An overview of Greece's wholesale electricity market with emphasis on ancillary services

Greece's wholesale electricity market is a mandatory pool in which the commodities of energy and ancillary services are simultaneously traded and dispatched on the generation units. In this paper, we provide an overview of the Greek wholesale electricity market with emphasis on ancillary services. Considering the wide range of ancillary services, our goal is to contribute to the growing literature on individual case studies and comparisons of different ancillary services markets worldwide, pointing out similarities and differences with other market models. In addition, we discuss several aspects, and report on some of the strengths and weaknesses of the Greek wholesale electricity market model.     

Transmission loss allocation through zonal aggregation

This paper presents a methodology for the aggregation of nodal generation loss factors into zonal loss factors, taking into account the geographic as well as the “electrical” proximity of the nodes to the zone centers. The annual net economic consequence (gain or loss) of each generator from the aggregation is estimated and used as an index for the evaluation of the methodology. Additionally, an algorithm for the automated zonal configuration with pre-defined economic consequences is presented. Starting from one zone comprising the whole power system, the algorithm finds the number of zones that keep the economic consequences of zonalization below a pre-defined threshold, and the resulting zonal configuration. By performing an exhaustive search using this algorithm for the “best” initial root node, an optimal zonal configuration can be identified that achieves the pre-defined level of economic consequences with the minimum number of zones. Numerical results from a real power system, the Greek power system, are presented and discussed.     

Co-existence of OFDM and FBMC for resilient photonic millimeter-wave 5G mobile fronthaul

Photonic Network Communications - This paper presents a novel co-existence of multiple Fifth-Generation (5G) services employing Orthogonal Frequency Division Multiplexing (OFDM) and Filter Bank...     

Natural selection of academic papers

Academic papers, like genes, code for ideas or technological innovations that structure and transform the scientific organism and consequently the society at large. Genes are subject to the process of natural selection which ensures that only the fittest survive and contribute to the phenotype of the organism. The process of selection of academic papers, however, is far from natural. Commercial for-profit publishing houses have taken control over the evaluation and access to scientific information with serious consequences for the dissemination and advancement of knowledge. Academic authors and librarians are reacting by developing an alternative publishing system based on free-access journals and self-archiving in institutional repositories and global disciplinary libraries. Despite the emergence of such trends, the journal monopoly, rather than the scientific community, is still in control of selecting papers and setting academic standards. Here we propose a dynamical and transparent peer review process, which we believe will accelerate the transition to a fully open and free-for-all science that will allow the natural selection of the fittest ideas.     

A note on preemptive scheduling of multiclass jobs with geometric service times and hard deadlines

We consider the scheduling of multiclass jobs with deadlines to the completion of their service. Deadlines are deterministic and job arrivals in each class occur at the times of deadline expirations in the respective class. Assuming geometric service times with class dependent means, we derive structural properties of preemptive server allocation policies that maximize the expected number of job completions. Our work extends results that have appeared in the real-time wireless scheduling literature.     

Multiobjective Linear Programming Model for Scheduling Linear Repetitive Projects

Linear repetitive construction projects require large amounts of resources which are used in a sequential manner and therefore effective resource management is very important both in terms of project cost and duration. Existing methodologies such as the critical path method and the repetitive scheduling method optimize the schedule with respect to a single factor, to achieve minimum duration or minimize resource work breaks, respectively. However real life scheduling decisions are more complicated and project managers must make decisions that address the various cost elements in a holistic way. To respond to this need, new methodologies that can be applied through the use of decision support systems should be developed. This paper introduces a multiobjective linear programming model for scheduling linear repetitive projects, which takes into consideration cost elements regarding the project’s duration, the idle time of resources, and the delivery time of the project’s units. The proposed model can be used to generate alternative schedules based on the relative magnitude and importance of the different cost elements. In this sense, it provides managers with the capability to consider alternative schedules besides those defined by minimum duration or maximizing work continuity of resources. The application of the model to a well known example in the literature demonstrates its use in providing explicatory analysis of the results.     

Understanding the role of open peer review and dynamic academic articles

We welcome the commentary by L. Egghe (Scientometrics, this issue) stimulating discussion on our recent article “Natural selection of academic papers” (NSAP) (Scientometrics, 85(2):553–559, 2010) that focuses on an important modern issue at the heart of the scientific enterprise—the open and continuous evaluation and evolution of research. We are also grateful to the editor of Scientometrics for giving us the opportunity to respond to some of the arguments by L. Egghe that we believe are inaccurate or require further comment.     

Benzocyclobutane,Benzocycloheptane and Heptene Derivatives as Melatonin Agonists and Antagonists

Two series of analogues were designed, synthesised and evaluated as potential human melatonin type 1 and 2 receptor (hMT₁ and hMT₂) ligands. Their biological effects were assessed by a well‐established, specific model of melatonin action, the pigment response of Xenopus laevis melanophores. Compounds containing a benzocyclobutane scaffold and a methoxy group in the “melatonin” orientation were found to be potent agonists, with one of the analogues exhibiting activity comparable to melatonin. In contrast, analogues with a methoxy group in non‐melatonin positions or with multiple methoxy groups showed either weaker agonist activity or were antagonists. Benzocycloheptene derivatives with one methoxy group are found to be weak agonists, whereas those with two methoxy groups were found to be antagonists, as were all of the benzocycloheptane derivatives evaluated. The most active compounds were assessed in a human receptor radio ligand binding assay but showed little discrimination between MT₁ and MT₂. These results again show that the indole nitrogen of melatonin is not a necessary component for analogue activity and also illustrate that replacement of the indole ring with a 4‐membered carbocycle can provide highly active compounds when the methoxy group is in the melatonin position.     

A multicriteria satisfaction analysis approach in the assessment of operational programmes

Ex-post evaluation European Operational Programmes could provide useful information and knowledge that can be used as a guide in future planning.The different concerns of the operational programme stakeholders along with the operating constraints make programme evaluation a difficult and fuzzy task. This paper presents the application of concepts and methodologies of multicriteria data analysis to identify critical success and risk factors in achieving the strategic objectives of a programme. The MUSA (multicriteria satisfaction analysis) method was used for analyzing the satisfaction of project managers with respect to satisfaction criteria associated with four dimensions: the project’s results, the operations of the programme organization, the support of the project organization and the performance of the project team.The specific case study refers to a sample of projects in the Operational Programme for Education and Initial Training in Greece which was funded by the 3rd Common Support Framework. The results show that the proposed methodology can be a valuable tool for programme organizations, especially in the case of “soft” action projects where the deliverables are intangible and project management at beneficiary organizations is provided at an ad-hoc basis.