コウサ カテゴリー オ モチイタ ステレオ タイプ ノ カッセイカ ガ タイジン ニンチ ニ アタエル エイキョウ

A number of studies have shown that the activation of stereotypes affects subsequent information processing. Moreover, individuals typically belong to multiple categories at the same time and are evaluated differently depending on which category is focus of attention. The present study examined the effect of activation of stereotype dimensions on interpersonal perception and memory in the context of cross categorization. 　Eighty participated in the experiment. First, participants performed the cognitive tasks to activate either occupation or gender. They were asked to make some combinations between pictures of various vocations and names of the job in occupation-activation condition, and between pictures of boys and girls and male or female names in gender-activation condition. Next, after completing the distraction task, participants read one of the two vignettes. The vignette described one day of a male or female hairdresser. Thus there were four conditions as a whole（two kinds of activation by gender of the target）. Finally, participants rated the impression of the target and recalled the content of the vignette. 　When occupation dimension was activated, the impression and memory of the target was largely affected by the prototype of hairdresser, whereas in case of activating gender dimension, the impression and memory of the target was mainly based on the gender stereotype. Thus, the current study demonstrated that the activation of the category dimension influenced following interpersonal cognition even if neither specific stereotypes themselves nor stereotypical traits were activated. 　The results suggest the cognitive mechanism involved in processing information. Activating the category dimension leads to activation of the specific stereotype that applies to the target person, which in turn, directs perceivers’ attention to stereotypic traits or attributes and then has impact on their impression and memory. The present study showed that the impressions of the same person’s behavior were different according to which category dimension the judgment was based on

Synthesis of as-grown superconducting MgB_2 thin films by molecular beam epitaxy in UHV conditions

As-grown superconducting MgB_2 thin films have been grown on SrTiO_3(001), MgO(001), and Al_2O_3(0001) substrates by a molecular beam epitaxy (MBE) method with novel co-evaporation conditions of low deposition rate in ultra-high vacuum. The structural and physical properties of the films were studied by RHEED, XRD, electrical resistivity measurements, and SQUID magnetometer. The RHEED patterns indicate three-dimensional growth for MgB_2. The highest T_c determined by resistivity measurement was about 36K in these samples. And a clear Meissner effect below T_c was observed using magnetic susceptibility measurement. We will discuss the influence of B buffer layer on the structural and physical properties.Comment: 9 pages with 4 figures, ISS2003 proceedin

Transverse voltage in zero external magnetic fields, its scaling and violation of the time reversal symmetry in MgB2

The longitudinal and transverse voltages (resistances) have been measured for MgB$_2$ in zero external magnetic fields. Samples were prepared in the form of thin film and patterned into the usual Hall bar shape. In close vicinity of the critical temperature T$_c$ non-zero transverse resistance has been observed. Its dependence on the transport current has been also studied. New scaling between transverse and longitudinal resistivities has been observed in the form $\rho{_{xy}}\sim d\rho{_{xx}}/dT$. Several models for explanation of the observed transverse resistances and breaking of reciprocity theorem are discussed. One of the most promising explanation is based on the idea of time-reversal symmetry violation

Ultrathin MgB2 films fabricated on Al2O3 substrate by hybrid physical-chemical vapor deposition with high Tc and Jc

Ultrathin MgB2 superconducting films with a thickness down to 7.5 nm are epitaxially grown on (0001) Al2O3 substrate by hybrid physical-chemical vapor deposition method. The films are phase-pure, oxidation-free and continuous. The 7.5 nm thin film shows a Tc(0) of 34 K, which is so far the highest Tc(0) reported in MgB2 with the same thickness. The critical current density of ultrathin MgB2 films below 10 nm is demonstrated for the first time as Jc ~ 10^6 A cm^{-2} for the above 7.5 nm sample at 16 K. Our results reveal the excellent superconducting properties of ultrathin MgB2 films with thicknesses between 7.5 and 40 nm on Al2O3 substrate.Comment: 7 pages, 4 figures, 2 table

Higher harmonics of ac voltage response in narrow strips of YBa2Cu3O7 thin films: Evidence for strong thermal fluctuations

We report on measurements of higher harmonics of the ac voltage response in strips of YBa2Cu3O7 thin films as a function of temperature, frequency and ac current amplitude. The third (fifth) harmonic of the local voltage is found to exhibit a negative (positive) peak at the superconducting transition temperature and their amplitudes are closely related to the slope (derivative) of the first (Ohmic) harmonic. The peaks practically do not depend on frequency and no even (second or fourth) harmonics are detected. The observed data can be interpreted in terms of ac current induced thermal modulation of the sample temperature added to strong thermally activated fluctuations in the transition region.Comment: 9 pages, 4 figures (PDF file

Observation of Individual Josephson Vortices in YBCO Bicrystal Grain-boundary Junctions

The response of YBCO bicrystal grain-boundary junctions to small dc magnetic fields (0 - 10 Oe) has been probed with a low-power microwave (rf) signal of 4.4 GHz in a microwave-resonator setup. Peaks in the microwave loss at certain dc magnetic fields are observed that result from individual Josephson vortices penetrating into the grain-boundary junctions under study. The system is modeled as a long Josephson junction described by the sine-Gordon equation with the appropriate boundary conditions. Excellent quantitative agreement between the experimental data and the model has been obtained. Hysteresis effect of dc magnetic field is also studied and the results of measurement and calculation are compared.Comment: 11 pages, 4 figure

Systematic characterization of upper critical fields for MgB2_2 thin films using the two-band superconducting theory

We present experimental results of the upper critical fields $H_{\rm c2}$ of various MgB$_2$ thin films prepared by the molecular beam epitaxy, multiple-targets sputtering, and co-evaporation deposition apparatus. Experimental data of the $H_{\rm c2}(T)$ are successfully analyzed by applying the Gurevich theory of dirty two-band superconductivity in the case of $D_{\pi}/D_{\sigma}>1$, where $D_{\pi}$ and $D_{\sigma}$ are the intraband electron diffusivities for $\pi$ and $\sigma$ bands, respectively. We find that the parameters obtained from the analysis are strongly correlated to the superconducting transition temperature $T_{\rm c}$ of the films. We also discuss the anormalous narrowing of the transition width at intermediate temperatures confirmed by the magnetoresistance measurements.Comment: 7 pages, 7 figures, submitted to Phys. Rev.

コストノヘンドウスルグラフニオケルケイロタンサクシュホウ:AntNetノテキヨウトカイリョウ

本研究ではテーマパークやイベント会場において経路決定の支援を行うシステムを構築することを最終目標とし、その部分問題であるコストの変動する重み付きグラフにおける経路探索問題に対して、AntNetを適用した。AntNetとは蟻コロニー最適化の考えを応用して提案された経路探索手法である。AntNetのアルゴリズムは、複数の蟻が以下のステップを任意の回数まで繰り返す。まず、蟻が始点から目的頂点までフェロモンを参照しながら、確率的に経路を選択していく。次に、完成した経路の評価に応じてフェロモンを分泌する。実験の結果、AntNetはグラフの規模が大きくなるほど、探索時間の面で有効であることを示した。しかし、コストの変動間隔が長い場合に、フェロモンの過成熟によって経路が固定されてしまい、解の精度が下がってしまう問題が明らかになった。そこで、この問題を解決するために、フェロモンの過成熟を防ぐことで解の精度を上げる手法を提案し、その評価を行った。結果として、実験を行った環境においては解精度が通常のAntNetによる探索と比較して3.89倍の精度と非常に良い結果が得られることを示したIn this research, we applied AntNet to shortest path problems in weighted graphs with weight changes. AntNet is a previously proposed method applying ant colony optimization. In the AntNet algorithm multiple ants repeat the following steps. First, each ant selects a path stochastically while referring to pheromone values from the source vertex to destination vertex. Next, pheromone is secreted according to the evaluation of each completed route. Through experiment it was verified that AntNet showed strong advantage over compared methods in calculation time for very large graphs. On the other hand, when the time interval between weight changes is extended, over-maturation of pheromone trails caused the search route to be fixed, leading to an increase in error. In order to overcome this problem, a new method to improve the accuracy by preventing over-maturation was proposed. It was verified by experiment that under the same conditions, the proposed method showed approximately 3.89 times search accuracy compared to normal AntNet