32 research outputs found

    Load Shifting Versus Manual Frequency Reserve: Which One is More Appealing to Flexible Loads?

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    This paper investigates how a thermostatically controlled load can deliver flexibility either in form of manual frequency restoration reserves (mFRR) or load shifting, and which one is financially more appealing to such a load. A supermarket freezer is considered as a representative flexible load, and a grey-box model describing its temperature dynamics is developed using real data from a supermarket in Denmark. Taking into account price and activation uncertainties, a two-stage stochastic mixed-integer linear program is formulated to maximize the flexibility value from the freezer. For practical reasons, we propose a linear policy to determine regulating power bids, and then linearize the mFRR activation conditions through the McCormick relaxation approach. For computational ease, we develop a decomposition technique, splitting the problem to a set of smaller subproblems, one per scenario. Examined on an out-of-sample simulation based on real Danish spot and balancing market prices in 2022, load shifting shows to be more profitable than mFRR provision, but is also more consequential for temperature deviations in the freezer

    Electronic Structure Calculations and Adaptation Scheme in Multi-core Computing Environments

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    Multi-core processing environments have become the norm in the generic computing environment and are being considered for adding an extra dimension to the execution of any application. The T2 Niagara processor is a very unique environment where it consists of eight cores having a capability of running eight threads simultaneously in each of the cores. Applications like General Atomic and Molecular Electronic Structure (GAMESS), used for ab-initio molecular quantum chemistry calculations, can be good indicators of the performance of such machines and would be a guideline for both hardware designers and application programmers. In this paper we try to benchmark the GAMESS performance on a T2 Niagara processor for a couple of molecules. We also show the suitability of using a middleware based adaptation algorithm on GAMESS on such a multi-core environment

    Genetic diversity and genetic similarities between Iranian rose species

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    Wild rose species were collected from different regions of Iran for a rose breeding programme. They included accessions from Rosa persica, R. foetida, R. pimpinellifolia, R. hemisphaerica, R. canina, R. iberica, R. damascena, R. beggeriana, and R. orientalis. Ten microsatellite (simple sequence repeat; SSR) markers were used to analyse the genetic variation among these rose species. The SSR markers amplified alleles in all species, even if they were from different sections within the genus. An unweighted pair group method cluster analysis (UPGMA) based on similarity values revealed five main Groups. The data showed no support for any distinction between R. canina and R. iberica, as all the accessions were placed in one Group, and accessions of these two species were more closely-related to each other within a Province than to accessions of the same species in other Provinces. Accessions of sect. Pimpinellifoliae were combined with plants from sect. Rosa and Cinnamomeae in two different Groups. Genetically, R. persica clustered distinctly from all others, with few alleles shared with the other taxa. We discuss the use of SSR markers for phylogenetic analysis when these markers are amplified in all species of a genu

    First-line anti-tuberculosis drug resistance patterns and trends at the national TB referral center in Iran—eight years of surveillance

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    Resistance to anti-tuberculosis (anti-TB) drugs is becoming a major and alarming threat in most regions worldwide. This was a descriptive cross-sectional study at a tertiary hospital in Iran, using patient medical records for 2000–2003. The findings were analyzed following the same framework as that used for previous reports from this center. Among 1556 TB patients, drug susceptibility testing (DST) was performed for 548 culture-positive cases. Anti-TB drug resistance to both isoniazid and rifampin was identified in 10 (2.8%) of the new TB cases (multidrug-resistant TB; MDR-TB). Any resistance was detected in 228 (41.6%), showing an increasing trend in both new and retreatment cases. The data analysis revealed that drug-resistant TB had a statistically significant association with Afghan ethnicity, age >65 years, and the type of disease (retreatment vs. new TB case) ( p < 0.05). Also, assessment of the drug resistance trends showed a significant increase in resistance to any anti-TB agent, to isoniazid, and to streptomycin in new cases, and to all of the first-line anti-TB drugs in retreatment patients. There has been an increasing trend in drug resistance in recent years, particularly in retreatment cases. Hence, revision of the national TB control program, reevaluation of the role of the World Health Organization category II (CAT II) regimen, as well as the conducting of a nationwide drug resistance survey, are recommended
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