Operations Research in Healthcare: a survey

Optimisation problems in Healthcare have received considerable attention for more than three decades. More recently, however, with decreasing birth rates in nearly all of the developed countries and increasing average longevity globally, optimisation issues in Healthcare have become noticeably important and attract keen interest from the Operations Research community. Over the years, attention has gradually expanded from resource allocation and strategic planning to include operational issues such as resource scheduling and treatment planning. This paper surveys several applications of Operations Research in the domain of Healthcare. In particular, the paper reviews key contributions addressing contemporary optimisation issues in this area. It highlights current research activities, focusing on a variety of optimisation problems as well as solution techniques used for solving the optimisation problems.     

Automation of Tracking Trajectories in a Crowded Situation

Studies on pedestrians using microscopic simulation require large amounts of trajectory data from real-world pedestrian crowds. The collection of such data, if done manually, involves tremendous efforts and is very time-consuming. Although many studies have asserted the possibility of automating this task using video cameras, we have found that only a few have demonstrated good performance in very crowded situations or from a top-angled view scene. This paper deals with tracking pedestrian crowd under heavy occlusion and from an angular scene using only a single non-stereo video camera. Our automated tracking system consists of three modules that are performed sequentially. The first module detects moving objects as blobs. The second module computes feature values from the blob information in order to generate what we call a possibility matrix. The third module is a tracking system, which employs a Bayesian update of the probability tree derived from the possibility matrix and from the detection of each pedestrian, in order to track the next position of the pedestrian. The result of such tracking is a database of pedestrian trajectories over time and space. With certain prior information, we show that the system is able to track a large number of people under occlusion and clutter scene.     

Geographical distribution of cancer in India with special reference to stomach cancer

There are regional variations in the occurrence of different types of cancers in India. A cancer intensity map has been prepared in order to identify the dominance of different types of carcinomas in various geographical regions. The study shows that the pattern of cancer distribution is apparently linked to a great extent with the type of nutrition habits and socio‐economic and cultural environment in each region. Various types of nutrition habits are discussed in order to study the relationship between the type of diet and the incidence to stomach cancer in India.     

Simulation and experimental analysis of an intelligent tissue for controlled drug delivery

In this research, an antibiotic was loaded in the composites of polyethylene glycol (PEG), acrylamide (AAm) and acrylic acid (AAc) hydrogels matrices and their drug deliveries were tested. Effect of some parameters on the drug delivery was checked by UV‐spectrophotometer. Temperature enhancement considerably increased hydrogel swelling and the drug release in the AAc and AAm. A dynamic model based on the Maxwell–Stefan equation was developed to model the drug delivery of hydrogels. COMSOL software was also applied to simulate buffer diffusion inside the hydrogels.     

Performance of jet impingement in unglazed air collectors

Jet impingement is effective at improving the heat transfer between air and a heated surface. Studies have shown that jet impingement can marginally improve the thermal efficiency of a glazed collector. However, little attention has been placed on applying jet impingement to an unglazed solar air collector. This paper presents a theoretical and experimental investigation identifying the performance characteristics of jet impingement. Overall, jet impingement was able to improve the thermal efficiency of the collector by 21%. An increase in the pressure loss was also measured but found to be small. The flow distribution of jets along the collector was the most significant factor in determining the efficiency. Increasing the hole spacing was found to improve the efficiency.     

A phase change processor method for solving a one-dimensional phase change problem with convection boundary

A simple yet accurate iterative method for solving a one-dimensional phase change problem with convection boundary is described. The one-dimensional model takes into account the variation in the wall temperature along the direction of the flow as well as the sensible heat during preheating/pre-cooling of the phase change material (PCM). The mathematical derivation of convective boundary conditions has been integrated into a phase change processor (PCP) algorithm that solves the liquid fraction and temperature of the nodes. The algorithm is based on the heat balance at each node as it undergoes heating or cooling which inevitably involves phase change. The paper presents the model and its experimental validation.     

Adsorption studies on Parthenium hysterophorous weed: removal and recovery of Cd(II) from wastewater

The efficiency of parthenium weed as an adsorbent for removing Cd(II) from water has been studied. Parthenium is found to exhibit substantial adsorption capacity over a wide range of initial Cd(II) ions concentration. Effect of time, temperature, pH and concentration on the adsorption of Cd(II) was investigated by batch process. Pseudo-first-order and Pseudo-second-order models were evaluated. The kinetics data for the adsorption process obeyed second-order rate equation. The equilibrium data could be described well by the Langmuir and Freundlich isotherms. Thermodynamic parameters such as DeltaH degrees , DeltaS degrees and DeltaG degrees were calculated. The adsorption process was found to be endothermic and spontaneous. The maximum adsorption of Cd(II) ions (99.7%) in the pH range 3-4 indicated that material could be effectively utilized for the removal of Cd(II) ions from wastewater. The desorption studies showed 82% recovery of Cd(II) when 0.1 M HCl solution was used as effluent.     

Organic electrolytes for corrosion testing of aluminium and Al-Li binary alloys

The electrochemical behavior of high purity aluminium and Al-Li alloy has been investigated in various organic environments. Various lithium- and aluminium-compatible solvents were considered before selecting propylene carbonate (PC) and tetrahydrofuran (THF) with addition of either chloride or perchlorate ions. THF finally proved to be the most suitable solvent for these tests. The aluminium dissolution reaction in a THF environment is fast and reversible. The Al/Al(III) couple can therefore be used as a reference electrode. Aluminium salts can be reduced by lithium, making the Li/Li⁺ couple unsuitable for the reference electrode. The voltammograms obtained show voltage characteristics (protective potentialE _p and breakdown potentialE _b) similar to those found in aqueous environments. The voltage variations recorded by potentiometric measurements could be associated with changes in the alloy surface state.     

New heuristic methods for the single-source capacitated multi facility Weber problem

In this paper, a generalized variant of the multi facility Weber problem is proposed, where each customer must be satisfied by a single capacitated facility. To solve the problem, the allocation phase of the alternate location–allocation (ALA) is strengthened by a priority-based approach. Computational experiments are implemented on a set of random test instances, along with a set of instances taken from the literature. Computational results compared with GAMS/BARON indicate that the priority-based ALA solves large-scale instances within promising computational time and outperforms GAMS/BARON in terms of solution quality. This success rate is achieved in nearly 80 % of studied cases. Finally, some guidelines for future research are presented.     

Hydraulic Performance of PK Weirs Based on Experimental Study and Kernel-based Modeling

Water Resources Management - A piano key weir (PK weir) is a non-linear, labyrinth-type weir that benefits of a high discharge capacity, and is well suited for low head dams. Determination of the...