Über den statischen Regelfaktor der menschlichen Pupille
SummaryThe static regulation factor of the pupil servosystem in man, as dependent on the intensity of the light-stimulus, was calculated. Data were collected from own experiments, in which the whole field of view of one eye was homogeneously illuminated by white light. For these calculations the author developped a suitable definition of the regulation factor, using ordinary and partial differential quotients. The optimum of the regulation factor was found to be 2/3 at a luminance of 200 abs, i.e., at this point 1/3 of the slight variations in light intensity are compensated.
Grundlagen für eine klinische Pupillographie
The darkness-diameter was meashured with the electronic pupillograph by Lowenstein and Loewenfeld in 136 normal persons whose ages ranged from 6 to 72 years. A dependence on age especially was found after the 3rd and 4th decade. After dividing the investigated persons into larger age groups (6 to 29 years, 30 to 49 years, 50 to 72 years) significant differences were found. The values showed a nearly normal distribution. The anisocoria—calculated by the difference of both eyes—was found to be in 48% between 0 and 0,3 mm. Larger differences (1.0 to 1.4 mm) were only measured in 6 of the 136 persons. Normal ranges for the darknessdiameter and the anisocoria in darkness are stated. Der Pupillendurchmesser in Dunkelheit wurde bei 136 Personen im Alter von 6–72 Jahren mit dem Pupillographen nach Lowenstein und Loewenfeld gemessen. Eine Abhängigkeit vom Lebensalter zeigt sich besonders nach dem 3. und 4. Lebensjahrzehnt. Faßt man die untersuchten Personen zu größeren Altersgruppen zusammen (6–29 Jahre, 30–49 Jahre, 50–72 Jahre), so ergeben sich — bei einer annähernden Normalverteilung der Einzelwerte — signifikante Unterschiede. Die Anisokorie — errechnet durch die Differenz der Meßwerte beider Augen — liegt in 48% zwischen 0 und 0,3 mm. Größere Differenzen (1,0 bis 1,4 mm) wurden nur bei 6 der 136 Personen gemessen. Es werden Normbereiche für den Pupillendurchmesser und die Anisokorie in Dunkelheit angegeben.
Surface roughness monitoring by singular spectrum analysis of vibration signals
Abstract This study assessed two methods for enhanced surface roughness (Ra) monitoring based on the application of singular spectrum analysis (SSA) to vibrations signals generated in workpiece-cutting tool interaction in CNC finish turning operations i.e., the individual analysis of principal components (I-SSA), and the grouping analysis of correlated principal components (G-SSA). Singular spectrum analysis is a non-parametric technique of time series analysis that decomposes a signal into a set of independent additive time series referred to as principal components. A number of experiments with different cutting conditions were performed to assess surface roughness monitoring using both of these methods. The results show that singular spectrum analysis of vibration signal processing discriminated the frequency ranges effective for predicting surface roughness. Grouping analysis of correlated principal components (G-SSA) proved to be the most efficient method for monitoring surface roughness, with optimum prediction and reliability results at a lower analytical-computational cost. Finally, the results show that singular spectrum analysis is an ideal method for analyzing vibration signals applied to the on-line monitoring of surface roughness.