Many networks in the real world have spatial attributes, such as location of nodes and length of edges, called spatial networks. When these networks are subject to some random or deliberate attacks, some nodes in the ...Many networks in the real world have spatial attributes, such as location of nodes and length of edges, called spatial networks. When these networks are subject to some random or deliberate attacks, some nodes in the network fail, which causes a decline in the network performance. In order to make the network run normally, some of the failed nodes must be recovered. In the case of limited recovery resources, an effective key node identification method can find the key recovering node in the failed nodes, by which the network performance can be recovered most of the failed nodes. We propose two key recovering node identification methods for spatial networks, which are the Euclidean-distance recovery method and the route-length recovery method. Simulations on homogeneous and heterogeneous spatial networks show that the proposed methods can significantly recover the network performance.展开更多
The logistics nodes and logistics enterprises are the core carriers and organiza- tional subjects of the logistics space, and their location characteristics and differentiation strategies are of key importance to opti...The logistics nodes and logistics enterprises are the core carriers and organiza- tional subjects of the logistics space, and their location characteristics and differentiation strategies are of key importance to optimizing urban logistics spatial patterns and ensuring reasonable resource allocation. Based on Tencent Online Maps Platform from December 2014, 4396 logistics points of interest （POI） were collected in Beijing, China. By the methods of industrial concentration evaluation and kernel density analysis, the spatial distribution pattern of logistics in Beijing are explored, the interaction mechanism among the type differ- ence, supply-demand side factors and location choice behavior are clarified, and the internal mechanism of spatial differentiation under the combined influence of transportation, land rent and assets are revealed. The following conclusions are drawn in the paper. （1） Logistics en- terprises and logistics nodes exhibit the characteristic of both co-agglomeration and spatial separation in location, and logistics activities display the spatial pattern of ＂marginal area of downtown area, suburbs and exurban area＂, which have a weak coupling degree with logis- tics employment space. （2） The public logistics space, namely, logistics parks and logistics centers, is produced under the guidance of the government, and the terminal logistics space consisting of logistics distribution centers serving for the specific industries and terminal users is dominated by enterprises. The Iocational differentiation between the two modes of logistics space is significant. （3） In the formation of the logistics spatial location, the government can change the traffic condition by re-planning the transport routes and freight station locations, and control the land rent and availability of different areas by increasing or decreasing the land use of logistics, to impact the enterprise behavior and form different types of logistics space and function differentiation. In comparison, logistics enterprises meet the diverse de- mands of service objects through differentiation of asset allocation to promote the specializa- tion of division and form the object differentiation of logistics space.展开更多
A bidirectional ribbed concrete beam slab structure was widly adopted for the upper space of industrial buildings.To maintain ample space and minimize the presence of conventional columns,a bidirectional prestressed c...A bidirectional ribbed concrete beam slab structure was widly adopted for the upper space of industrial buildings.To maintain ample space and minimize the presence of conventional columns,a bidirectional prestressed concrete beam is often employed.The intersection node of the prestressed concrete frame beam column was characterized by a high density of steel reinforcement,significant structural loads,and complex construction requirements.To ensure the quality,safety,and progress of prestressed frame beamcolumn intersection nodes during construction,this article proposed a new technology for constructing such nodes,which includes setting the tensioning and haunching ends of nodes at different positions,using ABAQUS finite element software to optimize the design of cross-sectional dimensions,conducting stress analysis simulations.展开更多
Nowadays, urban transit system has become one of the major forces underlying urban pace transformation via changing accessibility of related land parcels, which leads to the changes of land value and land use structur...Nowadays, urban transit system has become one of the major forces underlying urban pace transformation via changing accessibility of related land parcels, which leads to the changes of land value and land use structure. This paper studied the interaction between land use changes and related transport routes, particular about how different transport routes and road nodes influence the conversion of industrial lands to residential and commercial uses respectively. Taking Changchun, an old industrial city in the rust belt of China as a case of study, we explored and compared the influences of different transport routes and road nodes on industrial land conversion. We found that surrounding the studied transport routes, more industrial lands were replaced by residential lands than by commercial lands. Also, apparent differences exist in the corridor effects of different transport routes(i.e., light rail, expressway and trunk road) and road nodes(i.e., expressway nodes and trunk road nodes) while the industrial lands convert to residential and commercial uses. Our research findings help us to illuminate the interactive relationships between transportation and industrial land conversion in old industrial cities which are undergoing social, economic and the related urban transition in Northeast China.展开更多
目的联合空间位置-临床-影像特征探讨可切除肺腺癌淋巴结转移的危险因素,并构建淋巴结转移预测模型。方法回顾性纳入2016年6月—2020年6月于南京医科大学第一附属医院接受胸部CT,并经手术确诊为有或无淋巴结转移的浸润性肺腺癌患者。根...目的联合空间位置-临床-影像特征探讨可切除肺腺癌淋巴结转移的危险因素,并构建淋巴结转移预测模型。方法回顾性纳入2016年6月—2020年6月于南京医科大学第一附属医院接受胸部CT,并经手术确诊为有或无淋巴结转移的浸润性肺腺癌患者。根据有无淋巴结转移,将患者分为阳性组与阴性组。收集患者的临床及影像学资料,采用单因素和多因素logistic回归分析可切除肺腺癌淋巴结转移的独立危险因素,并建立淋巴结转移的空间位置-临床-影像特征联合预测模型,将其与不包含空间位置特征的传统淋巴结转移预测模型进行对比。结果共纳入611例患者,阳性组333例,其中男172例、女161例,平均年龄(58.9±9.7)岁;阴性组278例,其中男127例、女151例,平均年龄(60.1±11.4)岁。单因素及多因素logistic回归分析显示,病灶距离肺门的空间位置关系、结节类型、胸膜改变、血清癌胚抗原(carcinoembryonic antigen,CEA)水平是淋巴结转移的独立危险因素,以此为基础构建的空间位置-临床-影像特征联合预测模型敏感性为91.67%,特异性为74.05%,准确性为87.88%,曲线下面积(area under the curve,AUC)为0.885。不包含空间位置特征的传统淋巴结转移预测模型敏感性为76.40%,特异性为72.10%,准确性为53.86%,AUC为0.827。两种预测方法的AUC差异有统计学意义(P=0.026)。与传统预测模型相比,空间位置-临床-影像特征联合预测模型的预测效能有显著提升。结论在可切除肺腺癌患者中,空间位置、实性密度、胸膜改变为宽基底凹陷以及血清CEA水平升高者发生淋巴结转移的风险更高。展开更多
基金Project supported by Zhejiang Provincial Natural Science Foundation of China (Grant No. LQ23F030012)the Fundamental Research Funds for the Provincial Universities of Zhejiang (Grant No. GK229909299001-018)。
文摘Many networks in the real world have spatial attributes, such as location of nodes and length of edges, called spatial networks. When these networks are subject to some random or deliberate attacks, some nodes in the network fail, which causes a decline in the network performance. In order to make the network run normally, some of the failed nodes must be recovered. In the case of limited recovery resources, an effective key node identification method can find the key recovering node in the failed nodes, by which the network performance can be recovered most of the failed nodes. We propose two key recovering node identification methods for spatial networks, which are the Euclidean-distance recovery method and the route-length recovery method. Simulations on homogeneous and heterogeneous spatial networks show that the proposed methods can significantly recover the network performance.
基金Foundation： National Natural Science Foundation of China, No.41501123, No.71703219
文摘The logistics nodes and logistics enterprises are the core carriers and organiza- tional subjects of the logistics space, and their location characteristics and differentiation strategies are of key importance to optimizing urban logistics spatial patterns and ensuring reasonable resource allocation. Based on Tencent Online Maps Platform from December 2014, 4396 logistics points of interest （POI） were collected in Beijing, China. By the methods of industrial concentration evaluation and kernel density analysis, the spatial distribution pattern of logistics in Beijing are explored, the interaction mechanism among the type differ- ence, supply-demand side factors and location choice behavior are clarified, and the internal mechanism of spatial differentiation under the combined influence of transportation, land rent and assets are revealed. The following conclusions are drawn in the paper. （1） Logistics en- terprises and logistics nodes exhibit the characteristic of both co-agglomeration and spatial separation in location, and logistics activities display the spatial pattern of ＂marginal area of downtown area, suburbs and exurban area＂, which have a weak coupling degree with logis- tics employment space. （2） The public logistics space, namely, logistics parks and logistics centers, is produced under the guidance of the government, and the terminal logistics space consisting of logistics distribution centers serving for the specific industries and terminal users is dominated by enterprises. The Iocational differentiation between the two modes of logistics space is significant. （3） In the formation of the logistics spatial location, the government can change the traffic condition by re-planning the transport routes and freight station locations, and control the land rent and availability of different areas by increasing or decreasing the land use of logistics, to impact the enterprise behavior and form different types of logistics space and function differentiation. In comparison, logistics enterprises meet the diverse de- mands of service objects through differentiation of asset allocation to promote the specializa- tion of division and form the object differentiation of logistics space.
基金Funded by the Nantong Science and Technology Plan Project(No.JC2021172)the Cyan and Blue Project of Universities in Jiangsu Province。
文摘A bidirectional ribbed concrete beam slab structure was widly adopted for the upper space of industrial buildings.To maintain ample space and minimize the presence of conventional columns,a bidirectional prestressed concrete beam is often employed.The intersection node of the prestressed concrete frame beam column was characterized by a high density of steel reinforcement,significant structural loads,and complex construction requirements.To ensure the quality,safety,and progress of prestressed frame beamcolumn intersection nodes during construction,this article proposed a new technology for constructing such nodes,which includes setting the tensioning and haunching ends of nodes at different positions,using ABAQUS finite element software to optimize the design of cross-sectional dimensions,conducting stress analysis simulations.
基金Under the auspices of National Natural Science Foundation of China(No.41871158)。
文摘Nowadays, urban transit system has become one of the major forces underlying urban pace transformation via changing accessibility of related land parcels, which leads to the changes of land value and land use structure. This paper studied the interaction between land use changes and related transport routes, particular about how different transport routes and road nodes influence the conversion of industrial lands to residential and commercial uses respectively. Taking Changchun, an old industrial city in the rust belt of China as a case of study, we explored and compared the influences of different transport routes and road nodes on industrial land conversion. We found that surrounding the studied transport routes, more industrial lands were replaced by residential lands than by commercial lands. Also, apparent differences exist in the corridor effects of different transport routes(i.e., light rail, expressway and trunk road) and road nodes(i.e., expressway nodes and trunk road nodes) while the industrial lands convert to residential and commercial uses. Our research findings help us to illuminate the interactive relationships between transportation and industrial land conversion in old industrial cities which are undergoing social, economic and the related urban transition in Northeast China.
文摘目的联合空间位置-临床-影像特征探讨可切除肺腺癌淋巴结转移的危险因素,并构建淋巴结转移预测模型。方法回顾性纳入2016年6月—2020年6月于南京医科大学第一附属医院接受胸部CT,并经手术确诊为有或无淋巴结转移的浸润性肺腺癌患者。根据有无淋巴结转移,将患者分为阳性组与阴性组。收集患者的临床及影像学资料,采用单因素和多因素logistic回归分析可切除肺腺癌淋巴结转移的独立危险因素,并建立淋巴结转移的空间位置-临床-影像特征联合预测模型,将其与不包含空间位置特征的传统淋巴结转移预测模型进行对比。结果共纳入611例患者,阳性组333例,其中男172例、女161例,平均年龄(58.9±9.7)岁;阴性组278例,其中男127例、女151例,平均年龄(60.1±11.4)岁。单因素及多因素logistic回归分析显示,病灶距离肺门的空间位置关系、结节类型、胸膜改变、血清癌胚抗原(carcinoembryonic antigen,CEA)水平是淋巴结转移的独立危险因素,以此为基础构建的空间位置-临床-影像特征联合预测模型敏感性为91.67%,特异性为74.05%,准确性为87.88%,曲线下面积(area under the curve,AUC)为0.885。不包含空间位置特征的传统淋巴结转移预测模型敏感性为76.40%,特异性为72.10%,准确性为53.86%,AUC为0.827。两种预测方法的AUC差异有统计学意义(P=0.026)。与传统预测模型相比,空间位置-临床-影像特征联合预测模型的预测效能有显著提升。结论在可切除肺腺癌患者中,空间位置、实性密度、胸膜改变为宽基底凹陷以及血清CEA水平升高者发生淋巴结转移的风险更高。
