Semiconductor Noise

Contains a report on a research project

Semiconductor Noise

Contains research objectives and reports on two research projects

Stochastic nonlinear differential equation generating 1/f noise

Starting from the simple point process model of 1/f noise we derive a stochastic nonlinear differential equation for the signal exhibiting 1/f noise in any desirably wide range of frequency. A stochastic differential equation (the general Langevin equation with a multiplicative noise) that gives 1/f noise is derived for the first time. The solution of the equation exhibits the power-law distribution. The process with 1/f noise is demonstrated by the numerical solution of the derived equation with the appropriate restriction of the diffusion of the signal in some finite interval.Comment: 3 figure

Semiconductor Noise

Contains reports on four research projects

Electrodynamics of Moving Media

Contains reports on two research projects.Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 36-039-AMC-03200(E

Electrical and Noise Characteristics of Graphene Field-Effect Transistors: Ambient Effects and Noise Sources

We fabricated a large number of single and bilayer graphene transistors and carried out a systematic experimental study of their low-frequency noise characteristics. A special attention was given to determining the dominant noise sources in these devices and the effect of aging on the current-voltage and noise characteristics. The analysis of the noise spectral density dependence on the area of graphene channel showed that the dominant contributions to the low-frequency electronic noise come from the graphene layer itself rather than from the contacts. Aging of graphene transistors due to exposure to ambient for over a month resulted in substantially increased noise attributed to the decreasing mobility of graphene and increasing contact resistance. The noise spectral density in both single and bilayer graphene transistors either increased with deviation from the charge neutrality point or depended weakly on the gate bias. This observation confirms that the low-frequency noise characteristics of graphene transistors are qualitatively different from those of conventional silicon metal-oxide-semiconductor field-effect transistors.Comment: 26 pages with 8 figure

The Life of a Professor: Stress and Coping

The life of a professor is a balancing act, both professionally and personally. Professors must weigh the demands of research, publishing, teaching, and service with the requirements of their personal responsibilities. The purpose of this mixed-methods study was to explore the role of stress on the work-life balance of a professor. This study was conducted by an interdisciplinary research team and included participants from a wide-range of academic fields. A mixed-methods approach, utilizing an electronic survey composed of demographic questions, Likert-scale responses, and open-ended questions, yielded data related to the benefits and challenges of being a professor from 31 states in the United States as well as from other countries. Structured interviews were then conducted to reveal the coping methods of the participants. In addition, this article incorporated embedded media in the form of audio sound bites and animated video, which provided the ‘voice’ of the faculty. The triangulated data revealed that lack of supports, both social and institutional, significantly increased the stress experienced by professors. Mechanisms for coping with stress that could be utilized by individual professors as well as institutional stress management strategies were discussed

Physical Electronics

Contains research objectives and reports on two research projects

Semiconductor Noise

Contains reports on five research projects

Diversity, competition, extinction: the ecophysics of language change

As early indicated by Charles Darwin, languages behave and change very much like living species. They display high diversity, differentiate in space and time, emerge and disappear. A large body of literature has explored the role of information exchanges and communicative constraints in groups of agents under selective scenarios. These models have been very helpful in providing a rationale on how complex forms of communication emerge under evolutionary pressures. However, other patterns of large-scale organization can be described using mathematical methods ignoring communicative traits. These approaches consider shorter time scales and have been developed by exploiting both theoretical ecology and statistical physics methods. The models are reviewed here and include extinction, invasion, origination, spatial organization, coexistence and diversity as key concepts and are very simple in their defining rules. Such simplicity is used in order to catch the most fundamental laws of organization and those universal ingredients responsible for qualitative traits. The similarities between observed and predicted patterns indicate that an ecological theory of language is emerging, supporting (on a quantitative basis) its ecological nature, although key differences are also present. Here we critically review some recent advances lying and outline their implications and limitations as well as open problems for future research.Comment: 17 Pages. A review on current models from statistical Physics and Theoretical Ecology applied to study language dynamic