Design, implementation and testing of an integrated branch and bound algorithm for piecewise linear and discrete programming problems within an LP framework

A number of discrete variable representations are well accepted and find regular use within LP systems. These are Binary variables, General Integer variables, Variable Upper Bounds or Semi Continuous variables, Special Ordered Sets of type One and type Two. The FortLP system has been extended to include these representations. A Branch and Bound algorithm is designed in which the choice of sub-problems and branching variables are kept general. This provides considerable scope of experimentation with tree development heuristics and the tree search can then be guided by search parameters specified by user subroutines. The data structures for representing the variables and the definition of the branch and bound tree are described. The results of experimental investigation for a few test problems are reported

Comparison of the Sedative Effect and Recovery Time of Dexmedetomidine and Fentanyl during Elective Colonoscopy

BACKGROUND AND OBJECTIVE: Various medications such as propofol or midazolam are used with or without fentanyl as sedatives for colonoscopy. Dextroduromedine is a new sedative that activates the alpha-2 adrenergic receptor in the brain and the spinal cord with sedative, analgesic and sympatholytic effects. The aim of this study was to compare the sedative effect and recovery time of dexmedetomidine and fentanyl during elective colonoscopy. METHODS: In this double – blind clinical trial, 80 colonoscopy candidates aged 20-70 years old were randomly divided into two equal groups. 1 mcg/kg dexmedetomidine was administered to the intervention group and 0.5 mcg / kg fentanyl was administered to the control group before the start of the colonoscopy. Propofol (20 mg) was administered as bolus dose if needed during colonoscopy. The sedation rate was recorded based on Ramsay standard and mean bolus dose of propofol during colonoscopy. Recovery time and pain were recorded based on Visual Analog Scale (VAS) before discharge. FINDINGS: The two groups did not have a significant difference in terms of age, gender and sedation rate. The mean bolus dose of propofol in the fentanyl group was 72±14 and in the dexmedetomidine group was 7±0.24 mg (p=0.000). The recovery time in the fentanyl group was 4.38±2.38 minutes and in the dexmedetomidine group was 2.63±1.22 minutes (p=0.000). The pain after colonoscopy was 2.30±0.69 in the fentanyl group and 1.98±0.7 in the dexmedetomidine group (p=0.039). CONCLUSION: The results of this study showed that the combination of dexmedetomidine and propofol are more suitable for colonoscopy compared to the combination of fentanyl and propofol due to shorter recovery time

Benchmarking predictive models in electronic health records : sepsis length of stay prediction

Forecasting Sepsis length of stay is a challenge for hospitals worldwide. Although there are many attempts to improve sepsis length of stay prediction; however, there is still lack of baselining prediction metrics that can give better results for sepsis length of stay prediction in management hospital systems. This paper introduces a research architecture to predict and benchmark the Length of Stay (LOS) for Sepsis diagnoses from electronic medical records using the machine learning models. The architecture considered the time factor to identify the outperforming algorithms for Sepsis LOS prediction. This work contributes to the field of predictive modelling and information visualization for hospital management systems. Our results showed that the ensemble methods in particular the random forest (RF) outdo other classification models to predict the LOS for Sepsis from electronic medical records for Intensive Care Unit “ICU”-based hospitalizations