24,294 research outputs found
The Long and the Short End of the Term Structure of Policy Rules
We first document a large secular shift in the estimated response of the entire term structure of interest rates to inflation and output in the United States. The shift occurred in the early 1980s. We then derive an equation that links these responses to the coefficients of the central bank's monetary policy rule for the short-term interest rate. The equation reveals two countervailing forces that help explain and understand the nature of the link and how its sign is determined. Using this equation, we show that a shift in the policy rule in the early 1980s provides an explanation for the observed shift in the term structure. We also explore a shift in the policy rule in the 2002-2005 period and its possible effect on long-term rates.
Spectral mixture modeling: Further analysis of rock and soil types at the Viking Lander sites
A new image processing technique was applied to Viking Lander multispectral images. Spectral endmembers were defined that included soil, rock and shade. Mixtures of these endmembers were found to account for nearly all the spectral variance in a Viking Lander image
Compositional variability of the Martian surface
Spectral reflectance data from Viking Landers and Orbiters and from telescopic observations were analyzed with the objective of isolating compositional information about the Martian surface and assessing compositional variability. Two approaches were used to calibrate the data to reflectance to permit direct comparisons with laboratory reference spectra of well characterized materials. In Viking Lander multispectral images (six spectral bands) most of the spectral variation is caused by changes in lighting geometry within individual scenes, from scene to scene, and over time. Lighting variations are both wavelength independent and wavelength dependent. By calibrating lander image radiance values to reflectance using spectral mixture analysis, the possible range of compositions was assessed with reference to a collection of laboratory samples, also resampled to the lander spectral bands. All spectra from the lander images studied plot (in six-space) within a planar triangle having at the apexes the respective spectra of tan basaltic palagonite, gray basalt, and shale. Within this plane all lander spectra fit as mixtures of these three endmembers. Reference spectra that plot outside of the triangle are unable to account for the spectral variation observed in the images
Student understanding of the Boltzmann factor
We present results of our investigation into student understanding of the
physical significance and utility of the Boltzmann factor in several simple
models. We identify various justifications, both correct and incorrect, that
students use when answering written questions that require application of the
Boltzmann factor. Results from written data as well as teaching interviews
suggest that many students can neither recognize situations in which the
Boltzmann factor is applicable, nor articulate the physical significance of the
Boltzmann factor as an expression for multiplicity, a fundamental quantity of
statistical mechanics. The specific student difficulties seen in the written
data led us to develop a guided-inquiry tutorial activity, centered around the
derivation of the Boltzmann factor, for use in undergraduate statistical
mechanics courses. We report on the development process of our tutorial,
including data from teaching interviews and classroom observations on student
discussions about the Boltzmann factor and its derivation during the tutorial
development process. This additional information informed modifications that
improved students' abilities to complete the tutorial during the allowed class
time without sacrificing the effectiveness as we have measured it. These data
also show an increase in students' appreciation of the origin and significance
of the Boltzmann factor during the student discussions. Our findings provide
evidence that working in groups to better understand the physical origins of
the canonical probability distribution helps students gain a better
understanding of when the Boltzmann factor is applicable and how to use it
appropriately in answering relevant questions
Input-Output Analysis with Public Policy Objectives: A Case Study of the Georgia Cotton Industry
Farm bill legislation directed at agricultural commodities contributes to economies of rural areas. This research quantifies the economic impacts of the Georgia cotton industry for the U.S. economy. A cotton industry model with cotton and peanut acreage is utilized with IMPLAN to estimate impacts. The Georgia cotton industry creates 4% more tax revenues for federal, state, and local governments than it receives in commodity support payments. Stochastic simulation analysis indicates that the Georgia cotton industry is not likely to remain viable without government payments.economic impact, FSRI, IMPLAN, industry model, multivariate empirical distribution, Simetar, social welfare analysis, stochastic simulation, Agribusiness, Research and Development/Tech Change/Emerging Technologies,
Traditional Sayings as Reflexes of Household, Barn, and Byre
on of which can in turn add to our knowledge and under-standing of the sayings. This seems to be borne out by scrutiny of the saying to stick one’s spoon in the wall for “to die”, the literal meaning of which emerges from an examination of traditional eating habits and implements. Along with proverbialisms originating in the household, others that have grown out of the wider rural environment are dis-cussed. Although we proceed from English sayings, many of them dialectal, not a few of these have Continental counterparts, the study of which can cast further light, but also raise questions as to origin, development, and transmission
Traditional Sayings as Reflexes of Household, Barn, and Byre
on of which can in turn add to our knowledge and under-standing of the sayings. This seems to be borne out by scrutiny of the saying to stick one’s spoon in the wall for “to die”, the literal meaning of which emerges from an examination of traditional eating habits and implements. Along with proverbialisms originating in the household, others that have grown out of the wider rural environment are dis-cussed. Although we proceed from English sayings, many of them dialectal, not a few of these have Continental counterparts, the study of which can cast further light, but also raise questions as to origin, development, and transmission
THE LOCATION DECISION OF HARDWOOD MANUFACTURING IN THE NORTHERN AND CENTRAL APPALACHIAN STATES
This study's objective is to identify and understand the factors important to hardwood processors' location decisions in the northern and central Appalachian region. Concepts from neoclassical and behavioral location theories were integrated to develop a general framework for analyzing these decisions. Logit regression analysis was used to determine those establishment characteristics related to the likelihood of location search. To a great extent, establishments locate based on personal ties and do not conduct searches. Most variables found to influence the likelihood of search are not controllable by state or local governments. The implications are that existing establishments should be targeted for retention and expansion, rather than focusing on recruitment.Community/Rural/Urban Development, Industrial Organization,
Identifying Student Difficulties with Entropy, Heat Engines, and the Carnot Cycle
We report on several specific student difficulties regarding the Second Law
of Thermodynamics in the context of heat engines within upper-division
undergraduates thermal physics courses. Data come from ungraded written
surveys, graded homework assignments, and videotaped classroom observations of
tutorial activities. Written data show that students in these courses do not
clearly articulate the connection between the Carnot cycle and the Second Law
after lecture instruction. This result is consistent both within and across
student populations. Observation data provide evidence for myriad difficulties
related to entropy and heat engines, including students' struggles in reasoning
about situations that are physically impossible and failures to differentiate
between differential and net changes of state properties of a system. Results
herein may be seen as the application of previously documented difficulties in
the context of heat engines, but others are novel and emphasize the subtle and
complex nature of cyclic processes and heat engines, which are central to the
teaching and learning of thermodynamics and its applications. Moreover, the
sophistication of these difficulties is indicative of the more advanced
thinking required of students at the upper division, whose developing knowledge
and understanding give rise to questions and struggles that are inaccessible to
novices
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