7,245 research outputs found

    Application of teletraffic engineering modelling techniques for studying smart lighting systems on energy saving

    Get PDF
    Limited natural energy resources compel humankind to search for efficient utilization of energy, and thus increasing number of fluorescent lamps are adopted for lighting systems. However, previous study showed that there exists a tradeoff between energy saving and lifespan for fluorescent lamps. Consequently, it becomes an important topic on how to design an efficient and effective automatic control algorithm in illuminating engineering. This problem has been traditionally studied by conducting surveys and experiments, which are unavoidably costly and rather time-consuming. This paper presents a novel application of teletraffic engineering modelling techniques in studying automatic lighting control systems. A queuing model is proposed to study typical lighting systems and a simple closed-loop algorithm is illustrated to effectively adapt the system control parameters. Through computer simulation, it is shown that the proposed method provides an alternative way of studying lighting systems in a costeffective manner, while providing adequate accuracy

    Joint Concurrent Routing and Multi-Pointer Packet Scheduling in IEEE 802.16 Mesh Networks

    Get PDF
    IEEE 802.16, also known as Worldwide Interoperability for Microwave Access (WiMAX), is a standardization effort carried out by the IEEE to provide last-mile broadband access to end users. The IEEE 802.16 standard supports two medium access control (MAC) modes - a mandatory point to multipoint (PMP) mode and an optional mesh mode. In this paper, we propose an asymmetric interference aware routing algorithm and a new multipointer approach in implementing scheduling algorithms for IEEE 802.16 mesh networks. We modify three different centralized scheduling algorithms, fixed scheduling, ordered scheduling and per-slot scheduling using multipointer approach to allow for spatial reuse (SR) in IEEE 802.16 mesh networks. Simulation results reveal that fixed scheduling with SR provides the best performance

    High compression ratio image processing techniques using combinations of WT and IFS

    Get PDF
    Many works of compressing image based on wavelet transformation have been presented in recent years. Also, the method of fractals is used in this field. The first method uses the pyramid subband decomposition, and the second takes advantage of the self-similarity between the basic image and subimages. We combine these two methods as a hybrid algorithm to complete the image compression. The experiments show that this method has a better performance than many others, especially, in a high compression ratio situation. A comparison with the famous embedded zero tree wavelet (EZW) algorithm shows that its performance is close to the EZW algorithm.published_or_final_versio

    Associative classifier for uncertain data

    Get PDF
    Associative classifiers are relatively easy for people to understand and often outperform decision tree learners on many classification problems. Existing associative classifiers only work with certain data. However, data uncertainty is prevalent in many real-world applications such as sensor network, market analysis and medical diagnosis. And uncertainty may render many conventional classifiers inapplicable to uncertain classification tasks. In this paper, based on U-Apriori algorothm and CBA algorithm, we propose an associative classifier for uncertain data, uCBA (uncertain Classification Based on Associative), which can classify both certain and uncertain data. The algorithm redefines the support, confidence, rule pruning and classification strategy of CBA. Experimental results on 21 datasets from UCI Repository demonstrate that the proposed algorithm yields good performance and has satisfactory performance even on highly uncertain data

    Asymmetric hydroformylation of styrene catalyzed by pyranoside diphosphite-rh(Ⅰ) complexes

    Get PDF
    2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Relative edge energy in the stability of transition metal nanoclusters of different motifs

    Get PDF
    When a structure is reduced to a nanometer scale, the proportion of the lowly-coordinated edge atoms increases significantly, which can play a crucial role in determining both their geometric and electronic properties, as demonstrated by the recently established generalized Wulff construction principle [S. F. Li, et al., Phys. Rev. Lett., 2013, 111, 115501]. Consequently, it is of great interest to clarify quantitatively the role of the edge atoms that dominate the motifs of these nanostructures. In principle, establishing an effective method valid for determining the absolute value of the surface energy and particularly the edge energy for a given nanostructure is expected to resolve such a problem. However, hitherto, it is difficult to obtain the absolute edge energy of transition metal clusters, particularly when their sizes approach the nanometer regime. In this paper, taking Ru nanoclusters as a prototypical example, our first-principles calculations introduce the concept of relative edge energy (REE), reflecting the net edge atom effect over the surface (facet) atom effect, which is fairly powerful to quasi-quantitatively estimate the critical size at which the crossover occurs between different configurations of a given motif, such as from an icosahedron to an fcc nanocrystal. By contrast, the bulk effect should be re-considered to rationalize the power of the REE in predicting the relative stability of larger nanostructures between different motifs, such as fcc-like and hcp-like nanocrystals

    PPI-IRO: A two-stage method for protein-protein interaction extraction based on interaction relation ontology

    Full text link
    Mining Protein-Protein Interactions (PPIs) from the fast-growing biomedical literature resources has been proven as an effective approach for the identifi cation of biological regulatory networks. This paper presents a novel method based on the idea of Interaction Relation Ontology (IRO), which specifi es and organises words of various proteins interaction relationships. Our method is a two-stage PPI extraction method. At fi rst, IRO is applied in a binary classifi er to determine whether sentences contain a relation or not. Then, IRO is taken to guide PPI extraction by building sentence dependency parse tree. Comprehensive and quantitative evaluations and detailed analyses are used to demonstrate the signifi cant performance of IRO on relation sentences classifi cation and PPI extraction. Our PPI extraction method yielded a recall of around 80% and 90% and an F1 of around 54% and 66% on corpora of AIMed and Bioinfer, respectively, which are superior to most existing extraction methods. Copyright © 2014 Inderscience Enterprises Ltd

    Competition between ferromagnetic metallic and paramagnetic insulating phases in manganites

    Get PDF
    La 0.67Ca 0.33Mn 1-xCu xO 3 (x=0 and 0.15) epitaxial thin films were grown on the (100) LaAlO 3 substrates, and the temperature dependence of their resistivity was measured in magnetic fields up to 12 T by a four-probe technique. We found that the competition between the ferromagnetic metallic (FM) and paramagnetic insulating (PI) phases plays an important role in the observed colossal magnetoresistance (CMR) effect. Based on a scenario that the doped manganites approximately consist of phase-separated FM and PI regions, a simple phenomenological model was proposed to describe the CMR effect. Using this model, we calculated the resistivity as functions of temperature and magnetic field. The model not only qualitatively accounts for some main features related to the CMR effect, but also quantitatively agrees with the experimental observations. © 2002 American Institute of Physics.published_or_final_versio

    Hole dispersions in the G- and C-type orbital ordering backgrounds: Doped manganese oxides

    Get PDF
    In the framework of the linear spin-wave theory and orbital-charge separation, we calculate quasiparticle (QP) dispersions for two different antiferromagnetic orbital structures in the fully saturated spin phase of manganese oxides. Although with the same orbital wave excitations, the QP bands of C- and G-type orbital structures exhibit completely different shapes. The pseudogap observed in the density of states and spectral functions around ω=0 is related with the large antiferromagnetic orbital fluctuation. The minimal band energy for G-type is lower than that for C-type orbital order, while these band curves almost coincide in some momentum points. Larger energy splitting occurs between the two branches of k z=0 and k z=π when increasing the superexchange coupling J, suggesting that the orbital scattering plays an essential role in the QP dispersions. ©2000 The American Physical Society.published_or_final_versio

    Literature review and analysis of the application of health outcome assessment instruments in Chinese medicine

    Full text link
    OBJECTIVE: To evaluate the application of health assessment instruments in Chinese medicine. METHODS: According to a pre-defined search strategy, a comprehensive literature search for all articles published in China National Knowledge Infrastructure databases was conducted. The resulting articles that met the defined inclusion and exclusion criteria were used for analysis. RESULTS: A total of 97 instruments for health outcome assessment in Chinese medicine have been used in fundamental and theoretical research, and 14 of these were also used in 29 clinical trials that were randomized controlled trials, or descriptive or cross-sectional studies. In 2 152 Chinese medicine-based studies that used instruments in their methodology, more than 150 questionnaires were identified. Among the identified questionnaires, 51 were used in more than 10 articles (0.5%). Most of these instruments were developed in Western countries and few studies (4%) used the instrument as the primary evidence for their conclusions. CONCLUSION: Usage of instruments for health outcome assessment in Chinese medicine is increasing rapidly; however, current limitations include selection rationale, result interpretation and standardization, which must be addressed accordingly
    corecore