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

Characterisations of FeCl/Cu Multilayers Produced by a DC Sputtering Technique: Effect of Different Deposition Rates of FeCl Layers

The magnetic films have important applications due to their unique properties and can be produced with many techniques, such as sputtering. The properties of the films mainly depend on the parameters used during production. In this study, FeCl/Cu multilayer films were produced by using a DC magnetron sputtering, and effect of different deposition rates of FeCl layer was investigated. The total thicknesses of all multilayers were determined as 120 nm and the thicknesses of the FeCl and Cu layers were decided as 6 nm, such as 10[FeCl(6 nm/Cu(6 nm)]. For investigation, the deposition rate of FeCl layers was changed from 0.01 nm/s to 0.08 nm/s. An energy dispersive x-ray (EDX) spectroscopy technique was used to find out the content of the films. According to EDX measurements, while the Fe and Cl content were 7 at. % and 66 at. %, respectively, the Cu content of the films was detected as 27 at. %. The x-ray diffraction analysis indicated that two main peaks were detected at 20 positions of 43° and 45°. A mixture of the face centered cubic and the, body centered cubic structure formed in all multilayers. According to scanning electron microscope images, the film surfaces were smooth and bright. The magnetic measurements were done by using a vibrating sample magnetometer. It was shown that the coercivity of the films changed between 14 Oe and 27 Oe depending on deposition rate of FeCl layer

On the growth of the scaldfish Arnoglossus laterna (Walbaum, 1792) from İzmir Bay, central Aegean Sea [Izmir Körfezi'ndeki (Ege Denizi) küçük pisi baliginin (Arnoglossus laterna (Walbaum, 1792)) büyüme özellikleri üzerine]

Scaldfish (Arnoglossus laterna) (n = 1892) were caught in Izmir Bay (Aegean Sea) from January 2005 to December 2006. Total length and weight of all specimens ranged from 3.9 to 16.0 cm and from 0.47 to 41.63 g, respectively. The overall ratio of females to males was 1:1.91. The length-weight relationships for females, males, and all specimens combined were estimated, respectively, as W = 0.0096 × L2.921, W = 0.0111 × L2.857, and W = 0.0096 × L2.917; and the parameters of the von Bertalanffy growth equations were, respectively, L?= 17.58, 15.36, and 17.19 cm; k = 0.412, 0.461, and 0.495 year-1; and t0 = -0.379, -0.332, and -0.380 year. The growth performance index values (?') were 2.105, 2.036, and 2.165, respectively. © TÜBİTAK

Relationship between organizational commitment and organizational silence: A study in the insurance industry

In the study, it was aimed to determine the effect of organizational commitment on organizational silence. In this context, the related research was conducted on 416 employees working in an insurance sector company in Istanbul. In the study, after the concepts of organizational commitment and organizational silence are presented in a theoretical framework, to measure organizational commitment; the scale of organizational commitment by Meyer and Allen, which Wasti and Can translated into Turkish and adapted, and the organizational silence scale developed by Dyne et al. (Journal of Management Studies 40(6), 1359–1392) was used to measure organizational silence. As a result of the questionnaires, the data were evaluated and the relationship between organizational commitment and organizational silence was tried to be explained. The results of multiple regression analysis, which measures the effect of organizational commitment on organizational silence, were interpreted by correlation analysis, which measures the relationships of organizational commitment and organizational silence subdimensions. The results of the T-tests and ANOVA (F) tests, which measure the relationship between demographic variables and research variables, are also included. As a result of the analyzes, it was found that among the subdimensions of organizational commitment, continuing commitment, normative and emotional commitment, only continuing commitment and emotional commitment had a significant effect on accepting silence

Spawning period of Mediterranean marine fishes

We collected all available information (i.e. international and local journals, conference proceedings, theses, technical reports) on the spawning season (n = 511 stocks, 168 species), gonadosomatic index (n = 237 stocks, 81 species) and sex ratio (n = 97 stocks, 68 species) of Mediterranean marine fish. The 511 stocks represented 20 orders (most were Perciformes, 283 stocks) and 65 families (most were Sparidae: 17 species and 63 stocks). Overall, 346 stocks (128 species) spawned between April and August, 139 stocks (60 species) between September and March, while the remaining 26 stocks (13 species) were all-year-round spawners. In addition, 174 stocks (34.1%) were characterised by an extended (> 4 months) spawning season, but, for most stocks (332 stocks, 64.4%), spawning duration ranged from 2 to 4 months inclusive. Regardless of the onset and the duration of spawning, the spawning period of 284 and 287 stocks included June and July, respectively, indicating that most Mediterranean species are summer spawners. Female gonadosomatic index ranged between 0.06 and 37 (mean +/- A SE = 8.55 +/- A 0.647, n = 95) and was significantly higher (t-test: t = 5.58, P < 0.001) than the corresponding male one, which ranged between 0.06 and 30 (mean +/- A SE = 4.21 +/- A 0.431, n = 95). Congeneric species that occupied the same area and share the same requirements exhibited successive and non-overlapping spawning (e.g. Sparidae in the Adriatic Sea, Mugilidae in the Ionian Sea and Tunisian waters). The knowledge of the spawning period coupled with information on spawning and nursery grounds and detailed knowledge of mating systems, social interactions, maturity and fecundity may be very useful for fisheries management