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1.
We present a model for anchoring categorical conceptual information which originates from physical perception and the web. The model is an extension of the anchoring framework which is used to create and maintain over time semantically grounded sensor information. Using the augmented anchoring framework that employs complex symbolic knowledge from a commonsense knowledge base, we attempt to ground and integrate symbolic and perceptual data that are available on the web. We introduce conceptual anchors which are representations of general, concrete conceptual terms. We show in an example scenario how conceptual anchors can be coherently integrated with perceptual anchors and commonsense information for the acquisition of novel concepts.  相似文献   
2.
Smell, think and act: A cognitive robot discriminating odours   总被引:1,自引:0,他引:1  
In this paper, we explore the integration of an electronic nose and its odour discrimination functionalities into a multi-sensing robotic system which works over an extended period of time. The robot patrols an office environment, collecting odour samples of objects and performing user requested tasks. By considering an experimental platforms which operates over an extended period of time, a number of issues related to odour discrimination arise such as the drift in the sensor data, online learning of new odours, and the correct association of odour properties related to objects. In addition to an electronic nose our robotic system consists of other sensing modalities (vision and sonar), behaviour-based control and a high level symbolic planner.  相似文献   
3.
Internet addiction is “an individual’s inability to control their Internet use, which in turn leads to feelings of distress and functional impairment of daily activities” [Shapira, N., Lessig, M., Goldsmith, T., Szabo, S., Lazoritz, M., Gold, M. et al. (2003). Problematic Internet use: Proposed classification and diagnostic criteria. Depression and Anxiety, 17(4), 207–216]. Previous research in this field has offered inconclusive data on whether Internet addiction can be classified as a disorder. This study provides an in-depth and comprehensive analysis of internet addiction through a meta-synthesis of qualitative studies on excessive Internet use published during the period of 1996–2006. Several constructs pertaining to the domain of Internet addiction have been identified and a theoretical model of Internet addiction has been proposed.  相似文献   
4.
The authors have previously demonstrated that their Positron Emission Mammography-1 (PEM-1) system can successfully detect small (<2 cm diameter) tumors. Images in the current system are judged qualitatively for the presence of focal uptake of 18F-FDG. The authors are presently taking steps toward quantifying the emission images. To this end they have constructed a breast phantom and developed a novel technique for fabricating very small wall-less radioactive hot-spots. The hot-spots are made by adding 18F-FDG to a 25 mg/cc solution of Agarose in water. The heated solution is poured into spherical molds which are separated upon congealing to yield robust wall-less radioactive hot-spots. The hot-spots were uniform to within 1-5 parts in 100. Less than 0.1% of the total hot-spot activity leaked into the background in 30 minutes. Contrast resolution experiments have been performed with 12 mm and 16 mm diameter hot-spots in the breast phantom containing water with various amounts of background activity. In both cases, the observed contrast values agree well with the ideal values. In the case of the 12 mm hot-spot with a 350-650 keV energy window, image contrast differed from the ideal by an average of 11%. The image contrast for 12 mm hot-spot improved by 40% and the number of detected events decreased by 35% when the low energy threshold was increased from 300 keV to 450 keV  相似文献   
5.
Logic-based models have been already proposed for information retrieval purpose. However, there is a need for new formalisms providing more generic frameworks. For this purpose, an information retrieval axiomatic theory is proposed in this paper, independently of any model. Our proposal which mainly relies on many-sorted logic allows to consider various sets in the domain of discourse that provides us a rich framework to model the different items such as documents, index terms, queries. The theory relies on a sound set of axioms driving the retrieval process as proof of theorems. As such the genericity consists of a main motivation; it will be proved that three classical information retrieval models, namely the Boolean model; the fuzzy-set-based extension of the Boolean model; and the vector space model, satisfy the proposed theory, establishing then its consistency. Beyond the genericity, the proposed approach may face concrete problems. Indeed, it is well known that the use of the classical settings of formal concept analysis theory for information retrieval does not allow disjunctions and negations in queries. For this purpose, this paper gives a characterization of these queries forms using appropriates theorems of the theory. Useful algebraic properties (i.e., isomorphisms) are then established for this end.  相似文献   
6.
In an ad-hoc network, mobile stations communicate with each other using multi-hop wireless links. There is no stationary infrastructure such as base stations. Each node in the network also acts as a router, forwarding data packets for other nodes. In this architecture, mobile stations have a multi-hop path, via other mobile stations acting as intermediaries or relays, to indirectly forward packets from source to destination. Adjusting the transmitted power is extremely important in ad-hoc networks due to at least the following reasons. The transmitted power of the radio terminals determines the network topology. The network topology in turn has considerable impact on the throughput (fraction of packets, sent by a source, and successfully received at the receiver) performance of the network. The need for power efficiency must be balanced against the lifetime of each individual node and the overall life of the network. Power control problem can be classified in one of three categories. The first class comprises of strategies to find an optimal transmitted power to control the connectivity properties of the network. The second class of approaches could be called power aware routing. Most schemes use some shortest path algorithm with a power based metric, rather than a hop count based metric. The third class of approaches aim at modifying the mac layer. We use distributed power control algorithms initially proposed for cellular networks. We establish a classification of power control algorithms for wireless ad-hoc networks. We evaluate these algorithms in anIeee 802.11b multi-hop wireless ad-hoc LAN environment. Results show the advantage of power control in maximizing signal-to-interference ratio and minimizing transmitted power.  相似文献   
7.
Smell, it helps remind us when it's time to take out the garbage or change the baby's diaper. We use it to detect danger, such as a gas leak or food burning on the stove. Industries that develop products to help us either smell good or prevent aromatic offense testify to the aesthetic importance of odors, as well as to economic value. Still, olfaction's significance is unparalleled in the animal kingdom, where many species' survival would be jeopardized without the ability to detect and recognize odors. Integrating electronic noses with other sensors on complex, intelligent platforms offers exciting application possibilities and considerable development challenges.  相似文献   
8.
Present concepts of the mechanism of reactivation of synthesis of fetal hemoglobin (HbF) in the adult under conditions of erythropoietic stress are briefly reviewed. Since HbF can be considered an effective natural antisickling agent, the reactivation of its synthesis in patients with sickle cell anemia as a desirable therapeutic goal has been extensively explored since the discovery in 1982 that 5-azacytidine increases HbF levels in the baboon. Hydroxyurea (HU) has become the most widely used agent, although its effectiveness in increasing HbF levels and the number of F cells is highly variable. Recent investigations are cited showing that other agents such as butyrate, and the addition of recombinant hemopoietic growth factors, such as erythropoietin and stem cell factor, especially in combination with HU, offer important therapeutic possibilities. Transacting nuclear proteins are briefly discussed as possibly having a future role in the efforts of stimulating gamma-chain synthesis.  相似文献   
9.
One of the important aspects of a mobile ad hoc network (MANET) is the limitation of the amount of available energy and the network lifetime. The tremendous amount of using mobile nodes in wireless communication medium makes energy efficiency a fundamental requirement for MANETs. In this paper, we propose a novel energy aware clustering algorithm for the optimized link state routing (OLSR) routing protocol. This algorithm takes into account the node density and mobility and gives major improvements regarding the number of elected cluster heads. Our objective is to elect a reasonable number of cluster heads that will serve for hierarchical routing based on OLSR. The proposed algorithm aims to increase the network lifetime by considering the ad hoc residual energy while taking routing decisions. It also optimizes the delay of carried flows by adopting a selective forwarding approach based on a hierarchical routing model.  相似文献   
10.
The aim of the present study is to suggest two new fluids as alternatives of R12 in a vapour compression cycle. These fluids are the methyl trifluoromethyl ether (E143a) and the hexafluorocyclopropane (C216), which belong to halogenated derivatives of dimethyl ether and cyclopropane, respectively. The two suggested fluids have low degree of toxicity and a quite short atmospheric life. They also have suitable boiling points and a relatively simple molecular structure.A method of estimation of the thermodynamic properties of E143a and C216 is presented. The theoretical performance of the new fluids are evaluated and compared to those of the R12.  相似文献   
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