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1.
Multi-label learning originated from the investigation of text categorization problem, where each document may belong to several predefined topics simultaneously. In multi-label learning, the training set is composed of instances each associated with a set of labels, and the task is to predict the label sets of unseen instances through analyzing training instances with known label sets. In this paper, a multi-label lazy learning approach named ML-KNN is presented, which is derived from the traditional K-nearest neighbor (KNN) algorithm. In detail, for each unseen instance, its K nearest neighbors in the training set are firstly identified. After that, based on statistical information gained from the label sets of these neighboring instances, i.e. the number of neighboring instances belonging to each possible class, maximum a posteriori (MAP) principle is utilized to determine the label set for the unseen instance. Experiments on three different real-world multi-label learning problems, i.e. Yeast gene functional analysis, natural scene classification and automatic web page categorization, show that ML-KNN achieves superior performance to some well-established multi-label learning algorithms.  相似文献   

2.
Different neuropsychological studies clearly show that the perception of our body and its surrounding space is not a given fact but it is influenced by the outcome of our actions (both direct and mediated by the use of tools). In this view, a possible starting point for a better understanding of Presence in computer-mediated interactions is the study of mediated action and its effects on our spatial experience.Following a cognitive perspective, the presented framework describes Presence as an intuitive feeling which is the outcome of an experience-based metacognitive judgment that controls our action. This process monitors pre-reflexively our activity by using an embodied intuitive simulation of the intended action developed through practice (implicit learning).When actions are implemented using one or more tools, it is possible to distinguish between two different types of mediated action: first-order (I use the body to control a proximal artifact, e.g. a tennis player striking the ball with the racquet) or second-order (I use the body to control a proximal artifact that controls a different distal one, e.g. a cranemen using a lever to move a mechanical boom to lift materials). These two mediated actions, when produced intuitively, have different effects on our experience of body and space: a successfully learned first-order mediated action produces incorporation – the proximal tool extends the peripersonal space of the subject – while a successfully learned second-order mediated action produces also incarnation – a second peripersonal space centered on the distal tool.  相似文献   

3.
In this paper we investigate the manipulation of large sets of 2-dimensional data representing multiple overlapping features (e.g. semantically distinct overlays of a given region), and we present a new access method, the MOF-tree. We perform an analysis with respect to the storage requirements and a time analysis with respect to window query operations involving multiple features (e.g. to verify if a constraint defined on multiple overlays holds or not inside a certain region). We examine both the pointer-based as well as the pointerless MOF-tree representations, using as space complexity measure the number of bits used in main memory and the number of disk pages in secondary storage respectively. In particular, we show that the new structure is space competitive in the average case, both in the pointer version and in the linear version, with respect to multiple instances of a region quadtree and a linear quadtree respectively, where each instance represents a single feature. Concerning the time performance of the new structure, we analyze the class of window (range) queries, posed on the secondary memory implementation. We show that the I/O worst-case time complexity for processing a number of window queries in the given image space, is competitive with respect to multiple instances of a linear quadtree, as confirmed by experimental results. Finally, we show that the MOF-tree can efficiently support spatial join processing in a spatial DBMS.  相似文献   

4.
This paper aims at describing the transition procedure from conventional data files to a data base, beginning with data models of reality and ending with the data definition using the CODASYL DDL. The transition process is explained and a case study is also provided.  相似文献   

5.
Internet measured data collected via passive measurement are analyzed to obtain localization information on nodes by clustering (i.e., grouping together) nodes that exhibit similar network path properties. Since traditional clustering algorithms fail to correctly identify clusters of homogeneous nodes, we propose the NetCluster novel framework, suited to analyze Internet measurement datasets. We show that the proposed framework correctly analyzes synthetically generated traces. Finally, we apply it to real traces collected at the access link of Politecnico di Torino campus LAN and discuss the network characteristics as seen at the vantage point.  相似文献   

6.
This article presents an integrated framework for the development of home automation systems following the model-driven approach. By executing model transformations the environment allows developers to generate executable code for specific platforms. The tools presented in this work help developers to model home automation systems by means of a domain specific language which is later transformed into code for home automation specific platforms. These transformations have been defined by means of graph grammars and template engines extended with traceability capabilities. Our framework also allows the models to be reused for different applications since a catalogue of requirements is provided. This framework enables the development of home automation applications with techniques for improving the quality of both the process and the models obtained. In order to evaluate the benefits of the approach, we conducted a survey among developers that used the framework. The analysis of the outcome of this survey shows which conditions should be fulfilled in order to increase reusability.  相似文献   

7.
The exploration of social dilemmas is being considered a major foundation for encountering the enforced necessities of cooperation in self-organizing environments. Such environments are characterized by self-interested parties and the absence of trusted third parties. Recent approaches apply evolutionary socio-inspired games to formally prove the existence and further prolongation of cooperation patterns within communities. For instance, the Prisoner’s Dilemma game has thus provided a rich opportunity to examine self-interested behaviors in pure peer-to-peer networks. However, assuming a total absence of coalitions, incentives and punishment mechanisms, several works argue against a durable maintenance of cooperation neither at single-shot nor repeated-scenarios. In this article, we formally and experimentally demonstrate a counterexample for the latter by applying evolutionary game theory and a particular instance of the Rock–Scissors–Paper game. Our framework proves that the cyclic dominance of certain type of nodes within a P2P system has an impact and introduces a strategic aspect to the evolution of the overall community.  相似文献   

8.
In this article, we present a cognitive system based on artificial curiosity for high-level knowledge acquisition from visual patterns. The curiosity (perceptual curiosity and epistemic curiosity) is realized through combining perceptual saliency detection and Machine-Learning based approaches. The learning is accomplished by autonomous observation of visual patterns and by interaction with an expert (a human tutor) detaining semantic knowledge about the detected visual patterns. Experimental results validating the deployment of the investigated system have been obtained on the basis of a humanoid robot acquiring visually knowledge from its surrounding environment interacting with a human tutor. We show that our cognitive system allows the humanoid robot to discover the surrounding world in which it evolves, to learn new knowledge about it and describe it using human-like (natural) utterances.  相似文献   

9.
Earlier studies have suggested that higher education institutions could harness the predictive power of Learning Management System (LMS) data to develop reporting tools that identify at-risk students and allow for more timely pedagogical interventions. This paper confirms and extends this proposition by providing data from an international research project investigating which student online activities accurately predict academic achievement. Analysis of LMS tracking data from a Blackboard Vista-supported course identified 15 variables demonstrating a significant simple correlation with student final grade. Regression modelling generated a best-fit predictive model for this course which incorporates key variables such as total number of discussion messages posted, total number of mail messages sent, and total number of assessments completed and which explains more than 30% of the variation in student final grade. Logistic modelling demonstrated the predictive power of this model, which correctly identified 81% of students who achieved a failing grade. Moreover, network analysis of course discussion forums afforded insight into the development of the student learning community by identifying disconnected students, patterns of student-to-student communication, and instructor positioning within the network. This study affirms that pedagogically meaningful information can be extracted from LMS-generated student tracking data, and discusses how these findings are informing the development of a customizable dashboard-like reporting tool for educators that will extract and visualize real-time data on student engagement and likelihood of success.  相似文献   

10.
Vibrating microcantilevers are used to measure the density and the viscosity of surrounding fluids. The classical procedure involves experimental acquisition of the deflection spectrum of the beam, but a systematic calibration step is mandatory for obtaining viscosity and density. In the present study, a method is proposed to facilitate these measurements for Newtonian fluids with only one calibration step in air during the cantilever lifetime. Our approach relies on a complete theoretical analysis allowing to approximate semi-analytically the deflection spectrum with a second-order transfer function and to determine an analytical relationship between viscosity, density and the parameters of the transfer function. Fluid parameter determination results are shown for validation and discussed.  相似文献   

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