3,735 research outputs found

    Oil and the G7 business cycle : Friedman's Plucking Markov Switching Approach

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    To analyze whether oil price can account for the business cycle asymmetries in the G7, this paper adopts the Friedman’s Plucking Markov Switching Model to decompose G7 real GDPs into common permanent components, common transitory components, infrequent Markov Switching negative shock and domestic idiosyncratic components. The findings show that Hamilton’s 3 year net oil price increases account for 1973-75, 1980, partially 1990-1991 recessions and LNR oil price increases account for 1973-75, 1980, partially 1960, partially 1970, partially 1990-1991 recessions. These results indicate that oil price shocks have not been a principal determinant of common recessions in the G7 except two major OPEC oil price increases in 1973-1974, 1979-1980oil, OPEC, G7, GDP, business cycle, Friedman’s Plucking Markov Switching, permanent, transitory

    Has the G7 business cycle become more synchronized ?

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    This paper adopts Friedman’s Plucking Markov Switching Model to decompose G7 real GDPs into common permanent components, common transitory components, infrequent Markov Switching negative shock and domestic idiosyncratic components. The findings show that the common components explain a 53.1% average volatility of G7 GDPs from 1960 to 2002. Despite the moderated volatility of G7 economies, the G7 business cycle (except Japan) has become more synchronized in its fluctuations. In addition, from the dynamic factor model with Markov switching, there appears to have been a common permanent synchronized fluctuation in the Euro-zone countries after 1984. The probability that the common transitory component is contracting, accords quite well with U.S recessionary dates.G7, GDP, business cycle, Friedman’s Plucking Markov Switching Model, permanent, transitory

    MOBICORS-Movie: A MOBIle COntents Recommender System for Movie

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    In spite of the rapid growth of mobile multimedia contents market, most of the customers experience inconvenience, lengthy search processes and frustration in searching for the specific multimedia contents they want. These difficulties are attributable to the current mobile Internet service method based on inefficient sequential search. To overcome these difficulties, this paper proposes a MOBIle COntents Recommender System for Movie (MOBICORS-Movie), which is designed to reduce customers’ search efforts in finding desired movies on the mobile Internet. MOBICORS-Movie consists of three agents: CF (Collaborative Filtering), CBIR (Content-Based Information Retrieval) and RF (Relevance Feedback). These agents collaborate each other to support a customer in finding a desired movie by generating personalized recommendations of movies. To verify the performance of MOBICORS-Movie, the simulation-based experiments were conducted. The experiment results show that MOBICORS-Movie significantly reduces the customer’s search effort and can be a realistic solution for movie recommendation in the mobile Internet environment

    Isolation of p-hydroxycinnamaldehyde as an antibacterial substance from the saw fly, Acantholyda parki S.

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    AbstractWe purified an antibacterial substance from larvae of the saw fly, Acantholyda parki S., and identified its molecular structure as p-hydroxycinnamaldehyde. We then synthesized it by reduction of p-hydroxycinnamic acid. The antibacterial activity of the synthetic p-hydroxycinnamaldehyde was equal to that of the authentic substance. This molecule was found to have a broad antibacterial spectrum against not only Gram-negative, but also Gram-positive bacteria. Furthermore, it showed antifungal activity against Candida albicans. We suggest that this substance may play a role in the defense system of this insect. This is the first report of p-hydroxycinnamaldehyde of animal origin

    Impact of Toxocariasis in Patients with Unexplained Patchy Pulmonary Infiltrate in Korea

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    Toxocariasis is one of the causes of pulmonary eosinophilic infiltrate that is increasing in Korea. This study was designed to identify the prevalence of toxocara seropositivity in patients with unexplained pulmonary patchy infiltrate and to evaluate associated factors. We evaluated 102 patients with unexplained pulmonary patchy infiltrate on chest computed tomography (CT) scan. As a control set, 116 subjects with normal chest CT were also evaluated. History of allergic disease, drug use, parasitic disease and raw cow liver intake were taken. Blood eosinophil count and total IgE level were measured. Specific serum IgG antibody to Toxocara canis larval antigen and specific IgG antibodies to 4 other parasites were measured by enzyme-linked immunosorbent assay (ELISA). In the infiltrate group, 66.7% subjects were toxocara seropositive whereas 22.4% of the control group were seropositive (p<0.001). In the infiltrate group, patients with a history of eating raw cow liver (odds ratio [OR], 7.8) and patients with eosinophilia (OR, 5.2) had a higher incidence of toxocara seropositivity. Thirty-five percent of toxocara seropositive patients with infiltrate exhibited migrating infiltrate and 48% had decreased infiltrate on the follow-up CT. We recommend that toxocara ELISA should be performed in patients with unexplained pulmonary patchy infiltrate, and that the eating of raw cow liver should be actively discouraged

    Topological beaming of light

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    Nanophotonic light emitters are key components in numerous application areas because of their compactness and versatility. Here, we propose a topological beam emitter structure that takes advantage of submicrometer footprint size, small divergence angle, high efficiency, and adaptable beam shaping capability. The proposed structure consists of a topological junction of two guided-mode resonance gratings inducing a leaky Jackiw-Rebbi state resonance. The leaky Jackiw-Rebbi state leads to in-plane optical confinement with funnel-like energy flow and enhanced emission probability, resulting in highly efficient optical beam emission. In addition, the structure allows adaptable beam shaping for any desired positive definite profiles by means of Dirac mass distribution control, which can be directly encoded in lattice geometry parameters. Therefore, the proposed approach provides highly desirable properties for efficient micro–light emitters and detectors in various applications including display, solid-state light detection and ranging, laser machining, label-free sensors, optical interconnects, and telecommunications

    Construction cost estimation using a case-based reasoning hybrid genetic algorithm based on local search method

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    Estimates of project costs in the early stages of a construction project have a significant impact on the operator\u27s decision-making in essential matters, such as the site\u27s decision or the construction period. However, it is not easy to carry out the initial stage with confidence, because information such as design books and specifications is not available. In previous studies, case-based reasoning (CBR) is used to estimate initial construction costs, and genetic algorithms are used to calculate the weight of the retrieve phase in CBR\u27s process. However, it is difficult to draw a better solution than the current one, because existing genetic algorithms use random numbers. To overcome these limitations, we reflect correlation numbers in the genetic algorithms by using the method of local search. Then, we determine the weights using a hybrid genetic algorithm that combines local search and genetic algorithms. A case-based reasoning model was developed using a hybrid genetic algorithm. Then, the model was verified with construction cost data that were not used for the development of the model. As a result, it was found that the hybrid genetic algorithm and case-based reasoning applied with the local search performed better than the existing solution. The detail mean error value was found to be 3.52%, 6.15%, and 0.33% higher for each case than the previous one
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