Classification and Grading Systems

Classification of age-related macular degeneration is required for studies investigating the condition in order to make reliable comparisons between findings. For this reason, the international classification and grading system for... 

Bird AEC, Bressler NM, Bressler SB, Chisholm IH, Coscas G, Davis MD, Dejong P, Klaver CCW, Klein BEK, Klein R, Mitchell P, Sarks JP, Sarks SH, Sourbane G, Taylor HR, Vingerling JR (1995) An International classification and grading system for age- related maculopathy and age-related macular degeneration. Surv Ophthalmol 39 367-374... 

Dixon, M. et al.. Classification and grading of gastritis the updated Sydney system, J. 

All of these documents stress a requirement for room classifications according to the concentration of non-viable airborne particles at 0.5 pm and larger. The EU GMPs subordinate classification of the various areas applicable to sterile manufacture according a broader based grading system. Grades A to D are defined in terms of a range of independent characteristics such as the concentration of non-viable airborne particles at two sizes in operational and non-operational conditions, the concentration of airborne... 

As in acute liver failure, the main symptoms of HE are alterations in consciousness, cognitive dysfunction and motor disturbances. While patients with ALE often appear irritable and restless in the very beginning, psychomotor slowing is characteristic for type C HE. The alteration of consciousness is the basis for the 4-stage grading system of hepatic encephalopathy used world wide (West Haven classification) (Atterbury et al., 1978). 

Chapter 4). It is unnecessary to repeat this discussion except to note that this particular aspect of coal science (petrography) deals with the individual components of coal as an organic rock (Chapter 4) whereas the nomenclature, terminology, and classification systems are intended for application to the whole coal. Other general terms that are often applied to coal include rank and grade, which are two terms that describe the particular characteristics of coal. 

Annual bleeding rate of AVM is estimated 2%-4%, but caution is advised since data on bleeding rate are inhomogenous The classification of Spetzler and Martin is a grading system to assess the surgical risk of complications... 

As illustrated in Chapter 13, there are two staging systems employed in penile carcinoma the Jackson classification and the TNM classification. Staging criteria include tumor size, depth, localization, histological type, grade of differentiation and involvement of the erectile bodies. Neoplastic embolization of lymphatic and venous vessels is predictive for positive groin lymph nodes (Sanz Mayayo et al. 2004). 

Finally, the plant and business systems should be graded according to the potential impact of cyber-attacks. Within the nuclear industry, the International Atomic Energy Agency s (IAEA) publication 1527 makes reconunendations for minimum countermeasures according to security classification. A simplified version of the IAEA s classification is as shown in Table 3.4. 

Several grading systems of JAF have been presented but the Fisch classification [] is the most extensively used one. Fisch classifies JAF into four types. Fisch type 1 is when the tumor is limited to the nasopharynx and nasal cavity without bony erosion. Fisch type 2 defines a JAF that invades the pterygomaxil-lary fossa and the maxillary, ethmoid and parasellar region but remains lateral to the cavernous sinus. Type 3 is defined as JAF tumors that invade the infratemporal fossa, orbit and parasellar region but remain lateral to the cavernous sinus. Finally, the type 4 tumors are those that show massive invasion of the cavernous sinus, the optic chiasmal region, or the pituitary fossa. 

The amount of risk reduction means the residual risk presented by the device. The SIL table provides a class of safety integrity. An SIL 1 device is not as reliable in providing risk reduction as a SIL 2 device SIL 3 is better and SIL 4 is best. An SIL is the safety classification or grading of a system. The more LOP, the greater the RRF, where RRF = 1/PFD. The particular SIL that is required drives the device architecture to achieve that level. 

Many piping standards still reference the older type and grade designation system. To assist in the conversion, new releases of ASTM D 1784 include a table (see Table 2.5) that cross-references the older with the new cell classifications. 

In order to get a scale of performance safety practitioners have adopted the concept of safety integrity levels or (SILs). The SILs are derived from earlier concepts of grading or classification of safety systems. The principle is illustrated in the next figure where the layer of protection provided by an SIS is seen to be quantified as a risk reduction factor from which it can be converted to a PFDavg and referenced to an SIL classification table. 

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