This study examined the deterioration of pultruded Hybrid FRP material due to outdoor exposure. The outdoor exposure test was conducted for 2 and 21-year using Hybrid FRP which consists of Carbon and Glass fibers, revealed the residual strength through the material tests. Moreover, the microstructure of the deteriorated Hybrid FRP was examined through SEM observation and IR analysis. As a result of the test, it was clarified that the tensile strength in the transverse direction decreased by 36% of the initial strength due to 21-years of outdoor exposure. SEM observation revealed that the voids inherent in the glass fiber layer expanded, leading to the loss of the resin and glass fiber. In addition, the examination was conducted on specimens with top coating. Although the coating increased the residual strength in the roving direction, it had little effect on the mechanical performance in the 90° tensile strength and in-plane shear strength. The observation confirmed that small holes on the coating appeared after 21-years of outdoor exposure, implying the deterioration of coating.

 The number of older drivers is increasing, along with the progress of aging society. The physical ability is deteriorating with aging, so that driving become uneasy to most of older drivers. However, the lack of alternative of mobility forced to a certain number of old drivers to drive continuously. Therefore, in this study, we assume a hypothesis that the local transportation environment affects the driving frequency of older drivers and tested them using the data collected by Chiba Prefecture Police. We found that the transportation environment such as accessibility by car and public transport and walkability of the area is related to the driving frequency of the older drivers.

 In recent years, theories based on spatial economics have been applied to econometric analysis. However, the analytical framework only outputs the result that "improvement of inter-regional transportation always increases the population of regional cities (decreases the population of large cities), " which is the opposite of the long-term trend of population distribution change in Japan (e.g., population increase in large cities). This is an important issue because it means that proper prediction of the impact of transportation improvements is impossible. This study develops an econometric method to solve this problem by applying the theory of monopolistic competition, which can take into account price competition among firms. Then, through an econometric analysis for Japan, we show that this method can output the result that "interregional transport improvements increase the population of large cities.

 This paper presents an efficient algorithm for solving dynamic user equilibrium (DUE) traffic assignment problems with one-to-many origin-destination demand. We first formulate the DUE problem, with the point queue model, as a linear complementarity problem (LCP). Then, we transform the LCP into a quadratic programming problem (QP). The QP enables us to build an efficient algorithm based on the convex combination method (Frank–Wolfe algorithm). Numerical experiments reveal that the proposed algorithm can (i) solve extremely large-scale problems to which no conventional methods can be applied, (ii) calculate the solution more than 1000 times faster than a general-purpose solver for optimization problems, and (iii) yield an extremely accurate equilibrium solution.

 This study proposes an efficient algorithm for the Fujita-Ogawa (FO) model in large-scale discrete space. We first generalize the choice behaviors of households and firms using the random utility theory (logit model) and introduce a stochastic FO model, which includes the original FO model as a special case. Subsequently, we reveal that this stochastic FO model has an equivalent optimization problem. We then transform the equivalent problem into a hierarchical optimization problem consisting of a master problem for firms and a subproblem for households. The subproblem, which determines the commuting pattern of households, has the structure of an optimal transport problem with an entropy regularization term. The master problem, which determines the location pattern of firms, is a nonconvex programming problem with constraints. By exploiting these mathematical structures, we propose a hierarchical optimization algorithm composed of the balancing method for the subproblem and the accelerated gradient method for the master problem. Finally, numerical experiments verify the efficiency and accuracy of the proposed method.

 Yukigata is described as “a shape formed by the disappearance of snow on the hillside.” It was once used as an agricultural calendar, but folklore is disappearing in various places due to the advancements in agriculture. Yukigata, a topography with 6 mountains, was described as “A Landscape that appears due to unique weather” and “Mixed landscape” in the 2005 report titled “A research report on the Conservation of Cultural Landscape Related to Agriculture, Forestry and Fisheries (Issued by Agency for Cultural Affairs)”. Yukigata was selected as a cultural landscape candidate, but it had not been certified due to lack of consistency with the conditions of the cultural landscape.

 The aims of this research are: (1) Understanding Yukigata and its distribution of the whole country; (2) Constructing Yukigata database and setting evaluation items; (3) Analyzing and categorizing the landscape characteristics of Yukigata; (4) Clarifying the correlation between industrial/ cultural characteristics and landscape characteristics of Yukigata. Through this, we examined the value evaluation of Yukigata.

 Corrosion of steel bars in underground RC structures due to inflow of groundwater containing salt has been reported. Since underground structures are sometimes subjected to external loads such as ground subsidence, it is becoming increasingly important to predict the superimposed effects of salt-induced deterioration. In this study, loading tests were conducted with 80% of a steel-corroded RC hollow circular specimen buried underground to investigate the effects of external loads under underground restraint. The results showed that the deformation capacity and bearing capacity of the underground circular tunnel structure were not significantly affected by steel corrosion, but shear failure through the cross-section along the leading bending cracks sometimes occurred. This shear failure can occur outside of the corroded zone if there is asymmetry in the corroded zone of the rebar. Furthermore, the shear strength of the subsequent shear failure along the bending crack may be lower than the preceding shear strength equation, which should be taken into account in maintenance.

 In this study, a dynamic back-analysis method that estimates degradation stage as well as layer modulus from FWD deflection basin was developed. Using the developed method, effects of dynamic loading of FWD test on structural evaluation of back-analysis for concrete pavement was investigated. FWD test data measured on the concrete test pavement on the circular accelerating pavement testing (ATP) facility was analyzed with static and dynamic back-analysis. As a whole, although dynamic back-analysis evaluates slightly more serious degradation stage and higher bending stress than static one, it was found that the evaluated results with both analysis methods are not so much different with each other.

 From April to May 2020, 20 people infected with COVID-19 occurred at a road related company to which the author belongs, and an infection cluster occurred. This research, revaluated the measures taken based on the existing infectious disease BCP based on resilience. Therefore “size of resilience” was defined as the ability to reduce the risk of infection and recover from the spread of infection. Also “size of damage” was defined as the impact of actual infected people, close contacts, and people waiting at home on normal work. Then both values were compared, and this “Comprehensive evaluation” was revaluated for the validity of the countermeasures. Furthermore, using the revaluation results and the results of applying the existing BCP for infectious diseases, measures to be reflected in the BCP for COVID-19 were proposed.

 In recent years, the number of cases of comprehensive private consignment for sewage treatment plant management has been increasing. For continuous improvement of asset management of sewage treatment plants, it is important to quantitatively evaluate the effects of comprehensive private consignment on reducing maintenance and management costs and increasing management efficiency, as well as to identify best practices and to improve management and operation methods. This study therefore quantitatively assesses the effectiveness of comprehensive private consignment of sewage treatment plants based on cost efficiency. Specifically, a methodology is proposed to quantify the comprehensive private consignment effect by non-parametric testing of the distributions of cost efficiency parameters estimated using a stochastic cost frontier model. The methodology is applied to a national database consisting of the maintenance and management costs of sewage treatment plants and the volume of treated water, to quantify the effects of comprehensive private consignment in practice.

 There are many kinds of proper use of the term “value”, and also a general idea of the value is not grasped fine distinction in meaning. This paper attempts to make clear the value of civil engineering business and propose the useful plans to concrete the value of them for the actual performance of civil engineering structure efficiently. The values of civil engineering structure with concrete examples are classified into large categories, it was possible to find out the simple skeletons of values of civil engineering structure consists of the some categories of values. Finally, the standard of judgement of value and the several ways of appraisal of value are considered in civil engineering field.

 This article examines the diffusion of net-zero declarations across Japan, elucidating the mechanisms that drove what can be considered a turning point in domestic climate policy. Based on theory from the literature on policy diffusion, we carry out a case study on Kanagawa Prefecture to investigate the dynamic process by which mutual interactions across national and sub-national governments, horizontal diffusion across city government drove the diffusion of net-zero targets across Japan. We also verify the effect of transnational networks along with other drivers and barriers. Using data from semi-structured interviews and document analysis, we find that adoption of the net-zero target began with progressive cities belonging to transnational networks. After this trend was noticed and promoted by the Ministry of the Environment, the increase of declarations at the sub-national then spurred the adoption of a net-zero target by the national government, which further propelled the emergence of net-zero declarations across Japan’s municipalities.