994 resultados para holographic and volume memories


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The modern stereologic method of vertical sections was applied to the retina as a means of generating unbiased estimates of three-dimensional structure. The method is illustrated with real data on the volume and surface area of the capillary basement membrane from the central retina of the rat. Novel methods of estimating the volume of retina sampled and of creating accurate vertical sections are described. The advantages of using stereologic methods to generate quantitative information on the three-dimensional structure of the retina are discussed and compared to those of previous quantitative methods that provide data on two-dimensional structure only.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper attempts to develop an improved tool, which would read two dimensional(2D) cardiac MRI images and compute areas and volume of the scar tissue. Here the computation would be done on the cardiac MR images to quantify the extent of damage inflicted by myocardial infarction on the cardiac muscle (myocardium) using Interpolation

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Relativistic multi-configuration Dirac Fock (MCDF) wavefunctions coupled to good angular momentum J have been calculated for low lying states of Ba I and Ba II. These wavefunctions are compared with semiempirical ones derived from experimental atomic energy levels. It is found that significantly better agreement is obtained when close configurations are included in the MCDF wavefunctions. Calculations of the electronic part of the field isotope shift lead to very good agreement with electronic factors derived from experimental data. Furthermore, the slopes of the lines in a King plot analysis of many of the optical lines are predicted accurately by these calculations. However, the MCDF wavefunctions seem not to be of sufficient accuracy to give agreement with the experimental magnetic dipole and electric quadrupole hyperfine structure constants.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

It is well known that there is a dynamic relationship between cerebral blood flow (CBF) and cerebral blood volume (CBV). With increasing applications of functional MRI, where the blood oxygen-level-dependent signals are recorded, the understanding and accurate modeling of the hemodynamic relationship between CBF and CBV becomes increasingly important. This study presents an empirical and data-based modeling framework for model identification from CBF and CBV experimental data. It is shown that the relationship between the changes in CBF and CBV can be described using a parsimonious autoregressive with exogenous input model structure. It is observed that neither the ordinary least-squares (LS) method nor the classical total least-squares (TLS) method can produce accurate estimates from the original noisy CBF and CBV data. A regularized total least-squares (RTLS) method is thus introduced and extended to solve such an error-in-the-variables problem. Quantitative results show that the RTLS method works very well on the noisy CBF and CBV data. Finally, a combination of RTLS with a filtering method can lead to a parsimonious but very effective model that can characterize the relationship between the changes in CBF and CBV.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The temporal relationship between changes in cerebral blood flow (CBF) and cerebral blood volume (CBV) is important in the biophysical modeling and interpretation of the hemodynamic response to activation, particularly in the context of magnetic resonance imaging and the blood oxygen level-dependent signal. Grubb et al. (1974) measured the steady state relationship between changes in CBV and CBF after hypercapnic challenge. The relationship CBV proportional to CBFPhi has been used extensively in the literature. Two similar models, the Balloon (Buxton et al., 1998) and the Windkessel (Mandeville et al., 1999), have been proposed to describe the temporal dynamics of changes in CBV with respect to changes in CBF. In this study, a dynamic model extending the Windkessel model by incorporating delayed compliance is presented. The extended model is better able to capture the dynamics of CBV changes after changes in CBF, particularly in the return-to-baseline stages of the response.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Historical narratives help construct social identities, which are maintained through differentiation between in-groups and "others." In this article, we contend that Fatima Besnaci-Lancou's texts, as well as her reconciliation work—in which she enjoins Beurs and Harkis' offspring to write a new, inclusive, polyphonic narrative of the Algerian War—are an example of the positive use of textually mediated identity (re)construction. Her work suggests the possibility of implementing a moderate politics of empathetic recognition of the (often migration-related) memories of "others" so as to reinforce French national belongingness.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper examines the stock price and volume effects surrounding the announcement of constituent changes to the S&P/ASX 200 and four supplementary indices. Between April 2000 and December 2002 additions to (deletions from) the ASX 200 were associated with a significant price rise (fall) over the 10 day period following the market announcement of the change. Deletions were also associated with a significant fall on the announcement date itself These findings were corroborated by significant increases in trading volume over the same intervals, suggesting heavy trading activity by index funds in response to changes to the ASX 200. Following the implementation of these changes, both additions and deletions experienced a significant price reversion, supporting the price pressure hypothesis. By contrast, none of the supplementary indices displayed evidence of stock price or volume effects, which precludes the information and liquidity hypotheses as viable explanations for the findings of this research.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The author presents a number of children's misconceptions concerning mathematical problems involving perimeter, area, volume and mass. A number of examples of interventions to assist students to understand how to solve these problems correctly are presented.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

There is continuing debate in the US over full introduction of electronic trading in those index futures contracts that are still traded at the CME via open outcry. Since the late 1990s major international exchanges trading index futures contracts have converted to full electronic trading. Recent empirical studies have focused on effects on bid/ask spreads and related price volatility following these changes. We take a different approach and investigate and test for structural change in conditional volatility and volume effects following the shift to electronic trading in the Australian Share Price Index futures contract. Multiple Switching point GARCH models are employed with the data sampled at 5, 15 and 30-minute intervals from transaction records supplied by the Sydney Futures Exchange. There is significant evidence of structural changes in both the persistence of volatility shocks and simultaneous volume effects following the change to screen trading in this futures market.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A 10 cm x10 cm x 10 cm "SI cube", which helps students learn SI units, is presented. Students cn physically handle and manipulate the SI cube, which also helps them to have a better appreciation of volume. A template for making the cube is available as supplementary material.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Pacific War is an umbrella term that refers collectively to a disparate set of wars, however, this book presents a strong case for considering this assemblage of conflicts as a collective, singular war.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We study the relationship between the volatility and the price of stocks and the impact that variables such as past volatility, financial gearing, interest rates, stock return and turnover have on the present volatility of these securities. The results show the persistent behavior of volatility and the relationship between interest rate and volatility. The results also showed that a reduction in stock prices are associated with an increase in volatility. Finally we found a greater trading volume tends to increase the volatility.