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The underlying mechanism of the ongoing seismic swarm in the Noto Peninsula, Japan, which generates earthquakes at 10 times the average regional rate, remains elusive. We capture the evolution of the subsurface stress state by monitoring changes in seismic wave velocities over an 11-year period. A sustained long-term increase in seismic velocity that is seasonally modulated drops before the earthquake swarm. We use a three-dimensional hydromechanical model to quantify environmentally driven variations in excess pore pressure, revealing its crucial role in governing the seasonal modulation with a stress sensitivity of 6 × 10-9 per pascal. The decrease in seismic velocity aligns with vertical surface uplift, suggesting potential fluid migration from a high-pore pressure zone at depth. Stress changes induced by abnormally intense snow falls contribute to initiating the swarm through subsequent perturbations to crustal pore pressure. [ABSTRACT FROM AUTHOR]

Already a multibillion-dollar global industry, shrimp aquaculture, is growing all the time. The intensive method, which is the most common method in shrimp aquaculture, remains commercially challenged due to the expenditures associated with environmental pollution abatement. Although the comprehensive understanding of this intricate aquaculture environment has been advanced using mathematical modeling, recent attempts to improve the model's structure have not yielded enough results. This work upgraded the previous method to a three-dimensional hydrodynamic ecosystem model with the effects of shrimps being replaced by approximation equations for the environmental assessment of a shrimp aquaculture pond in Kyushu District, Japan. Our approach was successful, as demonstrated by the high consistency of the simulation results when compared to observation data and the previous results. Additionally, we first revealed the impacts of stratification and confirmed the notable daily variation in the water quality. Our case study offers significant practical information on the characteristics of intensive shrimp aquaculture, implications for long-term sustainable operations, and future research priorities on local-scale ecosystem modeling. [ABSTRACT FROM AUTHOR]

This study examines how middle managers support their employees' strengths use via three sequential analyses. In Study 1, an open‐ended questionnaire survey of high‐performing middle managers at a global manufacturer in Japan (n = 144) was conducted to collect comments on strengths use support (SUS). The grounded theory approach was used to generate four categories of SUS, and a quantitative questionnaire was developed based on the analysis. In Study 2, three dimensions of SUS (understanding employees' strengths and interests, developing strengths through challenging assignments, and supporting the accomplishment) were identified by exploratory factor analyses using the questionnaire survey data of middle managers in Japanese firms (n = 208). Study 3 examined the validity and reliability of the three‐dimensional model using confirmatory factor analysis of the questionnaire survey data of middle managers in Japanese firms (n = 209). [ABSTRACT FROM AUTHOR]

This study aims to clarify the development and utilization of highly accurate and open 3D city models (3DCMs), which began in Japan in 2020. The background of the project is explained based on a review of past efforts in Japan for making geospatial information accessible, the flow of data standardization around CityGML, and the introduction of Free and Open Source Software for Geo-spatial (FOSS4G) tools for data management and visualization. Two aspects of the analysis are reported: quantitative geospatial analysis of LOD1 building data and qualitative evaluation of 40 use cases using these data. The results indicate that approximately 18 million building data points covering 150 cities in Japan have been converted to open data in formats such as CityGML with high accuracy, complementing OpenStreetMap (OSM) data in urban areas. In addition, a total of 40 use cases for these data are demonstrated in new fields, such as urban planning, citizen participation, and even entertainment, with a few of these tools becoming open-source software. Through this project, data related to 3DCMs, which have not necessarily been produced in a unified format or specification in Japan, can now be easily handled as CityGML through a one-stop viewer, and the data are expected to be enhanced, and new geo-services using 3DCMs will be provided under the concept of openness, regardless of the city scale. [ABSTRACT FROM AUTHOR]

Widely employed in hydrate exploitation, the single well method is utilized to broaden the scope of hydrate decomposition. Optimizing the well structure and production strategy is necessary to enhance gas recovery efficiency. Complex wells represented by the multilateral wells have great application potential in hydrate mining. This study focused on the impact of multilateral well production methods on productivity, taking the Nankai Trough in Japan as the study area. The spatial distribution of physical parameters such as porosity, permeability, and hydrate saturation in the Nankai Trough has significant heterogeneity. For model accuracy, the Sklearn machine learning and Kriging interpolation methods were used to construct a three-dimensional heterogeneous geological model to describe the structure and physical property parameters in the study area of the hydrate reservoir. The numerical simulation model was solved using the TOUGH + Hydrate program and fitted with the measured data of the trial production project to verify its reliability. Finally, we set the multilateral wells for hydrate high saturation area to predict the gas and water production of hydrate reservoir with different exploitation schemes. The main conclusions are as follows: ① The Sklearn machine learning and Kriging interpolation methods can be used to construct a three-dimensional heterogeneous geological model for limited site data, and the fitting effect of the heterogeneous numerical simulation model is better than that of the homogeneous numerical simulation model. ② The multilateral well method can effectively increase the gas production rate from the hydrate reservoir compared with the traditional single well method by approximately 8000 m3/day on average (approximately 51.8%). ③ In the high saturation area, the number of branches of the multilateral well were set to 2, 3, and 4, and the gas production rate was increased by approximately 51.8%, 52.5%, and 53.5%. Considering economic consumption, the number of branching wells should be set at 2–3 in the same layer. [ABSTRACT FROM AUTHOR]

Excessive flood flow over the historic diversion weir in the vegetated Asahi River in Okayama Prefecture, Japan, was recently recorded for the first time after its renovation work. Fluvial researchers analysed the diversion discharge for flood mitigation measures through laboratory studies and conventional two-dimensional (2-D) depth-averaged simulations. The existing model was insufficient for simulation of certain phenomena such as flow resistance caused by vegetation branches and leaves and vertical flow distribution around the river corridor. Therefore, we developed a three-dimensional (3-D) vegetation resistance porous model by estimating topography, land cover, and vegetation distribution from airborne light detection and ranging (LiDAR) topo-bathymetry (ALB) data. Results show that the water level and flow regime were more reproducible than by referenced 2-D calculations when compared to space-time image velocimetry (STIV) data and field measurements. The diversion discharge designed using the proposed model is feasible with the current riverbed and vegetation conditions. [ABSTRACT FROM AUTHOR]

Bowing is an act, commonly used in Japan, involving lowering the head and bending the upper body towards another person as a greeting. Studies have shown that the bowing action increases the subjective attractiveness of the face. Specifically, the attractiveness rating of a bowing 3D computer graphics model was found to be higher than those of the bending‐backward or the standing‐still conditions. However, previous studies did not manipulate the duration of the bowing action. This study examined whether the effect of bowing on the facial impression increases as the duration of bowing actions (the bending motion, the bent posture, and the return motion) was prolonged. In Experiment 1, we compared two durations of the bent posture at the peak point under the bending‐forward condition (0 or 1.5 s). In Experiment 2, we also manipulated the effect of the bowing speed (0.5 or 1 s). The results indicated that the effect of bowing on the rating scores of subjective attractiveness increased as the duration of bowing actions was prolonged. Moreover, an identical pattern of results was obtained in judgments of politeness and submissiveness. These findings suggest that the bowing effect is closely related to the cognitive schema of politeness and submissiveness, and thus the formal bowing action produces a positive evaluation by further activating this schema. [ABSTRACT FROM AUTHOR]

Bowing is an act, commonly used in Japan, involving lowering the head and bending the upper body towards another person as a greeting. Studies have shown that the bowing action increases the subjective attractiveness of the face. Specifically, the attractiveness rating of a bowing 3D computer graphics model was found to be higher than those of the bending‐backward or the standing‐still conditions. However, previous studies did not manipulate the duration of the bowing action. This study examined whether the effect of bowing on the facial impression increases as the duration of bowing actions (the bending motion, the bent posture, and the return motion) was prolonged. In Experiment 1, we compared two durations of the bent posture at the peak point under the bending‐forward condition (0 or 1.5 s). In Experiment 2, we also manipulated the effect of the bowing speed (0.5 or 1 s). The results indicated that the effect of bowing on the rating scores of subjective attractiveness increased as the duration of bowing actions was prolonged. Moreover, an identical pattern of results was obtained in judgments of politeness and submissiveness. These findings suggest that the bowing effect is closely related to the cognitive schema of politeness and submissiveness, and thus the formal bowing action produces a positive evaluation by further activating this schema. [ABSTRACT FROM AUTHOR]

Summary: Areal BMD (aBMD) from DXA is not a sufficiently accurate predictor of fracture. Novel volumetric BMD derived from 3D modeling of the hip from DXA images significantly improved the predictive ability for hip fracture relative to aBMD at the femoral neck, but not aBMD at the total hip. Introduction: To clarify whether volumetric and geometric indices derived from novel three-dimensional (3D) modeling of the hip using dual-energy X-ray absorptiometric (DXA) images improve hip fracture prediction relative to areal bone mineral density (aBMD). Methods: We examined 1331 women who had completed the baseline survey and at least one follow-up survey over 20 years (age 40–79 years at baseline). Each survey included aBMD measurement at the hip by DXA. Volumetric and geometric indices of the hip at baseline and the 10-year follow-up were estimated from DXA images using a 3D modeling algorithm. Incident hip fractures during the 20-year follow-up period were identified through self-report. Cox proportional hazards regression models allowing for repeated measurements of predictors and outcomes were constructed, and their predictive ability for hip fracture was evaluated using areas under receiver operating characteristic curves (AUCs) and net reclassification improvement (NRI) over aBMD at the femoral neck (FN) and total hip (TH) as references. Results: During a median follow-up of 19.8 years, 68 incident hip fractures were identified (2.22/1000 person-years). A significantly larger AUC of trabecular volumetric BMD (vBMD) at the total hip (AUC = 0.741), femoral neck (AUC = 0.748), and intertrochanter (AUC = 0.738) and significant NRI (0.177, 0.149, and 0.195, respectively) were observed compared with FN-aBMD (AUC = 0.701), but not TH-aBMD. Conclusions: vBMD obtained from 3D modeling using routinely obtained hip DXA images significantly improved hip fracture risk prediction over conventional FN-aBMD, but not TH-aBMD. Trial registration: The Japanese Population-Based Osteoporosis (JPOS) Cohort Study was retrospectively registered as UMIN000032869 in the UMIN Clinical Trials Registry on July 1, 2018. [ABSTRACT FROM AUTHOR]

• This study examines lake Shinji, a mesohaline lake with intermittent saline water intrusion. • It employs a 3-D hydrodynamic model, EcoPARI, in hindcast mode for 2012 (Jan-Sep). • The focus was on optimizing the vertical turbulence diffusion model and identifying ideal parameters. • Differential model constants for temperature and salinity are explored, enhancing simulation results. • The tuned model successfully replicates a historical upwelling event in September, driven by strong westerly winds from a nearby typhoon. Lake Shinji is a mesohaline lake that has intermittent saline water intrusion from its east coast connection of Ohashi River. This intrusion is often in the shape of a very thin layer that moves along the Lake bottom and stayed at the center due to bowl shape bathymetry of the Lake having maximum depth at the center. To elucidate the intrusion mechanism a 3-D hydrodynamic model (EcoPARI) was employed in a hindcast mode covering the year 2012 from the beginning of January to the end of September. Initially, the core emphasis was given to the vertical turbulence diffusion model and optimum model parameters were determined to accurately simulate the hydrodynamics. It was highlighted by the numerical simulations that alteration of one model constant, which is the multiplying coefficient of Richardson number, "α", is influential instead of altering all the constants to tune the turbulence model. The possibility of using differential model constants for temperature and salinity was also tested and it helped in the improvement of simulations. Finally, the performance of the model was also assessed under extreme weather conditions and a historical upwelling event was simulated. The model was able to reproduce the intrusion in the summer months as well as the upwelling event in September due to strong westerly winds caused by a nearby passing typhoon. [ABSTRACT FROM AUTHOR]

We conducted centroid moment tensor (CMT) inversions of moderate (Mw 4.5–6.5) earthquakes in the Kanto region, Japan, using a local three-dimensional (3D) model. We then investigated the effects of our 3D CMT solutions on long-period ground motion simulations. Grid search CMT inversions were conducted using displacement seismograms for periods of 25–100 s. By comparing our 3D CMT solutions with those from the local one-dimensional (1D) catalog, we found that our 3D CMT inversion systematically provides magnitudes smaller than those in the 1D catalog. The Mw differences between 3D and 1D catalogs tend to be significant for earthquakes within the oceanic slab. By comparing ground motion simulations between 1D and 3D velocity models, we confirmed that observed Mw differences could be explained by differences in the rigidity structures around the source regions between 3D and 1D velocity models. The 3D velocity structures (especially oceanic crust and mantle) are important for estimating seismic moments in intraslab earthquakes, which are related to fault size estimation. A detailed discussion for intraslab seismicity can be conducted using the 3D CMT catalog. The seismic moments also directly affect the amplitudes of ground motions. The 3D CMT catalog allows us to directly conduct the precise forward and inverse modeling of long-period ground motion without adjusting source models, which have been typically applied in the cases using the 1D CMT catalog. We also conducted long-period ground motion simulations using our 3D CMT solutions to evaluate the reproducibility of long-period ground motions at stations within the Kanto Basin. The simulations of our 3D CMT solutions well-reproduced observed ground motions for periods longer than 10 s, even at stations within the Kanto Basin. The reproducibility of simulations was improved from those using solutions in the 1D catalog. [ABSTRACT FROM AUTHOR]

Typhoon-induced P-wave microseisms can be observed using seismological arrays and analyzed for the seismic monitoring of ocean storms. This paper presents a frequency-domain beamforming (FB) method that integrates a three-dimensional (3-D) Earth model to better capture the heterogeneities in the subsurface structure, and therefore yield more accurate ray-tracing and travel-time predictions. This method is applied to the Super Typhoon Lupit (2009) using seismological array observations from the Northeast China Extended Seismic Array (NECESSArray) and high-sensitivity seismograph network in Japan (Hi-net). The results show that the localized P-wave microseism source regions based on the 3-D model are in better agreement with the theoretical source regions and typhoon centers than those based on a conventional one-dimensional (1-D) model. The significance of using a 3-D model instead of a 1-D model in the FB method is further investigated by comparing the consistency of the localization results for the two different arrays, with the localized source regions being more mutually concordant when using the 3-D model. The results demonstrate that integrating the 3-D model into the FB method improves the accuracy of locating the typhoon-induced P-wave microseism source regions. [ABSTRACT FROM AUTHOR]

In this study, we investigate the source rupture process of the 2018 Hokkaido Eastern Iburi earthquake in Japan (MJMA 6.7) and how the ground motion can be reproduced using available source and velocity models. First, we conduct a multiple-time-window kinematic waveform inversion using strong motion waveforms, which indicates that a large slip area located at a depth of 25–30 km in the up-dip direction from the hypocenter was caused by a rupture propagating upward 6–12 s after its initiation. Moreover, the high-seismicity area of aftershocks did not overlap with the large-slip area. Subsequently, using the obtained source model and a three-dimensional velocity structure model, we conduct a forward long-period (< 0.5 Hz) ground-motion simulation. The simulation was able to reproduce the overall ground-motion characteristics in the sedimentary layers of the Ishikari Lowland. [ABSTRACT FROM AUTHOR]

It is well known that ocean acidification (OA) inhibits growth of marine calcifying organisms. Therefore, the adverse effects of acidification on marine ecosystems and aquaculture, such as oyster farming, are of concern. Since eelgrass beds in neritic areas have a high potential for carbon assimilation, this study focuses on local scale mitigation of OA effects. Using a three-dimensional lower-trophic system ecosystem model, we modeled nitrogen and carbon cycles, and the dynamics of carbonate parameters in a subarctic shallow lagoon and bay, where nitrogen availability limits the photosynthesis of primary producers. Simulation of the present conditions allowed reproduction of spatiotemporal variations in water quality and, by assuming future environmental changes quantitatively, revealed that the progress of OA significantly elevated the probability of shell malformation in juvenile oysters. The results represent the spatiotemporal variations in carbonate parameters inside and outside eelgrass beds and enable the evaluation of the alleviation effect on local acidification by the presence of a dense eelgrass bed. Our study shows that in the absence of the eelgrass bed scenario, the effect of OA on oysters became more remarkable. The simulations revealed that maintaining eelgrass beds is essential to mitigate the effects of acidification on oysters. • An ecosystem model representing carbonate systems in a lagoon was developed. • The effect of ocean acidification on oyster malformation was evaluated. • Simulation under the absence of eelgrass bed was also performed. • The model could reproduce the spatiotemporal variations of the observed values. • Eelgrass beds mitigate the adverse effects of acidification on oyster growth. [ABSTRACT FROM AUTHOR]

Thin-walled partially concrete-filled steel tubular (PCFT) columns have come to be used as the piers of elevated-girder bridges widely in Japan because of their excellent seismic performance: strength, ductility, and energy dissipation capacity. To consider this excellent seismic performance in design, it is essential to provide an analysis method to assess the ultimate behavior of the thin-walled PCFT columns by considering the cyclic local buckling of the steel tube, the behavior of the confined infilled concrete with cracks, and the interface action between the steel tube and infilled concrete. Up to the present, the shell–solid element model analysis has been the only numerical method that can be used to consider these complicated behaviors of PCFT columns in a direct manner. However, the use of this model requires unrealistically long computation time and often encounters numerical difficulty to obtain convergent solutions when applied to large structural systems such as the elevated-girder bridge systems with the multiple thin-walled PCFT piers. The objective of the present research is to propose a practical three-dimensional fiber-based model with a failure segment that is computationally efficient, yet accurate enough to assess the ultimate behavior of PCFT columns. This model was calibrated by an optimization technique, only referring to the in-plane hysteretic behavior of each single PCFT column calculated by the shell–solid element model analysis. The calibrated model is applicable to the seismic analysis of large structural systems with multiple PCFT piers under arbitrary multidirectional seismic accelerations. The accuracy and numerical efficiency of the proposed fiber-based model in the analysis of PCFT columns were confirmed extensively by the comparison to the shell–solid element model analysis results and the results of tests, such as cyclic loading tests and shake table tests. [ABSTRACT FROM AUTHOR]

In this study, we investigate the source rupture process of the 2018 Hokkaido Eastern Iburi earthquake in Japan (MJMA 6.7) and how the ground motion can be reproduced using available source and velocity models. First, we conduct a multiple-time-window kinematic waveform inversion using strong-motion waveforms, which indicates that a large-slip area located at a depth of 25–30 km in the up-dip direction from the hypocenter was caused by a rupture propagating upward 6–12 s after its initiation. Moreover, the high-seismicity area of aftershocks did not overlap with the large-slip area. Subsequently, using the obtained source model and a three-dimensional velocity structure model, we conduct a forward long-period (< 0.5 Hz) ground-motion simulation. The simulation was able to reproduce the overall ground-motion characteristics in the sedimentary layers of the Ishikari Lowland. [ABSTRACT FROM AUTHOR]

Many three-dimensional hydrodynamic models were developed to investigate saltwater intrusion in estuaries. However, the horizontal grid discretization remains a challenge to achieve high accuracy as well as to reduce the cost in grid generation and computation. A three-dimensional hydrodynamic simulator, Fantom-Refined was developed to address this issue. A structured gridding technique which enables a flexible local mesh refinement was used for the horizontal gridding to analyze the multi-resolution phenomena from coastal bay to river upstream. The model is based on a collocated finite-volume method with second or higher-order spatial and temporal numerical schemes. The model was calibrated and validated using the data measured in a meso-macrotidal Chikugo River estuary, Japan. The simulated water level and vertical and longitudinal distribution of salinity were reasonably matched with the measured data. The salinity intrusion length (SIL) and salinity interface gradient (SIG) calculated from measured and simulated results were in good agreement with R2 value of 0.99 and 0.98 respectively. Although there were limited studies that reproduced continuous change in mixing condition from well mixed to salt wedge via partially mixed type, the present study successfully verified the change with intensive observations. The effect of channel meanderings and width on horizontal salinity distribution in the estuary was explained using the model results. Furthermore, the effect of horizontal grid resolution on saltwater intrusion and mixing conditions was investigated with three different grid resolutions and three different bathymetry resolutions. The results showed that both of the horizontal grid and bathymetry resolutions have significant effect on the prediction of the salinity distribution as well as the surface level in the estuary. • Fantom-Refined is described for the saltwater intrusion problem in estuaries. • A flexible local mesh refinement technique is used for horizontal gridding. • Calibration and validation is done with measured data in Chikugo River estuary. • The effect of bathymetry on horizontal salinity distribution is investigated. • The effect of grid resolution on saltwater intrusion and mixing condition is analyzed. [ABSTRACT FROM AUTHOR]