Anti-multipath digital signal detector

Detector operates in conjunction with radio frequency portion of receiver to detect digital signals transmitted in known modulation formats. Signal is constructed by assigning known and distinct modulation waveforms to sequence of message symbols. It reconstructs transmitted digital sequence with minimum probability that any reconstructed digit will be in error

Mathematical models for chemotaxis and their applications in self-organisation phenomena

Chemotaxis is a fundamental guidance mechanism of cells and organisms, responsible for attracting microbes to food, embryonic cells into developing tissues, immune cells to infection sites, animals towards potential mates, and mathematicians into biology. The Patlak-Keller-Segel (PKS) system forms part of the bedrock of mathematical biology, a go-to-choice for modellers and analysts alike. For the former it is simple yet recapitulates numerous phenomena; the latter are attracted to these rich dynamics. Here I review the adoption of PKS systems when explaining self-organisation processes. I consider their foundation, returning to the initial efforts of Patlak and Keller and Segel, and briefly describe their patterning properties. Applications of PKS systems are considered in their diverse areas, including microbiology, development, immunology, cancer, ecology and crime. In each case a historical perspective is provided on the evidence for chemotactic behaviour, followed by a review of modelling efforts; a compendium of the models is included as an Appendix. Finally, a half-serious/half-tongue-in-cheek model is developed to explain how cliques form in academia. Assumptions in which scholars alter their research line according to available problems leads to clustering of academics and the formation of "hot" research topics.Comment: 35 pages, 8 figures, Submitted to Journal of Theoretical Biolog

Saskatchewan Wheat Pool

In 1996, Saskatchewan Wheat Pool embarked on a strategy for growth and diversification by significantly expanding its asset base. This expansion brought with it many new costs, especially new fixed costs such as interest and depreciation. They failed to achieve the new revenues needed to support the higher fixed costs and consequently, found themselves in financial distress. In 2000, Mayo Schmidt was brought in as CEO to turn the company back to profitability. His strategy was to sell off all non-core assets and focus on the core businesses that built the company; grain handling and supplying farm inputs. 2004 would be a crucial year for Saskatchewan Wheat Pool.Publicly traded co-operative, Business strategy, Financial distress, Agribusiness, Crop Production/Industries,

Canadian Farmers' Adaptation to Declining Commodity Prices

The five major agricultural producing provinces are compared in terms of farm labour and management incomes, return on investment to farm capital, total farm family income, and farm family net worth. In each province, comparisons are made with non-farm incomes, investment returns and net worth levels. The results show that farm family incomes in Canada are much better today than 30 years ago, returns on farmland investment are very comparable to average stock market returns, and average farm family net worth is significantly higher than the average for all families. The conclusion is that Canadian farmers have adapted well to declining commodity prices mainly by being adapters of and investors in new technologies, allowing them to increase farm size (increased cost efficiencies) and by diversifying their income sources to include more off-farm income.Farm Labour and Management Income, Return on Invested Farm Capital, Real Commodity Prices, Farm Family Income, Off-Farm Employment, Farm Family Net Worth, Farm Management, Labor and Human Capital,

Bounds for the zeros of polynomials Final report, 1 Apr. 1966 - 30 Sep. 1967

Theorem application to companion matrix of polynomia

Efficient Investment in Saskatchewan Farmland

Farm Management,

A study to determine the applicability of noise abatement approach procedures to McDonnell Douglas Aircraft

Analyses of McDonnell Douglas DC-8, DC-9, and DC-10 jet transports were conducted to investigate the applicability of two segment approach noise abatement procedures to these airplanes. All models had the required glide slope capability at the certified landing flap settings. The DC-8 models would probably be limited to an upper segment glide slope of 5.5 degrees and would probably not be suitable for the two segment procedure in icing conditions. The DC-8 would not be compatible with this procedure at a reduced landing flap setting. The feasibility of installing a two segment approach system in the Douglas-built fleet of commercial jet transports from a hardware viewpoint is discussed. The candidate system consists of a two segment computer plus the necessary peripheral equipment interfaced with the existing autopilot and associated avionics. The required modifications and additions to existing equipment are described and the attendant costs estimated. Potential problems which may be encountered are also discussed

Beyond the Rayleigh scattering limit in high-Q silicon microdisks: theory and experiment

Using a combination of resist reflow to form a highly circular etch mask pattern and a low-damage plasma dry etch, high-quality-factor silicon optical microdisk resonators are fabricated out of silicon-on-insulator (SOI) wafers. Quality factors as high as Q = 5×10^6 are measured in these microresonators, corresponding to a propagation loss coefficient as small as α ~ 0.1 dB/cm. The different optical loss mechanisms are identified through a study of the total optical loss, mode coupling, and thermally-induced optical bistability as a function of microdisk radius (5-30 µm). These measurements indicate that optical loss in these high-Q microresonators is limited not by surface roughness, but rather by surface state absorption and bulk free-carrier absorption

Self-induced optical modulation of the transmission through a high-Q silicon microdisk resonator

Direct time-domain observations are reported of a low-power, self-induced modulation of the transmitted optical power through a high-Q silicon microdisk resonator. Above a threshold input power of 60 μW the transmission versus wavelength deviates from a simple optical bistability behavior, and the transmission intensity becomes highly oscillatory in nature. The transmission oscillations are seen to consist of a train of sharp transmission dips of width approximately 100 ns and period close to 1 μs. A model of the system is developed incorporating thermal and free-carrier dynamics, and is compared to the observed behavior. Good agreement is found, and the self-induced optical modulation is attributed to a nonlinear interaction between competing free-carrier and phonon populations within the microdisk

Accurate measurement of scattering and absorption loss in microphotonic devices

We present a simple measurement and analysis technique to determine the fraction of optical loss due to both radiation (scattering) and linear absorption in microphotonic components. The method is generally applicable to optical materials in which both nonlinear and linear absorption are present and requires only limited knowledge of absolute optical power levels, material parameters, and the structure geometry. The technique is applied to high-quality-factor (Q=1×10^6 to Q=5×10^6) silicon-on-insulator (SOI) microdisk resonators. It is determined that linear absorption can account for more than half of the total optical loss in the high-Q regime of these devices