Percentage error (relative to the observed value) is often felt to be more meaningful than the absolute error in isolation. The mean absolute percentage error (MAPE) is widely used in forecasting as a basis of comparison, and regression models can be fitted which minimize this criterion. Unfortunately, no formula exists for the coefficients, and models for a given data set may not be unique. We...

Penalization procedures often suffer from their dependence on multiplying factors, whose optimal values are either unknown or hard to estimate from the data. We propose a completely data-driven calibration algorithm for this parameter in the least squares regression framework, without assuming a particular shape for the penalty. Our algorithm relies on the concept of minimal penalty, recently i...

We consider the problem of learning, from K data, a regression function in a linear space of high dimensionN using projections onto a random subspace of lower dimension M . From any algorithm minimizing the (possibly penalized) empirical risk, we provide bounds on the excess risk of the estimate computed in the projected subspace (compressed domain) in terms of the excess risk of the estimate b...

PURPOSE The primary purpose of this study was to measure the in vitro scaphoid and lunate motion during 9 different variations of a wrist dart throw motion. Another goal was to determine the specific dart throw motion that minimized scaphoid and lunate motion. METHODS Scaphoid and lunate motion were recorded in 7 cadaver forearms during various combinations of wrist dart throw motions caused ...

objectives: accurate localization of the inferior alveolar canal (iac) is extremely important in some dental treatments. anatomical variation of the canal means that it can be difficult to locate. the purpose of this study was to assess the relationship of the gonial angle (ga) size and iac position using cone beam computed tomography (cbct). materials and methods: in this in vitro study, 61 dr...

INTRODUCTION A rare case of congenital bipartite lunate in a child is reported. Carpal variants are very uncommon as independent entities, with only three previous reports of this condition in the English literature. CASE PRESENTATION An 11-year-old Caucasian boy presented with pain in the left wrist after a fall. Radiographs in the emergency department demonstrated a lunate that was divided ...

Aeolian sand dunes originate from wind flow and sand bed interactions. According to wind properties and sand availability, they can adopt different shapes, ranging from huge motion-less star dunes to small and mobile barchan dunes. The latter are crescentic and emerge under a unidirectional wind, with a low sand supply. Here, a 3d model for barchan based on existing 2d model is proposed. After ...

Kienbock’s disease (lunatomalacia), first described by Robert Kienbock as ligamentous trauma to the lunate resulting in the interruption of internal arterial supply to the bone [1], is defined as a specific form of avascular osteonecrosis affecting the lunate. Kienbock’s disease is characterized by sclerosis, cystic changes, fragmentation, and articular surface collapse as present on plain radi...

Aeolian desert sand dunes birth from wind flow and sand bed interactions: depending on wind properties and sand availability, they can adopt several different shapes from huge motionless star dunes to small and fast mobile barchan dunes. These latter have a characteristic crescentic shape and form on hard ground with low sand supply under a monodirectional wind . Here, a 3d barchan model based ...