On comparison of constrained and unconstrained evolutions in analogue electronics on the example of “LC” low-pass filters

The Evolutionary Electronics refers to the design method of electronic circuits with the help of Evolutionary Algorithms. Over the years huge experience has been accumulated and tremendous results have been achieved in this field. Two obvious tendencies are prevailing in the area over designers to improve the performance of Evolutionary Algorithms. First of all, as with any solution-search-algorithm, the designers try to reduce the potential solution space in order to reach the optimum solution faster, putting some constrains onto search algorithm as well as onto potential solutions. At the same time, the second tendency of unconstraining the Evolutionary Algorithms in its search gives unpredictable breakthroughs in results. Enabling the evolution to optimize with more experimental parameters devoted to drive the evolution and adjusted previously manually, is one of an example where such kind of unconstraining takes place. The evolution with the maximum freedom of search can be addressed as unconstrained evolution. The unconstrained evolution has already been applied in the past towards the design of digital circuits, and extraordinary results have been obtained, including generation of circuits with smaller number of electronic components. Recently, the similar method has been introduced by authors of this paper towards the design of analogue circuits. The new algorithm has produced promising results in terms of quality of the circuits evolved and evolutionary resources required. It differed from constrained method by its simplicity and represented one of the first attempts to apply Evolutionary Strategy towards the analogue circuit design. In this paper both conventional constrained evolution and newly developed unconstrained evolution in analogue domain are compared in detail on the example of "LC" low-pass filter design. The unconstrained evolution demonstrates the superior behaviour over the constrained one and exceeds by quality of results the best filter evolved previously by 240%. The experimental results are presented along with detailed analysis. Also, the obtained results are compared in details with low-pass filters designed previously

Absolutely free extrinsic evolution of passive low-pass filter

Evolutionary electronics is a brunch of evolvable hardware, where the evolutionary algorithm is applied towards electronic circuits. The success of evolutionary search most of all depends on variable length representation methodology. The low-pass filter is a standard task in evolutionary electronics to start with. The results of evolution enable one to qualify whether the methodology is good for further experiments. In this paper the maximum freedom for evolutionary search has been proclaimed as a main target during development of new VLR methodology. The introduction of R-support elements enables to perform an unconstrained evolution of analogue circuits for the first time. The proposed algorithm has been tested on the example of analogue low-pass filter. The experimental results demonstrate that the evolved filter is comparable with filters evolved previously using genetic programming and genetic algorithms techniques. The obtained results are compared in details with low-pass filters previously designed

Characterization of the Evolution of IC Emissions after Accelerated Aging

9 pagesInternational audienceWith the evolving technological development of integrated circuits (ICs), ensuring electromagnetic compatibility (EMC) is becoming a serious challenge for electronic circuit and system manufacturers. Although electronic components must pass a set of EMC tests to ensure safe operations, the evolution over time of EMC is not characterized and cannot be accurately forecast. This paper presents an original study about the consequences of the aging of circuits on electromagnetic emission. Different types of standard applicative and accelerated-life tests are applied on a mixed power circuit dedicated to automotive applications. Its conducted emission is measured before and after these tests showing variations in EMC performances. Comparisons between each type of aging procedure show that the emission level of the circuit under test is affected differently

A comparison of the Bravyi-Kitaev and Jordan-Wigner transformations for the quantum simulation of quantum chemistry

The ability to perform classically intractable electronic structure calculations is often cited as one of the principal applications of quantum computing. A great deal of theoretical algorithmic development has been performed in support of this goal. Most techniques require a scheme for mapping electronic states and operations to states of and operations upon qubits. The two most commonly used techniques for this are the Jordan-Wigner transformation and the Bravyi-Kitaev transformation. However, comparisons of these schemes have previously been limited to individual small molecules. In this paper we discuss resource implications for the use of the Bravyi-Kitaev mapping scheme, specifically with regard to the number of quantum gates required for simulation. We consider both small systems which may be simulatable on near-future quantum devices, and systems sufficiently large for classical simulation to be intractable. We use 86 molecular systems to demonstrate that the use of the Bravyi-Kitaev transformation is typically at least approximately as efficient as the canonical Jordan-Wigner transformation, and results in substantially reduced gate count estimates when performing limited circuit optimisations.Comment: 46 pages, 11 figure

Evolving more efficient digital circuits by allowing circuit layout evolution and multi-objective fitness

We use evolutionary search to design combinational logic circuits. The technique is based on evolving the functionality and connectivity of a rectangular array of logic cells whose dimension is defined by the circuit layout. The main idea of this approach is to improve quality of the circuits evolved by the GA by reducing the number of active gates used. We accomplish this by combining two ideas: 1) using multi-objective fitness function; 2) evolving circuit layout. It will be shown that using these two approaches allows us to increase the quality of evolved circuits. The circuits are evolved in two phases. Initially the genome fitness in given by the percentage of output bits that are correct. Once 100% functional circuits have been evolved, the number of gates actually used in the circuit is taken into account in the fitness function. This allows us to evolve circuits with 100% functionality and minimise the number of active gates in circuit structure. The population is initialised with heterogeneous circuit layouts and the circuit layout is allowed to vary during the evolutionary process. Evolving the circuit layout together with the function is one of the distinctive features of proposed approach. The experimental results show that allowing the circuit layout to be flexible is useful when we want to evolve circuits with the smallest number of gates used. We find that it is better to use a fixed circuit layout when the objective is to achieve the highest number of 100% functional circuits. The two-fitness strategy is most effective when we allow a large number of generations