**7. References**

176 Advanced Topics in Measurements

Step-height: 10 µm

○: center of fingertip ●: top of fingertip

Fig. 10. Relationship among the fingertip region, the upper threshold for a 10 µm step-

according to the PEST algorithm and presented the step pairs to the subjects.

In this study, to measure the finger's fine step-height discrimination capability the computer-controlled measurement system that presents fine step-heights of 0 to 1000 µm to subjects' fingers was developed. Using the measurement system the paper examined the effects of the touching manner of human finger, finger's motion direction, and fingertip region on the tactile recognition of fine step-heights. In the psychophysical experiments, to determine the difference thresholds and subjective equalities for fine step-heights the measurement system calculated the amounts of step-height of the step pairs by computer


Presentation angle of step deg

First, the upper thresholds for the step-heights of 10 to 100 µm were determined in the active- and passive-touch experiments. The resulting thresholds became larger as the magnitude of step-height increased. Also the threshold of active-touch manner for each of the step-heights larger than 50 µm was smaller than that of passive-touch manner and the thresholds of the touching manners for each of the step-heights smaller than about 40 µm were almost equal regardless of the touching manners. Therefore it was found that the fingertip's discrimination ability of the fine step-heights depends on the amounts of stepheight and if a step-height is larger than 50 µm, the finger's tactile sense can increase the

height, and the presentation angle.

0

1

2

Upper threshold for step-height,

*ΔU* µm

3

4

5

6

sensitivity in active-touch manner.

**6. Conclusion** 


**Overview of Novel Post-Processing** 

**Techniques to Reduce Uncertainty** 

Manuel Sierra-Castañer, Alfonso Muñoz-Acevedo,

*Technical University of Madrid (Universidad Politécnica de Madrid - UPM),* 

The error analysis has been investigated since 1975 since recent publications, as shown in references as (Newell et al., 1975) where the classical 18 terms for planar near field systems where established. It is also worth mentioning the more recent studies developed inside the actions under the "Antenna Measurement" activity of the "Antenna Centre of Excellence (ACE)" within the sixth framework research program of the European Union. In particular, that work pretended to establish common error calculation criteria in spherical near-field and far-field antenna measurement systems. The results of that research were summarized in an exhaustive deliverable (Alexandridis et al., 2007), which detailed the observations stated by several research institutions. In that deliverable it was agreed that the causes of uncertainties and errors in a spherical near-field antenna measurement are divided in six

1. **Mechanical uncertainties and errors**: this group includes the axes intersection, the axes orthogonality, the horizontal pointing, the probe vertical position, the probe horizontal

2. **Electrical uncertainties and errors**: this class contains the amplitude and phase drift, the amplitude and phase noise, the leakage and crosstalk, the amplitude non-linearity

3. **Probe-related uncertainties and errors**: this kind of uncertainties takes into account the channel balance amplitude and phase, the polarization amplitude and phase and the

4. **Stray signals**: this type of uncertainties consists of the multiple reflections, the room

5. **Acquisitions errors**: this group involves the scan area truncation and the sampling

6. **Processing uncertainties and errors**: in this group the spherical mode truncation and

The second part of the chapter will deal with the description of four different classes of

and vertical pointing and the measurement distances.

and the amplitude and phase shift in rotary joints.

scattering and the AUT support scattering.

the total radiated power are considered.

correction techniques for antenna measurements.:

**1. Introduction** 

categories:

pattern knowledge.

point offset.

**in Antenna Measurements** 

Francisco Cano-Fácila and Sara Burgos

*Spain* 

Vallbo, Å.B. & Johansson, R.S. (1984). Properties of Cutaneous Mechanoreceptors in the Human Hand Related to Touch Sensation, *Human Neurobiology*, Vol. 3, pp. 3-14. **9** 
