Reducing zero offset of MEMS sensors under thermal hysteresis conditions

This paper investigates variations of zero offset of MEMS sensors under thermal hysteresis conditions. An experiment was carried out to study the characteristics of zero offset at a constant ambient temperature, abrupt (2 degrees per minute) heating up and abrupt cooling down. A method for identifying zero offset component dependent on thermal dynamics is described. A calibration methodology for this component is proposed for the initial zero offset and zero drift under different thermal dynamics conditions. Application of said methodology is considered for two output information options: direct gyroscope and accelerometer readout and navigation system parameters based thereon (orientation, linear velocities and coordinates).

A parallel algorithm for the sparse QR decomposition of a rectangular upper quasi-triangular matrix with ND-type sparsity

Рассматривается параллельный алгоритм вычисления разреженного $QR$-разложения специальным образом упорядоченной прямоугольной матрицы на основе разреженных блочных преобразований Хаусхолдера. Для построения необходимого упорядочивания можно использовать столбцевое упорядочивание типа вложенных сечений, построенное по структуре матрицы $A^{T}A$, где $A$ - исходная прямоугольная матрица. Для сеточных задач упорядочивание может быть построено на основе известного объемного разбиения расчетной сетки. В качестве базового алгоритма для организации параллельных вычислений используется $QR$-разложение для наборов строк матрицы с дополнением в виде нулевого начального блока. An algorithm for computing the sparse $QR$ decomposition of a specially ordered rectangular matrix is proposed. This decomposition is based on the block sparse Householder transformations. For ordering computations, the nested dissection ordering is used for the matrix $A^{T}A$, where $A$ is the original rectangular matrix. For mesh based problems, the ordering can be constructed starting from an appropriate volume partitioning of the computational mesh. Parallel computations are based on sparse $QR$ decomposition for sets of rows with an additional initial zero block.

A Novel Multiphase Level Set Method to Image Segmentation Combined with Edge-Link Method

An improved level set PDE based on the Chan-Vese multiphase level set method is proposed. Because the segmentation results is well influenced by the initial zero level set, we use the method based on Edge-Link to obtain initial zero level set of the proposed multiphase level set segmentation model. Experimental results of ambiguous edges in human motion image suggest the efficiency and accuracy of the algorithm in its segmentation operations.

Development of chemical composition of grain during growth and ripening

The development of chemical composition of barley and oat grains was investigated in samples taken weekly from the beginning of kernel development to about two weeks over the normal harvesting time. The chemical composition of both grain species, but especially that of barley, was complete when the colour of crops was turning from green to yellow: the starch content increased from the initial zero level to its maximum, the sugar and crude fibre contents decreased to the low level of ripe grains. Over-ripening decreased the starch content and kernel weight.