Abstract

Abstract
Hollow-core photonic crystal glass fibers have a high potential for gas sensing applications, since large light-gas interaction lengths can be effectively attained. Nevertheless, in order to enhance effective diffusion of gas into the hollow-core fiber, multi-coupling gaps are often needed, which raise coupling loss issues that must be evaluated prior to the development of practical systems. In this paper, a study on the coupling losses dependence on lateral and axial gap misalignment for single-mode fiber and two different types of hollow-core photonic crystal glass fibers is carried out. In addition, an experimental technique on splicing these glass fibers is also described and some results are presented showing that low splice losses can be obtained with high reproducibility. © (2010) Trans Tech Publications.

Abstract
It is recognized by the Information Retrieval community that context affects the retrieval process. Query formulation and relevance assessment are stages where the user role is central. The first determines what the system will search for and the second is frequently used to evaluate how the system behaved. With a large human involvement, these stages are expected to be largely influenced by user and task characteristics. To analyze the influence of these context features on the specified stages of health information retrieval, we conducted a user study in which we collected user features through two questionnaires. User characteristics include features like age, gender, web search experience, health search experience and familiarity with the medical topic. Task features include the medical specialty, the question type, the task's clarity and the task's easiness. Besides user and task features, the relevance assessment analysis also covered features related to the query and document. We found many variables do indeed affect query formulation and relevance judgment. Some of our results question evaluations using test collections and ask for evaluation models that incorporate other kind of success measures. Copyright 2010 ACM.

Abstract
We have conducted a user study to evaluate several generalist and health-specific search engines on health information retrieval. Users evaluated the relevance of the top 30 documents of 4 search engines in two different health information needs. We introduce the concepts of local and global precision and analyze how they affect the evaluation. Results show that Google surpasses the precision of all other engines, including the health-specific ones, and that precision differs with the type of clinical question and its medical specialty.

Abstract
A CMOS-compatible SiGeC superlattice design is proposed that offers the possibility of generating a range of direct bandgaps smaller than Ge's, down to broken-gap provided that sufficient substitutional carbon content can be incorporated. ©2010 IEEE.

Abstract
A common problem in computer programming use for education in general, not simply as a technical skill, is that children and teachers find themselves constrained by what is possible through limited expertise in computer programming techniques. This is particularly noticeable at the preliterate level, where constructs tend to be limited to extremely simple elements. Having worked for 4 years with over 150 children, aged 3 to 5, we present age-appropriate computer programming activities involving different computer programming techniques, from the basic (computer language syntax) to the advanced (client-server). These may contribute to expand the panorama on viable computer programming techniques available to children and educators, thus broadening the variety of educational activities and projects that can be approached in educational settings using computer programming.