基于GA和机器学习的启发式规则调度方法

采用基于遗传算法的启发式规则的新型调度方法来处理可变工艺路径的调度问题,同时建立起启发式调度规则库和用于选择规则的知识库,并利用机器学习和模糊推理机制进行样本与知识库的匹配,实现高效实用的调度。计算实例表明了该算法的优越性能。     

多星联合动态调度问题的启发式算法研究

对地观测多星联合动态调度问题是一类复杂的调度问题。在对多星联合动态调度问题的动态来源进行深入分析的基础上,对该问题进行了统一描述。针对问题的特点,提出了一种基于规则的启发式求解算法,设计了最大竞争度的退出启发式规则和最小冲突度的插入启发式规则。最后给出了一个应用实例,对算法进行了验证。     

基于启发式规则和蚁群算法的车间作业调度方法

车间作业调度问题是一个典型的NP-hard问题,也是一个前沿性的研究课题,已受到学术界和工业界的广泛关注。提出了一种基于启发式规则和蚁群算法的车间作业调度方法。该方法首先采用蚁群算法得到车间作业调度问题的一组可行解,然后采用一些启发式规则进一步优化这些可行解。通过将启发式规则有效地融入到蚁群算法中,使得该混合方法的优化效率得到极大的改进。仿真实例表明,方法是可行的、正确的和有效的。     

电脑客户服务中心知识库系统研究

设计了一种电脑故障维修知识库系统，用产生式规则表示知识，用关系数据库构建知识库及知识库管理系统，采用启发式搜索策略和正向推理机制，使客服人员与客户可以快速地检索到所需要的资料，为电脑故障排除提供指导，从而提高客户服务工作效率和客户满意度。     

启发式规则与GA结合的优化方法求解工作流动态调度优化问题

调度是工作流管理系统的核心问题，是保证工作流正确运行的关键。在工作流环境下，动态调度要比静态调度更切合实际。本文在总结前人工作的基础上，提出了一系列工作流动态调度的启发式规则，并以最小化任务总拖期时间和最大化任务总提前时间为目标，建立了工作流动态调度问题模型。采用启发式规则与遗传算法相结合的优化方法求解工作流动态调度优化问题。仿真结果说明了优化方法的可行性和有效性，同时比较了该方法与多种静态调度方法，进而说明了该方法的优越性。     

一种基于Rough集获取规则知识的增量式学习方法

将Rough集理论应用于规则归纳系统,提出了一种基于粗糙集获取规则知识库的增量式学习方法,能够有效处理决策表中不一致情形,采用启发式算法获取决策表的最简规则,当新对象加入时在原有规则集基础上进行规则知识库的增量式更新,避免了为更新规则而重新运行规获取算法。并用UCI中多个数据集从规则集的规则数目、数据浓缩率、预测能力等指标对该算法进行了测试。实验表明了该算法的有效性。     

基于混合蛙跳和遗传规划的跨单元调度方法

针对运输能力受限条件下的跨单元问题,提出了一种基于混合蛙跳与遗传规划的超启发式算法.将改进的混合蛙跳算法作为超启发式算法的高层框架,为跨单元调度问题搜索启发式规则,同时利用遗传规划产生可以兼顾多因素的优质规则,用于扩充超启发式算法的规则集.实验表明,提出的算法可以有效地搜索出优异的规则组合,并且通过遗传规划产生的规则可以在很大程度上改善候选规则集,提升算法性能.     

效率异质型员工项目调度算法研究

研究了员工具有异质效率、最小化项目工期的项目调度问题,并建立了相应的整数线性规划模型。为解决此NP-hard问题,提出了基于优先规则的启发式算法,其在每次迭代中根据优先约束和优先规则选择优先任务员工对以分配任务,直至所有任务都完成调度。通过应用启发式算法生成初始调度,选用交换邻域结构和插入邻域结构产生邻域调度,并使用改进的前向递归算法求解目标函数值,构造出混合模拟退火算法。数值实验显示该算法能快速准确地进行寻优。     

不相容决策系统的知识库构造研究

粗糙集理论为知识库构造提供了一种形式化的理论模型,但是针对不相容决策系统构造知识库仍然是值得深入研究的问题。基于决策系统分布约简定义规则的分布核与分布约简概念,提出一种基于分布约简构造知识库的方法。首先确定各条件类的分布核,进而采用启发式算法计算其分布约简,挖掘约简规则集,构造出决策系统的知识库。并对加入决策系统中新对象的各种情形进行分析,对原有知识库进行增量式更新,而无需为更新知识库重新运行知识库构造算法。该方法能适应不相容决策系统,同样也适用于相容决策系统。     

基于遗传算法的作业车间调度优化

将遗传算法和启发式调度规则相结合，研究了具有柔性加工路径的作业车间的智能优 化调度问题，调度规则的引入使该算法具有较高的搜索效率，遗传算法的引入保证了解的全 局最优性，对照算例，表明该算法在求解性能和效率两方面均具有显著的优势．     

基于XML的客户服务中心通用知识库系统研究

设计了一个客户服务中心通用知识库系统,采用分层和模块化的设计思想,基于XML技术表示并构建知识库系统,用产生式表示法表示知识,基于启发式搜索策略和正向推理机制,对规则库和事实库进行了有效设计,降低了系统复杂度,提升了知识的易管理性和易用性.系统具有通用性和良好的动态演化性,从根本上实现了知识的共享,提高了客户服务中心的工作效率和客户满意度,对客户服务中心知识管理建设具有较好的借鉴意义.     

面向语义信息查询的模糊本体模型

针对领域知识建模时的模糊性、不确定性与信息查询时的局限性,提出一种基于模糊控制规则的模糊本体模型。利用基于模糊聚类的本体机器学习方法构建模糊控制规则库,通过计算模糊相似矩阵得到模糊概念的语义关联,对词汇相关概念进行语义分析与扩展获取模糊概念间的本质语义关系,实现基于模糊概念属性值的信息查询与语义共用。实验结果表明,该模型在语义查询上有更完善的推理机制,能有效获取语义信息。     

Application of genetic algorithm for fuzzy rules optimization on semi expert judgment automation using Pittsburg approach

Genetic algorithm is well-known of its best heuristic search method. Fuzzy logic unveils the advantage of interpretability. Genetic fuzzy system exploits potential of optimization with ease of understanding that facilitates rules optimization. This paper presents the optimization of fourteen fuzzy rules for semi expert judgment automation of early activity based duration estimation in software project management. The goal of the optimization is to reduce linguistic terms complexity and improve estimation accuracy of the fuzzy rule set while at the same time maintaining a similar degree of interpretability. The optimized numbers of linguistic terms in fuzzy rules by 27.76% using simplistic binary encoding mechanism managed to improve accuracy by 14.29% and reduce optimization execution time by 6.95% without compromising on interpretability in addition to promote improvement of knowledge base in fuzzy rule based systems.     

A linguistic approach to non-identical parallel processor scheduling with fuzzy processing times

This study presents an application of non-identical parallel processor scheduling under uncertain operation times. We have been motivated from a real case scheduling problem that contains some uncommon welding operations to be processed by workers in an automotive subcontract company. Here each operator may weld each job but in different processing times depending on learning effect because of operator’s ability and experience, and batch sizes. To determine the crisp operation times in such a fuzzy environment, a linguistic reasoning approach (with a 75-“If- Then” rules) considering the learning effect is proposed in the study. Since the fuzzy linguistic approach allows the representation of expert information more directly and adequately, it can be more possible to make realistic schedules under uncertainty. With the objective to balance the workload among all operators, the longest processing time heuristic algorithm is been used and measured average makespan. For evaluating the effectiveness of this approach, it is compared with the scheduling method that use the random operation times generated from a uniform distribution. Results showed that the proposed fuzzy linguistic scheduling approach has balanced the workload of operators with a standard deviation of 0.37 and improved the Cmax value as 16%. A general conclusion can be drawn the proposed approach is able to generate realistic schedules and especially useful to solve non-identical parallel processor scheduling problem under uncertainty. An important contribution of this study is that Mamdani inference method with learning effect is the first time used to obtain the crisp processing times of non-identical processors by the help of a rule base with expert knowledge.     

Fuzzy rule generation for adaptive scheduling in a dynamic manufacturing environment

This paper proposes a fuzzy rule-based system for an adaptive scheduling, which dynamically selects and applies the most suitable strategy according to the current state of the scheduling environment. The adaptive scheduling problem is generally considered as a classification task since the performance of the adaptive scheduling system depends on the effectiveness of the mapping knowledge between system states and the best rules for the states. A rule base for this mapping is built and evolved by the proposed fuzzy dynamic learning classifier based on the training data cumulated by a simulation method. Distributed fuzzy sets approach, which uses multiple fuzzy numbers simultaneously, is adopted to recognize the system states. The developed fuzzy rules may readily be interpreted, adopted and, when necessary, modified by human experts. An application of the proposed method to a job-dispatching problem in a hypothetical flexible manufacturing system (FMS) shows that the method can develop more effective and robust rules than the traditional job-dispatching rules and a neural network approach.     

An improved artificial bee colony algorithm for flexible job-shop scheduling problem with fuzzy processing time

This study addresses flexible job-shop scheduling problem (FJSP) with fuzzy processing time. An improved artificial bee colony (IABC) algorithm is proposed for FJSP cases defined in existing literature and realistic instances in remanufacturing where the uncertainty of the processing time is modeled as fuzzy processing time. The objectives are to minimize the maximum fuzzy completion time and the maximum fuzzy machine workload, respectively. The goal is to make the scheduling algorithm as part of expert and intelligent scheduling system for remanufacturing decision support. A simple and effective heuristic rule is developed to initialize population. Extensive computational experiments are carried out using five benchmark cases and eight realistic instances in remanufacturing. The proposed heuristic rule is evaluated using five benchmark cases for minimizing the maximum fuzzy completion time and the maximum fuzzy machine workload objectives, respectively. IABC algorithm is compared to six meta-heuristics for maximum fuzzy completion time criterion. For maximum fuzzy machine workload, IABC algorithm is compared to six heuristics. The results and comparisons show that IABC algorithm can solve FJSP with fuzzy processing time effectively, both benchmark cases and real-life remanufacturing instances. For practical remanufacturing problem, the schedules by IABC algorithm can satisfy the requirement in real-life shop floor. The IABC algorithm can be as part of expert and intelligent scheduling system to supply decision support for remanufacturing scheduling and management.     

COMPRESSION AND EXPANSION OF FUZZY RULE BASES BY USING CRISP-FUZZY NEURAL NETWORKS

A fuzzy neural network with knowledge discovery FNNKD is designed to perform adaptive compensatory fuzzy reasoning based on more useful and more heuristic primary fuzzy sets. In order to overcome the weakness of the conventional crisp neural network and the fuzzy operation oriented neural network, we have developed a general fuzzy reasoning oriented fuzzy neural network called a crisp-fuzzy neural network CFNN that is capable of extracting high-level knowledge such as fuzzy IF-THEN rules from either crisp data or fuzzy data. A CFNN can effectively compress a 5 5 fuzzy IF-THEN rule base of a cart-pole balancing system to a 3 3 one, then to a 2 2 one, and finally to a 1 1 one, and can expand on invalid sparse 3 3 fuzzy IF-THEN rule base of a cart-pole balancing system to a valid 5 5 one. In addition, a CFNN can control a more complex cart-pole balancing system with random fuzzy noise inputs and outputs i.e., nonconventional using crisp inputs and outputs without any noise . The simulations have indicated that a CFNN is an efficient neurofuzzy system with abilities to discover new fuzzy knowledge from either numerical data or fuzzy data, compress and expand fuzzy knowledge, and do fuzzy reasoning.     

一种面向对象的模糊知识库模型

本文给出了一种专家系统模糊知识库的结构模型。重点讨论了该模型的体系结构和采用面向对象技术表示模糊规则的方法。并介绍了采用面向对象方法分析和设计模糊知识库的技术和采用面向对象串行化技术实现模糊知识库持久保存的方法。最后,分析了采用面向对象技术构建模糊知识库的优点。     

Heuristic constraints enforcement for training of and knowledgeextraction from a fuzzy/neural architecture. I. Foundation

Using fuzzy/neural architectures to extract heuristic information from systems has received increasing attention. A number of fuzzy/neural architectures and knowledge extraction methods have been proposed. Knowledge extraction from systems where the existing knowledge limited is a difficult task. One of the reasons is that there is no ideal rulebase, which can be used to validate the extracted rules. In most of the cases, using output error measures to validate extracted rules is not sufficient as extracted knowledge may not make heuristic sense, even if the output error may meet the specified criteria. The paper proposes a novel method for enforcing heuristic constraints on membership functions for rule extraction from a fuzzy/neural architecture. The proposed method not only ensures that the final membership functions conform to a priori heuristic knowledge, but also reduces the domain of search of the training and improves convergence speed. Although the method is described on a specific fuzzy/neural architecture, it is applicable to other realizations, including adaptive or static fuzzy inference systems. The foundations of the proposed method are given in Part I. The techniques for implementation and integration into the training are given in Part II, together with applications     

Expert guided integration of induced knowledge into a fuzzy knowledge base

This paper proposes a method for building accurate and interpretable systems by integrating expert and induced knowledge into a single knowledge base. To favor the cooperation between expert knowledge and data, the induction process is run under severe constraints to ensure the fully control of the expert. The procedure is made up of two hierarchical steps. Firstly, a common fuzzy input space is designed according to both the data and expert knowledge. The compatibility of the two types of partitions, expert and induced, is checked according to three criteria : range, granularity and semantic interpretation. Secondly, expert rules and induced rules are generated according to the previous common fuzzy input space. Then, induced and expert rules have to be merged into a new rule base. Thanks to the common universe resulting from the first step, rule comparison can be made at the linguistic level only. The possible conflict situations are managed and the most important rule base features, consistency, redundancy and completeness, are studied. The first step is thoroughly described in this paper, while the second is only introduced.