Search results for "Marginal"
showing 10 items of 350 documents
Exploring regression structure with graphics
1993
We investigate the extent to which it may be possible to carry out a regression analysis using graphics alone, an idea that we refer to asgraphical regression. The limitations of this idea are explored. It is shown that graphical regression is theoretically possible with essentially no constraints on the conditional distribution of the response given the predictors, but with some conditions on marginal distribution of the predictors. Dimension reduction subspaces and added variable plots play a central role in the development. The possibility of useful methodology is explored through two examples.
Estimating regression models with unknown break-points.
2003
This paper deals with fitting piecewise terms in regression models where one or more break-points are true parameters of the model. For estimation, a simple linearization technique is called for, taking advantage of the linear formulation of the problem. As a result, the method is suitable for any regression model with linear predictor and so current software can be used; threshold modelling as function of explanatory variables is also allowed. Differences between the other procedures available are shown and relative merits discussed. Simulations and two examples are presented to illustrate the method.
Dynamic copula models for the spark spread
2011
We propose a non-symmetric copula to model the evolution of electricity and gas prices by a bivariate non-Gaussian autoregressive process. We identify the marginal dynamics as driven by normal inverse Gaussian processes, estimating them from a series of observed UK electricity and gas spot data. We estimate the copula by modeling the difference between the empirical copula and the independent copula. We then simulate the joint process and price options written on the spark spread. We find that option prices are significantly influenced by the copula and the marginal distributions, along with the seasonality of the underlying prices.
Effect of disinfecting the cavity with chlorhexidine on the marginal gaps of Cl V giomer restorations
2017
Background Considering the effect of cavity disinfecting agents on the bonding and sealing ability of restorations bonded to dentin, the aim of this study was to evaluate the effect of chlorhexidine (CHX) disinfecting agent on the marginal gaps of Cl V giomer restorations. Material and Methods Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors in this in vitro study, with the occlusal and gingival margins in enamel and dentin, respectively. The teeth were randomly divided into two groups (n=30). The teeth in groups 1 and 2 were restored without and with the use of the disinfecting agent in the cavity, respectively, before applying the adhesive. BeautiBo…
Short implants (8mm) versus longer implants (≥8mm) with lateral sinus floor augmentation in posterior atrophic maxilla: A meta-analysis of RCT`s in h…
2019
Background One of the greatest challenges that dentists face today is to rehabilitate severe atrophied alveolar ridges in partially and completely edentulous patients with implants. Despite the high survival rate of implants placed next to sinus elevation, this technique presents complications that can be avoided by placing short implants, an option that also presents high survival rates. For this reason, the aim of this study is to compare the survival rate, marginal bone loss and complications associated with short implants (<8 mm) versus longer implants (≥8mm) placed with lateral sinus floor elevation in posterior atrophic maxillae. Material and Methods A literature search was conducted …
Microcosmi. Il teatro di Seneca a Palermo tra marginalità e canone
2012
In the last thirty years the study of Seneca’s theatre has become central in Italy, and particularly in the microcosm of Palermo University. This paper analyses the processes that have originated this development and attempts to document the consequences of the shift of Seneca’s theatre from the margins to the centre of the research interests. Three aspects will be taken into account: the renewal of the Latin literary canon in academic education, the diffusion of the study of Seneca at school, and the contribution of Seneca’s studies to the construction of relevant academic identities in contemporary scientific debate.
Pomological and quality traits of mulberry (Morus spp.) germplasm from Gorno Badakhshan in the Western Pamir
2017
The local fruit biodiversity can represent a good opportunity to maintain the agriculture and to develop economies in "marginal" territory such as those in the mountain rural areas. The genetic diversity of the Morus spp. is little known in the Western Pamir mountains, so that the objective of the present study was to improve the knowledge of the polymorphism of the species in the different poorly explored Tajik valleys by investigating the main quantitative and qualitative traits. Materials and methods - Six selected sites of the Gorno Badakhshan Autonomous Oblast (GBAO) region were investigated through field measurement on morphological traits of mulberry trees (both from wild and cultiva…
On the side of the marginals: the character of Ahmed in The Tower of Defense (1978) of Copy
2018
Copi, writer, playwright and draughtsman Ar- gentino settles in Paris in 1962 until his death in 1987. The experience of exile and wandering marks the personal and creative trajectory of this intercultural artist. Indeed, a whole series of vulnerable and marginal characters swarm in their particular universe and subvesivo. In this space of the excluded, the figure of the immi- grant Maghreb in France, embodied in the cha- racter of Ahmed, acquires all its significance. In this work we will try to analyse the symbolic value of Ahmed, heir to the colonial past mar- ked by rejection, which appears in the Teatro de Copi, specifically in La Défense Tour (1978). Ahmed’s image traces an invisible …
Following the Money: Revenue Stream Constituents in Case of Within-firm Variation
2014
The idea of this paper stems from the perception that the concept of revenue stream requires clarification and further division to be applicable to businesses with high internal variation in their methods of capturing revenue. Current study sets out to investigate the concept of revenue stream through an overview of previous literature and a case study to demonstrate how revenue streams of a b2b (business-to-business) software service firm can be analyzed by elaborating the concept further. The aim is to answer the following research questions: 1) What are the relevant constituents of the revenue stream concept within a b2b software services firm? 2) How revenue stream as part of the busine…
Profit Margin Ratio, Markup, Profit Margin Per Unit, Economic Profit, and Profitability as Objectives for the Firm: An Economic Point-of-View
2015
We study five operational objectives for the firm: three marketing objectives (maximizing profit-margin ratio, maximizing markup, and maximizing profit-margin-per-unit), and two financial objective (maximizing economic profit (i.e., EVA) and maximizing profitability), as alternatives to the scholarly objective of maximizing profit. We prove that (i) Sales are lowest for profit-margin-per-unit, intermediate for profit-margin ratio and markup, and highest for profit maximization. Input consumption, including labor, is lower. Prices are in the reverse order. In terms of profit, profit-margin ratio, markup, and profit-margin-per-unit are necessarily less efficient than the classical profit maxi…