一种可搜索无限个邻域的改进A*算法

传统A*算法在栅格地图上进行路径规划时,求解得到的路径长度不是最短并且转折点较多.针对这些不足,提出了一种改进A*算法,将传统A*算法的可搜索邻域个数从离散的8个拓展为无限个,可以沿任意方向进行搜索.这样不仅求解出来的路径长度更短,并且大大降低了其转折点的个数.该算法被应用于自主研发的"智能先锋"号系列无人驾驶车辆上,实车试验以及它们在"中国智能车未来挑战赛"中的优异表现证明该方法能够在栅格地图中求解出一条更优的可行驶路径,可以显著提升无人驾驶车辆行驶的效率和平稳性.     

建立和完善企业内部控制制度探讨

有效实施内部会计控制,关键在于单位内部会计控制系统自身的科学性、合理性,其运作管理的严肃性,对内部会计控制实施的监督检查的严格性。     

Advancements in the design and validation of an air pollution integrated assessment model for Spain

This paper describes the design and application of the Atmospheric Evaluation and Research Integrated model for Spain (AERIS). Currently, AERIS can provide concentration profiles of NO₂, O₃, SO₂, NH₃, PM, as a response to emission variations of relevant sectors in Spain. Results are calculated using transfer matrices based on an air quality modelling system (AQMS) composed by the WRF (meteorology), SMOKE (emissions) and CMAQ (atmospheric-chemical processes) models. The AERIS outputs were statistically tested against the conventional AQMS and observations, revealing a good agreement in both cases. At the moment, integrated assessment in AERIS focuses only on the link between emissions and concentrations. The quantification of deposition, impacts (health, ecosystems) and costs will be introduced in the future. In conclusion, the main asset of AERIS is its accuracy in predicting air quality outcomes for different scenarios through a simple yet robust modelling framework, avoiding complex programming and long computing times.     

An economic–ecological model to evaluate impacts of nutrient abatement in the Baltic Sea

This paper presents a coupled economic–ecological model that integrates a catchment model with a marine model and incorporates economic data to analyse the long-term economic and ecological consequences of nutrient abatement in the Baltic Sea. The spatially explicit model describes dynamics of soil phosphorus in arable land, developments of nutrient concentrations and phytoplankton biomass in the sea basins, and inter-annual variation in nutrient loads and biophysical processes. The performance of the model is demonstrated by computing the least-cost solution to reach the good environmental state of the sea – as implied by the Baltic Sea Action Plan – within a time span of 40 years. The total cost of achieving this target is 1487 M€ annually. Spatially optimal allocation of load reductions differs from the load reduction targets of the Baltic Sea Action Plan, and focuses more on the control of phosphorus loads.     

A data porting tool for coupling models with different discretization needs

The presented work is part of a larger research program dealing with developing tools for coupling biogeochemical models in contaminated landscapes. The specific objective of this article is to provide researchers with a data porting tool to build hexagonal raster using information from a rectangular raster data (e.g. GIS format). This tool involves a computational algorithm and an open source software (written in C). The method of extending the reticulated functions defined on 2D networks is an essential key of this algorithm and can also be used for other purposes than data porting. The algorithm allows one to build the hexagonal raster with a cell size independent from the geometry of the rectangular raster. The extended function is a bi-cubic spline which can exactly reconstruct polynomials up to degree three in each variable. We validate the method by analyzing errors in some theoretical case studies followed by other studies with real terrain elevation data. We also introduce and briefly present an iterative water routing method and use it for validation on a case with concrete terrain data.     

A comprehensive approach to evaluating watershed models for predicting river flow regimes critical to downstream ecosystem services

Selection of strategies that help reduce riverine inputs requires numerical models that accurately quantify hydrologic processes. While numerous models exist, information on how to evaluate and select the most robust models is limited. Toward this end, we developed a comprehensive approach that helps evaluate watershed models in their ability to simulate flow regimes critical to downstream ecosystem services. We demonstrated the method using the Soil and Water Assessment Tool (SWAT), the Hydrological Simulation Program–FORTRAN (HSPF) model, and Distributed Large Basin Runoff Model (DLBRM) applied to the Maumee River Basin (USA). The approach helped in identifying that each model simulated flows within acceptable ranges. However, each was limited in its ability to simulate flows triggered by extreme weather events, owing to algorithms not being optimized for such events and mismatched physiographic watershed conditions. Ultimately, we found HSPF to best predict river flow, whereas SWAT offered the most flexibility for evaluating agricultural management practices.     

有界闭域上的线性赋值循环终止性分析

对有界闭域上的线性赋值循环程序终止性问题进行研究.利用Jordan 标准型技术将原循环程序的终止性问题约减为终止性等价的具有简单结构的循环程序的终止性问题.证明了当线性迭代映射满足一定条件时,该类循环程序不可终止的充分必要条件是：迭代映射在有界闭域上有不动点或周期轨.     

Differential geometry based active fault tolerant control for aircraft

This work shows how to use a differential geometry tool to design a novel nonlinear active fault tolerant flight control system for aircraft. The proposed control scheme consists of two main subsystems: a controller, which is designed for the nominal plant, and a fault detection and diagnosis module, which provides fault estimation. A further feedback loop exploits the fault estimation to accommodate faults affecting the system. The estimate convergence and the stability of the active fault tolerant flight controller are theoretically proved. Finally, high fidelity simulations show the effectiveness of the scheme.     

Lerisk－i*框架自动建模与编辑工具介绍

在需求工程中,基于主体的i*建模框架(主要包括策略依赖模型及策略推理模型)已经成为最常用的早期需求建模与分析的工具之一,而且关于i*建模框架的编辑工具开发也有很多相关的研究工作。然而现有的这些工具往往只提供诸如模型图编辑、存储等基本功能,而笔者需要在需求工程小组的项目中为对需求文本进行建模的结果进行模型可视化,同时提供编辑存储及自动布局功能,并开发出新的基于i*建模框架的工具。文中首先对主流的i*建模工具进行了调研,研究了建模工具的基本功能,同时分析了其功能的不足点,在此基础上提出了新工具设计的功能补充点;然后对i*框架的布局问题进行介绍并详细描述了其自动布局算法的实现,给出了可视化工具的详细设计;最后在此工具的基础上,进行了实际需求文本的建模及模型编辑功能的实验,并将此工具与主流工具的功能进行对比,以展示本工具的功能特点。     

基于改进 GNY 逻辑的 Kerberos *协议安全性分析磁

为了增强通讯网络安全性,研究者致力于通讯协议的形式化分析与验证。 Abdelmajid 在 Kerberos 协议中添加用户物理位置作为新的认证因素得到改进协议,并用改进 BAN 逻辑说明改进协议的安全性。针对添加用户物理位置这一因素进一步完善后的协议 Kerberos *,结合可识别性和管辖性构造一种新的管辖规则,运用改进 GNY 逻辑对协议 Ker-beros *进行安全性分析。分析结果表明,协议 Kerberos *是安全的,运用改进 GNY 逻辑证明过程比改进 BAN 逻辑更详细、更严谨,此方法可运用于其它类似协议形式化分析。