Japan Architectural Review最新文献

The building, Sechie, is an architectural representation in which the activities of living become a “dwelling space” that clearly articulates what it is rather than a house as container. Also, Sechie delivers a modern adaptation of Japanese spatial principles by going back historically to their origins. The building traces the connection with previous research and architectural works referring to “Ai(Ma)” and ceremonial space. Its structure is based on the origins of space generated by a repository containing living functions and a stage without such functions. By connecting them three-dimensionally, the garden creates an architectural state in which human actions and nature coexist.

Droplet nuclei and tiny enough droplets to move as an aerosol are regarded as one of the modes of infection transmission SARS-CoV-2. Various measures have been taken to prevent it worldwide. Nevertheless, many scenarios cannot be avoided close-distance conversations, for example, in a consulting room, restaurant, or crowded train. A consulting room has significant potential for doctors to contact infected patients. Therefore, this study proposes a novel approach combining a local exhaust ventilation (LEV) and floor-supply displacement ventilation system (FSDV) in a consulting room. This study assumes that two persons (doctor and patient) are sitting face to face and talking without a mask in a simple room regarded as a consulting room. The velocity and volume of exhaled air from talking were acquired through field measurements. Then, computational fluid dynamics (CFD) steady analysis was carried out, using the results of exhaled air measurement with various parameters (hood height, hood flow rate, horizontal hood position, and air flow rate). The capture efficiency for tracer gas and contribution distribution for the hood (SVE5: scale for ventilation efficiency 5) have been calculated to reveal the hood's capture performance. In addition, infection risk for the doctor was also calculated using the Wells–Riley model to estimate the infection performance of this ventilation system. By measuring exhaled air from talking, a speed of 0.30 m/s, a volume of 5.21 L/min, and a vertical angle of 11.9° were obtained, and these values were installed into CFD. The CFD results showed that hood flow rate significantly impacts capture efficiency at SA 120 m³/h (6 ACH), and horizontal hood position significantly impacts at SA 1000 m³/h (50 ACH). SVE5 also showed hood's effective area is greatly influenced by the flow rate balance between the hood and the other exhaust routes. Under high air supply conditions: SA 1000 m³/h (50 ACH), there was almost no airborne transmission risk for a doctor with or without a hood. However, under 120 m³/h (6 ACH) conditions, the combination of the hood and FSDV system could reduce an infection risk sufficiently. The hood should be located above the infected person's head to keep the counter person's infectious risk low, indicating that the introduction of the hood is reasonable in the consulting room, where it is easy to find where the infected person is.

This paper focuses on the process of local government formation, from the Edo Period to the Meiji Era, in Kawagoe City, which has its roots in a castle town at the end of the Edo Period, in order to discover regional formation for urban reorganization. The daiku-shoku system and Rengo-choson organized early-modern towns and villages in the Edo Period as self-governing organizations, but the mass amalgamations during the Meiji Era created municipalities, forming the basis of the current city sphere. These phases of Meiji Restoration were influenced by the topography of rivers and farmland, and the urban expansion of castle towns, which formed the organization. Although some of the landforms that functioned as boundaries of the organization disappeared owing to mergers and urban development after the Meiji Era, most of the elements have been inherited by the current city master plan districts. Accordingly, by organizing the process of regional formation, we have derived the gradual changes in consciousness that occurred under the circumstances of conversion from different organizations. In addition, by comparing the current and past situations, the inheritance of the historical background is presented.

The introduction of semi-outdoor spaces to urban spaces and offices has increased in recent years. In previous studies, environmental grade has been defined as the level of control for the thermal environment set for an architectural space based on the use, where “semi-outdoor environment” is an environmental grade division that exists as a gradation between indoors and outdoors. This study aims to clarify effects of various environmental grades on thermal comfort. Field surveys were conducted in five semi-outdoor spaces in Tokyo from 9 to 25 September 2021, consisting of thermal environment measurement, questionnaires about thermal comfort and impression of surveyed spaces and real-time sensation voting. By impression evaluation and comparison of the regression curves of standard new effective temperature (SET*) against percentage of “uncomfortably warm,” the surveyed spaces were classified into two categories: “outdoor tendency” and “indoor tendency.” The difference in thermal comfort for the diverse semi-outdoor environment could be evaluated by the difference in spatial characteristics such as “sense of weight” of the top surface in addition to the difference in environment control. By regression analysis of real-time sensation voting result using hierarchical Bayesian approach, environmental grade was clarified to affect the correlation between pleasantness/unpleasantness and air velocity.

The paper deals with the exterior design of townhouses in an urban block of the eastern part of Bhaktapur in Kathmandu Valley. The primary purpose is to provide an analysis method to determine the typical combination among exterior design components of Nepalese townhouses. By using multiple correspondence analysis and cluster analysis, 118 samples are grouped into 13 clusters. Secondly, all the clustered samples were put onto the original plots on the map to see the characteristics of their locations. Such a process would help a designer/planner reflect on how they should compose a proper facade in reconstruction works of townhouses after the earthquake in 2015.

This paper presents an approach for the design of discrete architectural surfaces that are globally developable; that is, having zero Gaussian curvature at every interior node. This kind of architectural surface is particularly suitable for fast fabrication at a low cost, since their curved geometry can be developed into a plane. This highly non-linear design problem is broken down into two sub-problems: (1) find the member lengths of a triangular mesh that lead to zero Gaussian curvature, by employing the discrete surface Ricci flow developed in the field of discrete differential geometry; (2) realize the final geometry by solving an optimization problem, subject to the constraints on member lengths as well as the given boundary. It is demonstrated by the numerical examples that both of these two sub-problems can be solved with small computational costs and sufficient accuracy. In addition, the Ricci flow algorithm has an attractive feature—the final design is conformal to the initial one. Conformality could result in higher structural performance, because the shape of each panel is kept as close as possible to its initial design, suppressing possible distortion of the panels. This paper further presents an improved circle packing scheme implemented in the discrete surface Ricci flow to achieve better conformality, while keeping its simplicity in algorithm implementation as in the existing Thurston's scheme .

This study identifies some of the distinctive characteristics of the land acquired by foreigners in the zakkyochi (mixed-residential areas) of Kobe, Japan, during the Meiji era, and explores the various means by which foreigners were able to acquire this land. The primary focus is on Kitano-cho and Yamamoto-dori, a well-known residential area for foreigners, where ijinkan (historical Western-style residences) still stand to this day. By law, foreigners in zakkyochi were given only the right to lease land from Japanese citizens and the Japanese government. Nonetheless, foreigners such as E.H. Hunter expanded the area available to them by using the names of Japanese relatives. Although Japanese women who married foreigners were also prohibited from owning land, this restriction did not apply to their children. Thus, in the case of E.H. Hunter, a significant portion of the land he acquired was acquired in the name of his children, primarily in areas adjacent to the mountains, excluding the sites of graveyards and villages. Indeed, it was generally the case that the land used by foreigners in Kobe was concentrated in the hilly areas with good views that did not serve as graveyards or village sites.

To evaluate Q–Δ resonance, which is a torsional resonance phenomenon caused by geometric nonlinearity, a simplified model for a multistory non-eccentric building with a shear-type structure was proposed. A four-story small-scale specimen was designed and fabricated, assuming a non-eccentric steel structure with a height of 324 m, and conducted shaking table tests of the specimen. Q–Δ resonance was confirmed as predicted by the simplified model. In addition, the simplified model reproduced the resonance amplitude calculated using a finite element model of the specimen with constrained out-of-plane slab rotation. The simplified model can be used to predict the Q–Δ resonance response when the bending deformation of an entire building is very small.

Are street networks today dependent on history? This question is significant when considering the determinants of street connectivity and the potential for intervention toward walkable street networks. This study investigates the associations of two historical events—castle town origination and war damage during World War II (WWII)—with the street connectivity of 803 Japanese cities. We used the space syntax theory to measure street connectivity and conducted multiple linear regression analyses to determine the aforementioned associations. The results showed that street connectivity today tends to be low in cities that originated from castle towns and high in cities that suffered heavy damage during WWII. This may be due to complicated street networks that were constructed intentionally in castle towns to defend their territory from invasion. The remaining irregular layouts may have directly and indirectly influenced today's street networks. Furthermore, in the cities that suffered heavy war damage, the “postwar reconstruction city plan” was enforced to reconstruct affected areas, which may have improved street connectivity. These findings highlight the significance of historical events in the consideration of street connectivity determinants and the development of interventions to enhance them.

The effective cross-sectional area method for the outstanding leg is utilized as an ineffective area to evaluate the strength in the present Japanese design standard. Given that this evaluation method is fundamentally premised on experimental outcomes derived from relatively thick plates, it must be extended to brace members composed of thin plates. In this study, we conduct bolt joint experiments and numerical analyses on thin-plate angles and channel members, with the aim to elucidate the elements influencing the efficiency of the joint. We propose a unified bolt joint strength evaluation formula that also considers thin-plate members.