Search results

We examine the Stein-rule shrinkage estimator for possible improvements in estimation and forecasting when there are many predictors in a linear time series model. We consider the Stein-rule estimator of Hill and Judge (1987) that shrinks the unrestricted unbiased ordinary least squares (OLS) estimator toward a restricted biased principal component (PC) estimator. Since the Stein-rule estimator combines the OLS and PC estimators, it is a model-averaging estimator and produces a combined forecast. The conditions under which the improvement can be achieved depend on several unknown parameters that determine the degree of the Stein-rule shrinkage. We conduct Monte Carlo simulations to examine these parameter regions. The overall picture that emerges is that the Stein-rule shrinkage estimator can dominate both OLS and principal components estimators within an intermediate range of the signal-to-noise ratio. If the signal-to-noise ratio is low, the PC estimator is superior. If the signal-to-noise ratio is high, the OLS estimator is superior. In out-of-sample forecasting with AR(1) predictors, the Stein-rule shrinkage estimator can dominate both OLS and PC estimators when the predictors exhibit low persistence.

We develop a Bayesian approach for modeling brain activation and connectivity from functional magnetic resonance image (fMRI) data. Our approach simultaneously estimates local hemodynamic response functions (HRFs) and activation parameters, as well as global effective and functional connectivity parameters. Existing methods assume identical HRFs across brain regions, which may lead to erroneous conclusions in inferring activation and connectivity patterns. Our approach addresses this limitation by estimating region-specific HRFs. Additionally, it enables neuroscientists to compare effective connectivity networks for different experimental conditions. Furthermore, the use of spike and slab priors on the connectivity parameters allows us to directly select significant effective connectivities in a given network.

We include a simulation study that demonstrates that, compared to the standard generalized linear model (GLM) approach, our model generally has higher power and lower type I error and bias than the GLM approach, and it also has the ability to capture condition-specific connectivities. We applied our approach to a dataset from a stroke study and found different effective connectivity patterns for task and rest conditions in certain brain regions of interest (ROIs).

This paper covers different types of research designs, like, longitudinal, cross-section and sequential design, experimental design (including factorial experimental design), and correlational design, with illustrative examples. This paper will help a scholar to know how choice of research design depends on a number of parameters, highlighted by author.

Recent decades have witnessed a rising concern regarding the prosperity of the environment and utilisation of resources. A sustainable approach is being promoted in all sectors. In the field of tourism, sustainable tourism is widely discussed among researchers and practitioners. On the other hand, luxury tourism is criticised for lavish resource utilisation to serve the few luxury tourists. There is a need to include sustainability in luxury tourism to benefit the environment, local communities, tourist destination and luxury tourists. However, sustainable luxury tourism is an emerging concept and needs more investigation. This chapter attempts to present the existing knowledge about sustainable luxury tourism by implementing a systematic literature review. Further, the opportunities and challenges associated with sustainable luxury tourism are being highlighted. This study has identified the factors that need to be considered to promote sustainable luxury tourism. Moreover, suggestions of the researchers are being presented to serve as guidelines. This study includes an example of the Diphlu river lodge, which has practised sustainable luxury tourism for many years. The viewpoint of luxury tourists are being understood by analysing the reviews of tourists from TripAdvisor using NVIVO-12 qualitative data analysis software. The combination of literature review and practical information provides insight into sustainable luxury tourism.

Although delivery of goods is vitally important for residents and industries in urban areas, the presence and operations of goods transport vehicles in urban areas are often regarded more as a nuisance than an essential service. Relatively little has been done by many governments to facilitate the essential flows of goods in urban areas and to reduce the adverse impacts of urban goods transport on the communities being served. This has resulted in increasing problems associated with goods delivery including competition with passenger transport for access to road infrastructure and space for parking/delivery facilities. How should OECD countries deal with the difficult challenges they face in this area?

This report analyses measures taken in many cities in the OECD area and provides recommendations for dealing with these challenges.