Japan Architectural Review最新文献

In recent years, there has been an increasing demand for small-scale hostels, such as vacation rentals, known as “minpaku” in Japanese, which were originally single-family houses. To convert these buildings for use as accommodation facilities, improvements must be made to fire evacuation safety measures. An effective and reasonable measure for this improvement is the installation of wireless, interconnected alarm smoke detectors. We conducted experiments to examine how sleeping guests recognize these alarms when they are activated. Eleven participants experienced the alarm sounding while sleeping at night and while awake during the daytime at a wooden cottage. They were exposed to three different sounding patterns. In the sleeping experiment, 9 of 11 participants were woken up by alarms sounding in other rooms, while the remaining two were woken up by alarms in their own rooms. However, those two participants had difficulty understanding the meaning of the voice alarm clearly. The voice stated, “Other detector was activated,” indicating a fire in another room and urging evacuation, even though there was no smoke in their room. Comprehension of the alarm system is essential for guests to understand its intentions accurately and make proper decisions regarding evacuation.

This research conducted investigations of buildings equipped with radiant systems and expert interviews in 2021–2022 with manufacturers and mechanical, electrical, and plumbing (MEP) engineers in Japan who had experience designing radiant heating and cooling systems for non-residential buildings. In total, interviews were conducted with 56 respondents from 16 companies. Results from the building investigation showed that 69% of the identified buildings had radiant ceilings, and 30% had radiant floors. In terms of working fluid, 56% were water-based, and 43% were air-based. For the expert interview, 79% of all respondents answered that the use of radiant systems will continue to increase in the future. In total, 54% of all respondents answered that it has become easier to design radiant systems at present compared to the 2010s. Based on the results, knowledge gaps and challenges in the design of radiant systems were summarized in terms of design method, room temperature control, auxiliary systems, and their relevance to building decarbonization.

Short-period ground motions from earthquakes are calculated by semiempirical methods such as the empirical Green's function method or the stochastic Green's function method. In this review paper, I summarized source models developed for reproducing and predicting ground motions in the theoretical methods at first, and then reviewed the source models applied to reproducing and predicting ground motions in the empirical Green's function method in these about 40 years. Finally, I showed some issues to be solved about source modeling in order to predict accurate short-period motions in the near-fault regions.

The response spectrum method (RSM), specified by the Ministry of Construction notification Vol. 2009, is not part of the countermeasure to address the Nankai trough long-period and long-duration ground motions (LPGMs) announced in 2016. Consequently, in this study, an approach was proposed to assess the effect of changes in characteristics due to repeated deformations using the RSM for LPGMs and seismically isolated buildings using lead rubber bearings (LRBs). However, this study identified potential areas for improvement in the calculation of effective damping using the RSM. An effective damping calculation method of the RSM using an effective ductility factor is introduced to enhance the accuracy of the proposed method. The proposed RSM-based method was verified against the methods based on nonlinear time history analysis. The earthquake response prediction results using the proposed method were compared with those of not only the simplified method but also the precise and the quasi-precise methods. The accuracy of earthquake response prediction using the proposed approach is increased by 30%–50% when the effective ductility factor is used to compute the effective damping. Therefore, earthquake response can be predicted using the proposed method, and the accuracy achieved is similar to the nonlinear time history analysis.

Aiming to improve thermal environment for outdoor public spaces, the author had been developing a unit-type green parklet for parking lots that both introduce greenery into cities and produce walkable urban spaces. In this study, the author examined and created a full-size unit-type green parklet, installed it in a parking lot adjacent to sidewalk space next to a bus stop in the traditional urban area, Kyomachi district, of Kumamoto City, and investigated the improvement to summer thermal environment from a field measurement and its usage by people from user survey in summer (from August 30 to September 5, 2022). The results showed that although the parklet shaded with the parasol and greening units, air temperature dropped by only a maximum of 1°C in daytime. Given the characteristics of parking lot as a location, it was confirmed that not only the wind and airflow conditions was blocked and worsened, but reflected solar radiation from the surroundings and generated heat from parked cars degraded air temperature and MRT from the field measurement. Furthermore, it was confirmed to be ensured the visibility of the surroundings when sitting on the parklet bench for the users waiting for a bus from user survey.

In recent years, there has been concern about the occurrence of extreme ground motions that greatly exceed the amplitude levels and durations expected at the conventional design level. Therefore, seismically isolated buildings are required to ensure seismic isolation performance for small earthquakes and suppress the excessive displacement of the seismic isolation layer for extreme ground motions. In this paper, we analyze the seismic response of seismically isolated buildings with the dead zone mechanism connected to oil dampers to understand the response characteristics.

This study analyzed the mechanism of shopping difficulties for low-income groups in central Tokyo, where economic disparity is progressing due to gentrification. Through questionnaire and interview surveys, as well as analysis of time-series environmental changes, we found that since 2000, shopping difficulties have been induced by the decline of shopping streets and the upgrading of supermarkets in parallel. Furthermore, in the areas where the percentage of high-income groups due to redevelopments has significantly increased, luxury supermarkets opened at the same time as the construction of luxury condominiums, making it difficult for affordable supermarkets to locate.

We analyzed the mechanism of urban food desert expansion based on data at the block level. According to the food demand curve, elasticity was high, and the nutritional food dietary decreased as store prices increased. The store prices within 500 m of the redevelopment site would tend to increase because luxury supermarkets would dominate, while over 500 m they would often tend to decrease because new non-luxury supermarkets would compete for opening. There are two types of blocks with a high risk of food desert: A block surrounded by multiple redevelopments or a block whose store price has gone up considerably.

In this study, a thermally activated building system (TABS) installed on the exterior wall as the pipe-embedded wall (PEW) system in a school building was investigated. The basic performance of the PEW system utilizing well water cascade is verified by unsteady CFD analysis and field measurements. Moreover, in order to improve the utilization efficiency of the thermal potential from well water, the MPC-based optimal control method with the PEW system to maximize the heat extraction is proposed and verified by unsteady CFD analysis. The analysis results showed that: (1) The PEW system can reduce the peak load from the exterior wall facing different directions at different times. In addition, the PEW system has the effect of stabilizing the indoor thermal environment. (2) The proposed optimal operation strategy improves the energy efficiency, extracting up to 30% more heat and reducing the total heat transmission, which significantly develops the operation efficiency of the PEW system.

Text descriptions of buildings using onomatopoeic words are a form of communication frequently used by Japanese architects to express their design intent. The onomatopoeic word describes a building vividly and sensually as if it has life and expresses connotative architectural meanings imbued through building posture and gestures, as depicted by the architect. This paper investigates the materiality of architecture through a text analysis of onomatopoeic expressions used to describe architectural works in the Japanese architecture magazine Shinkenchiku (新建築), identifies 24 aspects of architectural materiality reflected in the onomatopoeia used by architects, and typifies their views of architecture as a physical object.