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Solar-Sail Orbit Capture at Celestial Bodies from L1 Periodic Orbits
Full text link九州工業大学博士（工学）1 INTRODUCTION| 2 DYNAMICAL MODEL| 3 OPTIMAL SRP-ASSISTED TRANSFERS FROM HALO ORBITS TO CELESTIAL BODIES| 4 SOLAR SAIL-BASED ORBITAL INSERTION| 5 CONCLUSIONS AND FUTUREWORK九州工業大学博士学位論文 学位記番号:工博甲第610号 学位授与年月日:令和7年9月25日令和7年度doctoral thesi
超小型衛星搭載One-Way測距システムに関する研究
Full text link九州工業大学博士（工学）1 序論| 2 SPATIUM-II TECシステム開発と試験結果 [30] | 3 OPERA軌道決定システム開発と地上試験結果| 4 総括九州工業大学博士学位論文 学位記番号:工博甲第611号 学位授与年月日:令和7年9月25日doctoral thesi
Synthesis of carbon nanocomposites consisting of nanocellulose-derived carbon and reduced graphene oxide for high-performance captive deionization
Full text linkSeveral types of nanocellulose-derived carbon/reduced graphene oxide (rGO) nanocomposites are synthesized using three nanocellulose types: cellulose nanofibers (CNF), long cellulose nanocrystals (CNC-L), and short cellulose nanocrystals (CNC-S). The nanocomposites achieve a large surface area due to the small nanocellulose fibers acting as spacers. For the capacitive deionization (CDI) test, the CNC-L/rGO is selected and compared with the rGO prepared without nanocelluloses. It achieves a high sodium ion adsorption capacity of 45.67 mg g−1 and a high salt adsorption capacity of 57.08 mg g−1 at a NaCl concentration of 2000 mg L−1. Excellent stability and performance are also confirmed across varying saline concentrations. These outstanding properties make the CNC-L/rGO a promising electrode material for efficient and sustainable water desalination.journal articl
外乱オブザーバの統一理論の構築に向けた包含関係と有効性の理論的解析
Full text link九州工業大学博士（情報工学）第1章 序論| 第2章 外乱オブザーバの包含関係| 第3章 外乱オブザーバの有効性|第4章 結論九州工業大学博士学位論文 学位記番号:情工博甲第409号 学位授与年月日:令和7年3月25日令和6年度doctoral thesi
Investigation report of damage to levee on the Kosegawa River due to July 2023 torrential rains
Full text linkFrom July 7 to 10, 2023, the activity of a stationary front intensified, prompting the issuance of the emergency warning for heavy rains in Fukuoka and Oita prefectures. In some observation points in northern Kyushu, the recorded rainfall reached the highest levels in history. As a result, the water levels of the Kose River, a primary tributary of the Chikugo River, rose significantly, causing flooding and inundation damage in surrounding areas due to overtopping and overflow. The authors conducted a comprehensive field survey around the affected river levees near the Kose River starting on July 16, 2023, approximately nine days after the disaster. The survey methods included meticulous on-site inspections and detailed aerial photography using UAVs. From the field survey, although the maximum river water level was observed, the damage to the levee was limited. This result suggests that rising water levels on the landside may affect the levee.journal articl
Research Group Introduction: Power Electronics Laboratory, Dept. of Electrical and Electronic Engineering, Kyushu Institute of Technology
Full text linkThis article introduces Power Electronics Laboratory at Department of Electrical and Electronic Engineering, Kyushu Institute of Technology, which focuses on reliability-related issues of power electronic converters including power semiconductor devices and capacitors.journal articl
Robust Positivizing and Stabilizing Controllers for Prescribed Positive Equilibria
Full text linkParameters and set pints of external variables in differential equations influence not only equilibria and their stability, but also system positivity. It sharply contrasts with the artificial but standard control formulation in which zero of the state is always an equilibrium, and we concentrate on the stability of the zero equilibrium. This paper deals with non-zero equilibria of nonlinear dynamics variables whose realizable domains are positive, such as mass, concentration, population, and logistic quantities. Once a desired positive point is picked in the state space, we first need to determine set points of input variables to render the point an equilibrium, Then, we design a feedback control to ensure the state variables their positivity and convergence to the equilibrium. Moreover, we want to have the control mechanism equipped with robustness for uncertainties and disturbances. This paper proposes a novel approach to this problem by using positivizing Lyapunov functions formulated with asymmetric supply rates.journal articl
身体特徴および動作特徴に基づく適応的着衣介助ロボットの開発
Full text link九州工業大学博士（工学）九州⼯業⼤学博⼠学位論⽂ 学位記番号：生工博甲第509号 学位授与年⽉⽇: 令和7年3⽉25⽇令和6年度doctoral thesi
Detecting Advanced Persistent Threat Exfiltration with Ensemble Deep Learning Tree Models and Novel Detection Metrics
Full text linkAdvanced Persistent Threats (APTs) involve attackers maintaining a long-term presence on victim systems, leading to the stealthy exfiltration of sensitive data during network transfers. Despite existing methods to detect and halt APT data exfiltration, these attacks continue to pose significant threats to sensitive information and result in substantial commercial losses. Current approaches primarily focus on preemptive measures, which are insufficient once early-stage detection fails due to a lack of continuous monitoring. We propose an effective and efficient network monitoring method to address this gap and detect APT exfiltration during data transfer. Our approach assumes the presence of an undetected APT attacker within the victim system. We examine data exfiltration across three exfiltration traffic environments: exfiltration over command control channels, exfiltration over transfer size limitations, and their combinations. We introduce two detection metrics: Package Transfer Rate and Byte Transfer Rate. Utilizing these metrics, we measure network traffic, categorize APT attack environments, and train deep neural network models, named EDXGB, using ensembled decision trees to predict APT exfiltration. Our method is validated on two public datasets and compared against six baseline methods. Additionally, we simulate real-world exfiltration scenarios by creating three exfiltration traffic environments for each dataset. The results demonstrate that our method effectively detects APT exfiltration across various network environments, enhancing data protection and secure transfer. The code is open source and available at https://github.com/cxjuan/EDXGB-for-APT.journal articl