OSAC Lexicon

Plastic materials that are hardened into a permanent shape in the manufacturing process and are not commonly subject to softening when heated; typically form char in a fire.

A method for calculating match probabilities, first described by Balding and Nichols (1994), to allow for population structure in the population for which a frequency database is constructed. It allows match probabilities for subpopulations to be calculated from whole population allele frequencies. It avoids the need to assume Hardy-Weinberg equilibrium at the whole-population level.

An element used in an impact printing device in which the fully formed characters are located on the ends of finger-like devices that are similar to a daisy wheel except that the device is formed to produce a cup-like or thimble structure. (SWGDOC E04-13)

conformity assessment activity that is performed by a person or organization that is independent of the provider of the object of conformity assessment (4.2) and has no user interest in the object
Note 1 to entry: The first-, second- and third-party descriptors used to characterize conformity assessment activities in relation to a given object are not to be confused with the legal identification of the relevant parties to a contract.
 

The total number of horizontal and vertical threads per in.² of fabric.

DetectionThe minimum and maximum concentration of a chemical vapor that can be detected by a canine or an instrument. BehavioralThe level of stimulation above or below which learning and/or performance is impaired.

Graphic representation of the events in a fire incident displayed in chronological order.

See vaccine titer.

The allowable range of deviation from the class resolution, symmetric around the classresolution value. For PIV single fingerprint scanners with the class resolution of 500 ppi,the tolerance is 2%. For all scanners other than PIV, the tolerance is 1%.

Subdiscipline of firearm and toolmark examination that includes the classification and comparison of microscopic toolmarks created by non-firearm tools.

NOTE The examination of non-firearm tools may also be included.
 

Quality of paper, or other writing surface that causes drag or resistance to the pen. A smooth, slick surface with no tooth can result in thick hairlines and lack of control in writing. Medium tooth causes just enough drag on the pen to facilitate control, produce fine hairlines, and allow the writing process to be rhythmical. Too much tooth impedes ink flow and progress of the pen.

A measurement of an objects surface geometry. Topographic data may be one, two, or three dimensional.

1D topography data is also known as a Linear Profile. A linear profile with n points shall be represented as a function of a single coordinate where at each point along a single axis (xi) (where i=1,...,n) there is a measured height (zi). Both xi and zi are measured in standard units (e.g., micrometers). An example of a linear profile is a cross-section through a striated toolmark (e.g., bullet land area); where xi is a spatial position measured in micrometers and zi is the corresponding height of the striation profile measured in micrometers.

2D topography data is also known as a Planar Image. An n-by-m planar image I shall be represented as a function of two coordinates where at each point (xi, yj) (where i=1,...,n; j=1,...,m) there is a measured surface color or intensity denoted I(xi, yj). An example of 2D topographic data is an image taken through a comparison microscope; where each point I (xi, yj) is the RGB (red, green, blue) color value measured at the specified (xi, yj) position. The measured color or intensity is a function of the surface geometry and the environmental conditions (e.g., light position). Although reference scales may be included in the collected image, the points (xi, yj) may or may not be measured in standard units (e.g., micrometers).

3D topography data is also known as a Heightmap. An n-by-m heightmap H shall be represented asa function of two coordinates where at each point (xi, yj) (where i=1,...,n; j=1,...,m) there is ameasured surface height zi,j = H(xi, yj). All three coordinates xi, yj, and zi,j are measured in standardunits (e.g., micrometers). The surface H is a 1-to-1 representation of the actual object. An exampleof 3D topographic data is a primer surface measured using a confocal microscope; where each pointH(xi, yj) represents the surface height (in micrometers) measured at the specified (xi, yj) position. 3Ddata captured on hardware compliant with ANSI/ASB Standard 061, Firearm and Toolmarks 3DMeasurement Systems and Measurement Quality Control can be used in virtual comparisonmicroscopy.

The branching structure of a phylogram

A fire scene where a fire continued to burn until most combustibles were consumed and the fire self-extinguished due to a lack of fuel or was extinguished when the fuel load was reduced by burning and there was sufficient suppression agent application to extinguish the fire.

physical evidence that can occur from the transfer of generally small quantities of materials (for example, fibers, glass, hairs, paint, tape).  

A minimal amount of target odor.

The property of a result of a measurement or value of a standard whereby it can be related with a stated uncertainty and to appropriate standards, generally international or national standards, through an unbroken chain of comparisons. The unbroken chain of comparisons is called a traceability chain. Traceability of a chemical species is frequently of equal or greater importance than the traceability of the calibration of the instruments used in the analysis.

Handwriting prepared by drawing the image of a genuine writing on a target document, which may be produced with the aid of carbon paper, transmitted light, or indented lines.

A path associated with a single read/write head on a data medium.

The scent pathway left by an individual moving.

The propensity or learned ability of a canine to methodically follow odor/scent on the ground (human/ground disturbance) by working the canine close to the pathway. Canines are not typically pre-scented on an object.

The format of transactions used in all versions of this standard prior to, and including thatof 2007. It is also included in this standard and is specified in Annex B: Traditionalencoding.

Solid or liquid fuel used to intentionally spread or accelerate the spread of a fire from one area to another.

The propensity or learned ability of a canine to methodically follow the target scent. The canine may follow a scent plume which could be either air borne or settled on the ground/vegetation. The canine will use whichever technique will get them to the target the most efficiently. Canines are typically pre-scented on an object.

The potential ability and the motivation on the part of the canine to learn and develop all the skills required, and the ability to learn from successes and failures.

An individual not yet authorized to conduct independent friction ridge examinations for the FSP, usually still in training.