SACM - Japan
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/63918
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Item Restricted A Comparative Study on the Characteristics of Architects' Licensure System in Different Regions(University of Tokyo, 2024) Almusallam, Nouh Abed; Otsuki, ToshioThere is constant pressure of globalization that demands constant and developed adaptation, particularly in response to the ever-evolving role and responsibilities of an architect. Many addressed the architect regulation through eligibility of education, experience and practice. However, a comparative study and analysis of different licensing systems encompassing backgrounds, current eligibilities, entities and regulation that influence licensure systems across nations, particularly considering the simultaneous inclusion of the Middle East and East Asia within the same analytical framework, has been overlooked. Therefore, this study identifies the characteristics of the variables systemizing the registration procedure that defines a licensed architect in different regions.10 0Item Restricted ANALYSIS OF CYBERSECURITY INTEGRATION AND LEGISLATIVE STRATEGIES IN JAPAN(Kyushu University, 2024-08-21) Aldhafeeire, Salman; Jiro, HasumiThis thesis analyzes Japan's national security strategy, which integrates cybersecurity and legislative strategies in response to evolving global cyber threats. The thesis emphasizes the growing importance of cybersecurity in an ever-evolving cyberspace, where state-sponsored cyber-attacks pose significant risks to national security, individual privacy, and economic stability. It explores Japan's proactive policies to cybersecurity integration, considering the interconnected nature of information warfare in the contemporary geopolitical landscape. Despite a historical aversion to militarization, the challenges posed by cyber threats necessitate a pragmatic response, resulting in the delicate balance between defending against cyber threats and upholding pacifist ideals. The research questions focus on understanding how Japan systematically integrates cybersecurity and information warfare measures, legislative frameworks, and proactive initiatives to fortify critical infrastructure and secure sensitive data. The literature review addresses the major policies and interventions by examining Japan's 2021 Cybersecurity Strategy, outlining the government's approach to addressing contemporary threats. The methodology employs a mixed research approach, incorporating document analysis and expert interviews of cybersecurity incidents. The analysis section will dissect secondary sources, resulting in a conclusion synthesizing key findings, academic contributions, and implications for policymakers, academics, and practitioners in cybersecurity and national security, aligning with the Cybersecurity Integration Framework (CIF) theoretical framework. The CIF model is used to assess the extent to which Japan's initiatives effectively reconcile pacifism and defensive cybersecurity measures and incorporates Pacifist Elements, Proactive Elements, Adaptability, and Integrated Analysis in its evaluation. The thesis contributes to a detailed understanding of Japan's cybersecurity strategies, highlighting the integration of information warfare, the impact of historical pacifism, and the effectiveness of legislative frameworks.36 0Item Restricted Application Study of Adaptive Mesh Refinement Method on Unsteady Wake Vortex Analysis(Tokai University, 2024) Alzahrani, Haneen; Sakai, TakaakiThere is a possibility of Ar cover gas filled in the upper part of the reactor vessel (RV) to get into the sodium coolant by vortices causing output disturbance. Hence, it is necessary to evaluate this gas entrainment phenomenon. To predict the flow pattern in the upper part of the RV by Compurational Fluid Dynamics (CFD) analysis, there is a need to establish an appropriate mesh arrangement. In this study, the applicability of the Adaptive Mesh Refinement (AMR) method to predict gas entrainment vortices accurately was examined. An initial coarse mesh (20mm) that simulate the test section of the experimental apparatus in the circulating water loop was created. The initial mesh was refined with two indexes: the first index (Index- 1) is when the second invariant Q of the velocity gradient tensor is negative and the second one (Index-2) is the pressure gradient index added to the Index-1. Then, transient calculation was performed on the refined meshes under each condition, and the results were compared with a Reference mesh with cubic cells of 5 mm width. As a result, comparing the pressure distribution of the Reference mesh with other meshes refined with the two indexes, Index-2 was found to be more similar to that of the Reference mesh. In conclusion, the applicability of the AMR method with the condition of the Index-2 was confirmed for this experimental system in which unsteady wake vortices are generated. In addition, to confirm the applicability of the AMR method on actual reactors, a simulation of the upper plenum of SFR was conducted. Results indicate that AMR method is also applicable, and the analysis load can be reduced up to 600%.7 0Item Restricted Control of the Interface Charge in Diamond Power Metal Oxide Semiconductor Field Effect Transistors(Saudi Digital Library) ALHASANI REEM MOHAMMED MUSTAFA; Professor Hiroshi KawaradaThe main aim of this Ph.D. dissertation was to study C-H diamond surface electrical properties and MOSFET performance by controlling the interface charge. Negatively charged adsorbate ions are required for the formation of a C-H conductive accumulation layer, while the positive charge plays an important role in controlling the threshold voltage, needed to achieve normally-off operation. 1. The mechanism regarding the conductivity of the C-H diamond surface, by the adsorption of negative ions on the C-H surface, using corona discharge ions, was investigated. From the results of this study, it was revealed that negatively charged adsorbates on the positive side of the C-H dipole induced accumulation of minority carriers (hole) by band-bending (inversion layer of MOSFET). A large number of negative ions O2− (found in the air) were introduced to the three different kinds of C-H diamond surface, which provided the holes. The three different kinds of C-H diamond substrate; pure C-H surface, partially oxidized C-H surface, and C-H surface after the adsorbates were removed when the diamond inside the chamber was annealed at 600 K. For the pure C-H surface, the value of the conductive surface was increased from the initial value of 6.8×10-5 S to 1.2×10-4 S, due to the negative ions. Regarding the second substrate, directing negative charge ions toward the oxidized C-H surface caused an increase in the carrier density, and the conductance, by three orders of magnitude, from 10−8 S to 10−5 S. The third substrate comprises a C-H diamond material, in which adsorbates have been removed from the surface, and is highly resistive due to the heat treatment in a vacuum. By depositing negatively charged ions to C-H diamond, the electrical conductivity for this third substrate demonstrated a significant increase by 5.5 orders of magnitude, to 3.5 ×10−6 S. Furthermore, the effect of positive corona discharge ions on the C-H conductivity was investigated in this chapter. The decrease in surface conductivity of C-H diamond can be related to a sharp decrease of carrier density, due to the presence of positive adsorbates ions, which are not common. The negatively charged ions must be responsible for the surface conductivity of C-H diamond. 2.The effect of the negative fixed surface charge model on C-H diamond MOSFETs conductivity, depicted using simulation, has been laid out in this Ph.D. dissertation. The p-type conductive channel with a high hole concentration of 7×1019 cm−3 was confirmed in C-H diamond using Atlas TCAD device simulator. The output characteristics showed high performance of MOSFETs, such as normally-on operation, with the negative surface charge 90 model. The maximum drain current density was obtained at IDS= −125 mA/mm, upon the application of a drain voltage of VDS= −50 V, and gate voltages within the range of VG= −26 V~ 26 V. Surface conductivity cannot be produced without negative ions on the C-H surface, although the Ohmic contact is also important to inject holes that flow from source into the channel and toward the material, as FETs. In this simulation, the SBH was 0.2 eV, which is responsible for the formation of Ohmic contacts at room temperature. When the negative interface charge is applied close to the interface, the SBH potential raises. This allows the holes to enter the valence band maximum indicated, forming a hole accumulation layer. In addition, the drain current maximum at IDS= −84 mA/mm with control mobility was obtained in the neutral charge model. In this model, the confirmed conductive channel is based on the limit of hole mobility. The hole mobility may have been limited due to the effect of neutral surface scattering, hence the increases in channel mobility, which may lead to improvement of device performance. The device demonstrated high electric performance in both models; negative interface charge and n5 0Item Restricted Development of a functional recovery training robot with a quantitative evaluation system for post-stroke patients with upper-limb impairment(Tokyo Denki University, 2024-03) Algrary, Sami; Ohnishi, Kengo; Inoue, Jun; Kuwana, Kenta; Inoue, TakahiroIn the past few decades, clinical treatments utilizing rehabilitation robotics have shown sustainable improvement in sensory motor recovery for post-stroke patients. In addition, analyzing patients exercise progression using robotics systems enable clinicians to objectify the assessment, and improve measurement reliability and precision. In this research, an upper-limb therapeutic robot for stroke patients with upper limb impairments, that supports patients to practice independently, while recording and evaluating their exercise performance was developed. Also, a unique quantitative assessment system to evaluate upper-limb motor function using Mahalanobis-Taguchi system, MTS, was investigated and proposed. First, a calibration experiment was conducted to generate an equation, to compute the force applied by the subject on the robot arm of the upper limb therapeutic robot. A fixed set of weights were attached to the central rotation shaft to apply constant torque to the rotation shaft. The rotation shaft was rotated in a non-load condition and load condition with weights added, and the angular signal of the potentiometer at that time was measured. From the experiment, a relational formula between the mean of central rotation shaft twist angle, and applied torque to the central rotation shaft was successfully generated. In addition, to increase the potentiometer angular signal precision and reliability, all control unit components were grounded. As results, the coefficient of variation reached a maximum of 8.7%, and the noise affecting the signal was suppressed. Next, to establish a quantitative assessment system to evaluate upper-limb motor function, an evaluation experiment with thirty able-body subjects, under six replicated joint of motion restraint conditions using the upper-limb therapeutic robot was conducted. MTA method, T(1), and variation pressure method’s applicability in distinguishing between able-body subjects, in arm-end force controllability between shoulder, elbow, and wrist joints under replicated joint restraint was investigated. In addition, these methods were compared with each other for their distinguishing quality. The subject’s task was to continuously apply a fine constant resistance force, in the opposite tangential direction of the robot arm rotation. No-restraint condition data were set as unit-space dataset and signal dataset. The other six joint restraint condition data were computed as targeted dataset since these were quasi-role data of pre-training condition of a paralyzed limb. From coefficient of variation, CV, results there was a similarity between MTA method and T(1) method in regards of distinguishing between subjects’ arm-end force controllability performance between single-joint restraint conditions and combined joint restraint conditions. For Single-joint restraint conditions, wrist restraint CV result for T(1) is 1.921, and MTA is 0.575. For Combined joint restraint conditions, elbow and wrist restraint CV result for T(1) is 1.955, and MTA is 0.385. As results, the small coefficient of variation with light shoulder joint restraint reflects the influence on force controllability performance, shows that MTA method and T(1) method are effective in detecting differences between joints. Finally, a measurement system of the force applied by the subject on the robot arm of the upper limb therapeutic robot was developed. Also, a unique quantitative assessment system using MTA method and T(1) method was investigated and proposed as promising analytic systems to evaluate upper-limb motor function.7 0Item Restricted Development of Nuclear Security Education Textbook for Universities in the Kingdom of Saudi Arabia(Tokai University, 2024) Faisal, Sarbaland; Takaaki, SakaiNuclear security is one of the most important matters to focus on in case any state decides to adopt nuclear power as a part of its energy sector. However, in recent years, there has been a noticeable need for nuclear security education all around the world. In this context, many recommended educational curriculums have been published. Nonetheless, all of these curriculums include a nuclear security introductory course as a required course. Therefore, in this research, we are aiming to create a comprehensive textbook that covers the different aspects of nuclear security. As a result, so far, we have managed to create a textbook that consists of three major sections. The first section is the introduction to nuclear security. This section covers the fundamentals of nuclear security. The second section focuses on nuclear security in a specific region. In this study, we will look at the region of Saudi Arabia and how its characteristics may affect nuclear security within the kingdom. The third and final section focuses on modern issues that affect international nuclear security. The primary objective of this study is to provide each section with essential and informative knowledge to assist in the development of human resources in the nuclear security industry.50 0Item Restricted Development of Quantitative Finite Element based Phase-Field model for the Precipitation of δZrH in αZr(Saudi Digital Library, 2023-09-22) Salman, Alrakan; Takahashi, HiroyukiDue to the excellent combination between its mechanical, thermal, physical, and nu- clear properties, Zirconium based alloys are the material of choice for cladding tubes in light water nuclear reactors. However, the interaction between the water coolant and the Zirconium cladding will result in a corrosion reaction. This will result in the formation of Zirconium Oxide and the release of Hydrogen. A portion of the released Hydrogen diffuses into the cladding, and as the concentration of Hydrogen increases, Zirconium hydrides will precipitate. Zirconium hydrides are brittle mate- rials which will result in a degradation of the long term structural integrity of the cladding. Several pioneering experimental investigations were implemented in the past 50 years. These important studies made considerable advancements in under- standing the properties of Zirconium and its hydride phases, and in addition, studied the effect of several important forces on the Zirconium hydride precipitation process such as stress, texture, and temperature. However, many of the precipitation induced mechanisms are still unknown, and were not clarified by experimental investigations. This is due to the fact that precipitation occurs at very fine length and time scales, which are beyond the capability of experimental investigations. Hence, a compu- tational investigation is required. Among computational techniques, the phase-field method established itself as the main continuum method for the investigation of ma- terial transformations at the miso-scale. This is due to its fundamental origins, the ability to depict specific material structural features such as grain boundaries and defects, and its intuitive approach to multi-physical coupling. In the past 15 years, several important models were proposed for Zirconium hydride precipitation. These models made considerable advancements in understanding, and clarifying key aspects associated with precipitation process, and paved the way for the development of fu- ture models. However, the inaccurate deception of the system properties, affected the clarity of the implemented studies, and in addition, the inefficient implementation re- sulted in low fidelity studies that did not reveal several aspects that are associated with the precipitation process. Hence, this study was implemented to develop a novel, quantitative, Finite Element-based, phase-field model to investigate the precipitation process of δ-Zirconium hydride in α-Zirconium. The model was built utilizing a novel nucleation model that is based on the classical nucleation theory which respects mass conservation in the system, and results in the natural and accurate determination of the equilibrium concentrations for the phases in the system. Furthermore, the model uses the modern matrix-free implementation, and adaptive mesh refinements strate- gies. These result in a very efficient implementation and relatively moderate system. This will allow the model to conduct high-fidelity investigations. The model can be applied to investigate any two phase system, and can be easily extended to inves- tigate multiple phases. Furthermore, it has the ability to investigate a wide range of phenomena including solidification, precipitation, and second-phase growth. The model was verified & validated by comparing the numerical solution of this model, and the analytical solution of the Kim-Kim-Suzuki model. Furthermore, the model was compared with current preferred software that is used for phase-field modeling, the MOOSE framework which is developed by the Idaho National Laboratory. The developed model showed a much higher runtime efficiency and at the same time, did not require an intensive hardware consumption. This allowed the developed model to run very high fidelity analysis cases on relatively moderate hardware. The model was applied to investigate the role of capillary-induced forces on the precipitation mecha- nisms of δ-Zirconium hydride in α-Zirconium, which to our best of knowledge have not been investigated before experimentally or computationally. A high-fidelity analysis in terms of particles simulated and the duration allowed the study to verify the role of precipitate size, shape, and stacking formation structure on the precipitation process. Furthermore, it clarified the role of hydride-hydride interaction as well. In addition, a very large domain size was generated preventing the development of excessive elastic energy during the precipitation process. The study was able to reveal key mechanisms associated with δ-Zirconium hydride precipitation in α-Zirconium. The shape of the precipitates changes from a spherical shape toward a disk-like shape precipitates that aligned along the basal plane of α-Zirconium as the size increases. At small precipi- tate sizes, the isotropic interfacial energy will dominate the shape formation process resulting in a spherical shape. As the size of the precipitate increases, the shape of precipitates will become more influenced by the elastic energy leading to a more disk- like shape where the precipitates will possess a larger radius along the basal plane relative to the c-axis. This is promoted by a stronger stiffness of α-Zirconium and a higher misfit strain along the c-axis relative to the basal plane. This is confirmed by the linear relationship that develops between the aspect ratio of precipitates, and the interface to area ratio. As precipitates grow and their shapes become more disk-like, the equilibrium concentration will be affected by the surface curvature of precipitates maximizing along the basal plane where the maximum curvature is located. This leads to a lower chemical potential which promotes precipitates realignment along the basal plane. The close proximity of aligned precipitates, results in an accumu- lation of hydrogen. This is promoted by capillary-induced surface diffusion. This leads to a decrease in the chemical potential between the precipitates. This promotes the migration process of precipitates toward each other and ultimately coalescence. At the onset of coalescence, a large increase in the precipitate growth rate occurs leading to the flattening of the newly formed single precipitate surface. This will lead to the development of large size variations within the local vicinity. This results in an acceleration of capillary-induced diffusion-limited coarsening. Here, larger precip- itates will keep growing and smaller precipitates will shrink and ultimately dissolve. This is promoted by a higher equilibrium concentration of hydrogen and a higher chemical in smaller precipitates which drives the diffusion of mass from smaller to larger precipitates. The sequence of precipitate realignment, migration, coalescence, and diffusion-limited coarsening keep re-emerging as the length scale of precipitates increases. These mechanisms are verified through a complete set of results that were provided by the study, they are originally proposed, and on par with fundamentals in material kinetics.31 0Item Restricted Effects of sealer and root canal filling method on root canal sealing ability after high-frequency current conduction(Hokkaido University, 2024-01-27) Alruwaili, Abdul Latif Farhan; Sugaya, TsutomuObjective: To assess the root canal sealing efficacy of two sealers and two root canal filling techniques following high-frequency current application. Methods: Simulated root canal models with a diameter of 0.1 mm were prepared from bovine teeth to replicate actual root canal anatomy. A demineralized layer was induced by administrating Plank-Rychlo solution to the simulated root canals for 5 minutes. These models were randomly assigned to 12 experimental groups. Each simulated root canal was irrigated with NaClO, and high-frequency electrical current was applied for 0, 3, or 5 seconds. The simulated root canals in each group were obturated using either Meta Seal Soft Paste (MSSP) or AH-Plus sealer, as well as either sealer alone or in conjunction with vertical condensation. Subsequently, the degree of dye penetration into the simulated root canals was meticulously quantified following immersion in a dye solution. The simulated root canal walls and the root canal wall-sealer interfaces were examined and observed using scanning electron microscopy equipped with an energy-dispersive X-ray spectrometer. Results: No statistically significant difference (P>0.05) was observed in dye leakage for MetaSeal Soft Paste sealer (MSSP) alone among any energization time, but significant leakage was observed when compared to the vertical condensation group. However, MSSP sealer alone resulted in significantly less dye leakage than AH-Plus sealer alone at 0 and 5 seconds of high-frequency energization (p<0.05). Examination of unfilled root canal walls revealed a porous, lava-like layer characterized by low carbon and high calcium and phosphorus content. In contrast, cross-sectional analysis of root canals filled with MSSP alone and subjected to 5 seconds of energization demonstrated a solid interface between dentin and MSSP, devoid of the porous layer. Furthermore, carbon, in addition to calcium and phosphorus, was detected at this interface, and resin tags were observed within dentinal tubules. These findings suggest that MSSP effectively established a monoblock structure encompassing the root canal filling material, the porous lava-like layer, and the dentin wall, resulting in a hermetic seal. Conversely, when root canals were filled with AH-Plus, only a few resin tags were observed in dentinal tubules, indicating a less robust interfacial seal. Conclusion: Irrespective of high-frequency energization, Meta Seal Soft Paste (MSSP) demonstrated significantly lower dye leakage compared to AH Plus when obturating inaccessible root canals. Subsequent to energization, MSSP infiltrated the porous lava-like layer of the root canal wall, exhibiting strong adhesion to dentin and superior sealing efficacy. Notably, vertical condensation compromised sealing performance for both sealers.9 0Item Restricted Empathy and Persona Based Arabic Conversational Agent(Saudi Digital Library) ABDULKARIM EMAD MOHAMMAD ALABDULKARIM; Yoshie OsamuArabic NLP has seen significant advances in Natural Language Understanding (NLU) with language models such as AraBERT and ArBert. Despite that, the Arabic Natural Language Generation (NLG) remains a challenge. Due to the lack of Arabic datasets suitable to train NLG models and the lack of pre-trained Arabic models for NLG. Therefore, we plan to pave the way for future Arabic chatbot research and Arabic NLG. By fine-tuning an empathetic and personified, Arabic conversational agent. By using “persona” we make the conversation more engaging. And with “empathy” we make the conversation more human-like. Currently, the state of Arabic chatbot research is led by the paper “Empathetic BERT2BERT Conversational Model: Learning Arabic Language Generation with Little Data.” which has the empathy part but it’s still lacking on the chit-chat model part. And so, we have managed to integrated persona into our final model by integrating and fine-tuning the model, which is a BERT2BERT architecture, on the ArabicPersonaChat dataset. Scoring 0.79 on the BLEU benchmark on the “ArabicEmpatheticDialogues” dataset compared to the previous SOTA which scored 0.675.8 0Item Restricted Fanous: A New Ecosystem Model to Legalize Anime Fansubbing and Combat Piracy(Keio University, 2025) Kinani, Ahmad; Ishido, Nanako; Sato, ChihiroThe ”Fanous” ecosystem model aims to legitimize fansubbing and combat piracy by integrating unofficial fansubbers with legal streaming services. The model enhances the viewing experience and provides fansubbers with opportunities for sustainable income, contributing to the growth of a legal anime ecosystem and helping reduce piracy globally. Positive feedback indicates the model’s potential to combat piracy and support legal fansubbing. The model has received strong support from fans and fansubbers, despite the need for some improvements. Distributors and streaming services are optimistic about collaborating with fansubbers under more regulated terms, while intellectual property holders have expressed openness to working through intermediaries to ensure quality and compliance. Despite its potential, the model faces limitations such as resistance from piracy site users, web browser-only support, and advancements in AI translation. Addressing these limitations involves future works to improve ad-free alternatives to attract users, integrate the model with streaming services, and research on using AI to enhance translations while preserving the role of human fansubbers.9 0Item Restricted Flash Flood Hazard Assessment using Hydrological and Machine Learning Models with Multi-Satellite-Based Precipitation and d4PDF Climate data sets in Saudi Arabia(Kyoto University, 2025) Alamoudi, Fahad; Kantoush, SamehFloods are among the most prevalent natural hazards globally, causing significant damage and loss of life. The primary tool for flood risk assessment and damage mitigation is hydrologic early warning systems, which predict flood events using rainfall observations from ground stations. However, challenges such as data scarcity, spatial disruption, network density issues, and measurement errors in ground stations have necessitated using satellite-based rainfall products to address these limitations. Satellite-based precipitation estimates (SbPEs) and reanalysis precipitation datasets (RPDs) have become increasingly accurate, offering improved spatial and temporal resolution beneficial for hydrological applications and rainfall-runoff modeling. The challenges posed by climate change, particularly the increasing frequency of extreme events like floods, further complicate flood risk assessments, especially in regions like Saudi Arabia. The main challenge in assessing rainfall and runoff in Saudi Arabia is the limited availability and accuracy of observational data (1) rainfall station and monitoring that can be measured with reliable and less uncertain data with low maintenance cost. In addition, the extreme climatic variability under climate change impact with dam management and mitigation measures in KSA (2) the identification of suitable locations for new dams where they can effectively serve multiple purposes, including groundwater recharge, flood control, water storage, and protection. Therefore, the main objectives of this research thesis are to (1) Examine both the hydrological model and Machine learning to develop the flash flood susceptibility maps, (2) Deep understand the Spatiotemporal climatic variability of extreme storms, (3) To evaluate SBP rainfall data and Re-analysis Rainfall data over KSA, and (4) To develop Flood Hazard Map based on SBP and hydrological modeling including distribution of dams locations and purposes. This thesis consists of seven chapters that explain the flood risk assessment from different sources of rainfall data and culminate in the analysis of extreme rainfall in the present and future, using hydrological models and machine learning techniques to find the hazard mapping over Saudi Arabia. The introduction and the literature review about the rainfall-runoff processing under climate change in Saudi Arabia were presented [Ch.1, 2]. Afterward, a set of investigations was conducted through various analyses and modeling to find out the flash flood hazard and susceptibility map [Ch.3, 4, 5, 6]. Finally, the recommendation and future prospects were proposed with research conclusions in [Ch.7].23 0Item Restricted Influence of gap width and distance between electrodes on eliminating organic material of the isthmus by high frequency electric current(Hokkaido University, 2023-11-21) Alkuwaykibi, Ahmed Saud; Sugaya, TsutomuBackground: Root canal disinfection is a critical step for the success of root canal therapy. However, traditional disinfection methods have limitations, and root canal treatment can fail because of the complex root canal system, which includes lateral branches and isthmuses, which are challenging to fully eliminate, leading to persistent bacterial infection. Cauterization is a novel method for disinfecting root canals which conducted a high frequency current that has been found to have several benefits in root canal therapy. Aim: The aim of this in vitro study was to evaluate how the isthmus gap width, distance between electrodes, and duration of high-frequency electrical current application affect the elimination of organic matter in the simulated isthmus inner surfaces. Methodology: Dentin blocks were prepared using bovine roots and immersed in Plank-Rychlo solution for 5 min. A simulated isthmus model was made with gaps of 0.1, 0.2, and 0.3 mm between the two walls with organic layers on the inner surfaces. In addition, two root canals of 0.4 mm diameter and 7 mm depth were prepared at a distance of 2 mm or 5 mm. Isthmus width with root canal distance, including root canal depth, were divided into six groups. The gap width was 0.1 mm for groups 1 and 4, 0.2 mm for groups 2 and 5, and 0.3 mm for groups 3 and 6, and the root canal distance was 2 mm for groups 1, 2, and 3, and 5 mm for groups 4, 5, and 6 mm. The root canals and isthmus were filled with NaClO, #35K files were inserted into the two root canals as electrodes, and a current of 225 V, 520 kHz was applied between the electrodes. Energizing times are 0, 5sec for groups 1,2,5,6, and 0,5,10 sec for groups 3,4, for 0, 5, or 10 seconds. The isthmus model was split, the morphological and elemental analysis of the isthmus inner surface were evaluated by SEM and EDS. Results: By electrification, a flat layer in the isthmus caused by demineralization was removed, and dentin tubules and lava-like surfaces were observed. At these sites, significant decreases in carbon and oxygen and increases in calcium were shown by EDS, resulting a significant difference (p<0.05) in the remaining organic residuals between Group 1 with a narrow isthmus gap of 0.1 mm and a closer root canal distance of 2 mm, and Groups 4 and 5 with a narrow isthmus gap of 0.1 mm and 0.2 mm and farther root canals of 5 mm distance. Groups 3 and 4 had significantly (p<0.05) less organic material remaining after high-frequency conduction for 10 seconds compared to 5 seconds. Increasing the cauterization time removed almost all organic materials. Conclusion: By applying high frequency electricity to the isthmus, it was possible to remove most of the organic matter. The effect varied based on the width of the isthmus gap and distance between the root canals. A narrower isthmus with closer canals had a higher effect from the electricity, and a wider gap between canals farther apart had less effect. More electrification time was needed to completely remove all organic material from wider gaps or farther distances. High frequency current, isthmus gap, cauterization, electrodes distance, organic material.12 0Item Open Access New Daily QA phantom for proton beam spot scanning(University of Tsukuba, 2024) Zakariya ,Maryam Zakariya A; Sakae, Takeji; Isobe, TomonoriPurpose: The purpose of this research is to create a new design for a daily quality assurance phantom in proton pencil beam system. Using a single spot of a proton beam, this phantom should measure some of the factors necessary for daily QA dosimetry, such as Range Check, Beam Size, and Position Accuracy. Material and Method: Measured depth dose data is used to determine the depth 90% (d90%), which is an important point for accurate measurements of the QA phantom thicknesses. The QA phantom experimental tests were conducted using broad beam and pencil beam systems. To get the results of range confirmation and QA dosimetry measurements, both systems used a QA phantom with a scintillator system. In the broad beam system, the QA phantom design was a One-Step phantom, and for the pencil beam system, the QA phantom design was modified to a check pattern and named as a (Check phantom). The check phantom was tested in the broad beam system, with a small aperture collimator to simulate the pencil beam. Analytical calculations of depth dose were performed for each system condition to get the comparison results of experimental data and analytical calculation. The final results of experimental and analytical calculation were evaluated by using the B/A ratio method, where A is the Proximal dose of d90% and B is the Distal dose of d90%. Results: The results of the one-step phantom for experimental data and analytical calculation are summarized in the B/A ratio figure. Using the scintillator system with the QA phantom caused a quenching effect in the experimental data. The quenching was calculated analytically, and the results of the quenching calculation and experimental data show similarity in the B/A ratio data. The experimental data of the check phantom was analyzed by using the 2D Gaussian fitting method. To obtain the results of experimental data and analytical calculation in B/A ratio, the analytical calculation of depth dose for the check phantom is processed with the same calculating methods as in the one-step phantom, except incorporating the scattering effect of pencil beam dose distribution. The final results for both QA phantoms (One-Step and Check) show a consistent B/A ratio, and the new design check phantom confirmed its usability for daily QA phantom. Conclusion: The check phantom is eligible for daily QA phantom, with a one-spot of beam, it analyzes the required dosimetry measurements for daily QA.5 0Item Restricted Photoluminescence Behavior of Rod-like Liquid-crystalline Molecules with Biphenylacetylene Core in Condensed Phases(Saudi Digital Library) ALJUZAYRI HUSSAIN SAMI MOHAMMED; Tsutsumi Osamustudy and design low-molecular weight materials to further gain insight into the mechanism and reason behind the thermo-chromic behavior and white color emission.6 0Item Restricted Role of Artificial Intelligence in Enhancing Metaverse Gaming Experience and Human Interaction: A Case Study of Roblox's AI Implementation(Tokyo University of Technology, 2025) Alotaibi, Omar; Kameda, HiroyukiArtificial Intelligence (AI) is a tool that is useful for enabling and sustaining the Metaverse gaming experience by infusing virtual reality (VR), augmented reality (AR), extended realities (XR), and blockchain. The current research focused on identifying the impact of AI in leveraging immersive experiences and improving human interaction, which plays a crucial role in Metaverse gaming. A quantitative analysis carried out surveys from 200 randomly sampled respondents involved in Metaverse gaming. Using SPSS 26.0, correlation analysis showed that association between the values of ‘r’ of variables Immersive Gaming Experience (r=0.983**), Deep Learning Collaboration (r=0.957**) and Increased Human Interaction (r=0.979**) are greater than 0.7 depicting strong correlation with Metaverse gaming. Regression analysis further confirmed that the role of AI in enhancing the Metaverse gaming experience and human interaction is significant. With the considerable success of AI in Metaverse, the role of DL algorithms is also groundbreaking in leveraging game balance in multiplayer games, satisfying play-testers and designers who own valuable features, real-time rendering, and multi-user design collaboration.12 0Item Restricted Spillover-Based Portfolio Management: Bayesian Diebold & Yilmaz Spillover Applications in Cryptocurrency Market(University of Tokyo, 2025) Bukhary , Husam; Gento, MOGIThis study evaluates the performance of various Bayesian priors in modeling and assessing financial and economic Diebold and Yilmaz spillover networks through simulations using the posterior distribution of spillover effects across multiple priors. A key contribution of this research is the introduction and validation of graph similarity analysis within spillover networks, demonstrating that even when the overall fit of the spillover is suboptimal, the interconnections between variables of interest are accurately captured in terms of directionality, albeit with slight discrepancies in magnitude. Building on this insight, we apply the Diebold and Yilmaz spillover approach to develop a novel portfolio optimization strategy that integrates Hierarchical Risk Parity (HRP) with the Louvain method, utilizing the optimized spillover values. This innovative method outperforms traditional HRP techniques when applied to both synthetic data and real cryptocurrency market data, providing a robust and efficient framework for managing interconnected financial assets.11 0Item Restricted Study of clinicopathological factors related to recurrence, metastasis, and prognosis in lower gingival squamous cell carcinoma(Hokkaido University, 2025-03) Alanazi, Hamad Khalaf; Wataru, Kakuguchi; Yoichi, OhiroLower gingival squamous cell carcinoma (LGSCC) poses a unique challenge in oncology due to its frequent early bone invasion, a characteristic stemming from its anatomical location. This often results in an overrepresentation of T4 staging within the traditional TNM system, which primarily relies on tumor size and extent. Consequently, the TNM staging may not accurately reflect the true biological behavior and prognosis of LGSCC, as it neglects other critical factors influencing disease progression. This study aimed to address this discrepancy by investigating the limitations of the current TNM system in predicting LGSCC outcomes and identifying additional prognostic factors that could contribute to a more comprehensive and accurate risk assessment. To investigate the limitations of the standard TNM staging system in lower gingival squamous cell carcinoma (LGSCC), a retrospective analysis was performed on 104 patients treated at Hokkaido University Hospital. This study expanded beyond traditional TNM staging by incorporating detailed histopathological evaluations, including YK classification for bone invasion, worst pattern of invasion (WPOI), grade of differentiation, and depth of invasion (DOI). Utilizing Kaplan-Meier survival analysis and chi-squared tests, the study aimed to identify additional prognostic factors that could refine risk assessment, demonstrating that DOI, patient age, and WPOI, in conjunction with traditional T staging, significantly influence disease outcomes, emphasizing the necessity of incorporating histopathological features for more accurate LGSCC prognostication.7 0Item Restricted Study of regional diversity of housing complex related to regional environment(2018-09-30) KOMO, WASEM; KOKI, KITANOThe research deals with the historical development for different parts in the Kingdom of Saudi Arabia through different ages, explaining the differences between them, especially the environmental and geographical differences at each stage with the presentation of some architectural models. The research also took apart to study and analyze the cooperative housing and its advantages, especially in the project scheme. After that a comparison is made between the survey on houses in Saudi Arabia and a survey on the cooperative houses in Japan. Finally, some of the advantages of the cooperative housing has been applied in an apartment building in Saudi Arabia. This research is useful when building an apartment house in Saudi Arabia. Also, it is useful when designing and planning of environmentally friendly apartment house in Saudi Arabia as a substitution to the conventional houses based on fossil fuel energy. Thus, the aim of this thesis is to provide an improvement to the residential environment of the Saudi Arabia family. After presenting the cooperative housing some of its main advantages found to be able to apply in Saudi Arabia. It has been shown that in Saudi Arabia heat can be collected from the bathroom and kitchen in order to be used as energy source. Furthermore, the idea of the spare room is exploited in the plan under study. Finally, an innovating idea of the Roshan with sliding windows is applied in the modern Saudi housing.5 0Item Restricted STUDY ON INTRODUCTION OF IOT TECNOLOGY INTO PRODUCATION SYSTEM AND HUMAN RESOURCE MANAGMENT(Saudi Digital Library) HUSSAM FAHAD ALAHMADI; Mr. Nishi GuchiResearch background and purpose 1- Speeding up the Internet, increasing the functionality and performance of information and communication equipment IoT (Internet of Things) technology, which connects “things” such as sensors and robots to networks and enables automated processing and remote processing using AI technology, is beginning to be introduced into our lives. Looking at the introduction of IoT technology into production systems, the main purpose is to improve productivity.11 0Item Restricted The integration process of the environmental, social and governance (ESG) factors to a firm's business model(Keio University, 2024) Aldowaish, Alaa; Kokuryo, Jiro; Isagai, Yoshinori; Kotosaka, Masahiro; Hoda, TakaakiThis thesis examines the integration process of ESG into the business model. It consists of three stages. In the first stage, we asked the research question of how the literature examines the relationship between ESG and business models. We conducted a systematic literature review of 326 papers about ESG and business models; we found only 29 discuss ESG and business models. Also, we found that the majority of the literature focuses on outcomes such as integration behavior, advantages, practices, and critical, and only two explain the process. We extended our literature and examined sustainability as a synonym of ESG. We found few discussions on the process and were limited to the early stage of sustainability integration. The second stage we asked is ESG integrated into the business model. We conducted a comparative analysis of corporate narrative reports in Japan and Europe. We used legitimacy theory to understand firms' behavior in integrating ESG into the business model; we applied a content analysis and analyzed 70 reports of 35 firms. We found the majority to be a general statement followed by concrete activities and aspirational targets, and only one mentioned a systematic dimension. We address the validity of this stage by examining the synonym of ESG, sustainability. We found that the same pattern exists for the findings. In the third stage, we examined the ESG integration process in two case studies. We asked our main research questions from an operational perspective: how is ESG integrated into the business model? Moreover, from a theoretical perspective, how do firms manage conflict in ESG integration? Finally, we used process theory to propose a framework for integrating ESG into a firm's business model. The framework synthesizes two process models identified from a systematic literature review of sustainability and business models and the successful case study.7 0