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Characterization of submicro-sized Ag/ZnO particles generated using the spray pyrolysis method
No full textapplication/pdfEnvironmental issues caused by the rapid industrialization and urbanization of modern society are a serious problem. For example, conventional wastewater treatment technologies such as adsorption, coagulation, and filtration are expensive and cannot completely treat the discharge of organic pollutants in industrial wastewater. A promising alternative is the decomposition treatment of organic pollutants using an eco-friendly metal oxide photocatalyst. However, the rapid recombination of excited electron-holes limits the photolytic activity of semiconductor photocatalysts. This study investigates the inhibition of electron-hole recombination by supporting Ag nanoparticles on a ZnO photocatalyst. Ag/ZnO particles are generated under various conditions using ultrasonic spray pyrolysis. XRD analysis confirms the presence of Ag and ZnO crystal peaks in the generated particles. EDX mapping and STEM images show that Ag nanoparticles are well dispersed in ZnO. The photolysis rate of organic dye (rhodamine-B) is faster than that of ZnO in all Ag/ZnO particles, and particles with a 0.2 mass% silver nitrate supported on ZnO particles exhibit twice the photolysis activity of P25. Additionally, the optimal photolysis activity in 100 mL of 5 mg/L rhodamine-B aqueous solution with 10 mg of Ag/ZnO particles are confirmed and had excellent persistence and stability even during 7 reuses.(c) 2022 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.journal articl
凍上に対するコンクリート舗装の設計法に関する研究
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdf本研究は，道路舗装における高耐久化，長寿命化による維持管理頻度の抑制，ライフサイクルコストの縮減に資するため，積雪寒冷地のコンクリート舗装における新たな路床設計法の提案を目指したものである．本研究の検討対象は路床の凍上対策であり，既存設計法の評価を行うため既設舗装の損傷調査，FEM解析・疲労度計算を用いた舗装寿命評価を実施した．さらに，新たな設計法の提案を行うため最大凍結深さの実測技術および推定手法について，試験舗装および供用中の道路を用いて検討した．「コンクリート舗装では微量凍上でもクラックが発生する」との指摘がある（北海道舗装史，1985.）．しかしながら，我が国の設計法（舗装設計便覧，2006.）は凍上を許容しており，設計期間内における凍結深さの70 %までを非凍上性の材料で置き換える設計法を採用している．本研究では，現在の設計法の妥当性を評価するためコンクリート舗装の現地調査を実施した．この結果，凍結深さより浅い位置に凍上性の路床土が存在する調査箇所において，コンクリート舗装版の構造的な損傷が多いことが明らかとなった．次に，FEM解析および疲労度計算を用いた舗装寿命評価手法を用いて凍上が舗装寿命に及ぼす影響を検討した．この結果，路床に凍結が入りわずかでも凍上が発生すると，舗装寿命が大幅に低下することが明らかとなった．また，現在道路設計に用いられている凍結深さの推定手法（舗装設計便覧，2006.）についてコンクリート舗装に対する適用性を評価するため，この推定値と実測値との比較を行った．凍結深さの実測にあたり，舗装体温度と電気抵抗を自動計測し凍結・不凍結・融解を判定する手法を開発し，精度の高い凍結深さ計測を可能とした．比較の結果，推定手値と実測値の間に乖離が確認された．このため，明色舗装であるコンクリート舗装の特徴を加味することが可能な熱収支解析・熱伝導解析を用いた新たな推定手法を検討し，実際の凍結深さとの比較を行い，±50 mm程度の精度で推定が可能であることを明らかにした．以上の成果に基づき，コンクリート舗装の置換厚を設定するための新らたな手法と，舗装体の凍結深度を自動計測する技術を提案した．本研究は，近年の社会的要請を踏まえ，舗装構造設計における社会問題解決型研究と理論的設計を連携させた取り組みに位置づけられる．また，コンクリート舗装における凍結深さの推定手法と凍上を考慮した設計条件を提案した研究成果は，その連携に大いに寄与するものであると考えられる．The purpose of this study is to propose a new subgrade design method for concrete pavement in cold snowy regions in order to contribute to the reduction of maintenance frequency and the reduction of life cycle cost by increasing the durability and life of road pavement. The subject of this study was measures against frost heaving of subgrade, and in order to evaluate the existing design method, damage investigation of the existing pavement, FEM analysis and pavement life evaluation using fatigue degree calculation were carried out. Furthermore, in order to propose a new design method, the measurement technique and estimation method of the maximum freezing depth were examined using the test pavement and the road in service. It has been pointed out that "cracks occur in concrete pavement even on slight frost heaving" (Hokkaido Pavement History, 1985.). However, Japan's design method (Pavement Design Handbook, 2006.) allows frost heaving, and adopts the design method in which up to 70% of the freezing depth within the design period is replaced with non-frost heaving material. In this study, field surveys of concrete pavement was conducted to evaluate the validity of the current design method. As a result, it was clarified that many structural damages of the concrete pavement slab occurred at the survey location where the frost heaving subgrade soil was present at a position shallower than the freezing depth. Next, the effect of frost heaving on pavement life was examined using a pavement life evaluation method using FEM analysis and fatigue calculation. As a result, it was clarified that if the subgrade freezes and even a slight frost heaving occurs, the pavement life will be significantly reduced. In addition, in order to evaluate the applicability of the maximum freezing depth estimation method (Pavement Design Handbook, 2006.) currently used for road design to concrete pavement, comparison with the actual freezing depth was performed. In order to obtain the freezing depth, the method has been developed that automatically measures the pavement temperature and electrical resistance to determine freezing, non-freezing, and thawing. This enables highly accurate automatic measurement. As a result of comparison, a discrepancy was confirmed between the currently used estimation method and the actual freezing depth. Therefore, a new estimation method using heat balance analysis and heat conduction analysis that can take into account the characteristics of concrete pavement, which is light-colored pavement, was investigated. It was clarified that the difference between the new estimated value and the actual freezing depth is about ± 50 mm, which proves to be highly accurate. Based on the above results, new method for setting the replacement thickness of concrete pavement, and technique for automatically measuring the freezing depth of the pavement was proposed. Based on recent social demands, this research is positioned as an initiative that links social problem-solving research in pavement structure design with theoretical pavement design. The research results that propose a method for estimating the freezing depth in concrete pavement and design conditions that take frost heaving into consideration are considered to greatly contribute to the cooperation.doctoral thesi
有段変速クレーンの高速制振搬送に関する研究
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdfクレーンによる吊り荷の高速自動搬送には，高度な自動制御技術が求められる．ワイヤロープを用いて玉掛けした吊り荷を，クラブトロリの巻き上げ装置を用いて吊り上げたあと，駆動装置によって目的地に向けて搬送すると，クラブトロリの加減速によって吊り荷に振り子運動が生じる．このとき，制振制御を考慮せずに目的地の直上まで搬送した場合，目的地に到着したあとも吊り荷には振れが残留する．このため，すぐに吊り荷を地面に着地させることができず，クレーンの総運搬時間が長くなり，運搬効率の低下を招く．したがって，クレーンで吊り荷の高速自動搬送を行うとき，吊り荷の振り子運動を制御して，目的地で振れを収束させるための制振制御技術が必要である．これまで，制振制御に関するさまざまな方法が提案されているが，トロリの駆動システムに加速度一定の制約を持つクレーンに対する制振制御法は報告されていない．このようなシステムは旧式の有段変速クレーンに多く採用されており，リレー回路によるOn/Off指令でトロリが駆動される．そこで本論文では，トロリ駆動システムに加速度一定の制約をもつクレーンに適用可能な，新たなフィードフォワード(FF)制振制御法を提案する．本手法は，時間多項式によるFF制御法(FFT)に基づき，制約条件を考慮するためにFFT法により生成した制御入力をパルス幅変調法(PWM)により近似する．FFT法は線形近似モデルによりFF制御入力を生成するためモデル化誤差が生じる．また，生成した制御入力をPWM制御入力で近似するため量子化誤差が生じる．これらの誤差の影響に対してロバストな制御入力を生成するアルゴリズムとして更新型FFT法(UFFT)と総当たり更新型FFT法(NSFTC)を構築した．これらは，残留振れが小さくなるように制御入力を繰り返し計算するアルゴリズムであり，シミュレーションによる性能評価によって，FFT法より有効な制振制御法であることを確認した．さらに，FFT法に比べてUFFT法が有効な制御法であることを，実験評価用クレーンを利用して実証した．実験ではさらに，吊り荷の質量変化に対してロバストな制御入力も探索できることを確認した．以上，本論文では，クレーントロリの駆動システムに加速度一定の制約を持つ有段変速クレーンにおいて，高速制振搬送のためのFF制御入力を生成できる新たなアルゴリズムを提案し，その有効性をシミュレーションと実験で明らかにした．Advanced automatic control technology is required for high-speed automatic transport of suspended loads by cranes. When a suspended load slung by a wire rope is lifted by a hoisting device of a crane's club trolley and transported to a destination by a driving device at high speed, a pendulum motion is caused by the acceleration and deceleration of the trolley. If the trolley is moved above the destination without considering sway control, the load continues to oscillate even after arrival. Therefore, the load cannot be immediately unloaded, and the crane transportation time increases, resulting in a deterioration in yard productivity. High-speed automatic transfer of suspended load by crane requires technology to sway control. A number of crane control methods have been proposed in the past. However, if the drive system of the crane has restrictions, the conventional anti-sway control method may not be directly applicable. This type of system is used for many older cranes which are driven of multistep speed by on/off relay circuits. In this study, we propose a feedforward (FF) control input generation method that can realize automatic anti-sway transport of a suspended load for a crane system with restrictions that the trolley can only accelerate or decelerate at a constant rate; the switching frequency of the acceleration input cannot be too high. The proposed method combines the FF control input generation using the time-polynomial (FFT) method and pulse width modulation (PWM) control. In the FFT method, the derived FF control input may be unable to suppress the swing of the suspended load because of the modeling error in deriving the FF control input and the quantization error in approximating the FF control input by the PWM control input. To solve these problems, we propose two algorisms. First algorism is the update type FF control input generation using the time-polynomial (UFFT) method, second algorism is the neo-style FF control input generation using the time-polynomial (NSFTC) method, both of which evaluates the residual sway at a constant time interval and updates the original FF control input derived by the FFT method. The effectiveness of these methods is confirmed through simulations. Moreover, the effectiveness of the UFFT method is experimentally confirmed, and it is also confirmed that a control input that is robust to the mass variation of the suspended load can be easily explored. In conclusion, we propose the new FF control input generation algorithms for high speed transfer in a multi-step speed operation crane.doctoral thesi
An interactive sketch-based CAD interface realizing geometrical and topological editing across multiple objects based on fuzzy logic
No full textapplication/pdfWith the widespread use of digital pen tablets and touch displays, sketch-based interactive computer-aided design (CAD) user interfaces have attracted considerable attention. In an existing interface called the Sketch Input Tracer (SKIT), however, the editing operation performed via an over-sketching stroke can target only a single geometric object at any given time. To overcome this limitation, in this study, we propose a new general-purpose sketch-based interface developed for use in two-dimensional CAD systems. In the proposed interface, a sketch-based editing operation can simultaneously modify the geometry and topology of multiple geometric objects via over-sketching. The interface was developed based on the fuzzy logic-based strategy of SKIT. With this interface, a user can draw in a creative manner; for example, they can begin with a rough sketch and progressively create a detailed design through repeated over-sketches. The results of experiments conducted demonstrate that experts can control the proposed interactive drawing interface and beginners can habituate to controlling it. (c) 2022 Elsevier Ltd. All rights reserved.journal articl
Enhancement of the hydrodesulfurization and C−S bond cleavage activities of rhodium phosphide catalysts by platinum addition
No full textapplication/pdfTo enhance the hydrodesulfurization (HDS) activity of SiO2-supported Rh phosphide catalysts, various second metal-added Rh–P catalysts were developed; furthermore, the effect of the addition of the second metal on the HDS performance was examined. The second metals (M: Ru, Pt, and Ir) were selected as per the Sabatier principle. In situ X-ray diffraction revealed the formation of an Rh2P phase in the Rh–M–P catalyst after reduction. The addition of Ru and Pt to the Rh–P catalyst enhanced the C−S bond cleavage activity, whereas the addition of Ir had virtually no effect. The Rh–Pt–P catalyst demonstrated the highest HDS activity among Rh–M–P catalysts. The characterization results revealed the presence of positively charged Pt on the Rh–Pt–P catalyst surface, in which Pt and Rh cooperatively act as active sites to enhance the C−S bond cleavage activity.journal articl
大規模火山災害時の避難所空港選択モデルに関する研究
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdf航空輸送は乗客と物流を通じて経済成長と繁栄を支えている。航空輸送がより広範かつ複雑に成長するにつれ、予期しない自然災害（台風や火山の噴火等）に対して、航空機の運用はより脆弱となる。日本では多くの活火山が管制領域に影響を及ぼしており、国の航空輸送や航空機等の重要な航空機器の運用に対する脅威と見なされている。この研究は主に火山噴火に対する航空機の避難所となる空港選択の問題の解決を目的とする。避難所空港選択モデルは、エアサイド、航空会社、および運用履歴データを使用して構築された。その後、遺伝的アルゴリズム（GA）を適用し、飛行時間が最小となる避難所の空港選択基準に最も適した航空機の避難方法を探索した。さらに本研究では、緊急時の避難所空港の航空機駐機位置問題を解決する戦略を提供するようにモデルを拡張した。航空機の割り当てに推奨される航空機駐機位置の使用率の効率化のために、2次元ビンパッキング（2DBP）手法とヒューリスティックなアプローチを組み合わせて、駐機位置の使用量を最小限に抑えながら空港の航空機運用能力を最大化する。提案されたモデルの性能について、国の航空輸送インフラを危険にさらす地震や火山噴火などの様々な自然災害に耐えてきた日本の空域をケーススタディとして、従来の航空機駐機位置の割り当てモデルと比較した。さらに提案された航空機と従来の航空機駐機位置割り当てモデルの両方を使用して、影響を受けた航空機の様々なシナリオを処理する避難所空港の能力と可能性を評価した。本論文は、航空防災に貢献する3つの関連する研究として、1）CARATSオープンデータセットを用いた大規模火山災害時の避難所選択に関する研究、2）大規模火山災害時の避難所空港選択モデルの改善：日本の箱根山の事例研究、3）航空機避難のための二次元ビンパッキングアルゴリズムを使用した航空機駐機位置の活用、以上から構成される。本論文では上記の様々な視点からの研究蓄積と重要な成果を通して包括的なレビューと提案を提供した。本論文の貢献は、航空機避難に関する緊急戦略の策定およびより良い航空防災につながる代替解決策を政策立案者に認識させる点にある。Air transport supports economic growth and prosperity through the movement of passengers and goods. As it grows more extensive and more complex, the more vulnerable its operations to unexpected natural disasters (e.g., typhoons and volcanic eruptions) will become. In Japan, many active volcanos are affecting its airspace and are considered a threat to the national air transportation and critical aviation equipment such as aircraft. The study is primarily concerned with resolving the issue of shelter airport selection during an aircraft evacuation during a volcanic eruption. The shelter airport selection model was constructed using the airside, airline, and historical data. Later, it was applied to a genetic algorithm (GA) to find an approximate solution for aircraft evacuation with the least amount of flight time and the best suitability for shelter airport selection criteria. Moreover, the study has extended to provide a strategy for resolving the issue of aircraft stand use at shelter airports during emergencies. The suggested aircraft stand utilization for aircraft assignment employs a two-dimensional bin packing (2DBP) technique combined with a heuristic approach to maximize the aircraft handling capability of the airport while minimizing stand usage. The performance of the proposed model was compared to the conventional aircraft assignment in a case study of Japanese airspace, which has endured various natural disasters, including earthquakes and volcanic eruptions, that endanger national air transport infrastructure. In addition, both the proposed aircraft and the conventional aircraft stand assignment models were employed to assess the capabilities and potential of shelter airports to handle various scenarios of affected aircraft. This dissertation addressed three contribution studies to the acknowledgement of aviation disaster prevention, which consists of; 1) a study on shelter airport selection during large-scale volcanic disasters using carats open dataset, 2) an improvement on shelter airport selection model during large-scale volcanic disasters: a case study of Hakoneyama Japan, and 3) aircraft parking stand utilization for aircraft evacuation using two-dimensional bin packing algorithm. Hence, a stack of varying viewpoints research provided a comprehensive review and suggestion throughout significant results. Therefore, the contribution of this dissertation could be an advantage for emergency strategy and policies planner to recognize alternative solutions leading to better aviation disaster prevention.doctoral thesi
単調および繰返し載荷条件下での人工軽量盛土材・標準砂混合材料の強度・変形挙動に関する研究
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdf軟弱な基礎部分では，しばしば残留沈下が発生して道路の性能に影響を与えたり，車両の正常な運行に影響を与えたりする。残留沈下の影響を低減する方法の一つとして，下層路盤の軽量化が挙げられる。そこで本研究では，一般的に使用されている下層路盤材料に代わる新たな軽量下層路盤材料の開発を目的とし，一連の単調および繰返し三軸試験を実施し，新たな路盤材料の強度・変形特性を検討した。1. 単調載荷三軸圧縮試験では，排気および排水条件にて0.18 mm/min の軸ひずみ速度で試験を実施した。繰返し三軸試験では，周波数0.125 Hzで，軸差応力を49.4±10 kPaにて正弦波載荷を行い，1万サイクルの繰返し載荷履歴を与えた。2. 単調載荷三軸圧縮試験においては，3種類の拘束圧（29.4，49.0，68.6 kPa）で載荷した供試体の強度・変形特性に及ぼす繰返し載荷履歴の影響を検討した。試験結果より，最大軸差応力qmax，初期変形係数E0は，拘束圧の増加に伴って大きくなること，また，繰返し載荷履歴を与えると，強度および剛性が大きくなることが明らかとなった。3. 最適含水比によって作製した供試体と絶乾状態で作製した供試体に対する単調載荷三軸圧縮試験を実施して，強度・変形特性に及ぼす供試体内の水分の影響について検討した。最適含水比で作製した供試体と絶乾状態で作製した供試体に対する試験結果の比較・検討から，絶乾状態で作製した供試体の最大軸差応力qmax，および接線変形係数Etan，初期変形係数E0は，最適含水比で作製した供試体に比べて大きくなることが明らかとなった。4. 変形特性に及ぼす間隙水，拘束圧，繰返し載荷回数の影響を検討した結果，3種類の拘束圧（29.4，49.0，68.6 kPa）の下では，拘束圧が等価変形係数Eeqに与える影響が大きいことが明らかとなった。また，絶乾状態で作製した供試体の等価変形係数Eeqは，最適含水比で作製した湿潤供試体の等価変形係数Eeqより大きくなった。一方，等価変形係数Eeqは，繰返し載荷回数の増加とともに，ほぼ一定の値を示しており，すべての供試体がシェイクダウン範囲の境界範囲Aに属すると考えられるとともに，ポアソン比は繰返し載荷回数の増加に伴って変動し，その変動幅は同条件で0.05 以内であることが明らかとなった。Residual settlement often appears in the soft foundation, which affects the road performance and impact on the normal operation. One way to reduce the effects of residual settlement is reducing the weight of the subbase course. Therefore, the objective of this study is to develop a new lightweight subbase course material to replace the commonly used upper subbase course material. A series of monotonic and cyclic triaxial tests were conducted to investigate the strength and deformation characteristics of the materials. 1. Through the monotonic triaxial tests were conducted under the exhaust and drainage conditions at a constant rate of 0.18 mm/min. The cyclic triaxial tests of specimens were conducted under 10,000 cycles of vertical loading at a frequency of 0.125 Hz, where the vertical stress was changed between 49.4±10 kPa in a sinusoidal wave. 2. Experimental research on the effects of cyclic loading on the strength and deformation under three confining pressures (29.4, 49.0, and 68.6 kPa) of the specimen are analyzed by monotonic triaxial test. The test results revealed that the maximum deviator stress qmax and initial Young's modulus E0 of specimen increase with the increase of confining pressure. After cyclic loading, the strength and stiffness of specimen becomes greater. It also increases cohesion and decreases friction angle in the specimen. 3. Experimental research on the effects of moisture on the strength and deformation of the specimen are analyzed by monotonic triaxial test. From the results of specimens studied with moisture and without moisture, it was found that maximum deviator stress qmax, the tangential Young’s modulus Etan and the initial Young's modulus E0 of the dry specimen were greater than the case of the wet specimen. 4. The effects of moisture, confining pressure and number of cyclic loadings on the deformation characteristics of specimen are analyzed. The results revealed that under three confining pressures (29.4, 49.0, and 68.6 kPa), it was found that the confining pressure has a greater impact on the equivalent Young's modulus Eeq of specimen. In addition, the moisture reduces the friction between the particles and the skeleton structure becomes unstable. The equivalent young's modulus of dry specimen is greater than the case in the wet specimen. The equivalent Young's modulus maintains stable with number of loading cycles of the specimens, all specimens belong to range “A” in the shakedown range boundaries. It was also found that the Poisson's ratio fluctuates with the increase of loading cycles and the fluctuation range is within 0.05 under the same condition.doctoral thesi
乾燥を考慮したコンクリートの凍害劣化予測手法と利用に関する研究
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）application/pdfコンクリートの凍害は，寒冷地において生じる劣化現象であり，強度の低下や美観の悪化を伴う重大な劣化の一つであるため，凍害危険度などの凍害環境の地域性の評価手法が提案・活用されている。また，コンクリートの長寿命化の観点から，ASTM相当サイクル数などの様々な凍害劣化予測手法が提案されている。一方で，乾燥を受けることにより直径40～2000nm細孔量が増加，耐凍害性が低下することが明らかとなっており，乾燥条件から直径40～2000nm細孔量の予測手法として温湿度時間積が確立されている。しかし，既往の凍害地域性評価や劣化予測手法では乾燥による影響を考慮することができない。そのため，本研究では，ASTM相当サイクル数と温湿度時間積を組み合わせることにより，乾燥による耐凍害性低下を考慮した凍害環境評価および凍害劣化予測手法の確立とその活用方法の提案を目的とした。年間の凍結融解回数であるASTM相当サイクル数と組み合わせて相対動弾性係数を予測するために，温湿度条件から劣化の兆候が現れる過程と明確な劣化が現れる過程における凍結融解1サイクルあたりの相対動弾性係数低下量を導出する式を誘導した。それにより，気象条件と環境条件，材料条件から任意の経過年数における相対動弾性係数や，相対動弾性係数が90％，85％，60％になるまでの年数である安全管理年数，維持管理限界年数，設計限界年数の予測が可能である。本予測手法を用いて凍害環境の地域性を評価するために，気象データの時間間隔や統計処理手法ごとに適した計算手法を検討し，その検討結果を踏まえ，気候変動による凍害環境の地域性の変化として比較的温暖な地域でのみ凍害リスクが減少したことを明らかにした。また，日本国内における凍害環境の地域性分布図の作成し，北海道と本州・九州の山岳部においてはほぼ同等の凍害環境であることを示した。さらに，世界の凍害環境に対する気候帯ごとの整理を行い，亜寒帯が厳しい凍害環境であることを示し，他の気候帯では条件によって凍害環境になる場合があることを明らかにした。本予測手法を用いる際にJIS A 1148 A法の試験結果が必須であるという問題を解決するために，LightGBMを用いた機械学習によって調合条件などからJIS A 1148 A法試験結果予測モデルの作成を試みた。その結果，学習データの偏りによって汎用性は乏しいものの特定条件下であれば十分な精度での試験結果の予測が可能なモデルの作成が行えた。これらの結果を踏まえたうえで，凍害劣化予測システムの提案とそれを利用した維持管理，調合選定への本予測手法の活用方法について提案した。Frost damage of concrete occurs in cold regions, and is one of the serious deteriorations. Therefore, a method for evaluating the regional characteristics of the frost damage environment, such as the Frost Damage Degree, has been proposed and utilized. In addition, various frost damage prediction methods such as Equivalent Cycles to ASTM Test (CyASTM) have been proposed. On the other hand, it has been clarified that the pore volume of 40 to 2000 nm in diameter increases and the frost resistance decreases due to drying. Based on this, the Maturity of Temperature and Humidity has been established as a method for predicting the pore volume of 40 to 2000 nm in diameter from the drying conditions. However, the effects of drying cannot be taken into consideration by the existing methods for evaluating or predicting frost damage. Therefore, in this study, I aimed to establish a frost damage environment evaluation and frost damage prediction method considering the decrease in frost resistance due to drying by combining CyASTM and Maturity of Temperature and Humidity, and to propose a method of utilizing. In order to predict the relative dynamic modulus of elasticity (RDM) in combination with the CyASTM, an equation to derive the amount of decrease in the RDM per freeze-thaw cycle from the temperature and humidity conditions has created. As a result, it is possible to predict the RDM over arbitrary number of years from climate data, environmental conditions, and material conditions. In order to evaluate the regional characteristics of frost damage environment using this prediction method, a calculation method suitable for each time interval of climate data and statistical processing method has examined. Based on the results of the study, regional distribution map of the frost damage environment in Japan has created, and the frost damage environment is almost the same in Hokkaido and mountainous areas of Honshu / Kyushu has shown. Furthermore, I organized the world’s frost damage environment by climatic zone, showed that the subarctic zone is severe frost damage environment. In order to solve the problem that the test results of the JIS A 1148 A method are indispensable when using this prediction method, a test results prediction model was created from the mix proportions by machine learning using LightGBM. As a result, a model that can predict test results with sufficient accuracy under specific conditions has created, although it is not versatile due to the bias of training data. Based on these results, a frost damage prediction system has proposed.doctoral thesi
A Note on the Intersection of Alternately Orientable Graphs and Cocomparability Graphs
Get PDFapplication/pdfWe studied whether a statement similar to the Ghouila-Houri's theorem might hold for alternating orientations of cocomparability graphs. In this paper, we give the negative answer. We prove that it is NP-complete to decide whether a cocomparability graph has an orientation that is alternating and acyclic. Hence, cocomparability graphs with an acyclic alternating orientation form a proper subclass of alternately orientable cocomparability graphs. We also provide a separating example, that is, an alternately orientable cocomparability graph such that no alternating orientation is acyclic.journal articl
浮力秤量法による浮上性球形粒子の粒径分布測定におよぼす秤量棒および容器形状の影響
Get PDF浮力計量法による粒径分布測定におよぼす秤量棒形状と容器形状の影響を実験的に調べた．中空ガラスビーズを浮上性粒子として使用した．秤量棒として円柱棒，角型棒，板を，容器として角型容器またはメスシリンダーを組み合わせて粒径分布を測定した．メスシリンダーを容器として使用した場合，角型棒や板を使用しても粒径分布の測定が可能であった．角型容器と円柱棒を組み合わせた場合も粒径分布を測定できた．秤量棒の位置は粒径分布に影響を与えない．The influences of the weighing tool shape and vessel shape in the buoyancy weighing-bar method for size distribution measurement of floating particles were experimentally investigated. Hollow glass beads were used as floating particles. The floating particle size distributions were measured using different combinations of weighing tools (rod, square rod, or sheet) and vessels (square vessel or graduate cylinder). When the graduated cylinder was used as the vessel, the floating particle size distribution could be measured using the square rod or sheet as the weighing tool. When the rod was used as the weighing tool, the floating particle size distribution could be measured using the square vessel. The location of the weighing tool did not influence the particle size distribution.journal articl