Resource-constrained project scheduling for timely project completion with stochastic activity durations.

We investigate resource-constrained project scheduling with stochastic activity durations. Various objective functions related to timely project completion are examined, as well as the correlation between these objectives. We develop a GRASP-heuristic to produce high-quality solutions, using so-called descriptive sampling. The algorithm outperforms other existing algorithms for expected-makespan minimization. The distribution of the possible makespan realizations for a given scheduling policy is studied, and problem difficulty is explored as a function of problem parameters.GRASP; Project scheduling; Uncertainty;

Meta-heuristics for stable scheduling on a single machine.

This paper presents a model for single-machine scheduling with stability objective and a common deadline. Job durations are uncertain, and our goal is to ensure that there is little deviation between planned and actual job starting times. We propose two meta-heuristics for solving an approximate formulation of the model that assumes that exactly one job is disrupted during schedule execution, and we also present a meta-heuristic for the global problem with independent job durationsMeta-heuristics; Robustness; Single-machine scheduling; Uncertainty;

Removal of pesticides from aqueous solutions by adsorption on zeolites as solid adsorbents

To prevent the contamination of groundwater and surface water by pesticides, appropriate measures should be taken to treat the contaminated water before discharge. Zeolites seem to be a promising material to adsorb pesticides. This paper deals with the removal of mobile pesticides from water on different types of zeolites. Experiments were performed to understand the adsorption mechanisms of bentazon, clopyralid, imidacloprid, isoproturon and metalaxyl-m on zeolites and to determine the most efficient adsorbent for the purification of water contaminated by these pesticides. More immobile pesticides (imidacloprid, isoproturon and metalaxyl-m) tended to associate with the zeolites, whereas more mobile pesticides (bentazon and clopyralid) partitioned in water. According to the adsorption percentage, zeolite of the types BEA and FAU showed the best results for adsorbing the pesticides. Two different kinetic models, namely, pseudo-first-order and pseudo-second-order models, were used to fit the kinetics data. The experimental data were best described by the pseudo-second-order model. The rate of adsorption was also in line with the mobility of the pesticides. The adsorption isotherms were determined and modelled based on the observed types according to International Union of Pure and Applied Chemistry. The type III isotherm was most frequently observed in this case. The Freundlich model, which describes this type of isotherm, gave a good fit for the adsorption of the pesticides. Different assumptions, that could describe the meaning of these type III isotherms, are discussed in this paper. These assumptions are based on the particle size of the adsorbates, the water adsorption on the zeolites and the modifications of the crystal structures

Fuzzy support vector machines for pattern classification

In response to the Ebola virus disease (EVD) outbreak in West Africa, the World Health Organization has advised all nations to prepare for the detection, investigation and management of confirmed and suspected EVD cases in order to prevent further spread through international travel. To gain insights into the state of preparedness of European hospitals, an electronic survey was circulated in August–September 2014 to 984 medical professionals representing 736 hospitals in 40 countries. The survey addressed the willingness and capacity to admit patients with suspected EVD as well as specific preparedness activities in response to the current Ebola crisis. Evaluable responses were received from representatives of 254 (32%) hospitals in 38 countries, mostly tertiary care centres, of which 46% indicated that they would admit patients with suspected EVD. Patient transfer agreements were in place for the majority of hospitals that would not admit patients. Compared with non-admitting hospitals, admitting hospitals were more frequently engaged in various preparedness activities and more often contained basic infrastructural characteristics such as admission rooms and laboratories considered important for infection control, but some gaps and concerns were also identified. The results of this survey help to provide direction towards further preparedness activities and prioritisation thereof

Compressive 3D ultrasound imaging using a single sensor

Three-dimensional ultrasound is a powerful imaging technique, but it requires thousands of sensors and complex hardware. Very recently, the discovery of compressive sensing has shown that the signal structure can be exploited to reduce the burden posed by traditional sensing requirements. In this spirit, we have designed a simple ultrasound imaging device that can perform three-dimensional imaging using just a single ultrasound sensor. Our device makes a compressed measurement of the spatial ultrasound field using a plastic aperture mask placed in front of the ultrasound sensor. The aperture mask ensures that every pixel in the image is uniquely identifiable in the compressed measurement. We demonstrate that this device can successfully image two structured objects placed in water. The need for just one sensor instead of thousands paves the way for cheaper, faster, simpler, and smaller sensing devices and possible new clinical applications

Age-related Differences in Tumour Characteristics and Prognostic Factors for Disease Progression in Cutaneous Squamous Cell Carcinoma of the Head and Neck

Guidelines for cutaneous squamous cell carcinoma of the head and neck do not take the age of the patient into account, but instead assume equal tumour characteristics and prognostic factors for poor outcome in younger and elderly patients. The aim of this study was to compare tumour characteristics of younger (< 75 years) and elderly (≥ 75 years) patients and identify age-specific risk factors for progression of disease, comprising local recurrence, nodal metastasis and distant metastasis. Patient and tumour characteristics were compared using χ2 or Fisher's exact tests. Multivariable competing risk analyses were performed to compare risk factors for progression of disease, incorporating the risk of dying before developing progression of disease. A total of 672 patients with primary cutaneous squamous cell carcinoma of the head and neck were retrospectively included. Larger tumour diameter, worse differentiation grade and deeper invasion were observed in older patients. In elderly patients, but not in younger patients, tumour diameter ≥ 40 mm, moderate differentiation grade and an invasion depth ≥ 2 mm were independent risk factors for progression of disease