Tokyo City University

This study focuses on restroom signs displayed in group homes for the elderly with dementia and clarifies the specifications necessary to design restroom signs that enable the elderly with dementia to independently locate restrooms by recognizing the signs. Restroom signs are commonly displayed in many group homes in Japan. The needs of staff regarding restroom signs include supporting the elderly with dementia in identifying restroom locations and promoting their independent use. When planning restroom signs for the elderly with dementia, it is essential to include text‐based signs that explicitly indicate the restroom, as relying solely on pictograms may result in insufficient information. Additionally, the appropriate font size for textual displays ranges from 50 to 90 mm. Regarding placement, restroom signs should be displayed on the restroom door at a height of approximately 1300–1400 mm from the floor. However, in some group homes, restroom doors are operated in an open position, making the door surface unavailable as a display area. In such cases, it is necessary to consider displaying the signs on the surrounding wall surfaces.

Background The success of dental restorations depends on achieving adequate surface integrity. However, grinding and polishing are generally ineffective because of the special physical and chemical compositions and properties of the composites. Polyurea resin is an elastomer with high elasticity, abrasion resistance, heat resistance, and toughness. When it is used as a bond, grinding wheels with high grain grip strength can be fabricated. Objective We fabricated a mounted wheel with a polyurea resin as the bond and used it to polish a composite resin and porcelain under clinical polishing conditions. The effects of the approach on the polished surface roughness and morphology were evaluated with respect to the type of mounted wheel, initial surface roughness, abrasive particle size, and polishing time. Methods This study fabricates a mounted wheel with polyurea resin as the bond and uses it to polish composite resin and porcelain under clinical polishing conditions. The effects of the approach on the polished surface roughness and morphology are evaluated against the type of mounted wheel, initial surface roughness, abrasive particle size, and polishing time. Results Among single-crystal diamond, siliconcon carbide (GC), and alumina (WA) abrasive grains, diamond abrasive grains produced the best finish for most tested resin composites. However, WA abrasive grains are effective for polishing Estenia (it has the highest filler content). The polishing performance of the porcelain varied with the initial surface roughness and abrasive particle diameter. Conclusion This study provides guidance for improving and developing mounted wheels for clinical applications.

Perovskite/silicon tandem solar cells are a novel class of solar cells that have recently attracted increasing attention due to their notable efficiency; however, they inherently suffer from loss of flexibility. Accordingly, in this study, we develop flexible perovskite/silicon tandem solar cells by fabricating perovskite solar cells atop bendable thin‐crystalline silicon solar cells. By reducing the thickness of the silicon substrate to approximately 60 µm, applying microtexturing to its surface, and incorporating a low‐refractive index‐doped layer, we produce a flexible silicon heterojunction solar cell with an efficiency exceeding 21%. Subsequently, by optimizing the self‐assembled monolayer processing conditions on the microtextured surface and constructing an inverted perovskite solar cell on the flexible SHJ, we achieve 26.5% efficiency for the flexible perovskite/silicon tandem solar cell. These findings could be valuable for the development of new, highly efficient, lightweight, and flexible solar cells, potentially accelerating their deployment in conditions where traditional silicon solar cells are impractical.

Our planet is currently confronted with a significant challenge of ecosystem disturbance, leading to a loss of biodiversity on a global scale. In previous studies within the field of life cycle impact assessment (LCIA), the inclusion of biodiversity loss in the endpoint categories has been proposed. However, there still remains a substantial research gap between LCIA and ecology. Therefore, in this study, we utilized species distribution models based on ecological predictions of habitat change, combined with land-use data for the year 2100 under the RCP8.5 scenario, to model the distribution of 160 species from four different biotic groups. After predicting the future distribution of species habitats, we established species damage factors by creating spatial potentially disappeared fraction (PDF). Our results indicate that under future land-use change scenarios, the four taxa and 160 species all experience varying degrees of loss on a global scale. Particularly, some underdeveloped regions, including South Africa, face higher risks and greater challenges with biodiversity loss. It is worth noting that agricultural land shows high-loss hotspots in South Africa under different land-use effects, which is closely related to the increasing demand for agricultural land due to population growth in the region.

Despite the development of three-dimensional (3D) tissues that promises remarkable advances in myocardial therapies and pharmaceutical research, vascularization is required for the repair of damaged hearts using cardiac tissue engineering. In this study, we developed a method for rapid generation of a 3D cardiac tissue, with extremely high engraftment efficiency, by stacking cardiomyocyte sheets using fibrin as an adhesive. Cell sheets were created by peeling off confluent cultured cells from a culture dish grafted with a polymer that induced surface hydrophilicity in response to low temperatures. The high engraftment rate was attributed to the retention of the adhesive protein. The multistacked vascularized cell sheets prepared using fibrin, when transplanted into the subcutaneous tissue and at myocardial infarction site in rats, yielded a transplanted 3D myocardial tissue. Furthermore, multilayered cardiomyocyte sheets were transplanted twice at 1-week intervals to create a 3D myocardial tissue. Our data suggest that fibrin-based rapidly layered cell sheets can advance tissue-engineered transplantation therapy and should aid the development of next-generation tissue-engineered products in the fields of regenerative medicine and drug screening.

One of the industrial applications of mesoporous silica is drug delivery since there is a possibility that the uniform mesopores can control storage and release of medicinal substances. In the present work, SBA-15 was selected as a candidate for the drug delivery carrier, and the effect of the pore size decreased by grafting propyl and octyl groups on the storage and release of vitamin E whose antioxidative ability is efficacious against diabetes, cardiovascular diseases and so on was investigated. N2 adsorption isotherm at 77 K verified that the octyl group reduced the pore size more than propyl group. Vitamin E soluble in ethanol was accommodated into pore channels under ambient condition, but an amount of the accommodated vitamin E decreased with pore size of the employed carriers. On the other hand, the release ratio of the accommodated vitamin E in ethanol increased with the decrease in the pore size. Based on the experimental results mentioned above, location model of vitamin E in the pore channels was discussed for the neat and the grafted carriers. Furthermore, the accelerated oxidization of linseed oil was operated at 373 K in the presence of the neat carrier to evaluate the controlled vitamin E release.

Extreme and intense atmospheric phenomena occur in complex urban areas, but stationary ground-based meteorological observations cannot capture the detailed meteorological conditions across urban blocks. Vehicle-based mobile observation provides a method to collect high spatiotemporal data in cities. We developed a small IoT observation system to mount vehicles easily and measure air temperature, humidity, pressure, wind speed and direction, together with local time and location. To evaluate this system, we conducted a case study of mobile observation in Tokyo almost daily for one and a half months. Mobile observation data had occasional missing and erroneous, so data extraction and processing were applied based on weather conditions and vehicle's speed. Using the quality-controlled data, we confirmed that given the mobile observation was within 2 km of the fixed-point observation, air temperature and humidity from mobile observation was highly correlated with reliable fixed-point observation (RMSD < 1°C and < 0.34 g/kg). Thus, the mobile observation system potentially provides those datasets comparable to conventional ground meteorological datasets. The spatial distributions of air temperature and humidity exhibited distinctive changes between urban blocks, influenced by land use and urban characteristics. This system enables long-term, extensive vehicle-based observations and aids in detecting extreme atmospheric phenomena in urban areas.

The elucidation of intricate fault geometries provides fundamental and essential information regarding seismology and other fields of solid Earth sciences. Hypocenter alignments typically reflect complex crustal fault structures, so spatial clustering of hypocenter distributions has been used to construct planar fault geometries. However, conventional spatial clustering inherently struggles with the complexity of hypocenter distributions. In this study, we integrated point‐cloud normal vectors, commonly used in object recognition to reflect the local surface geometry of an object, into a hypocenter‐based hierarchical clustering to construct intricate planar fault models. We applied this method to the aftershock sequences of the Mw 7.5 Noto Peninsula earthquake in central Japan on 1 January 2024, which caused notable crustal deformation. We identified fault planes aligning with the coastline from the western to northern coast. A southeast‐dipping plane was located between the two south‐southeast‐dipping planes along the northern coast, correlating with gravity anomalies and surface geology or reflecting the complexity of fault ruptures and dynamic stress perturbations. The east‐dipping fault in the southwestern area showed a different distribution from the aftershocks of the 2007 Mw 6.7 earthquake, suggesting that the 2024 earthquake did not reactivate the 2007's fault plane. The NS‐trending aftershock focal mechanisms in the southwestern area suggest that a reverse‐fault slip probably occurred on the plane. Further investigations based on the intricate fault planes will contribute to a deeper understanding of the spatial characteristics of the coseismic slip of the 2024 earthquake and seismotectonics of the Noto Peninsula.

Numerical simulations of Sequences of Earthquakes and Aseismic Slip (SEAS) have rapidly progressed to address fundamental problems in fault mechanics and provide self‐consistent, physics‐based frameworks to interpret and predict geophysical observations across spatial and temporal scales. To advance SEAS simulations with rigor and reproducibility, we pursue community efforts to verify numerical codes in an expanding suite of benchmarks. Here we present code comparison results from a new set of quasi‐dynamic benchmark problems BP6‐QD‐A/S/C that consider an aseismic slip transient induced by changes in pore fluid pressure consistent with fluid injection and diffusion in fault models with different treatments of fault friction. Ten modeling groups participated in problems BP6‐QD‐A and BP6‐QD‐S considering rate‐and‐state fault models using the aging (‐A) and slip (‐S) law formulations for frictional state evolution, respectively, allowing us to better understand how various computational factors across codes affect the simulated evolution of pore pressure and aseismic slip. Comparisons of problems using the aging versus slip law, and a constant friction coefficient (‐C), illustrate how aseismic slip models can differ in the timing and amount of slip achieved with different treatments of fault friction given the same perturbations in pore fluid pressure. We achieve excellent quantitative agreement across participating codes, with further agreement attained by ensuring sufficiently fine time‐stepping and consistent treatment of boundary conditions. Our benchmark efforts offer a community‐based example to reveal sensitivities of numerical modeling results, which is essential for advancing multi‐physics SEAS models to better understand and construct reliable predictive models of fault dynamics.

In recent years, advancements in artificial intelligence, especially in natural language processing (NLP) models, have progressed rapidly. These models demonstrate remarkable results through training on large datasets and extensive architectures. However, the output process is often a black box, and the decision-making process remains unclear. Our research focuses on the internal representations, specifically the latent variables, generated by NLP models. In earlier work, we explored the latent variables and spaces produced by Sentence-BERT using image generation models. This approach aimed to visualize these spaces by converting discrete textual embeddings into images, introducing continuity and revealing novel relationships. This paper presents the development of an image generation model that uses a common decoder for both GPT-2 and Sentence-BERT, aimed at examining how differences in model architecture affect their latent spaces. We also investigate the impact of training dataset differences by comparing models trained in English and Japanese. Our findings indicate that while the models often generate similar outputs, significant differences emerge in sentences containing multiple elements, attributable to the differing focuses and objectives of the models. Our goal is to understand these latent spaces and contribute to the development of explainable AI.

Plain Language Summary The Arctic Ocean is warming, partly due to the inflow of warmer Atlantic and Pacific waters. This warming is changing how water moves in the Arctic, but we still have limited understanding of the pathways of water in the western Arctic, where Atlantic and Pacific waters meet. To better understand these patterns, we measured ¹²⁹I in seawater samples collected from the western Arctic Ocean and Bering Sea in 2021. ¹²⁹I is a human‐made substance that spreads through the Arctic Ocean and varies widely in concentration, making it useful for tracking water movement. Our data show that Atlantic water enters the western Arctic through different routes. We also found that the top layer of this water may deviate from its usual path along the Arctic border and extend farther into the region. This newly identified behavior suggests that Atlantic water has a broader influence on the western Arctic than previously recognized. Additionally, our findings confirm that a cold, salty layer of water, called the halocline, acts as a strong barrier, preventing matter in deeper Atlantic water from reaching the surface.

This study focused on the guiding effect of residents' room signs and restroom signs displayed in group homes for elderly individuals with dementia. The results indicated that wandering behavior was primarily observed in residents with moderate dementia. An analysis of their behavior showed that while they had a general sense of the location and direction of their intended destination and could correctly reach the area around it, they were unable to identify the precise location in the final process of selecting the correct door. In contrast, when text‐based signs displaying residents' names or “restroom” were used, these served as cues to help identify the precise location, thereby preventing wandering behavior.

Thermal comfort is not a luxury; rather, a lack of it is a matter of life and death, particularly for vulnerable people, such as older people. This work systematically reviews and analyses the thermal comfort of older people and their health and mortality as it relates to exposure to extreme temperatures, and suggests acceptable thermal conditions and the related energy use of buildings. A total of 69 out of 198 papers were found on older people and these were analysed in detail. This was followed by an analysis of the UN and UK governments’ open access data. This work highlights the disparity regarding the definition of age for older people and encourages the use of the term ”older people”, rather than ”elderly”, which can be an offensive piece of terminology. The UK findings suggest a significant relationship between cold (below 5 °C) outdoor air temperatures and mortality in older people, particularly for those who are over 85 years old. In the UK, thermal conditions can lead to up to 175 deaths per degree temperature change up to two weeks after a cold spell or an overly hot period. The indoor comfort temperature of older people varies between 22.5 and 27 °C in natural ventilation mode. However, some studies found 18 °C to be comfortable in winter time, a finding which could lead to a significant energy saving in relation to space heating. Current gaps in and the recommended future direction of research include topics such as gender differences in terms of thermal comfort and during menopause; thermal comfort conditions, adaptive behaviours and naturally ventilated buildings; thermal conditions when sleeping and energy use as it relates to space heating or cooling for older people.

This study develops a globally adaptable and scalable methodology for high-resolution, building-level population mapping, integrating Earth observation techniques, geospatial data acquisition, and machine learning to enhance population estimation in rapidly urbanizing cities, particularly in developing countries. Using Bangkok, Thailand, as a case study, this research presents a problem-driven approach that leverages open geospatial data, including Overture Maps and OpenStreetMap (OSM), alongside Digital Elevation Models, to overcome limitations in data availability, granularity, and quality. This study integrates morphological terrain analysis and machine learning-based classification models to estimate building ancillary attributes such as footprint, height, and usage, applying micro-dasymetric mapping techniques to refine population distribution estimates. The findings reveal a notable degree of accuracy within residential zones, whereas performance in commercial and cultural areas indicates room for improvement. Challenges identified in mixed-use and townhouse building types are attributed to issues of misclassification and constraints in input data. The research underscores the importance of geospatial AI and remote sensing in resolving urban data scarcity challenges. By addressing critical gaps in geospatial data acquisition and processing, this study provides scalable, cost-effective solutions in the integration of multi-source remote sensing data and machine learning that contribute to sustainable urban development, disaster resilience, and resource planning. The findings reinforce the transformative role of open-access geospatial data in Earth observation applications, supporting real-time decision-making and enhanced urban resilience strategies in rapidly evolving environments.

Work has a purpose. In order to achieve that purpose, we think about solutions according to various rules such as social values, ethical interpretations, principles, phenomena, and logical thinking. This thinking is the linkage of information, and there is infinite freedom of choice, but the pattern of thinking cultivated in education (the pattern of information linkage) takes precedence. If you can't solve the problem at once, divide the problem-solving process into several parts and try to solve it step by step. Here, we repeat the thought of solving the problem until the goal is achieved. Systematic and comprehensive learning can be interpreted as an autonomous linkage of information to achieve a goal. Therefore, systematic and comprehensive learning is promoted by guaranteeing the linkage of information for the purpose of problem solving.

In this study, a peeling‐off technique is developed for fabricating flexible, lightweight, and bifacial perovskite/Cu(In,Ga)Se2 (CIGSe) tandem solar cells (TSCs). The process involves forming a perovskite/CIGSe TSC on a glass substrate and then peeling it off. The effectiveness of the proposed process is investigated using a CIGSe single‐junction solar cell. A MoSe2 atomic layer with a c‐axis orientation is observed at the Mo/CIGSe interface, which promotes the peeling‐off process. A flexible, lightweight CIGSe solar cell with a power conversion efficiency (PCE) of 12.3% is fabricated using the peeling‐off technique. The open‐circuit voltage of the flexible solar cell is similar to that of the rigid CIGSe solar cell. Furthermore, a perovskite/CIGSe TSC is fabricated with a PCE of 21.4% on a glass substrate. The TSC exhibited excellent current matching owing to the good match between the energy bandgaps of the perovskite and CIGSe. The proposed technique is used to detach the TSC from the substrate, and NiO and In2O3 transparent back layers are deposited on the peeled CIGSe rear surface. The device exhibits rectification and a PCE of 2.9%. Scanning electron microscopy reveals that the SnO2/C60 and/or C60/perovskite interfaces are peeled off. These results demonstrate that high‐efficiency, flexible, lightweight, and bifacial perovskite/CIGSe TSCs can be fabricated using the proposed technique by controlling adhesion at the device interfaces.

The thermodynamic information characteristics of fractal material structures, fabricated via a self-organization process, were analyzed using a ternary BaTiO3 (BT)/β-Si3N4 (SN)/polyvinylidene fluoride (PVDF) composite, notable for its combined thermal conductivity and dielectric properties. BT/SN/PVDF composites were prepared using (a) lamination, where prefabricated BT/PVDF and SN/PVDF melt sheets were alternately folded, and (b) simple mixing and kneading. To investigate the relationship between the materialographic characteristics and the material properties (dielectric properties and thermal conductivity) of self-assembled/self-organized fractal structures formed through the mixed diffusion of filler particles, the distribution of filler particle populations was analyzed via multifractal analysis. The resulting composite film texture was found to be process-independent, demonstrating a distinct microstructure where SN and BT formed separate aggregates. Notably, the mutual information, I, calculated using the information dimension D±1, revealed a strong correlation between the two filler particle groups. This indicates that like particles were attracted, while unlike particles were repelled, suggesting that the two fillers exist separately. These results suggest SN aggregates form a thermal conductive network, and BT aggregates contribute to high dielectric properties, each enhancing specific material properties. This study proposes a pathway to construct materials with independently controlled properties, offering a new design approach for multifunctional materials.

Boron carbide, one of the boron icosahedra cluster compounds, exhibits attractive thermoelectric properties. However, boron carbide is hard to sinter because of the strong covalent bonding of boron. We focused on the Reaction Boronizing Sintering (RBS) method to sintering of boron carbide materials. In RBS, the eutectic liquid phase between metal and boron promotes the densification of the borides. In this study, the effects of metal addition on the thermoelectric properties were investigated. Boron carbide base materials were synthesized by powder metallurgy method using SPS from B, C, and metal powders, Mn and Ni. According to XRD measurement of SPSed materials, boron carbide and metal boride, MB or MB2, were appeared. Microstructural observation by SEM results showed that phase formations of metal boride depend on additive metal species. Higher thermoelectric performance can be expected by further optimizing of the SPS condition and grain size and introducing of a mechanical milling process.

Transition metal diborides with an AlB2-type structure exhibit excellent mechanical properties, wear resistance, and high temperature stability. For example, TiB2 has excellent mechanical and wear resistance properties. However, the preparation of pure, dense, sintered transition metal diborides is difficult, as high temperatures, high pressure, and sintering aids are required in the sintering process. In this study, we applied spark plasma sintering (SPS), a powder metallurgy technique that enables rapid sintering via Joule heat generated by an electric current. We fabricated (Ti, M)B2 diboride solid solutions (M = V, Mo, W, etc.) by means of SPS. The X-ray diffraction results verified the AlB2-type structure of the prepared (Ti, M)B2 solid solutions.

Mo2NiB2-Ni cermets, one of the boride-base cermet, have been investigated as an alternative material to WC cemented carbides. By adding Cr and V to the Mo2NiB2-Ni cermet, the crystal structure of the Mo2NiB2 is changed from orthorhombic type to tetragonal type, and mechanical properties show enhancement. However, details of structure deformation and the mechanical properties of Mo2NiB2 phases still need to be discovered. In this study, we performed a nano indentation measurement to investigate the hardness of the Mo2NiB2 phases. Cr and V doped complex boride base cermets with tetragonal structure-type and non-doped Mo2NiB2-Ni cermet with orthorhombic type structure were sintered using Reaction Boronising Sintering method proposed K. Takagi. According to the nano-indentation measurement, the hardness of the tetragonal phase exhibited 25 - 28 GPa, while that of the orthorhombic phase showed 20 - 23 GPa.