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Search Results: 1 - 10 of 149911 matches for " H. Naoya "
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The Relationship between Beliefs in Cooperation, Motivation, and Engagement in Cooperative Learning  [PDF]
Takatoyo Umemoto, Naoya Yada
Psychology (PSYCH) , 2016, DOI: 10.4236/psych.2016.710135
Abstract: This study examined the relationship between beliefs in cooperation, motivation and engagement in cooperative learning. Beliefs in cooperation have three subscales: usefulness of cooperation, individual orientation and inequity. Self-reported questionnaire was administered to 181 undergraduate students at two universities. The results of path analysis indicated that usefulness of cooperation positively predicted self-efficacy and intrinsic value. Moreover, self-efficacy and intrinsic value positively predicted behavioral engagement, and intrinsic value positively predicted emotional engagement. On the other hand, individual orientation negatively predicted intrinsic value and inequity did not predict any motivational factors. The effects of beliefs in cooperation on cooperative learning process were discussed in light of the current findings.
Social Inequality and System-Justifying Function of Compensatory Judgments in Person Perception  [PDF]
Naoya Yada, Tomoko Ikegami
Psychology (PSYCH) , 2017, DOI: 10.4236/psych.2017.812130
Abstract: This study addressed the system-justifying function of compensatory judgments in person perception. We hypothesized that compensatory judgments of competence and warmth would create an illusion of equality, thereby fulfilling system-justifying motives in the economically unequal society. An experimental vignette study was conducted with 188 Japanese university students. Results indicated that evaluating target persons in a compensatory manner enhanced the perceived legitimacy of the current social system when participants were led to believe that a significant economic gap exists in Japan between the rich and the poor. This suggests that compensatory judgments serve to system justification through restoring the impaired belief in equality. We discussed the implications of our results for system justification theory and the literature on compensation effects in social judgments.
Optical Code Processing System, Device, and its Application
Naoya Wada
Journal of Networks , 2010, DOI: 10.4304/jnw.5.2.242-250
Abstract: Recent progress of optical code processing technology_ is explained. Ultra-high speed time domain, spectral domain, hybrid_ domain, and multiple optical code processing deices and systems are shown. As application of these technologies, OCDMA-PON, OPS network, and ultra high-speed optical clock generation will be demonstrated.
Generalized Empirical Likelihood-Based Focused Information Criterion and Model Averaging
Naoya Sueishi
Econometrics , 2013, DOI: 10.3390/econometrics1020141
Abstract: This paper develops model selection and averaging methods for moment restriction models. We first propose a focused information criterion based on the generalized empirical likelihood estimator. We address the issue of selecting an optimal model, rather than a correct model, for estimating a specific parameter of interest. Then, this study investigates a generalized empirical likelihood-based model averaging estimator that minimizes the asymptotic mean squared error. A simulation study suggests that our averaging estimator can be a useful alternative to existing post-selection estimators.
Solar Neutrinos: Hint for Neutrino Mass
Naoya Hata
Physics , 1994,
Abstract: The present status of the solar neutrino problem is reviewed. The strongest motivation for new neutrino physics comes from the complete phenomenological failure of astrophysical solutions: (1) The standard solar model is excluded by each of the solar neutrino experiments. (2) The combined results of Homestake and Kamiokande are incompatible with any astrophysical solution. (3) Even if the Homestake results were ignored entirely, there is no realistic solar model so far that describes the Kamiokande and gallium data simultaneously within their experimental uncertainties. On the other hand, the MSW solutions provide a complete description of the data, strongly hinting at the existence of mass and mixing of neutrinos. The MSW predictions for the future experiments are given in detail. It is stressed that solar model uncertainties are significant in determining the oscillation parameters and in making predictions for the future experiments. Especially, a $^8$B flux (or $S_{17}$) smaller by 20\% than that of the Bahcall-Pinsonneault model can make the interpretation of the charged to neutral current ratio measurement in SNO ambiguous.
Vacuum Oscillations and Future Solar Neutrino Experiments
Naoya Hata
Physics , 1994,
Abstract: Vacuum oscillations are considered for the combined solar neutrino observations, including the Kamiokande II spectrum data and incorporating theoretical uncertainties and their correlations. Despite the conceptual difficulty of the fine tuning between the neutrino parameters and the Sun-Earth distance, 2-flavor vacuum oscillations provide phenomenologically acceptable solutions. There are allowed regions at 99\% C.L. for $\Delta m^2 = (0.45 - 1.2) \times 10^{-10} \; \mbox{eV}\,^2$ and $\sin^22\theta = 0.6 - 1$; the best fit solution is $\chi^2 / \mbox{d.f.} = 19.2 / 16$, which is acceptable at 16\% C.L. Oscillations for sterile neutrinos are, however, excluded by the averaged data at 99.4\% C.L. The vacuum oscillation solutions predict characteristic energy spectrum distortions and seasonal variations in Sudbury Neutrino Observatory, Super-Kamiokande, and BOREXINO. Those predictions are given in detail, emphasizing that the vacuum solutions are distinguishable from the MSW solutions.
On the gap between an empirical distribution and an exponential distribution of waiting times for price changes in a financial market
Naoya Sazuka
Physics , 2006, DOI: 10.1016/j.physa.2006.10.094
Abstract: We analyze waiting times for price changes in a foreign currency exchange rate. Recent empirical studies of high frequency financial data support that trades in financial markets do not follow a Poisson process and the waiting times between trades are not exponentially distributed. Here we show that our data is well approximated by a Weibull distribution rather than an exponential distribution in a non-asymptotic regime. Moreover, we quantitatively evaluate how much an empirical data is far from an exponential distribution using a Weibull fit. Finally, we discuss a phase transition between a Weibull-law and a power-law in the asymptotic long waiting time regime.
Many-body effects on the resistivity of a multiorbital system beyond Landau's Fermi-liquid theory
Naoya Arakawa
Physics , 2015, DOI: 10.1142/S0217984915300057
Abstract: I review many-body effects on the resistivity of a multiorbital system beyond Landau's Fermi-liquid (FL) theory. Landau's FL theory succeeds in describing electronic properties of some correlated electron systems at low temperatures. However, the behaviors deviating from the temperature dependence in the FL, non-FL-like behaviors, emerge near a magnetic quantum-critical point. These indicate the importance of many-body effects beyond Landau's FL theory. Those effects in multiorbital systems have been little understood, although their understanding is important to deduce ubiquitous properties of correlated electron systems and characteristic properties of multiorbital systems. To improve this situation, I formulate the resistivity of a multiorbital Hubbard model using the extended \'{E}liashberg theory and adopt this method to the inplane resistivity of quasi-two-dimensional paramagnetic ruthenates in combination with the fluctuation-exchange approximation including the current vertex corrections arising from the self-energy and Maki-Thompson term. The results away from and near the antiferromagnetic quantum-critical point reproduce the temperature dependence observed in Sr$_{2}$RuO$_{4}$ and Sr$_{2}$Ru$_{0.075}$Ti$_{0.025}$O$_{4}$, respectively. I highlight the importance of not only the momentum and the temperature dependence of the damping of a quasiparticle but also its orbital dependence in discussing the resistivity of correlated electron systems.
Orbital-cooperative spin fluctuation and orbital-dependent transport in ruthenates
Naoya Arakawa
Physics , 2014, DOI: 10.1103/PhysRevB.90.245103
Abstract: Unusual transport properties deviating from the Fermi liquid are observed in ruthenates near a magnetic quantum-critical point (QCP). To understand the electronic properties of the ruthenates near and away from an antiferromagnetic (AF) QCP, I study the electronic structure and magnetic and transport properties for the $t_{2g}$-orbital Hubbard model on a square lattice in fluctuation-exchange approximation including Maki-Thompson (MT) current vertex correction (CVC). The results away from the AF QCP reproduce several experimental results of Sr$_{2}$RuO$_{4}$ qualitatively and provide new mechanisms about the enhancement of spin fluctuation at $Q_{\textrm{IC-AF}}\approx (0.66\pi,0.66\pi)$, larger mass enhancement of the $d_{xy}$ orbital than that of the $d_{xz/yz}$ orbital, and nonmonotonic temperature dependence of the Hall coefficient. Also, the results near the AF QCP explain the $T$-linear inplane resistivity in Sr$_{2}$Ru$_{0.075}$Ti$_{0.025}$O$_{4}$ and give an experimental test on the obtained temperature dependence of the Hall coefficient. I reveal spatial correlation including the self-energy of electrons beyond mean-field approximations is essential to determine the electronic properties of the ruthenates. I also show several ubiquitous transport properties near an AF QCP and characteristic transport properties of a multiorbital system by comparison with results of a single-orbital system near an AF QCP.
Microscopic theory on charge transports of a correlated multiorbital system
Naoya Arakawa
Physics , 2015,
Abstract: Current vertex correction (CVC), the back-flow-like correction to the current, comes from conservation laws, and the CVC due to electron correlation contains information about many-body effects. However, it has been little understood how the CVC due to electron correlation affects the charge transports of a correlated multiorbital system, although its considerable effects may be expected. To improve this situation, I studied the inplane resistivity, $\rho_{ab}$, and the Hall coefficient in the weak-field limit, $R_{\textrm{H}}$, for a $t_{2g}$-orbital Hubbard model on a square lattice in a paramagnetic state away from or near an antiferromagnetic (AF) quantum-critical point (QCP) besides the magnetic properties and the electronic structure in the fluctuation-exchange (FLEX) approximation with the CVCs arising from the self-energy, the Maki-Thompson (MT) irreducible four-point vertex function, and the main terms of the Aslamasov-Larkin (AL) one, and I found three main results about the CVCs. Those findings reveal several aspects of many-body effects on the charge transports of a correlated multiorbital system. I also showed the qualitative agreement with the experiments of Sr$_{2}$RuO$_{4}$ or Sr$_{2}$Ru$_{0.075}$Ti$_{0.025}$O$_{4}$ and remarked on several strong points of the present method compared with other theories.
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