OBJECTİVE: To compare the sensitivity and specificity of elevation maps obtained from different topographical reference surfaces used in the diagnosis of keratoconus. MATERİALS AND METHODS: In this ...study 40 eyes of 23 patients with keratoconus and 40 eyes of 25 refractive surgery candidates as a control group was measured with a Scheimpflug camera (Sirius CSO-Italy). Using the receiver operator characteristic curves (ROC), a comparison was made of the ability to differentiate keratoconus from a normal cornea with anterior elevation(AE) and posterior elevation(PE) measurements obtained from the spherical, aspherical, asphero-toric reference surfaces. RESULTS: The ROC curve analysis showed that posterior elevation measured from the aspherical and asphero-toric surfaces had a significantly higher area under the ROC curves (0.987, 0.973 respectively) thanthevalueobtainedfromthesphericalreferencesurfaces. According to the data obtained from the ROC curve analysis, the posterior elevation maps obtained from the aspherical and asphero-toric reference surfaces had the highest sensitivity (97.5% for both) and the posterior elevation map obtained from the aspherical reference surface had the highest specificity (90%). CONCLUSION: The highest sensitivity and specificity values were obtained from the aspherical and asphero-toric reference surfaces rather than from the spherical reference surface. When compared to the anterior elevation values, the posterior elevation values were found to be more sensitive and specific. Therefore, aspherical and asphero-toric reference surfaces and a posterior elevation map would seem to be more accurate in the differentiation of keratoconus and normal cornea.
To evaluate the contribution of reference bodies for elevation maps in diagnosis of keratoconus (KC) and forme fruste keratoconus (FFK).
Study groups included (1) 80 eyes with KC, (2) 55 eyes with ...FFK, and (3) 95 eyes as control eyes. The maximum elevation value at the central 5 mm of the posterior cornea (MEL) and the elevation value at thinnest corneal point (TEL) were evaluated for their diagnostic capacity using receiver operating characteristic curves under the following reference bodies: sphere, ellipsoid, toric ellipsoid, and torus, with autodiameter and fixed 8-mm-diameter settings. Moreover, characteristic parameters for each reference body and the root mean square (RMS) were evaluated for their diagnostic capacity.
Significant differences were detected in TEL, MEL, and RMS parameters among groups, for almost all reference bodies. The highest predictive accuracy (KC group, >99.97%; FFK group, >90.9%) was estimated for the TEL and MEL parameters using the toric ellipsoid (8 mm) reference body with a fixed eccentricity of 0.4. Moreover, the RMS parameter demonstrated sufficient diagnostic capacity (KC group, 99.95%; FFK group, 85.1%). The cutoff points for the TEL parameter were found to be 7 and 3 μm in the KC group and the FFK group, respectively; for the MEL parameter, they were 11 and 6 μm, respectively; and for the RMS parameter, they were 6.87 and 7.19 μm, respectively.
The posterior corneal elevation values and the RMS parameter can effectively discriminate KC from normal corneas, although measured values and cutoff points depend on the selection of reference body. Moreover, the use of a toric ellipsoid reference body, with a fixed eccentricity of 0.4, seems to be an effective tool even in diagnosis of FFK.
The derivation of reference values in 11 current dietary reference standards is often based on methods of extrapolation or interpolation, but these are not consistent across reports. Such methods are ...frequently employed to derive nutrient intake values (NIVs) for infants and children owing to the paucity of relevant research data available. The most common method is to extrapolate values for children down from those of adults, employing a weight or metabolic factor and adjusting for growth. In some instances, values for young children are extrapolated up from infants, values for adults are extrapolated up from children, or values for older adults are extrapolated up from young adults. Extrapolation is employed to estimate not only nutrient requirement or adequate intake but also the upper tolerable levels of intake. Extrapolation methods may also form the basis of estimates of tissue deposition of nutrients during growth in children and for the maternal/fetal dyad in pregnancy with adjustments for metabolic efficiency. Likewise, recommended intakes during lactation are extrapolated from known secretion of the nutrient in milk with adjustments for bioavailability. For future dietary standards, a first priority is to obtain relevant scientific data using current methodology, such as stable isotope tracers, body composition analysis, and appropriate biomarkers, from which NIVs for each age group can be derived. Extrapolation to derive an NIV is only acceptable in the sheer absence of sound scientific data and must be modeled with a consistent approach. For the purpose of harmonization of dietary standards, we recommend the following approaches that should be clearly described in reports: standardization of age groups on a biological basis (growth and pubertal stages) with consideration of relevant developmental milestones throughout childhood; application of internationally accepted standards for growth, body size, body composition, fetal and maternal nutrient accretion in pregnancy, and milk composition; and inclusion of appropriate adjustments (metabolic efficiency, weight change, or physical activity).
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
We previously derived a formula for calculating human body surface area (BSA) from V (body volume) and L (reference body length): BSA=(9 pi VL)(0.5). In this paper, we analyse first the effects of ...body density variation on BSA during growth and the scaling relation of BSA to body mass. Then we utilise the derived formula to calculate BSA of animals and compare the obtained data with the direct measurements on the same animals, including rat, chicken, dog, and cattle, from the literature. It is shown that two problems remain to be solved for applying the derived formula to all mammals and other animals: one is to find out the L for each species of animal by means of direct measurements, and the other is to obtain the variation of body density during growth.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
5.
Direct N-Body Codes Aarseth, Sverre J.
Cambridge N-Body Lectures,
2008, Volume:
760
Book Chapter
Peer reviewed
The classical formulation of the gravitational N-body problem is deceptively simple. Given initial values of N masses, coordinates and velocities, the task is to calculate the future orbits. Although ...the motions are in principle completely determined by the underlying differential equations, accurate solutions can only be obtained by numerical methods. Self-gravitating stellar systems experience highly complicated interactions, which require efficient procedures for studying the long-term behaviour.
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FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
6.
유아복의 KS 치수체계 개정을 위한 제안 연구 정명숙; Myoung Sook Jung; 서추연 ...
Fashion & textile research journal,
02/2014, Volume:
16, Issue:
1
Journal Article
Open access
This study proposed a revision of standard sizing system for infant clothing to provide exact information for consumers and manufacturers. The size designation was set up by compensating the defect ...of existing system. Basic body measurement and reference body measurement were analysed according to size designation. The ages of the infants ranged from 0 to 36 month in accordance with safety standard of KC Self-Regularity Safety Confirmation. The results are as follows: Size designation for infant clothing was based on height that was basic body measurement. Chest girth, waist girth, head girth, arm length, foot length and weight were also analysed according to age of the month. It was proposed that height could be written alone and height with age of month did together for size designation. Size intervals of basic and reference body measurements were fixed as follows: size intervals are 5 cm in height, 2 cm in chest girth, 2 cm in waist girth, 1 cm in head girth, 2 cm in arm length, 0.5 cm in foot length and 2 kg in weight. The distributions of height and chest girth showed normal distributions. As height was taller, chest girth was also bigger. But the distribution of waist irth didn``t show remarkable change with age of month. The distributions of arm length and weight showed remarkable difference with growth in 0~9 months, but the amount of growth variation got less in 12~18 months.
The standard interpretation of Newtonian physics takes the concept of mass to be a primitive property of bodies. The most elementary Newtonian object is a particle that occupies a point in space at a ...particular time. The particle has a trajectory, or a continuous mapping from instants of time into three-dimensional space. According to the standard interpretation, each point-particle carries with it an inherent property of mass which compels a body to resist the action of impressed forces. Thus, one often finds reference in expositions of Newtonian physics to a “point mass,” or a “particle of mass m,” as the most primitive material entity.
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FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Einstein's attempt to realize Machian ideas in the construction of general relativity was undoubtedly a very major stimulus to the creation of that theory. Indeed, the very name of the theory derives ...from Einstein's conviction that a theory which does justice to Mach's critique of Newton's notion of absolute space must be generally relativis-tic, or covariant with respect to the most extensive possible transformations of the spacetime coordinates.
The extent to which general relativity is actually Machian is, however, the subject of great controversy. During the last six months, I have been examining closely all of Einstein's papers that concern the special and general theory of relativity together with a substantial proportion of his correspondence related to relativity. There were several things that I wished to establish: 1) What precisely was the defect (or defects) in the Newtonian scheme that Einstein sought to rectify in his general theory of relativity? 2) How did Einstein propose to rectify the perceived defect(s)? 3) What relation does Einstein's work on his Machian ideas bear to the other ideas and work of his predecessors and contemporaries on the problem of absolute and relative motion? 4) Finally, to what extent did general relativity solve that great and ancient problem of the connection between and status of absolute and relative motion?
The present investigation is an attempt to improve the aerodynamic effectiveness of aero-spikes aerospike@aero-spike located at the nose of supersonic blunt bodies flying at a wide range of angles of ...attack (AoA). For this purpose, the use of pivoting spikes, which can maintain their favorable alignment relative to the incoming flow independent from the body’s orientation, is proposed. The proof-of-concept experiments for the pivoting spikes have been conducted in the Ludwieg Tube Facility at DLR Göttingen at Mach 2, 3 and 5 for angles of attack from 0 to 30 degrees. The model tested is a cylindrical body with a hemispherical nose. Additionally to the body equipped with a pivoting spike the reference body without a spike and the body with a conventional fixed spike were investigated. The results containing shadowgraph visualizations, direct force measurements and infrared heat flux measurements show the clear adventages of the pivoting spikes.
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