7,417 research outputs found
Estimating the Expected Value of Partial Perfect Information in Health Economic Evaluations using Integrated Nested Laplace Approximation
The Expected Value of Perfect Partial Information (EVPPI) is a
decision-theoretic measure of the "cost" of parametric uncertainty in decision
making used principally in health economic decision making. Despite this
decision-theoretic grounding, the uptake of EVPPI calculations in practice has
been slow. This is in part due to the prohibitive computational time required
to estimate the EVPPI via Monte Carlo simulations. However, recent developments
have demonstrated that the EVPPI can be estimated by non-parametric regression
methods, which have significantly decreased the computation time required to
approximate the EVPPI. Under certain circumstances, high-dimensional Gaussian
Process regression is suggested, but this can still be prohibitively expensive.
Applying fast computation methods developed in spatial statistics using
Integrated Nested Laplace Approximations (INLA) and projecting from a
high-dimensional into a low-dimensional input space allows us to decrease the
computation time for fitting these high-dimensional Gaussian Processes, often
substantially. We demonstrate that the EVPPI calculated using our method for
Gaussian Process regression is in line with the standard Gaussian Process
regression method and that despite the apparent methodological complexity of
this new method, R functions are available in the package BCEA to implement it
simply and efficiently
Review of \u3ci\u3eRachel Calof\u27s Story: Jewish Homesteader on the Northern Plains\u3c/i\u3e By Rachel Calof
Along with the original narrative this volume provides an epilogue by Jacob Calof, Rachel\u27s youngest child, and two essays, one by J. Sanford Rikoon, the other by Elizabeth Jameson. Jacob Calof\u27s comments confirm the strength and courage we find in his mother\u27s words.
The essays lend significant context to the narrative. Rikoon gives a concise and informative explanation of the history of Jewish families that left Russia and eastern Europe to settle on farms in the Heartland. Jameson\u27s analysis places Rachel\u27s narrative in historical perspective and emphasizes the importance of recognizing diversities of ethnicity, class, and gender in the interpretation of history.
This volume is among the finest work I have read in illuminating women\u27s roles and the intricacies of family dynamics. It gives strong support to a vital and more realistic settlement history
The common seaman in nineteenth century American fiction
Abstract: 3 p. at end.
Autobiography: 1 p. at end.
Thesis (Ph. D.)--Boston University.
Bibliography: p. 255-268.The role of the common seaman in nineteenth century American fiction is a revelation of the interest in the common man, the growth of democracy, the agitation for humanitarian reform, and the quest for nationalism which characterized the new nation between 1790 and 1865. The fictional seamen not only represent the actual men who shared the crowded quarters of the forecastle, but perhaps they are also a manifestation of the spirit of American democracy and the development of a native mythos. The sea has always been basic to American life and thought. In the opening years of the century, trade with the Orient was highly profitable. American whalers explored the islands of the Pacific and became familiar with the watery wastes from the Arctic to the Antarctic. With the establishment of a strong Navy following the War of 1812, America became one of the great maritime powers of the world. Later in the century when the frontier lured young men of adventure away from the sea and foreign crews filled the forecastles of ships, conditions on board American vessels worsened. Harsh treatment, bad food, long hours, and low pay discouraged men of ability from a maritime career. Yet there were always men who grew restless on land and, like Melville, returned to the sea.
It was a piece of extraordinary good fortune that the forecastles of American ships contained three such eloquent spokesmen as James Fenimore Cooper, Richard Henry Dana, Jr., and Herman Melville. The fiction written by these men reflect their own experiences at sea. Cooper sailed in the early days of the century when a young man of ability could begin at the bottom and rise to the quarter-deck. Captains felt a paternal interest in their crews, and men were loyal to their ships. Dana represented the gentlemen of good family who sailed before the mast to restore their health and see life firsthand. A lawyer in later years, he fought to bring about legal reforms for the betterment of seamen. Herman Melville served in every maritime branch-merchantman, whaler, and frigate--in the later years when captains were tyrannical and the crew represented the outcasts of all nations. He saw in their problems not only the need £or maritime reform but the universal suffering or all mankind. Of course, there were romantic novels of the sea. Henry Cheever, Edward Judson, and Captain Ingraham wrote of noble young tars and wicked villains, but to counterbalance these popular tales were the factual narratives of genuine seamen--Nathaniel Ames, Amasa Delano, J. Ross Browne, and Josiah Cobb.
Although English writers had already popularized maritime literature, America's unique contribution was the development of seamen such as Long Tom Coffin who, like Jonathan, the Yankee farmer, and Leather-Stocking, the frontiersman, represented a stock figure. Except for the legend of Captain Kidd and the tales of pirates who buried treasure or smuggled along the Atlantic coast, America had little folklore, but her writers created a feeling of mythos through the use of allegory and symbolism. The seaman hero of American fiction was based on fact, but he also was representative of the democratic individual freed from the stultifying restrictions of civilization. Closer to the sea than the land, he was part of the American dream which visualized the typical American as solitary, courageous, ingenious, and kin to the natural elements.
The invention of steam-driven vessels and the advent of the Civil War brought the age of sail to an end. New legislation and shorter voyages improved conditions for the common seamen. The "old salt" like the pioneer became part of America's heritage
Galsworthy's concept of Forsytism
Thesis (M.A.)--Boston University, 1947. This item was digitized by the Internet Archive
Sources of Social Capital for Malawi People Living With HIV.
With one of the highest rates of poverty and HIV in the world, Malawi faith-based organizations (FBOs), non-governmental organizations (NGOs), and community-based organizations (CBOs) are expected to provide tangible and emotional support to people living with HIV (PLWH). Using Lin's social capital theoretical approach, we examine the perspective of PLWH regarding the adequacy of support responses. Forty-six rural Malawi HIV+ adults provided interviews that were recorded digitally, translated, and transcribed by Malawi research assistants. Atlas.ti was used to organize the data and to aid in the analytic process. Participants expressed disappointment in the lack of resources that could be accessed through the FBOs although their expectations may have been unrealistic. Outcomes from accessing and mobilizing the FBO network were negative in terms of stigmatization by FBO leaders and members, whereas outcomes related to CBOs and NGOs were generally positive in terms of empowerment through HIV information and attendance at support groups
Coupled-cluster calculations of properties of Boron atom as a monovalent system
We present relativistic coupled-cluster (CC) calculations of energies,
magnetic-dipole hyperfine constants, and electric-dipole transition amplitudes
for low-lying states of atomic boron. The trivalent boron atom is
computationally treated as a monovalent system. We explore performance of the
CC method at various approximations. Our most complete treatment involves
singles, doubles and the leading valence triples. The calculations are done
using several approximations in the coupled-cluster (CC) method. The results
are within 0.2-0.4% of the energy benchmarks. The hyperfine constants are
reproduced with 1-2% accuracy
A wave function based ab initio non-equilibrium Green's function approach to charge transport
We present a novel ab initio non-equilibrium approach to calculate the
current across a molecular junction. The method rests on a wave function based
description of the central region of the junction combined with a tight binding
approximation for the electrodes in the frame of the Keldysh Green's function
formalism. In addition we present an extension so as to include effects of the
two-particle propagator. Our procedure is demonstrated for a dithiolbenzene
molecule between silver electrodes. The full current-voltage characteristic is
calculated. Specific conclusions for the contribution of correlation and
two-particle effects are derived. The latter are found to contribute about 5%
to the current. The order of magnitude of the current coincides with
experiments.Comment: 21 pages, 3 figure
Untangling the Myth of the Model Minority
The model minority stereotype depicts Asian Americans as a group that has succeeded in America and overcome discrimination through its hard work, intelligence, and emphasis on education and achievement - a modern-day confirmation of the American Dream. A large body of work by Asian critical scholars condemns this image and charges that it conceals more sinister beliefs about Asian Americans and other racial minorities in America. Is this critique correct? Does the model minority stereotype really mask hostility toward Asian Americans or breed contempt for other minorities? This article presents the results of an empirical study into the model minority stereotype. Using 1990, 1994, and 2000 General Social Survey data (including some of the very data used by critical scholars to establish the existence of this stereotype), we confirm claims that some non-Hispanic white Americans think that Asian Americans as a group are more intelligent, harder working, and richer than other minorities and that some think Asian Americans are more intelligent and harder working than whites. But we also discovered that these ideas are not usually linked with negative views of Asian Americans (or of other minorities, for that matter). Indeed, we found weak support for the contrary position - that those who rate Asian Americans higher than other minorities, or particularly higher than whites, are more likely to hold other positive views about Asian Americans, immigration, African Americans, and government programs supporting these groups. Our study nonetheless confirms the scholarly suspicions in one crucial respect: non-Hispanic whites who have positive views of Asian Americans are less likely to think that Asian Americans are discriminated against in both jobs and housing, thus tending to support the claims of some Asian critical scholars that positive stereotypes about Asian Americans tend to be associated with a failure to recognize continuing discrimination. In these data, however, this complacency by whites about prejudice against Asians does not translate into hostility toward government programs to alleviate the problems of Asian or African Americans
Resolving all-order method convergence problems for atomic physics applications
The development of the relativistic all-order method where all single,
double, and partial triple excitations of the Dirac-Hartree-Fock wave function
are included to all orders of perturbation theory led to many important results
for study of fundamental symmetries, development of atomic clocks, ultracold
atom physics, and others, as well as provided recommended values of many atomic
properties critically evaluated for their accuracy for large number of
monovalent systems. This approach requires iterative solutions of the
linearized coupled-cluster equations leading to convergence issues in some
cases where correlation corrections are particularly large or lead to an
oscillating pattern. Moreover, these issues also lead to similar problems in
the CI+all-order method for many-particle systems. In this work, we have
resolved most of the known convergence problems by applying two different
convergence stabilizer methods, reduced linear equation (RLE) and direct
inversion of iterative subspace (DIIS). Examples are presented for B, Al,
Zn, and Yb. Solving these convergence problems greatly expands the
number of atomic species that can be treated with the all-order methods and is
anticipated to facilitate many interesting future applications
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