著者

佐藤 一永 橋田 俊之

出版者

一般社団法人日本機械学会

雑誌

年次大会 : Mechanical Engineering Congress, Japan

巻号頁・発行日

vol.2013, pp."J061023-1"-"J061023-2", 2013-09-08

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The influence of uniaxial compressive stress on the oxygen ion and mixed conductivity of Zr_<0.82>Y_<0.18>O_<1.91>, Ce_<0.9>Gd_<0.1>O_<1.95-δ>,Yba_2Cu_3O_<7-δ>,and La_2NiO_<4+δ> were investigated by using AC 4 probe method under controlled oxygen partial pressure condition. The applied compressive stress was ranged from 0 Mpa to 350 MPa for these specimens in air at 600℃. In order to clarify the reason for the phenomenon of conductivity change, the mixed conductivity of Ce_<0.9>Gd_<0.1>O_<1.95-δ> for the application of stresses were measured under reducing conditions. The experimental result revealed that as the application compressive stress increases, the carrier concentration remain steady, whereas the mobility decreases. The conductivity was decreased with increasing compressive strain, this trend agreed with that of the simulation results. Therefore, the decrease of mobility was considered to be the reason for the decline conductivity under compressive strain/stress conditions.

著者

北川 哲平 福井 健一 佐藤 一永 水崎 純一郎 沼尾 正行

出版者

情報処理学会

雑誌

研究報告数理モデル化と問題解決(MPS) (ISSN:09196072)

巻号頁・発行日

vol.2010, no.25, pp.1-9, 2010-09-21

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複雑系において,事象過程の急激な遷移は潜在的に重要な相互作用の表れであるが,そのような事象の発生頻度は低い.本研究では,事象系列において比較的稀であるが,状態が遷移するときに共起する事象を抽出する Essential Event Extractor(E3) 法を提案した.E3 法では,自己組織化マップ (SOM) を符号化のためにベクトル量子化 (VQ) として,また共起グラフを生成するためにキーグラフを用いる.そして,VQ のトポロジーマップにおける発生密度推定を参照することで,共起グラフ上で事象遷移を得る.本論文では,燃料電池の損傷試験で観測されるAE事象系列に対して E3 法を適用し,燃料電池の損傷メカニズムを解明するために,有用な損傷事象系列を得た.Although sudden changes of the event phase in complex system may indicate potential essential forces, such events are rare. In the present paper, we propose an essential event extractor (E3) scheme to extract relatively rare but co-occurring event sequences in event transitions. In E3, the self-organizing map (SOM) is used as vector quantization (VQ) and KeyGraph as a co-occurrence graph. Afterwards, event transitions on the KeyGraph can be obtained by using occurrence density estimation on the topology map of VQ. We demonstrate the E3 using an acoustic emission (AE) event sequence observed during a damage test of fuel cells and obtain essential co-occurring damage sequences.