3,796 research outputs found
Gauge theory of Finance?
Some problems with the recent stimulating proposal of a ``Gauge Theory of
Finance'' by Ilinski and collaborators are outlined. First, the derivation of
the log-normal distribution is shown equivalent both in information and
mathematical content to the simpler and well-known derivation, dating back from
Bachelier and Samuelson. Similarly, the re-derivation of Black-Scholes equation
is shown equivalent to the standard one because the limit of no uncertainty is
equivalent to the standard risk-free replication argument. Both re-derivations
of the log-normality and Black-Scholes result do not provide a test of the
theory because it is degenerate in the limits where these results apply. Third,
the choice of the exponential form a la Boltzmann, of the weight of a given
market configuration, is a key postulate that requires justification. In
addition, the ``Gauge Theory of Finance'' seems to lead to ``virtual''
arbitrage opportunities for pure Markov random walk market when there should be
none. These remarks are offered in the hope to improve the formulation of the
``Gauge Theory of Finance'' into a coherent and useful framework.Comment: 4 page
Computer model for refinery operations with emphasis on jet fuel production. Volume 2: Data and technical bases
The FORTRAN computing program predicts the flow streams and material, energy, and economic balances of a typical petroleum refinery, with particular emphasis on production of aviation turbine fuel of varying end point and hydrogen content specifications. The program has provision for shale oil and coal oil in addition to petroleum crudes. A case study feature permits dependent cases to be run for parametric or optimization studies by input of only the variables which are changed from the base case. The report has sufficient detail for the information of most readers
Computer model for refinery operations with emphasis on jet fuel production. Volume 3: Detailed systems and programming documentation
The FORTRAN computing program predicts flow streams and material, energy, and economic balances of a typical petroleum refinery, with particular emphasis on production of aviation turbine fuels of varying end point and hydrogen content specifications. The program has a provision for shale oil and coal oil in addition to petroleum crudes. A case study feature permits dependent cases to be run for parametric or optimization studies by input of only the variables which are changed from the base case
Computer model for refinery operations with emphasis on jet fuel production. Volume 1: Program description
A FORTRAN computer program is described for predicting the flow streams and material, energy, and economic balances of a typical petroleum refinery, with particular emphasis on production of aviation turbine fuel of varying end point and hydrogen content specifications. The program has provision for shale oil and coal oil in addition to petroleum crudes. A case study feature permits dependent cases to be run for parametric or optimization studies by input of only the variables which are changed from the base case
Similarities of gauge and gravity amplitudes
We review recent progress in computations of amplitudes in gauge theory and
gravity. We compare the perturbative expansion of amplitudes in N=4 super
Yang-Mills and N=8 supergravity and discuss surprising similarities.Comment: Talk presented by Harald Ita at "Continuous Advances in QCD 2006", 7
page
Perturbative Gravity and Twistor Space
The recent progress in computing gauge theory amplitudes can be extended, in
many cases, to theories incorporating gravity. This has improved our
understanding of the perturbative expansion of N=8 supergravity supporting the
``no-triangle hypothesis'' that N=8 one-loop amplitudes may be expressed in
terms of scalar box integral functions.Comment: Talk presented by N. E. J. Bjerrum-Bohr at Loop and Legs 2006, 5
page
African-American Males, African-American Female Principals, & The Opportunity Gap
Over the past decade, research has been devoted to bridging the gap in academics and opportunity among African-American males. Missing from the dialogue however, are the voices of African-American female leaders. This voice will not only play an instrumental part in mediating cultural misunderstandings that occur in the classroom, but it will also facilitate a much needed conversation in understanding gender and race by displaying different views on educational leadership. Thus, the purpose of this study is to explore the perceptions of the opportunity gap among African-American female principals in Title I schools to raise the presence of their voice in this educational discussion. As the opportunity gap is an issue that has a global impact, this research can be transferred to various contexts in the educational setting. The findings that emerged from this study can assist both rural and Title I school districts in reevaluating existing educational programs or aid in designing new initiatives to improve outcomes for low-performing African-American males. Moreover, this data can support school districts in developing the cultural competence of teachers and staff through professional development and culturally sensitive pedagogy
An Email Attachment is Worth a Thousand Words, or Is It?
There is an extensive body of research on Social Network Analysis (SNA) based
on the email archive. The network used in the analysis is generally extracted
either by capturing the email communication in From, To, Cc and Bcc email
header fields or by the entities contained in the email message. In the latter
case, the entities could be, for instance, the bag of words, url's, names,
phones, etc. It could also include the textual content of attachments, for
instance Microsoft Word documents, excel spreadsheets, or Adobe pdfs. The nodes
in this network represent users and entities. The edges represent communication
between users and relations to the entities. We suggest taking a different
approach to the network extraction and use attachments shared between users as
the edges. The motivation for this is two-fold. First, attachments represent
the "intimacy" manifestation of the relation's strength. Second, the
statistical analysis of private email archives that we collected and Enron
email corpus shows that the attachments contribute in average around 80-90% to
the archive's disk-space usage, which means that most of the data is presently
ignored in the SNA of email archives. Consequently, we hypothesize that this
approach might provide more insight into the social structure of the email
archive. We extract the communication and shared attachments networks from
Enron email corpus. We further analyze degree, betweenness, closeness, and
eigenvector centrality measures in both networks and review the differences and
what can be learned from them. We use nearest neighbor algorithm to generate
similarity groups for five Enron employees. The groups are consistent with
Enron's organizational chart, which validates our approach.Comment: 12 pages, 4 figures, 7 tables, IML'17, Liverpool, U
Effect of local injection of Corynebacterium parvum on the growth of a murine fibrosarcoma.
Local injection (i.e. injection at the site of tumour inoculation) of strains of C. Parvum which have a significant anti-tumour effect when given systemically (i.e. intravenously or, in the case of subcutaneous tumour transplant, intraperitoneally) strongly inhibits the growth of isogeneic transplants of a fibrosarcoma in intact CBA mice but has little or no effect on subcutaneous transplants of the same tumour in T-cell deprived mice. The anti-tumour effect of local injection of C. parvum, unlike that of systemic injection in this particular tumour system, thus appears to be T-cell dependent
Close relationships: A study of mobile communication records
Mobile phone communication as digital service generates ever-increasing
datasets of human communication actions, which in turn allow us to investigate
the structure and evolution of social interactions and their networks. These
datasets can be used to study the structuring of such egocentric networks with
respect to the strength of the relationships by assuming direct dependence of
the communication intensity on the strength of the social tie. Recently we have
discovered that there are significant differences between the first and further
"best friends" from the point of view of age and gender preferences. Here we
introduce a control parameter based on the statistics of
communication with the first and second "best friend" and use it to filter the
data. We find that when is decreased the identification of the
"best friend" becomes less ambiguous and the earlier observed effects get
stronger, thus corroborating them.Comment: 11 pages, 7 figure
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