The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Low frequency error of star sensor that caused by the thermal distortion of star sensor and its installation structure is an important part of the star sensor's measurement error. And it is one of the most important factors that affect the satellite attitude determination accuracy and cannot be eliminated by traditional filtering method. In order to deal with this problem, a low frequency error compensation...
A new method to embed the watermarks in the amplitude of the quaternion is proposed this paper. Firstly, ununiformity of each unit quaternion block in host image is calculated to pick up the potential block adaptively. Secondly, frequency matrix of host color image is obtained by using quaternion Fourier transform. After that, the water marks are embedded into the amplitude of AC coefficient. Experimental...
In order to overcome the defects of traditional-method filtering which based on keywords, the OWL text filtering is presented in the semantic Web environment, which makes information filtering, has been raised to the level of semantics. Through distinguishing the information between the title and text, and then calculating the semantic similarity of semantic, using the integrated filtering methods,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.