33 research outputs found
Robust target functions in electromagnetic design
No full textUncertainties in the design variables of non-linear engineering optimization problems are often neglected. That could result in considerable deterioration of the target function value of an implemented design compared with the computed optimal solution. This effect can be reduced with robust optimization, where it is tried to achieve robust designs by actively embedding the uncertainties and robustness measures in the optimization process. A methodology for robust optimization of non-linear problems is presented, including practical methods for the solution of such programs. The benefits of the approach are discussed in a numerical field calculation example
UHF RFID antenna impedance characterization: Numerical simulation of interconnection effects on the antenna impedance
No full textEnhanced Identification of Hidden Conductive Objects with Deterministic and Stochastic Methods
No full textThe identification of conductive objects of known shape embedded in low- or non-conductive regions is a special application of non-destructive testing, with important applications in some surgical procedures. In particular, some classes of fractures are routinely stabilized and aligned by the use of intra-medullary nails. Identifying the position and the orientation of the drill holes hidden by bone and tissue is currently done by X-Ray with all the well known disadvantages of this technology. The idea of substituting this methodology with an eddy-current based one has been explored in previous work but the developed technique suffered from some hard to address shortcomings. In this paper we propose a new technique which is computationally efficient and inexpensive to implement
Synthesis of NFC Antenna Structure under Multi Card Condition
No full textWireless communication technologies such as Near
Field Communication (NFC) found its way into our everyday life.
The antenna structures used in such systems have to comply with
several standards to achieve all requirements defined for the
specific application. However, in practice there are scenarios for
such antennas which are not considered in standards or design
guides, but mainly influence the antenna behavior. In the present
paper the synthesis of an antenna used for NFC-cards in a
contactless payment system under multi-card condition is
presented. The optimization relies on the differential evolution
(DE) strategy. The computation of the forward problem is based
on the partial element equivalent circuit (PEEC) method
PEEC-Based Multi-Objective Synthesis of NFC Antennas in the Presence of Conductive Structures
No full textNear Field Communication (NFC) techniques
are widely used within everyday activities, e.g., contactless
payment systems or authentication. Regardless of the
application typically the requirements on the antenna
structure are manifold. Frequently limitations in the
available space make the antenna design quite challenging
especially if other conductive structures are close to
the NFC antenna. In the present paper we propose to
synthesize the geometry of proximity integrated circuit
card (PICC) antennas according to class 6 in the presence
of nearby metallic structures. The optimization relies on
the differential evolution strategy. The computation of
the forward problem is based on the partial element
equivalent circuit (PEEC) method
Real-Time Pose Detection for Magnetic-Assisted Medical Applications by Means of a Hybrid Deterministic/Stochastic Optimization Method
No full textSome classes of bone fractures are routinely stabilized and aligned by the use of intramedullary nails. The identification of the pose, i.e., the position and the orientation of the drill holes hidden by a bone and the tissue is currently obtained by X-ray with all the well-known disadvantages of this technology. The idea of substituting this methodology with an eddy-current-based one has been explored in the previous work, but, in spite of interesting features, the developed technique suffered from some shortcomings. In this paper, we propose a novel technique that is very computationally efficient and provides real-time identification performance
PEEC based Design Optimization of NFC Antennas Considering the Full System Quality Factor
No full textFirefly Algorithm for Finding Optimal Shapes of Electromagnetic Devices
No full textMany real-world optimization problems have to be treated as multi-objective optimization problems. An approach, well established in recent years, is to find Pareto optimal configurations of the trial variables by detecting nondominated solutions with the help of a suitable vector optimization method. Alternatively, relying on scalar optimization methods (both stochastic or deterministic), a suitable objective function taking all objectives into account simultaneously has to be defined. Depending on the number of trial variables, a scalar objective function of that type will exhibit a considerable number of feasible local solutions besides the global one. Therefore, a useful scalar optimization strategy should be able to end up (with a high probability) in the best of all possible solutions in the given search space and additionally detect as many local solutions as possible. Some population-based stochastic methods are implicitly suited for that task; others can be enhanced to fulfill these requirements. Higher order evolution strategies have successfully been tuned for that kind of problem by introducing cluster sensitive recombination [niching higher order evolution strategy (NES)]. The firefly algorithm (FFA) mimics the behavior of fireflies, which use a kind of flashing light to communicate with other members of their species. Since the intensity of the light of a single firefly diminishes with increasing distance, the FFA is implicitly able to detect local solutions on its way to the best solution for a given scalar objective function. The FFA will be applied to the well-known Rastrigin test function and to a shielding/shunting electromagnetic problem with two and three objectives, respectively, and its results will be compared with the ones obtained with an NE
SMES Optimization Benchmark Extended: Introducing Uncertainties and Pareto Optimal Solutions into TEAM22
No full textIn 1996, a superconducting magnetic energy storage arrangement was selected to become a benchmark problem for testing different optimization algorithms, both deterministic and stochastic ones. Since the forward problem can be solved semianalytically by Biot-Savart's law, this benchmark became quite popular. Nevertheless, the demands on optimization software have increased dramatically since then. To give an example, methods looking for Pareto-optimal points rather than for a single solution only have been introduced by several groups. In this paper, a proposal for an extended version of the benchmark problem will be made and some results will be presente
Christian Lange, Karl Pinggéra (Hrsg.). Die altorientalischen Kirchen. Glaube und Geschichte
No full textCet ouvrage est une présentation générale des principales Églises de l’Orient, leur formation, leur théologie et leurs traditions. L’Église syro-orientale (des “Assyriens”) et l’Église syro-orthodoxe sont présentées (K. Pinggéra), ainsi que leurs liturgies et leurs spiritualités respectives (E. Renhart), avec les tentatives de rapprochements œcuméniques (D. W. Winkler)
