This paper is concerned with coordinated control of combined heat and power (CHP) plants for regional-scale energy management. The objective of the control is to regulate electricity and gas ｆｌows (energy flows) through an regional energy system with two CHP plants. In order to manage energy imbalances of demand and supply inside the region, the gas flow is indirectly regulated with tracking control of boiler pressure to a suitable reference trajectory. The output tracking controller is designed by the input-output linearization of a nonlinear state-space model of the energy system. Effectiveness of the proposed controller is established with numerical simulations under a practical set of system parameters.
Recently, several hybrid spiking neuron models, which combine continuous spike-generation mechanisms and discontinuous resetting process to avert divergence after spiking, have been proposed. Izhikevich neuron model as this kind of model is known to be able to reproduce diverse spiking patterns including chaotic spiking. To reveal the factor for this high diversity, it is necessary to evaluate the influence of the state dependent jump on the trajectory in a continuous system through the comparison between the system with/without the resetting process. However, if the resetting process is removed, the orbit in Izhikevich neuron model exhibits only the divergent behavior at a spiking state. This means that Izhikevich neuron model can not be used to evaluate the changes of attractor's structure by adding the resetting process. In this paper, we introduced the resetting process to the conventional FitzHugh-Nagumo neuron model where the orbit at a spiking state does not diverge. And then we compared the bifurcation and the structure of attractors between this hybridized FitzHugh-Nagumo neuron model with this resetting process and the conventional one. As the result, it was confirmed that non-linear stretching and folding structure of the attractor is induced by the resetting process and the chaotic state emerges through a tangent bifurcation depending on the distance of jump.
In this paper, we propose a schedule revision method to enhance the project stability which is calculated based on the deviation between the actual activity starting time and the planned one. The proposed method revises the schedule by shrinking duration of the activities which start over the period in order to prevent the schedule from the activity delays. In the proposed method, the activity durations are shrunk so that the current schedule corresponds to the baseline schedule. In computational experiments, the proposed method is compared with some other revision methods in regard to the actual makespan and the activity delay. The experimental results indicate the effectiveness of the proposed method in the viewpoint of the project stability.
We propose a method for estimating the user's comfort/discomfort in response to the lighting condition during desk work. We fluctuate the lighting condition slightly, and the user's comfort/discomfort is estimated according to unconscious behaviors induced by the illuminance fluctuation. The experimental results show that the proposed method with illuminance fluctuation outperforms the conventional method with constant illuminance.
This paper concerns the parameter identification of a mathematical model describing the behavior of a metronome. The problem considered here is to find the values of the parameters, minimizing the output difference between the model and the metronome. By focusing on the discontinuity in the model and using particle swarm optimization, we obtain a solution to the problem. We demonstrate that our solution provides a model capturing the bahavior of the metronome.
This paper proposes an effective design method of brake-force distribution focusing on braking motion and pitch angle using developing model and simulation model-based optimization. First, we make the model of pitch motion and braking motion. Next, we introduce a virtual link connecting with these motions. In this paper, the angle of the link is constant. So, the model integrating these motions is under developing. When we try to optimize the brake force distribution using the developing model, the validity of the results is ensured by the model verification of the energy conservation law. We use simultaneous perturbation stochastic approximation (SPSA) because the number of calculating cost function is less than usual gradient method via finite difference approximation. We apply SPSA to simulation model-based optimization and discuss suitable constraints for SPSA based design. In addition, we discuss how to adjust the gradient of SPSA such that values of brake force distribution satisfy the design range in the update process. Consequently, the proposed design method achieves step-by-step optimization of specifications in vehicle.