831 research outputs found
An application of software design and documentation language
The software design and documentation language (SDDL) is a general purpose processor to support a lanugage for the description of any system, structure, concept, or procedure that may be presented from the viewpoint of a collection of hierarchical entities linked together by means of binary connections. The language comprises a set of rules of syntax, primitive construct classes (module, block, and module invocation), and language control directives. The result is a language with a fixed grammar, variable alphabet and punctuation, and an extendable vocabulary. The application of SDDL to the detailed software design of the Command Data Subsystem for the Galileo Spacecraft is discussed. A set of constructs was developed and applied. These constructs are evaluated and examples of their application are considered
One Thing After Another: Why the Passage of Time Is Not an Illusion
Does time seem to pass, even though it doesnât, really? Many philosophers think the answer is âYesââat least when âtimeâs passingâ is understood in a particular way. They take timeâs passing to be a process by which each time in turn acquires a special status, such as the status of being the only time that exists, or being the only time that is present. This chapter suggests that, on the contrary, all we perceive is temporal succession, one thing after another, a notion to which modern physics is not inhospitable. The contents of perception are best described in terms of âbeforeâ and âafterâ, rather than âpastâ, âpresent, and âfutureâ
The elastic instability of duralumin columns in compression
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautical Engineering, 1933.Microfiche copy available in Barker.Includes bibliographical references (leaf 46).by Archibald B. Callender.M.S
An Alternative Interpretation of Statistical Mechanics
In this paper I propose an interpretation of classical statistical mechanics that centers on taking seriously the idea that probability measures represent complete states of statistical mechanical systems. I show how this leads naturally to the idea that the stochasticity of statistical mechanics is associated directly with the observables of the theory rather than with the microstates (as traditional accounts would have it). The usual assumption that microstates are representationally significant in the theory is therefore dispensable, a consequence which suggests interesting possibilities for developing non-equilibrium statistical mechanics and investigating inter-theoretic answers to the foundational questions of statistical mechanics
Comparing high school students' attitudes towards borrowing for higher education in England and the United States: who are the most loan averse?
Student borrowing is a major higher education public policy issue, with students in both England and the United States increasingly relying on loans to finance postsecondary education. Our paper examines prospective higher education studentsâ attitudes towards debt in England and the United States. It exploits a unique dataset which allows us to compare studentsâ responses to similar surveys conducted in both countries during the same time period. Our study is the first of its kind to explore how studentsâ borrowing attitudes differ across the two countries. It confirms widespread loan aversion among prospective higher education students in both countries. But students in the United States are more debt averse than their peers in England. These debt averse attitudes also predict lower intentions to pursue higher education, potentially exacerbating existing inequalities in access. We consider how these attitudes to borrowing are likely shaped by each countryâs distinctive student loan system. We conclude that the design of loans matters. Englandâs income-contingent loan repayments, in contrast to Americaâs mortgage style repayments, make borrowing less risky and reduce the impact of loan aversion on participation decisions, while borrowing is commoner and the system less complicated in England. Thus, there are lessons for other countries considering introducing student loans or reforming their provision. We contribute to the extant literature on the determinants of, and socioeconomic differences in, higher education participation and the overlooked role of student debt aversion
Higher education, mature students and employment goals: policies and practices in the UK
This article considers recent policies of Higher Education in the UK, which are aimed at widening participation and meeting the needs of employers. The focus is on the growing population of part-time students, and the implications of policies for this group. The article takes a critical perspective on government policies, using data from a major study of mature part-time students, conducted in two specialist institutions in the UK, a London University college and a distance learning university. Findings from this study throw doubt on the feasibility of determining a priori what kind of study pathway is most conducive for the individual in terms of employment gains and opportunities for upward social mobility. In conclusion, doubts are raised as to whether policies such as those of the present UK government are likely to achieve its aims. Such policies are not unique to the UK, and lessons from this country are relevant to most of the developed world
T and CPT Symmetries in Entangled Neutral Meson Systems
Genuine tests of an asymmetry under T and/or CPT transformations imply the
interchange between in-states and out-states. I explain a methodology to
perform model-indepedent separate measurements of the three CP, T and CPT
symmetry violations for transitions involving the decay of the neutral meson
systems in B- and {\Phi}-factories. It makes use of the quantum-mechanical
entanglement only, for which the individual state of each neutral meson is not
defined before the decay of its orthogonal partner. The final proof of the
independence of the three asymmetries is that no other theoretical ingredient
is involved and that the event sample corresponding to each case is different
from the other two. The experimental analysis for the measurements of these
three asymmetries as function of the time interval {\Delta}t > 0 between the
first and second decays is discussed, as well as the significance of the
expected results. In particular, one may advance a first observation of true,
direct, evidence of Time-Reserval-Violation in B-factories by many standard
deviations from zero, without any reference to, and independent of,
CP-Violation. In some quantum gravity framework the CPT-transformation is
ill-defined, so there is a resulting loss of particle-antiparticle identity.
This mechanism induces a breaking of the EPR correlation in the entanglement
imposed by Bose statistics to the neutral meson system, the so-called
{\omega}-effect. I present results and prospects for the {\omega}-parameter in
the correlated neutral meson-antimeson states.Comment: Proc. DISCRETE 2010, Symposium on Prospects in the Physics of
Discrete Symmetries, December 2010, Rom
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