Zoekresultaten

A latent class transition model of interactions between the built environment, travel attitudes and travel behaviour

Establishing Typologies for Diverging Career Paths through the Life Course: A Comparison of two Methods

Discussions on policy and management initiatives to facilitate individuals throughout working careers take place without sufficient insight into how career paths are changing, how these changes are related to a modernization of life course biographies, and whether this leads to increased labour market transitions. This paper asks how new, flexible labour market patterns can best be analyzed using an empirical, quantitative approach. The data used are from the career module of the Panel Study of Belgian Households (PSBH). This module, completed by almost 4500 respondents consists of retrospective questions tracing lengthy and even entire working life histories. To establish any changes in career patterns over such extended periods of time, we compare two evolving methodologies: Optimal Matching Analysis (OMA) and Latent Class Regression Analysis (LCA). The analyses demonstrate that both methods show promising potential in discerning working life typologies and analyzing sequence trajectories. However, particularities of the methods demonstrate that not all research questions are suitable for each method. The OMA methodology is appropriate when the analysis concentrates on the labour market statuses and is well equipped to make clear and interpretable differentiations if there is relative stability in career paths during the period of observation but not if careers become less stable. Latent Class has the strength of adopting covariates in the clustering allowing for more historically connected types than the other methodology. The clustering is denser and the technique allows for more detailed model fitting controls than OMA. However, when incorporating covariates in a typology, the possibilities of using the typology in later, causal, analyses is somewhat reduced.

Relationship between socioeconomic status and quality of life in older adults

PURPOSE: The main objective of this study was to determine the relationship between quality of life, social functioning, depressive symptoms, self-efficacy, physical function, and socioeconomic status (SES) in community-dwelling older adults.METHODS: A cross-sectional design was used to examine the relationships. A sample of 193 community-dwelling older adults completed the measurements. Structural equation modeling with full information maximum likelihood in LISREL was used to evaluate the relationships between the latent variables (SES, social functioning, depressive symptoms, self-efficacy, physical function, and quality of life).RESULTS: The path analysis exhibited significant effects of SES on physical function, social functioning, depressive symptoms, and self-efficacy (γ = 0.42-0.73), and significant effects in regard to social functioning, depressive symptoms, and self-efficacy on quality of life (γ = 0.27-0.61). There was no direct effect of SES on the quality of life. The model fit indices demonstrated a reasonable fit (χ (2) = 98.3, df = 48, p < 0.001), matching the relative Chi-square criterion and the RMSEA criterion. The model explained 55.5 % of the variance of quality of life.CONCLUSIONS: The path analysis indicated an indirect effect of SES on the quality of life by social functioning, depressive symptoms, and self-efficacy in community-dwelling older adults. Physical function did not have a direct effect on the quality of life. To improve the quality of life in older adults, additional focus is required on the socioeconomic psychosocial differences in the community-dwelling older population.

Improving Electric vehicle charging station efficiency through pricing

Recent studies show that charging stations are operated in an inefficient way. Due to the fact that electric vehicle (EV) drivers charge while they park, they tend to keep the charging station occupied while not charging. This prevents others from having access. This study is the first to investigate the effect of a pricing strategy to increase the efficient use of electric vehicle charging stations. We used a stated preference survey among EV drivers to investigate the effect of a time-based fee to reduce idle time at a charging station. We tested the effect of such a fee under different scenarios and we modelled the heterogeneity among respondents using a latent class discrete choice model. We find that a fee can be very effective in increasing the efficiency at a charging station but the response to the fee varies among EV drivers depending on their current behaviour and the level of parking pressure they experience near their home. From these findings we draw implications for policy makers and charging point operators who aim to optimize the use of electric vehicle charging stations.

Acquiring English language competences in a multi-lingual situation: the learning experiences of Dutch second language learners.

Background to the problem Dutch society demonstrates a development which is apparent in many societies in the 21st century; it is becoming ethnically heterogeneous. This means that children who are secondlanguage speakers of Dutch are learning English, a core curriculum subject, through the medium of the Dutch language. Research questions What are the consequences of this for the individual learner and the class situation?Is a bi-lingual background a help or a hindrance when acquiring further language competences. Does the home situation facilitate or impede the learner? Additionally, how should the TEFL professional respond to this situation in terms of methodology, use of the Dutch language, subject matter and assessment? Method of approach A group of ethnic minority students at Fontys University of Professional Education was interviewed. The interviews were subjected to qualitative analysis. To ensure triangulation lecturers involved in teaching English at F.U.P.E. were asked to fill in a questionnaire on their teaching approach to Dutch second language English learners. Thier response was quantitatively and qualitatively analysed. Findings and conclusions The students encountered surprisingly few problems. Their bi-lingualism and home situation were not a constraint in their English language development. TEFL professionals should bear the heterogeneous classroom in mind when developing courses and lesson material. The introduction to English at primary school level and the assessment of DL2 learners require further research.

Classification of condom lubricants in cyanoacrylate treated fingerprints by desorption electrospray ionization mass spectrometry

Traces of condom lubricants in fingerprints can be valuable information in cases of sexual assault. Ideally, not only confirmation of the presence of the condom but also determination of the type of condom brand used can be retrieved. Previous studies have shown to be able to retrieve information about the condom brand and type from fingerprints containing lubricants using various analytical techniques. However, in practice fingerprints often appear latent and need to be detected first, which is often achieved by cyanoacrylate fuming. In this study, we developed a desorption electrospray ionization mass spectrometry (DESI-MS) method which, combined with principal component analysis and linear discriminant analysis (PCA-LDA), allows for high accuracy classification of condom brands and types from fingerprints containing condom lubricant traces. The developed method is compatible with cyanoacrylate (CA) fuming. We collected and analyzed a representative dataset for the Netherlands comprising 32 different condoms. Distinctive lubricant components such as polyethylene glycol (PEG), polydimethylsiloxane (PDMS), octoxynol-9 and nonoxynol-9 were readily detected using the DESI-MS method. Based on the analysis of lubricant spots, a 99.0% classification accuracy was achieved. When analyzing lubricant containing fingerprints, an overall accuracy of 90.9% was obtained. Full chemical images could be generated from fingerprints, showing the distribution of lubricant components such as PEG and PDMS throughout the fingerprint, while still allowing for classification. The developed method shows potential for the development of DESI-MS based analyses of CA treated exogenous compounds from fingerprints for use in forensic science.