In this article the authors describe a new 3D reconstruction system for X-ray tomography. The goal was to provide a surgeon 3D x-ray tomography images online during an operation. The system was designed, for the use w...
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In this article the authors describe a new 3D reconstruction system for X-ray tomography. The goal was to provide a surgeon 3D x-ray tomography images online during an operation. The system was designed, for the use with intraoperative, medical X-ray devices (C-arms). It consists of a 3D volume reconstruction algorithm, implemented using a common PC graphics accelerator, to minimize the computation time. Due to mechanical limitations of the X-ray system the algebraic reconstruction algorithm SART was used. The known reconstruction algorithm was enhanced for an iterative online reconstruction, where the computation is done at the same time the X-ray system acquires new images. The surgeon can add more X-ray images to improve the results of the 3D reconstruction. Due to this enhancement and the high speed computation, the surgeon is able to acquire the needed number of X-ray images for a specific clinical case and to avoid unnecessary radiation. For clinically relevant 3D data 30 to 100 X-ray images are needed, depending on the anatomical region and the needed information. The reconstruction system was verified and validated using a mathematically described phantom and human X-ray images from clinical trails. In less than ten seconds after the last image was taken a 3D reconstruction is calculate with the new online reconstruction approach. The results show no significant difference in terms of image quality compared to conventional SART reconstructed images, where the reconstruction time is about 3 minutes
A prototype concurrent engineering tool has been developed for the preliminary design of composite topside structures for modern navy warships. This tool, named GELS for the Concurrent engineering of Layered Structure...
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A prototype concurrent engineering tool has been developed for the preliminary design of composite topside structures for modern navy warships. This tool, named GELS for the Concurrent engineering of Layered Structures, provides designers with an immediate assessment of the impacts of their decisions on several disciplines which are important to the performance of a modern naval topside structure, including electromagnetic interference effects (EMI), radar cross section (RCS), structural integrity, cost, and weight. Preliminary analysis modules in each of these disciplines are integrated to operate from a common set of design variables and a common materials database. Performance in each discipline and an overall fitness function for the concept are then evaluated. A graphical user interface (GUI) is used to define requirements and to display the results from the technical analysis modules. Optimization techniques, including feasible sequential quadratic programming (FSQP) and exhaustive search are used to modify the design variables to satisfy all requirements simultaneously. The development of this tool, the technical modules, and their integration are discussed noting the decisions and compromises required to develop and integrate the modules into a prototype conceptual design tool.
作者:
CALVERT, TERODRIGUEZ, FASLEBZAK, JSThomas E. Calvert
P.E.: is a senior project engineer with the Propulsion and Auxiliary Systems Department David Taylor Research Center Annapolis Md. His interests include application of computers to all aspects of engineering with particular emphasis on utilization of small computers. Mr. Calvert is a licensed professional engineer in Maryland. He received a BSEE from Drexel University in 1969 and since that time has completed a number of graduate courses related to machinery acoustics. Francisco A. Rodriguez:is an engineer with the Propulsion and Auxiliary Systems Department
David Taylor Research Center. He was formerly with the Computer-Aided Design/Interactive Graphics Group of the Division of Engineering and Weapons U.S. Naval Academy. His interests include interfacing the computer aided design to the computer aided manufacturing along with related software and hardware development. Mr. Rodriguez received a BSEEfrom the University of Virginia in 1968. James S. Slebzak:is a mechanical engineering technician with the Propulsion and Auxiliary Systems Department
David Taylor Research Center. He received his machinists papers in 1971 after serving his apprenticeship at David Taylor Research Center. He continued his education and became the senior numerical control programmer at the Annapolis Laboratory. He completed his mechanical technology degree from Anne Arundel Community College in 1986. His interests are in the application of numerically controlled manufacturing techniques to prototype machinery components.
The machine shop at the Annapolis Laboratory of the David Taylor Research Center (DTRC) provides model making and prototype support to a large variety of naval ship related engineering projects. In order to meet these...
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The machine shop at the Annapolis Laboratory of the David Taylor Research Center (DTRC) provides model making and prototype support to a large variety of naval ship related engineering projects. In order to meet these challenging requirements, computer aided design/computer aided manufacturing (CAD/CAM) techniques are being used to produce “one of a kind” prototypes or very low volume production parts. The use of computer aides in these cases is to facilitate the accurate manufacture of a difficult part, rather than to improve manufacturing efficiencies. In addition, the approach provides the flexibility required to support research and development projects. Several examples of prototype shipboard components manufactured using CAD/CAM techniques are presented in this paper. The hardware and software that facilitated these projects are discussed. The examples described have met the requirements to produce a wide variety of prototype shipboard machinery components quickly and accurately.
A new model is introduced for avoiding accidents where a tugboat capsizes or trips when towing a larger vessel. The development of the Tripping Avoidance Knowledge Base (TAKB) is described in terms of the relevant des...
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A new model is introduced for avoiding accidents where a tugboat capsizes or trips when towing a larger vessel. The development of the Tripping Avoidance Knowledge Base (TAKB) is described in terms of the relevant descriptive parameters, the graphical representation of the knowledge base and its conversion to a decision matrix is also shown. As with any AI application in a new and promising area, there are many unclear points which this paper highlights. The paper closes with the authors' recommendations for future development and refinement of the knowledge base.
作者:
CHENG, BHDEAN, JSMILLER, RWCAVE, WLBill H. Cheng:is a physical scientist in the Numerical Fluid Dynamics Branch
Computation Mathematics and Logistics Department David Taylor Research Center (DTRC) Bethesda MD. Since joining DTRC in 1981 he has been the project leader for the XYZ Free Surface (XYZFS) Program. He received a B.S. in mechanical engineering from the National Taiwan University and a M.A.Sc. in mechanical engineering from the University of British Columbia and a S.M. degree in oceanography and meteorology from Harvard University. Mr. Cheng is a registered professional engineer in the Commonwealth of Virginia and a member of American Society of Mechanical Engineers and Sigma Xi. His experience in fluid dynamics has included theory experiments and computations. He has been the author and coauthor of numerous technical reports and papers. Janet S. Dean:is a mathematician in the Numerical Fluid Dynamics Branch
DTRC. She attended the College of William and Mary and received her B.S. degree in mathematics from The George Washington University. Mrs. Dean assisted Charles Dawson in the development of the original XYZFS Program. She has worked on improving and extending the capabilities of XYZFS and on the application of supercomputers to fluid dynamics problems. Ronald W. Miller:is a mechanical engineer in the Numerical Fluid Dynamics Branch
DTRC. He received his B.A. degree in mathematics from the University of Maryland—Baltimore County Campus in 1984 and his M.S. in ocean and marine engineering from The George Washington University in 1988. Mr. Miller is responsible for the preparation of hull geometry data used in ship hydrodynamic analysis computer codes and the graphical visualization of output from such codes. William L. Cave III:graduated from Stevens Institute of Technology in 1986 with a B.E. degree in ocean engineering. He is currently a naval architect in the Design Evaluation Branch
Ship Hydromechanics Department DTRC. He has been involved with model testing and evaluation of the CV-41 FFG-7 class USNSHayesCG-47 class
A computational capability has been developed to predict and visualize the flow about podded propulsors appended to the 154-foot transom stern research vessel, R/V Athena . The computer generation of a complex geometr...
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A computational capability has been developed to predict and visualize the flow about podded propulsors appended to the 154-foot transom stern research vessel, R/V Athena . The computer generation of a complex geometric model for the hull and appendages is an important part of this new capability. The flow field is computed using a free surface potential flow method. The steady flow induced by the propulsor is simulated by an idealized propeller model (actuator disk). The upstream effects of an actuator disk are examined and results are compared to the case without an actuator disk. Computed results for the inflow to the propeller disk are presented as velocity vector plots and contour plots. Harmonic analyses are performed on the computed velocity components. The numerical results can be used in conjunction with experiments performed at DTRC to aid in the design of podded propulsors. These flow studies are used to examine the proper alignment of the pod/strut system with the aim of obtaining the optimal flow into the propeller. The combined numerical and experimental approach is shown to be an efficient way to evaluate complex hull forms with podded propulsors. This powerful design approach can be used for future Navy ship designs.
This paper discusses the Interactive graphics System used by the General Electric Company, Medium Steam Turbine department (engineering & Manufacturing) for designing, drafting, and manufacturing applications. A b...
This paper discusses the Interactive graphics System used by the General Electric Company, Medium Steam Turbine department (engineering & Manufacturing) for designing, drafting, and manufacturing applications. A brief overview of the hardware malting up the system is described, followed by a more detailed description of the actual applications. Two-dimensional applications described include a Heat Balance Analysis, Flow Diagrams, and Electrical Schematics. A more fruitful area for increased productivity gains is described in the three-dimensional or mechanical applications including turbine design & layout and bucket design. coordination of the design with manufacturing for numerical control tape generation is described through CAM and Plate Frame Cutting applications. Finally, a short review of the engineeringdesign work using Interactive graphics is discussed. Productivity gains of 2.6 to 1 are being realized, and the overall savings to the Medium Steam department are outlined.
This book constitutes the joint refereed proceedings of the 11th International Conference on Artificial Intelligence and Symbolic Computation, AISC 2012, 19th Symposium on the Integration of Symbolic Computation and M...
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ISBN:
(数字)9783642313745
ISBN:
(纸本)9783642313738
This book constitutes the joint refereed proceedings of the 11th International Conference on Artificial Intelligence and Symbolic Computation, AISC 2012, 19th Symposium on the Integration of Symbolic Computation and Mechanized Reasoning, Calculemus 2012, 5th International Workshop on Digital Mathematics Libraries, DML 2012, 11th International Conference on Mathematical Knowledge Management, MKM 2012, Systems and Projects, held in Bremen, Germany as CICM 2012, the Conferences on Intelligent computer Mathematics. The 13 revised full papers out of 19 submissions for MKM 2012, 6 revised full papers out of 9 submissions for Calculemus 2012, 6 revised full papers out of 8 submissions for AISC 2012, 2 revised full papers out of 3 submissions for DML 2012, and 11 revised full papers out of 12 submissions for Systems and Project track presented were carefully reviewed and selected, resulting in 38 papers from a total of 52 submissions.
Progess in specific computer-assisted techniques (digital imaging , computer-aided diagnosis, image-guided surgery, MEMS, etc.) combined with computer-assisted integration tools offers a valuable complement to or repl...
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ISBN:
(数字)9783642561689
ISBN:
(纸本)9783540436553;9783642628443
Progess in specific computer-assisted techniques (digital imaging , computer-aided diagnosis, image-guided surgery, MEMS, etc.) combined with computer-assisted integration tools offers a valuable complement to or replacement for existing procedures in healthcare. Physicians are now employing PACS and telemedicine systems as enabling infrastructures to improve quality of and access to healthcare. Tools based on CAD and CAS facilitate completely new paths in patient care. To ensure that CARS tools benefit the patient, collaboration between various disciplines, specifically radiology, surgery, engineering, informatics, and healthcare management, is a critical factor. A multidisciplinary congress like CARS is a step in the desired direction of knowledge sharing and crossover education. It provides the necessary cooperative framework for advancing the development and application of modern computer-assisted technologies in healthcare.
After two decades, data processing has finally, and probably forever, found its niche among civil engineering and construction (CEC) professionnals, through word processors, digitizing tables, management software, and...
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ISBN:
(数字)9781468474046
ISBN:
(纸本)9781850912538
After two decades, data processing has finally, and probably forever, found its niche among civil engineering and construction (CEC) professionnals, through word processors, digitizing tables, management software, and increasingly via drawing software and computer-aided design (CAD), recently, robots have even started invading work sites. What are the main trends of CAD and robotics in the field of architecture and civil enginee ring? What type of R&D effort do university and industrial laboratories undertake to devise the professional software that will be on the market in the next three to five years? These are the issues which will be addressed during this symposium. To this effect, we have planned concurrently an equipment and software show, as well as a twofold conference. Robotic is just starting in the field of civil engineering and construction. A pioneer, the Civil engineering Departement of Carnegie-Mellon University, in the United States, organized the first two international symposia, in 1984 and 1985 in Pittsburgh. This is the third meeting on the subject (this year, however, we have also included CAD). It constitutes the first large international symposium where CAD experts, specialists in architecture and CEC robotics will meet. From this standpoint, it should be an ideal forum for exchanging views and expe riences on a wide range of topics, and we hope it will give rise to novel applications and new syntheses. This symposium is intented for scientists, teachers, students and also for manufacturers and all CEC professionals.
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