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Hiroshima, Japan

Hiroshima National College of Maritime Technology is one of five national colleges of maritime technology in Japan. Graduates can earn deck mariner or engineer qualifications. Wikipedia.

Sasa K.,Hiroshima National College of Maritime Technology | Incecik A.,University of Strathclyde
Ocean Engineering | Year: 2012

It is essential to maintain the safety of ships that are anchored in offshore harbors to avoid the influence of storms. Recently, marine casualties have been reported on anchored ships stranded in coastal areas after their anchors dragged in stormy weather. However, there have been very few studies on anchored ship motions in waves with dynamic mooring forces. In this study, information on the safety of ships in offshore harbors during storms was gathered through a nationwide questionnaire. Because previous numerical models for reproducing reported situations of marine casualties appear flawed, this study considers the dynamic calculation of chain forces and compares the results with those obtained by the catenary method. A new algorithm is constructed to reproduce the dragging anchor and grounding in waves and winds. This study is expected to contribute to the improvement of port planning related to anchorage. © 2012 Elsevier Ltd. All rights reserved.

Imai S.,Hiroshima National College of Maritime Technology | Yamamoto T.,Hiroshima University
IEEJ Transactions on Electronics, Information and Systems | Year: 2013

In this paper, a new design method of data-driven control systems is proposed, this scheme enables us to reduce the computational cost. According to the DD method, some local models are automatically generated by using imput/output data pairs of the control object stored in the plural databases. Especially, it is well known that the DD method works suitably on nonlinear systems. Therefore, even if the nonlinearities are contained in the controlled object, accuracy identification can be performed by the proposed method. Concretely, the nonlinear system to be controlled is divided into plural subsystems, and plural databases are first constructed corresponding to the subsystems. The effectiveness of the proposed control scheme is shown by simulation example. © 2013 The Institute of Electrical Engineers of Japan.

Imai S.,Hiroshima National College of Maritime Technology | Yamamoto T.,Hiroshima University
International Journal of Advanced Mechatronic Systems | Year: 2012

Almost real-world plants are represented by non-linear systems. Therefore, it is important to consider PID control schemes to cope with such systems. In this paper, a PID control method for non-linear systems is newly proposed. Some local linear models on typical equilibrium points are first designed, followed by linear PID controllers corresponding to these models. The distances between the query and these local models are calculated, and the weights are computed in proportion to the distances. These weights are put for local PID controllers, and the PID controller corresponding to the query can be designed. According to the proposed scheme, the good PID control performance can be easily obtained. The effectiveness of the PID control scheme is illustrated by some simulation examples and experiment. © 2012 Inderscience Enterprises Ltd.

Mu S.,Hiroshima National College of Maritime Technology | Tanaka K.,Yamaguchi University | Nakashima S.,Yamaguchi University | Djoewahir A.,Yamaguchi University
ICIC Express Letters | Year: 2014

A real-time intelligent PID control method combined with Inertia Weight Approach (IWA) type Particle Swarm Optimization (PSO) is proposed for ultrasonic motor (USM) in this paper. In the proposed method, an intelligent controller using Neural Network (NN) is designed for adjusting PID gains in real-time environment. The learning of NN is implemented by IWA-PSO updating the weights of NN on-line. The effectiveness of the method is confirmed by experiments. © 2014 ICIC International.

Zhou D.,Tokyo University of Marine Science and Technology | Izumi M.,Tokyo University of Marine Science and Technology | Miki M.,Tokyo University of Marine Science and Technology | Felder B.,Tokyo University of Marine Science and Technology | And 2 more authors.
Superconductor Science and Technology | Year: 2012

The paper contains a review of recent advancements in rotating machines with bulk high-temperature superconductors (HTS). The high critical current density of bulk HTS enables us to design rotating machines with a compact configuration in a practical scheme. The development of an axial-gap-type trapped flux synchronous rotating machine together with the systematic research works at the Tokyo University of Marine Science and Technology since 2001 are briefly introduced. Developments in bulk HTS rotating machines in other research groups are also summarized. The key issues of bulk HTS machines, including material progress of bulk HTS, insitu magnetization, and cooling together with AC loss at low-temperature operation are discussed. © 2012 IOP Publishing Ltd.

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