In this paper a class of single machine scheduling problems is discussed. It is assumed that job parameters, such as processing times, due dates, or weights are uncertain and their values are specified in the form of a discrete scenario set. The Ordered Weighted Averaging (OWA) aggregation operator is used to choose an optimal schedule. The OWA operator generalizes traditional criteria in decis...

In this paper we prove that, under suitable conditions, Atanassov’s Ka operators, which act on intervals, provide the same numerical results as OWA operators of dimension two. On one hand, this allows us to recover OWA operators from Ka operators. On the other hand, by analyzing the properties of Atanassov’s operators, we can generalize them. In this way, we introduce a class of aggregation fun...

We present the induced generalized hybrid averaging (IGHA) operator. It is a new aggregation operator that generalizes the hybrid averaging (HA) by using generalized means and order inducing variables. With this formulation, we get a wide range of mean operators such as the induced HA (IHA), the induced hybrid quadratic averaging (IHQA), the HA, etc. The ordered weighted averaging (OWA) operato...

For general type-2 fuzzy sets, the defuzzification process is very complex, and the exhaustive direct method of implementing type-reduction is computationally expensive and turns out to be impractical. This has inevitably hindered the development of type-2 fuzzy inferencing systems in real world applications. The present situation will not be expected to change, unless an efficient and fast met...

With rapid growth of information sources, it is essential to develop methods that retrieve most relevant information according to the user requirements. One way of improving the quality of retrieval is to use more than one retrieval engine and then merge the retrieved results and show a single ranked list to the user. There are studies that suggest combining the results of multiple search engin...

A Bag-based Data Model with Global Conditions for Incomplete Information Akinari YAMAGUCHI†, Shougo SHIMIZU††, Yasunori ISHIHARA†, and Toru FUJIWARA† † Graduate School of Information Science and Technology, Osaka University 1–5 Yamadaoka, Suita, Osaka, 565–0871 Japan †† Department of Computer and Media Technologies, Hiroshima City University 3–4–1 Ozuka-higashi, Asaminami-ku, Hiroshima, 731–319...

In practice, it is often necessary to combine information from different sources. For this task, one of aggregation operators can be used. Probably the best-known of them are the weighted average and the OWA (ordered weighted average) operator. The weighted average makes it possible to assign importances to the individual information sources. On the other hand, with the OWA operator, the import...

We describe the problem of decision making under ignorance and discuss the need of introducing a decision attitude or disposition in solving this problem. We show the OWA operators provide a general framework for evaluating the alternatives when the payoffs are numeric values. We then turn to the problem of decision making when the payoffs are linguistic values drawn from an ordinal scale. A so...