We examine the mechanism design problem for a single buyer to procure purchase-options for a homogeneous good when that buyer is required to satisfy an unknown future demand. Suppliers have 2dimensional types in the form of commitment costs and production costs. The efficient schedule of options depends on the distribution of demand. To implement an efficient outcome, we introduce a class of me...

In inrestigations o f the neural processes und¢rlytng tarious behavioural phenomena, it is often rerj di~icult to separate cause from effect, especially when the part of the nervous system central to this control is distant from both ¢h ~. sensory and the motor ends of :his behariour. Orercoming fheye di~eu_t~fas. Edmund Roi:~, with his colleagues, has carried out a series of rery elegant exper...

Online panels have become a prominent way to collect survey data. They are used in many fields including market research (Comley, 2007; Göritz, 2010; Postoaca, 2006), social research (Tortora, 2008), psychological research (Göritz, 2007), election studies (Clarke, Sanders, Stewart, & Whiteley, 2008), and medical research (Couper, 2007). Panel-based online survey research has grown steadily over...

We discuss issues related to constructing an orthomodular structure from an object in a category. In particular, we consider axiomatics related to Baer *-semigroups, partial semigroups, and various constructions involving dagger categories, kernels, and biproducts.

We present a characterisation of { 1(q+1)+ 0, 1;n, q}-minihypers, q square, q = ph, p > 3 prime, h ≥ 2, q ≥ 1217, for 0+ 1 < q 7/12 2 − q1/4 2 . This improves a characterisation result of S. Ferret and L. Storme [6], involving more Baer subgeometries contained in the minihyper.

We introduce a dynamic and secondary-memory-based variant of the List of Clusters, which is shown to be competitive with the literature, especially on higher-dimensional spaces, where it outperforms the M-tree in searches and I/Os used for insertions. The basic principles of our design are applicable to other secondary-memory structures.

This paper presents characterizations of M-fuzzifying matroids bymeans of two kinds of fuzzy operators, called M-fuzzifying derived operatorsand M-fuzzifying difference derived operators.