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1.
Ramification and causality in a modal action logic   总被引:4,自引:0,他引:4  
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Abstract

The SNePS inference engine is optimized for deductive efficiency, i.e. all beliefs acquired via inference are added to the agent's beliefs so that future queries may be answered by a retrieval rather than rederivation. An assumption-based truth maintenance system keeps track of the derivation histories of derived beliefs. We show how such an architecture simplifies the ontology of prepositional representations of plans; acts; preconditions, and effects of actions. In addition, the deductive efficiency of the basic system automatically extends itself to efficient search of plans, and hierarchical plan decompositions.  相似文献   

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This paper presents some of the results obtained in the VRIMOR project (virtual reality for inspection, maintenance, operation and repair of nuclear power plants). The general aim was to integrate environmental scanning technologies with human modelling and radiological dose estimation tools, and to deliver an intuitive and cost-effective system for use by operators involved with interventions in radiologically controlled areas. The usability of the resulting products was one of the main success criteria. This paper describes the general approach and design mechanisms used in the HeSPI (HeSPI stands for the Spanish for Herramienta para la Simulación y Planificación de Intervenciones, or tool for the simulation and planning of interventions) tool that has been developed by one of the teams. The tool provides the designer of an intervention with a humanoid 3D model, or mannequin, that can be loaded into the desired environment and will be used by the designer as if he was manipulating a puppet, making it move around the environment and perform different kinds of actions, adopting varied postures, interacting with the objects in the environment and manipulating tools and equipment. A combination of a graphical user interface (GUI) and a voice recognition system, together with the selected design mechanisms, has proven to offer good enough interaction possibilities for this kind of desktop virtual environment.  相似文献   

6.
Integrating Discrete and Continuous Change in a Logical Framework   总被引:1,自引:0,他引:1  
The goal of our work is to develop theoretical foundations for the representation of knowledge in domains in which properties may vary continuously. One achievement of our research is that it extends the applicability of current research on theories of action. Furthermore, we are able to apply known approaches to the frame and ramification problems, developed for discretely changing worlds, to domains in which the world changes continuously.
Our approach is based on the discrete situation calculus and on a monotonic solution to the frame problem. In order to address the combined frame and ramification problems, we extend Lin and Reiter's work. We use Pinto and Reiter's extension to the situation calculus to represent occurrences . We extend this work further to allow for reasoning by default. For example, if we know that a ball is falling and we do not have any reason to believe that an action would interfere with the ball's motion, then we assume that the ball will hit the ground. Finally, we extend the language of the situation calculus to allow for properties that change within situations. We also show that our proposed situation calculus inherits the solutions to the frame and ramification problems.  相似文献   

7.
We present a simple and effective technique for absolute colorimetric camera characterization, invariant to changes in exposure/aperture and scene irradiance, suitable in a wide range of applications including image‐based reflectance measurements, spectral pre‐filtering and spectral upsampling for rendering, to improve colour accuracy in high dynamic range imaging. Our method requires a limited number of acquisitions, an off‐the‐shelf target and a commonly available projector, used as a controllable light source, other than the reflected radiance to be known. The characterized camera can be effectively used as a 2D tele‐colorimeter, providing the user with an accurate estimate of the distribution of luminance and chromaticity in a scene, without requiring explicit knowledge of the incident lighting power spectra. We validate the approach by comparing our estimated absolute tristimulus values (XYZ data in ) with the measurements of a professional 2D tele‐colorimeter, for a set of scenes with complex geometry, spatially varying reflectance and light sources with very different spectral power distribution.  相似文献   

8.
对工作流的异常和案例推理(Case—Based Reasoning,简称CBR)的机制进行了介绍,给出了一个应用CBR技术进行异常处理的工作流模型.并研究了应用CBR方法处理工作流异常的机制。  相似文献   

9.
This article is a case study of the maintenance required to the case base of a commercially fielded case-based reasoning (CBR) system that provides support for HVAC engineers enabling them to better specify HVAC installations. The article briefly describes the system and details how the case base grew rapidly, causing a problem of case redundancy. A simple algorithm to identify and remove redundant cases is described, along with the results of applying it to the case base. Case obsolescence also was encountered and partially remedied using DBMS techniques. The article analyzes the case-base maintenance (CBM) required by the system in terms of Richter's knowledge containers and Leake and Wilson's CBM framework and contrasts this case study with experience from NEC and DaimlerChrysler. The article observes that had maintenance of the case base been considered more explicitly during system design and implementation, some of the resulting maintenance would have been unnecessary. The article concludes by identifying lessons learned and highlighting the relationship between the sophistication of the case-representation and similarity metrics and the ease with which CBM can be undertaken by nontechnical staff. This relationship does not always work in favor of the maintainer.  相似文献   

10.
Valuation-Based System (VBS for short) can represent knowledge indifferent domains including probability theory, Dempster-Shafertheory and possibility theory. More recent studies show that theframework of VBS is also appropriate for representing and solvingBayesian decision problems and optimization problems. In this paperafter introducing the valuation based system framework, we presentMarkov-like properties of VBS and a method for resolving queries toVBS.  相似文献   

11.
The primary aim of risk-based software quality classification models is to detect, prior to testing or operations, components that are most-likely to be of high-risk. Their practical usage as quality assurance tools is gauged by the prediction-accuracy and cost-effective aspects of the models. Classifying modules into two risk groups is the more commonly practiced trend. Such models assume that all modules predicted as high-risk will be subjected to quality improvements. Due to the always-limited reliability improvement resources and the variability of the quality risk-factor, a more focused classification model may be desired to achieve cost-effective software quality assurance goals. In such cases, calibrating a three-group (high-risk, medium-risk, and low-risk) classification model is more rewarding. We present an innovative method that circumvents the complexities, computational overhead, and difficulties involved in calibrating pure or direct three-group classification models. With the application of the proposed method, practitioners can utilize an existing two-group classification algorithm thrice in order to yield the three risk-based classes. An empirical approach is taken to investigate the effectiveness and validity of the proposed technique. Some commonly used classification techniques are studied to demonstrate the proposed methodology. They include, the C4.5 decision tree algorithm, discriminant analysis, and case-based reasoning. For the first two, we compare the three-group model calibrated using the respective techniques with the one built by applying the proposed method. Any two-group classification technique can be employed by the proposed method, including those that do not provide a direct three-group classification model, e.x., logistic regression and certain binary classification trees, such as CART. Based on a case study of a large-scale industrial software system, it is observed that the proposed method yielded promising results. For a given classification technique, the expected cost of misclassification of the proposed three-group models were significantly better (generally) when compared to the techniques direct three-group model. In addition, the proposed method is also evaluated against an alternate indirect three-group classification method.  相似文献   

12.
自适应软件需要能够根据环境的变化在运行时动态调整自己的行为以实现既定任务。为了解决这一类软件在开发过程中的一些挑战问题,如自适应逻辑修改困难、代码紧耦合等,设计并实现了一种基于规则的自适应软件系统应用框架(rule-based application framework for self-adaptive software systems,RAF)。RAF通过面向组件的方式解决了紧耦合问题,使用规则文件管理自适应逻辑,并将其与软件的其他部分分割开来。使用RAF开发软件可以灵活地制定与修改自适应逻辑,方便软件的开发、调试、升级等。通过一个案例展示了RAF在解决上述问题方面的能力。  相似文献   

13.
Abstract

With growing pressures for collaborative information systems (IS) partnerships, Enterprise Resource Planning (ERP) implementation has been an important activity for improving supply chains efficiency in Small and Medium-Sized Enterprises (SMEs). Historically ERP consultants usually take a product-selling approach in SMEs, providing limited management consultancy services. However, a more constructive role for management consultants has become an emerging and challenging issue. This study explored the involvement of management consultants in ERP implementation, particularly with internal managers, ERP consultants and other project members. Extensive interviews were conducted with management consultants as well as 47 project members from four different SMEs in Taiwan employing ERP consultants. Using a grounded theory methodology, prior literature was used to sensitize the findings to key concepts of importance. The results were then analyzed and we described how owner-managers regard management consultants and how the consultants use role negotiation skills to work with both internal managers and ERP consultants. The study found resistance toward management consultants primarily from managers in SMEs, and not owner-managers. The relationships between management consultants and SME managers also differed from similar relationships in large organizations. Suggestions are also provided for academics and practitioners along with areas for future research to extend these exploratory findings.  相似文献   

14.
With growing pressures for collaborative information systems (IS) partnerships, Enterprise Resource Planning (ERP) implementation has been an important activity for improving supply chains efficiency in Small and Medium-Sized Enterprises (SMEs). Historically ERP consultants usually take a product-selling approach in SMEs, providing limited management consultancy services. However, a more constructive role for management consultants has become an emerging and challenging issue. This study explored the involvement of management consultants in ERP implementation, particularly with internal managers, ERP consultants and other project members. Extensive interviews were conducted with management consultants as well as 47 project members from four different SMEs in Taiwan employing ERP consultants. Using a grounded theory methodology, prior literature was used to sensitize the findings to key concepts of importance. The results were then analyzed and we described how owner-managers regard management consultants and how the consultants use role negotiation skills to work with both internal managers and ERP consultants. The study found resistance toward management consultants primarily from managers in SMEs, and not owner-managers. The relationships between management consultants and SME managers also differed from similar relationships in large organizations. Suggestions are also provided for academics and practitioners along with areas for future research to extend these exploratory findings.  相似文献   

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Recently, dissipation elements have been gaining popularity as a mechanism for measurement of fundamental properties of turbulent flow, such as turbulence length scales and zonal partitioning. Dissipation elements segment a domain according to the source and destination of streamlines in the gradient flow field of a scalar function f : → ?. They have traditionally been computed by numerically integrating streamlines from the center of each voxel in the positive and negative gradient directions, and grouping those voxels whose streamlines terminate at the same extremal pair. We show that the same structures map well to combinatorial topology concepts developed recently in the visualization community. Namely, dissipation elements correspond to sets of cells of the Morse‐Smale complex. The topology‐based formulation enables a more exploratory analysis of the nature of dissipation elements, in particular, in understanding their stability with respect to small scale variations. We present two examples from combustion science that raise significant questions about the role of small scale perturbation and indeed the definition of dissipation elements themselves.  相似文献   

17.
Requirements management is being recognized as one of the most important albeit difficult phases in software engineering. The literature repeatedly cites the role of well-defined requirements and requirements management process in problem analysis and project management as benefiting software development throughout the life cycle: during design, coding, testing, maintenance and documentation of software. This paper reports on the findings of an investigation into industrial practice of requirements management process improvement and its positive effects on downstream software development. The evidence reveals a strong relationship between a well-defined requirements process and increased developer productivity, improved project planning through better estimations and enhanced ability for stakeholders to negotiate project scope. These results are important since there is little empirical evidence of the actual benefits of sound requirements practice, in spite of the plethora of claims in the literature. An account of these effects not only adds to our understanding of good requirements practice but also provides strong motivation for software organizations to develop programs for improvement of their requirements processes.  相似文献   

18.
Queueing networks have been widely used to evaluation performance of mainframe computer systems. In contrast, few results have been reported for modern open systems, so it was not clear whether queueing networks are useful for modern systems or not. We think this situation has partly been due to lack of handy evaluation tools. This paper presents tow tools that we developed to evaluate open system performance. On is a measuring tool that is capable of accurately obtaining the service times of system resources requested by an application transaction. The other is an estimating tool which calculates various performance measures based on queueing network models. This paper also describes a case study in which the performance of a medium-sized UNIX client–server system (up to 24 clients) is estimated using the tools and these estimates are then compared with experimental results. The estimates closely agree with the measured results and are accurate enough for practical applications. Based on this, we conclude that queueing network models are also useful for modern systems.  相似文献   

19.
The development of custom interactive visualization tools for specific domains and applications has been made much simpler recently by a surge of visualization tools, libraries and frameworks. Most of these tools are developed for classical data science applications, where a user is supported in analyzing measured or simulated data. But recently, there has also been an increasing interest in visual support for understanding machine learning algorithms and frameworks, especially for deep learning. Many, if not most, of the visualization support for (deep) learning addresses the developer of the learning system and not the end user (data scientist). Here we show on a specific example, namely the development of a matrix calculus algorithm, that supporting visualizations can also greatly benefit the development of algorithms in classical domains like in our case computer algebra. The idea is similar to visually supporting the understanding of learning algorithms, namely provide the developer with an interactive, visual tool that provides insights into the workings and, importantly, also into the failures of the algorithm under development. Developing visualization support for matrix calculus development went similar as the development of more traditional visual support systems for data analysts. First, we had to acquaint ourselves with the problem, its language and challenges by talking to the core developer of the matrix calculus algorithm. Once we understood the challenge, it was fairly easy to develop visual support that streamlined the development of the matrix calculus algorithm significantly.  相似文献   

20.
The importance of integrated management stems from the vision of merging telecommunications and distributed computing systems management within the same framework, rapid globalization of world enterprises, and the pressing need for networks and services to be more responsive to "end users." This paper proposes an integrated and distributed management platform which is in line with, but not limited to, the integration of DME, OSI, TMN, and ODP principles. Furthermore, it focuses on a specific layer of the platform describing formally (i) the management domain and management policy concepts; (ii) the services which manage and enforce them; (iii) the performance policy enforcement service; and (iv) how to build-up policy hierarchies. In addition, this paper defines an Intelligent Multimedia Message Handling System (IM3HS) and depicts the high applicability of the domain and policy concepts to its management. Finally, an integrated management architecture for the IM3HS, as well as implementation issues of the IM3HS distributed management platform services are presented.  相似文献   

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