Sequential decoding of trellis codes through ISI channels

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (leaves 56-57).by Patrick M. Maurer.M.S

CASE STUDY -- LEAN 94-01: Integrators, not Generalists Needed: A Case Study of IPD Teams at Textron Defense Systems

The following case study examines an organization that essentially eliminated traditional functional groups and assigned all employees to cross-functional product or process teams. Although the organizational and cultural change occurred throughout the enterprise, this case will focus primarily on the structure of teams and the management of skills and capabilities within the integrated product development (IPD) core process. In the IPD area, multi-disciplinary teams were established with the expectation that individuals would both retain their own area of expertise and broaden their understanding of the functional expertise of their fellow team members. In essence, team members were expected to become “integrators,” as opposed to “generalists.” Although a major cultural change has occurred over a two-year time period, the change to date is considered as only the first step in an evolutionary process. The transition of this organization from a traditional matrix with strong functional hierarchies to a team-based structure highlights a number of human resource implications, including team selection, performance evaluation and rewards, and career paths. The study will conclude with a summary of lessons learned and the applicability of such an organization to the defense aircraft industry

Remote Sub-Wavelength Addressing of Quantum Emitters with Chirped Pulses

We propose to use chirped pulses propagating near a bandgap to remotely address quantum emitters with sub-wavelength resolution. We introduce a particular family of chirped pulses that dynamically self-focus during their evolution in a medium with a quadratic dispersion relation. We analytically describe how the focusing distance and width of the pulse can be tuned through its initial parameters. We show that the interaction of such pulses with a quantum emitter is highly sensitive to its position due to effective Landau-Zener processes induced by the pulse chirping. Our results propose pulse engineering as a powerful control and probing tool in the field of quantum emitters coupled to structured reservoirs.Comment: 5+3 pages, 3+2 figure

Quantum Electrodynamics with a Nonmoving Dielectric Sphere: Quantizing Mie Scattering

We quantize the electromagnetic field in the presence of a nonmoving dielectric sphere in vacuum. The sphere is assumed to be lossless, dispersionless, isotropic, and homogeneous. The quantization is performed using normalized eigenmodes as well as plane-wave modes. We specify two useful alternative bases of normalized eigenmodes: spherical eigenmodes and scattering eigenmodes. A canonical transformation between plane-wave modes and normalized eigenmodes is derived. This formalism is employed to study the scattering of a single photon, coherent squeezed light, and two-photon states off a dielectric sphere. In the latter case we calculate the second-order correlation function of the scattered field, thereby unveiling the angular distribution of the Hong-Ou-Mandel interference for a dielectric sphere acting as a three-dimensional beam splitter. Our results are analytically derived for an arbitrary size of the dielectric sphere with a particular emphasis on the small-particle limit. This work sets the theoretical foundation for describing the quantum interaction between light and the motional, rotational and vibrational degrees of freedom of a dielectric sphere.Comment: 19 pages, 3 figure

Quantum Theory of Light Interaction with a Dielectric Sphere: Towards 3D Ground-State Cooling

We theoretically analyze the motional quantum dynamics of a levitated dielectric sphere interacting with the quantum electromagnetic field beyond the point-dipole approximation. To this end, we derive a Hamiltonian describing the fundamental coupling between photons and center-of-mass phonons, including Stokes and anti-Stokes processes, and the coupling rates for a dielectric sphere of arbitrary refractive index and size. We then derive the laser recoil heating rates and the information radiation patterns (the angular distribution of the scattered light that carries information about the center-of-mass motion) and show how to evaluate them efficiently in the presence of a focused laser beam, either in a running or a standing-wave configuration. This information is crucial to implement active feedback cooling of optically levitated dielectric spheres beyond the point-dipole approximation. Our results predict several experimentally feasible configurations and parameter regimes where optical detection and active feedback can simultaneously cool to the ground state the three-dimensional center-of-mass motion of dielectric spheres in the micrometer regime. Scaling up the mass of the dielectric particles that can be cooled to the center-of-mass ground state is not only relevant for testing quantum mechanics at large scales but also for current experimental efforts that search for new physics (e.g. dark matter) using optically levitated sensors.Comment: 16 + 12 pages, 8 + 4 figures, 1 tabl

Projected climate-induced faunal change in the western hemisphere

Climate change is predicted to be one of the greatest drivers of ecological change in the coming century. Increases in temperature over the last century have clearly been linked to shifts in species distributions. Given the magnitude of projected future climatic changes, we can expect even larger range shifts in the coming century. These changes will, in turn, alter ecological communities and the functioning of ecosystems. Despite the seriousness of predicted climate change, the uncertainty in climate-change projections makes it difficult for conservation managers and planners to proactively respond to climate stresses. To address one aspect of this uncertainty, we identified predictions of faunal change for which a high level of consensus was exhibited by different climate models. Specifically, we assessed the potential effects of 30 coupled atmosphere–ocean general circulation model (AOGCM) future-climate simulations on the geographic ranges of 2954 species of birds, mammals, and amphibians in the Western Hemisphere. Eighty percent of the climate projections based on a relatively low greenhouse-gas emissions scenario result in the local loss of at least 10% of the vertebrate fauna over much of North and South America. The largest changes in fauna are predicted for the tundra, Central America, and the Andes Mountains where, assuming no dispersal constraints, specific areas are likely to experience over 90% turnover, so that faunal distributions in the future will bear little resemblance to those of today

Chronic lymphocytic leukaemia: clinical-aetiological findings in 66 patients and their families

<p>Abstract</p> <p>Background</p> <p>Little is known about the aetiology of chronic lymphocytic leukaemia (CLL). The family medical history is a "genomic tool" capturing interactions of genetic susceptibility, shared environment and common behaviours.</p> <p>Methods</p> <p>A cohort of 66 consecutives patients with CLL (probands) was studied in a medical oncology practice (W.W.) from 1981 until 2005. A German version of the NCI medical history questionnaire for cancer aetiology was used. Familial clustering analysis was done by comparing the proportion of specific tumours in the first degree relatives of the CLL practice cohort with corresponding proportions of population-based cancer registry data.</p> <p>Results</p> <p>18 (41%) male and 5 (23%) female CLL probands had multiple malignancies, e.g. 2 meningiomas, 7 and 19 years after diagnosis of CLL. 46 (12%) first degree relatives had malignancies with an excess of CLL. Other conspicuous familial associations are CLL with malignancies of the upper GI tract (oesophagus, stomach) and of the nervous system.</p> <p>Conclusion</p> <p>1. Chronic lymphocytic leukaemia clusters in some families like any other disease. Predisposition genes should be searched. 2. Cancer prevention and early detection should be continued in CLL patients because of their longevity and high risk for multiple malignancies. 3. The overrepresentation of upper GI malignancies in first degree relatives of CLL patients calls for targeted oesophago-gastroscopy screening studies.</p

ESC CardioMed

Reprinted with permission from: Eur Heart J. 2018; 19: 959–961Reprinted with permission from: Eur Heart J. 2018; 19: 959–96