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1.
Though blogs and wikis have been used to support knowledge management and e-learning, existing blogs and wikis cannot support different types of knowledge and adaptive learning. A case in point, types of knowledge vary greatly in category and viewpoints. Additionally, adaptive learning is crucial to improving one’s learning performance. This study aims to design a semantic bliki system to tackle such issues. To support various types of knowledge, this study has developed a new social software called “bliki” that combines the advantages of blogs and wikis. This bliki system also applies Semantic Web technology to organize an ontology and a variety of knowledge types. To aid adaptive learning, a function called “Book” is provided to enable learners to arrange personalized learning goals and paths. The learning contents and their sequences and difficulty levels can be specified according to learners’ metacognitive knowledge and collaborative activities. An experiment is conducted to evaluate this system and the experimental results show that this system is able to comprehend various types of knowledge and to improve learners’ learning performance.  相似文献   

2.
3.
The notion of an endofunctor having “greatest subcoalgebras” is introduced as a form of comprehension. This notion is shown to be instrumental in giving a systematic and abstract proof of the existence of limits for coalgebras—proved earlier by Worrell and by Gumm & Schröder. These insights, in dual form, are used to reinvestigate colimits for algebras in terms of “least quotient algebras”—leading to a uniform approach to limits of coalgebras and colimits of algebras. Finally, at an abstract level of fibrations, an equivalence is established between having greatest subcoalgebras (in a base category of types) and greatest invariants (in a total category of predicates).  相似文献   

4.
B2B (business-to-business) electronic commerce provides firms with different business value depending on how organizations use the online network. In this paper, we distinguish two different types of B2B e-commerce adoption: basic and collaborative B2B e-commerce. With “basic B2B e-commerce”, firms implement the electronic network simply to automate the exchange of commercial documents. In contrast, B2B networks are used to create new inter-firm operations with channel partners in “collaborative B2B e-commerce.” The central claim of this paper is that firms are unlikely to achieve significant benefits with Basic B2B e-commerce. B2B electronic networks offer dramatic performance improvement only when the B2B network is used to create new collaboration with channel partners. Based on the survey conducted in the grocery industry, this study suggests that the real source of performance improvement in the B2B electronic commerce is not an electronic linkage itself, but the collaboration enabled by the electronic network.  相似文献   

5.
We describe an operational semantics for the hardware compilation language Handel-C [7], which is a C-like language with channel communication and parallel constructs which compiles down to mainly synchronously clocked hardware. The work in this paper builds on previous work describing the semantics of the “prialt” construct within Handel-C [5] and a denotational semantics for part of the language [6]. We describe a key subset of the language and show how a design decision for the real language, namely that default guards in a prialt statement executed in “zero-time”, has consequences for the complexity of the operational semantics. We present the operational semantics, along with a revised and completed prialt semantics, indicating clearly the interface between them. We then describe a notion of observational equivalence and present an example illustrating how we handle the complexity of nested prialts in default guards.  相似文献   

6.
Many artificial intelligence tasks, such as automated question answering, reasoning, or heterogeneous database integration, involve verification of a semantic category (e.g. “coffee” is a drink, “red” is a color, while “steak” is not a drink and “big” is not a color). In this research, we explore completely automated on-the-fly verification of a membership in any arbitrary category which has not been expected a priori. Our approach does not rely on any manually codified knowledge (such as WordNet or Wikipedia) but instead capitalizes on the diversity of topics and word usage on the World Wide Web, thus can be considered “knowledge-light” and complementary to the “knowledge-intensive” approaches. We have created a quantitative verification model and established (1) what specific variables are important and (2) what ranges and upper limits of accuracy are attainable. While our semantic verification algorithm is entirely self-contained (not involving any previously reported components that are beyond the scope of this paper), we have tested it empirically within our fact seeking engine on the well known TREC conference test questions. Due to our implementation of semantic verification, the answer accuracy has improved by up to 16% depending on the specific models and metrics used.  相似文献   

7.
This paper gives a fresh look at my previous work on “epistemic actions” and information updates in distributed systems, from a coalgebraic perspective. I show that the “relational” semantics of epistemic programs, given in [BMS2] in terms of epistemic updates, can be understood in terms of functors on the category of coalgebras and natural transformations associated to them. Then, I introduce a new, alternative, more refined semantics for epistemic programs: programs as “epistemic coalgebras”. I argue for the advantages of this second semantics, from a semantic, heuristic, syntactical and proof-theoretic point of view. Finally, as a step towards a generalization, I show these concepts make sense for other functors, and that apparently unrelated concepts, such as Bayesian belief updates and process transformations, can be seen to arise in the same way as our “epistemic actions”.  相似文献   

8.
Extensional PERs     
A class of Partial Equivalence Relations (PERs) is described such that the resulting full subcategory of the realizability universe has the expected properties of a good category of CPOs; that is, it is a Cartesian closed category and every endomorphism has a canonical fixed point. Moreover, the reflection functor into the subcategory of strict maps (usually called the “lifting operation”) yields a good notion of “partial map,” a necessary condition if one wishes to maintain a connection between strict maps and partial maps. It is shown that all functors that arise in practice have canonical invariant objects; hence a host of domain equations are guaranteed to have solutions.  相似文献   

9.
Stability and performance analysis of mixed product run-to-run control   总被引:1,自引:1,他引:1  
Run-to-run control has been widely used in batch manufacturing processes to reduce variations. However, in batch processes, many different products are fabricated on the same set of process tool with different recipes. Two intuitive ways of defining a control scheme for such a mixed production mode are (i) each run of different products is used to estimate a common tool disturbance parameter, i.e., a “tool-based” approach, (ii) only a single disturbance parameter that describe the combined effect of both tool and product is estimated by results of runs of a particular product on a specific tool, i.e., a “product-based” approach. In this study, a model two-product plant was developed to investigate the “tool-based” and “product-based” approaches. The closed-loop responses are derived analytically and control performances are evaluated. We found that a “tool-based” approach is unstable when the plant is non-stationary and the plant-model mismatches are different for different products. A “product-based” control is stable but its performance will be inferior to single product control when the drift is significant. While the controller for frequent products can be tuned in a similar manner as in single product control, a more active controller should be used for the infrequent products which experience a larger drift between runs. The results were substantiated for a larger system with multiple products, multiple plants and random production schedule.  相似文献   

10.
Continued advances in computational resources are providing the opportunity to operate more sophisticated numerical models. Additionally, there is an increasing demand for multidisciplinary studies that include interactions between different physical processes. Therefore there is a strong desire to develop coupled modeling systems that utilize existing models and allow efficient data exchange and model control. The basic system would entail model “1” running on “M” processors and model “2” running on “N” processors, with efficient exchange of model fields at predetermined synchronization intervals. Here we demonstrate two coupled systems: the coupling of the ocean circulation model Regional Ocean Modeling System (ROMS) to the surface wave model Simulating WAves Nearshore (SWAN), and the coupling of ROMS to the atmospheric model Coupled Ocean Atmosphere Prediction System (COAMPS). Both coupled systems use the Model Coupling Toolkit (MCT) as a mechanism for operation control and inter-model distributed memory transfer of model variables. In this paper we describe requirements and other options for model coupling, explain the MCT library, ROMS, SWAN and COAMPS models, methods for grid decomposition and sparse matrix interpolation, and provide an example from each coupled system. Methods presented in this paper are clearly applicable for coupling of other types of models.  相似文献   

11.
We show that a certain simple call-by-name continuation semantics of Parigot's λμ-calculus is complete. More precisely, for every λμ-theory we construct a cartesian closed category such that the ensuing continuation-style interpretation of λμ, which maps terms to functions sending abstract continuations to responses, is full and faithful. Thus, any λμ-category in the sense of L. Ong (1996, in “Proceedings of LICS '96,” IEEE Press, New York) is isomorphic to a continuation model (Y. Lafont, B. Reus, and T. Streicher, “Continuous Semantics or Expressing Implication by Negation,” Technical Report 93-21, University of Munich) derived from a cartesian-closed category of continuations. We also extend this result to a later call-by-value version of λμ developed by C.-H. L. Ong and C. A. Stewart (1997, in “Proceedings of ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, Paris, January 1997,” Assoc. Comput. Mach. Press, New York).  相似文献   

12.
“Fuzzy Functions” are proposed to be determined by the least squares estimation (LSE) technique for the development of fuzzy system models. These functions, “Fuzzy Functions with LSE” are proposed as alternate representation and reasoning schemas to the fuzzy rule base approaches. These “Fuzzy Functions” can be more easily obtained and implemented by those who are not familiar with an in-depth knowledge of fuzzy theory. Working knowledge of a fuzzy clustering algorithm such as FCM or its variations would be sufficient to obtain membership values of input vectors. The membership values together with scalar input variables are then used by the LSE technique to determine “Fuzzy Functions” for each cluster identified by FCM. These functions are different from “Fuzzy Rule Base” approaches as well as “Fuzzy Regression” approaches. Various transformations of the membership values are included as new variables in addition to original selected scalar input variables; and at times, a logistic transformation of non-scalar original selected input variables may also be included as a new variable. A comparison of “Fuzzy Functions-LSE” with Ordinary Least Squares Estimation (OLSE)” approach show that “Fuzzy Function-LSE” provide better results in the order of 10% or better with respect to RMSE measure for both training and test cases of data sets.  相似文献   

13.
This paper is concerned with a proof-theoretic observation about two kinds of proof systems for regular cyclic objects. It is presented for the case of two formal systems that are complete with respect to the notion of “recursive type equality” on a restricted class of recursive types in μ-term notation. Here we show the existence of an immediate duality with a geometrical visualization between proofs in a variant of the coinductive axiom system due to Brandt and Henglein and “consistency-unfoldings” in a variant of a 'syntactic-matching' proof system for testing equations between recursive types due to Ariola and Klop.Finally we sketch an analogous result of a duality between a similar pair of proof systems for bisimulation equivalence on equational specifications of cyclic term graphs.  相似文献   

14.
An approach to the discrete location problem is presented. The formulation is based on the set partitioning problem with the emphasis being placed on the weighted objective function and the importance of the “value” or “attractiveness” of the potential “covers”, i.e. the number of centres served by a specific location, FORTRAN programs were written to generate the potential subsets of centres to be served, for a specific county in northern Greece, and a mathematical programming package (APEX III) was used in its integer programming mode to provide solutions for various sets of subsets of centres which were generated according to certain criteria.  相似文献   

15.
The complete structure of an AGV control system is described in the first part of this paper. The AGV control system is hierarchical and consists of five levels. The structure of one level does not depend on the structures of the other levels. This means that the control system depends on the design of the AGV at the lowest level only, at the actuator servo-control level and its coordination in realizing AGV primitive functions.The second part of the paper describes rules applicable to AGV steering. The structure of these rules depends on two groups of factors. The first group is dependent on information groups fed to the AGV processor by the position sensor. The second group of factors represents aims and conditions and AGV steering such as positioning accuracy, positioning time, allowed room for maneuver, the shape of the given trajectory, etc. The AGV steering rules contain sequences of primitive functions. These primitive functions are of such types as “turn left”, “straighten” (correct), “go straight on”, etc. Trajectory, as one of the basic factors, is defined at the level of controlling an elementary movement. The term “to control an elementary movement” means to select a transport road throughout the transport network and to code it using “elementary movement” such as “go straight” (relating to road section), “turn left” (relating to turning at a crossroad) etc.The results of the AGV steering simulation are presented in the third part of the paper. An exact kinematic AGV model used for stimulating control models is also presented.  相似文献   

16.
While terminology and some concepts of behavior-based robotics have become widespread, the central ideas are often lost as researchers try to scale behavior to higher levels of complexity. “Hybrid systems” with model-based strategies that plan in terms of behaviors rather than simple actions have become common for higher-level behavior. We claim that a strict behavior-based approach can scale to higher levels of complexity than many robotics researchers assume, and that the resulting systems are in many cases more efficient and robust than those that rely on “classical AI” deliberative approaches. Our focus is on systems of cooperative autonomous robots in dynamic environments. We will discuss both claims that deliberation and explicit communication are necessary to cooperation and systems that cooperate only through environmental interaction. In this context we introduce three design principles for complex cooperative behavior—minimalism, statelessness and tolerance—and present a RoboCup soccer system that matches the sophistication of many deliberative soccer systems while exceeding their robustness, through the use of strict behavior-based techniques with no explicit communication.  相似文献   

17.
We show that the negative feedback interconnection of two causal, stable, linear time-invariant systems, with a “mixed” small gain and passivity property, is guaranteed to be finite-gain stable. This “mixed” small gain and passivity property refers to the characteristic that, at a particular frequency, systems in the feedback interconnection are either both “input and output strictly passive”; or both have “gain less than one”; or are both “input and output strictly passive” and simultaneously both have “gain less than one”. The “mixed” small gain and passivity property is described mathematically using the notion of dissipativity of systems, and finite-gain stability of the interconnection is proven via a stability result for dissipative interconnected systems.  相似文献   

18.
The literature suggests the existence of critical success factors (CSFs) for the development of information systems that support senior executives. Our study of six organizations gives evidence for this notion of CSFs. The study further shows an interesting pattern, namely that companies either “get it right”, and essentially succeed on all CSFs, or “get it completely wrong”, that is, fall short on each of the CSFs. Among the six cases for which data were collected through in-depth interviews with company executives, three organizations seemed to manage all the CSFs properly, while two others managed all CSFs poorly. Only one organization showed a mixed scorecard, managing some factors well and some not so well. At the completion of the study, this organization could neither be judged as a success, nor as a failure. This dichotomy between success and failure cases suggests the existence of an even smaller set of “meta-success” factors. Based on our findings, we speculate that these “meta-success” factors are “championship”, “availability of resources”, and “link to organization objectives”.  相似文献   

19.
An essential prerequisite to construct a manifold trihedral polyhedron from a given natural (or partial-view) sketch is solution of the “wireframe sketch from a single natural sketch (WSS)” problem, which is the subject of this paper. Published solutions view WSS as an “image-processing”/“computer vision” problem where emphasis is placed on analyzing the given input (natural sketch) using various heuristics. This paper proposes a new WSS method based on robust tools from graph theory, solid modeling and Euclidean geometry. Focus is placed on producing a minimal wireframe sketch that corresponds to a topologically correct polyhedron.  相似文献   

20.
This study considers those questions posed by students during e-mail “tutorials” to elicit information from “guest lecturers” and the use of that information by students in their essays. The “tutorials” were conducted for students in the U.K. by a “guest lecturer” in France. The “guest lecturer” was accredited as a tutor on the module for which the students were enrolled, and participated in the module by the provision of lecture notes prior to the e-mail tutorials. Data for the study, drawn from a comparative education assignment set for undergraduate students enrolled on the module, comprised surveys of students' perceived IT capabilities and attitudes towards IT, analyses of students' questions and analyses of students' essays. The findings of the study indicate (1) that tutees tend to pose questions to elicit information or clarification rather than to elicit the viewpoint or opinions of the “guest lecturer” and (2) that two-thirds of tutees' essays cited information elicited from the “guest lecturer”.  相似文献   

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