Japan Architectural Review最新文献

Microplastics, defined as plastic particles smaller than 5 mm, are widely spread in aquatic, terrestrial, and atmospheric environments, which is a marked environmental concern. However, research on indoor microplastic pollution remains limited, particularly in Japan. Therefore, the aim of this study was to investigate the shape and composition of microplastics in house dust from single-person households in four regions of Japan, including Tohoku, Kanto, Chubu, and Kansai. Micro-Fourier-transform infrared spectroscopy, a technique that combines infrared spectroscopy with optical microscopy was used, allowing a detailed analysis by obtaining the specific interference patterns and absorption spectra of the materials. The influence of building structure, flooring, and wall materials on microplastic composition in indoor environments was also investigated. This study addresses crucial knowledge gaps regarding the extent, forms, and sources of indoor microplastics. These findings contribute to the development of targeted measures to mitigate indoor microplastic exposure, support efforts to improve indoor air quality, and protect public health.

A laboratory experiment was conducted to investigate an evaluation method for building habitability based on subjective responses to vibrations caused by external sources. Twenty-five individuals participated in the experiment, which involved 76 input stimulus conditions, including vibrations based on field records and sinusoidal vibrations in the horizontal direction. Subjective responses were measured in terms of “magnitude,” “concern,” and “discomfort,” The study compared several domestic and international evaluation methods for environmental vibrations with subjective responses, revealing that the vibration dose value, which accounts for the effect of vibration duration raised to the fourth power, was the most reasonable method.

Following schematic design in November 1948, the design effort continued through working design (detailed design prepared for construction work), which was completed in June 1950, and subsequent detailed construction instruction design. These phases included dome installation over the sanctuary, crypt redesign, window design, and tower design, all of which are impressive manifestations seen in the built work. This paper depicts the architect's creative and strategic design thinking during these phases by analyzing formal manipulations observed in sketches and drawings created until just before the cathedral's dedication on August 6, 1954.

This study explores the pre- and post-renovation differences in communication behaviors of office workers at a construction company's research facility that had carried out renovations to promote open innovation through internal and external interactions. We conducted an analysis by combining both objective survey of conversation time, conversation partners, and stay location information using sensing terminals and subjective evaluations by office workers using a questionnaire survey. As the work style transitioned from fixed seats pre-renovation to activity-based working post-renovation, the attendance rate analysis around each worker's personal workspace throughout the measurement period decreased from 74% to 60%, and the tendency to use various places in the office increased. Additionally, the number of conversation partners increased by 1.9 times on average and inter-department conversation rate increased from 46% to 53% when activity-based working was performed post-renovation. However, while the introduction of activity-based working significantly increased the level of communication satisfaction among workers in other departments, it tended to decrease the level of communication satisfaction within a department. This study maintains that organizational and operational efforts must sustain and promote intra-departmental communication when activity-based working is introduced and confirms that the introduction of activity-based working was effective in promoting interaction between office workers.

A new processing method of ground acceleration data is proposed for the fast and accurate evaluation of the maximum seismic structural responses. The proposed method consists of a trimming method and a down-sampling method. The proposed trimming method is based on ground acceleration power and contains compensation procedures for the trimmed ground acceleration. The proposed down-sampling method effectively uses FIR filter, whose weight coefficients are derived from the correspondence between the responses under a triangular wave and the equivalent impulse input. It is demonstrated through numerical examples for response spectrums and a full-scale high-rise building model that the proposed method enables fast and accurate evaluation of the maximum seismic structural responses.

A continuous beam-type connection has been proposed as a new type of concrete-filled steel tubular beam-to-column connection without a diaphragm exhibits good seismic performance. However, in a 2-way configuration, the performance of the connection in a direction orthogonal to the continuous beam may be suboptimal due to beam splitting. In this study, a new detail of a split orthogonal beam joint was proposed and 4 specimens were constructed and tested under quasi-static conditions. All the specimens attained the full-plastic flexural strength for the beams and exhibited a stable inelastic behavior. The specimen in which the depth of the orthogonal continuous beam was 100 mm greater than that of the split beam exhibited good inelastic cyclic behavior, whereas two other specimens with a split beam exhibited slipping and pinching. Minor fractures were observed in the tube wall; however, the strength and stiffness did not deteriorate significantly, though a slight pinched hysteresis was observed. In addition, a finite element analysis was conducted. The split beam was largely rotationally constrained by the bearing pressure of the concrete above and/or below the beam flange. If the split beam's flange was sufficiently inserted into the connection panel, the stiffness and strength were ensured.

This study investigated how disaster case management (DCM) and disaster public housing reconstruction influence housing recovery using 4 open-data sources. The trends in the number of households under designated temporary housing in Sendai and 18 other cities in Miyagi Prefecture were analyzed. The results revealed that both DCM and the reconstruction of public housing for disaster recovery promote housing restoration from temporary housing. Finally, Mary Richmond's discussion of wholesale and retail methods was used to elucidate policy implications for disaster victim support.

Causal hysteretic damping, extended Rayleigh damping, and uniform damping models exhibit frequency-independent damping ratios over a wide frequency range. However, several points remain unclear regarding their applicability to inelastic problems. Therefore, in this study, to compare the vibration characteristics of these damping models, analyses are performed by inputting white noise into simple models with various natural frequencies. Results confirm that these damping models are frequency-independent even under inelastic conditions. Further, the causal hysteretic and extended Rayleigh damping models have the same computation order as that of conventional Rayleigh damping and can therefore be calculated in approximately the same time.

As urban public spaces evolve to accommodate human activities, there arises a pressing need for effective methodologies to understand public life within these environments. This pilot study assesses the accuracy of the Real-Time Kinematic Global Navigation Satellite System (RTK GNSS) in the Toyohashi South Side Station Square, aiming to validate its utility as a privacy-sensitive tool for studying public life, particularly in tracking movable chairs in urban settings. The findings indicate that RTK GNSS exhibits sufficient accuracy in recording the positions of movable chairs, thus facilitating public life studies. Given the variability of GNSS accuracy across environments, we propose the Silhouette Index as a metric for evaluating GNSS suitability across different scales. A Silhouette Index exceeding 0.9 signifies highly accurate data, suitable for comprehending the spatial arrangement and utilization of movable chairs in compact urban spaces. Conversely, an index below 0.8 indicates insufficient accuracy for this purpose. Nevertheless, RTK GNSS, akin to GPS, offers diverse applications in urban research. It can aid in analyzing pedestrian flows in city centers or expansive parks, as well as elucidating spatial behavioral patterns among distinct demographic groups in large-scale urban public spaces.

In his book Gaibu kūkan no kōsei (Exterior Space in Architecture), Yoshinobu Ashihara criticized modern architecture and urban planning and searched for ways to realize plazas suitable for humans. This study analyzes how Ashihara designed the Komazawa Park Gymnasium, a wrestling venue for the 1964 Tokyo Olympics, and the Central Plaza. It focuses on the distinctive hyperbolic paraboloid shells of Komazawa Park Gymnasium. Concurrently, this study evaluates Ashihara's uniqueness as an architect while comparing the Komazawa Central Plaza with Hiroshima Peace Memorial Park, designed by Kenzo Tange.