8,224 research outputs found
Monetary Perspective On Underground Economic Activity In The United States
There are widespread reports of a growing underground, or unobserved, economy in the United States and in other countries. The unobserved economy seems to develop principally from efforts to evade taxes and government regulation. Although no single definition of such activity has been universally accepted, the term generally refers to activity – whether legal or illegal – generating income that either is underreported or not reported at all (see Chapter 1 in this volume). Some authors narrow the definition to cover income produced in legal activity that is not set down in the recorded national income statistics.
Recent discussion of underground economic activity was stimulated by publication of two estimates, one by Gutmann (1977) and the other by Feige (1979), of the size of the underground economy in the United States; these estimates were derived from aggregate monetary statistics. In the ensuing years, numerous other estimates have been made of the underground economy in the United States and in other countries. The magnitude of some of these estimates has prompted congressional hearings and various government studies. In 1979, the Internal Revenue Service (IRS, 1979) estimated that, for 1976, individuals failed to report between 100 billion in income from legal sources and another 35 billion from three types of illegal activity – drugs, gambling, and prostitution. In a more recent study, the IRS estimated that unreported income from legal sources rose from 249.7 billion in 1981 whereas unreported income from these same three illegal activities rose from 34 billion (IRS, 1983)
PuLSE-I: Deriving instances from a product line infrastructure
Reusing assets during application engineering promises to improve the efficiency of systems development. However, in order to benefit from reusable assets, application engineering processes must incorporate when and how to use the reusable assets during single system development. However, when and how to use a reusable asset depends on what types of reusable assets have been created.Product line engineering approaches produce a reusable infrastructure for a set of products. In this paper, we present the application engineering process associated with the PuLSE product line software engineering method - PuLSE-I. PuLSE-I details how single systems can be built efficiently from the reusable product line infrastructure built during the other PuLSE activities
Agency or Agencies? Catalysts of Resilience in Drop-In Participants
In this thesis, the factors that contribute to resilience are explored in a sample of participants who attend a food bank/clothing bank drop-in program in North Hamilton, Ontario. Resilience is defined as obtaining positive outcomes despite a level of risk to development. This thesis expands on the literature clarifying the concept of resilience. This thesis also contributes importantly to the smaller amount of literature on resilience in adults and older adults. Purposive sampling was used to obtain participants from the drop-in program at which the researcher volunteers. Phenomenology was utilized for this research, semi-structured interviews were used for data collection, and textural analysis was used to analyze the data. Eight participants were interviewed about their experiences with attempting to overcome adversity in their lives. Factors that were significant in participants’ resilience through adverse situations were psychological characteristics, social support, neighbourhood characteristics, voluntary sector services, and government services. A significant barrier to resilience for participants was housing issues. A factor that affected every aspect of the journey to resilience was the sociopolitical structure. The structural landscape and its transformation over the past several decades is discussed, as well as the effects of neo-liberalism on the ability to be resilience. Results are discussed in light of the current literature. Learning of the researcher, limitations of the thesis, policy and practice implications, and possibilities for future research are discussed
Multigraded Castelnuovo-Mumford Regularity
We develop a multigraded variant of Castelnuovo-Mumford regularity. Motivated
by toric geometry, we work with modules over a polynomial ring graded by a
finitely generated abelian group. As in the standard graded case, our
definition of multigraded regularity involves the vanishing of graded
components of local cohomology. We establish the key properties of regularity:
its connection with the minimal generators of a module and its behavior in
exact sequences. For an ideal sheaf on a simplicial toric variety X, we prove
that its multigraded regularity bounds the equations that cut out the
associated subvariety. We also provide a criterion for testing if an ample line
bundle on X gives a projectively normal embedding.Comment: 30 pages, 5 figure
Automatic landmarking for building biological shape models
We present a new method for automatic landmark extraction from the contours of biological specimens. Our ultimate goal is to enable automatic identification of biological specimens in photographs and drawings held in a database. We propose to use active appearance models for visual indexing of both photographs and drawings. Automatic landmark extraction will assist us in building the models. We describe the results of using our method on drawings and photographs of examples of diatoms, and present an active shape model built using automatically extracted data
(Bi-)Cohen-Macaulay simplicial complexes and their associated coherent sheaves
Via the BGG correspondence a simplicial complex Delta on [n] is transformed
into a complex of coherent sheaves on P^n-1. We show that this complex reduces
to a coherent sheaf F exactly when the Alexander dual Delta^* is
Cohen-Macaulay. We then determine when both Delta and Delta^* are
Cohen-Macaulay. This corresponds to F being a locally Cohen-Macaulay sheaf.
Lastly we conjecture for which range of invariants of such Delta it must be a
cone.Comment: 16 pages, some minor change
Spin coherence of holes in GaAs/AlGaAs quantum wells
The carrier spin coherence in a p-doped GaAs/(Al,Ga)As quantum well with a
diluted hole gas has been studied by picosecond pump-probe Kerr rotation with
an in-plane magnetic field. For resonant optical excitation of the positively
charged exciton the spin precession shows two types of oscillations. Fast
oscillating electron spin beats decay with the radiative lifetime of the
charged exciton of 50 ps. Long lived spin coherence of the holes with dephasing
times up to 650 ps. The spin dephasing time as well as the in-plane hole g
factor show strong temperature dependence, underlining the importance of hole
localization at cryogenic temperatures.Comment: 5 pages, 4 figures in PostScript forma
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