TACTILE GRAPHICS WITH MATHEMATICA

Tactile diagrams require considering specific features like resolution, size, density and even fonts to be perceived properly. Mathematica, as a powerful tool, provides integrated environment for technical computing, and has introduced a new generation of mathematical and algebraic capabilities. By the way, by default it does not respect the features necessary for graphs to be drawn to be fully tactile perceivable. In this paper, we have studied different aspects of graphing with the package and have investigated a criterion regarding the density feature for the drawn graphs to be judged how far are tactile perceivable

SATISFACTION IN E-TOURISM A CASE OF EUROPEAN ONLNE CUSTOMERS

As information is the life-blood of the travel industry (Sheldon, 1994), utilizing and managing a suitable Information Technology is essential for tourism organizations to satisfy their customers. Despite the importance of e-tourism on one hand and the key role of customer satisfaction on the other hand there have been less research related to this topic yet. Current research is going to fill this gap by categorizing items which are important for satisfaction in e-tourism and as a result introduces the main factors which are the determinant for customer satisfaction in online tourism. Moreover it illustrates if satisfaction of a website positively affect customer's intention of buying from that website. The present paper incorporates the method of distributing the questionnaire for addressing the determinants of customer satisfaction in online tourism, among a group of European online trip buyers. It also uses factor analysis method for analyzing the data. This research yields rich insights for managers of e-tourism firms, by introducing the factors which have the most impact on e-satisfaction

Clustering E-Satisfaction Factors in Tourism Industry

The emergence of the Internet has led to the rapid growth of e-commerce which has had an effect on the nature of different businesses. Tourism industry is not exempted from that. Despite the growing body of literature dealing with tourism industry and online consumer behavior, few researches have been done on satisfaction in e-tourism. This research is going to fill this gap by clustering items that affect customer satisfaction in online tourism which results in investigating main factors which are the determinants of e-satisfaction. In the next step it has been shown that customers' satisfaction will make customers recommend tourism product to the others. This research has collected the data among a group of European people who has experienced e-tourism at least once before. The result helps managers of tourism firms by introducing them the factors namely Convenience, Product offered, Offered information, Web site design which can affect the satisfaction of their customers

New opportunities for blind students : assistive tools for science learning

1. Introduction Thanks to the development of speech and tactile technologies, totally new learning opportunities opened up for visually impaired students. On the one hand screen readers and Braille displays enabled visually impaired students to actively read and write text, to exchange documents with sighted people and to use mainstream programs (e.g. for web browsing or for word processing). On the other hand, many difficulties still exist as far as scientific subjects are concerned. Scientific documents are made up of different content types, in particular: text, mathematical notation and graphical representations. Text is the written form of the spoken language and it generally does not pose problems to reading and writing through Braille or speech devices. Instead, visually impaired readers meet problems with mathematical expressions [1]. Actually, mathematical notation is represented through two-dimensional structures which are usually read by sighted readers through an overall glance at the structure and then by exploring details [2]. The overall glance allows for planning the transformations to be achieved on the expressions. Tactile and auditive perception cannot rely on this technique to understand mathematical expressions, so assistive tools are necessary to provide readers with alternative exploration and processing techniques to write, read and process mathematical expressions. Also graphical representations can be hardly accessed by visually impaired readers. They need to be represented in alternative forms in order to enable visually impaired to understand the meaning conveyed through a drawing. In particular the forms mainly used are tactile representations, verbal descriptions, which are often conveyed through speech or Braille output and a combination of audio and tactile feedback. In order to overcome the issues which are met by visually impaired students to access mathematical expressions and drawings, some assistive tools and techniques have been recently developed. They aim to facilitate blind students to go through scientific and technical studies which are highly unattended often because of the difficulties posed by mathematical notation and graphics. These tools will be described and analysed with respect to the advantages in an educational context. 2. The LAMBDA system The LAMBDA system [3], [4] is the result of the European LAMBDA project (www.lambdaproject.org). The LAMBDA system aims to facilitate reading, writing and processing of mathematical expressions through Braille device and audio-synthesis, especially taking into account the needs of visually impaired students who share their learning experience with sighted students in an educational context (e.g. in a classroom, attending a lesson, taking an exam, etc.). The core component is the mathematical editor which provides many features to compensate for the lack of sight. The mathematical expression is written in the LAMBDA editor in a linear form which is rendered by speech and on the Braille display through an 8-dots mathematical Braille code. The mathematical symbols are synchronously displayed in traditional notation on the screen so as to facilitate the sighted reader without any knowledge of Braille to understand what the blind student is writing. In order to compensate for the lack of overall glance, the expression can be browsed hierarchically. Specific operations to work on blocks which have a mathematical meaning are available. For example it is possible to select, cut and paste a fraction, the argument of a function, etc. A Python-based scripting language is available to extend the system. The system communicates with mainstream applications through converters from or to XHTML+MathML markup languages [5]. 3. Mathematics on the web: MathPlayer Up to recently, mathematical expressions have been represented on the web through images. Images cannot be read by screen readers, so mathematical resources on the web have been totally unexploited by blind people for years. Thanks to the widespread using of MathML markup language, mathematical expressions can be represented on the web through a description which can be interpreted by screen readers in order to generate the right speech output or Braille output. At present, the software MathPlayer [6] is able to interpret MathML expressions embedded in a web page and generate the corresponding speech output. Further extensions will take into account also Braille output. This tool is a step forward towards the full exploitation of scientific resources published on the web. 4. Access to computation software Symbolic and numerical computation programs are often key tools in many scientific and technical courses. The main accessibility issues concerning symbolic and numerical computation applications are related to the user interface. Generally speaking, these programs are made up of: an interpreter of a language specifically designed to express computations (e.g. "^" is often used to express powers, etc.), a kernel which performs computations, one or more front-end components which have many features to input, edit and process text and mathematical expressions, a protocol to enable client applications to communicate with the kernel. Problems rise with the user interface employed by the front-end. It often implements visually oriented interaction paradigms (e.g. the main working window is split into many boxes containing the expressions to be computed or the results of a computation, vertical or horizontal bars are used to mark a portion of text or expression as computed or to be calculated, etc.). Furthermore, the text-based language is usually rendered in traditional mathematical notation by the front-end thus making impossible reading through Braille display. Many symbolic and numerical computation programs also have a front-end with a command-line user interface. It can be used through mainstream screen readers and it is often a good alternative to the main front-end. Furthermore, the communication protocol between the kernel and a client application enables expert users to develop specialized front-end components which take into account accessibility features. The opportunities to use some symbolic and numerical programs are described in details. In particular, MATHEMATICA and SciLab programs are analysed. 5. Exploring and generating technical drawings The main techniques to explore drawings through non-visual perceptions are based on: verbal descriptions, tactile drawings and audio-tactile drawings. The most known tools to produce tactile drawings are graphical embossers [7], which can produce raised lines on paper. They prove to be extremely useful with graphical representations where text descriptions are absent or very short (e.g. in function diagrams or geometric shapes, etc.). Graphical representations which are rich of text descriptions can be successfully represented through audio-tactile representations. The tactile figure describes the structure of the image, whereas speech messages are associated to relevant spots which can be selected (e.g. by pressing on a tablet). This technique proves to be extremely useful for example with UML diagrams used in software engineering courses. The tools and techniques available are described in details with respect to drawings used in scientific courses (e.g. function diagrams, geometric shapes, automata, etc.)

Improving Tactile Graphics with MATHEMATICA

Graph as an indispensable part of mathematics, plays a central role in learning and teaching mathematics. Access to mathematical-graphical description and information, broaden the visually impaired people\u2019s horizon in the discipline, however lack of appropriate tools, either hardware or software, is the main burden. Variety of methods exists for providing tactile images which are discussed e.g. in [2], [3] and [5] however the following construction techniques are more popular: - Thermoform Graphics in which a sheet of plastic is heated and vacuumed on top of a model which represents the shape to be perceived by touch. This results in the production of high quality tactile drawings, but it is necessary to mould a totally new model when a new drawing has to be produced. Besides being expensive, the resulting graph is rather static, i.e. for enlarging the graph a new mould is required. - Swell-Paper Graphics in which a special paper with a special coating of heat reactive microcapsules is used which enables special printers to shape raised areas. Variable height raised lines and areas can be obtained, but it is a very expensive process. - Embossed Graphics. There are several Braille embossers to produce tactile images by punching dots into paper in such a way as to form graphics. This is the best cost-effective technique. Nonetheless only few embossers (e.g. Tiger embossers) are able to produce high-quality, variable-height tactile drawings [4]. This research pursuing [1] is to address criteria based on which describing a graph to be fully tactile perceivable, before actually being embossed, would be feasible. As such we can granulate the graphs into three granules namely, fully-perceivable, suspicious-perceivable, non-perceivable. Toward the aim we have used MATHEMATICA which is a powerful tool that provides integrated environment for technical computing and also enable symbolic manipulation. It is important to remind that MATHEMATICA can be used by visually impaired students through a command-line user interface that permits performing all required calculations and symbolic manipulations. Moreover, MATHEMATICA allows for producing quality graphics through its powerful symbolic language, hence visually impaired students can command creating graphics by themselves. Besides MATHEMATICA we have exploit Tiger Graphic Embosser. Regarding the preferred resolution for an image to be tactile perceivable \u2013 25.4 dots/inch [6]- and the density of the graph to be embossed we granulate the graph into aforementioned granules. Moreover and specially for the graphs that are granulated in the suspicious-perceivable granule, based on the mentioned factors and considering the limitations of the embosser, the image will be zoomed. The zooming degree will be calculated to be the minimum, through considering the image density, tactile resolution and the embosser specifications. It is important to notice that perception and interpretation of an image is mainly due to the distribution of entities in the image. If entities in an image have overlapping, their perception will be difficult. That is why indicating a zooming degree while issuing a graph-drawing command in MATHEMATICA, regarding the algorithms applied by MATHEMATICA to draw graphs, will lead to the reduced overlapping. However to keep the size of the graph as small as possible we will find the minimum zooming degree. This is due to the two main features of diagram understanding, namely, easiness to search and immediacy to recognize. Therefore, the following exploration features were taken into account while working on graphs: -The possibility to easily recognize basic components in the diagram (e.g. Braille labels and figures). -The possibility to identify relationships between basic components. -The possibility to easily search for components. -Techniques to hierarchically explore the graphical representation. Be reminded that detailed graphs to be perceivable by blind people must be abstracted to a proper level, however we argue that mathematical graphs are themselves a type of abstraction and thinking of putting them in a different level of abstraction is realizable mainly through a hierarchical structure by introducing some black boxes in higher levels and demonstrating the black boxes in the subsequent levels. This is in accordance with the model presented in [4]. The model shows that the visual image is analyzed hierarchically, from the overall structure down to the fundamental features or elements

Study of Average Static Hold-up Along a Rotary Disc Contactor in the Presence of Nanoparticles

Regarding the important role of static hold-up in both hydrodynamic and mass transfer rate in extraction columns, average static hold-up has been studied in a Rotary Disc Contactor (RDC) as a function of rotor speed, average mother drop size and number of stages using several chemical systems. In the light of the promising potential of nanofluids in mass transfer applications, in a quite novel investigation, nanofluids were applied as dispersed phases to the RDC column. Two types of SiO2 nanoparticles with different hydrophobicities were employed in nanofluids preparation, which stabilities were appraised by sedimentation method and UV-vis spectrophotometry. Transmission Electron Microscopy was also applied to examine the size and shape of SiO2 nanoparticles

Concave type-2 fuzzy sets : properties and operations

In this article, concave type-2 fuzzy sets are investigated. The calculation of union and intersection of concave type-2 fuzzy sets using the min t-norm and the max t-conorm are explored and it is proved that the set of concave type-2 fuzzy sets is closed under those operations. It is also shown that the set of LR-normal concave type-2 fuzzy sets forms a commutative semiring under join and meet