Methodologies for the design of LCC voltage-output resonant converters

Abstract: The paper presents five structured design methodologies for third-order LCC voltage output resonant converters. The underlying principle of each technique is based on an adaptation of a FMA equivalent circuit that accommodates the nonlinear behaviour of the converter. In contrast to previously published methods, the proposed methodologies explicitly incorporate the effects of the transformer magnetising inductance. Furthermore, a number of the methodologies allow the resonant-tank components to be specified at the design phase, thereby facilitating the use of standard off-the-shelf components. A procedure for sizing the filter capacitor is derived, and the use of error mapping, to identify parameter boundaries and provide the designer with a qualitative feel for the accuracy of a proposed converter design, is explored

An Innovative On-Board Processor for Lightsats

The Applied Physics Laboratory has developed a flightworthy custom microprocessor that increases capability and reduces development costs of lightsat science instruments. This device, which APL calls the FRISC (Forth Reduced Instruction Set Computer), directly executes the high level language called Forth, which is ideally suited to the multitasking control and data processing environment of a spaceborne instrument processor. The FRlSC (which is available commercially as the SC32) will be flown as the on-board processor in the Magnetic Field Experiment on the Swedish Space Corporations’ Freja satellite. APL has achieved a significant increase in on-board processing capability with no increase in cost when compared to the magnetometer instrument on Freja\u27s predecessor, the Viking satellite. These advantages are attributable to the high instruction execution rate, reduced software development effort, and shortened system integration time made possible by the nature of the microprocessor and the Forth language

Twenty eight years of ICP Vegetation: an overview of its activities

Here we look back at the activities and achievements in the 28 years of the International Cooperative Programme on the Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation). The ICP Vegetation is a subsidiary body of the Working Group on Effects of the UNECE Convention on Long-range Transboundary Air Pollution (LTRAP), established in 1979. An important role of the ICP Vegetation is to provide evidence for air pollution impacts on vegetation in support of policy development and review of the LRTAP Convention and its Protocols. The activities and participation in the ICP Vegetation have grown over the years. The main activities include: • Collate evidence of ozone impacts on vegetation, assess spatial patterns and temporal trends across Europe; • Develop dose-response relationships, establish critical levels for vegetation and provide European risk maps of ozone impacts; • Reviewing the literature on ozone impacts on vegetation and produce thematic scientific reports and policy-relevant brochures; • Determine spatial patterns and temporal trends of heavy metals, nitrogen and persistent organic pollutants concentrations in mosses as a biomonitoring tool of atmospheric deposition of these compounds

The Sexual health of pupils in years 4 to 6 of primary schools in rural Tanzania

Background/objectives: There is an urgent need for effective interventions to improve the sexual and\ud reproductive health of adolescents. Reliable data on the sexual health of adolescents are needed to guide\ud the development of such interventions. The aim was to describe the sexual health of pupils in years 4 to 6 of\ud 121 rural primary schools in north western Tanzania, before the implementation of an innovative sexual\ud health intervention in 58 of the schools.\ud Methods: A cross sectional survey of primary school pupils in rural Tanzania was carried out. The study\ud population comprised pupils registered in years 4 to 6 of 121 primary schools in 20 rural communities in\ud 1998. Basic demographic information was collected from all pupils seen. Those born before 1 January\ud 1985 (aged approximately 14 years and over) were invited to participate in the survey, and asked about\ud their knowledge and attitudes towards sexual health issues, and their sexual experience. A urine specimen\ud was requested and tested for HIV, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and, for\ud females, pregnancy.\ud Results: 9283 pupils born before 1 January 1985 were enrolled and provided demographic information\ud and a urine sample. Male pupils were significantly older than females (mean age 15.5 years v 14.8 years,\ud p,0.001), but all other demographic characteristics were similar between the sexes. 14 (0.2%) of the\ud enrolled pupils (four male and 10 female) were HIV positive, 83 (0.9%) were positive for CT, and 12\ud (0.1%) for NG. 32 female pupils (0.8%) were positive by pregnancy test. Sexual experience was reported\ud by one fifth of primary school girls, and by almost half of boys. Only 45/114 (39%) girls with biological\ud markers of sexual activity reported having had sex.\ud Conclusions: HIV, CT, NG, and pregnancy were present though at relatively low levels among pupils in\ud years 4 to 6 of primary school. A high proportion of pupils with a biological marker of sexual activity\ud denied ever having had sex. Alternative ways of collecting sensitive data about the sexual behaviour of\ud school pupils should be explored

Correlation of pharmacogenetic genotype with steady‐state metabolic profiles of tamoxifen: effect on active metabolite concentrations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110007/1/cptclpt2003216.pd

Pharmacogenetic variants influence tamoxifen's estrogenic effect on bone density

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109849/1/cptclpt200586.pd

Knowledge engineering with image data in real-world settings

We report on experiences in adding ML-trained visual recognition modules to a human-oriented image semantic annotation tool which creates RDF descriptions of images and scene contents. We conclude that ML cannot replace expert humans but can aid them in various ways, some unexpected. Semantic markup systems can be to designed to align human and machine blind spots. Finally, we briefly outline directions for future work

Emotional engagements predict and enhance social cognition in young chimpanzees

Social cognition in infancy is evident in coordinated triadic engagements, that is, infants attending jointly with social partners and objects. Current evolutionary theories of primate social cognition tend to highlight species differences in cognition based on human-unique cooperative motives. We consider a developmental model in which engagement experiences produce differential outcomes. We conducted a 10-year-long study in which two groups of laboratory-raised chimpanzee infants were given quantifiably different engagement experiences. Joint attention, cooperativeness, affect, and different levels of cognition were measured in 5- to 12-month-old chimpanzees, and compared to outcomes derived from a normative human database. We found that joint attention skills significantly improved across development for all infants, but by 12 months, the humans significantly surpassed the chimpanzees. We found that cooperativeness was stable in the humans, but by 12 months, the chimpanzee group given enriched engagement experiences significantly surpassed the humans. Past engagement experiences and concurrent affect were significant unique predictors of both joint attention and cooperativeness in 5- to 12-month-old chimpanzees. When engagement experiences and concurrent affect were statistically controlled, joint attention and cooperation were not associated. We explain differential social cognition outcomes in terms of the significant influences of previous engagement experiences and affect, in addition to cognition. Our study highlights developmental processes that underpin the emergence of social cognition in support of evolutionary continuity

Cutoff for the Ising model on the lattice

Introduced in 1963, Glauber dynamics is one of the most practiced and extensively studied methods for sampling the Ising model on lattices. It is well known that at high temperatures, the time it takes this chain to mix in $L^1$ on a system of size $n$ is $O(\log n)$. Whether in this regime there is cutoff, i.e. a sharp transition in the $L^1$-convergence to equilibrium, is a fundamental open problem: If so, as conjectured by Peres, it would imply that mixing occurs abruptly at $(c+o(1))\log n$ for some fixed $c>0$, thus providing a rigorous stopping rule for this MCMC sampler. However, obtaining the precise asymptotics of the mixing and proving cutoff can be extremely challenging even for fairly simple Markov chains. Already for the one-dimensional Ising model, showing cutoff is a longstanding open problem. We settle the above by establishing cutoff and its location at the high temperature regime of the Ising model on the lattice with periodic boundary conditions. Our results hold for any dimension and at any temperature where there is strong spatial mixing: For $\Z^2$ this carries all the way to the critical temperature. Specifically, for fixed $d\geq 1$, the continuous-time Glauber dynamics for the Ising model on $(\Z/n\Z)^d$ with periodic boundary conditions has cutoff at $(d/2\lambda_\infty)\log n$, where $\lambda_\infty$ is the spectral gap of the dynamics on the infinite-volume lattice. To our knowledge, this is the first time where cutoff is shown for a Markov chain where even understanding its stationary distribution is limited. The proof hinges on a new technique for translating $L^1$ to $L^2$ mixing which enables the application of log-Sobolev inequalities. The technique is general and carries to other monotone and anti-monotone spin-systems.Comment: 34 pages, 3 figure

New experimental data for the decays ϕ→μ+μ−\phi\to\mu^+\mu^- and ϕ→π+π−\phi\to\pi^+\pi^- from SND detector

The processes $e^+e^-\to\mu^+\mu^-$ and $e^+e^-\to\pi^+\pi^-$ have been studied with SND detector at VEPP-2M $e^+e^-$ collider in the vicinity of $\phi(1020)$ resonance. The branching ratios $B(\phi\to\mu^+\mu^-)=(3.30\pm 0.45\pm 0.32)\times 10^{-4}$ and $B(\phi\to\pi^+\pi^-)=(0.71\pm 0.11\pm 0.09)\times 10^{-4}$ were obtained.Comment: 5 pages, 4 figures, talk given at 8th International Conference on Hadron Spectroscopy (HADRON 99), Beijing, China, 24-28 Aug 199