DECtalk, What is fatigue!

~ Field Service Pilot ~

This note presents a web-based audio-visual education, training and support program for inspectors of marine units prone to fatigue fracturing. As appear from Figure 1, the service consists of four components. Those are explained in the sequel, and are operative on Internet.

Figure 1: Components of the Fatigue Inspection Field Service program with links to the audio- and the visual- parts. From http://www.dnv.com/Ocean/Guest/MoBee.htm

1 - Fatigue Course

The Fatigue Course is web-based and audified. It displays foils with voice narration, as shown in Figure 2. It has online calculators, customised for particular numerical problems, as shown in Figure 3. Instructive images of structural details sensitive to fatigue damages, as in Figure 4, may be displayed. Text pages from compendium with illustrations and possible mathematics are provided, as in Figure 5. Address to the course entrance is: http://www.dnv.com/nbt/Fatigue/zFrame.htm

Figure 2: Foils for presentation of the course appear in the right frame of the web-page. The left frame has links to foils, calculators, compendium and other tools. The horizontal blue-white bar above the foil text activates the talker narrating the foil.
Figure 3: Online calculator fitted to a special numerical problem. Talk bar is as in Figure 2.
Figure 4: For illustration purposes, structural details of elements sensitive to fatigue cracks may be drawn up on the screen.
Figure 5: Course compendium and related texts and reports, may be reproduced in the screen frame. Navigation may partly take place from hyperlinks on the instruction foils, from the of Compendium link in the left frame, or from the internal Calling in the same. Talk file exists to all text, sections and equations, usually linked in from the page headings.

2 - Field Phone Simulator

Talk files and links to audible text are attached to most web-pages of the fatigue course. In combination with the screen graphics, the audio part may enforce the learning process by activating more sensory capabilities. For pure text, the audible alternative may also sometimes be less boring than visual reading. On the other hand, the layout of the talk is, as far as possible, prepared as a self-contained, audible presentation of the course elements. It may thus support a mobile telephone alternative, serving as a field work reminder under out-of-office conditions. To train this alternative in advance, a simulated phone network is included in the course, in parallel with the graphic screen and HTML edition. Entrance to the fatigue course field phone simulator is: http://www.dnv.com/ocean/nbt/FatiguePh.htm also shown in Figure 6.

Figure 6: Voice narration to foils, and audible reading of compendium and other text, may be activated through the telephone simulator pages. This may work as a training instrument for remote field work.

3 - "Mobile Worker" Crax-2 Phone Simulator

The web service "Crax" for remote evaluation of cracks, is linked to the fatigue course, and appears on the address: http://www.dnv.com/Ocean/Guest/Crax.htm A field phone simulator to the simplest of these web computers ("Crax 2"), has been devised for the MoBee research program. The front panel is displayed in Figure 7 and appears in the right frame. The left frame contains a short instruction for use. The devise is a combination of a mobile telephone and a calculator. Input data may be provided by keystrokes, or by written or spoken text. Written text may be accomplished by the audible Braille editor (DNV Report No. 92-2034, See: http://www.dnv.com/Ocean/nbt/Audit/Docs/Report.htm). Spoken text input requires a local speech recogniser, and is not yet operative. Output from the computer operations are keystroke echoes and short text messages, facilitated to spoken output. Markup for voice layout follows the DECtalk standard.

Figure 7: The MoBee_Crax field phone simulator is shown in the right frame. The left frame gives some user guidance, and includes also the 8-bit Braille table for keystroke text input.

4 - HardWare Handset

The front panel layout of a suitable field phone may be much similar to that of an ordinary mobile telephone. The voice control, however, will need some functions similar to that of a cassette player, such as pause, rewind, repeat, fast forward, volume etc. In the case of keystroke input, the phone should have a loud-speaker, possibly also with a plug to external audio, car stereo etc. This will serve listening to long texts, instructions and reports.
On the software side, the handset should have modem, web-browser and text-to-speech software with multiple voices. Markup in the course texts and MoBee_Crax messages follow the DECtalk mode square practice.
Speech recogniser should be speaker-independant and working dynamically on small, site-specific vocabularies.
Since the application input consists essentially of numbers and numerical computer and calculator input, the ISO standard calculator keyset is recommended.
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Figure 8: Layout of different front panels for virtual field phone simulators applied in the Course.

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Work Note, (Sgra 1.October 1999).