3D variable-grid full-waveform inversion on GPU

Full-waveform inversion(FWI)is a powerful tool to reconstruct subsurface geophysical parameters with high resolution.As3 D surveys become widely implemented,corresponding 3 D processing techniques are required to solve complex geological cases,while a large amount of computation is the most challenging problem.We propose an adaptive variable-grid 3 D FWI on graphics processing unit devices to improve computational efficiency without losing accuracy.The irregular-grid discretization strategy is based on a dispersion relation,and the grid size adapts to depth,velocity,and frequency automatically.According to the transformed grid coordinates,we derive a modified acoustic wave equation and apply it to full wavefield simulation.The 3 D variable-grid modeling is conducted on several 3 D models to validate its feasibility,accuracy and efficiency.Then we apply the proposed modeling method to full-waveform inversion for source and residual wavefield propagation.It is demonstrated that the adaptive variable-grid FWI is capable of decreasing computing time and memory requirements.From the inversion results of the 3 D SEG/EAGE overthrust model,our method retains inversion accuracy when recovering both thrust and channels.

Clinical study on bladder function recovery of 360 cases after radical hysterectomy treated by acupuncture

Objective:To analysis the clinical curative effect on bladder function recovery after radical hysterectomy with acupuncture and acu-physiotherapy.Methods:A total of 564 cervical cancer patients in the gynecology department who received radical hysterectomy from January 2011 to December 2017 in Qilu Hospital of Shandong University were collected.According to the inclusion and exclusion criteria,we studied 360 case records at last,with 120 cases respectively.Patients got treatment of acupuncture[acupuncture at Zhongwan(中脘CV12),Tianshu(天枢ST25),Shuidao(水道ST28),TAichong(太冲LI3),Sanyinjiao(三阴交SP6),Zusanli(足三里ST36)and Yinlingquan(阴陵泉SP9)],or acu-physiotherapy with two large-size electrodes placed on the bladder area above the pubic symphysis besides acupuncture,from the 3 rd day after operation once a day till the14 th day that removing the indwelling catheter.And the blank group got no other auxiliary treatment except scrubbed the meatus orifice with iodophor twice a day.We tested the residual urine volume 6 h later after removement of indwelling catheter.Residual urine volume more than 100 mL was defined as urinary retention,and the volume less than 50 mL was defined as adequate bladder emptying.Results:We analyzed patients’age,the International Federation of Gynecology and Obstetrics(FIGO)stage,operation duration,amount of hemorrhage,depth of myometrium infiltration,cancer embolus,parametrium invasion,lymphatic metastasis,treating methods and residual urine volume recorded in case records,and there was no significant difference between every two groups(P>0.05).The incidences of urinary retention of the acupuncture group,the acu-physiotherapy group and the blank group were 24.17%,21.67%,and 44.17%,indicating that both treating methods have significant effects(P<0.05),and acupuncture group was a little better than acu-physiotherapy group.The bladder function recovery rates of the 3 groups were 44.17%,56.67%,and 40.83%correspondingly,which had significant difference between acu-physiotherapy group and blank group(P<0.05).Both acupuncture and acu-physiotherapy could reduce the incidence of urinary retention for the patients of Ibl and IIal stages(P<0.01),whilst for patients of Ib2 and IIa2 stages,neither of the two methods was effective(P>0.05).Conclusion:Both acupuncture and acu-physiotherapy could prevent urinary retention after radical hysterectomy for local early cervical cancer(Ibl and IIal stages)effectively,and acupuncture was a little more effective than acu-physiotherapy group.Acupuncture together with modulated medium frequency eletro-therapy could improve the cure rate of bladder function and minimize the residual urine volume.