On properties related to going-up for commutative rings

This work develops concepts related to the going-up property in commutative ring theory. In Chapter 1, we collect some facts in commutative ring theory essential for understanding this work. In Chapter 2, we focus on concepts related to the notion of quasi-going-up, as defined by Dobbs and Fontana. We define quasi-going-up domains and develop various results for quasi-going-up domains. Such results include a characterization of quasi-going-up domains in terms of going-down domains, results concerning ascent and descent, and various necessary and sufficient conditions for a domain to be a quasi-going-up domain. We next introduce the related concepts of absolutely quasi-going-up domains and universally quasi-going-up domains . We characterize both absolutely quasi-going-up domains and universally quasi-going-up domains. We conclude Chapter 2 by introducing and briefly studying the quasigoing- up ring notion, which generalizes the concept of quasi-going-up domains . In Chapter 3, we define the notion of generalized going-up analogously to the notion of generalized going-down that was recently introduced by Dobbs, Fontana, and G. Pica vet. We develop analogous results for arbitrary ring homomorphisms satisfying the generalized going-up property. We conclude Chapter 3 with a discussion of 2-chain morphisms ( or subtrusive morphisms) and show that universally 2-chain morphisms descend the generalized going-up property

Analytical ground state for the three-band Hubbard model

For the calculation of charge excitations as those observed in, e.g., photo-emission spectroscopy or in electron-energy loss spectroscopy, a correct description of ground-state charge properties is essential. In strongly correlated systems like the undoped cuprates this is a highly non-trivial problem. In this paper we derive a non-perturbative analytical approximation for the ground state of the three-band Hubbard model on an infinite, half filled CuO_2 plane. By comparison with Projector Quantum Monte Carlo calculations it is shown that the resulting expressions correctly describe the charge properties of the ground state. Relations to other approaches are discussed. The analytical ground state preserves size consistency and can be generalized for other geometries, while still being both easy to interpret and to evaluate.Comment: REVTeX, 8 pages, 6 figures, to appear in Phys. Rev.

The Search for Effective and Cost-Efficient Housing Strategies: Enforcing Housing Condition Standards Through Code Inspections at Time of Sale or Transfer

Federal funding for housing programs in the United States has been cut about seventy-five percent during the 1980s compared to funding levels in the 1970s. This reduction in federal support has meant that local governments, which rely heavily on federal housing funds and are relied upon to carry out federal housing policies at the local level, have been forced to look to alternative housing strategies and funding sources

Providing Low and Moderate Income Housing Through Non-Profit Housing Associations: Lessons from the British

The conflicting needs of associations and government-separation from government versus control over public funds--led to the creation in 1964 of a national Housing Corporation. Its functions are to promote and register associations, to channel funds, and to monitor association activities. This system of registration, cost limits, and individual project review has been remarkably effective in assuring proper use of the substantial subsidies that have stimulated the rapid and significant contributions of associations

Terra Nova 2.0 - The New World of MMORPGs

This is a preprint of an article whose final and definitive form has been published in the journal Critical Studies in Media Communication.The dominant metaphor used to describe and situate MMORPGs, or massively multiplayer online role playing games (e.g. Ultima Online, EverQuest, World of Warcraft, Second Life, etc.), has been “new world” and “new frontier.” By deploying this powerful imagery, game developers, players, the popular media, and academic researchers draw explicit connections between the technology of MMORPGs and the European encounter with the Americas and the western expansion of the United States. Although providing a compelling and often recognizable explanation of the innovations and opportunities of this new technology, the use of this terminology comes with a considerable price, one that had been demonstrated and examined by scholars of the Internet, cyberspace, and virtual reality over a decade ago. This essay explores the impact and significance of the terms “new world” and “frontier” as they have been deployed to explain and describe MMORPGs

The Model Cities Program

The period from 1961 through 1965 saw a dramatic increase in the number of federal grant-in-aid programs and the total federal funding levels directed at curing the ills of the urban community. There was a persistent anxiety, however, that, despite the proliferation of new drugs administered to the patient for his array of symptoms, the progress was not satisfactory, and that time was running out. In October, 1965, a Task Force on Urban Problems was appointed by President Johnson to study urban problems and recommend action. The Task Force looked at the prior efforts and decided a new approach was necessary-a treatment to be commenced in selected cities as a demonstration. They recommended that the federal, state and local medicine men consult with each other in order to develop a program of drug therapy which would be comprehensive, and coordinated. They also recommended that massive new types and higher dosage levels of drugs were necessary if the patient was to be revitalized. The basic Task Force recommendation was accepted by the President and presented to the Congress in his message of January 26, 1966. A proposed Demonstration Cities Act of 1966 was introduced into Congress, which was later consolidated with other provisions into an omnibus bill, and finally was enacted as Title I of the Demonstration Cities and Metropolitan Development Act of 1966. As HUD commenced to implement the new program, it was given its popular name, the Model Cities Program, a designation not appearing in the Act. This article presents this, program in its historical perspective and its posture as developed administratively by the Johnson Administration. Its full potential and direction will unfold during the Nixon Administration. Secretary of Housing and Urban Development, George W. Romney, has endorsed the concept underlying the Program and announced Presidential approval of certain revisions in the administration of the Program.\u2