Accurate and efficient online parameter identification and state estimation are crucial for leveraging digital twin simulations to optimize the operation of near-carbon-free nuclear energy systems.In previous studies,...Accurate and efficient online parameter identification and state estimation are crucial for leveraging digital twin simulations to optimize the operation of near-carbon-free nuclear energy systems.In previous studies,we developed a reactor operation digital twin(RODT).However,non-differentiabilities and discontinuities arise when employing machine learning-based surrogate forward models,challenging traditional gradient-based inverse methods and their variants.This study investigated deterministic and metaheuristic algorithms and developed hybrid algorithms to address these issues.An efficient modular RODT software framework that incorporates these methods into its post-evaluation module is presented for comprehensive comparison.The methods were rigorously assessed based on convergence profiles,stability with respect to noise,and computational performance.The numerical results show that the hybrid KNNLHS algorithm excels in real-time online applications,balancing accuracy and efficiency with a prediction error rate of only 1%and processing times of less than 0.1 s.Contrastingly,algorithms such as FSA,DE,and ADE,although slightly slower(approximately 1 s),demonstrated higher accuracy with a 0.3%relative L_2 error,which advances RODT methodologies to harness machine learning and system modeling for improved reactor monitoring,systematic diagnosis of off-normal events,and lifetime management strategies.The developed modular software and novel optimization methods presented offer pathways to realize the full potential of RODT for transforming energy engineering practices.展开更多
The rapid development of digital education provides new opportunities and challenges for teaching model innovation.This study aims to explore the application of the BOPPPS(Bridge-in,Objective,Pre-assessment,Participat...The rapid development of digital education provides new opportunities and challenges for teaching model innovation.This study aims to explore the application of the BOPPPS(Bridge-in,Objective,Pre-assessment,Participatory learning,Post-assessment,Summary)teaching method in the development of a blended teaching model for the Operations Research course under the background of digital education.In response to the characteristics of the course and the needs of the student group,the teaching design is reconstructed with a student-centered approach,increasing practical teaching links,improving the assessment and evaluation system,and effectively implementing it in conjunction with digital educational technology.This teaching model has shown significant effectiveness in the context of digital education,providing valuable experience and insights for the innovation of the Operations Research course.展开更多
BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innova...BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.展开更多
With the development and progress of science and technology,road and bridge design has experienced rapid development,from the initial manual drawing design to the popularity of Computer-Aided Design(CAD),and then to t...With the development and progress of science and technology,road and bridge design has experienced rapid development,from the initial manual drawing design to the popularity of Computer-Aided Design(CAD),and then to today’s digital software design era.Early designers relied on hand-drawn paper design forms which was time-consuming and error-prone.Digital support for road and bridge design not only saves the design time but the design quality has also achieved a qualitative leap.This paper engages in the application of digital technology in road and bridge design,to provide technical reference for China’s road and bridge engineering design units,to promote the popularity of Civil3D and other advanced design software in the field of engineering design and development,ultimately contributing to the sustainable development of China’s road and bridge engineering.展开更多
To improve the human-physical-virtual coordination and integration of the digital twin workshop,3D visual monitoring and human-computer interaction of the digital twin workshop was studied.First,a novel 6D model of th...To improve the human-physical-virtual coordination and integration of the digital twin workshop,3D visual monitoring and human-computer interaction of the digital twin workshop was studied.First,a novel 6D model of the 3D visualization interactive system for digital twin workshops is proposed.As the traditional 5D digital twin model ignores the importance of human-computer interaction,a new dimension of the user terminal was added.A hierarchical real-time data-driven mapping model for the workshop production process is then proposed.Moreover,a real-time data acquisition method for the industrial Internet of things is proposed based on OPC UA(object linking and embedding for process control unified architecture).Based on the 6D model of the system,the process of creating a 3D visualization virtual environment based on virtual reality is introduced,in addition to a data-driven process based on the data management cloud platform.Finally,the 6D model of the system was confirmed using the blade rotor test workshop as the object,and a 3D visualization interactive system is developed.The results show that the system is more transparent,real-time,data-driven and more efficient,as well as promotes the coordination and integration of human-physical-virtual,which has practical significance for developing digital twin workshops.展开更多
We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach-Zehnder interferometer, the interference of the ...We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach-Zehnder interferometer, the interference of the multiple objects beams and the one reference beam is used to simultaneously encrypt multiple objects into a ciphertext. During decryption, each three-dimensional object can be decrypted independently without having to decrypt other objects. Since the single- pixel digital holography based on compressive sensing theory is introduced, the encrypted data of this method is effectively reduced. In addition, recording fewer encrypted data can greatly reduce the bandwidth of network transmission. Moreover, the compressive sensing essentially serves as a secret key that makes an intruder attack invalid, which means that the system is more secure than the conventional encryption method. Simulation results demonstrate the feasibility of the proposed method and show that the system has good security performance.展开更多
An optimized device structure for reducing the RESET current of phase-change random access memory (PCRAM) with blade-type like (BTL) phase change layer is proposed. The electrical thermal analysis of the BTL cell ...An optimized device structure for reducing the RESET current of phase-change random access memory (PCRAM) with blade-type like (BTL) phase change layer is proposed. The electrical thermal analysis of the BTL cell and the blade heater contactor structure by three-dimensional finite element modeling are compared with each other during RESET operation. The simulation results show that the programming region of the phase change layer in the BTL cell is much smaller, and thermal electrical distributions of the BTL cell are more concentrated on the TiN/GST interface. The results indicate that the BTL cell has the superiorities of increasing the heating efficiency, decreasing the power consumption and reducing the RESET current from 0.67mA to 0.32mA. Therefore, the BTL cell will be appropriate for high performance PCRAM device with lower power consumption and lower RESET current.展开更多
Objective:To evaluate the clinical efficacy of the preoperative digita1 design combined with three dimensional(3D)printing models to assist percutaneous kyphoplasty(PKP)treatment for thoracolumbar compression frac tur...Objective:To evaluate the clinical efficacy of the preoperative digita1 design combined with three dimensional(3D)printing models to assist percutaneous kyphoplasty(PKP)treatment for thoracolumbar compression frac tures.Methods:From January 2018 to August 2020,we obtained data of 99 patients diagnosed thoracolumbar compression fractures.These patients were divided into control group(n=50)underwent traditional PKP surgery,and observation group(n=49)underwent preoperative digital design combined with 3D printing model assisted PKP treatment.The clinical efficacy was evaluated with five parameters,including operation time,number of intraoperative radiographs,visual analogue scale(VAS)score,Cobb Angle change,and high compression rate of injured vertebrae.Results:There were statistically significant differences of operation time and number of intraoperative radio graphs between the two groups(P<0.05).For VAS score,Cobb Angle change and vertebral height compression rate,all of these three parameters were significantly improved when the patients accepted surgery teatment in two groups(P<0.05).However,there were no significant differences between control group and observation group for these three parameters either before or after surgery(P>0.05).Conclusions:Through the design of preoperative surgical guide plate and the application of 3D printing model to guide the operation,the precise design of preoperative surgical puncture site and puncture Angle of the injured vertebra was realized,the number of intraoperative radiographs was reduced,the operation time was shortened and the operation efficiency was improved.展开更多
[Objective] The aim was to construct a virtuous eco-system covering multi-populations, multi-layers and multi-products and to explore timber production of physical and non-physical products, in order to extend product...[Objective] The aim was to construct a virtuous eco-system covering multi-populations, multi-layers and multi-products and to explore timber production of physical and non-physical products, in order to extend products operated in forestry engineering and seek a novel model for forestry engineering. [Method] A three-dimensional operation project was designed based on forestry lands in Bagua Zhou in Nanjing City. [Result] In the project, timber products, by-products in forest and relaxing products supplimented and supported each other, and a virtuous circle has been achieved. [Conclusion] The novel model makes simultaneous relaxing and working possible, which creat vaule together.展开更多
Aim: Maxillary dental arch widths were evaluated in individuals having unilateral (UCLP) and bilateral (BCLP) cleft lip and palate (CLP) using three-dimensional (3D) digital models. Material and Method: The study had ...Aim: Maxillary dental arch widths were evaluated in individuals having unilateral (UCLP) and bilateral (BCLP) cleft lip and palate (CLP) using three-dimensional (3D) digital models. Material and Method: The study had been conducted on 80 individuals aged between 14 - 17 years having UCLP and BCLP. 40 of the individuals had UCLP, whereas 40 had BCLP. The maxillary dental models taken from patients before the treatment were scanned using Orthomodel Programme (v.1.01, Orthomodel Inc., Istanbul, Turkey) to obtain 3D imagery. Student’s t-test was used in order to assess the data obtained by using SPSS software version 22.0. Results: In BCLP, the average inter-canine distance was 17.44 ± 1.31 mm, the average inter-molar distance was 36.57 ± 1.12 mm, while inter-canine/inter-molar ratio was 0.47. Whereas in UCLP, it was 25.10 ± 0.63 mm, 42.20 ± 0.53 mm and 0.59. The inter-canine distance in UCLP was found to be large enough to be statistically significant (p 0.05), even though there were differences in inter-molar widths. Conclusion: For the stable orthodontic treatment results, one of the most important points is arch form and widths to be coherent with each other. In our study, the increase of inter-canine distance seen in UCLP indicates that in the cleft region, the maxillary arch is inclined over to the back, while the same situation in BCLP suggests that the maxillary segments are collapsed inside. The difference in the arch is highly affected by the primary surgical treatment.展开更多
Objective: To explore a new effective approach for treatment of the local irritable symptoms and signs resulted from myoporthosis operation. Methods: 263 cases of radial keratotomy outpatients were divided into contro...Objective: To explore a new effective approach for treatment of the local irritable symptoms and signs resulted from myoporthosis operation. Methods: 263 cases of radial keratotomy outpatients were divided into control group (n=49, 90 eyes) and treatment group (n=214, 412 eyes). Patients of control group were treated with 0.5% Chloramphenicol eye drops, 3 times daily, 1-2 drops/time, and with 0.5% Erythromycine eye ointment every night. In treatment group, patients were treated with acupoint and hand reflection area digital pressing method except with the same eye drops and eye ointment. Body acupoints used were Cuanzhu (BL 2), Yuyao (EX HN 4), Sizhukong (TE 23), Sibai (ST 2) and Taiyang (EX HN 5). The hand reflex areas used were Eye Area, Liver Area, Kidney Area, Spleen Area, Heart Area and Lung Area. Five days constituted a therapeutic course. Results: Following 3 courses (15 days) of treatment, the markedly effective rate and total effective rate of treatment group and control group were 74.51% and 38.89%, 94.17% and 66.67% respectively. There was a significant difference between two groups in the total effective rate (P<0.05), showing the therapeutic effect of treatment group being better than that of control group. Conclusion: Acupoint digital pressing is rather effective in treatment of myoporthosis post operation irritable symptoms and signs.展开更多
Objective To discuss the measurement of bone tumor volume on the basis of three dimensional images segmentation technology. Methods Twenty patients with lacunar bone tumor from Tianjin Hospital and Tongji Hospital wer...Objective To discuss the measurement of bone tumor volume on the basis of three dimensional images segmentation technology. Methods Twenty patients with lacunar bone tumor from Tianjin Hospital and Tongji Hospital were included in the展开更多
BACKGROUND : Digital subtraction angiography (DSA) is always regarded as the golden standard for diagnosis of intracranial aneurysm; however, the procedure is complex, traumatic, expensive and easy to induce vascul...BACKGROUND : Digital subtraction angiography (DSA) is always regarded as the golden standard for diagnosis of intracranial aneurysm; however, the procedure is complex, traumatic, expensive and easy to induce vascular complication. Three-dimensional computed tomography angiography (3D-CTA) can make up deficiencies of DSA; therefore, it is used in clinical therapy wider and wider. OBJECTIVE : To evaluate the clinical effect of 3D-CTA on disruption and hemorrhage of intracranial aneurysm pre- and post-operation and compare with the effect of DSA. DESIGN : Auto-control contrast observation SETTING : Department of Neurosurgery, Shengjing Hospital of China Medical University PARTICIPANTS : A number of 106 patients with disruption and hemorrhage of intracranial aneurysm were selected from the Department of Neurosurgery, Shengjing Hospital of China Medical University from January 2003 to April 2006. All patients were diagnosed with cranial operation and consent. There were 47 males and 59 females aged from 3-76 years with the mean age of (47±13) years. Among them, 82 patients had extensive subarachnoid hemorrhage (SAH), 7 had hemorrhage at longitudinal fissure, and 17 had hemorrhage at ambiens cistema and lateral fissure. Moreover, intraventricular hematocele was accompanied on 13 patients and hematom on 9 patients. METHODS: (1) 3D-CTA examination: Siemens SOMATOM Sensation 64 CT was used in this study. The thickness was 1 mm and interval of reconstruction was 0.8 mm. Localizing section was plainly scanned as the standard of canthus line. Scan ranged from 30 mm below sella to 50 mm above sella. Non-ion contrast medium of Omnipaque 350 (concentration of iodine was 350 g/L) was inserted into anterior vein of elbow with 18G trochar retained with high-pressured injectoc pum. The speed was 4.5 mL/s and the total volume was 80-100 mL with the means of 90 mL. Scan started at 10-20 s after injection of contrast medium. Original image was dealt with Leonardo workstation and retreated with Syngo software. Volume rendering and maximum intensity projection were used to reconstructed images, (2) All 106 patients suffered from occlusion of aneurysm clamp. Before operation, 3D-CTA was undertaken and DSA was followed. After operation, patients were rechecked with 3D-CTA. MAIN OUTCOME MEASURES: Comparisons between 3D-CTA and DSA. RESULTS : All 106 patients were involved in the final analysis. (1) Examination of 3D-CTA and DSA: Among 118 patients with aneurysm, 110 were checked with 3D-CTA and the detected rate was 93.2% (110/118). Among other 8 cases, 3 were negative and checked again with DSA; 1 had pericallosal aneurysm, 1 ophthalmic aneurysm, and 1 anterior choroidal artery of aneurysm. 3D-CTA results of other 5 cases were suspicious, and then, they were regarded as having aneurysm with DSA. Before operation, correlation among site, body, neck of aneurysm and peripheral anatomic structure were shown sufficiently. After operation, 82 patients were rechecked with 3D-CTA, which was complete occlusion, precise, unobvious constriction, emphraxis or remains as compared with 3D-CTA those pre-operation. (2) Characteristics of 3D-CTA: With multiple vessels and angles, 3D-CTA observed the relationship between aneurysm neck and carried artery and showed thrombosis in cavity of aneurysm, calcification of aneurysm wall and peripheral structure of vessel at the same time. However, DSA could not detect the reactions mentioned above. It could delete image of cranium, simulate image of operative route, eliminate artifact induced by metal, but not distinguish blood stream direction. Meanwhile, posterior communicating artery was always poor during circle of Willis artery showing. CONCLUSION: (1) 3D-CTA is characterized by simple operation and non-invasive showing vascular stereo structure and correlation. Therefore, it is significant for diagnosis and designing plan of operative approach and focal location pre-operation and evaluating effect post-operation. (2) 3D-CTA does not completely replace DSA on the diagnosis of intracranial aneurysm.展开更多
Due to the need for improvement in the diagnosis and minimally invasive therapy of the bile duct disorders new technologies for cholangioscopy have been recently developed. Per-oral cholangioscopy has become an import...Due to the need for improvement in the diagnosis and minimally invasive therapy of the bile duct disorders new technologies for cholangioscopy have been recently developed. Per-oral cholangioscopy has become an important diagnostic and therapeutic tool leading to avoidance of aggressive and unnecessary surgery in many clinical scenarios. This paper focuses on the newly developed SpyGlass DS technology, its advantages, and the technique of single-operator cholangioscopy(SOC), biliary indications and possible adverse events. We also review the available literature; discuss the limitations and future expectations.Digital SOC(D-SOC) is a useful technique, which provides endoscopic imaging of the biliary tree, optical diagnosis, biopsy under direct vision and therapeutic interventions. The implementations are diagnostic and therapeutic. Diagnostic indications are indeterminate biliary strictures, unclear filling defects, staging of cholangiocarcinoma, staging of ampullary tumors(extension into the common bile duct), unclear bile duct dilation, exploring cystic lesions of the biliary tree,unexplained hemobilia, posttransplant biliary complications. Therapeutic indications are lithotripsy of difficult stones, retrieval of migrated stents, foreign body removal, guide wire placement, transpapillary gallbladder drainage and endoscopic tumor ablative therapy. Most studied and established indications are the diagnosis of indeterminate biliary stricture and intraductal lithotripsy of difficult stones. The adverse events are not different and more common compared to those of Endoscopic retrograde cholangiopancreatography(ERCP)alone. D-SOC is a safe and effective procedure, adjunct to the standard ERCP and the newly available digital technology overcomes many of the limitations of the previous generations of cholangioscopes.展开更多
A digital arc welding power supply was designed with the advanced reduced instruction set computer machine (ARM) and embedded real-time multi-task operating system micro C/OS- Ⅱ. The ARM, with its powerful calculat...A digital arc welding power supply was designed with the advanced reduced instruction set computer machine (ARM) and embedded real-time multi-task operating system micro C/OS- Ⅱ. The ARM, with its powerful calculating speed and complete peripheral equipments, is very suitable to work as the controller of the digital power supply. The micro C/OS- Ⅱ transplanted in ARM, helps to improve the respondent speed against various welding signals, as well as the reliability of the controlling software. The welding process consists of nine tasks. The tasks of great significance on reliability of the welder, for example, the A/D conversion of current and voltage, enjoy top priority. To avoid simultaneous-sharing on A/D converter and LCD module, two semaphores are introduced in to ensure the smooth performance of the welding power supply. Proven by experiments ,the ARM and the micro C/OS- Ⅱ can greatly improve both the respondent speed and the reliability of the digital welder.展开更多
Archaeological excavation involves disintegration, removal, and reassembly of the archaeological record;as such it is considered by many to be an unrepeatable, destructive activity. This perception has contributed to ...Archaeological excavation involves disintegration, removal, and reassembly of the archaeological record;as such it is considered by many to be an unrepeatable, destructive activity. This perception has contributed to an advancement in archaeological practice, namely, the development of computerized recording systems that digitally record archaeological excavations spatially and volumetrically during fieldwork. This paper is concerned with those archaeological sites where digital field recording has not been done. These sites, recorded by traditional methods, should not be excluded from attempts to restructure the spatial, volumetric, and stratigraphic archaeological data. A thorough methodology for the conversion of traditional records into digitized data is presented, including the detailed procedures required for three-dimensional plotting of recorded data—both the excavated material and the drawn site maps and cross-sections. Finally, the use of these methods is demonstrated on a complex Early to Middle Pleistocene site, illustrating the benefits of digitization and three-dimensional reconstruction in resolving stratigraphic and spatial questions.展开更多
Background The trochanter of the femur is a common site for bone tumors.However,locating the specificboundary of bone tumor infiltration and determining the surgical method can be challenging.The objective of thisstud...Background The trochanter of the femur is a common site for bone tumors.However,locating the specificboundary of bone tumor infiltration and determining the surgical method can be challenging.The objective of thisstudy was to review the diagnosis,treatment,and surgical outcomes of patients with tumors or tumor-like changesin the femoral trochanter after computer-assisted precise tumor resection and hip-preserving reconstruction ofthe trochanter.Methods From January 2005 to September 2020,11 patients with trochanteric tumors(aged:18–53 years;sixmales and five females)were treated in Guangzhou First People’s Hospital.The cases included aneurysmal bonecyst(n=1),giant cell tumor of bone(n=2),fibrous histiocytoma of bone(n=1),endochondroma(n=1),andfibrous dysplasia of bone(n=6).For patients with trochanteric tumors,computed tomography and magnetic resonance imaging scanning were performed before operation to obtain two-dimensional image data of the lesion.Athree-dimensional digital model of bilateral lower limbs was reconstructed by computer technology,the boundary of tumor growth was determined by computer simulation,the process of tumor resection and reconstructionwas simulated,and the personalized guide template was designed.During the operation,the personalized guideplate guided the precise resection of the tumor,and the allogeneic bone was trimmed to match the shape of thebone defect.Results All 11 patients underwent accurate resection of the tumor or tumor-like lesion and reconstruction ofthe hip.In eight cases,the lesion was confined to the trochanter,which was fixed with large segment allogeneicbone,autologous iliac bone,and proximal femoral anatomic plate.In three cases,allogeneic bone,autologousiliac bone,and femoral reconstruction nail were used to fix the tumor under the trochanter.Postoperative Xray examination showed that the repair and reconstruction of the bone defect was effective,and callus bridgingbetween the allogenic bone and autogenous bone was observed 6 months after operation.All patients recoveredtheir walking function 3–6 months after operation.The duration of the follow-up period ranged from 6 monthsto 6 years.A patient experienced recurrence of endochondroma;pathological examination revealed chondrocyticsarcoma.The remaining 10 patients were treated with segmental resection and reconstruction.The operationtime ranged 2.5–4.5 h(average:3.2 h).Intraoperative blood loss ranged from 300 to 500 ml(average:368 ml).The local recurrence rate was 9.1%,and the overall survival rate was 100%.The average Musculoskeletal TumorSociety score was 27(excellent and good for eight and three patients,respectively).Conclusions Three-dimensional computer skeleton modeling and simulation-assisted resection and reconstruction of femoral trochanteric tumor is a new surgical technique,which might markedly improve the surgical effect,shorten the surgical time,increase the overall survival rate of patients with tumors,reduce the local recurrencerate,assist in the digitization and programming of femoral trochanteric tumor surgery,and improve surgicalaccuracy.展开更多
基金supported by the Natural Science Foundation of Shanghai(No.23ZR1429300)Innovation Funds of CNNC(Lingchuang Fund,Contract No.CNNC-LCKY-202234)the Project of the Nuclear Power Technology Innovation Center of Science Technology and Industry(No.HDLCXZX-2023-HD-039-02)。
文摘Accurate and efficient online parameter identification and state estimation are crucial for leveraging digital twin simulations to optimize the operation of near-carbon-free nuclear energy systems.In previous studies,we developed a reactor operation digital twin(RODT).However,non-differentiabilities and discontinuities arise when employing machine learning-based surrogate forward models,challenging traditional gradient-based inverse methods and their variants.This study investigated deterministic and metaheuristic algorithms and developed hybrid algorithms to address these issues.An efficient modular RODT software framework that incorporates these methods into its post-evaluation module is presented for comprehensive comparison.The methods were rigorously assessed based on convergence profiles,stability with respect to noise,and computational performance.The numerical results show that the hybrid KNNLHS algorithm excels in real-time online applications,balancing accuracy and efficiency with a prediction error rate of only 1%and processing times of less than 0.1 s.Contrastingly,algorithms such as FSA,DE,and ADE,although slightly slower(approximately 1 s),demonstrated higher accuracy with a 0.3%relative L_2 error,which advances RODT methodologies to harness machine learning and system modeling for improved reactor monitoring,systematic diagnosis of off-normal events,and lifetime management strategies.The developed modular software and novel optimization methods presented offer pathways to realize the full potential of RODT for transforming energy engineering practices.
文摘The rapid development of digital education provides new opportunities and challenges for teaching model innovation.This study aims to explore the application of the BOPPPS(Bridge-in,Objective,Pre-assessment,Participatory learning,Post-assessment,Summary)teaching method in the development of a blended teaching model for the Operations Research course under the background of digital education.In response to the characteristics of the course and the needs of the student group,the teaching design is reconstructed with a student-centered approach,increasing practical teaching links,improving the assessment and evaluation system,and effectively implementing it in conjunction with digital educational technology.This teaching model has shown significant effectiveness in the context of digital education,providing valuable experience and insights for the innovation of the Operations Research course.
文摘BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.
文摘With the development and progress of science and technology,road and bridge design has experienced rapid development,from the initial manual drawing design to the popularity of Computer-Aided Design(CAD),and then to today’s digital software design era.Early designers relied on hand-drawn paper design forms which was time-consuming and error-prone.Digital support for road and bridge design not only saves the design time but the design quality has also achieved a qualitative leap.This paper engages in the application of digital technology in road and bridge design,to provide technical reference for China’s road and bridge engineering design units,to promote the popularity of Civil3D and other advanced design software in the field of engineering design and development,ultimately contributing to the sustainable development of China’s road and bridge engineering.
基金The National Natural Science Foundation of China(No.51875332)the Capacity Building Projects of Some Local Universities of Shanghai Science and Technology Commission(No.18040501600).
文摘To improve the human-physical-virtual coordination and integration of the digital twin workshop,3D visual monitoring and human-computer interaction of the digital twin workshop was studied.First,a novel 6D model of the 3D visualization interactive system for digital twin workshops is proposed.As the traditional 5D digital twin model ignores the importance of human-computer interaction,a new dimension of the user terminal was added.A hierarchical real-time data-driven mapping model for the workshop production process is then proposed.Moreover,a real-time data acquisition method for the industrial Internet of things is proposed based on OPC UA(object linking and embedding for process control unified architecture).Based on the 6D model of the system,the process of creating a 3D visualization virtual environment based on virtual reality is introduced,in addition to a data-driven process based on the data management cloud platform.Finally,the 6D model of the system was confirmed using the blade rotor test workshop as the object,and a 3D visualization interactive system is developed.The results show that the system is more transparent,real-time,data-driven and more efficient,as well as promotes the coordination and integration of human-physical-virtual,which has practical significance for developing digital twin workshops.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61405130 and 61320106015)
文摘We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach-Zehnder interferometer, the interference of the multiple objects beams and the one reference beam is used to simultaneously encrypt multiple objects into a ciphertext. During decryption, each three-dimensional object can be decrypted independently without having to decrypt other objects. Since the single- pixel digital holography based on compressive sensing theory is introduced, the encrypted data of this method is effectively reduced. In addition, recording fewer encrypted data can greatly reduce the bandwidth of network transmission. Moreover, the compressive sensing essentially serves as a secret key that makes an intruder attack invalid, which means that the system is more secure than the conventional encryption method. Simulation results demonstrate the feasibility of the proposed method and show that the system has good security performance.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDA09020402the National Integrate Circuit Research Program of China under Grant No 2009ZX02023-003+1 种基金the National Natural Science Foundation of China under Grant Nos 61261160500,61376006,61401444 and 61504157the Science and Technology Council of Shanghai under Grant Nos 14DZ2294900,15DZ2270900 and 14ZR1447500
文摘An optimized device structure for reducing the RESET current of phase-change random access memory (PCRAM) with blade-type like (BTL) phase change layer is proposed. The electrical thermal analysis of the BTL cell and the blade heater contactor structure by three-dimensional finite element modeling are compared with each other during RESET operation. The simulation results show that the programming region of the phase change layer in the BTL cell is much smaller, and thermal electrical distributions of the BTL cell are more concentrated on the TiN/GST interface. The results indicate that the BTL cell has the superiorities of increasing the heating efficiency, decreasing the power consumption and reducing the RESET current from 0.67mA to 0.32mA. Therefore, the BTL cell will be appropriate for high performance PCRAM device with lower power consumption and lower RESET current.
基金supported in part by the General Program of Natural Science Foundation of Hubei Province,China(Grant No.2020CFB548)a Project in 2021 of Science and Technology Support Plan of Guizhou Province,China(Grant No.202158413293820389).
文摘Objective:To evaluate the clinical efficacy of the preoperative digita1 design combined with three dimensional(3D)printing models to assist percutaneous kyphoplasty(PKP)treatment for thoracolumbar compression frac tures.Methods:From January 2018 to August 2020,we obtained data of 99 patients diagnosed thoracolumbar compression fractures.These patients were divided into control group(n=50)underwent traditional PKP surgery,and observation group(n=49)underwent preoperative digital design combined with 3D printing model assisted PKP treatment.The clinical efficacy was evaluated with five parameters,including operation time,number of intraoperative radiographs,visual analogue scale(VAS)score,Cobb Angle change,and high compression rate of injured vertebrae.Results:There were statistically significant differences of operation time and number of intraoperative radio graphs between the two groups(P<0.05).For VAS score,Cobb Angle change and vertebral height compression rate,all of these three parameters were significantly improved when the patients accepted surgery teatment in two groups(P<0.05).However,there were no significant differences between control group and observation group for these three parameters either before or after surgery(P>0.05).Conclusions:Through the design of preoperative surgical guide plate and the application of 3D printing model to guide the operation,the precise design of preoperative surgical puncture site and puncture Angle of the injured vertebra was realized,the number of intraoperative radiographs was reduced,the operation time was shortened and the operation efficiency was improved.
文摘[Objective] The aim was to construct a virtuous eco-system covering multi-populations, multi-layers and multi-products and to explore timber production of physical and non-physical products, in order to extend products operated in forestry engineering and seek a novel model for forestry engineering. [Method] A three-dimensional operation project was designed based on forestry lands in Bagua Zhou in Nanjing City. [Result] In the project, timber products, by-products in forest and relaxing products supplimented and supported each other, and a virtuous circle has been achieved. [Conclusion] The novel model makes simultaneous relaxing and working possible, which creat vaule together.
文摘Aim: Maxillary dental arch widths were evaluated in individuals having unilateral (UCLP) and bilateral (BCLP) cleft lip and palate (CLP) using three-dimensional (3D) digital models. Material and Method: The study had been conducted on 80 individuals aged between 14 - 17 years having UCLP and BCLP. 40 of the individuals had UCLP, whereas 40 had BCLP. The maxillary dental models taken from patients before the treatment were scanned using Orthomodel Programme (v.1.01, Orthomodel Inc., Istanbul, Turkey) to obtain 3D imagery. Student’s t-test was used in order to assess the data obtained by using SPSS software version 22.0. Results: In BCLP, the average inter-canine distance was 17.44 ± 1.31 mm, the average inter-molar distance was 36.57 ± 1.12 mm, while inter-canine/inter-molar ratio was 0.47. Whereas in UCLP, it was 25.10 ± 0.63 mm, 42.20 ± 0.53 mm and 0.59. The inter-canine distance in UCLP was found to be large enough to be statistically significant (p 0.05), even though there were differences in inter-molar widths. Conclusion: For the stable orthodontic treatment results, one of the most important points is arch form and widths to be coherent with each other. In our study, the increase of inter-canine distance seen in UCLP indicates that in the cleft region, the maxillary arch is inclined over to the back, while the same situation in BCLP suggests that the maxillary segments are collapsed inside. The difference in the arch is highly affected by the primary surgical treatment.
文摘Objective: To explore a new effective approach for treatment of the local irritable symptoms and signs resulted from myoporthosis operation. Methods: 263 cases of radial keratotomy outpatients were divided into control group (n=49, 90 eyes) and treatment group (n=214, 412 eyes). Patients of control group were treated with 0.5% Chloramphenicol eye drops, 3 times daily, 1-2 drops/time, and with 0.5% Erythromycine eye ointment every night. In treatment group, patients were treated with acupoint and hand reflection area digital pressing method except with the same eye drops and eye ointment. Body acupoints used were Cuanzhu (BL 2), Yuyao (EX HN 4), Sizhukong (TE 23), Sibai (ST 2) and Taiyang (EX HN 5). The hand reflex areas used were Eye Area, Liver Area, Kidney Area, Spleen Area, Heart Area and Lung Area. Five days constituted a therapeutic course. Results: Following 3 courses (15 days) of treatment, the markedly effective rate and total effective rate of treatment group and control group were 74.51% and 38.89%, 94.17% and 66.67% respectively. There was a significant difference between two groups in the total effective rate (P<0.05), showing the therapeutic effect of treatment group being better than that of control group. Conclusion: Acupoint digital pressing is rather effective in treatment of myoporthosis post operation irritable symptoms and signs.
文摘Objective To discuss the measurement of bone tumor volume on the basis of three dimensional images segmentation technology. Methods Twenty patients with lacunar bone tumor from Tianjin Hospital and Tongji Hospital were included in the
文摘BACKGROUND : Digital subtraction angiography (DSA) is always regarded as the golden standard for diagnosis of intracranial aneurysm; however, the procedure is complex, traumatic, expensive and easy to induce vascular complication. Three-dimensional computed tomography angiography (3D-CTA) can make up deficiencies of DSA; therefore, it is used in clinical therapy wider and wider. OBJECTIVE : To evaluate the clinical effect of 3D-CTA on disruption and hemorrhage of intracranial aneurysm pre- and post-operation and compare with the effect of DSA. DESIGN : Auto-control contrast observation SETTING : Department of Neurosurgery, Shengjing Hospital of China Medical University PARTICIPANTS : A number of 106 patients with disruption and hemorrhage of intracranial aneurysm were selected from the Department of Neurosurgery, Shengjing Hospital of China Medical University from January 2003 to April 2006. All patients were diagnosed with cranial operation and consent. There were 47 males and 59 females aged from 3-76 years with the mean age of (47±13) years. Among them, 82 patients had extensive subarachnoid hemorrhage (SAH), 7 had hemorrhage at longitudinal fissure, and 17 had hemorrhage at ambiens cistema and lateral fissure. Moreover, intraventricular hematocele was accompanied on 13 patients and hematom on 9 patients. METHODS: (1) 3D-CTA examination: Siemens SOMATOM Sensation 64 CT was used in this study. The thickness was 1 mm and interval of reconstruction was 0.8 mm. Localizing section was plainly scanned as the standard of canthus line. Scan ranged from 30 mm below sella to 50 mm above sella. Non-ion contrast medium of Omnipaque 350 (concentration of iodine was 350 g/L) was inserted into anterior vein of elbow with 18G trochar retained with high-pressured injectoc pum. The speed was 4.5 mL/s and the total volume was 80-100 mL with the means of 90 mL. Scan started at 10-20 s after injection of contrast medium. Original image was dealt with Leonardo workstation and retreated with Syngo software. Volume rendering and maximum intensity projection were used to reconstructed images, (2) All 106 patients suffered from occlusion of aneurysm clamp. Before operation, 3D-CTA was undertaken and DSA was followed. After operation, patients were rechecked with 3D-CTA. MAIN OUTCOME MEASURES: Comparisons between 3D-CTA and DSA. RESULTS : All 106 patients were involved in the final analysis. (1) Examination of 3D-CTA and DSA: Among 118 patients with aneurysm, 110 were checked with 3D-CTA and the detected rate was 93.2% (110/118). Among other 8 cases, 3 were negative and checked again with DSA; 1 had pericallosal aneurysm, 1 ophthalmic aneurysm, and 1 anterior choroidal artery of aneurysm. 3D-CTA results of other 5 cases were suspicious, and then, they were regarded as having aneurysm with DSA. Before operation, correlation among site, body, neck of aneurysm and peripheral anatomic structure were shown sufficiently. After operation, 82 patients were rechecked with 3D-CTA, which was complete occlusion, precise, unobvious constriction, emphraxis or remains as compared with 3D-CTA those pre-operation. (2) Characteristics of 3D-CTA: With multiple vessels and angles, 3D-CTA observed the relationship between aneurysm neck and carried artery and showed thrombosis in cavity of aneurysm, calcification of aneurysm wall and peripheral structure of vessel at the same time. However, DSA could not detect the reactions mentioned above. It could delete image of cranium, simulate image of operative route, eliminate artifact induced by metal, but not distinguish blood stream direction. Meanwhile, posterior communicating artery was always poor during circle of Willis artery showing. CONCLUSION: (1) 3D-CTA is characterized by simple operation and non-invasive showing vascular stereo structure and correlation. Therefore, it is significant for diagnosis and designing plan of operative approach and focal location pre-operation and evaluating effect post-operation. (2) 3D-CTA does not completely replace DSA on the diagnosis of intracranial aneurysm.
文摘Due to the need for improvement in the diagnosis and minimally invasive therapy of the bile duct disorders new technologies for cholangioscopy have been recently developed. Per-oral cholangioscopy has become an important diagnostic and therapeutic tool leading to avoidance of aggressive and unnecessary surgery in many clinical scenarios. This paper focuses on the newly developed SpyGlass DS technology, its advantages, and the technique of single-operator cholangioscopy(SOC), biliary indications and possible adverse events. We also review the available literature; discuss the limitations and future expectations.Digital SOC(D-SOC) is a useful technique, which provides endoscopic imaging of the biliary tree, optical diagnosis, biopsy under direct vision and therapeutic interventions. The implementations are diagnostic and therapeutic. Diagnostic indications are indeterminate biliary strictures, unclear filling defects, staging of cholangiocarcinoma, staging of ampullary tumors(extension into the common bile duct), unclear bile duct dilation, exploring cystic lesions of the biliary tree,unexplained hemobilia, posttransplant biliary complications. Therapeutic indications are lithotripsy of difficult stones, retrieval of migrated stents, foreign body removal, guide wire placement, transpapillary gallbladder drainage and endoscopic tumor ablative therapy. Most studied and established indications are the diagnosis of indeterminate biliary stricture and intraductal lithotripsy of difficult stones. The adverse events are not different and more common compared to those of Endoscopic retrograde cholangiopancreatography(ERCP)alone. D-SOC is a safe and effective procedure, adjunct to the standard ERCP and the newly available digital technology overcomes many of the limitations of the previous generations of cholangioscopes.
基金Supported by the National Natural Science Foundation of China under Grant No 50575074by the Scientific and TechnologicalProject of Guangdong Province, China, under Grant No 2003A1040310
文摘A digital arc welding power supply was designed with the advanced reduced instruction set computer machine (ARM) and embedded real-time multi-task operating system micro C/OS- Ⅱ. The ARM, with its powerful calculating speed and complete peripheral equipments, is very suitable to work as the controller of the digital power supply. The micro C/OS- Ⅱ transplanted in ARM, helps to improve the respondent speed against various welding signals, as well as the reliability of the controlling software. The welding process consists of nine tasks. The tasks of great significance on reliability of the welder, for example, the A/D conversion of current and voltage, enjoy top priority. To avoid simultaneous-sharing on A/D converter and LCD module, two semaphores are introduced in to ensure the smooth performance of the welding power supply. Proven by experiments ,the ARM and the micro C/OS- Ⅱ can greatly improve both the respondent speed and the reliability of the digital welder.
文摘Archaeological excavation involves disintegration, removal, and reassembly of the archaeological record;as such it is considered by many to be an unrepeatable, destructive activity. This perception has contributed to an advancement in archaeological practice, namely, the development of computerized recording systems that digitally record archaeological excavations spatially and volumetrically during fieldwork. This paper is concerned with those archaeological sites where digital field recording has not been done. These sites, recorded by traditional methods, should not be excluded from attempts to restructure the spatial, volumetric, and stratigraphic archaeological data. A thorough methodology for the conversion of traditional records into digitized data is presented, including the detailed procedures required for three-dimensional plotting of recorded data—both the excavated material and the drawn site maps and cross-sections. Finally, the use of these methods is demonstrated on a complex Early to Middle Pleistocene site, illustrating the benefits of digitization and three-dimensional reconstruction in resolving stratigraphic and spatial questions.
文摘Background The trochanter of the femur is a common site for bone tumors.However,locating the specificboundary of bone tumor infiltration and determining the surgical method can be challenging.The objective of thisstudy was to review the diagnosis,treatment,and surgical outcomes of patients with tumors or tumor-like changesin the femoral trochanter after computer-assisted precise tumor resection and hip-preserving reconstruction ofthe trochanter.Methods From January 2005 to September 2020,11 patients with trochanteric tumors(aged:18–53 years;sixmales and five females)were treated in Guangzhou First People’s Hospital.The cases included aneurysmal bonecyst(n=1),giant cell tumor of bone(n=2),fibrous histiocytoma of bone(n=1),endochondroma(n=1),andfibrous dysplasia of bone(n=6).For patients with trochanteric tumors,computed tomography and magnetic resonance imaging scanning were performed before operation to obtain two-dimensional image data of the lesion.Athree-dimensional digital model of bilateral lower limbs was reconstructed by computer technology,the boundary of tumor growth was determined by computer simulation,the process of tumor resection and reconstructionwas simulated,and the personalized guide template was designed.During the operation,the personalized guideplate guided the precise resection of the tumor,and the allogeneic bone was trimmed to match the shape of thebone defect.Results All 11 patients underwent accurate resection of the tumor or tumor-like lesion and reconstruction ofthe hip.In eight cases,the lesion was confined to the trochanter,which was fixed with large segment allogeneicbone,autologous iliac bone,and proximal femoral anatomic plate.In three cases,allogeneic bone,autologousiliac bone,and femoral reconstruction nail were used to fix the tumor under the trochanter.Postoperative Xray examination showed that the repair and reconstruction of the bone defect was effective,and callus bridgingbetween the allogenic bone and autogenous bone was observed 6 months after operation.All patients recoveredtheir walking function 3–6 months after operation.The duration of the follow-up period ranged from 6 monthsto 6 years.A patient experienced recurrence of endochondroma;pathological examination revealed chondrocyticsarcoma.The remaining 10 patients were treated with segmental resection and reconstruction.The operationtime ranged 2.5–4.5 h(average:3.2 h).Intraoperative blood loss ranged from 300 to 500 ml(average:368 ml).The local recurrence rate was 9.1%,and the overall survival rate was 100%.The average Musculoskeletal TumorSociety score was 27(excellent and good for eight and three patients,respectively).Conclusions Three-dimensional computer skeleton modeling and simulation-assisted resection and reconstruction of femoral trochanteric tumor is a new surgical technique,which might markedly improve the surgical effect,shorten the surgical time,increase the overall survival rate of patients with tumors,reduce the local recurrencerate,assist in the digitization and programming of femoral trochanteric tumor surgery,and improve surgicalaccuracy.