When a robot arm(s) conducts some tasks on a satellite, the satellite attitude stability is necessary against the robot arm's motion to maintain the communication link and to generate electrical power from the solar panel(s). However the reaction from the robot arm is much stronger than the natural environmental disturbance torque that the traditional satellite attitude control system cares. Na...

Satellite image classification process involves grouping the image pixel values into meaningful categories. Several satellite image classification methods and techniques are available. Satellite image classification methods can be broadly classified into three categories 1) automatic 2) manual and 3) hybrid. All three methods have their own advantages and disadvantages. Majority of the satellit...

We have identified and determined the sequence and organization of a new rat satellite DNA in Rattus rattus, the roof rat. This satellite DNA, which we call R. rattus satellite I', consists of tandem arrays of a 185 base pair (bp) repeat unit that we call a'. a' is 86% homologous to a 185 bp portion of the 370 bp repeat unit of the previously described rat satellite [Pech et al. (1979) Nucleic ...

Different from terrestrial networks, satellite network topology is time-varying. Moreover, satellite networks communication resources are scare and expensive. So it is important to research on the fault management for satellite networks to insure it work safely and smoothly. However, the traditional fault management method for terrestrial networks is difficult to use for satellite networks. In ...

Satellite cells are quiescent muscle stem cells that promote postnatal muscle growth and repair. Here we show that myostatin, a TGF-beta member, signals satellite cell quiescence and also negatively regulates satellite cell self-renewal. BrdU labeling in vivo revealed that, among the Myostatin-deficient satellite cells, higher numbers of satellite cells are activated as compared with wild type....

Skeletal muscle has great regenerative capacity which is dependent on muscle stem cells, also known as satellite cells. A loss of satellite cells and/or their function impairs skeletal muscle regeneration and leads to a loss of skeletal muscle power; therefore, the molecular mechanisms for maintaining satellite cells in a quiescent and undifferentiated state are of great interest in skeletal mu...

invention of satellite and the use of it in the broadcasting technology ,evolved the broadcasting organizations activities. on one hand, it developed the scope of broadcasting geographically and to some extent solved the limitations and problems of transmitting signals such as difficulties in receiving the signals in mountainous or wood areas. on the other hand, the use of satellites on transmi...

A long time ago, since the launch of the first artificial satellite in 1957, controling attitude of satellites has been considered by the designers and engineers of aerospace industry. Considering the importance of this issue various methods of control in response to this need have been presented and analyzed until now. In this paper, we propose and analyze a three-axis optimal control on the s...