In a dynamic CT, the acquired projections are corrupted due to strong dynamic nature of the object, for example: lungs, heart etc. In this paper, we present fan-beam reconstruction algorithm without position-dependent...In a dynamic CT, the acquired projections are corrupted due to strong dynamic nature of the object, for example: lungs, heart etc. In this paper, we present fan-beam reconstruction algorithm without position-dependent backprojection weight which compensates for the time-dependent translational, uniform scaling and rotational deformations occurring in the object of interest during the data acquisition process. We shall also compare the computational cost of the proposed reconstruction algorithm with the existing one which has position-dependent weight. To accomplish the objective listed above, we first formulate admissibility conditions on deformations that is required to exactly reconstruct the object from acquired sequential deformed projections and then derive the reconstruction algorithm to compensate the above listed deformations satisfying the admissibility conditions. For this, 2-D time-dependent deformation model is incorporated in the fan-beam FBP reconstruction algorithm with no backprojection weight, assuming the motion parameters being known. Finally the proposed reconstruction algorithm is evaluated with the motion corrupted projection data simulated on the computer.展开更多
The M7.9 Nepal earthquake of 25 April2015 had over 8, 500 fatalities and was the most destructive earthquake in Nepal since the Bihar-Nepal earthquake in 1934.In this study, we imaged the rupture process of this Nepal...The M7.9 Nepal earthquake of 25 April2015 had over 8, 500 fatalities and was the most destructive earthquake in Nepal since the Bihar-Nepal earthquake in 1934.In this study, we imaged the rupture process of this Nepal event by back-projecting the teleseismic P-wave energy recorded at the three regional networks in Alaska, Australia and Europe. The back-projection images of the three subarrays revealed that the Nepal earthquake propagated along the strike in a southeast direction over a distance of ～ 160–170 km with the duration of ～ 50–55 s. The rupture process was found to be a simple, unilateral event with a near constant velocity of 3.3 km/s.The beam power was mainly distributed in the geographic region just north of Kathmandu and the peak intensity for the source time function curve occurred at about 30 s. The earthquake was destructive due to its occurrence at shallow depth(～ 12–15 km) and the fact that the capital lies in a basin of soft sediment. Additionally, the resonance effect for the longer period waves that occurred in the Kathmandu valley led to destructive aggravation, impacting mainly the taller buildings.展开更多
OBJECTIVE:To investigate the effect of acupressure on postpartum low back pain(LBP),salivary cortisol,physical limitations,and postpartum depression.METHODS:Participants were 70 postpartum women who were randomly assi...OBJECTIVE:To investigate the effect of acupressure on postpartum low back pain(LBP),salivary cortisol,physical limitations,and postpartum depression.METHODS:Participants were 70 postpartum women who were randomly assigned to either an intervention(n=35)or a control(n=35)group.The intervention group received 10 acupressure sessions(1 session per day,5 d per week).The control group received 10 sham acupressure sessions.Outcomes were assessed using a visual analogue scale(LBP intensity),salivary cortisol values(LBP biomarker),and Chinese versions of the Roland-Morris Disability Questionnaire(daily activity limitations),Oswes-try Disability Index(physical activity limitations),and the Edinburgh Postnatal Depression Scale(postpartum depression).RESULTS:Participants in the intervention group had significantly lower levels of LBP intensity,daily activity limitations,physical activity limitations,and postpartum depression than those in the control group.There was no significant between-group difference in salivary cortisol.CONCLUSION:Acupressure may reduce postpartum LBP intensity and limitations in daily and physical activity,and alleviate postpartum depressive symptoms.Acupressure should be offered in postpartum care settings as an alternative treatment for postpartum women with LBP.展开更多
文摘In a dynamic CT, the acquired projections are corrupted due to strong dynamic nature of the object, for example: lungs, heart etc. In this paper, we present fan-beam reconstruction algorithm without position-dependent backprojection weight which compensates for the time-dependent translational, uniform scaling and rotational deformations occurring in the object of interest during the data acquisition process. We shall also compare the computational cost of the proposed reconstruction algorithm with the existing one which has position-dependent weight. To accomplish the objective listed above, we first formulate admissibility conditions on deformations that is required to exactly reconstruct the object from acquired sequential deformed projections and then derive the reconstruction algorithm to compensate the above listed deformations satisfying the admissibility conditions. For this, 2-D time-dependent deformation model is incorporated in the fan-beam FBP reconstruction algorithm with no backprojection weight, assuming the motion parameters being known. Finally the proposed reconstruction algorithm is evaluated with the motion corrupted projection data simulated on the computer.
基金supported by the National Natural Science Foundation of China (No.41604049)
文摘The M7.9 Nepal earthquake of 25 April2015 had over 8, 500 fatalities and was the most destructive earthquake in Nepal since the Bihar-Nepal earthquake in 1934.In this study, we imaged the rupture process of this Nepal event by back-projecting the teleseismic P-wave energy recorded at the three regional networks in Alaska, Australia and Europe. The back-projection images of the three subarrays revealed that the Nepal earthquake propagated along the strike in a southeast direction over a distance of ～ 160–170 km with the duration of ～ 50–55 s. The rupture process was found to be a simple, unilateral event with a near constant velocity of 3.3 km/s.The beam power was mainly distributed in the geographic region just north of Kathmandu and the peak intensity for the source time function curve occurred at about 30 s. The earthquake was destructive due to its occurrence at shallow depth(～ 12–15 km) and the fact that the capital lies in a basin of soft sediment. Additionally, the resonance effect for the longer period waves that occurred in the Kathmandu valley led to destructive aggravation, impacting mainly the taller buildings.
基金Supported by the Chang Gung Memorial Hospital:the Effects of Acupressure on Postpartum Low Back Pain(No.CMRPG8G0941).
文摘OBJECTIVE:To investigate the effect of acupressure on postpartum low back pain(LBP),salivary cortisol,physical limitations,and postpartum depression.METHODS:Participants were 70 postpartum women who were randomly assigned to either an intervention(n=35)or a control(n=35)group.The intervention group received 10 acupressure sessions(1 session per day,5 d per week).The control group received 10 sham acupressure sessions.Outcomes were assessed using a visual analogue scale(LBP intensity),salivary cortisol values(LBP biomarker),and Chinese versions of the Roland-Morris Disability Questionnaire(daily activity limitations),Oswes-try Disability Index(physical activity limitations),and the Edinburgh Postnatal Depression Scale(postpartum depression).RESULTS:Participants in the intervention group had significantly lower levels of LBP intensity,daily activity limitations,physical activity limitations,and postpartum depression than those in the control group.There was no significant between-group difference in salivary cortisol.CONCLUSION:Acupressure may reduce postpartum LBP intensity and limitations in daily and physical activity,and alleviate postpartum depressive symptoms.Acupressure should be offered in postpartum care settings as an alternative treatment for postpartum women with LBP.
