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アフガニスタンにおける地盤工学的問題とその対策に関する研究
Get PDFSince humans have historically used soils as a construction material and foundations support for allthe super structures, thus it's very important to enhance up the human knowledge regarding the soilsmechanical or engineering properties.Ignoring or less attention to the soils behavioural properties could direct the civil engineeringstructures to problematic, sometimes to an unsolvable or a catastrophic problem, such as waterdames, underground tunnels, elevated transportation facilities and railway tracks, offshore structuresand etcetera. Investment in such kind of civil engineering facility, long-life and proper performancerequires and desires from each project, wither vertical or horizontal structure such as high-raisebuilding, memorial towers, elevated highways, elevated water storage structures, Dam barriers,offshore structures, roads, railway tracks etc. The long term performance of all the above-mentionedfacilities could encamp surface study of structures reliability and lifetime proper perfonnance, butthere are also some essential studies to be focused on, that called sub-surface study or geotechnicalengineering. Enhancing up geotechnical engineering study and its proper application can direct thewhole civil engineering structures to a safe and future, by improving the geotechnical and soilengineering the investor and beneficiaries could achieved their assigned goals and paved the way ofsociety to a developing or developed nation.For better safety of the super structures, against slope instabilities and earthquakes, the followingstudy and focusing is vital to be considered.The slopes that involve rock-cut, natural rock slopes mainly. The effect of structural geology anddiscontinuous nature of rock mass on both slope-cuts and natural rock slopes is considered and somepreliminary assessments on the stable and unstable rock slopes are presented. Furthermore, theseismic effect on their stability is also considered. It is also pointed out that similar issues could beobserved in open-pit mines, which may be exploited in years to come, moreover, the 2022 Paktikaearthquake will be discussed that happened in Paktika and Khost Provinces of Afghanistan. Thisstudy will be concerned with the evaluation of strong motions caused by the earthquake by utilizingempirical methods, finite element method and empirical green function method. The evaluations andestimations of maximum ground acceleration, velocity and permanent ground deformations.In specific, the research study will be focusing on Geotechnical Issues in Afghanistan and SomeSolutions with a Special Emphasis on Kandahar Region.博士（工学）琉球大学University of the Ryukyu
アフガニスタン・ヘラート旧市街における伝統的モスクの物的特徴、類型、変容と保存に関する研究
Get PDFThis study comprehensively identifies a possible period of development, architectural typology,physical features (distribution, height, and plan shapes), transformation, and presents a preservation plan forthe mosques in the Quzzat quarter of the Herat Old City, Afghanistan.First, the study analyzes architectural typology and determines the period of construction of thepreserved traditional mosques in the study area. Twenty-nine mosques were in the quarter, 3 of which aremodem and 26 traditional. Twelve out of 26 are still Traditional, preserving the traditional landscape. Using an.analogy analysis on water supply cisterns and mosques to determine when each mosque was developed, ap eriodof development was established for each mosque. Aichitectural analysis and typologies of the mosques suggestthat・five buildings were developed before the Timurids, two of them during the Timurid Dynasty (AC 1370-1507), and one was developed after the Timurid Dynasty. Two mosques incorporating elements of differentperiods are counted as exceptions, and two are considered transitional periods.Secondly, the study examines the physical features of traditional mosques in Quzzat quarter of HeratOld City, Afghanistan. Traditional mosques are constructed with local available materials and are planned basedon cultural and climatic conditio謳Mosquesare categorized as modem or traditional. Traditional mosques aredivided into three subcategories:_ preserved, damaged (defaced), and transformed. Transformed mosques areformerly traditional mosques reconstructed with modem materials (concrete). This study explores thedistribution of mosques and analyzes their plan typology. Mosques are categorized into five plan types, andthree case stttdies are described in detail to provide abe tter understanding and an in-depth analysis of mosquefeatures.Thirdly, the study discovered the utban developments, typology of mosques, as well as destructions,changes, and transformations of the traditional mosques. It involved compiling data, conducting a field survey,examining historical maps, reviewing published works to explain constructions, and fmding out howtransformations took place. In total, twenty-nine mosques are constructed in the study area. Twenty-five of themwere originally constructed before WWII with traditional local material, and four were constructed after WWII;of these four, three are modem (concrete), and one is built with traditional material. Twelve out of the twentyfivetraditional mosques still e:xist in traditional form, while twelve have been transformed, and one has beendamaged. Modem mosques are found northwest of the quarter, where the city wall was razed, flattened, andtransformed in-to are sidential area. Transformations started after WWII and have occurred mainly in the southemparts of the quarter. The majority of the mosques in the northern areas are preserved, while in the southernregions they are transformed, and modem constructions were carried out in the newly urbanized areas.Finally, the study analyzes the preservation activities, plans, regulations, e:xisting situations, andconsiders some possibilities to preserve the structures from destruction.博士（工学）琉球大学University of the Ryukyu
A Study on Visual Intentions Estimation for Operation Assistance in Electric \Vheelchair Riding
Get PDF重度の身体障がい者の日常生活の支援に向けて,ジョイスティックの代わりにユーザの視線を用いて操作可能な電動車いすが開発されている.視線追跡インタフェースには不随意な眼球運動も入力操作として扱われるMidastouchproblemが存在するため,視覚的意図を分類することが重要である.そこで,肢体不自由者の電動車いす走行における操作支援のために,自然な眼球・頭部動作で操作可能な電動車いすの開発を目的として,ユーザの視覚的意図をリアルタイムに推定するモデルの開発と,その意図推定に基づいて操作できるよう制御系の設計・開発を行う.本論文は三部から構成される.第一部では,固視検出による視覚的意図推定手法を用いた制御系を開発した.ユーザの移動したい方向や注意が向いている方向を正確に識別するために視線滞留時間方式による固視検出アルゴリズムを実装し,走行実験を行った.実験の結果から,従来手法と比較して走行経路に優位な差は見られなかったが,被験者のアジケート結果では,従来手法よりも安全に走行できたとの意見が得られた.以上より,視線滞留時間方式を用いた視覚的意図推定手法の有用性を確認することができた.第二部では,眼球運動と頭部運動からユーザの視覚的意図をリアルタイムに推定するモデルを開発し,推定精度について評価した.推定精度の評価実験により得られた結果から,提案モデルによって｢前進｣,｢右折｣,｢左折｣といった移動に関する意図を高い精度で推定することができた.また,正確な推定には時間的な要素が不可欠であることが示唆された.第三部では,視覚的意図推定モデルを電動車いすの制御系に実装し,その操作性について評価した.操作性評価実験のアンケート結果から,著者が開発した制御システム(lDCNN-LSTMモデル＋視線滞留時間方式）は,視線滞留時間方式のみを用いた従来方法よりも有意に操作性が良いことが示された.また,自由回答アンケートでは,開発した制御システムを用いることで,意図したタイミングで曲がることができた他,曲がる際に壁に接近しすぎることなくスムーズに走行することができたとの回答が得られた.従来手法と比較して操作する際の労力が軽減され,操作性の向上が認められたことから,開発した視線入力型電動車いすの有用性を確認することができた.博士（工学）琉球大学University of the Ryukyu
共感的システムの構築のための音声と音響分析に関する研究
Get PDFThis thesis pioneers a comprehensive framework for empathetic systems, enhancing human interaction via advanced speech and acoustics analysis. Using generative models like variational autoencoders and conditional generative adversarial networks, our approach delves into classifying emotions in speech, enabling emotional transfer, and assessing risks via speech and ambient sounds. We begin with foundational emotion recognition, identifying "Happy," "Sad," "Angry," and "Neutral" states using variational autoencoders. In the pivotal phase, users select a voice agent and specify emotions ("Happy," "Angry," "Sad," or "Neutral"). The system generates nuanced speech audio, fostering empathetic responses, crucial for future home assistants'caregiving roles. Extending to risk analysis, we associate emotional speech with environmental noises, enhancing threat detection without compromising user privacy. Prioritizing detection as a fundamental step, our system enables artificial agents to identify abnormal situations, ensuring user safety. This work not only advances empathetic system creation but also contributes significantly to empathetic home assistance, safeguarding vulnerable populations in indoor environments.博士（工学）琉球大学University of the Ryukyu
下行大動脈ステント内挿術(TEVAR)時の運動誘発電位(MEP)を用いた脊髄虚血モニタリングの有用性および脊髄虚血リスク因子の解析~300例の検討から~
Get PDFObjective: This study investigated the usefulness of motor evoked potentials (MEPs) for intra-operative monitoring to detect the risk of spinal cord ischaemia (SCI) during thoracic endovascular aortic repair (TEVAR). Risk factors for SCI in TEVAR were also analysed.
Methods: Among 330 TEVARs performed from February 2009 to October 2018, 300 patients underwent intraoperative MEP monitoring. SCI risk groups were extracted based on MEP amplitude changes using a cutoff value of 50%. When the amplitude decreased to < 50% of the pre-operative value, intra-operative mean arterial pressure (MAP) was increased by about 20 mmHg using noradrenaline, whereas MAP was usually controlled to about 80 mmHg during surgery. Other efforts were also made to increase MEP amplitude by increasing cardiac output, correcting anaemia, and finishing the surgery promptly. Based on MEP amplitude data, SCI risk groups were extracted and risk factors for SCI in TEVAR were analysed.
Results: A total of 283 non-SCI risk patients and 17 SCI risk patients by MEP monitoring were extracted; only 1.0% developed immediate paraplegia and none developed delayed paraplegia. Bivariable analysis showed significant differences in chronic kidney disease, haemodialysis, artery of Adamkiewicz closure, and stent graft (SG) covered length 8 vertebral bodies. Logistic regression analysis showed hyperlipidaemia (odds ratio [OR] 3.55, 95% confidence interval [CI] 1.08 e 11.67; p ¼ .037), SG covered length 8 vertebral bodies (OR 1.35, 95% CI 1.02 e 1.78; p ¼ .034), and haemodialysis (OR 27.78, 95% CI 6.02 e 128.22; p < .001) were the most influential risk factors for SCI in TEVAR.
Conclusion: MEPs might be a useful monitoring tool to predict SCI in TEVAR. In addition, hyperlipidaemia, SG covered length 8 vertebral bodies, and haemodialysis represent key risk factors for SCI during TEVAR.博士（医学）琉球大学University of the Ryukyu
需要側の柔軟的管理戦略を考慮したレジリエントな再生可能エネルギーベ ースのマイクログリッドのための多目的基準計画の導入
Get PDFInherent variability ofVREs presents challenges in capacity sizing and operational planning of power systems. Conventional systems, with controllable generation sources, maintained a balance between supply and demand. In contrast, VREs, being weather-dependent, easily exacerbate power imbalances with possibilities of power interruptions. This dictates the need for improved planning approaches and the integration of flexible management strategies and technologies to enhance system responsiveness, stability and reliability. Flexibility refers to a power system's capacity to balance electricity supply and demand, especially with significant VRE integration. Although energy storage systems (ESS) offer promise in managing these fluctuations, their feasibility diminishes as VRE penetration increases, primarily due to cost constraints. Thus, a holistic approach is developed in this study to successfully integrate multiple VREs and ensure operational resilience even during unfavourable weather events. In the first approach, an integrated planning framework incorporates short-term operational strategies into long-term capacity planning for an isolated microgrid, aiming for increased VREs penetration fraction is proposed and investigated using Mixed ?integer linear programming algorithm. In the second approach, a bi-objective joint optimization planning approach with DRP strategies for a VRE-based microgrid is implemented. An enhanced demand response program with dynamic pricing devised based on instantaneous imbalances between surplus, deficit, and the battery's power capacity is developed with a quantitative metric for assessing energy storage performance. In the third approach, a multi-objective planning considering ESS and DRP for a VREs?based microgrid is investigated. Finally, the study proposes an integrated and comprehensive strategy for microgrid capacity and operation planning, utilizing forecasting and DRP strategies to manage VREs uncertainties. Uncertainties in VREs and load fluctuations are modelled using Monte Carlo simulations, while forecasting is based on the long Short-Term Memo巧model. To determine the best techno?economic planning approach, several cases are formulated and solved using multi-objective particle swarm optimization with multicriteria ranking for three objectives: total lifecycle costs, reliability criteria, and surplus VRE curtailment. Shortage?surplus adaptive pricing combined with variable peak critical peak pricing (SSAP VP-CPP) DRP is devised and compared with a time?of?use VP-CPP DRP in mitigating the impacts of both critical and non-critical events in the system.博士（工学）琉球大学University of the Ryukyu
西アフリカにおける再生可能エネルギーを利用したマイクログリッド電源の計画と運用：シエラレオネの事例
Get PDFWest Africa, to which Sierra Leone belongs, holds one of the largest populations on the continent. In 2017, only 51.3% of the region's population had access to electricity. Sierra Leone is suffering from a persistent electricity gap that has crippled its economic growth and prevented it from attaining several health and education development goals. This persistent electricity gap has generated significant interest in tackling the country's long-lasting energy deficiency. Providing electricity in a reliable, sustainable, and costeffective manner in Sierra Leone requires adopting robust integrated energy planning and appropriate technologies. Despite various interventions by the government, a balance between electricity demand and supply has yet to be achieved. As part of this study, we analyze potential alternatives to conventional electricity generation systems aimed at providing electricity in a sustainable, reliable, and affordable manner, including the use of renewable energy sources and technologies with less CO2 emissions. The thesis carried out A review of the power sector of Sierra Leone for the expansion of electricity access through the integration ofrenewable energy sources into the power grid. RES is clean, efficient, and reliable and it is expected to address global challenges such as climate change, energy security, and greenhouse gas emissions. The country possesses vast potential in ?renewable energy in the form of biomass from agricultural wastes, hydro, and solar power, which remain virtually untapped. However, the country has yet to harness its renewable potential due to inadequate planning. This work proposes integrated resource planning (IRP) that assesses the country's current and future electricity supply and demand. The rationale behind this IRP is to ensure that generation meets the need, enhances reliability, minimizes the total cost, and reduces enviromnental costs and greenhouse gas emissions (GHG). The Long-range Energy Alternatives Planning System (LEAP), model was used to assess Sierra Leone's energy supply and demand for. 2019-2040, based on forecasted demand, resource potential, techno-economic parameters, and CO2 emissions. Overall, 60% of the Sierra Leone population lives in rural areas with little or no access to electricity. This situation is seen as a significant factor hampering the social and economic development of the country. The application of micro-grid (grid-connected and Islanded mode) for the electrification of rural towns with no access to the central electricity grid or communities where the extension of the main _ grid is not cost-effective can eliminate power shortages, thereby bringing electricity and development opportunities to those towns and villages that have never enjoyed those benefits, spur on industrial growth, create entrepreneurs, and support increased prosperity across the country. They can also facilitate a cost effective transformation to a cleaner and more secure power sector. The thesis also aims to analyze the techno-economic feasibility of a hybrid renewable energy system (HRES) for sustainable. rural electrification in Sierra Leone. Optimization, economic, reliability, and sustainability analyses were carried out using a genetic algorithm (GA), with the main objectives of minimizing the loss of power supply probability (LPSP) and cost of energy (COE).博士（工学）琉球大学University of the Ryukyu
