Inverse Avalanches On Abelian Sandpiles

A simple and computationally efficient way of finding inverse avalanches for Abelian sandpiles, called the inverse particle addition operator, is presented. In addition, the method is shown to be optimal in the sense that it requires the minimum amount of computation among methods of the same kind. The method is also conceptually nice because avalanche and inverse avalanche are placed in the same footing.Comment: 5 pages with no figure IASSNS-HEP-94/7

Phase Diagram Of The Biham-Middleton-Levine Traffic Model In Three Dimensions

We study numerically the behavior of the Biham-Middleton-Levine traffic model in three dimensions. Our extensive numerical simulations show that the phase diagram for this model in three dimensions is markedly different from that in one and two dimensions. In addition to the full speed moving as well as the completely jamming phases, whose respective average asymptotic car speeds $$ equal one and zero, we observe an extensive region of car densities $\rho$ with a low but non-zero average asymptotic car speed. The transition from this extensive low average asymptotic car speed region to the completely jamming region is at least second order. We argue that this low speed region is a result of the formation of a spatially-limited-extended percolating cluster. Thus, this low speed phase is present in $n > 3$ dimensional Biham-Middleton-Levine model as well.Comment: Minor clarifications, 1 figure adde

Statistics Of The Burst Model At Super-critical Phase

We investigate the statistics of a model of type-I X-ray burst [Phys. Rev. E, {\bf 51}, 3045 (1995)] in its super-critical phase. The time evolution of the burnable clusters, places where fire can pass through, is studied using simple statistical arguments. We offer a simple picture for the time evolution of the percentage of space covered by burnable clusters. A relation between the time-average and the peak percentage of space covered by burnable clusters is also derived.Comment: 11 Pages in Revtex 3.0. Two figures available by sending request to [email protected]

Parity Problem With A Cellular Automaton Solution

The parity of a bit string of length $N$ is a global quantity that can be efficiently compute using a global counter in ${O} (N)$ time. But is it possible to find the parity using cellular automata with a set of local rule tables without using any global counter? Here, we report a way to solve this problem using a number of $r=1$ binary, uniform, parallel and deterministic cellular automata applied in succession for a total of ${O} (N^2)$ time.Comment: Revtex, 4 pages, final version accepted by Phys.Rev.

Enhancing Organizational Performance by Knowledge Sharing

Knowledge management can be regarded as one of the key processes of organizational learning. It is well accepted that learning organizations can enhance their capability and hence competitiveness and performance through learning. Recognizing the importance of knowledge management, researchers are interested in exploring knowledge sharing activities because such activities are the cornerstone of other knowledge management activities. It is argued that a fundamental purpose of managing knowledge is to establish a shared context in organizations. As such, what factors affect interpersonal knowledge sharing and how they affect interpersonal knowledge sharing in organizations are critical and worth noting. A preliminary model from an organizational behavior perspective is proposed which will serve as the framework for further study

THE CENTER OF VACCINE CONTROVERSY: WI-38 CELLS

Throughout history, there exists no bigger killer than disease. For centuries, families have fought against sickness and death, and ancient culture has spent thousands of years developing their own methods for healing. In the most recent years, the field of medicine has greatly expanded, allowing for cures and medicine to be greatly distributed to the general public. Millions of lives have been saved, and today society can live without fear of lurking diseases snatching away loved ones with a blink of an eye. This senior thesis focuses on the development of vaccines made from the WI-38 cell line. This cell line was developed from a 1960s aborted Swedish fetus, which marks the source of controversy. Today, this cell line is primarily used in the MMR (mumps, measles, and rubella), varicella (chickenpox), hepatitis A, and a certain rabies vaccine. However, because of the development origin of the vaccine virus, many people refuse to take these life-saving vaccines because they contain the cells of an abortion. So here lies the question – was the use of this cell line necessary, and should they be continued to be used to immunize millions of children and infants every year? With thorough research and careful analysis, the answer is yes. The WI-38 cell line was indeed a necessary foundation in the vaccines’ development. This paper explores the struggles, the disasters, and the controversies that surround the vaccines made from this cell line, and ultimately narrows down on two main facts supporting the usage of these cells: versatility and abundance, and safety. Thoroughly conducted research has proved that the WI-38 cell line to be a safe and reliable method of vaccine growth, which has only been supported by the impact that the cells have left on human history. According to researchers, the WI-38 cells has treated and prevented an estimated 198 million cases of polio, measles, mumps, rubella, varicella, rabies, and hepatitis A in the U.S alone. These cells have offered hope to desperate families, and promises security to those living today. The WI-38 cell line has been a center of controversy ever since it was established. However, when one delves deeper into the research and history behind these cells, they realize that these cells are needed in the development of life-saving vaccines. The vaccines developed from these cells have saved and ensured millions of children’s lives for the past sixty years, and will continue being a life-saving source to years to come

Destabilization control of a chaotic motor for industrial mixers

Industrial mixers are among the most expensive and ineffective equipment in food, drug, chemical and semiconductor industries. Chaotic mixing has been proposed to improve the energy efficiency and the degree of homogeneity using either mechanical or electrical means. This paper presents the destabilization control of the DC motor (the agitator) for industrial mixing processes through the pole placement technique which is more analytically accessible compared with time-delay control proposed before. Theoretical derivation and computer simulation are provided to illustrate the controllable chaotic motion. Moreover, the mixing effectiveness is experimentally verified by an acid-base neutralization reaction. © 2005 IEEE.published_or_final_versio

Direct CP violation in two-body hadronic charmed meson decays

Motivated by the recent observation of CP violation in the charm sector by LHCb, we study direct CP asymmetries in the standard model (SM) for the singly Cabibbo-suppressed two-body hadronic decays of charmed mesons using the topological-diagram approach. In this approach, the magnitude and the phase of topological weak annihilation amplitudes which arise mainly from final-state rescattering can be extracted from the data. Consequently, direct CP asymmetry $a_{dir}^{\rm (tree)}$ at tree level can be reliably estimated. In general, it lies in the range $10^{-4}<a_{dir}^{\rm (tree)}<10^{-3}$. Short-distance QCD penguins and penguin annihilation are calculated using QCD factorization. Their effects are generally small, especially for $D\to VP$ modes. Since weak penguin annihilation receives long-distance contributions from the color-allowed tree amplitude followed by final-state rescattering, it is expected to give the dominant contribution to the direct CP violation in the decays $D^0\to K^+K^-$ and $D^0\to \pi^+\pi^-$ in which $a_{dir}^{\rm (tree)}$ is absent. The maximal $\Delta a_{CP}^{\rm dir}$, the direct CP asymmetry difference between the above-mentioned two modes, allowed in the SM is around -0.25%, more than $2\sigma$ away from the current world average of $-(0.645\pm 0.180)$.Comment: 19 pages, 2 figures; typos correcte

Design of permanent magnets to chaoize PM synchronous motors for industrial mixers

In this paper, the permanent magnet synchronous motor (PMSM) is used as the agitator because of its inherent advantages of high power density, high efficiency and maintenance-free operation. The effect of PM sizing on the performance of the chaotic motion of PMSM is discussed. Simulation as well as experimental results of the proposed mixer is presented to verify the effectiveness.published_or_final_versio