側鎖のコンフォメーションとダイナミクスに関連したボトルブラシポリマーの基礎および応用研究

京都大学新制・課程博士博士(工学)甲第23224号工博第4868号新制||工||1760(附属図書館)京都大学大学院工学研究科高分子化学専攻(主査)教授 辻井 敬亘, 教授 秋吉 一成, 教授 竹中 幹人学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA

Integration of Imitation Learning using GAIL and Reinforcement Learning using Task-achievement Rewards via Probabilistic Graphical Model

Integration of reinforcement learning and imitation learning is an important problem that has been studied for a long time in the field of intelligent robotics. Reinforcement learning optimizes policies to maximize the cumulative reward, whereas imitation learning attempts to extract general knowledge about the trajectories demonstrated by experts, i.e., demonstrators. Because each of them has their own drawbacks, methods combining them and compensating for each set of drawbacks have been explored thus far. However, many of the methods are heuristic and do not have a solid theoretical basis. In this paper, we present a new theory for integrating reinforcement and imitation learning by extending the probabilistic generative model framework for reinforcement learning, {\it plan by inference}. We develop a new probabilistic graphical model for reinforcement learning with multiple types of rewards and a probabilistic graphical model for Markov decision processes with multiple optimality emissions (pMDP-MO). Furthermore, we demonstrate that the integrated learning method of reinforcement learning and imitation learning can be formulated as a probabilistic inference of policies on pMDP-MO by considering the output of the discriminator in generative adversarial imitation learning as an additional optimal emission observation. We adapt the generative adversarial imitation learning and task-achievement reward to our proposed framework, achieving significantly better performance than agents trained with reinforcement learning or imitation learning alone. Experiments demonstrate that our framework successfully integrates imitation and reinforcement learning even when the number of demonstrators is only a few.Comment: Submitted to Advanced Robotic

コトナルドジョウヨウブンノウドデイクセイシタブナナエノコウゴウセイトセイチョウニタイスルオゾンノエイキョウ

博士（農学)東京農工大

Synthesis and two-dimensional ordering of asymmetrically polymer–brush–decorated cellulose nanocrystals

Rod-shaped cellulose nanocrystals (CNCs) are typically obtained by hydrolyzing cellulose nanofibers bearing an formyl group at their reducing end. In this study, we prepare CNCs bearing densely grafted polymer brushes of different molecular weights (asymmetrically polymer-brush–decorated CNCs; aPB-CNCs). aPB-CNCs exhibit good dispersion in organic solvents and form a monolayer at the air/water interface. The compression of this monolayer induces a phase transition of a long polymer brush at the reducing end and a change in the orientation of the CNC core due to repulsive interactions. A CNC is identified as a key intermediate, possessing dormant moieties for reversible addition–fragmentation polymerization and atom transfer radical polymerization at the reducing end and other surfaces, respectively (bifunctional dormant CNC). This functional CNC facilitates the polymerization of a wide range of monomers and enables the synthesis of aPB-CNCs with diverse chemical properties. The developed synthetic route not only provides a basis for exploring the ordered structure of nanoparticles but is also useful for modifying the reducing ends of CNCs

Anti-icing properties of nonionic/hydrophilic concentrated polymer brushes and mechanistic insights via their swollen-state analysis

濃厚ポリマーブラシの防着氷機能を実証 --その場分析により機能発現メカニズムを解明-- . 京都大学プレスリリース. 2025-02-10.Anti-icing surfaces are important to prevent snow and ice accumulation, which can pose significant risks. Here, we analyze the anti-icing performance of concentrated polymer brushes (CPBs) consisting of a versatile nonionic/hydrophilic monomer and discuss the low-temperature properties of the CPB-retaining water. The anti-icing functionality is evaluated by measuring the ice adhesion strength as a function of the temperature and the structural parameters (e.g., density and length) of the polymer brushes. We demonstrate that only the CPB region (σ* ≥ 0.15) exhibits both high anti-icing functionality and excellent durability. Furthermore, the thickening of the CPBs is key to achieving a detailed characterization of the water present in the CPBs at low temperatures using in situ microscopic Fourier-transform infrared spectroscopy and differential scanning calorimetry. These results suggest that the water effectively remaining via quasi-equilibrium partial deswelling formed a lubricating layer, contributing to high anti-icing functionality and durability

Variation in growth enhancement by elevated CO2 in Japanese mustard spinach (Brassica rapa var. perviridis)

The atmospheric CO2 is projected to increase in the future. The elevated CO2 generally enhances the growth and yield of crops through the acceleration of the net photosynthetic rate. It is well known that, for major crops such as rice and soybean, the elevated CO2‑induced enhancement varies with environmental conditions. However, there is limited information regarding the variation in the enhancement in leafy vegetables. To understand the growth response of leafy vegetables to elevated CO2, in the present study, Japanese mustard spinach (Brassica rapa var. perviridis), a year‑round leafy vegetable cultivated under various environmental conditions, was grown in pots inside open‑top chambers and exposed to ambient CO2 or elevated CO2 (ambient + 200 μmol mol‑1). The experiment was conducted eight times from September 2020 to November 2021. The extent of elevated CO2‑induced stimulation of relative growth rate (RGR) of whole‑plant (RGRW) differed among the experiments. The extents were less pronounced in the experiments with higher net assimilation rate (NAR) in the ambient CO2 treatment, which was due to higher photosynthetic photon flux density. This result suggests that the environmental conditions conducive to higher source strength suppressed the elevated CO2‑induced growth enhancement. In contrast, the ratio of RGR of root and stem to that of leaf (RGRR+S/RGRL), which could roughly reflect sink‑source balance, was significantly and positively correlated with the extent of elevated CO2‑induced stimulation in the RGRW. Although it is unclear which environmental factors were responsible for higher RGRR+S /RGRL, this result suggests that higher sink strength relative to source strength intensified the elevated CO2‑induced growth enhancement. Therefore, it was concluded that sink‑source relationship could be important determinant for the growth enhancement of Japanese mustard spinach by the elevated CO2.Journal of Agricultural Meteorology, 81(2), pp.66-72; 2025journal articl

フェノールフタレイン溶液を利用した コンクリート構造物の火害調査手法に関する研究

東京理科大学博士（工学）2024doctoral thesi

Inspiratory and Expiratory Computed Tomography Imaging Clusters Reflect Functional Characteristics in Chronic Obstructive Pulmonary Disease

Purpose: Disease probability measure (DPM) is a useful voxel-wise imaging assessment of gas-trapping and emphysematous lesions in patients with chronic obstructive pulmonary disease (COPD). To elucidate the progression of COPD, we performed a cluster analysis using the following DPM parameters: normal (DPMNormal), gas-trapping (DPMGasTrap), and emphysematous lesions (DPMEmph). Our findings revealed the characteristics of each cluster and the 3-year disease progression using imaging parameters. Patients and methods: Inspiratory and expiratory chest computed tomography (CT) images of 131 patients with COPD were examined, of which 84 were followed up for 3 years. The percentage of low attenuation volume (LAV%) and the square root of the wall area of a hypothetical airway with an internal perimeter of 10 mm (√Aaw at Pi10) were quantitatively measured using inspiratory chest CT. A hierarchical cluster analysis was performed using the DPM parameters at baseline. Five clusters were named according to the dominant DPM parameters: normal (NL), normal-GasTrap (NL-GT), GasTrap (GT), GasTrap-Emphysema (GT-EM), and Emphysema (EM). Results: Women were predominantly diagnosed with GT. Forced expiratory volume in 1 s gradually decreased in the following order: NL, NL-GT, GT, GT-EM, and EM. DPMEmph correlated well with LAV%. Four clusters other than NL showed significantly higher values of √Aaw at Pi10 than NL; however, no significant differences were observed among them. In all clusters, DPMEmph increased after 3 years. DPMNormal only increased in the GT cluster. Conclusion: Clusters using DPM parameters may reflect the characteristics of COPD and help understand the pathophysiology of the disease.journal articl

Insights into Land Plant Evolution Garnered from the Marchantia polymorpha Genome.

The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP

Dorsal horn-enriched genes identified by DNA microarray, in situ hybridization and immunohistochemistry

BACKGROUND: Neurons in the dorsal spinal cord play important roles in nociception and pain. These neurons receive input from peripheral sensory neurons and then transmit the signals to the brain, as well as receive and integrate descending control signals from the brain. Many molecules important for pain transmission have been demonstrated to be localized to the dorsal horn of the spinal cord. Further understanding of the molecular interactions and signaling pathways in the dorsal horn neurons will require a better knowledge of the molecular neuroanatomy in the dorsal spinal cord. RESULTS: A large scale screening was conducted for genes with enriched expression in the dorsal spinal cord using DNA microarray and quantitative real-time PCR. In addition to genes known to be specifically expressed in the dorsal spinal cord, other neuropeptides, receptors, ion channels, and signaling molecules were also found enriched in the dorsal spinal cord. In situ hybridization and immunohistochemistry revealed the cellular expression of a subset of these genes. The regulation of a subset of the genes was also studied in the spinal nerve ligation (SNL) neuropathic pain model. In general, we found that the genes that are enriched in the dorsal spinal cord were not among those found to be up-regulated in the spinal nerve ligation model of neuropathic pain. This study also provides a level of validation of the use of DNA microarrays in conjunction with our novel analysis algorithm (SAFER) for the identification of differences in gene expression. CONCLUSION: This study identified molecules that are enriched in the dorsal horn of the spinal cord and provided a molecular neuroanatomy in the spinal cord, which will aid in the understanding of the molecular mechanisms important in nociception and pain