The strain energy method for the analysis of pin‐jointed redundant frameworks is expressed in matrix form suitable for solution on electronic computers. This is…
The strain energy method for the analysis of pin‐jointed redundant frameworks is expressed in matrix form suitable for solution on electronic computers. This is illustrated by its application to a zero‐length launcher framework having sixty‐three members, nine of which are redundant, using the Ferranti Pegasus computer. It is concluded that a framework must be reasonably complex before the use of this method is justified but that problems of greater complexity than would normally be attempted can readily be solved.
The purpose of this paper is to describe how a discrete element model is used to predict the penetration depth and the perforation caused by a non‐deformable missile…
The purpose of this paper is to describe how a discrete element model is used to predict the penetration depth and the perforation caused by a non‐deformable missile against a thin reinforced concrete slab.
Initial calibration of the model was done with a series of flat‐nose missile tests. Additional simulations were performed with varying the percentage of reinforcement. The present numerical model is compared to experimental test data provided by the French Atomic Energy Agency (CEA) and the French Electrical Power Company (EDF).
For thin concrete slabs, the evolution of the penetration depth in terms of percentage of reinforcement was compared with experimental results: quantitatively the results are very coherent.
The modeling scale is higher than the heterogeneity scale, so the model may be used to simulate real structures, which means that the discrete element method is mainly used here for its ability to account for discontinuities; an identification process based on quasi‐static tests is used, so the quasi‐static behavior of concrete is reproduced. This identification process is the key point, to allow a complete predictive computation for complex impact configurations, especially when the missile diameter and the thickness of the concrete slab are on the same order in size.
Efficiency and productivity has always being a key issue in economic science. The analysis of the impact of research and development (R&D) has been extensively studied in…
Efficiency and productivity has always being a key issue in economic science. The analysis of the impact of research and development (R&D) has been extensively studied in industries and countries of more or less aggregated level. This chapter aims to investigate the impact of corporate R&D in performance of low-tech industries, medium-tech, and high-tech in OECD countries.
This chapter aims to answer the questions: Is the impact of R&D significant for all types of industries? If so, what are the differences and the magnitude of these effects in each of these types of industries?
To this end, an unbalanced data set from 2000 to 2011 was collected for the main countries of Europe and the United States concerning low-, medium-, and high-tech to analyze the impact of the magnitude of corporate R&D and capital accumulation on productivity of these industries. The productivity of industries was measured by stochastic parametric frontier functions, in order to measure the efficiency of R&D and accumulation of capital on labor productivity.
The main results highlight the impact of corporate R&D on productivity of high-tech industries, but for other industries those relations are not clear. However, capital accumulation became crucial on low technology to improve their performance. These results, although needing to include a more extensive data set of industries across countries, refer the need for policy and decision makers to allocate public funds for R&D in high-tech industries, while the investment in capital seems crucial, particularly in low-tech industries to improve the productivity.
The orientation of a rigid body is described by a position‐tensor, composed of three unit vector axes fixed in the body; rotation is effected by tensor transformations in…
The orientation of a rigid body is described by a position‐tensor, composed of three unit vector axes fixed in the body; rotation is effected by tensor transformations in which a rotational operator is a Cartesian matrix, formed from the co‐ordinates of the pivot axis and components of the angle of rotation; rotational sequences are represented by matrix products. Three practical applications are discussed: sequences of aircraft manoeuvres, which include composite rotations of roll and pitch, or roll, pitch and yaw, applied simultaneously; the variation of sweep, incidence and dihedral of a wing moving on any axis fixed in the aircraft; the direction of the pivot axis and the angle of rotation in the motion of a retractable undercarriage between two specified positions.
This study aims to examine the effects of participating in physical activities on female college graduates' starting salaries. We used an instrumental variable (IV…
This study aims to examine the effects of participating in physical activities on female college graduates' starting salaries. We used an instrumental variable (IV) approach to address the possible endogeneity problem. By using the Taiwan Higher Education Dataset, we discovered that participating in physical activities during college increased an individual's earnings by 3.06%. The significant positive effect of physical activity on salary demonstrated in this study is consistent with that in other relevant studies. This study also discovered that both the intensity and the persistence of participation in physical activities affected salary outcomes. Individuals earned 0.17%–2.41% more if they exercised for an additional hour per week, suggesting the importance of the intensity of participation in physical activities. In addition, persistent participation in physical activities was associated with a 3.08% higher salary.
The optimal design of a laminated cylindrical shell is obtained with the objectives defined as the maximisation of the axial and torsional buckling loads. The ply angle is…
The optimal design of a laminated cylindrical shell is obtained with the objectives defined as the maximisation of the axial and torsional buckling loads. The ply angle is taken as the design variable. The symbolic computational software package MATHEMATICA is used in the implementation and solution of the problem. This approach simplifies the computational procedure as well as the implementation of the analysis/optimisation routine. Results are given illustrating the dependence of the optimal fiber angle on the cylinder length and radius. It is shown that a general purpose computer algebra system like MATHEMATICA is well suited to solve small boundary value problems such as structural design optimisation involving composite materials.
The purpose of this paper is to investigate the effects of dipentaerythritol hexaacrylate (DPHA) and 3-(trimethoxysilyl)propyl methacrylate-modified silica nanoparticles…
The purpose of this paper is to investigate the effects of dipentaerythritol hexaacrylate (DPHA) and 3-(trimethoxysilyl)propyl methacrylate-modified silica nanoparticles (MSiO2) contents on the performances of the Disperse Red 1 (DR1)-grafted-silica/poly(acrylate) color hard coatings.
The organic dye DR1 was silylated by reaction with the coupling agent 3-isocyanatopropyltriethoxysilane in methyl ethyl ketone. The silylated-DR1 thus obtained was grafted on MSiO2 to form dye-grafted silica (GSiO2). This hybrid dye was then UV-cured with the cross-linking agent, DPHA, to yield color coatings. Thermal durability of the coatings was evaluated based on their CIE (international commission on illumination) chromaticity coordinates and UV/Vis transmittances.
The results indicated that GSiO2-coatings could tolerate thermal attack better than pristine DR1-coatings or dye-absorbed silica (DSiO2)-coatings because of the fact that DR1 was more finely dispersed in the polymer binder when covalently bonded to the silica particles. Under optimal conditions, coatings with very small change of saturation and hue after high-temperature treatments were obtainable. These coatings appeared transparent, had 3H-6H pencil hardness and adhered perfectly onto the poly(methyl methacrylate) substrates.
Dye-grafted color coatings may find applications such as color filter photoresists for displays, microelectronics, printed circuit boards, etc.
The performances of the coatings were evaluated in terms of mechanical strength, adherence to the substrate, transmittance and color stability against heat treatments, which have not been disclosed. Also, using a newly developed triangular composition diagram, suitable ranges for preparing useful color coatings were accessed. The present method deserves further research studies on green and blue dyes.
THE orthodox solution of Lagrangian frequency equations involves the expansion into polynomial form of the characteristic determinantal equation in the latent roots, but…
THE orthodox solution of Lagrangian frequency equations involves the expansion into polynomial form of the characteristic determinantal equation in the latent roots, but this method becomes exceedingly laborious if a large number of frequencies and their associated modes are required accurately for any system of equations of high order, say above the sixth. We define a system of Lagrangian frequency equations to be of the nth order if it consists of n equations for n homogeneous unknowns, which we call modes. A useful contribution to the problem was made by the iteration solution of Duncan and Collar, which is especially valuable when only the highest one or two latent roots are required. But when an aircraft propeller vibration problem required the first seven frequencies and their associated modes for a 12th‐order equation whose coefficients involved a variable pitch angle, the labour of calculation by this method appeared at that time (1941) to be prohibitive. The ‘Escalator’ method was therefore devised jointly by the author and Captain J. Morris of the Royal Aircraft Establishment as an alternative. In the propeller problem all the latent roots involved were necessarily real. Dr L. Fox, using relaxation methods, has recently solved a similar problem in a remarkably short time. Unfortunately, relaxation methods cannot easily be extended to the case of complex latent roots, which can occur in connexion with flutter, radio circuits and other problems. In this paper it is shown how the Escalator method can be adapted without essential change to cases in which complex quantities occur.
This paper seeks to explore the applicability and implications of Bourdieu's field‐capital theory for marketing using original research with a typical European society…
This paper seeks to explore the applicability and implications of Bourdieu's field‐capital theory for marketing using original research with a typical European society. Bourdieu's field‐capital theory proposes that people acquire economic, social and cultural capital which they deploy in social arenas known as “fields” in order to compete for positions of distinction and status. This exploratory study aims to examine how Bourdieu's theory may explain competitive behavior in fields of interest to marketers.
A total of 61 in‐depth interviews were completed with respondents that were representative of each of 61 geodemographic “types” – clusters that enable marketers to segment an entire population.
The findings suggest that examining human behaviour through the lens of field and capital theory highlights the importance of the competition motive in explaining consumers' behaviour. New “fields” were identified which seem to have assumed primary importance, particularly in middle‐class people's lives.
Viewing consumer behaviour as social competition implies that new segmentation approaches may yield successful marketing outcomes, and opens consumer psychology and behaviour itself to new interpretations.
Very few research papers that apply field‐capital theory to marketing are present in the literature. It is hoped that this work addresses an important area, and one that is particularly prevalent in twenty‐first century consumerism.
This chapter presents the indirect preferences for all full rank Gorman and Lewbel demand systems. Each member in this class of demand models is a generalized quadratic…
This chapter presents the indirect preferences for all full rank Gorman and Lewbel demand systems. Each member in this class of demand models is a generalized quadratic expenditure system (GQES). This representation allows applied researchers to choose a small number of price indices and a function of income to specify any exactly aggregable demand system, without the need to revisit the questions of integrability of the demand equations or the implied form and structure of indirect preferences. This characterization also allows for the calculation of exact welfare measures for consumers, either in the aggregate or for specific classes of individuals, and other valuations of interest to applied researchers.