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地球温暖化に伴う気候変動が積雪寒冷地の水環境に及ぼす影響の定量評価手法の研究
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdf地球温暖化に伴う気候変動の影響は既に顕在化しており，降雪・積雪・融雪に大きく依存する積雪寒冷地の水環境や生態系ではより強い影響を受ける．気温上昇に伴う水温上昇，植物プランクトン異常増殖頻度の増加等が顕著となり，内水面漁業等の地域経済に影響が及ぶことが懸念される．気候変動が及ぼす影響は，温室効果ガスの排出削減等の「緩和策」を最大限実施しても完全に避けられず，影響に備えるための「適応策」の実施が重要となっている．しかしながら，気候変動による影響は地域の特性によって大きく異なるため，市町村等の地域レベルで気候変動の影響リスクを評価することが課題である．そこで本研究は，気候変動に対する地域レベルでの「適応策」立案に資することを目的として，既に脆弱性を有する積雪寒冷地の汽水湖及び河川環境を対象に，まず1つ目として，地域レベルの変動特性を把握可能な気候変動予測データの高解像度化手法を構築し，次に2つ目として，湖沼環境における水質解析モデルを構築し，水質変化の観点から気候変動の影響を定量的に評価し，最後に3つ目として，河川水温を推定可能な解析モデルを構築し，水温変化と冷水性魚類の生息環境の観点から気候変動の影響を定量的に評価した．具体的な研究内容として，統計的ダウンスケーリングによる高解像度気候変動予測データの推定では，バイアス補正を適用した統計的ダウンスケーリング手法を構築し，地域気候モデルMRI-NHRCM20の気候変動予測データを解像度1kmへ細分化した．観測値との比較によりバイアス補正の妥当性を検証するとともに，気候変動に伴う水文特性を分析した．次に，積雪寒冷地汽水湖の水環境変化の分析では，水質解析モデルを構築してシミュレーションを行い，気候変動に対する水質特性及び既に顕在化しているアオコの発生頻度増加のリスクについて検証した．最後に，積雪寒冷地河川の水温変化と冷水性魚類の生息環境に対する影響の分析では，河川流量と水温の積による熱フラックスの河道追跡モデルを構築し，気候変動に対する水温特性及び水温が上昇した場合のイトウHucho perryi，サクラマス（ヤマメ）Oncorhynchus masouの生息に最適な水温域の変化について検証した．以上より，本論文は，積雪寒冷地の地域レベルにおける気候変動の影響を水環境の観点から定量的に評価する上で有効な手法を提示するものである．気候変動に対する地域レベルでの水環境管理や生態系保全のあり方を検討し，地域に根差した効果的・効率的な「適応策」を立案する上で非常に有益であり，本論文の社会的意義は極めて高いと考える．The water environment has been strongly affected by climate change in snowy cold regions. The effects of climate change is inevitable, even if mitigation plans for greenhouse gas reduction are implemented. It is necessary to evaluate quantitatively the effects of climate change on the water environment to formulate adaptation plans in snowy cold regions. Therefore, in this research, I first estimated high-resolution data that can predict meteorological characteristics with climate change in snowy cold regions. Secondly, I quantitatively evaluated the future change of water quality in brackish lake, water temperature and the impact on cold water fish habitat in snowy cold river. Present climate data in MRI-NHRCM20 with spatial resolution of 20km was reliably modified by the bias correction scheme using DSJRA-55, which is regional downscaling data with spatial resolution of 5km resulting from the observation data. Then, by applying the statistical downscaling method based on a spatial interpolation, high resolution climate information with spatial resolution of 1km became available. In Lake Abashiri, which is brackish lake in Eastern Hokkaido, blue tide and blue-green algae occur frequently from the mid 1970's. These obstacles in water quality have big influence on natural environments in Lake Abashiri. For the water quality simulation with climate change, the analysis model was constructed that considered fluid movement and advective diffusion of water temperature and water quality. The results of water quality simulation indicated that climate change is expected to raise brackish lake surface temperature by approximately 4°C and increase salinity of surface of the lake by approximately 1psu during blue-green algae developmental period. Sorachi River, which is snowy cold river in Hokkaido, has suitable habitat for salmonid fish, such as Hucho perryi and Oncorhynchus masou. Hucho perryi is designated as an endangered fish and the impact of raising water temperature with climate change is concerned. For the river water temperature simulation with climate change, the analysis model was constructed that based on channel tracking of heat flux. The results of river water temperature simulation indicated that climate change is expected to raise river water temperature by approximately 4.7℃ in March, also river water temperature area suitable for spawning of Hucho perryi might be limited. In the future, the quantitative evaluation method will be used for formulating effective and efficient adaptation plans based on characteristics of snowy cold regions. The analysis model will be further developed for evaluating the influence of climate change accurately and the water environmental management.doctoral thesi
A study on self-heating characteristics of carbonized sewage sludge and technologies to control it
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdf下水汚泥は，他のバイオマスと比較して量・質ともに年間を通して安定しており，収集や運搬についても既存の都市インフラを活用できる等，メリットの多い純国産のバイオマスである。下水汚泥の燃料利用については，2012年度頃より普及が進んでおり，政策的にもさらに後押しする大きな流れが形成されつつある。一方で，RDFに代表される廃棄物由来の固形燃料の自己発熱性に起因して，重大な火災・爆発事故につながるケースが顕在化しており，その特性を十分に理解し，対策につなげることが求められている。本来廃棄物である下水汚泥から製造した炭化物（以下，下水汚泥炭化物という）は，下水汚泥特有の不快臭が軽減され，性状が石炭に近いため，石炭代替燃料として利用しやすい。しかし，下水汚泥には人間活動に伴って排出される成分や，下水処理場の処理工程で添加される薬剤が含まれる等，石炭と同列に自己発熱性を評価することはできない。石炭においても，自己発熱のメカニズムが全て明らかになっているわけではないことを勘案すると，下水汚泥炭化物の自己発熱性について個別に十分な検証が必要である。本研究では，下水汚泥炭化物の性状と自己発熱性の関係を明らかにし，実際に下水汚泥炭化物を製造する商用プラントを対象として，適用可能な自己発熱性抑制技術について検討するとともに，下水汚泥炭化物の自己発熱性を従来手法よりも簡便に評価可能な試験方法を開発することを目的とした。本論文の構成は以下の通りである。第1章では，本研究の背景ならびに目的について述べている。第2章では，下水汚泥炭化物について，炭化度と炭化物性状の関係（炭化特性）を明らかにするとともに，石炭との比較を行い，固形燃料としてのポテンシャルについて論述した。また，炭化度と自己発熱性の関係，鉄化合物含有率と自己発熱性の関係について検証した。第3章では，下水処理場の処理工程で広く使用されている薬剤であるポリ硫酸第二鉄に注目し，自己発熱性へ与える影響について検証した。鉄化合物の酸化反応による発熱挙動については，TG-DTAによる測定にて確認した。また，酸化反応に寄与する鉄化合物を特定するため，大型放射光施設（SPring-8）を用いたXAFS測定ならびにXRDによる鉄化合物の形態解析を行った。第4章では，下水汚泥炭化物を製造する商用プラントに適用可能な自己発熱性抑制技術の検討を行った。検討した技術は大きく分けて「炭化物の搬送過程における強制酸化」と「炭化物の貯留過程における強制酸化」の2種類である。第5章では，自己発熱性の試験方法に関して従来の試験方法では試験期間約3日間試料量約8Lが必要であり，日常管理に取り込みにくいという課題があったことから，従来方式よりも短期間かつ少量の試料量で評価できる試験手法の開発を行った。そして，以上で得られた成果を第6章にて総括している。Sewage sludge is a biomass expected to be utilized as energy source, but due to its moisture and odor it is difficult to utilize as it is. Carbonization technology makes sewage sludge similar to coal and remove odor, so it becomes easier to utilize as fuel. On the other hand, carbonized sewage sludge has self-heating characteristics like coal, so it is important to understand its characteristics and deal with carefully. In this study, properties of carbonized sewage sludge and self-heating characteristics were measured, and the relationships between them were revealed. And technologies to control self-heating characteristics were examined for commercial plants that actually produce carbonized sewage sludge. In addition, a test method that can evaluate self-heating characteristics of carbonized sewage sludge more easily than conventional methods was developed. The structure of this thesis is as follows. Chapter 1 describes the background and objectives of this study. Chapter 2 revealed the relationships between degree of carbonization and properties of carbonized sewage sludge, and potential as a solid fuel was discussed compared with coal. And the relationships between self-heating characteristics and degree of carbonization, iron compound content were verified. Chapter 3 focused on poly ferric sulfate that is one of the chemicals widely used in sewage treatment plants, and the influence of poly ferric sulfate on self-heating characteristics was examined. Thermal behavior of iron compounds due to low temperature oxidation was measured by TG-DTA. In order to identify the iron compounds causing low temperature oxidation, elemental speciation of iron compounds was conducted by XAFS and XRD. In Chapter 4, technologies to control self-heating characteristics for commercial plants that actually produce carbonized sewage sludge were examined. Examined technologies are roughly divided into two types: "forced oxidation in transport process" and "forced oxidation in storage process". In Chapter 5, a test method that can evaluate self-heating characteristics of carbonized sewage sludge more easily than conventional methods was developed. Because the developed method reduced test period and sample volume, it has become easier to apply to daily management. Chapter 6 summarizes the results obtained through all chapters.doctoral thesi
細菌ロドプシン類タンパク質の生物物理学的研究
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdfMicrobial rhodopsins are typical membrane proteins with seven transmembrane alpha-helices (helices A-G). This type of protein has a retinal molecule as the chromophore. The microbial rhodopsins use the retinal chromophore attached at a conserved lysine residue to absorb photons for light-energy conversion and light-signal transduction. The molecular mechanisms of microbial rhodopsins have been discussed at the individual amino acid level. In this study, we have prepared amino acid replaced mutants for sensory rhodopsin II from Halobacterium salinarum (HsSRII), and archaerhodopsin discovered by our group from salt lake in Inner Mongolia of China (HeAR). Their photochemical properties were studied by flash photolysis and the the function of amino acids which have been not reported until now was clarified. HsSRII is a negative phototaxis receptor, which makes bacterium avoid blue-green light. In this study. The amino acid replaced mutants of aspartic acid 103 (D103) of HsSRII were prepared and analyzed with flash photolysis. Aspartic acid 103 of HsSRII corresponds to D115 of bacteriorhodopsin (BR). This amino acid residue D115 is functionally important in BR. Aspartic acid D103 were replaced with asparagine (D103N) or glutamic acid (D103E). The work revealed that a substitution of D103 with asparagine (D103N) or glutamic acid (D103E) can resulted in large changes in HsSRII photocycle. These alterations include acceleration of the decay of the M intermediate, prolonging the lifetime of intermediates in the later part of photocycle, and appearance of a long-lived shorter-wavelength photoproduct. Thus, D103 of HsSRII may play an important role in regulation of the photocycle of HsSRII. HeAR is a light driven outward proton pump like to BR. All key functional amino acid residues for proton pump of BR are conserved in HeAR. In the present work, we payed attention to amino acids which are only conserved in ARs, prepared the mutants T164A, S165A and T164A/S165A (T164 and/or S165 were replaced with an alanine) and analyzed the photocycles of the mutants with flash photolysis. The amino acid replacements caused profound changes to the photocycle of HeAR including acceleration of the decay of M intermediate, prolonging lifetime of intermediates in the later part of photocycle, and appearance of additional two intermediates which were evident in the photocycles of T164 mutants. These results suggest that although T164 and S165 are located at the far end of the photoactive center, these two amino acid residues are important for regulation of the HeAR photocycle. Moreover, the thermal stability of three-dimensional structure of HeAR and its mutants were investigated by small angle x-ray scattering (SAXS). In addition, the photocycles of HeAR reconstituted into lipid and HeAR in the presence of detergent were compared and the influence of the different environment on HeAR photocycle was investigated.細菌ロドプシン類タンパク質は7本のα-へリックスから構成され、発色団としてビタミンAアルデヒド（レチナール）を持つ光受容膜タンパク質であり、レチナールに吸収された光エネルギーの生体エネルギーへの変換や、外界の光情報の受容に関わっている。細菌ロドプシン類タンパク質は、生体膜中での立体構造が明らかにされた最初の膜タンパク質であり、モデル膜タンパク質として、詳細に研究され、それらの機能について、個々のアミノ酸レベルで、その分子機構が議論されている。本研究では、センサリーロドプシンII（SRII）と、中国内モンゴルの塩湖から我々のグループによって発見されたHalorubrum sp. ejinoor の持つアーキロドプシン(HeAR)について、新たなアミノ酸変異体を作成し、その光化学的性質を調べ、これまで分かっていなかったアミノ酸の働きを明らかにした。SRIIは、細菌が青緑光から逃げる負の走光性の光受容体である。本研究では、バクテリオロドプシン（BR）のプロトンポンプ機能に重要なアミノ酸残基であるアスパラギン酸（D）115に対応するSRIIのD103の変異体を作成した。SRIIのD103をアスパラギン（D103N）やグルタミン酸（D103E）に置換した変異体を作成し、その光反応を調べた。その結果、変異体では、M中間体の崩壊は速くなるが、光反応サイクル後半の中間体の寿命が長くなること、また、長寿命の副産物の生成が観察され、SRIIのD103は、SRIIの光反応サイクルの回転速度の調節に重要な役割を果たすことが分かった。HeARは、BRと同様に光駆動外向きプロトンポンプとして働く。ARのアミノ酸配列はBRとよく似ており、これまで、プロトンポンプ機能に必須であることが明らかになっているアミノ酸は全て保存されていた。しかし、ARだけに共通して保存されているアミノ酸があることに注目し、これらのアミノ酸（N末より164番目のトレオニン；T164と165番目のセリン；S165）をアラニン（A）に置換した変異体、T164A、S165AとT164A/S165Aを作製し、それらの光化学的性質を調べた。その結果、変異体では、M中間体の崩壊は速くなるが、光反応サイクル後半の中間体の寿命が長くなり、また、T164の変異では光反応中間体の数が増加した。発色団レチナールから離れた場所にあるにもかかわらず、HeARのT164とS165は、HeARの光反応サイクルの回転速度の調節に重要な役割を果たすことが分かった。また、HeARの立体構造の熱安定性をX線小角散乱法（SAXS）によって調べた。脂質に再構成したHeARと界面活性剤存在下でのHeARの光反応を比較検討し、タンパク質周辺環境の違いの影響についても調べた。doctoral thesi
異なる環境条件によるモルタルの細孔構造変化と劣化過程との関係
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdfService lifetime refers to the period during which a structure fulfills its performance requirements. Structures in areas that experience cold temperatures are exposed to freeze-thaw cycles which can cause frost damage, carbonation and reduce service lifetime. The modelling of service lifetime deterioration is the main aim of this research, (Chapter 1). For this purpose (Chater 2), the experimental program was designed in the following two series. In Series 1, mortar specimens subjected to drying conditions in the laboratory as one test set, and exposed to different natural climate conditions at three outdoor locations in 10 years as another test set. Next, in Series 2 a large tests was performed in the laboratory by adding not only different temperature but also different relative humidities and curing times. Mortar specimens were prepared using water, ordinary Portland cement, and sand. Pore structure of mortar specimens was evaluated using Mercury Intrusion Porosimetry method. The results indicated that most of the pore structure change in the outdoor exposure test and the laboratory test showed the same tendency due to drying temperature. Test results confirmed that pore structure of mortar was coarsened and the pore volume with a diameter range of 40-2000 nm and 150-15000 nm were increased (Chapter 3, 4). Furthermore, this study reports evidence for the relationship between pore structure change and maturity, and an improved maturity function is proposed. The change in the pore structure is determined by the proposed maturity function, which considers the curing temperature history and the relative humidity. The relative humidity is an additional and novel factor forming the new maturity function for the prediction of pore structure change. Finally, the experimental results presented are useful information for understanding the pore structure of mortar changes due to environmental conditions. In this study, by analyzing the influence of environmental conditions on the change of pore structure, quantifying the relationship of frost damage from pore structure change, conducting laboratory experiment and exposure to real environment, the method for forecasting frost damage deterioration calculated by ASTM equivalent cycle number including winter environment and dry condition in summer is proposed. The service life of mortar is calculated for each region as forecasting method of frost damage by taking into consideration the effect of summer pore structure change on frost damage resistance in addition to prediction of frost damage by conventional cycle number corresponding to ASTM using the proposal of indicator FD-CI (Chapter 5).建築物の寿命とは、構造物がその性能要件を満たす期間を指す。日本の北海道のような寒冷地における構造物は、凍害の原因となる凍結解凍サイクルや中性化に曝され、耐用年数の短縮を引き起こす可能性がある。本研究の目的は、建築物の寿命の低下のモデル化である(第1章)。この目的のために(第2章)、2つのシリーズで実験を計画した。シリーズ1では、モルタル試験体を実験室で乾燥条件下で養生し、もう一つの試験として室蘭、東京、沖縄の3つの異なる都市で屋外の自然気候条件に10年間曝露した。次に、シリーズ2では、異なる温度だけでなく、異なる相対湿度および硬化時間を新たな実験要因として追加することによって、実験室で試験が行った。モルタル試験体は、水、普通ポルトランドセメントおよび砂を用いて調製した。モルタル試験体の細孔構造は水銀圧入法を用いて評価した。その結果、屋外暴露試験では細孔構造の大部分が変化することが確認され、実験室試験では乾燥温度によって同じ傾向が見られた。このことから乾燥によりモルタルの細孔構造が粗くなっており、直径40~2000nmの細孔容積および直径150~15000nmの細孔容積が増加していることを確認した(第3章、第4章)。さらに、この研究は、細孔構造の変化と温湿度時間積の関係についての証拠を報告し、温湿度時間積の算定式を提案した。細孔構造の変化は、硬化温度および相対湿度を考慮して提案された温湿度時間積によって決定される。細孔構造の変化の予測のために相対湿度を考慮し温湿度時間積に組み込んだ事が付加的かつ新規な因子である。最後に、実験結果は環境条件によるモルタルの変化の細孔構造を理解するのに有益な情報である。本研究では、細孔構造の変化に及ぼす環境条件の影響を分析と、細孔構造変化による凍害の関係の定量化、実験室実験と実環境での暴露試験から、ASTM相当サイクル数に冬の環境や夏の乾燥状態を含めて計算する凍害の予測方法を提案した。本研究で提案した夏期における耐凍害性に関係する細孔構造変化の影響をASTM相当サイクル数に加えた凍害予測手法であるFD-CIを用いてそれぞれの地域のモルタルの耐用年数を算出した(第5章)。doctoral thesi
エナンチオ選択的不斉反応に用いる新規アミノアミド有機分子触媒の開発
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdfMany biologically active compounds, including pharmaceuticals, are optically active and often only one of the enantiomer shows a high biologically activity. Therefore, it is important to develop the synthetic methodology for providing only necessary enantiomer. As the methodology, catalytic asymmetric synthesis, in which the use of a low amount of a chiral catalyst theoretically enables infinite production of optically active compounds, is the most efficient in the synthetic organic chemistry field. Moreover, this methodology is also important in terms of energy saving and environmental friendliness. The chiral catalysts used in catalytic asymmetric syntheses can be divided into two categories of organometallic catalyst and metal-free organocatalyst. Particularly, organocatalyst is stable in air, easy to handle, and inexpensive, so they are being focused on as next-generation, environmentally friendly catalysts. Author developed the new type amino amide organocatalyst. This catalyst is expected to work as multipoint recognition catalyst having both covalent and non-covalent hydrogen bonding sites in the single molecule. This catalyst was successfully derived from commercially available amino acids, and the excellent catalytic activities were demonstrated in both (1) the aldol reaction and (2) the Michael addition. (1)The enantioselective asymmetric aldol reaction of ketones with aldehydes using amino amide organocatalysts was carried out to provide chiral aldol products in excellent chemical yields, diastereoselectivities and enantioselectivities. The obtained aldol products are important synthetic precursors of the synthesis of many biologically active compounds including pharmaceuticals. (2)The enantioselective asymmetric Michael reaction of ?-keto esters with nitro olefins using amino amide organocatalysts was carried out to provide chiral Michael adducts in excellent chemical yields, diastereoselectivities and enantioselectivities. The obtained Michael adducts with chiral quaternary carbon center are important synthetic precursors of the synthesis of many biologically active compounds including pharmaceuticals such as platencin (antibiotic). In this study, author revealed that the new explored amino amide organocatalyst showed satisfactory catalytic activities in both (1) the aldol reaction and (2) the Michael addition. It is expected that this results should be able to greatly contribute the development of new drug and its related compounds.薬品を含む多くの生物活性化合物は光学活性物質であり, その鏡像異性体は異なる生体内活性を示すことが多いため, 有効な一方の鏡像異性体を高選択的に合成するための不斉合成反応，特に不斉触媒を用いる触媒的不斉合成反応の開発が重要である.その不斉触媒の中で，金属を含有しない有機分子触媒は空気中で安定であり取り扱いやすく安価であるという利点などを有するため, 次世代の環境調和型触媒として現在活発に研究開発が行なわれている.著者は, 新規多点認識型有機分子触媒としてアミノアミド型触媒を設計し, それを, エナンチオ選択的 (1) ケトン類とアルデヒド類との不斉アルドール反応，(2) s-ケトエステル類とニトロスチレン類 との不斉マイケル付加反応にそれぞれ適用し，その有機分子触媒としての機能性を明らかにした.(1) 新規有機分子触媒としてアミノアミド有機分子触媒Aを合成し, 触媒Aを用いるケトン類とアルデヒド類との不斉アルドール反応を検討した．その結果, 触媒Aが本反応において不斉触媒活性を示し，優れた化学収率と良好な光学収率で光学活性アルドール生成物を与えることを見出した. 得られた反応生成物は，創薬のための様々な生物活性化合物の合成中間体として有用であり，この合成中間体から新薬候補化合物を創製できることが期待される．(2) アミノアミド有機分子触媒Aを用いるs-ケトエステル類 とニトロスチレン類との不斉マイケル反応を検討した．その結果，触媒Aが不斉触媒活性を示し, 本反応によってほぼ完全な化学収率と優れた光学収率で光学活性マイケル付加体が得られることを見出した．得られたマイケル付加体は，創薬のための様々な生物活性化合物の合成中間体として有用であり，この合成中間体から新薬候補化合物を創製できることが期待される．本研究において著者は，「基質との共有結合部位と水素結合部位，さらには反応のエナンチオ選択性の制御に有効な多環式芳香族環部位を併せ持つ多点認識型アミノアミドハイブリッド型触媒」を開発することに成功し, それらが創薬に有効な不斉アルドール反応および不斉マイケル付加反応においてそれぞれ良好な不斉触媒活性を示すことを明らかにした. また，本反応によって得られる化合物は様々な医薬品をはじめとする生物活性化合物の合成中間体として有用であることから，本研究の成果は, 新薬創製の合成開発研究に大きく貢献できると期待される.doctoral thesi
高度道路交通システムにおける情報伝送、ユーザ体験および持続性の研究
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdfITS (Intelligent transportation system) is a modern way of urban transportation management. By improving road throughput, managing traffic, and enhancing human mobility, it can improve the service performance of urban transport networks in a holistic way. Ultimately, through better traffic management, congestion can be slowed and traffic safety improved. The large-scale deployment of ITS is very meaningful, which can greatly affect all aspects of urban life. The traditional means of traffic management cannot deal with real time traffic management very well. The advanced ITS, in keeping with the times, is the integration of as much IoT as possible (Internet of Things) equipment, for the human to provide new service experience. Recently, the spectrum band beyond 60GHz has attracted attentions with the growth of traffic demand. Previous studies assumed that these bands are not suitable for vehicle communications due to the short range and high rate of blockage. However, it also means there is no existing service or regulation designed for these bands, which makes this area free to apply. One purpose of this study is to construct an applicable map of 0.1-1 THz supported autonomous vehicle system through the study of channel capacity, autonomous relaying and self-driving. For sending a large volume of data, the vehicles keep a gigabit level link through line of sight channels, which share information about traffic condition and captured videos for further processing. The full use of this research can significantly improve the performance of autonomous driving. A brief overview of possible waveforms followed by specific channel characteristics in 0.1-1 THz band is discussed and an autonomous relay system for the gigabit road communication is presented. At last, we describe how the highrate short-range communication helps complement extra data to support the advanced new self-driving technologies. To improve the user experience, taxi sharing service aims to share the taxi resource efficiently between passengers with specific relevant plans. However, due to the lack of social interactions, it is hard to improve user experience without considering passengers’ inner connections. To overcome this problem, we propose a cloud-based taxi-sharing system, which provides real-time taxi sharing services both considering the practical travel needs and QoS in the journey. The purpose of this service is to minimize the travel cost through sharing calculated schemes reasonably and quickly and improve the sharing experience as much as possible. We model the citywide level map into blocks and indexed, in order to search for the potential paths of ride-sharing dynamically and intelligently. Meaning while, we explore the paths among communities to find suitable companions as well. Finally, synthesizing the suggestions of edge exploration on road network and social network, we design a heuristic algorithm called SONETS to achieve the designing goal and make a real deployment. As well as the establishment of the mobile application and online service, we also conduct a large-scale simulation to evaluate the performance with others. The result shows that the proposed solution could make the whole taxi-sharing system less calculation complexity, higher sharing QoS, and most of all, keeping the minimum cost of travel cost within 1.16% increment than distance optimal algorithms. To keep the sustaibility of urban ITS, we also investigate the maintenance of city-wide sharing pedelecs, which apply battery-powered motor to assist pedaling and significantly extend the riding coverage. The large-scale deployment of pedelecs, however, requires a careful design of maintenance system to replace the batteries of pedelecs regularly, which can be very costly. This study develops an optimal path planning scheme for replenishment trucks based on big data analytic and prediction. To the best of our knowledge, we are the first to use the systematic methodology of Analysis/Modeling/Test to advance the bike prediction process using the captured datasets, and conduct the hybrid prediction process learns internal connections between different dataset dimension as well as optimize the overall maintenance efficiency.ITS（Intelligent Transportation System）は都市交通管理の現代的な方法である。道路のスループットを改善し、交通を管理し、人間のモビリティを強化することにより、都市交通ネットワークのサービスパフォーマンスを全体的に向上させることができる。最終的には、トラフィック管理の改善により、輻輳が緩和され、交通安全性が向上する。大規模なITSの展開は非常に意味があり、都市生活のあらゆる側面に大きな影響を与える可能性がある。高度なITSは、時代に即して、可能な限り多くのIoT（Internet of Things）機器の統合であり、人間が新しいサービス経験を提供するためのものである。近年、交通需要の増加に伴い注目を集めている 60GHzを超える周波数帯域が注目されている。これらのバンド用に設計された既存のサービスや規制が存在しないで、この領域を自由に適用することができる。本研究の目的の 1つは、チャネル容量、自律リレーおよび自己運転の研究を通して、0.1-1 THzに対応した自律車両システムの適用可能なしくみを構築することである。大量のデータを送信するために、0.1-1 THz帯域における特定のチャネル特性に続く可能な波形の簡単な概観が論議され、ギガビット道路通信のための自律リレーシステムが提案される。しかしながら、社会的相互作用の欠如のために、乗客の内部接続を考慮せずにユーザ体験を改善することは困難である。この問題を克服するため、実際の旅行ニーズと旅行のQoSを考慮したリアルタイムのタクシー共有サービスを提供するクラウドベースのタクシー共有システムを提案する。 このサービスの目的は、道路網とソーシャルネットワーク上のエッジ探索の提案を合成し、SONETSというヒューリスティックなアルゴリズムを設計し、設計目標を達成し、実際の展開を行う。提案されたソリューションは、共有QoSを高め、とりわけ移動コストの最小コストを遠距離最適アルゴリズムより1.16％増以内に抑えることができた。都市ITSの持続可能性を維持するために、E-Bikeを助けるためにバッテリー駆動のモーターを適用し、乗車範囲を大幅に拡張する都市規模の共有車のメンテナンスについて研究を続ける。しかしながら、大規模なpedelecsのバッテリーを定期的に交換するメンテナンスシステムを慎重に設計する必要がある。本研究では、大規模なデータ分析と予測に基づく補充トラックの最適な経路計画手法を開発する。我々は捕捉されたデータセットを使用して自転車予測プロセスを進めるために、分析/モデリング/テストの体系的な方法論を使用し、ハイブリッド予測プロセスを実行して、異なるデータセット次元間の最適な結合で、全体的なメンテナンス効率を上昇する。doctoral thesi
Full-vectorial analysis of optical waveguide discontinuities using a propagation operator method based on the finite element scheme discontinuities using a propagation operator method based on the finite element scheme
Get PDFapplication/pdfWe propose an efficient numerical method for the full-vectorial analysis of three-dimensional (3-D) optical waveguide discontinuities. In this method, the finite element method with higher adaptability and flexibility is employed to discretize the waveguide cross section. In order to calculate the square root of the characteristic matrix, the Denman-Beavers iterative scheme is used. Applying this method to 3-D strongly guiding waveguide discontinuity problems, the modal reflectivities of the fundamental TE-like and TM-like modes are calculated. These results show unique vector properties and significantly differ from those of scalar analysis because various mode couplings between the field components occur at the discontinuity facet and they cannot be ignored.journal articl
Computational study on silicon oxide plasma enhanced chemical vapor deposition (PECVD) process using tetraethoxysilane/oxygen/argon/helium
Get PDFapplication/pdfPlasma enhanced chemical vapor deposition (PECVD) of silicon oxide (SiO2) using tetraethoxysilane (TEOS) was investigated theoretically by developing an unprecedented plasma chemistry model in TEOS/O2/Ar/He gas mixture. In the gas phase reactions, a TEOS molecule is decomposed by the electron impact reaction and/or chemically oxidative reaction, forming intermediate TEOS fragments, i.e., silicon complexes. In this study, we assume that SiO is the main precursor that contributes to SiO2 film growth under a particular process or simulation condition. The surface reaction was also investigated using quantum mechanical simulations with density functional theory. Based on the gas and surface reaction models, we constructed a computational plasma model for SiO2 film deposition in a PECVD process. The simulation results using CHEMKIN pro and CFD-ACE + have shown that the neutral atomic O and SiO as well as the charged O2 + are the dominant species to obtain a high deposition rate and uniformity. The spatial distributions of various species in the TEOS/O2/Ar/He gas mixture plasma were shown in the study. The uniformity of deposited film due to the change in the plasma bulk property was also discussed.journal articl
Methoxy-Group Control of Helical Pitch in Stereoregular Poly(2-ethynylmethoxynaphthalene) Prepared by Rhodium Complex Catalyst
Get PDFapplication/pdfThe position of the methoxy group in a poly(n-methoxy-2-ethynylnaphthalene) (PnMeO2EN) was found to control the helical pitch of the π-conjugated polymer in the solid state. These PnMeO2ENs were stereoregularly synthesized using an Rh-complex catalyst in ethanol or toluene as the solvent. The helical structure in the solid phase was confirmed by conventional analytical methods, namely diffuse reflective ultraviolet–visible light (UV–Vis) and Raman spectroscopies, X-ray diffraction, and 13C cross-polarization magic angle spinning NMR spectroscopy, together with molecular mechanics calculations, because the as obtained polymers were insoluble in common solvents. The color of poly(6-methoxy-2-ethynylnaphthalene) (P6MeO2EN) (yellow or red) depended on the polymerization solvent, whereas no such dependency was observed for the yellow-colored P7MeO2EN and P8MeO2EN. The helical structures energetically optimized by molecular mechanics indicate that the red- and yellow-colored P6MeO2ENs form contracted and stretched helices, respectively. Due to the relatively unconstrained rotations of the 6-methoxynaphthyl moieties, the methoxy groups in P6MeO2EN are less sterically hindered along the helical axis. On the contrary, P7MeO2EN and P8MeO2EN have stretched helices due to the considerable steric hindrance imparted by their methoxy groups. The thermal cis-to-trans isomerization of P6MeO2EN in the contracted-helix form required a somewhat higher temperature than that of the stretched helix.journal articl
Preparation of silk resins by hot pressing Bombyx mori and Eri silk powders
Get PDFapplication/pdfWe investigate the mechanical properties and structure of silk resins as potential alternatives to tortoiseshell for producing eyeglass frames and various ornaments. Silk powders are obtained from Bombyx mori and Eri silk waste fibers before the degumming process. The powders are fabricated into resins via simple hot pressing under a pressure of 31.2 MPa at temperatures in the range 150–180 °C. The results indicate that the B. mori resins have higher micro-Vickers hardness, three-point bending strength, and elastic modulus (66 Hv, 122 MPa, and 8.7 GPa, respectively) compared to the Eri silk resins (58 Hv, 95 MPa, and 8.2 GPa, respectively). The better mechanical properties of the fibroin resins are related directly to longer drying times. The optimum drying conditions are found to be at a temperature of 100 °C under a–vacuum of −0.1 MPa for a time of 7 d. ATR-FTIR and XRD results show how the fibroin structure changes after resinification and drying. The morphology and the distribution size of particle of the silk powders and the fractured surfaces of the resins are analyzed from SEM micrographs. The present findings demonstrate that silk resins are suitable materials for developing useful applications because of their favorable mechanical properties.journal articl