We examine the range of anonymity that is compatible with a Paretian social welfare relation (SWR) on infinite utility streams. Three alternative coherence properties of an SWR are considered, namely, acyclicity, quasi-transitivity, and Suzumura consistency. For each case, we show that a necessary and sufficient condition for a set of permutations to be the set of permissible permutations of some Paretian SWR is given by the cyclicity of permutations and a weakening of group structure. Further, for each case of coherence (...) property, we show that the extended Pareto rule is the least element of the class of anonymous Paretian SWRs. (shrink)

日本人はグローバル化の潮流といかに向き合うべきなのか―そのヒントは「国学」にあった。先人たちが葛藤した問いのなかを私たちはいまも生きている。.

The recent renewed interest in the foundation of quantum statistical mechanics and in the dynamics of isolated quantum systems has led to a revival of the old approach by von Neumann to investigate the problem of thermalization only in terms of quantum dynamics in an isolated system [1, 2]. It has been demonstrated in some general or concrete settings that a pure initial state evolving under quantum dynamics indeed approaches an equilibrium state [3–9]. The underlying idea that a single pure (...) quantum state can fully describe thermal equilibrium has also become much more concrete [10–12]. (shrink)

Discovery of representative Web pages regarding specific topics is important for assisting users' information retrieval from the Web. Researches on Web structure mining, whose goals are to discover or to rank important Web pages based on the graph structure of hyperlinks, have been very active recently. A complete bipartite of Web graph, which is composed of centers (containing useful information regarding specific topic) and fans (containing hyperlinks to centers), can be regarded as a Web community sharing a common interest. Although (...) Murata's method for discovering Web communities is a simple method for finding related Web pages, it has the following weaknesses: (1) since the number of centers increases monotonously, pages irrelevant to the members of Web communities may be added in the process of discovery, and (2) since the number of fans decreases monotonously according as the number of centers increases, the method may suffer topic drift. This paper describes an improved method for refining Web communities in order to acquire representative Web pages of the topics of input Web communities. The method is based on the assumption that most of the fans contain hyperlinks pointing to representative pages regarding their topic, and that hyperlinks to the pages of the same quality often co-occur. In our new method, both fans and centers are renewed iteratively by the result of the majority vote of the members of previous Web community. Results of our experiments show that the new method has abilities of finding desirable pages for several topics. (shrink)

This paper proposes a method for discovering Web communities. A complete bipartite graph K i, j of Web pages can be regarded as a community sharing a common interest. Discovery of such community is expected to assist users’ information retrieval from the Web. The method proposed in this paper is based on the assumption that hyperlinks to related Web pages often co-occur. Relations of Web pages are detected by the co-occurrence of hyperlinks on the pages which are acquired from a (...) search engine by backlink search. In order to find a new member of a Web community, all the hyperlinks contained in the acquired pages are extracted. A page which is pointed by the most frequent hyperlinks is regarded as a new member of the community. We have build a system which discovers complete bipartite graphs based on the method. Only from a few URLs of initial community members, the system succeeds in discovering several genres of Web communities without analyzing the contents of Web pages. (shrink)

We study the problem of the approach to equilibrium in a macroscopic quantum system in an abstract setting. We prove that, for a typical choice of “nonequilibrium subspace”, any initial state (from the energy shell) thermalizes, and in fact does so very quickly, on the order of the Boltzmann time τ B := h/(k B T ). This apparently unrealistic, but mathematically rigorous, conclusion has the important physical implication that the moderately slow decay observed in reality is not typical in (...) the present setting. (shrink)

It is shown that the application of the Lax-Phillips scattering theory to quantum mechanics provides a natural framework for the realization of the ideas of the “Many-Hilbert-Space” theory of Machida and Namiki to describe the development of decoherence in the process of measurement. We show that if the quantum mechanical evolution is pointwise in time, then decoherence occurs only if the Hamiltonian is time-dependent. If the evolution is not pointwise in time (as in Liouville space), then the decoherence may occur (...) even for closed systems. These conclusions apply as well to the general problem of mixing of states. (shrink)

Le présent article a pour but de proposer une méthode de constitution de corpus pour transcrire les traits tant prosodiques que gestuels, qui avaient été peu pris en compte jusqu’à présent. Comme constitutifs du corpus, les aspects formels et kinésiques de l’activité gestuelle, ainsi que le rapport temporel et fonctionnel entre geste et discours sont expliqués, afin de mieux appréhender l’organisation du discours et de l’interaction. A titre d’exemple, une thématisation est analysée.

Le présent article a pour but de proposer une méthode de constitution de corpus pour transcrire les traits tant prosodiques que gestuels, qui avaient été peu pris en compte jusqu’à présent. Comme constitutifs du corpus, les aspects formels et kinésiques de l’activité gestuelle, ainsi que le rapport temporel et fonctionnel entre geste et discours sont expliqués, afin de mieux appréhender l’organisation du discours et de l’interaction. A titre d’exemple, une thématisation est analysée.

明治維新を支えた志士たちは、儒教を行動の指針としていた。尊王攘夷という中国からの思想は、やがて日本中心主義へと置き変わる。.

Virtual reality (VR) through a head-mounted display (HMD) can provide new experiences. However, it remains unclear how the characteristics of HMDs affect users’ memory. To use HMDs more effectively and appropriately in several applied fields, including education, it is necessary to clarify what characteristics of HMDs affect users’ memory. A head-tracking function mounted on an HMD helps to detect the user’s head direction to enable a simulation experience akin to the real world. When we experience a simulation on an HMD, (...) we actively perceive the visual world. In this study, we assessed how active/passive viewing affects users’ memory of VR content. We conducted a psychological experiment in which participants watched a movie on an HMD. In the active viewing condition, the presented view changed depending on the participant’s head direction. In the passive viewing condition, the presented view was a recorded movie that was shown to the participants in the active viewing condition. All participants took a memory test about the content presented in the movie on the day of viewing and two weeks later. The results showed that performance on the memory test in the active viewing condition was significantly lower than that in the passive viewing condition after two weeks. This result indicated that active viewing in VR inhibited users’ memory compared to passive viewing. The current study contributes to the development of new VR techniques, such as educational learning. (shrink)

Let H be a proof system for quantified propositional calculus (QPC). We define the Σqj-witnessing problem for H to be: given a prenex Σqj-formula A, an H-proof of A, and a truth assignment to the free variables in A, find a witness for the outermost existential quantifiers in A. We point out that the Σq1-witnessing problems for the systems G*1and G1 are complete for polynomial time and PLS (polynomial local search), respectively. We introduce and study the systems G*0 and G0, (...) in which cuts are restricted to quantifier-free formulas, and prove that the Σqj-witnessing problem for each is complete for NC1. Our proof involves proving a polynomial time version of Gentzen’s midsequent theorem for G*0 and proving that G0-proofs are TC0-recognizable. We also introduce QPC systems for TC0 and prove witnessing theorems for them. We introduce a finitely axiomatizable second-order system VNC1 of bounded arithmetic which we prove isomorphic to Arai’s first order theory AID + Σb0-CA for uniform NC1. We describe simple translations of VNC1 proofs of all bounded theorems to polynomial size families of G*0 proofs. From this and the above theorem we get alternative proofs of the NC1 witnessing theorems for VNC1 and AID. (shrink)

This paper reports the results of questionnaire-based research conducted at an exhibition of interactive humanoid robots that was held at the Osaka Science Museum, Japan. The aim of this exhibition was to investigate the feasibility of communication robots connected to a ubiquitous sensor network, under the assumption that these robots will be practically used in daily life in the not-so-distant future. More than 90,000 people visited the exhibition. A questionnaire was given to the visitors to explore their opinions of the (...) robots. Statistical analysis was done on the data of 2,301 respondents. It was found that the visitors’ opinions varied according to age; younger visitors did not necessarily like the robots more than elderly visitors; positive evaluation of the robots did not necessarily conflict with negative evaluations such as anxiety; there was no gender difference; and there was almost no correlation between opinions and the length of time spent near the robots. (shrink)

あらゆるものごとを平準化する「デジタル化」の中で、人間の身体・脳・心や社会のしくみがいま大きく変容しつつある。「国民の欲望」の自己統治、新たな共同関係の創出、リスクをめぐる正義の対立の調整、人間観・存 在観の再構築。これらの課題群に対して、健康とエンハンスメント、脳と人格の改造、動物とロボットの境界、リスク言説と研究規制の根拠等を論じながら、システム倫理学の視点から大胆な解法を提示する。.

In recent papers the authors have discussed the dynamical properties of “large Poincaré systems” (LPS), that is, nonintegrable systems with a continuous spectrum (both classical and quantum). An interesting example of LPS is given by the Friedrichs model of field theory. As is well known, perturbation methods analytic in the coupling constant diverge because of resonant denominators. We show that this Poincaré “catastrophe” can be eliminated by a natural time ordering of the dynamical states. We obtain then a dynamical theory (...) which incorporates a privileged direction of time (and therefore the second law of thermodynamics). However, it is only in very simple situations that this time ordering can be performed in an “extended” Hilbert space. In general, we need to go to the Liouville space (superspace) and introduce a time ordering of dynamical states according to the number of particles involved in correlations. This leads then to a generalization of quantum mechanics in which the usual Heisenberg's eigenvalue problem is replaced by a complex eigenvalue problem in the Liouville space. (shrink)

Short-term motor practice leads to plasticity in the primary motor cortex. The purpose of this study is to investigate the factors that determine the increase in corticospinal tract excitability after motor practice, with special focus on two factors; “the level of muscle activity” and “the presence/absence of a goal of keeping the activity level constant.” Fifteen healthy subjects performed four types of rapid thumb adduction in separate sessions. In the “comfortable task” and “forceful task”, the subjects adducted their thumb using (...) comfortable and strong forces. In the “comfortable with a goal task” and “forceful with a goal task”, subjects controlled the muscle activity at the same level as in the C and F, respectively, by adjusting the peak electromyographic amplitude within the target ranges. Paired associative stimulation, which combines peripheral nerve stimulation and transcranial magnetic stimulation, with an inter-stimulus interval of 25 ms was also done. Before and after the motor tasks and PAS25, TMS was applied to the M1. None of the four tasks showed any temporary changes in behavior, meaning no learning occurred. Motor-evoked potential amplitude increased only after the FG and it exhibited a positive correlation with the MEP increase after PAS25, suggesting that FG and PAS25 share at least similar plasticity mechanisms in the M1. Resting motor threshold decreased only after FG, suggesting that FG would also be associated with the membrane depolarization of M1 neurons. These results suggest task-dependent plasticity from the synergistic effect of forceful muscle activity and of setting a goal of keeping the activity level constant. (shrink)

Since the inception of modern approaches to grammar, Japanese ga has been treated as a marker indicating the grammatical relation `subject.' If this is an accurate characterization of ga, then we would expect ga to occur to mark a grammatical category consisting of `A' and `S'. Our examination of the contexts in which ga is actually used in everyday Japanese conversations shows that this expectation is not borne out. Our findings suggest that it is not appropriate to describe ga in (...) terms of a grammatical relation such as `subject', and that ga may be much less a grammatical marker than a discourse-pragmatic one. (shrink)