Pub Date : 2012-11-01DOI: 10.3969/J.ISSN.0253-374X.2012.11.009
Wanjing Ma, Yan Lu, K. An, J. Zhao
{"title":"Probabilistic model for signalized intersection capacity with short lanes","authors":"Wanjing Ma, Yan Lu, K. An, J. Zhao","doi":"10.3969/J.ISSN.0253-374X.2012.11.009","DOIUrl":"https://doi.org/10.3969/J.ISSN.0253-374X.2012.11.009","url":null,"abstract":"","PeriodicalId":17444,"journal":{"name":"Journal of Tongji University","volume":"1 1","pages":"1641-1646"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84835416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-01-01DOI: 10.3969/J.ISSN.0253-374X.2012.01.012
T. Xin, Liang Gao, Hong Xiao, Cun Qu
Based on the investigation and analysis of different sleeper types at home and abroad,primary schemes of sleeper type on bridge in high speed railway were determined according to the structure characteristics of ballast track on bridge in high speed railway of China.The sleeper types proposed in the primary schemes including type Ⅲ sleeper,wide sleeper,ladder sleeper and frame sleeper.Then a vehicle-track-bridge coupling system dynamic analysis model was established,with which the dynamic performances of the primary selected sleeper types were compared and analyzed to select the suitable sleeper type for bridge.The selected sleeper type was optimized,and the wide sleeper is recommended for high speed railway in China.Based on a comprehensive consideration of the track maintenance,type Ⅲ sleeper was proposed for sleeper scheme.The dynamic analysis results show that the widening sleeper with 2~4 cm type Ⅲ sleeper can well reduce ballast stress and be easy to maintain.Study results are helpful for the design of new sleeper structures on bridge.
{"title":"Comparative study on dynamic characteristics of different sleeper types on bridge in high speed railway","authors":"T. Xin, Liang Gao, Hong Xiao, Cun Qu","doi":"10.3969/J.ISSN.0253-374X.2012.01.012","DOIUrl":"https://doi.org/10.3969/J.ISSN.0253-374X.2012.01.012","url":null,"abstract":"Based on the investigation and analysis of different sleeper types at home and abroad,primary schemes of sleeper type on bridge in high speed railway were determined according to the structure characteristics of ballast track on bridge in high speed railway of China.The sleeper types proposed in the primary schemes including type Ⅲ sleeper,wide sleeper,ladder sleeper and frame sleeper.Then a vehicle-track-bridge coupling system dynamic analysis model was established,with which the dynamic performances of the primary selected sleeper types were compared and analyzed to select the suitable sleeper type for bridge.The selected sleeper type was optimized,and the wide sleeper is recommended for high speed railway in China.Based on a comprehensive consideration of the track maintenance,type Ⅲ sleeper was proposed for sleeper scheme.The dynamic analysis results show that the widening sleeper with 2~4 cm type Ⅲ sleeper can well reduce ballast stress and be easy to maintain.Study results are helpful for the design of new sleeper structures on bridge.","PeriodicalId":17444,"journal":{"name":"Journal of Tongji University","volume":"1 1","pages":"68-72"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80778955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-01-01DOI: 10.3969/J.ISSN.0253-374X.2012.09.017
Lijun Zhang, Meng Huang
A 2 DOF nonlinear dynamic model of the automotive wiper system based on the theory of stick-slip vibration was established. Bifurcation diagram and trajectories on the phase plane were adopted to confirm the pervasive phenomenon of stick-slip vibration and to study its characteristics under various wiping velocities through numerical computation. Spatial and temporal distribution of stick-slip vibration was analyzed by means of time histories and contour maps. Quantitative index of duty ratio of stick motion and quantity statistics of scraping were introduced to evaluate the wiping effect. The results indicate that the occurring of stick-slip vibration and its characteristics under various wiping velocities possess complicated nonlinearity. The nonlinear stick-slip vibration vanishes only when the nominal wiping velocity is higher than 0.725 m·s-1. Increasing the wiping velocity benefits the control of stick-slip vibration and reduces the adverse influence on wiping effect caused by the heterogeneous distribution of scrapings.
{"title":"Nonlinear stick-slip vibration and its influence on wiping effect of automotive wiper system","authors":"Lijun Zhang, Meng Huang","doi":"10.3969/J.ISSN.0253-374X.2012.09.017","DOIUrl":"https://doi.org/10.3969/J.ISSN.0253-374X.2012.09.017","url":null,"abstract":"A 2 DOF nonlinear dynamic model of the automotive wiper system based on the theory of stick-slip vibration was established. Bifurcation diagram and trajectories on the phase plane were adopted to confirm the pervasive phenomenon of stick-slip vibration and to study its characteristics under various wiping velocities through numerical computation. Spatial and temporal distribution of stick-slip vibration was analyzed by means of time histories and contour maps. Quantitative index of duty ratio of stick motion and quantity statistics of scraping were introduced to evaluate the wiping effect. The results indicate that the occurring of stick-slip vibration and its characteristics under various wiping velocities possess complicated nonlinearity. The nonlinear stick-slip vibration vanishes only when the nominal wiping velocity is higher than 0.725 m·s-1. Increasing the wiping velocity benefits the control of stick-slip vibration and reduces the adverse influence on wiping effect caused by the heterogeneous distribution of scrapings.","PeriodicalId":17444,"journal":{"name":"Journal of Tongji University","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79901979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-01-01DOI: 10.3969/J.ISSN.0253-374X.2011.08.028
Yi Lin, C. Pan, Yingying Chen, Ren Wenwei
Based on the analysis of spectral curve and features of cyanobacteria bloom and other typical ground object,the normalized difference cyanobacteria bloom index(NDI_CB)was constructed to distinguish between cyanobacteria bloom and turbid water with the Landsat-7 ETM+ image in Lake Dianshan.In this study two other different vegetation indexes,normalized difference vegetation index(NDVI)and ratio vegetation index(RVI),together with NDI_CB,were applied to extracting the cyanobacteria bloom information from the same image via unsupervised classification method(k-means).The results show that NDI_CB is the best one for low-density cyanobacteria bloom extraction.In order to recognize the cyanobacteria bloom better,support vector machine(SVM)classification method was used to classify the image based on spectral features and NDI_CB,and to obtain the spatial distribution and the area of cyanobacteria bloom in Lake Dianshan.Through studying the laws of the cyanobacteria bloom distribution at a particular time,a sound,efficient and objective basis has been achieved for the ecological analysis of the prevention and the treatment of cyanobacteria bloom.
{"title":"Recognition of Cyanobacteria Bloom Based on Spectral Analysis of Remote Sensing Imagery","authors":"Yi Lin, C. Pan, Yingying Chen, Ren Wenwei","doi":"10.3969/J.ISSN.0253-374X.2011.08.028","DOIUrl":"https://doi.org/10.3969/J.ISSN.0253-374X.2011.08.028","url":null,"abstract":"Based on the analysis of spectral curve and features of cyanobacteria bloom and other typical ground object,the normalized difference cyanobacteria bloom index(NDI_CB)was constructed to distinguish between cyanobacteria bloom and turbid water with the Landsat-7 ETM+ image in Lake Dianshan.In this study two other different vegetation indexes,normalized difference vegetation index(NDVI)and ratio vegetation index(RVI),together with NDI_CB,were applied to extracting the cyanobacteria bloom information from the same image via unsupervised classification method(k-means).The results show that NDI_CB is the best one for low-density cyanobacteria bloom extraction.In order to recognize the cyanobacteria bloom better,support vector machine(SVM)classification method was used to classify the image based on spectral features and NDI_CB,and to obtain the spatial distribution and the area of cyanobacteria bloom in Lake Dianshan.Through studying the laws of the cyanobacteria bloom distribution at a particular time,a sound,efficient and objective basis has been achieved for the ecological analysis of the prevention and the treatment of cyanobacteria bloom.","PeriodicalId":17444,"journal":{"name":"Journal of Tongji University","volume":"41 1","pages":"1247-1252"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88766598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-01-01DOI: 10.1201/9781439828434.ch399
Zhang Qiwei
A study is made of the effects of vibration of deck on the non-uniform cross-sectional stress distribution on short suspenders of arch bridges with vertical suspenders.It is assumed that the suspenders are fixed at the connections with the ribs and the deck.The stress of suspender caused by the vertical vibration and longitudinal vibration of deck is derived and the influence factors are discussed,such as vehicle speed,vehicle frequency,driving frequencies with shift,etc.From the stress time history of suspender,the non-uniform stress distribution of short suspender is illustrated,and the range of the dynamic enhancement coefficient of stress is suggested based on an engineering project.
{"title":"Vibration Effect on Cross-sectional Stress Distribution of Short Suspenders in Arch Bridges","authors":"Zhang Qiwei","doi":"10.1201/9781439828434.ch399","DOIUrl":"https://doi.org/10.1201/9781439828434.ch399","url":null,"abstract":"A study is made of the effects of vibration of deck on the non-uniform cross-sectional stress distribution on short suspenders of arch bridges with vertical suspenders.It is assumed that the suspenders are fixed at the connections with the ribs and the deck.The stress of suspender caused by the vertical vibration and longitudinal vibration of deck is derived and the influence factors are discussed,such as vehicle speed,vehicle frequency,driving frequencies with shift,etc.From the stress time history of suspender,the non-uniform stress distribution of short suspender is illustrated,and the range of the dynamic enhancement coefficient of stress is suggested based on an engineering project.","PeriodicalId":17444,"journal":{"name":"Journal of Tongji University","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91026971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-05DOI: 10.1007/S11709-007-0060-9
Liu Qijian, Yang Lin-de
{"title":"New Model of Load Transfer Function for Pile Analysis Based on Disturbed State Model","authors":"Liu Qijian, Yang Lin-de","doi":"10.1007/S11709-007-0060-9","DOIUrl":"https://doi.org/10.1007/S11709-007-0060-9","url":null,"abstract":"","PeriodicalId":17444,"journal":{"name":"Journal of Tongji University","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2007-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74846241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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