A high-performance low cost inverse integer transform architecture for AVS video standard

A high-performance, low cost inverse integer transform architecture for advanced video standard (AVS) video coding standard was presented. An 8×8 inverse integer transform is required in AVS video system which is compute-intensive. A hardware transform is inevitable to compute the transform for the real-time ap-plication. Compared with the 4×4 transform for H.264/AVC, the 8×8 integer transform is much more complex and the coefficient in the inverse transform matrix Ts is not inerratic as that in H.264/AVC. Dividing the Ts into matrix S8 and R8, the proposed architecture is implemented with the adders and the specific CSA-trees instead of multipliers, which are area and time consuming. The architecture obtains the data processing rate up to 8 pixels per-cycle at a low cost of area. Synthesized to TSMC 0.18 μm COMS process, the architecture attains the operating frequency of 300 MHz at cost of 34 252 gates with a 2-stage pipeline scheme. A reusable scheme is also introduced for the area optimization, which results in the operating frequency of 143 MHz at cost of only 19 758 gates.     

An optimal pole-matching observer design for estimating tyre–road friction force

In this paper, considering the dynamical model of tyre–road contacts, we design a nonlinear observer for the on-line estimation of tyre–road friction force using the average lumped LuGre model without any simplification. The design is the extension of a previously offered observer to allow a muchmore realistic estimation by considering the effect of the rolling resistance and a term related to the relative velocity in the observer. Our aim is not to introduce a new friction model, but to present a more accurate nonlinear observer for the assumed model. We derive linear matrix equality conditions to obtain an observer gain with minimum pole mismatch for the desired observer error dynamic system. We prove the convergence of the observer for the non-simplified model. Finally, we compare the performance of the proposed observer with that of the previously mentioned nonlinear observer, which shows significant improvement in the accuracy of estimation.     

An investigation into the mechanism of the polygonal wear of metro train wheels and its effect on the dynamic behaviour of a wheel/rail system

This paper presents a detailed investigation conducted into the mechanism of the polygonal wear of metro train wheels through extensive experiments conducted at the sites. The purpose of the experimental investigation is to determine from where the resonant frequency that causes the polygonal wear of the metro train wheels originates. The experiments include the model tests of a vehicle and its parts and the tracks, the dynamic behaviour test of the vehicle in operation and the observation test of the polygonal wear development of the wheels. The tracks tested include the viaducts and the tunnel tracks. The structure model tests show that the average passing frequency of a polygonal wheel is approximately close to the first bending resonant frequency of the wheelset that is found by the wheelset model test and verified by the finite element analysis of the wheelset. Also, the dynamic behaviour test of the vehicle in operation indicates the main frequencies of the vertical acceleration vibration of the axle boxes, which are dominant in the vertical acceleration vibration of the axle boxes and close to the passing frequency of a polygonal wheel, which shows that the first bending resonant frequency of the wheelset is very exciting in the wheelset operation. The observation test of the polygonal wear development of the wheels indicates an increase in the rate of the polygonal wear of the wheels after their re-profiling. This paper also describes the dynamic models used for the metro vehicle coupled with the ballasted track and the slab track to analyse the effect of the polygonal wear of the wheels on the wheel/rail normal forces.     

Dynamic location: an iconic model to synchronize temporal and spatial transportation data

This paper describes a model to synchronize the management and query of temporal and spatially referenced transportation data in geographic information systems (GIS). The model employs a method referred to as dynamic location, which facilitates spatial intersect queries from geographic shapes without the use of topological relationships. This is the inverse of how dynamic segmentation works in GIS. In contrast to dynamic segmentation, dynamic location stores geometry as an object within a single database field. This is an efficient, precise iconic model superseding the need for data decomposition into a complex set of tables. As an object model, the dynamic location process lends itself to high performance in an Internet, data-intensive, enterprise environment. Linear events are stored as {x, y} features, and not referenced to any route system. Route systems are built from {x, y, m} values (m for measure) and serve as number lines for mathematical operations. Any {x, y} object can then be referenced to either the Cartesian grid or any selected number line. This method offers the benefits of linear referencing, while making full use of a stable geodetic datum. Combinations of any {x, y} events may be placed over any {x, y, m} number line (route) and an intersect determined by looking through stacked {x, y, m} vertices of the coincident shapes. Since both geometry and shape reside in the same record, the use of “begin” and “end” dates facilitates full spatial and temporal version control. From a business process perspective, this creates a spatially enabled database, pulling GIS business functions back into the information technology mainstream.     

基于交通约束的城市最佳用地结构模糊规划模型研究

提出了基于交通系统容量约束的城市土地使用模糊规划模型.该模型以最大开发强度为目标,以交通总生成量不超过路网交通容量为约束条件,确定土地使用优化结构.作为城市规划分析模型中的1个子模型,该模型已在城市的总体规划中得到应用.规划实践表明,模型具有重要的理论价值和较强的可操作性.     

桥梁超重荷载与限载标准的确定

为了分析公路运营中超重荷载对桥梁的影响，以陕西省府谷-店塔公路上运煤超载车辆为调查对象，根据车辆装载特点和轴型分布特征，将超载车辆分为9种类型，分析了9种车型的超载、超限情况；利用线性回归，得出超载与超限的函数关系。利用等代荷载方法，与公路-Ⅰ级荷载相比较，确定出9种车型的限载系数和限载标准，评价了限载后车辆荷载特性，认为车辆限载后宜使用多轮、多轴运营车型。     

贵州省滑坡灾害危险性分区图编制研究

基于GIS对贵州省区域内的滑坡危险性进行评估.首先,研究将历史地质灾害分布、地形、地层岩性、断裂构造、河流水系和年均降雨量作为相互独立的滑坡诱发因子,并对各因子按照一定标准再次分级,形成滑坡危险性评价指标体系,绘制各因子的分级图层;然后,考虑因子贡献率,以黄金分割法确定6个因子对发生滑坡灾害的权重;最后,在GIS环境下,应用权重线性组合模型建立滑坡危险性分区图.根据该图,研究区域被划分成4个危险等级:灾害密集发育区、灾害中等密集发育区、灾害偶发区、灾害基本不发育区.通过将滑坡危险性分区图与历史滑坡分布图叠加对比,验证分区图的准确性和可靠性.     

Design of robust-stable and quadratic finite-horizon optimal controllers with low trajectory sensitivity for uncertain active suspension systems

This paper presents a design method for designing the robust-stable and quadratic-finite-horizon-optimal controllers of uncertain active suspension systems. The method integrates a robust stabilisability condition, the orthogonal functions approach (OFA) and the hybrid Taguchi-genetic algorithm (HTGA). Using the integrative computational method, a robust-stable and quadratic-finite-horizon-optimal controller with low-trajectory sensitivity can be obtained such that (i) the active suspension system with elemental parametric uncertainties is stabilised and (ii) a quadratic-finite-horizon-integral performance index including a quadratic trajectory sensitivity term for the nominal active suspension system is minimised. The robust stabilisability condition is proposed in terms of linear matrix inequalities (LMIs). Based on the OFA, an algebraic algorithm only involving the algebraic computation is derived for solving the nominal active suspension feedback dynamic equations. By using the OFA and the LMI-based robust stabilisability condition, the dynamic optimisation problem for the robust-stable and quadratic-finite-horizon-optimal controller design of the linear uncertain active suspension system is transformed into a static-constrained-optimisation problem represented by the algebraic equations with constraint of LMI-based robust stabilisability condition; thus greatly simplifies the design problem. Then, for the static-constrained-optimisation problem, the HTGA is employed to find the robust-stable and quadratic-finite-horizon-optimal controllers of the linear uncertain active suspension systems. A design example is given to demonstrate the applicability of the proposed integrative computational approach.     

Lane-harmonised passenger car equivalents for heterogeneous expressway traffic

In order to account for variations in traffic composition during traffic analysis, passenger car equivalent (PCE) factors are used to convert flow rates of various vehicle classes into flow rates in terms of passenger car units (PCUs). Earlier studies have developed various methods to estimate PCE values but only a few of them are based on uninterrupted traffic flow, particularly for flow regimes with heterogeneous traffic where differential (lower) speed limits are imposed on commercial vehicles. This paper proposes a lane-harmonisation approach, which leverages on the high variation in traffic composition across the lanes, to estimate PCE factors for urban expressways. Multiple linear regression is used and the PCE factors obtained for motorcycles, light goods vehicles, and heavy goods vehicles are 0.65, 1.53, and 2.75, respectively. The estimated capacity flow rate after the application of the obtained PCE factors is around 2200 PCUs per hour per lane.     

基于线性诱导的公路隧道入口区域交通安全优化研究

为达到驾驶人早发现隧道洞门、早适应环境变化、早决策驾驶行为的目的，通过分析隧道入口区域行车环境下的视距视区与交通安全问题，借鉴常见的线条形视线诱导设施（如反光环、反光条、弹性交通柱等），构建隧道线性诱导系统，并提出基于线性诱导的隧道入口区域改善方法。另外，通过室内模拟试验，采集白天与夜间环境下注视点的位置数据； 将注视区域分为5类，并分析注视点在各区域的视觉转移特性，评价隧道入口区域改善前后的效果。结果表明： 1）隧道线性诱导系统具备形式多样、较大尺寸、可以勾勒轮廓、发光分散等特点，同时可以以低成本提升隧道光环境的安全性。2）隧道入口区域改善前，驾驶人的注视点以较大概率出现在前方近处。3）改善后，驾驶人的注视点以较大的概率出现在前方远处，表明改善方案使得驾驶人的视距充足； 改善后注视点在主要分布区域的注视概率变动比改善前更为缓和，表明驾驶人的视区变化得到缓解。