83 resultados para Asymmetric bending


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In this article, we examine whether per-capita health expenditures and per-capita GDP for 11 OECD countries can be characterized by asymmetric behaviour. We achieve this goal by using the nonparametric Triples test suggested by Randles et al. (1980). We examine two forms of asymmetries, namely deepness and steepness. Our main finding is that for 6 out of 11 countries, namely for the USA, the UK, Japan, Spain, Finland and Iceland, either per-capita health expenditures or per-capita GDP are characterized by asymmetric behaviour. This finding to some extent casts doubt on those studies that model the relationship between health and GDP using unit-root and cointegration tests that assume symmetric disturbances.

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In this paper, we test for asymmetric behaviour of industrial and residential electricity demand for the G7 countries, using the entropy-based test for symmetry suggested by [Racine, J., and Maasoumi, E., 2007. A versatile and robust metric entropy test of time-reversibility, and other hypotheses. Journal of Econometrics 138(2), 547–567; Racine, J., and Maasoumi, E., 2008. A robust entropy-based test of asymmetry for discrete and continuous processes. Econometric Reviews 28, 246–261], the Triples test of [Randles, R., Flinger, M., Policello, G., and Wolfe, D., 1980. An asymptotically distribution-free test for symmetry versus asymmetry. Journal of the American Statistical Association 75, 168–172] and the [Bai, J., and Ng, S., 2001. A consistent test for conditional symmetry in time series models. Journal of Econometrics 103, 225–258] test for conditional symmetry. Using data that spans over three decades, we find overwhelming evidence of conditional symmetry of residential and industrial electricity consumption. This finding implies that the use of econometric tests based on linear data generating processes is credible.

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The aim of this paper is to analyze the asymmetric recognition of good and bad news on reported earnings of Malaysian-listed firms. The study uses both descriptive and regression analyses to ascertain whether there is a contemporaneous relationship between news (good and bad) and reported earnings. The analysis is based on a sample of 150 firms listed on the Bursa Malaysia Index over a period of 10 years, from 1990 to 2000. Two regression models were adopted based on Basu (1997) and Giner and Rees (2001). The first model aims to capture asymmetric recognition of good and bad news into reported earnings while the latter model is developed to capture both asymmetric recognition of information shock and permanent earnings effect on contemporaneous earnings. The evidence from this study reported the steady increase in earnings per share till 1997. However, a drastic decline was observed for the period 1997 to 1999 because of Asian financial crisis. The findings from the regression model one suggested that the asymmetric recognition of good news was more prominent during the good time compare to bad time and vice versa. The findings from model two also suggested that autoregressive effect of permanent effect was very prominent both for crisis and non crisis periods.

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Xinwei Zheng examines if common factors of liquidity can be determined by ownership structure measured by asymmetric information in an emerging market that has adopted an order-driven trading system. Using China as a case for the study, I select a broad sample of stocks from two separate Chinese stock exchanges to measure and
analyse the relationship. My empirical evidence seems significant and pervasive. These findings about the Chinese stock market provide useful pointers for understanding commonality in emerging economies and shed critical light
on a new dimension of the working of emerging markets.

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Dramatic changes in the information security risk landscape over several decades have not yet been matched by similar changes in organizational information security which is still mainly based on a mindset that security is achieved through extensive preventive controls. As a result, maintenance cost of information security is increasing rapidly, but this increased expenditure has not really made an attack more difficult. The opposite seems to be true, information security attacks have become easier to perpetrate and appear more like information warfare tactics. At the same time, the damage caused by a successful attack has increased significantly and may sometimes become critical to an organization. In this paper we evaluate one particular extremely asymmetric risk where a strongly motivated attacker unleashes a prolonged attack on an organization with the aim to do maximum damage, and suggest that the probability of such an attack is increasing. We discuss how preventive controls are unlikely to ever be effective against such an attack and propose more advanced strategies that aim to limit the damage when such an attack occurs. One crucial lesson to be learned for those organizations that are dependant on their information security, such as critical infrastructure organizations, is the need to deny motivated attackers access to any information about the success of their attack. Successful deception in this area is likely to significantly reduce any potential escalation of the incident.

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In a bending mechanism for glass capillary, the positioning jig to hold the capillary in place is one of the most important components to ensure the bending quality. The tapered shoulder of the capillary is used as the positioning reference. Since the dimension of the shoulder of individual capillaries varies slightly, the geometry of the capillaries is studied to identify the desired positioning spot on the shoulder. Upon determination of the positioning spot, a positioning jig is designed, which is composed of positioning, holding, and clamping units. A prototype is made and assembled onto the bending mechanism for testing. The testing results show that the mechanism is able to achieve the desired functionalities demanded by the delicate bending process.

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This present work examines the load carrying capacity, energy absorption and fracture characteristics of wrought magnesium and aluminium alloy tubes in three-point bending. Magnesium alloy AZ31, and aluminium alloys 6063 and 7075, were extruded into cylindrical tubes of both equivalent thickness and mass. A strong thickness effect was present meaning that the AZ31 tube had significantly higher load and energy absorption performance than an equivalent mass 6063 tube, albeit not as high as the 7075 tube. Hinge formation and maximum load was delayed for the magnesium alloy, meaning that a high energy absorption rate persisted to higher deformation displacements than the aluminium alloys. It was also found that fracture during deformation was dependent on the indenter diameter, tube thickness and lower support separation.

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The performance of extruded AZ31, AZ61 and AM-EX1 tubes was examined in three-point bending. Different extrusion temperatures were used to investigate the effect of grain size on the load-carrying capacity, energy absorption and fracture propensity of the tubes. Results showed that while the peak load increased with a smaller average recrystallised grain size, the retention of large elongated un-recrystallised grains in the microstructure reduced the load. The presence of the large elongated grains also appeared detrimental to the ability of the tube to deform before fracture.

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Fabrics having an interesting unidirectional water-transfer effect have been prepared by a special coating technique to create a wettability gradient across the fabric thickness, and the treated fabrics also show considerably different breakthrough pressures on the two fabric sides.

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The metal strip used in roll forming has often been preprocessed by (tension or roller) leveling or by skin-pass rolling, and as a consequence, may contain residual stresses. These stresses are not well observed by the tensile test, but could have a significant effect on the bending and springback behavior. With the advent of improved process design techniques for roll forming, including advanced finite element techniques, the need for precise material property data has become important. The major deformation mode of roll forming is that of bending combined with unloading and reverse bending, and hence property data derived from bend tests could be more relevant than that from tensile testing.

This work presents a numerical study on the effect of skin passing on the material behavior of stainless steel strip in pure bending and tension. A two dimensional (2-D) numerical model was developed using Abaqus Explicit to analyze the affect of skin passing on the residual stress profile across a section for various working conditions. The deformed meshes and their final stress fields were then imported as pre-defined fields into Abaqus Standard, and the post-skin passing material behavior in pure bending was determined. The results show that a residual stress profile is introduced into the steel strip during skin passing, and that its shape and stress level depend on the overall thickness reduction as well as the number of rolling passes used in the skin passing process. The material behavior in bending and the amount of springback changed significantly depending on the skin pass condition.

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Theoretical solutions, finite element models, and experimental techniques are developed for three major sheet metal forming operations: bending (pure bending and cyclic bending), die bending, and deep drawing. These have been applied to two different commercial quality cold-rolled steels, one stainless steel, and one magnesium alloy.