Parameter estimations of the generalized extreme value distributions for small sample size

The standard method of the maximum likelihood has poor performance in GEV parameter estimates for small sample data. This study aims to explore the Generalized Extreme Value (GEV) parameter estimation using several methods focusing on small sample size of an extreme event. We conducted simulation study to illustrate the performance of different methods such as the Maximum Likelihood (MLE), probability weighted moment (PWM) and the penalized likelihood method (PMLE) in estimating the GEV parameters. Based on the simulation results, we then applied the superior method in modelling the annual maximum stream flow in Sabah. The result of the simulation study shows that the PMLE gives better estimate compared to MLE and PMW as it has small bias and root mean square errors, RMSE. For an application, we can then compute the estimate of return level of river flow in Sabah

Effect of different deposition techniques of PCDTBT:PC<inf>71</inf>BM composite on the performance of capacitive-type humidity sensors

The performance and hence pragmatic use of organic humidity sensors requires various factors to be addressed outside of progress in high-performance organic-based sensing materials. While important, evaluation of fabrication techniques also requires attention to optimise performance. Herein we report the effect of different application techniques on the humidity sensing performance of poly[N-90-heptadecanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothiadiazole)] (PCDTBT) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) organic composites. Spin-coating, immersion and drop-casting techniques have been applied to prepare sensors. Field-emission scanning electronic microscopy (FESEM) analysis of the prepared films revealed different types of self-assembled nanorods and nanotubes to be formed. The morphological and self-assembled differences could be attributed to various crystallisation processes as a result of different deposition techniques. Capacitive responses of all three sensors have been studied as a function of relative humidity at room temperature. PCDTBT:PC71BM composites prepared through the immersion technique showed superior sensing performance including higher sensitivity (62.34 pF/%RH) than sensors prepared through the spin coating (0.2 pF/%RH) and drop-casting (7.5 pF/%RH) techniques. The superior sensing performance of the sensor prepared through the immersion technique can be ascribed to both the nanotube and porous morphology exhibited

To serve or to leave: a question faced by public sector healthcare providers in Pakistan

BACKGROUND: The availability of properly trained and motivated providers is a prerequisite for provision of easily accessible healthcare. Pakistan has been listed by the World Health Organization in its World Health Report 2006 as one of 57 countries with a critical health workforce deficiency. This study examines the factors associated with the willingness of public sector healthcare providers to leave government service and recommends measures that can be adopted to attract and retain staff in the country’s public healthcare system. METHODS: A stratified, random sampling methodology was adopted to recruit a nationally representative sample of 1,296 public sector healthcare providers, including paramedics, medical doctors, and specialists. A semi-structured questionnaire was used to interview these providers. Logistic regressions measured the association with determinants of their willingness to leave the public health sector for better prospects elsewhere. RESULTS: A third of all healthcare providers who were interviewed were of the view that, provided the opportunity, they would leave government service. The odds of willingness to leave service were highest among providers from the region of Azad Jammu and Kashmir (adjusted odds ratio [AOR] = 4.33; 95% CI, 2.49–7.54) followed by the province of Balochistan (AOR = 4.21; 95% CI, 2.41–7.33), and the region of Gilgit Baltistan (AOR = 3.34; 95% CI, 1.67–6.67). Providers who expressed dissatisfaction in the manner their performance was evaluated and those who were dissatisfied with the current salary, each had higher odds of considering leaving government service (AOR = 1.67; 95% CI, 1.18–2.40 and AOR = 2.03; 95% CI, 1.47–2.81, respectively). Providers who reported experiencing interference in their work by influential politicians of the area were more inclined to leave (AOR = 1.44; 95% CI, 1.05–1.98). CONCLUSION: This study clearly highlights the need to implement more focused strategies in the public healthcare system in Pakistan in order to build sufficient staff motivation and prevent providers from leaving government service. In order to improve coverage of healthcare services in Pakistan, the government will have to introduce more focused interventions to attract and retain healthcare providers, especially in remote and rural areas of the country