Control/display ratio

Accuracy - the ratio between the movement of the control and the display response, the control/display ratio (C/D), is important in determining the degree of accuracy. Large control movement for relatively small display movement can give great accuracy but tends to be slow, whereas small control movement for large display movement can be very fast but is not so accurate. 

The proposed technique for finger and thumb interaction improves the Take-off method [22] and allows precise interaction even when many small objects are displayed on the screen. It is based on a differentiation between the visual space and the motor space of the touch screen device. An interesting extension would consist in studying how methods that perform advanced control/display ratio adaptation, such as semantic pointing [5], could be integrated in our technique to improve selection. 

Blanch, R., Guiard, Y., Beaudouin-Lafon, M. Semantic pointing improving target acquisition with control-display ratio adaptation. In Proc. of CHI 2004 (Vienna, Austria), pp. 519-526. ACM, New York (2004)... 

Electronic ratio controller. In this type of controller, a proportion of both gas and air is diverted through a bypass in which a thermistor sensor measures the flow. The air and gas flows can be compared and the ratio calculated and displayed. A ratio control valve in the air or gas supply, depending on whether the mode of operation is gas- or air-led, will automatically restore a deviation from the pre-set ratio. The electronic controller maintains ratio over a 19 1 turndown. The principle of operation is based on mass flow, so that it can be used with preheated air in recuperative systems. 

There are many factors that affect the selection and design of controls. Included are control/display (C/D) ratio, direction-of-movement relationships, control resistance, grip, control coding, control function, the control or tracking task, information needs of the operator, space avaUabUity and consequences of inadvertent activation. A brief review of some of these factors follows. For fiufher details on control design, refer to more complete discussions in works cited in the Bibliography. 

An ethylene plant contains more than 300 equipment items. Traditionally, operators were trained at the site alongside experienced co-workers. With the advent of modem computers, the plant operation can be simulated on a real-time basis, and the results displayed on monitors (107). Computers are used in a modem plant to control the entire operation, eg, they are used to control the heaters and the recovery section (108). A weU-controUed plant is much more profitable than a poorly controlled plant. For the heaters, a model-based control system is gaining importance (109). Instead of simply controlling the coil outlet temperature (COT), severity is actually controlled. The measurement of severity (either or C H /CH ratio) requires on-line effluent... 

The unit was built in a loop because the needed 85 standard m /hour gas exceeded the laboratory capabilities. In addition, by controlling the recycle loop-to-makeup ratio, various quantities of product could be fed for the experiments. The adiabatic reactor was a 1.8 m long, 7.5 cm diameter stainless steel pipe (3 sch. 40 pipe) with thermocouples at every 5 centimeter distance. After a SS was reached at the desired condition, the bypass valve around the preheater was suddenly closed, forcing all the gas through the preheater. This generated a step change increase in the feed temperature that started the runaway. The 20 thermocouples were displayed on an oscilloscope to see the transient changes. This was also recorded on a videotape to play back later for detailed observation. 

The discussion below will focus briefly on the design of the graphic displays in order to illustrate the methodology used. The aim of the furnace operation (see Figure 7.15) is to achieve a specified output temperature of the crude oil. This is done by means of a master temperature controller which regulates the pressures of the fuels used. An air/fuel ratio controller regulates the flow of the combustion air, receiving as input the flow rates of the fuels... 

Display space-filling models of endo adduct and exo adduct. Which appears to be the less crowded Identify specific interactions which disfavor the higher-energy adduct. Next, compare energies of the two adducts. Which is the more stable Were the reaction under thermodynamic control, which would be the major product and what would be the ratio of major to minor products Use equation (1). 

Although lithium aldolates generally display a rather moderate preference for the u/f/z-isomer4, considerable degrees of diastereoselectivity have been observed in the reversible addition of doubly deprotonated carboxylic acids to aldehydes20. For example, the syn- and uw/z-alkox-ides, which form in a ratio of 1.9 1 in the kinctically controlled aldol addition, equilibrate in tetrahydrofuran at 25 C after several hours to a 1 49 mixture in favor of the anti-product20. 

Experimental Results. The inhibition of NDEIA formation after days at 37 forthree water-soluble and three oil-soluble inhibitors is displayed in Tables II and III, respectively. So that relative effectiveness could be compared, the concentration of each inhibitor was chosen to provide an inhibitor/nitrite mole ratio = 10, Each inhibitor was tested in two separate emulsion batches with two or more aliquots analyzed. The data shown for positive controls are from similar replicate experiments. 

We first demonstrate the switch function of our transistor, namely we show that the system can act like a good heat conductor or an insulator depending on the control temperature. This is illustrated in Fig.lO(b), where we plot JG, Js, and Jd versus Trj. When TG increases from 0.03 to 0.135, both Jd and Js increase. In particular, at three points TG 0.04,0.09 and 0.135, Jd = Js thus JG is exactly zero. These three points correspond to off , semi-on and on states, at which Jd is 2.4 x 10-6,1.2 x 10-4 and 2.3 x 10-4, respectively. The ratio of the heat current at the on state and that at the off state is about 100, hence our model displays one important function - switch -just like the function of a MOSFET used in a digital circuit. 

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