Null Value

DBSASLABEL By default, the SAS label for an imported variable is set to the column name. Setting DBSASLABEL=NONE places null values into the SAS labels. 

The attributes in a type model define which snapshots are legal. As shown in Figure 2.6, the course attribute of a session must link to a valid Course. A given snapshot need not depict all attributes of an object, so if you omit an attribute from a snapshot you have said nothing about its value. If you want the attribute to be unconnected, it must be marked with a null value. 

These dyadic distributions do not exhibit a null value for R / 0. However, these distributions satisfy the following properties ... 

The left-handed side of this equation represents a magnetic energy included in the volume V, which is a positively defined quantity. As a consequence, the magnetic field cannot have a null value on the surface S. 

The vector P satisfies the condition P 7 0. In order to demonstrate this claim, we must only prove that this vector cannot be null-valued. Indeed, if it were null, the equality A2K = (A K)A would be verified, or A1 K1 = (A K)2, specifically, cos20 = (A )2/(AK)1 = 1, which contradicts the very fact that KAA O. 

The so-called Aharonov-Bohm effect is observed with another experimental setup. A solenoid is placed immediately after the plate, between the slits, and its axis is parallel to the slits, and therefore normal to the beam trajectory beam. If the solenoid is long enough, the magnetic field remains confined in it as a consequence, the magnetic field is shown to have a null value in the region crossed by electrons beamed on either sides of the solenoid. The Lorentz force exerted on the electrons is expected to be null in the absence of any external electrical field. 

Outside the solenoid, the magnetic held has a null value = 0. Therefore, it would be very tempting to chose A = 0. Unfortunately, this choice is not possible. The reason is simple. Stokes theorem, when applied to an open surface S leaning on a closed contour C encircling the solenoid, gives us... 

The enzyme reaction is performed in duplicate. Incubation buffer (200 pi) is mixed with 50 pi diluted hemolysate and incubated at 37°C for 5 min, then 50 pi substrate solution is added and the tubes are kept at 37°C in the dark for a further 60 min. One null value per experiment with hemolysis buffer instead of erythrocytes is treated the same way. 

The abstract class LsiValidator has two attributes the correct length of the LSI that is being validated and a list of validators. Each element in the list is the validator of one particular component in the LSI. LsiValidator implements the common validation logic Check null value and the length of the input and call the validator objects to validate the LSI components. 

Another important point of the I-E curve is the crossing potential or equilibrium potential for which the current takes a null value,/pl i"e = 0 (see Fig. 2.4a). By inserting this condition in Eq. (2.27),... 

X is the coded value of the i-th factor (nondimensional magnitude) x , xi0 are natural or the real factor values, their current and null values, respectively Ax(e) is the natural value of the factor-variation interval. In a design matrix when we vary factors on two levels (+1 -1) only signs (+ -) exist. 

In all the experiments, the measurements using the CIE L a b coordinates did not give any conclusive results, the CIE L varies in the same way as the ISO brightness, the CIE a does not vary significantly from a null value and the CIE b shows very small variations, not much bigger than the variations of the experimental errors. Therefore, most analyses of the optical properties used ISO brightness measurements that showed measurable variations. 

Here (3He/4He)s is the observed sample ratio. Note that the normalization is the air ratio, not an expected ratio. The distinction is significant for He dissolved in water, for which there is a perceptible isotopic fractionation (Weiss, 1970b), so that the null value, for solubility equilibrium with air, is <53He -1.4%. 

Unless A is singular, as it is at the null values of mu, this implies the consistency condition, restoring summation indices,... 

Grey value Be aware that no result is present though transferring to some software packages could erroneously reset this to 0... 

Cells containing null values are counted, but cells containing zero values are not counted. 

The boundary conditions, both the mechanical and those for hydrogen entry into metal, are depicted in fig. 2. There an arbitrary axial load is applied over the boundary SL, a definite environmentally controlled equilibrium concentration of hydrogen, Ceq, is imposed over the boundary Seq exposed to the hydrogenating environment, and on both symmetry axes denoted Sf, the null values of the hydrogen flux, J, and of the normal component of displacement are imposed. 

However, Pearce et al. [14(NC)] have written that the problem of information bias is of particular concern in asthma epidemiology issues because of the difficulties in defining and measuring asthma, allergic rhinoconjunctivitis and atopic eczema, and the difficulties in obtaining exposure information in the aetiologically relevant time period. However, provided that the information has been collected in a standardized manner, then misclassification will be non-differential, and any bias it produces will usually be towards the null value. 

Sometimes, there is no value available for a particular column or a particular row. Rather than inventing a special value to represent this, such as 99999 for numeric or "" for text, the relational database provides a special null value. This should be used when a value is unknown or unavailable. When actual data becomes available, the null value can be updated. 

In standard SQL, a text column may contain data, or not. The null value is used to denote that no value is contained in that column of any particular row. The null value can be used in SQL statements, for example ... 

In Oracle, an empty text string is considered equivalent to the null value. In PostgreSQL, an empty string is a valid, nonnull value. Neither approach is more correct than the other, but it may require some programming adjustments when moving from PostgreSQL to Oracle, or the other way around. 

Since the range float function only interprets exact(=) range values as float, null is returned whenever a range value contains < or >. So any function like sqrt, will also return a null value. Since range values can now be implicitly interpreted as float, many useful functions, such as sqrt, max, and avg and operators such as +, - and become available for range data. These return the expected value for exact ranges, but null for < and > values. 

All the concentration profiles exhibit a zero change in AC, between 0 < (x/L)1 2 < 1, because of the competition between the progress of the electrochemical reaction along y and the direction of the inlet flux along x. However, there are some important points to be noted. Those curves in which the increase in D, or in a is observed show the lowest AC, null value in the abscissa (those with the highest conversion of the reactive). Besides, it is also important to say that the increase in cp produces no changes in the AC, null value at the abscissa (i.e., at (x/L)1 2 = 0.05). On the other hand, the most perceptible feature of this characteristic is the increase in U0, that is, at (x/L)1/2 = 0.15. 

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