The effects of non-controllable factors in efficiency evaluation of Turkish Coal Enterprises

In this study, which aims to examine the effects of non-controllable factors as well as input parameters on the efficiency performances of Turkish Coal Mine Enterprises, eight enterprises within Turkish Coal Enterprises (TCE) were examined. In order to keep the study as up-to-date as possible, data from the latest year (2005) was examined. For each enterprise, the outputs consisted of the amount of the production sold and the total income gained in the corresponding year; the controllable inputs consisted of investment expenditure, overburden stripping and number of staff; and non-controllable inputs consisted of total reserve and low heat values. In order to measure the effects of non-controllable inputs on enterprise efficiency, three-stage modified data envelopment analysis (DEA) model was employed. In the first stage, information concerning the efficiency of the enterprises was gained by using only the controllable inputs and outputs. In the second stage, the effects of non-controllable inputs on controllable inputs in inefficient enterprises were examined. Lastly in the third stage, the new efficiency values were calculated by means of DEA where controllable inputs and outputs modified according to non-controllable inputs were used. Considering the non-controllable inputs as a result of the analyses conducted with three-stage DEA model, it was determined that the average efficiency value of Turkish Coal Enterprises increased from 87.5% to 92.3%

A primal dual modified subgradient algorithm with sharp Lagrangian

Nonsmooth optimization, Nonconvex optimization, Duality scheme, Sharp Lagrangian, Modified subgradient algorithm, 90C26, 49M29, 49M37,

Piecewise linear classifiers based on nonsmooth optimization approaches

Nonsmooth optimization provides efficient algorithms for solving many machine learning problems. In particular, nonsmooth optimization approaches to supervised data classification problems lead to the design of very efficient algorithms for their solution. In this chapter, we demonstrate how nonsmooth optimization algorithms can be applied to design efficient piecewise linear classifiers for supervised data classification problems. Such classifiers are developed using a max–min and a polyhedral conic separabilities as well as an incremental approach. We report results of numerical experiments and compare the piecewise linear classifiers with a number of other mainstream classifiers

An inexact modified subgradient algorithm for nonconvex optimization

Nonconvex optimization, Nonsmooth optimization, Sharp augmented Lagrangian, Modified subgradient method, Inexact minimization, Bang-bang control,

Hypertensive disorders in women with peripartum cardiomyopathy: insights from the ESC EORP PPCM Registry

Aims: Hypertensive disorders occur in women with peripartum cardiomyopathy (PPCM). How often hypertensive disorders co-exist, and to what extent they impact outcomes, is less clear. We describe differences in phenotype and outcomes in women with PPCM with and without hypertensive disorders during pregnancy. Methods: The European Society of Cardiology PPCM Registry enrolled women with PPCM from 2012-2018. Three groups were examined: 1) women without hypertension (‘PPCM-noHTN’); 2) women with hypertension but without pre-eclampsia (‘PPCM-HTN’); 3) women with pre-eclampsia (‘PPCM-PE’). Maternal (6-month) and neonatal outcomes were compared. Results: Of 735 women included, 452 (61.5%) had PPCM-noHTN, 99 (13.5%) had PPCM-HTN and 184 (25.0%) had PPCM-PE. Compared to women with PPCM-noHTN, women with PPCM-PE had more severe symptoms (NYHA IV in 44.4% and 29.9%, p<0.001), more frequent signs of heart failure (pulmonary rales in 70.7% and 55.4%, p=0.002), higher baseline LVEF (32.7% and 30.7%, p=0.005) and smaller left ventricular end diastolic diameter (57.4mm [±6.7] and 59.8mm [±8.1], p<0.001). There were no differences in the frequencies of death from any cause, re-hospitalization for any cause, stroke, or thromboembolic events. Compared to women with PPCM-noHTN, women with PPCM-PE had a greater likelihood of left ventricular recovery (LVEF≥50%) (adjusted OR 2.08 95% CI 1.21-3.57) and an adverse neonatal outcome (composite of termination, miscarriage, low birth weight or neonatal death) (adjusted OR 2.84 95% CI 1.66-4.87). Conclusion: Differences exist in phenotype, recovery of cardiac function and neonatal outcomes according to hypertensive status in women with PPCM