海洋台站不确定性数据表示方法的研究

针对当前海洋台站数据存在不确定性的现状,在分析Trio和MayBMS两种不确定数据表示方法的基础上,结合海洋台站数据属性不确定的特点,提出一种适合于海洋台站不确定性数据的表示方法。实验结果表明,该方法能够消除现有表示方法可能产生的冗余信息并有效减少生成的关系表的数量,为今后海洋台站不确定性数据高效查询方法的研究奠定了基础。     

汶川一线的CIO

2008年5月12日下午14点28分，一场罕见的大地震将震中汶川瞬间与外界隔绝。就在地震发生的几分钟内，大部分人本能的反应是迅速逃离建筑物，不过此时阿坝州政府副秘书长、办公室主任、州政府外网办主任何彪则是镇定地坐在办公室内，不停地用手机、座机、小灵通与州防震减灾局联系，确定地震级数和震中位置。     

甘孜地震地表破裂带影像信息提取

一、引言四川省甘孜县地处北西向鲜水河断裂带与甘孜——玉树断裂带呈左行雁列的“岩桥”部位,这里有强烈的地震活动。1854年前后,在岩桥区南侧边缘的甘孜——绒坝岔之间,发生过7.5级强烈地震。根据近年来对史料的考证和调查,初步将震中确定在甘孜——绒坝岔之间(图1)。然而,目前对这次地震的研究仍缺少直接的地震构造资料和依据。 1.主干活动断裂(虚线为隐伏段):2.一般断裂:3.第四纪盆地:4.1854年前后甘孜地震震中:5.1854年前后甘孜地震极震区;6.卫片处理子区范围;F_1:鲜水河断裂;F_2:甘孜——玉树主干活动断裂我们用计算机数字图像增强方法,提取与该次地震有关的地震构造影像信息,用以辅助查明发震断裂和确切震中位置;对影像信息的解译结果用实地调查法进行了验证。本文同时也是利用计算机数字图像处     

基于图像识别的震象云地震预测方法

利用卫星热红外异常判别技术进行地震预测的方法都是纯手工或半手工的,在分析处理海量遥感数据时具有局限性,并且传统方法对地震三要素的预测准确率不高,尤其是震中位置的预测。针对上述问题,提出一种综合震象云颜色、纹理以及浮现频率等特征来自动预测地震的方法。利用灰度共生矩阵对热红外数据进行纹理特征提取,使用BP神经网络模型训练目标神经网络,将纹理特征输入目标神经网络进行识别,提取疑似目标,同时滤掉非目标并跟踪,将疑似目标浮现频率超过5次的区域精确定位为目标出现的位置,从而实现智能化和自动化的地震预测。反演实验验证结果表明,该方法是一种震中位置预测较为准确的中短期地震预测方法。     

复杂环境下的军用机场跑道识别算法研究

针对复杂环境下的军用机场遥感图像,提出了一种新的跑道识别算法.该方法提出构造基于边缘模式的图像灰度直方图,自动确定初始图像分割阈值并二值化图像;用Hough变换确定跑道位置与方向,利用军用机场的结构特征确定跑道的水平、垂直起始位置,并进一步标识.实验证明该方法稳健可行.     

NU2RA:一种路网中不确定移动对象范围查询分析方法

目前移动对象的各类查询研究大多假设对象的位置确切可知,但实际上除了更新时刻外,其他时间对象的位置只是一个可能的范围.因而大多数基于确切位置的查询算法并不可行.而现有的涉及不确定性的查询方法大多仅针对自由移动的不确定查询或者不确定目标.针对道路网中查询和目标位置均不确定的情况,提出了一种NU2RA分析方法.根据查询范围对网络进行划分,用分布码表示目标的可能分布,得到不确定目标与不确定查询范围的22类拓扑关系,并且给出了目标在不确定查询范围内的概率计算方法.该方法不依赖于具体的不确定移动对象模型,对不确定历史轨迹和不确定的近期将来运动趋势同样适用.     

BP神经网络在地震震相识别中的应用

在自动地震数据解释中的一个重要问题是用三分量台站记录的数据来进行初始震相识别本文利用ARCESS、NORESS、FINESA、GERESS台阵的三分量台站以及波兰KSP和前苏联GRAM三分量台站记录数据的震相偏振属性设计了一个3层BP神经网络,实现了对震相的识别.由于输入数据的多维度和对台站的依赖特性,该方法在一定程度上解决了传统方法中存在的问题.     

经纬度坐标下矿山微震震源深度的测定方法

针对经纬度坐标下矿山微震震源深度难以确定或误差较大的问题,提出了一种震源深度的测定方法。该方法在只利用微震P波走时的情况下,通过改进微震线性定位法计算微震震源的平面位置和发震时刻,然后通过震源到台站的震中距和微震走时,先进行TD模式拟合,在剔除错误数据后进行DT模式拟合,最后依据拟合直线的截距确定震源深度。实际应用结果表明,该方法能有效降低错误实测数据的干扰,提高震源深度的测定精度。     

飞行器大气数据传感器布局分析设计

在对大气数据系统的功能和大气数据传感器的基本工作原理进行介绍的后,详细的分析了大气数据传感器安装要求.经过理论分析,提出了一种利用计算机仿真CFD软件定位大气数据系统传感器位置的设计方法.并以某型号飞行器为例,从静压的要求入手,详细的阐述了数据的建模,确定飞行器构型,选点,数据对比分析,确定最终位置和角度.本方法对于飞行器设计初期,特别是风洞试验和试飞前大气数据探头的位置确定具有实际意义.     

空间机械臂柔性连杆的弯曲形状

研究单连杆旋转柔性空间机械臂的弯曲形状,以确定空间柔性机械臂末端的位置.在考虑连杆变形对力矩影响和曲率表示式中不忽略形状函数一阶导数平方的情况下,利用Taylor展式表示连杆的变形,导出了连杆变形的数学模型.通过降阶方法导出形状函数一阶导数的解析式,并给出了由此解析式利用数值积分确定形状函数的方法.给出了利用二分法确定变形后的连杆在其固连坐标系中最大横坐标的方法.针对一组参数进行了仿真,证实了这种方法确定空间柔性机械臂末端的位置的可行性.     

A hub location inventory model for bicycle sharing system design: Formulation and solution

This study addresses a strategic design problem for bicycle sharing systems incorporating bicycle stock considerations. The problem is formulated as a hub location inventory model. The key design decisions considered are: the number and locations of bicycle stations in the system, the creation of bicycle lanes between bicycle stations, the selection of paths of users between origins and destinations, and the inventory levels of sharing bicycles to be held at the bicycle stations. The design decisions are made with consideration for both total cost and service levels (measured both by the availability rate for rental requests at the pick-up rental stations and coverage of the origins and destinations). The optimal design of this system requires an integrated view of the travel costs of users, bicycle inventory costs and facility costs of bicycle stations and bicycle lanes as well as service levels. The purpose of this study is to create a formal model that provides such an integrated view, and to develop methods for obtaining solutions for the design variables in practical situations. The complexity of the problem precludes the exact solution of the optimization problem for instances of realistic size, and so we propose a heuristic method for efficiently finding near-optimal solutions. In the test problem for which enumeration is possible, the heuristic solution is within 2% optimal. Finally, a numerical example is created to illustrate the model and proposed solution algorithm.     

Optimization of natural gas pipeline transportation using ant colony optimization

In this paper, an ant colony optimization (ACO) algorithm is proposed for operations of steady flow gas pipeline. The system is composed of compressing stations linked by pipelegs. The decisions variables are chosen to be the operating turbocompressor number and the discharge pressure for each compressing station. The objective function is the power consumed in the system by these stations. Until now, essentially gradient-based procedures and dynamic programming have been applied for solving this no convex problem. The main original contribution proposed, in this paper, is that we use an ACO algorithm for this problem. This method was applied to real life situation. The results are compared with those obtained by employing dynamic programming method. We obtain that the ACO is an interesting way for the gas pipeline operation optimization.     

A heuristic algorithm for optimal location of flow‐refueling capacitated stations

Constructing refueling stations in the transportation network is one of the most important steps toward the promotion of alternative‐fuel vehicles. The capacity of these stations is usually limited. In this paper, a new capacitated refueling station location model and a solution algorithm are proposed. The algorithm is divided into two main steps. At first step, a restricted capacitated problem on core sets is constructed. Then, a modified Lagrangean iterative method is used for obtaining solutions. The Lagrangean method decomposes the restricted problem into two subproblems that are easy to solve. Information from subproblems is used to generate valid inequalities for tightening the upper and lower bounds. The approach is evaluated by considering a set of networks and randomly generated instances. The obtained results indicate that the large problems are efficiently tractable by the proposed algorithm in a reasonable time.     

The optimal location of inspection stations using a rule-based methodology

The location of inspection stations is a significant component of production systems. In this paper, a prototype expert system is designed for deciding the optimal location of inspection stations. The production system is defined as a single channel of n serial operation stations. The potential inspection station can be located after any of the operation stations. Non-conforming units are generated from a compound binomial distribution with known parameters at any given operation station.

Traditionally Dynamic programming, Zero-one integer programming or Non-linear programming techniques are used to solve this problem. However a problem using these techniques is that the computation time becomes prohibitively large when the number of potential inspection stations are fifteen or more. An expert system has the potential to solve this problem using a rule-based system to determine the near optimal location of inspection stations.

The prototype expert system is divided into a static database, dynamic database and knowledge base. Based on defined production systems, the sophisticated rules are generated by the simulator as part of a knowledge base. A generate-and-test inference mechanism is utilized to search the solution space by applying appropriate symbolic and quantitative rules. The goal of the system is to determine the location of inspection stations while minimizing total cost.     

Extensions of the dynamic programming method in the deterministic and stochastic assembly-line balancing problems

The dynamic programming method which minimizes the number of stations for a given cycle time is extended here to solve two variants of the assembly-line balancing problem. The extended method minimizes cycle time for a given number of stations or, more generally, computes all nondominated pairs of cycle time and number of stations. The method is also applied to the stochastic case where minimizing critical cycle time, the number of stations and maximizing confidence level is desired.     

基于TND的无线基站自动定位及最佳配置

综合考虑无线组网的覆盖范围和规划的技术要求,首次将计算几何中的几何拓扑网络设计(TND)的最大间隙问题分析方法(MAXG)成功地应用于通信网络的基站规划问题,利用Voronoi图的影响范围特性、最大空心圆特性和局部动态特性,解决了无线通信网络中的无线基站自动定位及最优配置(增加或调整无线基站站点数),提高了无线网络的通信效能.实践证明,和传统的数学规划方法,组合优化方法相比较已显示出明显的优势,具有一定的有效性和合理性.     

成像卫星星地联合成像调度

成像卫星星地联合调度问题,涉及调度对象众多,约束条件复杂,需要考虑任务的观测、回传2个过程,是一个具有两层时间窗口约束的双层优化问题,统一建模困难。根据问题的特点,采用基于阶段优化的方式,降低了问题的复杂性。把问题分为观测调度阶段和数据回传调度阶段,分别给出了优化目标和约束条件,建立了基于阶段优化的成像卫星星地联合调度模型,实现了从任务观测到数据回传的全过程调度。仿真实例表明,该方法能够有效解决多星多站的协同任务调度问题。     

A multi-objective genetic algorithm for mixed-model assembly line rebalancing

When demand structure or production technology changes, a mixed-model assembly line (MAL) may have to be reconfigured to improve its efficiency in the new production environment. In this paper, we address the rebalancing problem for a MAL with seasonal demands. The rebalancing problem concerns how to reassign assembly tasks and operators to candidate stations under the constraint of a given cycle time. The objectives are to minimize the number of stations, workload variation at each station for different models, and rebalancing cost. A multi-objective genetic algorithm (moGA) is proposed to solve this problem. The genetic algorithm (GA) uses a partial representation technique, where only a part of the decision information about a candidate solution is expressed in the chromosome and the rest is computed optimally. A non-dominated ranking method is used to evaluate the fitness of each chromosome. A local search procedure is developed to enhance the search ability of moGA. The performance of moGA is tested on 23 reprehensive problems and the obtained results are compared with those by other authors.     

基于遗传算法的焊接生产线工位平衡规划方法

在现代化大规模大批量的流水装配制造业中,数量众多的作用分配和多工位的合理安排使工位平衡问题显得更为突出。针对第一类工位平衡问题,即在给定的生产节拍下最小化工位数,首先分析了该问题并建立了数学模型,进而提出了一种基于改进遗传算法求解工位平衡问题的方法。该算法以焊接任务的操作顺序优先关系为约束前提,在初始种群的生产以及交叉和变异过程中保证了染色体解的可行性,同时在遗传算法的选择过程中考虑了具有相同工位数的最优作业方案的工时标准差,从而提高了算法的搜索效率和解的可靠性。最后通过实例求解验证了该算法的有效性。     

基于IEC 61850的能源站智能电气监控管理方法

针对传统电气监控管理系统信息管理能力差的问题,提出了新型的能源站智能电气监控管理方法。该方法建立在DL/T 860（IEC 61850）标准规范的基础上,采用微机应用交流采样算法对能源站电气设备运行数据进行处理,并将该算法进行系统集成优化设计,构建出全智能自动化的电气监控管理系统。本研究系统加强了各监控设备的联系,系统误差数据低。实验表明,本研究系统的监测数据误差低于10%,解决了传统电气监控误差较大的问题。