Set-partition tableaux and representations of diagram algebras

The partition algebra is an associative algebra with a basis of set-partition diagrams and multiplication given by diagram concatenation. It contains as subalgebras a large class of diagram algebras including the Brauer, planar partition, rook monoid, rook-Brauer, Temperley-Lieb, Motzkin, planar rook monoid, and symmetric group algebras. We give a construction of the irreducible modules of these algebras in two isomorphic ways: first, as the span of symmetric diagrams on which the algebra acts by conjugation twisted with an irreducible symmetric group representation and, second, on a basis indexed by set-partition tableaux such that diagrams in the algebra act combinatorially on tableaux. The first representation is analogous to the Gelfand model and the second is a generalization of Young's natural representation of the symmetric group on standard tableaux. The methods of this paper work uniformly for the partition algebra and its diagram subalgebras. As an application, we express the characters of each of these algebras as nonnegative integer combinations of symmetric group characters whose coefficients count fixed points under conjugation

Regulation of New Economy Markets: the Case of Wired Residential Internet Service Provision

The ISP market in Ireland is relatively immature. Although Ireland’s first Service Provider IEUnet was established in 1991, it is only in the last two or three years that a choice of provider and access price points has emerged under the regulatory regime of the Office of the Director of Telecommunications Regulation (OTDR). This has been achieved through the introduction of a telecommunications licensing regime by the ODTR, the specifics of which are available from the ODTR website.2 From a position where there was only one telecommunications operator, the former PTO3 namely Eircom, there are currently 77 other licensed operators (OLOs) in the State. The regulation imposes on ISPs that provide the initial connection to the Internet the need to obtain a licence. ISPs that provide portal sites and search engines but not the telecommunication access to the user - like international companies Yahoo and Alta Vista, or Irish companies like Ireland.com - are not required to obtain a telecommunications licence. This form of ISP provides services after the initial connection to the Internet is made. The ISPs under investigation here are those that supply the initial physical connection to the Internet as well as access to the World Wide Web. This level of Internet connectivity constitutes a telecommunications service and thus an operator requires a telecommunications licence.4 We further focus on the market specifically for residential Internet service provision

Measurement errors in body size of sea scallops (Placopecten magellanicus) and their effect on stock assessment models

Body-size measurement errors are usually ignored in stock assessments, but may be important when body-size data (e.g., from visual sur veys) are imprecise. We used experiments and models to quantify measurement errors and their effects on assessment models for sea scallops (Placopecten magellanicus). Errors in size data obscured modes from strong year classes and increased frequency and size of the largest and smallest sizes, potentially biasing growth, mortality, and biomass estimates. Modeling techniques for errors in age data proved useful for errors in size data. In terms of a goodness of model fit to the assessment data, it was more important to accommodate variance than bias. Models that accommodated size errors fitted size data substantially better. We recommend experimental quantification of errors along with a modeling approach that accommodates measurement errors because a direct algebraic approach was not robust and because error parameters were diff icult to estimate in our assessment model. The importance of measurement errors depends on many factors and should be evaluated on a case by case basis

The Grizzly, February 23, 1993

Helen Thomas, White House Correspondent Speaks • Pledging: Girls\u27 Results From Fall 1992 Versus Outward Bound, 1993 • Clinton\u27s Plans for Peace • Airband, MTV Here • Evaluating the Curriculum of Ursinus • Ursinus Welcomes Ishmael Reed • Movie Review: Sommersby • South Street: An Informative Perspective • Senior Profile: Casey Price • Who\u27s in Charge at 1600? • Letter to the Editor • Gymnasts Achieve Season-High • Two Ursinus Legends Step Down • Thomas adds Sports Manager Duties • Swimmers Done • Bears Finish 7-17; Look to Bright Futurehttps://digitalcommons.ursinus.edu/grizzlynews/1310/thumbnail.jp

The Grizzly, March 23, 1993

Ursinus Mourns The Loss of One of Our Own • Worst Storm of the Century • Danceteller Performs at Ursinus • Ursinus\u27s Own Ticketron • Consider Women\u27s Studies • Wismer Rolls Out the Red Carpet • College Needs Policy on Closing • No Class • The Right to Life • U.C. Baseball Heading in Right Direction • Softball Breaks Even in the Carolinas • Three Outstanding Jens • Gymnasts at Nationalshttps://digitalcommons.ursinus.edu/grizzlynews/1312/thumbnail.jp

Bostonia: 1993-1994, no. 2-3

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Bostonia: 1998-1999, no. 1, 3-4

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs