Cosmic rays, solar activity, magnetic coupling, and lightning incidence

A theoretical model is presented and described that unifies the complex influence of several factors on spatial and temporal variation of lightning incidence. These factors include the cosmic radiation, solar activity, and coupling between geomagnetic and interplanetary (solar wind) magnetic fields. Atmospheric electrical conductivity in the 10 km region was shown to be the crucial parameter altered by these factors. The theory reconciles several large scale studies of lightning incidence previously misinterpreted or considered contradictory. The model predicts additional strong effects on variations in lightning incidence, but only small effects on the morphology and rate of thunderstorm development

Solar influence on terrestrial weather and global lightning patterns via cosmic ray modulations

A series of cosmic ray neutron monitor data which were used in three analyses: (1) solar activity influence on ionization of the upper troposphere and tropopause; (2) solar activity influence on Canadian high stratus in winter; and (3) the S3-4 satellite study of IMF/GMF magnetic coupling effects are reported. The magnetic coupling model of solar activity influence on atmospheric processes were investigated. The magnetic coupling model is used to explain a number of seemingly diverse studies lightning incidence is emphasized

Stock returns and inflation: further tests of the proxy and debt- monetization hypotheses

Inflation (Finance) ; Stock - Prices

Consolidation, technology, and the changing structure of banks' small business lending

The U.S. banking industry continues to consolidate, with large, complex banking organizations becoming more important. Traditionally, these institutions have not emphasized small business lending. On the other hand, technological advances, particularly credit scoring models, make it easier for banks to extend small business credit. To see what effects these influences might have generated on small business lending, David Ely and Kenneth Robinson explore the small business lending patterns at U.S. banks from 1994 through 1999. They find that larger banks are increasing their market share, most noticeably in the smallest segment of the small business loan market. The authors also present evidence that the size of the average small business loan has declined, especially at larger organizations, and that the gap in lending focus on the smallest small business loans has narrowed between small and large banks. These trends are consistent with increasing use of credit scoring models.Credit ; Credit scoring systems

Common learning

Consider two agents who learn the value of an unknown parameter by observing a sequence of private signals. The signals are independent and identically distributed across time but not necessarily across agents. We show that when each agent's signal space is finite, the agents will commonly learn the value of the parameter, that is, that the true value of the parameter will become approximate common knowledge. The essential step in this argument is to express the expectation of one agent's signals, conditional on those of the other agent, in terms of a Markov chain. This allows us to invoke a contraction mapping principle ensuring that if one agent's signals are close to those expected under a particular value of the parameter, then that agent expects the other agent's signals to be even closer to those expected under the parameter value. In contrast, if the agents' observations come from a countably infinite signal space, then this contraction mapping property fails. We show by example that common learning can fail in this case

The determinants of the wealth effects of banks' expanded securities powers

After several unsuccessful attempts by Congress to repeal Glass-Steagall restrictions on banks, the Federal Reserve more than doubled the revenue that commercial banking organizations' securities subsidiaries may earn from certain securities activities. The wealth effects associated with this event for a sample of publicly traded banking organizations are examined. We find evidence that indicates the revenue limit resulted in a less-than-optimal mix of activities for securities subsidiaries. However, subsequent merger activity that could have been generated by the revenue increase was not viewed favorably by investors.Securities

Approximate Sparse Recovery: Optimizing Time and Measurements

An approximate sparse recovery system consists of parameters $k,N$, an $m$-by-$N$ measurement matrix, $\Phi$, and a decoding algorithm, $\mathcal{D}$. Given a vector, $x$, the system approximates $x$ by $\widehat x =\mathcal{D}(\Phi x)$, which must satisfy $\| \widehat x - x\|_2\le C \|x - x_k\|_2$, where $x_k$ denotes the optimal $k$-term approximation to $x$. For each vector $x$, the system must succeed with probability at least 3/4. Among the goals in designing such systems are minimizing the number $m$ of measurements and the runtime of the decoding algorithm, $\mathcal{D}$. In this paper, we give a system with $m=O(k \log(N/k))$ measurements--matching a lower bound, up to a constant factor--and decoding time $O(k\log^c N)$, matching a lower bound up to $\log(N)$ factors. We also consider the encode time (i.e., the time to multiply $\Phi$ by $x$), the time to update measurements (i.e., the time to multiply $\Phi$ by a 1-sparse $x$), and the robustness and stability of the algorithm (adding noise before and after the measurements). Our encode and update times are optimal up to $\log(N)$ factors

Society and Science: Ancient Astronomy.

Astronomy is the oldest scientific field in human history. As such, it is linked heavily with Ancient History as a central part of understanding, scientific development and cultural appreciation in the world of antiquity. The goal of this thesis will be to investigate the importance of the ancient astronomers, their discoveries, the differences in cultural understandings of the universe due to environmental and political reasons, planets and the cosmos, and the impacts their discoveries had on the ancient world. Primary sources will be various writings and documents by ancient astronomers and philosophers such as Eratosthenes, Hipparchus, Plato and the Pythagorean concept. Also to be consulted will be ancient documents that explain the cosmos and nature of this universe from the cultural aspect of the Egyptian, Maya, Mesopotamian, and Hellenistic civilizations. Secondary sources will a variety of modern historical and scientific writings about the history of astronomy. These will include Astronomy of the Ancients by Kenneth Brecher and Michael Feirtag, Ancient Egyptian Science by Marshall Clagett, and A History of The Ancient Mathematical Astronomy by Neugebauer. Also included will be modern sources that explain astronomical events and notions