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Purpose: To evaluate real-world evidence for young Japanese patients with rhegmatogenous retinal detachment (RRD) by retrospectively examining surgical procedures and clinical outcomes in the Japan Clinical Retina Study group., Methods: This was a multicentre retrospective study of the medical records of 562 young patients (384 males and 178 females; mean age: 33.0 ± 11.8 years) who had been diagnosed with RRD and who underwent surgical procedures in participating centres during the period between April 2013 and August 2016., Results: The selected surgeries were scleral buckling (SB) for 295 eyes (49.7%) and pars plana vitrectomy (PPV) for 262 eyes (44.1%). Between the two surgical procedures, there was no significant difference in the primary anatomical reattachment rate (PARR, SB = 92.2%, PPV = 93.9%); improvements in vision were noted in both groups. The incidences of proliferative vitreoretinopathy and cataract formation within 1 year of PPV were 2.3% (p = 0.0047) and 6.5% (p = 0.0005), whereas they were 0% and 1.0% in the SB group, respectively., Conclusion: Scleral buckling (SB) and PPV were chosen with almost equal frequency for young patients with RRD. Clinical outcomes for SB and PPV exhibited a similar PARR. The incidence of cataract formation after PPV may constitute an important limitation of the procedure., (© 2019 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

In the last ten years, Chile and Japan have experienced several subduction earthquakes that lasted for extended periods of time. These occurrences have emphasized the need for a thorough examination of how the duration of ground motion impacts the performance of the components of the lateral load resisting system. In the present study, three large‐scale experiments were conducted on the wide‐flange brace member to evaluate the seismic vulnerability of the braces under the hazard consistent loading protocol. The loading sequences consider in the study are standard symmetric cyclic loading sequences, collapse‐consistent loading sequences representing subduction zone tension dominated and collapse‐consistent loading sequences representing subduction zone compression dominated. The subassemblage test‐set‐up was taken in the study to consider the effect of the end‐protect zone on the seismic assessments of the brace members. The evolution of strain at the mid‐section of the brace member is observed to be higher in case of the standard loading sequences as compared to the subduction zone loading sequences. The post yielding stiffness and the collapse resistance of the brace member under the subduction zone earthquake are present. The damage state of the open section brace member and evolution of the local bucking at the mid of the brace member were discussed. It is observed that open section delays the accumulation of strain at brace member and delay the fracture initiation. The ductility of the different brace members is compared to highlight the influence of the cross‐section properties of the brace on the ductility of the braced system. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the ultimate behavior of slender base-isolated buildings caused by buckling fracture in laminated rubber bearings through the use of shaking table tests in Japan. It mentions that the practical use of base isolation which is a structural technology is on the 1980s which was effectively recognize since the 1995 Hyogo-ken Nanbu Earthquake. It states that the shaking table test was performed with unidirectional input during the occurrence of fracture in the bearings. The result of the study shows that the buckling behavior of the bearings can be expressed in the large deformation range through the proposed model, time history response analysis.

A computational study was conducted to examine the seismic performance of steel moment‐resisting frames (MRFs) provided with chevron concentric braces. Such steel systems are widely used for buildings in Japan. Nonlinear finite‐element‐method models were validated against data and observations from previously tested chevron‐braced MRF specimens. The validated models were used to conduct a parametric study to understand how the cyclic‐loading performance of chevron‐braced MRFs may be affected by the torsional and translational restraint of the beam intersected by braces, the relative strength of the beam with respect to the braces, and the type of bracing connection. The results suggest that the lack of bracing of the beam intersected by braces may not be detrimental to the global hysteretic behavior of the structural system, although out‐of‐plane buckling of the braces can cause severe inelastic lateral‐torsional deformation of the beam. The torsional moment delivered by the braces was evaluated for the unfavorable arrangement where the bracing connections are rigid, and the braces are oriented to buckle out of the plane. A design procedure was examined that can account for the dependency of the energy dissipation mechanism on the cyclic loading history. [ABSTRACT FROM AUTHOR]

Summary: An efficient component model has been developed that captures strength and stiffness deterioration of steel hollow structural section (HSS) columns. The proposed model consists of two fiber‐based segments at a member's ends along with an elastic segment in between. The fibers exhibit nonlinear uniaxial stress–strain behavior, which is explicitly defined by uniaxial monotonic tensile and cyclic round coupon tests. The postbuckling behavior of an HSS column is traced through a proposed uniaxial effective stress–strain constitutive formulation, which includes a softening branch in compression and an energy‐based deterioration rule to trace the influence of cyclic deterioration in the inelastic cyclic straining. These may be inferred by uniaxial stub‐column tests. The component model captures the coupling between the column axial force and flexural demands. Consistent model parameters for a number of steel materials used in the steel construction in North America and Japan are proposed along with the associated model calibration process. The efficiency of the proposed model in predicting the hysteretic behavior of HSS columns is demonstrated by comparisons with physical steel column tests subjected to various loading histories, including representative ones of ratcheting prior to earthquake‐induced collapse. The proposed model is implemented in an open‐source finite element software for nonlinear response history analysis of frame structures. The effectiveness of the proposed model in simulating dynamic instability of steel frame buildings is demonstrated through nonlinear response simulations of a four‐story steel frame building, which was tested at full‐scale through collapse. Limitations as well as suggestions for future work are discussed. [ABSTRACT FROM AUTHOR]

In Europe, a monopile is the most commonly used foundation type for offshore wind turbines. Existing connections between the monopile (MP) and transition piece (TP) are generally bolts or grout, but another new method is the slip joint. In this method, the joints between the MP and TP are conically shaped and are simply joined together, which is expected to improve workability and reduce maintenance and management costs. In order to apply this structure in Japan, it is necessary to verify its seismic resistance. This paper reports the results of shaking table tests using a scaled specimen to verify the structural safety of the structure against earthquakes. [ABSTRACT FROM AUTHOR]

In recent years, resonance in high‐rise buildings due to long‐period ground motion, which induces large‐amplitude cyclic deformation of seismic dampers, has become a matter of significant concern. Performance requirements for seismic dampers that are installed in vibration‐controlled buildings have become more stringent, and durability against cyclic deformation has become essential. An Fe‐15Mn‐4Si‐10Cr‐8Ni alloy with enhanced low‐cycle fatigue resistance has been developed to produce steel seismic dampers that are durable against large‐amplitude cyclic deformations. We used this alloy to develop two types of fatigue‐resistant seismic dampers (shear panel and brace‐type) that counteract long‐period ground motion. Furthermore, cyclic loading tests were conducted to validate the deformation performance and fatigue resistance of the developed damper. The results indicated that these dampers exhibit significantly better fatigue life than conventional steel dampers and exhibit outstanding deformation performance and durability under low‐cycle fatigue. The proposed two types of dampers were installed on steel structure buildings in Japan. These dampers ensured that the buildings with seismic performance margins can withstand long‐period and long‐duration ground motion and repeated after‐quakes. [ABSTRACT FROM AUTHOR]

SUMMARY A series of large-scale dynamic tests was conducted on a passively controlled five-story steel building on the E-Defense shaking table facility in Japan to accumulate knowledge of realistic seismic behavior of passively controlled structures. The specimen was tested by repeatedly inserting and replacing each of four damper types, that is, the buckling restrained braces, viscous dampers, oil dampers, and viscoelastic dampers. Finally, the bare steel moment frame was tested after removing all dampers. A variety of excitations was applied to the specimen, including white noise, various levels of seismic motion, and shaker excitation. System identification was implemented to extract dynamic properties of the specimen from the recorded floor acceleration data. Damping characteristics of the specimen were identified. In addition, simplified estimations of the supplemental damping ratios provided by added dampers were presented to provide insight into understanding the damping characteristics of the specimen. It is shown that damping ratios for the specimen equipped with velocity-dependent dampers decreased obviously with the increasing order of modes, exhibiting frequency dependency. Damping ratios for the specimen equipped with oil and viscoelastic dampers remained constant regardless of vibration amplitudes, whereas those for the specimen equipped with viscous dampers increased obviously with an increase in vibration amplitudes because of the viscosity nonlinearity of the dampers. In very small-amplitude vibrations, viscous and oil dampers provided much lower supplemental damping than the standard, whereas viscoelastic dampers could be very efficient. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Shear thinning and brittle failure of silicate melt control the dynamics of volcanic eruptions, but their molecular‐scale origin is still unclear. Here, we conducted tension and compression experiments on silicate melts, using time‐resolved X‐ray diffraction. Our experiments revealed that the intermediate‐range ordering of silicate structures, that is, the ring size formed by the SiO4 tetrahedra, demonstrated elastic and anisotropic dilation under tension and shrinkage under compression in the non‐Newtonian regime. In contrast, there were no significant changes in short‐range ordering, such as Si–O and Si–Si distances. Based on these findings, we inferred that shear thinning observed under high stress originates from the formation of anisotropically deformed large and small rings in silicate structures that are energetically unfavorable and unstable. Brittle failure occurred under high‐stress conditions, in both tension and compression. We propose a stress criterion as a necessary and sufficient condition for magma failure, rather than a strain rate criterion. Plain Language Summary: Explosive volcanic eruptions occur when magma fragments and volcanic gases are released to the surface. However, magma is originally a continuous fluid that behaves like a liquid in the crust. To understand how magma fails during volcanic eruptions, we need to uncover the underlying mechanisms. This challenge was identified over four decades ago, and researchers proposed conducting molecular‐scale experiments on magma deformation to shed light on its complex behavior, including brittle failure. However, this has been difficult to achieve experimentally. In this study, we used powerful X‐ray sources at SPring‐8 in Japan to address this challenge. Our findings reveal that the complex behavior of magma originates from previously unrecognized molecular‐scale elastic and anisotropic deformation. Finally, we propose a criterion for magma failure that can help determine whether an eruption will be explosive. Key Points: Molecular‐scale elastic and anisotropic deformation of the silicate melt was observed under tension (dilation) and compression (shrinkage)Formation of large and small rings by the SiO4 tetrahedra could be the origin of shear thinning and brittle failure in the silicate meltStress condition is "the necessary and sufficient condition" for the magma failure criterion [ABSTRACT FROM AUTHOR]

Transformer is a key equipment for constructing power system, and its safe and stable operation is the basis of power system. In order to solve the problems of difficult identification and low detection accuracy of transformer winding at operating state, in this paper, a diagnosis method based on digital twinning technique for transformer winding failure is proposed. Firstly a digital twin transformer model with high simulation degree based on transformer entities was built, and then multiple physical field simulation were used to deduce the information change of oil tank surface vibration information of digital twin transformer under different working conditions, various winding failures. Here, the vibration signal on oil tank is effectively decomposed to extract the feature vector by independent component analysis method and wavelet packet transform, which in turn is based on neural network algorithm to learn and diagnose the failure signal of winding. In order to test the accuracy and feasibility of the method, the diagnostic test of oil tank vibration signal detection of health and fault transformer is carried out on an experimental prototype of transformer with 110 kV, and the diagnostic results show that this method can diagnose the problems occurred in transformer windings with high efficiency and accuracy. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Summary: The damped outrigger system is known to efficiently provide additional damping in buildings with heights of over 250 m. However, particularly for supertall buildings in the center of Tokyo, Japan, the outrigger truss from the center core to the exterior columns need to span distances of more than 20 m. This increases the flexural stiffness demand on the outrigger that leads to larger truss depths making the damped outrigger system inefficient. For such tall buildings with large plans, a new damping modification system, the "damped braced tube system" is proposed, where the exterior surface of the elastic mega braces are partially removed vertically to create a split and are replaced with dissipaters (energy‐dissipation devices). The damped braced tube system enhances the seismic performance as the exterior surfaces of the elastic mega braces work together with the damped slits like in a coupled wall system and increases the overall damping ratio. In this paper, numerical models were constructed based on a real project in Japan consisting of a 397‐m supertall building employing the damped tubular braced system using oil dampers (referred to as viscous dissipaters). A series of generalized response spectrum based numerical analyses and optimizations were performed to minimize the seismic response. The proposed system exhibited improved damping performance with the first to third mode damping ratios reaching to more than 7% while providing a wide range of options for dissipater distribution for design. Finally, the elevation of the slit's base is recommended to be equal to 0.22 of the total building height considering the trade‐off relationship between the first modal damping ratio and the fundamental period. [ABSTRACT FROM AUTHOR]

Fire damage to bridges occurs frequently in Japan and in other countries. Previous bridge fire accidents suggest that it is important to understand the structural performance of bridges after their exposure to fire. The Japan Society of Civil Engineering has proposed guidelines for the diagnosis and repair of steel bridges that have been exposed to fire. This guideline shows that the judgement temperature of steel members is 400°C. This temperature was established based on previous bridge fire accident reports and material testing after fire. It is unclear if the basis for evaluation has been the structural members. Therefore, it is necessary to clarify the effect of the rigidity reduction on the structural performance and judgement temperature of steel girder bridges after fire. The authors have studied the mechanical properties of steel–concrete composite girders as a medium span bridge before and after fire. A fire test was carried out to clarify the temperature distribution of the steel–concrete composite girder and static loading tests before and after fire were conducted to confirm the effect of the rigidity reduction from the fire. This study considers the validity of the judgment temperature from the test results. [ABSTRACT FROM AUTHOR]

In Japan, the steel‐concrete composite girder bridge is widely used to reduce construction and maintenance cost, and improve constructability and the construction period. As an effort to decrease box girder construction cost, the narrow box girder bridge, which has a reduced box girder width, has been developed. Compared with a conventional box girder bridge, this type of box girder bridge simplifies the structure inside the box by narrowing the space between web plates. Furthermore, it is possible to reduce the number of members, welding length and painting area. The average economical span length is approximately 90m. Similarly, in European countries, a new type of composite girder bridge was developed and constructed for the same purpose as the bridge in Japan. The steel‐concrete double composite girder bridge, which has two concrete slabs on the upper and lower surfaces of the girder only in the region of the intermediate supports, is a type of medium span bridge. An advantage of adopting this structural system is that the cross sections of both the sagging and hogging bending moment areas are classified into the compact section at the ultimate limit state; that is, the maximum flexural strength of these sections can be taken full plastic moment. There are few constructed examples of this type of bridge in Japan. Because of the handling difficulty, the shop manufacturing cost of a box girder is, generally, more expensive than that of an I‐girder. Additionally, the design method for bridges has been revised since January 2018 and has changed from the allowable stress design method to the limit state design method in Japan. Therefore, the authors propose a new type of steel‐concrete double composite I‐girder bridge. The trial design of three‐span continuous girder bridges was conducted. In this paper, the effect of double composite action, for instance, the reduction of the girder height in the region of the intermediate supports, and applicable span length are discussed. [ABSTRACT FROM AUTHOR]

Past earthquakes highlighted the vulnerability of the suspended ceiling, especially in earthquake‐prone countries like Japan; the post‐earthquake reconnaissance showed that damage to ceiling systems led to immeasurable economic loss and disturbance of the timely rescue of casualty. The existing studies have mostly focused on the seismic performance of regular square and leveled ceilings, whereas the inevitable requirements to accommodate air ducts, nonstructural piping, and electrical equipment resulted in a two‐elevation ceiling system. This paper reports a series of full‐scale shake table tests on a typical two‐elevation ceiling system, which includes electrical equipment, piping system, and commonly used suspended ceiling structure. Experimental observations showed that the two‐elevation ceiling system performed well under earthquake excitation. No fallen panels or overall system collapse occurred during shaking. This paper discusses the effects of a temporary‐positioning‐bracing bar (TPBB) between two ceiling elevations and peripheral constraints by surrounding wall on the acceleration and displacement response and torsional behavior in the ceiling system. Then, a simplified analytical model was established and verified with the experimental response of different ceiling configurations. The test results indicated that a sufficiently strong TPBB is essential to reduce the relative displacement between two ceiling elevations, and it ensures the integrity of two ceiling elevations in the ceiling system. In conclusion, the TPBB shall remain in the ceiling system after the construction stage. [ABSTRACT FROM AUTHOR]

In recent years, measurement of transformer vibration is being carried out as a means of detecting the looseness and deformation of its windings. Conventionally, the vibration components of even multiples of the power supply frequency (electrically generated vibration) were analyzed to diagnose the transformer. On the other hand, the natural vibrational frequencies of the winding structures represent their conditions, and the changes of these frequencies must be representing the changes in their pre‐stress or displacement. We have measured the tank vibration of an extra‐high‐voltage transformer and investigated the dependence of load current, voltage, and temperature of the oil. As a result, although the electrically generated vibration has a complicated dependence, the winding's natural frequency is not affected by the current and voltage, and the influence of the oil temperature is not very large. It is considered that the natural vibrational frequencies of the windings are a suitable index for transformer diagnosis. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Summary: Most anthropogenic material stocks and flows are associated with the building sector. Several recent studies have developed material composition indicators (MCIs) suitable for calculating material stocks and flows of the building sector using bottom‐up approaches, which hold great potential to provide information to support resource efficiency policies. A major limitation is the lack of country‐specific MCIs. This study aims to introduce a concept for a better transferability of MCI across different contexts by proposing requirements for defining MCIs and to discuss options and limits of the transferability. We take existing MCIs for residential buildings in Germany and Japan as case studies and make them comparable by applying harmonization methods. Based on that, similarities and differences are systematically identified and discussed, considering their socioeconomic, cultural, technical, and environmental factors. Our results indicate significant limitations to the transferability of MCIs for detached houses, while bigger apartment complexes show greater homogeneity despite the very different environments in which they are constructed. This indicates that while it is possible to assume foreign MCIs as plausible for large constructions, local coefficients need to be estimated for smaller single‐family homes. [ABSTRACT FROM AUTHOR]

In Japan, structural control is widely recognized as a fundamental technology for exceeding the performance limitations of conventional earthquake/wind‐resistant buildings. Over the last three decades, research and development (R & D) has been implemented in construction, mechanical industries, and universities. Additionally, many types of control strategies have been proposed through theoretical, experimental, and numerical investigations. In comparison with other countries, Japan has successfully and rapidly developed remarkable engineering applications for actual buildings using advanced structural control technologies, because Japanese construction companies promote R & D in cooperation with mechanical industries, structural design offices, and universities. This review paper introduces the recent structural control advances in Japan. The state‐of‐the‐art report is based on papers published by the Architectural Institute of Japan, the Proceedings of the 16th World Conference on Earthquake Engineering, articles published in a structural engineering magazine, the special theme sessions at the 7th World Conference on Structural Control and Monitoring, and other relevant information. The key research directions are the simplification of control laws and mechanical devices, high performance with either little or no energy supply, device magnification, use of structural frames and substructures, new materials, adaptability, and cautious uses serving various purposes. [ABSTRACT FROM AUTHOR]

Aim To examine whether the chronicity and intensity of low back pain (LBP) or knee pain (KP) was associated with the occurrence of falls among a community-dwelling older population. Methods This was a community-based 3-year prospective cohort study. In 2009, baseline questionnaires were mailed to 3080 randomly selected residents aged 60-79 years; 2534 residents (82.3%) responded to the baseline survey, and 1- and 3-year follow-up surveys were subsequently mailed to them. The data for 1890 respondents who had no falls in the past year at baseline were analyzed. Associations between pain status (chronicity, intensity and persistence) and the occurrence of falls were analyzed by multivariable-adjusted logistic regression. Results A total of 197 (13.6%) participants had at least one fall during 12 months at 3-year follow up; of those, 68 (4.8%) had multiple falls, and 65 (4.5%) resulted in an injury. Chronicity and intensity of LBP were associated with injurious falls ( P for trend = 0.033 and P for linearity = 0.041, respectively), and KP was associated with at least one fall ( P for trend = 0.021 and P for linearity = 0.040, respectively). In addition, participants who had chronic pain persistently at both baseline and 1-year follow up had a higher risk of falls (LBP for injurious falls; adjusted odd ratio 2.46, 95% confidence interval 1.08-5.63, KP for at least one fall; adjusted odd ratio 2.39, 95% confidence interval 1.29-4.44), compared with those who had no pain at both time-points. Conclusions LBP and KP chronicity, intensity and persistence of chronic pain were associated with a greater risk of falls in older adults. Geriatr Gerontol Int 2017; 17: 875-884. [ABSTRACT FROM AUTHOR]

We compared several methods for quantifying the culm surface area ( S) of one of the most common bamboos in Japan, Phyllostachys pubescens Mazel ex Houz. Nine sample culms of P. pubescens were felled, and the true S was determined by the fine resolution analysis of the culm form ( S ). The S was then calculated independently with the sectional measurement method from the successive diameters measured at equal intervals of one-twentieth ( S ), one-tenth ( S ), one-fifth ( S ) and one-half ( S ) of the total culm length. The S was also quantified geometrically from the total culm length and the diameter at breast height or at base by assuming that the culm form could be approximated by a cone ( S and S ). The S was compared with each of the computed S values. For S , S and S , both the mean relative bias (%BIAS) and relative root mean square error (%RMSE) decreased with an increase in the number of measured diameters. The %BIAS and %RMSE of the S were, respectively, comparable and smaller compared to those of S . The bias of the S and S suggested that the cone assumption of the culm form was violated. In conclusion, we recommend that the S should be quantified from the successive diameters measured at equal intervals of one-tenth of the total culm length using the sectional measurement method. [ABSTRACT FROM AUTHOR]

This paper verifies the feasibility of the proposed system identification methods by utilizing shaking table tests of a full-scale four-story steel building at E-Defense in Japan. The natural frequencies, damping ratios and modal shapes are evaluated by single-input-four-output ARX models. These modal parameters are prepared to identify the mass, damping and stiffness matrices when the objective structure is modelled as a four degrees of freedom (4DOF) linear shear building in each horizontal direction. The nonlinearity in stiffness is expressed as a Bouc-Wen hysteretic system when it is modelled as a 4DOF nonlinear shear building. The identified hysteretic curves of all stories are compared to the corresponding experimental results. The simple damage detection is implemented using single-input-single-output ARX models, which require only two measurements in each horizontal direction. The modal parameters are equivalent-linearly evaluated by the recursive Least Squares Method with a forgetting factor. When the structure is damaged, its natural frequencies decrease, and the corresponding damping ratios increase. The fluctuation of the identified modal properties is the indirect information for damage detection of the structure. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY Steel rectangular section columns with stiffened plates are commonly used for elevated highway bridges in the urban areas of Japan. The seismic design of bridge piers is usually performed by dynamic analysis in the horizontal direction using various independent directional seismic acceleration data. However, this simple treatment does not reflect the effect of bilateral loading as a structural response to inelastic interaction. In this study, unidirectional and bidirectional loading hybrid tests were conducted to examine the seismic response and performance of square cross-sections of steel bridge piers subjected to bidirectional seismic accelerations. Comparison of the results of unidirectional and bidirectional loading tests revealed that the maximum load is the same as the average of unidirectional loading in the NS and EW directions; however, the maximum response displacement and residual displacement increase in proportion with hard to soft ground types. Moreover, a modified seismic design is proposed considering these bidirectional loading effects. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

One type of braking system for railway vehicles is the eddy current brake. Because this type of brake has the problem of rail heating, it has not been used for practical applications in Japan. Therefore, we proposed the use of a linear induction motor (LIM) for dynamic braking in eddy current brake systems. The LIM reduces rail heating and uses an inverter for self excitation. We estimated the performance of an LIM from experimental results of a fundamental test machine and confirmed that the LIM generates an approximately constant braking force under constant current excitation. At relatively low frequencies, this braking force remains unaffected by frequency changes. The reduction ratio of rail heating is also approximately proportional to the frequency. We also confirmed that dynamic braking resulting in no electrical output can be used for drive control of the LIM. These characteristics are convenient for the realization of the LIM rail brake system. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(2): 29-38, 2012; Published online in Wiley Online Library (). DOI 10.1002/eej.21209 [ABSTRACT FROM AUTHOR]

The Island Tower Sky Club is a super high-rise RC apartment block constructed in Fukuoka City, Japan, which makes inventive use of the most advanced building technologies. The building is 145 m tall with 42 storeys. It is composed of three similar, slender towers with three-fold rotational symmetry. The towers are connected at three different levels by aerial gardens and contain various vibration control devices to assure a high level of safety. The aerial gardens are connected to the towers by vibration control dampers to reduce the overturning effects of the towers caused by seasonal winds and large earthquakes. An elaborate control system can reduce the storey acceleration response by 30 %. At the upper two storeys of each tower, super-plastic zincaluminium alloy dampers are also used. To reduce the storey acceleration response, the base of the building is isolated using a hybrid system of bearing supports and dampers. The validity of the control system implemented is confirmed by human power vibration tests conducted at the aerial gardens. [ABSTRACT FROM AUTHOR]

The article presents a research in which collapse of a steel frame structure is predicted numerically, and the accuracy of prediction is validated experimentally through earthquake simulator tests. The impact of beam-to-column connection fractures on the behavior of steel moment-resisting frames was investigated through a series of shaking table experiments and numerical simulations. Tests through collapse of a full-scale steel 4-story building were conducted recently at the E-Defense earthquake simulator in Miki, Japan. It is stated that the accurate prediction of collapse of frame structures under earthquake shaking requires the development of models that include rules for stiffness and strength deterioration.

The article presents a study on the capacity of beam-to-column connections in high-rise buildings in Japan to resist seismic pressure through the use of E-Defense shaking table test. Field-welded connection and shop-welded connection are the two types of connections adopted for the examination of seismic capacity of buildings. The test results indicate that some field-welded connections fractured from the bottom flange weld boundary due to the failure in the actual field welding where ensuring and inspection performance should have been done well. The shop-welded connections, on the otherhand, are able to endure many cycles of plastic rotation.

Morphological variation in current-year shoots within plants was examined in five deciduous and four evergreen liana species from temperate forests in Japan to elucidate the role differentiation in shoots. All lianas had both shoots that twined or developed adventitious roots to gain support on host materials (searcher shoots) and self-supporting shoots with no climbing structures (ordinary shoots). Searcher shoots were 20–295 times longer than ordinary shoots. The allometric relationships between stem length and leaf area differed between searcher and ordinary shoots, and the stem length for a given leaf area was greater in searcher shoots. Leaf area per shoot mass was 1.4–4.3 times higher in ordinary shoots because of the greater allocation to leaf biomass. Searcher shoots comprised only 1–6% of total shoots but 30–85% of total shoot length in deciduous lianas. Ordinary shoots accounted for 70–95% of the total leaf area in these liana species. These results suggest that the exploration of new space was primarily achieved by searcher shoots, whereas a large proportion of current photosynthetic production was achieved by ordinary shoots. The range of stem length and leaf mass ratio of ordinary shoots was similar to that in shoots of tree species. Specialization of shoots in lianas is discussed. [ABSTRACT FROM AUTHOR]

The Median Tectonic Line (MTL) is a first-order tectonic boundary that separates the Sanbagawa and Ryoke Metamorphic Belts. Strike-slip movements on the MTL have been well documented by many workers. New field based structural studies in the Sanbagawa Belt close to the MTL reveal a large number of secondary faults and semibrittle shear bands indicating a top-to-the-north normal sense of displacement. The strikes of these shear zones and their spatial distributions suggest that development of these structures is related to movements on the MTL. These results imply that the MTL has a large-scale normal shear component on a regional scale that can help account for the exhumation of the Sanbagawa Belt. Our proposed history of the MTL can also account for changes in the geometry of folds in the Sanbagawa Belt. [ABSTRACT FROM AUTHOR]

The 30 May 2015 M w 7.9 Bonin Islands earthquake, Japan, is one of the largest deep‐focus earthquakes ever recorded. Its occurrence, close to 700‐km depth, in an area without any known historical seismicity, along with its magnitude, was a surprise to scientists. Deep earthquakes are generally believed to have few aftershocks and no foreshocks. Here, we explore the earthquake productivity in the hypocentral surroundings and detect 49 not previously identified earthquakes, 28 of which occurred during an accelerating preseismic phase that started 3 months prior to the main shock. This is the first time that such foreshock activity has been observed for a deep earthquake. The preseismic and postseismic activity suggests transformational faulting within a metastable olivine wedge (MOW) inside the slab at depth as the triggering principal mechanism for this deep earthquake sequence, the seismicity starting where the backward bending of the subducting Pacific plate is maximum. Plain Language Summary: Deep earthquakes have been puzzling seismologists for almost a century, since their discovery in the 1920s. Earthquakes deeper than 50 km represent about 25 % of the global seismicity, and deep‐focus earthquakes are defined as those located at 300‐km depth or more. They can be exceedingly large and occur at temperatures and pressures where sliding and fracture are inhibited, thus the brittle fracture/friction mechanism, valid in Earth's crust, cannot hold. Despite their abundance, the physical mechanism behind deep‐focus earthquakes is still a subject of ongoing debate. The Bonin Islands earthquake (30 May 2015, M w7.9) occurred at 680‐km depth in a previously quiet area. In order to better understand why and how it occurred there, we searched for previously unknown earthquakes in the surroundings. For the first time, we identify a preseismic phase preceding such a very deep‐focus earthquake. The location of the newly detected earthquakes reveals the geometry of the slab at depth, and their spatiotemporal distribution supports transformation of metastable olivine as the rupture initiation process. Key Points: We present the first evidence of intense foreshock activity before a deep‐focus earthquake49 newly detected EQs reveal slab geometry and the possible existence of metastable olivine wedge at depthWe find a low productivity aftershock sequence that follows Omori's law [ABSTRACT FROM AUTHOR]