Toeplitz algebras and spectral results for the one-dimensional Heisenberg model

We determine the structure of the spectrum and obtain non-propagation estimates for a class of Toeplitz operators acting on a subset of the lattice $\Z^N$. This class contains the Hamiltonian of the one-dimensional Heisenberg model.Comment: 13 page

Conflicts on Export Controls and Defense Trade Matters

export controls and defense--United States, export controls and defense--Canad

Conflicts on Export Controls and Defense Trade Matters

export controls and defense--United States, export controls and defense--Canad

Collection and rejuvenation of rare/scarce plants for the nursey stock industry.

End of Project ReportThe main objectives of this project were: • Location of scarce/rare or new plants of high garden merit with tolerance to disease and pests • Rejuvenation. • Conservation of rejuvenated plants in the original gardens from which they were collected, at the Kinsealy Research Centre and in other selected locations. • Evaluation of the collection for a variety of uses – foliage, patio etc. over a range of different conditions and locations. • Plant identification. • Commercialisation of these plants by the trade to extend their range of plants.European Union Structural Funds (EASSF

Internal Strategies for Assessing Organizational Communication Channel Effectiveness

Evolving communication technology, the increased volume of information needed by businesses and the intensified competitive environment have made internal company communication more critical to business success. The purpose of this multiple case study was to explore strategies for assessing the effectiveness of internal communication channels used by managers and leaders of three law firms in the Commonwealth of Virginia. The participating firms were recognized by their peers as being exceptionally well managed. Data from interviews and company documents were analyzed through the conceptual lens of channel expansion theory and the use of software coding to identify patterns and themes. Three important themes emerged: informal assessment strategies, indirect assessment strategies, and efficient versus timely assessments. The first theme suggested the effectiveness of an informal assessment strategy, depending on the size and complexity of the organization. The second theme reflected the effectiveness of an indirect assessment for organizations that lack the resources to support a more direct and specific assessment process. The third theme reflected the participants’ perceptions of informal and indirect assessments may be more efficient, the feedback from the assessments are often less timely. Managers may consider these themes in formulating communication policies. Small professional service firms, such as legal firms, provide important services to individuals, families, and businesses in their community

CAPS Simulation Environment Development

The final design for an effective Comet/Asteroid Protection System (CAPS) will likely come after a number of competing designs have been simulated and evaluated. Because of the large number of design parameters involved in a system capable of detecting an object, accurately determining its orbit, and diverting the impact threat, a comprehensive simulation environment will be an extremely valuable tool for the CAPS designers. A successful simulation/design tool will aid the user in identifying the critical parameters in the system and eventually allow for automatic optimization of the design once the relationships of the key parameters are understood. A CAPS configuration will consist of space-based detectors whose purpose is to scan the celestial sphere in search of objects likely to make a close approach to Earth and to determine with the greatest possible accuracy the orbits of those objects. Other components of a CAPS configuration may include systems for modifying the orbits of approaching objects, either for the purpose of preventing a collision or for positioning the object into an orbit where it can be studied or used as a mineral resource. The Synergistic Engineering Environment (SEE) is a space-systems design, evaluation, and visualization software tool being leveraged to simulate these aspects of the CAPS study. The long-term goal of the SEE is to provide capabilities to allow the user to build and compare various CAPS designs by running end-to-end simulations that encompass the scanning phase, the orbit determination phase, and the orbit modification phase of a given scenario. Herein, a brief description of the expected simulation phases is provided, the current status and available features of the SEE software system is reported, and examples are shown of how the system is used to build and evaluate a CAPS detection design. Conclusions and the roadmap for future development of the SEE are also presented