The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing paramet...The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing parameter design method, this paper proposes an optimization design scheme based on orthogonal testing and support vector machines （SVMs）. Orthogonal testing design is used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iterations and improve the identification accuracy and efficiency. Orthogonal tests consisting of three factors and three levels are designed to analyze the parameters of pressure, uniform applied load and the number of chambers that affect the bending response of inflatable wings. An SVM intelligent model is established and limited orthogonal test swatches are studied. Thus, the precise relationships between each parameter and product quality features, as well the signal-to-noise ratio （SNR）, can be obtained. This can guide general technological design optimization.展开更多
Augmented reality is widely used in aeronautics and is a developing concept within surgery. In this pilot study, we developed an application for use on Google Glass optical head-mounted display to train urology reside...Augmented reality is widely used in aeronautics and is a developing concept within surgery. In this pilot study, we developed an application for use on Google Glass optical head-mounted display to train urology residents in how to place an inflatable penile prosthesis. We use the phrase Augmented Reality Assisted Surgery to describe this novel application of augmented reality in the setting of surgery. The application demonstrates the steps of the surgical procedure of inflatable penile prosthesis placement. It also contains software that allows for detection of interest points using a camera feed from the optical head-mounted display to enable faculty to interact with residents during placement of the penile prosthesis. Urology trainees and faculty who volunteered to take part in the study were given time to experience the technology in the operative or perioperative setting and asked to complete a feedback survey. From 30 total participants using a lO-point scale, educational usefulness was rated 8.6, ease of navigation was rated 7.6, likelihood to use was rated 7.4, and distraction in operating room was rated 4.9. When stratified between trainees and faculty, trainees found the technology more educationally useful, and less distracting. Overall, 81% of the participants want this technology in their residency program, and 93% see this technology in the operating room in the future. Further development of this technology is warranted before full release, and further studies are necessary to better characterize the effectiveness of Augmented Reality Assisted Surgery in urologic surgical training.展开更多
The presence of wrinkles in the membrane is the main factor to induce the reflector surface inaccuracy of the space inflatable antenna.Based on the commercial finite element package ABAQUS,a numerical procedure for me...The presence of wrinkles in the membrane is the main factor to induce the reflector surface inaccuracy of the space inflatable antenna.Based on the commercial finite element package ABAQUS,a numerical procedure for membrane wrinkle analysis was set up and used to analyze a space inflatable antenna which was under inner pressure to evaluate its wrinkle characteristics.First,the inner pressure effect on the reflector's wrinkle pattern was studied thoroughly.As inner pressure increases,both the number and the amplitude of the wrinkles decrease,but the total deformation of the whole reflector surface increases much.Second,the influence of the interactions between antenna's parts was investigated comprehensively.Any kind of unwanted interaction deteriorates reflector's wrinkle characteristics.The works are valuable to the development and research of the space inflatable antenna.展开更多
An inflatable cuff wrapped around the upper arm is widely used in noninvasive blood pressure measurement.However, the mechanical interaction between cuff and arm tissues, a factor that potentially affects the accuracy...An inflatable cuff wrapped around the upper arm is widely used in noninvasive blood pressure measurement.However, the mechanical interaction between cuff and arm tissues, a factor that potentially affects the accuracy of noninvasive blood pressure measurement, remains rarely addressed. In the present study, finite element（FE） models were constructed to quantify intra-arm stresses generated by cuff compression, aiming to provide some theoretical evidence for identifying factors of importance for blood pressure measurement or explaining clinical observations. Obtained results showed that the simulated tissue stresses were highly sensitive to the distribution of cuff pressure on the arm surface and the contact condition between muscle and bone. In contrast, the magnitude of cuff pressure and small variations in elastic properties of arm soft tissues had little influence on the efficiency of pressure transmission in arm tissues. In particular, it was found that a thickened subcutaneous fat layer in obese subjects significantly reduced the effective pressure transmitted to the brachial artery, which may explain why blood pressure overestimation occurs more frequently in obese subjects in noninvasive blood pressure measurement.展开更多
The availability of high‐strength fabrics and progress in the development of large‐scale inflatable technology made possible the creation of temporary and quickly deployable structures for protection of underground ...The availability of high‐strength fabrics and progress in the development of large‐scale inflatable technology made possible the creation of temporary and quickly deployable structures for protection of underground infrastructure.Inflatable structures are relatively lightweight and portable,and can maintain the required rigidity while in operation.These benefits have prompted the development of inflatable structures for use in confined spaces,such as tunnels and large‐diameter pipes to act as barriers for containing flooding with minimal infrastructure modification.This work presents experimental results obtained from the evaluation of frictional characteristics of the fabric material that constitute the structural membrane of confined inflatable structures developed for protection of underground transportation tunnels and other large conduits.Friction tests at coupon level and slippage tests in a reduced‐scale inflatable structure were performed in order to evaluate the frictional characteristics of Vectran webbings.Tests at coupon level were performed to determine the friction coefficient for different surface types and conditions.Tests with the reduced‐scale inflatable structure contributed to the understanding of the friction characteristics at system level when subjected to different pressurization or depressurization sequences designed to induce slippage.Test results indicate that friction coefficient values at coupon level are about 29 percent higher than values derived from reduced‐scale tests.展开更多
This paper extends Le van＇s work to the case of nonlinear problem and the complicated configuration. The wrinkling stress distribution and the pressure effects are also included in our analysis. Pseudo-beam method is...This paper extends Le van＇s work to the case of nonlinear problem and the complicated configuration. The wrinkling stress distribution and the pressure effects are also included in our analysis. Pseudo-beam method is presented based on the inflatable beam theory to model the inflatable structures as a set of inflatable beam elements with a prestressed state. In this method, the discretized nonlinear equations are given based upon the virtual work principle with a 3-node Timoshenko＇s beam model. Finite element simulation is performed by using a 3-node BEAM189 element incorporating ANSYS nonlinear program. The pressure effect is equivalent included in our method by modifying beam element cross-section parameters related to pressure. A benchmark example, the bending case of an inflatable cantilever beam, is performed to verify the accuracy of our proposed method. The comparisons reveal that the numerical results obtained with our method are close to open published analytical and membrane finite element results. The method is then used to evaluate the whole buckling and the loadcarrying characteristics of an inflatable support frame subjected to a compression force. The wrinkling stress and region characteristics are also shown in the end. This method gives better convergence characteristics, and requires much less computation time. It is very effective to deal with the whole load-carrying ability analytical problems for large scale inflatable structures with complex configuration.展开更多
文摘The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing parameter design method, this paper proposes an optimization design scheme based on orthogonal testing and support vector machines （SVMs）. Orthogonal testing design is used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iterations and improve the identification accuracy and efficiency. Orthogonal tests consisting of three factors and three levels are designed to analyze the parameters of pressure, uniform applied load and the number of chambers that affect the bending response of inflatable wings. An SVM intelligent model is established and limited orthogonal test swatches are studied. Thus, the precise relationships between each parameter and product quality features, as well the signal-to-noise ratio （SNR）, can be obtained. This can guide general technological design optimization.
文摘Augmented reality is widely used in aeronautics and is a developing concept within surgery. In this pilot study, we developed an application for use on Google Glass optical head-mounted display to train urology residents in how to place an inflatable penile prosthesis. We use the phrase Augmented Reality Assisted Surgery to describe this novel application of augmented reality in the setting of surgery. The application demonstrates the steps of the surgical procedure of inflatable penile prosthesis placement. It also contains software that allows for detection of interest points using a camera feed from the optical head-mounted display to enable faculty to interact with residents during placement of the penile prosthesis. Urology trainees and faculty who volunteered to take part in the study were given time to experience the technology in the operative or perioperative setting and asked to complete a feedback survey. From 30 total participants using a lO-point scale, educational usefulness was rated 8.6, ease of navigation was rated 7.6, likelihood to use was rated 7.4, and distraction in operating room was rated 4.9. When stratified between trainees and faculty, trainees found the technology more educationally useful, and less distracting. Overall, 81% of the participants want this technology in their residency program, and 93% see this technology in the operating room in the future. Further development of this technology is warranted before full release, and further studies are necessary to better characterize the effectiveness of Augmented Reality Assisted Surgery in urologic surgical training.
基金the National Natural Science Foundation of China(Nos. 50878128 and 50808122)the Shanghai Committee of Science and Technology(No. 06DZ22105)
文摘The presence of wrinkles in the membrane is the main factor to induce the reflector surface inaccuracy of the space inflatable antenna.Based on the commercial finite element package ABAQUS,a numerical procedure for membrane wrinkle analysis was set up and used to analyze a space inflatable antenna which was under inner pressure to evaluate its wrinkle characteristics.First,the inner pressure effect on the reflector's wrinkle pattern was studied thoroughly.As inner pressure increases,both the number and the amplitude of the wrinkles decrease,but the total deformation of the whole reflector surface increases much.Second,the influence of the interactions between antenna's parts was investigated comprehensively.Any kind of unwanted interaction deteriorates reflector's wrinkle characteristics.The works are valuable to the development and research of the space inflatable antenna.
基金supported in part by the National Natural Science Foundation of China (Grant 81370438)the SJTU Medical-Engineering Cross-cutting Research Project (Grant YG2015MS53)supported by the Hui-Chun Chin and Tsung-Dao Lee Chinese Undergraduate Research Program Endowment
文摘An inflatable cuff wrapped around the upper arm is widely used in noninvasive blood pressure measurement.However, the mechanical interaction between cuff and arm tissues, a factor that potentially affects the accuracy of noninvasive blood pressure measurement, remains rarely addressed. In the present study, finite element（FE） models were constructed to quantify intra-arm stresses generated by cuff compression, aiming to provide some theoretical evidence for identifying factors of importance for blood pressure measurement or explaining clinical observations. Obtained results showed that the simulated tissue stresses were highly sensitive to the distribution of cuff pressure on the arm surface and the contact condition between muscle and bone. In contrast, the magnitude of cuff pressure and small variations in elastic properties of arm soft tissues had little influence on the efficiency of pressure transmission in arm tissues. In particular, it was found that a thickened subcutaneous fat layer in obese subjects significantly reduced the effective pressure transmitted to the brachial artery, which may explain why blood pressure overestimation occurs more frequently in obese subjects in noninvasive blood pressure measurement.
基金This work was sponsored by the U.S.Department of Homeland Security Science and Technology Directorate(S&T)Homeland Security Advanced Research Projects Agency(HSARPA).The reduced‐scale inflatable plug was manufactured by ILC Dover.
文摘The availability of high‐strength fabrics and progress in the development of large‐scale inflatable technology made possible the creation of temporary and quickly deployable structures for protection of underground infrastructure.Inflatable structures are relatively lightweight and portable,and can maintain the required rigidity while in operation.These benefits have prompted the development of inflatable structures for use in confined spaces,such as tunnels and large‐diameter pipes to act as barriers for containing flooding with minimal infrastructure modification.This work presents experimental results obtained from the evaluation of frictional characteristics of the fabric material that constitute the structural membrane of confined inflatable structures developed for protection of underground transportation tunnels and other large conduits.Friction tests at coupon level and slippage tests in a reduced‐scale inflatable structure were performed in order to evaluate the frictional characteristics of Vectran webbings.Tests at coupon level were performed to determine the friction coefficient for different surface types and conditions.Tests with the reduced‐scale inflatable structure contributed to the understanding of the friction characteristics at system level when subjected to different pressurization or depressurization sequences designed to induce slippage.Test results indicate that friction coefficient values at coupon level are about 29 percent higher than values derived from reduced‐scale tests.
基金supported by the Specialized Fund for the Doctoral Program of Higher Education of China (200802131046)China Postdoctoral Science Foundation Funded Major Project (200801290)+1 种基金Development Program of Outstanding Young Teachers in Harbin Institute of Technology (HITQNJS.2008.004)Specialized Fund for Innovation Talents of Science and Technology in Harbin (2008RFQXG057).
文摘This paper extends Le van＇s work to the case of nonlinear problem and the complicated configuration. The wrinkling stress distribution and the pressure effects are also included in our analysis. Pseudo-beam method is presented based on the inflatable beam theory to model the inflatable structures as a set of inflatable beam elements with a prestressed state. In this method, the discretized nonlinear equations are given based upon the virtual work principle with a 3-node Timoshenko＇s beam model. Finite element simulation is performed by using a 3-node BEAM189 element incorporating ANSYS nonlinear program. The pressure effect is equivalent included in our method by modifying beam element cross-section parameters related to pressure. A benchmark example, the bending case of an inflatable cantilever beam, is performed to verify the accuracy of our proposed method. The comparisons reveal that the numerical results obtained with our method are close to open published analytical and membrane finite element results. The method is then used to evaluate the whole buckling and the loadcarrying characteristics of an inflatable support frame subjected to a compression force. The wrinkling stress and region characteristics are also shown in the end. This method gives better convergence characteristics, and requires much less computation time. It is very effective to deal with the whole load-carrying ability analytical problems for large scale inflatable structures with complex configuration.
