Improving efficiency of merging symbolic rules into integrated rules: splitting methods and mergability criteria

Neurules are a type of neuro‐symbolic rules integrating neurocomputing and production rules. Each neurule is represented as an adaline unit. Neurules exhibit characteristics such as modularity, naturalness and ability to perform interactive and integrated inferences and provide explanations for reached conclusions. One way of producing a neurule base is through conversion of an existing symbolic rule base yielding an equivalent but more compact rule base. The conversion process merges symbolic rules having the same conclusion into one or more neurules. Because of the inability of the adaline unit to handle inseparability, more than one neurule for each conclusion may be produced by splitting the initial set of symbolic rules into subsets. This paper presents research work improving the conversion process in terms of runtime and number of produced neurules. First, we show how easier it is to construct a neurule base than a connectionist one. Second, we present alternative rule set splitting methods. Finally, we define criteria concerning the ability or inability to convert a rule set into a single, equivalent, but more compact rule. With application of such mergability criteria, the conversion process of symbolic rules into neurules becomes more time‐efficient. All the aforementioned are supported by experimental results.     

Multivalued type dissimilarity measure and concept of mutual dissimilarity value for clustering symbolic patterns

A successful attempt in exploring a dissimilarity measure which captures the reality is made in this paper. The proposed measure unlike other measures (Pattern Recognition 24(6) (1991) 567; Pattern Recognition Lett. 16 (1995) 647; Pattern Recognition 28(8) (1995) 1277; IEEE Trans. Syst. Man Cybern. 24(4) (1994)) is multivalued and non-symmetric. The concept of mutual dissimilarity value is introduced to make the existing conventional clustering algorithms work on the proposed unconventional dissimilarity measure.     

Transforming linear functional systems into fully integrable systems

A linear (partial) functional system consists of linear partial differential, difference equations or any mixture thereof. We present an algorithm that determines whether linear functional systems are ∂$\partial$-finite, and transforms ∂$\partial$-finite systems to fully integrable ones. The algorithm avoids using Gröbner bases in Laurent–Ore modules when ∂$\partial$-finite systems correspond to finite-dimensional Ore modules.     

Analysis of Productivity of a Technological Cell Taking into Account Its Reliability

A semi-Markovian model with a discrete-continuous phase space of states is constructed for a technological cell. The productivity of the technological cell operating with failures of different types is determined.     

Nondeterministic dependencies in relations: An extention of the concept of functional dependency

In the present article, some special semantic integrity constraints—so called nondeterministic dependencies—are proposed. These dependencies can be regarded as stochastic extensions of functional dependencies. After some basic definitions, the concept of nondeterministic dependency is introduced. Examples are given and an implementation for a statistical analysis system is described. Some properties are discussed.     

相幅组合的函数型数据特征提取方法研究

当前函数型数据分析更多关注于函数的振幅变化而忽略相位变化,很多场合下,相位变化中含有对统计分析有用的信息.基于偏最小二乘法提出了相幅组合的函数型数据特征提取方法,首先使用函数对齐技术获得刻画相位变化的时间弯曲函数,再将对齐函数和弯曲函数通过分段函数的方式重新组合,最后利用偏最小二乘法提取相幅组合函数的成分特征,并应用在回归和分类模型上.实验结果表明,与主成分分析方法相比,所提方法具有更优越的预测性能.     

一种基于时间自动机的实时系统测试方法

基于时间自动机(timed automata,简称TA)的一种变体--时间安全输入/输出自动机(timed safety input/output automata,简称TSIOA),提出了一种实时系统测试方法.该方法首先将时间安全输入/输出自动机描述的系统模型转换为不含抽象时间延迟迁移的稳定符号状态迁移图(untimed stable transition graph of symbolic state,简称USTGSS);然后采用基于标号迁移系统(labeled transition system,简称LTS)的测试方法来静态生成满足各种结构覆盖标准的包含时间延迟变量迁移动作序列;最后,给出了一个根据迁移动作序列构造和执行测试用例的过程,该过程引入了时间延迟变量目标函数,并采用线性约束求解方法动态求解迁移动作序列中的时间延迟变量.     

Mediation of user models for enhanced personalization in recommender systems

Provision of personalized recommendations to users requires accurate modeling of their interests and needs. This work proposes a general framework and specific methodologies for enhancing the accuracy of user modeling in recommender systems by importing and integrating data collected by other recommender systems. Such a process is defined as user models mediation. The work discusses the details of such a generic user modeling mediation framework. It provides a generic user modeling data representation model, demonstrates its compatibility with existing recommendation techniques, and discusses the general steps of the mediation. Specifically, four major types of mediation are presented: cross-user, cross-item, cross-context, and cross-representation. Finally, the work reports the application of the mediation framework and illustrates it with practical mediation scenarios. Evaluations of these scenarios demonstrate the potential benefits of user modeling data mediation, as in certain conditions it allows improving the quality of the recommendations provided to the users.

Behaviour Analysis of Distributed Systems Using the Tracta Approach

Behaviour analysis should form an integral part of the software development process. This is particularly important in the design of concurrent and distributed systems, where complex interactions can cause unexpected and undesired system behaviour. We advocate the use of a compositional approach to analysis. The software architecture of a distributed program is represented by a hierarchical composition of subsystems, with interacting processes at the leaves of the hierarchy. Compositional reachability analysis (CRA) exploits the compositional hierarchy for incrementally constructing the overall behaviour of the system from that of its subsystems. In the Tracta CRA approach, both processes and properties reflecting system specifications are modelled as state machines. Property state machines are composed into the system and violations are detected on the global reachability graph obtained. The property checking mechanism has been specifically designed to deal with compositional techniques. Tracta is supported by an automated tool compatible with our environment for the development of distributed applications.     

Stability of impulsive stochastic functional differential systems in terms of two measures via comparison approach

Comparison principles for general impulsive stochastic functional differential systems are established.Employing the comparison principles and the theory of differential inequalities,stability and instability,involving two measures,of impulsive stochastic functional differential systems are investigated.Several stability and instability criteria are obtained,and two examples are also given to illustrate our results.     

Multivariate point process models for response times in multiprogrammed systems

We consider the formulation of marked multivariate point process models for job response times in multiprogrammed computer systems. Complementing queueing network representation of the structure of the system to be modeled, the particularR-process (Response time process) model we propose permits representation of resource contention, facilitates the incorporation of realistic workload characteristics into system performance predictions, and can reproduce inhomogeneities observed in running systems. Specification of the structure of theR-process model is conditional on workload marks; this effectively separates the difficult problem of formal representation of workload characteristics from the overall problem of response time prediction. To illustrate these ideas, an application to database management systems is considered. Evidence of the predictive capability of theR-process model, based on statistical analysis of response time data from an IMS system, is also given.     

Mapping plant functional types from MODIS data using multisource evidential reasoning

Reliable information about the geographic distribution and abundance of major plant functional types (PFTs) around the world is increasingly needed for global change research. Using remote sensing techniques to map PFTs is a relatively recent field of research. This paper presents a method to map PFTs from the Moderate Resolution Imaging Spectroradiometer (MODIS) data using a multisource evidential reasoning (ER) algorithm. The method first utilizes a suite of improved and standard MODIS products to generate evidence measures for each PFT class. The multiple lines of evidence computed from input data are then combined using Dempster's Rule of combination. Finally, a decision rule based on maximum support is used to make classification decisions. The proposed method was tested over the states of Illinois, Indiana, Iowa, and North Dakota, USA where crops dominate. The Cropland Data Layer (CDL) data provided by the United States Department of Agriculture were employed to validate our new PFT maps and the current MODIS PFT product. Our preliminary results suggest that multisource data fusion is a promising approach to improve the mapping of PFTs. For several major PFT classes such as crop, trees, and grass and shrub, the PFT maps generated with the ER method provide greater spatial details compared to the MODIS PFT. The overall accuracies increased for all the four states, with the biggest improvement occurring in Iowa from 51% (MODIS) to 64% (ER). The overall kappa statistic also increased for all the four states, with the biggest improvement occurring in Iowa from 0.03 (MODIS) to 0.38 (ER). The paper concludes with a discussion of several methodological issues pertaining to the further improvement of the ER approach.     

Coupling of quantum angular momenta: an insight into analogic/discrete and local/global models of computation

In the past few years there has been a tumultuous activity aimed at introducing novel conceptual schemes for quantum computing. The approach proposed in (Marzuoli and Rasetti, 2002, 2005a) relies on the (re)coupling theory of SU(2) angular momenta and can be viewed as a generalization to arbitrary values of the spin variables of the usual quantum-circuit model based on ‘qubits’ and Boolean gates. Computational states belong to finite-dimensional Hilbert spaces labelled by both discrete and continuous parameters, and unitary gates may depend on quantum numbers ranging over finite sets of values as well as continuous (angular) variables. Such a framework is an ideal playground to discuss discrete (digital) and analogic computational processes, together with their relationships occurring when a consistent semiclassical limit takes place on discrete quantum gates. When working with purely discrete unitary gates, the simulator is naturally modelled as families of quantum finite states-machines which in turn represent discrete versions of topological quantum computation models. We argue that our model embodies a sort of unifying paradigm for computing inspired by Nature and, even more ambitiously, a universal setting in which suitably encoded quantum symbolic manipulations of combinatorial, topological and algebraic problems might find their ‘natural’ computational reference model.     

Reliable approximation of separatrix manifolds in competition models with safety niches

In dynamical systems saddle points partition the domain into basins of attractions of the remaining locally stable equilibria. This situation is rather common especially in population dynamics models, like prey–predator or competition systems. Focusing on squirrels population models with niche, in this paper we design algorithms for the detection and the refinement of points lying on the separatrix manifold partitioning the phase space. We consider both the two populations and the three populations cases. To reconstruct the separatrix curve and surface, we apply the Partition of Unity method, which makes use of Wendland's functions as local approximants.     

A step toward STEP-compatible engineering data management: the data models of product structure and engineering changes

In an iterative design process, there is a large amount of engineering data to be processed. Well-managed engineering data can ensure the competitiveness of companies in the competitive market. It has been recognized that a product data model is the basis for establishing engineering database. To fully support the complete product data representation in its life cycle, an international product data representation and exchange standard, STEP, is applied to model the representation of a product. In this paper, the architecture of an engineering data management (EDM) system is described, which consists of an integrated product database. There are six STEP-compatible data models constructed to demonstrate the integratibility of EDM system using common data modeling format. These data models are product definition, product structure, shape representation, engineering change, approval, and production scheduling. These data models are defined according to the integrated resources of STEP/ISO 10303 (Parts 41-44), which support a complete product information representation and a standard data format. Thus, application systems, such as CAD/CAM and MRP systems, can interact with the EDM system by accessing the database based on the STEP data exchange standard.     

Intelligent support for systems development: The notion and the issues

Enterprise modelling and information systems modelling have traditionally utilized techniques developed in the earlier disciplines of systems analysis and operational analysis. However, these tools have proved insufficient even for information systems modelling and their inadequacies make them less than ideal for enterprise modelling. Furthermore, it has proved difficult to integrate the techniques into a uniform framework representation. Extensive research since the early 1980s has produced support tools for information systems engineering in the academic sector which have generally failed to reach widespread commercial use. Commercially developed integrated support systems aimed at enterprise modelling and information system modelling use traditional techniques, with a lack of formalism. The purpose of this paper is to introduce a technique which overcomes the major inadequacies and which provides an integrating framework to represent both the information and the processing, at enterprise and systems modelling levels of abstraction. The technique is based on the use of a transition network, but extended to represent enterprise and system models in a meaningful way. The use of an intelligent repository, with associated processing of the formally defined requirements, specification and design statements, is novel, and provides the additional support to make the technique amenable to handling the design process from informal to formal specification. The use of a graphical user interface, linked directly to the deductive system and repository, ensures intuitive ease of use.     

Validating a size measure for effort estimation in model-driven Web development

Web development is moving towards model-driven processes whose goal is the development of Web applications at a higher level of abstraction based on models and model transformations. This brings new opportunities to the Web project manager to make early estimates of the size and the effort required to produce Web applications based on their conceptual models. In the last few years, several studies for size and effort estimation have been performed. However, there are no studies regarding effort estimation in model-driven Web development. In this paper, we present the validation of a model-based size measure (OO-HFP) for Web effort estimation in the context of a model-driven Web development method. The validation is performed by comparing the prediction accuracy that OO-HFP provides with the accuracy provided by the standard function point analysis (FPA) method. The results of the study (using industrial data gathered from 31 Web projects) show that the effort estimates obtained for projects that are sized using OO-HFP are more accurate than the effort estimates obtained using the standard FPA method. This suggests that by following a model-driven development approach, the size measure obtained at the conceptual model of a Web application can be considered a suitable predictor of effort.