基于多目标分阶段的跑道调度计划算法*

针对多条跑道环境下离港飞机调度问题,提出了一种基于多目标、两阶段算法。算法第一阶段以飞机重量类型为主要分解参数,生成离港飞机序列。该参数在跑道调度计划问题上比其他参数更具影响力和稳定性。算法第二阶段从离港飞机队列池中选取可用序列,将特殊航班指配到目标类型序列中,生成优化的飞行航班时刻表。实验表明,采用两阶段跑道调度计划算法进行多跑道离港飞机调度比采用先来先服务算法调度在跑道总吞吐量上有明显改善,能有效降低机场航班延误,提高跑道运营效率。     

人工鱼群—粒子群混合算法优化进港航班排序

针对空中交通管理中的进港航班排序问题, 提出了人工鱼群—粒子群混合算法(AFPSO)这一航班排序算法来优化进港航班排序, 使时段内进港航班队列总延误时间最少。算法结合了基本人工鱼群算法(AFSA)和基本粒子群算法(PSO)各自的优点, 先以AFSA在全局寻找满意的解域, 再以PSO算法在这些解域中进行快速的局部搜索获得精确解, 最终使算法提高收敛速度和搜索精度。仿真结果表明, 在单跑道和双跑道情况下, AFPSO算法使得航班队列总延误时间比FCFS调度方法减少了20. 9%和34. 4%, 比基本AFSA减少了3. 2%和3. 5%。算法得到的满意解能够为自动化空中交通管理提供实时支持。     

基于多目标两阶段的跑道起飞调度模型

为了减少起飞延误,针对优化飞机起飞调度问题,提出一种基于多目标、两阶段的跑道调度模型。该模型由培植器、穿越发生器、一阶段组件、二阶段组件组成。培植器建立机场模型,根据飞机重量类别输出飞机从推出到跑道的最短时间。穿越发生器通过扫描进场航班,计算需穿越飞机时间。一阶段组件计算以上输出,从各种飞机类别序列中选择最优序列。二阶段组件将具体航班指配到最优序列得出飞机推出时间,生成优化的离场航班时刻表。实验表明,该模型较之传统的先来先服务模型,跑道吞吐量加大,延迟减少,可节约可观运营成本。     

精确求解进港飞机调度双目标优化问题的epsilon约束算法

随着机场客流的持续增长,航班延误日益严重。同时,对于机场最重要的跑道资源而言,积雪结冰等会造成 飞机 打滑,从而出现事故。对于机场管理者,周期性地维护跑道至关重要,以防雨雪天气出现飞机打滑事故。该研究主要针对跑道上的 航班调度问题,考虑恶劣天气环境下跑道的周期性维护(如周期性喷洒除雪盐等)。为了在保证航班的服务质量的同时提高机场跑道的使用效率,文中以最小化航班总延误和跑道使用时间为优化的双目标。首先,提出该双目标优化问题混合整数规划模型;其次,为了精确求解出Pareto前沿,开发出epsilon约束算法;最后,给出算例来说明模型和算法的可行性。通过数学规划理论建模并开发精确求解算法,为机场资源优化研究提供参考。     

终端区航班排序的遗传算法

为提高空域利用率和航班调度效率,建立了以航班延误总时间为目标函数的规划模型,利用遗传算法中的交叉和变异运算,针对多跑道航班排序问题设计了编码方式和遗传算子,进行了仿真计算,并与先到先服务算法进行了对比研究.同时,结合空中交通管制中的实际情况,引入了一些约束条件.以三跑道为例,仿真结果表明:与先到先服务算法相比,设计的遗传算法大大降低了时间延误,明显提高了航班调度效率.     

时间有色佩特里网在航班进离港中应用

为了解决目前和以后越来越严重的空中交通拥挤问题,文中对终端区空中交通流量管理中航班进离港部分连续航班动态飞机排序问题进行研究.提出了基于时间有色佩特里网(TCPN)的航班进离港的调度方法,用MATLAB软件中的M函数编写了算法程序,然后进行了仿真.仿真结果表明,该方法选用的算法是合理的,而且可以明显的减少航班总的延误,优化效率高,算法简单可行,而且更符合实际的要求.该方法在一定程度上可以帮助空管人员进行调度决策,从而更加快速有序地对飞机进离港进行调度,对目前空管优化调度,减少延误等情况的处理具有一定的参考研究价值.     

基于状态空间模型序号编码进化算法的航班优化调度

多跑道航班进离港优化调度是将某一时间窗内进离港航班看作一个整体，对进离港航班进行统一优化排序，属于典型的组合优化问题。求解组合优化问题时，采用序号编码比二进制编码和实数编码等方式更直接、更方便。本文提出一种基于状态空间模型序号编码进化算法（OSEA），通过构造状态进化矩阵等操作来实现变异算子的功能，简化了遗传操作，并研究其在航班进离港优化调度中的应用。仿真实验表明：OSEA算法与先到先服务（FCFS）航班排序相比，航班总延误损失降低32.88％，且运算速度更快。     

双交叉算子遗传算法在终端区飞机排序中的应用

当今，普遍的航班延误现象不仅增加了巨额飞行成本，还影响乘客体验. 对终端区待降飞机队列进行合理调整，可以提高跑道利用率，减少航班延误，达到降低延误代价的效果. 针对终端区飞机排序问题，提出一种包含双交叉算子的遗传算法，针对不同适应度染色体采取不同的交叉操作，使得在交叉过程中既能保护优质染色体，也能使其它染色体继续进化. 同时引入重排算子对变异后的子代进行优化，共同加快遗传算法收敛速度，使其更加符合实际使用需求. 实验结果表明，算法收敛速度得到改进，能在可接受时间内得到可行解.     

航班着陆调度的多目标优化研究

航班着陆调度问题是多目标优化问题,难以使用最优化方法求解。为了解决这一难题,以减少航班延迟时间和降低飞行延误成本为目标,提出一种整合的启发式方法。该方法使用吱呀轮算法SWO(Squeaky-Wheel Optimization)进行导向式搜索,并利用改进的GA充分扩展SWO的搜索空间,最后通过合理整合GA和SWO,取得求解效率和求解质量的提高。通过实验仿真对比表明该算法能高效求解该问题,满足了实时调度的需求,同时求解质量也优于其他启发式算法,节省了更多降落时间和成本。     

求解机场终端区飞机着陆调度问题的遗传算法

空中管制员需为到达的飞机安排跑道并计算着陆时间,以飞机空中延误最小为出发点研究了多跑道的飞机着陆调度问题,约束条件为每架飞机的着陆时间应落在规定的时间窗内及相邻两架飞机应满足最小时间间隔。针对该问题设计了一种遗传算法对问题进行求解,其中染色体由飞机排序链表和跑道链表组成,相应的交叉和变异算子也做了改进设计。仿真实验用数据库OR-Library中的实例验证了该算法的有效性。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。