PURPOSE The Health Behavior in School-aged Children (HBSC) study is a cross-national survey examining health and lifestyle behaviors of adolescents, traditionally administered by paper and pencil in a school setting. The purpose of the present study was to investigate if a computer format of the questionnaire would affect the responses of the adolescents in comparison with the paper and pencil ...

Nonmonetary incentives lead to small increases in response rates to mailed questionnaires. However, inclusion of a pen or pencil, which may be a facilitating factor as well as a reward, has not been shown to improve response to health surveys in prior trials. In 2001 and 2002, the authors conducted two US trials in which a study-logo pen or pencil was randomly included in a second questionnaire...

Type Ia supernovae (SNe Ia) can be calibrated to be good standard candles at cosmological distances. However, at z > ∼ 1, gravitational lensing leads to significant level of noise in a SN Hubble diagram. We propose a pencil beam survey of SNe Ia which would yield a significant number of SNe in redshift bins of 0.1 for z up to 2. The SN number count can provide a direct probe of cosmology which ...

For cubic pencils we define the notion of an involution curve. This is a curve which intersects each pencil in exactly one non-base point pencil. Involution curves can be used to construct integrable maps plane leave invariant

2 Singularities and Extreme Points 4 2.1 Singularities and Genus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 Parameterizing with a Pencil of Lines . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3 Parameterizing with a Pencil of Curves . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.4 Algebraic Space Curves . . . . . . . . . . . . . . . . . . . . . ...

We illustrate properties of the conics in Poncelet’s pencil using some new insights motivated by some elementary triangle constructions of Garcı́a.

Global illumination is an important area of computer graphics, having direct applications in architectural visualization, lighting design and entertainment. Indirect illumination effects such as soft shadows, color bleeding, caustics and glossy reflections provide essential visual information about the interaction of different regions of the environment. Global illumination is a research area t...

Convolution/superposition software has been used to produce a library of photon pencil beam dose matrices. This library of pencil beams is designed to serve as a tool for both education and investigation in the field of radiotherapy optimization. The elegance of this pencil beam model stems from its cylindrical symmetry. Because of the symmetry, the dose distribution for a pencil beam from any ...

BACKGROUND AND PURPOSE New treatment techniques in radiotherapy employ increasing dose calculation complexity in treatment planning. For an adequate check of the results coming from a modern treatment planning system, clinical tools with almost the same degree of generality and accuracy as the planning system itself are needed. To fulfil this need we propose a photon pencil kernel parameterizat...