1,720,980 research outputs found
Mechanism design for information aggregation within the smart grid
No full textThe introduction of a smart electricity grid enables a greater amount of information exchange between consumers and their suppliers. This can be exploited by novel aggregation services to save money by more optimally purchasing electricity for those consumers. Now, if the aggregation service pays consumers for said information, then both parties could benefit. However, any such payment mechanism must be carefully designed to encourage the customers (say, home-owners) to exert effort in gathering information and then to truthfully report it to the aggregator. This work develops a model of the information aggregation problem where each home has an autonomous home agent, which acts on its behalf to gather information and report it to the aggregation agent. The aggregator has its own historical consumption information for each house under its service, so it can make an imprecise estimate of the future aggregate consumption of the houses for which it is responsible. However, it uses the information sent by the home agents in order to make a more precise estimate and, in return, gives each home agent a reward whose amount is determined by the payment mechanism in use by the aggregator. There are three desirable properties of a mechanism that this work considers: budget balance (the aggregator does not reward the agents more than it saves), incentive compatibility (agents are encouraged to report truthfully), and finally individual rationality (the payments to the home agents must outweigh their incurred costs). In this thesis, mechanism design is used to develop and analyse two mechanisms. The first, named the uniform mechanism, divides the savings made by the aggregator equally among the houses. This is both Nash incentive compatible, strongly budget balanced and individually rational. However, the agents' rewards are not fair insofar as each agent is rewarded equally irrespective of that agent's actual contribution to the savings. This results in a smaller incentive for agents to produce precise reports. Moreover, it encourages undesirable behaviour from agents who are able to make the loads placed upon the grid more volatile such that they are harder to predict. To resolve these issues, a novel scoring rule-based mechanism named sum of others' plus max is developed, which uses the spherical scoring rule to more fairly distribute rewards to agents based on the accuracy and precision of their individual reports. This mechanism is weakly budget balanced, dominant strategy incentive compatible and individually rational. Moreover, it encourages agents to make their loads less volatile, such that they are more predictable. This has obvious advantages to the electricity grid. For example, the amount of spinning reserve generation can be reduced, reducing the carbon output of the grid and the cost per unit of electricity. This work makes use of both theoretical and empirical analysis in order to evaluate the aforementioned mechanisms. Theoretical analysis is used in order to prove budget balance, individual rationality and incentive compatibility. However, theoretical evaluation of the equilibrium strategies within each of the mechanisms quickly becomes intractable. Consequently, empirical evaluation is used to further analyse the properties of the mechanisms. This analysis is first performed in an environment in which agents are able to manipulate their reports. However, further analysis is provided which shows the behaviour of the agents when they are able to make themselves harder to predict. Such a scenario has thus far not been discussed within mechanism design literature. Empirical analysis shows the sum of others' plus max mechanism to provide greater incentives for agents to make precise predictions. Furthermore, as a result of this, the aggregator increases its utility through implementing the sum of others' plus max mechanism over the uniform mechanism and over implementing no mechanism. Moreover, in settings which allow agents to manipulate the volatility of their loads, it is shown that the uniform mechanism causes the aggregator to lose utility in comparison to using no mechanism, whereas in comparison to no mechanism, the sum of others' plus max mechanism causes an increase in utility to the aggregator
1957 -- Correspondence, Miscellaneous -- letter, 1957-07-19
No full textLetter from Rose, Harry M. to Sabin, Albert B. dated 1957-07-19.Sabin Collection Fair Use Policy</a
Mechanism Design for Aggregated Demand Prediction in the Smart Grid
No full textThis paper presents a novel scoring rule-based mechanism that encourages agents to produce costly estimates of future events and truthfully report them to a centre when the budget for payments to the agents is itself determined by their reports. This is applied to a model of aggregated demand prediction within a microgrid where, given estimates of future consumptions, an aggregator must optimally purchase electricity for a set of homes, each represented by self-interested, rational home agents. This in turn reduces the need for costly standby generation within the grid. The aggregator has prior information about the amount each home will consume, and determines the amount to pay each agent based on savings resulting from using the agents' reported information, over its own prior information. Agents use sensory information regarding their property and its occupants to generate these estimates, which they transmit to the aggregator using smart grid technology. The proposed mechanism is dominant strategy incentive compatible and empirical evaluation shows that it encourages agents to exert effort in producing precise estimates. We show that the mechanism is ex ante individually rational for the aggregator, and that it outperforms a simpler mechanism whereby savings are distributed evenly
A Scoring Rule-Based Mechanism for Aggregate Demand Prediction in the Smart Grid
No full textThis paper presents a novel scoring rule-based strictly dominant incentive compatible mechanism that encourages agents to produce costly estimates of future events and report them truthfully to a centre. Whereas prior work has assumed a fixed budget for payment towards agents, this work makes use of prior information held by the centre and assumes a budget that is determined by the savings made through the use of the agents' information over the centre's own prior information. This mechanism is compared to a simple benchmark mechanism wherein the savings are divided equally among all home agents, and a cooperative solution wherein agents act to maximise social welfare. Empirical analysis is performed in which the mechanism is applied to a simulation of the smart grid whereby an aggregator agent must use home agents' information to optimally purchase electricity. It is shown that this mechanism achieves up to 77% of the social welfare achieved by the cooperative solution
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
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