The Impact of Galactic Disc Environment on Star-Forming Clouds

We explore the effect of different galactic disc environments on the properties of star-forming clouds through variations in the background potential in a set of isolated galaxy simulations. Rising, falling and flat rotation curves expected in halo dominated, disc dominated and Milky Way-like galaxies were considered, with and without an additional two-arm spiral potential. The evolution of each disc displayed notable variations that are attributed to different regimes of stability, determined by shear and gravitational collapse. The properties of a typical cloud were largely unaffected by the changes in rotation curve, but the production of small and large cloud associations was strongly dependent on this environment. This suggests that while differing rotation curves can influence where clouds are initially formed, the average bulk properties are effectively independent of the global environment. The addition of a spiral perturbation made the greatest difference to cloud properties, successfully sweeping the gas into larger, seemingly unbound, extended structures and creating large arm-interarm contrasts.Comment: Accepted to MNRAS on 3rd December, 201

Picture coding in viewdata systems

Viewdata systems in commercial use at present offer the facility for transmitting alphanumeric text and graphic displays via the public switched telephone network. An enhancement to the system would be to transmit true video images instead of graphics. Such a system, under development in Britain at present uses Differential Pulse Code Modulation (DPCM) and a transmission rate of 1200 bits/sec. Error protection is achieved by the use of error protection codes, which increases the channel requirement. In this thesis, error detection and correction of DPCM coded video signals without the use of channel error protection is studied. The scheme operates entirely at the receiver by examining the local statistics of the received data to determine the presence of errors. Error correction is then undertaken by interpolation from adjacent correct or previousiy corrected data. DPCM coding of pictures has the inherent disadvantage of a slow build-up of the displayed picture at the receiver and difficulties with image size manipulation. In order to fit the pictorial information into a viewdata page, its size has to be reduced. Unitary transforms, typically the discrete Fourier transform (DFT), the discrete cosine transform (DCT) and the Hadamard transform (HT) enable lowpass filtering and decimation to be carried out in a single operation in the transform domain. Size reductions of different orders are considered and the merits of the DFT, DCT and HT are investigated. With limited channel capacity, it is desirable to remove the redundancy present in the source picture in order to reduce the bit rate. Orthogonal transformation decorrelates the spatial sample distribution and packs most of the image energy in the low order coefficients. This property is exploited in bit-reduction schemes which are adaptive to the local statistics of the different source pictures used. In some cases, bit rates of less than 1.0 bit/pel are achieved with satisfactory received picture quality. Unlike DPCM systems, transform coding has the advantage of being able to display rapidly a picture of low resolution by initial inverse transformation of the low order coefficients only. Picture resolution is then progressively built up as more coefficients are received and decoded. Different sequences of picture update are investigated to find that which achieves the best subjective quality with the fewest possible coefficients transmitted

Report on Phase One: The social work curriculum.

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Probing neutrino and Higgs sectors in SU(2)1×SU(2)2×U(1)YSU(2)_1 \times SU(2)_2 \times U(1)_Y model with lepton-flavor non-universality

The neutrino and Higgs sectors in the \mbox{SU(2)}_1 \times \mbox{SU(2)}_2 \times \mbox{U(1)}_Y model with lepton-flavor non-universality are discussed. We show that active neutrinos can get Majorana masses from radiative corrections, after adding only new singly charged Higgs bosons. The mechanism for generation of neutrino masses is the same as in the Zee models. This also gives a hint to solving the dark matter problem based on similar ways discussed recently in many radiative neutrino mass models with dark matter. Except the active neutrinos, the appearance of singly charged Higgs bosons and dark matter does not affect significantly the physical spectrum of all particles in the original model. We indicate this point by investigating the Higgs sector in both cases before and after singly charged scalars are added into it. Many interesting properties of physical Higgs bosons, which were not shown previously, are explored. In particular, the mass matrices of charged and CP-odd Higgs fields are proportional to the coefficient of triple Higgs coupling $\mu$. The mass eigenstates and eigenvalues in the CP-even Higgs sector are also presented. All couplings of the SM-like Higgs boson to normal fermions and gauge bosons are different from the SM predictions by a factor $c_h$, which must satisfy the recent global fit of experimental data, namely $0.995<|c_h|<1$. We have analyzed a more general diagonalization of gauge boson mass matrices, then we show that the ratio of the tangents of the $W-W'$ and $Z-Z'$ mixing angles is exactly the cosine of the Weinberg angle, implying that number of parameters is reduced by 1. Signals of new physics from decays of new heavy fermions and Higgs bosons at LHC and constraints of their masses are also discussed.Comment: 40 pages, 1 figure; Journal vesio

Validating foundry technologies for extended mission profiles

This paper presents a process qualification and characterization strategy that can extend the foundry process reliability potential to meet specific automotive mission profile requirements. In this case study, data and analyses are provided that lead to sufficient confidence for pushing the allowed mission profile envelope of a process towards more aggressive (automotive) applications.\ud \u

Evaluation of human epididymal secretory protein E4 (HE4) for monitoring for ovarian cancer recurrence

INTRODUCTION: Serum HE4, a new biomarker for ovarian cancer, was shown to have a better sensitivity for detecting ovarian cancer compared to Ca 125, especially in early disease. In this study, we measured the HE4 levels in patients who had relapsed ovarian cancer in an attempt to elucidate its role in disease monitoring and recurrence detection. METHODS: HE4 levels were measured at pre-treatment, immediately post ...postprin

Durational Dimensions of English Syntax Spoken by Vietnamese Speakers

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The influences of cleanliness and employee attributes on perceived service quality in restaurants in a developing country

© 2017, © Emerald Publishing Limited. Purpose: The purpose of this paper is to investigate the service quality of full-service restaurants in Vietnam to explore possible factors that may impact customer perception, which subsequently influences customer satisfaction and behavioural intentions. Based on the DINESERV model and service clues, the possible dimensions to construct customer perception were realised, and four key dimensions were suggested. Design/methodology/approach: Data were collected from four urban local full-service restaurants in Vietnam, and factor analysis and SEM-PLS were then performed to uncover the relationship between customer perception, satisfaction and behavioural intentions. Findings: The results suggest that customer perception significantly influences customer satisfaction and behavioural intentions, and customer satisfaction itself is also found to have influence on behavioural intentions. Originality/value: This is an original piece of work which contributes to the exploration of service quality in developing countries and to the incorporation of cleanliness into analyses of restaurant service quality in particular