51,962 research outputs found
Glacial Processes and Their Relationship to Streamflow Flute Glacier, Alaska
Flute Glacier is located at the head of the South Fork of Eagle River,
Alaska, about twenty air-miles east northeast of Anchorage. It is a small
north-facing glacier, approximately two miles long and half a mile wide,
situated in a deep glacial valley (see Figure 1). Elevations on the glacier
range from 3,500 feet at the terminous to 5,800 feet at the top of the
accumulation area.
Water from Flute Glacier becomes the South Fork of Eagle River, draining
about 32 square miles of area compared to a 192 square mile drainage basin
for Eagle River. Limited discharge measurements made during October 1968
suggest that the South Fork contributes about 20% of the water flowing down
Eagle River. Glacial meltwater forms an important percentage of the waters
of the Eagle River system.
Glaciers feeding the main Eagle River are large, complex and difficult to
study. Flute Glacier, relatively small and of simple plan, was selected for
study because of its small size and proximity to the metropolitan area of
Anchorage. Water from the Eagle River system is presently included in the
plans for future water supply for Anchorage. The Eagle River valley up to
the 500 ft contour is a federal power reserve.
The climate of the area surrounding Flute Glacier is alpine with cool
temperatures and higher than average precipitation for the area. All the
glacier is above treeline so no plant life is obvious. Mountain sheep
inhabit the sharp alpine peaks surrounding the glacier.The work upon which this report is based was supported by funds (Project A-021-
ALAS) provided by the United States Department of the Interior, Office
of Water Resources Research, as authorized under the Water Resources Act of
1964 as amended
Beyond Bathsheba: Managing Ethical Climates Through Pragmatic Ethics
This paper explores the puzzling nature of leader behavior in order to understand the conditions that encourage unethical decision-making. Building on the extant literature of pragmatic ethics, I explore how leaders can increase the quality of ethical decision-making within their organizations by understanding the incentives of rational choice. I have developed a rational choice-based ethical decision-making model to understand the incentives behind ethical leader behavior and find that ethical behavior is likely to be rational as long as audience costs remain higher than the savings benefits incurred by unethical behavior. I conclude with analysis of how the ethical rational model compares to other prominent theories that explain unethical leader behavior and propose that the probable outcomes derived from my model better explain bad leader behavior than competing control-oriented models. The results of this inquiry underscore the transactional and practical characteristics of leadership as a tool to help leaders manage their ethical climates, improve business practices and management policies, understand the nature of individual incentives, and capture transactional components of leader behavior
Overlay Protection Against Link Failures Using Network Coding
This paper introduces a network coding-based protection scheme against single
and multiple link failures. The proposed strategy ensures that in a connection,
each node receives two copies of the same data unit: one copy on the working
circuit, and a second copy that can be extracted from linear combinations of
data units transmitted on a shared protection path. This guarantees
instantaneous recovery of data units upon the failure of a working circuit. The
strategy can be implemented at an overlay layer, which makes its deployment
simple and scalable. While the proposed strategy is similar in spirit to the
work of Kamal '07 & '10, there are significant differences. In particular, it
provides protection against multiple link failures. The new scheme is simpler,
less expensive, and does not require the synchronization required by the
original scheme. The sharing of the protection circuit by a number of
connections is the key to the reduction of the cost of protection. The paper
also conducts a comparison of the cost of the proposed scheme to the 1+1 and
shared backup path protection (SBPP) strategies, and establishes the benefits
of our strategy.Comment: 14 pages, 10 figures, accepted by IEEE/ACM Transactions on Networkin
Quantifying parameters for Bayesian prior assumptions when estimating the probability of failure of software
Software reliability has become increasingly important, especially in life-critical situations. The ability to measure the results of testing and to quantify software reliability is needed. If this is accomplished, a certain minimum amount of reliability for a piece of software can be specified, and testing and/or other analysis may be done until that minimum number has been attained. There are many models for estimating software reliability. The accuracy of these models has been challenged and many revisions for the models and recalibration techniques have been devised. Of particular interest is the method of estimating the probability of failure of software when no failures have yet occurred in its current version as described by Miller. This model uses black box testing with formulae based on Bayesian estimation. The focus is on three interrelated issues: estimating the probability of failure when testing has revealed no errors; modifying this estimation when the input use distribution does not match the test distribution; and combining the results from random testing with other relevant information to obtain a possibly more accurate estimate of the probability of failure. Obtaining relevant information about the software and combining the results for a better estimate for the Miller model are discussed
Spectroscopic analysis of radiation-generated changes in tensile properties of a polyetherimide film
The effects of electron radiation on Ultem, a polyetherimide were studied for doses from 2 x 10 to the 9th power to 6 x 10 to the 9th power rad. Specimens were studied for tensile property testing and for electron paramagnetic resonance and infrared spectroscopic measurements of molecular structure. A Faraday cup design and a method for remote temperature measurement were developed. The spectroscopic data show that radiation caused dehydrogenation of methyl groups, rupture of main-chain ether linkage, and opening of imide rings, all to form radicals and indicate that the so-formed atomic hydrogen attached to phenyl radicals, but not to phenoxyl radicals, which would have formed hydroxyls. The observed decays of the radiation-generated phenoxyl, gem-dimethyl, and carbonyl radicals were interpreted as a combining of the radicals to form crosslinking. This crosslinking is the probable cause of the major reduction in the elongation of the tensile specimens after irradiation. Subsequent classical solubility tests indicate that the irradiation caused massive crosslinking
Electron and proton absorption calculations for a graphite/epoxy composite model
The Bethe-Bloch stopping power relations for inelastic collisions were used to determine the absorption of electron and proton energy in cured neat epoxy resin and the absorption of electron energy in a graphite/epoxy composite. Absorption of electron energy due to bremsstrahlung was determined. Electron energies from 0.2 to 4.0 MeV and proton energies from 0.3 to 1.75 MeV were used. Monoenergetic electron energy absorption profiles for models of pure graphite, cured neat epoxy resin, and graphite/epoxy composites are reported. A relation is determined for depth of uniform energy absorption in a composite as a function of fiber volume fraction and initial electron energy. Monoenergetic proton energy absorption profiles are reported for the neat resin model. A relation for total proton penetration in the epoxy resin as a function of initial proton energy is determined. Electron energy absorption in the composite due to bremsstrahlung is reported. Electron and proton energy absorption profiles in cured neat epoxy resin are reported for environments approximating geosynchronous earth orbit
Moisture diffusion parameter characteristics for epoxy composites and neat resins
The moisture absorption characteristics of two graphite/epoxy composites and their corresponding cured neat resins were studied in high humidity and water immersion environments at elevated temperatures. Moisture absorption parameters, such as equilibrium moisture content and diffusion coefficient derived from data taken on samples exposed to high humidity and water soak environments, were compared. Composite swelling in a water immersion environment was measured. Tensile strengths of cured neat resin were measured as a function of their equilibrium moisture content after exposure to different moisture environments. The effects of intermittent moderate tensile loads on the moisture absorption parameters of composite and cured neat resin samples were determined
Thermoluminescent aerosol analysis
A method for detecting and measuring trace amounts of aerosols when reacted with ozone in a gaseous environment was examined. A sample aerosol was exposed to a fixed ozone concentration for a fixed period of time, and a fluorescer was added to the exposed sample. The sample was heated in a 30 C/minute linear temperature profile to 200 C. The trace peak was measured and recorded as a function of the test aerosol and the recorded thermoluminescence trace peak of the fluorescer is specific to the aerosol being tested
Robust and Resilient State-dependent Control of Continuous-time Nonlinear Systems with General Performance Criteria
A novel state-dependent control approach for continuous-time nonlinear systems with general performance criteria is presented in this paper. This controller is optimally robust for model uncertainties and resilient against control feedback gain perturbations in achieving general performance criteria to secure quadratic optimality with inherent asymptotic stability property together with quadratic dissipative type of disturbance reduction. For the system model, unstructured uncertainty description is assumed, which incorporates commonly used types of uncertainties, such as norm-bounded and positive real uncertainties as special cases. By solving a state-dependent linear matrix inequality at each time, sufficient condition for the control solution can be found which satisfies the general performance criteria. The results of this paper unify existing results on nonlinear quadratic regulator, H∞ and positive real control. The efficacy of the proposed technique is demonstrated by numerical simulations of the nonlinear control of the inverted pendulum on a cart system
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