Under many aspects Italy would be ideal for cycling:the weather is favourable for a good part of the year and many historic centres are characterized by roads which would mainly be suitable for bicycle traffic.The pos...Under many aspects Italy would be ideal for cycling:the weather is favourable for a good part of the year and many historic centres are characterized by roads which would mainly be suitable for bicycle traffic.The positive aspects relating to cycling are well known,but unfortunately,the use of bicycles in Italy is still poor and the main cause of this phenomenon is certainly relating to a general lack of safety in cycling.In the last decade,in Italy the trend of road accidents and victims is generally decreasing,but,at the same time,the number of cyclists involved in road accidents increased by 24,5%,therefore,more attention to cyclists as Vulnerable Road Users is absolutely needed.The causes of this high accident rate is mainly relating to a lack of national legislation or to standards which are old,often overlapped to regional guidelines,uneven,confusing and in some case also contradictory.In terms of cycle network planning,it should be reminded that in Italy there is no regulation that establishes the criteria for a functional classification of bicycle paths.As a consequence,the infrastructure geometry and facilities(bicycle parking,places of refreshments,cycle repair shops,etc.)are not properly put in relation to the role played by the cycle path in the territory.In the course of time,we assisted to the realization of isolated cycle path trunks,generally out of a planning strategy and characterized by their own geometry.Therefore,taking also inspiration by the standards developed in other European Countries,this research tries to provide guidelines for pre-normative functional classification of cycle paths,for their design and planning,in order to obtain safe and homogeneous cycling routes in Italy.It should be noted that the technical solutions,devices and traffic regulations,adopted in other countries,are very effective for a safe cycle mobility,but need to be revised in relation to the existing Italian law.展开更多
For positive numbers j and k, an L（j,k）-labeling f of G is an assignment of numbers to vertices of G such that ｜f（u）-f（v）｜≥j if uv∈E（G）, and ｜f（u）-f（v）｜≥k if d（u,v）=2. Then the span of f is the di...For positive numbers j and k, an L（j,k）-labeling f of G is an assignment of numbers to vertices of G such that ｜f（u）-f（v）｜≥j if uv∈E（G）, and ｜f（u）-f（v）｜≥k if d（u,v）=2. Then the span of f is the difference between the maximum and the minimum numbers assigned by f. The L（j,k）-number of G, denoted by λj,k（G）, is the minimum span over all L（j,k）-labelings of G. In this paper, we give some results about the L（j,k）-number of the direct product of a path and a cycle for j≤k.展开更多
The recession and revitalization of old industrial cities concerns urban industrial evolution and its characteristics. Based on the theory of evolutionary resilience, we developed an analytical framework for the indus...The recession and revitalization of old industrial cities concerns urban industrial evolution and its characteristics. Based on the theory of evolutionary resilience, we developed an analytical framework for the industrial structure evolution of old industrial cities, and applied the framework to a case study in Shenyang. The following conclusions are drawn. First, since 1978, Shenyang's industrial growth capacity has shown fluctuation between ‘contraction-expansion'. As the secondary industry has a much stronger expansionary and contractionary capacity for growth, this results in lacking stability leading to industrial structure transformation. Second, since 1999, the orientation towards a high-end manufacturing industry in Shenyang has weakened, and the evolution of the new and old growth path is characterized by low-end orientation. Third, since 2007, Shenyang's industrial innovation output capacity has dropped sharply which has been significantly affected by scientific and technological personnel and enterprise-owed science and technology institutions and to a less extent by R&D expenditure. We applied the resilience theory to study the industrial evolution of an old industrial city, explored new study perspectives on industrial evolution and verified the applicability of the resilience theory. This paper provides a scientific reference for understanding the recent deceleration in economic growth in the Northeast old industrial base, and for exploring new paths toward revitalization.展开更多
This paper gives new sufficient conditions for a connected graph to be Hamiltonian and Hamiltonian connected by independence number and neighbourhood intersections of three independent vertices with distance 2.
For a graph G and two positive integers j and k, an m-L（j, k）-edge-labeling of G is an assignment on the edges to the set {0,..., m}, such that adjacent edges receive labels differing by at least j, and edges which ...For a graph G and two positive integers j and k, an m-L（j, k）-edge-labeling of G is an assignment on the edges to the set {0,..., m}, such that adjacent edges receive labels differing by at least j, and edges which are distance two apart receive labels differing by at least k. The λ′j,k-number of G is the minimum m of an m-L（j, k）-edge-labeling admitted by G.In this article, we study the L（1, 2）-edge-labeling for paths, cycles, complete graphs, complete multipartite graphs, infinite ？-regular trees and wheels.展开更多
文摘Under many aspects Italy would be ideal for cycling:the weather is favourable for a good part of the year and many historic centres are characterized by roads which would mainly be suitable for bicycle traffic.The positive aspects relating to cycling are well known,but unfortunately,the use of bicycles in Italy is still poor and the main cause of this phenomenon is certainly relating to a general lack of safety in cycling.In the last decade,in Italy the trend of road accidents and victims is generally decreasing,but,at the same time,the number of cyclists involved in road accidents increased by 24,5%,therefore,more attention to cyclists as Vulnerable Road Users is absolutely needed.The causes of this high accident rate is mainly relating to a lack of national legislation or to standards which are old,often overlapped to regional guidelines,uneven,confusing and in some case also contradictory.In terms of cycle network planning,it should be reminded that in Italy there is no regulation that establishes the criteria for a functional classification of bicycle paths.As a consequence,the infrastructure geometry and facilities(bicycle parking,places of refreshments,cycle repair shops,etc.)are not properly put in relation to the role played by the cycle path in the territory.In the course of time,we assisted to the realization of isolated cycle path trunks,generally out of a planning strategy and characterized by their own geometry.Therefore,taking also inspiration by the standards developed in other European Countries,this research tries to provide guidelines for pre-normative functional classification of cycle paths,for their design and planning,in order to obtain safe and homogeneous cycling routes in Italy.It should be noted that the technical solutions,devices and traffic regulations,adopted in other countries,are very effective for a safe cycle mobility,but need to be revised in relation to the existing Italian law.
基金Supported by Faculty Research Grant, Hong Kong Baptist University
文摘For positive numbers j and k, an L（j,k）-labeling f of G is an assignment of numbers to vertices of G such that ｜f（u）-f（v）｜≥j if uv∈E（G）, and ｜f（u）-f（v）｜≥k if d（u,v）=2. Then the span of f is the difference between the maximum and the minimum numbers assigned by f. The L（j,k）-number of G, denoted by λj,k（G）, is the minimum span over all L（j,k）-labelings of G. In this paper, we give some results about the L（j,k）-number of the direct product of a path and a cycle for j≤k.
基金Under the auspices of National Natural Science Foundation of China(No.41571152,41771179,41630749,41601124)the Key Deployment Projects of the Chinese Academy of Sciences(No.ZDBS-SSW-SQC)135 Planning and Featured Services Projects of IGA,Chinese Academy of Sciences(No.Y6H2091001)
文摘The recession and revitalization of old industrial cities concerns urban industrial evolution and its characteristics. Based on the theory of evolutionary resilience, we developed an analytical framework for the industrial structure evolution of old industrial cities, and applied the framework to a case study in Shenyang. The following conclusions are drawn. First, since 1978, Shenyang's industrial growth capacity has shown fluctuation between ‘contraction-expansion'. As the secondary industry has a much stronger expansionary and contractionary capacity for growth, this results in lacking stability leading to industrial structure transformation. Second, since 1999, the orientation towards a high-end manufacturing industry in Shenyang has weakened, and the evolution of the new and old growth path is characterized by low-end orientation. Third, since 2007, Shenyang's industrial innovation output capacity has dropped sharply which has been significantly affected by scientific and technological personnel and enterprise-owed science and technology institutions and to a less extent by R&D expenditure. We applied the resilience theory to study the industrial evolution of an old industrial city, explored new study perspectives on industrial evolution and verified the applicability of the resilience theory. This paper provides a scientific reference for understanding the recent deceleration in economic growth in the Northeast old industrial base, and for exploring new paths toward revitalization.
文摘This paper gives new sufficient conditions for a connected graph to be Hamiltonian and Hamiltonian connected by independence number and neighbourhood intersections of three independent vertices with distance 2.
基金Supported by the National Natural Science Foundation of China(Grant Nos.1097102510901035)
文摘For a graph G and two positive integers j and k, an m-L（j, k）-edge-labeling of G is an assignment on the edges to the set {0,..., m}, such that adjacent edges receive labels differing by at least j, and edges which are distance two apart receive labels differing by at least k. The λ′j,k-number of G is the minimum m of an m-L（j, k）-edge-labeling admitted by G.In this article, we study the L（1, 2）-edge-labeling for paths, cycles, complete graphs, complete multipartite graphs, infinite ？-regular trees and wheels.
