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区域轨道交通路网图系统的设计和实现
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作者 张晔伟 《铁路通信信号工程技术》 2024年第5期70-74,共5页
针对区域轨道交通协同运输一体化的需求,提出构建区域轨道交通路网图系统。将接入区域路网的线路基础设备状态、客流数据、列车开行情况、列车设备状态以及气象状况等各专业信息以车站和区间为节点进行拆分,并对拆分后的数据计算和重构... 针对区域轨道交通协同运输一体化的需求,提出构建区域轨道交通路网图系统。将接入区域路网的线路基础设备状态、客流数据、列车开行情况、列车设备状态以及气象状况等各专业信息以车站和区间为节点进行拆分,并对拆分后的数据计算和重构,生成以车站和区间为单位的节点数据模型,在同一个底图上进行显示,从而对区域路网内各线路的列车分布、实时客流、设备状态以及安全预警等信息提供直观、全面的展示,为人工决策提供便利,为整个系统智能决策和智能指挥提供数据基础。 展开更多
关键词 路网图 区域轨道交通 协同运输
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大规模路网图下关键词覆盖最优路径查询优化 被引量:5
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作者 郝晋瑶 牛保宁 康家兴 《软件学报》 EI CSCD 北大核心 2020年第8期2543-2556,共14页
游客倾向于采用个性化的旅游路线,规划这样的路线需要综合考量路径长度、路径开销和路径覆盖的兴趣点.关键词覆盖最优路径查询(KOR)就是用于规划这样的路线的一类查询,其处理过程通常包括预处理和路径拓展.由于路网图规模的不断扩大,现... 游客倾向于采用个性化的旅游路线,规划这样的路线需要综合考量路径长度、路径开销和路径覆盖的兴趣点.关键词覆盖最优路径查询(KOR)就是用于规划这样的路线的一类查询,其处理过程通常包括预处理和路径拓展.由于路网图规模的不断扩大,现有算法预处理所需内存开销急剧上升,由于内存不足,导致较大规模的路网不能处理;路径拓展搜索空间快速膨胀,应用场景可扩展性与查询实时性难以保证.针对这些问题,提出一种大规模路网图下关键词覆盖最优路径查询算法KORL.KORL在预处理阶段将路网划分为若干子图,仅保存子图内路径和子图之间路径的信息,以减小预处理所需内存.在路径拓展阶段,综合运用最小代价剪枝、近似支配剪枝、全局优先拓展和关键词顶点拓展等策略对现有算法进行优化,以高效地搜索近似最优解.采用美国各地区的路网图,在16G内存环境下进行实验,突破了现有算法只能处理顶点数不超过25K路网图的限制.实验结果表明,KORL算法具有良好的可扩展性. 展开更多
关键词 个性化旅游路线 关键词覆盖最优路径 大规模路网图 路网图划分 最小代价剪枝
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广州铁路(集团)公司路网图辅助生成系统的研发及应用
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作者 简宏 《中国铁路》 2012年第12期49-51,共3页
结合我国铁路发展和广州铁路(集团)公司铁路建设的特点,介绍广州铁路(集团)公司路网图辅助生成系统的研发背景、目标和原则;论述系统的技术要点、结构与功能及应用特点和模块。
关键词 路网图 辅助生成系统 系统功能 广 州铁路(集团)公司
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SV300系统在编制县乡公路网图中的应用
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作者 郑秀丽 寇靖华 邢民权 《山西交通科技》 2002年第3期28-29,31,共3页
利用 SV30 0测绘软件制作县乡公路网数字地图 ,是使用公路部门熟悉的 Auto CAD为平台的 ,解决了 CAD中没有专用地形符号 ,图块填充颜色少的问题 ,所制成的数字图便于修改、编辑、更新 ,且可与数据库连接 ,为将来数据的再利用奠定了基础... 利用 SV30 0测绘软件制作县乡公路网数字地图 ,是使用公路部门熟悉的 Auto CAD为平台的 ,解决了 CAD中没有专用地形符号 ,图块填充颜色少的问题 ,所制成的数字图便于修改、编辑、更新 ,且可与数据库连接 ,为将来数据的再利用奠定了基础。该文详细介绍了县乡公路网图的制作方法 。 展开更多
关键词 编制 县乡公路网图 SV300测绘软件 地形符号 填充颜色 应用
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路网宏观基本图中磁滞现象的产生机理 被引量:3
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作者 王鹏飞 岳昊 关宏志 《城市交通》 2018年第2期89-95,102,共8页
为尽快将路网宏观基本图理论应用于实际交通管控中,利用车流波动理论从交通流状态演化的角度分析路网宏观基本图中磁滞现象的产生机理。以日本京都市的实际观测数据验证部分结论的可靠性。通过理论研究及案例分析发现:1)路网中低密度、... 为尽快将路网宏观基本图理论应用于实际交通管控中,利用车流波动理论从交通流状态演化的角度分析路网宏观基本图中磁滞现象的产生机理。以日本京都市的实际观测数据验证部分结论的可靠性。通过理论研究及案例分析发现:1)路网中低密度、高流量的交通流状态经过拥堵流状态后转化为低密度、低流量的交通流状态是磁滞现象产生的重要原因;2)在相同路网车辆数的条件下,相较形成过程,磁滞环的消除过程会使得路网中产生更多的拥堵路段及拥堵溢出点;3)当路网中存在非拥堵路段可供逐渐增加的车辆选择时,路网宏观基本图有可能在磁滞环形成过程中出现路网车辆数持续增加、但路网总流量保持不变的奇异现象。 展开更多
关键词 交通工程 路网宏观基本 磁滞现象 车流波动理论 拥堵溢出
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基于空间关系认知的新模式地图设计——以路网构架图表达“一带一路”路线为例 被引量:1
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作者 白亭颖 王昭 +1 位作者 张琰光 韩珊珊 《测绘与空间地理信息》 2017年第10期50-53,共4页
地图所要表达的空间结构通常通过空间关系来建构和描述,包括距离关系、方向关系和拓扑关系。本文基于空间关系认知,从定名量表、顺序量表、间隔量表、比率量表4个量表分析了传统地图与新模式地图的空间关系分辨率的变化过程,并以路网架... 地图所要表达的空间结构通常通过空间关系来建构和描述,包括距离关系、方向关系和拓扑关系。本文基于空间关系认知,从定名量表、顺序量表、间隔量表、比率量表4个量表分析了传统地图与新模式地图的空间关系分辨率的变化过程,并以路网架构图为例,对比了传统地图与新模式地图的认知效果,提出在制图中要重视认知效率和表现对象的细节程度。 展开更多
关键词 空间关系 新模式地 路网构架 空间认知
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Oracle Spatial中基于电子地图的路径寻优预处理研究 被引量:1
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作者 周鹏 张骏 史忠科 《计算机应用研究》 CSCD 北大核心 2006年第3期144-147,共4页
电子地图不能直接用于路径寻优,从研究电子地图的绘制方式出发,首先基于路层创建一个虚拟点层,然后根据虚拟点层对路层中满足合并、分解条件的路段进行合并、分解,再对基于预处理路层和虚拟点层建立用于路径寻优的路网图,最后根据电子... 电子地图不能直接用于路径寻优,从研究电子地图的绘制方式出发,首先基于路层创建一个虚拟点层,然后根据虚拟点层对路层中满足合并、分解条件的路段进行合并、分解,再对基于预处理路层和虚拟点层建立用于路径寻优的路网图,最后根据电子地图将用户输入的起点与终点映射到虚拟点层上,得到用于路径寻优的起点和终点。给出了Oracle空间数据库中分解路层,合并路层,建立路网图和映射起点与终点的具体算法,并通过仿真验证了它们的正确性。 展开更多
关键词 电子地 虚拟点层 路层 路网图 映射
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基于Visum的路网容量计算理论研究 被引量:7
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作者 李晶 于雷 《城市交通》 2006年第2期68-73,共6页
道路网容量问题是交通规划中的基本问题之一,大量学者对该问题进行过研究,其中与交通分配结合起来的交通模拟分配法计算路网容量的模型在实际规划中被广泛应用。将运筹学中图论的理论与传统交通分配方法相结合,提出通过建立路网辅助图... 道路网容量问题是交通规划中的基本问题之一,大量学者对该问题进行过研究,其中与交通分配结合起来的交通模拟分配法计算路网容量的模型在实际规划中被广泛应用。将运筹学中图论的理论与传统交通分配方法相结合,提出通过建立路网辅助图的方法计算路网容量。在研究方法中,利用交通规划软件PTV的Visum,对北京中关村地区OD实际交通量分配的结果,运用路网辅助图的方法计算出该地区路网的容量。然后,通过改建该地区的路网结构,对新的路网结构进行新OD实际交通量分配,计算新的路网结构中的路网容量。最后对两次路网容量的计算结果进行分析比较,得出改建后路网是否增容的结论。 展开更多
关键词 路网容量 交通分配 路网辅助
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New atom movement mechanism for tracking path on disordering AuCuI(A_8^(Au)A_4^(Cu)) compound 被引量:3
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作者 谢佑卿 彭红建 +2 位作者 刘心笔 李小波 聂耀庄 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第10期3221-3256,共36页
Taking experimental path on disordering AuCuI(AAuCu8A4)composed of A Au8 and ACu4 stem alloy genes as an example, three discoveries and a method were presented. The ability of Au Cu I(AAu Cu8 A4)to keep structure ... Taking experimental path on disordering AuCuI(AAuCu8A4)composed of A Au8 and ACu4 stem alloy genes as an example, three discoveries and a method were presented. The ability of Au Cu I(AAu Cu8 A4)to keep structure stabilization against changing temperature is attributed to the fact that the AAu8 and ACu4 potential well depths greatly surpass their vibration energies, which leads to the subequilibrium of experimental path. A new atom movement mechanism of AuCuI(AAuACu84)to change structure for suiting variation in temperature is the resonance activating-synchro alternating of alloy genes, which leads to heterogeneous and successive subequilibrium transitions. There exists jumping order degree, which leads to the existence of jumping Tj-temperature and an unexpected so-called "retro-effect" about jumping temperature retrograde shift to lower temperatures upon the increasing heating rate. A set of subequilibrium holographic network path charts were obtained by the experimental mixed enthalpy path method. 展开更多
关键词 INTERMETALLICS alloy gene order/disorder transformation resonance activating-synchro alternating mechanism thermodynamic properties equilibrium and subequilibrium holographic network path charts
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Optimal path finding algorithms based on SLSD road network model 被引量:3
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作者 张小国 王庆 龚福祥 《Journal of Southeast University(English Edition)》 EI CAS 2010年第4期558-562,共5页
A solution to compute the optimal path based on a single-line-single-directional(SLSD)road network model is proposed.Unlike the traditional road network model,in the SLSD conceptual model,being single-directional an... A solution to compute the optimal path based on a single-line-single-directional(SLSD)road network model is proposed.Unlike the traditional road network model,in the SLSD conceptual model,being single-directional and single-line style,a road is no longer a linkage of road nodes but abstracted as a network node.Similarly,a road node is abstracted as the linkage of two ordered single-directional roads.This model can describe turn restrictions,circular roads,and other real scenarios usually described using a super-graph.Then a computing framework for optimal path finding(OPF)is presented.It is proved that classical Dijkstra and A algorithms can be directly used for OPF computing of any real-world road networks by transferring a super-graph to an SLSD network.Finally,using Singapore road network data,the proposed conceptual model and its corresponding optimal path finding algorithms are validated using a two-step optimal path finding algorithm with a pre-computing strategy based on the SLSD road network. 展开更多
关键词 optimal path finding road network model conceptual model digital map vehicle navigation system A algorithm Dijkstra algorithm
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Schematic Road Network Map Progressive Generalization Based on Multiple Constraints 被引量:1
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作者 DONG Weihua GUO Qingsheng LIU Jiping 《Geo-Spatial Information Science》 2008年第3期215-220,共6页
Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including prog... Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a con- crete experiment while maintaining topological consistency of the road network between the original and the schematic map 展开更多
关键词 schematic map spatial cognition progressive cartographic generalization graphic simplification
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Edge span of L(d,1)-labeling on some graphs
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作者 冯桂珍 宋增民 《Journal of Southeast University(English Edition)》 EI CAS 2005年第1期111-114,共4页
Given a graph G and a positive integer d, an L( d, 1) -labeling of G is afunction / that assigns to each vertex of G a non-negative integer such that |f(u)-f (v) | >=d ifd_c(u, v) =1;|f(u)-f(v) | >=1 if d_c(u, v... Given a graph G and a positive integer d, an L( d, 1) -labeling of G is afunction / that assigns to each vertex of G a non-negative integer such that |f(u)-f (v) | >=d ifd_c(u, v) =1;|f(u)-f(v) | >=1 if d_c(u, v) =2. The L(d, 1)-labeling number of G, lambda_d(G) is theminimum range span of labels over all such labelings, which is motivated by the channel assignmentproblem. We consider the question of finding the minimum edge span beta_d( G) of this labeling.Several classes of graphs such as cycles, trees, complete k-partite graphs, chordal graphs includingtriangular lattice and square lattice which are important to a telecommunication problem arestudied, and exact values are given. 展开更多
关键词 L(d 1)-labeling edge span triangular lattice square lattice choralgraphs r-path
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Computing All Pairs Shortest Paths on Sparse Graphs with Articulation Points
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作者 Carlos Roberto Arias Von-Wun Soo 《Computer Technology and Application》 2011年第11期866-883,共18页
In most network analysis tools the computation of the shortest paths between all pairs of nodes is a fundamental step to the discovery of other properties. Among other properties is the computation of closeness centra... In most network analysis tools the computation of the shortest paths between all pairs of nodes is a fundamental step to the discovery of other properties. Among other properties is the computation of closeness centrality, a measure of the nodes that shows how central a vertex is on a given network. In this paper, the authors present a method to compute the All Pairs Shortest Paths on graphs that present two characteristics: abundance of nodes with degree value one, and existence of articulation points along the graph. These characteristics are present in many real life networks especially in networks that show a power law degree distribution as is the case of biological networks. The authors' method compacts the single nodes to their source, and then by using the network articulation points it disconnects the network and computes the shortest paths in the biconnected components. At the final step the authors proposed methods merges the results to provide the whole network shortest paths. The authors' method achieves remarkable speedup compared to state of the art methods to compute the shortest paths, as much as 7 fold speed up in artificial graphs and 3.25 fold speed up in real application graphs. The authors' performance improvement is unlike previous research as it does not involve elaborated setups since the authors algorithm can process significant instances on a popular workstation. 展开更多
关键词 Graph algorithms all pairs shortest paths articulation points
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Graph-based single-copy routing in delay tolerant networks
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作者 于海征 Ma Jianfeng 《High Technology Letters》 EI CAS 2011年第1期52-56,共5页
This paper presents a new graph-based single-copy routmg method m delay tolerant networks (DTN). With time goes on in the networks, a DTN connectivity graph is constituted with mobility of nodes and communication, a... This paper presents a new graph-based single-copy routmg method m delay tolerant networks (DTN). With time goes on in the networks, a DTN connectivity graph is constituted with mobility of nodes and communication, and a corresponding greedy tree is obtained using a greedy algorithm in DTN connectivity graph. While there are some bad nodes such as disabled nodes or selfish nodes in delay tolerant networks, the nodes can choose the next p^oper intermediate node to transmit the mes- sage by comparing the location of neighboring nodes in the greedy tree. The single-copy routing method is very appropriate for energy-constrained, storage-constrained and bandwidth-constrained applications such as mobile wireless DTN networks. We show that delivery ratio is increased significantly by using the graph-based single-copy routing when bad nodes exist. 展开更多
关键词 delay tolerant network DTN) MESSAGE single-copy ROUTING GRAPH
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Bitmap lattice index in road networks
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作者 Doohee Song Keun-Ho Lee Kwangjin Park 《Journal of Central South University》 SCIE EI CAS 2014年第10期3856-3863,共8页
A novel technique called the bitmap lattice index(BLI) is proposed, which combines the advantages of a wireless broadcasting environment with a road network. Existing road networks are based on the on-demand method: a... A novel technique called the bitmap lattice index(BLI) is proposed, which combines the advantages of a wireless broadcasting environment with a road network. Existing road networks are based on the on-demand method: a server's workload increases as the query request increases when a server sends a client information. To solve this problem, we propose the BLI. The BLI denotes an object and a node as 0 and 1 in the Hilbert curve(HC) map. The BLI can identify the position of a node and an object through bit information; it can also reduce the broadcasting frequency of a server by reducing the size of the index, thereby decreasing the access latency and query processing times. Moreover, the BLI is highly effective for data filtering, as it can identify the positions of both an object and a node. In a road network, if filtering is done via the Euclidean distance, it may result in an error. To prevent this, we add another validation procedure. The experiment is conducted by applying the BLI to kNN query, and the technique is assessed by a performance evaluation experiment. 展开更多
关键词 road network wireless broadcast spatial query bitmap lattice index(BLI)
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Global Solar Radiation Maps of Saudi Arabia
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作者 M. Mohandes S. Rehman 《Journal of Energy and Power Engineering》 2010年第12期57-63,共7页
This paper uses Abductive network to predict global solar radiation in any location in the Kingdom of Saudi Arabia (KSA) based on sunshine duration, month number, latitude, longitude, and altitude of the location. R... This paper uses Abductive network to predict global solar radiation in any location in the Kingdom of Saudi Arabia (KSA) based on sunshine duration, month number, latitude, longitude, and altitude of the location. Results indicate good agreement between measured and predicted GSR values for each of the 35 locations with known GSR values. Finally, the data from all available stations are used to train an abductive network to estimate the GSR values anywhere in the Kingdom based on latitude and longitude. GSR values are estimated using the developed method at 25 additional locations throughout the kingdom and used with the measured data from the 35 available measurement stations to draw a comprehensive contour map of GSR values for KSA. 展开更多
关键词 Abductory induction mechanism (AIM) group method of data handling (GMDH) solar radiation map renewable energy.
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云南省大件运输路径管理模式的探讨 被引量:1
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作者 余晓江 刘华 +1 位作者 谢海明 刘家顺 《公路交通科技(应用技术版)》 CAS CSCD 北大核心 2015年第2期280-282,共3页
通过整理云南省目前的大件运输路径,分析大件运输路径管理和选择的影响因素,提出构建大件运输路径网和数据库,更好的运用计算机科学、高效的决策和管理运输路径,保障大件安全、迅速、经济的运输。
关键词 大件运输 路径管理 交通路网图 运输路径数字化 信息化 智能化
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Deriving Network-Constrained Trajectories from Sporadic Tracking Points Collected in Location-Based Services 被引量:2
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作者 李响 张喜慧 林珲 《Geo-Spatial Information Science》 2009年第2期85-94,共10页
The paper proposes an economical and fast algorithm for deriving trajectories from sporadic tracking points collected in location-based services (LBS). Although many traffic studies or applications can benefit from th... The paper proposes an economical and fast algorithm for deriving trajectories from sporadic tracking points collected in location-based services (LBS). Although many traffic studies or applications can benefit from the derived trajectories, the sporadic tracking points are always implicitly overlooked by most of existing map-matching algorithms. The algorithm proposed in this paper finds network paths or trajectories traveled by vehicles through augmenting GPS data with odometer data. An odometer can provide data of traveled distance which are compared with the lengths of candidate network paths in order to find the most approximate network path approaching the trajectory of a vehicle. Tracking points are classified into anchor points and non-anchor points. The former are used to divide trajectories, and the latter screen candidate network paths. An elliptic selection zone and a reduction process are applied to the selection of possible road segments composing candidate network paths. A brute-force searching algorithm is developed to find candidate network paths and calculate their lengths. A two-step screening process is designed to select the final result from candidate network paths. Finally, a series of experiments are conducted to validate the proposed algorithm. 展开更多
关键词 LBS GPS TRAJECTORY ODOMETER tracking point map-matching algorithm
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A Fault-tolerant Routing Control for Double Loop Networks
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作者 Hongmei Liu 《Journal of Systems Science and Information》 2006年第1期141-147,共7页
This paper divides the vertex set into several disjoined subsets and provides an optimal fault-tolerance routing algorithm based on the vertex set partition. This algorithm is efficient and convergent, in polynomial t... This paper divides the vertex set into several disjoined subsets and provides an optimal fault-tolerance routing algorithm based on the vertex set partition. This algorithm is efficient and convergent, in polynomial time, we can get the output if the vertex is given. 展开更多
关键词 circulant graph loop networks routing algorithm
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On the complexity of average path length for biological networks and patterns
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作者 Waqar Asif Hassaan Khaliq Qureshi +1 位作者 Adnan Iqbal Muttukrishnan Rajarajan 《International Journal of Biomathematics》 2014年第4期51-61,共11页
Path length calculation is a frequent requirement in studies related to graph theoretic problems such as genetics. Standard method to calculate average path length (APL) of a graph requires traversing all nodes in t... Path length calculation is a frequent requirement in studies related to graph theoretic problems such as genetics. Standard method to calculate average path length (APL) of a graph requires traversing all nodes in the graph repeatedly, which is computationally expensive for graphs containing large number of nodes. We propose a novel method to calculate APL for graphs commonly required in the studies of genetics. The proposed method is computationally less expensive and less time-consuming compared to standard method. 展开更多
关键词 REDUCTIONISM average path length protein protein interaction.
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