4,826 research outputs found
[Book review] "The Economics of Involuntary Resettlement: Questions and Challenges edited by Michael M. Cernea"
Developing countries, Latin America, India, Community development, Settlements, Economic policy
[Book review] "Catching Up and Falling Behind: Post-Communist Transformation in Historical Perspective by David A. Dyker"
Soviet, Russia, East Europe, Socialist economy, Economic development
[Book review] "System for Infrastructure - Japan's Experience edited by Yuzo Akatsuka and Tsuneaki Yoshida"
Japan, Social capital
[Book review] "David S. Landes, The Wealth and Poverty of Nations: Why Some Are So Rich and Some So Poor"
Europe, Japan, China, Asia, South America, Economic history, Poverty
[Book review] "The Siberian Curse: How Communist Planners Left Russia Out in the Cold by Fiona Hill and Clifford G. Gaddy"
Soviet, Economic conditions, Economic geography
[Book review] "Voices of the Poor: Can Anyone Hear Us?; Voices of the Poor: Crying Out for Change; Voices of the Poor: From Many Lands, by Deepa Narayan...[et al.]"
Developing countries, Poverty, Social couditions, Social policy, Gender, Quality of life
Determining Minimal Polynomial of Proper Element by Using Higher Degree Traces
Modern communication engineerings, such as elliptic curve cryptographies, often requires algebra on finite extension field defined by modulus arithmetic with an irreducible polynomial. This paper provides a new method to detemine the minimal (irreducible) polynomial of a given proper element in finite extension field. In the conventional determination method, as we have to solve the simultaneous equations, the computation is very involved. In this paper, the well known "trace" is extended to higher degree traces. Using the new traces, we yield the coefficient formula of the desired minimal polynomial. The new method becomes very simple without solving the simultaneous equations, and about twice faster than the conventional method in computation speed
The 1996-1997 Fading of V651 Mon, the Binary Central Star of the Planetary Nebula NGC 2346
V651 Mon is the binary central star of the bipolar planetary nebula NGC 2346.
The star showed the second-ever deep fading in 1996-1997, which was presumably
caused by obscuration by a dust cloud in the planetary nebula, as was proposed
to explain the 1981-1985 event. The entire duration of the 1996-1997 event was
\~400 d, remarkably shorter than the 1981-1985 event, suggesting that the
obscuring body was smaller or had a larger tangential velocity. The most
remarkable feature in this event was the presence of a sharply defined
transient clearing (brightening). From the time-scale of the variation, we
propose an upper limit of the projected scale of several times ~10^11 cm of the
structure responsible for the brightening. This observation provides the first
evidence for a sharply defined, small lucent structure within the obscuring
body around the central star of NGC 2346Comment: 4 pages, 3 figures (using a non-standard style file
Dirac's hole theory versus quantum field theory
Dirac's hole theory and quantum field theory are usually considered
equivalent to each other. For models of a certain type, however, the
equivalence may not hold as we discuss in this Letter. This problem is closely
related to the validity of the Pauli principle in intermediate states of
perturbation theory.Comment: No figure
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