実社会の課題解決のためのデータ収集・分析・管理およびシステム化に関する研究

九州工業大学博士（情報工学）第１章 序論| 第２章 材料開発における実験フローデータ管理及び類似実験フロー検索| 第３章 対話型サービスロボットの開発における評価・改善のための業務ログデータ分析| 第４章 送配電網損傷に対する早期復旧のためのデータ収集システム復旧計画策定| 第５章 サービスロボット移動効率化のためのビル内状態データ収集及び経路探索システム| 第６章 結言センサ類や小型デバイスの設置によって種々の事象を観測し，大量のデータが蓄積・利用可能となって以来，様々な業種において，IT 技術により業務の効率化を図るデジタルトランスフォーメーション（DX）に対する期待が高まっている．DX において重要なのは期待する業務改善の効果を明確にすることと，それを実現するためのデータセットを整理することであるが，このためには（１）業務改善に必要なデータが既存システムにおいて利用可能でない（２）データ項目，フォーマットが統一されておらず，データの理解や統合が難しい（３）計測機器の生データやロボットの行動ログなど，そのままではデータ分析に活用できないデータが存在したり，複数のデータソースにデータが分散したりしており，データが分析に適した形式になっていない（４）実験データや生産実績データなど，類似データの横断的な検索や共通部分の抽出のように，データを柔軟に検索する方法がない，などの課題が存在する． 本研究はこのような背景に基づき，材料開発，サービスロボット，電力，ビル管理の４つの産業分野において，必要となるデータ収集・分析・管理およびシステム化に関して検討を行い，前述の課題をそれぞれの産業分野において解決するための具体的な手法について検討するとともに，その背後にある課題解決のための統一的な指針の明確化を目指す． 以下，本論文の構成に従って，概要を説明する．第１章では，DX の概要と，それを実現するためのデータ処理技術について概説し，実社会の課題解決のためにDX 推進におけるデータ収集・分析・管理の要件と課題を整理し，その解決方法を包括的に検討する． 第２章では材料開発(Material Informatics)における実験データ管理のためのシステム開発と，データ利活用を促進する類似実験フローの効率的な検索について説明する．材料開発の分野において，実験フローを材料研究者にとって統一的な形式で記述する実験データ管理基盤と，複数の実験フローを含む実験フローセットの中から，指定した条件に合致した実験フローを検索し，対象の実験フローからデータ分析に必要なデータセットを取得するための，類似実験フロー検索技術を提案する．仮想実験フローと検索を高速化するためのメタデータにより，典型的な材料開発のプロジェクトにおいて，類似実験フロー検索技術と単純手法とを比較し，提案手法が検索高速化において十分な効果が見込めることを確認した． 第３章では，対話型サービス（コンシェルジュ）ロボットの開発における評価・改善のための業務ログデータ分析について説明する．ユーザに対して対話を通して汎用的なサービスを提供するサービスロボットに対し，サービス提供者が目標と定めた業務指標値を改善するために必要なデータを，サービスロボットの行動データから特徴量として抽出するための行動ログデータ分析手法について検討し，技術展示会でのサービスコンシェルジュサービスを題材として，実社会でのデータ取得とデータ分析による評価を行った．サービスロボットの行動ログデータから，サービス品質の評価に有用な特徴量を抽出し，クラスタリングによる分類を行った．来場者の傾向を３パターンに分類した時の各クラスタ内のデータを詳細に分析した結果，来場者への対応が望ましい結果でなかったパターンが見られ，これを改善するようサービスロボットのシナリオを修正することで，業務改善の余地があることを知見として得た． 第４章では，台風によって発生した電力網への損傷に対する復旧計画の策定において，電柱の状態と，それによって付加的に得られる道路交通状況を勘案した，正確性の高い復旧計画策定技術について説明する．復旧計画の策定においては，電力網上において電柱，電線の損傷による故障点に対し，必要な人員と機器，資源，車両を送るスケジューリングが課題となるが，正確性の高いスケジューリングを実現するため，電柱に設置した柱上ジャイロセンサから得られる傾斜角および方位と，道路データから道路上の不通箇所を特定することで，道路上の閉塞区間と，これによる影響を加味した故障点間の移動コストを求める技術を提案した．提案手法を試作して，評価用の電力網に対して復旧計画の策定を行い，復旧にかかる時間を最適化計算として定式化して検証した結果，柱上ジャイロセンサによる移動コストを正確に計算した場合の方が，移動コストに誤りがある場合と比べて，短い時間で故障点を復旧することができ，なおかつ作業によって達成される復電容量も大きな値になるという結果を得た． 第５章はビル内における移動体経路検索技術について説明する．ビルIoT プラットフォーム向けに，ビル内で活動するロボット等の移動体に対し，ビル内状態に応じた最適経路を検索するビル内移動体経路探索技術の検討を行った．商業施設でのロボットによるサービス提供を想定し，ロボットの経路探索に必要な移動経由点の設定について検討した後，商業施設におけるカメラ配置の事例に基づき，移動経由点間の移動コストを監視カメラの映像分析や，施設設計時のシミュレーション結果などから類推する方法を提案した．移動経由点の集合で構成される移動経由点グラフを用いて，ロボットに対して移動経路を計算する移動経路探索システムを試作し，有用性を確認した． 第６章は結言であり，４つの分野の事例を通して，実社会の課題解決におけるデータ利活用の統一的指針と，配慮すべき点を検証した結果を総括した後，今後の展望について述べる．九州工業大学博士学位論文 学位記番号:情工博乙第61号 学位授与年月日:令和7年3月25日令和6年度doctoral thesi

Associative Decision Processes on Converging Branch System

In this paper, we consider finite-stage deterministic decision processes. The objective function is associative and the transition follows a converging branch system which is one of the nonserial systems. By using dynamic programming and invariant imbedding technique, the recursive equation is derived under the assumption that the order of decisions is predetermined.departmental bulletin pape

Assertive Communication Practice Using GPT: Development, Practice and Challenges

With the release of ChatGPT by OpenAI, the use of generative AI in education is accelerating. While various AI technologies have already been introduced into educational settings, the adoption of generative AI raises concerns about dependency and ethical issues, and researchers are warning to carefully evaluate its educational effectiveness. Collaborating with a researcher specializing in AI development for service robots, a teacher-researcher in language and culture education, explored the possibility of incorporating GPT into an educational module for intercultural communication. This paper is an empirical study examining chat data, GPT’s evaluation of learners, and learners’ self-evaluation obtained from the module. The study investigates the efficacy and limitations of the module by using the critical discourse analysis method. The findings suggest that the module provides opportunities to train learners in intercultural communication skills, however, it also highlights the need for improvements to maximize the effective use of GPT.departmental bulletin pape

Effects of various parameters on guidewire and catheter behavior during catheter introduction

Many guidewire penetration accidents occur during catheter introduction. Therefore, we have evaluated the behavior of medical devices such as guidewires and catheters during catheter introduction using numerical simulations. In our previous study, we evaluated the effects of the insertion velocity of the guidewire and the catheter and confirmed that during catheter introduction, the guidewire imparted a greater load on the vessel wall than that exerted by the guidewire alone. However, it was unclear whether the above phenomenon could also occur under other conditions. In the present study, in addition to these effects, we evaluate the effects of the blood vessel elastic modulus, device insertion length, blood vessel centerline curvature, and their interactions. Furthermore, we evaluate the behavior of the medical devices during guidewire removal after catheter introduction, which was not evaluated in our previous study. We determine the simulation conditions based on the design of experiments and investigate the dominant parameters that affect the contact force between the medical devices and the blood vessel wall using two methods (one that considers parameter interactions and one that does not). We confirm that during guidewire insertion and removal, the device velocity and the vessel centerline curvature have the largest effects, respectively. For the guidewire and the catheter during catheter introduction, the vessel elastic modulus and the insertion velocity have the largest effects, respectively, and the parameter interactions have large effects. These findings are clinically important because they are counterintuitive. During catheter introduction, the average contact forces are larger than those during both guidewire insertion and removal. Furthermore, during guidewire removal, the catheter tip moves in the distal direction.journal articl

Position control of a 3-link dual-arm underwater robot using model error compensator -Considering the difference in response speed between a vehicle and manipulators-

Research and development efforts are ongoing to control underwater robots equipped with manipulators (known as Underwater Vehicle-Manipulator Systems, or UVMS) that can perform underwater tasks in place of humans. We have also proposed a Resolved Acceleration Control (RAC) method, a position control approach for UVMS, and have validated its usefulness through experiments using a free-floating, 3-link dual-arm underwater robot. Now, the model of fluid forces used to control underwater robots has modeling errors. Furthermore, the response speed of the vehicle is much slower than that of the manipulator. To solve these problems, we propose a RAC method for UVMS with MEC, which takes into account the difference in response speed between the vehicle and manipulator, and demonstrate its effectiveness through experiments on the position control of a robot affected by periodic wave disturbances.conference pape

Detection of Diffusion-Generated Images Using Sparse Coding

This paper proposes a method for detecting images generated by diffusion models using sparse coding. In the diffusion model, an image can be generated by removing noise from a noisy image. This different generation process from real images leads us to believe that there may be a statistical difference in pixels between the real and the generated images. Specifically, the image is divided into small patch regions, and all patch images are reconstructed using the basis image. In this process, sparse coefficients that contain many zeros are obtained using sparse coding, and features are calculated from the obtained coefficients. Then, a simple discriminator using the features as input is trained with a small number of data to discriminate the diffusion-generated images. In our experiments, we evaluated the proposed method on six datasets created using three diffusion models and two real image datasets. Experiments were also conducted to evaluate the robustness of the proposed method against JPEG compression. Experimental results show that our proposed method is sufficiently robust against JPEG compression with as few as 1800 training data.journal articl

Comparative Study of Reinforcement Effects of Different Herbaceous Plant Roots on Fine-Grained Soil

This study investigates the reinforcement effects of the roots of three herbaceous plants—Kentucky bluegrass, Red fescue, and Hard fescue—on the shear strength of fine-grained soil. A series of direct shear tests were conducted to evaluate how root penetration influences the shear behavior and structural stability of root-soil composites. Results indicated that root-reinforced specimens demonstrated greater ductility, with shear stress increasing in later stages of shearing, thereby contributing to soil stability. Quantitative analysis revealed that Kentucky bluegrass roots increased cohesion by 2.29 kPa and the internal friction angle by 2.6°, while Red fescue roots increased cohesion by 2.84 kPa with a slight reduction in the internal friction angle by 0.35°. For Hard fescue, cohesion increased by 3.03 kPa, with the internal friction angle decreasing by 1.54°. These findings showed that root reinforcement varied significantly under different vertical stress conditions, emphasizing the importance of environmental factors in soil behavior assessment. Comparative analysis demonstrated that each plant species exhibited unique reinforcement effects under both low and high vertical stress, providing valuable insights for designing ecological slope stabilization solutions aimed at enhancing soil stability and promoting environmental sustainability.journal articl

Wireframe DNA Origami Capable of Vertex-protruding Transformation

Regulating dynamic behavior of the designed molecular structures provides a foundation for the construction of functional molecular devices. DNA nanotechnology allows conformational changes in two-dimensional and three-dimensional DNA origami nanostructures by introducing flexibility between the faces of the structures. However, dynamic transformations in wireframe DNA origami, composed solely of vertices and edges, remain challenging due to vertex-specific flexibility. We report a wireframe DNA origami capable of vertex-protruding transformation between the open- and closed-form with eight protruding vertices. This reversible transformation is driven by DNA hybridization and a toehold-mediated strand displacement reaction. Spacer strands between vertices and edges were designed to introduce flexibility. Coarse-grained molecular dynamics simulations demonstrated that a longer spacer increases conformational flexibility and can achieve the narrow angles required for the vertex-protruding transformation. The experimental results showed the successful assembly of the open-form structure under optimized salt conditions, as visualized through transmission electron microscopy images. Furthermore, the transformation between the open- and closed-form structures was demonstrated by the sequential addition of signal strands. This vertex-protruding transformation mechanism will expand the design approach of dynamic DNA nanostructures and help develop functional molecular devices for artificial molecular systems.journal articl

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凸多面体の重なりを持つ/持たない展開図

九州工業大学博士（情報工学）1 Introduction| 2 Preliminaries| 3 Overlapping unfolding for convex polyhedral| 4 The number of non-overlapping unfoldings in convex polyhedral| 5 ConclusionAn unfolding of a polyhedron is a flat polygon obtained by cutting along the polyhedron’s cutting lines and flattening its faces onto a plane. The origin of unfoldings can be traced back to Albrecht D¨urer’s work in 1525. Depending on the shape of the polyhedron and the method of unfolding, the resulting shape may overlap, where two distinct faces intersect on the plane, or their boundaries are in touch. When the cutting lines are restricted to the edges of the polyhedron, the unfolding is called an edge unfolding. Shephard proposed the conjecture that for any convex polyhedron, at least one non-overlapping edge unfolding exists; however, this conjecture remains unsolved. To solve this conjecture, some studies are ongoing. Horiyama et al. showed that the edge unfoldings of Platonic solids and five types of Archimedean solids do not have overlaps. On the other hand, overlapping edge unfoldings have been found for five other types of Archimedean solids. There remains the problem of whether overlapping edge unfoldings exist for other convex regular-faced polyhedra, such as the snub cube, icosidodecahedron, rhombitruncated cuboctahedron, Archimedean prisms, Archimedean antiprisms, and Johnson solids. For cuboids, when the cutting lines are aligned with the unit squares on the faces, the unfolding is called a lattice unfolding. Uno showed that the lattice unfolding of a 1×1×z cuboid, where z ≥ 3, has overlapping lattice unfoldings, and Mitani et al. showed an overlapping lattice unfolding for an x × y × z cuboid with x ≥ 1, y ≥ 2, and z ≥ 3. Conversely, Hearn showed that the lattice unfolding of a 1×1×2 cuboid does not overlap, and Sugihara demonstrated the same for a 2 × 2 × 2 cuboid. However, determining the conditions under which overlapping lattice unfoldings exist for cuboids with diagonal lattice cutting lines remains an open problem. In this study, we address two main problems. The first problem is determining whether a given polyhedron has overlapping unfoldings. The second problem is counting the number of overlapping and non-overlapping unfoldings when a given polyhedron has overlapping unfoldings. For the first problem, we introduce an algorithm called rotational unfolding, which efficiently determines whether overlapping unfoldings exist for a given polyhedron. The basic principle of our method is similar to the rolling and unfolding method proposed by DeSplinter et al., but it is extended to n-gons by proposing pruning techniques that use a polyhedron’s distance properties and symmetry. Using this algorithm, we show the existence of overlapping unfoldings for both edge unfoldings of convex regular-faced polyhedra and lattice unfoldings of cuboids. As a result, we solve the problem of whether overlapping edge unfoldings exist for convex regular-faced polyhedra and present the conditions for overlapping lattice unfoldings in cuboids with diagonal lattice cutting lines. For the second problem, we propose an algorithm to count non-overlapping unfoldings in polyhedra that have overlapping unfoldings. The algorithm first enumerates the minimal overlapping partial unfoldings (MOPUs), which are the minimal units of edge unfoldings with overlaps. Then, we construct a zero-suppressed binary decision diagram (ZDD) representing non-overlapping unfoldings by subtracting the ZDDs of overlapping edge unfoldings containing the MOPUs from the ZDD representing all edge unfoldings. By applying this algorithm, we calculate the number of non-overlapping edge unfoldings for several convex regular-faced polyhedra and lattice unfoldings of cuboids. These results provide partial answers to the problems of counting overlapping and non-overlapping unfoldings for given polyhedra.九州工業大学博士学位論文 学位記番号:情工博甲第408号 学位授与年月日:令和7年3月25日令和6年度doctoral thesi