44,032 research outputs found
Projective Root-Locus: An Extension of Root-Locus Plot to the Projective Plane
In this paper we present an extension of the classical Root-Locus (RL) method
where the points are calculated in the real projective plane instead of the
conventional affine real plane; we denominate this extension of the Root-Locus
as "Projective Root-Locus (PjRL)". To plot the PjRL we use the concept of
"Gnomonic Projection" in order to have a representation of the projective real
plane as a simi-sphere of radius one in . We will see that the
PjRL reduces to the RL in the affine plane, but also we can plot the RL
onto another affine component of the projective plane, like affine plane
for instance, to obtain what we denominate complementary plots of the
conventional RL. We also show that with the PjRL the points at infinity of the
RL can be computed as solutions of a set algebraic equations.Comment: 13 pages, 8 figure
Bettering Humanity through Biology
Biology is arguably referred to as the “science of the XXIth century”. This prestigious
title intrinsically contains a huge responsibility. For many centuries, Biology has
contributed directly or indirectly to bettering humankind, although its obvious and
objective effects have only been made evident since the XIXth century. There are
three main domains to which Biology has made significant contributions: Agriculture,
Environment and Medicine. Several scientific disciplines connected to Biology have
been involved such as Genetics (mendelian and molecular), Cell Biology, Ecology,
Microbiology, and what was known for a long time as “Natural History” (today we
would include these roughly within Botany and Zoology). Agronomy, a relatively
recent science, has made a tremendous impact by providing knowledge on growing
plants and animals, and developing new and better crops. One specific moment in time,
following WW II, known as the “Green Revolution” benefitted humanity immensely,
by combating hunger in countries such as India and Mexico. The “father” of the Green
Revolution, Norman Borlaug, was awarded the 1970 Peace Nobel Prize for such
achievements. In the XXIth century, biologists and agronomists are working hard to
develop new and better crops to feed almost 8 billion people. In the medical field, the
contributions are inumerable, from the discovery and development of vaccines (Jenner
and Pasteur), to antibiotics (Fleming) and combatting diseases. This has increased the
average life expectancy of humans from around 30-40 in the beginning of the XXth
century, to a present value of around 75 (depending on the country). These achievements
have been recognized by society, through dozens of Nobel Prizes in Medicine. All these
successes have been made possible through Biology. In the past 30-40 years, numerous
voices have been raised alerting for the environmental degradation of our planet, its
land and oceans, its biomes and ecosystems. We have been depleting our planet at an
incredible rate. But today, biologists and environmental scientists have the knowledge
and tools to better the planet. We know how the ecosystems function and what causes
harm them. There is still time, together with a strong public opinion, to halt the damage.
Once again, Biology is a principal actor
Dear Students of Color
Why are we hated for the things that we cannot control? Why is the killing of a black man just another sequel? Why don’t black lives matter
Denying the Dream: How the Proposed Changes to the US Naturalization Test Would Prevent Immigrants from Becoming Citizens
This report details how (as of September 2003) efforts by the US Citizenship and Immigration Service (former Immigration and Naturalization Service) to redesign the citizenship test could threaten the aspirations of many immigrants, particularly Latinos and others with lower levels of education, to gain US citizenship
Astrophysical Configurations with Background Cosmology: Probing Dark Energy at Astrophysical Scales
We explore the effects of a positive cosmological constant on astrophysical
and cosmological configurations described by a polytropic equation of state. We
derive the conditions for equilibrium and stability of such configurations and
consider some astrophysical examples where our analysis may be relevant. We
show that in the presence of the cosmological constant the isothermal sphere is
not a viable astrophysical model since the density in this model does not go
asymptotically to zero. The cosmological constant implies that, for polytropic
index smaller than five, the central density has to exceed a certain minimal
value in terms of the vacuum density in order to guarantee the existence of a
finite size object. We examine such configurations together with effects of
in other exotic possibilities, such as neutrino and boson stars, and
we compare our results to N-body simulations. The astrophysical properties and
configurations found in this article are specific features resulting from the
existence of a dark energy component. Hence, if found in nature would be an
independent probe of a cosmological constant, complementary to other
observations.Comment: 23 pages, 11 figures, 2 tables. Reference added. Mon. Not. Roy.
Astro. Soc in prin
Hide It or Unbundle It: A Comparison of the Antitrust Investigations Against Microsoft in the U.S. and the E.U.
[Excerpt] Microsoft Corporation, the world’s largest software company, has been facing antitrust scrutiny globally. In the U.S., after what’s been called the antitrust trial of the century, a consent decree was reached between Microsoft, the United States government, and several states, that closely resembled the litigated remedy that the remaining states received. Only Massachusetts appealed the litigated remedy, which was approved by the appeals court on June 30, 2004. In the United States, Microsoft was required to hide, but not remove, the Internet Explorer browser on the Windows Operating System. While antitrust litigation was ongoing in the United States against Microsoft, the European Union (“E.U.”) was also investigating Microsoft under E.U. antitrust law. In March, 2004, after a five year investigation, the European Union Commission fined Microsoft 497 million euros, required Microsoft to offer the Windows operating system without Windows Media Player, and required Microsoft to disclose interfaces to competitors. On December 22, 2004, the E.U.’s Court of First Instance denied Microsoft’s request for a stay of this order, and ordered Microsoft to comply; the full appeal is pending at the time of this publication. This article will examine, compare, and contrast the protracted antitrust litigation that Microsoft has faced in the U.S. and the E.U. This article will then examine what further antitrust problems Microsoft may be facing
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