIDS), which has by now became an international standard. The modelling process has yielded some theoretical results and can be considered as a major step towards the policy application of the results. We have verified that the inclusion of quadratic income terms, controlling the goods? transition between being a luxury and a necessity, is indispensable in certain cases. At the same time we have shown that the detailed modelling of demographics can dampen this effect. We have demonstrated that analysis based on household-level microdata necessarily leads to results that are at odds with the assumptions of the corresponding theory. The share of food expenditures proved to be very sensitive to re-organisation of the expenditure groups. This behaviour and the overall great importance of consumption from own production points to a great importance of food demand. Both of these findings lead potentially to a future research. We have shown three applications based on the results. We have calculated theory-consistent cost of living indices, equivalence scales, and used the modelling results to calculate the welfare effect of price changes

Háztartási fogyasztói magatartás és jólét Magyarországon : Kísérlet egy modell adaptációjára

The outcome of the economic performance of individuals is utilised in the form of consumption and consequent welfare. Despite this truism, there is relatively little information available on household consumption behaviour in Hungary stemming from investigations based on economic theory. The study sets out to fill the gap with an estimate based on the now-basic demand model. The authors apply the results of the estimate to verifying the robustness of the theoretical assumptions and then show how this framework can be used to quantify the effects of price changes and to calculate household consumption units. Within limits, the model proves applicable to the situation in Hungary. The results are comparable to those in international literature. The most instructive finding in practice is the one obtained from the examination of welfare; the model can correct significantly the results obtainable from a naive estimate of the effect of price changes that ignores adjustment by consumers. Additionally, it can be concluded from the consumption unit calculations that applying the widely used equivalence scales in Hungary may lead to over-estimation of the relative income position of families with children, especially those with several children