We consider a nonlinear discrete-time system and a control specification including safety properties. In general, there exists a computation delay to compute a control input in a controller and the delay degrades control performances. To compensate the computation delay, we propose a safe controller using Mita's method and the shield synthesis, where the satisfaction of the safety properties is decided using a high-order control barrier function. First, we show an effect of the computation delay on the relative degree of the system. Next, we show the reduction of the number of functions that specify the high-order control barrier function. Finally, we propose a safe controller consisting of a predictor, a controller, and a shield. Then, we illustrate the proposed method on safe control of mobile robots.

A vector product Hopfield network (VPHN) is a 3-D Hopfield model. A VPHN provides excellent noise tolerance. Since projection rule is not available, it is not applicable for large numbers of data. Vector product appears in the multiplication of quaternions. In this work, the VPHNs are extended to the quaternionic VPHNs (QVPHNs). The projection rule is available for the QVPHNs. We evaluate the QVPHNs by computer simulations and show that they provide excellent noise tolerance.

Service-Oriented Architecture (SOA) is an information system architecture. In SOA, the problem of synthesizing the concrete model from an abstract specification is known as the Choreography Realization Problem (CRP). So far, we proposed to use event structures as a modeling formalism; we studied conflict reduction of event structures to check the realizability of a choreography. In this paper, we study the method to generate event structure from choreography.

The stream version of asymmetric binary systems (ABS) invented by Duda is an entropy coder for information sources with a finite alphabet. It has the state parameter l of a nonnegative integer and the probability parameter p with 0 < p < 1. Firstwe observe that the edge shift X_G associated with the stream version of ABS has the topological entropy h(X_G) = log 2. Then we define the edge shift X_H associated with output blocks from the stream version of ABS, and show that h(X_H) = h(X_G), which implies that X_G and X_H are finitely equivalent. The encoding and decoding algorithms for the stream version of ABS establish a bijection between X_G and X_H. We consider the case where p = 1/β with the golden mean β = (1 + √5)/2. Eventually we show that X_G and X_H are conjugate for l = 7, and that they are almost conjugate for l = 10.