1,721,041 research outputs found
Local Electricity Markets: Evaluating Pricing Mechanisms, Fairness and Privacy
Full text linkThe global energy sector is undergoing a significant transition driven by technological advancements and environmental concerns. This shift leads to a more digitalised and decentralised energy system, where end-users are anticipated to become active “prosumers”. Local energy communities and markets are emerging as potential platforms for engagement and interaction. From a systemic viewpoint, local electricity markets can help alleviate grid problems, enhance demand response coordination, delay grid investments, and boost local resilience.
However, the success of these market structures hinges on people’s willingness to participate. Studies indicate that economic factors significantly influence participation. Hence, it is vital to develop pricing mechanisms that all market participants perceive as fair to ensure widespread acceptance of local electricity markets. Nevertheless, including households in digital trading platforms could lead to potential misuse of information, necessitating careful privacy considerations. Despite the existence of privacy and transparency regulations, their effectiveness can differ. As such, data protection should be incorporated into the market’s algorithmic design.
This PhD research aims to assess the performance of various pricing mechanisms for local electricity markets in terms of fairness and privacy, as well as other factors like transparency and complexity. This is achieved by testing some of the most prevalent pricing mechanisms on identical case studies and comparing their results. Additionally, the research discusses alternative bounds for local trading prices to maintain the viability of prosumers when policy-enforced subsidies are removed. The research also explores definitions of distributive energy justice in a local electricity market and evaluates the performance of fairness indicators. Finally, the research proposes a secure identity management framework for local trading platforms, leveraging the features of distributed ledger technology and self-sovereign identities.
The findings of this PhD work have implications for various stakeholders involved in shaping future local electricity markets. Policymakers and local market operators can learn how the lower pricing bound of local trading prices is critical for the viability of prosumers and that the average levelised cost of electricity could be a potential candidate. They can also understand that rule-based, optimisation-based, and game theoretic pricing mechanisms each have their advantages and disadvantages and use the findings and framework to decide which one to implement based on their prioritised criteria. Additionally, the discussions on fairness and the proposed definition of distributive energy justice can serve as a benchmark when formulating market rules. These should align with the market’s goal and consider the viewpoint of all entity types, as highlighted in this thesis. Market platform developers should also consider the proposed identity management framework, as it ensures both data confidentiality and provenance. In essence, the PhD research underscores the importance of thoroughly evaluating the performance of pricing mechanisms and considering the potential advantages for all stakeholders within local electricity markets
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Co-Simulation Model for Optimal Wind-Hydro Coordination Using Wind Farm Control Dynamics: A Case Study of a Hybrid Wind and Hydro Plant System
Full text linkDen økende andelen variabel fornybar energi i kraftsystemene medfører utfordringer for reguleringsmyndigheter, nettoperatører og energiprodusenter. Variable energikilder har begrenset fleksibilitet i driften sin, da de er sterkt avhengige av omgivelsene. Videre må man ta hensyn til teknisk pålitelighet og kraftsvingninger. For å håndtere disse utfordringene må beslutningstakere vurdere flere målsetninger. Blant disse er inntekter, kraftsystemtjenester og mekanisk belastning på vindturbiner. Koordinert drift av flere kraftverk og ulike kontrollstrategier for vindparker er eksempler på tiltak som kan bidra til å oppnå disse målene.
Denne studien presenterer en modell for flerobjektiv lineær programmering for å simulere optimal drift av vind- og vannkraftverk som deler begrenset overføringskapasitet. Videre inkluderes kontrolldynamikker for windparken for å oppnå realistisk resultater for kraftproduksjon og akkumulert skade på vindturbinene. Dette resulterer i en samkjørende simuleringsmodell for optimal koordinering av vind- og vannkraft. Basert på dette presenteres en referansestudie basert på en relevant lokasjon i Norge for å analysere den forbedrede effekten av vind-vannkraft koordinering og vindparkkontroll, med tanke på objektivene for akkumulert skade på vindturbiner og total inntekt for det hybride kraftsystemet. Studien vurderer også de potensielle fordelene ved å legge til en pumpe med mulighet for varierende hastighet i vannkraftverket ved bruk av en forenklet tilnærming der kun inntekt som objektiv for optimeringsproblemet.
Resultatene viser potensielle forbedringer i den samlede ytelsen ved å bruke flere motstridende objektiver i optimaliseringen i stedet for kun et objektiv. Ved å utnytte fleksibiliteten fra lagring i vannmagasin og kontrollstrategier for vindparken, kan beslutningstakerene gjøre tilpassninger for å oppnå ønsket resultat. Målsetningene til de to objektivene er motstridende, der den optimale løsningen for å minimere skadeakkumulering resulterer i en reduksjon på 74.3 % i total inntekt, noe som ikke er økonomisk levedyktig for en kraftprodusent. Imidlertid kan betydelig reduksjon i skade oppnås fra andre kandidater. For eksempel viser resultatene at når man utnytter seg av koordinert produksjon og gir inntekten høyere prioritet i optimaliseringsprosessen, kan den akkumulerte skaden reduseres med 8.2 %, med en betydelig mindre nedgang på 5.84 % i inntekt.
Videre viser den økte fleksibiliteten ved å bruke en pumpe til å transportere vann til lagring i magasinet store forbedringer på opptil 5.6 % i samlet inntekt for kraftverkene og en reduksjon i ubenuttet vindpotensial til om lag 36 % sammenlignet med resultater oppnådd uten bruk a pumpe. Imidlertid er fordelen svært sensitiv for variasjoner i strømprisene, noe som er demonstrert ved simuleringer som bruker historiske spotpriser fra 2019 og 2021. Videre observeres det mindre påvirkning på resultatene ved bruk av en pumpe med mulighet for variabel hastighet sammenlignet med en pumpe med fast hastighet.The growing share of Variable Renewable Energy Sources (VRES) in power systems presents challenges for regulators, grid operators and energy producers. The VRES’ have limited flexibility in their operations, as they are highly dependent on ambient environments. Further, issues of technical reliability and power fluctuations should be considered. To address these challenges, decision-makers must consider multiple objectives. Among these are revenue, power system services and mechanical load on wind turbines. Coordinated operation of power plants and different wind farm control strategies are examples of measures that can benefit these objectives.
This study proposes a Multi-Objective Linear Programming (MOLP) model to simulate the optimum operation of wind and hydropower plants that share limited transmission capacity. Further, wind farm control dynamics are included to obtain realistic output power and accumulated damage. Resulting in a co-simulation model for optimal wind and hydropower coordination. From this, a case study based on a relevant location in Norway is presented to analyze the improved effect of wind-hydro coordination and wind farm control in achieving the objectives of accumulated wind turbine damage and total revenue of the hybrid power system. In addition, the study considers the potential advantages of adding a variable speed pump to the hydropower plant using a baseline approach of single-objective optimization.
The results demonstrate the potential improvements in the overall performance by using multiple conflicting objectives in the optimization rather than a single objective. By utilizing the flexibility of hydro storage and control options for the wind farm, the decision maker may adjust to obtain the most desired outcome. The objectives are conflicting, where the optimal solution for minimizing damage accumulation results in a reduction by 74.3 % for the total revenue, which is not an economically viable solution. However, a significant reduction in damage may be obtained from other candidates. For example, when considering coordinated operations and granting the revenue a higher priority in the optimization process, the results show that the accumulated damage can be reduced by 8.2 %, with a substantially less decline of 1.5 % in revenue.
Moreover, the added flexibility provided by utilizing a pump for hydro storage offers great benefits, including improvements as high as 5.6 % in the combined revenue of the power plants and a reduction in wind energy curtailments to approximately 36% compared to results obtained without Pumped Hydro Storage (PHS). However, the benefit is highly sensitive to the variations in the power prices, showcased by simulations using historical spot prices from 2019 and 2021. Furthermore, less impact is observed from using a variable speed pump compared to a fixed speed pump
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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