摘要:
A repeater for a multibeam communications satellite combines the features of coaxial channel interbeam switching and subchannelization of some of the channels. In one embodiment described, the input radio-frequency signals from the input beams are fed through the input multiplexers to form channels. Some, but not all, channels are subsequently subchannelized for interbeam switching. In another embodiment of the invention, a portion of the incoming radio frequency signals bypasses the input demultiplexer and is filtered for noise-limiting reasons, converted down to an intermediate frequency and then subchannelized using SAW filters. The specification also teaches that digital techniques can be used to obtain the same results. Especially in the case of satellites with a large number of beams and a large number of channels, it is not necessary to have full interbeam switching of all the subchannels derived from one channel: instead, the specification proposes the use of parallel configurations of smaller, less complex switching networks.
摘要:
A method and apparatus to determine an optimum collimator angle of a multi-leaf collimator having an opening and multiple leaf pairs for closing portions of the opening to form a radiation beam arrangement having multiple radiation beam segments. The method and apparatus include application of a cost function to determine a collimator angle which provides for delivery efficiency and target conformity. The user can preferentially either selectively enhance delivery efficiency of the radiation beam arrangement, reducing a number of radiation beam segments and reducing a number of radiation beam monitor units required for delivery of the desired prescription, or selectively enhance conformity of the radiation beam arrangement to a target shape. The optimum collimator angle is then used for delivery of an optimized radiation beam arrangement to a patient by a radiation delivery device.
摘要:
An elective healthcare insurance model using an individual's own peripheral blood stem cells for the individual's future healthcare uses. An individual can elect to have his or her own stem cells collected, processed and preserved, while he or she is in healthy or “pre-disease” state, for future distribution for his or her healthcare needs. The process includes methods of collection, processing, preservation and distribution of adult (including pediatric) peripheral blood stem cells during non-diseased state. The stem cells collected will contain adequate dosage amounts, for one or more transplantations immediately when needed by the individual for future healthcare treatments. The collected adult or non-neonate child peripheral blood stem cells can be aliquoted into defined dosage fractions before cryopreservation so that cells can be withdrawn from storage without the necessity of thawing all of the collected cells.
摘要:
The invention provides for measurement of an actual magnitude of an applied magnetic field, rather than providing a value of magnetic field which is relative to an unknown quiescent value. In particular, by providing a SQUID (100) having an effective area which varies in response to applied flux, an absolute value of magnetic field can be determined due to the change in effective area of the SQUID (100).