143 resultados para Bids
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The power systems operation in the smart grid context increases significantly the complexity of their management. New approaches for ancillary services procurement are essential to ensure the operation of electric power systems with appropriate levels of stability, safety, quality, equity and competitiveness. These approaches should include market mechanisms which allow the participation of small and medium distributed energy resources players in a competitive market environment. In this paper, an energy and ancillary services joint market model used by an aggregator is proposed, considering bids of several types of distributed energy resources. In order to improve economic efficiency in the market, ancillary services cascading market mechanism is also considered in the model. The proposed model is included in MASCEM – a multi-agent system electricity market simulator. A case study considering a distribution network with high penetration of distributed energy resources is presented.
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(from the journal abstract) A new observational procedure, Trilogue Play with Still-face, revealed 4-month-olds' capacities to address both their fathers and mothers, by rapidly shifting gaze and affect between them. Infants were observed in four interactive contexts: (1) '3-together' play with both parents; (2) '2 + 1' play with one parent engaging and the other as third party; (3) the same, with one parent posing a still-face; (4) '3-together' play. Infants were able to discriminate between the four contexts. They coordinated three social poles of attention in each one. Their affect configurations were context sensitive. These findings demonstrate the infant's social capacities for triangular, three-person interactions, in addition to dyadic, two-person, and triadic, two-person plus object, ones. They support a view of intersubjectivity as primary and point to a promising field of investigation for the study of family process. (PsycINFO Database Record (c) 2005 APA, all rights reserved)
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This paper analyzes the problem of abnormally low tenders in theprocurement process. Limited liability causes firms in a bad financialsituation to bid more aggressively than good firms in the procurementauction. Therefore, it is more likely that the winning firm is a firm infinancial difficulties with a high risk of bankruptcy. The paper analyzesthe different regulatory practices to face this problem with a specialemphasis on surety bonds used e.g. in the US. We characterize the optimalsurety bond and show that it does not coincide with the current USregulation. In particular we show that under a natural assumption the USregulation is too expensive and provides overinsurance to the problem ofabnormally low tenders.
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Formal and analytical models that contractors can use to assess and price project risk at the tender stage have proliferated in recent years. However, they are rarely used in practice. Introducing more models would, therefore, not necessarily help. A better understanding is needed of how contractors arrive at a bid price in practice, and how, and in what circumstances, risk apportionment actually influences pricing levels. More than 60 proposed risk models for contractors that are published in journals were examined and classified. Then exploratory interviews with five UK contractors and documentary analyses on how contractors price work generally and risk specifically were carried out to help in comparing the propositions from the literature to what contractors actually do. No comprehensive literature on the real bidding processes used in practice was found, and there is no evidence that pricing is systematic. Hence, systematic risk and pricing models for contractors may have no justifiable basis. Contractors process their bids through certain tendering gateways. They acknowledge the risk that they should price. However, the final settlement depends on a set of complex, micro-economic factors. Hence, risk accountability may be smaller than its true cost to the contractor. Risk apportionment occurs at three stages of the whole bid-pricing process. However, analytical approaches tend not to incorporate this, although they could.
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Recent developments in the area of Bid Tender Forecasting have enabled bidders to implement new types of easy-to-use tools for increasing their chances of winning contracts. Although these new tools (such as iso-Score Curve Graphs, Scoring Probability Graphs, and Position Probability Graphs) are designed for bidders in capped tendering (tenders with an upper price limit), some of their principles can also be applied by a Contracting Authority to detect which bidders do not follow a standard pattern, that is, their bids are extremely high or low. Since a collusive bid generally needs to be sufficiently high or low to make an impact on the bid distribution, any person in charge of supervising capped tenders can be alerted to any bidder that might be involved in a cartel after identifying the same abnormal behavior in a series of tenders through simple calculations and a new type of graph.
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In the global construction context, the best value or most economically advantageous tender is becoming a widespread approach for contractor selection, as an alternative to other traditional awarding criteria such as the lowest price. In these multi-attribute tenders, the owner or auctioneer solicits proposals containing both a price bid and additional technical features. Once the proposals are received, each bidder’s price bid is given an economic score according to a scoring rule, generally called an economic scoring formula (ESF) and a technical score according to pre-specified criteria. Eventually, the contract is awarded to the bidder with the highest weighted overall score (economic + technical). However, economic scoring formula selection by auctioneers is invariably and paradoxically a highly intuitive process in practice, involving few theoretical or empirical considerations, despite having been considered traditionally and mistakenly as objective, due to its mathematical nature. This paper provides a taxonomic classification of a wide variety of ESFs and abnormally low bids criteria (ALBC) gathered in several countries with different tendering approaches. Practical implications concern the optimal design of price scoring rules in construction contract tenders, as well as future analyses of the effects of the ESF and ALBC on competitive bidding behaviour.
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http://digitalcommons.winthrop.edu/deanscorner/1019/thumbnail.jpg
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Mode of access: Internet.
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At head of title: The Port of New York authority created by compact between the states of New York and New Jersey with the consent of Congress.
Biased Random-key Genetic Algorithms For The Winner Determination Problem In Combinatorial Auctions.
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Abstract In this paper, we address the problem of picking a subset of bids in a general combinatorial auction so as to maximize the overall profit using the first-price model. This winner determination problem assumes that a single bidding round is held to determine both the winners and prices to be paid. We introduce six variants of biased random-key genetic algorithms for this problem. Three of them use a novel initialization technique that makes use of solutions of intermediate linear programming relaxations of an exact mixed integer-linear programming model as initial chromosomes of the population. An experimental evaluation compares the effectiveness of the proposed algorithms with the standard mixed linear integer programming formulation, a specialized exact algorithm, and the best-performing heuristics proposed for this problem. The proposed algorithms are competitive and offer strong results, mainly for large-scale auctions.
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Introdução: A regulamentação e a fiscalização têm sido os principais instrumentos do Estado para promover a melhoria da segurança e da saúde no trabalho (SST). Neste estudo, argumenta-se que a combinação desses instrumentos com o uso de incentivos governamentais pode ser mais eficaz para promover essa melhoria. A questão que direcionou este estudo foi: "Quais incentivos governamentais, se implementados, seriam os mais promissores para influenciar a alta administração das organizações na melhoria da SST?". Metodologia: Na busca de respostas para essa questão foram entrevistados membros da alta administração de cinco companhias que operam 11 terminais marítimos para granéis líquidos no país. Utilizou-se um questionário contendo 43 questões que permitiu coletar informações sobre seis tipos de incentivos: flexibilização das alíquotas de contribuição do seguro acidente do trabalho (SAT), flexibilização da ocorrência das fiscalizações programadas dos ambientes e condições de trabalho, reconhecimento público em SST, publicidade negativa em SST, publicidade de dados comparativos do desempenho da SST entre organizações do mesmo segmento e estabelecimento de requisitos de SST nas licitações públicas. Resultados e conclusão: Os incentivos estudados têm potencial para exercer influência nas decisões dos entrevistados, com exceção do incentivo na forma de estabelecimento de requisitos de SST nas licitações públicas, pois essas companhias não possuem relações comerciais com o governo. Os incentivos na forma de flexibilização das alíquotas do SAT e na forma de flexibilização da ocorrência das fiscalizações programadas foram apontados como os mais promissores para promover a melhoria da SST
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Suppose a seller wants to sell k similar or identical objects and there are n > k potential buyers. Suppose that each buyer wants only one object. In this case, we suggest the use of a simultaneous auction that would work as follows. Players are asked to submit sealed bids for one object. The individual with the highest bid chooses an object first; the individual with the second-highest bid chooses the next object; and this process continues until the individual with the kth highest bid receives the last object. Each individual pays the equivalent to his or her bid. When objects are identical, we show that the proposed auction generates the same revenue as a first-price sealed-bid sequential auction. When objects are perfectly correlated, there is no known solution for sequential auctions, whereas we can characterize bidding strategies in the proposed auction. Moreover, the proposed auction is optimal (given an appropriately chosen reserve price), and it may be easier and cheaper to run than a sequential auction.