DISTRIBUTED HMI SYSTEM FOR MANAGING ALL SPAN OF PLANT CONTROL AND MAINTENANCE

Yoshikawa, Hidekazu Korean Nuclear Society 2009 Nuclear Engineering and Technology Vol.41 No.3

Digitalization of not only non-safety but also safety-grade I &C systems with full computerized Main Control Room (MCR) is the recent trend of I&C systems of nuclear power plants (NPP) around the world, while plant maintenance has been shifting from traditional time based maintenance to condition based maintenance. In order to cope with the new trend of operation and maintenance in NPP, a concept of online distributed diagnostic system for both plant operation and maintenance has been proposed in order to further improve both the plant efficiency and the work environment of plant operation staff members by organizational learning. In this respect, the research subjects of human machine interface (HMI) for the online distributed diagnostic system are also discussed for supporting the plant personnel at both MCR and local working places in the plant by the application of advanced ICT (Information and Communication Technologies).

Pre-dispersal Seed Predation by a Granivorous Bird, the Masked Grosbeak (Eophona personata), in Two Bird-dispersed Ulmaceae Species

Yoshikawa, Tetsuro,Kikuzawa, Kihachiro The Ecological Society of Korea 2009 Journal of Ecology and Environment Vol.32 No.3

Pre-dispersal seed predation by a granivorous bird, the masked grosbeak (Eophona personata, Fringillidae), was investigated in two bird-dispersed trees, Celtis sinensis and Aphananthe aspera (Ulmaceae). The objectives of this study were to 1) measure direct damage of predation by grosbeaks on plant crops, 2) reveal the temporal pattern of predation within each tree species and its causal factors, and 3) test whether foraging grosbeaks hinder foraging of frugivorous birds, thereby indirectly impacting the reproduction of both tree species. A substantial amount of fruit and seed crop was consumed by grosbeaks (24.3% in Celtis; 55.5% in Aphananthe), and only 17.7% (Celtis) and 16.7% (Aphananthe) were removed by frugivorous birds. At the study site, the grosbeak population size fluctuated greatly during the fruiting seasons of both plant species. As for Celtis, predated seed density also fluctuated temporally, and the local population size of grosbeaks was responsible for predated seed density. In Aphananthe, predation was not fully explained by grosbeak populations or plant phenology, but its peak coincided with that of grosbeak population. These results suggest that predispersal seed predation by granivorous birds can have large negative impacts on the bird-dispersed plants. Changes in local population size of granivorous birds can influence predatation and can affect reproductive success of the bird-dispersed plants available to the birds.

Seasonal Transport Variations in the Japan Sea

Yoshikawa, Yutakawa,Awaji, Toshiyuki,Akitomo, Kazunori 대한원격탐사학회 1995 International Symposium on Remote Sensing Vol.11 No.1

The Japan(East) Sea circulation has been examined with an $quot;incomplete$quot; robust diagnostic model. The simulated Japan Sea circulation shows strong seasonal variations, the major features being in good agreement with observational findings. To identify the sources and pathways of water masses in such a complicated current system, the Lagrangian water-mass movement is examined, providing useful informations about water-mass formation processes. The renewal time of the water masses is estimated to be at least tens years.

Mechanical Properties of CVD Diamond

Yoshikawa, Masanori,Hirata, Atsushi The Korean Ceramic Society 1996 The Korean journal of ceramics Vol.2 No.4

This paper focuses the strength and wear resistance of CVD diamond films. The strength of free-standing CVD diamond films synthesized by microwave plasm CVD, DC plasma CVD, RF plasma CVD and arc discharge plasma jet CVD has been measured by three-point bending test. The wear resistance of CVD diamod films has been evaluated by the pin-on-disk type testing. diamond films coated on the base of sintered tungsten carbide pin by hot filament CVD have been rubbed with a sintered diamond disk in muddy water. Volume removed wear of CVD diamond has been compared with stellite, WC alloy and bearing steel.

Watershed/Urban Regeneration in Accord with Nature

Yoshikawa Katsuhide 한국수자원학회 2002 한국수자원학회 학술대회 Vol.2002 No.1

Evaluation of Antibacterial Effects of an Experimental Primer Containing MDPB for Resin-based Root Canal Filling System

Yoshikawa R,Izutani N,Imazato S,Kitagawa H,Ebisu S 대한치과재료학회 2011 대한치과기재학회 학술대회 Vol.2011 No.5

A REVIEW ON DEVELOPING INDUSTRIAL STANDARDS TO INTRODUCE DIGITAL COMPUTER APPLICATION FOR NUCLEAR I&C AND HMIT IN JAPAN

Yoshikawa, Hidekazu Korean Nuclear Society 2013 Nuclear Engineering and Technology Vol.45 No.2

A comprehensive review on the technical standards about human factors (HF) design and software reliability maintenance for digital instrumentation and control (I&C) and human-machine interface technology (HMIT) in Japanese light water reactor nuclear power plants (NPPs) was given in this paper mainly by introducing the relevant activities at the Japan Electric Association to set up many industrial standards within the traditional framework of nuclear safety regulation in Japan. In Japan, the Fukushima Daiichi accident that occurred on March 11, 2011 has great impact on nuclear regulation and nuclear industries where concerns by the general public about safety have heightened significantly. However for the part of HF design and software reliability maintenance of digital I&C and HMIT for NPP, the author believes that the past practice of Japanese activities with the related technical standards can be successfully inherited in the future, by reinforcing the technical preparedness for the prevention and mitigation against any types of severe accident occurrence.

HUMAN-MACHINE INTERACTION IN NUCLEAR POWER PLANTS

YOSHIKAWA HIDEKAZU Korean Nuclear Society 2005 Nuclear Engineering and Technology Vol.37 No.2

Advanced nuclear power plants are generally large complex systems automated by computers. Whenever a rare plant emergency occurs the plant operators must cope with the emergency under severe mental stress without committing any fatal errors. Furthermore, The operators must train to improve and maintain their ability to cope with every conceivable situation, though it is almost impossible to be fully prepared for an infinite variety of situations. In view of the limited capability of operators in emergency situations, there has been a new approach to preventing the human error caused by improper human-machine interaction. The new approach has been triggered by the introduction of advanced information systems that help operators recognize and counteract plant emergencies. In this paper, the adverse effect of automation in human-machine systems is explained. The discussion then focuses on how to configure a joint human-machine system for ideal human-machine interaction. Finally, there is a new proposal on how to organize technologies that recognize the different states of such a joint human-machine system.

The Medial Eminence Line for Predicting Tibial Fracture Risk after Unicompartmental Knee Arthroplasty

Yoshikawa Ryo,Hiranaka Takafumi,Okamoto Koji,Fujishiro Takaaki,Hida Yuichi,Kamenaga Tomoyuki,Sakai Yoshitada 대한정형외과학회 2020 Clinics in Orthopedic Surgery Vol.12 No.2

Background: Tibial fracture after cementless Oxford unicompartmental knee arthroplasty (OUKA) is a rare but serious complication. It is reported more frequently in Asian countries. The aim of this retrospective study was to assess the morphological characteristics of the tibia by using a simple novel measurement method in patients with tibial fractures after OUKA. Methods: Six knees (all women) with tibial fractures after cementless OUKA (fracture group) and 150 knees without an obvious complication after cementless OUKA (control group) were examined retrospectively at our institution between January 2016 and April 2017. We drew a medial eminence line (ME line) defined as a line extending from the tip of the medial intercondylar eminence parallel to the tibial axis. The ME line was classified into two types (intramedullary type [type I] and extramedullary type [type E]), and the proportion of each type was compared between fracture patients and controls. Results: In the fracture group, there were four (66.7%) type E cases and two (33.3%) type I cases; in the control group, there were 18 (12%) type E cases and 132 (88%) type I cases. Fisher exact tests showed that the proportion of type E was higher in the fracture group than in the control group (p < 0.01). Conclusions: Measurement of the ME line can be recommended as a useful method to assess the risk of postoperative fracture after cementless OUKA.

DISTRIBUTED HMI SYSTEM FOR MANAGING ALL SPAN OF PLANT CONTROL AND MAINTENANCE

HIDEKAZU YOSHIKAWA 한국원자력학회 2009 Nuclear Engineering and Technology Vol.41 No.3

Digitalization of not only non-safety but also safety-grade I &C systems with full computerized Main Control Room (MCR) is the recent trend of I&C systems of nuclear power plants (NPP) around the world, while plant maintenance has been shifting from traditional time based maintenance to condition based maintenance. In order to cope with the new trend of operation and maintenance in NPP, a concept of online distributed diagnostic system for both plant operation and maintenance has been proposed in order to further improve both the plant efficiency and the work environment of plant operation staff members by organizational learning. In this respect, the research subjects of human machine interface (HMI) for the online distributed diagnostic system are also discussed for supporting the plant personnel at both MCR and local working places in the plant by the application of advanced ICT (Information and Communication Technologies).