9,119 research outputs found
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 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 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 is a global quantity that can be
efficiently compute using a global counter in 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 binary, uniform, parallel and deterministic
cellular automata applied in succession for a total of 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
at tree level can be reliably estimated. In general, it
lies in the range . Short-distance QCD
penguins and penguin annihilation are calculated using QCD factorization. Their
effects are generally small, especially for 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
and in which is absent. The maximal
, the direct CP asymmetry difference between the
above-mentioned two modes, allowed in the SM is around -0.25%, more than
away from the current world average of .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
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