双腕アームロボットによる布被覆作業に関する研究

本研究の目的は，物体を布で包む作業（被覆作業）をモデル化し，ロボットによる被覆作業を実現させることである．本論文では「目標線」の概念に基づいて物体を布で包む作業（被覆作業）をモデル化することを提案した．これにより，まず人間が大まかな包み方を教示し，次に布と物体の形状から被覆作業を計画し，最終的にロボットの動作を生成し，ロボットによる被覆作業を実現した．近年，工場のロボット化が行われているが，ロボット化できない作業はまだまだ存在している．それらは，人間にしか行えないような巧みで複雑な作業，あるいは，ロボットより人間の方が効率的にできてしまうような作業である．そのような作業の１つとして，布を扱う作業が挙げられる．布を扱う作業の中には，布単体だけでなく，物体も一緒に取り扱っていく被覆作業が多く存在している．しかし，この被覆作業をロボットに指示するための有効な作業モデルは確立されていない．先行研究では，ロボットによる布操作の記述方法として，点，折り線や手先経路が用いられている．また，コンピュータグラフィクス分野では目標線という記述方法があり，これは被覆を表現するために用いられている．被覆作業をロボット化する上では，まず，実世界のロボットのために，汎用的な被覆モデルとして必要となる物体と布の関係や作業手順を，どのように記述すればいいのかという問題に直面する．このような点を考慮し，被覆作業に適した記述モデルを導入しなければならない．次に，そのような被覆のための作業記述を，実際のロボットにどのように入力すればいいのかという問題がある．煩雑な指示方法ではなく，実空間上で人間が考えている被覆作業を，直感的にロボットに指示できるのが望ましい．最後に，その作業記述から実際のロボットの動きをどのように生成すればよいのかという問題が現れてくる．ロボットが被覆作業を達成するためには，実際の手先軌道や干渉を回避するための動作を，状況に合わせて生成しなければならない．以上を踏まえて，本研究ではロボットによる被覆作業の課題に取り組んだ．具体的には以下の課題について取り組んだ．・布と物体の関係を適切に表す記述方法・直感的な被覆手順の指示方法・ロボットの動作軌道の生成方法まず，布と物体の関係を適切に表す記述方法について検討した．本研究では，コンピュータグラフィクス分野で用いられた目標線という記述方法を，実空間のロボットに導入することを提案した．この目標線は平面だけでなく曲面形状への指示が行いやすい．そして，物体のどこを布で包んでいくかという被覆の本質的な情報を自然に表せる利点を持つ．その中では，凹凸が存在するような物体に対しても被覆を行う場合があり，その凹凸を適切に処理して，作業を記述する必要がある．そこで，物体の埋めるべき凹部と埋めるべきでない凹部分を考慮し，凹凸へ適切な目標線指示を行うための局所凸という概念，及び局所凸生成方法を提案した．次に，直感的な被覆手順の指示方法について検討した．本研究では，人間の大まかな包む指示と被覆の関係を考え，物体と布のどこを重ね合わせるかという人間の被覆の意図を目標線として入力する方法を提案した．本研究は，作業指示を行う手の正確な３次元的な軌跡ではなく，手の軌跡とその軌跡が通過していく物体表面の関係に注目した．そして，デプスセンサとモーションキャプチャセンサを組合せた教示デバイスを用いて，人間の被覆の意図を抽出した．その中では，指示中の手振れの影響を小さくするための目標線逆走防止処理手法とスムージングと間引き処理を合わせた補正処理手法を提案した．最後に，ロボットの動作軌道の生成方法について検討した．本研究では，目標線と把持点から布の動きを表す手先経路を生成する方法と，その手先経路を実行するためのロボット動作の生成方法を提案した．実際のロボットを動かすためには，目標線だけでなく，手先経路や動作指令が必要であり，可動域や物体との干渉を考慮し，右手と左手を用いた布の持ち替えや持ち直しを行わなければならない．これらの情報を生成する上で，目標線が被覆の本質的な情報を保持している．そのため，手先経路・動作指令は自動的に生成可能である．動作生成手法の中では，各操作の布への重力の影響，動作ステップ数やロボットと布の位置関係を考慮した確実性を求め，それを基に生成された動作遷移グラフを用いて，最適な持ち替えや持ち直し操作の組み合わせを計画する方法を提案した．以上，本研究では，物体を布で包むという被覆作業について，ロボット化のための枠組みを提案した．さらに，各課題に対する提案方法を統合し，一連の被覆作業システムとして実装した．これにより，実際に人間の大まかな指示から，目標線を用いて布と物体の関係を記述し，そこから布の動きを表す手先経路，状況に合わせた最適なロボット動作を生成できるようになりロボットによる被覆作業が実現した．電気通信大学201

Crystallographic orientation control of pure chromium via laser powder bed fusion and improved high temperature oxidation resistance

This is the first comprehensive study on the development of a cubic crystallographic texture in pure chromium (Cr) manufactured using laser powder bed fusion (LPBF) with different laser energy densities to alter its microstructure and high-temperature oxidation behavior. An increase in the laser energy density led to the formation of a strong crystallographic texture, which was preferentially oriented in the (100) plane, and there were microstructural improvements in the pure Cr. The grain size of the (100)-oriented Cr was larger than that of the randomly oriented Cr. In addition, the high-angle grain boundary and coincident site lattice (CSL) boundary characteristics were altered. The (100)-oriented Cr exhibited a decrease in the oxide thickness that was due to the decrease in the grain boundary density with a larger grain size and an increase in the CSL boundary ratio. In contrast, the Cr with a random texture showed higher oxidation kinetics and spallation of the oxide layer. The oxidation kinetics of the pure Cr manufactured using LPBF obeyed the parabolic rate law. However, the crystal orientation affected the oxidation of the Cr as the (100)-oriented pure Cr displayed a lower parabolic rate constant, indicating that the (100)-oriented Cr was oxidation-resistant. This is the first report to demonstrate the cubic crystallographic texture formation and the improvement of high-temperature oxidation resistance in Cr manufactured using LPBF.Gokcekaya O., Hayashi N., Ishimoto T., et al. Crystallographic orientation control of pure chromium via laser powder bed fusion and improved high temperature oxidation resistance. Additive Manufacturing, 36, 101624. https://doi.org/10.1016/j.addma.2020.101624

Oxidative Dehydrogenation of Methane When Using TiO2- or WO3-Doped Sm2O3 in the Presence of Active Oxygen Excited with UV-LED

There are active oxygen species that contribute to oxidative coupling or the partial oxidation during the oxidative dehydrogenation of methane when using solid oxide catalysts, and those species have not been definitively identified. In the present study, we clarify which of the active oxygen species affect the oxidative dehydrogenation of methane by employing photo-catalysts such as TiO2 or WO3, which generate active oxygen from UV-LED irradiation conditions under an oxygen flow. These photo-catalysts were studied in combination with Sm2O3, which is a methane oxidation coupling catalyst. For this purpose, we constructed a reaction system that could directly irradiate UV-LED to a solid catalyst via a normal fixed-bed continuous-flow reactor operated at atmospheric pressure. Binary catalysts prepared from TiO2 or WO3 were either supported on or kneaded with Sm2O3 in the present study. UV-LED irradiation clearly improved the partial oxidation from methane to CO and/or slightly improved the oxidative coupling route from methane to ethylene when binary catalysts consisting of Sm2O3 and TiO2 are used, while negligible UV-LED effects were detected when using Sm2O3 and WO3. These results indicate that with UV-LED irradiation the active oxygen of O2− from TiO2 certainly contributes to the activation of methane during the oxidative dehydrogenation of methane when using Sm2O3, while the active oxygen of H2O2 from WO3 under the same conditions afforded only negligible effects on the activation of methane

Nationwide patient registry for GNE myopathy in Japan

BACKGROUND: GNE myopathy is a slowly progressive autosomal recessive myopathy caused by mutations in the GNE (glucosamine (UDP-N-acetyl)-2-epimerase/N-acetylmannosamine kinase) gene. This study aimed to (1) develop a nationwide patient registry for GNE myopathy in order to facilitate the planning of clinical trials and recruitment of candidates, and (2) gain further insight into the disease for the purpose of improving therapy and care. METHODS: Medical records of genetically-confirmed patients with GNE myopathy at the National Center Hospital of the National Center of Neurology and Psychiatry (NCNP) were retrospectively reviewed in order to obtain data reflecting the severity and progression of the disease. We also referred to items in the datasheet of the nationwide registry of dystrophinopathy patients in the Registry of Muscular Dystrophies (Remudy). Items selected for the registration sheet included age, sex, age at onset, past history and complications, family history, body weight and height, pathological findings of muscle biopsy, grip power, walking ability, respiratory function, cardiac function, willingness to join upcoming clinical trials, and participation in patient associations. A copy of the original genetic analysis report was required of each patient. RESULTS: We successfully established the Remudy-GNE myopathy. Currently, 121 patients are registered nationwide, and 93 physicians from 73 hospitals collaborated to establish the registry. The mean age at onset was 27.7 ± 9.6 years, and 19.8% (24/121) of patients could walk without assistance. Mean presumed durations from onset to use of assistive devices (cane and/or braces) and a wheelchair, and loss of ambulation were 12.4, 15.2, and 21.1 years, respectively. Three patients had a past history and/or complication of idiopathic thrombocytopenia. To share the progress of this study with the community, newsletters were published on a regular basis, and included information regarding new phase I clinical trials for GNE myopathy. The newsletters also served as a medium to bring attention to the importance of respiratory evaluation and care for respiratory insufficiency. CONCLUSION: The Japanese Remudy-GNE myopathy is useful for clarifying the natural history of the disease and recruiting patients with genetically-confirmed GNE myopathy for clinical trials. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13023-014-0150-4) contains supplementary material, which is available to authorized users

Contributions of phase resetting and interlimb coordination to the adaptive control of hindlimb obstacle avoidance during locomotion in rats: a simulation study.

Obstacle avoidance during locomotion is essential for safe, smooth locomotion. Physiological studies regarding muscle synergy have shown that the combination of a small number of basic patterns produces the large part of muscle activities during locomotion and the addition of another pattern explains muscle activities for obstacle avoidance. Furthermore, central pattern generators in the spinal cord are thought to manage the timing to produce such basic patterns. In the present study, we investigated sensory-motor coordination for obstacle avoidance by the hindlimbs of the rat using a neuromusculoskeletal model. We constructed the musculoskeletal part of the model based on empirical anatomical data of the rat and the nervous system model based on the aforementioned physiological findings of central pattern generators and muscle synergy. To verify the dynamic simulation by the constructed model, we compared the simulation results with kinematic and electromyographic data measured during actual locomotion in rats. In addition, we incorporated sensory regulation models based on physiological evidence of phase resetting and interlimb coordination and examined their functional roles in stepping over an obstacle during locomotion. Our results show that the phase regulation based on interlimb coordination contributes to stepping over a higher obstacle and that based on phase resetting contributes to quick recovery after stepping over the obstacle. These results suggest the importance of sensory regulation in generating successful obstacle avoidance during locomotion

Toward understanding transcriptional regulatory networks in abiotic stress responses and tolerance in rice

長崎大学学位論文 [学位記番号]博（医歯薬）甲第1168号 [学位授与年月日]令和元年6月5

Management of Multiple Primary Lung Cancer in Patients with Centrally Located Early Cancer Lesions

BackgroundPatients with centrally located early lung cancer (CLELC) are often heavy smokers with a considerably high risk of multiple primary lung cancer (MPLC) lesions; treatment strategies for such patients must preserve the cardiopulmonary function.MethodsBetween July 2004 and July 2008, patients with CLELC underwent photodynamic therapy (PDT) using NPe6, second-generation photosensitizer at Tokyo Medical University Hospital. Among these patients, we retrospectively analyzed MPLC, which was treated by surgery plus PDT or PDT alone and examined the effectiveness of PDT, and we propose a treatment strategy for patients with MPLC.ResultsA total of 64 patients with CLECL received NPe6-PDT, and MPLCs were found in 22 patients (34.4%) using sputum cytology and a bronchoscopical examination using autofluorescence bronchoscopy. Among these 22 patients, 10 patients underwent surgery for primary lung cancer and underwent NPe6-PDT for the treatment of secondary primary CLELC, one patient underwent PDT for CLELC as a primary lesion followed by an operation for peripheral-type lung cancer as a secondary primary lesion, and 11 patients underwent PDT alone for MPLC lesions (28 lesions) that were roentgenographically occult lung cancers. Among these 22 patients with MPLC including peripheral-type lung cancers, which were resected by surgery, all 39 CLELC lesions exhibited a complete response after PDT, and all patients were alive.ConclusionsFor patients with lung cancer with a long-term history of smoking, careful follow-up examinations after surgical resection are needed considering the incidence of metachronous primary lung cancers. PDT can play an important role for the treatment strategy for MPLC

Chest Wall Invasion by Peripheral Lung Cancer: Preoperative Assessment with Respiratory Dynamic MRI

Purpose: The purpose of our study was to evaluate the usefulness of dynamic cine MRI during respiration in the assessment of chest wall invasion by lung cancer. Materials and Methods: We prospectively performed respiratory dynamic MRI in 34 patients with peripheral lung cancer, in whom the presence of chest wall invasion was indeterminate on CT. Sequential images were obtained during respiration by using fast spoiled GRASS (SPGR) sequence, and were analyzed in cine mode display. Results: In all 23 patients with free movement of the tumor along the chest wall on respiratory dynamic cine MRI, no chest wall invasion was found at surgery (negative predictive value 100%). In eleven patients with fixation of the tumor to the chest wall, invasion was confirmed pathologically in five patients, while benign fibrous adhesion was found in six. Conclusion: Although it has some limitations, dynamic cine MRI during respiration is useful in evaluating chest wall invasion in patients with lung cancer, particularly when CT findings are indeterminate

Inhalation of 10% carbon dioxide rapidly terminates Scn1a mutation-related hyperthermia-induced seizures

The aim of this study was to assess the anticonvulsant effect of carbon dioxide (CO2) on Scn1a mutation-related febrile seizures. We examined physiological changes in the blood gas levels after the induction of hyperthermia-induced seizures (HISs), which were associated with the Scn1a missense mutation. We determined the efficacy of inhalation of 5% or 10% CO2 to treat HISs. HISs were evoked in Scn1a mutant and wild-type (WT) rats by hot water baths. To determine the anticonvulsant effect of CO2 inhalation, rats were placed in a chamber filled with air or mixed gas containing 5% CO2 or 10% CO2 for 3 min, immediately after the induction of HISs. We also analyzed the blood gas levels at the end of inhalation of CO2. Hot water bathing induced a significant reduction in the partial pressure of CO2 (pCO2) and respiratory alkalosis in the WT and Scn1a mutant rats. HISs were evoked in 100% of the Scn1a mutant rats within 5 min, but in none of the WT rats. The Scn1a mutant rats demonstrated a higher HISs susceptibility associated with respiratory alkalosis than the WT rats. Inhalation of 10% CO2 shortened the seizure duration from 62.6±12.1 s to 15.5±1.0 s. Blood gas analysis after the inhalation of 10% CO2 demonstrated an elevated pCO2 level and respiratory acidosis. Inhalation of 10% CO2 demonstrated a potent and fast-acting anticonvulsant effect against HISs