Making Scientific and Technical Materials Pervasively Accessible

In this paper, the question is explored of what policies, standards and practices are desirable to ensure that hardware, software and publications in the sciences and associated disciplines are created from the outset to be accessible to people with disabilities. Insight into this question can be obtained by considering the unique accessibility challenges that these materials pose, including complexities of notation, language, and graphical representation. Having analyzed what sets this problem apart from broader issues of accessibility, the advantages and limitations of current international standards are reviewed, and contemporary developments in standards and policies are considered from a strategic perspective. These developments include the establishment of accessibility requirements for e-books and e-readers under the European Accessibility Act, the potential role of process-oriented accessibility standards such as ISO/IEC 30071-1:2019, and opportunities for enhancing the standards applicable to scientific materials via future revisions of the World Wide Web Consortium’s Web Content Accessibility Guidelines (WCAG). The accessibility of scientific and technical content is ultimately supported by several interrelated human rights recognized in international disability rights law, which constitute a foundation for further evaluation and development of policies. It is argued that attaining pervasive accessibility in scientific and technical fields requires an unprecedented level of commitment and collaboration among educators, scientists, content and software producers, regulators, and people with disabilities

Using Markup Languages for Accessible Scientific, Technical, and Scholarly Document Creation

In using software to write a scientific, technical, or other scholarly document, authors have essentially two options. They can either write it in a ‘what you see is what you get’ (WYSIWYG) editor such as a word processor, or write it in a text editor using a markup language such as HTML, LaTeX, Markdown, or AsciiDoc. This paper gives an overview of the latter approach, focusing on both the non-visual accessibility of the writing process, and that of the documents produced. Currently popular markup languages and established tools associated with them are introduced. Support for mathematical notation is considered. In addition, domain-specific programming languages for constructing various types of diagrams can be well integrated into the document production process. These languages offer interesting potential to facilitate the non-visual creation of graphical content, while raising insufficiently explored research questions. The flexibility with which documents written in current markup languages can be converted to different output formats is emphasized. These formats include HTML, EPUB, and PDF, as well as file formats used by contemporary word processors. Such conversion facilities can serve as means of enhancing the accessibility of a document both for the author (during the editing and proofreading process) and for those among the document’s recipients who use assistive technologies, such as screen readers and screen magnifiers. Current developments associated with markup languages and the accessibility of scientific or technical documents are described. The paper concludes with general commentary, together with a summary of opportunities for further research and software development

Quasiballistic correction to the density of states in three-dimensional metal

We study the exchange correction to the density of states in the three-dimensional metal near the Fermi energy. In the ballistic limit, when the distance to the Fermi level exceeds the inverse transport relaxation time $1/\tau$, we find the correction linear in the distance from the Fermi level. By a large parameter $\epsilon_{\rm F} \tau$ this ballistic correction exceeds the diffusive correction obtained earlier.Comment: 2 pages, 1 figur

Mission Design and Operations: SPARTAN-Halley as a Paradigm for Small Satellites

The SPARTAN reusable spacecraft opened a new arena for innovative scientific and engineering experimentation in low earth orbit. SPARTAN\u27s a free flying, 3-axis inertially stabilized spacecraft which is deployed and retrieved by the Space Shuttle. The spacecraft is unique in that it performs all scientific observations as well as its guidance, navigation, and control functions completely autonomously. This paper will describe the innovative approach that was taken in the design of the SPARTAN guidance and navigation system for a 48-hour observation of Halley\u27s Comet near perihelion passage. Autonomous vehicle navigation techniques that utilized solar sensors, a single star tracker, a 3-axis gyro package, and two independent cooperative microprocessors will be discussed. Ephemeris development and structure will be detailed. Creative techniques used to tune the navigation and science observations with respect to the actual achieved mission orbit will also be described. Text will also be devoted to describing the vehicle and its sensor and instrument configuration. Lessons learned from SPARTAN will be discussed in the context of small satellite mission operations

Vibration Analysis of a Split Path Gearbox

Split path gearboxes can be attractive alternatives to the common planetary designs for rotorcraft, but because they have seen little use, they are relatively high risk designs. To help reduce the risk of fielding a rotorcraft with a split path gearbox, the vibration and dynamic characteristics of such a gearbox were studied. A mathematical model was developed by using the Lagrangian method, and it was applied to study the effect of three design variables on the natural frequencies and vibration energy of the gearbox. The first design variable, shaft angle, had little influence on the natural frequencies. The second variable, mesh phasing, had a strong effect on the levels of vibration energy, with phase angles of 0 deg and 180 deg producing low vibration levels. The third design variable, the stiffness of the shafts connecting the spur gears to the helical pinions, strongly influenced the natural frequencies of some of the vibration modes, including two of the dominant modes. We found that, to achieve the lowest level of vibration energy, the natural frequencies of these two dominant modes should be less than those of the main excitation sources

The Hubbard model with smooth boundary conditions

We apply recently developed smooth boundary conditions to the quantum Monte Carlo simulation of the two-dimensional Hubbard model. At half-filling, where there is no sign problem, we show that the thermodynamic limit is reached more rapidly with smooth rather than with periodic or open boundary conditions. Away from half-filling, where ordinarily the simulation cannot be carried out at low temperatures due to the existence of the sign problem, we show that smooth boundary conditions allow us to reach significantly lower temperatures. We examine pairing correlation functions away from half-filling in order to determine the possible existence of a superconducting state. On a $10\times 10$ lattice for $U=4$, at a filling of $\langle n \rangle = 0.87$ and an inverse temperature of $\beta=10$, we did find enhancement of the $d$-wave correlations with respect to the non-interacting case, a possible sign of $d$-wave superconductivity.Comment: 16 pages RevTeX, 9 postscript figures included (Figure 1 will be faxed on request

Numerical renormalization group study of the 1D t-J model

The one-dimensional (1D) $t-J$ model is investigated using the density matrix renormalization group (DMRG) method. We report for the first time a generalization of the DMRG method to the case of arbitrary band filling and prove a theorem with respect to the reduced density matrix that accelerates the numerical computation. Lastly, using the extended DMRG method, we present the ground state electron momentum distribution, spin and charge correlation functions. The $3k_F$ anomaly of the momentum distribution function first discussed by Ogata and Shiba is shown to disappear as $J$ increases. We also argue that there exists a density-independent $J_c$ beyond which the system becomes an electron solid.Comment: Wrong set of figures were put in the orginal submissio

The impact of parent-created motivational climate on adolescent athletes' perceptions of physical self-concept

This is a preliminary version of this article. The official published version can be obtained from the link below.Grounded in expectancy-value model (Eccles, 1993) and achievement goal theory (Nicholls, 1989), this study examined the perceived parental climate and its impact on athletes' perceptions of competence and ability. Hierarchical regression analyses with a sample of 237 British adolescent athletes revealed that mothers and fathers' task- and ego-involving climate predicted their son's physical self-concept; the father in particular is the strongest influence in shaping a son's physical self-concept positively and negatively. It was also found that the self-concept of the young adolescent athlete is more strongly affected by the perceived parental-created motivational climate (both task and ego) than the older adolescent athlete's self-concept. These findings support the expectancy-value model assumptions related to the role of parents as important socializing agents, the existence of gender-stereotyping, and the heavy reliance younger children place on parents' feedback

Interaction potentials for soft and hard ellipsoids

Using results from colloid science we derive interaction potentials for computer simulations of mixtures of soft or hard ellipsoids of arbitrary shape and size. Our results are in many respects reminicent of potentials of the Gay-Berne type but have a well-defined microscopic interpretation and no adjustable parameters. Since our potentials require the calculation of similar variables, the modification of existing simulation codes for Gay-Berne potentials is straightforward. The computational performance should remain unaffected.Comment: 8 pages, 4 figure