Eccentric installation of splice plates for compressive strength improvement of rectangular hollow section braces     

Hiroshi Tagawa  Yuki Tanaka  Shohei Moriwake 《Bulletin of Earthquake Engineering》2018,16(11):5489-5502

Steel hollow section members are often applied as bracing in steel structures. Field-bolted connections of the slotted-in single splice plate and the gusset plate are popular because of their ease of construction. However, eccentricity between the splice and gusset plate axes reduces the compressive strength of the brace. This study proposes compressive strength improvement of rectangular hollow section braces using eccentrically installed splice plates such that the gusset plate axis coincides with the brace axis. To demonstrate the efficacy of the proposed concept, four compressive loading test results are examined in this study. Test results reveal the influences of splice plate eccentric installation on the brace compressive strength, the out-of-plane displacement, and the strain distribution. The proposed concept is effective for the brace with stiffened splice plates for inducing overall buckling with plastic hinges in the gusset plates. Variation of compressive strength is finally discussed based on the discrepancy between the brace axis and the axis of the plates in which the plastic hinges form at the overall buckling mode ends.  相似文献   

The Application of GIS in Education Administration: Protecting Students from Hazardous Roads     

Fatemah Admadi Nejad Masouleh  Yuji Murayama  Todd Wendell Rho'Dess 《Transactions in GIS》2009,13(1):105-123

Though enrolment by proximity is an official educational policy in Iran, the lack of clearly defined school attendance areas has resulted in an informal open enrolment system where parents may choose public schools outside their residential areas. Two major consequences of parental choice are longer commutes to schools and increased use of motor vehicle transport. To delineate school attendance areas for public female junior high schools in the city of Rasht in Northern Iran, this research used the multiplicatively weighted Voronoi diagram (MWVD) technique to construct school attendance areas. The approach was shown to be useful in developing countries like Iran where accident fatalities are not only disproportionately high but the public school system lacks sufficient educational diversity to offset the societal costs of opting out of neighbourhood schools. A GIS-based specialist package was used for constructing the proposed school attendance areas. Given the MWVD utility in demarcating spaces so that all journeys within them are closest to a chosen point, the research concluded that proposed school attendance areas can result in shorter and more convenient commutes on foot for students. This can eliminate the need to travel by vehicle for the overwhelming majority of students and thus make their journeys more convenient and safer.  相似文献   

A GIS Approach to Estimation of Building Population for Micro-spatial Analysis   总被引：4，自引：0，他引：4  

KoKo Lwin  Yuji Murayama 《Transactions in GIS》2009,13(4):401-414

Population data used in GIS analyses is generally assumed to be homogeneous and planar (i.e. census tracts, townships or prefectures) due to the public unavailability of building population data. However, information on building population is required for micro-spatial analysis for improved disaster management and emergency preparedness, public facility management for urban planning, consumer and retail market analysis, environment and public health programs and other demographic studies. This article discusses a GIS approach using the Areametric and Volumetric methods for estimating building population based on census tracts and building footprint datasets. The estimated results were evaluated using actual building population data by visual, statistical and spatial means, and validated for use in micro-spatial analysis. We have also implemented a standalone GIS tool (known as 'PopShape GIS') for generating new building footprint with population attribute information based on user-defined criteria.  相似文献   

Modeling deforestation in Dzalanyama Forest Reserve,Lilongwe, Malawi: a multi-agent simulation approach     

Kondwani Godwin Munthali  Yuji Murayama 《GeoJournal》2015,80(5):743-757

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Large-scale thermodynamics of the stratosphere and mesosphere during the major stratospheric warming in 2003/2004   总被引：1，自引：0，他引：1  

P. Mukhtarov  D. Pancheva  B. Andonov  N.J. Mitchell  E. Merzlyakov  W. Singer  W. Hocking  C. Meek  A. Manson  Y. Murayama 《Journal of Atmospheric and Solar》2007,69(17-18):2338

The stratosphere–mesosphere response to the major sudden stratospheric warming (SSW) in the winter of 2003/2004 has been studied. The UKMO (UK Meteorological Office) data set was used to examine the features of the large-scale thermodynamic anomalies present in the stratosphere of the Northern Hemisphere. The vertical and latitudinal structure of the genuine anomalies, emphasized by removing the UKMO climatology, has been investigated as well. The features of the stratospheric anomalies have been related to the mesospheric ones in measured neutral winds from radars and temperatures from meteor radars (90 km). It was found that the stratospheric warming spread to the lower mesosphere, while cooling occurred in the upper mesosphere, a feature that may be related to the large vertical scales of the stationary planetary waves (SPWs). It was shown also that the beginning of the eastward wind deceleration in the stratosphere–mesosphere system coincided with the maximum amplification of the SPW1 accompanied by short-lived bursts of waves 2 and 3.  相似文献   

城市土地利用变化中邻域相互作用的特征——日本三大都市圈的比较研究     

赵耀龙  崔秉良  村山祐司 《地理学报(英文版)》2011,21(1):65-78

Local spatial interaction between neighborhood land-use categories (i.e. neighborhood interaction) is an important factor which affects urban land-use change patterns. Therefore,it is a key component in cellular automata (CA)-based urban geosimulation models towards the simulation and forecast of urban land-use changes. Purpose of this paper is to interpret the similarities and differences of the characteristics of neighborhood interaction in urban land-use changes of different metropolitan areas in Japan for providing empirical materials to understand the mechanism of urban land-use changes and construct urban geosimulation models. Characteristics of neighborhood interaction in urban land-use changes of three metropolitan areas in Japan,i.e. Tokyo,Osaka,and Nagoya,were compared using such aids as the neighborhood interaction model and similarity measure function. As a result,urban land-use in the three metropolitan areas was found to have had similar structure and patterns during the study period. Characteristics of neighborhood interaction in urban land-use changes are quite different from land-use categories,meaning that the mechanism of urban land-use changes comparatively differs among land-use categories. Characteristics of neighborhood interaction reveal the effect of spatial autocorrelation in the spatial process of urban land-use changes in the three metropolitan areas,which correspond with the characteristics of agglomeration of urban land-use allocation in Japan. Neighborhood interaction amidst urban land-use changes between the three metropolitan areas generally showed similar characteristics. The regressed neighborhood interaction coefficients in the models may represent the general characteristics of neighborhood effect on urban land-use changes in the cities of Japan. The results provide very significant materials for exploring the mechanism of urban land-use changes and the construction of universal urban geosimulation models which may be applied to any city in Japan.  相似文献   

The Zurich Extragalactic Bayesian Redshift Analyzer and its first application: COSMOS     

R. Feldmann  C. M. Carollo  C. Porciani  S. J. Lilly  P. Capak  Y. Taniguchi  O. Le Fèvre  A. Renzini  N. Scoville  M. Ajiki  H. Aussel  T. Contini  H. McCracken  B. Mobasher  T. Murayama  D. Sanders  S. Sasaki  C. Scarlata  M. Scodeggio  Y. Shioya  J. Silverman  M. Takahashi  D. Thompson  G. Zamorani 《Monthly notices of the Royal Astronomical Society》2006,372(2):565-577

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Identification of yield drift deformations and evaluation of the degree of damage through the direct sensing of drift displacements          下载免费PDF全文

Ping Xiang  Akira Nishitani  Shohei Marutani  Kenzo Kodera  Tomohiko Hatada  Ryuta Katamura  Kiyoshi Kanekawa  Takashi Tanii 《地震工程与结构动力学》2016,45(13):2085-2102

Inter‐story drift displacement data can provide useful information for story damage assessment. The authors' research group has developed photonic‐based sensors for the direct measurement of inter‐story drift displacements. This paper proposes a scheme for evaluating the degree of damage in a building structure based on drift displacement sensing. The scheme requires only measured inter‐story drift displacements without any additional finite element analysis. A method for estimating yield drift deformation is proposed, and then, the degree of beam end damage is evaluated based on the plastic deformation ratios derived with the yield drift deformation values estimated by the proposed method. The validity and effectiveness of the presented scheme are demonstrated via experimental data from a large‐scale shaking table test of a one‐third‐scale model of an 18‐story steel building structure conducted at E‐Defense. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Influence of Surface-Based Stable Layer Development on Asian Dust Behaviour Over Tokyo     

Nobumitsu Tsunematsu  Hironori Iwai  Shoken Ishii  Motoaki Yasui  Yasuhiro Murayama  Kohei Mizutani 《Boundary-Layer Meteorology》2009,131(2):263-275

The relationship between local meteorological fields and the behaviour of airborne Asian dust that arrived in the Tokyo metropolitan area on 1 April 2007 with the passage of a synoptic-scale cold front has been investigated through Doppler lidar observations, experiments using a regional atmospheric numerical model, and analyses of surface and upper-air meteorological observations. Results of the Doppler lidar observations showed that the Asian dust passed above the metropolitan area with strong south-westerly winds with speeds of 15–26 m s⁻¹. Meteorological fields reproduced by the numerical experiments showed the development of a surface-based stable layer in the metropolitan area caused by nocturnal radiational cooling near the ground surface and south-westerly warm air advection at upper levels. The blocking effect of the mountainous region located to the west of the metropolitan area induced an area of stagnant air inside the metropolitan area and promoted the stable layer development. Although strong downdrafts prevailed in the upper air, the airborne Asian dust did not spread to the ground when the stable layer was formed. These results strongly indicate that the developed stable layer prevented strong downdrafts from spreading to the ground, acting as an obstacle to the transport of the Asian dust particles from the upper air towards the ground. This is considered to be one of the main causes of the low appearance frequency of Asian dust phenomena near the ground in the Tokyo metropolitan area and eastern Japan.  相似文献   

Performance evaluation of a ground-source heat pump system utilizing a flowing well and estimation of suitable areas for its installation in Aizu Basin,Japan     

Gaurav Shrestha  Youhei Uchida  Satoru Kuronuma  Mutsumi Yamaya  Masahiko Katsuragi  Shohei Kaneko  Naoaki Shibasaki  Mayumi Yoshioka 《Hydrogeology Journal》2017,25(5):1437-1450

Development of a ground-source heat pump (GSHP) system with higher efficiency, and evaluation of its operating performance, is essential to expand the growth of GSHP systems in Japan. A closed-loop GSHP system was constructed utilizing a flowing (artesian) well as a ground heat exchanger (GHE). The system was demonstrated for space-heating and space-cooling of a room (area 126.7 m²) in an office building. The average coefficient of performance was found to be 4.5 for space-heating and 8.1 for space-cooling. The maximum heat exchange rate was 70.8 W/m for space-heating and 57.6 W/m for space-cooling. From these results, it was determined that a GSHP system with a flowing well as a GHE can result in higher performance. With this kind of highly efficient system, energy saving and cost reduction can be expected. In order to assess appropriate locations for the installation of similar kinds of GSHP systems in Aizu Basin, a suitability map showing the distribution of groundwater up-flowing areas was prepared based on the results of a regional-scale three-dimensional analytical model. Groundwater up-flowing areas are considered to be suitable because the flowing well can be constructed at these areas. Performance evaluation of the GSHP system utilizing the flowing well, in conjunction with the prepared suitability map for its installation, can assist in the promotion of GSHP systems in Japan.  相似文献