快速路匝道入口智能网联车协同合并控制研究

针对快速路匝道入口场景在高车流量的情况下容易发生交通拥堵的问题,提出了一种快速路匝道入口智能网联车(connected and automated vehicles, CAV)协同合并控制的解决方案,将问题解耦成多车顺序决策和车辆运动规划两部分。其中多车顺序决策对通行效率起到重要作用,因此设计了一种基于状态评价模型(state evaluation model, SEM)的多车顺序决策算法。该算法首先建立状态空间并初始化,考虑通行效率和车辆延迟设计状态评价函数,通过状态转移关系选择出最优状态,最终回溯得到最优通行顺序。根据车辆状态和到达冲突点时间,控制器实时推导各车辆纵向速度的解析解,实现车辆运动规划。仿真和实验结果表明,该方案在满足交通系统实时性要求的同时能有效提高快速路匝道入口的通行效率,缩短车辆延迟,降低燃油消耗。     

Disjunctive merging: Quota and Gmin merging operators

When aggregating information from a group of agents, accepting the pieces of information shared by all agents is a natural requirement. In this paper, we investigate such a unanimity condition in the setting of propositional merging. We discuss two interpretations of the unanimity condition. We show that the first interpretation is captured by existing postulates for merging. But the second interpretation is not, and this leads to the introduction of a new disjunction postulate (Disj). It turns out that existing operators satisfying (Disj) do not perform well with respect to the standard criteria used to evaluate merging operators: logical properties, computational complexity and strategy-proofness. To fill this gap, we introduce two new families of propositional merging operators, quota operators and Gmin operators, which satisfy (Disj), and achieve interesting trade-offs with respect to the logical, computational, and strategy-proofness criteria.     

Statistical region merging

This paper explores a statistical basis for a process often described in computer vision: image segmentation by region merging following a particular order in the choice of regions. We exhibit a particular blend of algorithmics and statistics whose segmentation error is, as we show, limited from both the qualitative and quantitative standpoints. This approach can be efficiently approximated in linear time/space, leading to a fast segmentation algorithm tailored to processing images described using most common numerical pixel attribute spaces. The conceptual simplicity of the approach makes it simple to modify and cope with hard noise corruption, handle occlusion, authorize the control of the segmentation scale, and process unconventional data such as spherical images. Experiments on gray-level and color images, obtained with a short readily available C-code, display the quality of the segmentations obtained.     

Sublinear merging and natural mergesort

The complexity of merging two sorted sequences into one is linear in the worst case as well as in the average case. There are, however, instances for which a sublinear number of comparisons is sufficient. We consider the problem of measuring and exploiting such instance easiness. The merging algorithm presented, Adaptmerge, is shown to adapt optimally to different kinds of measures of instance easiness. In the sorting problem the concept of instance easiness has received a lot of attention, and it is interpreted by a measure of presortedness. We apply Adaptmerge in the already adaptive sorting algorithm Natural Mergesort. The resulting algorithm, Adaptive Mergesort, optimally adapts to several, known and new, measures of presortedness. We also prove some interesting results concerning the relation between measures of presortedness proposed in the literature.     

Discovering and merging related analytic datasets

The production of analytic datasets is a significant big data trend and has gone well beyond the scope of traditional IT-governed dataset development. Analytic datasets are now created by data scientists and data analysts using big data frameworks and agile data preparation tools. However, despite the profusion of available datasets, it remains quite difficult for a data analyst to start from a dataset at hand and customize it with additional attributes coming from other existing datasets. This article describes a model and algorithms that exploit automatically extracted and user-defined semantic relationships for extending analytic datasets with new atomic or aggregated attribute values. Our framework is implemented as a REST service in SAP HANA and includes a careful theoretical analysis and practical solutions for several complex data quality issues.     

Multiway merging in parallel

The problem of merging k (k⩾2) sorted lists is considered. We give an optimal parallel algorithm which takes O((n log k/p)+log n) time using p processors on a parallel random access machine that allows concurrent reads and exclusive writes, where n is the total size of the input lists. This algorithm achieves O(log n) time using p=n log k/log n processors. Most of the previous log n research for this problem has been focused on the case when k=2. Very recently, parallel solutions for the case when k=2 have been reported. Our solution is the first logarithmic time optimal parallel algorithm for the problem when k⩾2. It can also be seen as a unified optimal parallel algorithm for sorting and merging. In order to support the algorithm, a new processor assignment strategy is also presented     

Configurable three-way model merging

Software development is a collaborative activity that requires teams of software engineers to cooperate and work in parallel on versions of models. However, model management techniques such as model differencing, merging, and versioning have turned out to be difficult challenges, due to the complexity of operations and graph-like nature of models. Therefore, a well-developed support for model merging process, as well as conflict management, is highly desired. This paper presents a novel process for model merging, called the Epsilon-based Three-way Merging Process (E3MP) process. Model merging is a significant problem where there are different versions of a system model amongst modeler teams. E3MP includes three components implemented into the Epsilon framework. First, modelers can define domain-specific rules that customize the merging process. Second, E3MP enables an automated method for syntactic and semantic conflict detection amongst different versions of the system model. Third, E3MP puts forward a pattern-based approach for conflict resolution. We applied two generic benchmarks to assess conflict detection and resolution capabilities of our approach and carried out an initial scalability evaluation for the model merge with large models and large change sets. The results of our experiments revealed that the proposed process allows generating consistent and semantically correct merged models.     

On merging software extensions

Summary The problem of combining independent updates to a program is examined in the context of applicative programs. A partial semantic merge rule is given together with the conditions under which it is guaranteed to be correct, and the conditions under which a string merge corresponds to a semantic merge are examined. The theoretical work reported here contains initial steps towards a solution of the software merging problem and is not sufficient for producing a practical system.     

Differencing and merging of architectural views

Differencing and merging architectural views is an important activity in software engineering. However, existing approaches are still based on restrictive assumptions, such as requiring view elements to have unique identifiers or exactly matching types, which is often not the case in many application domains. We propose an approach based on structural information. We generalize a published polynomial-time tree-to-tree correction algorithm that detects inserts, renames and deletes, into a novel algorithm that additionally detects restricted moves. Our algorithm also supports forcing and preventing matches between view elements. We incorporate the algorithm into tools to compare and merge Component-and-Connector (C&C) architectural views. We provide an empirical evaluation of the algorithm. We illustrate the tools using extended examples, and use them to detect and reconcile interesting differences between real architectural views. This article is an expanded version of the following paper: Abi-Antoun, M., Aldrich, J., Nahas, N., Schmerl, B., and Garlan, D: 2006, ‘Differencing and Merging of Architectural Views’. In: Proceedings of the 21st IEEE International Conference on Automated Software Engineering, pp. 47–58.     

Parallel merging with restriction

In this paper, we study the merging of two sorted arrays and on EREW PRAM with two restrictions: (1) The elements of two arrays are taken from the integer range [1,n], where n=Max(n ₁,n ₂). (2) The elements are taken from either uniform distribution or non-uniform distribution such that , for 1≤i≤p (number of processors). We give a new optimal deterministic algorithm runs in time using p processors on EREW PRAM. For ; the running time of the algorithm is O(log ^(g) n) which is faster than the previous results, where log ^(g) n=log log ^(g−1) n for g>1 and log ⁽¹⁾ n=log n. We also extend the domain of input data to [1,n ^k ], where k is a constant.

快速路系统控制器构造与算法设计

快速路系统由于拥挤的产生而影响其利用效率。为了消除拥挤,在假设快速路系统中的驾驶员完全服从命令并能即刻调整其运行状态的基础上,提出了密度控制器的构造方法。宏观层次,此密度控制器依据最优交通状况来计算速度值,然后把所得的速度值发给行驶的车辆。微观层次,每个车辆都即刻按此速度行驶。然后在此基础上,设计了一个适时、高效的算法。仿真实例既表明了每一段的交通密度都指数收敛于期望的交通密度,同时也论证了所提方法在降低拥挤方面有显著的提高。     

An adaptive freeway traffic state estimator

Real-data testing results of a real-time nonlinear freeway traffic state estimator are presented with a particular focus on its adaptive features. The pursued general approach to the real-time adaptive estimation of complete traffic state in freeway stretches or networks is based on stochastic nonlinear macroscopic traffic flow modeling and extended Kalman filtering. One major innovative aspect of the estimator is the real-time joint estimation of traffic flow variables (flows, mean speeds, and densities) and some important model parameters (free speed, critical density, and capacity), which leads to four significant features of the traffic state estimator: (i) avoidance of prior model calibration; (ii) automatic adaptation to changing external conditions (e.g. weather and lighting conditions, traffic composition, control measures); (iii) enabling of incident alarms; (iv) enabling of detector fault alarms. The purpose of the reported real-data testing is, first, to demonstrate feature (i) by investigating some basic properties of the estimator and, second, to explore some adaptive capabilities of the estimator that enable features (ii)-(iv). The achieved testing results are quite satisfactory and promising for further work and field applications.     

高速公路挖掘数据预处理的研究

将数据挖掘技术应用于高速公路系统中,利用挖掘得到的模式对高速公路管理提供有效支持,数据预处理关系到收费数据的挖掘质量,针对丢卡、坏卡、回头车等存在的问题,对数据预处理进行了改正,并给予算法实现。     

Parallel merging: algorithm and implementation results

An efficient parallel algorithm for merging two sorted lists is presented. The algorithm is based on a novel partitioning algorithm that splits the two lists among the processors, in a way that ensures load balance during the merge. The partitioning algorithm can itself be efficiently parallelized, allowing the solution to scale with increased numbers of processors. A shared memory multiprocessor is assumed. The time complexity for partitioning and merging is O(N/p + log N), where p is the number of processors and N is the total number of elements in the two lists. Implementation results on a twenty node Sequent Symmetry multiprocessor are also presented.     

高速公路挖掘数据预处理的研究

将数据挖掘技术应用于高速公路系统中，利用挖掘得到的模式对高速公路管理提供有效支持，数据预处理关系到收费数据的挖掘质量，针对丢卡、坏卡、回头车等存在的问题，对数据预处理进行了改正，并给予算法实现。     

高速公路快速放行提示系统

为了解决高速公路出口存在的车辆驶出高速收费口耗时长、高速出口拥堵的问题,采用STC单片机STC 11F32XE作为主要控制芯片,设计了一套高速公路快速放行提示系统.该系统由上位机、下位机和倒计时控制器3部分组成.其中,上位机通过地感线圈和车辆检测器获取车辆位置信息,控制语音模块给出语音提示,并由串口下发控制命令给下位机;下位机接收到控制命令后控制室外显示屏显示相应信息,同时与倒计时控制器通过并行通信方式控制倒计时屏计时.实际运行结果表明,本系统能达到提高高速公路放行速度的要求.该系统已在山西运城高速各路口安装使用.