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1.
In this paper we discuss reasoning about reasoning in a multiple agent scenario. We consider agents that are perfect reasoners, loyal, and that can take advantage of both the knowledge and ignorance of other agents. The knowledge representation formalism we use is (full) first order predicate calculus, where different agents are represented by different theories, and reasoning about reasoning is realized via a meta-level representation of knowledge and reasoning. The framework we provide is pretty general: we illustrate it by showing a machine checked solution to the three wisemen puzzle. The agents' knowledge is organized into units: the agent's own knowledge about the world and its knowledge about other agents are units containing object-level knowledge; a unit containing meta-level knowledge embodies the reasoning about reasoning and realizes the link among units. In the paper we illustrate the meta-level architecture we propose for problem solving in a multi-agent scenario; we discuss our approach in relation to the modal one and we compare it with other meta-level architectures based on logic. Finally, we look at a class of applications that can be effectively modeled by exploiting the meta-level approach to reasoning about knowledge and reasoning.  相似文献   

2.
Evidence Combination in an Environment With Heterogeneous Sources   总被引:1,自引:0,他引:1  
A framework for the combination of evidence in an environment where data are generated from heterogeneous sources possessing partial or incomplete knowledge about the global network scenario is presented. The approach taken is based on the conditional belief and plausibility notions in Dempster-Shafer evidence theory that allow one to condition these partial knowledge bases so that only that portion of the incoming evidence that is relevant is utilized for updating an existing knowledge base. The strategy proposed enables one to accommodate some of the most challenging, yet essential, features that are encountered when evidence is generated from possibly a large numbers of sources. These include heterogeneity and reliability of incoming evidence, inertia and integrity of evidence already gathered, and potentially limited resources at the nodes where evidence updating is carried out. The proposed framework is applied in robot map discovery using ultrasonic sensors and a real-world scenario where sensor data generated by heterogeneous sensors are used for potential threat carrier-type detection  相似文献   

3.
Rough Problem Settings for ILP Dealing With Imperfect Data   总被引:1,自引:0,他引:1  
This paper applies rough set theory to Inductive Logic Programming (ILP, a relatively new method in machine learning) to deal with imperfect data occurring in large real-world applications. We investigate various kinds of imperfect data in ILP and propose rough problem settings to deal with incomplete background knowledge (where essential predicates/clauses are missing), indiscernible data (where some examples belong to both sets of positive and negative training examples), missing classification (where some examples are unclassified) and too strong declarative bias (hence the failure in searching for solutions). The rough problem settings relax the strict requirements in the standard normal problem setting for ILP, so that rough but useful hypotheses can be induced from imperfect data. We give simple measures of learning quality for the rough problem settings. For other kinds of imperfect data (noise data, too sparse data, missing values, real-valued data, etc.), while referring to their traditional handling techniques, we also point out the possibility of new methods based on rough set theory.  相似文献   

4.
The objective of this paper is to present a measurement-based control-design approach for single-input single-output linear systems with guaranteed bounded error. A wide range of control-design approaches available in the literature are based on parametric models. These models can be obtained analytically using physical laws or via system identification using a set of measured data. However, due to the complex properties of real systems, an identified model is only an approximation of the plant based on simplifying assumptions. Thus, the controller designed based on a simplified model can seriously degrade the closed-loop performance of the system. In this paper, an alternative approach is proposed to develop fixed-order controllers based on measured data without the need for model identification. The proposed control technique is based on computing a suitable set of fixed-order controller parameters for which the closed-loop frequency response fits a desired frequency response that meets the desired closed-loop performance specifications. The control-design problem is formulated as a nonlinear programming problem using the concept of bounded error. The main advantages of our proposed approach are: (1) it guarantees that the error between the computed and the desired frequency responses is less than a small value; (2) the difficulty of finding the globally optimal solution in the error minimisation problem is avoided; (3) the controller can be designed without the use of any analytical model to avoid errors associated with the identification process; and (4) low-order controllers can be designed by selecting a fixed low-order controller structure. To experimentally validate and illustrate the efficacy of the proposed approach, proportional-integral measurement-based controllers are designed for a DC (direct current) servomotor.  相似文献   

5.
In the public safety service context, government big data governance (GBDG) is a challenging decision-making problem that encompasses uncertainties in the arenas of big data and its complex links. Modeling and collaborating the key scenario information required for GBDG decision-making can minimize system uncertainties. However, existing scenario-building methods are limited by their rigidity as they are employed in various application contexts and the associated high costs of modeling. In this paper, using a design science paradigm, a model-driven scenario modeling approach is proposed to achieve flexible scenario modeling for various applications through the transfer of generic domain knowledge. The key component of the proposed approach is a scenario meta-model that is built from existing literatures and practices by integrating qualitative, quantitative, and meta-modeling analysis. An instantiation mechanism of the scenario meta-model is also proposed to generate customized scenarios under Antecedent-Behavior-Consequence (ABC) theory. Two real-world safety service cases in Wuhan, China were evaluated to find that the proposed approach reduces GBDG decision-making uncertainties significantly by providing key information for GBDG problem identification, solution design, and solution value perception. This scenario-building approach can be further used to develop other GBDG systems for public safety services with reduced uncertainties and complete decision-making functions.  相似文献   

6.
One of the most impressive characteristics of human perception is its domain adaptation capability. Humans can recognize objects and places simply by transferring knowledge from their past experience. Inspired by that, current research in robotics is addressing a great challenge: building robots able to sense and interpret the surrounding world by reusing information previously collected, gathered by other robots or obtained from the web. But, how can a robot automatically understand what is useful among a large amount of information and perform knowledge transfer? In this paper we address the domain adaptation problem in the context of visual place recognition. We consider the scenario where a robot equipped with a monocular camera explores a new environment. In this situation traditional approaches based on supervised learning perform poorly, as no annotated data are provided in the new environment and the models learned from data collected in other places are inappropriate due to the large variability of visual information. To overcome these problems we introduce a novel transfer learning approach. With our algorithm the robot is given only some training data (annotated images collected in different environments by other robots) and is able to decide whether, and how much, this knowledge is useful in the current scenario. At the base of our approach there is a transfer risk measure which quantifies the similarity between the given and the new visual data. To improve the performance, we also extend our framework to take into account multiple visual cues. Our experiments on three publicly available datasets demonstrate the effectiveness of the proposed approach.  相似文献   

7.
Top-k queries on large multi-attribute data sets are fundamental operations in information retrieval and ranking applications. In this article, we initiate research on the anytime behavior of top-k algorithms on exact and fuzzy data. In particular, given specific top-k algorithms (TA and TA-Sorted) we are interested in studying their progress toward identification of the correct result at any point during the algorithms’ execution. We adopt a probabilistic approach where we seek to report at any point of operation of the algorithm the confidence that the top-k result has been identified. Such a functionality can be a valuable asset when one is interested in reducing the runtime cost of top-k computations. We present a thorough experimental evaluation to validate our techniques using both synthetic and real data sets.  相似文献   

8.
In this paper, we propose a multi-agent framework to deal with situations involving uncertain or inconsistent information located in a distributed environment which cannot be combined into a single knowledge base. To this end, we introduce an inquiry dialogue approach based on a combination of possibilistic logic and a formal argumentation-based theory, where possibilistic logic is used to capture uncertain information, and the argumentation-based approach is used to deal with inconsistent knowledge in a distributed environment. We also modify the framework of earlier work, so that the system is not only easier to implement but also more suitable for educational purposes. The suggested approach is implemented in a clinical decision-support system in the domain of dementia diagnosis. The approach allows the physician to suggest a hypothetical diagnosis in a patient case, which is verified through the dialogue if sufficient patient information is present. If not, the user is informed about the missing information and potential inconsistencies in the information as a way to provide support for continuing medical education. The approach is presented, discussed, and applied to one scenario. The results contribute to the theory and application of inquiry dialogues in situations where the data are uncertain and inconsistent.  相似文献   

9.
Rudiments of rough sets   总被引:17,自引:0,他引:17  
Worldwide, there has been a rapid growth in interest in rough set theory and its applications in recent years. Evidence of this can be found in the increasing number of high-quality articles on rough sets and related topics that have been published in a variety of international journals, symposia, workshops, and international conferences in recent years. In addition, many international workshops and conferences have included special sessions on the theory and applications of rough sets in their programs. Rough set theory has led to many interesting applications and extensions. It seems that the rough set approach is fundamentally important in artificial intelligence and cognitive sciences, especially in research areas such as machine learning, intelligent systems, inductive reasoning, pattern recognition, mereology, knowledge discovery, decision analysis, and expert systems. In the article, we present the basic concepts of rough set theory and point out some rough set-based research directions and applications.  相似文献   

10.
Recently, various smart application services have been developed using GPS (Global Positioning System), RFID (Radio Frequency IDentification) and sensor networks. The GPS has been successfully applied for outdoor location tracking by many applications, but it might still be insufficient in an indoor environment where GPS signals are often severely obstructed. The RFID technology has been utilized to play an important role in location tracking for indoor smart applications. Therefore, in this paper, we present the scenario and architecture of an indoor location tracking service for things or space in an exhibition environment based on mobile RFID. The RFID tags of things or spaces are identified as the locations of point being passed and we obtain the spatial data from the tags using mobile RFID readers, Web server and Database server. We have designed and implemented the prototype of location tracking system for exhibition scenario using Microsoft .NET framework. Additionally, we have verified the functionality of this system so various other indoor smart services may be provided using the proposed system.  相似文献   

11.
Prediction in a small-sized sample with a large number of covariates, the “small n, large p” problem, is challenging. This setting is encountered in multiple applications, such as in precision medicine, where obtaining additional data can be extremely costly or even impossible, and extensive research effort has recently been dedicated to finding principled solutions for accurate prediction. However, a valuable source of additional information, domain experts, has not yet been efficiently exploited. We formulate knowledge elicitation generally as a probabilistic inference process, where expert knowledge is sequentially queried to improve predictions. In the specific case of sparse linear regression, where we assume the expert has knowledge about the relevance of the covariates, or of values of the regression coefficients, we propose an algorithm and computational approximation for fast and efficient interaction, which sequentially identifies the most informative features on which to query expert knowledge. Evaluations of the proposed method in experiments with simulated and real users show improved prediction accuracy already with a small effort from the expert.  相似文献   

12.
The Inter-organisational systems (IOS) Motivation Model (IMM) has recently been proposed as a theory that explains variations in IOS implementation processes initiated by organisations. The IMM classifies IOS adoption projects (regardless of the underlying technology used) into four generic motivation scenarios and explains different implementation processes for each motivation scenario. The theory was tested in the Australian pharmaceutical industry where it received broad support. In order to enhance its generality, in this study we explore the applicability of part of the IMM theory to a different industry context by addressing the research objective that organisations with the same motive for implementing an IOS initiate the same implementation activities regardless of differences in the industry contexts within which they operate. We have used a multiple case study approach and compared the implementation of a proprietary in-house built e-ordering system in a large Australian pharmaceutical manufacturing company with that of a web-based EDI system used by a large automotive manufacturing company using IMM as a theoretical lens. The empirical results indicate a striking similarity in the implementation processes of these two different IOS applications; this can largely be explained using the IMM theory. Furthermore, the differences in industry contexts do not appear to have a direct influence on the activities associated with implementing these systems.  相似文献   

13.
There is a large amount of heterogeneous data distributed in various sources in the upstream of PetroChina. These data can be valuable assets if we can fully use them. Meanwhile, the knowledge graph, as a new emerging technique, provides a way to integrate multi-source heterogeneous data. In this paper, we present one application of the knowledge graph in the upstream of PetroChina. Specifically, we first construct a knowledge graph from both structured and unstructured data with multiple NLP (natural language progressing) methods. Then, we introduce two typical knowledge graph powered applications and show the benefit that the knowledge graph brings to these applications:compared with the traditional machine learning approach, the well log interpretation method powered by knowledge graph shows more than 7.69% improvement of accuracy.  相似文献   

14.
We propose a novel method, called Semi-supervised Projection Clustering in Transfer Learning (SPCTL), where multiple source domains and one target domain are assumed. Traditional semi-supervised projection clustering methods hold the assumption that the data and pairwise constraints are all drawn from the same domain. However, many related data sets with different distributions are available in real applications. The traditional methods thus can not be directly extended to such a scenario. One major challenging issue is how to exploit constraint knowledge from multiple source domains and transfer it to the target domain where all the data are unlabeled. To handle this difficulty, we are motivated to construct a common subspace where the difference in distributions among domains can be reduced. We also invent a transferred centroid regularization, which acts as a bridge to transfer the constraint knowledge to the target domain, to formulate this geometric structure formed by the centroids from different domains. Extensive experiments on both synthetic and benchmark data sets show the effectiveness of our method.  相似文献   

15.
This paper presents an outline of a risk assessment system for evaluating the expected damage of structures and the consequent financial losses and casualties due to a likely earthquake under elevated uncertain conditions; namely where neither the statistical data nor the seismological and engineering knowledge required for such evaluations are sufficient. In such cases, we should consider extra dimensions of uncertainty, in addition to probability that is usually sufficient for expressing the risk of losses and casualties due to an earthquake where such knowledge and data is available. In the present paper, the uncertainties caused by the insufficient knowledge about the interdependency of various parameters have been considered by means of fuzzy relations. Moreover, the uncertainties in eliciting the likelihood of the seismic hazard have been expressed by fuzzy probability in the form of possibility-probability distributions (PPDs). In other words, fuzzy set theory is employed to complement the standard probability theory with a second dimension of uncertainty. By composition of the fuzzy probability of the seismic hazard and fuzzy vulnerability relation of target structure, the fuzzy probability of damage can be derived. The proposed approach has also been compared with an alternative approach for obtaining a PPD of the hazard. As a case study, the risk assessment system has been tested on a sample structure in the Istanbul metropolitan area.  相似文献   

16.
A decentralized approach for convention emergence in multi-agent systems   总被引:1,自引:0,他引:1  
The field of convention emergence studies how agents involved in repeated coordination games can reach consensus through only local interactions. The literature on this topic is vast and is motivated by human societies, mainly addressing coordination problems between human agents, such as who gets to redial after a dropped telephone call. In contrast, real-world engineering problems, such as coordination in wireless sensor networks, involve agents with limited resources and knowledge and thus pose certain restrictions on the complexity of the coordination mechanisms. Due to these restrictions, strategies proposed for human coordination may not be suitable for engineering applications and need to be further explored in the context of real-world application domains. In this article we take the role of designers of large decentralized multi-agent systems. We investigate the factors that speed up the convergence process of agents arranged in different static and dynamic topologies and under different interaction models, typical for engineering applications. We also study coordination problems both under partial observability and in the presence of faults (or noise). The main contributions of this article are that we propose an approach for emergent coordination, motivated by highly constrained devices, such as wireless nodes and swarm bots, in the absence of a central entity and perform extensive theoretical and empirical studies. Our approach is called Win-Stay Lose-probabilistic-Shift, generalizing two well-known strategies in game theory that have been applied in other domains. We demonstrate that our approach performs well in different settings under limited information and imposes minimal system requirements, due to its simplicity. Moreover, our technique outperforms state-of-the-art coordination mechanisms, guarantees full convergence in any topology and has the property that all convention states are absorbing.  相似文献   

17.
Commonsense reasoning plays a pivotal role in the development of intelligent systems for decisionmaking, system analysis, control and other applications. As Prof. L. Zadeh mentions a kernel of the theory of commonsense is the concept of usuality. Zadeh suggested main principles of the theory of usuality, unfortunately up to present day; a fundamental and systemic approach to reasoning with usual knowledge is not developed.
In this study, we develop a new approach to calculus of usual numbers (U-numbers). We consider a U-number as a Z-number, where the second component is “usually”. Validity of the suggested approach is verified by examples.  相似文献   

18.
Using a peer-to-peer approach for live multimedia streaming applications offers the promise to obtain a highly scalable, decentralized, and robust distribution service. When constructing streaming topologies, however, specific care has to be taken in order to ensure that quality of service requirements in terms of delay, jitter, packet loss, and stability against deliberate denial of service attacks are met. In this paper, we concentrate on the latter requirement of stability against denial-of-service attacks. We present an analytical model to assess the stability of overlay streaming topologies and describe attack strategies. Building on this, we describe topologies, which are optimally stable toward perfect attacks based on global knowledge, and give a mathematical proof of their optimality. The formal construction and analysis of these topologies using global knowledge lead us to strategies for distributed procedures, which are able to construct resilient topologies in scenarios, where global knowledge can not be gathered. Experimental results show that the topologies created in such a real-world scenario are close to optimally stable toward perfect denial of service attacks.  相似文献   

19.
Query processing in the uncertain database has played an important role in many real-world applications due to the wide existence of uncertain data. Although many previous techniques can correctly handle precise data, they are not directly applicable to the uncertain scenario. In this article, we investigate and propose a novel query, namely probabilistic top-k star (PTkS) query, which aims to retrieve k objects in an uncertain database that are “closest” to a static/dynamic query point, considering both distance and probability aspects. In order to efficiently answer PTkS queries with a static/moving query point, we propose effective pruning methods to reduce the PTkS search space, which can be seamlessly integrated into an efficient query procedure. Finally, extensive experiments have demonstrated the efficiency and effectiveness of our proposed PTkS approaches on both real and synthetic data sets, under various parameter settings.  相似文献   

20.
Fuzzy cognitive maps (FCMs) are one of the representative techniques in developing scenarios that include future concepts and issues, as well as their causal relationships. The technique, initially dependent on deductive modeling of expert knowledge, suffered from inherent limitations of scope and subjectivity; though this lack has been partially addressed by the recent emergence of inductive modeling, the fact that inductive modeling uses a retrospective, historical data that often misses trend-breaking developments. Addressing this issue, the paper suggests the utilization of futuristic data, a collection of future-oriented opinions extracted from online communities of large participation, in scenario building. Because futuristic data is both large in scope and prospective in nature, we believe a methodology based on this particular data set addresses problems of subjectivity and myopia suffered by the previous modeling techniques. To this end, text mining (TM) and latent semantic analysis (LSA) algorithm are applied to extract scenario concepts from futuristic data in textual documents; and fuzzy association rule mining (FARM) technique is utilized to identify their causal weights based on if-then rules. To illustrate the utility of proposed approach, a case of electric vehicle is conducted. The suggested approach can improve the effectiveness and efficiency of scanning knowledge for scenario development.  相似文献   

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