VALIDATION OF LIDAR SURVEY DATA BY COMPARISON OF SEVERAL UNCERTAINTY MODELS

This paper introduce a new method for validating the precision of an airborne or a mobile LiDAR data set. The proposed method is based on the knowledge of an a Combined Standard Measurement Uncertainty (CSMU) model which describes LiDAR point covariance matrix and thus uncertainty ellipsoid. The model we consider includes timing errors and most importantly the incidence of the LiDAR beam. After describing the relationship between the beam incidence and other variable uncertainty (especially attitude uncertainty), we show that we can construct a CSMU model giving the covariance of each oint as a function of the relative geometry between the LiDAR beam and the point normal. The validation method we propose consist in comparing the CSMU model (predictive a priori uncertainty) t the Standard Deviation Alog the Surface Normal (SDASN), for all set of quasi planr segments of the point cloud. Whenever the a posteriori (i.e; observed by the SDASN) level of uncertainty is greater than a priori (i.e; expected) level of uncertainty, the point fails the validation test. We illustrate this approach on a dataset acquired by a Microdrones mdLiDAR1000 system.

Insulin resistance: associations of personal characteristics and factors of lifestyle

Objective — to study the relationship of IR with some clinical characteristics (body weight, BMI, level of HbA1c) and social and psychological parameters in patients with type 2 diabetes and IGT.Material and methods.IR was assessed by determining fasting blood glucose and insulin (HOMA — homeostasis model assessment, the calculation of the IR index), patients were tested by using valid questionnaires (Strategic Approach to Coping Scale, The Level of Subjective Control, Self-attitude Questionnaire), and life style questionnaires.Results.Multiple associations of IR index with personal characteristics are revealed. The psychological profile of a patient with a high IR includes the reduction of positive self-attitude, uncertainty in their own abilities, especially in the interpersonal relationships. Such features can provoke rejection of the active and targeted overcome the difficulties of life, the desire to avoid decisions, and if it is impossible — aggressive reactions with defensive character and reflect the uncertainty in their forces. The association of body weight and results of psychological tests were detected: the more the worse self-attitude in a number of aspects. The correlations of IR index and weight with some characteristics of lifestyle (dietary habits, especially sleep) were also revealed.Conclusions.The observed association of IR and personal characteristics and lifestyle features are of interest and required larger studies.