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1 – 10 of over 6000The objective of this chapter is to estimate the parameters defining female labor participation and occupation decisions in mexico. Based on a theoretical framework, we use micro…
Abstract
The objective of this chapter is to estimate the parameters defining female labor participation and occupation decisions in mexico. Based on a theoretical framework, we use micro data to estimate the wage-participation elasticity in urban Mexico. Consistency between the selectivity-adjusted wages and the multinomial participation equations is achieved via a two-step estimation procedure following Lee (1983). We use the results of our model to test and quantify three hypotheses explaining recent increases in female labor participation in urban mexico. Our results show that the observed 12 percent increase in female labor participation in mexico between 1994 and 2000 is explained by the combination of a negative income shock caused by the 1994–1995 participation; wage differentiaeso crisis, the increase in expected wages taking place in the manufacturing sector during the post-North American Free Trade Agreement (NAFTA) period, and a reduction in female reservation wage.
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Xiaoyu Liu, Suchuan Dong and Zhi Xie
This paper aims to present an unconditionally energy-stable scheme for approximating the convective heat transfer equation.
Abstract
Purpose
This paper aims to present an unconditionally energy-stable scheme for approximating the convective heat transfer equation.
Design/methodology/approach
The scheme stems from the generalized positive auxiliary variable (gPAV) idea and exploits a special treatment for the convection term. The original convection term is replaced by its linear approximation plus a correction term, which is under the control of an auxiliary variable. The scheme entails the computation of two temperature fields within each time step, and the linear algebraic system resulting from the discretization involves a coefficient matrix that is updated periodically. This auxiliary variable is given by a well-defined explicit formula that guarantees the positivity of its computed value.
Findings
Compared with the semi-implicit scheme and the gPAV-based scheme without the treatment on the convection term, the current scheme can provide an expanded accuracy range and achieve more accurate simulations at large (or fairly large) time step sizes. Extensive numerical experiments have been presented to demonstrate the accuracy and stability performance of the scheme developed herein.
Originality/value
This study shows the unconditional discrete energy stability property of the current scheme, irrespective of the time step sizes.
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The engagement–addiction dilemma has been commonly observed in the information technology (IT) industry. However, this issue has received limited research attention in the…
Abstract
Purpose
The engagement–addiction dilemma has been commonly observed in the information technology (IT) industry. However, this issue has received limited research attention in the information system (IS) discipline. Drawing on the stimulus–organism–response (SOR) framework, this study explores the engagement–addiction dilemma in the use of mobile games and highlights the impacts of game design features, namely, mobile user interface and mobile game affordance.
Design/methodology/approach
The research model was empirically validated using a longitudinal survey data from 410 mobile game users in China.
Findings
The empirical results offer several key findings. First, mobile user interface and mobile game affordance positively affect telepresence and social presence, which lead to meaningful engagement and mobile game addiction. Second, a high-quality of mobile user interface positively moderates the effects of mobile game affordance on telepresence and social presence.
Originality/value
This study contributes to the literature by theorizing and empirically testing the impacts of game design features on the engagement-addiction dilemma.
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L. Peng, X. Gong, K. Wong and L. Guillaumat
The parameters of cohesive elements have to be chosen correctly in the simulation of composite delamination by finite element method: such as interface strength, interface…
Abstract
The parameters of cohesive elements have to be chosen correctly in the simulation of composite delamination by finite element method: such as interface strength, interface stiffness and shape of cohesive law. The purpose of this work is to investigate their influence on the accuracy of the results obtained. A three-dimensional cohesive-zone model has been established using Ls-dyna to simulate Double-Cantilever-Beam mode I (DCB) and Edge-Notched-Flexure mode II (ENF) tests. The influence of these parameters of cohesive element on the maximum load and the slope of load-displacement curve have been discussed by comparing experimental and numerical results. Four traction-separation laws: bilinear, linear-parabolic, exponential and trapezoidal were considered associated with a large variation of the interface strength and of the initial interface stiffness.
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S. Sarath and P. Sam Paul
A new cutting tool is always well-defined and sharp at the onset of the metal cutting process and gradually losses these properties as the machining process advances. Similarly…
Abstract
Purpose
A new cutting tool is always well-defined and sharp at the onset of the metal cutting process and gradually losses these properties as the machining process advances. Similarly, at the beginning of the machining process, amplitude of tool vibrations is considerably low and it increases gradually and peaks at the end of the service period of the cutting tool while machining. It is significant to provide a corresponding real-time varying damping to control this chatter, which directly influences accuracy and quality of productivity. This paper aims to review the literature related to the application of smart fluid to control vibration in metal cutting and also focused on the challenges involved in the implementation of active control system during machining process.
Design/methodology/approach
Smart dampers, which are used as semi-active and active dampers in metal cutting, were reviewed and the research studies carried out in the field of the magnetorheological (MR) damper were concentrated. In smart materials, MR fluids possess some disadvantages because of their sedimentation of iron particles, leakage and slow response time. To overcome these drawbacks, new MR materials such as MR foam, MR elastomers, MR gels and MR plastomers have been recommended and suggested. This review intents to throw light into available literature which exclusively deals with controlling chatter in metal cutting with the help of MR damping methods.
Findings
Using an MR damper popularly known for its semi-active damping characteristics is very adaptable and flexible in controlling chatter by providing damping to real-time amplitudes of tool vibration. In the past, many researchers have attempted to implement MR damper in metal cutting to control vibration and were successful. Various methods with the help of MR fluid are illustrated.
Research limitations/implications
A new cutting tool is always well-defined and sharp at the onset of metal cutting process and gradually losses these properties as the machining process advances. Similarly, at the beginning of the machining process, amplitude of tool vibrations is considerably low and it increases gradually and peaks at the end of service period of cutting tool while machining. Application of MR damper along with the working methodology in metal cutting is presented, challenges met are analyzed and a scope for development is reviewed.
Practical implications
This study provides corresponding real-time varying damping to control tool vibration which directly influences accuracy and quality of productivity. Using an MR damper popularly known for its semi-active damping characteristics is very adaptable and flexible in controlling chatter by providing damping to real-time amplitudes of tool vibration.
Social implications
This study attempts to implement smart damper in metal cutting to control vibrations.
Originality/value
It is significant to provide corresponding real-time varying damping to control tool vibration which directly influences accuracy and quality of productivity.
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Beichuan Yan, Richard A. Regueiro and Stein Sture
The purpose of this paper is to develop a discrete element (DE) and multiscale modeling methodology to represent granular media at their particle scale as they interface solid…
Abstract
Purpose
The purpose of this paper is to develop a discrete element (DE) and multiscale modeling methodology to represent granular media at their particle scale as they interface solid deformable bodies, such as soil‐tool, tire, penetrometer, pile, etc., interfaces.
Design/methodology/approach
A three‐dimensional ellipsoidal discrete element method (DEM) is developed to more physically represent particle shape in granular media while retaining the efficiency of smooth contact interface conditions for computation. DE coupling to finite element (FE) facets is presented to demonstrate initially the development of overlapping bridging scale methods for concurrent multiscale modeling of granular media.
Findings
A closed‐form solution of ellipsoidal particle contact resolution and stiffness is presented and demonstrated for two particle, and many particle contact simulations, during gravity deposition, and quasi‐static oedometer, triaxial compression, and pile penetration. The DE‐FE facet coupling demonstrates the potential to alleviate artificial boundary effects in the shear deformation region between DEM granular media and deformable solid bodies.
Research limitations/implications
The research is being extended to couple more robustly the ellipsoidal DEM code and a higher order continuum FE code via overlapping bridging scale methods, in order to remove dependence of penetration/shear resistance on the boundary placement for DE simulation.
Practical implications
When concurrent multiscale computational modeling of interface conditions between deformable solid bodies and granular materials reaches maturity, modelers will be able to simulate the mechanical behavior accounting for physical particle sizes and flow in the interface region, and thus design their tool, tire, penetrometer, or pile accordingly.
Originality/value
A closed‐form solution for ellipsoidal particle contact is demonstrated in this paper, and the ability to couple DE to FE facets.
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John A. Bishop, Haiyong Liu and Buhong Zheng
Rising incomes in China have not led to a smaller degree of undernutrition as measured by percentage of population below calorie and protein recommended daily allowances. The weak…
Abstract
Rising incomes in China have not led to a smaller degree of undernutrition as measured by percentage of population below calorie and protein recommended daily allowances. The weak relationship between income and nutrition is further demonstrated by our income elasticity estimates for calories and protein, which are generally zero. We do find that the percentage of fat in the calorie source is a normal good.
Pervez N. Ghauri, Xiaolan Fu and Juha Väätänen
The relationship between multinational enterprises (MNEs) and host governments has seen different waves of trust and mistrust. Over the years, it has changed from a period of…
Abstract
The relationship between multinational enterprises (MNEs) and host governments has seen different waves of trust and mistrust. Over the years, it has changed from a period of conflict after World War II, where MNEs were investing for purposes felt to be contradictory to government policies, to a more cooperative one, where countries are providing incentives and competing with each other to attract foreign direct investment (FDI). The 1990s saw the cooperative relationship leading to the danger of race to the bottom through excessive locational competition. In this chapter, we look at the past, present, and future state of this relationship as reported by different scholars from these periods. We look at the most influential literature from the 1970s onward and the current state of this relationship. Our analysis reveals that the increased tensions are caused by anxiety owing to unanticipated developments in the political economy, company strategies, and government policies. Thanks to globalization MNEs are increasingly becoming more powerful and often this process is accelerated owing to lack of any collaboration between MNEs and the governments. Thus, governments, particularly in emerging markets, are becoming more and more frustrated by the fact that on the one hand they want the MNEs to come and invest in their countries and, on the other hand, they feel that they cannot direct these MNEs to contribute toward economic development and poverty alleviation in their countries. In this chapter, we intend to evaluate the past and the present literature and look ahead to the future. Finally, on the basis of our own studies performed in this project and reported in different chapters of this book, we provide some policy guidelines for host country governments as to how they can encourage MNEs to contribute toward sustainable development and poverty reduction.
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Bingjun Li, Shuhua Zhang, Wenyan Li and Yifan Zhang
Grey modeling technique is an important element of grey system theory, and academic articles applied to agricultural science research have been published since 1985, proving the…
Abstract
Purpose
Grey modeling technique is an important element of grey system theory, and academic articles applied to agricultural science research have been published since 1985, proving the broad applicability and effectiveness of the technique from different aspects and providing a new means to solve agricultural science problems. The analysis of the connotation and trend of the application of grey modeling technique in agricultural science research contributes to the enrichment of grey technique and the development of agricultural science in multiple dimensions.
Design/methodology/approach
Based on the relevant literature selected from China National Knowledge Infrastructure, the Web of Science, SpiScholar and other databases in the past 37 years (1985–2021), this paper firstly applied the bibliometric method to quantitatively visualize and systematically analyze the trend of publication, productive author, productive institution, and highly cited literature. Then, the literature is combed by the application of different grey modeling techniques in agricultural science research, and the literature research progress is systematically analyzed.
Findings
The results show that grey model technology has broad prospects in the field of agricultural science research. Agricultural universities and research institutes are the main research forces in the application of grey model technology in agricultural science research, and have certain inheritance. The application of grey model technology in agricultural science research has wide applicability and precise practicability.
Originality/value
By analyzing and summarizing the application trend of grey model technology in agricultural science research, the research hotspot, research frontier and valuable research directions of grey model technology in agricultural science research can be more clearly grasped.
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