Professor Y. Oono received the 2015 IEEE Gustav Robert Kirchhoff Award. This manuscript summarizes his great contribution to the synthesis of passive n-port synthesis. In addition his other important works on n-port synthesis are described.

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A convolutionally encoded data is usually decoded by applying the Viterbi algorithm to the associated code trellis. On the other hand, syndrome decoding based on error trellises was proposed by Schalkwijk et al. This paper mainly focuses on error trellises and syndrome decoding based on them. Error trellises have a kind of nonuniformity, which enables decoding with remarkably low average complexity. It is shown that scarce-state-transition (SST) Viterbi decoding based on a code trellis is equivalent to syndrome decoding based on the corresponding error trellis. Code/error trellises for tail-biting convolutional codes are also discussed in this paper.

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A recent trend in conversation analytic studies is to explicate the development of a participant’s interactional competence over time. Revealing the developmental stages and the way interactional competence develops leads to pedagogical developments such as the construction of the evaluative framework and teaching materials. In this paper, we aim to explain the method and the value of longitudinal conversation analysis by investigating the actual data of one-to-one job interviews where a second-language English-speaking interviewer consecutively participated in interviews with 27 candidates. After illustrating the theory and the method of conversation analysis and the notion of interactional competence, previous longitudinal conversation analytic studies are reviewed. On the basis of the detailed analysis of the longitudinal data, we conclude with a discussion of the implications for pedagogical practices as well as with a suggestion for the data collection method.

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More than 15 years have passed since the large revision of the JIS Z 8115 Dependability (reliability) term in 2000. Some terms and expressions in it have been found to no longer be suitable to the current state of the industry. For this reason, the committee, which was established by the Japanese Standards Association, has studied the amendment of reliability terms. Since the international standard IEC60050-192 Ed.1 Dependability was issued in 2015, the committee has been working on reviewing the order to match the content. In this paper, we introduce the outline of typical reliability terms, and also explain new areas of reliability, such as service reliability, using reliability terms.

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The distance to a target is important information in various engineering fields. When measuring the distance to a target using audible sound, in general, an impulsive sound is transmitted toward the target and the time difference between the transmitted and reflected waves is obtained to determine the distance. However, this method cannot be applied to short distances where a reflected wave is buried in a transmitted wave. On the other hand, in the field of microwave radar, this distance measurement method has been proposed for plural targets, and can be applied to distances close to 0 m (i.e., a standing-wave radar). We have extended this distance measurement method so as to measure precisely the distance to the target in ranges close to 0 m by applying the principle of the standing wave radar to distance measurement using a sound signal. In this paper, first we will explain the principle of acoustical distance measurement methods based on phase interference using audible sound, and then by introducing an analytic signal, we describe in detail an acoustical distance measurement method, especially for a target that exists at a distance of around 0 m. Simulation results and experimental results are also shown.

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It is a universal problem to keep workflows correct in system development. Workflow nets, a subclass of Petri nets, are suited to creating a model of workflows. They have many verification algorithms for a simpler structure class. In this paper, a given workflow net to apply the verification algorithms. Furthermore, we show applications of the techniques in system development.

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In mobile communication systems such as a wireless cellular system, there have been continuously growing demands for higher capacity in recent decades. In the development of mobile communications systems, the orthogonalization and non-orthogonalization of wireless resources such as carrier, space, time, frequency, and spreading code elements have occurred in turn, in accordance with the progress of semiconductor integration, and nonlinear signal processing has been increasing utilized in wireless communications. In this paper, we introduce several nonlinear signal processing schemes in wireless communications to support the evolution of wireless access systems. First, the requirement of higher frequency efficiency and higher capacity in mobile communication systems is described, and the non-orthogonalization utilized in recent wireless access system is explained. As an example, multiple-input multiple-output (MIMO) transmission and faster than Nyquist (FTN) signaling are briefly reviewed. The non-orthogonal multiple access (NOMA) is currently considered as an advanced access technique in fifth-generation mobile communications system (5G). Then, the architecture of NOMA using nonlinear signal processing and its performance are introduced. In addition, the utilization of non-orthogonal mapping using chaos in modulation is introduced, and its performance is shown through numerical simulations. With these examples, we try to highlight the importance of nonlinear signal processing in next-generation wireless communication systems.

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