Geographic information is based on observations or measurements. The Open Geospatial Consortium (OGC) has developed an implementation specification for observations and measurements (O&M). It specifies precisely how to encode information. Yet, the O&M conceptual model does not specify precisely which real-world entities are denoted by the specified information objects. We provide formal semanti...

Radiatively inefficient (or advection dominated) disks are discussed at an introductory level. Ion supported and radiation supported flows are discussed, the different consequences of advection dominated flows onto black holes vs. solid surfaces (neutron stars, white dwarfs), hydrodynamics, the role of the ratio of specific heats, and the possible connection between ADAFs and outflows.

Within the data envelopment analysis context, problems of discrimination between efficient and inefficient decision-making units often arise, particularly if there are a relatively large number of variables with respect to observations. This paper applies Monte-Carlo simulation to generalize and compare two discrimination-improving methods; principal component analysis applied to data envelopme...

In the data envelopment analysis context, problems related to discrimination between efficient and inefficient decision-making units often arise, particularly if there are a relatively large number of variables with respect to observations. This paper presents a comparison of two discrimination-improving methods published in the literature that do not require additional preferential information...

Data Envelopment Analysis (DEA) is a technique that uses all collected observations to measure performance. This method presents no data about how to operate on DMU. The present research attempted to study a unit with all its subunits, if the unit is efficient, it means that all its subunits are efficient too and if it is an inefficient, it shows clearly that which one of the subunits makes ine...

The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Abstract We identify conditions under which a bargainer makes inefficiently large (small) investments in search for information about the opponent's reservation price. The analysis starts with the observation that a player will invest too much (too little) if the opponent's exp...

We analyze a setting common in privatizations, public tenders, and takeovers in which the ex post efficient allocation, i.e., the first best, is not implementable. Our first main result is that the open ascending auction is not second best because it is prone to rushes, i.e., all active bidders quitting simultaneously, that undermine its efficiency. Our second main result is that the second bes...