An inexpensive 28-V timer circuit using solid state and relay devices

An easily constructed 28-V dc timer circuit is described. The circuit is as precise, reliable, and versatile as some commercially available units, but is much less expensive to construct.     

A photoelectric sound-activated relay

By activating photocell control circuits by a low voltage lamp in parallel with speaker outputs on conventional recorders, it is possible to obtain reliable and inexpensive program capability.     

A programmable circuit for varying light intensity

An inexpensive circuit is described for the control of light intensity. The control is obtained by a method that produces no color changes and may be programmed by any system that can express itself in four-digit binary numbers.     

A CRT blanking circuit for video terminals

A simple and inexpensive modification for the ADDS 980 video terminal is described which permits the characters displayed on the CRT to be blanked and restored (under software control). This circuit is useful in applications, such as RT measurement, where precise definition of stimulus onset is important. The technique described is general enough to be applied to a variety of other video terminals.     

A goal programming model for crew duties generation

An Erratum has been published for this article in Journal of Multi‐Criteria Decision Analysis 10(5) 2001, 285. This paper proposes a model for the generation of daily work duties of airside crew (being bus drivers) at the Hong Kong International Airport. The results can be adopted as a good crew schedule, in the sense that it is both feasible, satisfying requirements of various work conditions, and ‘optimal’ in minimizing overtime shifts. It is formulated as a goal programme, specifically designed to cater for the manpower planning issues to handle frequent changes of flight schedules by flexibility in work patterns of driver duties. Illustrative results from an actual case study are given. Copyright © 2001 John Wiley & Sons, Ltd.