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Book part
Publication date: 4 September 2017

Yue Qian

The gender-gap reversal in education could have far-reaching consequences for marriage and family lives in the United States. This study seeks to address the following…

Abstract

The gender-gap reversal in education could have far-reaching consequences for marriage and family lives in the United States. This study seeks to address the following question: As women increasingly marry men with less education than they have themselves, is the traditional male breadwinner model in marriage challenged?

This study takes a life course approach to examine how educational assortative mating shapes trajectories of change in female breadwinning status over the course of marriage. It uses group-based trajectory models to analyze data from the National Longitudinal Survey of Youth 1979.

The results reveal substantial movement by wives in and out of the primary breadwinner role across marital years and great heterogeneity in female breadwinning trajectories across couples. In addition, educational assortative mating plays a role in shaping female breadwinning trajectories: Compared with wives married to men whose educational levels equal or exceed their own, wives married to men with less education than themselves are more likely to have a continuously high probability of being primary earners and are also more likely to gradually or rapidly transition into primary earners if initially they are not.

This study examines couples’ breadwinning arrangements over an extended period of time and identifies qualitatively distinct patterns of change in female breadwinning that are not readily identifiable using ad hoc, ex ante classification rules. The findings suggest that future research on the economics of marriage and couple relations in families would benefit from a life course approach to conceptualizing couples’ dynamic divisions of breadwinning.

Book part
Publication date: 24 May 2007

Frederic Carluer

“It should also be noted that the objective of convergence and equal distribution, including across under-performing areas, can hinder efforts to generate growth

Abstract

“It should also be noted that the objective of convergence and equal distribution, including across under-performing areas, can hinder efforts to generate growth. Contrariwise, the objective of competitiveness can exacerbate regional and social inequalities, by targeting efforts on zones of excellence where projects achieve greater returns (dynamic major cities, higher levels of general education, the most advanced projects, infrastructures with the heaviest traffic, and so on). If cohesion policy and the Lisbon Strategy come into conflict, it must be borne in mind that the former, for the moment, is founded on a rather more solid legal foundation than the latter” European Commission (2005, p. 9)Adaptation of Cohesion Policy to the Enlarged Europe and the Lisbon and Gothenburg Objectives.

Details

Managing Conflict in Economic Convergence of Regions in Greater Europe
Type: Book
ISBN: 978-1-84950-451-5

Article
Publication date: 11 February 2019

Seth D. Baum, Stuart Armstrong, Timoteus Ekenstedt, Olle Häggström, Robin Hanson, Karin Kuhlemann, Matthijs M. Maas, James D. Miller, Markus Salmela, Anders Sandberg, Kaj Sotala, Phil Torres, Alexey Turchin and Roman V. Yampolskiy

This paper aims to formalize long-term trajectories of human civilization as a scientific and ethical field of study. The long-term trajectory of human civilization can be…

4860

Abstract

Purpose

This paper aims to formalize long-term trajectories of human civilization as a scientific and ethical field of study. The long-term trajectory of human civilization can be defined as the path that human civilization takes during the entire future time period in which human civilization could continue to exist.

Design/methodology/approach

This paper focuses on four types of trajectories: status quo trajectories, in which human civilization persists in a state broadly similar to its current state into the distant future; catastrophe trajectories, in which one or more events cause significant harm to human civilization; technological transformation trajectories, in which radical technological breakthroughs put human civilization on a fundamentally different course; and astronomical trajectories, in which human civilization expands beyond its home planet and into the accessible portions of the cosmos.

Findings

Status quo trajectories appear unlikely to persist into the distant future, especially in light of long-term astronomical processes. Several catastrophe, technological transformation and astronomical trajectories appear possible.

Originality/value

Some current actions may be able to affect the long-term trajectory. Whether these actions should be pursued depends on a mix of empirical and ethical factors. For some ethical frameworks, these actions may be especially important to pursue.

Details

foresight, vol. 21 no. 1
Type: Research Article
ISSN: 1463-6689

Keywords

Open Access
Article
Publication date: 12 July 2022

Nianfei Gan, Miaomiao Zhang, Bing Zhou, Tian Chai, Xiaojian Wu and Yougang Bian

The purpose of this paper is to develop a real-time trajectory planner with optimal maneuver for autonomous vehicles to deal with dynamic obstacles during parallel parking.

Abstract

Purpose

The purpose of this paper is to develop a real-time trajectory planner with optimal maneuver for autonomous vehicles to deal with dynamic obstacles during parallel parking.

Design/methodology/approach

To deal with dynamic obstacles for autonomous vehicles during parking, a long- and short-term mixed trajectory planning algorithm is proposed in this paper. In long term, considering obstacle behavior, A-star algorithm was improved by RS curve and potential function via spatio-temporal map to obtain a safe and efficient initial trajectory. In short term, this paper proposes a nonlinear model predictive control trajectory optimizer to smooth and adjust the trajectory online based on the vehicle kinematic model. Moreover, the proposed method is simulated and verified in four common dynamic parking scenarios by ACADO Toolkit and QPOASE solver.

Findings

Compared with the spline optimization method, the results show that the proposed method can generate efficient obstacle avoidance strategies, safe parking trajectories and control parameters such as the front wheel angle and velocity in high-efficient central processing units.

Originality/value

It is aimed at improving the robustness of automatic parking system and providing a reference for decision-making in a dynamic environment.

Details

Journal of Intelligent and Connected Vehicles, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2399-9802

Keywords

Article
Publication date: 16 October 2020

Jinxin Liu, Hui Xiong, Tinghan Wang, Heye Huang, Zhihua Zhong and Yugong Luo

For autonomous vehicles, trajectory prediction of surrounding vehicles is beneficial to improving the situational awareness of dynamic and stochastic traffic environments…

Abstract

Purpose

For autonomous vehicles, trajectory prediction of surrounding vehicles is beneficial to improving the situational awareness of dynamic and stochastic traffic environments, which is a crucial and indispensable element to realize highly automated driving.

Design/methodology/approach

In this paper, the overall framework consists of two parts: first, a novel driver characteristic and intention estimation (DCIE) model is built to indicate the higher-level information of the vehicle using its low-level motion variables; then, according to the estimation results of the DCIE model, a classified Gaussian process model is established for probabilistic vehicle trajectory prediction under different motion patterns.

Findings

The whole method is later applied and analyzed in the highway lane-change scenarios with the parameters of models learned from the public naturalistic driving data set. Compared with other traditional methods, the performance of this proposed approach is proved superior, demonstrated by the higher accuracy in the long prediction horizon and a more reasonable description of uncertainty.

Originality/value

This hierarchical approach is proposed to make trajectory prediction accurately both in the short term and long term, which can also deal with the uncertainties caused by the perception system or indeterminate vehicle behaviors.

Details

Industrial Robot: the international journal of robotics research and application, vol. 48 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 22 March 2019

Fen-may Liou

Based on a strategic group concept, the purpose of this paper is to examine the effects of resource employments on persistent performance in the pharmaceutical industry.

Abstract

Purpose

Based on a strategic group concept, the purpose of this paper is to examine the effects of resource employments on persistent performance in the pharmaceutical industry.

Design/methodology/approach

In departing from previous research, this paper takes an inverted approach to mapping firms into heterogeneous groups with distinct long-term performance trajectories, given that strategic profiles and characteristics were unknown. The methodology used is latent class growth analysis, a person-centred approach focussing on the relationships among individuals. Regression models were subsequently used to examine the strategy variables-performance relationship between groups and within groups.

Findings

First, firms were grouped into upper-performance and lower-performance trajectory subpopulations. Second, the effects of marketing and R&D on performance significantly differed within subpopulations and presented a U shape or an inverse U shape relation. Third, the employment of R&D resources was more effective in the lower-performance trajectory group, the average scale of which is smaller than in the upper-performance trajectory group. On the contrary, the employment of marketing resources had a greater benefited in the upper-performance trajectory group.

Research limitations/implications

Intangible strategy features are ignored due to measure problem in the long period.

Practical implications

Strategic competition is more significant among intragroup members than inter groups. That the U-shape or invert U-shape effects of resource employments on performance among intragroup members reminds the researchers that the law of diminishing return or increasing return should not be ignored when test the group-performance relationship in future research.

Originality/value

The current study introduces an effective approach to investigate the strategic group concept.

Details

Management Decision, vol. 58 no. 1
Type: Research Article
ISSN: 0025-1747

Keywords

Open Access
Article
Publication date: 18 August 2022

Joyce B. Main

The underrepresentation of women in engineering has important consequences for meeting the need for a larger, talented scientific and technological labor force. Increasing…

Abstract

Purpose

The underrepresentation of women in engineering has important consequences for meeting the need for a larger, talented scientific and technological labor force. Increasing the proportion of women faculty in engineering will help increase the persistence probabilities of women undergraduate and graduate students in engineering, as well as contribute to the range and diversity of ideas toward innovations and solutions to the greatest engineering challenges. This study aims to examine the association among gender, family formation and post-PhD employment patterns of a cohort of engineering doctorates.

Design/methodology/approach

Using the National Science Foundation’s Survey of Doctorate Recipients data, 2001–2010, descriptive and multinomial logit regression analyses are conducted to illustrate the career trajectories of engineering PhDs over a ten-year period.

Findings

The career trajectories of engineering PhDs are nonlinear, and transitions between employment sectors commonly occur over the ten-year time period studied. Although women engineering PhDs with young dependents are less likely to be employed initially after PhD completion, they tend to enter the workforce in the academic sector as time progresses. Early post-PhD employment as a postdoctoral researcher or in the academic sector contributes to the pursuit of the professoriate downstream.

Originality/value

While previous studies tend to focus on the early career outcomes of science and engineering students, this study contributes to the literature by focusing on the long-term career outcomes of engineering doctorates. Research findings provide engineering PhD students and PhDs with more information regarding potential post-PhD career trajectories, highlighting the multitude of career options and transitions that occur over time. Research findings also provide higher education administrators and doctoral program stakeholders with foundational information toward designing and revitalizing professional development programs to help PhD students prepare for the workforce. The findings have the potential to be applied toward helping increase diversity by shaping policies and programs to encourage multiple alternative career pathways to the professoriate.

Details

Studies in Graduate and Postdoctoral Education, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-4686

Keywords

Article
Publication date: 18 September 2017

Nevena Zhelyazkova and Gilbert Ritschard

The purpose of this paper is to present an analysis of parental leave use and long-term employment trajectories of parents in Luxembourg based on anonymous administrative…

Abstract

Purpose

The purpose of this paper is to present an analysis of parental leave use and long-term employment trajectories of parents in Luxembourg based on anonymous administrative records. This is the first systematic analysis of parental leave take-up rates and return rates for Luxembourg using a large and reliable data set.

Design/methodology/approach

The authors use highly detailed administrative data to calculate take-up and return rates for parental leave for both men and women working in Luxembourg. To gain deeper insights into the employment trajectories of parents, the authors deploy the visualisation tools of the TraMineR package, which allow the authors to trace developments over time.

Findings

The authors estimate take-up rates for parental leave at 72 per cent for mothers and 13 per cent for fathers. The return rates for mothers are 88.4, 99.4 and 70.8 per cent depending on whether they took full-time, part-time or no parental leave. In contrast, over 95 per cent of fathers remain employed following parental leave. The trajectory analysis reveals that the event of birth is a clear turning point for the majority of the female trajectories, but not for the male ones.

Originality/value

The paper contributes to the literature in at least several ways. First, this is the first available paper presenting the situation in Luxembourg using a large and reliable data set. Second, by including fathers in the analysis, the authors contribute to the available knowledge of male use of parental leave, which has been the subject of continued policy efforts in the past decades. Finally, the authors show how parental leave can be analysed using sequence analysis tools and how this method offers additional, holistic insights into work-family patterns over time.

Details

Equality, Diversity and Inclusion: An International Journal, vol. 36 no. 7
Type: Research Article
ISSN: 2040-7149

Keywords

Article
Publication date: 19 December 2018

Álvaro Rodríguez-Sanz, Fernando Gómez Comendador, Rosa M. Arnaldo Valdés, Javier A. Pérez-Castán, Pablo González García and Mar Najar Godoy Najar Godoy

The use of the 4D trajectory operational concept in the future air traffic management (ATM) system will require the aircraft to meet very accurately an arrival time over a…

Abstract

Purpose

The use of the 4D trajectory operational concept in the future air traffic management (ATM) system will require the aircraft to meet very accurately an arrival time over a designated checkpoint. To do this, time intervals known as time windows (TW) are defined. The purpose of this paper is to develop a methodology to characterise these TWs and to manage the uncertainty associated with the evolution of 4D trajectories.

Design/methodology/approach

4D trajectories are modelled using a point mass model and EUROCONTROL’s BADA methodology. The authors stochastically evaluate the variability of the parameters that influence 4D trajectories using Monte Carlo simulation. This enables the authors to delimit TWs for several checkpoints. Finally, the authors set out a causal model, based on a Bayesian network approach, to evaluate the impact of variations in fundamental parameters at the chosen checkpoints.

Findings

The initial results show that the proposed TW model limits the deviation in time to less than 27 s at the checkpoints of an en-route segment (300 NM).

Practical implications

The objective of new trajectory-based operations is to efficiently and strategically manage the expected increase in air traffic volumes and to apply tactical interventions as a last resort only. We need new tools to support 4D trajectory management functions such as strategic and collaborative planning. The authors propose a novel approach for to ensure aircraft punctuality.

Originality/value

The main contribution of the paper is the development of a model to deal with uncertainty and to increase predictability in 4D trajectories, which are key elements of the future airspace operational environment.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 11 July 2016

Andrej Christian Lindholst, Morten Balle Hansen and Ole Helby Petersen

– The purpose of this paper is to improve the understanding of the evolution of marketization in the public sector as a process of institutional change.

Abstract

Purpose

The purpose of this paper is to improve the understanding of the evolution of marketization in the public sector as a process of institutional change.

Design/methodology/approach

The paper is based on a study of marketization and gradual changes in the involvement of private contractors (as providers of maintenance services) in the municipal road and park sectors in Denmark over the past 30 years. The study draws theoretically on historical institutionalism as an interpretive framework and empirically on findings from earlier research, register data from municipal accounts as well as new survey data.

Findings

Marketization within the road and park sectors has historically taken place through gradual changes, in particular by processes of layering and displacement, which has added up to substantial transformations in both sectors. Transformations relate to the levels of private sector involvement, the purpose of using private contractors, the extent of competition and the design of contractual arrangements. The road sector has been a frontrunner in this marketization process, while the park sector increasingly has been “catching up.”

Originality/value

The paper contributes to the understanding of the historical development and differential pathways of marketization within the public sector. In particular, the study highlights how pathways of gradual change, spurred by the influx of long-term policy pressures, over time can lead to substantial institutional transformations.

Details

International Journal of Public Sector Management, vol. 29 no. 5
Type: Research Article
ISSN: 0951-3558

Keywords

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