作者：
Wagner, Robert F.US FDA
Off & Engn Labs Ctr Devices & Radiol Hlth Silver Spring MD 20993 USA
This editorial refers to the article \"Potential effect of different radiologist reporting methods on studies showing benefit of CAD\" by Horsch et al in the present issue of Academic Radiology (1).There are...
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This editorial refers to the article \"Potential effect of different radiologist reporting methods on studies showing benefit of CAD\" by Horsch et al in the present issue of Academic Radiology (1).There are several communities or \"cultures\" that will find common ground in this article. One community includes the public and private funding sponsors and developers of new technologies for medical imaging-in particular, the technology of computer algorithms that assist radiologists in their decision making. Another community therefore is that of the radiologists themselves who will use these technologies. Then there is the community developing study designs and statistical assessment methodologies for evaluating the new technologies. Downstream we encounter the community of public policy makers who approve and clear these technologies for entrance to the marketplace for their specified task and the third-party payers who determine when a combination of a technology and a diagnostic task meet their criteria for reimbursement.
To annotate newly sequenced organisms, cross-species sequence comparison algorithms can be applied to align gene sequences to the genome of a related species. To improve the accuracy of alignment, spaced seeds must be...
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To annotate newly sequenced organisms, cross-species sequence comparison algorithms can be applied to align gene sequences to the genome of a related species. To improve the accuracy of alignment, spaced seeds must be optimized for each comparison. As the number and diversity of genomes increase, an efficient alternative is to cluster pairwise comparisons into groups and identify seeds for groups instead of individual comparisons. Here we investigate a measure of comparison closeness and identify classes of comparisons that show similar seed behavior and therefore can employ the same seed.
This Paper presents a temperature control algorithm for the skunk of the skunk cabbage Symplocarpus foetidus, a plant which holds its spadix temperature nearly constant. We derive the control algorithm from a proposed...
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This Paper presents a temperature control algorithm for the skunk of the skunk cabbage Symplocarpus foetidus, a plant which holds its spadix temperature nearly constant. We derive the control algorithm from a proposed thermoregulation model of the spadix of S. foetidus. In addition, we investigate the control algorithm of *** for general industrial applications from a control engineering perspective by running simulations and applying it to actual equipment. The temperature control algorithm responds to the rate of change of the controlled variable over time and adjusts the output of the controller as required to minimize the rate of change. The control algorithm of the spadix of *** is robust to perturbations in the controlled object and the Control algorithm incorporated into a microprocessor successfully controls the performance actual equipment.
Friction stir welding is a new solid state joining technology, which is suitable for joining some hard-to-weld materials, such as aluminum alloy, magnesium alloy, etc. The modeling of material flows can provide an eff...
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Friction stir welding is a new solid state joining technology, which is suitable for joining some hard-to-weld materials, such as aluminum alloy, magnesium alloy, etc. The modeling of material flows can provide an efficient method for the investigation on the mechanism of friction stir welding. So, 3D material flows under different process parameters in the FSW process of 1018 steel are studied by using rate-dependent constitutive model. Numerical results indicate that the border of the shoulder can affect the material flow near the shoulder-plate interface. The mixture of the material in the lower half of the friction stir weld can benefit from the increase in the angular velocity or the decrease in the welding speed. But flaws may occur when the angular velocity is very high or the translational velocity is very small. When the angular velocity applied on the pin is small or the welding speed is high, the role of the extrusion of pin on transport of the material in FSW becomes more important. Swirl or vortex occurs in the tangent material flow and may be easier to be observed with the increase in the angular velocity of the pin.
Asymptotic torque-reactive power vector control algorithm based on full doubly-fed induction machine model is designed and investigated. Full-scale experimental testing of the doubly-fed induction machine control algo...
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ISBN:
(纸本)9781424416653
Asymptotic torque-reactive power vector control algorithm based on full doubly-fed induction machine model is designed and investigated. Full-scale experimental testing of the doubly-fed induction machine control algorithms with matrix converter at rotor side is performed. Doubly-fed induction machine control algorithm has been implemented in real time using DSP-controller and successfully tested on the experimental rig.
The last progresses in power mechanical engineering and power electronics had permitted to construct gas turbine power units (GTPU) with high frequency synchronous generators (HFSG) and static frequency converters (SF...
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ISBN:
(纸本)9781424416097
The last progresses in power mechanical engineering and power electronics had permitted to construct gas turbine power units (GTPU) with high frequency synchronous generators (HFSG) and static frequency converters (SFC) operating as asynchronous tie (AT). Such GTPU has a number of advantages over conventional one: 1) does not have a reduction gear between turbine and generator shafts; 2) gives an opportunity to minimize weight and dimensions of a turboset and power plant as a whole; 3) permits to optimize turbine's modes by means of it's rotation speed control; 4) gives additional opportunities of GTPU states control and required power quality support with the help of SFC control; 5) owing to this control, allows to improve operating speed of states control and the unit protection. These features make AT GTPUs of great practical interest, so that a considerable number of power stations with such units is planned to put into operation in Russia in the nearest future. Mention that they are designed to operate both in parallel with the power system and autonomous supplying a local load. The most attractive field of AT GTPU's application is power supply of distant regions and areas difficult of access. So the new electrotechnical complex appears: GTPU with HFSG and AT - centralized power system (CPS) - local load (LL) (fig. 1). The AT GTPUs' appearance poses a number of standard and specific problems concerning projection, putting into operation and maintenance of the complex. In this situation at the absence of a sufficient argumentation of how the AT should be arranged the following problem was posed and solved: to determine the interconnections between the complex's state parameters (CSPs) by presenting SFC as AT. It is expedient to find the interconnections in an analytical form (formulas) so far as digital (or numerical) models being realized in specialized programs (Simulink, PSCAD, etc.) are not clear and universal enough for many problems such as the complex's s
Catastrophe control was discussed in high-dimensional nonlinear systems without getting eigenvalues. Using the coefficients of characteristic equations, the linear control gains for catastrophe critical conditions wer...
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ISBN:
(纸本)9780769533575
Catastrophe control was discussed in high-dimensional nonlinear systems without getting eigenvalues. Using the coefficients of characteristic equations, the linear control gains for catastrophe critical conditions were determined. The nonlinear gains were chosen by utilizing the center manifold theory and normal form reduction to assure the stability of limit cycle. Applications were illustrated for submarine motion model to create a catastrophe with preferred properties at a desired location. This convenient and effective control algorithm has a bright future in nonlinear control system design.
Among the many challenges to deal with when a robot is interacting with its environment, friction at the contact surface and/or at the joints is one of the most important to be considered. Recently a force control alg...
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ISBN:
(纸本)9781424416653
Among the many challenges to deal with when a robot is interacting with its environment, friction at the contact surface and/or at the joints is one of the most important to be considered. Recently a force control algorithm for robot manipulators was proposed. This scheme was designed to work under the assumption that only viscous friction is present. Since in general this may be restrictive, in this work we test experimentally the robustness of this control scheme against more rigorous conditions of friction.
In this paper, we introduce a control algorithm based on the delayed feedback control method to stabilize a fractional order system on an unstable fixed point. The control input is defined as the difference between th...
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ISBN:
(纸本)9781424416653
In this paper, we introduce a control algorithm based on the delayed feedback control method to stabilize a fractional order system on an unstable fixed point. The control input is defined as the difference between the future, and current state. The gain matrix is obtained using the pole placement method. To illustrate the effectiveness of the proposed algorithm, we give simulation results of the control of fractional chaotic Chua's system.
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