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1.
The design of the database is crucial to the process of designing almost any Information System (IS) and involves two clearly identifiable key concepts: schema and data model, the latter allowing us to define the former. Nevertheless, the term model is commonly applied indistinctly to both, the confusion arising from the fact that in Software Engineering (SE), unlike in formal or empirical sciences, the notion of model has a double meaning of which we are not always aware. If we take our idea of model directly from empirical sciences, then the schema of a database would actually be a model, whereas the data model would be a set of tools allowing us to define such a schema.The present paper discusses the meaning of model in the area of Software Engineering from a philosophical point of view, an important topic for the confusion arising directly affects other debates where model is a key concept. We would also suggest that the need for a philosophical discussion on the concept of data model is a further argument in favour of institutionalizing a new area of knowledge, which could be called: Philosophy of Engineering. 相似文献
2.
推荐系统利用从客户的行为中分析出的知识和商品的自身特点来指导用户选择最适合自己需要的商品,同时为电子商务企业实现增值。推荐系统正逐渐成为电子商务系统的标准模块之一。首先回顾了到目前为止推荐系统主要的实现方法,然后指出了其中尚待改进和完善的地方以及未来研究的方向。 相似文献
3.
In the QBIC (Query By Image Content) project we are studying methods to query large on-line image databases using the images' content as the basis of the queries. Examples of the content we use include color, texture, shape, position, and dominant edges of image objects and regions. Potential applications include medical (Give me other images that contain a tumor with a texture like this one), photo-journalism (Give me images that have blue at the top and red at the bottom), and many others in art, fashion, cataloging, retailing, and industry. We describe a set of novel features and similarity measures allowing query by image content, together with the QBIC system we implemented. We demonstrate the effectiveness of our system with normalized precision and recall experiments on test databases containing over 1000 images and 1000 objects populated from commercially available photo clip art images, and of images of airplane silhouettes. We also present new methods for efficient processing of QBIC queries that consist of filtering and indexing steps. We specifically address two problems: (a) non Euclidean distance measures; and (b) the high dimensionality of feature vectors. For the first problem, we introduce a new theorem that makes efficient filtering possible by bounding the non-Euclidean, full cross-term quadratic distance expression with a simple Euclidean distance. For the second, we illustrate how orthogonal transforms, such as Karhunen Loeve, can help reduce the dimensionality of the search space. Our methods are general and allow some false hits but no false dismissals. The resulting QBIC system offers effective retrieval using image content, and for large image databases significant speedup over straightforward indexing alternatives. The system is implemented in X/Motif and C running on an RS/6000.On sabbatical from Univ. of Maryland, College Park. His work was partially supported by SRC, by the National Science Foundation under the grant IRI-8958546 (PYI). 相似文献
4.
Harnad's proposed robotic upgrade of Turing's Test (TT), from a test of linguistic capacity alone to a Total Turing Test (TTT) of linguistic and sensorimotor capacity, conflicts with his claim that no behavioral test provides even probable warrant for attributions of thought because there is no evidence of consciousness besides private experience. Intuitive, scientific, and philosophical considerations Harnad offers in favor of his proposed upgrade are unconvincing. I agree with Harnad that distinguishing real from as if thought on the basis of (presence or lack of) consciousness (thus rejecting Turing (behavioral) testing as sufficient warrant for mental attribution) has the skeptical consequence Harnad accepts — there is in fact no evidence for me that anyone else but me has a mind. I disagree with his acceptance of it! It would be better to give up the neo-Cartesian faith in private conscious experience underlying Harnad's allegiance to Searle's controversial Chinese Room Experiment than give up all claim to know others think. It would be better to allow that (passing) Turing's Test evidences — even strongly evidences — thought. 相似文献
5.
This paper discusses some of the key drivers that will enable businesses to operate effectively on-line, and looks at how the notion of website will become one of an on-line presence which will support the main activities of an organisation. This is placed in the context of the development of the information society which will allow individuals-as consumers or employees-quick, inexpensive and on-demand access to vast quantities of entertainment, services and information. The paper draws on an example of these developments in Australasia. 相似文献
6.
The number of virtual connections in the nodal space of an ATM network of arbitrary structure and topology is computed by a method based on a new concept—a covering domain having a concrete physical meaning. The method is based on a network information sources—boundary switches model developed for an ATM transfer network by the entropy approach. Computations involve the solution of systems of linear equations. The optimization model used to compute the number of virtual connections in a many-category traffic in an ATM network component is useful in estimating the resource of nodal equipment and communication channels. The variable parameters of the model are the transmission bands for different traffic categories. 相似文献
7.
We formulate a variational principle of Fermat type for chemical kinetics in heterogeneous reacting systems. The principle is consistent with the notion of intrinsic reaction coordinate (IRC), the idea of chemical resistance (CR) and the second law of thermodynamics. The Lagrangian formalism applies a nonlinear functional of entropy production that follows from classical (single-phase) nonequilibrium thermodynamics of chemically reacting systems or its extension for multiphase systems involving interface reactions and transports. For a chemical flux, a law of bending is found which implies that — by minimizing the total resistance — the chemical ray spanned between two given points takes the shape assuring its relatively large part in a region of lower chemical resistivity (a rarer region of the medium). In effect, the chemical flux bends into the direction that ensures its shape consistent with the longest residence of the chemical complex in regions of lower resistivity. The dynamic programming method quantifies the chemical rays and related wavefronts along the reaction coordinate. 相似文献
8.
A key managerial challenge, of interest to academics and practitioners alike, is the assessment and management of customer satisfaction. In this paper, we examine the underlying processes involving consumer satisfaction and switching patterns among ISPs using different satisfaction models, including the expectations-disconfirmation model, the attribution model, and an affective model. Our results indicate that the satisfaction levels of ISP consumers are generally relatively low, despite the fact that consumer expectations of ISPs are also low, reflecting mediocrity in the marketplace. In addition, consumers attribute their dissatisfaction to ISP indifference and believe that managing dissatisfaction is within the control of the ISP. Moreover, affective factors play an important role in satisfaction processes and switching behavior. Customer service including technical support and responsiveness of service staff is an important determinant factor in ISP selection. We suggest that as the ISP market matures, service providers that pay attention to affective factors and to building relationships with their customers will have a competitive advantage in the marketplace of the future. 相似文献
9.
The human-centred debate in Britain focuses on the idea of human-machine symbiosis, and the Dialogue debate in Scandinavia focuses on the deep understanding of human communication, through a process of inner reflection. Both of these debates provide a framework for the participatory design of AI systems.The emergence of social Europe creates the desirability for a sharing of social and cultural knowledge and resources among the citizens of Europe. This raises the possibility of exploiting the potential of new technology for the distribution and transfer of knowledge and skill among the citizens of Europe whilst retaining the diversity of their cultures and languages. These issues of transfer have been the focus of many AI researchers who have been concerned with the design of AI systems for the education, training and welfare of disadvantaged citizens. It is suggested that central to such a transfer is the design of participatory learning systems which focus on the mediation and distribution of knowledge in diverse socio-cultural contexts.In this paper, the SEAKE Centre's projects, especially Brighton Parosi, and Adult Literacy are discussed to provide an insight into the concepts and practice of designing such participatory systems. The philosophy of these projects was rooted in the sharing of social and cultural experiences, through participatory learning. The development of the projects involved a process of exchange of language and culture in both formal and informal learning environments. For the Parosi Project social interaction was the central core for the exchange of cultural experiences and the language acquisition process. The Adult Literacy project built on the exchange process, and used the idea of the mediation of knowledge for the design of a knowledge based system. The design process developed by the above two projects could be described as a participatory design approach which builds upon and extends the human-machine symbiosis and dialogue approaches. 相似文献
10.
This paper describes research into the development of an intelligent simulation environment. The environment was used to analyze reactive scheduling scenarios in a specific flexible manufacturing systems (FMS) configuration. Using data from a real FMS, simulation models were created to study the reactive scheduling problem and this work led to the concept of capturing instantaneous FMS status data as snapshot data for analysis. Various intelligent systems were developed and tested to asses their decision-making capabilities. The concepts of History Logging and expert system learning is proposed and these ideas are implemented into the environment to provide decision-making and control across a FMS schedule lifetime. This research proposes an approach for the analysis of reactive scheduling in an FMS. The approach and system that was subsequently developed was based on the principle of automated intelligent decision-making via knowledge elicitation from FMS status data, together with knowledge base augmentation to facilitate a learning ability based on past experiences. 相似文献
11.
Summary Making use of the fact that two-level grammars (TLGs) may be thought of as finite specification of context-free grammars (CFGs) with infinite sets of productions, known techniques for parsing CFGs are applied to TLGs by first specifying a canonical CFG G — called skeleton grammar — obtained from the cross-reference of the TLG G. Under very natural restrictions it can be shown that for these grammar pairs ( G, G) there exists a 1 — 1 correspondence between leftmost derivations in G and leftmost derivations in G. With these results a straightforward parsing algorithm for restricted TLGs is given. 相似文献
12.
The adaptiveness of agents is one of the basic conditions for the autonomy. This paper describes an approach of adaptiveness forMonitoring Cognitive Agents based on the notion of generic spaces. This notion allows the definition of virtual generic processes so that any particular actual process is then a simple configuration of the generic process, that is to say a set of values of parameters. Consequently, generic domain ontology containing the generic knowledge for solving problems concerning the generic process can be developed. This lead to the design of Generic Monitoring Cognitive Agent, a class of agent in which the whole knowledge corpus is generic. In other words, modeling a process within a generic space becomes configuring a generic process and adaptiveness becomes genericity, that is to say independence regarding technology. In this paper, we present an application of this approach on Sachem, a Generic Monitoring Cognitive Agent designed in order to help the operators in operating a blast furnace. Specifically, the NeuroGaz module of Sachem will be used to present the notion of a generic blast furnace. The adaptiveness of Sachem can then be noted through the low cost of the deployment of a Sachem instance on different blast furnaces and the ability of NeuroGaz in solving problem and learning from various top gas instrumentation. 相似文献
13.
The purpose of this research was to determine whether computer-aided instruction may be effectively utilized in stimulating prewriting composition when the CAI is based upon (1) conceptual (cognitive) strategies, (2) data-driven guidance (resulting from CAE techniques), and (3) recent findings in tutorial strategies research. If this specifically designed CAI is as good a means of prewriting instruction as personal tutoring and a better means than classroom instruction, then the practical and economical implications may be weighed in a decision to use such techniques. Forty-three college freshmen in three basic writing classes participated in this study. One class was exposed to a CAI medium, the other two either to a human tutor or to classroom instruction. A computer-aided evaluation of previous essays provided focus, and other intellectual processing cues provided information on an expository topic; this database was then used to construct a CAI program to encourage specificity and depth of intellectual processing in students' prewriting composition. The program also possessed and was designed to provide conceptual guidance through the use of five heuristic procedures; thus it contained two key elements that a human tutor would possess in working with a topic—knowledge of the topic, and a means for eliciting that knowledge from the tutee. The second treatment method used consisted of instruction by human tutors, utilizing the same methodology. The control for the study consisted of a classroom instruction group. Results showed the CAI group demonstrating gains in every category of measurement utilized in this study, and its performances was significantly better than both the tutorial group on two of the post-test measures. The CAI group was superior, through not significantly, on post-test performances in every category used in the study except fluency. 相似文献
14.
The new economy is the result of the information revolution, of shrinking and ever more powerful computers, and the emergence of an efficient, ubiquitous and invisible communications infrastructure. It is characterized by three distinctive attributes: it is global, it favors intangible things—ideas, information, knowledge, relationships, and it is intensely inter-linked. As more and more organizations prepare to go digital, only few of them really seem to recognize what implications this transition will have on their business processes and on the organization as a whole. The transformation involves much more than setting up a digital infrastructure and requires even more than the ability to enter into a virtual collaboration with other partners. Organizations need to become smart, i.e. knowledge driven, internetworked, dynamically adaptive to new organizational forms and practices, learning as well as agile in their ability to create and exploit the opportunities offered by the digital economy. The article considers technologies and trends towards inter-operable tools for organizational agility and flexibility based on distributed business operations. The European Commission has been supporting these developments through its various research programmes since the early 1980s. Besides the notable research and technological development (RTD) achievements, important progress has also been made in the area of standardization and through consensus building between the research and business communities in Europe. It is further recognised that technology alone will not be able to sustain the creative potential of the digital economy if the socio-economic, the legal and regulatory frameworks are not adequately taken into account. 相似文献
15.
Interactive expert systems seek relevant information from a user in order to answer a query or to solve a problem that the user has posed. A fundamental design issue for such a system is therefore its information-seeking strategy, which determines the order in which it asks questions or performs experiments to gain the information that it needs to respond to the user. This paper examines the problem of optimal knowledge acquisition through questioning in contexts where it is expensive or time-consuming to obtain the answers to questions. An abstract model of an expert classification system — considered as a set of logical classification rules supplemented by some statistical knowledge about attribute frequencies — is developed and applied to analyze the complexity and to present constructive algorithms for doing probabilistic question-based classification. New heuristics are presented that generalize previous results for optimal identification keys and questionnaires. For an important class of discrete discriminant analysis problems, these heuristics find optimal or near-optimal questioning strategies in a small fraction of the time required by an exact solution algorithm. 相似文献
16.
This paper addresses several issues related to the use of conceptual modeling to support service-oriented, advanced information systems. It shows how conceptual modeling of information resources can be used to integrate information obtained from multiple data sources, including both internal and external data. The notion of an intelligent thesaurus is presented and a meta-model of the thesaurus is developed. It is then used to create a three-layer architecture consisting of the actual data source schemas, a wrapped object-oriented abstraction of the schemas expressed in terms of the thesaurus primitives, and an integrated version which serves as the federation schema. The sharing of information among constituents is also addressed, and a special export schema—the export data/knowledge/task schema—is proposed that ties together the objects, their constraints, and their usage rules. Knowledge sharing among constituents during cooperative query processing is accomplished using data/knowledge packets. 相似文献
17.
In this paper, we propose a two-layer sensor fusion scheme for multiple hypotheses multisensor systems. To reflect reality in decision making, uncertain decision regions are introduced in the hypotheses testing process. The entire decision space is partitioned into distinct regions of correct, uncertain and incorrect regions. The first layer of decision is made by each sensor indepedently based on a set of optimal decision rules. The fusion process is performed by treating the fusion center as an additional virtual sensor to the system. This virtual sensor makes decision based on the decisions reached by the set of sensors in the system. The optimal decision rules are derived by minimizing the Bayes risk function. As a consequence, the performance of the system as well as individual sensors can be quantified by the probabilities of correct, incorrect and uncertain decisions. Numerical examples of three hypotheses, two and four sensor systems are presented to illustrate the proposed scheme. 相似文献
18.
This paper describes work carried out atUniversity College London to evaluate the use of MobileAgents (MA), written in Java, in network and systemmanagement. The work draws on experience fromconventional management systems based on ISO CommonManagement Information Protocol (CMIP) andInternet Simple Network ManagementProtocol (SNMP). These systems make use of theconcept of a Managed Object (MO). The paper describes the way in which the MOconcept has been translated into a form suitable forMA-based management and how the features of the Javalanguage may be used to express management information and to implement MOs. A platform has beenimplemented which allows MOs to be instantiated,controlled and stored. The platform also allows the easyproduction of MAs, their launching into the system and their subsequent management. Details of theplatform implementation are given and an initialassessment of performance is presented. 相似文献
19.
Summary A formal functional specification of a serializable interface for an interactive database is given and refined into two different versions with distinct strategies for solving read/write conflicts. The formalization is based on techniques of algebraic specification for defining the basic data structures and functional system specification by streams and stream processing functions for defining the properties concerning interaction. It is especially demonstrated how different specification techniques can be used side by side.
Manfred Broy finished his studies with the Diplom in Mathematics and Computer Science at the Technical University of Munich. Till 1983 he was research and teaching assistant at the Institut für Informatik and the Sonderforschungsbereich 49 Programmiertechnik. At the Technical University of Munich he also did his Ph.D. (in February 1980 with the subject: Transformation parallel ablaufender Programme) and qualified as an university lecturer (in 1982 with the subject: A Theory for Nondeterminism, Parallelism, Communication and Concurrency). In April 1983 he became a Full Professor for Computer Science at the Faculty of Mathematics and Computer Science at the University of Passau. Since October 1989 he has been Full Professor for Computer Science at the Technical University of Munich. His fields of interests are: Programming languages, program development, programming methodology and distributed systems.This work was supported by the DFG Project Transformation paralleler Programme and by the Sonderforschungsbereich 342 Werkzeuge und Methoden für die Nutzung paralleler Architekturen 相似文献
20.
Recommender systems are contributing a significant aspect in information filtering and knowledge management systems. They provide explicit and reliable recommendations to the users so that user can get information about all products in e-commerce domain. In the era of big data and large complex information delivery system, it is impossible to get the right information in the online environment. In this research work, we offered a novel movie-based collaborative recommender system which utilizes the bio-inspired gray wolf optimizer algorithm and fuzzy c-mean (FCM) clustering technique and predicts rating of a movie for a particular user based on his historical data and similarity of users. Gray wolf optimizer algorithm was applied on the Movielens dataset to obtain the initial clusters, and also the initial positions of clusters are obtained. FCM is used to classify the users in the dataset by similarity of user ratings. Our proposed collaborative recommender system performed extremely well with respect to accuracy and precision. We analyzed our proposed recommender system over Movielens dataset which is available publically. Various evaluation metrics were utilized such as mean absolute error, standard deviation, precision and recall. We also compared the performance of projected system with already established systems. The experiment results delivered by proposed recommender system demonstrated that efficiency and performance are enhanced and also offered better recommendations when compared with our previous work [1]. 相似文献
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