{"created":"2023-06-19T10:29:53.195176+00:00","id":9953,"links":{},"metadata":{"_buckets":{"deposit":"c7482317-2ac8-402b-9343-2fa11f574b0f"},"_deposit":{"created_by":18,"id":"9953","owners":[18],"pid":{"revision_id":0,"type":"depid","value":"9953"},"status":"published"},"_oai":{"id":"oai:muroran-it.repo.nii.ac.jp:00009953","sets":["41:227"]},"author_link":["56148"],"item_81_date_granted_17":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2019-03-25"}]},"item_81_degree_grantor_10":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_language":"ja","subitem_degreegrantor_name":"室蘭工業大学"},{"subitem_degreegrantor_language":"en","subitem_degreegrantor_name":"Muroran Institute of Technology"}],"subitem_degreegrantor_identifier":[{"subitem_degreegrantor_identifier_name":"10103","subitem_degreegrantor_identifier_scheme":"kakenhi"}]}]},"item_81_degree_name_11":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士（工学）","subitem_degreename_language":"ja"}]},"item_81_description_25":{"attribute_name":"フォーマット","attribute_value_mlt":[{"subitem_description":"application/pdf","subitem_description_type":"Other"}]},"item_81_description_7":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Polarization sensors have attracted attention and been researched as they can be constructed with a very simple experimental setup. They utilize the polarization characteristic of light propagating in an optical fiber and determine the strain, stress, pressure, etc. from changes in the polarization state of light propagating in a single-mode optical fiber when the sensor is affected by external factors. However, in previous research, the use of either Hi-Bi fiber or polarization maintaining fiber made the cost of the sensor system very high and operate difficultly. In this work, we present a polarization sensor system that determine strains by measuring changes in polarization state in a single-mode fiber which are commercially available inexpensive fibers. This greatly reduces the cost of the sensor system. In the experiment, we use the fiber wound in a coil shape as a sensor. When strains are applied, the sensor is rotated by the invar wire that is attached to the sensor. Strains applied in the experiment can be determined from the measured polarization states when the sensor rotates. In addition, we propose to calculate an arbitrary optical path using the Jones matrices of two rotated wave plates. The calculated polarization states obtained using the proposed method are in good agreement with the measured values, which demonstrated the feasibility of the proposed method. Therefore, when two Jones matrices representing the optical path are obtained, the polarization state of the transmitted light can be calculated from that of the reflected light on this optical path and vice versa. Also, the strains applied in experiment are in good agreement with the calculated ones. These all verified the feasibility of the strain sensor system developed in this work. Therefore, when the object (building, slope, etc.) connected to the other end of invar wire is deformed, the strain amount can be obtained by this method. However, when a multipoint measurement is performed by connecting sensors in series, the size of the experimental data becomes enormous and it will become very difficult to use function fitting for data processing. Taking that problem into account, we performed data processing using a 3-layer feedforward neural network. The experimental data are used as training data for learning, that is, we take the measured polarization state as the input and the rotation angle of the sensor as the output for training the neural network. In addition, to test the trained neural network, we provided a newly measured polarization state to the trained network. The output of the trained network, namely, the rotation angle of the sensor, is almost the same as that applied in experiment that generated the test data. These results demonstrate the feasibility of both the sensor system and the data processing methods proposed in the study.","subitem_description_language":"en","subitem_description_type":"Abstract"},{"subitem_description":"近年、自然災害の発生に伴い、建物の構造や変形、山間部の崩落などを観察することが急務となっている。光ファイバセンサは、小型軽量、耐電磁誘導性、耐腐食性、防爆性などの利点を有するため、インフラインの監視分野の技術として積極的に研究されている。多くの種類の光ファイバセンサの中で、偏光光ファイバセンサは、単純な構造で構築することができるので、私たちは偏光光ファイバセンサを歪みセンサとして研究を行っている。偏光光ファイバセンサは、センサが外部から影響を受けると、光ファイバ中を伝搬する光の偏光状態の変化から外部の影響を測定する。しかし、これまでの研究では、高複屈折率ファイバまたは偏波面保存ファイバを使用するため、センサシステムのコストが非常に高く、操作も困難になっている。本研究では、小型で低コストの偏光歪みセンサシステムを開発している。実験では、市販の安価なシングルモード光ファイバをコイル状に巻いてセンサとして使用されるため、従来の偏光光ファイバセンサと比べ、値段が安くなった。実験では、歪みが加えられると、センサは取り付けられたインバーワイヤによって回転される。センサを回転させるときにセンサの後ろに接続された反射鏡から反射された光の偏光状態の変化を測定する。測定された偏光状態の変化から加わった歪みを求めることができる。従って、インバーワイヤの他端に接続された対象物（建物や斜面など）が変形した場合、この方法で歪み量を求めることができる。さらに、本研究で開発したセンサシステムは、外部温度変化の影響を受けず、温度補償を必要としない。また、二つの回転した波長板のジョーンズ行列を用いて任意の光路を計算することを提案し、その実現可能性は実験結果により実証された。偏光状態の測定値は、ジョーンズ行列を用いて得られた計算値とよく一致する。さらに、計算された偏光状態を用いて得られた歪みは、実験で加わった歪みと一致している。しかし、センサを直列に接続して多点測定を行うと、実験データのサイズが膨大になり、データ処理のための関数フィッティングを行うことが非常に困難になる。この問題を考慮して、ニューラルネットワークを用いてデータ処理を行った。入力層、中間層と出力層からなる3層のフィードフォワードニューラルネットワークを使用した。学習は、学習データとして実験データを用いて設計されたネットワークを訓練することによって行われた。さらに、訓練されたネットワークを使用してテストデータに対して得られた出力は、テストデータとして使用された実験データとよく一致している。これらの結果は、本研究で開発したセンサシステムとデータ処理方法の実現可能性を実証している。","subitem_description_language":"ja","subitem_description_type":"Abstract"}]},"item_81_dissertation_number_13":{"attribute_name":"学位授与番号","attribute_value_mlt":[{"subitem_dissertationnumber":"甲第428号"}]},"item_81_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15118/00009901","subitem_identifier_reg_type":"JaLC"}]},"item_81_subject_9":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"512","subitem_subject_scheme":"NDC"}]},"item_81_text_12":{"attribute_name":"学位の種別","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"課程博士"}]},"item_81_text_14":{"attribute_name":"報告番号","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"甲第428号"}]},"item_81_text_15":{"attribute_name":"学位記番号","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"博甲第428号"}]},"item_81_text_16":{"attribute_name":"研究科・専攻","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"工学専攻"}]},"item_81_version_type_24":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_access_right":{"attribute_name":"アクセス権","attribute_value_mlt":[{"subitem_access_right":"open 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optical fiber strain sensor system based on Jones calculus and neural networks","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Study on polarization optical fiber strain sensor system based on Jones calculus and neural networks","subitem_title_language":"en"},{"subitem_title":"ジョーンズ計算法とニューラルネットワークを用いた偏光光ファイバ歪みセンサシステムに関する研究","subitem_title_language":"ja"}]},"item_type_id":"81","owner":"18","path":["227"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2019-06-25"},"publish_date":"2019-06-25","publish_status":"0","recid":"9953","relation_version_is_last":true,"title":["Study on polarization optical fiber strain sensor system based on Jones calculus and neural networks"],"weko_creator_id":"18","weko_shared_id":-1},"updated":"2024-01-22T02:41:20.179375+00:00"}