9,740 research outputs found

    Topics in ordinal logistic regression and its applications

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    Sample size calculation methods for ordinal logistic regression are proposed to test statistical hypotheses. The author was motivated to do this work by the need for statistical analysis of the red imported fire ants data. The proposed methods use the concept of approximation by the moment-generating function. Some correction methods are also suggested. When a prior data set is available, an empirical method is explored. Application of the proposed methodology to the fire ant mating flight data is demonstrated. The proposed sample size and power calculation methods are applied in the hypothesis testing problems. Simulation studies are also conducted to illustrate their performance and to compare them with existing methods

    The structure of gauge-invariant ideals of labelled graph CC^*-algebras

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    In this paper, we consider the gauge-invariant ideal structure of a CC^*-algebra C(E,L,B)C^*(E,\mathcal{L},\mathcal{B}) associated to a set-finite, receiver set-finite and weakly left-resolving labelled space (E,L,B)(E,\mathcal{L},\mathcal{B}), where L\mathcal{L} is a labelling map assigning an alphabet to each edge of the directed graph EE with no sinks. Under the assumption that an accommodating set B\mathcal{B} is closed under taking relative complement, it is obtained that there is a one to one correspondence between the set of all hereditary saturated subsets of B\mathcal{B} and the gauge-invariant ideals of C(E,L,B)C^*(E,\mathcal{L},\mathcal{B}). For this, we introduce a quotient labelled space (E,L,[B]R)(E,\mathcal{L},[\mathcal{B}]_R) arising from an equivalence relation R\sim_R on B\mathcal{B} and show the existence of the CC^*-algebra C(E,L,[B]R)C^*(E,\mathcal{L},[\mathcal{B}]_R) generated by a universal representation of (E,L,[B]R)(E,\mathcal{L},[\mathcal{B}]_R). Also the gauge-invariant uniqueness theorem for C(E,L,[B]R)C^*(E,\mathcal{L},[\mathcal{B}]_R) is obtained. For simple labelled graph CC^*-algebras C(E,L,Eˉ)C^*(E,\mathcal{L},\bar{\mathcal{E}}), where Eˉ\bar{\mathcal{E}} is the smallest accommodating set containing all the generalized vertices, it is observed that if for each vertex vv of EE, a generalized vertex [v]l[v]_l is finite for some ll, then C(E,L,Eˉ)C^*(E,\mathcal{L},\bar{\mathcal{E}}) is simple if and only if (E,L,Eˉ)(E,\mathcal{L},\bar{\mathcal{E}}) is strongly cofinal and disagreeable. This is done by examining the merged labelled graph (F,LF)(F,\mathcal{L}_F) of (E,L)(E,\mathcal{L}) and the common properties that C(E,L,Eˉ)C^*(E,\mathcal{L},\bar{\mathcal{E}}) and C(F,L,Fˉ)C^*(F,\mathcal{L},\bar{\mathcal{F}}) share

    The Effect of Presence on Consumers\u27 Responses to Virtual Mirror Technology

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    Virtual mirror, an increasingly popular application of augmented reality (AR), allows consumers to view their visages overlaid with product images on digital displays. This study investigates the effect of presence on consumers\u27 responses to AR- (versus virtual reality (VR-) based virtual mirror technology. Results show that AR-based presentation is more likely to induce presence than VR-based presentation, thereby leading to greater mental imagery, favorable virtual mirror attitude, and stronger purchase intentions. Implications for digital retailers in the fashion industry are discussed

    NOMINAL EXCHANGE RATE MISALIGNMENT: IS IT PARTICULARLY IMPORTANT TO AGRICULTURAL TRADE?

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    This paper examines whether exchange rate misalignment negatively affects agricultural trade, compared to other industry sectors. Nominal exchange rate misalignment is obtained from the percentage deviation of real exchange rates from their long-run equilibrium based on the theory of purchasing power parity. In order to explore this issue, a bilateral trade matrix involving trade flows between 10 developed countries is constructed. Using panel data analysis, a gravity model is estimated for 4 industry sectors over the period 1974-1999. The study finds that over-valuation (under-valuation) of the nominal exchange rate negatively (positively) affects export performance of the agricultural sector in particular. In the large-scale manufacturing sectors considered in this paper, exports are not significantly affected by exchange rate misalignment.exchange rate misalignment, agricultural trade, gravity model, International Relations/Trade,
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