Large-scale unit commitment under uncertainty: an updated literature survey

The Unit Commitment problem in energy management aims at finding the optimal production schedule of a set of generation units, while meeting various system-wide constraints. It has always been a large-scale, non-convex, difficult problem, especially in view of the fact that, due to operational requirements, it has to be solved in an unreasonably small time for its size. Recently, growing renewable energy shares have strongly increased the level of uncertainty in the system, making the (ideal) Unit Commitment model a large-scale, non-convex and uncertain (stochastic, robust, chance-constrained) program. We provide a survey of the literature on methods for the Uncertain Unit Commitment problem, in all its variants. We start with a review of the main contributions on solution methods for the deterministic versions of the problem, focussing on those based on mathematical programming techniques that are more relevant for the uncertain versions of the problem. We then present and categorize the approaches to the latter, while providing entry points to the relevant literature on optimization under uncertainty. This is an updated version of the paper "Large-scale Unit Commitment under uncertainty: a literature survey" that appeared in 4OR 13(2), 115--171 (2015); this version has over 170 more citations, most of which appeared in the last three years, proving how fast the literature on uncertain Unit Commitment evolves, and therefore the interest in this subject

pH-induced reversible molecular self-assembly of perylene based imidazolate ester: a probable marker for biological species

7-11Dianhydrides of perylene-3,4,9,10-tetracarboxylic acid (PTCDA) provide an excellent backbone for design and synthesis of various molecules of interest. Many water-soluble perylene derivatives with stimuli responded functionality being reported but there is few pH responded perylene derivatives were synthesized. The PTCDA derivatives so far synthesized are pH sensitive. These derivatives in an acid medium exist in its monomer form and undergo self-assembly with an increase in pH. In this paper, we report synthesis of pH-sensitive perylene based imidazolate ester, which exists in monomer form at pH 12 and undergo self-assembly with the decrease in pH contrary to the earlier reports. This phenomenon can be well explained for a probable marker in biological processes occurring specifically at pH 12

Temporal asymmetry in aerosol optical characteristics:A case study at ahigh-altitude station, Hanle, in Ladakh region

Diurnal features of aerosol optical depth (AOD) at a high-altitude station, Hanle (4500 m amsl) in the western Himalayas, were studied using direct/diffuse solar irradiance measurement from a Skyradiometer (Prede) during October 2007 to December 2010. The study reveals a diurnal asymmetry in the measured aerosol characteristics, with three types of diurnal variation in AOD. Among them, Types I and II are prominent during pre-monsoon, while Type III dominates during post-monsoon. Type I appears to be associated with new-particle formation process from gaseous precursors, in addition to the combination of anthropogenic and desert-dust aerosols, probably brought by the prevailing westerly/south-westerly winds during the pre-monsoon season. The diurnal feature of the Type II may be attributed by the transported desert-dust aerosols brought by the prevailing winds. Further, Type III may be associated with the aged background aerosols over the region, pertaining to a small contribution from gaseous precursors

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Study of relationship between recurrent lower respiratory tract infection (rLRTI), bronchial asthma and gastroesophageal reflux (GER) in children.

GesondheidswetenskappeKerngeneeskundePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

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Is Tc-99m-sestamibi scintimammography complementary to conventional mammography for detecting breast cancer in patients with palpable masses?

The aim of this trial was to evaluate in developing countries from different regions the diagnostic performance of Tc-99m-sestamibi scintimammography (SM) in palpable breast lesions and to verify the clinical usefulness of a joint evaluation with mammography and SM. Methods: From 10 countries, a total of 238 patients with palpable breast masses (n = 245) were included in this prospective multicenter trial. Prone SM was performed 10 min and 60-90 min (157 patients) after injection using an isotime acquisition of 10 min. Mammography was assessed by the same dedicated imaging radiologist according to breast imaging reporting and data system (BI-RADS) categories for malignancy and breast density. Masked SM findings and mammography findings were checked for a correlation with histopathology findings for excisional biopsy samples. Diagnostic values for breast cancer detection were calculated per lesion. Results: Histopathology revealed 189 cancerous lesions and 56 benign lesions. The sensitivity and specificity of SM were 0.83 and 0.77, respectively. SM diagnostic values did not depend on the incidence of breast cancer in the country of origin or on the timing of imaging (early vs. delayed scans). On mammography, the technique yielded a sensitivity and specificity of 0.85 and 0.66, with 27 mammograms classified as BI-RADS category 1, 33 as category 2, 5 as category 3, 56 as category 4, and 124 as category 5. Thirty-seven lesions were considered to show increased radiologic density. No significant difference was found in SM diagnostic values among different BI-RADS categories or between the groups with low and high breast density. A sensitivity of 96% was calculated when SM and mammography results were combined, with 75% of all false-negative mammography findings classified as true-positive results by SM. Conclusion: SM complements mammography in patients with palpable masses and negative mammography findings