Knowledge modelling for contract disputes and change control

The construction industry involves many participants with different perspectives and requirements. Contracts can provide significant value, and yet ineffective contract management frequently leads to disputes. In practice, contracts are hardly reviewed, and contract management is limited. This study aims to investigate how firms can improve their internal processes relating to knowledge management (KM) through effective contract management to aid construction practitioners in managing contract disputes and changes. Using a questionnaire survey and a workshop involving experienced industry practitioners and researchers, the findings reveal that project- and individual-level implementation of KM processes is stronger than at the organizational level, and also there are substantial human resources (HR) practices that support contractual KM. Workshop participants believe efficient and effective KM can minimise losses from contract changes and disputes. A construction contract management process framework, a 19-step benchmarking model for contract management and a construction planning checklist for contractors are proposed.     

Gender as a Moderator of the Relation Among Social Support Functions and Life Satisfaction in Older Malaysians

The aim of this study was to examine the moderating role of gender on relations among social support functions and life satisfaction in older Malaysians. The study sample was 1,800 older residents in a community; all were at least 60 years old. This study was a cross-sectional and corelational survey, and the data were collected by multistage stratified sampling. This study revealed that fewer social support functions, and therefore less life satisfaction, were available for females than for males. The results of moderated regression analyses demonstrated that gender interacted only on the relationship between positive social interaction support and tangible support with life satisfaction. Specifically, at a high tangible support level, females had lower life satisfaction when compared to a low tangible support level. There may be a need for new programs and services to provide other aspects of social support to older female adults to improve and maintain life satisfaction in later life.     

Exploring the underlying factors inducing design changes during building production

Although design changes is a significant inhibiting factor to schedule management and cost control in building projects globally, however, the reasons remain largely unknown, and the construction industry is unable to manage the problem effectively. A triangulated approach was employed where 39 reasons were first explored through semi-structured interviews with experienced practitioners. Subsequently, a national survey was used to rank the reasons. ‘Value engineering’, ‘lack of coordination among various professional consultants’ and ‘change of requirement’ ranked the highest. Next, exploratory factor analysis revealed eight underlying factors. Finally, the influence of these manifested factors was validated statistically using partial least squares based structural equation modelling. The three most critical factors found are ‘competency of project team', ‘quality and workmanship’, and ‘site constraints and safety consideration’. This paper contributes to the development of new underlying factors inducing design changes, which largely explain design changes as well as enable practitioners and researchers to devise effective preventive measures in controlling design changes in building projects.     

Parameter estimation of complex mixed models based on meta-model approach

Complex biological processes are usually experimented along time among a collection of individuals, longitudinal data are then available. The statistical challenge is to better understand the underlying biological mechanisms. A standard statistical approach is mixed-effects model where the regression function is highly-developed to describe precisely the biological processes (solutions of multi-dimensional ordinary differential equations or of partial differential equation). A classical estimation method relies on coupling a stochastic version of the EM algorithm with a Monte Carlo Markov Chain algorithm. This algorithm requires many evaluations of the regression function. This is clearly prohibitive when the solution is numerically approximated with a time-consuming solver. In this paper a meta-model relying on a Gaussian process emulator is proposed to approximate the regression function, that leads to what is called a mixed meta-model. The uncertainty of the meta-model approximation can be incorporated in the model. A control on the distance between the maximum likelihood estimates of the mixed meta-model and the maximum likelihood estimates of the exact mixed model is guaranteed. Eventually, numerical simulations are performed to illustrate the efficiency of this approach.     

Evaluation of the statistical power for multiple tests: a case study

It is challenging to estimate the statistical power when a complicated testing strategy is used to adjust for the type-I error for multiple comparisons in a clinical trial. In this paper, we use the Bonferroni Inequality to estimate the lower bound of the statistical power assuming that test statistics are approximately normally distributed and the correlation structure among test statistics is unknown or only partially known. The method was applied to the design of a clinical study for sample size and statistical power estimation.     

Measuring revisions to subjective expectations

This paper develops a new metric to measure revisions to subjective expectations and proposes a survey design strategy that enables the estimation of the metric. As an application, I analyze how women update their ex pectations about the effectiveness of contraception methods. The women interviewed exhibit substantial heterogeneity in the way they revise their expectations with receipt of the same information. When relating the heterogeneity in the updating process to observable characteristics, I find that schooling, having a regular sexual partner and knowledge and use of birth control methods have a large impact on the revision process about the effectiveness of contraceptives.