4,975 research outputs found

    Computation of rotor aerodynamic loads in forward flight using a full-span free wake analysis

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    The development of an advanced computational analysis of unsteady aerodynamic loads on isolated helicopter rotors in forward flight is described. The primary technical focus of the development was the implementation of a freely distorting filamentary wake model composed of curved vortex elements laid out along contours of constant vortex sheet strength in the wake. This model captures the wake generated by the full span of each rotor blade and makes possible a unified treatment of the shed and trailed vorticity in the wake. This wake model was coupled to a modal analysis of the rotor blade dynamics and a vortex lattice treatment of the aerodynamic loads to produce a comprehensive model for rotor performance and air loads in forward flight dubbed RotorCRAFT (Computation of Rotor Aerodynamics in Forward Flight). The technical background on the major components of this analysis are discussed and the correlation of predictions of performance, trim, and unsteady air loads with experimental data from several representative rotor configurations is examined. The primary conclusions of this study are that the RotorCRAFT analysis correlates well with measured loads on a variety of configurations and that application of the full span free wake model is required to capture several important features of the vibratory loading on rotor blades in forward flight

    Multilingual advertising in the linguistic landscape of Seoul

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    This study examines commercial signs in arguably the two most visited tourism districts in Seoul, namely Myeongdong and Insadong. It focuses on beauty and food businesses and analyzes featured languages and their content and roles in signage. This article argues that business types, specialized marketing focus, and intended sales pitch influence business owners’ linguistic choices. The findings of the study suggest that the beauty industry relies heavily on English in general, but the power of K‐Beauty popularized by ‘Hallyu’ (The Korean Wave) beyond Korea inevitably invites linguistic accommodation in the form of using Chinese and Japanese. In general, the business category of beauty features a more prevalent use of English than the gastronomic business in this study. Moreover, as an area specializing in traditions and cultural heritage, Insadong shows more signs exclusively in Korean than in Myeongdong.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151302/1/weng12427_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151302/2/weng12427.pd

    Patterns of RAPD markers and heavy metal concentrations in Perna viridis (L.), collected from metal-contaminated and uncontaminated coastal waters: Are they correlated with each other?

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    Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s) caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR) technique, namely Random Amplified Polymorphic DNA (RAPD), to determine the genetic diversity of the populations of the green-lipped mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively uncontaminated sites (reference sites). Heavy metal levels (Cd, Cu, Pb, and Zn) were also measured in the soft tissues and byssus of the mussels from all the sites. Cluster analyses employing UPGMA based on the RAPD markers grouped the populations into two major clusters; the Bagan Tiang, Pantai Lido, Pontian, and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution

    Detection of Gravitational Wave - An Application of Relativistic Quantum Information Theory

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    We show that a passing gravitational wave may influence the spin entropy and spin negativity of a system of NN massive spin-1/2 particles, in a way that is characteristic of the radiation. We establish the specific conditions under which this effect may be nonzero. The change in spin entropy and negativity, however, is extremely small. Here, we propose and show that this effect may be amplified through entanglement swapping. Relativistic quantum information theory may have a contribution towards the detection of gravitational wave.Comment: 9 page

    Evidence for Factorization in Three-body B --> D(*) K- K0 Decays

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    Motivated by recent experimental results, we use a factorization approach to study the three-body B --> D(*) K- K0 decay modes. Two mechanisms are proposed for kaon pair production: current-produced (from vacuum) and transition (from B meson). The Bbar0 --> D(*)+ K- K0 decay is governed solely by the current-produced mechanism. As the kaon pair can be produced only by the vector current, the matrix element can be extracted from e+ e- --> K Kbar processes via isospin relations. The decay rates obtained this way are in good agreement with experiment. Both current-produced and transition processes contribute to B- --> D(*)0 K- K0 decays. By using QCD counting rules and the measured B- --> D(*)0 K- K0 decay rates, the measured decay spectra can be understood.Comment: 17 pages, 6 figure

    Nonleptonic charmless two-body BATB \to AT decays

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    In this work we have studied hadronic charmless two-body B decays involving p-wave mesons in final state. We have calculated branching ratios of BATB\to AT decays (where AA and TT denotes a 3P1^3P_1 axial-vector and a tensor meson, respectively), using BTB \to T form factors obtained in the covariant light-front (CLF) approach, and the full effective Hamiltonian. We have obtained that B(B0a1+a2)=42.47×106\mathcal{B}(B^{0} \to a_{1}^{+}a_{2}^{-}) =42.47 \times10^{-6}, B(B+a1+a20)=22.71×106\mathcal{B}(B^{+} \to a_{1}^{+}a_{2}^{0}) = 22.71 \times10^{-6}, B(Bf1K2)=(2.84)×106\mathcal{B}(B \to f_{1}K_{2}^{*}) = (2.8-4) \times 10^{-6} (with f1=,f1(1285),f1(1420)f_{1}=, f_{1}(1285),f_{1}(1420)) for θ3P1=53.2\theta_{^{3}P_{1}} = 53.2^{\circ}, B(Bf1(1420)K2)=(5.916.42)×106\mathcal{B}(B \to f_{1}(1420)K_{2}^{*}) = (5.91-6.42) \times 10^{-6} with θ3P1=27.9\theta_{^{3}P_{1}} = 27.9^{\circ}, B(BK1a2)=(1.75.7)[19.3]×106\mathcal{B}(B \to K_{1}a_{2})= (1.7 - 5.7) [1-9.3] \times10^{-6} for θK1=37[58]\theta_{K_{1}} = -37^{\circ} [-58^{\circ}] where K1=K1(1270),K1(1400)K_1 = K_1(1270), K_1(1400). It seems that these decays can be measured in experiments at BB factories. Additionally, we have found that B(BK1(1270)a2)/B(BK1(1400)a2)\mathcal{B}(B \to K_{1}(1270)a_{2})/\mathcal{B}(B \to K_{1}(1400)a_{2}) and B(Bf1(1420)K2)/B(Bf1(1285)K2)\mathcal{B}(B \to f_1(1420)K_{2}^{*})/\mathcal{B}(B \to f_1(1285)K_{2}^{*}) ratios could be useful to determine numerical values of mixing angles θK1\theta_{K_{1}} and θ3P1\theta_{^{3}P_{1}}, respectively.Comment: 12 page

    Constructing habitus: promoting an international arts trend at the Singapore Arts Festival

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    The Singapore Arts Festival (SAF) is Singapore’s largest government-supported international arts festival. SAF presents the best in international and local arts, in an attempt, to develop what it perceives to be a lack of cultural knowledge of the Singaporean arts-going public. Using Pierre Bourdieu’s key concept of ‘habitus’ together with an analysis of the programming of the festival, this paper will highlight how the festival seeks to create a specific cultural taste in Singaporean art-goers through privileging and promoting works that are internationally marketable to European countries. The paper will conclude that this programming style occurs at the expense of Singaporean artists and hinders the development of the city’s state cultural and artistic development

    Interacting classical and quantum particles

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    We apply Hall and Reginatto's theory of interacting classical and quantum ensembles to harmonically coupled particles, with a view to understanding its experimental implications. This hybrid theory has no free parameters and makes distinctive predictions that should allow it to be experimentally distinguished from quantum mechanics. It also bears on the questions of quantum measurement and quantum gravity.Comment: 7 pages, 6 figure

    An examination of the influence of emotional solidarity on value cocreation with international muslim travelers

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    Given the rising Muslim travel market and the scarcity of research on Muslim inbound market, it is important to elucidate how international Muslim travelers are perceived through the lens of residents in non-Islamic countries. This study provided an insight into how value cocreation is created through emotional solidarity and attitudes in the context of the Muslim travel market. Results of the structural model for American residents were comparatively similar to those of their Korean counterparts, which is indicative of both countries’ acceptance and tolerance of international Muslim travelers. In particular, residents’ openness to experience and the perceived benefit of international Muslim travelers for development of the tourist destination were significant predictors of emotional solidarity. Residents’ emotional solidarity subsequently explained their attitude toward international Muslim travelers. Attitude toward international Muslim travelers would lead to a positive attitude toward Muslim tourism, which in turn, triggered value cocreation behavior with international Muslim travelers.info:eu-repo/semantics/acceptedVersio

    Non-invertible transformations and spatiotemporal randomness

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    We generalize the exact solution to the Bernoulli shift map. Under certain conditions, the generalized functions can produce unpredictable dynamics. We use the properties of the generalized functions to show that certain dynamical systems can generate random dynamics. For instance, the chaotic Chua's circuit coupled to a circuit with a non-invertible I-V characteristic can generate unpredictable dynamics. In general, a nonperiodic time-series with truncated exponential behavior can be converted into unpredictable dynamics using non-invertible transformations. Using a new theoretical framework for chaos and randomness, we investigate some classes of coupled map lattices. We show that, in some cases, these systems can produce completely unpredictable dynamics. In a similar fashion, we explain why some wellknown spatiotemporal systems have been found to produce very complex dynamics in numerical simulations. We discuss real physical systems that can generate random dynamics.Comment: Accepted in International Journal of Bifurcation and Chao
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