Abstract The ability to efficiently solve topology optimization problems is of great importance for many practical applications. Hence, there a demand efficient solution algorithms. In this paper, we propose novel quasi-Newton methods solving PDE-constrained problems. Our approach based on and extends the popular algorithm Amstutz Andrä (J Comput Phys 216: 573–588, 2006). To do so, introduce ne...

Soft Switcing techniques have recently been applied in the design of dc-ac converters, in order to achive better performance, higher efficiency, and power density. One of the soft switching techniques uesd in inverters is resonant dc links. These topologies have some disadvantages such as irregular current peaks, large voltage peaks, uncotrollble pulse width, etc. Another soft switching method ...

This paper deals mainly with the Chu duality of discrete groups. Among other results, we give sufficient conditions for an FC group to satisfy Chu duality and characterize when the Chu quasi-dual and the Takahashi quasi-dual of a group G coincide. As a consequence, it follows that when G is a weak sum of a family of finite simple groups, if the exponent of the groups in the family is bounded th...

Comodules over Hopf algebroids are of central importance in algebraic topology. It is well-known that a Hopf algebroid is the same thing as a presheaf of groupoids on Aff , the opposite category of commutative rings. We show in this paper that a comodule is the same thing as a quasi-coherent sheaf over this presheaf of groupoids. We prove the general theorem that internal equivalences of preshe...

In this project reduced switching losses and high efficiency is proposed for quasi resonant converter. An AC/DC quasi resonant converter with push pull topology is coupled to two distributed boost inductors into a single magnetic core which hereby reducing the circuit volume and the cost are the development targets of switching power supply today. The quasi resonant converter has ideally zero s...

1. Review of Thurston’s hyperbolization theorem and quasi-Fuchsian representations 2. Review of Thurston’s Surgery Theorem 3. Review of Freedman’s surfaces and Cooper-Long-Reid extension of Freedman’s work 4. Proof of the Surgery Theorem 5. A fundamental trihotomy for π1injective surfaces 6. Proof of the double coset theorem 7. Quasi-Fuchsian knots and analytic proof of Freedman-Cooper-Long the...

We introduce topological magnetic field in two-dimensional flat space, which admits a solution of scalar monopole that describes the nontrivial topology. In the Chern-Simons gauge field theory of anyons, we interpret the anyons as the quasi-particles composed of fermions and scalar monopoles in such a form that each fermion is surrounded by infinite number of scalar monopoles. It is the monopol...

We show that the space of subprobability measures, equivalently continuous valuations, on an algebraic (resp., continuous) complete quasi-metric is again and complete, when equipped with Kantorovich-Rubinstein quasi-metrics dKR (unbounded) or dKRa (bounded), themselves asymmetric forms well-known metric. also dKR-Scott dKRa-Scott topologies then coincide weak topology. obtain similar results fo...