More than 50 years ago, Golomb and Welch conjectured that there is no perfect Lee codes C of packing radius xmlns:xlink="http://www.w3.org/1999/xlink">r in Zn for ≥ 2 xmlns:xlink="http://www.w3.org/1999/xlink">n 3. Recently, Leung the second author proved if linear, then Golomb-Welch co...

Within a yearly time framework this tutorial paper describes stochastic programming models to determine the electricity market strategies pertaining to producers, consumers and retailers. A year-ahead forward market and a day-ahead pool market are considered. Hourly pool prices as well as the hourly demands of consumers and retailers are modeled as stochastic variables. Decisions pertaining to ...

One of the better studied properties for operators in judgment aggregation is independence, which essentially dictates that the collective judgment on one issue should not depend on the individual judgments given on some other issue(s) in the same agenda. Independence, although considered a desirable property, is too strong, because together with mild additional conditions it implies dictatorsh...