On the stability of randomly sampled systems

Stability of randomly sampled linear systems studied by Liapunov function metho

Wangari Maathai: Righteous Leader of Environmental and Social Change

This Africentric historical inquiry introduces Wangari Maathai, 2004 Nobel Peace Prize recipient, as a visionary adult educator and leader of the liberatory environmental movement known as The Green Belt Movement. The study describes Maathai’s philosophy and how it informed her leadership of adult education for environmental, political, and social change

Environmental projects. Volume 2: Underground storage tanks compliance program

Six large parabolic dish antennas are located at the Goldstone Deep Space Communications Complex north of Barstow, California. As a large-scale facility located in a remote, isolated desert region, the GDSCC operations require numerous on-site storage facilities for gasoline, diesel and hydraulic oil. These essential fluids are stored in underground storage tanks (USTs). Because USTs may develop leaks with the resultant seepage of their hazardous contents into the surrounding soil, local, State and Federal authorities have adopted stringent regulations for the testing and maintenance of USTs. Under the supervision of JPL's Office of Telecommunications and Data Acquisition, a year-long program has brought 27 USTs at the Goldstone Complex into compliance with Federal, State of California and County of San Bernadino regulations. Of these 27 USTs, 15 are operating today, 11 have been temporary closed down, and 1 abandoned in place. In 1989, the 15 USTs now operating at the Goldstone DSCC will be replaced either by modern, double-walled USTs equipped with automatic sensors for leak detection, or by above ground storage tanks. The 11 inactivated USTs are to be excavated, removed and disposed of according to regulation

Values-based ethical leadership: Developing leaders with integrity

Values-based leadership and ethical decision-making are hot topics. However, the expectations and frameworks surrounding these characteristics are often unclear. The purpose of this article is to analyze values-based, ethical leadership by defining values and ethics, summarizing values-based ethical decision-making frameworks, and examining how leadership educators (scholars and practitioners) can develop students who lead with integrity

Linear interference and the initiation of extratropical stratosphere-troposphere interactions

Vertical fluxes of wave activity from the troposphere to the stratosphere correlate negatively with the Northern Annular Mode (NAM) index in the stratosphere and subsequently in the troposphere. Recent studies have shown that stratospheric NAM variability is also negatively correlated with the amplitude of the wave pattern coherent with the large-scale climatological stationary wavefield; when the climatological stationary wavefield is amplified or attenuated, the stratospheric jet correspondingly weakens or strengthens. Here we quantify the importance of this linear interference effect in initiating stratosphere-troposphere interactions by performing a decomposition of the vertical wave activity flux using reanalysis data. The interannual variability in vertical wave activity flux in both the Northern and Southern Hemisphere extratropics is dominated by linear interference of quasi-stationary waves during the season of strongest stratosphere-troposphere coupling. Composite analysis of anomalous vertical wave activity flux events reveals the significant role of linear interference and shows that "linear" and "nonlinear" events are essentially independent. Linear interference is the dominant contribution to the vertical wave activity flux anomalies preceding displacement stratospheric sudden warmings (SSWs) while split SSWs are preceded by nonlinear wave activity flux anomalies. Wave activity variability controls the timing of stratospheric final warmings, and this variability is shown to be dominated by linear interference, particularly in the Southern Hemisphere. The persistence of the linear interference component of the vertical wave activity flux, corresponding to persistent constructive or destructive interference between the wave-1 component of climatological stationary wave and the wave anomaly, may help improve wintertime extratropical predictability

Theorizing embodied, collective and societal learning through prefigurative social movements

This paper theorizes adult learning as a multi-leveled, emergent process of interactions between individuals, groups, and societal systems. We theorize from the context of prefigurative social movements that are enacting values of direct democracy, solidarity economics, and equity. We analyze Occupy encampments as sites in which individuals, movement groups, and society learn as complex adaptive systems. The theorizing of these learning processes has implications for adult education theory, research, and practice

A robust empirical seasonal prediction of winter NAO and surface climate

A key determinant of winter weather and climate in Europe and North America is the North Atlantic Oscillation (NAO), the dominant mode of atmospheric variability in the Atlantic domain. Skilful seasonal forecasting of the surface climate in both Europe and North America is reflected largely in how accurately models can predict the NAO. Most dynamical models, however, have limited skill in seasonal forecasts of the winter NAO. A new empirical model is proposed for the seasonal forecast of the winter NAO that exhibits higher skill than current dynamical models. The empirical model provides robust and skilful prediction of the December-January-February (DJF) mean NAO index using a multiple linear regression (MLR) technique with autumn conditions of sea-ice concentration, stratospheric circulation, and sea-surface temperature. The predictability is, for the most part, derived from the relatively long persistence of sea ice in the autumn. The lower stratospheric circulation and sea-surface temperature appear to play more indirect roles through a series of feedbacks among systems driving NAO evolution. This MLR model also provides skilful seasonal outlooks of winter surface temperature and precipitation over many regions of Eurasia and eastern North America

Bellman equations for optimal feedback control of qubit states

Using results from quantum filtering theory and methods from classical control theory, we derive an optimal control strategy for an open two-level system (a qubit in interaction with the electromagnetic field) controlled by a laser. The aim is to optimally choose the laser's amplitude and phase in order to drive the system into a desired state. The Bellman equations are obtained for the case of diffusive and counting measurements for vacuum field states. A full exact solution of the optimal control problem is given for a system with simpler, linear, dynamics. These linear dynamics can be obtained physically by considering a two-level atom in a strongly driven, heavily damped, optical cavity.Comment: 10 pages, no figures, replaced the simpler model in section

Improving palliative treatment of patients with non-operable cancer of the oesophagus: training doctors and nurses in the use of self-expanding metal stents (SEMS) in Malawi

Cancer of the oesophagus is the 6th most common cancer in Malawi. Nationwide only three hospitals are able to perform oesophagectomies, and there is no radiotherapy- or chemotherapy available. Owing to late presentation of the patients (sometimes in combination with co-morbidities such as HIV/AIDS or tuberculosis) the vast majority of patients are not suitable for surgery. Self-expanding metal stents (SEMS) of the oesophagus provide a suitable palliative option to improve the quality of life  for patients. This project took a nationwide approach, raising funds for both technical equipment and training of endoscopists and nursing staff throughout Malawi