A generalized simulation method of the tracking,telemetry and control（TT＆C） channel,which is applicable to wideband and arbitrary radio frequency（RF） signal,is proposed.It can accurately simulate the dynamic tran...A generalized simulation method of the tracking,telemetry and control（TT＆C） channel,which is applicable to wideband and arbitrary radio frequency（RF） signal,is proposed.It can accurately simulate the dynamic transmission delay of the arbitrary RF signal in channels,especially regardless of any prior knowledge including signal form,signal parameters,and so on.The proposed method orthogonally demodulates the wideband and arbitrary RF signal to complex baseband by a known local oscillator（LO） signal.Whereafter,it takes measures to obtain the delay reconstruction signal of baseband signals based on the dynamic transmission delay between a ground station and a responder.Meanwhile,it manages to obtain the delay reconstruction signal of LO signals.The simulation output signal（the delayed RF signal） can be achieved through the synthesis of the two delay reconstruction signals mentioned above.The principle and its related key technology are described in detail,and the realizable system architecture is given.展开更多
Aim:Reconstruction of orofacial soft tissue defect is often challenging and this is more difficult in resource challenged environment.This retrospective study highlights our experience with the use of forehead flap to...Aim:Reconstruction of orofacial soft tissue defect is often challenging and this is more difficult in resource challenged environment.This retrospective study highlights our experience with the use of forehead flap to overcome some of the challenges of orofacial reconstruction in a resource depleted environment.Methods:A 23-year retrospective analysis of all patients who had orofacial defect reconstruction using forehead flap in our department was undertaken.Information was sourced from patient’s case notes and operating theatre records.Data was analyzed using Statistical Package for Social Sciences(SPSS)version 16(SPSS Inc.,Chicago,IL,USA)and Microsoft Excel 2007(Microsoft,Redmond,WA,USA).Results:A total of 43 patients were managed within the period reviewed and consisted of 31(72.1%)males and 12(27.9%)females.Trauma 24(55.8%)accounted for most defect and the lip was the commonest site of defect.Complete forehead flap was used in 31(72.1%)of cases and when timing of defect repair is considered,delayed reconstruction was the preferred method.Postoperative complications was observed in 8(18.6%)patients and consisted of failed flap in 2(25.0%)patients,tumor recurrence in reconstructed site in 2(25.0%)patients and tumor occurrence in forehead flap donor site in 1(12.5%)patient.Conclusion:The forehead flap remains a reliable option in orofacial soft tissue defect reconstruction.It is easy to raise and can provide coverage for wide defects as far as the paramandibular and submandibular regions.Moreover,it does not require patient repositioning.展开更多
基金supported by the Foundation of Shanghai Aerospace Science and Technology(20120541088)
文摘A generalized simulation method of the tracking,telemetry and control（TT＆C） channel,which is applicable to wideband and arbitrary radio frequency（RF） signal,is proposed.It can accurately simulate the dynamic transmission delay of the arbitrary RF signal in channels,especially regardless of any prior knowledge including signal form,signal parameters,and so on.The proposed method orthogonally demodulates the wideband and arbitrary RF signal to complex baseband by a known local oscillator（LO） signal.Whereafter,it takes measures to obtain the delay reconstruction signal of baseband signals based on the dynamic transmission delay between a ground station and a responder.Meanwhile,it manages to obtain the delay reconstruction signal of LO signals.The simulation output signal（the delayed RF signal） can be achieved through the synthesis of the two delay reconstruction signals mentioned above.The principle and its related key technology are described in detail,and the realizable system architecture is given.
文摘Aim:Reconstruction of orofacial soft tissue defect is often challenging and this is more difficult in resource challenged environment.This retrospective study highlights our experience with the use of forehead flap to overcome some of the challenges of orofacial reconstruction in a resource depleted environment.Methods:A 23-year retrospective analysis of all patients who had orofacial defect reconstruction using forehead flap in our department was undertaken.Information was sourced from patient’s case notes and operating theatre records.Data was analyzed using Statistical Package for Social Sciences(SPSS)version 16(SPSS Inc.,Chicago,IL,USA)and Microsoft Excel 2007(Microsoft,Redmond,WA,USA).Results:A total of 43 patients were managed within the period reviewed and consisted of 31(72.1%)males and 12(27.9%)females.Trauma 24(55.8%)accounted for most defect and the lip was the commonest site of defect.Complete forehead flap was used in 31(72.1%)of cases and when timing of defect repair is considered,delayed reconstruction was the preferred method.Postoperative complications was observed in 8(18.6%)patients and consisted of failed flap in 2(25.0%)patients,tumor recurrence in reconstructed site in 2(25.0%)patients and tumor occurrence in forehead flap donor site in 1(12.5%)patient.Conclusion:The forehead flap remains a reliable option in orofacial soft tissue defect reconstruction.It is easy to raise and can provide coverage for wide defects as far as the paramandibular and submandibular regions.Moreover,it does not require patient repositioning.
