1,721,463 research outputs found
Lake Macquarie, Rathmines Estate [cartographic material] : for private sale by Henry F. Halloran & Co. /
No full textInset: Local sketch.; Map 96 from Ferguson Collection.; On verso: Locality plan of Lake Macquarie and Newcastle. Shows estate for sale.; Sales plan for Rathmines Estate, N.S.W.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.map-f96
Necessary and sufficient conditions for optimal offers in electricity markets
No full textIn this paper, we consider the optimal policy for a generator offering power into a wholesale electricity market operating under a pool arrangement. Anderson and Philpott [Math. Oper. Res., 27 (2002), pp. 82--100] recently discussed necessary conditions for an optimal offer curve when there is uncertainty in the demand and in the behavior of other participants in the market. They show that the objective function in these circumstances can be expressed as a line integral along the offer curve of a profit function integrated with respect to a market distribution function. In this paper, we prove the existence of an optimal offer stack, and we extend the analysis of [Math. Oper. Res., 27 (2002), pp. 82--100] to include necessary conditions of a higher order in the presence of horizontal and/or vertical sections in an offer curve. Finally, we establish sufficient conditions for an offer curve to be locally optimal
Epsilon-optimal bidding in electricity markets with discontinuous market distribution function
No full textThis paper investigates the optimal bidding strategy (supply function) for a generator offering power into a wholesale electricity market. The model has three characteristics: the uncertainties facing the generator are described by a single probability function, namely the market distribution function; the supply function to be chosen is nondecreasing but need not be smooth; the objective function is the expected profit which can be formulated as a Stieltjes integral along the generator's supply curve. In previous work the market distribution function has been assumed smooth, but in practice this assumption may not be satisfied. This paper focuses on the case that the market distribution function is not continuous, and hence an optimal supply function may not exist. We consider a modified optimization problem and show the existence of an optimal solution for this problem. Then we show constructively how such an optimum can be approximated with an epsilon-optimal supply function by undercutting when the generator does not hold a hedging contract (and possibly overcutting when the generator has a hedging contract). Our results substantially extend previous work on the market distribution model
Online scheduling of a single machine to minimize total weighted completion time
No full textThis paper considers the online scheduling of a single machine in which jobs arrive over time, and preemption is not allowed. The goal is to minimize the total weighted completion time. We show that a simple modification of the shortest weighted processing time rule has a competitive ratio of two. This result is established using a new proof technique that does not rely explicitly on a lower bound on the optimal objective function value. Because it is known that no online algorithm can have a competitive ratio of less than two, we have resolved the open issue of determining the minimum competitive ratio for this problem
Competition through capacity investment under asymmetric existing capacities and costs
No full textThis paper discusses the way that different operational characteristics including existing capacity, scale economies, and production policy have an important influence on the capacity outcomes when firms compete in the market place. We formulate a game-theoretical model where each firm has an existing capacity and faces both fixed and variable costs in purchasing additional capacity. Specifically, the firms simultaneously (or sequentially) make their expansion decisions, and then simultaneously decide their production decisions with these outputs being capacity constrained. We also compare our results with cases where production has to match capacity. By characterizing the firms’ capacity and production choices in equilibrium, our analysis shows that the operational factors play a crucial role in determining what happens. The modeling and analysis in the paper gives insight into the way that the ability to use less production capacity than has been built will undermine the commitment value of existing capacity. If a commitment to full production is not possible, sinking operational costs can enable a firm to keep some preemptive advantage. We also show that the existence of fixed costs can introduce cases where there are either no pure strategy equilibrium or multiple equilibria. The managerial implications of our analysis are noted in the discussion. Our central contribution in this paper is the innovative integration of the strategic analysis of capacity expansion and well-known (s,S) policy in operations and supply chain theory
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
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