A Novel Synthetization Approach for Multi Coupled Line Section Impedance Transformers in Wideband Applications

In this paper, a novel synthetization approach is proposed for filter-integrated wideband impedance transformers (ITs). The original topology consists of N cascaded coupled line sections (CLSs) with 2N characteristic impedance parameters. By analyzing these characteristic impedances, a Chebyshev response can be derived to consume N + 2 design conditions. To optimize the left N − 2 variable parameters, CLSs were newly substituted by transmission lines (TLs) to consume the remaining variable parameters and simplify the circuit topology. Therefore, there are totally 2N − N − 2 substituting possibilities. To verify the proposed approach, 25 cases are listed under the condition of N = 5, and 7 selected cases are compared and discussed in detail. Finally, a 75–50 Ω IT with 100% fractional bandwidth and 20 dB bandpass return loss (RL) is designed and fabricated. The measured results meet the circuit simulation and the EM simulation accurately.

Modified Fourth-Order Buck-Boost Converter

Some hundred DC/DC converters have been constructed. Here a modified one is investigated. The modification consists in the position of the output capacitor. This does not change the voltage transformation ratio, but leads to constant input current compared to a pulsating one in the original topology. The function of the converter is investigated by inspection and by constructing the signals, the large and small signal model of the converter and the transfer function are derived, dimensioning hints are given and simulations are shown.

Effect of parameter selection on different topological structures for Particle Swarm Optimization algorithm

Particle Swarm Optimization is an evolutionary optimization algorithm, largely studied during the years: analysis of convergence, determination of the optimal coefficients, hybridization of the original algorithm and also the determination of the best relationship structure between the swarm elements (topology) have been investigated largely. Unfortunately, all these studies have been produced separately, and the same coefficients, derived for the original topology of the algorithm, have been always applied. The intent of this paper is to identify the best set of coefficients for different topological structures. A large suite of objective functions are considered and the best compromise coefficients are identified for each topology. Results are finally compared on the base of a practical ship design application.

Krein-Smulian-Type Theorems

Let (E, ℱ) be a weakly compactly generated Frechet space and let ℱ0 be another weaker Hausdorff locally convex topology on E. Let X be an ℱ-bounded compact subset of (E, ℱ0). The ℱ0-closed convex hull of X in E is then ℱ0-compact. We also give a new proof, without using Riemann–Lebesgue-integrable (Birkoff-integrable) functions, with the result that if (E, ∥ · ∥) is any Banach space and ℱ0 is fragmented by ∥ · ∥, then the same result holds. Furthermore, the closure of the convex hull of X in ℱ0-topology and in the original topology of E is the same.

On Topology Dependence of Explosive Shock Properties

When explosive material is ignited, a detonation wave is generated causing a chemical reaction to take place. This chemical reaction results in the creation of a shockwave in the air surrounding the explosive material. The properties of this shockwave are dependent upon many different variables including but not limited to the type of explosive material used, the amount of material used, the surrounding fluid and the distance that the shockwave travels from the point of ignition. One variable that is not often considered is how the topology of the explosive material may affect the properties of a shockwave. If all other properties are held constant, the shockwave created by a spherical explosive charge will have different properties from those created by a cylindrical or cubical charge. This work uniquely applies an explicit finite element approach to simulate different shapes of explosives and the effects of explosive surface topology on the ensuing shockwaves. In order to fully observe these varying shockwaves, a target wall was included in the simulations. The propagating shockwaves damage the wall on impact, while creating a series of reflective shock- and strain-waves. By thoroughly examining the damaged portions of the target wall in conjunction with wave propagation patterns, it is possible to study the strength of the shockwave and the mechanism by which the reflective waves are created. Through these investigations, shockwave pressure, velocity, patterns and shapes, as well as damage sustained by the wall will be considered. The paper will conclude how shockwave properties are influenced by the original topology of the explosive mass.

Escher's Ants as Metaphor: Topological Marching for the Well-Composed, Genus Zero Crowd

Topological considerations for segmentation results are important for such applications as proper brain segmentation from digital image data. We present an enhancement of the FastMarchingImageFilter which allows for topologically constrained evolution of the level set. Identical to the original functionality of the FastMarchingImageFilter, the evolution of the level set of a single or multiple genus zero, well-composed seed objects proceeds according to the specified parameters. With our proposed enhancements, the user can either choose to prevent the level set from merging with itself such that the original topology of the initial seed object(s) is not violated or that no handles are created during the evolution process. However, in contrast to earlier approaches which relied on the concept of the simple point implicitly requiring the definition of a user-specified foreground/background connectivity, we use the related, but more restrictive concept of well-composed sets to topologically constrain the evolution of the level set. Utility of our submission is demonstrated on both 2-D and 3-D brain images. Note that this submission is a companion piece to a more theoretical discussion of our work given in [9]

HYPERCHAOS IN A CHUA'S CIRCUIT WITH TWO NEW ADDED BRANCHES

In this work a fourth-order Chua's circuit, capable of generating hyperchaotic oscillations in a wide range of parameters, is presented. The circuit is obtained by adding two new branches to the original topology of the Chua's double scroll circuit. One of the added branches is a linear inductor-resistor series connection, and the other one is a nonlinear voltage-controlled current source. A theoretical analysis of the circuit equations is presented, along with numerical and experimental results.

EFFECTS OF LONG-RANGE CONNECTIONS IN DISTRIBUTED CONTROL OF COLLECTIVE MOTION

The introduction of long-range connections in locally connected networks leads to the so-called small-world effect: when few long-range connections are added to the original topology, the characteristic path length decreases, whereas a high clustering coefficient is preserved. In this paper, it is shown that long-range connections introduced in a network model describing the interactions of a group of mobile robots increase the tendency to form a coordinated group of robots which travel in the same direction. The leadership of informed individuals in the group is also increased.

Stability of a Human SWI-SNF Remodeled Nucleosomal Array

ABSTRACT SWI-SNF alters DNA-histone interactions within a nucleosome in an ATP-dependent manner. These alterations cause changes in the topology of a closed circular nucleosomal array that persist after removal of ATP from the reaction. We demonstrate here that a remodeled closed circular array will revert toward its original topology when ATP is removed, indicating that the remodeled array has a higher energy than that of the starting state. However, reversion occurs with a half-life measured in hours, implying a high energy barrier between the remodeled and standard states. The addition of competitor DNA accelerates reversion of the remodeled array by more than 10-fold, and we interpret this result to mean that binding of human SWI-SNF (hSWI-SNF), even in the absence of ATP hydrolysis, stabilizes the remodeled state. In addition, we also show that SWI-SNF is able to remodel a closed circular array in the absence of topoisomerase I, demonstrating that hSWI-SNF can induce topological changes even when conditions are highly energetically unfavorable. We conclude that the remodeled state is less stable than the standard state but that the remodeled state is kinetically trapped by the high activation energy barrier separating it from the unremodeled conformation.