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制御対象の局所モデルを考慮したデータベース駆動形制御に関する研究
Get PDF九州工業大学博士（工学）1 序論| 2 局所モデルを考慮したデータベース駆動型制御の設計| 3 数値シミュレーション| 4 極配置解析による安定解析| 5 結論と今後の展望九州工業大学博士学位論文 学位記番号:生工博甲第482号 学位授与年月日:令和6年3月25日令和5年度doctoral thesi
A Dissipativity Framework for Input-to-State Stability with Positivity of Dynamical Systems with Interior Equilibria
Get PDFThis paper proposes a module-based framework for analyzing and designing dynamical systems evolving on positive orthants and having stationary points in their interior. Dissipativity theory is a widely-used concept that allows one to assess a property of a system by aggregating dissipativity of its components. Popular storage functions and supply rates do apply to positive systems, but do not give information about the positivity. This paper employs non-vector space storage functions encompassing logarithmic functions to formulate input-to-state stability (ISS) with positivity guarantee, and shows how its dissipativity characterization can effectively address system interconnections. The developed supply rates and criteria are not only asymmetric to fit non-vector state spaces, but also carry equilibrium information which is inherent in positive systems exhibiting interior equilibria. Mathematical and practical examples illustrate that the proposed framework offers flexibility in applying to various system interconnections.journal articl
Relationship Between Fish Community Structure and Environmental Factors of Urban Streams in The Tsurumi River System
Get PDF本研究は環境劣化が著しく，生物相の情報が不足する鶴見川流域の支川域を中心に，魚種の生息状況および魚類群集構造と環境要因との関係を解明したものである．調査対象とした71地点は，魚類相の類似度から感潮域，非感潮域および種多様性が低い地点の3群に分類された．非感潮域では国内外来種が指標種として選択され，また，種多様性が低い群では，大陸系統のドジョウ属が多く確認された地点がみられ，在来魚種への影響が懸念される．一方，魚食性の外来魚は極めて少なく，都市化による河道物理環境の劣化が，種多様性低下の最も大きな要因と考えられる．また，種多様性が低い場所は，流速や水深の多様度が小さく，都市率や河床のコンクリート被覆度が環境を劣化させる主要因であることが明らかとなった．Urbanization causes river environmental degradation and reduction of biodiversity. The purpose of this study is to reveal the relationship between environmental factors and fish community structure of highly urbanized small and medium sized river. The 71 sites surveyed were classified into three groups based on similarity of fish fauna: tidal, non-tidal, and low species diversity. In the non-tidal area, domestic alien species were selected as indicator species, and in the low species diversity area, many non-native loach species (Misgurnus sp (clade B2)) were observed, which may have an impact on native fish species. On the other hand, the number of carnivorous non-native fish species was extremely low, and the degradation of the physical environment of the stream channel due to urbanization is considered to be the most significant factor in the decline in species diversity. The low species diversity was also associated with low velocity and depth diversity, indicating that the urbanization rate and the degree of concrete coverage of the streambed are the main causes of the environmental degradation.journal articl
Control System Design Using Optimization Solvers for Achieving Time-Domain and Frequency-Domain Performances Simultaneously
Get PDFThe objective of this paper is to give a controller design method using optimization solvers for achieving desired time-domain and frequency-domain performances simultaneously in discretetime systems. The time-domain performance is described by constraint conditions for overshoots, undershoots, rising times and so on. The frequency-domain performance is described by an H-infinity norm condition for robust stability. The proposed design method reduces the controller design problem for achieving these performances to a nonconvex nonlinear optimization problem. Although the obtained problem is not convex, the optimization solvers of Matlab can yield a local optimal solution which satisfies the constraint conditions for achieving the performances, which is demonstrated by a numerical example.journal articl
Preparation and characterizations of antibacterial poly(methyl methacrylate) bone cement via copolymerization with a quaternary ammonium monomer of dimethylaminotriclosan methacrylate
Get PDFPoly (methyl methacrylate) (PMMA) bone cement relies on the loaded antibiotic to realize the antibacterial purpose. But the exothermic behavior during setting often makes temperature-sensitive antibiotics inactivated. It is necessary to develop new material candidates to replace antibiotics. In this study, a new quaternary ammonium methacrylate (QAM) monomer called dimethylaminetriclosan methacrylate (DMATCM) was designed by the quaternization between 2-(Dimethylamino)ethyl methacrylate and triclosan, then employed as the modifier to explore the feasibility of equipping bone cement with antibacterial activity, and to investigate the variations on the physical and biological performances brought by the substitution ratio of DMATCM to MMA. Results showed that DMATCM opened its C=C bonding to participate in the MMA polymerization, and the quaternary ammonium group helped it to perform broad-spectrum antibacterial property against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. With an increased substitution ratio of DMATCM to MMA, the glass transition temperatures, the maximum exothermic temperatures, and the contact angles of bone cements declined, but the residual monomer contents, the fluid uptakes, and the setting times under Vical indentation increased. Long-term soaking made almost no changes to the weight loss and the mechanical properties of DMATCM-modified cements with lower substitution ratios of 0∼20%, and the activation rather enhanced the strengths of uncured AMBC-4 and AMBC-5 samples. Owing to more DMATCM exposed on the cement surface, the inhibition ring diameter produced by modified cement was improved to a maximum of 28.09 mm, and MC3T3-E1 cells performed the cell viabilities all beyond 70% and healthy adhesion after 72 h co-culturing. Taking all measured properties and ISO standards into account, the antibacterial bone cement under the ratio of 10% performed better, besides its good bactericidal effect, the other properties satisfied the requirements for clinical application.journal articl
A Monocular Fisheye Video-Based 2D to 3D Pose Lift Technique with Multiperson Spatial Context Integration
No full textIn this paper, we propose a person intrinsic scaling method for our novel spatio-temporal encoding based 2D to 3D pose lifting technique from monocular fisheye video. While 2D pose estimation has advanced significantly, it lacks depth information and cannot capture out-of-plane movements. To handle this problem, 3D pose estimation is required. This paper proposes a framework for 2D to 3D pose lifting that tackles challenges in fisheye videos. Our method addresses fisheye deformation through a person's intrinsic scaling approach and leverages a transformer architecture with spatio-temporal self attention for pose lifting. We introduce a novel per-person scaling method to handle the depth ambiguity inherent in fisheye images. In a real life care facility data set, our framework outperformed Mediapipe, a state-of-the art method for pose lifting, in 4 different type of activity poses with a mean rmse, mae and mape value of 0.082, 0.047, and 0.046 respectively. This approach shows a new direction for 2D to 3D pose lifting technique.journal articl
XCLIMBER: Design and Development of an Energy-Efficient Free-Climbing Robot with Self-Locking Mobility for Extreme Terrain
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A Denoising Method from Low-dose CT Images Based on Improved U-Net with Attention Mechanism
Get PDFJapan has the highest number of CT scanners per million population among developed countries, and the annual medical radiation dose is about four times the world average. Screening of high-risk populations with low-dose CT has been shown to reduce lung cancer mortality. However, in order to obtain image quality comparable to that of normal-dose CT, it is necessary to accurately estimate the image noise of low-dose CT. In this paper, we apply a noise reduction method using convolutional neural networks: the CNN model is based on U-Net, a fully convolutional network with encoder-decoder structure, with two convolutional layer modifications and three attention mechanisms. Experimental results using whole body slice CT images of piglets show that the proposed method is useful by comparing with CT images of normal dose and by evaluating image quality using peak signal-to-noise ratio (PSNR).conference pape
Nanobioengineered Al2O3 Core–Shell Nanoparticle Preparation Using Bauhinia Variegate Plant Extract for Efficient Photocatalysis and Electrochemical Sensing
Get PDFCore–shell-based nanomaterials have garnered considerable attention in the recent past not only in catalytic applications but also in their potentiality in selective and efficient sensing. Present research reports the first and successful biosynthesis of the core (c-Al2O3)–shell nanoparticles (NPs) using Bauhinia variegate blossom extract as reducing and capping agents. The synthesized c-Al2O3 NPs were characterized and utilized to fabricate nanobioengineered electrodes on indium tin oxide (ITO) substrates via electrophoretic deposition. Electrochemical analysis, including cyclic voltammetry and differential pulse voltammetry, revealed quasi-reversible processes with high electron-transfer rates (Ks = 0.66 s–1) and a diffusion coefficient (D = 5.84 × 10–2 cm2 s–1). The electrode exhibited a very high sensitivity (23.44 μA μM–1 cm–2) and a low detection limit (0.463 μM) for sodium azide (NaN3) over two linear ranges of 1–6 and 8–20 μM. Additionally, c-Al2O3 NPs demonstrated the effective photocatalytic degradation of crystal violet dye under visible light, following pseudo-first-order kinetics. The fabricated electrode showed excellent selectivity, stability, and reproducibility, highlighting its potential for environmental monitoring and clinical diagnostics.journal articl
A Transparent Method of Microservices for Monolithic Programs toward Effective Utilization of Edge Resources
Get PDFThere has recently been a lot of research and development on edge computing technology. As the number of servers in an edge network is limited, efficient management of computational resource utilization is important. To address the issues, our research group has been developing a method that partitions a program into small processes and executes each process on a different edge server to maximize edge resource utilization [1]. However, this research assumes that a program is developed as a set of small processes. We did not consider how to create specific that processes. In this study, to maximize the efficiency of resource utilization in edge networks, we propose a method for partitioning a single (monolithic) program into small processes (called unit processes) and providing them as microservices by embedding a communication function into each unit process.conference pape