Search results

11 – 20 of 187
Book part
Publication date: 22 October 2020

Charis Gerosideris and Ioanna Ferra

The mobilisations against the wildfires in Greece (2007) redefined the notion of environmentalism in the country, and it was one of the first examples which showcased the…

Abstract

The mobilisations against the wildfires in Greece (2007) redefined the notion of environmentalism in the country, and it was one of the first examples which showcased the potential of digital media for protests and resistance in the Greek context. At the same time, the global recession strongly affected the environmental politics and policies applied in Greece, indicating threats, risks and areas of conflict (e.g., privatisation of recourses, water, etc.). Following the environmental protests of 2007, this study provides an insight into the case of #Skouries forest and the antimining protests, focussing on the period 2015–2017. The study developed through the analysis of online data (Twitter) which was collected during the period March 2015 to March 2017 (#skouries). This chapter develops an insight into the online networks, coalitions and dominant actors (SNA) and also investigates the hashtags evolution and discourse (Semantic analysis). The collection and visualisation of the data developed using NodeXL. This case is considered one of the most indicative examples of the Greek environmental movement, as this shaped during the evolution of social media and in the crisis context. As such, this chapter demonstrates that the importance of the use of Twitter for the organisation of the movement, as well as an alternative space for public engagement/debate on climate change and environmental-related issues.

Details

The Emerald Handbook of Digital Media in Greece
Type: Book
ISBN: 978-1-83982-401-2

Keywords

Article
Publication date: 1 June 1993

B.S. MANJUNATHA and T. KANT

This paper attempts to evaluate the transverse stresses that are generated within the interface between two layers of laminated composite and sandwich laminates by using Cℴ finite…

Abstract

This paper attempts to evaluate the transverse stresses that are generated within the interface between two layers of laminated composite and sandwich laminates by using Cℴ finite element formulation of higher‐order theories. These theories do not require the use of a fictitious shear correction coefficient which is usually associated with the first‐order Reissner‐Mindlin theory. The in‐plane stresses are evaluated by using constitutive relations. The transverse stresses are evaluated through the use of equilibrium equations. The integration of the equilibrium equations is attempted through forward and central direct finite difference techniques and a new approach, named as, an exact surface fitting method. Sixteen and nine‐noded quadrilateral Lagrangian elements are used. The numerical results obtained by the present approaches in general and the exact surface fitting method in particular, show excellent agreement with available elasticity solutions. New results for symmetric sandwich laminates are also presented for future comparisons.

Details

Engineering Computations, vol. 10 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 July 2014

Enrico Cestino and Giacomo Frulla

This study aims to analyse slender thin-walled anisotropic box-beams. Fiber-reinforced laminated composites could play an important role in the design of current and future…

Abstract

Purpose

This study aims to analyse slender thin-walled anisotropic box-beams. Fiber-reinforced laminated composites could play an important role in the design of current and future generations of innovative civil aircrafts and unconventional unmanned configurations. The tailoring characteristics of these composites not only improve the structural performance, and thus reduce the structural weight, but also allow possible material couplings to be made. Static and dynamic aeroelastic stability can be altered by these couplings. It is, therefore, necessary to use an accurate and computationally efficient beam model during the preliminary design phase.

Design/methodology/approach

A proper structural beam scheme, which is a modification of a previous first-level approximation scheme, has been adopted. The effect of local laminate stiffness has been investigated to check the possibility of extending the analytical approximation to different structural configurations. The equivalent stiffness has been evaluated for both the case of an isotropic configuration and for simple thin-walled laminated or stiffened sections by introducing classical thin-walled assumptions and the classical beam theory for an equivalent system. Coupling effects have also been included. The equivalent analytical and finite element beam behaviour has been determined and compared to validate the considered analytical stiffness relations that are useful in the preliminary design phase.

Findings

The work has analyzed different configurations and highlighted the effect of flexural/torsion couplings and a local stiffness effect on the global behaviour of the structure. Three types of configurations have been considered, namely, a composite wing box configuration, with and without coupling effects; a wing box configuration with sandwich and cellular constructions; and a wing box with stiffened panels in a coupled or an uncoupled configuration. An advanced aluminium experimental test sample has also been described in detail. Good agreement has been found between the theoretical and numerical analyses and the experimental tests, thus confirming the validity of the analytical relations.

Practical implications

The equivalent beam behaviour that has been determined and the stiffness calculation procedure that has been derived could be useful for future dynamic and aeroelastic analyses.

Originality/value

The article presents an original derivation of the sectional characteristics of a thin-walled composite beam and a numerical/experimental validation.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 86 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 1 February 1993

T. KANT and J.R. KOMMINENI

A unified approach is presented for the pseudo‐transient (static) linear and geometrically non‐linear analyses of composite laminates. A finite element idealization with a…

Abstract

A unified approach is presented for the pseudo‐transient (static) linear and geometrically non‐linear analyses of composite laminates. A finite element idealization with a four‐noded linear and a nine‐noded quadrilateral isoparametric elements, both belonging to the Lagrangian family are used in space discretization. An explicit time marching scheme is employed for time integration of the resulting discrete ordinary differential equations with the special forms of diagonal fictitious mass and/or damping matrices. The accuracy of the formulation is then established by comparing the presnt pseudo‐transient analysis results with the present static Newton‐Raphson method results and other available analytical closed‐form two dimensional and finite element solutions. The usefulness and effectiveness of this approach is established by comparing computational time required by this approach and Newton‐Raphson's approach.

Details

Engineering Computations, vol. 10 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 March 1982

Joseph R. MAUTZ and Roger F. HARRINGTON

The magnetic field integral equation for electromagnetic scattering from a perfectly conducting body of revolution is solved by the method of moments. A Fourier series in ø is…

Abstract

The magnetic field integral equation for electromagnetic scattering from a perfectly conducting body of revolution is solved by the method of moments. A Fourier series in ø is used. The t dependence of the expansion functions is subsectional. Pulses are used for the ø component of the unknown electric current induced on the surface S of the body of revolution. Triangles divided by the cylindrical coordinate radius are used for the t component. Here, t and ø are orthogonal coordinates on S, t being the arc length along the generating curve of S and ø the azimuthal angle.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 1 no. 3
Type: Research Article
ISSN: 0332-1649

Open Access
Article
Publication date: 23 February 2024

Bonha Koo and Ryumi Kim

Using the next-day and next-week returns of stocks in the Korean market, we examine the association of option volume ratios – i.e. the option-to-stock (O/S) ratio, which is the…

Abstract

Using the next-day and next-week returns of stocks in the Korean market, we examine the association of option volume ratios – i.e. the option-to-stock (O/S) ratio, which is the total volume of put options and call options scaled by total underlying equity volume, and the put-call (P/C) ratio, which is the put volume scaled by total put and call volume – with future returns. We find that O/S ratios are positively related to future returns, but P/C ratios have no significant association with returns. We calculate individual, institutional, and foreign investors’ option ratios to determine which ratios are significantly related to future returns and find that, for all investors, higher O/S ratios predict higher future returns. The predictability of P/C depends on the investors: institutional and individual investors’ P/C ratios are not related to returns, but foreign P/C predicts negative next-day returns. For net-buying O/S ratios, institutional net-buying put-to-stock ratios consistently predict negative future returns. Institutions’ buying and selling put ratios also predict returns. In short, institutional put-to-share ratios predict future returns when we use various option ratios, but individual option ratios do not.

Details

Journal of Derivatives and Quantitative Studies: 선물연구, vol. 32 no. 1
Type: Research Article
ISSN: 1229-988X

Keywords

Open Access
Article
Publication date: 1 February 2024

Phuong Thi Ly Nguyen, Nha Thanh Huynh and Thanh Thanh Canh Huynh

The authors investigate how foreign investment in securities market informs about the future firm performance in emerging markets.

Abstract

Purpose

The authors investigate how foreign investment in securities market informs about the future firm performance in emerging markets.

Design/methodology/approach

The authors define the independent variable, abnormal foreign investment (AFI) as the residuals of the foreign ownership equation. The authors regress foreign ownership on its first lag and factors and define the residuals as the AFI. The AFI is the over- or under-investment reflecting foreign conscious (clear-purpose) investment, thus better indicating how foreign investment affects firm performance. The dependent variable is Tobin’s q (Q), which represents the firm performance. Then, the authors regress the Tobin’s q next quarters (Qt + k) on the AFI current quarter (AFIt). The authors use a two-step generalized method of moments (GMM) and check endogeneity with the D-GMM model for the regression.

Findings

The results show that the current AFI is positively correlated with the firm performance in each of the next four quarters (the following one year). This positive relationship is pronounced for large firms, firms with no large foreign investors, liquid firms and firms listed in the active market. The results suggest that foreign investment might choose well-productive firms already. Also, the current AFI is significantly positively correlated with stock returns in each of the next three quarters. These results suggest that the AFI is informative up to one-year period.

Research limitations/implications

The results suggest that foreign investors (most of them are small) in the Vietnamese market might choose well-productive firms already. However, if the large investors have long-term investment in tangible, intangible, human capital and so on, and lead to a significant increase in firms’ performance is still the limitation of this paper.

Practical implications

The results of this paper may guide investors whose portfolios are composed of stocks with foreign investment.

Originality/value

This paper adds to the literature to enrich the conclusion of a positive relationship between foreign ownership and firm performance.

Details

Journal of Economics and Development, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1859-0020

Keywords

Book part
Publication date: 16 January 2014

Jean Paul Rabanal

The chapter studies strategic default using an experimental approach.

Abstract

Purpose

The chapter studies strategic default using an experimental approach.

Design/methodology/approach

The experiment considers a stochastic asset process and a loan with no down-payment. The treatments are two asset volatilities (high and low) and the absence and presence of social interactions via a direct effect on the subject's payoff.

Findings

I demonstrate that (i) people appear to follow the prediction of the strategic default model quite closely in the high asset volatility treatment, and that (ii) incorporating social interactions delays the strategic default beyond what is considered optimal.

Originality/value

The study tests adequately the strategic default using a novel experimental design and analyzes the neighbor's effect on that decision.

Details

Experiments in Financial Economics
Type: Book
ISBN: 978-1-78350-141-0

Keywords

Article
Publication date: 26 December 2023

Matthew Egan and Barbara de Lima Voss

Big 4 professional services firms increasingly lay claim to recruiting and including staff of diverse genders, cultures, ages and sexualities. Drawing on Foucauldian insights…

Abstract

Purpose

Big 4 professional services firms increasingly lay claim to recruiting and including staff of diverse genders, cultures, ages and sexualities. Drawing on Foucauldian insights, this study explores how LGBTIQ+ staff navigated shifting technologies of client power, at the time marriage equality was legislated in Australia.

Design/methodology/approach

This article explores changing experiences of LGBTIQ+ staff and allies, through 56 semi-structured interviews undertaken through 2018–2019.

Findings

Technologies of client power were central to shaping workplace experiences for LGBTIQ+ staff. However, each firm was also keen to carve unique and bold responses to changing societal attitudes regarding sexuality and gender. These progressive moves did not sit comfortably with all clients, and so this article provides insight into the limitations of client privilege within professional services firms. For staff, this increasing complexity of sometimes opaque, contradictory and shifting technologies of client and firm power, enabled agency to explore a sense of self for some, but continued to exclude others.

Originality/value

Little attention has been directed to exploring challenges for staff of sexual and gendered diversity within professional services firms, or to exploring how staff navigate changing perceptions of client power.

Details

Accounting, Auditing & Accountability Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0951-3574

Keywords

Book part
Publication date: 24 October 2019

Don N. MacDonald and Hirofumi Nishi

This chapter develops a no-arbitrage, futures equilibrium cost-of-carry model to demonstrate that the existence of cointegration between spot and futures prices in the New York…

Abstract

This chapter develops a no-arbitrage, futures equilibrium cost-of-carry model to demonstrate that the existence of cointegration between spot and futures prices in the New York Mercantile Exchange (NYMEX) crude oil market depends crucially on the time-series properties of the underlying model. In marked contrast to previous studies, the futures equilibrium model utilizes information contained in both the quality delivery option and convenience yield as a timing delivery option in the NYMEX contract. Econometric tests of the speculative efficiency hypothesis (also termed the “unbiasedness hypothesis”) are developed and common tests of this hypothesis examined. The empirical results overwhelming support the hypotheses that the NYMEX future price is an unbiased predictor of future spot prices and that no-arbitrage opportunities are available. The results also demonstrate why common tests of the speculative efficiency hypothesis and simple arbitrage models often reject one or both of these hypotheses.

Details

Essays in Financial Economics
Type: Book
ISBN: 978-1-78973-390-7

Keywords

11 – 20 of 187